浮法玻璃切裁横断面白碴的解决

针对玻璃横切出现白碴缺陷情况,分析其产生的原因,并提出有效的解决办法。     

Perfluorosulfonated ionomers membranes: Melt‐processing and characterization for ion exchange applications

Perflurosulfonated ionomers membranes with different ionic‐exchange capacity were successfully fabricated via melt‐extruding and casting of their –SO₂F precursors. A systematical investigation of the thermal stability, crystallinity, and rheological properties of the precursors was performed to secure their optimized processing conditions. The tensile properties of acid‐form membranes are found to increase with base‐hydrolysis time, where a tensile strength of 38.2 MPa is readily obtained after 24 h's base‐hydrolysis. The content of –SO₂F or –SO₃H containing side‐chains plays an important role in the thermal stability, rheological, and mechanical properties of the precursor or the acid‐form membranes. The strong ionic interactions, attributed to the –SO₃H groups, lead to decreased crystallinity and tensile strength for different IEC membranes. The acid‐form membranes exhibit good proton conductivity and low methanol crossover in comparison with reference Nafion membrane. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39944.     

Studies on the electrical conductivity of carbon black filled polymers

The conductivity mechanism for a carbon black (CB) filled high-density polyethylene (HDPE) compound was investigated in this work. From the experimental results obtained, it can be seen that the relation between electrical current density (J) and applied voltage across the sample (V) coincides with Simmons's equation (i.e., the electrical resistivity of the compound decreases with the applied voltage, especially at the critical voltage). The minimum electrical resistivity occurs near the glass transition temperature (T_g) of HDPE (198 K). It can be concluded that electron tunneling is an important mechanism and a dominant transport process in the HDPE/CB composite. A new model of carbon black dispersion in the matrix was established, and the resistivity was calculated by using percolation and quantum mechanical theories. © 1996 John Wiley & Sons, Inc.     

Electrochemical synthesis of polyacrylonitrile (PAN)–copper composite conductive film

Polyacrylonitrile–copper composite film was synthesized by electrochemical reduction of a swollen film made by blend solution of a polyacrylonitrile–copper(II) ion which was coated on a electrode surface. The morphological structure of this composite film in the cross section was measured by a scanning electronic microscope and it showed three composite layers: a densely deposited layer, a transition layer, and an undeposited layer. The deposited layer consisted of the copper element and gave a high conductivity (10⁰ S-cm⁻¹). In the transition layer, there was a great amount of a tree-shaped copper deposit, but no such deposit can be found in the undeposited layer. The experiment data showed that the conductivity of the film increases with increase of electrochemical reduction time and decreases with increase of ratio of nitrile group to the copper(II) ion. The viscosity of polyacrylonitrile-copper(II) ion solution is enhanced by a decrease of the ratio of the nitrile group to the copper(II) ion. © 1996 John Wiley & Sons, Inc.     

质量标杆盛宴汇聚卓越力量

由中国电子质量管理协会和广州巨流信息科技传媒有限公司共同主办的“第二届国际电子质量论坛暨第二届中国电子企业质量百强颁奖典礼”,于8月27日在深圳会展中心五楼牡丹厅圆满举行。各个企业的高层领导纷纷亲自出席,为质量百强企业的努力与成绩做出见证。     

嵌入式Linux的低功耗策略研究

功耗是嵌入式设备的一个十分重要的性能指标。在硬件设计和选型之后,功耗水平在极大程度上取决于软件的设计。鉴于Linux在嵌入式设备中的应用日益广泛。提出在嵌入式Linux下软件编写的几种策略。通过这些软件编写方式,能有效降低最终产品的功耗水平。     

高压输变电系统对通信电磁干扰的影响分析

本文对通信机房的电磁干扰问题及相关规范做了详细的综述,并以某省通信生产楼拟建局址电磁环境的实测数据为例,对高压输变电系统对通信机房的电磁干扰影响进行分析和论证.对今后通信机房的建设及相关规范的更新与制定具有较好的参考价值.     

GPRS与内容计费

随着数据业务的快速发展,业务种类越来越丰富。丰富的业务向其承载网GPRS提出了内容计费的要求。本文针对GPRS实现内容计费的方案进行了讨论,提出了GGSN改造和WAP网关改造两个方案并对两个方案进行了对比分析。     

浅谈电信运营商的转型

随着中国电信集团转型口号的正式提出,一时间基础电信运营商的战略转型成为行业关注的热点问题.本文系统地分析了电信运营商转型的必要性和转型的方向,探讨了转型给电信运营商所带来的运营模式和竞争模式的改变等问题.本文认为电信运营商未来运营的核心将是运营一个资源系统,运营商所担当的角色不仅仅是管道提供商,更多的是一个产业链、价值链的管理者和协调者.对于价值链的核心环节,电信运营商必须牢牢控制,而对于非核心的或者辅助性的环节,大可放心地采取外包方式,让更为专业的独立第三方运营.     

ad hoc网络的可生存性问题及设计挑战

本文介绍了ad hoc网络可生存性面临的问题和挑战,特别强调了军事需求.其中从三个方面探讨了ad hoc网络的可生存性问题:可生存的网络连接、可生存的通信服务及可生存性技术,尤其是对可生存性技术进行了较全面的剖析.