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Role of liver transplantation in human immunodeficiency virus positive patients
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作者 Deepak Joshi Kosh Agarwal 《World Journal of Gastroenterology》 SCIE CAS 2015年第43期12311-12321,共11页
End-stage liver disease(ESLD) is a leading cause of morbidity and mortality amongst human immunodeficiency virus(HIV)-positive individuals. Chronic hepatitis B and hepatitis C virus(HCV) infection,drug-induced hepatot... End-stage liver disease(ESLD) is a leading cause of morbidity and mortality amongst human immunodeficiency virus(HIV)-positive individuals. Chronic hepatitis B and hepatitis C virus(HCV) infection,drug-induced hepatotoxicity related to combined antiretro-viral therapy,alcohol related liver disease and non-alcohol related fatty liver disease appear to be the leading causes. It is therefore,anticipated that more HIV-positive patients with ESLD will present as potential transplant candidates. HIV infection is no longer a contraindication to liver transplantation. Key transplantation outcomes such as rejection and infection rates as well as medium term graft and patient survival match those seen in the non-HIV infected patients in the absence of co-existing HCV infection. HIV disease does not seem to be negatively impacted by transplantation. However,HIV-HCV coinfection transplant outcomes remain suboptimal due to recurrence. In this article,we review the key challenges faced by this patient cohort in the pre- and posttransplant period. 展开更多
关键词 HEPATITIS B VIRUS HEPATITIS C VIRUS HUMAN immunode
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Proteinuria in paediatric patients with human immunodefi ciency virus infection 被引量:1
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作者 Vania Giacomet Paola Erba +3 位作者 Francesca Di Nello Sonia Coletto Alessandra Viganò Gian Vincenzo Zuccotti 《World Journal of Clinical Cases》 SCIE 2013年第1期13-18,共6页
In human immunodef iciency virus(HIV)-infected people kidney disease is as an important cause of morbidity and mortality. Clinical features of kidney damage in HIV-infected patients range from asymptomatic microalbumi... In human immunodef iciency virus(HIV)-infected people kidney disease is as an important cause of morbidity and mortality. Clinical features of kidney damage in HIV-infected patients range from asymptomatic microalbuminuria to nephrotic syndrome. The lack of specif ic clinical features despite the presence of heavy proteinuria may mask the renal involvement. Indeed, it is important in HIV patients to monitor renal function to early discover a possible kidney injury. After the introduction of antiretroviral therapy, mortality and morbidity associated to HIV-infection have shown a substantial reduction, although a variety of side effects for longterm use of highly active antiretroviral therapy, including renal toxicity, has emerged. Among more than 20 currently available antiretroviral agents, many of them can occasionally cause reversible or irreversible nephrotoxicity. At now, three antiretroviral agents, i.e., indinavir, atazanavir and tenofovir disoproxil fumarate have a well established association with direct nephrotoxicity. This review focuses on major causes of proteinuria and other pathological f indings related to kidney disease in HIV-infected children and adolescents. 展开更多
