Access to distribution grid for distributed photovoltaic （short for PV）,technically, it determines solutions in the economic evaluation method.The method combines with comprehensive scoring method, Access to the dis...Access to distribution grid for distributed photovoltaic （short for PV）,technically, it determines solutions in the economic evaluation method.The method combines with comprehensive scoring method, Access to the distribution grid will be different from each program in economic construction,load flow,voltage,power quality,supply reliability and other aspects .Also the transformation of the distribution grid to rate the degree by the weighted average method that determines each PV access solutions the final performance of grid PV Construction method of the process, mainly AHP through index calculation,the access of PV program is evaluated to determine the economic and technical level access solution.This study will greatly enhance the PV grid security that helps PV in our country to develop PV.展开更多
The supercritical CO_(2) Brayton cycle is considered a promising energy conversion system for Generation IV reactors for its simple layout,compact structure,and high cycle efficiency.Mathematical models of four Brayto...The supercritical CO_(2) Brayton cycle is considered a promising energy conversion system for Generation IV reactors for its simple layout,compact structure,and high cycle efficiency.Mathematical models of four Brayton cycle layouts are developed in this study for different reactors to reduce the cost and increase the thermohydraulic performance of nuclear power generation to promote the commercialization of nuclear energy.Parametric analysis,multi-objective optimizations,and four decision-making methods are applied to obtain each Brayton scheme’s optimal thermohydraulic and economic indexes.Results show that for the same design thermal power scale of reactors,the higher the core’s exit temperature,the better the Brayton cycle’s thermo-economic performance.Among the four-cycle layouts,the recompression cycle(RC)has the best overall performance,followed by the simple recuperation cycle(SR)and the intercooling cycle(IC),and the worst is the reheating cycle(RH).However,RH has the lowest total cost of investment(C_(tot))of$1619.85 million,and IC has the lowest levelized cost of energy(LCOE)of 0.012$/(kWh).The nuclear Brayton cycle system’s overall performance has been improved due to optimization.The performance of the molten salt reactor combined with the intercooling cycle(MSR-IC)scheme has the greatest improvement,with the net output power(W_(net)),thermal efficiencyη_(t),and exergy efficiency(η_(e))improved by 8.58%,8.58%,and 11.21%,respectively.The performance of the lead-cooled fast reactor combined with the simple recuperation cycle scheme was optimized to increase C_(tot) by 27.78%.In comparison,the internal rate of return(IRR)increased by only 7.8%,which is not friendly to investors with limited funds.For the nuclear Brayton cycle,the molten salt reactor combined with the recompression cycle scheme should receive priority,and the gas-cooled fast reactor combined with the reheating cycle scheme should be considered carefully.展开更多
The multi-objective particle swarm optimization algorithm(MOPSO)is widely used to solve multi-objective optimization problems.In the article,amulti-objective particle swarm optimization algorithmbased on decomposition...The multi-objective particle swarm optimization algorithm(MOPSO)is widely used to solve multi-objective optimization problems.In the article,amulti-objective particle swarm optimization algorithmbased on decomposition and multi-selection strategy is proposed to improve the search efficiency.First,two update strategies based on decomposition are used to update the evolving population and external archive,respectively.Second,a multiselection strategy is designed.The first strategy is for the subspace without a non-dominated solution.Among the neighbor particles,the particle with the smallest penalty-based boundary intersection value is selected as the global optimal solution and the particle far away fromthe search particle and the global optimal solution is selected as the personal optimal solution to enhance global search.The second strategy is for the subspace with a non-dominated solution.In the neighbor particles,two particles are randomly selected,one as the global optimal solution and the other as the personal optimal solution,to enhance local search.The third strategy is for Pareto optimal front(PF)discontinuity,which is identified by the cumulative number of iterations of the subspace without non-dominated solutions.In the subsequent iteration,a new probability distribution is used to select from the remaining subspaces to search.Third,an adaptive inertia weight update strategy based on the dominated degree is designed to further improve the search efficiency.Finally,the proposed algorithmis compared with fivemulti-objective particle swarm optimization algorithms and five multi-objective evolutionary algorithms on 22 test problems.The results show that the proposed algorithm has better performance.展开更多
In the independent electro-hydrogen system(IEHS)with hybrid energy storage(HESS),achieving optimal scheduling is crucial.Still,it presents a challenge due to the significant deviations in values ofmultiple optimizatio...In the independent electro-hydrogen system(IEHS)with hybrid energy storage(HESS),achieving optimal scheduling is crucial.Still,it presents a challenge due to the significant deviations in values ofmultiple optimization objective functions caused by their physical dimensions.These deviations seriously affect the scheduling process.A novel standardization fusion method has been established to address this issue by analyzing the variation process of each objective function’s values.The optimal scheduling results of IEHS with HESS indicate that the economy and overall energy loss can be improved 2–3 times under different optimization methods.The proposed method better balances all optimization objective functions and reduces the impact of their dimensionality.When the cost of BESS decreases by approximately 30%,its participation deepens by about 1 time.Moreover,if the price of the electrolyzer is less than 15¥/kWh or if the cost of the fuel cell drops below 4¥/kWh,their participation will increase substantially.This study aims to provide a more reasonable approach to solving multi-objective optimization problems.展开更多
Background:Rosa chinensis Jacq.and Rosa rugosa Thunb.are not only of ornamental value,but also edible flowers and the flower buds have been listed in the Chinese Pharmacopoeia as traditional medicines.The two plants h...Background:Rosa chinensis Jacq.and Rosa rugosa Thunb.are not only of ornamental value,but also edible flowers and the flower buds have been listed in the Chinese Pharmacopoeia as traditional medicines.The two plants have some differences in efficacy,but the flower buds are easily confused for similar traits.In addition,large-scale cultivation of ornamental rose flowers may lead to a decrease in the effective components of medicinal roses.Therefore,it is necessary to study the chemical composition and make quality evaluation of Rosae Chinensis Flos(Yueji)and Rosae Rugosae Flos(Meigui).Methods:In this study,40 batches of samples including Meigui and Yueji from different regions in China were collected to establish high-performance liquid chromatography fingerprints.Then,the fingerprints data was analyzed using principal component analysis,hierarchical cluster analysis,and partial least squares discriminant analysis analysis chemometrics to obtain information on intergroup differences,and non-targeted metabolomic techniques were applied to identify and compare chemical compositions of samples which were chosen from groups with large differences.Differential compounds were screened by orthogonal partial least-squares discriminant analysis and S-plot,and