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Analysis of Additional Damping Control Strategy and Parameter Optimization for Improving Small Signal Stability of VSC-HVDC System

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Energy Engineering 2023年第4期120卷 931-948页

作者： hui Fang Jingsen Zhou Hanjie liu Yanxu Wang Hongji Xiang Yechun Xin State Grid Chongqing Electric Power Company Research Institute Chongqing401120China Northeast Electric Power University Jilin132000China

The voltage source converter based high voltage direct current(VSC-HVDC)system is based on voltage source converter,and its control system is more *** affected by the fast control of power electronics,oscillation phenomenon in wide frequency domain may *** address the problem of small signal stability of the VSCHVDC system,a converter control strategy is designed to improve its small signal stability,and the risk of system oscillation is reduced by attaching a damping controller and optimizing the control *** on the modeling of the VSC-HVDC system,the general architecture of the inner and outer loop control of the VSCHVDC converter is established;and the damping controllers for DC control and AC control are designed in the phase-locked loop and the inner and outer loop control parts respectively;the state-space statemodel of the control system is established to analyze its *** the electromagnetic transient simulation model is built on the PSCAD/EMTDC simulation platform to verify the accuracy of the small signal *** influence of the parameters of each control part on the stability of the system is *** main control parts affecting stability are optimized for the phenomenon of oscillation due to changes in operation mode occurring on the AC side due to faults and other reasons,which effectively eliminates system oscillation and improves system small signal stability,providing a certain reference for engineering design.

关键词： VSC-HVDC system small signal modeling eigenvalue analysis parameter optimization

Short-term wind speed forecasting bias correction in the Hangzhou area of China based on a machine learning model

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Atmospheric and Oceanic Science Letters 2023年第4期16卷 37-44页

作者： yi Fang Yunfei Wu Fengmin Wu Yan Yan Qi liu Nian liu Jiangjiang Xia Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina Key Laboratory of Regional Climate–Environment for Temperate East Asia Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijingChina Zhejiang Institute of Meteorological Sciences HangzhouChina 93110 Troops People's Liberation Army of ChinaBeijingChina

准确的风速预报具有重要的社会意义.在本研究中,使用名为WSFBC-XGB的XGBoost机器学习模型对中国浙江省杭州市自动气象站的短期风速预报误差进行校正.WSFBC-XGB使用本地数值天气预报系统的产品作为输入.将WSFBC-XGB校正的结果与传统MOS(... 详细信息

准确的风速预报具有重要的社会意义.在本研究中,使用名为WSFBC-XGB的XGBoost机器学习模型对中国浙江省杭州市自动气象站的短期风速预报误差进行校正.WSFBC-XGB使用本地数值天气预报系统的产品作为输入.将WSFBC-XGB校正的结果与传统MOS(模型输出统计)方法校正的结果进行了比较.结果表明:WSFBC-XGB预报风速的均方根误差(RMSE)/准确率(ACC)分别比NWP和MOS降低/提高了26.1%和7.64%/35.6%和7.02%;对于90%的站点WSFBC-XGB的RMSE/ACC均小于/高于MOS.此外,采用平均杂质减少法对WSFBC-XGB的可解释性进行分析,以帮助用户增加对模型的信任.结果表明:10米风速(47.35%),10米风的经向分量(12.73%),日循环(9.97%)和1000百帕风的经向分量(7.45%)是前4个最重要的特征.WSFBC-XGB模型将有助于提高短期风速预报的准确性,为大型户外活动提供支持.

