Magnesium(Mg),being the lightest structural metal,holds immense potential for widespread applications in various fields.The development of high-performance and cost-effective Mg alloys is crucial to further advancing ...Magnesium(Mg),being the lightest structural metal,holds immense potential for widespread applications in various fields.The development of high-performance and cost-effective Mg alloys is crucial to further advancing their commercial utilization.With the rapid advancement of machine learning(ML)technology in recent years,the“data-driven''approach for alloy design has provided new perspectives and opportunities for enhancing the performance of Mg alloys.This paper introduces a novel regression-based Bayesian optimization active learning model(RBOALM)for the development of high-performance Mg-Mn-based wrought alloys.RBOALM employs active learning to automatically explore optimal alloy compositions and process parameters within predefined ranges,facilitating the discovery of superior alloy combinations.This model further integrates pre-established regression models as surrogate functions in Bayesian optimization,significantly enhancing the precision of the design process.Leveraging RBOALM,several new high-performance alloys have been successfully designed and prepared.Notably,after mechanical property testing of the designed alloys,the Mg-2.1Zn-2.0Mn-0.5Sn-0.1Ca alloy demonstrates exceptional mechanical properties,including an ultimate tensile strength of 406 MPa,a yield strength of 287 MPa,and a 23%fracture elongation.Furthermore,the Mg-2.7Mn-0.5Al-0.1Ca alloy exhibits an ultimate tensile strength of 211 MPa,coupled with a remarkable 41%fracture elongation.展开更多
The increasing demand for high-end equipment in crucial sectors such as aerospace,aeronautics, energy, power, information and electronics continues growing. However, the manufacturing of such advanced equipment poses ...The increasing demand for high-end equipment in crucial sectors such as aerospace,aeronautics, energy, power, information and electronics continues growing. However, the manufacturing of such advanced equipment poses significant challenges owing to high-level requirements for loading, transmission, conduction, energy conversion, and stealth. These challenges are amplified by complex structures, hard-to-cut materials, and strict standards for surface integrity and precision. To overcome these barriers in high-end equipment manufacturing, high-performance manufacturing(HPM) has emerged as an essential solution.This paper firstly discusses the key challenges in manufacturing technology and explores the essence of HPM, outlining a quantitative relationship between design and manufacturing.Subsequently, a generalized framework of HPM is proposed, accompanied by an in-depth exploration of the foundational elements and criteria. Ultimately, the feasible approaches and enabling technologies, supported by the analysis of two illustrative case studies are demonstrated. It is concluded that HPM is not just a precision and computational manufacturing framework with a core focus on multiparameter correlation in design, manufacturing, and service environments. It also represents a performance-geometry-integrated manufacturing framework for an accurate guarantee of the optimal performance.展开更多
To mitigate the massive volume expansion of Si-based anode during the charge/discharge cycles,we synthesized a superstructure of Si@Co±NC composite via the carbonization of zeolite imidazolate frameworks incorpor...To mitigate the massive volume expansion of Si-based anode during the charge/discharge cycles,we synthesized a superstructure of Si@Co±NC composite via the carbonization of zeolite imidazolate frameworks incorporated with Si nanoparticles.The Si@Co±NC is comprised of Sinanoparticle core and N-doped/Co-incorporated carbon shell,and there is void space between the core and the shell.When using as anode material for LIBs,Si@Co±NC displayed a super performance with a charge/discharge capacity of 191.6/191.4 mA h g^(-1)and a coulombic efficiency of 100.1%at 1000 mA g^(-1)after 3000 cycles,and the capacity loss rate is 0.022%per cycle only.The excellent electrochemical property of Si@Co±NC is because its electronic conductivity is enhanced by doping the carbon shell with N atoms and by incorporating with Co particles,and the pathway of lithium ions transmission is shortened by the hollow structure and abundant mesopores in the carbon shell.Also,the volume expansion of Si nanoparticles is well accommodated in the void space and suppressed by the carbon host matrix.This work shows that,through designing a superstructure for the anode materials,we can synergistically reduce the work function and introduce the confinement effect,thus significantly enhancing the anode materials’electrochemical performance in LIBs.展开更多
Carbendazim belongs to the benzimidazole fungicides,which can be used for control lots of fungi pathogens.High-performance liquid chromatography is frequently used for the analysis of carbendazim in all kinds of sampl...Carbendazim belongs to the benzimidazole fungicides,which can be used for control lots of fungi pathogens.High-performance liquid chromatography is frequently used for the analysis of carbendazim in all kinds of samples.In most occasions,the developed methods were applied for the simultaneous detection of a huge number of pesticides.Thus,an analytical method via UPLC-FLD was developed,and the sample preparation process was optimized by studying the effect of extraction solvent,approach,time and purification absorbent on the recovery rate of carbendazim.The results showed the optimized method for analysis was ultrasonication-assisted extraction with acetonitrile for 1 min,and subsequent purification by C18.In this occasion,the established analytical method of carbendazim in tomato samples displayed good linearity,accuracy and precision.展开更多
This study embarks on a comprehensive examination of optimization techniques within GPU-based parallel programming models,pivotal for advancing high-performance computing(HPC).Emphasizing the transition of GPUs from g...This study embarks on a comprehensive examination of optimization techniques within GPU-based parallel programming models,pivotal for advancing high-performance computing(HPC).Emphasizing the transition of GPUs from graphic-centric processors to versatile computing units,it delves into the nuanced optimization of memory access,thread management,algorithmic design,and data structures.These optimizations are critical for exploiting the parallel processing capabilities of GPUs,addressingboth the theoretical frameworks and practical implementations.By integrating advanced strategies such as memory coalescing,dynamic scheduling,and parallel algorithmic transformations,this research aims to significantly elevate computational efficiency and throughput.The findings underscore the potential of optimized GPU programming to revolutionize computational tasks across various domains,highlighting a pathway towards achieving unparalleled processing power and efficiency in HPC environments.The paper not only contributes to the academic discourse on GPU optimization but also provides actionable insights for developers,fostering advancements in computational sciences and technology.展开更多
