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Availability growth models and verification of power equipment

Jinyuan SHI, Jiamin XU

《能源前沿（英文）》 2021年第15卷第2期页码 529-538 doi: 10.1007/s11708-019-0624-0

摘要： The general availability growth models for large scale complicated repairable system such as electric generating units, power station auxiliaries, and transmission and distribution installations are presented. The calculation formulas for the maintenance coefficient, mathematical expressions for general availability growth models, ways for estimating, and fitting on checking the parameters of the model are introduced. Availability growth models for electric generating units, power station auxiliaries, and transmission and distribution installations are given together with verification examples for availability growth models of 320–1000 MW nuclear power units and 1000 MW thermal power units, 200–1000 MW power station auxiliaries, and 220–500 kV transmission and distribution installations. The verification results for operation availability data show that the maintenance coefficients for electric generating units, power station auxiliaries, transmission and distribution installations conform to the power function, and general availability growth models conform to rules of availability growth tendency of power equipment.

关键词： repairable system power equipment electric generating unit power station auxiliary transmission and distribution installation reliability availability availability growth model

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Reliability analysis of urban gas transmission and distribution system based on FMEA and correlation

Su LI,Weiguo ZHOU

《能源前沿（英文）》 2014年第8卷第4期页码 443-448 doi: 10.1007/s11708-014-0336-4

摘要： In order to improve the safety management of urban gas transmission and distribution system, failure mode and effects analysis (FMEA) was used to construct the reliability analysis system of the pipeline network. To solve the problem of subjectivity and uncertainty of the multi-expert decision making, the correlation operator was introduced into the calculation of the risk priority number (RPN). Using FMEA along with weight analysis and expert investigation approach, the FMEA evaluation table was given, including five failure modes, risk priority numbers, failure causes and effects, as well as corrective actions. The results show that correlation operator can directly process the linguistic terms and quantify the priority of the risks.

关键词： gas transmission and distribution system risk evaluation reliability analysis failure mode and effects analysis (FMEA) correlation operator

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Lifting installation and prestressed cable construction of suspendome roof for Wuhan Gymnasium

GUO Zhengxing, SHI Kairong, LUO Bin, TIAN Qiliang, WU Julong, BI Shuiyong

《结构与土木工程前沿（英文）》 2008年第2卷第1期页码 87-92 doi: 10.1007/s11709-008-0005-y

摘要： The steel roof of Wuhan Gymnasium is a long-span suspendome structure system. According to the structural characteristics of the roof, the lifting installation of upper latticed shell and the installation and tension of lower prestressed cables are introduced in detail. The cable tension is completed successfully on June 27, 2006, while the test results of cable forces and structural deformation are comparatively consistent with the theoretical analysis results. Moreover, Strut-adjustment Method is innovated and applied successfully in the construction of long-span suspendome structure for the first time, and the theoretical and practical experiences can be used for the research and application of similar new-type spatial structures.

关键词： practical new-type installation consistent Gymnasium

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三峡升船机平衡重系统安装技术

蔡春华,罗彬

《中国工程科学》 2013年第15卷第9期页码 70-76

摘要：

针对三峡升船机平衡重系统安装要求并结合现场综合环境，对三峡升船机平衡重系统安装技术进行研究。提出了适宜三峡升船机平衡重系统安装的总体程序，并分别对总体程序中的平衡链导向装置安装、平衡滑轮组安装、主提升钢丝绳安装和平衡重组安装等子工序提出了详细的施工流程以及施工方法，建立了一套完整的升船机平衡重系统安装技术体系。该项施工技术有效解决了三峡升船机平衡重系统安装过程中面临的工程规模大、构件尺寸质量大、技术精度要求高、安装高程高、施工难度大、施工点多面广和施工现场条件复杂等技术难点，为国内外类似工程实践提供了很好的参考。

关键词：三峡升船机平衡重系统安装程序安装技术

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Experimental and modeling studies on installation of arc sprayed Zn anodes for protection of reinforced

Xianming SHI

《结构与土木工程前沿（英文）》 2016年第10卷第1期页码 1-11 doi: 10.1007/s11709-016-0312-7

摘要： Arc sprayed zinc (Zn) anode on concrete surfaces has been an emerging technology for protecting reinforced concrete structures from rebar corrosion in coastal environments. Many cathodic protection (CP) systems with arc sprayed Zn anodes will reach or exceed their design life in the near future and thus may function improperly or insufficiently, making it necessary to replace the aged anodes. However, prior to this study, little was known about the most effective profile for the concrete surface, for either new concrete or old concrete with existing Zn anodes removed. This work develops criteria to properly prepare the concrete surface before the application of new Zn anode. Experimental studies were conducted both in the laboratory and for a field structure in Oregon. Artificial neural network was used to achieve better understanding of the complex cause-and-effect relationships inherent in the Zn-mortar or Zn–concrete systems and was successful in finding meaningful, logical results from the bond strength data. The goal is to achieve strong initial bond strength of new Zn to concrete, which is essential for long-term performance of the CP system. The results from this case study suggest that it is necessary to adjust the anode removal and surface sandblasting based on the electrochemical age of the existing concrete. In all cases of sandblasting, minimize the exposure of large aggregates (e.g., those bigger than 19 mm in diameter).