关键词 HUMAN immunodeFIciency virus-infection NEPHROPATHY PROTEINURIA ANTIRETROVIRAL therapy Children
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Artificial Intelligence for Maximizing Agricultural Input Use Efficiency: Exploring Nutrient, Water and Weed Management Strategies
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作者 Sumit Sow Shivani Ranjan +8 位作者 Mahmoud F.Seleiman Hiba M.Alkharabsheh Mukesh Kumar Navnit Kumar Smruti Ranjan Padhan Dhirendra Kumar Roy Dibyajyoti Nath Harun Gitari Daniel O.Wasonga 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第7期1569-1598,共30页
Agriculture plays a crucial role in the economy,and there is an increasing global emphasis on automating agri-cultural processes.With the tremendous increase in population,the demand for food and employment has also i... Agriculture plays a crucial role in the economy,and there is an increasing global emphasis on automating agri-cultural processes.With the tremendous increase in population,the demand for food and employment has also increased significantly.Agricultural methods traditionally used to meet these requirements are no longer ade-quate,requiring solutions to issues such as excessive herbicide use and the use of chemical fertilizers.Integration of technologies such as the Internet of Things,wireless communication,machine learning,artificial intelligence(AI),and deep learning shows promise in addressing these challenges.However,there is a lack of comprehensive documentation on the application and potential of AI in improving agricultural input efficiency.To address this gap,a desk research approach was used by utilizing peer-reviewed electronic databases like PubMed,Scopus,Goo-gle Scholar,Web of Science,and Science Direct for relevant articles.Out of 327 initially identified articles,180 were deemed pertinent,focusing primarily on AI’s potential in enhancing yield through better management of nutrients,water,and weeds.Taking into account researchfindings worldwide,we found that AI technologies could assist farmers by providing recommendations on the optimal nutrients to enhance soil quality and deter-mine the best time for irrigation or herbicide application.The present status of AI-driven automation in agricul-ture holds significant promise for optimizing agricultural input utilization and reducing resource waste,particularly in the context of three pillars of crop management,i.e.,nutrient,irrigation,and weed management. 展开更多
关键词 Agriculture artificial intelligence crop management NUTRIENT IRRIGATION weed management resource use efficiency
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一种农杆菌介导的糜子高效遗传转化方法
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作者 夏启玉 降彦苗 +5 位作者 刘亚男 李海权 程汝宏 郭安平 刘国庆 赵辉 《热带作物学报》 北大核心 2025年第1期44-50,共7页
糜子(Panicum miliaceum L.)是我国传统的粮食作物,截至目前,针对糜子遗传转化方法的研究仍较少,本研究旨在建立农杆菌介导的糜子高效遗传转化方法。以糜子品种冀黍5号的成熟种子为外植体,在CIM和MSD诱导培养基上分别诱导糜子的胚性愈伤... 糜子(Panicum miliaceum L.)是我国传统的粮食作物,截至目前,针对糜子遗传转化方法的研究仍较少,本研究旨在建立农杆菌介导的糜子高效遗传转化方法。以糜子品种冀黍5号的成熟种子为外植体,在CIM和MSD诱导培养基上分别诱导糜子的胚性愈伤,以其作为转化受体材料,用含植物表达载体的农杆菌侵染60min并共培养6d,转接至含0.025g/L潮霉素的筛选培养基上筛选出抗性愈伤,接着在含0.015g/L潮霉素的分化培养基上分化,最后在含0.015g/L潮霉素的生根培养基上生根成苗,用载体特异性引物对再生植株进行PCR检测,鉴定其是否为阳性转基因植株。根据多个批次的转化实验统计糜子的抗性再生植株的筛选效率和转化效率。结果表明:CIM和MSD诱导培养基均能诱导出糜子胚性愈伤,但CIM培养基诱导的糜子胚性愈伤效果更好;糜子胚性愈伤在被农杆菌侵染及与农杆菌共培养后,经在含潮霉素的培养基上筛选、分化和生根后获得多株抗性再生糜子植株,3次试验获得的糜子抗性再生植株的PCR鉴定阳性率为100%,平均转化效率为30%以上。本研究成功建立了农杆菌介导的糜子遗传转化方法,操作简单,转化效率高,成本低廉,且转化不受季节限制,能规模化开展,为糜子的遗传改良提供有效的技术手段。 展开更多
关键词 糜子 农杆菌 遗传转化 转化效率
