格构梁设计计算系统的开发研究     

曾勇辉  刘亚 《岩土工程技术》2010,24(1):12-15,43

格构梁作为一种新型的边坡防护体系,目前在工程实践中已广泛应用。然而工程设计中往往将格构梁拆分为单片梁计算,忽略了格构梁作为整体框架的特点,且设计主要采用手工计算和手工绘图,设计质量和设计速度都难以令人满意。基于以上考虑,利用十字交叉基础设计方法,对纵横梁的荷载分配情况进行讨论,采用Winkler弹性地基梁理论对格构梁的内力进行分析。在此基础上,将格构梁内力计算、配筋计算及施工图绘制集于一体,构建格构梁设计计算系统流程图,利用可视化程序设计语言Visual Basic结合CAD二次开发技术,开发相应的设计计算程序,实现了格构梁设计的智能化和一体化。  相似文献   

关于测量中可靠性理论的哲学思想     

张正禄  张松林 《测绘科学》2012,37(3):54-55

本文从可靠性理论出发,阐述了可靠性与精度以及权的关系,由测量上的可靠性,上升到哲学上的可靠性。指出:可靠性的哲学意义是:在一个社会系统中,一个人的可靠性与他的权成反比,权越大,其可靠性越低,却是不可缺少的;权越小,越可靠,虽然如此,但宜除去不用。  相似文献   

人体健康气象指数的设计及预报技术探讨   总被引：3，自引：2，他引：1  

严明良  缪启龙  沈树勤  刘新华  沈兴建 《气象科学》2008,28(6):678-682

影响人类健康的疾病发生的直接致病因素可能并非气象要素,但这些控制疾病发生的因素却主要受制于气象要素,根据气象要素对疾病的影响规律可以设计出有利人类预防疾病、增进健康的气象指数.本文通过对大量的医疗和气象资料的统计分析,找出了一些疾病和气象要素的实际相关关系,得出疾病对气象要素的敏感度和依从性,并根据这些特性,探讨了人体健康气象指数的普遍性设计方法、分级原理和预报技术.文中还特别以急性上呼吸道感染为例作了详细介绍.  相似文献   

省级气象信息综合数据库系统的设计与实现     

王宏记  王海军  曾又枝  罗建国 《湖北气象》2008,27(3):283-286

为不断发展和完善现阶段我国现代气象业务体系,针对省级气象信息综合数据库建设面临的诸多问题,结合2006年湖北省气象信息与技术保障中心成功开发的湖北省气象信息综合数据库系统（HBMDBS）,描述了省级综合气象数据库的设计目标和技术路线．在阐明HBMDBS总体结构与功能的基础上．从总体数据流程、数据采集、数据存储、数据库管理界面、质量控制、可扩展性等方面,综合介绍了HBMDBS的相关特性。  相似文献   

Treatment of Loose to Medium Dense Sands by Granular Piles: Improved SPT ‘N<Subscript>1</Subscript>’ Values     

A. Murali Krishna  M. R. Madhav 《Geotechnical and Geological Engineering》2009,27(3):455-459

The effect of granular pile installation on the modifications induced in loose to medium dense granular deposits is studied. SPT is the most often used to evaluate the in situ soil properties. Expressions for modified SPT N₁ values for different soils, i.e., for different initial SPT N₁ values, were determined as functions of replacement ratio from the available field data. Improvements in the ground are presented in the form of modified or improved SPT N₁ values versus replacement ratio charts, which can then be used to design the required degree of treatment for the expected improvement or to estimate the improved values of treated ground for different initial states of sands.  相似文献   

The Potsdam plates of the Carte du Ciel project: I. Present inventory and plate catalogue     

K. Tsvetkova  M. Tsvetkov  P. Bhm  M. Steinmetz  W.R. Dick 《Astronomische Nachrichten》2009,330(8):878-884

We present an inventory ofthe Carte du Ciel (CdC) plates stored in the Astrophysical Institute Potsdam. The Potsdam CdC zone (+32° to +39°) was divided into 1232 areas and about 2200 plates from the first and second epochs were obtained within the framework of the CdC project. At present, only 977 plates (45% of all) are stored in AIP, the others got lost during the Second World War. The plates for the first epoch measurements had been obtained during the period 1893 May– 1900 February. The plates for the second epoch (1913 August–1924 February) can be separated into two time intervals according to the observer and the observing method used: from 1913 August till 1914 July, and from 1916 February to 1924 February. The present work aims to provide online access to the plate information, given in the plate catalogue and is the first step to online access to the plate images digitized with flatbed scanners.  相似文献   

Optics and the nature of light illustrated in the rare book collection of the Astronomy Library in Vienna     

I. Müller  F. Kerschbaum 《Astronomische Nachrichten》2009,330(6):540-543

The Astronomy Library in Vienna has a significant collection of rare books, consisting of more than 500 titles dating from the end of the 15th to the 18th century. Since the collection was to be the basis of research and of teaching, the books represent a variety of scientific topics that have been of interest at that time. Thus the rare book collection of the Astronomy Library in Vienna also offers the opportunity for scientific historical research. In the following, certain aspects on the development of the telescope and of optics in general will be illustrated (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

The short history of infrared space telescopes     

D. Lemke 《Astronomische Nachrichten》2009,330(6):562-567

While astronomical telescopes developed rather slowly over the last four centuries, infrared telescopes made a fast career in only four decades from high mountains to aircraft, balloons and satellites. They cover the huge wavelength region from 1 to 350 μ m and have uncovered the cold and dust hidden universe. While until today all infrared space telescopes had diameters of <1 m, cooled infrared observatories with 3.5 to 6.5m mirrors will be sent into heliocentric orbits at L2 within the next few years (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

Venus 1882 and Jean‐Charles Houzeau     

C. Sterken 《Astronomische Nachrichten》2009,330(6):582-585

This paper focuses on one particular type of telescope – the heliometer – designed for solving one specific basic problem in astronomy: the scale factor of the solar system. One very special instrument of this type was the “heliometer with unequal focal lengths” designed by the Belgian astronomer Jean‐Charles Houzeau for the 1882 transit of Venus. We also draw attention to the most interesting personality of Houzeau, and to his social engagement that went much beyond his work as a scientist (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

Gnomon shadow lengths recorded in the Zhoubi Suanjing： the earliest meridian observations in China？     

Yong Li  ;Xiao-Chun Sun 《天体物理学报》2009,(12):1377-1386

The Zhoubi Suanjing, one of the most important ancient Chinese books on mathematical astronomy, was compiled about 100 BC in the Western Han dynasty （BC 206 - AD 23）. We study the gnomon shadow lengths for the 24 solar terms as recorded in the book. Special attention is paid to the so-called law of ‘cun qian li’, which says the shadow length of a gnomon of 8 chi （about 1.96 m） high will increase （or decrease） 1 cun （1/10chi） for every 10001i （roughly 400kin） the gnomon moves northward （or south- ward）. From these data, one can derive the time and location of the observations. The resuits, however, do not fit historical facts. We suggest that compilers of the Zhoubi Suanjing must have modified the original data according to the law of ‘cun qian li’. Through reversing the situation, we recovered the original data, our analysis of which reveals the best possible observation time as 564 BC and the location of observation as 35.78° N latitude. We conclude that this must be the earliest records of solar meridian observations in China. In the meantime, we give the errors of solar altitudes for the 24 solar terms. The average deviation is 5.22°, and the mean absolute deviation is 5.52°, signifying the accuracy of astronomical calculations from that time.  相似文献