finally multi-component quantification was performed to comprehensively evaluate the quality of Yueji and Meigui.Results:The similarity between the fingerprints of 40 batches roses and the reference print R was 0.73 to 0.93,indicating that there were similarities and differences between the samples.Through principal component analysis and hierarchical cluster analysis of fingerprints data,the samples from different origins and varieties were intuitively divided into four groups.Partial least-squares discriminant analysis analysis showed that Meigui and Yueji cluster into two categories and the model was reliable.A total of 89 compounds were identified by high resolution mass spectrometry,mainly were flavonoids and flavonoid glycosides,as well as phenolic acids.Eight differential components were screened out by orthogonal partial least-squares discriminant analysis and S-plot analysis.Quantitative analyses of the eight compounds,including gallic acid,ellagic acid,hyperoside,isoquercitrin,etc.,showed that Yueji was generally richer in phenolic acids and flavonoids than Meigui,and the quality of Yueji from Shandong and Hebei was better.It is worth noting that Xinjiang rose is rich in various components,which is worth focusing on more in-depth research.Conclusion:In this study,the fingerprints of Meigui and Yueji were established.The chemical components information of roses was further improved based on non-targeted metabolomics and mass spectrometry technology.At the same time,eight differential components of Meigui and Yueji were screened out and quantitatively analyzed.The research results provided a scientific basis for the quality control and rational development and utilization of Rosae Chinensis Flos and Rosae Rugosae Flos,and also laid a foundation for the study of their pharmacodynamic material basis.展开更多
Introduction: The WHO’s measles control strategy is based on epidemiological surveillance and vaccination. Little is currently known about the performance of the surveillance system, particularly in outlying areas. I...Introduction: The WHO’s measles control strategy is based on epidemiological surveillance and vaccination. Little is currently known about the performance of the surveillance system, particularly in outlying areas. It is in this context that the present study was carried out to evaluate the measles epidemiological surveillance system in the Kangaba health district. Method: This was a descriptive cross-sectional study with retrospective data collection for the period from 1 January to 31 December 2022 in the Kangaba health district with 18 epidemiological surveillance officers. Data were collected using an observation grid and documentary analysis. Results: We found a simplicity of 97%, a representativeness of 95% and a reactivity of 53%. Not all notified cases were sampled (64%). Of the 17 CSCom, 8 were positive. A total of 34 confirmed cases of measles were recorded, with one death. Conclusion: Overall, the system is functional and well-established in the health centres, but it remains important to ensure that suspected cases are investigated and that the time between sampling and the availability of laboratory results is respected.展开更多
Under the rapid impetus of artificial intelligence(AI)technology,human society is stepping into the age of intelligence at an unprecedented speed.A new generation of information technology such as AI is not only a new...Under the rapid impetus of artificial intelligence(AI)technology,human society is stepping into the age of intelligence at an unprecedented speed.A new generation of information technology such as AI is not only a new engine of economic development,but also a gas pedal of social development,which has had a profound impact on the field of education.In the face of the opportunities and challenges of the AI era,it is particularly urgent to build a scientific and reasonable education evaluation system.This paper combines the context of the times with the new technology of AI to discuss the opportunities,challenges,and implementation strategies of educational evaluation reform in the era of AI,with a view to providing references for the construction of the educational evaluation system and the development of high-quality education in the new era.展开更多
Introduction: Arbovirus diseases such as dengue and chikungunya threaten public health worldwide. Early and rapid diagnosis and surveillance of dengue virus (DENV) and chikungunya virus (CHIKV) infections are essentia...Introduction: Arbovirus diseases such as dengue and chikungunya threaten public health worldwide. Early and rapid diagnosis and surveillance of dengue virus (DENV) and chikungunya virus (CHIKV) infections are essential to the control of these diseases. In this study, we evaluate the diagnostic performance of our new in-house multiplex RT-qPCR method for detecting DENV serotypes and CHIKV in an external laboratory. Methodology: The evaluation study was conducted on 200 clinical samples of suspected patients for arbovirus disease infection, collected in Centre de Recherche Biomoléculaire Pietro Annigoni (CERBA), Ouagadougou, Burkina Faso. Our new multiplex RT-qPCR was compared to the commercial kit, the Zika, Dengue, and Chikungunya (ZDC) Real-Time PCR Assays kit (Bio-Rad, California, USA). Results and Conclusions: Among 200 samples, 21.5% (43/200) were DENV-positive by multiplex RT-qPCR, and 21.5% (43/200) were also DENV-positive by reference real-time RT-PCR. 157 (78.5%) samples tested negative for DENV by both tests (new mRT-qPCR and reference test). The sensitivity and specificity of mRT-qPCR were 100%. The DENV serotypes detected were DENV-1 60.5% (26/43) and DENV-3 39.5% (17/43). CHIKV was not detected in this study. Our new mRT-qPCR is sensitive, cost-effective, simple, and can be used in developing country laboratories.展开更多
BACKGROUND Despite the developments in the field of kidney transplantation,the already existing diagnostic techniques for patient monitoring are considered insufficient.Protein biomarkers that can be derived from mode...BACKGROUND Despite the developments in the field of kidney transplantation,the already existing diagnostic techniques for patient monitoring are considered insufficient.Protein biomarkers that can be derived from modern approaches of proteomic analysis of liquid biopsies(serum,urine)represent a promising innovation in the monitoring of kidney transplant recipients.AIM To investigate the diagnostic utility of protein biomarkers derived from proteomics approaches in renal allograft assessment.METHODS A systematic review was conducted in accordance with PRISMA guidelines,based on research results from the PubMed and Scopus databases.The primary focus was on evaluating the role of biomarkers in the non-invasive diagnosis of transplant-related com-plications.Eligibility criteria included protein biomarkers and urine and blood samples,while exclusion criteria were language other than English and the use of low resolution and sensitivity methods.The selected research articles,were categorized based on the biological sample,condition and methodology and the significantly and reproducibly differentiated proteins were manually selected and extracted.Functional and network analysis of the selected proteins was performed.RESULTS In 17 included studies,58 proteins were studied,with the cytokine CXCL10 being the most investigated.Biological pathways related to immune response and fibrosis have shown to be enriched.Applications of biomarkers for the assessment of renal damage as well as the prediction of short-term and long-term function of the graft were reported.Overall,all studies have shown satisfactory diagnostic accuracy of proteins alone or in combination with conventional methods,as far as renal graft assessment is concerned.CONCLUSION Our review suggests that protein biomarkers,evaluated in specific biological fluids,can make a significant contribution to the timely,valid and non-invasive assessment of kidney graft.展开更多
