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基于单芯移相变压器的差动保护配置研究

电力系统保护与控制 2024年第14期52卷 59-70页

作者：郑涛申由于佳旭眭程曦薛玉石张栋新能源电力系统国家重点实验室(华北电力大学) 北京102206 国网石家庄供电公司河北石家庄050031 保定天威保变电气股份有限公司河北保定071000

移相变压器能够有效调控潮流,为保障电力系统安全可靠运行,为移相变压器配置性能优良的保护不可或缺。以某示范工程的35 kV单芯对称型移相变压器为研究对象,提出相应的本体保护方案。首先,基于基尔霍夫电流定律和电磁感应定律分析其运... 详细信息

移相变压器能够有效调控潮流,为保障电力系统安全可靠运行,为移相变压器配置性能优良的保护不可或缺。以某示范工程的35 kV单芯对称型移相变压器为研究对象,提出相应的本体保护方案。首先,基于基尔霍夫电流定律和电磁感应定律分析其运行特性。然后,结合其拓扑结构,设计了保护用电流互感器的安装位置,构建了电平衡差动保护和磁平衡差动保护方案。此方案可覆盖单芯移相变压器内部各绕组和绕组引线相间故障以及各绕组匝间故障。最后,基于Matlab/Simulink平台搭建单芯移相变压器模型,通过设置本体内部典型故障,验证了提出的两种差动保护配置方案的有效性。

关键词：单芯移相变压器区内故障电平衡差动保护磁平衡差动保护

水稻全田块无人收获作业自动打点系统设计与试验

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农业机械学报 2024年第6期55卷 60-67,79页

作者：崔冰波杜卓文韩逸朱耀辉魏新华江苏大学农业工程学院镇江212013 江苏大学现代农业装备与技术教育部重点实验室镇江212013

谷物收获机械无人化作业可有效解决收获季用工短缺问题,全田块自动导航作业是无人收获机智能化的核心。为解决水稻无人收获作业自动打点问题,基于边界线跟踪与地头区域检测实现水稻田块最外圈导航与剩余作业区域自动打点,并提出一种目... 详细信息

谷物收获机械无人化作业可有效解决收获季用工短缺问题,全田块自动导航作业是无人收获机智能化的核心。为解决水稻无人收获作业自动打点问题,基于边界线跟踪与地头区域检测实现水稻田块最外圈导航与剩余作业区域自动打点,并提出一种目标区域先验形态辅助的动态感兴趣区域设定方法,改善作物边界线提取可靠性。采用自控小车对所提方法进行验证,试验结果表明,当车辆作业速度为0.8m/s时,水稻未收获区域直线边界跟踪平均误差小于5cm,单帧图像检测时间小于50ms。水稻边界自动打点试验结果表明,所设计自动打点系统打点平均误差为3.5cm,满足直角梯形水稻田块自动打点需求。

关键词：水稻全田块自动导航无人收获作业自动打点作物边界提取

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商品化血小板病原体灭活技术的应用现状及质量评价

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中国实验血液学杂志 2024年第4期32卷 1300-1304页

作者：樊斌杨春晖李彬陈利民中国医学科学院、北京协和医学院输血研究所输血传播传染病省级重点实验室四川成都610062 中国医学科学院输血研究所、南宁中心血站输血传播疾病(TTD)联合实验室南宁中心血站广西南宁530007

随着输血医学的发展,血小板病原体污染问题越来越受到行业的关注。目前病原体灭活技术(PRT)已经成功应用于血小板并取得了很好的效果。本文对已经商品化的血小板PRT研究进展进行概述,对血小板PRT的应用现状、临床前机制研究、临床队列... 详细信息

随着输血医学的发展,血小板病原体污染问题越来越受到行业的关注。目前病原体灭活技术(PRT)已经成功应用于血小板并取得了很好的效果。本文对已经商品化的血小板PRT研究进展进行概述,对血小板PRT的应用现状、临床前机制研究、临床队列研究及替代或补充策略等方面的内容进行综合分析并提出建议,为保障我国血液安全、开发适用于我国国情的血小板PRT产品提供科学依据。

关键词：输血传播病原体灭活血小板输注

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独柱墩连续梁桥横向倾覆稳定性研究

工程建设与设计 2024年第3期 93-95页

作者：段伦良唐光武拉菲桥梁工程结构动力学国家重点实验室重庆400067 重庆交通大学重庆400074

目前,关于独柱墩桥梁倾覆倒塌事故的报道屡见不鲜,论文以某独柱墩连续梁桥为工程背景,依据相关文件,采用有限元软件midaS CIVIL建立了独柱墩连续梁数值模型,分析了该桥最不利工况下的横向倾覆特性。

关键词：独柱墩连续梁倾覆 midaSCIVIL

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A GOOD eXAMPLe OF PAReNT ADVOCACY FOR RIGHTS IN INCLUSIVe eDUCATION IN CHINA

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Frontiers of Law in China-Selected Publications from Chinese Universities 2016年第2期11卷 323-338页

作者： C ui Fengm ing education of Boston University Director of China Program Harvard Law School Project on Disability Cambridge US.

