薄壁内压容器静强度的模糊可靠度与安全系数

应用基于模糊数学与常规可靠性理论相结合的模糊可靠性设计方法,讨论钢制薄壁内压容器模糊静强度在不同工况时,有关标准可接受的模糊可靠度范围;对钢制薄壁内压容器静强度的模糊可靠度范围与安全系数的关系进行研究。分析认为容器静强度在满足最小模糊可靠度要求的前提下,可取屈服安全系数ns≥1.55与抗拉安全系数nb≥1.95。     

黑方台焦家4号黄土滑坡发育特征及滑动机理

20世纪60年代以来,大量的灌溉系统在黄土地区建设运营,解决了农业的干旱问题,但同时灌溉也诱发了大量的滑坡。其中,2015年1月28日20:00,甘肃省永靖县焦家村发生了一起中等规模的黄土滑坡,滑坡严重影响其下方309国道线和六盘峡水库的安全。采用对裂缝分布、水文地质的调查,结合低空摄影测量、精细工程地质测绘、室内三轴试验等研究方法,对焦家4号滑坡的基本特征进行了分析,对形成滑坡的成灾机理有了初步认识。结果表明:(1)滑坡发生前,后缘裂缝有明显的变形情况;(2)滑坡滑动距离为548.3 m,体积为15.35万m~3,面积为6.6万m~2;(3)饱和黄土应力应变模式表现为强烈的应变软化剪缩型,并具有一定的静态液化特性;(4)滑坡是饱和黄土层静态液化引起的。     

静态混合器气液两相流压降的数值模拟及实验研究

气泡流经过静态混合器的压降问题涉及到舰船动力系统性能的好坏。在分析了气泡平均驰豫时间的基础上,结合k ε湍流模型,利用平衡流模型模拟静态混合器内形成的稀疏湍流气泡流,得到了混合器内两相流流场。空气—水系统的压力降实验表明,计算流体力学模拟能够很好地预测SMV型静态混合器内气泡流的压降,是静态混合器设计的有效手段。     

向家坝水电站不同埋设方式蜗壳结构有限元分析

针对向家坝地面电站,采用三维有限元法分析比较蜗壳不同埋设方式下的流道及其外围混凝土结构的静力特性,为蜗壳埋设方式的选择提供依据。研究表明:直埋方案所需配筋最多,不经济,且可能产生贯穿性裂缝;垫层方案应力普遍较小,垫层沿水流向敷设至蜗壳45°断面的组合方案仅局部区域有较大拉应力。推荐采用垫层埋设方式或垫层敷设至蜗壳45°断面的组合埋设方式,但同时应采取有效工程措施避免局部产生贯穿性裂缝。     

三江盆地二维地震资料处理方法研究与应用

三江盆地二位地震资料处理存在着较多的难题。如:静校正复杂;在逐步压制各类干扰的同时,难于保护低频有效信息和波组特征;波场复杂,准确拾取叠加速度比较困难。利用各种新技术新方法提高该地区地震资料的精度,是该地区地震资料处理的目标。通过综合应用各种静校正、地表一致性处理、噪声衰减、偏移等技术和方法,解决了该地区资料处理的难题,提高了地震资料的精度。实际地震资料处理的结果表明,以上处理技术和方法对该区复杂的资料处理效果明显。     

软件测试模型的探讨

软件测试是软件工程的一个阶段,也是保障软件质量必不可少的重要一环。软件测试模型是软件测试的工作框架,用于指导软件测试过程。本文在深入研究各种综合测试技术的基础上,通过对比分析各种主流的测试模型,提出了一种新的软件测试模型,包括静态测试、动态测试,测试评估等活动,把这些活动嵌入到软件开发的整个生命周期,能更好地规划软件开发和测试等一系列活动,提高了软件生产效率及其质量,该模型还适合于迭代开发。     

太安的降静电表面处理

介绍了用表面活性剂处理太安的方法，对处理后的太安进行了静电性能测试和分析，得出最佳抗静电用表面活性剂的种类及使用浓度。实验结果表明。太安炸药经过表面活性剂处理后，其静电得到大幅度降低，有利于导爆索生产工艺与质量。     

Continuous hydrogenation of vegetable oils in reactors equipped with static mixers

Continuous hydrogenation of industrially refined soybean oil with Harshaw Ni catalyst was achieved in a slurry column equipped with Sulzer SMV motionless mixers. The influence of the operating parameters (temperature, pressure, catalyst concentration and gas velocity) was investigated. The presumption that, in this equipment, the liquid-solid mass transfer limits the rate of the process is in good agreement with the experimental data.     

On the ‘curiosity’ of electrical self‐heating,static charge and electromagnetic shielding effectiveness from carbon black/aluminium flakes reinforced epoxy‐resin composites

This paper shows the wide application range (such as electrical self‐heating and electromagnetic shielding effectiveness) of composites consisting of conductive carbon black/aluminum flakes (CBA) filler and epoxy insulative matrix. The effect of CBA content on the network structure of epoxy matrix was investigated in detail. Static electrical conductivity increases linearly with the increase of filler concentration at the interface in epoxy composites. The large decrease of the conductivity as a function of the temperature is analyzed in terms of the negative temperature coefficient of conductivity (NTCC) effect. The influence of viscosity, surface energy and barrier highest energy on the NTCC behaviour in the composite is also considered. Based on these results, a new interpretation is proposed to explain the NTCC phenomena by computing the swelling force among conductive phases. The correlations of conductivity during the temperature cycling and activation energy were analyzed. The effects of dynamic ageing at various temperatures on the resistivity are reported. Current–voltage–temperature characteristics for epoxy with different contents of CBA were examined in detail. A model based on the law of energy conservation is proposed to calculate the specific heat and amount of heat dissipation. The static charge of the epoxy–CBA composites was estimated. The correlation between electromagnetic wave‐shielding effectiveness (EMS), conductivity and frequency of epoxy composites with different filler contents is also discussed. Furthermore, the effect of annealing on EMS of epoxy composites was examined. © 2002 Society of Chemical Industry     

Gas/liquid dispersions with a SMX static mixer in the laminar regime

A Sulzer SMX mixer was used to disperse gas into viscous, Newtonian and non-Newtonian fluids. The investigation covered the effect of the dispersed phase volume fraction, the viscosity of the continuous phase, the mixer length and the power draw. The flow regime was kept laminar in all the experiments. The dispersion of gas was carried out with gas concentrations between 1% and 7% in volume. Using the “process viscosity” concept, it was possible to collapse all the measured sizes on a single master curve by using the energy consumption in the mixer as the common variable between the experiments. Comparison was made with a Kenics mixer. The SMX mixer was found to be better adapted to the dispersion task due to its internal structure.