An investigation of the unstable region for dense phase conveying in sliding bed flow

For fine powdered materials, capable of being conveyed in dense phase, a conveying region exists in which instability in flow and pipeline blockage can occur if the pressure gradient available is insufficient to maintain a minimum value of solids loading ratio. A reduction in material flow rate can also lead to pipeline blockage in this region. Conveying trials under-taken with cement are used to illustrate the nature of the problem.     

引子渡水电站大坝施工质量控制及成果简析

混凝土面板堆石坝是引子渡水电站的主要水工建筑物,在大坝坝体填筑及混凝土面板的施工过程中,通过室内及现场试验确定了质量控制参数,并采取了必要的质量控制措施,从而保证了工程质量。本文主要对质量控制情况及检测成果作简要介绍。     

岩金矿山采空区处理现状及对策

岩金矿山以浅眼留矿法为代表的空场采矿法为主要开采手段，约占50％，每年形成数百万m^3采空区，并绝大多数未进行专门处理。本文介绍数例岩金矿山采空区处理方法及效果与对策，供有关企业参考。     

矿用立式旋风水膜除尘器除尘性能的试验研究

本文通过对立式旋风水膜除尘器除尘性能的模型试验,揭示了几个主要参数对其除尘性能的影响,确定了合理的取值范围,对该种除尘器的设计和应用提供了依据。     

关于电视群信号对光纤副载波调频传输中的信噪比平衡问题的分析

本文对微波副载波用电视群信号调频的光纤传输中的信噪比平衡问题进行了分析,推导出VSB-AM信号在解调后的信噪比表达式,引入了信噪比恶化系数的概念.为了实现多路VSB-AM信号间的信噪比的平衡,相应的微波副载波频偏应有确定的比例关系.     

表面稳定模式铁电液晶的电光特性测试

采用一种改进的高分子膜摩擦定向法成功地实现了表面稳定模式铁电液晶的光学双稳态，对比度大于１４０，响应时间达１００微秒。     

强度型光纤传感器的信号检测系统

本文阐述了一种可提高强度型光纤传感器测量精度的检测系统。该系统利用同一检测电路交替检测信号、参考通道的输出信号，并将信号、参考两通道的检测结果相除，从而消除了因发光二极管光源波动及检测电路系统不稳定所带来的误差。采用同步相关技术抑制了噪声，提高了输出信噪比。实验证明，当时间常数ＲＣ为０．０５Ｓ时，采用该检测系统可获得优于千分之一的零点稳定性和优于２×１０３的输出信噪比。     

Influence of two-step process and of different stoichiometric ratios on morphologies generated in castor oil epoxy resins

Phase separation during polymerization was studied in a model system consisting of a diepoxide based on diglycidyl ether of bisphenol A (DGEBA), variable amounts of ethylenediamine (EDA) and the mass of castor oil (CO) necessary to obtain a mass fraction equal to 0-15 in a final system where the stoichiometric ratio of amine to epoxy equivalents, r, was equal to 1. A two-step polymerization process was performed by curing first a system with r = 0-5, during variable times before phase separation, and then carrying the system to r = 1. Thermodynamic analysis of samples with different r values led to a linear relationship between the Flory-Huggins interaction parameter and r. The concentration (P) and average size (D?) of dispersed-phase particles followed opposite trends, i.e. P increased while D? decreased, when either r was increased or the time of curing in the first step of a two-step process was decreased. This was explained by assuming that the competition between nucleation and growth was determined by the viscosity at the cloud point, η_cp. Low values of η_cp favoured growth over nucleation and led to fewer but larger particles.     

无间隙原子钢的微观结构特征和塑性应变比

采用Ｘ射线衍射的ＯＤＦ和ＬＰ分析技术，ＳＥＭ电子通道花样和蚀坑技术观测，研究了超深冲无间隙原子钢板的微观结构特征。结果表明：控制化学成分、保证基体纯净、优选工艺参数，促进强的γ－〈１１１〉∥Ｎ．Ｄ纤维织构的形成是获得优异成型性的关键。用ＣＭＴＰ方法，由ＯＤＦ织构数据从理论计算了塑性应变比（ｒ），表明ｒｍ值高达３．１８。文中讨论了再结晶织构形成机制。     

90°分束偏光镜光强分束比研究

给出了90°分束偏光镜的e,o光光强分束比的计算公式,以及光强分束比随光波长的变化曲线;在6328Å测得的光强分束比与计算值是一致的。