In order to identify the nutrient level and environmental quality of paddy fields in Wanchang area,and to provide scientific basis and technical support for planting rice in Wanchang area, the soil geochemicalsurvey w...In order to identify the nutrient level and environmental quality of paddy fields in Wanchang area,and to provide scientific basis and technical support for planting rice in Wanchang area, the soil geochemicalsurvey was carried out, 30 samples were collected from paddy soil in Wanchang area, and 20 elements(indicators) were analyzed. The characterization of the elemental content of soils in the study area was carriedout, and the geochemical level for soil nutrients, the geochemical level for the soil environment, and thecomprehensive geochemical level of soil quality were evaluated. The results showed that the average valuesof K content and pH of the soil in the study area were smaller than the background values of Jilin Province,and the average values of 18 elements including N, P, Ca, S, Pb, Zn etc. were bigger than the backgroundvalues of Jilin Province. The results of the evaluation of soil single element nutrient in the study area showedthat the available state nutrient levels of Mn, Zn, Cu, and K increased compared with the total amounts ofnutrients level, with Cu increasing the most;the available state nutrient level of N, P, B, and Mo decreasedcompared with the total amounts of nutrients level, with Mo decreasing the most. The comprehensive levelof soil nutrients geochemistry in paddy fields was mainly Level III (medium), accounting for 53.33%, andthe low abundance level was caused by the lack of P element;the comprehensive level of soil environmentalgeochemistry was mainly Level I (clean), accounting for 96.67%, with only slight pollution caused byCd. The comprehensive geochemical level of soil quality was mainly Level II, accounting for 66.67%.Suggestions were put forward for the rational utilization of soil resources in paddy fields in the study area.展开更多
The ease of accessing a virtually unlimited pool of resources makes Infrastructure as a Service (IaaS) clouds an ideal platform for running data-intensive workflow applications comprising hundreds of computational tas...The ease of accessing a virtually unlimited pool of resources makes Infrastructure as a Service (IaaS) clouds an ideal platform for running data-intensive workflow applications comprising hundreds of computational tasks. However, executing scientific workflows in IaaS cloud environments poses significant challenges due to conflicting objectives, such as minimizing execution time (makespan) and reducing resource utilization costs. This study responds to the increasing need for efficient and adaptable optimization solutions in dynamic and complex environments, which are critical for meeting the evolving demands of modern users and applications. This study presents an innovative multi-objective approach for scheduling scientific workflows in IaaS cloud environments. The proposed algorithm, MOS-MWMC, aims to minimize total execution time (makespan) and resource utilization costs by leveraging key features of virtual machine instances, such as a high number of cores and fast local SSD storage. By integrating realistic simulations based on the WRENCH framework, the method effectively dimensions the cloud infrastructure and optimizes resource usage. Experimental results highlight the superiority of MOS-MWMC compared to benchmark algorithms HEFT and Max-Min. The Pareto fronts obtained for the CyberShake, Epigenomics, and Montage workflows demonstrate closer proximity to the optimal front, confirming the algorithm’s ability to balance conflicting objectives. This study contributes to optimizing scientific workflows in complex environments by providing solutions tailored to specific user needs while minimizing costs and execution times.展开更多
The multi-objective optimization of backfill effect based on response surface methodology and desirability function(RSM-DF)was conducted.Firstly,the test results show that the uniaxial compressive strength(UCS)increas...The multi-objective optimization of backfill effect based on response surface methodology and desirability function(RSM-DF)was conducted.Firstly,the test results show that the uniaxial compressive strength(UCS)increases with cement sand ratio(CSR),slurry concentration(SC),and curing age(CA),while flow resistance(FR)increases with SC and backfill flow rate(BFR),and decreases with CSR.Then the regression models of UCS and FR as response values were established through RSM.Multi-factor interaction found that CSR-CA impacted UCS most,while SC-BFR impacted FR most.By introducing the desirability function,the optimal backfill parameters were obtained based on RSM-DF(CSR is 1:6.25,SC is 69%,CA is 11.5 d,and BFR is 90 m^(3)/h),showing close results of Design Expert and high reliability for optimization.For a copper mine in China,RSM-DF optimization will reduce cement consumption by 4758 t per year,increase tailings consumption by about 6700 t,and reduce CO_(2)emission by about 4758 t.Thus,RSM-DF provides a new approach for backfill parameters optimization,which has important theoretical and practical values.展开更多
The coastal zone ecological restoration project has successfully restored a cumulative shoreline length of 76 km in Fanhe Harbor and Kaozhou Bay ecological restoration shoreline (mangrove forest) located in Huidong Co...The coastal zone ecological restoration project has successfully restored a cumulative shoreline length of 76 km in Fanhe Harbor and Kaozhou Bay ecological restoration shoreline (mangrove forest) located in Huidong County, Huizhou City. Additionally, 5 619.5 m of artificial shoreline has been developed as part of the ecological restoration efforts. Various methods, including UAV remote sensing, orthophoto acquisition, and analysis using ArcGIS software, were employed to assess the length, width, coverage, and other relevant indicators of the newly established ecologically restored shoreline. The findings indicate that the average width, coverage, and ecosystem stability of mangrove forests in the restored area satisfy the criteria for the acceptance of ecological shoreline restoration. Furthermore, a relatively stable ecosystem has been established for over two years. This study offers a scientific foundation for the ecological restoration of mangrove forests and holds considerable significance for the conservation and utilization of mangrove forest resources.展开更多
In the context of the digital transformation of vocational education,a quality evaluation index system has been constructed.Based on a questionnaire survey conducted among higher vocational colleges and enterprises in...In the context of the digital transformation of vocational education,a quality evaluation index system has been constructed.Based on a questionnaire survey conducted among higher vocational colleges and enterprises in Hainan Province,it has been found that the quality of vocational education generally depends on the talent training program and professional construction at the macro level.At the meso level,the teacher level and teaching environment are critical,while at the micro level,the evaluation of talent training quality cannot be underestimated.Strategies for quality improvement in vocational education are proposed from the perspectives of talent training programs,major construction,teacher development,teaching environment,and talent training quality,all under the lens of digital transformation.展开更多