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膜下滴灌减量施肥对甘蔗脱毒原种苗田间繁育效率和养分利用率的影响
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作者 彭李顺 曹峥英 +2 位作者 蔡文伟 杨本鹏 杨学 《热带作物学报》 北大核心 2025年第1期115-122,共8页
本研究探讨不同膜下滴灌减量施肥模式对甘蔗脱毒原种苗生长、繁育效率及肥料利用率的影响,并分析最佳减量施肥模式,旨在为科学指导甘蔗脱毒原种苗田间繁育过程中滴灌施肥技术的应用提供理论依据。在所有对照和处理均配备膜下滴灌系统并... 本研究探讨不同膜下滴灌减量施肥模式对甘蔗脱毒原种苗生长、繁育效率及肥料利用率的影响,并分析最佳减量施肥模式,旨在为科学指导甘蔗脱毒原种苗田间繁育过程中滴灌施肥技术的应用提供理论依据。在所有对照和处理均配备膜下滴灌系统并进行水分管理的条件下,以空白对照(CK_(0))、常规施肥(CK_(1))为对照,设置1个膜下滴灌施肥处理T_(100)(施肥量同CK_(1))以及3个膜下滴灌减量施肥处理T_(80)、T_(70)和T_(60)(减量施肥20%、30%和40%),对甘蔗脱毒原种苗繁育过程中主要农艺性状、种茎产量、总芽数、繁育效率及养分利用率等指标进行比较分析。研究结果表明:在各项农艺指标中,2022、2023年T_(100)和T_(80)的平均分蘖率略低于CK_(1),但在成茎率、单株芽数、有效茎数方面较CK_(1)均有显著提升。在繁育总种芽数上,T_(100)和T_(80)最高,年平均分别达到(1480.87×10^(3))/hm^(2)和(1477.87×10^(3))/hm^(2),显著高于CK_(1)的(1302.50×10^(3))/hm^(2);T_(70)与CK_(1)间差异不显著;T_(60)最低仅为(1170.53×10^(3))/hm^(2)。在繁育效率方面,原种苗田间繁育倍数T_(100)和T_(80)最高,分别达到66.64倍和66.50倍;其次为T_(70)和CK_(1),繁育倍数为59.61倍和58.61倍;T_(60)繁育倍数最低,为52.67。在繁育收益方面,相较于CK_(0),T_(100)和T_(80)收益增幅最高,分别达到5.82和5.87万元/hm^(2);其次为T_(70),收益增幅为4.19万元/hm^(2),略高于CK_(1)(3.84万元/hm^(2));T_(60)最低,仅为2.51万元/hm^(2)。在肥料投入产出比方面,T_(80)最高,达到1∶21.89,明显高于T_(100)(1∶17.36);CK_(1)最低,为1∶11.45。在肥料利用率方面,所有施肥处理中,氮、磷、钾肥的利用率均为CK_(1)最低。而T_(80)最高,试验平均氮、磷、钾肥利用率分别达到51.57%、27.37%和67.45%,分别较CK_(1)提高了21.21、10.37和23.13个百分点。综上所述,在中等肥力红壤蔗区,采用T_(80)膜下滴灌减量施肥模式,可以同时获得较理想的甘蔗脱毒原种苗繁育效率和收益。 展开更多
关键词 甘蔗脱毒种苗 膜下滴灌施肥 化肥减施 繁育效率 养分利用率
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不同缓控释氮肥对甘薯生长、氮素吸收及利用的影响
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作者 许泽康 石琨 +4 位作者 欧阳宇珺 吴建燕 马洪波 张小贝 汪吉东 《热带作物学报》 北大核心 2025年第3期688-694,共7页
甘薯田间施氮通常采用一次性基施氮肥后不再追施氮肥,因此研发和遴选符合甘薯不同生育期氮素需求的缓控释氮肥对甘薯增产、氮肥减施很重要。本研究以苏薯16为试验材料,采用盆栽试验,在等量氮、磷、钾投入下,分析不同缓控释氮肥(草酰胺... 甘薯田间施氮通常采用一次性基施氮肥后不再追施氮肥,因此研发和遴选符合甘薯不同生育期氮素需求的缓控释氮肥对甘薯增产、氮肥减施很重要。本研究以苏薯16为试验材料,采用盆栽试验,在等量氮、磷、钾投入下,分析不同缓控释氮肥(草酰胺、硫包衣尿素、脲甲醛、尿素结合硝化抑制剂)对甘薯不同生育期(苗期、封垄期、膨大期和收获期)生长和氮含量、氮利用效率及土壤矿质氮含量的影响。结果表明:(1)与对照相比,硫包衣尿素和草酰胺控释氮肥分别提高甘薯的块根生物量96.79%和103.59%,且显著高于脲甲醛和尿素结合硝化抑制剂处理(P<0.05)。在膨大期和收获期,硫包衣尿素处理的光合速率显著高于对照,有利于提高块根的生物量。(2)硫包衣尿素和草酰胺在甘薯苗期和封垄期氮素释放量较少,在甘薯膨大期和收获期释放量较多,铵态氮和硝态氮之和是脲甲醛和尿素结合硝化抑制剂的1.24~1.60倍,氮肥利用率提高了1.17~1.80倍。因此,硫包衣尿素和草酰胺较为符合甘薯生产上的一次性氮肥投入。本研究结果可为甘薯的养分管理和氮肥减施增效提供科学依据。 展开更多
关键词 缓控释氮肥 甘薯 光合速率 矿质氮 氮肥利用率
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基于AIGC的UI设计自动化提升效率的技术路径探索
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作者 胡名杰 《丝网印刷》 2025年第3期136-138,共3页
人工智能生成内容(AIGC)技术为UI设计自动化带来新机遇,通过生成界面元素、优化交互逻辑等显著提升效率,释放设计师专注于创意表达。本文探讨AIGC的技术路径、应用案例及挑战,展望其推动UI设计智能化与创新发展的潜力。
关键词 UI设计 设计自动化 设计效率
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汽车零部件生产企业设备维修管理改进研究
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作者 高源 《时代汽车》 2025年第3期163-165,共3页
在汽车零部件生产企业中,设备的稳定运行和高效维护直接关系到企业的生产效率和产品质量。然而,许多企业在设备维修管理方面仍面临诸多挑战,如设备故障频繁、维修时间长、维修成本高等问题,这些问题不仅影响企业的正常生产,还制约了企... 在汽车零部件生产企业中,设备的稳定运行和高效维护直接关系到企业的生产效率和产品质量。然而,许多企业在设备维修管理方面仍面临诸多挑战,如设备故障频繁、维修时间长、维修成本高等问题,这些问题不仅影响企业的正常生产,还制约了企业的可持续发展。近年来,随着信息技术飞速发展,智能化和数字化技术在设备维修管理中的应用越来越广泛,为企业提供了新的解决方案。通过引入先进的维修技术和管理方法,企业可以显著提高设备的可靠性和维修效率,降低维修成本,提升整体竞争力。因此,研究和优化设备维修管理方法,对于推动制造业的转型升级和高质量发展具有重要意义。 展开更多
关键词 生产效率 可持续发展 设备维修管理
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中国城市园林绿化增汇减排研究热点与趋势
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作者 易扬 张桂莲 张浪 《园林》 2025年第3期50-56,共7页
全球气候变化背景下,利用低碳理念对园林景观进行营建、养护和管理,是实现城市“双碳”目标的重要举措。“节能减排”是园林绿化领域增汇减排的研究热点,多学科交叉融合是该领域的主要特征之一。总结中国园林绿化增汇减排的研究进展,并... 全球气候变化背景下,利用低碳理念对园林景观进行营建、养护和管理,是实现城市“双碳”目标的重要举措。“节能减排”是园林绿化领域增汇减排的研究热点,多学科交叉融合是该领域的主要特征之一。总结中国园林绿化增汇减排的研究进展,并构建城市园林绿化增汇减排技术框架,以期为构建中国高碳汇功能的园林绿化体系提供借鉴。园林绿化的增汇措施主要包含增加绿化面积、营建高碳汇植物群落和提升土壤有机质含量等;减排措施主要包含园林绿化生产阶段、建造阶段和管护阶段中的各种低碳技术方案和可再生能源的利用。城市园林绿化应该充分利用新技术手段,明确绿地碳库组成、碳循环特征、碳收支结构及固碳增汇措施,加强对监测数据的管理和分析,构建体系化的标准、规范和指南,指导城市园林绿化的低碳建设和运营,巩固提升园林绿化固碳增汇能力,促进园林绿化减污降碳协同增效。 展开更多
