Oligo(ethylene oxide) side‐chain steric screening effects on conductimetric properties of grafted poly(4‐vinylpyridinium) salts in aqueous solutions

A set of poly[N‐oligo(ethylene oxide)yl 4‐vinylpyridinium tosylate] (P4VOEOOTs) has been prepared by spontaneous polymerization of 4‐vinylpyridine. This method gives a grafted polyelectrolyte having a positive charge on every backbone pyridinic moiety. The P4VP15Ts, P4VP164Ts, P4VP350Ts and P4VP750Ts aqueous solution conductivities were determined in the concentration range from 6 × 10^?4 to 10^?2 M at 25 °C. The variation of the conductivity versus concentration of the investigated system exhibits typical polyelectrolyte behaviour. The polyelectrolyte mobility was found to be dependent on the oligo(ethylene oxide) (OEO) side‐chain length. Manning's rod‐like model fails to describe these results. A simple steric effect is proposed to explain the influence of the OEO length. Copyright © 2003 Society of Chemical Industry     

动力环境集中监控系统可靠性的提高

为实现电源设备乃至通信机房的少人或无人值守和集中维护,必须建立一套完善的电信局动力环境集中监控系统。文中结合番禺区电信局的实际,讨论了提高系统运行可靠性的几点措施,包括硬件方面与软件方面的手段,关键在于加强系统的运行管理。     

动力环境网络监控精细管理

叙述动力环境运行质量分析管理，包括故障管理，性能管理和专题分析管理，以动力环境网络监控细致八微、言之有据的月度分析管理实例展现了其精细管理的效果。     

浅谈东深供水改造工程的设计监理工作

施工图阶段设计监理工作的内容归纳起来主要是对设计质量进行控制.依据<水利建设工程招标、施工图阶段设计监理试行规定>,其具体工作内容仅限于设计成果的合法性和安全性,没有充分发挥设计监理作用,对施工图阶段设计质量的理解是不全面的.施工图阶段的设计质量不仅仅是提交合法和安全的图纸,而且图纸的提交时限性、可实施性及经济性也应是考核设计质量的重要组成部分,为此东深供水改造工程的设计监理工作内容确定为"五项控制"和"两项权利",全面地对施工图阶段的设计质量进行控制.     

Science in High Magnetic Fields: What Could Be Learned?

High magnetic fields are one of the most powerful tools available to scientists for the study, modification and control of matter. This includes the knowledge on correlations effects, interaction mechanisms, structural information and understanding of mesoscopic effects. In this context, a review of recent scientific achievements at the Grenoble High Magnetic Laboratory is given to illustrate, on specific examples, the power of the Magnetic Field probe.     

对印制电路板环境冲击评估的研究

随着印制电路板产业飞速发展,其引发的环境问题日益受到广泛的关注。然而长期以来如何有效地进行环境冲击评估是业内研究的重点和难点。而本文采用了一种智能的简化分析方法来进行全面的环境冲击评估,以提高评估的经济效益和准确度,并希望能为决策者提供一个可供参考的环境冲击评估的理念和方法。     

The Precedence Effect in Three Species of Birds (Melopsittacus undulatus, Serinus canaria, and Taeniopygia guttata).

The perceived locations of paired auditory images, simulating direct sounds and their echoes, have been recently studied in budgerigars (Melopsittacus undulatus; M. L. Dent & R. J. Dooling, 2003a, 2003b). In this article, the authors extend those experiments to include measurements of the precedence effect using a discrimination paradigm in two additional bird species: canaries (Serinus canaria) and zebra finches (Taeniopygia guttata). Although time courses of summing localization, localization dominance, and echo thresholds were similar across all species, budgerigars had slightly higher overall levels of discrimination. The results from these experiments add further support that the precedence effect in birds is similar to that found in other animals and that the ability to suppress echoes that might degrade localization and auditory object perception may be a general property of the vertebrate auditory system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

高功率脉冲水中放电的应用及其发展

首先介绍了高功率脉冲水下放电的机理，然后综合论述了其应用和研究的状况，从较为成熟的脉冲水处理技术到医疗领域的ESWL应用技术，以及在脉冲电场食品杀菌和水下目标探测方面的最新发展和研究，最后指出了高功率脉冲电技术应用前景以及进行更系统和深入研究的必要性。     

基于ADSP21XXC运行环境下FFT的实现

介绍了数字信号处理器ADSP21XX芯片的特点以及实现FFT(快速离散付里叶变换)的方法，给出了ADSP21XX的C和汇编混合编程的特点及技巧。     

基于有限状态的全周期序列混沌映射的研究

在有限长度的数字计算机中，混沌迭代序列是一个有限周期序列，其相关性能远远低于理想序列。基于skew tent映射，提出一种离散化的有限状态混沌映射，它允许精确的数值计算，没有舍入误差，通过选择合适的参数，映射能产生全周期长度的序列。仿真实验表明，归一化的序列平均周期对计算机精度不敏感，生成的二进制序列具有良好的相关性能。