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Reliability Assessment of Interconnected Power Systems with HVDC Links Considering Frequency Regulation Process

Journal of Modern Power Systems and Clean Energy 2023年第2期11卷 662-673页

作者： Chengjin ye Libang Guo Yi Ding Ming Ding Peng Wang Lei Wang College of Electrical Engineering Zhejiang UniversityHangzhouChina School of Electrical Engineering and Automation Hefei University of TechnologyHefeiChina Electrical and Electronic Engineering School Nanyang Technological UniversitySingapore the State Grid Zhejiang Electric Power Co. Economic and Technological Research InstituteHangzhouChina

With various components and complex topologies,the applications of high-voltage direct current(HVDC)links bring new challenges to the interconnected power systems in the aspect of frequency security,which further influence their reliability ***,this paper presents an approach to evaluate the impacts of the HVDC link outage on the reliability of interconnected power system considering the frequency regulation process during system ***,a multi-state model of an HVDC link with different available loading rates(ALRs)is established based on its reliability ***,dynamic frequency response models of the interconnected power system are presented and integrated with a novel frequency regulation scheme enabled by the HVDC *** proposed scheme exploits the temporary overload capability of normal converters to compensate for the imbalanced power during system ***,it offers frequency support that enables the frequency regulation reserves of the sending-end and receiving-end power systems to be mutually *** indices are established to measure the system reliability based on the given models in terms of abnormal frequency duration,frequency deviation,and energy losses of the frequency regulation process during system ***,a modified two-area reliability test system(RTS)with an HVDC link is adopted to verify the proposed approach.

关键词： Reliability multi-state modeling interconnected power system high-voltage direct current(HVDC)link frequency regulation

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AZ31镁合金管TIG焊焊接工艺及性能研究

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电焊机 2009年第7期39卷 30-32页

作者：包晔峰张国伟蒋永锋河海大学江苏常州213022

采用φ2mm镁合金焊丝,在焊接电流30～50A,焊接速度10～15mm/s的条件下,交流TIG焊焊接AZ31镁合金管,用光学显微镜观察镁合金母材、焊缝及热影响区的显微组织,测定了接头和母材硬度。结果表明:焊缝与热影响区之间的熔合线清晰可见;热影响... 详细信息

采用φ2mm镁合金焊丝,在焊接电流30～50A,焊接速度10～15mm/s的条件下,交流TIG焊焊接AZ31镁合金管,用光学显微镜观察镁合金母材、焊缝及热影响区的显微组织,测定了接头和母材硬度。结果表明:焊缝与热影响区之间的熔合线清晰可见;热影响区组织由于过热影响而晶粒粗大;焊缝区的晶粒比热影响区细小,由细小的等轴晶组成,是典型的铸造急冷组织;Mg17Al12和Mg17(AlZn)12共晶体呈不连续网状分布在晶界上。由于焊缝表面的晶粒细小且排列紧密,焊缝硬度比母材低,比热影响区高。

关键词：镁合金管焊接微观组织硬度测定

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Container Introspection: Using External Management Containers to Monitor Containers in Cloud Computing

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Computers, Materials & Continua 2021年第12期69卷 3783-3794页

作者： Dongyang Zhan Kai Tan Lin ye Haining Yu Hao Liu School of Cyberspace Science Harbin Institute of TechnologyHarbin150001China Temple University Philadelphia19122USA City University of Hong Kong Kowloon Tong518057Hong Kong Qianxin Technology Group Co. Ltd.Beijing100000China

Cloud computing plays an important role in today’s Internet environment,which meets the requirements of scalability,security and reliability by using virtualization *** technology is one of the two mainstream virtualization *** lightweight,high deployment efficiency make container technology widely used in large-scale cloud *** container technology has created huge benefits for cloud service providers and tenants,it cannot meet the requirements of security monitoring and management from a tenant ***,tenants can only run their security monitors in the target container,but it is not secure because the attacker is able to detect and compromise the security *** this paper,a secure external monitoring approach is proposed to monitor target containers in another management *** management container is transparent for target containers,but it can obtain the executing information of target containers,providing a secure monitoring *** monitors running inside management containers are secure for the cloud host,since the management containers are not *** implement the transparent external management containers by performing the one-way isolation of processes and *** process one-way isolation,we leverage Linux namespace technology to let management container become the parent of target *** mounting the file system of target container to that of the management container,file system one-way isolation is *** with the existing host-based monitoring approach,our approach is more secure and suitable in the cloud environment.