关键词 园林绿化 碳汇 减排 效能提升
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Risk factors and predictive model of adrenocortical insuffi ciency in patients with traumatic brain injury 被引量:9
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作者 Gui-long Feng Miao-miao Zheng +6 位作者 Shi-hong Yao Yin-qi Li Shao-jun Zhang Wei-jing Wen Kai Fan Jia-li Zhang Xiao Zhang 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2021年第3期179-184,共6页
BACKGROUND:Neuroendocrine dysfunction after traumatic brain injury(TBI)has received increased attention due to its impact on the recovery of neural function.The purpose of this study is to investigate the incidence an... BACKGROUND:Neuroendocrine dysfunction after traumatic brain injury(TBI)has received increased attention due to its impact on the recovery of neural function.The purpose of this study is to investigate the incidence and risk factors of adrenocortical insuffi ciency(AI)after TBI to reveal independent predictors and build a prediction model of AI after TBI.METHODS:Enrolled patients were grouped into the AI and non-AI groups.Fourteen preset impact factors were recorded.Patients were regrouped according to each impact factor as a categorical variable.Univariate and multiple logistic regression analyses were performed to screen the related independent risk factors of AI after TBI and develop the predictive model.RESULTS:A total of 108 patients were recruited,of whom 34(31.5%)patients had AI.Nine factors(age,Glasgow Coma Scale[GCS]score on admission,mean arterial pressure[MAP],urinary volume,serum sodium level,cerebral hernia,frontal lobe contusion,diff use axonal injury[DAI],and skull base fracture)were probably related to AI after TBI.Three factors(urinary volume[X4],serum sodium level[X5],and DAI[X8])were independent variables,based on which a prediction model was developed(logit P=-3.552+2.583X4+2.235X5+2.269X8).CONCLUSIONS:The incidence of AI after TBI is high.Factors such as age,GCS score,MAP,urinary volume,serum sodium level,cerebral hernia,frontal lobe contusion,DAI,and skull base fracture are probably related to AI after TBI.Urinary volume,serum sodium level,and DAI are the independent predictors of AI after TBI. 展开更多
关键词 Adrenocortical insuffi ciency Risk factor PREDICTOR Traumatic brain injury
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Effect of sedation on short-term and long-term outcomes of critically ill patients with acute respiratory insufficiency 被引量:7
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作者 Xue-zhong Xing Yong Gao +6 位作者 Hai-jun Wang Shi-ning Qu Chu-lin Huang Hao Zhang Hao Wang Qing-ling Xiao Ke-lin Sun 《World Journal of Emergency Medicine》 CAS 2015年第2期147-152,共6页
BACKGROUND: The present study aimed to determine the short-term and long-term outcomes of critically ill patients with acute respiratory insuffi ciency who had received sedation or no sedation.METHODS: The data of 91 ... BACKGROUND: The present study aimed to determine the short-term and long-term outcomes of critically ill patients with acute respiratory insuffi ciency who had received sedation or no sedation.METHODS: The data of 91 patients who had received mechanical ventilation in the first 24 hours between