用可靠度理论确定屈曲约束支撑钢框架的设计原则

根据同济大学采用国产低碳钢Q195、Q235与宝钢新开发的低屈服点钢BLY160、BLY225研制的两种型号屈曲约束支撑(TJ-I型与TJ-II型)的大量试验结果,应用统计分析与可靠度理论,确定了屈曲约束支撑钢框架的设计原则。给出了具有明确概率意义的,在使屈曲约束支撑达到其极限承载力的外荷载下,框架柱、梁的内力与其设计承载力的比例极限。可保证在罕遇地震作用下,屈曲约束支撑能充分发挥其抗震耗能作用,同时框架柱、梁的可靠度指标β分别不低于3.2与2.7,为国产屈曲约束支撑在抗震工程中的应用提供参考。     

非接触式支架与手持方式校验静电放电发生器之差异

静电是电子设备的一个主要的干扰源,在校验静电放电发生器时应尽量避免人体静电等外界干扰的存在。该文分析校验静电放电发生器时外界干扰的影响,提出研制通用的可自由升降式的非接触式测试支架的解决方案,通过对多种型号的样品进行实验比对,证实能消除人体电容等外界因素带来的校验误差。     

Equilibrium and kinetic studies for the biosorption system of copper(II) ion from aqueous solution using Tectona grandis L.f. leaves powder

The biosorption of copper(II) ions from aqueous solution by Tectona grandis L.f. was studied in a batch adsorption system as a function of pH, metal ion concentration, adsorbent concentration and adsorbent size. The biosorption capacities and rates of copper(II) ions onto T. grandis L.f. were evaluated. The Langmuir, Freundlich, Redlich-Peterson and Temkin adsorption models were applied to describe the isotherms and isotherm constants. Biosorption isothermal data could be well interpreted by the Langmuir model with maximum adsorption capacity of 15.43 mg/g of copper(II) ion on T. grandis L.f. leaves powder. The kinetic experimental data properly correlated with the second-order kinetic model. Various thermodynamic parameters such as deltaG(o), deltaH(o), and deltaS(o) were calculated indicating that this system was a spontaneous and exothermic process.     

松辽盆地东南部油气、煤层气后生蚀变硫同位素特征

对松辽盆地东南部上白孚统泉头组、姚家组和嫩江组岩石中黄铁矿及硫同位素特征研究表明,泉头组、姚家组中后生还原褪色作片j形成的灰色、灰绿色砂岩中的黄铁矿及硫同位素均显示出了深部来源的油气、煤层气有机流体作用成分特征.该区原生沉积成岩岩石及黄铁矿中硫同位素的δ34SV-CDT为正值,油气、煤层气有机流体还原作用岩石及黄铁矿中δ34SV-CDT为负值.油气、煤层气还原作用不仅使杂色、紫红色原生氧化砂岩还原为灰色、灰绿色还原性砂岩,还使岩石还原容量大大增强,而且油气、煤层气在有机流体与岩石的相互作用过程中有铀的叠加富集,岩石铀含量普遍增加,局部可形成铀异常、铀矿化.首次在门达地区姚家组含矿砂岩中发现网脉状水云母化,显示铀成矿具有低温热液蚀变特征,铀矿化与低温热流体作用有关.     

光纤放大器对通信系统容量的影响

本文研究了带光纤放大器的通信系统容量．在忽略光纤非线性效应与色散情况下,从信息熵的定义出发,得出带光纤放大器的通信系统容量的数学表达式,结果表明光纤放大器的引入使得系统的信息量减少,得到4～11 bit／s／Hz的信息容量．     

V型缀管钢管混凝土格构柱极限承载力试验

目的对钢管混凝土之间采用V型钢管连接的格构柱进行试验研究,探讨V型缀管钢管混凝土格构柱承载能力及其实用算法．方法采用柱轴压和偏压试验研究,对不同长细比和偏心率的格构柱进行承载力试验,建立经过验证的有限元模型,确定格构柱承载力的双参数计算方法．结果斜缀管为压弯受力或拉弯受力且受力较大;柱肢之间受力有一定差别;随着长细比的增加,试件由分肢屈曲向整体失稳转变．长细比较小的试件其承载力应进行单肢承载力验算．结论V型缀管格构柱存在相关屈曲的问题,得到了V型缀管钢管混凝土格构柱考虑偏心率折减系数和稳定系数的极限承载力计算方法．     

Crossover SAFT Equation of State and Thermodynamic Properties of Propan-1-ol

In this work we have developed a new equation of state (EOS) for propan-1-ol on the basis of the crossover modification (CR) of the statistical-associating-fluid-theory (SAFT) EOS recently developed and applied to n-alkanes. The CR SAFT EOS reproduces the nonanalytical scaling laws in the asymptotic critical region and reduces to the analytical-classical SAFT EOS far away from the critical point. Unlike the previous crossover EOS, the new CR SAFT EOS is based on the parametric sine model for the universal crossover function and is able to represent analytically connected van der Waals loops in the metastable fluid region. The CR SAFT EOS contains 10 system-dependent parameters and allows an accurate representation of the thermodynamic properties of propan-1-ol over a wide range thermodynamic states including the asymptotic singular behavior in the nearest vicinity of the critical point. The EOS was tested against experimental isochoric and isobaric specific heats, speed of sound, PVT, and VLE data in and beyond the critical region. In the one-phase region, the CR SAFT equation represents the experimental values of pressure with an average absolute deviation (AAD) of less than 1% in the critical and supercritical regions and the liquid densities with an AAD of about 1%. A corresponding states principle is used for the extension of the new CR SAFT EOS for propan-1-ol to higher n-alkanols.