关键词： Container introspection management container external approach one-way isolation

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Neither Biased Sex Ratio nor Spatial Segregation of the Sexes in the Subtropical Dioecious Tree Eurycorymbus cavaleriei(Sapindaceae)

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Journal of Integrative Plant Biology 2009年第6期51卷 604-613页

作者： Puxin Gao Ming Kang Jing Wang Qigang ye Hongwen Huang Wuhan Botanical Garden the Chinese Academy of Sciences Wuhan 430074 China Key Laboratory of Plant Resources Conservation and Sustainable Utilization the Chinese Academy of Sciences Guangzhou 510650 China South China Botanical Garden the Chinese Academy of Sciences Guangzhou 510650 China Lushan Botanical Garden Jiangxi Province and the Chinese Academy of Sciences Lushan 332900 China

Knowledge of sex ratio and spatial distribution of males and females of dioecious species is both of evolutionary interest and of crucial importance for biological conservation. Eurycorymbus cavaleriei, the only species in the genus Eurycorymbus （Sapindaceae）, is a dioecious tree endemic to subtropical montane forest in South China. Sex ratios were investigated in 15 natural populations for the two defined ages （young and old）. Spatial distribution of males and females was further studied in six large populations occurring in different habitats （fragmented and continuous）. The study revealed a slight trend of male- biased sex ratio in both ages of E. cavaleriei, but sex ratio of most populations （13 out of 15） did not display statistically significant deviation from equality. All of the four significantly male-biased populations in the young class shifted to equality or even female-biased, The Ripley＇s K analysis of the distribution of males with respect to females suggested that individuals of the opposite sexes were more randomly distributed rather than spatially structured. These results suggest that the male-biased sex ratio in E. cavaleriei may result from the precocity of males and habitat heterogeneity. The sex ratio and the sex spatial distribution pattern are unlikely to constitute a serious threat to the survival of the species.

关键词： dioecy Eurycorymbus cavaledei rare species sex ratio spatial segregation of the sexes.

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Azo dye degradation behavior of AlFeMnTiM(M = Cr, Co, Ni) high-entropy alloys

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International Journal of Minerals,Metallurgy and Materials 2019年第1期26卷 124-132页

作者： Shi-kai Wu ye Pan Ning Wang Tao Lu Wei-ji Dai School of Materials Science and Engineering Southeast University Jiangsu Key Laboratory for Advanced Metallic Materials

Because of the potential carcinogenic effects and difficult degradation of azo dyes, their degradation has been a longstanding problem. The degradation of azo dye Direct Blue 6(DB6) using ball-milled(BM) high-entropy alloy(HEA) powders was characterized in this work. Newly designed AlFeMnTiM(M = Cr, Co, Ni) HEAs synthesized by mechanical alloying(MA) showed excellent performance in the degradation of azo dye DB6. The degradation efficiency of AlFeMnTiCr is approximately 19 times greater than that of the widely used commercial Fe–Si–B amorphous alloy ribbons and more than 100 times greater than that of the widely used commercial zero-valent iron(ZVI) powders. The galvanic-cell effect and the unique crystal structure are responsible for the good degradation performance of the BM HEAs. This study indicates that BM HEAs are attractive, valuable, and promising environmental catalysts for wastewater contaminated by azo dyes.

关键词： high entropy alloy mechanical alloying AlFeMnTiM degradation performance azo dye

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Epithelial-mesenchymal transition effect of fine particulate matter from the Yangtze River Delta region in China on human bronchial epithelial cells

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Journal of Environmental Sciences 2018年第4期30卷 155-164页

作者： Yulang Chi Qiansheng Huang Yi Lin Guozhu ye Huimin Zhu Sijun Dong Center for Excellence in Urban Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences Key Lab of Urban Environment and Health Institute of Urban Environment Chinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences

