On the Cultural Difference in the Teaching

This paper makes an analysis on the Cultural difference in the teaching. Cultural difference can be reflected in many aspects in the teaching, so the foreign language teachers should fill their course with cultural factors.     

FTIR<Emphasis Type="Italic">in situ</Emphasis> study of supersaturated solutions of MgSO<Subscript>4</Subscript> and NaClO<Subscript>4</Subscript> aerosols

The continuous sampling FTIR/AFT (aerosol flow tube) has been constructed in the present work, leading to the in situ observation of the supersaturated solutions of MgSO4 and NaCIO4 aerosols. The observation suggests that the MgSO4 aerosol show serious mass transfer limitation at low RH (relative humidity), while the NaCIO4 aerosol deliquesce without notable effect of kinetic factors. It is also shown that the v3 band of SO4^2- is very sensitive to the formation of contact ion pairs in the supersaturated solutions of MgSO4 aerosol.     

The terrestrial NPP simulations in China since Last Glacial Maximum

Based on Atmosphere-Vegetation Interaction Model （AVIM）, the magnitude and spatial distribution of terrestrial net primary productivity （NPP） in China is simulated during three different geological eras, Last Glacial Maximum （LGM）, Mid-Holocene （MH） and the present. The simulation shows that the glacial-interglacial variation of East Asian summer monsoon in China is the key factor affectfng the NPP change. During the three eras, mean NPPs are 208 g/m^2·a, 409 g/m^2·a, and 355 g/m^2·a. The total NPPs are 2.05 Pg/a, 3.89 Pg/a and 3.33 Pg/a, respectively. The terrestrial NPP in China during warm-humid climate is larger than that during cold-arid eras, and the correlation analysis between NPP and climate factors suggests that temperature is the primary factor affecting the terrestrial NPP during 21 kaBP （LGM）, and for 6 kaBP （MH） and the present the primary factor is precipitation.     

Fuzzy Set-Based Risk Evaluation Model for Real Estate Projects

With the rapid development of residential real estate market, risk evaluation has been an important task in the process of project. This paper describes a risk evaluation method for residential real estate projects based on fuzzy set theory which uses linguistic variables and respective fuzzy numbers to evaluate the factors. The primary weights of factors and evaluation of alternatives are determined by applying linguistic variables and fuzzy numbers. The notion of Shapley value is used to determine the global value of each factor in accomplishing the overall objective of the risk evaluation process, so the primary weights are revised, thus the importance of factors can be reflected more precisely. A major advantage of the method is that it allows experts and engineers to express their opinions on project risk evaluation in linguistic variables rather than crisp values. An illustration is presented to demonstrate the application of the method in risk evaluation. The results are consistent with the results calculated by conventional risk evaluation method. The research demonstrates that the method is objective and accurate, and is of an application value in the risk evaluation for residential real estate project.     

Mechanism and development of dip-pen nanolithography （DPN）

Dip-pen nanolithography is a new scanning probe lithography （SPL） technique based on atomic force microscopy （AFM） , and now has made a great progress. The process of dip-pen lithography involves the adsorption of ink molecules on AFM tip, the formation of water meniscus, the transport of ink molecules, and diffusion of ink molecules on the substrate. More factors such as temperature, humidity, tip, scanning speed and so on will influence the process of dip-pen lithography. The paper analyzes in detail the mechanism of this technique, introduces synthetically the latest development, including electrochemical DPN, more-mode DPN, multiple DPN, multi-probe array DPN and so on. Finally, the paper describes the characteristics and the application of DPN.     

Development and Application of Maintenance Template in Pressurized Water Reactor Nuclear Power Plant

Good practices of maintenance optimization in nuclear power field need to be effectively consolidated and inherited,and maintenance optimization can provide technology support to create a long-term reliable and economic operation for nuclear power plants( NPPs) especially for a large number of nuclear powers under construction. Based on the development and application of maintenance template in developed countries,and combining with reliability-centered maintenance( RCM) analysis results and maintenance experience data over the past ten years in domestic NPPs, the development process of maintenance template was presented for Chinese pressurized water reactor( PWR) NPP,and the application of maintenance template to maintenance program development and maintenance optimization combined with cases were demonstrated. A shortcut was provided for improving the efficiency of maintenance optimization in domestic PWR NPP,and help to realize a safe,reliable,and economic operation for domestic NPPs.     