This study proposes a moderated mediation model to investigate the relationship between organizational learning and firm performance. We argue that entrepreneurial orientation mediates the positive effect of organizat...This study proposes a moderated mediation model to investigate the relationship between organizational learning and firm performance. We argue that entrepreneurial orientation mediates the positive effect of organizational learning on firm performance. Furthermore, the relationship between organizational learning and entrepreneurial orientation is strengthened when firms employ a higher level of high-performance work system. Hypotheses are supported by data from 181 firms operating in the manufacturing and service industries in China. Statistical results further reveal that a high-performance work system has different moderating effects on exploitative learning and exploratory learning. This research extends our understanding of organizational learning theory, entrepreneurship and human resource management literature by cross-fertilizing constructs in these fields with empirical evidence.展开更多
Objective To investigate the relationship between trans, trans-muconic acid （ttMA） as benzene metabolite of occupational workers and benzene concentration in air. Methods A rapid and sensitive high-performance liqui...Objective To investigate the relationship between trans, trans-muconic acid （ttMA） as benzene metabolite of occupational workers and benzene concentration in air. Methods A rapid and sensitive high-performance liquid chromatography was developed to determine the level of urinary ttMA. ttMA was extrated from urinary samples in liquid-liquid phase a ODS （2） （5u） column （Ф4.6 min× 150 mm） and detected at wavelength 264 nm in a UV detector using vanillic acid as an internal standard. The mobile phase was acetaticacid/tetrahydrofuran/methanol/water （v/v, 1：2：10：87）. The method was validated with 56 urine samples collected from occupationally benzene-exposed individuals. Results A correlation coefficient （r = 0.9963 ） was found for ttMA ranging 0.10-10.00 μg/mL. The limit of detection was 0.10μ g/mL. The recovery and reproducibility were generally over 90%. There was a positive correlation between ttMA and benzene level in air. The equation was Y=0.859＋0.108C （before work, r=0.6200） or Y=1.980＋0.179C （after work, r=0.7930）. Conclusion This method can be used to determine and control the level of urinary ttMA in those who are occupationally exposed to benzene.展开更多
BACKGROUND Return to work(RTW)serves as an indication for young and middle-aged colorectal cancer(CRC)survivors to resume their normal social lives.However,these survivors encounter significant challenges during their...BACKGROUND Return to work(RTW)serves as an indication for young and middle-aged colorectal cancer(CRC)survivors to resume their normal social lives.However,these survivors encounter significant challenges during their RTW process.Hence,scientific research is necessary to explore the barriers and facilitating factors of returning to work for young and middle-aged CRC survivors.AIM To examine the current RTW status among young and middle-aged CRC survivors and to analyze the impact of RTW self-efficacy(RTW-SE),fear of progression(FoP),eHealth literacy(eHL),family resilience(FR),and financial toxicity(FT)on their RTW outcomes.METHODS A cross-sectional investigation was adopted in this study.From September 2022 to February 2023,a total of 209 participants were recruited through a convenience sampling method from the gastrointestinal surgery department of a class A tertiary hospital in Chongqing.The investigation utilized a general information questionnaire alongside scales assessing RTW-SE,FoP,eHL,FR,and FT.To analyze the factors that influence RTW outcomes among young and middle-aged CRC survivors,Cox regression modeling and Kaplan-Meier survival analysis were used.RESULTS A total of 43.54%of the participants successfully returned to work,with an average RTW time of 100 days.Cox regression univariate analysis revealed that RTW-SE,FoP,eHL,FR,and FT were significantly different between the non-RTW and RTW groups(P<0.05).Furthermore,Cox regression multivariate analysis identified per capita family monthly income,job type,RTW-SE,and FR as independent influencing factors for RTW(P<0.05).CONCLUSION The RTW rate requires further improvement.Elevated levels of RTW-SE and FR were found to significantly increase RTW among young and middle-aged CRC survivors.Health professionals should focus on modifiable factors,such as RTW-SE and FR,to design targeted RTW support programs,thereby facilitating their timely reintegration into mainstream society.展开更多
Background: First responders (firefighters, paramedics, and police) working in an urban setting can be exposed to a high-stress environment caused by strenuous physical exertion, potentially dangerous work conditions,...Background: First responders (firefighters, paramedics, and police) working in an urban setting can be exposed to a high-stress environment caused by strenuous physical exertion, potentially dangerous work conditions, sleep deprivation due to shift work, poor dietary habits, psychological stress and noise levels that are excessive. This may induce chronic increases in blood pressure. The purpose of this study was to determine the presence of hypertension in people working in occupations generally accepted as high stress in comparison to those working in an environment where less of these obvious high stressors were present. Methods: Resting blood pressure was measured by TrUBP in 1067 on-duty first responders (fire, paramedic, and police), and in participants generally associated with a lower-stress work environment (transit workers, city and bank employees, factory workers and legislature employees). Results: The average age, systolic and diastolic blood pressures were significantly lower in those employees working in a high-stress environment than those in a low-stress job. This difference was observed in both male and female sexes. Conclusions: Our data do not support an association of high resting blood pressure values in those employed in activities typically associated with a high-stress urban working environment.展开更多
