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Arc Erosion Behavior of Cu–0.23Be–0.84Co Alloy after Heat Treatment: An Experimental Study

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Acta Metallurgica Sinica(English Letters) 2016年第4期29卷 399-408页

作者： Yanjun Zhou Kexing Song Jiandong Xing Zhou Li xiuhua guo State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and Engineering Xi’an Jiaotong University Collaborative Innovation Center of Nonferrous Metals Henan University of Science and Technology School of Materials Science and Engineering Henan University of Science and Technology School of Materials Science and Engineering Central South University

The arc erosion behavior of Cu-0.23Be-0.84Co alloy after heat treatment was investigated experimentally by a JF04C electric contact test system. The arc duration, arc energy, contact resistance and contact pressure of Cu-0.23Be- 0.84Co alloy after solution treatment and aging treatment were analyzed. The arc erosion morphologies were contrastively observed by a three-dimensional measuring system and scanning electron microscopy. For the Cu-0.23Be-0.84Co alloy in solution state and aging state, the maximum values of arc duration are 90 and 110 ms, and the arc energies are 15,000 and 18,000 mJ, respectively. The maximum value of the contact resistance of Cu-0.23Be-0.84Co alloy in different states is about 33 mΩ The contact pressure of Cu-0.23Be-0.84Co alloy in solution state generally changes between 50 and 60 cN during whole make-and-break contacts, while in aging state, it has a larger fluctuation range. Moreover, the quality of moving contact （anode） decreases, while static contact （cathode） increases. The materials transfer from anode to cathode during make-and-break contacts. The total mass losses of Cu-0.23Be-0.84Co alloy in solution state and aging state are 3 and 1.2 mg, respectively. In addition, a number of discrete corrosion pits, molten droplet, porosity and cavity distribute on the surface of moving contact and static contact. The arc erosion model of Cu-0.23Be-0.84Co alloy in make-and-break contact was built. The arc erosion resistance of Cu-0.23Be-0.84Co alloy after heat treatment is closely related to the microstructure and the properties of contact materials. This experimental study is important to evaluate the anode or cathode electrocorrosion fatigue life.

关键词： Cu-Be-Co alloy Arc erosion Aging Morphology

STUDY ON THE SIGNATURE OF GROUND MOVING TARGET FOR AIRBORNE SQUINT SAR IMAGING

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Journal of Electronics(China) 2012年第6期29卷 477-484页

作者： Shi Hongyin guo xiuhua Hou Zhitao Zhou Yinqing School of Information Science & Engineering Yanshan University School of Electrical & Information Engineering Beijing University of Aeronautics & Astronautics

Compared with the side-looking Synthetic Aperture Radar (SAR), the flexible beampointing of squint SAR makes great application value. This paper derives the image signature of the ground moving target after the processing of Range-Doppler (RD) algorithm, the SAR signatures of ground moving targets are analyzed, including the geometry correction, the offsets and defocusing in both range and azimuth direction. Finally, computer simulation results validate its effectiveness. The research results are especially significant for moving targets detection and parameters estimation in squint mode SAR.

关键词： Synthetic Aperture Radar (SAR) Squint Moving targets imaging Geometric correction

Maternal health and its affecting factors in Nepal

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Family Medicine and Community Health 2016年第3期4卷 30-34页

作者： Gehendra Mahara Jill Barr Janeeta Thomas Wei Wang xiuhua guo Department of Epidemiology and Health Statistics School of Public HealthCapital Medical UniversityBeijingChina Beijing Municipal Key Laboratory of Clinical Epidemiology BeijingChina School of Health and Well-Being University of WolverhamptonUK Ashwani Ayruvedic Hospital KeralaIndia School of Medical and Health Sciences Edith Cowan UniversityPerthAustralia

Maternal health is still a public health problem in developing countries,especially in low-resource settings rural and poor *** main aim of this article is to critically evaluate and explore the situation of maternal health in Nepal based on published or unpublished governmental or nongovernmental organization’s scientific reports regarding maternal *** found that there were several direct or indirect causes and affecting factors of maternal death in Nepal,which are *** have been facing different consequences during pregnancy and delivery,attributed to lack of proper knowledge or less available and affordable health facilities in rural ***,there is needed an essential maternal health knowledge to women and also establish health facilities with a quality health care service on affordable and accessible to prevent maternal death and minimize complications.

关键词： Maternal health maternal mortality Nepal

Long-term exposure to air pollution and cerebrovascular disease:findings from Beijing Health Management Cohort study

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Frontiers of Environmental Science & Engineering 2023年第7期17卷 79-89页

作者： Yuhan Zhao Xiaoping Kang Xue Tian Lulu Liu Zemeng Zhao Lili Luo Lixin Tao Xiangtong Liu Xiaonan Wang xiuhua guo Juan Xia Yanxia Luo School of Public Health Capital Medical UniversityBeijing 100069China Beijing Municipal Key Laboratory of Clinical Epidemiology Capital Medical UniversityBeijing 100069China Beijing Xiaotangshan Hospital Beijing 102211China