The feed industry serves as a critical intermediary between agriculture and animal husbandry,providing essential support for the modern breeding industry.Utilizing the annual financial report data from 19 publicly lis...The feed industry serves as a critical intermediary between agriculture and animal husbandry,providing essential support for the modern breeding industry.Utilizing the annual financial report data from 19 publicly listed companies within the feed industry in 2023,a comprehensive evaluation index system was developed to assess the financial performance of these companies from four dimensions:debt paying ability,operational ability,profitability,and development ability.Factor analysis and hierarchical cluster analysis were employed to assess the financial performance of publicly listed companies within the feed industry.By comparing the mean classifications and comprehensive scores,this study analyzed the strengths and weaknesses of these listed feed companies.Ultimately,it offered recommendations for improvement in areas such as product optimization and enhancement,reasonable liability management,and the advancement of company governance practices.展开更多
Theoretical education and practical education are very important in clinical laboratory teaching.The teaching evaluation system is one of the important means to test the quality of course teaching.The traditional summ...Theoretical education and practical education are very important in clinical laboratory teaching.The teaching evaluation system is one of the important means to test the quality of course teaching.The traditional summative evaluation needs to be improved in terms of scientificity and impartiality,and its guiding effect on teaching reform is limited.Therefore,this paper proposes to apply formative evaluation to clinical laboratory teaching to remobilize students'learning enthusiasm and provide valuable guidance for the subsequent teaching reform,hoping to achieve the purpose of improving the quality of laboratory teaching.展开更多
This paper proposes a multivariate data fusion based quality evaluation model for software talent cultivation.The model constructs a comprehensive ability and quality evaluation index system for college students from ...This paper proposes a multivariate data fusion based quality evaluation model for software talent cultivation.The model constructs a comprehensive ability and quality evaluation index system for college students from a perspective of engineering course,especially of software engineering.As for evaluation method,relying on the behavioral data of students during their school years,we aim to construct the evaluation model as objective as possible,effectively weakening the negative impact of personal subjective assumptions on the evaluation results.展开更多
As an evaluation index,the natural frequency has the advantages of easy acquisition and quantitative evaluation.In this paper,the natural frequency is used to evaluate the performance of external cable reinforced brid...As an evaluation index,the natural frequency has the advantages of easy acquisition and quantitative evaluation.In this paper,the natural frequency is used to evaluate the performance of external cable reinforced bridges.Numerical examples show that compared with the natural frequencies of first-order modes,the natural frequencies of higher-order modes are more sensitive and can reflect the damage situation and external cable reinforcement effect of T-beam bridges.For damaged bridges,as the damage to the T-beam increases,the natural frequency value of the bridge gradually decreases.When the degree of local damage to the beam reaches 60%,the amplitude of natural frequency change exceeds 10%for the first time.The natural frequencies of the firstorder vibration mode and higher-order vibration mode can be selected as indexes for different degrees of the damaged T-beam bridges.For damaged bridges reinforced with external cables,the traditional natural frequency of the first-order vibration mode cannot be used as the index,which is insensitive to changes in prestress of the external cable.Some natural frequencies of higher-order vibration modes can be selected as indexes,which can reflect the reinforcement effect of externally prestressed damaged T-beam bridges,and its numerical value increases with the increase of external prestressed cable force.展开更多
The evaluation of social practice outcomes is a critical component of the social practice mechanisms in colleges and universities,serving as a core index to assess the effectiveness of practice activities and the qual...The evaluation of social practice outcomes is a critical component of the social practice mechanisms in colleges and universities,serving as a core index to assess the effectiveness of practice activities and the quality of student training.This paper employs CiteSpace to analyze references,keyword co-occurrence maps,time zone maps,and time diagrams,identifying key research hotspots in social practice evaluation systems domestically and internationally.These hotspots include the construction of evaluation indicators,evaluation pathways,and methods.Additionally,this study compares and summarizes the evolution of social practice evaluation systems across regions.It highlights that foreign social practice evaluation systems are characterized by diverse interpretative paradigms,an emphasis on students’self-reflection during the evaluation process,and more robust theoretical foundations.These findings provide valuable insights for domestic colleges and universities seeking to build social practice evaluation systems with relevant content and effective results.展开更多
Purpose–The study aims to build a high-precision longitudinal dynamics model for heavy-haul trains and validate it with line test data,present an optimization method for multi-stage cyclic brakes based on the model a...Purpose–The study aims to build a high-precision longitudinal dynamics model for heavy-haul trains and validate it with line test data,present an optimization method for multi-stage cyclic brakes based on the model and conduct a multi-objective detailed evaluation of the driver’s manipulation during cyclic braking.Design/methodology/approach–The high-precision longitudinal train dynamics model was established and verified by the cyclic braking test data of the 20,000 t heavy-haul combination train on the long and steep downgrade.Then the genetic algorithm is employed for optimization subsequent to decoupling multiple cyclic braking procedures,with due consideration of driver operation rules.For evaluation,key manipulation assessments in the scenario are prioritized,supplemented by multi-objective evaluation requirements,and the computational model is employed for detailed evaluation analysis.Findings–Based on the model,experimental data reveal that the probability of longitudinal force error being less than 64.6 kN is approximately 68%,95%for less than 129.2 kN and 99.7%for less than 193.8 kN.Upon optimizing manipulations during the cyclic braking,the maximum reduction in coupler force spans from 21%∼23.9%.Andtheevaluation scoresimply that a proper elevationof the releasingspeed favorssafety.A high electric braking force,although beneficial to some extent for energy-saving,is detrimental to reducing coupler force.Originality/value–The results will provide a theoretical basis and practical guidance for further ensuring the safety and energy-efficient operation of heavy haul trains on long downhill sections and improving the operational quality of heavy-haul trains.展开更多
文摘Access to distribution grid for distributed photovoltaic （short for PV）,technically, it determines solutions in the economic evaluation method.The method combines with comprehensive scoring method, Access to the distribution grid will be different from each program in economic construction,load flow,voltage,power quality,supply reliability and other aspects .Also the transformation of the distribution grid to rate the degree by the weighted average method that determines each PV access solutions the final performance of grid PV Construction method of the process, mainly AHP through index calculation,the access of PV program is evaluated to determine the economic and technical level access solution.This study will greatly enhance the PV grid security that helps PV in our country to develop PV.