Coronavirus is a Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) caused by a novel coronavirus belonging to the family Coronaviridae. The disease was first discovered in December 2019 in Wuhan City, Hubei...Coronavirus is a Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) caused by a novel coronavirus belonging to the family Coronaviridae. The disease was first discovered in December 2019 in Wuhan City, Hubei Province, China. A few months later, the disease spread all over the world and became an epidemic. The infection for most people is mild to moderate but in Vulnerable groups, if they have the infections, they might experience severe COVID-19. Saudi Arabia initiated its response plan early, and all sectors and agencies worked in an integrated way to combat the disease. It has maintained proper communication during the pandemic and ensured community involvement, epidemiologic surveillance, and activation of rapid response teams. The COVID-19 pandemic significantly affected daily lives. Schools and daycares were closed, education was online, traveling stopped, work was suspended, gathering in social activities and practicing religious rituals, like praying or doing Umrah or Hajj, were banded. Changing lifestyles as a response to COVID-19 impacted whole communities with different categories of children, parents, and families. Women usually take the majority of daily responsibilities. The sudden change in lifestyle during COVID-19 put pressure on mothers, especially those who are working to balance work and family obligations. This study aims to identify the impact of Coronavirus disease 2019 on working mothers in Saudi Arabia. Method: Data of the study was collected through survey posted on social media and analyzed through Excel. It focuses on five aspects: health, lifestyle, social relations, work production and financial status. Our target population was working mothers in Saudi Arabia aged at least 25 years. Results: In this study, all factors affected working mothers categorized under two groups: Social Economic Status and Work suspension. For Social Economic Status factors, we find five factors which are monthly income, main breadwinner, number of children at school age, type of housing, and type of work. Almost all mothers include spiritual activities to their routine to cope with stress during this period. About half of our sample have negative impact on their mental health because they are the main breadwinner, and mothers with a smaller number of children at school age have more challenges to cope up. We found that mothers who own a house or work at governmental sector have better outcome of health. After analyzing data related to Work suspension, we found that mothers who have work support have better management for life circumstances, however their health outcomes were negatively affected. In addition, mothers working at education sector have the highest positive impact among other sectors. Our data shows that working mothers’ abilities to follow up with their children decreased. This study recommends that there is need to invest more in working mothers’ research and supportive programs and ensure collaboration globally to address working mothers’ needs and share experiences.展开更多
This study proposes a novel approach to optimizing individual work schedules for book digitization using mixed-integer programming (MIP). By leveraging the power of MIP solvers, we aimed to minimize the overall digiti...This study proposes a novel approach to optimizing individual work schedules for book digitization using mixed-integer programming (MIP). By leveraging the power of MIP solvers, we aimed to minimize the overall digitization time while considering various constraints and process dependencies. The book digitization process involves three key steps: cutting, scanning, and binding. Each step has specific requirements and limitations such as the number of pages that can be processed simultaneously and potential bottlenecks. To address these complexities, we formulate the problem as a one-machine job shop scheduling problem with additional constraints to capture the unique characteristics of book digitization. We conducted a series of experiments to evaluate the performance of our proposed approach. By comparing the optimized schedules with the baseline approach, we demonstrated significant reductions in the overall processing time. In addition, we analyzed the impact of different weighting schemes on the optimization results, highlighting the importance of identifying and prioritizing critical processes. Our findings suggest that MIP-based optimization can be a valuable tool for improving the efficiency of individual work schedules, even in seemingly simple tasks, such as book digitization. By carefully considering specific constraints and objectives, we can save time and leverage resources by carefully considering specific constraints and objectives.展开更多
This paper defines and explores the concept of social reproduction work,highlighting its significance and the fact that women are its primary contributors.It identifies key social issues faced by social reproduction w...This paper defines and explores the concept of social reproduction work,highlighting its significance and the fact that women are its primary contributors.It identifies key social issues faced by social reproduction workers,including marginalization,neglect,and unequal access to resources.Additionally,the study examines the primary challenges encountered by these workers:the lack of direct economic benefits,difficulty in balancing work and family responsibilities,and the significant physical and mental strain associated with unpaid labor.Using the theoretical framework of the capitalist economic system,the paper delves into the root causes of the caregiving crisis.Furthermore,it critiques the applicability of reproduction work theories in explaining unpaid care work in the Global South.Three key limitations are outlined:the neglect of informal economic systems in the Global South,persistent gender inequality,and the dynamic nature of global economic migration.展开更多
This study focuses on the relationship between job stress and intention to leave among obstetric(OB)nurses in the context of China's birth policy adjustment,and provides a scientific basis for policymakers and hea...This study focuses on the relationship between job stress and intention to leave among obstetric(OB)nurses in the context of China's birth policy adjustment,and provides a scientific basis for policymakers and healthcare administrators.This study used a non-experimental descriptive correlation design with a purposive sampling of 230 OB nurses from three tertiary hospitals in Jinan,Shandong Province.Participants were surveyed using three questionnaires and descriptive analysis;ANOVA and correlation analyses were used to analyze the relationship between participants'stressor levels and turnover intention.Pearson's correlation coefficient analysis showed that there was a positive correlation between nurses‘work stressors and turnover intention,with a correlation coefficient of r=0.53,a moderate positive correlation(P<0.001).Based on the survey data from three tertiary hospitals in Shandong Province,the obstetric nurses group has a medium level of work stressors,but a high turnover intention,highlighting the professional identity crisis.展开更多
