三维流动传热空隙率计算程序FASTOR—3D开发研究

1引言大粘度（大r）和大系数（ss和sc）法是处理流动区域中障碍物的常用方法山。但当流动区域中障碍物数量较多时，宜采用空隙率来模拟障碍物，如模拟反应堆流动传热的商用程序COMMIX［’］。我们根据空隙率模拟的基本概念，针对采用交错网格的压力校正法，自行编制了多障碍物流动传热三维计算的全部源程序代码，应用于某核反应堆钠池流动传热的数值模拟，获得了比较合理的结果。2数学模型和数值方法2．1控制方程空隙率修整的质量、动量、能量及湍流动能与耗散率的守恒方程通式的三维柱坐标形式为其中中一1，。，。，。，T，k，。分别表…     

Simulation of Vacuum Microelectronic Triode Made of Single Carbon Nanotube

Vacuum microelectronic triode performance, based upon a unit cell with a nanotube field emitter, gate, and anode, was evaluated via computer simulation. Electron emission was calculated from the modified Fowler-Nordheim equation. The dependence of emitted current, upon geometrical factors, e.g., nanotube radius, nanotube height, and gate's hole radius, is shown. The device design parameters of trans-conductance, and cutoff frequency have been calculated, which show that this structure can be used as a microwave and millimeter wave amplifier. Electron current flux is shown for time-dependent 1–Thz sinusoidal variation frequency input.     

Effect of glass bead packing on the fibrillation of liquid‐crystalline polymer in polycarbonate

Polycarbonate (PC) was melt blended with small amount of liquid‐crystalline polymer (LCP) and various contents of glass beads (GB) having different diameters. The rheological measurements indicated that the GB addition increased the viscosity ratio and seemed unfavorable to the LCP fibrillation. However, the morphological observation showed that the LCP fibrillation was promoted by the GB addition and varied with the GB packing. With the increased GB packing by increasing the GB content and/or decreasing the GB diameter, LCP deformed from spheres and ellipsoids into stretched ellipsoids at lower shear rates and into long fibrils at higher shear rates. Although higher content of smaller GB jammed into the larger LCP droplets and inhibited the LCP fibrillation, very long LCP fibrils formed at higher shear rates at a high enough packing of GB. The relationship between GB packing and LCP fibrillation revealed two kinds of hydrodynamic effects of GB promoting the LCP fibrillation: at lower GB packing, the shear flow was enhanced by the high local shear between GB, in quantity; and for a high enough GB packing, the shear flow was changed, in quality, into elongational flow, which was more effective for the LCP fibrillation. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1020–1030, 2006     

LF λ-subgroup Generated by LF Subset

In this paper .an important property layer-preserving of LF group and an concept LF λ-subgroup generated by LF subset will be introduced. On the height of LF group theory ,we recognize the concept generated subgroup more clearly.     

L—fuzzy Ring and L—fuzzy Module

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兖州高硫煤的加氢热解脱硫及脱硫动力学

在加压热天平上，考察了氢气和氮扬气氛下高硫煤的热解脱硫。利用气相色谱在线分析研究了硫化氢氢气的逸出规律。结果表明，加氢热解比氮气下的热解有着更显著的脱友作用，脱硫率可达９０％以上。而且加氢热解下６５％的脱除硫转化为气相硫化氢，而氮气下热解是有８０％的硫转化为液相。     

外加无机电解质对煤浆性质调控作用的研究

考察了数种无机电解质对煤浆分散体系流变特性的影响。结果发现，煤浆的流变特性不仅与电解质种类有关，还取决于煤质特征。某些煤适，适量的无机电解质可使浆体的屈报胀塑料转化为屈服假塑性。     

团聚纳米SiO_2在苯乙烯乳液聚合过程中的再分散过程及机理

用二氧化硅 (SiO2 )存在下的乳液聚合法制备了聚苯乙烯 (PSt) 纳米SiO2 复合材料 ,研究了苯乙烯(St)乳液聚合过程中团聚纳米SiO2 的解离与再分散过程及分散的机理 .发现商品纳米SiO2 粒子以团聚体形式存在 ,团聚体大小远超出纳米级范围 .随聚合时间的延长 ,St的转化率逐渐增加 ,而PSt SiO2 复合微胶囊的粒径逐渐减小 ,反应 12 0min后 ,转化率和复合微胶囊粒子的粒径趋于稳定 .透射电镜 (TEM)也显示PSt SiO2 复合微胶囊粒子具有海岛结构 ,而SiO2 粒子的粒径在纳米范围内 ,表明在乳液聚合过程中SiO2 团聚体被逐渐解离 ,并重新分散到纳米尺度 .红外光谱研究发现 ,在乳液聚合过程中 ,除生成PSt均聚物外 ,还在纳米SiO2 表面生成了PSt接枝共聚物 ,改善了无机纳米粒子与聚合物之间的界面相容性 .聚合过程中的反应热和剪切搅拌是团聚体被解离和重新分散的主要原因 ,而生成的聚合物起到隔离作用     

超声催化反应的研究现状和发展趋势

综述了近几十年来超声在催化反应领域中的研究成果,包括超声在均相和多相催化反应中的应用,探讨了超声在催化反应领域中的发展趋势。     

Cu－Zn／γ－Al2O3催化剂的制备及其在选择加氢反应中的催化性能

 通过浸渍法制备了不同Cu／Zn比的γ－Al2O3和改性γ－Al2O3负载的Cu－Zn催化剂，并用XRD，XPS和SEM等手段对催化剂进行了表征．XRD表征结果表明，还原活化前催化剂中的Cu和Zn分别以CuO和ZnO的形式存在；还原活化后Cu以单质的形式存在；催化剂失活后，单质Cu又转变成CuO．XPS和SEM分析结果表明，催化剂中金属的价态及颗粒的形貌在反应前后发生了变化．所制备的催化剂在糠醛加氢制糠醇反应中表现出较高的选择性．用Co改性的γ－Al2O3负载的Cu－Zn催化剂不仅具有较高的催化活性和选择性，而且还呈现出较长的寿命．催化剂中的Cu晶相是催化活性中心；催化剂中的Cu晶相转变成CuO和烧结是催化剂失活 的主要原因．