关键词： arc sprayed Zn anode replacement reinforced concrete bridge preservation neural networks surface profile

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Choosing configurations of transmission line tower grounding by back flashover probability value

Dmitry KUKLIN

《能源前沿（英文）》 2016年第10卷第2期页码 213-226 doi: 10.1007/s11708-016-0398-6

摘要： There is a considerable number of works devoted to electrical characteristics of grounding. These characteristics are important in general. However, in application to grounding of transmission line towers they are not enough to determine what grounding construction is preferable in some particular case, because these characteristics are calculated or measured apart from the grounded object, and only limited number of current (or voltage) source waveforms is used. This paper indicates reasons in favor of the fact that to choose the optimum design of grounding, the calculation model should include the tower as it is. The probability of back flashover, which provides both qualitative and quantitative estimate of the grounding structure efficiency, can be taken as the criterion for the grounding design. The insulation flashover probability is calculated on the basis of engineering method, which evaluates breakdown strength of insulation for nonstandard waveshapes, and probability data on lightning currents. Different approaches are examined for identifying the back flashover probability, as not only amplitudes but also other parameters can be taken into account. Finite-difference time-domain method is used for calculations of transients. It is found that lightning current waveform can greatly influence calculated back flashover probability value.

关键词： grounding transmission line tower back flashover probability FDTD method

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Energy and economic analysis of a point-focus concentrating photovoltaic system when its installation

C. RENNO, A. PERONE

《能源前沿（英文）》 2021年第15卷第2期页码 384-395 doi: 10.1007/s11708-020-0717-9

摘要： The concentrating photovoltaic (CPV) systems are a promising technology to obtain clean energy. However, these systems are not equally convenient worldwide due to different climatic conditions. The main aim of this paper is to analyze energy and economic performances of a point-focus CPV system for a residential user when its installation site varies. Three locations, Riyadh, Copenhagen, and Palermo, characterized by very different weather conditions are chosen. A model that links the electrical power of a triple-junction (TJ) cell with its temperature and concentrated radiation incident on it is experimentally developed to evaluate the energy performance of the CPV system. A comparison of the three localities for typical winter and summer sunny days indicates that the higher values of the TJ cell temperature are reached in summer, over 70°C at Riyadh, and its electrical power is reduced compared to a winter day. In winter, a TJ cell in Riyadh supplies an electric power of about 20% higher than that in other two cities, while in summer, the maximum power is observed at Copenhagen. On the contrary, the electrical producibility also depends on the sunlight daily hours number during the year. Hence, considering the real distribution of direct normal irradiance (DNI) and the environmental temperature for each locality, a CPV system composed of modules of 90 cells adopted for a residential user is sized. The electric producibility of the CPV system, by varying its module number, is evaluated for different localities together with the optimal number of the modules which is able to maximize the investment profitability.

关键词： CPV system point-focus experimental model energy and economic analysis

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三峡升船机贝雷架安装与拆除技术

刘勇,陈建峡

《中国工程科学》 2013年第15卷第9期页码 77-82

摘要：

三峡升船机塔柱横梁贝雷架支撑体系的安装与拆除属于高空立体交叉作业，而且施工场地狭窄、施工强度大，贝雷架的安装与拆除所受到的施工干扰大，是三峡升船机塔柱施工中的难题之一。本文通过对贝雷架施工作业环境的系统分析，根据不同部位的特点与要求，制定了有针对性的包括施工设备布置、吊装单元划分、吊点设置、各部位拆除方案在内的塔柱横梁贝雷架安装及拆除施工技术体系。该技术体系在三峡升船机贝雷架安装及拆除工程中得到顺利实施，塔柱横梁贝雷架支撑系统的施工进度、施工成本及施工安全均实现了良好的效果，表明该技术方案合理可靠。本文中贝雷架的安装与拆除施工技术体系可为类似条件下的贝雷架安装和拆除施工提供参考借鉴。

关键词：升船机贝雷架安装拆除三峡工程

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李正烁：分布式输配协同方法初探（2020年8月18日）

2022年10月17日

关键词：信息技术能源

Recent transmission of Mycobacterium tuberculosis in China: the implication of molecular epidemiology

null

《医学前沿（英文）》 2018年第12卷第1期页码 76-83 doi: 10.1007/s11684-017-0609-5

摘要：

Tuberculosis (TB) has remained an ongoing concern in China. The national scale-up of the Directly Observed Treatment, Short Course (DOTS) program has accelerated the fight against TB in China. Nevertheless, many challenges still remain, including the spread of drug-resistant strains, high disease burden in rural areas, and enormous rural-to-urban migrations. Whether incident active TB represents recent transmission or endogenous reactivation has helped to prioritize the strategies for TB control. Evidence from molecular epidemiology studies has delineated the recent transmission of ( ) strains in many settings. However, the transmission patterns of TB in most areas of China are still not clear. Studies carried out to date could not capture the real burden of recent transmission of the disease in China because of the retrospective study design, incomplete sampling, and use of low-resolution genotyping methods. We reviewed the implementations of molecular epidemiology of TB in China, the estimated disease burden due to recent transmission of strains, the primary transmission of drug-resistant TB, and the evaluation of a feasible genotyping method of strains in circulation.