November 2008 and October 2009 were retrospectively analyzed. These patients were divided into two groups: a sedation group(n=28) and a non-sedation group(n=63). The patients were also grouped in two groups: deep sedation group and daily interruption and /or light sedation group.RESULTS: Overall, the 91 patients who had received ventilation ≥48 hours were analyzed. Multivariate analysis demonstrated two independent risk factors for in-hospital death: sequential organ failure assessment score(P=0.019, RR 1.355, 95%CI 1.051–1.747, B=0.304, SE=0.130, Wald=50483) and sedation(P=0.041, RR 5.015, 95%CI 1.072–23.459, B=1.612, SE=0.787, Wald=4.195). Compared with the patients who had received no sedation, those who had received sedation had a longer duration of ventilation, a longer stay in intensive care unit and hospital, and an increased in-hospital mortality rate. The Kaplan-Meier method showed that patients who had received sedation had a lower 60-month survival rate than those who had received no sedation(76.7% vs. 88.9%, Log-rank test=3.630, P=0.057). Compared with the patients who had received deep sedation, those who had received daily interruption or light sedation showed a decreased in-hospital mortality rate(57.1% vs. 9.5%, P=0.008). The 60-month survival of the patients who had received deep sedation was signifi cantly lower than that of those who had daily interruption or light sedation(38.1% vs. 90.5%, Log-rank test=6.783, P=0.009).CONCLUSIONS: Sedation was associated with in-hospital death. The patients who had received sedation had a longer duration of ventilation, a longer stay in intensive care unit and in hospital, and an increased in-hospital mortality rate compared with the patients who did not receive sedation. Compared with daily interruption or light sedation, deep sedation increased the in-hospital mortality and decreased the 60-month survival for patients who had received sedation. 展开更多
关键词 SEDATION Respiratory insuffi ciency PROGNOSIS Critical illness
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Measuring effi ciency of listed tourism companies in China
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作者 SUN Yuan-yuan 《Ecological Economy》 2015年第1期72-80,共9页
This study seeks to evaluate the comparative productivity of 32 listed tourism companies which are the main suppliers of China tourism, using the popular methodology known as the data envelopment analysis(DEA). This s... This study seeks to evaluate the comparative productivity of 32 listed tourism companies which are the main suppliers of China tourism, using the popular methodology known as the data envelopment analysis(DEA). This study analyzes the productivity of listed tourism companies from business and region aspects based on the calculation of Malmquist index. The results show that(1) the overall productivity is non-effi cient(0.954);(2) the productivity of accommodation and catering is biggest, which shows the tourism develops quickly with supports from technology;(3) the productivity in western China is highest, where the economy and tourism attraction are better than other regions; and(4) the effi ciency differences among the listed tourism companies are not signifi cant, and they attribute to the scale effi-ciency, that is the input of the fi nance, resource, talents and policy. 展开更多
关键词 LISTED TOURISM COMPANIES OPERATIONAL effi ciency MALMQUIST index DEA China
