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Quantitative deterministic versus probability analyses based on a safety margin criterion

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Science China(Technological Sciences) 2014年第10期57卷 1988-2000页

作者： chen ZuYu chen LiHong XU Jiacheng SUN Ping WU Chao WANG YuJie State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin Department of Geotechnical Engineering China Institute of Water Resources and Hydropower Research School of Civil Engineering Beijing Jiaotong University China International Engineering Consulting Corporation

This paper proposes a new criterion called the ratio of safety margin(RSM)for use in the areas of the global factor of safety,reliability and limit states analyses with reference to their respective allowable *** equation for calculating RSM based on the reliability index is *** for proving the applicability of this criterion include a theoretical demonstration in a simple one-variable case;an investigation on a test problem involving two random variables,followed by a slope stability study on a 156 m high embankment dam and an illustrative example presented in a EuroCode 7 *** of the ratios of safety margin in the three areas provides a quantitative way to accommodate the analytical results within the same theoretical framework and makes the outcomes mutually comparable and supportive,which is much more enlightening than that would be the case by considering only one of *** RSMs for reliability and limit states methods has also helped solve the key issue concerning the uniqueness of the partial factors calibrated from a particular‘target case’.

关键词： factor of safety reliability index partial factor ratio of safety margin embankment dam reliability analysis

THREE-DIMENSIONAL FINITE ELEMENT ANALYSIS AND ALLOWABLE DEFECT ASSESSMENT OF THE CENTRIFUGE BOWL BODY

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Transactions of Nonferrous Metals Society of China 1996年第1期6卷 141-146页

作者： Xu Zhenxing chen Fanjun Wang Zhaoqi Xu Yan Liu Yaodong chen Yijun Mechanical Engineering Department Xiangtan UniversityXiangtan 411105 Shanghai Branch of 701 Research Institute of General Co.of Shipping Industry of China Xiangtan Centrifuge Plant

For the first time,an allowable defect analysis of the bowl body of XZZ 1200-G Centrifuge was made by using fatigue fracture mechanics method;and,again for the first time,the design fatigue curve of the dangerous sect... 详细信息

关键词： bowl body of centrifuge fatigue fracture mechanics method crack

Characterization of a New HIV-1 Circulating Recombinant Form CRF142_BC—Yunnan,China,2015 and 2021

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China CDC weekly 2024年第42期6卷 1080-1085页

作者： Min chen Huichao chen Shouxiong Lei Jie Dai Yanling Ma Manhong Jia Yunnan Provincial Key Laboratory of Public Health and Biosafety&Health Laboratory Center Yunnan Center for Disease Control and PreventionKunming CityYunnan ProvinceChina Institute for AIDS/STD Control and Prevention Yunnan Center for Disease Control and PreventionKunming CityYunnan ProvinceChina Division for AIDS/STD Control and Prevention Zhaotong Center for Disease Control and PreventionZhaotong CityYunnan ProvinceChina Yunnan Provincial Key Laboratory of Public Health and Biosafety&Institute for AIDS/STD Control and Prevention Yunnan Center for Disease Control and PreventionKunming CityYunnan ProvinceChina

What is already known about this topic?Recombinant strains dominate the human immunodeficiency virus 1(HIV-1)epidemic in *** Province was the first region in China to report HIV-1 infections in *** long-term HIV-1 epidemic led to the generation of various recombinant *** the 47 circulating recombinant forms(CRFs)reported in China,more than 20 were first identified in Yunnan *** is added by this report?This study reported a previously unrecognized HIV-1 CRF(CRF142_BC)characterized by the insertion of four short subtype B fragments into the subtype C ***142_BC was estimated to have emerged in the mid-1990s,close to the time of the emergence of most known CRF_BCs in *** are the implications for public health practice?The discovery of new CRFs will provide a basis for HIV-1 molecular tracing and intervention *** addition,HIV-1 recombination can alter viral biological *** study of HIV-1 gene variants needs to be intensified.