The relationship between air pollution and cerebrovascular disease has become a popular topic,yet research findings are highly *** study aims to investigate this association based on detailed individual health data and a precise evaluation of their exposure *** integrated models of generalized additive model,land use regression model and back propagation neural network were used to evaluate the exposure *** doubly robust additive model was conducted to explore the association between cerebrovascular disease and air pollution after adjusted for demographic characteristics,physical examination,disease information,geographic and socioeconomic status.A total of 25097 subjects were included in the Beijing Health Management Cohort from 2013 to *** a 1µg/m^(3)increase in the concentrations of PM_(2.5),SO_(2)and NO_(2),the incidence risk of cerebrovascular disease increased by 1.02(95%CI:1.008–1.034),1.06(95%CI:1.034–1.095)and 1.02(95%CI:1.010–1.029)*** CO exposure could decrease the risk,with an odds ratio of 0.38(95%CI:0.212–0.626).In the subgroup analysis,individuals under the age of 50 with normal BMI were at higher risk caused by PM2.5,and So2 was considered more hazardous to ***,the protective effect of CO on women and those with normal BMI was *** reduction of long-term exposure to PM2.5,SO_(2)and NO_(2)would lead to substantial benefits for decrease the risk of cerebrovascular disease especially for the health of the susceptible individuals.

关键词： Air pollution Cerebrovascular disease Incidence Long-term exposure Doubly robust additive model

The Malaysian health care system:Ecology,plans,and reforms

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Family Medicine and Community Health 2016年第3期4卷 19-29页

作者： Andrea Sebastian Mohamed Ali Alzain Collins Otieno Asweto Gehendra Mahara xiuhua guo Manshu Song Youxin Wang Wei Wang School of Public Health Capital Medical UniversityBeijingChina Beijing Municipal Key Laboratory of Clinical Epidemiology BeijingChina Beijing Municipal Key Laboratory of Environmental Toxicology BeijingChina School of Medical and Health Sciences Edith Cowan UniversityPerthWAAustralia Community Medicine Department Faculty of Medicine and Health SciencesUniversity of DongolaSudan

Malaysia is on its way to achieving developed nation status in the next 4 ***,Malaysia is on track for three Millennium Development Goals(MDG1,MDG4,and MDG7).The maternal mortality rate,infant mortality rate,and mortality rate of children younger than 5 years improved from 25.6%(2012)to 6.6%(2013),and 7.7%(2012)per 100,000 live births,respectively whereas immunization coverage for infants increased to an average of 90%.As of 2013 the ratio of physicians to patients improved to 1:633 while the ratio of health facilities to the population was 1:10,*** current government administration has proposed a reform in the form of the 10th Malaysian Plan coining the term“One Care for One Malaysia”as the newly improved and reorganized health care plan,where efficiency,effectiveness,and equity are the main *** review illustrates Malaysia’s transition from pre-independence to the current state,and its health and socioeconomic achievement as a *** aims to contribute knowledge through identifying the plans and reforms by the Malaysian government while highlighting the challenges faced as a nation.

关键词： Health care health care reform One Care Malaysia

Space-Time Cluster Analysis of Tuberculosis Incidence in Beijing, China

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Journal of Tuberculosis Research 2018年第4期6卷 302-319页

作者： Gehendra Mahara Mina Karki Kun Yang Sipeng Chen Wei Wang xiuhua guo Department of Epidemiology and Health Statistics School of Public Health Capital Medical University Beijing China Department of Medical Statistics and Epidemiology School of Public Health Sun Yat-sen University Guangzhou China Beijing Municipal Key Laboratory of Clinical Epidemiology Beijing China Mental Hospital Kathmandu Nepal Department of Evidence-Based Medicine Xuanwu Hospital Beijing China Fuwai Hospital Chinese Academy of Medical Science Beijing China School of Medical Sciences Edith Cowan University Perth Australia

Tuberculosis is one of the top killer diseases in the globe. The aim of this study was to explore the geographic distribution patterns and clustering characteristics of the disease incidence in terms of both space and time with high relative risk locations for tuberculosis incidence in Beijing area. A retrospective space-time clustering analysis was conducted at the districts level in Beijing area based on reported cases of sputum smear-positive pulmonary tuberculosis (TB) from 2005 to 2014. Global and local Moran’s I, autocorrelation analysis along with Ord (Gi*) statistics was applied to detect spatial patterns and the hotspot of TB incidence. Furthermore, the Kuldorff’s scan statistics were used to analyze space-time clusters. A total of 40,878 TB cases were reported in Beijing from 2005 to 2014. The annual average incidence rate was 22.11 per 100,000 populations (ranged from 16.55 to 25.71). The seasonal incidence occurred from March to July until late autumn. A higher relative risk area for TB incidence was mainly detected in urban and some rural districts of Beijing. The significant most likely space-time clusters and secondary clusters of TB incidence were scattered diversely in Beijing districts in each study year. The risk population was mainly scattered in urban and dense populated districts, including in few rural districts.