Analysis of the Impact of Asian Financial Crisis on Shanghai''''s Utilization of Foregin Direct Investment

The Asian financial crisis has increasingly shown its in-fluence on the utilization of foreign direct investment inShanghai. To further explain this, the main factors thatplay important roles in the decision of foreign direct in-vestment in Shanghai are analyzed. The extent of influ-ence is measured according to the changes of those decis-ive factors. A simple linear regression model is intro-duced to help the analysis.     

Process-based modeling analyses of Sabina przewalskii growth response to climate factors around the northeastern Qaidam Basin

Sabina przewalskii is the longest living endemic tree species in the northeastern Tibetan Plateau,and has been widely employed in tree ring based climate research in China.However,most dendroclimatic reconstructions have been primarily based on empirical relationships between tree growth and climate factors identified by statistical assessment.To date,the physiological relationships between tree growth and their limiting climate factors have not been properly assessed.Here,we simulated the physiological response of Sabina przewalskii tree growth to major limiting climate factors based on the Vaganov-Shashkin (VS) model.The VS modeled results validated the relationships between tree ring and climate factors constructed by statistical models,both approaches suggesting that precipitation during the early growing season,especially in May and June,has significant effect on tree growth,while temperature mainly affects tree growth by warming-induced drought and by extending the growing season.Under current and projected climate scenarios,our modeling results predict an increase in radial growth of Sabina przewalskii around the Qaidam Basin,with the potential outcome that regional forests will increase their capacity to sequester carbon.     

Nuclear Power Plant Life Extension - How Aging Affects Performance of Containments Other Structures

This paper focuses on how aging can affect performance of safety-related structures in nuclear power plants (NPPs). Knowledge and assessment of impacts of aging on structures is essential to Plant Life Extension analysis, especially performance to severe loadings such as loss-of-coolant-accidents or major seismic events. Plant life extension issues are of keen interest in countries (like the United States) which have a large, aging fleet of NPPs. Seismic issues are of heightened interest to the worldwide nuclear community in the wake of the 2011 Tohoku Earthquake and Tsunami. This paper addresses the overlap and relationship of structure aging to severe loading performance, with particular emphasis on containment structures.     

基于浮动式核电站的严重事故源项分析评估技术体系研究

目前针对陆地核电站严重事故开展的源项分析不完全适用于浮动式核电站。以浮动核电站严重事故为研究领域,基于对国内外核电站、研究堆、船用堆源项分析方法和后果评价方法的相关研究,根据浮动核电站的特点,确定了严重事故源项分析计算软件和计算方法,构建出源项分析技术路线图,从而建立了基于浮动核电站严重事故的“MELCOR耦合FLUENT-MACCS”源项评估技术体系。为浮动式核电站的安全运行、安全审评及环境评价提供放射性源项方面的数据支持,为核应急决策提供进一步的理论基础。     

反应堆保护系统紧急停堆响应时间测试分析

反应堆保护系统的响应时间是核电厂安全级数字化仪表控制系统的关键性能指标。为确保核电厂的安全,提高反应堆保护系统响应时间测量准确性和快速性,通过对反应堆保护系统各大数据处理环节的特点,构建了反应堆保护系统紧急停堆响应时间测试平台,采用自动测试装置对响应时间测试方法进行分析总结,并提出了优化反应堆保护系统紧急停堆响应时间的方法。     

基于故障树分析法的核电厂氢气系统爆炸危害性分析

本文针对在核电厂内广泛使用的氢气系统可能引发爆炸事故的实际情况,利用故障树分析法,对可能导致氢气爆炸的各种因素及逻辑关系进行了全面、简洁和形象的描述,查明了系统内固有的或潜在的各种危险、有害因素,并分析总结了导致氢气爆炸的主要根本原因,提出了针对这些基本原因改善系统安全性的建议,为核电厂氢气系统的安全相关设计、施工和管理提供了理论支持.     

北京化工大学CAE中心数值仿真工程应用研究

介绍了北京化工大学计算机辅助机械工程研究中心应用计算机辅助机械工程（CAE）技术对一些重要工程设备或装置进行数值模拟和安全评定的案例,包括大型真空容器、聚丙烯环管反应器、超大型连续式跨声速风洞洞体、大型直立设备组合结构、核电一级冷凝器以及大型火电机组回热系统高压加热器。     

