Formation of Zinc–Antimony-Based Spinel Phases

Formation of spinel phases in ZnO–Sb₂O₃and ZnO–Sb₂O₃–Bi₂O₃systems is studied by the use of X-ray diffraction. The formation of nonstoichiometric Zn_2.33Sb_0.67O₄phase is observed in both the systems at ∼900°C. However, in these systems, at higher temperatures ( T ≥ 1100°C), formation of the inverse spinel phase Zn₇Sb₂O₁₂is observed. The study has been extended to understand the effect of CrO₃doping on the stability of the different spinel phases in the previously mentioned systems. Interestingly, in both the systems, samples doped with CrO₃, displayed the presence of Zn_2.33Sb_0.67O₄phase <1200°C, indicating the stabilization of the spinel phase by CrO₃.     

基于广义预测控制的船舶编队

针对多船舶之间的编队合作问题,对船舶的编队控制进行研究。利用广义预测控制方法在船舶运行中对理想路径曲线进行预测,得出船舶的运动控制策略;通过运用领导-跟随者编队方法,在Cartesian坐标系下建立船舶编队控制模型,基于这种模型建立一系列船舶航迹约束,得到船队跟随者成员的控制策略。同时在船舶运行过程中,加入风浪的扰动,进行模拟仿真,得到船队的运行轨迹。     

炼厂外排污水回用于循环冷却水腐蚀影响因素初探

从单因素、多因素和复杂水系考察了炼厂外排污水回用于循环冷却水腐蚀的影响因素，结果表明，碳钢腐蚀的主要影响因素取决于离子特性、氧化膜的形成和溶解氧的扩散等综合协同作用，其中以离子特性的,影响为最大（如：Cl^-、Ca^2 、CO3^2-的腐蚀性较强）。碳钢腐蚀反应又可由以上三种主要影响因素分为三个反应控制区，而当电导率在0．1－2．0mS/cm范围时，其水质属于腐蚀危险高发区。从而也进一步说明水质的低电导率处理，其防腐效果并不理想，相反在高电导率情况下却表现出相对较好的低腐蚀性能。     

Elastohydrodynamic theory for wet oblique collisions

This paper presents a model for oblique collisions of spherical particles with a plane surface covered with a thin liquid layer. Elastohydrodynamic theory developed previously for fully immersed collisions [Davis, Serayssol and Hinch 1986 JFM 63 479-497] is modified for the normal component of motion to account for the finite thickness of the liquid layer. The resulting time evolution of the film thickness profile is then used along with sliding lubrication to determine the tangential component of motion. The critical Stokes number (dimensionless ratio of particle inertia and viscous forces), below which no rebound is seen, is predicted in terms of the physical properties of the materials involved in the collision, as described by a compliance parameter representing a dimensionless measure of elastic deformation due to viscous forces. Beyond the critical Stokes number, the normal restitution coefficient is found to increase with the Stokes number and the compliance parameter, asymptoting to the dry restitution coefficient at high Stokes numbers. The lubrication suction resistance during rebound is limited by cavitation. The tangential restitution is independent of the impact angle and is linearly dependent on the ratio of the fluid layer thickness to the sphere radius, in addition to depending on the Stokes number and compliance parameter. The tangential restitution is found to be close to unity and is generally higher for a larger value of the compliance parameter. Moreover, the tangential restitution is seen to increase with the Stokes number at small compliance and decrease with the Stokes number at large compliance. The change in rotational velocity exhibits trends that are the reverse of the tangential restitution. Finally, closed-form expressions have been developed for describing the restitution coefficients and dimensionless change in rotational velocity.     

内循环流化床固体循环速率的研究

研究一种加料不独立的垂直气力输送装置，并以流化床作为料仓和混合区，两者构成固体循环系统。由于系统特性，加料喷嘴的插入高度与加料结构将会直接影响操作的稳定性，从力的平衡出发导出临界结构为ｈｅ／Ｄｅ＜ｆＨＬ／Ｒ，其中ｆ是颗粒特性的函数。     

FOF-18结构与性能的量子化学研究

用B3LYP法,在6-31G基组水平上优化了FOF-18的几何构型,得其稳定的几何构型;在振动分析的基础上求得体系的振动频率、IR谱;采用Monte-Carlo方法预估了密度;设计等键等电子反应计算了生成焓;运用Kamlet公式预测爆速、爆压和爆热;将计算性能与CL-20的性能作比较。结果表明,FOF-18整个分子呈N字形,且存在7个强吸收峰,密度2.06g/cm3、生成焓501.03kJ/mol、爆速9411.82m/s、爆压42440.76MPa、爆热6637.46kJ/kg,该化合物的性能与CL-20接近。     

核壳型乳液聚合研究进展

综述了近年来核/壳结构聚合物乳液的聚合工艺、性能及核/壳结构的表征方法进行,讨论了影响核/壳结构聚合物乳胶粒子形态的各种因素。     

Simulation of swirling combustion and NO formation using a USM turbulence-chemistry model

A unified second-order moment (USM) turbulence-chemistry model is used to simulate methane-air swirling combustion and NO formation for different swirl numbers. The simulation results are compared with those using the EBU-Arrhenius (E-A) combustion model, the simplified PDF model of NO formation in turbulent flows and the corresponding experimental results. The comparison indicates that the USM model is obviously better than the E-A model and the simplified PDF model. The E-A model cannot reasonably simulate the finite-rate kinetics, while the simplified PDF model, using a product of two single-variable PDF's instead of a joint PDF, remarkably under-predicts the NO reaction rate. The USM model gives the best agreement with the experimental results. Predictions show that as the swirl number increases the total NO formation at first decreases and then increases, which is in agreement with the experimental results.     

高聚合度聚氯乙烯的加工性能

本文对高聚合度聚氯乙烯(H-PVC)的发展及其优异的物理机械性能作了简要介绍;着重分析了H-PVC的加工性能和表征方法,并讨论了分子特性和颗料特性及加工组成、加工条件对加工性能的影响,提出了改进H-PVC加工性能的方法。     

尖晶石粒度对高纯刚玉-尖晶石浇注料性能的影响

研究了尖晶石粒度对高纯刚玉 -尖晶石浇注料的抗折强度、抗热震性、抗侵蚀性等性能的影响。实验表明 :(1)随着配料中尖晶石颗粒含量的增加 ,试样的烧后强度呈先升高后降低趋势 (烘后强度变化不明显 ) ,烧后收缩减少 ,然后变为膨胀 ;(2 )尖晶石细粉与颗粒为 1:3的试样抗热震性较好 ;(3)对于高碱度渣 ,尖晶石颗粒加入量较多的试样抗侵蚀性较好 ;(4)对于低碱度渣 ,尖晶石细粉加入量较多的试样抗侵蚀性和抗渗透性均较好。