Growth and morphology of nanometer LiMn2O4 powder

The growth of Li_1+xMn₂O₄ via detonation reaction was investigated with respect to the presence of an energetic precursor, such as the metallic nitrate and the degree of confinement of the explosive charge. The detonation products were characterized by scanning electron microscopy. Powder X-ray diffraction and transmission electron microscopy were used to characterize the products. Li_1+xMn₂O₄ with 1-2 μm spherical morphology and more uniform secondary particles, but with smaller primary particles of diameters from 20 to 60 nm and a variety of morphologies were found. The oxides produced by this cheap method affirmed the validity of detonation synthesis of nano-size powders.     

Study of miscibility enhancement in poly(styrene‐co‐4‐vinylphenol)/poly(ethylene oxide) blends by the spin labelling method

The electron spin resonance (ESR) spectra of end‐group spin labelled poly(ethylene oxide) (SLPEO) using 2,2,6,6‐tetramethyl‐piperdine‐1‐oxyl nitroxide and its blends with poly(styrene‐co‐4‐vinylphenol) (STVPhs) of different hydroxyl contents were recorded over a wide temperature range. For a blend of SLPEO and pure polystyrene (PS), the ESR spectrum was composed of a single motion component, indicating that PS was immiscible with PEO. For blends composed of SLPEO and different‐hydroxyl‐content STVPhs, two spectral components with different motion rates were observed over a certain temperature range. The difference between the motion rates should be attributed to micro‐heterogeneity in the blends, with the faster rate corresponding to a nitroxide radical motion trapped in the PEO‐rich domain and the slower rate corresponding to a nitroxide radical motion trapped in the STVPh‐rich domain. Variations in the values of a number of the ESR parameters (T_a, T_d and T_50G) and the apparent activation energy (E_a) with hydroxyl content in the blends indicated that the miscibility of the blends increased with increasing hydrogen‐bonding density due to specific interactions between the hydroxyl groups in STVPh and the ether oxygens in PEO. Copyright © 2004 Society of Chemical Industry     

陶瓷材料高速高效磨削温度研究的进展

介绍了陶瓷材料磨削温度理论的研究现状；阐述了几种热源模型，总结了磨削参数与表面磨削温度的关系，分析了几种磨削热分配系数模型，讨论了到目前为止的几种温度测量及其后处理技术，展望了磨削温度研究的发展趋势。     

BKX-Ⅰ型并联机床的谐响应分析

应用有限元分析软件(ANSYS),对BKXⅠ型并联机床进行谐响应分析,分别得到了机床各节点沿机床的虚拟轴X、Y和Z向的位移谐响应曲线。在此基础上,还分析了该机床的谐响应规律,并明确了谐响应的特点,为改善此类机床的动态特性提供了一定的参考依据。     

十年磨一剑--访西安超滤(集团)总经理李大明先生

位于西安高新技术产业开发区的西安超滤(集团)是国内专业从事压缩空气／气体过滤、干爆、分离设备开发，生产和经营的高新技术企业，公司自1994年成立以来，一直致力于气体净化行业的科研，开发，2004年公司迎未了十周年庆典，而2005年是西安超滤发展的新的十年的第一年，近日，本刊记者采访了西安超滤(集团)总经理李大明先生。     

浅谈小型局域网的组建与应用

随着计算机应用技术与通讯技术的发展以及在实践中的广泛应用,智能化和网络化成为必然趋势,局域网的应用可以营造一个现代化的高效、快捷、安全的环境,也可以使计算机以及其他硬件的功能得到充分的发挥。     

低铁耗条件下转炉高碳低磷工艺实践与应用

对转炉炼钢实现低铁耗和高碳低磷工艺进行了分析，介绍了南钢公司转炉炼钢实践低铁耗条件下高碳低磷工艺的具体应用措施。     

强夯法处理大块填石地基的应用实践

对用大块填石的地基，通过试验，采用合适能量的夯锤进行强夯处理，改变地基结构排列、使其致密，从而提高地基承载力，是一种经济有效的地基处理方法。     

Hydrodynamic force between two hard spheres tangentially translating in a power-law fluid

The hydrodynamic interaction between two hard spheres tangentially translating in a power-law fluid is investigated. By considering the gap between the two spheres being sufficiently small such that the Reynolds’ lubrication theory applies, an analytical equation to the pressure in the gap is obtained using truncated Fourier series. To a good approximation, the pressure equation can be further simplified. The simplified approximate equation over-predicts the pressure for shear thickening fluid (n>1) but under-predicts the pressure for shear-thinning fluid (n<1). However, the errors in the predicted tangential force and moment are relatively small. In particular, for a Newtonian fluid, the accurate solution and the simplified approximate solution degenerate to the asymptotic solution of Goldman et al. [1967. Slow viscous motion of a sphere parallel to a plane wall-motion through a quiescent fluid. Chemical Engineering Science 22, 637-651.] and O’Neill and Stewartson [1967. On the slow motion of a sphere parallel to a nearby plane wall. Journal of Fluid Mechanics 27, 705-724.]. Both solutions predict that for shear thickening fluid (n>1), the hydrodynamic force converged in the inner region of the gap between the two spheres and the contribution from the outer region is sufficiently small. For shear thinning fluid (n<1), the contribution from the outer region is also significant.     

内复合换热管与复合管板焊接工艺试验研究

介绍复合管与复合管板的管头设计及其焊接试验,结果表明,如果管内壁不锈钢复合层的厚度达到或大于0.5mm,则管头的焊接质量能满足要求,否则管头焊缝容易开裂。内、外双面复合管和复合管板的管头焊接工艺,与仅有内壁单层不锈钢复合层的复合管和复合管板的管头焊接工艺相同。