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Smart Nutrient Deficiency Prediction System for Groundnut Leaf
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作者 Janani Malaisamy JebakumarRethnaraj 《Intelligent Automation & Soft Computing》 SCIE 2023年第5期1845-1862,共18页
Prediction of the nutrient deficiency range and control of it through application of an appropriate amount of fertiliser at all growth stages is critical to achieving a qualitative and quantitative yield.Distributing f... Prediction of the nutrient deficiency range and control of it through application of an appropriate amount of fertiliser at all growth stages is critical to achieving a qualitative and quantitative yield.Distributing fertiliser in optimum amounts will protect the environment’s condition and human health risks.Early identification also prevents the disease’s occurrence in groundnut crops.A convo-lutional neural network is a computer vision algorithm that can be replaced in the place of human experts and laboratory methods to predict groundnut crop nitro-gen nutrient deficiency through image features.Since chlorophyll and nitrogen are proportionate to one another,the Smart Nutrient Deficiency Prediction System(SNDP)is proposed to detect and categorise the chlorophyll concentration range via which nitrogen concentration can be known.The model’sfirst part is to per-form preprocessing using Groundnut Leaf Image Preprocessing(GLIP).Then,in the second part,feature extraction using a convolution process with Non-negative ReLU(CNNR)is done,and then,in the third part,the extracted features areflat-tened and given to the dense layer(DL)layer.Next,the Maximum Margin clas-sifier(MMC)is deployed and takes the input from DL for the classification process tofind CCR.The dataset used in this work has no visible symptoms of a deficiency with three categories:low level(LL),beginning stage of low level(BSLL),and appropriate level(AL).This model could help to predict nitrogen deficiency before perceivable symptoms.The performance of the implemented model is analysed and compared with ImageNet pre-trained models.The result shows that the CNNR-MMC model obtained the highest training and validation accuracy of 99%and 95%,respectively,compared to existing pre-trained models. 展开更多
关键词 CNN CHLOROPHYLL groundnut crop deep learning nitrogen deficiency
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Input-output Efficiency of Elements of Urban Construction Land in Beijing: Empirical Analysis Based on Panel Data of Jurisdiction
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作者 GU Yuekun 《Journal of Landscape Research》 2020年第2期49-53,56,共6页
Based on the Data Envelopment Analysis method,and by using CCR and BCC model,Super Efficiency model and Malmquist model guided by input efficiency,the input-output efficiency of elements of urban construction land in ... Based on the Data Envelopment Analysis method,and by using CCR and BCC model,Super Efficiency model and Malmquist model guided by input efficiency,the input-output efficiency of elements of urban construction land in different jurisdictions of Beijing from 2005 to 2015 was studied.The results showed that there were obvious differences between input-output efficiency of elements of urban construction land in different jurisdictions of Beijing,among which the efficiency of the core area of capital,Yanqing District,Fangshan District and Huairou District was relatively high,while the efficiency