关键词：机器学习极端梯度提升算法风速后处理平均杂质减少

Effect and Safety of Hydroxysafflor Yellow A for Injection in Patients with Acute Ischemic Stroke of Blood Stasis Syndrome: A Phase Ⅱ , Multicenter, Randomized, Double-Blind, Multiple-Dose, Active-Controlled Clinical Trial

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Chinese Journal of Integrative Medicine 2020年第6期26卷 420-427页

作者： HU Ming-zhe ZHOU Zi-yi ZHOU Zhong-yu LU hui GAO Min liu Long-min SONG Hai-qing LIN An-ji WU Qing-ming ZHOU Hong-fei LI Lei WANG Xia CAI Ye-feng The Second Clinical College of Guangzhou University of Chinese Medicine Guangzhou(510006)China Department of Neurology The Second Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou(510120)China Department of Acupuncture and Moxibustion Hubei Provincial Hospital of Traditional Chinese MedicineWuhan(430061)China Department of Neurology Ruikang Hospital Affiliated to Guangxi University of Chinese MedicineNanning(530011)China Department of Neurology Guangdong Second Traditional Chinese Medicine HospitalGuangzhou(510095)China Department of Traditional Chinese Medicine Putuo HospitalShanghai University of Traditional Chinese MedicineShanghai(200062)China Department of Neurology Xuanwu HospitalCapital Medical UniversityBeijing(100053)China Department of Traditional Chinese Medicine Xiamen Hospital of Traditional Chinese MedicineXiamen(361001)China Departm ent of Acupuncture and Moxibustion The Second Affiliated Hospital of Hunan University of Traditional Chinese MedicineChangsha(410005)China Departm ent of Neurology The Affiliated Hospital of Liaoning University of Traditional Chinese MedicineShenyang(110032)China School of Public Health Tongji Medical CollegeHuazhong University of Science and TechnologyW uhan(430030)China Youcare Pharm aceutical Group Dingcheng Branch Beijing(100176)China

Objective:To assess the effect and safety of Hydroxysafflor Yellow A for Injection(HSYAI)in treating patients with acute ischemic stroke(AIS)and blood stasis syndrome(BSS).Methods:A multicenter,randomized,double-blind,multiple-dose,active-controlled phaseⅡtrial was conducted at 9 centers in China from July 2013 to September *** with moderate or severe AIS and BSS were randomly assigned to low-,medium-,high-dose HSYAI groups(25,50 and 70 mg/d HSYAI by intravenous infusion,respectively),and a control group(Dengzhan Xixin Injection(灯盏细辛注射液,DZXXI)30 mL/d by intravenous infusion),for 14 consecutive *** primary outcome was the Modified Rankin Scale(mRS)score 1 at days 90 after *** secondary outcomes included the National Institute of Health Stroke Scale(NIHSS)score 1,Barthel Index(BI)score 95,and BSS score reduced 30%from baseline at days 14,30,60,and 90 after *** safety outcomes included any adverse events during 90 days after ***:Of the 266 patients included in the effectiveness analysis,66,67,65 and 68 cases were in the low-,medium-,and high-dose HSYAI and control groups,*** proportions of patients in the medium-and high-dose HSYAI groups with mRS score 1 at days 90 after treatment were significantly larger than the control group(P0.05).Conclusions:HSYAI was safe and well-tolerated at all doses for treating AIS patients with *** medium(50 mg/d)or high dose(75 mg/d)might be the optimal dose for a phaseⅢtrial.

关键词： hydroxysafflor yellow A acute ischemic stroke randomized controlled trial blood stasis syndrome Chinese medicine

Discussion on the Mechanism of Boric Acid and Phosphoric Acid to Improve the Hardening of Complex Calcium Lubricating Grease

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China Petroleum Processing & Petrochemical Technology 2019年第4期21卷 112-118页

作者： Zheng hui Sun Hongwei He yifeng Su Shuo Zhuang Minyang liu Xinyang SINOPEC Research Institute of Petroleum Processing

In order to solve the hardening problem of complex calcium lubricating grease, the water absorption test of several calcium salts was carried out, and it was found that calcium 12-hydroxystearate did not absorb water, and calcium acetate, calcium phosphate and calcium borate had different degrees of water absorption. Calcium acetate has the highest water absorption rate, while calcium phosphate and calcium borate show comparable water absorption rates. Upon using the molecular simulation technology, it is found that in the complex calcium grease system, calcium phosphate and calcium borate tend to combine with water, which inhibits the water absorption of calcium acetate and alleviate the hardening problem.

