Numerical Calculation of Concrete Slab Response to Blast Loading

In the present paper, a dynamic plastic damage model for concrete has been employed to estimate responses of a reinforced concrete slab subjected to blast loading. The interaction between the blast wave and the concrete slab is considered in 3D simulation. In the first stage, the initial detonation and blast wave propagation is modelled in 2D simulation before the blast wave reaches the concrete slab, then the results obtained from 2D calculation are remapped to a 3D model. The calculated blast load is compared with that obtained from TM5-1300. Numerical results of the concrete slab response are compared with the explosive test carried out- in the Weapons System Division, Defence Science and Technology Organisation, Department of Defence, Australia.     

磨削加工中砂轮堵塞影响因素的试验分析

砂轮堵塞是影响砂轮耐用度的主要原因，本文通过正交设计试验方法，研究了在纵向磨削时，工件转速、修整速度、冷却方式、磨削厚度等因素对砂轮堵塞的影响。     

Refreshing File Aggregate of Distributed Data Warehouse in Sets of Electric Apparatus

Integrating heterogeneous data sources is a precondition to share data for enterprises. Highly-efficient data updating can both save system expenses, and offer real-time data. It is one of the hot issues to modify data rapidly in the pre-processing area of the data warehouse. An extract transform loading design is proposed based on a new data algorithm called Diff-Match, which is developed by utilizing mode matching and data-filtering technology. It can accelerate data renewal, filter the heterogeneous data, and seek out different sets of data. Its efficiency has been proved by its successful application in an enterprise of electric apparatus groups.     

基于XML的高职学分制选课系统的设计与实现

XML语言是目前网络上标准的数据描述语言和交换语言,在网络上的应用也越来越广泛,阐述基于XML的高职学分制选课系统的设计和实现方法。     

压缩模量随深度线性变化的软粘土地基一维固结解析解

采用解析法求解了土体压缩模量随深度线性变化的软粘土地基一维固结问题，得到了不同排水边界和加载条件下以Bessel函数表示的超静孔压、固结度及沉降的解析式．并通过计算分析及与太沙基解的比较，讨论了这种非均质地基的一维固结性状．     

循环荷载作用下铝合金轴压构件稳定性能分析

研究了循环荷载作用下铝合金轴压构件的力学性能,并与钢轴压构件进行比较。采用通用有限元分析软件ANSYS对铝合金轴压构件的滞回性能进行有限元分析。分析方法考虑了材料非线性、几何非线性和初始缺陷的影响。根据计算结果,得到了6061-T6铝合金、6061-T4铝合金和Q235钢3种材料轴压构件的滞回曲线、恢复力骨架曲线和刚度退化曲线,并进行了比较研究。分析结果显示,铝合金轴压构件的滞回性能与低碳钢轴压构件较为类似,并受到材料本构关系的显著影响。     

动载作用下沥青混凝土路面反射裂缝粘弹性响应分析

为研究沥青混凝土路面内部反射裂缝在动态荷载作用下的力学响应,采用ABAQUS有限元软件建立分析模型.通过对沥青混凝土蠕变试验曲线进行非线性拟合,得到Prony级数以赋予模型中面层粘弹性材料属性.基于粘弹性理论、时温等效原理、断裂力学及动力学有限元方法,利用半正弦荷载模拟动荷载作用,以断裂参数J积分以及复合应力强度因子作为裂缝扩展评价指标,对路面反射裂缝在不同车速、不同环境温度以及不同材料阻尼系数等条件下的力学响应进行分析.计算结果表明:反射裂缝断裂参数值随车辆行驶速度的增加而减小;不同结构温度下的断裂参数差异不明显;断裂参数曲线随阻尼比的增大而逐渐后移,且最大值逐渐减小.因此,通过改善车辆行驶条件以提高车辆行驶速度,以及通过改进材料组成来增大沥青混凝土阻尼系数,都能够有效延缓反射裂缝扩展速度,延长路面的正常使用寿命.     

钢管混凝土柱节点的研究现状

论述了目前钢管混凝土柱节点的常见型式,分析了加强环式节点、穿心牛腿环梁节点、钢筋贯通式刚接节点、锚定式节点、十字板式节点、分层式节点和环梁式节点的构造特点和各自的优缺点。指出钢管混凝土柱节点在理论研究和实际应用中的一些问题。     

人工湿地技术在我国北方地区的试验研究

本研究在邯郸构建了二级串联人工湿地系统,进行污水净化试验．试验结果表明,构建的人工湿地系统对污染物去除效果良好,出水水质较稳定,系统对COD、TN、TP的去除率分别在25％～65％、29％-94％、30％-80％之间．在相同的水力负荷下,植物生长状况良好的人工湿地污水处理效果明显高于植物生长状况差的人工湿地．潜流人工湿地子系统对污水的净化效果和稳定性明显好于表层人工湿地系统．人工湿地处理污水受温度和季节影响较大,在温度较高的夏季去除率远远高于温度较低的冬季．     

Increased dietary carbohydrate and endurance during single‐leg cycling using a limb with normal muscle glycogen concentration

The purpose of this study was to test the hypothesis that increased availability of blood‐borne glucose would improve endurance after carbohydrate loading. A single‐leg exercise model was employed, taking advantage of the fact that supercompensation of muscle glycogen occurs only in a previously exercised limb. Endurance time to exhaustion at 70% of maximal oxygen uptake (VO₂max) was determined for 11 males and three females who were then allocated to a control group or a high‐carbohydrate (CHO) group. For 3 days following Test 1 the control group maintained a prescribed normal diet whilst the CHO group increased the proportion of energy derived from carbohydrate (62.1 ± 4.3% cf. 43.9 ± 2.0%, P < 0.01). The endurance test was then repeated using the leg that was inactive during Test 1. Endurance time was increased on Test 2 (123.7 ± 43.2 min cf. 98.5 ± 21.9 min, P <0.05 one‐tailed test) for the CHO group but not for the control group (101.8 ± 21.7 min cf. 107.5 ± 9.1 min, NS). There was no indication of enhanced carbohydrate metabolism during Test 2 for the CHO group but mean heart rate was lower during Test 2 than during Test 1 (145 ± 14 beat min ^‐1 cf. 152 ± 12 beat min ^‐1, P<0.05). These results suggest that the prior consumption of a high‐carbohydrate diet improves endurance during high‐intensity cycling with a limb with normal muscle glycogen concentration.