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具有一致相对尺寸的流盒定理
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作者 韩波 《数学物理学报(A辑)》 CSCD 北大核心 2018年第4期625-630,共6页
该文讨论了Banach空间中Lipschitz向量场的流盒定理,证明了:若X是一个以L为Lipschitz常数的李氏向量场,则存在与L相关的一个一致常数r_0,使得对X的任意常点x处,存在一个大小为r_0‖X(x)‖的流盒,相应的流盒映射的李氏同胚的Lipschitz常... 该文讨论了Banach空间中Lipschitz向量场的流盒定理,证明了:若X是一个以L为Lipschitz常数的李氏向量场,则存在与L相关的一个一致常数r_0,使得对X的任意常点x处,存在一个大小为r_0‖X(x)‖的流盒,相应的流盒映射的李氏同胚的Lipschitz常数大小也有一致的控制. 展开更多
关键词 Lipschitz向量场 流盒 GRONWALL不等式
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气垫式条盒物流下降收集装置的研发
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作者 禄建伟 《机械工程师》 2013年第4期194-195,共2页
针对滑道式及垂直排包式条盒下降收集方式存在的效率和可靠性问题,研发了气垫式条盒下降收集装置,利用气体在密闭容器中形成的反力来抵消条盒的重力,从而减缓条盒的下降速度,对条盒起到保护作用。
关键词 气垫排包机 专利设计 下降收集
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条盒物流柔性缓存装置的设计
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作者 禄建伟 《机械工程师》 2013年第3期177-178,共2页
在食品自动化生产线中,为了在条盒物流系统出现故障时不影响上游机的运行,需要把条盒暂时储存起来。当物流系统故障排除后,柔性缓存装置将储存的条盒动态补充到运行的条盒输送线中。堆栈式条盒缓存装置结构紧凑,功能可靠,能很好地解决... 在食品自动化生产线中,为了在条盒物流系统出现故障时不影响上游机的运行,需要把条盒暂时储存起来。当物流系统故障排除后,柔性缓存装置将储存的条盒动态补充到运行的条盒输送线中。堆栈式条盒缓存装置结构紧凑,功能可靠,能很好地解决条盒物流系统的短暂故障停机问题,使条盒物流系统具备了柔性输送功能,提高了生产效率。 展开更多
关键词 堆栈式 缓存 动态补条 柔性输送
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池式钠冷快堆堆内自然循环余热排出设计研究
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作者 周志伟 薛秀丽 +3 位作者 林超 余新太 杨勇 杨红义 《原子能科学技术》 EI CAS CSCD 北大核心 2024年第9期1817-1824,I0001,共9页
基于装量功率比约为1 t/MW的较典型池式钠冷大功率快堆的堆内自然循环设计,采用ERAC程序,对两组4种不同事故余热排出系统(DHRS)输入条件下,反应堆在紧急停堆后堆内的自然循环余热排出特性进行分析。结果表明,从DHRS启用到其对堆芯产生... 基于装量功率比约为1 t/MW的较典型池式钠冷大功率快堆的堆内自然循环设计,采用ERAC程序,对两组4种不同事故余热排出系统(DHRS)输入条件下,反应堆在紧急停堆后堆内的自然循环余热排出特性进行分析。结果表明,从DHRS启用到其对堆芯产生显著冷却效应,需要较长时间,在千秒量级。在该段时间内,堆芯余热的排出依靠反应堆固有的热工流体安全特性。随后,在堆内关键温度上升到限值之前启用DHRS带出池内热量,使堆内关键温度处于下降趋势即可满足安全要求;相比将独立热交换器(DHX)布置在冷池,将其布置在热池时,热池温度及主容器壁温相对要低,这有利于主容器的温度控制,其效果要优于布置于冷池。另外,不同布置会对堆芯盒内、盒间流流量产生影响,但总体上对堆芯的冷却效应影响不大;池式钠冷快堆余热排出设计中,要充分利用固有热工流体安全特性,降低对DHRS的时效性要求。可以考虑将全部的DHX都布置在热池,并缩小设备体积、降低散热功率设计值,或在不降低安全性的前提下选用其他更经济便捷的有效方式等,以此大幅降低余热排出设备投入成本,降低反应堆运行成本,提高经济性。本文研究结果可为我国后续的商用快堆、一体化快堆等池式液态金属堆的堆内自然循环设计提供重要参考。 展开更多
关键词 大功率快堆 钠冷快堆 自然循环 余热排出 固有安全 热工体安全特性
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钠冷快堆关键热工水力问题研究现状及展望
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作者 杨红义 薛秀丽 +7 位作者 周志伟 林超 李虹锐 高鑫钊 余新太 马晓 肖宇白 罗锐 《原子能科学技术》 EI CAS CSCD 北大核心 2024年第9期1797-1816,共20页
钠冷快堆因其高热效率、高燃料利用率和固有安全性,以及能够实现闭式燃料循环以减少长寿命放射性废物的独特优势,被认为是第四代核能系统的首选堆型,也是目前国际核能领域的研究热点。本文概述了国际钠冷快堆及热工水力领域的发展历程... 钠冷快堆因其高热效率、高燃料利用率和固有安全性,以及能够实现闭式燃料循环以减少长寿命放射性废物的独特优势,被认为是第四代核能系统的首选堆型,也是目前国际核能领域的研究热点。本文概述了国际钠冷快堆及热工水力领域的发展历程和未来方向,并指出了当前钠冷快堆热工水力领域发展所面临的主要问题。结合我国的发展现状和挑战,本文针对热工水力研究领域的三个关键核心方面进行了深入分析:冷却剂钠的流动换热特性、堆芯热工水力分析方法,以及自然循环余热排出的设计与验证。总结了国际范围内的研究成果,分析了遇到的技术挑战和未来研究的发展趋势,并探讨了我国在这些领域的研究现状及未来的研究方向。这些分析和总结旨在为中国钠冷快堆技术在提高安全性和经济性方面的技术挑战提供指导,同时也为未来钠冷快堆的热工水力设计和优化提供重要的参考依据,以推动我国钠冷快堆技术的进一步发展。 展开更多
关键词 钠冷快堆 热工水力 自然循环 固有安全 非能动安全 固有热工体安全性 模型
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基于子通道思想的液态金属堆盒间流模拟方法研究
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作者 梁禹 王啸宇 +5 位作者 邓坚 刘余 宋功乐 钟睿诚 张大林 朱大欢 《核动力工程》 EI CSCD 北大核心 2023年第S02期61-66,共6页
为探究液态金属堆盒内-盒间冷却剂共轭传热效应,运用子通道思想为盒间特殊结构提供新的模拟手段。基于稳定高效的压力耦合方程组的半隐式方法(SIMPLE算法)求解盒间子通道模型,解决了经典子通道算法在面对低流量、倒流和回流现象上难以... 为探究液态金属堆盒内-盒间冷却剂共轭传热效应,运用子通道思想为盒间特殊结构提供新的模拟手段。基于稳定高效的压力耦合方程组的半隐式方法(SIMPLE算法)求解盒间子通道模型,解决了经典子通道算法在面对低流量、倒流和回流现象上难以收敛的问题。以3组件钠工质实验(CCTL-CFR)为对象,通过组件盒内、盒间冷却剂以及壁面温度的对比,验证了盒间子通道模拟方法的可靠性。针对典型液态金属堆,开展全堆芯热工分析,发现盒间流在展平堆芯径向温度分布、降低温度峰值等方面起重要作用,证明了堆芯热工分析考虑盒间流的必要性。本研究成果为液态金属堆堆芯热工及安全分析提供了可行的分析方法。 展开更多