Epidemiological studies have demonstrated that fine particulate matter（PM（2.5）） exposure causes airway inflammation, which may lead to lung cancer. The activation of epithelial–mesenchymal transition（EMT） is assumed to be a crucial step in lung tumor metastasis and development. We assessed the EMT effect of low concentrations（0, 0.1, 1.0, and 5.0 μg/m L）of PM（2.5） organic extract on a human bronchial epithelial cell line（BEAS-2 B）. PM（2.5） samples were collected from three cities（Shanghai, Ningbo, and Nanjing） in the Yangtze River Delta（YRD） region in autumn 2014. BEAS-2 B cells were exposed to the PM（2.5） extract to assess cell viability, invasion ability as well as the relative m RNA and protein expressions of EMT markers. Our findings revealed that BEAS-2 B cells changed from the epithelial to mesenchymal phenotype after exposure. In all groups, PM（2.5） exposure dose-dependently decreased the expression of E-cadherin and increased the expression of Vimentin. The key transcription factors, including ZEB1 and Slug, were significantly up-regulated upon exposure. These results indicated that the PM（2.5） organic extract induced different degrees of EMT progression in BEAS-2 B cells. The cell invasion ability increased in a concentration-dependent manner after 48 hr of treatment with the extract. This study offers a novel insight into the effects of PM（2.5） on EMT and the potential health risks associated with PM（2.5） in the YRD region.

关键词： PM2.5 BEAS-2B Epithelial–mesenchymal transition Cell invasion

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Effect of H_2 Reduction Temperature on the Properties of Reduced Graphene Oxide and Copper Matrix Composites

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Acta Metallurgica Sinica(English Letters) 2014年第5期27卷 924-929页

作者： Lidong Wang ye Cui Ruiyu Li Guojian Cao Bin Li Weidong Fei School of Materials Science and Engineering Harbin Institute of Technology Shanghai Institute of Space Power-Sources School of Materials Science and Engineering Harbin University of Science and Technology School of Mechanical Engineering Qinghai University

Reduced graphene oxide （RGO） and copper composites （RGO/Cu） were successfully fabricated based on a molecular-level mixing method （MLM）. The composite powders were reduced in H2 at 350, 450, and 550℃ and then consolidated by spark plasma sintering （SPS） in order to evaluate the effect of H2 reduction temperature on the properties of the composites. The results indicate that the strengths of the composite decrease with the increase of H2 reduction temperature, while the electrical conductivity reaches its maximum at 450 ℃ and minimum at 550 ℃. Hot rolling could benefit the electrical conductivity. The yield strength of the RGO/Cu composite reduced to 337 MPa at 350℃. The electrical conductivity of the RGO/Cu composite reduced at 450℃ after hot rolling reaches 60.26% IACS. The properties of the RGO/Cu composites can be designed by adjusting the reduction degree of RGO and by hot rolling.

关键词： Nanostructure Copper Composites Hydrogen Mechanical properties

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Crustal Structure Revealed by a Deep Seismic Sounding Profile of Baijing-Gaoming-Jinwan in the Pearl River Delta

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Journal of Ocean University of China 2018年第1期17卷 186-194页

作者： ZHANG Xiang ye Xiuwei LV Jinshui SUN Jinlong WANG Xiaona CAS Key Laboratory of Ocean Geology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China University of Chinese Academy of Sciences Beijing 100049China Guangdong Earthquake Agency China Earthquake AdministrationGuangzhou 510070China

The Pearl River Estuary area, located in the middle part of the southern China coastal seismic belt, has long been considered a potential source of strong earthquakes above magnitude 7.0. To scientifically assess the potential strong earthquake risk in this area, a three-dimensional artificial seismic sounding experiment, consisting of a receiving array and seabed seismograph, was performed to reveal the deep crustal structure in this region. We used artificial ship-borne air-gun excitation shots as sources, and fixed and mobile stations as receivers to record seismic data from May to August 2015. This paper presents results along a line from the western side of the Pearl River Estuary to the western side of the Baijing-Gaoming-Jinwan profile. A two-dimensional velocity structure was constructed using seismic travel-time tomography. The inversion results show that the Moho depth is 27 km in the coastal area and 30 km in the northwest of the Pearl River Estuary area, indicating that the crust thins from land to sea. Two structural discontinuities and multiple low-velocity anomalies appear in the crustal section. Inside both discontinuity zones, a low-velocity layer, with a minimum velocity of 6.05 km s^(-1), exists at a depth of about 15 km, and another, with a minimum velocity of 6.37 km s^(-1), exists at a depth of about 21.5 km between the middle and lower crust. These low velocities suggest that the discontinuities may consist of partly molten material. Earthquakes with magnitudes higher than 5.0 occurred in the low-velocity layer along the profile. The deep Kaiping-Enping fault, rooted in the crust, may be one of the most important channels for deep material upwelling and is related to tectonic movement since the Cretaceous in the Pearl River Delta tectonic rift basin.