关键词： properties. China. intensified

Agronomic performance of drought-resistance rice cultivars grown under alternate wetting and drying irrigation management in southeast China

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The Crop Journal 2018年第5期6卷 482-494页

作者： Guang Chu Tingting chen Song chen Chunmei Xu Danying Wang Xiufu Zhang China National Rice Research Institute Chinese Academy of Agricultural Sciences

Compared to drought-susceptible rice cultivars(DSRs),drought-resistance rice cultivars(DRRs)could drastically reduce the amount of irrigation water input and simultaneously result in higher grain yield under water-saving irrigation ***,the mechanisms underlying these properties are *** investigated how improved agronomic traits contribute to higher yield and higher water use efficiency(WUE)in DRRs than in DSRs under alternate wetting and drying(AWD).Two DRRs and two DSRs were field-grown in 2015 and 2016 using two different irrigation regimes:continuous flooding(CF)and *** CF,no statistical differences in grain yield and WUE were observed between DRRs and *** water under the AWD regime was 275–349 mm,an amount 49.8%–56.2% of that(552–620 mm)applied under the CF *** to CF,AWD significantly decreased grain yield in both DRRs and DSRs,with a more significant reduction in DSRs,and WUE was increased in DRRs,but not in DSRs,by 9.9%–23.0% under *** AWD,DRRs showed a 20.2%–26.2% increase in grain yield and an 18.6%–24.5% increase in WUE compared to *** to DSRs,DRRs showed less redundant vegetative growth,greater sink capacity,higher grain filling efficiency,larger root biomass,and deeper root distribution under *** conclude that these improved agronomic traits exert positive influences on WUE in DRRs under AWD.

关键词： Agronomic traits Alternate wetting and drying Drought-resistance rice cultivars Grain yield Water use efficiency

Oligoaniline Assisted Dispersion of Carbon Nanotubes in Epoxy Matrixfor Achieving the Nanocomposites with Enhanced Mechanical, Thermaland Tribological Properties

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Chinese Journal of Polymer Science 2017年第3期35卷 446-454页

作者： Bin chen Jia chen Jing-yu Li Xin Tong 赵海超王立平 School of Materials Science and Engineering Shenyang University of Chemical Technology Shenyang 11 O142 China Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials andProtective Technologies Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo 315201 China

A critical challenge for initiating many applications of the carbon nanotubes(CNTs) is their dispersion in organic solvent or in polymer melt. In the present study, we described a novel strategy for fabricating carbon nanotubes(CNTs)-reinforced epoxy nanocomposite by utilizing aniline trimer(AT) as the noncovalent dispersant. Tensile testing showed that the tensile modulus of the CNTs-reinforced epoxy composites was considerably improved by adding a small amount of AT functionalized CNTs. Additionally, the as-prepared CNTs-epoxy nanocomposites exhibited superior tribological properties with much lower frictional coefficients and wear rates compared to those of neat epoxy resin. The well dispersed AT-functionalized CNTs in epoxy matrix played an important role in enhancing the mechanical properties, as well as acting as a solid lubricant for improving the tribological performance of epoxy/CNTs nanocomposite.

关键词： Carbon nanotubes Epoxy Mechanical Tribological Nanocomposites

Research on Security of Key Algorithms in Intelligent Driving System

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Chinese Journal of Electronics 2019年第1期28卷 29-38页

作者： LIU Shangdong WU Ye JI Yimu chen chen BI Qiang JIAO Zhipeng GONG Jian WANG Ruchuan School of Computer Science and Engineering Southeast University School of Computer Science Nanjing University of Posts and Telecommunications Jiangsu Provincial Key Laboratory of Computer Network Technology Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks

With the rapid development of the smart driving technology, the security of smart driving algorithms is becoming more and more important. Four core smart driving algorithms are determined by studying the architecture of smart driving algorithm. These algorithms comprise local path planning, pedestrian detection, lane detection and obstacle detection. The security issues of these algorithms are investigated by closely examining the work carried out by the algorithms. We found that there are vulnerabilities in all four algorithms. These vulnerabilities can cause abnormality and even road accidents for the smart cars. The final experiment shows that the vulnerabilities of these algorithms do exist under certain circumstances and therefore have high security risks. This study will lay a foundation to improve the security of the smart driving system.