关键词： Tuberculosis Spatial Statistics Space-Time Analysis Beijing China

Estimation of the population,death,and quality of life in Shaanxi Province,western China:a cross-sectional study

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Chinese Medical Journal 2023年第15期136卷 1832-1838页

作者： Xinlei Miao Jun Chen Qiong Wu Wen Meng Lin Ren Zhiyuan Wu xiuhua guo Xiang Zhang Qun Meng School of Public Health Capital Medical UniversityBeijing 100069China Health Management Center the Second Hospital of Dalian Medical UniversityDalianLiaoning 116023China Center of Information Statistics Health Information Center of Shaanxi ProvinceXi’anShaanxi 710003China Center of Information Statistics National Health Commission of the People’s Republic of ChinaBeijing 100044China Department of Infection Prevention&Control Peking University People’s HospitalBeijing 100044China Information Management Center Affiliated Zhongshan Hospital of Dalian UniversityLiaoning 116001China Comprehensive Supervision Bureau National Health Commission of the People’s Republic of ChinaBeijing 100044China

Background:Measuring the health of the population is of great significance to the development of a *** aimed to estimate the population,probability of death,and quality of life in western ***:We calculated the age-specific mortality rate and prevalence rate of diseases and injuries using the Full Population Database and the Home Page of Inpatient Medical *** used multiple interpolation methods to insert missing information from the death data and the model of Kannisto to adjust the mortality rate for elderly *** age-specific prevalence rate of diseases and injuries was adjusted according to the standard ratio of age and methods of equal proportional *** expectancy was calculated by a life table,and the quality of life was estimated using the Sullivan ***:The total population continued to increase in 2015 to 2019 in the Shaanxi Province,*** mortality rate of children under five has improved,and the mortality rate of people over 65 is decreasing year by *** expectancy increased from 74.66 years in 2015 to 77.19 years in *** with the total risk of disease and injury,the health-adjusted life expectancy increased by 1.90 years within 5 years,and the number of unhealthy years significantly ***-adjusted life expectancy increased by 1.75 years when only considered the ten major disease systems(tumors;endocrinology,nutrition and metabolism;mental and behavioral disorders;nervous system;sensory diseases;circulatory system;respiratory system;digestive system;genitourinary system;musculoskeletal system and connective tissue),and the number of unhealthy years increased ***:In the past five years,Shaanxi Province has made progress in improving life expectancy and controlling the development of chronic *** is necessary to take specific preventive measures and improve the quality of basic public health services.

关键词： China Chronic disease Life expectancy Mortality rate Quality of life

一种新的可变数目机动目标联合检测与跟踪算法

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中南大学学报（自然科学版） 2016年第10期47卷 3424-3435页

作者：胡秀华郭雷李晖晖燕攀登西北工业大学自动化学院陕西西安710129

在低信噪比多传感器观测环境下,针对机动目标数目变化时跟踪性能不高的问题,提出一种新的目标联合检测与跟踪算法。依据粒子存在变量进行预测状态粒子集的采样,考虑状态粒子集与当前观测值的关联程度,利用模糊拍卖算法与粒子群优化理论... 详细信息

在低信噪比多传感器观测环境下,针对机动目标数目变化时跟踪性能不高的问题,提出一种新的目标联合检测与跟踪算法。依据粒子存在变量进行预测状态粒子集的采样,考虑状态粒子集与当前观测值的关联程度,利用模糊拍卖算法与粒子群优化理论解决状态集与观测集之间的关联问题,并给出目标出现与消失的判定准则,实现粒子权值更新;依据混合采样方法得到包含模型信息和状态信息的粒子集,并按照目标模型概率进行粒子状态融合得到目标局部状态后验估计值和均方误差;最后,对关联的各传感器局部航迹信息进行加权融合,得到各目标的全局状态估计值,并与经典多模粒子滤波算法的仿真试验对比分析。研究结果表明:新算法在运动模型概率估计、状态估计及目标数目估计方面具有有效性。

关键词：多模粒子滤波检测与跟踪关联判定目标混合采样

内氧化法制备Al_2O_3/Cu复合材料的电蚀特性

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特种铸造及有色合金 2007年第11期27卷 876-879页

作者：国秀花宋克兴郜建新刘瑞华河南科技大学材料科学与工程学院

以Cu2O为氧源,采用内氧化法制备了Al2O3/Cu复合材料,通过电火花试验研究了该复合材料的电蚀特性,并进行了微观组织结构分析。结果表明,采用内氧化法制备的Al2O3/Cu复合材料,在铜基体中弥散分布着纳米级的Al2O3颗粒;在基本保证与紫铜相... 详细信息

以Cu2O为氧源,采用内氧化法制备了Al2O3/Cu复合材料,通过电火花试验研究了该复合材料的电蚀特性,并进行了微观组织结构分析。结果表明,采用内氧化法制备的Al2O3/Cu复合材料,在铜基体中弥散分布着纳米级的Al2O3颗粒;在基本保证与紫铜相同加工速度的前提下,Al2O3/Cu复合材料工具电极的相对损耗和工件表面粗糙度均小于紫铜工具电极,且在试验范围内Al2O3/Cu复合材料工具电极损耗和工具表面粗糙度均随Al2O3含量的增加而降低。

关键词：内氧化 Al2O3/Cu复合材料电蚀电火花