关键词 液态金属堆 (IWF) 子通道方法 SIMPLE算法
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快堆浸入式事故余热排出系统程序开发
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作者 钱鸿涛 李政昕 +1 位作者 胡文军 宫宇 《中国科技论文》 CAS 北大核心 2015年第23期2711-2715,共5页
针对示范快堆的设计需要,在法国快堆系统程序OASIS的基础上,引入热分层与盒间流模型,开发了浸入式事故余热排出系统分析程序。利用该程序对CEFR的非能动事故余热排出系统进行了整体建模,分析了稳态和全厂断电工况下的性能,并利用其他系... 针对示范快堆的设计需要,在法国快堆系统程序OASIS的基础上,引入热分层与盒间流模型,开发了浸入式事故余热排出系统分析程序。利用该程序对CEFR的非能动事故余热排出系统进行了整体建模,分析了稳态和全厂断电工况下的性能,并利用其他系统程序的结果进行了验证。结果表明:该程序能较好地反映事故余热排出系统的瞬态变化过程。 展开更多
关键词 快堆 非能动 事故余热排出系统 全厂断电
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池式钠冷快堆事故余热排出系统一回路仿真研究 被引量:4
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作者 姜博 张智刚 +2 位作者 于洋 陈广亮 张志俭 《原子能科学技术》 EI CAS CSCD 北大核心 2015年第5期863-870,共8页
池式钠冷快堆事故余热排出系统采用了非能动工作原理,依靠液态钠及空气的自然对流排出堆芯余热。为研究事故工况下余热排出系统一回路的换热能力,基于FORTRAN语言,建立堆芯单通道及盒间流模型,采用全隐二阶迎风差分格式及改进的欧拉法... 池式钠冷快堆事故余热排出系统采用了非能动工作原理,依靠液态钠及空气的自然对流排出堆芯余热。为研究事故工况下余热排出系统一回路的换热能力,基于FORTRAN语言,建立堆芯单通道及盒间流模型,采用全隐二阶迎风差分格式及改进的欧拉法离散求解,对事故余热排出系统一回路系统进行数值模拟,并对全厂断电事故进行仿真计算验证。结果表明:该程序能较好地反映事故余热排出系统瞬态变化过程,并可达到超实时仿真。 展开更多
关键词 余热排出系统 自然循环 模型 数值模拟
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Effective Thermal Conductivity with Convection and Radiation in Packed Bed 被引量:1
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作者 Yusuke Asakuma Tsuyoshi Yamamoto 《Journal of Energy and Power Engineering》 2013年第4期639-646,共8页
Effective thermal conductivity with convection and radiation is analyzed by the homogenization method. This method can precisely represent the microstructure of a packed bed. In this study, the effects of parameters s... Effective thermal conductivity with convection and radiation is analyzed by the homogenization method. This method can precisely represent the microstructure of a packed bed. In this study, the effects of parameters such as the radiation emissivity, temperature, contact area and particle size of the packed bed on the conductivity have been estimated. For example, heat transfer by radiation does not dominate if the material has voids of less than l mm in size. Moreover, the effects of contact area and pressure on effective thermal conductivity are negligible for thermal radiation. By considering the microscopic behavior of a packed bed, the homogenization method is thus a powerful tool for estimating the bed's effective thermal conductivity. 展开更多
关键词 Effective thermal conductivity homogenization method multiscale analysis MICROSTRUCTURE thermal radiation.
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Research and Application of VOD System on Teaching
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作者 沈聿农 张伟敏 李建成 《Journal of China University of Mining and Technology》 2003年第2期214-217,共4页
Structure and working theory of VOD system on teaching is discussed in this paper. The 50M data stream adapter is effective to debase the needs for video server and to enhance the ratio of performance to price.The flo... Structure and working theory of VOD system on teaching is discussed in this paper. The 50M data stream adapter is effective to debase the needs for video server and to enhance the ratio of performance to price.The flow chart for NVOD/TVOD is displayed and a 64-channel VOD system for teaching was construted. 展开更多
关键词 VOD video server set-top box j concurrent data stream
