抗折强度试验的加荷速率

叙述了抗折强度试验的载荷速率、位移速率与应力速率的关系，以及使用普通液压试验机和普通机械试验机作抗折强度试验时实现应力速率加荷的方法。试验表明，以选定的位移速率加荷与以应力速率加荷所得的抗折强度结果一致。     

ZYCl5装运车工作装置连杆机构设计

装运车是八十年代出现的新型工程机械,是一种对松散物料集、装、运、卸于一体的短距离运输车,还可用于场地清理、刮平及牵引等作业。本文介绍了装运车工作装置的连杆机构设计。     

循环荷载作用下结构性土性状研究进展

土结构性是土最为内在的根本特性之一，土结构性对土的动、静特性有显著影响。本文主要论述国内外循环荷载作用下土结构性对土的动力特性的影响研究现状，展望土结构性动力特性研究方向。     

夹芯桩应用趋势分析

通过对水泥土搅拌桩和夹芯桩的比较分析 ,得出夹芯桩具有承载能力高而造价低的优势 ;同时又根据河北某地区的地址特点 ,得出夹芯桩在某地区具有良好的应用前景的结论     

Optimal operator assignment and cell loading when lot-splitting is allowed

This paper is an extension of a previous work where a product could be assigned to only one of its feasible cells. Here, that assumption is relaxed and lot-splitting is allowed. The impact of lot-splitting is also discussed in terms of setup times. The proposed approach has two phases; 1) generating alternative operator levels, and 2) finding the optimal operator and product assignments to the cells. Mathematical models proposed in the previous work are modified to allow for lot-splitting and to consider setup times. The results obtained by using the same example problem are discussed later in the paper.     

Meso–macroporous monolithic CuO–CeO2/γ/α-Al2O3 catalysts for CO preferential oxidation in hydrogen-rich gas: Effect of loading methods

Meso–macroporous alumina supported CuO–CeO₂ catalysts were prepared by citrate, urea combustion and impregnation methods. The effect of loading methods on the microstructure of the catalysts, the interaction between copper and ceria and the catalytic performance for preferential oxidation of CO in hydrogen-rich gases was investigated. The prepared monolithic catalysts were characterized by using techniques of N₂ adsorption and desorption, SEM, XRD, HRTEM and TPR. The results showed that the loading methods markedly influenced the catalyst structure and the catalytic performance. The citrate and urea combustion methods favored the formation of the interaction between copper and ceria. Compared with the urea combustion method, the citrate method led to smaller ceria particles on the alumina support. The meso–macroporous monolithic catalysts prepared by the citrate method maintained the structural characteristics of the highly active CuO–CeO₂ catalysts, and showed good catalytic performance in CO preferential oxidation in the simulated reformate gases containing water and CO₂.     

大型钢筋混凝土多纵梁渡槽模型试验加载方法的研究

根据南水北调工程钢筋混凝土多纵梁渡槽结构受力性能大比例尺仿真模型试验的需要，结合三维有限元分析结果，研制了一套符合渡槽受力特点且便于实施的加载系统，其成功经验对类似结构试验加载方案的确定具有重要的参考价值．     

空气静压圆柱轴承结构参数匹配关系的研究

研究了低偏心率下轴承平均半径间隙和节流孔直径对空气静压圆柱轴承承载特性的影响，导出了轴承平均半径间隙与节流孔直径之间的最佳匹配关系式．对空气静压圆柱轴承的设计与制造具有一定的指导意义．     

A study of loading history effect for thermoviscoelastic solid propellant grains

The results of an investigation on solid propellant grains considering loading history effect are presented. Traditionally, the thermal loading history effect of solid propellant grains was not considered for simplifying the analytical task, and a higher safety factor was inevitable for structural integrity. But this does not mean that the thermal loading history effect is not useful and could be neglected arbitrarily, and this effect usually plays a very important role for some critical design. In order to simulate the time–temperature-dependent behavior of thermoviscoelastic and incompressible polymer materials, concepts of time–temperature shift principle, cumulative damage theory and reduced integration were used. In addition, five different types of thermal loading history assumption were performed using the finite element method for discussing the thermal loading history effect. Results show that the thermal loading history effect is important for structural integrity of solid propellant grains, and improper negligence may cause structural failure of missile systems.     

Reliability of the vertical spinal creep response measured in sitting (asymptomatic and low-back pain subjects)

Vertical spinal creep (or change in stature) has been used as an index of spinal loading, yet reliability of the testing protocol has not been fully examined. This study investigated the reliability of a vertical spinal creep response in 10 asymptomatic and five low-back pain subjects. Each subject performed the 25-min testing protocol, which consisted of three phases (5-min preload, 10-min loaded and 10-min unloaded), at the same time on two separate days. Good reliabilities in vertical spinal creep response between two days of testing were demonstrated for both asymptomatic and low-back pain subjects.