关键词： lubricating grease complex calcium hardening

Abnormal meiosis in fertile and sterile triploid cyprinid fish

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Science China(Life Sciences) 2021年第11期64卷 1917-1928页

作者： Chun Zhang Qi Li La Zhu Wangchao He Conghui Yang hui Zhang Yu Sun Luojing Zhou Yuandong Sun Shurun Zhu Chang Wu Min Tao yi Zhou Rurong Zhao Chenchen Tang Shaojun liu State Key Laboratory of Developmental Biology of Freshwater Fish College of Life SciencesHunan Normal UniversityChangsha 410081China School of Life Sciences Hunan University of Science and TechnologyXiangtan 411201China

Meiosis is the key process for producing mature gametes. A natural fertile triploid Carassius auratus population(3nDTCC) and an artificially derived sterile triploid crucian carp(3nCC) have been previously observed, providing suitable model organisms for investigating meiosis characteristics in triploid fish. In the present study, the microstructures and ultrastructures of spermatogenesis were studied in these fishes. Td T-mediated d UTP nick end labeling detection was performed to investigate the apoptosis of spermatocytes. Fluorescence in situ hybridization was employed to trace chromatin pairing. In addition, the m RNA expressions of cell cycle-related genes(i.e., cell division control 2 and cell cycle protein B) were determined by quantitative realtime polymerase chain reaction to illustrate the molecular mechanism of abnormal meiosis in the 3nCC. The results showed that the 3nCC undergoes an irregular prophase I, with the chromosomes distributed in a unipolar radial manner and exhibiting partial pairing, hindered metaphase I, and degenerated cells in the subsequent stages. Meanwhile, the 3nDTCC presented a relatively regular meiotic prophase I with complete conjugate chromosome pairs and chromosomes distributed along the karyotheca,which were presented as a ring structure by slicing. Only the spreads with 130–150 irregular chromosomes can be easily detected in the 3nDTCC, suggesting that it may undergo an abnormal metaphase I. This study provides new insights into the meiosis of fertile and sterile triploid cyprinid fish.

关键词： triploid meiotic configuration partial pairing telomere degenerated cells

High-throughput volumetric reconstruction for 3D wheat plant architecture studies

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Journal of Innovative Optical Health Sciences 2016年第5期9卷 101-113页

作者： Wei Fang hui Feng Wanneng Yang Lingfeng Duan Guoxing Chen Lizhong Xiong Qian liu Britton Chance Center for Biomedical Photonics Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology 1037 Luoyu Rd.Wuhan 430074 P.R.China National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research Huazhong Agricultural University Wuhan 430070 P.R.China College of Engineering Huazhong Agricultural University Wuhan 430070 P.R.China MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River Huazhong Agricultural University Wuhan 430070 P.R.China

For many tller crops,the plant archit ecture(PA),including the plant fresh weight,plant height,number of tllrs,tller angle and stem diameter,sigificantly afects the grain *** this study,we propose a method based on volumetric reconstruction for high-throughput three-dimensional(3D)wheat PA *** proposed methodology involves plant volumetric reconst ruction from multiple images,plant model processing and phenotypic parameter estimation and *** study was performed on 80 Triticum aestium plants,and the results were *** the automated measurements with manual measurements,the mean absolute per-centage error(MAPE)in the plant height and the plant fresh weight was 2.71%(1.08cm with an average plant height of 40.07cm)and 10.06%(1.41g with an average plant fresh weight of 14.06 g),*** root mean square error(RMSE)was 137 cm and 1.79g for the plant height and plant fresh weight,*** correlation cofficients were 0.95 and 0.96 for the plant height and plant fresh weight,***,the proposed methodology,in-cluding plant reconstruction,model processing and trait ext raction,required only approximately 20s on average per plant using parallel computing on a graphics processing unit(GPU),dem-onstrating that the methodology would be valuable for a high-throughput phenotyping platform.