基金This work was supported of National Natural Science Foundation of China Fund(No.52306033)State Key Laboratory of Engines Fund(No.SKLE-K2022-07)the Jiangxi Provincial Postgraduate Innovation Special Fund(No.YC2022-s513).
文摘The supercritical CO_(2) Brayton cycle is considered a promising energy conversion system for Generation IV reactors for its simple layout,compact structure,and high cycle efficiency.Mathematical models of four Brayton cycle layouts are developed in this study for different reactors to reduce the cost and increase the thermohydraulic performance of nuclear power generation to promote the commercialization of nuclear energy.Parametric analysis,multi-objective optimizations,and four decision-making methods are applied to obtain each Brayton scheme’s optimal thermohydraulic and economic indexes.Results show that for the same design thermal power scale of reactors,the higher the core’s exit temperature,the better the Brayton cycle’s thermo-economic performance.Among the four-cycle layouts,the recompression cycle(RC)has the best overall performance,followed by the simple recuperation cycle(SR)and the intercooling cycle(IC),and the worst is the reheating cycle(RH).However,RH has the lowest total cost of investment(C_(tot))of$1619.85 million,and IC has the lowest levelized cost of energy(LCOE)of 0.012$/(kWh).The nuclear Brayton cycle system’s overall performance has been improved due to optimization.The performance of the molten salt reactor combined with the intercooling cycle(MSR-IC)scheme has the greatest improvement,with the net output power(W_(net)),thermal efficiencyη_(t),and exergy efficiency(η_(e))improved by 8.58%,8.58%,and 11.21%,respectively.The performance of the lead-cooled fast reactor combined with the simple recuperation cycle scheme was optimized to increase C_(tot) by 27.78%.In comparison,the internal rate of return(IRR)increased by only 7.8%,which is not friendly to investors with limited funds.For the nuclear Brayton cycle,the molten salt reactor combined with the recompression cycle scheme should receive priority,and the gas-cooled fast reactor combined with the reheating cycle scheme should be considered carefully.
基金supported by National Natural Science Foundations of China(nos.12271326,62102304,61806120,61502290,61672334,61673251)China Postdoctoral Science Foundation(no.2015M582606)+2 种基金Industrial Research Project of Science and Technology in Shaanxi Province(nos.2015GY016,2017JQ6063)Fundamental Research Fund for the Central Universities(no.GK202003071)Natural Science Basic Research Plan in Shaanxi Province of China(no.2022JM-354).
文摘The multi-objective particle swarm optimization algorithm(MOPSO)is widely used to solve multi-objective optimization problems.In the article,amulti-objective particle swarm optimization algorithmbased on decomposition and multi-selection strategy is proposed to improve the search efficiency.First,two update strategies based on decomposition are used to update the evolving population and external archive,respectively.Second,a multiselection strategy is designed.The first strategy is for the subspace without a non-dominated solution.Among the neighbor particles,the particle with the smallest penalty-based boundary intersection value is selected as the global optimal solution and the particle far away fromthe search particle and the global optimal solution is selected as the personal optimal solution to enhance global search.The second strategy is for the subspace with a non-dominated solution.In the neighbor particles,two particles are randomly selected,one as the global optimal solution and the other as the personal optimal solution,to enhance local search.The third strategy is for Pareto optimal front(PF)discontinuity,which is identified by the cumulative number of iterations of the subspace without non-dominated solutions.In the subsequent iteration,a new probability distribution is used to select from the remaining subspaces to search.Third,an adaptive inertia weight update strategy based on the dominated degree is designed to further improve the search efficiency.Finally,the proposed algorithmis compared with fivemulti-objective particle swarm optimization algorithms and five multi-objective evolutionary algorithms on 22 test problems.The results show that the proposed algorithm has better performance.
基金sponsored by R&D Program of Beijing Municipal Education Commission(KM202410009013).
文摘In the independent electro-hydrogen system(IEHS)with hybrid energy storage(HESS),achieving optimal scheduling is crucial.Still,it presents a challenge due to the significant deviations in values ofmultiple optimization objective functions caused by their physical dimensions.These deviations seriously affect the scheduling process.A novel standardization fusion method has been established to address this issue by analyzing the variation process of each objective function’s values.The optimal scheduling results of IEHS with HESS indicate that the economy and overall energy loss can be improved 2–3 times under different optimization methods.The proposed method better balances all optimization objective functions and reduces the impact of their dimensionality.When the cost of BESS decreases by approximately 30%,its participation deepens by about 1 time.Moreover,if the price of the electrolyzer is less than 15¥/kWh or if the cost of the fuel cell drops below 4¥/kWh,their participation will increase substantially.This study aims to provide a more reasonable approach to solving multi-objective optimization problems.
