PROBABILISTIC EVALUATION FOR STEEL FRAME COLUMNS OF TALL BUILDINGS

Based on properties of parameters and test data of dom-estic steel,this paper analyses the reliability and partial coefficient forresistance of steel frame columns of tall builings.The result may serveas a scientific basis.It is not only for domestic steel instead of importedsteel in building tall steel structures,but also for compiling concerendstandards.     

Study on DAQ System by Using LabVIEW

Dong village is very valuable for research work because of its special regional and national character and rich cultural implication. In this paper, some information about the location, form and features of Dong village is given. Then, the relationship between the culture and the settlement is analyzed, which provides a clue for understanding Dong village and will be beneficial to creating modern human settlements.     

Compensation of Dead Time Effects Based on the New Switching Strategy

The dead-time inserted into the switching signals of inverters case the dead-time effect of output voltage distortion. The influence of dead-time on output voltage in inverters is analyzed in detail, Then, a new switching strategy, which can provide excellent inverter output voltage distortion correction, is proposed. At last, the experiment results of inverter are presented to demonstrate the practicability and validity of the control strategy.     

COUPLING ANALYSIS METHOD FOR INTERACTION BETWEEN FOUNDATION WITH CAVERN AND FRAME STRUCTURE

In this paper,the interaction between foundation withcavern and frame structure is studied by the coupling methods of BEMand FEM.On the interface between the foundation and structure,thecoupling analysis needs to satisfy both the condition of displacementcompatibility and force equilibrum.A calculating program for two-dim-ensional problem is worked out in the computer,SIEMENS 7570C.Twoengineering examples are calculated and the results are compared withthose obtained by the comventional simplified method and with the observedresults from the engieering structures.It indicates that it is necessaryfor the weak rock foundation with shallow cavern,in the buried depth,to take the interaction into account.     

半粒稻米直链淀粉测定方法的研究及应用

本文提出一个简便易行的分析方法,用1粒稻米既可测出其中的直链淀粉含量,还可用以繁种,便于在育种早代选择优良个体、提高效率,加快进程。用本方法测得的直链淀粉含量与用中华人民共和国国标法GB_(7648-87),测得的结果经t检验,差异不显著。利用本法分析了F_1代种子及其亲本的直链淀粉含量,结果表明,在非糯品种与糯稻品种的两     

黄土高原北部垄膜沟植田间集雨高效栽培技术研究

在黄土高原北部,采用起垄覆膜(垄上覆膜种植马铃薯,垄沟种植谷子)的垄沟间作田间集雨补灌栽培并结合增施氮、磷、钾化肥,具有显著的增产、增收效果。该技术可大大提高化肥的增产效果和肥料利用率,有明显的集雨增墒效果,同时采用起垄覆膜种植马铃薯与垄沟种植谷子能够合理利用有限的工程集雨,有利于充分利用有限的降水资源,进行节约化农业经营。     

鄂尔多斯高原北部沙区主要植被类型下土壤要素的空间分析

鄂尔多斯北部沙区存在着极为显著的风沙地貌,在此格局基础之上,特别是在植被与土壤的相互响应过程中,二者的相互关系逐渐密切,这种反馈作用使得该区域的植被与土壤要素形成的空间分布格局具有一定的耦合性。研究这种关系可以为该地区保护植被和合理利用土地资源提供科学依据。     

棉花对红铃虫抗性及有关性状的遗传分析

1990～1991年选用对红铃虫抗性有显著差异的8个棉花稳定基因型,按第二种双列杂交方案分析棉花对红铃虫的抗性遗传行为,测试48个性状,结果表明:(1)侵入率和子害率的h_B中等,GCV较大;铃壳厚度、衣指和衣分的h_B较高,GCV也较大;铃壳致密度、单铃重和子指h_B较高而GCV较小;铃壳含水量等11个性状h_B中偏低,GCV也较小。(2)子指和绒长的GCA和SCA差异均显著,子仁丹宁含量的SCA差异显著而GCA不显著,子害率、铃壳含水量、子仁淀粉、单铃重、衣指、衣分、纤维比强度、伸长率和麦克隆值均为GCA差异显著而SCA不显著。(3)以83—82、7211、7209、1118和华棉101为亲本可提高后代的抗性。(4)铃壳的4个厚度性状、致密度、含水量、丹宁含量和子仁的类黄酮、总酚共9个理化性状与抗性至关,而遗传特点较好或中等,子害率与主要经济性状间的遗传相关系数多为较高正值。本文还就有关问题进行了讨论。