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The Soret and Dufour Effects in Non-thermal Equilibrium Packed Beds with Forced Convection and Endothermic Reactions* 被引量:1
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作者 李明春 赵中亮 +2 位作者 静宇 刘家涛 吴玉胜 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第8期867-875,共9页
To study the influence of the Soret and Dufour effects on the reactive characteristics of a porous packed bed with endothermic reactions and forced convection, a two-dimensional mathematical model considering the cros... To study the influence of the Soret and Dufour effects on the reactive characteristics of a porous packed bed with endothermic reactions and forced convection, a two-dimensional mathematical model considering the cross-diffusion effects was developed in accordance with the thermodynamics of irreversible processes and the local thermal non-equilibrium model. The simulation results were validated by comparing with experimental data. The influence of the Soret and Dufour effects on the heat transfer, mass transfer and endothermic chemical reaction in the non-thermal equilibrium packed bed is discussed. It was found that when the Peclet number reaches 1865, the maximum relative error of the concentration of gas product induced by the Soret effect is 34.7% and that of the solid fractional conversion caused by the Dufour effect is 10.8% at reaction time 160 s and initial temperature 1473 K. The differences induced by the Soret and Dufour effects are demonstrated numerically to increase gradually with the initial temperature of feeding gas and the Peclet number. 展开更多
关键词 heat and mass transfer thermal decomposition cross-diffusion effects porous packed bed
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Demand analysis of an intelligent medication administration system for older adults with chronic diseases based on the Kano model 被引量:6
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作者 Jiayi Mao Liling Xie +4 位作者 Qinghua Zhao Mingzhao Xiao Shuting Tu Wenjing Sun Tingting Zhou 《International Journal of Nursing Sciences》 CSCD 2022年第1期63-70,I0004,共9页
Objectives Gerontechnology has great potential in promoting older adults’well-being.With the accelerated aging process,gerontechnology has a promising market prospect.However,most technological developers and healthc... Objectives Gerontechnology has great potential in promoting older adults’well-being.With the accelerated aging process,gerontechnology has a promising market prospect.However,most technological developers and healthcare professionals attached importance to products’effectiveness,and ignored older adults’demands and user experience,which reduced older adults'adoption intention of gerontechnology use.The inclusion of older adults in the design process of technologies is essential to maximize the effect.This study explored older adults’demands for a self-developed intelligent medication administration system and proposed optimization schemes,thus providing reference to developing geriatric-friendly technologies and products.Methods A cross-sectional survey was conducted to explore older adults’technological demands for the self-developed intelligent medication administration system,and data were analyzed based on the Kano model.A self-made questionnaire was administered from July 2020 to October 2020 after participants used this system for two weeks.The study was registered with the Chinese Clinical Trial Registry(ChiCTR2000040644).Results A total