To elucidate the yielding performance of compact yielding anchor cables in working state,a yielding mechanical model incorporating extrusion friction and fastening rotation under confining pressure is constructed.The ...To elucidate the yielding performance of compact yielding anchor cables in working state,a yielding mechanical model incorporating extrusion friction and fastening rotation under confining pressure is constructed.The yielding resistance enhancement effect(ω)caused by working environment constraints is evaluated through multi-layer composite sleeve hole expansion analysis,forming a theoretical framework for calculating the working yielding force.Laboratory and in-situ pull-out tests are conducted to determine the yielding performance and validate the analytical theory.The main conclusions are:(1)Yielding force and energy-release capacity increase withω,significantly outperforming the unconfined state.(2)In-situ tests under varying rockmass and geostress conditions(F1–F3)determine the yielding force increases to 183.4–290.1,204.0–290.8,and 235.0–327.1 kN.(3)The slight deviation(–12.5%to 6.2%)between the theoretical and measured yielding force confirms that the analytical theory effectively describes the working yielding performance.(4)ωincreases with higher geostress and improved rock mechanical properties,with initial geostress(σ_(0))and elastic modulus of surrounding rock(E_(3))identified as critical parameters.展开更多
In order to investigate the effects of two mineral admixtures （i. e., fly ash and ground slag）on initial defects existing in concrete microstructures, a high-resolution X-ray micro-CT（ micro-focus computer tomogra...In order to investigate the effects of two mineral admixtures （i. e., fly ash and ground slag）on initial defects existing in concrete microstructures, a high-resolution X-ray micro-CT（ micro-focus computer tomography）is employed to quantitatively analyze the initial defects in four series of highperformance concrete （HPC）specimens with additions of different mineral admixtures. The nigh-resolution 3D images of microstructures and filtered defects are reconstructed by micro- CT software. The size distribution and volume fractions of initial defects are analyzed based on 3D and 2D micro-CT images. The analysis results are verified by experimental results of watersuction tests. The results show that the additions of mineral admixtures in concrete as cementitious materials greatly change the geometrical properties of the microstructures and the spatial features of defects by physical-chemistry actions of these mineral admixtures. This is the major cause of the differences between the mechanical behaviors of HPC with and without mineral admixtures when the water-to-binder ratio and the size distribution of aggregates are constant.展开更多
The peroxyoxalate chemiluminescence(CL)detection of fatty acids in human se- rum combined with high-performance liquid chromatography (HPLC)is described.Some fatty acids in serum were extracted with a 1 :1(v/v)mixture...The peroxyoxalate chemiluminescence(CL)detection of fatty acids in human se- rum combined with high-performance liquid chromatography (HPLC)is described.Some fatty acids in serum were extracted with a 1 :1(v/v)mixture of chloroform-n-heptane.2-(4-Hydrazinocarbonyl- phenyl)-4,5-diphenylimidazole (HCPI) was used as a fluorescent labelling reagent of the fatty acids. The labelling reaction was carried out at 30℃ for 1 h at pH 6.5 and the resulting reaction mixture was sudjected to HPLC. The labelled fatty acid C_(17)(P-C_(17))was used as the internal standard. The la- belled fatty acids C_(16) and C_(18) were separated within 18 min on an ODS-8OTM column (150 mm× 6 mm ID,5μm,Tosoh Japan).The calibrlation curves of fatty acids from the spiked control serum were Y_1=-0.003 7 + 0.0028X_1,r=0.994 for FA C_( 16) and Y_2=0.00 1 2 + 0.00098X_2,r=0.999 for FA C_( 18),respectively.The average recoveries of facids from the spiked contrl serum were 107.2%(n=8,RSD=4.3%)for FA C_(16) and 97.35%(n=8, RSD=4.0%)for FA C_(18),respectively.The lower detection limits of fatty acids after reaction were 12μmol per 20μl injection for FA C_(16) and 18 μmol per 20μl injection for FA C_(18),respectively(signal to noise ratio, S/N=2).The HPLC/CL method was applied to the determination of FA C_(16) and FA C_(18) in normal human serum and the results showed that the concentrations of fatty acids in normal human serum were 0.134 ± 0.009 μ mol/ml serum(n=5) for FA C_(16) and 0.052±0.028 μmol/ml serum(n=5)for FA C_(18),respectively.展开更多
Aim To quantitatively determine five nucleosides and nucleobases, including cytidine, uridine, guanosine, adenosine and uracil in different parts of Panax notoginseng. Methods Separation was performed on a Zorbax SB-A...Aim To quantitatively determine five nucleosides and nucleobases, including cytidine, uridine, guanosine, adenosine and uracil in different parts of Panax notoginseng. Methods Separation was performed on a Zorbax SB-Aq column using a gradient elution with mobile phase of 8 mmol^L-1 ammonium acetate aqueous solution （A） and methanol （B）. The assay was carried out at a flow rate of 1 mL·min^-1 at 25 ℃ with the diode-array detection at 260 nm. Results Cytidine, uridine, guanosine, adenosine and uracil had good linearity in the ranges of 1.79 - 57.40 μg·mL^-1 （r^2 = 1.0000）, 3.30 - 105.60 μg·mL^-1 （r^2 = 1.0000）, 3.09 - 98.80 μg·mL^ -1（r^2 = 0.9999）, 2.77 - 88.60 μg·mL^-1 （r^2 = 1.0000） and 0.38 - 12.30 μg·mL ^-1 （r^2 = 1.0000） with average recoveries of 93.9%, 96.5%, 92.7%, 93.2% and 98.8%, respectively. The content of cytidine, uridine, guanosine, adenosine and uracil in different parts of P. notogingeng were significantly different. Conclusion This is the first report on quantitative determination of nucleosides and nucleobases in P notoginseng.展开更多
