可注射性骨组织工程支架材料不饱和聚磷酸酯的合成

以富马酸、1,2-丙二醇和三氯氧磷为起始原料,合成了主链重复结构单元中含不饱和双键的聚磷酸酯.FTIR及NMR研究表明.不饱和聚磷酸酯(UPPE)主链结构中含有富马酸二(1,2-丙二醇)酯(BPGF)的三种异构体.利用GPC研究了反应时间对聚合反应的影响,结果表明,延长反应时间有利于提高分子量,聚合物趋向于单分散性.反应18 h后,聚合物重均分子量达到5 956 g/mol,分散度为1.12.通过测定UPPE与N-乙烯基吡咯烷酮(NVP)的交联温度曲线,确定交联反应最高温度为41.14-82.30℃,固化时间在1.95-10.28 m in之间.     

时变垂向入渗影响下河渠-潜水非稳定渗流模型的解及应用

在河渠边界控制下的半无限含水层中,对时变垂向入渗影响下的潜水非稳定渗流模型,利用Boussinesq第一线性化方法,通过Laplace变换并结合卷积原理,导出模型的解析解．根据不同水文地质条件下解的数学特征,建立相应的含水层参数求解方法;在此基础上,建立计算河渠与含水层之间水量交换的公式,以及计算潜水蒸发强度的递推公式．以安徽淮北平原某河流-潜水含水层系统为例,阐述上述方法的计算过程与步骤．     

Global composite element iteration for analysis of seepage free surface

ＩｎｔｒｏｄｕｃｔｉｏｎＳｅｅｐａｇｅｆｒｅｅｓｕｒｆａｃｅｉｓｏｆｔｅｎｅｎｃｏｕｎｔｅｒｅｄｉｎｔｈｅｃｏｕｒｓｅｏｆｓｅｅｐａｇｅｐｒｏｂｌｅｍｔｈｒｏｕｇｈｍｅｄｉａｏｆｓｌｏｐｅ,ｅａｒｔｈｄａｍａｎｄｔｕｎｎｅｌｅｎｇｉｎｅｅｒｉｎｇ．Ｔｈｅｐｈｅｎｏｍｅｎａｏｆｓｅｅｐａｇｅｆｒｅｅｓｕｒｆａｃｅｉｓｏｎｅｏｆｔｈｅｉｍｐｏｒｔａｎｔａｎｄｄｉｆｆｉｃｕｌｔｔｏｐｉｃｓｏｆｒｏｃｋｍａｓｓｈｙｄｒｏｍｅｃｈａｎｉｃｓ［１～３］,ａｎｄｑｕｉｔｅａｎｉｍｐｏｒｔａｎｔｒｅｓｅａｒｃｈ…     

Free boundary problem of non-steady state seepage flow

１ＶａｒｉａｔｉｏｎａｌＩｎｅｑｕａｌｉｔｙＭｏｄｅｌｉｎｇｆｏｒＮｏｎ＿ＳｔｅａｄｙＳｔａｔｅＣｏｍｐｒｅｓｉｂｌｅＳｅｅｐａｇｅＦｌｏｗｏｆＷｅｌＴａｋｅａｃｏｍｐｒｅｓｉｂｌｅｐｕｍｐｉｎｇｗｅｌｉｎｔｈｅｕｎｉｆｏｒｍｉｓｏｔｒｏｐｉｃｍｅｄ...     

改性聚乙二醇修饰高交联度不饱和聚酯网络结构的动态力学分析

合成了一系列含有反应活性端基的改性聚乙二醇,并用其对BMC(团状模塑料)专用的高交联度不饱和聚酯进行增韧.结果表明,含有反应性马来酸酐端基的聚乙二醇参与了不饱和聚酯的固化反应,可在交联网络中构成不同长度的柔性链段,在显著提高不饱和聚酯的韧性的同时,基本保持了材料的模量及其它力学性能.用动态力学分析(DMA)对不饱和聚酯交联网络结构进行了系统研究.     

关于岩石水力模型

本文对近几年来岩石水力模型、试验及工程应用情况进行了分析和讨论。      

水坝渗流自由边值问题的解法

本文给出一个变换,它将水坝渗流自由边值问题化为一个矩形(二维情况)或长方体(三维情况)区域上的拟线性椭圆型方程组的固定边值问题。它很容易用有限差分方法及SOR算法求解。本文方法适用于二维、三维以及有排水井的情况。     

Fe－ZSM－5分子筛中Fe的化学环境研究

本文应用ＥＳＲ、ＸＰＳ、ＤＲＳ、Ｍｏｓｓｂａｕｅｒ谱和首次运用ＴＰＲ技术结合ＸＰＳ、ＸＲＤ对Ｆｅ－ＺＳＭ－５中Ｆｅ的化学环境进行了研究。结果表明，碱性介质条件下合成的Ｆｅ－ＺＳＭ－５分子筛中，铁仅有一种价态Ｆｅ（Ⅲ），但却有多种存在形式。非骨架Ｆｅ（Ⅲ）包括分子筛孔道内及外表面上沉积的氧化铁；骨架Ｆｅ至少有两种状态，即骨架不饱和配位Ｆｅ（Ⅲ）和骨架畸变四配位的Ｆｅ（Ⅲ）．各种测试方法的结果表明Ｆｅ主要位于分子筛的骨架上，非骨架Ｆｅ（Ⅲ）很少．     

Reactions of selenium dichloride and dibromide with unsaturated ethers. Annulation of 2,3-dihydro-1,4-oxaselenine to the benzene ring

Highly chemo-, regio-, and stereoselective syntheses of novel organoselenium compounds from selenium dichloride or dibromide and unsaturated ethers are described. The reactions of selenium dichloride with allyl and propargyl phenyl ethers afford either annulated products or bis-adducts depending on the conditions. The first examples of annulation of 3-chloromethyl- and 3-chloromethylene-2,3-dihydro-1,4-oxaselenine to the benzene ring are reported.     

A study of the combustion and fire-retardance behaviour of unsaturated polyester/phenolic resin blends

The thermal degradation and combustion behaviour of an interpenetrating network (IPN) structure of unsaturated polyester UP resin and a resole type of phenolic resin was studied. Thermal gravimetric analysis (TGA) was used to monitor the degree of thermal decomposition for the UP/phenol IPN structure and the change of the oxygen index (OI) was used to describe the variation of the combustion behaviour. The smoke density was measured via a non-flaming process to detect the amount of smoke generated during the combustion. A homemade cone calorimetric dynamic flammability evaluation system was assembled to analyse the gas evolved and to measure the heat release rate (HRR) during the combustion. Under simulated conditions of a burning field at the temperature of 757°C, the variation of the concentration of carbon monoxide (CO) and the HRR of the UP/phenol IPN structure were studied. The results show that modification of the essentially flammable UP resin by the phenol structure to form an IPN system cannot only remarkably improve the heat resistance but also help to suppress the smoke, toxic gas and heat release during the combustion.