福建省能源发展科技月谈会建议 重视洁净新能源和可再生能源开发利用

6月21日,省科协举行福建能源发展科技月谈会.省委粱绮萍副书记、省政府黄小晶常务副省长出席会议并讲了话.省能源研究会的专家、省直有关单位和部门的负责人以及新闻记者参加了会议.月谈会由省科协党组书记、副主席刘群英主持.     

氨蒸发式冷凝器性能测试与计算

蒸发式冷凝器是氨制冷系统中常用的一种冷凝器。本文建立了实际产品的测试台,可全真模拟氨制冷系统的运行情况;针对某一喷淋水经由填料冷却的蒸发式冷凝器的实际产品,通过测试和对采集到的数据进行分析计算,测出其排热量;再根据实测工况和结果,综合文献中的设计方法进行计算,与实测值比较,得出一种较能反应被测蒸发式冷凝器产品性能的计算方法,为产品的开发提供了较为可靠的理论依据。     

能源和石油

一、世界和中国能源现状及中国面对的挑战 人类使用的能源有一个历史演变过程。19世纪上半叶以柴薪作为燃料，于20世纪中叶石油超过煤炭。目前，世界上的一次能源主要由石油、天然气、煤炭三种化石燃料所组成。据BP统计，2007年一次能源总量为11099．3百万吨油当量，化石燃料占世界一次能源的88％，     

氨冷发酵罐的特点及其控制

本文通过对氨冷却式发酵罐供液回液管路的分析论述了酒液温度的控制过程。     

从耕地和劳动力资源看中国农业技术构成和发展

一、引言 我国的农业生产经历了为实现农业机械化而全民动员的历史时期(农业部科技教育司,1999).由于与农业生产资源的禀赋程度和农村经济发展水平不相适应,这样的努力最后导致了农业生产的高产和高投入,农民不仅未能在实现机械化的过程中受益,反而由于高投入所导致的高成本,使农业和农村经济的发展受到影响.改革开放二十多年来,随着农村联产承包责任制的实行,全国性的实现农业机械化的"农业机械化论"已被否定.     

战略网络理论溯源与研究综述

简单探讨战略网络的理论渊源,重点从战略网络的形成与进化、组织间的相互联系、价值创造及功能等几个方面,总结目前国内外战略网络理论研究的现状,并进一步指出其不足以及对有关研究方向的建议。     

CORS定位误差来源与精度分析

主要介绍了网络RTK的差分信息生产方式VRS的工作原理、优势、劣势及其误差来源和应对措施,结合SDCORS在工程中的应用,对其测量精度进行分析,提出了精度检测方法,并展望其应用前景。     

Light distribution from rectangular sources

The rectangular light source is more frequently encountered in engineering practice than any other form. Thus, both for artificial lighting and natural lighting, it is desirable to have convenient methods of obtaining the light distributions produced by rectangular sources. We have attempted to supply this need by calculating pharosage from sources of uniform helios and also for the non-uniform sources representing average overcast skies. Figures 5 to io are found to be particularly convenient in the visualization of light distributions.The results of these graphs are readily extended to any point and to surfaces tilted at any angle, provided that the plane of the illuminated surface does not cut the source.In conclusion, we wish to express our appreciation of the careful work of the computers: Messrs. L. S. Castlemann M. S. Cettei, J. C. Gibbs, A. L. Keller, G. J. Laurent, V. Lippitt, J. M. Margolskee, L. Mautner, J. Topalian.     

Radiation fields from polygonal sources

The calculation of the radiation field D(x, y, z) produced by a uniform polygonal source is of considerable practical importance. Fock showed that there are advantages in replacing the traditional surface integral by a contour integral, using Stokes' theorem. This innovation, however, has not yet penetrated very deeply. It seemed worthwhile, therefore, to systematize the procedure and to show how easily results can be obtained by the Fock method. An incidental conclusion of the paper is that the radiation field from a polygonal source often differs by less than one per cent from the field produced by a circular disk of the same area. Thus the simple disk formula can often be substituted for the more complicated polygonal formula.