结构稳定性

The Diels-Alder cycloadditions of [60] fullerene for preparation of optical limitingmaterials are discussed in chapter 3 and 6. Soluble cycloaddition derivatives of 〓aresynthesized by the reaction of 〓 with indene,1,1'-biindene andcyclopentadiene derivatives.〓Particular, the Diels-Alder cycloaddition of 〓 with1,1'-biindene under controlled conditions affords the stable monoadduct 〓〓of novel structure, which was confirmed by HPLC, FTIR, FD-MS,〓NMR,〓 NMR, HMQC and HMBC spectra, Its two bridgehead cage carbons resonate at70.91ppm, The 〓 NMR spectra showed 38 lines consistent with the 〓 symmetryassociated with [6,6] addition. The 〓 shows similar optical limitingproperties to that of 〓 in toluene for 8ns laser at wave length 532nm. Moreover, thehigh solubility of this adduct in polar solvents such as THF, acetone enables itsincorporation into sol-gel glass matrix. The thin films prepared via the sol-gel methodshow improved OL behaviour compared to those of 〓. The langmuir-Blodgett filmformation and uv-visible absorption of 〓 are also investigated. LBmonolayer of this compound is prepared on the air-water interface at 〓 mol/l. In chapter 4, three water-soluble derivatives of [60] fullerene: fullerol(1), theaddition product (2)of fullerol (1)with polyvinylpyrrolidone and fumaric acidderivative of 〓(3) are synthesized and characterized.

通过Diels-Alder环加成反应，用茚〓和1，1'-联茚〓及取代茂合成了一系列可溶性的〓环加成衍生物，发现可控制反应条件，使1，1'-联茚与〓反应，并高产率地得到具有新颖结构的单加成物，用HPLC、FTIR、FD-MS 及〓、HMQC、HMBC等多种波谱技术对其结构进行表征，测得它的两个〓杂化的桥头碳的化学位移为〓ppm，证明生成的衍生物为6∶6闭式环加成，〓NMR谱中共给出38个信号，表明〓联茚衍生物分子具有〓对称性；在波长532nm，脉冲宽度8ns的激光下，〓联茚衍生物的甲苯溶液的光限幅性能与〓的甲苯溶液相近，由于〓联茚单加成衍生物熱稳定性好，在四氢呋喃，丙酮等极性溶剂中溶解性好，能分别均匀地掺入溶胶-凝胶中，已发现它的溶胶(so1)光限幅性能优于纯〓的光限幅性能；使用Langmuir-Blodgett技术将〓联茚衍生物在空气和水的界面进行了LB单层膜和多层膜实验以及UV-Vis吸收谱研究，通过等温压缩曲线测试，证明浓度为〓〓时，〓联茚衍生物能够形成单层膜。

This has resulted in more rational consideration of the effects of inelasticity and stability at maximum design load level.

在当前各国的钢结构设计规范中，极限状态设计方法已被广为应用，结构在最大设计荷载下的非弹性和稳定性效应得到了更为全面而合理的考虑。

Aim at the special structure form for the first time used of the long span space truss and cross inhaul cable of the Guangzhou gymnasium light steel roof, supply the theoretical basis for the construction, therefore, improved feasibility and advanced nature of construction scheme greatly, and gained very good economic and social benefit.

5针对广州体育馆大跨度空间桁架+交叉支撑拉索轻型钢结构屋盖这一国内首次使用的结构形式，加之构件几何尺寸细小、刚度小、稳定性差，安装和拆除过程中各工况内力变化复杂且相互影响的技术难题，运用虚拟建造技术对施工方案中八大难题进行仿真分析，为实际施工提供科学的理论依据，大大提高了施工方案的可行性和先进性，取得了很好的经济和社会效益。

This dissertation has studied various architectures of Sigma-Delta modulator systematically. According to power dissipation, stability and circuit implementation, a 2-2 cascade architecture is introduced. Oversampling ratio is 32. The attenuation factors of each integrator and interstage coefficients are obtained from behavioral simulation.

本论文系统地研究了∑A调制器的各种体系结构，根据功耗、稳定性以及电路实现等方面综合考虑，∑A调制器采用级联2—2结构，过采样比为32，并通过行为级仿真确定了积分器的增益衰减因子及级间耦合系数。

For achieving the real-time identificatoin, the method of fast calculation of general inverse matrix based on second residual is taken.

变时基方法对框架结构数字仿真、海洋平台模型试验以及在环境激励下实际结构的动力参数进行了识别，结果表明了该方法的有效性和稳定性。

Some key points in designing the roof truss structure were analyzed, including lectotype of structure,load value and calculation method of the main steel members.

对屋盖桁架结构设计中风荷载的取值、屋盖结构的强度、刚度和稳定性分析、主要构件的计算等方面做了深入的工作。

The ecological type structure and biomass structure of community had lower variation and didn't change dramatically with the loss of species.

群落的生态类型结构和生物量结构具有相对的稳定性，并不因某些物种的丢失而发生明显的改变。

Using of optical microscopy, X-ray diffraction, transmission electron microscopy, hardness and tensile testing, the effect of thermal exposure at high temperatures on the microstructures and of high-temperature tensile properties of rapidly solidified AlCrYZr have been studied. The results show that there are two main phases,Al20Cr2Y(cubic, a=1.437 nm) and DO23Al3Zr(terganal, a=0.4 013 nm , c= 1.732 nm), in the as-solidified alloy. The Al20Cr2Y phase can maintain its cubic structure at 500℃, but the particles coarsen remarkably and even become lumpish. In coarse lumpish Al20Cr2Y phase the plane faults and twin structures exist.

摘 要：采用金相、 X射线衍射、透射电镜、硬度测定和拉伸试验研究了高温热暴露对快速凝固AlCrYZr合金显微组织影响和高温下力学性能的热稳定性，结果表明，快速凝固AlCrYZr合金主要第二相为Al20Cr2Y(立方，a=1.437nm)和DO23Al3Zr(正方，a=0.401 3nm， c=1.732nm)，Al20Cr2Y在500℃热暴露尚能保持其立方结构，但质点明显粗化，甚至块状化，在粗大的Al20Cr2Y相中存在有层错和孪晶结构。

The metastability of Co fine particles with sub-micrometer and micrometer scale was investigated by cooling from high temperature and by applying external stress.

报道了亚微米以及微米尺寸的Co微粒在高温冷却以及应力作用下亚稳结构的稳定性及其结构转变特性。

The structural modulability and chemical stability of hydrogenated amorphous Silicon Carbide a-Si_xC_(1-x:H films makes it suitable as a barrier layer for low K porous dielectric films.

非晶碳化硅薄膜的结构可调制性及化学稳定性使其成为Cu/超低k多孔介电薄膜结构的扩散阻挡层优异候选材料。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。