关键词： Pearl River Estuary seismic sounding profile crustal structure Kaiping-Enping fault earthquake potential

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治理理念下的西部民族地区自然灾害应对转型研究

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青海民族研究 2017年第3期28卷 60-63页

作者：叶宏姜流南开大学天津300071 玉溪师范学院云南玉溪653100

在西部民族地区,灾害应对效度与民族地区的政治稳定息息相关。我国既有的灾害应对模式是由政府主导的"行政区行政"管理,灾害管理体制的系统性和能动性体现不足。"汶川地震"以来,在治理理念的推动下,西部民族地区的灾害应对启动了社会治... 详细信息

在西部民族地区,灾害应对效度与民族地区的政治稳定息息相关。我国既有的灾害应对模式是由政府主导的"行政区行政"管理,灾害管理体制的系统性和能动性体现不足。"汶川地震"以来,在治理理念的推动下,西部民族地区的灾害应对启动了社会治理的新思路,出现了由关注应急救灾到重视重建发展、进而到加强防灾减灾建设的策略转变。实现从应急管理到多元治理,将治理与灾害发生周期耦合,创新行政协调机制促进府际合作,推动制度建设,倡导多元主体有序参与,可以降低灾害风险,形成区域灾害综合治理网络。

关键词：西部民族地区灾害应对治理

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Macroporous composite capacitive bioanode applied in microbial fuel cells

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Chinese Chemical Letters 2020年第1期31卷 205-209页

作者： Yuyang Wang Hongtao Zheng ye Chen Qing Wen Jiansong Wu Key Laboratory of Superlight Materials and Surface Technology of Ministry of Education College of Material Science and Chemical EngineeringHarbin Engineering UniversityHarbin 15001China College of Power and Energy Engineering Harbin Engineering UniversityHarbin 15001China College of Light Industry Harbin University of CommerceHarbin 15001China Department of Infection Diseases General Hospital of the PLA Rocket ForceBeijing 10088China

Interfacial electron transfer between electroactive biofilm and the electrode was crucial step for microbial fuel cells(MFCs).A three-dimensional multilayer porous sponge coating with nitrogen-doped carbon nanotube/polyaniline/manganese dioxide(S/N-CNT/PANI/MnO2)electrode has been developed for MFC ***,the S/N-CNT/PANI/MnO2 anode can function as a biocapacitor,able to store electrons generated from the degradation of organic substrate under the open circuit state and release the accumulated electrons upon ***,the mismatching of the production and demand of the electricity can be *** with the sponge/nitrogen-doped carbon nanotube(S/N-CNT)bioanode,S/N-CNT/PANI/MnO2 capacitive bioanode displays a strong interaction with the microbial biofilm,advancing the electron transfer from exoelectrogens to the *** maximum power density of MFC with S/N-CNT/PANI/MnO2 capacitive bioanode is 1019.5 mW/m^2,which is 2.2 and5.8 times as much as that of S/N-CNT/MnO2 bioanode and S/N-CNT bioanode(470.7 mW/m^2 and176.6 mW/m^2),*** the chronoamperometric experiment with 60 min of charging and 20 min of discharging,the S/N-CNT/PANI/MnO2 capacitive bioanode was able to store 10743.9 C/m^2,whereas the S/N-CNT anode was only able to store 3323.4 C/m^*** a capacitive bioanode,it is possible to use the MFC simultaneously for production and storage of electricity.

关键词： Capacitive bioanode Three-dimensional hierarchical composite Microbial fuel cell Energy storage Porous sponge

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