建(构)筑物机械拆除方法综述

介绍了几种常用的建(构)筑物机械拆除方法,对其工作原理、特点、应用条件及局限性加以分析和说明。     

转动玻璃圆筒激光器

本文介绍了转动玻璃圆筒激光器的设计及实验结果,得到了脉冲能量为13J,重复频率为15Hz的激光输出。电光转换效率为2.2％,斜效率为3.4％。     

Postbuckling analysis of plates on an elastic foundation by the boundary element method

The postbuckling behavior of plates on an elastic foundation is studied by using the boundary element method (BEM). A new fundamental solution of lateral deflection is derived through the resolution theory of a differential operator, and a set of boundary element formulae in incremental form is presented. By using these formulae, the BEM solution procedure becomes relatively simple. The results of a number of numerical examples are compared with existing solutions and good agreement is observed. It shows that the proposed method is effective for solving the postbuckling problems of plates with arbitrary shape and various boundary conditions.     

加固改造中的结构承重体系转换

从加固改造工程的实践出发 ,探讨了混合结构向框架结构体系转换的方法和构造措施 ,为实际工程提供了新的技术思路     

A generalized equation for the prediction of melting temperatures of homopolymers and copolymers

A generalized equation was derived to calculate the melting temperatures of homopolymers and copolymers. The Gibbs‐Thomson equation for homopolymers and a modified application to copolymers were derived using the proposed equation. The melting temperature T_m⁰ in the Flory equation corresponds to the melting temperature T_m^C,∞ of copolymer crystals with stems of infinite length. Also, T_m^C,n*, the melting temperature for copolymer crystals with stems containing the maximum possible number of structural units, n*, should be used instead of T_m⁰ as the basis of supercooling in crystallization. The proposed equation shows good agreement with experimental data for α‐alkene‐ethylene homogeneous copolymers.     

用欢喜岭油田低凝稠油生产AH-90重交通道路沥青

针对欢喜岭油田低微稠油的特点，采用常压蒸馏—氧化沥青联合装五的工艺流程，生产出AH-90重交通道路沥青。经测试表明，各项性能均达到我国现行重主通道路沥青技术指标。在高温稳定性、低温抗裂性等方面都优于新加坡壳牌沥青。是一种优质的道路沥青。     

住宅设计的几个消防问题

对住宅消防设计中若干规范交叉问题进行了分析 ,提出几个有待解决的问题。     

聚酰胺的改性与加工应用

本文介绍了有关尼龙树脂材料改性，共聚和新品种尼龙等聚合物设计技术，聚合物合金等复合技术，以DSI等胶粘技术为中心的相关加工技术的动向和具体事例。     

Acicular ferrite transformation in deformed austenite of an alloy-steel weld metal

The effect of different amounts (5, 10 and 15%) of compressive deformation of austenite on the isothermal transformation of acicular ferrite in an alloy-steel weld metal has been investigated. It was found that prior deformation of austenite significantly enhanced acicular ferrite transformation. At the same isothermal transformation temperature, as a higher amount of prior deformation was applied, a greater quantity of acicular ferrite could be obtained and the size of acicular ferrite plates became much finer. These results implied that the effective nucleation sites of acicular ferrite increased with increasing amount of prior deformation. The other results also emphasized that the accumulated strain (due to prior deformation of austenite) could trigger acicular ferrite to nucleate on inclusions at high temperatures, where undeformed austenite remained stable. The acicular ferrite start temperature was found to be raised continuously by increasing the amount of prior deformation of austenite. Further evidence suggests that the application of deformation can boost the driving force for acicular ferrite formation. This phenomenon is similar to the case in which martensite forms under the influence of deformation.     

Experimentally Verified Mn–Zn Ferrites' Intrinsic Complex Permittivity and Permeability Tracing Technique Using Two Ferrite Capacitors

After setting up a mathematical model for rectangular-shaped Mn-Zn ferrite capacitors, this paper investigates dimensional effects on the intrinsic complex permittivity and the measured apparent complex permittivity of Mn-Zn ferrite blocks. The simple block structure of the samples guarantees their easy and precise preparation. Above a few hundred kilohertz, dimensional effects make the measured apparent complex permittivity deviate from its intrinsic value. This paper uses a Newton-Raphson based method to trace the intrinsic complex permittivity and permeability from the measured impedances of two rectangular-shaped Mn-Zn ferrite capacitors in the frequency range from a few hundred kilohertz to 40 MHz. From the traced intrinsic complex permittivity and permeability, the apparent complex permittivity of a third sample with different dimensions is then calculated theoretically. The papers also presents results of experiments carried out to measure the apparent complex permittivity of the third sample; agreement between the measured and the calculated values is very good. This justifies the validity of the method presented in this paper, when used to determine the dimension-independent intrinsic complex permittivity and permeability of Mn-Zn ferrites