基金supported by the key project at the central government level:The ability establishment of sustainable use for valuable Chinese medicine resources(Grant number 2060302)the National Natural Science Foundation of China(Grant number 82373982,82173929).
文摘Background:Rosa chinensis Jacq.and Rosa rugosa Thunb.are not only of ornamental value,but also edible flowers and the flower buds have been listed in the Chinese Pharmacopoeia as traditional medicines.The two plants have some differences in efficacy,but the flower buds are easily confused for similar traits.In addition,large-scale cultivation of ornamental rose flowers may lead to a decrease in the effective components of medicinal roses.Therefore,it is necessary to study the chemical composition and make quality evaluation of Rosae Chinensis Flos(Yueji)and Rosae Rugosae Flos(Meigui).Methods:In this study,40 batches of samples including Meigui and Yueji from different regions in China were collected to establish high-performance liquid chromatography fingerprints.Then,the fingerprints data was analyzed using principal component analysis,hierarchical cluster analysis,and partial least squares discriminant analysis analysis chemometrics to obtain information on intergroup differences,and non-targeted metabolomic techniques were applied to identify and compare chemical compositions of samples which were chosen from groups with large differences.Differential compounds were screened by orthogonal partial least-squares discriminant analysis and S-plot,and finally multi-component quantification was performed to comprehensively evaluate the quality of Yueji and Meigui.Results:The similarity between the fingerprints of 40 batches roses and the reference print R was 0.73 to 0.93,indicating that there were similarities and differences between the samples.Through principal component analysis and hierarchical cluster analysis of fingerprints data,the samples from different origins and varieties were intuitively divided into four groups.Partial least-squares discriminant analysis analysis showed that Meigui and Yueji cluster into two categories and the model was reliable.A total of 89 compounds were identified by high resolution mass spectrometry,mainly were flavonoids and flavonoid glycosides,as well as phenolic acids.Eight differential components were screened out by orthogonal partial least-squares discriminant analysis and S-plot analysis.Quantitative analyses of the eight compounds,including gallic acid,ellagic acid,hyperoside,isoquercitrin,etc.,showed that Yueji was generally richer in phenolic acids and flavonoids than Meigui,and the quality of Yueji from Shandong and Hebei was better.It is worth noting that Xinjiang rose is rich in various components,which is worth focusing on more in-depth research.Conclusion:In this study,the fingerprints of Meigui and Yueji were established.The chemical components information of roses was further improved based on non-targeted metabolomics and mass spectrometry technology.At the same time,eight differential components of Meigui and Yueji were screened out and quantitatively analyzed.The research results provided a scientific basis for the quality control and rational development and utilization of Rosae Chinensis Flos and Rosae Rugosae Flos,and also laid a foundation for the study of their pharmacodynamic material basis.
文摘Introduction: The WHO’s measles control strategy is based on epidemiological surveillance and vaccination. Little is currently known about the performance of the surveillance system, particularly in outlying areas. It is in this context that the present study was carried out to evaluate the measles epidemiological surveillance system in the Kangaba health district. Method: This was a descriptive cross-sectional study with retrospective data collection for the period from 1 January to 31 December 2022 in the Kangaba health district with 18 epidemiological surveillance officers. Data were collected using an observation grid and documentary analysis. Results: We found a simplicity of 97%, a representativeness of 95% and a reactivity of 53%. Not all notified cases were sampled (64%). Of the 17 CSCom, 8 were positive. A total of 34 confirmed cases of measles were recorded, with one death. Conclusion: Overall, the system is functional and well-established in the health centres, but it remains important to ensure that suspected cases are investigated and that the time between sampling and the availability of laboratory results is respected.
文摘Under the rapid impetus of artificial intelligence(AI)technology,human society is stepping into the age of intelligence at an unprecedented speed.A new generation of information technology such as AI is not only a new engine of economic development,but also a gas pedal of social development,which has had a profound impact on the field of education.In the face of the opportunities and challenges of the AI era,it is particularly urgent to build a scientific and reasonable education evaluation system.This paper combines the context of the times with the new technology of AI to discuss the opportunities,challenges,and implementation strategies of educational evaluation reform in the era of AI,with a view to providing references for the construction of the educational evaluation system and the development of high-quality education in the new era.
文摘Introduction: Arbovirus diseases such as dengue and chikungunya threaten public health worldwide. Early and rapid diagnosis and surveillance of dengue virus (DENV) and chikungunya virus (CHIKV) infections are essential to the control of these diseases. In this study, we evaluate the diagnostic performance of our new in-house multiplex RT-qPCR method for detecting DENV serotypes and CHIKV in an external laboratory. Methodology: The evaluation study was conducted on 200 clinical samples of suspected patients for arbovirus disease infection, collected in Centre de Recherche Biomoléculaire Pietro Annigoni (CERBA), Ouagadougou, Burkina Faso. Our new multiplex RT-qPCR was compared to the commercial kit, the Zika, Dengue, and Chikungunya (ZDC) Real-Time PCR Assays kit (Bio-Rad, California, USA). Results and Conclusions: Among 200 samples, 21.5% (43/200) were DENV-positive by multiplex RT-qPCR, and 21.5% (43/200) were also DENV-positive by reference real-time RT-PCR. 157 (78.5%) samples tested negative for DENV by both tests (new mRT-qPCR and reference test). The sensitivity and specificity of mRT-qPCR were 100%. The DENV serotypes detected were DENV-1 60.5% (26/43) and DENV-3 39.5% (17/43). CHIKV was not detected in this study. Our new mRT-qPCR is sensitive, cost-effective, simple, and can be used in developing country laboratories.
