两道循环效率题的启示

由两道循环效率题的解答，总结计算循环效率时应注意的两个问题。     

外墙保温对夏热冬冷地区住宅空调负荷的影响

采用DeST软件,对夏热冬冷地区外墙保温的住宅进行了全年的能耗模拟,分析了不同外墙保温形式对住宅负荷的影响·     

电子商务对现代营销理论基本缺陷的矫正

现代市场营销理论是指导企业进行营销活动的科学理论 ,它在营销实践中不断得到补充和完善 ,历经百余年而不衰 .它对于指导企业营销具有不可替代的作用 .但是 ,现代市场营销理论具有其先天性的理论缺陷 .电子商务的产生和完善对现代营销理论的基本缺陷进行了矫正 ,解决了传统的营销方式难以解决的企业与市场对接的难题 ,极大地丰富和发展了现代市场营销理论 .电子商务对现代市场营销理论的矫正 ,主要表现在对以下几对矛盾的解决上 :营销的主动性与消费的被动性之间的矛盾、生产方式与生活方式之间的矛盾、双赢理念与现实困惑之间的矛盾、“产品效用”与“消费利益”之间的矛盾、营销活动的无限性与地理环境的约束性之间的矛盾、竞争的公平与不公平之间的矛盾等     

对《黄遵宪集》的补遗与正误

2003年10月,天津人民出版社出版的由南开大学吴振清、徐勇等先生编校整理的《黄遵宪集》,是目前收录黄遵宪诗文最全面的集子,编者尽了最大努力广搜博采,采择的范围遍及海内外,但还是不免遗珠之憾。对个别散佚的黄遵宪作品,编者未能参校更好的版本出处,也未能最大限度地利用已有成果,因此而造成参校有所疏误。通过对《黄遵宪集》的补遗与正误,以方便同道更全面了解至目前为止黄遵宪诗文的存佚情况。     

Numerical Simulation of Heat Transfer Characteristics of Horizontal Ground Heat Exchanger in Frozen Soil Layer

At present ,during the design of ground source heatpump (GSHP) systems ,technical attention is always fo-cused on vertical borehole heat exchangers and surroundingsoil[1 ,2],butthe effects of their shallowhorizontal connect-ing pipes ,or horizontal ground…     

Modeling water and carbon fluxes above summer maize field in North China Plain with back-propagation neural networks

INTRODUCTION Dynamics of carbon and water vapor fluxesexchange between the atmosphere and the ecosystembiosphere, depend on complex and non-liner interplayamong physiological, ecological, biochemical andedaphic factors and meteorological conditions (Jarvis,1995; Leuning et al., 1995). There are many studiesquantifying the fluxes across different time and spacescales as well as assessing the environment con-straints on them by some kinds of biophysical orempirical models whose resul…     

大体积混凝土污水处理工程的施工技术

为防止大体积砼产生裂缝，采用HE微膨胀剂与LNF泵送剂行之有效。同时应进行温度应力与浇筑长度验算和精心施工。     

温度概念的热力学

热量是由温度来定义的,因而用热冷程度来定义温度就是不科学的.本文以热力学第一定律和第二定律为基础,用可逆热机的运转来建立温度概念.温度是体系的单一决定可逆热机效率的宏观可测性质.此一宏观可测性质的特征由可逆热机运转的三种情形可以明确地揭示出来.     

Measurement of conversion efficiency of soft X-ray from 0.35μm laser-irradiated aluminum planar targets

Conversion efficiency of soft X-ray from 0.35 μm pulse laser-irradiated aluminium planar target at laser intensities 10¹³–10¹⁵ W/cm² on the Xingguang-II facility (laser energy 5–90 J, focal spot ⊃ Ф 200 μm full width of half maximun (FWHM) 400–800 ps) was measured. A simple model was given to explain soft X-ray conversion efficiency. In this model, because of the heat conduction from the laser-heated spot, the conversion was very small at lower irradiance limit, while at higher limit it was bounded by the energy lost in blow off plasma. Consequently, at the laser intensity around 2×10¹⁴ W/cm², the X-ray conversion efficiency reaches a maximum. Project suppoted by Shanghai Leading Academic Discipline Foundation (Grant No. T0104), and Science Foundation of Shanghai Municipal Commission of Education (Grant No. 214680)     

滑步推铅球技术的能力培养和训练

滑步推铅球的技术动作比较复杂，本主要就加强滑步推铅球专项技术能力的培养和训练进行阐述，介绍了一些常见错误的纠正方法，以改善滑步推铅球的教学。