of Daxing District,Fengtai District and Miyun District was relatively low.There was no obvious correlation between efficiency differentiation and location factors,which is mainly caused by whether the land use in each jurisdiction has scale effect,whether the technology is improved,whether the input is redundant and whether the output is insufficient.For the jurisdiction of inefficient land use,we should strengthen the consciousness of intensive land use,improve the technical level,appropriately reduce the redundancy of input elements,and pay attention to the output of social and ecological benefits. 展开更多
关键词 Data Envelopment Analysis Urban construction LAND INPUT and OUTPUT Effi ciency
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Airline efficiency and environmental impacts–Data envelopment analysis
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作者 Arun Saini Dothang Truong Jing Yu Pan 《International Journal of Transportation Science and Technology》 2023年第2期335-353,共19页
Airline efficiency has been a research interest for decades.While early airline efficiency research focused primarily on revenue generation and profitability,growing airline social responsibility is driving greater inves... Airline efficiency has been a research interest for decades.While early airline efficiency research focused primarily on revenue generation and profitability,growing airline social responsibility is driving greater investment into understanding and improving the environmental impact on airline efficiency.This study developed a two-phase,two-stage model using a data envelopment analysis(DEA)approach to simultaneously evaluate airline operations for available seat mile(ASM)generation,revenue passenger mile(RPM)generation,carbon dioxide emissions abatement,and revenue generation on a sample of thirteen airlines.Efficiency evaluation was performed for the years between 2013 and 2015,between U.S.and non-U.S.carriers,and between full-service carriers(FSCs)and low-cost carriers(LCCs).Results indicated more accurate measurement of airlines’overall efficiency using the proposed DEA model,which included operational and cost factors as input variables and environmental impact as both the input and output variables in the model.Service and environmentalfactors were found to be significantin determining airline efficiency,with environmental abatement affecting the overall efficiency of airline performance both inside and outside the U.S.when emission reduction effort was properly accounted for.Thefindings provided theoretical and managerial implications in the assessment of airline efficiency with a special emphasis on incorporating environmental impact in the overall evaluation. 展开更多
关键词 Airline efficiency Data envelopment analysis Environmental impacts Airline performance
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不同赋存形式H_(2)映震特征及机理分析
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作者 李娜 向阳 +1 位作者 李新勇 汪成国 《地震》 CSCD 北大核心 2024年第3期138-155,共18页
乌鲁木齐04泉水中溶解气H_(2)和阿克苏断层土壤气H_(2)监测点均属新疆地震监测预报评估A类。本文以二者为研究对象,分析不同赋存形式H_(2)浓度的动态变化特征;利用R值评分方法和Molchan图表法对H_(2)浓度进行映震效能检验,并提取异常指... 乌鲁木齐04泉水中溶解气H_(2)和阿克苏断层土壤气H_(2)监测点均属新疆地震监测预报评估A类。本文以二者为研究对象,分析不同赋存形式H_(2)浓度的动态变化特征;利用R值评分方法和Molchan图表法对H_(2)浓度进行映震效能检验,并提取异常指标;探讨和分析不同赋存形式H_(2)的映震机理。结论如下:乌鲁木齐04泉水中溶解气H_(2)浓度受气象因素影响较小,而阿克苏断层土壤气H_(2)浓度受气压和气温双重影响,其中以气温影响为主。R值评分方法和Molchan图表法检验显示,两个监测点均具有较好的短期预测效能。H_(2)浓度测项具有较好的短临预测效能,这得益于H_(2)的物理化学性质稳定且迁移速度极快。 展开更多