The compositions and contents of ginsenbsides in Panax ginseng,P.quinquefolium and P.notoginseng were determined and compared by reversed-phase High-Performance Liquid Chro- matography(HPLC).The method was performed o...The compositions and contents of ginsenbsides in Panax ginseng,P.quinquefolium and P.notoginseng were determined and compared by reversed-phase High-Performance Liquid Chro- matography(HPLC).The method was performed on an Alltech Adsorbosphere HS C_(18) column,using 5×10^(-3)M NaH_2PO_4-H_3PO_4 buffer solution(pH 3.0)and acetonitrile-water(50:50)as gradient eluents. The baseline separation of ginsenosides Rb_1,Rb_2,Rb_1,Rc,Rd,Rf,Ro,and Re+Rg_1 was obtained in one analytical run.The ginsenosides are directly detected at 203 nm.The detection limit is 40μg at a signal to noise ratio of 3:1.The improved sample preparation and clean-up prior to injection with SEP-PAK C_(18)cartridge strongly reduced the front peaks caused by the impurities in the methanolic extracts of samples to afford a smooth baseline and clear background.The HPLC patterns of methanolic extracts mainly including the ginsenosides were found capable of serving as chemical fingerprints to differentiate the three species from each other.It was also found that there are no significant diffe- rences of the HPLC patterns between the wild Panax ginseng and the cultivated,the white and the red ginsengs,Chinese and Korean red ginsengs,and the tap roots of Panax ginseng collected in four consecutive months,only certain differences in contents of ginsenosides do exist.The contents of the nine major ginsenosides present in the rhizome,tap root and rootlet as well as the leaf of Panax quinquefolium were also determined and compared.展开更多
基金supported by the National Natural the Science Foundation of China(51971042,51901028)the Chongqing Academician Special Fund(cstc2020yszxjcyj X0001)+1 种基金the China Scholarship Council(CSC)Norwegian University of Science and Technology(NTNU)for their financial and technical support。
文摘Magnesium(Mg),being the lightest structural metal,holds immense potential for widespread applications in various fields.The development of high-performance and cost-effective Mg alloys is crucial to further advancing their commercial utilization.With the rapid advancement of machine learning(ML)technology in recent years,the“data-driven''approach for alloy design has provided new perspectives and opportunities for enhancing the performance of Mg alloys.This paper introduces a novel regression-based Bayesian optimization active learning model(RBOALM)for the development of high-performance Mg-Mn-based wrought alloys.RBOALM employs active learning to automatically explore optimal alloy compositions and process parameters within predefined ranges,facilitating the discovery of superior alloy combinations.This model further integrates pre-established regression models as surrogate functions in Bayesian optimization,significantly enhancing the precision of the design process.Leveraging RBOALM,several new high-performance alloys have been successfully designed and prepared.Notably,after mechanical property testing of the designed alloys,the Mg-2.1Zn-2.0Mn-0.5Sn-0.1Ca alloy demonstrates exceptional mechanical properties,including an ultimate tensile strength of 406 MPa,a yield strength of 287 MPa,and a 23%fracture elongation.Furthermore,the Mg-2.7Mn-0.5Al-0.1Ca alloy exhibits an ultimate tensile strength of 211 MPa,coupled with a remarkable 41%fracture elongation.
文摘The increasing demand for high-end equipment in crucial sectors such as aerospace,aeronautics, energy, power, information and electronics continues growing. However, the manufacturing of such advanced equipment poses significant challenges owing to high-level requirements for loading, transmission, conduction, energy conversion, and stealth. These challenges are amplified by complex structures, hard-to-cut materials, and strict standards for surface integrity and precision. To overcome these barriers in high-end equipment manufacturing, high-performance manufacturing(HPM) has emerged as an essential solution.This paper firstly discusses the key challenges in manufacturing technology and explores the essence of HPM, outlining a quantitative relationship between design and manufacturing.Subsequently, a generalized framework of HPM is proposed, accompanied by an in-depth exploration of the foundational elements and criteria. Ultimately, the feasible approaches and enabling technologies, supported by the analysis of two illustrative case studies are demonstrated. It is concluded that HPM is not just a precision and computational manufacturing framework with a core focus on multiparameter correlation in design, manufacturing, and service environments. It also represents a performance-geometry-integrated manufacturing framework for an accurate guarantee of the optimal performance.
基金financial supports by the National Natural Science Foundation of China(No.51772295)support of GTIIT for the collaboration,and the start-up fund provided by GTIIT
文摘To mitigate the massive volume expansion of Si-based anode during the charge/discharge cycles,we synthesized a superstructure of Si@Co±NC composite via the carbonization of zeolite imidazolate frameworks incorporated with Si nanoparticles.The Si@Co±NC is comprised of Sinanoparticle core and N-doped/Co-incorporated carbon shell,and there is void space between the core and the shell.When using as anode material for LIBs,Si@Co±NC displayed a super performance with a charge/discharge capacity of 191.6/191.4 mA h g^(-1)and a coulombic efficiency of 100.1%at 1000 mA g^(-1)after 3000 cycles,and the capacity loss rate is 0.022%per cycle only.The excellent electrochemical property of Si@Co±NC is because its electronic conductivity is enhanced by doping the carbon shell with N atoms and by incorporating with Co particles,and the pathway of lithium ions transmission is shortened by the hollow structure and abundant mesopores in the carbon shell.Also,the volume expansion of Si nanoparticles is well accommodated in the void space and suppressed by the carbon host matrix.This work shows that,through designing a superstructure for the anode materials,we can synergistically reduce the work function and introduce the confinement effect,thus significantly enhancing the anode materials’electrochemical performance in LIBs.
基金Supported by Youth Talent Project of Education Department Scientific Research Plan of Hubei Province(Q20232904).
文摘Carbendazim belongs to the benzimidazole fungicides,which can be used for control lots of fungi pathogens.High-performance liquid chromatography is frequently used for the analysis of carbendazim in all kinds of samples.In most occasions,the developed methods were applied for the simultaneous detection of a huge number of pesticides.Thus,an analytical method via UPLC-FLD was developed,and the sample preparation process was optimized by studying the effect of extraction solvent,approach,time and purification absorbent on the recovery rate of carbendazim.The results showed the optimized method for analysis was ultrasonication-assisted extraction with acetonitrile for 1 min,and subsequent purification by C18.In this occasion,the established analytical method of carbendazim in tomato samples displayed good linearity,accuracy and precision.
