微波辐射下氯化铁催化合成柠檬酸三正丁酯

以柠檬酸与正丁醇为原料，氯化铁（Ⅲ）作催化剂，采用微波辐射法合成了柠檬酸三正丁酯．考察了微波辐射功率，辐射时间，催化剂的用量以及酸醇摩尔比等对酯化率的影响，确定了最佳反应条件，酸醇摩尔比1：6，氯化铁用量为3％（以酸的摩尔量计），微波功率140w，辐射时间5min，酯化率可达95．5％。     

Advances in Biological Water-saving Research:Challenge and Perspectives

Increasing the efficiency of water use by crops continues to escalate as a topic of concern because drought is a restrictive environmental factor for crop productivity worldwide.Greater yield per unit rainfall is one of the most important challenges in wa     

电子档案系统特点及功能综述

本文概述了电子档案具有易改易写的特性及内容和载体可分离，不再具有特定的字迹，也无法借助印章或签署等特点。并提出如何让查阅者相信其原始性和法律效力，从而发挥“历史纪录”和“社会记忆”的功能，是电子文件制作者、管理者和从事档案管理工作的人员应思考和解决的难题。     

高性能沥青路面(Superpave)的施工工艺

传统AC-I型、AK混合料在高速公路应用中均存在不同程度的缺陷，部分省份对推广使用Superpave沥青路面已经逐渐形成共识。但由于Superpave沥青路面出现较晚，国内外经验相对缺乏，关于Superpave的争论也不断，本文结合国内苏嘉杭高速公路的工程实践，通过介绍Superpave的施工工艺和关键工序质量控制点，希望能对推广使用Superpave沥青路面，提高路面施工质量起一定的作用。     

A New Method to Extract Text from Natural Scenes

This paper presents a new method for text detection, location and binarization from natural scenes. Several morphological steps are used to detect the general position of the text, including English, Chinese and Japanese characters. Next bonnding boxes are processed by a new “Expand, Break and Merge” （EBM） method to get the precise text areas. Finally, text is binarized by a hybrid method based on Otsu and Niblack. This new approach can extract different kinds of text from complicated natural scenes. It is insensitive to noise, distortedness, and text orientation. It also has good performance on extracting texts in various sizes.     

高应力软岩煤巷锚网索支护技术研究

为了研究锚网索支护技术在软岩煤巷的适用性,对2407巷道原锚网索支护方案出现的问题和软岩巷道破坏原因进行了分析,根据有限元计算结果确定支护关键部位。在此基础上,对支护方案进行优化设计,确定了具体的耦合支护参数。     

提高篮板球争夺效率的探讨

篮板球的争抢在篮球运动中起着决定性的作用，如何能够抢到更多的篮板球，对获取最后胜利有着更有力的保障。探讨篮板球的争抢要领，可为教学训练提供必要的帮助。     

A new improved structure of dye-sensitized solar cells with reflection film

DYE-SENSITIZED NANOCRYSTALLINE SOLAR CELLS (DSSC), RECENTLY DEVELOPED BY MICHAEL GR?TZEL[1], HAVE BEEN ATTRACTING CONSIDERABLE ATTENTIONS BECAUSE OF ITS HIGH EFFICIENCY, SIMPLE FABRICATION PROCESS AND LOW FABRICA- TION COST[2]. TYPICAL DSSC[3] IS BASED ON A SANDWICH STRUCTURE, WHICH CONSISTS OF TWO GLASS PLATES WITH A TRANSPARENT CONDUCTING OXIDE (TCO) COATING AS SUBSTRATE. O…     

计入横向剪切变形的均布载荷作用下的圆板大挠度弯曲问题渐近解

导出了图板轴对称变形的混合法基本方程组，用修正迭代法求出了均布荷载作用下，考虑横向剪切变形的圆板大挠度弯曲问题二阶渐近解．     

异核金属环戊二烯基羰基簇合物的合成与表征

本文报道了Ｍｏ２Ｐｄ２（μ３一Ｓ）２（μ２－ＣＯ）４（η－Ｃｐ）２（Ｐｐｈ２）２和Ｎａ［Ｍｏ２Ｃｕ（ＣＯ）２（μ２－ＣＯ）３（η－Ｃｐ）２（Ｐｐｈ３）３］两个簇合物的合成及元素分析、红外光谱、核磁共振谱等表征数据．并对这两个簇合物的结构进行了讨论．