of 354 older adults participated in the survey.Four items,namely larger font size,simpler operation process,scheduled medication reminders and reliable hardware,were classified as must-be attributes;three items,namely searching drug instructions through WeChat,more sensitive system and longer battery life,as attractive attributes;one item,viewing disease-related information through WeChat,as the one-dimensional attribute;and the rest were indifferent attributes,including simple and beautiful displays,blocking advertisements automatically,providing user privacy protection protocol,viewing personal medical information only by logged-in users,recording all the medications,ordering medications through WeChat.The satisfaction values were between 0.24 and 0.69,and dissatisfaction values were between 0.06 and 0.94.Conclusion This study suggested that older adults had personalized technology demands.Including their technological demands and desire may assist in decreasing the digital divide and promoting the satisfaction of e-health and/or m-health.Based on older adults’demands,our study proposed optimization schemes of the intelligent medication administration system,which may help developers design geriatric-friendly intelligent products and nurses to perform older adults-centered and efficient medication management. 展开更多
关键词 Aged COMMUNICATION Data collection Electronic medication device Medication therapy management Mobile applications Needs assessment Personal satisfaction
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Development of Multiple ELISAs for the Detection of Antibodies against Classical Swine Fever Virus in Pig Sera 被引量:2
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作者 Zhen-hua Yang Ling Li Zi-shu Pan 《Virologica Sinica》 CAS CSCD 2012年第1期48-56,共9页
The major immunogenic proteins (Ems, E2 and NS3) of classical swine fever virus (CSFV) (Shimen strain) were expressed in E. coli and purified by affinity chromatography. The recombinant antigens were applied to ... The major immunogenic proteins (Ems, E2 and NS3) of classical swine fever virus (CSFV) (Shimen strain) were expressed in E. coli and purified by affinity chromatography. The recombinant antigens were applied to develop multiple enzyme-linked immunosorbent assays (ELISAs) for the detection of specific antibodies in pig sera. Optimum cut-off values were determined by receiver operating characteristic (ROC) analysis after testing 201 sera of vaccinated pigs and 64 negative sera of unvaccinated piglets. The multiple ELISAs were validated with 265 pig sera yielding high sensitivity and specificity in comparison with the virus neutralization results. The results demonstrated that multiple ELISAs can be a valuable tool for the detection of CSFV infection and serological surveys in CSFV-free countries or for the evaluation of the antibody responses in pigs induced by a live attenuated C-strain vaccination 展开更多
关键词 Classical swine fever virus Recombinant antigens ELISA
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本期新闻
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《卫星电视与宽带多媒体》 2014年第9期10-13,共4页
11日中国趋势控股有限公司宣布,与碟视亚洲卫星有限公司签署正式合作协议。碟视亚洲旗下高清电视DishHD将率先代表电视营运商,加入中国趋势于四月九日宣布的"天网"计划,通过使用中国趋势打造的免费卫星移动互联网,在向亚太地... 11日中国趋势控股有限公司宣布,与碟视亚洲卫星有限公司签署正式合作协议。碟视亚洲旗下高清电视DishHD将率先代表电视营运商,加入中国趋势于四月九日宣布的"天网"计划,通过使用中国趋势打造的免费卫星移动互联网,在向亚太地区所有客户提供免费卫星上网的同时,提供免费卫星电视及收费卫星电视服务。 展开更多
