Facile modifications of polyimide via chloromethylation: II. Synthesis and characterization of thermocurable transparent polyimide having methylene acrylate side groups

From chloromethylated polyimide, a useful starting material for modification of aromatic polyimides, a thermocurable transparent polyimide having acrylate side groups was prepared. In the presence of 1,8‐diazabicyclo[5,4,0]undec‐7‐ene, chloromethylated polyimide was esterified with acrylic acid to synthesize poly(imide methylene acrylate). The polymer was soluble in organic solvent, which makes it possible to prepare a planar film by spin coating. The polymer film became insoluble after thermal treatment at 230 °C for 30 min. Optical transparency of the film at 400 nm (for 1 µm thickness) was higher than 98 % and not affected by further heating at 230 °C for 250 min. Adhesion properties measured by the ASTM D3359‐B method ranged from 4B to 5B. Preliminary results of planarization testing showed a high degree of planarization (DOP) value (>0.53). These properties demonstrate that poly(imide methylene acrylate) could be utilized as a thermocurable transparent material in fabricating display devices such as TFT‐LCD. Copyright © 2004 Society of Chemical Industry     

铝液夹杂物检测DMIRT－Ⅲ法的试验研究

提出了一种新的铝液夹杂物快速检测方法。导出了该法的检测原理方程。分析并试验研究了影响检测重复性和分辨率的因素。试验选择了较好的检测参数，并获得了较好的检测结果。     

The Effect of Initial Inventories in a Two-Echelon System

A model in which jointly optimal stocks of material and finished products are to be chosen is reexamined. While it costs less to hold material, a certain percentage of the random demand not immediately satisfied by previously finished products is lost. We pay particular attention to the dependence of the optimal stocks on the initial ones, which assumes an interesting form. For example, if the stock of finished products is high but the combined stock is low, die quantity of material ordered depends on the stock of finished products.     

混合结构楼房爆破拆除倒塌范围的确定

通过对混合结构楼房爆破倾倒过程特点的分析,提出了楼房在倾倒过程中的运动计算模型,并应用体积平衡原理,得到这类楼房爆破爆堆参数计算公式,用该公式计算的结果与实例中爆堆实测数据相比较,相对误差不超过11%.     

对高校图书馆参考咨询服务的探讨

面对现代信息时代的挑战，高校图书馆参考咨询服务进行着深刻的变革，其系统化、网络化、合作化、社会化、高效化是这种变革的集中体现。     

非织造布印花技术探讨

介绍了应用于非织造布印花的技术及工艺，对非织造布印花时应注意的事项进行了说明。     

首尔地面公交系统改革的成功经验

随着经济、人口的快速发展,首尔开展了一次针对地面公交系统的成功而深刻的变革。其中包括组建以公众参与为基础的公交系统改革公民委员会,形成了“以线路连接为导向的公交系统”,采用新型公交智能卡、票价新制度以及信息一体化的管理系统。     

High-cycle fatigue characterization of titanium 5Al-2.5Sn alloy

High-cycle fatigue behaviour of titanium 5Al-2.5Sn alloy at room temperature has been studied. S-N curve characterization is performed at different stress ratios ranging from 0 to 0.9 on a subsized fatigue specimen. Both two-stress and three-stress level tests are conducted at different stress ratios to study the cumulative fatigue damage. Life prediction techniques of linear damage rule, double linear damage rule and damage curve approaches are applied, and results are compared with the experimental data. The agreement between prediction and experiment is found to be excellent.     

Specifying transformer winter and summer peak-load limits

This paper presents a methodology for specifying the winter and summer peak-load limits for substation transformers that carry a temperature-sensitive load, taking into account the random nature of load and ambient temperature as well as their correlation. With this methodology, we can easily and accurately specify the peak-load limits for each substation transformer once the historical ambient temperature and load data are available. Also, we can collectively specify the peak-load limits for the transformer of each cooling type (OA, OA/FA, or OA/FA/FA) in a geographic region based on the mean and standard deviation of ambient temperatures in that region. Such peak-load limits are useful for power system planning.