混凝土静力与动力损伤本构模型研究进展述评

对混凝土材料在静力和动力载荷作用下的损伤本构关系模型进行了评述.梳理了混凝土本构关系研究的历史脉络和逻辑脉络;归纳总结了在混凝土本构关系研究发展过程中具有代表性意义、并且对重大工程建设具有参考意义的若干混凝土静力和动力损伤本构模型.基于对混凝土材料非线性及随机性的理解和诠释,阐述了混凝土静力和动力本构关系研究的发展趋势.      

液体的爆炸抛撒特征

针对液体爆炸抛撒过程设计了实验装置,利用高速摄像仪进行记录。通过研究不同中心装药量和 填充液体的抛撒过程,发现在壳体破裂后,液体沿裂缝处向外飞散。药量较小时,液体分散成树枝状形态,然 后破碎成液滴;药量较大时,则形成液体环状区。对于不同粘度的液体,环状区分别由小液滴及已雾化、汽化 的液体,或大液滴、液体丝及液膜等组成,抛撒过程中其宽度越来越大,大液滴、液体丝及液膜等也逐渐破碎成 细小的液滴。     

人体动脉瘤生成与破裂的力学分析

在大变形超弹性理论框架下研究了内压、轴向拉伸和扭转联合作用下人体动脉壁的力学响应,应用结构不稳定性理论对动脉瘤生成的可能性进行了解释,应用材料强度理论对动脉瘤破裂的可能性进行了分析．考虑动脉壁中残余应力和平滑肌主动作用的影响,用纤维加强各向异性不可压超弹性复合材料两层厚壁圆筒模型来模拟动脉壁的力学特性．给出了正常和几种非正常状态下动脉壁的变形曲线和应力分布．变形和稳定性分析结果表明该文模型可以模拟正常状态下动脉壁的均匀变形,还可以模拟在动脉壁中弹性蛋白纤维和胶原蛋白纤维强度降低的非正常状态下动脉瘤生成的可能性及动脉瘤的增长．应力和强度分析结果表明该文模型可以模拟当动脉瘤中的最大应力超过管壁的强度时动脉瘤破裂的可能性．     

Optimization of the Acoustic Pressure Distribution in a Resonant Photoacoustic Cell

The size of a cylindrical photoacoustic cell with suitable size was selected so that the resonant frequency of the first radial mode was equal to that of a longitudinal higher mode. By maintaining two thin coaxial tubes at each end, a enhanced photoacoustic cell was constructed with two tubes of 1/2 and 1/4 of the wavelength. In this enhanced photoacoustie cell, both the first radial resonance and the higher longitudinal resonance were excited adequately. Coupling of two acoustic modes makes the acoustic energy concentrating in the middle of the cell. The surface loss was decreased, the acoustic quality factor and pressure amplitude increased obviously as compared with conventional cylindrical cell.     

The Role of Silicon Oxide Layers in Luminescence of Ensembles of Silicon Quantum Dots

Based on the quantum confinement-luminesecence center model,to ensembles of spherical silicon nanocrystals (nc-Si)containg two kinds of luminescence centers(LCs) in the SiOx layers surrounding the nc-Si,the relationship between the photolumincescence(PL) and the thickness of the SiOx layer is studied with the excitation energy flux density as a parameter.When there is no SiOx layer surrounding the nc-Si,the electron-heavy hole pair can only recombine inside the nc-Si,then the PL bluehift with reducing particle sizes roughly accords with the rule predicted by the quantum confinement model of Canham.When there presences a SiOx layer,some of the carriers may tunnel into it and recombine outside the nc-Si at the LCs to emit visible light.The thicker the SiOx layer is,the higher the radiative recombination rate occurred outside the nc-Si will be.When the central Scale of the nc-Si is much smaller than the critical scale,the radiative recombination rate outside the nc-Si dominates,and visible PL will be possible for some nc-Si samples with big average radius,greater than 4nm,for example.When there is only one kind of LC in the SIOx layer,the PL peak position does not shift with reducing particle sizes.All these conclusions are in accord with the experimental results.When there are two or more kinds of LCs in the SiOx layer,the PL peak position energy and intensity swing with reducing particle sizes.     

[(ButC5H4)2NdMe]2催化聚合甲基丙烯酸甲酯

茂基钕甲基化合物;亲核取代反应;[(ButC5H4)2NdMe]2催化聚合甲基丙烯酸甲酯     

Halodemetallation of (Z)-1-[2-(Triarylstannyl)vinyl]-cyclooctanol and Correlation of Proton Chemical Shift with Electronegativity

IntroductionOrganotin compounds have attracted attentionas an optimal model for antitumour agents due tothe function of the interesting intramolecularO→Sn coordination[1,2 ] . Our recent concern hasbeen focused on the preparation of ( Z) - 1 - [2 -( triarylstannyl) vinyl]- cyclooctanol[3 ] .In order tofind more appropriate compounds used asanticancer agents and explore the effect of thecoordinate O→ Sn interaction to the antitumoractivity,the new compounds werehalodemetallated and characte…     

苯酚的敞开体系化学振荡反应动力学法测定

利用KBrO3-Ce(SO4)2-Ch2(COOH)2-H2SO4敞开体系研究测定黄河水中苯酚污染物的新方法,在连续搅拌反应器（CSTR）中,当[KBrO3]=0.0625mol/L,[CH2(COOH)2]=0.187mol/,[Ce(SO4)2]=0.002mol/,[H2SO4]=0.8mol/L,蠕动泵单路流速为1.2mL/min时,苯酚的质量浓度在0.10-25mg/L范围内与振幅的改变、周期的改变呈线性关系,检出限为0.05mg/L;苯酚的加标回收率为95%-102%。     

新有机锡化合物的合成及分子内O→Sn配位键的离解与~1HNMR相关性的研究(英文)

用具有抗癌活性的(Z) - 1-[2 - (二卤化苯基锡基乙烯基)] -环辛醇与含氮的双齿配体作用,合成了一系列新的有机锡络合物,通过IR,1HNMR,元素分析和摩尔电导值的测定对其结构、性质进行了表征,特别对有机锡化合物分子内O→Sn配位键的离解与配体中烯基质子化学位移(1HNMR)的相关性进行了讨论     

型钢柱(压杆)稳定设计的直接法

在稳定设计中,根据已知轴向荷载来确定型钢柱的截面尺寸,当前国内外均采用试算的方法,设计过程非常繁琐。本提出一种确定型钢柱截面尺寸的简捷方法-直接法,使设计工作摆脱了繁琐的试算,大大提高了计算效率。