关键词 数字电视用户 互联网电视 广电网络 增值电信业务 康卡 无线发射台 超高清电视 歌华有线 电信增值业务 频道 鸣鹤 迪信通 传媒产业 自由贸易试验区 湖南卫视 媒体机顶 九城 广播电视台 OTT 社保 新闻
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观片指南
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《大众电影》 2003年第9期14-15,共2页
出品年:2000/出品公司:哥伦比亚影片公司/类型:科幻、动作片/导演:罗杰·斯波蒂斯伍德/主要演员:阿诺德·施瓦辛格、托尼·高德温、罗伯特·杜瓦尔、迈克尔·拉帕波特 “第六日”发生在不远的将来,牛、鱼甚至宠物... 出品年:2000/出品公司:哥伦比亚影片公司/类型:科幻、动作片/导演:罗杰·斯波蒂斯伍德/主要演员:阿诺德·施瓦辛格、托尼·高德温、罗伯特·杜瓦尔、迈克尔·拉帕波特 “第六日”发生在不远的将来,牛、鱼甚至宠物都可以任意克隆,但克隆人类是非法的。 展开更多
关键词 动作片 出量 艾迪 电影 瓦利 亚当 影片 流盒 哥伦比亚 翻青
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问答四则
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《水族世界》 2008年第6期103-103,共1页
问题一:开缸一星期发现滤槽里有虫.是一种很常见的虫,但不知是什么名,新开的缸是80上滤,新缸新滤材,全新,表面见到都有10~20条,40缸新造外加背滤,新环,不同期买.也发现几条,答:你的是草缸吧,幼虫估计是草根上带进去的,可以挑出来喂鱼,... 问题一:开缸一星期发现滤槽里有虫.是一种很常见的虫,但不知是什么名,新开的缸是80上滤,新缸新滤材,全新,表面见到都有10~20条,40缸新造外加背滤,新环,不同期买.也发现几条,答:你的是草缸吧,幼虫估计是草根上带进去的,可以挑出来喂鱼,鱼非常喜欢吃。 展开更多
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Effect of opening the Drake Passage on the oceanic general circulation:A box model study 被引量:2
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作者 SHAO QiuLi CHEN XianYao HUANG RuiXin 《Science China Earth Sciences》 SCIE EI CAS 2013年第9期1588-1598,共11页
The impacts of opening the Drake Passage(DP) on the oceanic general circulation are examined.When the DP is open,wind stress at mid-and high latitudes gives rise to a wind-driven gyre,which induces a meridional heat e... The impacts of opening the Drake Passage(DP) on the oceanic general circulation are examined.When the DP is open,wind stress at mid-and high latitudes gives rise to a wind-driven gyre,which induces a meridional heat exchange between mid-and high latitudes in the Southern Ocean.After the opening of the DP,the Antarctic Circumpolar Current(ACC) forms and its associated strong temperature front blocks the heat transport from mid-latitudes to high latitudes.A simple box model is formulated,in which the effects of the wind stress(for the case of DP closed) and the thermal front(for the case of DP open) on the variability of Antarctic Bottom Water(AABW) and North Atlantic Deep Water(NADW) are explored.The sensitivity experiments demonstrate that:(1) When the DP is closed,the enhancement of the wind-driven gyre leads to the decline of AABW formation in the Southern Ocean and the increase of NADW formation in the North Atlantic.As a result,water in high latitudes of the Southern Ocean becomes warmer,so does the bottom water of global ocean.(2) When the DP is open,there is no formation of AABW until the intensity of thermal front along ACC exceeds a threshold value(it is 4.03℃ in our model).Before the formation of AABW,temperature in most of the oceans is higher than that after the formation of AABW,which usually leads to the cooling of high latitudes of the Southern Hemisphere and the bottom water in global ocean.When the strength of the thermal front is lower than the critical value,there is no AABW formation,and temperature in most of the oceans is slightly higher.These results demonstrate that during the opening of the DP,changes in wind stress and the formation of the thermal front in the Southern Ocean can substantially affect the formation of AABW and NADW,thus changing the state of meridional overturning circulation in the global ocean. 展开更多
关键词 Effect of opening the Drake Passage on the oceanic general circulation:A box model study
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