文摘This study embarks on a comprehensive examination of optimization techniques within GPU-based parallel programming models,pivotal for advancing high-performance computing(HPC).Emphasizing the transition of GPUs from graphic-centric processors to versatile computing units,it delves into the nuanced optimization of memory access,thread management,algorithmic design,and data structures.These optimizations are critical for exploiting the parallel processing capabilities of GPUs,addressingboth the theoretical frameworks and practical implementations.By integrating advanced strategies such as memory coalescing,dynamic scheduling,and parallel algorithmic transformations,this research aims to significantly elevate computational efficiency and throughput.The findings underscore the potential of optimized GPU programming to revolutionize computational tasks across various domains,highlighting a pathway towards achieving unparalleled processing power and efficiency in HPC environments.The paper not only contributes to the academic discourse on GPU optimization but also provides actionable insights for developers,fostering advancements in computational sciences and technology.
文摘This study proposes a moderated mediation model to investigate the relationship between organizational learning and firm performance. We argue that entrepreneurial orientation mediates the positive effect of organizational learning on firm performance. Furthermore, the relationship between organizational learning and entrepreneurial orientation is strengthened when firms employ a higher level of high-performance work system. Hypotheses are supported by data from 181 firms operating in the manufacturing and service industries in China. Statistical results further reveal that a high-performance work system has different moderating effects on exploitative learning and exploratory learning. This research extends our understanding of organizational learning theory, entrepreneurship and human resource management literature by cross-fertilizing constructs in these fields with empirical evidence.
文摘Objective To investigate the relationship between trans, trans-muconic acid （ttMA） as benzene metabolite of occupational workers and benzene concentration in air. Methods A rapid and sensitive high-performance liquid chromatography was developed to determine the level of urinary ttMA. ttMA was extrated from urinary samples in liquid-liquid phase a ODS （2） （5u） column （Ф4.6 min× 150 mm） and detected at wavelength 264 nm in a UV detector using vanillic acid as an internal standard. The mobile phase was acetaticacid/tetrahydrofuran/methanol/water （v/v, 1：2：10：87）. The method was validated with 56 urine samples collected from occupationally benzene-exposed individuals. Results A correlation coefficient （r = 0.9963 ） was found for ttMA ranging 0.10-10.00 μg/mL. The limit of detection was 0.10μ g/mL. The recovery and reproducibility were generally over 90%. There was a positive correlation between ttMA and benzene level in air. The equation was Y=0.859＋0.108C （before work, r=0.6200） or Y=1.980＋0.179C （after work, r=0.7930）. Conclusion This method can be used to determine and control the level of urinary ttMA in those who are occupationally exposed to benzene.
基金Supported by the Chongqing Medical University Program for Youth Innovation in Future Medicine,No.W0019Chongqing Municipal Education Commission’s 14th Five-Year Key Discipline Support Project,No.20240101 and No.20240102。
文摘BACKGROUND Return to work(RTW)serves as an indication for young and middle-aged colorectal cancer(CRC)survivors to resume their normal social lives.However,these survivors encounter significant challenges during their RTW process.Hence,scientific research is necessary to explore the barriers and facilitating factors of returning to work for young and middle-aged CRC survivors.AIM To examine the current RTW status among young and middle-aged CRC survivors and to analyze the impact of RTW self-efficacy(RTW-SE),fear of progression(FoP),eHealth literacy(eHL),family resilience(FR),and financial toxicity(FT)on their RTW outcomes.METHODS A cross-sectional investigation was adopted in this study.From September 2022 to February 2023,a total of 209 participants were recruited through a convenience sampling method from the gastrointestinal surgery department of a class A tertiary hospital in Chongqing.The investigation utilized a general information questionnaire alongside scales assessing RTW-SE,FoP,eHL,FR,and FT.To analyze the factors that influence RTW outcomes among young and middle-aged CRC survivors,Cox regression modeling and Kaplan-Meier survival analysis were used.RESULTS A total of 43.54%of the participants successfully returned to work,with an average RTW time of 100 days.Cox regression univariate analysis revealed that RTW-SE,FoP,eHL,FR,and FT were significantly different between the non-RTW and RTW groups(P<0.05).Furthermore,Cox regression multivariate analysis identified per capita family monthly income,job type,RTW-SE,and FR as independent influencing factors for RTW(P<0.05).CONCLUSION The RTW rate requires further improvement.Elevated levels of RTW-SE and FR were found to significantly increase RTW among young and middle-aged CRC survivors.Health professionals should focus on modifiable factors,such as RTW-SE and FR,to design targeted RTW support programs,thereby facilitating their timely reintegration into mainstream society.
文摘Background: First responders (firefighters, paramedics, and police) working in an urban setting can be exposed to a high-stress environment caused by strenuous physical exertion, potentially dangerous work conditions, sleep deprivation due to shift work, poor dietary habits, psychological stress and noise levels that are excessive. This may induce chronic increases in blood pressure. The purpose of this study was to determine the presence of hypertension in people working in occupations generally accepted as high stress in comparison to those working in an environment where less of these obvious high stressors were present. Methods: Resting blood pressure was measured by TrUBP in 1067 on-duty first responders (fire, paramedic, and police), and in participants generally associated with a lower-stress work environment (transit workers, city and bank employees, factory workers and legislature employees). Results: The average age, systolic and diastolic blood pressures were significantly lower in those employees working in a high-stress environment than those in a low-stress job. This difference was observed in both male and female sexes. Conclusions: Our data do not support an association of high resting blood pressure values in those employed in activities typically associated with a high-stress urban working environment.