文摘BACKGROUND Despite the developments in the field of kidney transplantation,the already existing diagnostic techniques for patient monitoring are considered insufficient.Protein biomarkers that can be derived from modern approaches of proteomic analysis of liquid biopsies(serum,urine)represent a promising innovation in the monitoring of kidney transplant recipients.AIM To investigate the diagnostic utility of protein biomarkers derived from proteomics approaches in renal allograft assessment.METHODS A systematic review was conducted in accordance with PRISMA guidelines,based on research results from the PubMed and Scopus databases.The primary focus was on evaluating the role of biomarkers in the non-invasive diagnosis of transplant-related com-plications.Eligibility criteria included protein biomarkers and urine and blood samples,while exclusion criteria were language other than English and the use of low resolution and sensitivity methods.The selected research articles,were categorized based on the biological sample,condition and methodology and the significantly and reproducibly differentiated proteins were manually selected and extracted.Functional and network analysis of the selected proteins was performed.RESULTS In 17 included studies,58 proteins were studied,with the cytokine CXCL10 being the most investigated.Biological pathways related to immune response and fibrosis have shown to be enriched.Applications of biomarkers for the assessment of renal damage as well as the prediction of short-term and long-term function of the graft were reported.Overall,all studies have shown satisfactory diagnostic accuracy of proteins alone or in combination with conventional methods,as far as renal graft assessment is concerned.CONCLUSION Our review suggests that protein biomarkers,evaluated in specific biological fluids,can make a significant contribution to the timely,valid and non-invasive assessment of kidney graft.
基金Supported by the Special Study on Mineral Resources Planning in Changchun City(No.JM-2020-11-13594)Jilin Agricultural Geological Survey Project(No.12120105111208)。
文摘In order to identify the nutrient level and environmental quality of paddy fields in Wanchang area,and to provide scientific basis and technical support for planting rice in Wanchang area, the soil geochemicalsurvey was carried out, 30 samples were collected from paddy soil in Wanchang area, and 20 elements(indicators) were analyzed. The characterization of the elemental content of soils in the study area was carriedout, and the geochemical level for soil nutrients, the geochemical level for the soil environment, and thecomprehensive geochemical level of soil quality were evaluated. The results showed that the average valuesof K content and pH of the soil in the study area were smaller than the background values of Jilin Province,and the average values of 18 elements including N, P, Ca, S, Pb, Zn etc. were bigger than the backgroundvalues of Jilin Province. The results of the evaluation of soil single element nutrient in the study area showedthat the available state nutrient levels of Mn, Zn, Cu, and K increased compared with the total amounts ofnutrients level, with Cu increasing the most;the available state nutrient level of N, P, B, and Mo decreasedcompared with the total amounts of nutrients level, with Mo decreasing the most. The comprehensive levelof soil nutrients geochemistry in paddy fields was mainly Level III (medium), accounting for 53.33%, andthe low abundance level was caused by the lack of P element;the comprehensive level of soil environmentalgeochemistry was mainly Level I (clean), accounting for 96.67%, with only slight pollution caused byCd. The comprehensive geochemical level of soil quality was mainly Level II, accounting for 66.67%.Suggestions were put forward for the rational utilization of soil resources in paddy fields in the study area.
文摘The ease of accessing a virtually unlimited pool of resources makes Infrastructure as a Service (IaaS) clouds an ideal platform for running data-intensive workflow applications comprising hundreds of computational tasks. However, executing scientific workflows in IaaS cloud environments poses significant challenges due to conflicting objectives, such as minimizing execution time (makespan) and reducing resource utilization costs. This study responds to the increasing need for efficient and adaptable optimization solutions in dynamic and complex environments, which are critical for meeting the evolving demands of modern users and applications. This study presents an innovative multi-objective approach for scheduling scientific workflows in IaaS cloud environments. The proposed algorithm, MOS-MWMC, aims to minimize total execution time (makespan) and resource utilization costs by leveraging key features of virtual machine instances, such as a high number of cores and fast local SSD storage. By integrating realistic simulations based on the WRENCH framework, the method effectively dimensions the cloud infrastructure and optimizes resource usage. Experimental results highlight the superiority of MOS-MWMC compared to benchmark algorithms HEFT and Max-Min. The Pareto fronts obtained for the CyberShake, Epigenomics, and Montage workflows demonstrate closer proximity to the optimal front, confirming the algorithm’s ability to balance conflicting objectives. This study contributes to optimizing scientific workflows in complex environments by providing solutions tailored to specific user needs while minimizing costs and execution times.
基金Funded by the Deep Underground National Science&Technology Major Project gram of China(No.2024ZD1003704)the National Natural Science Foundation of China(Nos.51834001 and 52374111)。
文摘The multi-objective optimization of backfill effect based on response surface methodology and desirability function(RSM-DF)was conducted.Firstly,the test results show that the uniaxial compressive strength(UCS)increases with cement sand ratio(CSR),slurry concentration(SC),and curing age(CA),while flow resistance(FR)increases with SC and backfill flow rate(BFR),and decreases with CSR.Then the regression models of UCS and FR as response values were established through RSM.Multi-factor interaction found that CSR-CA impacted UCS most,while SC-BFR impacted FR most.By introducing the desirability function,the optimal backfill parameters were obtained based on RSM-DF(CSR is 1:6.25,SC is 69%,CA is 11.5 d,and BFR is 90 m^(3)/h),showing close results of Design Expert and high reliability for optimization.For a copper mine in China,RSM-DF optimization will reduce cement consumption by 4758 t per year,increase tailings consumption by about 6700 t,and reduce CO_(2)emission by about 4758 t.Thus,RSM-DF provides a new approach for backfill parameters optimization,which has important theoretical and practical values.
文摘The coastal zone ecological restoration project has successfully restored a cumulative shoreline length of 76 km in Fanhe Harbor and Kaozhou Bay ecological restoration shoreline (mangrove forest) located in Huidong County, Huizhou City. Additionally, 5 619.5 m of artificial shoreline has been developed as part of the ecological restoration efforts. Various methods, including UAV remote sensing, orthophoto acquisition, and analysis using ArcGIS software, were employed to assess the length, width, coverage, and other relevant indicators of the newly established ecologically restored shoreline. The findings indicate that the average width, coverage, and ecosystem stability of mangrove forests in the restored area satisfy the criteria for the acceptance of ecological shoreline restoration. Furthermore, a relatively stable ecosystem has been established for over two years. This study offers a scientific foundation for the ecological restoration of mangrove forests and holds considerable significance for the conservation and utilization of mangrove forest resources.