高温气冷堆示范电站堆芯放射性总量计算方法

 高温气冷堆作为21世纪新一代先进核电站堆型，以安全性好、发电效率高、系统简化的优点越来越受到重视。中国第一个高温气冷堆示范电站（HTR-PM）在山东荣成石岛湾开始兴建，为准确分析核电站放射性对环境的影响，本文以KORIGEN程序为工具对高温气冷堆堆芯放射性总量计算方法进行了研究。首先为了使该程序能适应堆芯中子能谱变化的情况，对其进行了优化编译，并对数据库中的半衰期数据进行了更新和修正。在根据堆芯实际情况构造的流道模型条件下，得到了贴近堆芯真实情况的放射性总量，为高温气冷堆示范电站的安全审评、后续的安全管理和堆芯放射性核素物料衡算提供了基础和保证。     

Sensitivity Analysis of Relap5 Simulation on AP1000 Nuclear Power Plant

During the simulation of AP1000 nuclear power plant,the values of input parameters, core nodalization methods and calculation models, may have important influence on the code outputs. Therefore, it is necessary to identify and evaluate the influence of these parameters and modeling approaches quantitatively. Based on the best estimate thermal-hydraulic system code RELAP5,sensitivity analyses have been performed on core partition methods,parameters and models in AP1000 nuclear power plant,such as the core channel number,pressurizer node number,and feedwater temperature. The results show that code channel number,code channel node number, and the pressurizer node number have apparent influences on the coolant temperature variation and pressure drop in the reactor. The feedwater temperature is a sensitive factor to the steam generator( SG) outlet temperature and the SG outlet pressure. In addition,the influence of the cross-flow model on coolant temperature variation and pressure drop through the reactor is insignificant,both in steady state and loss of power transient. Furthermore, some suitable parameters and modes also have been put forward for the nuclear system simulation.     

AP1000核电站蒸汽发生器主给水管道双端断裂事故下第一跨空间三维流动特性数值模拟

AP1000核电厂第一跨空间内布置了设备冷却水系统(component cooling water system,CCS)驱动泵,能够保证核电厂事故工况下设备冷却水系统、余热排出系统等关键安全系统的正常运行,从而保证核电厂安全.然而在蒸汽发生器主给水管道双端断裂事故下,大量的水会泄放到第一跨空间内,对第一跨空间内的关键设备造成严重威胁.因此,对AP1000核电站蒸汽发生器主给水管道双端断裂事故下第一跨空间内泄放流体三维流动特性进行数值模拟.采用ANSYS系列软件,建立第一跨空间三维模型,基于流体体积模型(volume of fluid model,VOF)计算冷却剂喷放事故下,第一跨空间内流动特性及水位变化规律.计算结果表明,破口水从入口进入第一跨空间后在5.334 m层漫流,绝大部分泄放水通过该层设置的预留开孔流出,部分水在该层堆积.但是,由于设置挡水沿,泄洪水并未漫流到0 m层与-3.8 m层,随着冷却剂喷放引发给水泵跳泵,第一跨空间内水位将逐渐下降,不会造成重要设备防水台的漫流淹没.计算结果对核电厂主要泄洪途径、关键设备布置设计与优化提供了数值参考.     

中国核电装备的国产化

 参考中国3大核电设备制造基地——东方电气集团公司、上海电气集团公司和哈尔滨电气集团公司,依据在建核电项目中核电装备的研发、制造等公开资料对目前核电装备的国产化进行了概要性描述。核电站的大型关键主设备包括核电站核岛的安全壳、反应堆、稳压器、蒸汽发生器、主循环泵,常规岛的汽轮机、冷凝器、除氧器、给水泵、汽水分离再热器等设备。对核电装备国产化整体现状的研究有助于对中国核电设备制造能力的认识,也指出了中国核电装备制造需要努力的方向。     

小型核电站堆芯方案

 具有长寿命、非能动安全的小型核电站是核电发展的一个重要方向。本研究设计了一个小型核电站堆芯方案。该方案为池式钠冷快堆,采用移动反射层和堆内固定吸收体实现较长的堆芯寿期。进一步计算表明,该堆芯方案的寿期可达30年,功率分布合理,各种反应性系数为负值,控制方式的价值足够,满足设计要求。     

LBB在AP1000技术中的应用

压水堆核电厂的设计基准事故定义为主管道双端断裂,这一假设过于保守.管道的失效方式往往是先出现破口而后再泄漏,即所谓的先漏后破(Leak Before Break,简称LBB),而不是双端断裂.LBB准则是防止核电厂压力管道发生灾难性破裂事故的重要评定准则.本文介绍了LBB评定技术在国外的发展情况和意义,阐述了LBB在AP1000核电厂中的应用情况及LBB评价的理论基础.