含多源损伤的胶接修补结构有限元分析方法

采用有限元法研究含多源损伤结构的胶接修补问题,利用二维三层有限元模型对损伤区进行了数值模拟,并选取典型多源损伤情况中含共线双裂纹铝板结构为算例,详细分析了含多裂纹胶接修补结构中两裂纹相对位置、补片尺寸、铺层和厚度对应力强度因子的影响.结果表明,复合材料胶接修补可明显降低含共线双裂纹母板的应力强度因子;对于确定的裂纹和应力场,应对复合材料补片长度和厚度等参数进行优化设计,以获得最佳的修补效果.     

基于仪器线型订正的开放光程FTIR测量中的水汽谱在线扣除方法

水汽吸收分布于整个中红外波段,它的存在干扰红外光谱的定量分析。文章介绍了一种从傅里叶变换红外光谱仪的测量数据中扣除水汽干扰信号的新方法。该方法首先通过气象参数测量获得气压、温度和相对湿度,结合HITRAN数据库中提供的水汽线强、自展宽、空气展宽等参数,使用逐线积分方法计算出高分辨率水汽吸收谱,再通过仪器线型订正,合成出与仪器分辨率相匹配的水汽谱,将其作为干扰组分直接从测量所得到的含有水汽的混合光谱中扣除。对开放光程FTIR系统的实测数据的分析结果表明,使用该方法可以有效消除水汽干扰,扣除后的光谱包含待测组分的吸收特征和噪声。在开放光程FTIR等无法使用干燥设备去水的观测条件下,使用该方法可以达到较理想的水汽扣除效果。     

傅里叶变换红外光谱仪探测器仪器响应函数研究

由于傅里叶变换红外光谱仪探测器在各个波段的仪器响应不相同,在应用过程中无论是利用光谱的绝对强度还是相对强度,都需要应用标准黑体对仪器进行定标,找出仪器响应函数。该文对加拿大BOMAN公司MR154型傅里叶变换红外光谱议配带的两个红外探测器(锑化铟InSb、碲镉汞MCT)的仪器响应函数进行了研究,并找出了它们随黑体温度(辐射亮度)的变化规律。该规律对傅里叶变换红外光谱仪的定标和保证所测辐射谱的正确性有重要意义。     

三(三甲基硅氧基)甲基丙烯酰氧丙基硅烷的合成研究

用3种方法合成了三（三甲基硅氧基）甲基丙烯酰氧丙基硅烷，通过核磁共振氢谱和红外吸收光谱确证其结构，其中一步法产率可达60%以上，纯度可达98%以上，与文献报道方法相比，产率提高了10%，成本降低了30%。     

塔里木盆地绿洲分布与水源的关系

通过对整个塔里木盆地绿洲分布与水系分布概况进行野外调查与室内数据分析,探讨塔里木盆地绿洲分布与水资源的关系,证明了绿洲与水资源的内在联系.二者的关系是:塔里木盆地绿洲分布由水系分布限定的.大部分大小绿洲都是位于在河流流域.塔里木盆地绿洲规模大小随水资源开发利用变化而不断地变化.     

广义LipschitzΦ-增生算子的带误差项的Ishikawa迭代序列的收敛性及应用

在一致光滑Banach空间中,证明了广义LipschitzΦ-增生算子的带误差项的Ishikawa迭代序列强收敛于方程Tx=f的解,其结果改进和扩展了近期许多相关结果.并由此得出了Ishikawa迭代序列稳定性的一些结果.     

钨系催化丁二烯聚合动力学的研究——聚合速率方程的建立及活化能的确定

本文研究了WCl_6-C_4H_9OH-Al(i-Bu)_2 OPhCH_3体系催化合成1,2-聚丁二烯的动力学特征,测定了单体、主催化剂和助催化剂的反应级数,建立了稳态期聚合速率方程,求得其表现活化能及Arrhenius因子,并对其反应动力学机理作了初步讨论。     

MODELING THE CHAIN CONFORMATION OF POLYMER MELTS IN CONTRACTION FLOW

A constitutive model of quasi-Newtonian fluid based on the type of flow is used in abrupt planar contraction now.The numerical results from finite element analysis are consistent with experimental data for stress patterns and velocityprofiles in the flow field. The chain conformations of polymer melts are then investigated in such a planar contraction byusing the phenomenological model with internal parameters proposed by the author. That is, the shape and orientation ofpolymer chain coils are predicted and discussed in different flow regions of the contraction flow field that possess simpleshear flow, extensional flow, vortical flow, and mixed flow respectively.     

TEMPERATURE AND pH RESPONSE, AND SWELLING BEHAVIOR OF POROUS ACRYLONITRILE-ACRYLIC ACID COPOLYMER HYDROGELS

Macroporous acrylonitrile-acrylic acid （AN-AA） copolymer hydrogels were synthesized by flee-radical solution polymerizations, using ammonium persulfate （APS）/N,N,N＇,N＇-tetramethylethylenediamine （TEMED） redox initiator system and alcohols porogens. The morphology, temperature and pH sensitive swelling behavior, and swelling kinetics of the resulting hydrogels were investigated. It was found that alcohol type and concentration had great influences on the pore structure and porosity of hydrogels. The pore size of hydrogel increases with the moderate increase of the length of alcohol alkyl chain. However, a further increase of alkyl length would result in the formation of cauliflower-like structure and the decrease of pore size. The porosity of hydrogels increases with the increase of porogen concentration in the polymerization medium. The hydrogels with macroporous structure swell or shrink much faster in response to the change of pH in comparison with the conventional hydrogel without macroporous structure. Furthermore, the response rate is closely related to the porosity of the hydrogels, which could be easily controlled by modulating the concentration of the porogen in the medium. The circular swelling behavior of hydrogels indicated the formation of a relaxing three-dimensional network.     

STUDY ON THE FORMATION MECHANISM OF MONODISPERSE PARTICLES IN THE EMULSIFIER-FREE EMULSION POLYMEAIZATION OF METHYL METHACRYLATE AND BUTYL ACRYLATE

The formation mechanism of monodisperse polymer latex particles in the emulsifier-free emulsion polymerizationof methyl methacrylate and butyl acrylate with potassium persulfate as initiator was investigated. A multi-step formationmechanism for the monodisperse polymer particles was proposed. The nucleation mechanism is considered to be thecoagulation of the precursor particles by homogeneous nucleation when the primary particles reach a critical size with highsurface charge density and sufficient stability. It had been proved by a special experiment that the early latex particles formedby the coagulation were stable. The primary particles grow by absorbing monomers and radicals in the polymerization systemand then become colloidally unstable again due to the understandable decrease of particle surface charge density, which leadsto the aggregation of the growing particles and the formation of larger latex pedicles therefrom. Aner the nucleation period,the preferential aggregation of the smaller particles in the propagation process leads to the change of the particles towards auniform size and narrower particle size distribution. The coexistence and competition of homogeneous nucleation,coagulation, propagation and aggregation result in the increase of the polydispersity index (U = D_(43)/D_(10)) in the first Stage,then its decrease in the later stage because of the competition of propagation and aggregation, and the gradual formation ofthe monodisperse particles.