关键词： Three-dimensional volumetric reconstruction plant architecture graphics processing unit high-throughput

Synthesis and HIV-1 Integrase Inhibitory Activity of Furanone Derivatives

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Chemical Research in Chinese Universities 2010年第2期26卷 225-229页

作者： YU Sheng-hui ZHAO Si-tai liu Chuan ZHONG Yuan ZHAO Gui-sen School of Pharmaceutical Sciences Shandong University Jinan 250012 P R. China

Twenty novel furanone derivatives, based on the structure of raltegravir which was the first HIV-1 inte- grase（IN） inhibitor approved by the United States Food and Drug Administration（US FDA）, were designed, synthesized and characterized by ^1H NMR, IR and MS. The biological activities of these compounds against HIV-1 IN in vitro were evaluated. The assay results indicate that the replacement of pyrimidinone with furanone decreased the inhibitory activity of the compounds to HIV-1 IN. Compounds 3i, 3j and 3t show moderate inhibitory activity against HIV-1 IN and selectively inhibit the strand transfer reaction.

关键词： HIV-1 integrase Diketoacid Furanone

The development of laser-produced plasma EUV light source

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Chip 2022年第3期1卷 50-60页

作者： De-Kun Yang Du Wang Qiu-Shi Huang yi Song Jian Wu Wen-Xue Li Zhan-Shan Wang Xia-hui Tang Hong-Xing Xu Sheng liu Cheng-Qun Gui The Institute of Technological Sciences Wuhan UniversityWuhan 430072China Key Laboratory of Advanced Micro-Structured Materials MOE Institute of Precision Optical EngineeringSchool of Physics Science and EngineeringTongji UniversityShanghai 200092China State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200241China School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan 430074China School of Physics and Technology Wuhan UniversityWuhan 430072China

Extreme ultraviolet lithography(EUVL)has been demonstrated to meet the industrial requirements of new-generation semiconductor *** development of high-power EUV sources is a long-term critical challenge to the implementation of EUVL in high-volume manufacturing(HVM),together with other technologies such as photoresist and ***,both theoretical studies and experiments have clearly indicated that the CO 2 laser-produced plasma(LPP)system is a promising solution for EUVL source,able to realize high conversion efficiency(CE)and output ***,ASML’s NXE:3400B EUV scanner configuring CO_(2) LPP source sys-tem has been installed and operated at chipmaker ***-while,other research teams have made different progresses in the development of LPP EUV ***,in their technologies,some critical areas need to be further improved to meet the requirements of 5 nm node and *** needed improvements include higher laser power,stable droplet generation system and longer collector *** this paper,we describe the performance characteristics of the laser system,droplet generator and mirror collector for different EUV sources,and also the new development results.

关键词： Extreme ultraviolet source Laser-produced plasma Sn target Long lifetime collector

Multi-floor laboratory transportation technologies based on intelligent mobile robots

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Transportation Safety and Environment 2019年第1期1卷 37-53页

作者： Kerstin Thurow Lei Zhang hui liu Steffen Junginger Norbert Stoll Jiahao Huang Center for Life Science Automation(CELISCA) University of RostockRostock 18119Germany Institute of Artificial Intelligence&Robotics(IAIR) Key Laboratory of Traffic Safety on Track of Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangsha 410075HunanChina Institute of Automation University of RostockRostock 18119Germany

Transportation technologies for mobile robots include indoor navigation,intelligent collision avoidance and target *** paper discusses the research process and development of these interrelated *** efficient multi-floor laboratory transportation system for mobile robots developed by the group at the Center for Life Science Automation(CELISCA)is then *** system is integrated with the multi-floor navigation and intelligent collision avoidance systems,as well as a labware manipulation system.A multi-floor navigation technology is proposed,comprising sub-systems for mapping and localization,path planning,door control and elevator *** on human-robot interaction technology,a collision avoidance system is proposed that improves the navigation of the robots and ensures the safety of the transportation *** and placing operation technologies using the dual arms of the robots are investigated and integrated into the multi-floor transportation *** proposed transportation system is installed on the H20 mobile robots and tested at the CELISCA *** results show that the proposed system can ensure the mobile robots are successful when performing multi-floor laboratory transportation tasks.

关键词： robots mobile robots laboratory transportation navigation