While children with disabilities experience exclusion and segregation in education, parents＇ involvement has been very limited due to the lack of parent support in China. Negative attitudes toward disability in an environment deeply influenced by the individual model of disability thinking makes it crucial for parents to advocate for their children＇s rights in inclusive education through collaborative and organized efforts. This article examines barriers obstructing disabled children＇s rights in pursuing inclusive education, barriers parents face to advocate for their children, and the development of parent support. The author argues that equal and inclusive education for all has a broader social impact beyond disability rights to eliminate barriers and pursue dignity for all. In doing so, the author reveals existing structural inequalities facing inclusive education, encourages the momentum for future changes, and utilizes a good example of parent advocacy for a deeper and meaningful policy advancement to overcome discrimination on the basis of disability that causes segregation and exclusion in education. Recommendations include strategies for the construction of a support network for parents to play their important roles in advancing the rights of their disabled children in inclusive education.

关键词： inclusive education parent involvement equal participation educational rights,good practice

Numerical Simulations of Heavy Rainfall over Central Korea on 21 September 2010 Using the WRF Model

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Advances in Atmospheric Sciences 2015年第6期32卷 855-869页

作者： ui-Yong BYUN Jinkyu HONG Song-You HONG Hyeyum Hailey SHIN Department of Atmospheric Sciences Yonsei University Korea Institute of Atmospheric Prediction Systems NCAR

On 21 September 2010, heavy rainfall with a local maximum of 259 mm d-1 occurred near Seoul, South Korea. We examined the ability of the Weather Research and Forecasting （WRF） model in reproducing this disastrous rainfall event and identified the role of two physical processes： planetary boundary layer （PBL） and microphysics （MPS） processes. The WRF model was forced by 6-hourly National Centers for environmental Prediction （NCeP） Final analysis （FNL） data for 36 hours form 1200 UTC 20 to 0000 UTC 22 September 2010. Twenty-five experiments were performed, consisting of five different PBL schemes--Yonsei University （YSU）, Mellor-Yamada-Janjic （MYJ）, Quasi Normal Scale elimination （QNSe）, Bougeault and Lacarrere （BouLac）, and University of Washington （UW）--and five different MPS schemes--WRF Single- Moment 6-class （WSM6）, Goddard, Thompson, Milbrandt 2-moments, and Morrison 2-moments. As expected, there was a specific combination of MPS and PBL schemes that showed good skill in forecasting the precipitation. However, there was no specific PBL or MPS scheme that outperformed the others in all aspects. The experiments with the UW PBL or Thompson MPS scheme showed a relatively small amount of precipitation. Analyses form the sensitivity experiments confirmed that the spatial distribution of the simulated precipitation was dominated by the PBL processes, whereas the MPS processes determined the amount of rainfall. It was also found that the temporal evolution of the precipitation was influenced more by the PBL processes than by the MPS processes.

关键词： heavy rainfall WRF model microphysics planetary boundary layer

Handling Class Imbalance in Online Transaction Fraud Detection

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Computers, Materials & Continua 2022年第2期70卷 2861-2877页

作者： Kanika Jimmy Singla Ali Kashif Bashir Yunyoung Nam Najam ui Hasan Usman Tariq School of Computer Science and engineering Lovely Professional UniversityPunjabIndia Department of Computing and Mathematics ManchesterMetropolitan UniversityUK&School of Electrical Engineering and Computer ScienceNational University of Science and TechnologyIslamabadPakistan Department of Computer Science and engineering Soonchunhyang UniversityAsan31538Korea Department of electrical and Computer engineering Dhofar UniversitySalalahOman College of Computer engineering and Sciences Prince Sattam bin Abdulaziz UniversityAl-Kharj11942Saudi Arabia

With the rise of internet facilities,a greater number of people have started doing online transactions at an exponential rate in recent years as the online transaction system has eliminated the need of going to the bank physically for every ***,the fraud cases have also increased causing the loss of money to the ***,an effective fraud detection system is the need of the hour which can detect fraudulent transactions automatically in ***,the genuine transactions are large in number than the fraudulent transactions which leads to the class imbalance *** this research work,an online transaction fraud detection system using deep learning has been proposed which can handle class imbalance problem by applying algorithm-level methods which modify the learning of the model to focus more on the minority class i.e.,fraud transactions.A novel loss function named Weighted Hard-Reduced Focal Loss(WH-RFL)has been proposed which has achieved maximum fraud detection rate i.e.,True PositiveRate(TPR)at the cost of misclassification of few genuine transactions as high TPR is preferred over a high True Negative Rate(TNR)in fraud detection system and same has been demonstrated using three publicly available imbalanced transactional ***,Thresholding has been applied to optimize the decision threshold using cross-validation to detect maximum number of frauds and it has been demonstrated by the experimental results that the selection of the right thresholding method with deep learning yields better results.