文摘Coronavirus is a Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) caused by a novel coronavirus belonging to the family Coronaviridae. The disease was first discovered in December 2019 in Wuhan City, Hubei Province, China. A few months later, the disease spread all over the world and became an epidemic. The infection for most people is mild to moderate but in Vulnerable groups, if they have the infections, they might experience severe COVID-19. Saudi Arabia initiated its response plan early, and all sectors and agencies worked in an integrated way to combat the disease. It has maintained proper communication during the pandemic and ensured community involvement, epidemiologic surveillance, and activation of rapid response teams. The COVID-19 pandemic significantly affected daily lives. Schools and daycares were closed, education was online, traveling stopped, work was suspended, gathering in social activities and practicing religious rituals, like praying or doing Umrah or Hajj, were banded. Changing lifestyles as a response to COVID-19 impacted whole communities with different categories of children, parents, and families. Women usually take the majority of daily responsibilities. The sudden change in lifestyle during COVID-19 put pressure on mothers, especially those who are working to balance work and family obligations. This study aims to identify the impact of Coronavirus disease 2019 on working mothers in Saudi Arabia. Method: Data of the study was collected through survey posted on social media and analyzed through Excel. It focuses on five aspects: health, lifestyle, social relations, work production and financial status. Our target population was working mothers in Saudi Arabia aged at least 25 years. Results: In this study, all factors affected working mothers categorized under two groups: Social Economic Status and Work suspension. For Social Economic Status factors, we find five factors which are monthly income, main breadwinner, number of children at school age, type of housing, and type of work. Almost all mothers include spiritual activities to their routine to cope with stress during this period. About half of our sample have negative impact on their mental health because they are the main breadwinner, and mothers with a smaller number of children at school age have more challenges to cope up. We found that mothers who own a house or work at governmental sector have better outcome of health. After analyzing data related to Work suspension, we found that mothers who have work support have better management for life circumstances, however their health outcomes were negatively affected. In addition, mothers working at education sector have the highest positive impact among other sectors. Our data shows that working mothers’ abilities to follow up with their children decreased. This study recommends that there is need to invest more in working mothers’ research and supportive programs and ensure collaboration globally to address working mothers’ needs and share experiences.
文摘This study proposes a novel approach to optimizing individual work schedules for book digitization using mixed-integer programming (MIP). By leveraging the power of MIP solvers, we aimed to minimize the overall digitization time while considering various constraints and process dependencies. The book digitization process involves three key steps: cutting, scanning, and binding. Each step has specific requirements and limitations such as the number of pages that can be processed simultaneously and potential bottlenecks. To address these complexities, we formulate the problem as a one-machine job shop scheduling problem with additional constraints to capture the unique characteristics of book digitization. We conducted a series of experiments to evaluate the performance of our proposed approach. By comparing the optimized schedules with the baseline approach, we demonstrated significant reductions in the overall processing time. In addition, we analyzed the impact of different weighting schemes on the optimization results, highlighting the importance of identifying and prioritizing critical processes. Our findings suggest that MIP-based optimization can be a valuable tool for improving the efficiency of individual work schedules, even in seemingly simple tasks, such as book digitization. By carefully considering specific constraints and objectives, we can save time and leverage resources by carefully considering specific constraints and objectives.
文摘This paper defines and explores the concept of social reproduction work,highlighting its significance and the fact that women are its primary contributors.It identifies key social issues faced by social reproduction workers,including marginalization,neglect,and unequal access to resources.Additionally,the study examines the primary challenges encountered by these workers:the lack of direct economic benefits,difficulty in balancing work and family responsibilities,and the significant physical and mental strain associated with unpaid labor.Using the theoretical framework of the capitalist economic system,the paper delves into the root causes of the caregiving crisis.Furthermore,it critiques the applicability of reproduction work theories in explaining unpaid care work in the Global South.Three key limitations are outlined:the neglect of informal economic systems in the Global South,persistent gender inequality,and the dynamic nature of global economic migration.
文摘This study focuses on the relationship between job stress and intention to leave among obstetric(OB)nurses in the context of China's birth policy adjustment,and provides a scientific basis for policymakers and healthcare administrators.This study used a non-experimental descriptive correlation design with a purposive sampling of 230 OB nurses from three tertiary hospitals in Jinan,Shandong Province.Participants were surveyed using three questionnaires and descriptive analysis;ANOVA and correlation analyses were used to analyze the relationship between participants'stressor levels and turnover intention.Pearson's correlation coefficient analysis showed that there was a positive correlation between nurses‘work stressors and turnover intention,with a correlation coefficient of r=0.53,a moderate positive correlation(P<0.001).Based on the survey data from three tertiary hospitals in Shandong Province,the obstetric nurses group has a medium level of work stressors,but a high turnover intention,highlighting the professional identity crisis.
基金supported by the National Natural Science Foundation of China(Nos.U2468217,U2034205,and 52308391)。
文摘To elucidate the yielding performance of compact yielding anchor cables in working state,a yielding mechanical model incorporating extrusion friction and fastening rotation under confining pressure is constructed.The yielding resistance enhancement effect(ω)caused by working environment constraints is evaluated through multi-layer composite sleeve hole expansion analysis,forming a theoretical framework for calculating the working yielding force.Laboratory and in-situ pull-out tests are conducted to determine the yielding performance and validate the analytical theory.The main conclusions are:(1)Yielding force and energy-release capacity increase withω,significantly outperforming the unconfined state.(2)In-situ tests under varying rockmass and geostress conditions(F1–F3)determine the yielding force increases to 183.4–290.1,204.0–290.8,and 235.0–327.1 kN.(3)The slight deviation(–12.5%to 6.2%)between the theoretical and measured yielding force confirms that the analytical theory effectively describes the working yielding performance.(4)ωincreases with higher geostress and improved rock mechanical properties,with initial geostress(σ_(0))and elastic modulus of surrounding rock(E_(3))identified as critical parameters.