关键词： tuberculosis recent transmission molecular epidemiology China

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海上风电场机组分体安装法及其应用

孙广喜,黄亚新

《中国工程科学》 2010年第12卷第11期页码 53-59

摘要：

对世界各国海上风电场的安装方法进行了归纳分类，分析风机海上分体安装法的工艺流程、装配基地设置的必要性和设置原则，归纳出8种典型的陆上组装方案及主要风机组件的装配工艺；提出一种海上风机潜水船坐底安装法：在潜水船上配置起重机构成风机潜水安装船，作业时潜水安装船潜入海底并坐落于海床，进行风机部件的吊装，该安装法适用于近海风电场建设；最后介绍了潜水船安装法在江苏响水近海风电场试验机组项目中的应用。

关键词：海上风电场陆上组装法分体安装法应用

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三峡升船机齿条、螺母柱安装精度控制措施

魏艳,彭翰林,林凡

《中国工程科学》 2013年第15卷第9期页码 91-96

摘要：

针对三峡升船机齿条、螺母柱安装高精度的技术要求与特点，结合现场综合环境进行了安装方法及安装精度控制要素的详细分析，提出了适宜三峡升船机齿条、螺母柱安装的施工流程和控制措施。在工程实践中，采用基准点检测得到对齿条、螺母柱的精度控制，提出了精加工工艺螺杆配合千斤顶调整的方法作为齿条、螺母柱安装加固措施，解决了齿条、螺母柱安装中面临的各项高精度标准技术难题，为类似工程施工提供了有益的借鉴。

关键词：三峡升船机齿条螺母柱安装控制精度控制

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Antibiotic resistome mostly relates to bacterial taxonomy along a suburban transmission chain

《环境科学与工程前沿（英文）》 2022年第16卷第3期 doi: 10.1007/s11783-021-1466-7

摘要：

• The α-diversities of resistome were lower in manure and compost than in soils.

关键词： Antibiotic resistance genes Resistome Bacterial taxonomy Transmission chain

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Planet position errors in planetary transmission: Effect on load sharing and transmission error

Miguel IGLESIAS, Alfonso FERNáNDEZ, Ana DE-JUAN, Ramón SANCIBRIáN, Pablo GARCíA

《机械工程前沿（英文）》 2013年第8卷第1期页码 80-87 doi: 10.1007/s11465-013-0362-7

摘要：

In this paper an advanced model of spur gear transmissions developed by the authors is used to study the influence of carrier planet pin hole position errors on the behaviour of the transmission. The model, initially conceived for external gear modeling, has been extended with internal meshing features, and thus increasing its capabilities to include planetary transmission modeling. The new features are presented, along with the summary of the model general approach. The parameters and characteristics of the planetary transmission used in the paper are introduced. The influence of carrier planet pin hole position errors on the planet load sharing is studied, and several static cases are given as examples in order to show the ability of the model. Tangential and radial planet pin hole position errors are considered independently, and the effect of the load level is also taken into account. It is also given attention to the effect on the transmission error of the transmission. Two different configurations for the planetary transmission are used, attending to the fixed or floating condition of the sun, and the differences in terms of load sharing ratio are shown.

关键词： gear planetary epicyclic transmission load sharing transmission error

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Eliminating mother-to-child transmission of HBV: progress and challenges in China

Wenzhan Jing, Jue Liu, Min Liu

《医学前沿（英文）》 2020年第14卷第1期页码 21-29 doi: 10.1007/s11684-020-0744-2

摘要： China has the world’s largest burden of hepatitis B virus (HBV) infection, but the country has made considerable progress in preventing its mother-to-child transmission (MTCT) in the past three decades. This feat is made possible due to the high coverage of birth-dose hepatitis B vaccine (HepB,>95%), hepatitis B surface antigen (HBsAg) screening for pregnant women (>99%), and hepatitis B immunoglobulin plus HepB for newborns whose mothers are HBsAg positive (>99%). Studies on the optimal antiviral treatment regimen for pregnant women with high HBV-DNA load have also been conducted. However, China still faces challenges in eliminating MTCT of HBV. The overall HBsAg prevalence among pregnant women is considered an intermediate endemic. The prevalence of HBsAg among pregnant women from remote, rural, or ethnic minority areas is higher than that of the national level because of limited health resources and public health education for HBV. The coverage for maternal and child healthcare and immunization services should be improved, especially in western regions. Integration of current services to prevent MTCT of HBV with other relevant health services can increase the acceptability, efficiency, and coverage of these services, particularly in remote areas and ethnic minority areas. By doing so, progress toward key milestones and targets to eliminate hepatitis B as the main public health threat by 2030 can be achieved.

关键词： hepatitis B virus mother-to-child transmission progress challenge