文摘In the context of the digital transformation of vocational education,a quality evaluation index system has been constructed.Based on a questionnaire survey conducted among higher vocational colleges and enterprises in Hainan Province,it has been found that the quality of vocational education generally depends on the talent training program and professional construction at the macro level.At the meso level,the teacher level and teaching environment are critical,while at the micro level,the evaluation of talent training quality cannot be underestimated.Strategies for quality improvement in vocational education are proposed from the perspectives of talent training programs,major construction,teacher development,teaching environment,and talent training quality,all under the lens of digital transformation.
文摘The feed industry serves as a critical intermediary between agriculture and animal husbandry,providing essential support for the modern breeding industry.Utilizing the annual financial report data from 19 publicly listed companies within the feed industry in 2023,a comprehensive evaluation index system was developed to assess the financial performance of these companies from four dimensions:debt paying ability,operational ability,profitability,and development ability.Factor analysis and hierarchical cluster analysis were employed to assess the financial performance of publicly listed companies within the feed industry.By comparing the mean classifications and comprehensive scores,this study analyzed the strengths and weaknesses of these listed feed companies.Ultimately,it offered recommendations for improvement in areas such as product optimization and enhancement,reasonable liability management,and the advancement of company governance practices.
文摘Theoretical education and practical education are very important in clinical laboratory teaching.The teaching evaluation system is one of the important means to test the quality of course teaching.The traditional summative evaluation needs to be improved in terms of scientificity and impartiality,and its guiding effect on teaching reform is limited.Therefore,this paper proposes to apply formative evaluation to clinical laboratory teaching to remobilize students'learning enthusiasm and provide valuable guidance for the subsequent teaching reform,hoping to achieve the purpose of improving the quality of laboratory teaching.
基金supported in part by the Education Reform Key Projects of Heilongjiang Province(Grant No.SJGZ20220011,SJGZ20220012)the Excellent Project of Ministry of Education and China Higher Education Association on Digital Ideological and Political Education in Universities(Grant No.GXSZSZJPXM001)。
文摘This paper proposes a multivariate data fusion based quality evaluation model for software talent cultivation.The model constructs a comprehensive ability and quality evaluation index system for college students from a perspective of engineering course,especially of software engineering.As for evaluation method,relying on the behavioral data of students during their school years,we aim to construct the evaluation model as objective as possible,effectively weakening the negative impact of personal subjective assumptions on the evaluation results.
基金supported by Henan Province Science and Technology Research Funding Project(No.222102320129)the Key Research Project of Henan Higher Education Institutions(Grant Nos.22A560004,22A56005).
文摘As an evaluation index,the natural frequency has the advantages of easy acquisition and quantitative evaluation.In this paper,the natural frequency is used to evaluate the performance of external cable reinforced bridges.Numerical examples show that compared with the natural frequencies of first-order modes,the natural frequencies of higher-order modes are more sensitive and can reflect the damage situation and external cable reinforcement effect of T-beam bridges.For damaged bridges,as the damage to the T-beam increases,the natural frequency value of the bridge gradually decreases.When the degree of local damage to the beam reaches 60%,the amplitude of natural frequency change exceeds 10%for the first time.The natural frequencies of the firstorder vibration mode and higher-order vibration mode can be selected as indexes for different degrees of the damaged T-beam bridges.For damaged bridges reinforced with external cables,the traditional natural frequency of the first-order vibration mode cannot be used as the index,which is insensitive to changes in prestress of the external cable.Some natural frequencies of higher-order vibration modes can be selected as indexes,which can reflect the reinforcement effect of externally prestressed damaged T-beam bridges,and its numerical value increases with the increase of external prestressed cable force.
基金supported by the Zhejiang Provincial Department of Education’s General Scientific Research Project(Project No.2023-007)the Zhejiang Provincial Graduate Education Association(Project No.2023-007).
文摘The evaluation of social practice outcomes is a critical component of the social practice mechanisms in colleges and universities,serving as a core index to assess the effectiveness of practice activities and the quality of student training.This paper employs CiteSpace to analyze references,keyword co-occurrence maps,time zone maps,and time diagrams,identifying key research hotspots in social practice evaluation systems domestically and internationally.These hotspots include the construction of evaluation indicators,evaluation pathways,and methods.Additionally,this study compares and summarizes the evolution of social practice evaluation systems across regions.It highlights that foreign social practice evaluation systems are characterized by diverse interpretative paradigms,an emphasis on students’self-reflection during the evaluation process,and more robust theoretical foundations.These findings provide valuable insights for domestic colleges and universities seeking to build social practice evaluation systems with relevant content and effective results.
文摘Purpose–The study aims to build a high-precision longitudinal dynamics model for heavy-haul trains and validate it with line test data,present an optimization method for multi-stage cyclic brakes based on the model and conduct a multi-objective detailed evaluation of the driver’s manipulation during cyclic braking.Design/methodology/approach–The high-precision longitudinal train dynamics model was established and verified by the cyclic braking test data of the 20,000 t heavy-haul combination train on the long and steep downgrade.Then the genetic algorithm is employed for optimization subsequent to decoupling multiple cyclic braking procedures,with due consideration of driver operation rules.For evaluation,key manipulation assessments in the scenario are prioritized,supplemented by multi-objective evaluation requirements,and the computational model is employed for detailed evaluation analysis.Findings–Based on the model,experimental data reveal that the probability of longitudinal force error being less than 64.6 kN is approximately 68%,95%for less than 129.2 kN and 99.7%for less than 193.8 kN.Upon optimizing manipulations during the cyclic braking,the maximum reduction in coupler force spans from 21%∼23.9%.Andtheevaluation scoresimply that a proper elevationof the releasingspeed favorssafety.A high electric braking force,although beneficial to some extent for energy-saving,is detrimental to reducing coupler force.Originality/value–The results will provide a theoretical basis and practical guidance for further ensuring the safety and energy-efficient operation of heavy haul trains on long downhill sections and improving the operational quality of heavy-haul trains.