基金The Scholarship Supported by Ministry of Education of China for Research Abroad(No.3037[2006])the Excellent Doctoral Dissertation Foundation of Southeast University (No.YBTJ-0512)the National Basic Research Program of China(973Program)(No.2009CB623203)
文摘In order to investigate the effects of two mineral admixtures （i. e., fly ash and ground slag）on initial defects existing in concrete microstructures, a high-resolution X-ray micro-CT（ micro-focus computer tomography）is employed to quantitatively analyze the initial defects in four series of highperformance concrete （HPC）specimens with additions of different mineral admixtures. The nigh-resolution 3D images of microstructures and filtered defects are reconstructed by micro- CT software. The size distribution and volume fractions of initial defects are analyzed based on 3D and 2D micro-CT images. The analysis results are verified by experimental results of watersuction tests. The results show that the additions of mineral admixtures in concrete as cementitious materials greatly change the geometrical properties of the microstructures and the spatial features of defects by physical-chemistry actions of these mineral admixtures. This is the major cause of the differences between the mechanical behaviors of HPC with and without mineral admixtures when the water-to-binder ratio and the size distribution of aggregates are constant.
文摘The peroxyoxalate chemiluminescence(CL)detection of fatty acids in human se- rum combined with high-performance liquid chromatography (HPLC)is described.Some fatty acids in serum were extracted with a 1 :1(v/v)mixture of chloroform-n-heptane.2-(4-Hydrazinocarbonyl- phenyl)-4,5-diphenylimidazole (HCPI) was used as a fluorescent labelling reagent of the fatty acids. The labelling reaction was carried out at 30℃ for 1 h at pH 6.5 and the resulting reaction mixture was sudjected to HPLC. The labelled fatty acid C_(17)(P-C_(17))was used as the internal standard. The la- belled fatty acids C_(16) and C_(18) were separated within 18 min on an ODS-8OTM column (150 mm× 6 mm ID,5μm,Tosoh Japan).The calibrlation curves of fatty acids from the spiked control serum were Y_1=-0.003 7 + 0.0028X_1,r=0.994 for FA C_( 16) and Y_2=0.00 1 2 + 0.00098X_2,r=0.999 for FA C_( 18),respectively.The average recoveries of facids from the spiked contrl serum were 107.2%(n=8,RSD=4.3%)for FA C_(16) and 97.35%(n=8, RSD=4.0%)for FA C_(18),respectively.The lower detection limits of fatty acids after reaction were 12μmol per 20μl injection for FA C_(16) and 18 μmol per 20μl injection for FA C_(18),respectively(signal to noise ratio, S/N=2).The HPLC/CL method was applied to the determination of FA C_(16) and FA C_(18) in normal human serum and the results showed that the concentrations of fatty acids in normal human serum were 0.134 ± 0.009 μ mol/ml serum(n=5) for FA C_(16) and 0.052±0.028 μmol/ml serum(n=5)for FA C_(18),respectively.
文摘Aim To quantitatively determine five nucleosides and nucleobases, including cytidine, uridine, guanosine, adenosine and uracil in different parts of Panax notoginseng. Methods Separation was performed on a Zorbax SB-Aq column using a gradient elution with mobile phase of 8 mmol^L-1 ammonium acetate aqueous solution （A） and methanol （B）. The assay was carried out at a flow rate of 1 mL·min^-1 at 25 ℃ with the diode-array detection at 260 nm. Results Cytidine, uridine, guanosine, adenosine and uracil had good linearity in the ranges of 1.79 - 57.40 μg·mL^-1 （r^2 = 1.0000）, 3.30 - 105.60 μg·mL^-1 （r^2 = 1.0000）, 3.09 - 98.80 μg·mL^ -1（r^2 = 0.9999）, 2.77 - 88.60 μg·mL^-1 （r^2 = 1.0000） and 0.38 - 12.30 μg·mL ^-1 （r^2 = 1.0000） with average recoveries of 93.9%, 96.5%, 92.7%, 93.2% and 98.8%, respectively. The content of cytidine, uridine, guanosine, adenosine and uracil in different parts of P. notogingeng were significantly different. Conclusion This is the first report on quantitative determination of nucleosides and nucleobases in P notoginseng.
文摘The compositions and contents of ginsenbsides in Panax ginseng,P.quinquefolium and P.notoginseng were determined and compared by reversed-phase High-Performance Liquid Chro- matography(HPLC).The method was performed on an Alltech Adsorbosphere HS C_(18) column,using 5×10^(-3)M NaH_2PO_4-H_3PO_4 buffer solution(pH 3.0)and acetonitrile-water(50:50)as gradient eluents. The baseline separation of ginsenosides Rb_1,Rb_2,Rb_1,Rc,Rd,Rf,Ro,and Re+Rg_1 was obtained in one analytical run.The ginsenosides are directly detected at 203 nm.The detection limit is 40μg at a signal to noise ratio of 3:1.The improved sample preparation and clean-up prior to injection with SEP-PAK C_(18)cartridge strongly reduced the front peaks caused by the impurities in the methanolic extracts of samples to afford a smooth baseline and clear background.The HPLC patterns of methanolic extracts mainly including the ginsenosides were found capable of serving as chemical fingerprints to differentiate the three species from each other.It was also found that there are no significant diffe- rences of the HPLC patterns between the wild Panax ginseng and the cultivated,the white and the red ginsengs,Chinese and Korean red ginsengs,and the tap roots of Panax ginseng collected in four consecutive months,only certain differences in contents of ginsenosides do exist.The contents of the nine major ginsenosides present in the rhizome,tap root and rootlet as well as the leaf of Panax quinquefolium were also determined and compared.