关键词： Class imbalance deep learning fraud detection loss function thresholding

The effectiveness and safety of acupuncture for poor semen quality in infertile males： a systematic review and meta-analysis

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Asian Journal of Andrology 2014年第6期16卷 884-891页

作者： ui Min Jerng Jun-Young Jo Seunghoon Lee Jin-Moo Lee Ohmin Kwon Class of Oncology Class of Gynecology Department of Clinical Korean Medicine Kyung Hee University Graduate School Seoul Korea Conmaul Hospital Seoul Korea Class of Acupuncture and Moxibustion Department of Clinical Korean Medicine Kyung Hee University Graduate School Seoul Korea Medical History and Literature Group Korea Institute of Oriental Medicine Daejeon Korea

The aim of this review is to evaluate the effectiveness and safety of acupuncture for poor semen quality in infertile men. We searched for relevant trials registered up to May 2013 in 14 databases. We selected randomized controlled trials （RCTs） that compared acupuncture, with or without additional treatment, against placebo, sham, no treatment, or the same additional treatment. Two reviewers independently performed the study selection, data extraction, risk of bias and reporting quality appraisal. Risk of bias and reporting quality were appraised by the Cochrane risk of bias tool, the consolidated standards of reporting trials and Standards for Reporting Interventions in Clinical Trials of Acupuncture. The outcomes were sperm motility, sperm concentration, pregnancy rate, and adverse events. Pregnancy was defined as a positive pregnancy test. Four RCTs met the eligibility criteria. Acupuncture increased the percentage of sperm with rapid progression （mean difference - 6.35, 95% confidence interval （CI）. 4.38-8.32, P〈 0.00001） and sperm concentration （mean difference - 6.42, 95% CI. 4.91-7.92, P〈 0.00001）, but these two outcomes were substantially heterogeneous among the studies （F = 72% and 58%, respectively）. No differences in pregnancy rate were found between acupuncture and control groups （odds ratio 1.60, 95% CI. 0.70-3.69, P= 0.27, F = 0%）. No participants experienced adverse events. The current evidence showing that acupuncture might improve poor semen quality is insufficient because of the small number of studies, inadequacy of procedures and/or insufficient information for semen analysis, high levels of heterogeneity, high risk of bias, and poor quality of reporting. Further large, well-designed RCTs are required.

关键词： acupuncture asthenozoospermia male infertility oligozoospermia sperm quality

Mechanical and thermodynamical stability of BiVO4 polymorphs using first-principles study

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Chinese Physics B 2017年第3期26卷 395-403页

作者： A K M Farid ui Islam Md Nurul Huda Liton H M Tariqul Islam Md Al Helal Md Kamruzzaman Department of Computer Science and engineering Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Department of Physics Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Department of Chemistry Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Department of Physics and Materials Science and Center of Super-Diamond and Advanced Films (COSDAF) City University of Hong Kong Hong Kong SAR China

First principles calculations of structural, electronic, mechanical, and thermodynamic properties of different poly- morphs of BiVO4 are performed using Bender-type plane/wave ultrasoft pseudopotentials within the generalized gradient approximation （GGA） in the flame of density functional theory （DFT）. The calculated structural and electronic properties are consistent with the previous theoretical and experimental results. The electronic structures reveal that m-BiVO4, op- BiVO4, and st-BiVO4 have indirect band gaps, on the other hand, zt-BiVO4 has a direct band gap. From the DOS and Mulliken＇s charge analysis, it is observed that only m-BiVO4 has 6s2 Bi lone pair. Bond population analysis indicates that st-BiVO4 shows a more ionic nature and a similar result is obtained from the elastic properties. From the elastic prop- erties, it is observed that st-BiVO4 is more mechanically stable than the others, st-BiVO4 is more ductile and useful for high electro-optical and electro-mechanical coupling devices. Our calculated thermodynamic properties confirm the similar characteristics found from electronic and elastic properties, m-BiVO4 is useful as photocatalysts, solid state electrolyte, and electrode and other polymorphs are applicable in electronic device fabrications.

关键词： BiVO4 crystal structure lone pair mechanical stability