基于Griffith强度理论的空腔膨胀模型与应用研究

根据混凝土材料受高速冲击时产生大量碎裂的特点,假设其粉碎(塑性)区介质服从Griffith 强度理论,发展了弹丸深侵彻混凝土靶的动态空腔膨胀模型,建立了弹丸深侵彻理论计算公 式. 对比表明：基于Griffith强度理论的球形动态空腔膨胀模型的计算结果与实验数据吻合 较好.     

基于欧拉摩擦的皮带内力分布及载荷变形关系

围绕圆轮的皮带在达到临界状态前外载增加或降低过程中,局部静摩擦力会发生大小 和方向的改变. 皮带任一点处内力变化可以沿指数曲线增加或减小,取决于加载历史. 皮带 本身是线弹性材料,但变形与力之间是非线性关系,且加载与卸载过程不同,形成滞回圈. 滞回圈内每一点都是皮带可能出现的载荷和变形状态.     

对液压法测杨氏模量的实验研究

引入了液压法测量杨氏模量,用液压微位移放大原理来表征微小变化量,用液压微位移放大器对传统的实验装置进行改进,通过实验原理、误差分析,结合测量结果,对此实验方法进行分析与讨论,由此给出了一种测量杨氏模量新的方法.     

无衍射 Mathieu光束自重建特性的理论和实验研究

首次对无衍射Mathieu光束的自重建特性进行理论和实验研究, 利用Mathieu-Hankel波理论分析了Mathieu光束的自重建机理. 基于菲涅尔衍射积分理论, 推导出了高斯吸收型圆形障碍物部分遮挡后的Mathieu光场重建后的解析表达式, 并数值模拟了无衍射Mathieu光束的经圆形障碍物部分遮挡后光场的自重建过程. 采用柱透镜-轴棱锥组合光学系统产生近似零阶无衍射Mathieu光束, 实验分别验证了轴上和轴外障碍物遮挡时近似零阶无衍射Mathieu光束的自重建特性. 理论模拟与实验结果相符.     

跟踪β-淀粉样肽聚集体的探针—1,4-二苯基三氮唑衍生物的合成

Aβ聚集体在大脑中的聚集与阿尔茨海默病的发生发展密切相关,Aβ聚集体的靶向探针对于阿尔茨海默病的诊断有着十分重要的意义.本文报道具有跟踪Aβ聚集体功能的探针——1,4-二苯基三氮唑衍生物的合成,从4-碘苯酚与4-氨基苯乙炔出发,经8步反应,以39％的总收率得到目标化合物1.本文以Salen-Cu(L1-Cu)及其类似物...     

一个反向Hilbert型积分不等式及其等价式

引入权函数,建立一个含多参量的新的反向Hilbert型积分不等式及其等价式.并证明了其常数因子为最佳值.作为应用,给出了其几个特殊结果.     

蚊子体表面的微纳米结构与浸润性

通过光学显微镜及自行设计的接触角测试系统研究了成蚊体表面(如翅膀、 复眼)的浸润行为, 发现了不同的体表面由于不同的生物功能而具有不同的超疏水特性. 通过扫描电子显微镜检测成蚊翅膀和复眼表面, 揭示了分布在成蚊体表面上的不同的微观结构形貌, 另外, 微米结构表面上还包含了纳米结构是其体表面微观结构的共同属性. 因此, 微纳米等级结构与浸润性之间存在重要的依赖关系.     

Comparative adsorption of methylene blue by magnetic baker’s yeast and EDTAD-modified magnetic baker’s yeast: Equilibrium and kinetic study

Magnetic baker’s yeast (MB) was prepared using glutaraldehyde cross-linking method and chemical modification with ethylenediaminetetraacetic dianhydride (EDTAD). The fabricated EDTAD-modified magnetic baker’s yeast (EMB) was then employed to remove methylene blue. Comparative adsorption of methylene blue by EMB and MB was systematically investigated with respect to pH, contact time, initial concentration and reaction temperature. The mechanism of methylene blue adsorption by EMB and MB was investigated by SEM, FTIR and Special surface area using methylene blue method. The results revealed that Fe₃O₄ nanoparticles were steadily cross-linked/incorporated with baker’s yeast biomass and the EDTA was modified on the surface of the magnetic baker’s yeast. The equilibrium adsorption data were fitted better by Langmuir isotherm, and the specific surface areas were 42.953–226.07 m²/g for MB and 94.972–499.85 m²/g for EMB, respectively. Kinetic studies suggested that the pseudo-second-order model was suitable to describe the adsorption process. Thermodynamic studies indicated that the adsorption was feasible, spontaneous and endothermic. The recovery efficiencies were above 80% by using 0.1 M HCl.     

在位企业适应突破性创新的投资策略研究

突破性技术创新的出现对企业的生存环境和技术基础产生巨大的冲击,在位企业应对突破性创新时一般有被动适应和主动适应两种策略。当突破性创新已经发生,在位企业只能根据企业自身条件和特点被动地适应技术变革。当突破性创新有可能发生时,在位企业会从战略视角作出预期,采取灵活性的投资策略,主动地适应突破性创新的冲击。本文通过一个简单的投资模型,对在位企业适应突破性创新的两种不同策略进行了分析,并给出相应的算例。     

Synchronized stationary distribution for stochastic multi-links systems with Markov jump

This paper is concerned with the existence of a synchronized stationary distribution for stochastic multi-links systems with Markov jump (SMMJs). By employing Lyapunov method, Kirchhoff’s Matrix Tree Theorem in graph theory as well as M-matrix method, several criteria are given to guarantee the existence of a synchronized stationary distribution of SMMJs, including the Lyapunov-type theorem and a coefficients-type theorem. As a subsequent, the theoretical results are applied to a class of stochastic Markov jump oscillators with multi-links and stochastic multi-links Chua’s circuits with Markov jump, which indicates the results present widely applied prospect in various physical systems. Eventually, two examples together with numerical simulations are provided to validate the effectiveness of the theoretical results.