关键词 地震监测 H_(2) 影响因素 映震效能 异常指标 机理
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游戏化教学策略在模具设计课程中的实施与评估 被引量:1
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作者 陈茜 文杰 《模具工业》 2024年第4期73-79,共7页
探讨了游戏化教学策略在模具设计课程中的实施并进行了效果评估,通过综合运用理论分析和实证研究,考察了游戏化教学的核心元素及其如何融入模具设计教学中。通过引入游戏元素,分析其对提升学生学习动机、认知能力、情感态度和合作交流... 探讨了游戏化教学策略在模具设计课程中的实施并进行了效果评估,通过综合运用理论分析和实证研究,考察了游戏化教学的核心元素及其如何融入模具设计教学中。通过引入游戏元素,分析其对提升学生学习动机、认知能力、情感态度和合作交流的影响,并分析和评估该策略的有效性,发现游戏化教学提高了学生的课堂参与度和学习成效,学生对游戏元素的接受度高,反馈积极,显示游戏化教学在增强学习体验方面的有效性。此外,教学实践的成果分析表明,游戏化教学有助于学生更好地掌握模具设计的专业知识和技能,为高职模具设计课程的教学改革提供了新的视角和方法,展示了游戏化教学在技术教育领域的潜力和价值。 展开更多
关键词 游戏化教学 模具设计 高职教育 学习成效 教学策略
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东北半干旱区浅埋滴灌下玉米高产高效的尿素硝酸铵溶液投入阈值
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作者 孔丽丽 尹彩侠 +4 位作者 侯云鹏 张磊 赵胤凯 刘志全 徐新朋 《中国生态农业学报(中英文)》 CAS CSCD 北大核心 2024年第12期2081-2093,共13页
为探明滴灌玉米尿素硝酸铵溶液(UAN)对尿素的增效作用及适宜投入阈值,在吉林省半干旱区(乾安县)开展连续2年(2020-2021年)的田间定位试验,以UAN为试验材料,设6个氮肥用量[0 kg(N)·hm^(-2)、100 kg(N)·hm^(-2)、140 kg(N)·... 为探明滴灌玉米尿素硝酸铵溶液(UAN)对尿素的增效作用及适宜投入阈值,在吉林省半干旱区(乾安县)开展连续2年(2020-2021年)的田间定位试验,以UAN为试验材料,设6个氮肥用量[0 kg(N)·hm^(-2)、100 kg(N)·hm^(-2)、140 kg(N)·hm^(-2)、180 kg(N)·hm^(-2)、220 kg(N)·hm^(-2)和260 kg(N)·hm^(-2)],并以尿素优化用量处理[Urea,220 kg(N)·hm^(-2)]为对照,研究玉米产量与构成、干物质积累、叶面积指数、氮素利用率、土壤氮素含量及氮素平衡差异。结果表明,施氮显著提高了玉米产量,并随施氮量增加而增加,当氮肥用量超过180 kg·hm^(-2)后,增产幅度不显著,且高于Urea处理,两年平均增幅为2.02%。增产原因是施用UAN提高了玉米每穗粒数和百粒重。对于施用UAN的处理来说,玉米各生育期叶面积指数、干物质积累量、干物质转运量和吐丝后干物质积累对籽粒贡献率总体随施氮量增加呈增加趋势,当施氮量增至180 kg·hm^(-2)后以上指标不再显著增加,但均高于Urea处理(2021年吐丝后干物质积累对籽粒贡献率除外);氮素回收率、氮素农学利用率和氮素偏生产力随氮肥用量的增加呈下降趋势,且相同氮肥用量下,UAN处理较Urea处理分别提高4.45%、2.09 kg·kg^(-1)和2.09 kg·kg^(-1)。与Urea处理相比,相同用量下UAN处理降低了60~100 cm土壤无机氮含量,使氮素损失量较Urea处理降低7.51%。通过拟合施氮量与玉米产量、氮素回收率和土壤表观氮素损失量,确定UAN适宜用量为188.90 kg·hm^(-2),相应玉米产量为11 863.42 kg·hm^(-2),氮素回收率为44.21%,氮素表观损失量为151.79 kg(N)·hm^(-2)。与传统尿素优化用量处理(Urea)相比,UAN的施用可在降低14.14%氮肥用量的前提下,使得玉米产量增加4.78%,氮素回收率增加7.61%,氮素表观损失量降低29.55%。以理论最高产量施氮量95%为置信区间,确定UAN适宜施氮范围为179~198 kg(N)·hm^(-2)。综上所述,与施用尿素相比,施用UAN可减少氮素投入总量,获得更高的玉米产量和氮素利用效率,并降低氮素损失,是东北半干旱区实现玉米减氮增效的有效途径。 展开更多
关键词 玉米 浅埋滴灌 尿素硝酸铵溶液 东北半干旱区 氮素利用效率 氮素表观平衡
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应用主频带约束高精度Radon变换的多次波压制方法
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作者 马继涛 赵凯歌 廖震 《石油地球物理勘探》 EI CSCD 北大核心 2024年第6期1286-1296,共11页
Radon变换是地震资料处理中常用的一种算法,通过特定路径求和实现地震数据插值、多次波压制和波场分离。然而,由于采集数据和算法限制,变换域的分辨率较低,提高Radon域分辨率一直是研究的热点。最常用的提高分辨率方法是多次迭代重加权... Radon变换是地震资料处理中常用的一种算法,通过特定路径求和实现地震数据插值、多次波压制和波场分离。然而,由于采集数据和算法限制,变换域的分辨率较低,提高Radon域分辨率一直是研究的热点。最常用的提高分辨率方法是多次迭代重加权算法,通过迭代更新权重,将加权值聚焦到地震数据曲率上,但很难将加权值聚焦到真实曲率位置。文中提出了一种优化提高变换域分辨率的新方法,即在地震数据的主频带内求取一个加权矩阵,并将加权值聚焦至真实地震曲率位置。首先,计算地震数据的主频,并以主频为中心频率,向低频和高频方向各取一个范围作为约束频带;对主频带内的地震数据采用低频约束策略,从低频到高频迭代计算加权矩阵;从主频带的最后一个加权矩阵得到最终的加权矩阵,并应用于所有其他频率的计算。主频带数据的信噪比高、振幅强,因此,该方法更加稳定,得到的加权矩阵可以显著增强变换域的分辨率。此外,与其他迭代方法相比,它避免了每个频率加权矩阵的迭代过程,计算效率更高。合成数据和实际数据的测试结果证明了该方法的在多次波压制方面的有效性和优势。 展开更多
关键词 RADON变换 多次波压制 高分辨率 主频带 约束 效率
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基于Cuk变换的MCR-WPT系统阻抗匹配研究
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作者 姜建国 江骁 《化工自动化及仪表》 CAS 2024年第6期1123-1128,共6页
在分析无线充电系统的基础上,在发射端检测电流电压相位并加入锁相环调整系统频率,使系统处于谐振状态,提升系统的传输效率。同时,为满足无线充电系统在不同负载阻值下都具有较高效率,在负载端接入Cuk变换器并采用PID控制策略实现系统... 在分析无线充电系统的基础上,在发射端检测电流电压相位并加入锁相环调整系统频率,使系统处于谐振状态,提升系统的传输效率。同时,为满足无线充电系统在不同负载阻值下都具有较高效率,在负载端接入Cuk变换器并采用PID控制策略实现系统恒功率输出。用Simulink仿真平台搭建模型,当系统处于谐振状态后,负载阻值在20、30、40Ω时系统传输效率最终稳定在0.84,并且稳定持续输出5 kW的功率。 展开更多
关键词 无线充电 阻抗匹配 CUK变换器 锁相环 传输效率
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