关键词： Smart driving algorithm Local path planning Pedestrian detection Lane line detection Obstacle detection

Determination of Steroid Hormone Residues in Fish Tissues Using Gel Permeation Chromatography and Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

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Journal of Ocean University of China 2018年第5期17卷 1171-1177页

作者： LI Peipei YAN Zhongyong SUN Xiumei chen Si chen Yin ZHANG Xiaojun Marine Fishery Institute of Zhejiang Province Zhoushan 316021China Key Laboratory of Sustainable Utilization of Technology Research for Fishery Resource of Zhejiang Province Zhoushan 316021China Zhejiang Ocean University Zhoushan 316022China

A highly sensitive method was developed for the simultaneous determination of 8 steroid hormones in high-fat fish tissues using ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The 8 steroid hormones were extracted from the tissues with diethyl *** from other common purification methods,the extract solutions were cleaned by gel permeation chromatography(GPC) using ethyl acetate-cyclohexane solution(1:1,v/v) as the mobile *** separation of target compounds was carried out by a BEH C18 column and a gradient elution consisting of acetonitrile and 0.2% aqueous formic acid(v/v).The compounds were detected under the multiple reaction monitoring(MRM) mode and quantified with external standard *** method was validated with respect to linearity,specificity,accuracy and precision.A linearity with correlation coefficient larger than 0.995 was achieved in the range of 0.5 to 50 ng m L^(-1).The average recoveries at the spiked levels of 1.0,5.0,and 10.0 μg kg^(–1) varied between 81.7% and 90.8%,with the relative standard deviations(n=5) ranged from 3.50% to 10.0%.The limit of quantification(LOQ) for 8 steroid hormones ranged from 0.2 to 1.5 μg kg^(-1).It was concluded that this method can be successfully applied for the determination of 8 steroid hormones in complicated matrices including high-fat fish tissues.

关键词： ultra performance liquid chromatography-tandem mass spectrometry anabolic hormone gel permeation chromatography fish tissue

High precision and efficiency robotic milling of complex parts:Challenges,approaches and trends

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Chinese Journal of Aeronautics 2022年第2期35卷 22-46页

作者： Zerun ZHU Xiaowei TANG chen chen Fangyu PENG Rong YAN Lin ZHOU Zepeng LI Jiawei WU School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China Wuhan Digital Design and Manufacturing Innovation Centre Co. Ltd.Wuhan 430074China

Due to the advantages of large workspace,low cost and the integrated vision/force sensing,robotic milling has become an important way for machining of complex *** recent years,many scholars have studied the problems existing in the applications of robotic milling,and lots of results have been made in the dynamics,pose planning,deformation control etc.,which provides theoretical guidance for high precision and high efficiency of robotic *** the perspective of complex parts robotic milling,this paper focuses on machining process planning and control techniques including the analysis of the robot-workspace,robot trajectory planning,vibration monitoring and control,deformation monitoring and *** well as the principles of these technologies such as robot stiffness characteristics,dynamic characteristics,chatter mechanisms,and deformation *** methods and characteristics related to the theory and technology of robotic milling of complex parts are summarized *** latest research progress and achievements in the relevant fields are *** is hoped that the challenges,strategies and development related to robotic milling could be clarified through the carding work in this paper,so as to promote the application of related theories and technologies in high efficiency and precision intelligent milling with robot for complex parts.

关键词： Complex parts Deformation Dynamics Robotic milling Stiffness Vibration control

Global mapping of artificial surfaces at 30-m resolution

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Science China Earth Sciences 2016年第12期59卷 2295-2306页

作者： chen XueHong CAO Xin LIAO AnPing chen LiJun PENG Shu LU Miao chen Jin ZHANG WeiWei ZHANG HongWei HAN Gang WU Hao LI Ran State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University National Geomatics Center of China Institute of Agricultural Resources and Regional Plannings Chinese Academy of Agricultural Sciences

Urbanization is expected to accelerate with population growth and economic development at the global scale. The artificial surface is the main land cover form of urbanization. On the one hand, urbanization provides spaces for industry, economic activities and residence. On the other hand, artificial surfaces change the earth surface to a large extent, thus significantly affecting natural processes such as the heat exchange, hydrological processes and ecological balance. Therefore, the global mapping of artificial surfaces is valuable for both natural science and social science. This study produced the global artificial surface maps at 30-m resolution for two base-years using the satellite images acquired around 2000 and 2010. First, we proposed a new definition of "artificial surface" based on patch level with consideration of its geographic meaning and image features at 30-m resolution. Second, pixel-based and object-based image processing techniques were combined for the extraction of artificial surface patches. Finally, human editing and a quality control system were employed to guarantee the quality of global mapping. Independent accuracy assessments show that the user’s accuracy of this product is higher than 80%. It can be concluded that the product is the most reliable one among all the available global datasets of artificial surfaces(or related types). The data can significantly contribute to various research fields, such as urbanization and ecosystem assessment.

关键词： Artificial surface 30-m resolution Classification approach Land cover mapping Remote sensing