Observation and Analysis of Gypsum Particleboard using SEM

The microstructures of gypsum board and gypsum particleboard were observed by SEM. The effects of retarder and waterproof agent on the shape and the average dimension of the gypsum crystal were discussed. The mechanism was investigated as well. Four typical instances, i e, the gypsum crystal shape, the gypsum combined with particles on the particles surface, the gypsum combined with particles on the wood cross section and the gypsum combined with particles inside the wood cell cavity were selected and observed. Furthermore, the agglomeration and cementation mechanism between gypsum and particle were studied.     

西北江三角洲来水来沙的非线性分形特征

根据西、北江干流高要、石角及西北江三角洲网河区顶点马口、三水四个水文站的流量和含沙量资料 ,应用非线性分形原理的R S方法 ,计算西北江干流及西北江网河区顶点四个水文站的流量、含沙量的赫斯特数H和分形维数D ;探讨西、北江干流来水来沙的分形特征及西北江三角洲的分水分沙规律。结果表明 ,流量的分维数略大于含沙量的分维数 ,三水站流量及含沙量的分维数与其上游的石角站流量、含沙量的分维数相差较大 ,与思贤的分水分沙造成西北江的水沙交换有关     

国外大型调水工程渠道运行控制综述

与常规的以经验为主的运行方式相比，考虑了水动力学影响、以多渠池串联的整个渠道系统为研究对象的渠道运行控制在增加调水工程的安全性、降低运行成本、提高输水效率等方面能取得更佳的效果。国外关于调水工程渠道控制的研究起步较早，基于非线性偏微分圣维南方程组发展了多种离散化、线性化等简化方法，建立了相应的控制模型，并从不同角度确定了其控制方法以及控制算法。参考已有的研究思路和方法，总结国外渠道运行控制的成果，对我国南水北调工程的运行控制有着重要的借鉴意义。     

负载化非茂单活性中心催化剂乙烯聚合的研究

在硅胶上负载了双(N-环己基-3-叔丁基水杨醛亚胺基)二氯化锆配合物,得到负载化非茂单活性中心催化剂。该催化剂用于乙烯聚合,考察了配合物用量、共聚单体1-己烯用量、聚合温度、聚合压力、聚合时间、三乙基铝用量对乙烯聚合性能的影响及对聚合物的相对分子质量、相对分子质量分布、熔体流动指数和密度的影响。实验结果表明,负载化非茂单活性中心催化剂保持了原均相催化剂的乙烯聚合性能;该催化剂在淤浆聚合工艺中聚合平稳,所得聚合物的颗粒形态良好。     

Use of Fiber Bragg Grating Sensors for Determination of a Simply Supported Rectangular Plane Plate Deformation

A measurement method has been developed to determine the full-field deformation of a simply supported plane plate under transverse load. The method utilizes strain information provided by a set of four fiber Bragg grating sensors mounted on the plate in a way that all sensors measure strains along one certain direction. The sensors were interrogated using a wavelength swept fiber laser. Utilizing the strain information and the first four terms of Navier solution of simply supported rectangular plate, the necessary parameters for determining the deflection could be computed. By substituting the values of x- and -y- coordinates of each position on the rectangle plate, the full-field deformation information can be obtained. Single-point loading tests were experimentally performed to verify the accuracy of the method.     

La2（MoO4）3：Eu均-花瓣状微／纳米结构的构筑及其荧光性能

在表面活性剂十二烷基硫酸钠（SDS）的作用下，采用温和的水热方法，成功制备了Eu掺杂的花瓣状L丑2（MoO4）3：Eu纳米微结构。这些形貌新颖的微米绒球的直径约3μm，由厚度30nm左右的纳米片次级结构单元自组装构筑而成，分散性良好，形貌规整、大小均一。通过XRD、SEM、TEM测试技术，研究了形貌的形成机理。由于具有良好的结晶度，这些花瓣状La2（MoO4）3：Eu纳米微结构显示出良好的发光性能。     

High-yield synthesis of single-crystalline 3C-SiC nanowires by a facile autoclave route

Single-crystalline 3C-SiC nanowires have been synthesized in large scale through a one-step autoclave route by the reaction of SiCl₄, (C₅H₅)₂Fe and metallic Na at 500 °C. Electron microscopy investigations show that the nanowires have typical diameters of 15-50 nm, lengths up to several tens of micrometers and grow along the [111] direction. The possible growth mechanism of the nanowires is discussed.     

国内外钻探用金刚石复合片性能的研究

主要介绍国内外金刚石复合片性能及采用四高复合片钻探硬岩的初试,为快速钻探提供一个新的途径.     

土酸溶液中溴化十六烷基吡啶对锌的缓蚀作用及吸附热力学研究

用失重法研究了土酸溶液中溴化十六烷基吡啶对锌的缓蚀作用，发现溴化十六烷基吡啶在锌表面上的吸附是产生缓蚀作用的重要原因，且吸附规律服从Langmuir吸附等温式。用Sekine方法处理实验数据，从而获得了吸附过程△H^0、△S^0和△G^0等一系列重要热力学参数。     

Bandwidth‐guaranteed QoS routing of multiple parallel paths in CDMA/TDMA ad hoc wireless networks

This paper investigates the issues of QoS routing in CDMA/TDMA ad hoc networks. Since the available bandwidth is very limited in ad hoc networks, a QoS request between two nodes will be blocked if there does not exist a path that can meet the QoS requirements, even though there is enough free bandwidth in the whole system. In this paper, we propose a new scheme of using multiple paths between two nodes as the route for a QoS call. The aggregate bandwidth of the multiple paths can meet the bandwidth requirement of the call and the delays of these paths are within the required bound of the call. We also propose three strategies by which to choose a set of paths as the route, namely, shortest path first (SPF), largest bandwidth first (LBF), and largest hop‐bandwidth first (LHBF). Extensive simulations have been conducted to evaluate the performance of the three strategies in comparison with a traditional single path routing algorithm. The simulation results show that the proposed multiple paths routing scheme significantly reduces the system blocking rates in various network environments, especially when the network load is heavy. Copyright © 2005 John Wiley & Sons, Ltd.