Effect of organic dopants on electrodeposition and characteristics of polyaniline under the varying influence of H2SO4 and HClO4 electrolyte media

Electrodeposition of conducting polyaniline (Pani) was made under potentiostatic condition at pH 1.0 in different electrolyte media (H₂SO₄ and HClO₄) in the absence and presence of two organic dopants, disodium salts of naphthalene-1,5-disulphonic acid (NSA) and of catechol-3,5-disulphonic acid (CSA). The rate and yield of Pani deposition were dependent on the acid medium and the dopant employed. NSA in H₂SO₄ caused an increase in rate and yield but CSA decrease when compared to the rate and yield of H₂SO₄ alone. In HClO₄ medium, both the dopants showed a decrease. With regard to DC electrical conductivity, both the dopants exhibited an enhancement in H₂SO₄ medium but NSA a decline in HClO₄. Characterisation of the electrosynthesised polymer samples by various instrumental techniques (cyclic voltammetric: CV, FTIR, UV-Visible: UV-Vis, EPR, XRD, TGA and DTG methods) revealed that between the two acid media, H₂SO₄ was the better one. Further, it enlightened the role of two organic dopants in relation to the acid media. The advantageous role of NSA in H₂SO₄ had origin on its molecular characteristics such as non-polarity, larger π-electron cloud etc., while CSA could not perform such a role because of its easily oxidisable hydroxyl groups. In HClO₄, however, both the dopants could play only an unfavourable role owing to its greater polarity and oxidizing power than H₂SO₄.     

特低渗透油藏驱替及开采特征的影响因素

应用非达西渗流理论和非线性弹性渗流理论，分析了影响特低渗透油藏驱替及开采特征的主要因素。研究结果表明，启动压力梯度和毛细管压力是影响特低渗透油藏驱替特征的主要因素；而影响特低渗透油藏开采特征的主要因素是储层的弹塑性，即储层的压力敏感性。在特低渗透油藏的开发中应适当缩小注采井距提高驱替压力梯度，采取整体压裂措施减小启动压力梯度，通过气驱或活性水驱油减小毛细管压力，及时补充地层能量以减少压力敏感性对储层的伤害。     

掺杂铁电纳米粉的液晶的电光特性

铁电纳米粒子悬浮在向列相液晶母体中，增强介电各向异性，而且对施加的电场信号敏感。本文也展示了纳米粒子对所述复合材料可实现的总的相变的作用。这种方法也许可应用于设计新型显示材料。     

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.     

苏北及邻区前志留基础层的综合地球物理研究

在前新生代油气资源选区评价中，前志留面之下未变质沉积地层（简称前志留基础层）的分布具有重要的参考价值。从提高纵向分辨率的处理和反演技术的应用入手，结合约束条件,利用大地电磁测深数据反演,揭示前志留面等界面的埋深和分布；同时应用小波分析技术，从磁场中分解出区域磁异常，反演结晶基底的埋深。通过这2个界面埋深的差异来分析前志留基础层的分布     

海水冻融后轻骨料混凝土的双轴压压强度和变形性能

针对我国渤海湾北部海域轻骨料混凝土结构的工作环境和受力状态，进行了海水中不同冻融循环次数后轻骨料混凝土的双轴压压强度试验，考察了试件的破坏形态和表面裂缝的走向特征。根据试验结果，分析了极限抗压强度随冻融循环次数和应力比的变化规律，并在此基础上建立了考虑海水冻融影响的双轴压压强度准则。探讨了冻融循环作用后轻骨料混凝土的双轴压压变形性能，包括峰值应变、应力-应变关系随冻融循环次数和应力比的变化规律。研究结果说明，随冻融循环次数的增加各种应力比下的应力-应变关系曲线均逐渐扁平，峰值应力点明显下降并右移，说明混凝土的极限抗压强度逐渐降低。     

无线网状网技术与应用

无线网状网(WMNs)由网状路由器节点和客户机节点组成,其中的网状路由器节点组成了无线网状网的网络骨干,其移动性很小。他们一起为无线网状网和其他常规无线网络的客户机节点提供网络的无线接入。WMNs技术结合了中心式控制的蜂窝网与分布式控制的无线自组织网的优点,可有效克服这两种技术的缺陷并显著提高无线网络的性能,已经成为下一代无线通信网络的研究热点之一。WMNs可为无线个域网、局域网、校园网、城域网的一系列应用提供高速无线宽带接入服务。虽然目前WMNs技术发展很快,但其协议栈各层仍存在许多有待研究的课题。首先简要介绍了无线网状网的结构与特点;随后重点分析了其主要的几个应用领域;最后探讨了WMNs各协议层的研究现状与关键技术,并分析了该技术存在的问题及未来的研究方向。     

基于多数据库的异地业务实现

中国的电信市场已进入一个以服务为核心的时代,电信运营商之间的竞争愈趋激烈,服务将是赢得客户的关键因素。异地业务是指用户在漫游地办理业务。按照漫游地异地业务分为省内异地业务与跨省异地业务。实现异地业务涉及到多数据库技术、数据库复制技术、中间件技术等多项技术的融合。结合实际应用进行了深入分析,同时对于采用单数据库技术、交换技术实现的异地业务也进行了分析。     

Criteria and methodology for the evaluation of conservation interventions on treated porous stone susceptible to salt decay

Susceptibility of stone to salt decay is directly related to its microstructural and mechanical characteristics. In the present work, a porous stone from a quarry in Cyprus was examined. Samples of this stone were consolidated and protected with certain conservation materials. The modification of microstructural characteristics of the stone was evaluated by mercury intrusion porosimetry, while its mechanical characteristics were measured by compressive and bending strength tests. From these data, the susceptibility of Cyprus stone to salt (NaCl) decay was estimated. The values of crystallization pressure of NaCl were calculated and compared to the experimentally measured compressive and tensile strength of the stone, in order to examine the probability of stone disruption due to salt crystallization. The development of the phenomenon after coarse pores’ filling with crystals, i.e. crystallization of salts in capillaries or mechanical failure of the stone, was determined by thermodynamic analysis. Additionally, artificial weathering tests of marine salt spray were performed for the evaluation of stone’s durability after the conservation. The treated stone proved to be resistant to salt decay, as it presented ameliorated microstructural and mechanical characteristics, concerning decay due to soluble salt crystallization. The most possible thermodynamic scenario was small pores repletion with crystals, avoiding mechanical failure of the stone.     

有限转角无刷力矩电动机位置伺服系统的电流控制

提出了有限转角无刷力矩电动机 (LABLTM)位置伺服系统电流控制策略 ,给出了实施方法 ,进行了开关管频率特性的分析。该方法可实现在不同误差时自动调节电动机电流 ,进而控制输出转矩 ,并具有稳态精度高、动态响应快等特点。