CALCULATING SYSTEM FOR SECOND-ORDER EFFECT IN THE COLUMNS OF REINFORCED CONCRETE FRAMES

This paper makes an analysis and comparison of the calculatingsystem for second-order effect in columns of reinforced concrete frames proposedby scholars at home and abroad,and the systems adopted by codes of manycountries.The focus is on explaining the conceptual error and deficiency in somemethods.After expounding the basic law of the second-order effect in framecolumns with different restraints,this paper suggests an improvement of thecalculating system for second-order effect in frame columns for China's DesignCode of Concrete Structures.     

EFFECT OF SEMI-RIGID CONNECTIONS ON BEHAVIOR OF STEEL FRAME

Modeling of girder in steel frame with semi-rigid conn-ections as partially restrained beam element is proposed for elastic-plasticanalysis of steel frames with semi-rigid connections.The results whichare obtained from analyses of elasticity,plasticity and stability for steelframes with semi-rigid connections have significant effects on structuralbehavior.It is necessary to consider the influences of semi-rigid conn-ections on the analysis and design for steel frames.     

测定过氧化苯甲酰所需色谱柱的制备及老化方法研究

制备测定过氧化苯甲酰所需的色谱柱，用国产102担体（60－80目），代替国家标准中规定的进口担体Chromosorb W/AW DMCS(60-80目），可以节省费用。柱填充料经过预老化处理后，可以减少柱填料损失，缩短老化时间。     

小麦中杂色曲霉毒素的硅镁吸附柱层析分离纯化及HPLC的定量分析

目的:建立小麦中杂色曲霉毒素含量的高效液相色谱检测方法。方法:样品中的杂色曲霉毒素经正己烷提取后,采用国产硅镁型吸附剂制备层析柱净化后,运用高效液相色谱法测定,色谱柱为Nova-Pak C18柱,以甲醇-水(70∶30,V/V)为流动相,流速0.7mL/min,检测波长为246nm进行检测。结果:该方法平均加标回收率为79.26%,相对标准偏差为3.84%,最低检出量为0.017μg/kg。结论:本方法简便、准确、成本低,可用于小麦中杂色曲霉毒素含量的测定。     

免疫亲合柱在小麦真菌毒素检测中的应用及毒素污染分析

利用真菌毒素特异性抗体制备的免疫亲合柱净化样品，检测了31个小麦样品中5种真菌毒素的污染情况。结果显示，31个样品污染毒素比较普遍，但污染水平低，小麦样品处于安全状态。具体情况是：AFB1，阳性率为74．19％，平均值为1．13μg／kg，中值为0．3μg／kg，最大值为11μg／kg；OTA，阳性率为100％，平均值为1．59μg／kg，中值为1μg／kg，最大值为3μg／kg；ZON，阳性率为100％，平均值为83μg／kg，中值为71μg／kg，最大值为330μg／kg；T-2，阳性率为22．58％，平均值为49μg／kg，中值为0，最大值为500μg／kg；DON，阳性率为6．45％，平均值为200μg／kg，中值为0，最大值为3800μg／kg。     

THE OVERALL LOAD-BEARING CAPACITY AND EFFECTIVE LENGTHS OF STEPPED COLUMNS OF PINNED R.C.PORTAL FRAMES WITH FIXED BASES

In this paper,a computer program for nonlinear analysis ofa special frame is developed.The frame has all columns fixed at the base and hinged at the top.By taking the frame as a whole,the behavior ofthe frame is studied from the test results of three specimens of the frame andlarge amount of results of computer program.The minimun value of total sumof vertical loads sustained by the frame is found and a new method of deter-mining the effective length of stepped columns is suggested.     

THE STUDY OF ANTI-SEISMIC BEHAVIOR OF THE TOP CORNER JOINTS OF REINFORCED CONCRETE FRAME WITH THE INCLUSION OF STEEL FIBRES

This paper first discusses the limited effect of steel fibre reinforcement on plain concrete and reinforced concrete. Then, making a comparison among the test results of three full-scale top corner joint assemblies of frame, in which only two of them are added with steel fibres in joint zone. The advantageous and disadvantageous influence in anti-seismic aspect is investigated after adding steel fibres in the joint zone. Finally, this paper gives an overall comment on the application future of using the steel fibres in every kinds of joint of anti-seismic reinforced concrete frame.