基于振动响应的耦合杆系统损伤识别

 基于响应灵敏度分析法对两跨耦合杆系统的损伤识别问题进行了研究。建立了耦合杆系统的有限元运动方程,利用状态空间法计算系统在外激励下的响应。将系统的局部损伤模拟为杆单元抗拉刚度的减少,推导了响应对单元抗拉刚度的灵敏度。并利用此响应灵敏度进行系统的局部损伤识别。数值算例表明,文中方法能快速准确地识别出耦合杆的局部损伤,并且对模拟的人工噪声不敏感。说明该方法具有一定的工程应用前景。     

The p38/MAPK pathway regulates microtubule polymerization through phosphorylation of MAP4 and Op18 in hypoxic cells

In both cardiomyocytes and HeLa cells, hypoxia (1% O₂) quickly leads to microtubule disruption, but little is known about how microtubule dynamics change during the early stages of hypoxia. We demonstrate that microtubule associated protein 4 (MAP4) phosphorylation increases while oncoprotein 18/stathmin (Op18) phosphorylation decreases after hypoxia, but their protein levels do not change. p38/MAPK activity increases quickly after hypoxia concomitant with MAP4 phosphorylation, and the activated p38/MAPK signaling leads to MAP4 phosphorylation and to Op18 dephosphorylation, both of which induce microtubule disruption. We confirmed the interaction between phospho-p38 and MAP4 using immunoprecipitation and found that SB203580, a p38/MAPK inhibitor, increases and MKK6(Glu) overexpression decreases hypoxic cell viability. Our results demonstrate that hypoxia induces microtubule depolymerization and decreased cell viability via the activation of the p38/MAPK signaling pathway and changes the phosphorylation levels of its downstream effectors, MAP4 and Op18.     

带积分边界条件的共振边值问题正解的存在性

基于O’Regan和Zima所研究的范数形式的Leggett-Williams定理,利用Banach空间中锥和Leray-Schauder度的性质,研究了带有积分边界条件的二阶共振边值问题正解的存在性。最后给出了例子验证所得结论。     

多车场车辆路径问题及混合遗传算法

在多车场车辆路径问题中,综合考虑车辆的行驶路程和使用车辆的数量能有效降低配送成本,考虑了这两方面的因素建立了相应的数学模型,运用混合遗传算法进行了求解,并通过实例证明了模型和算法的有效性。     

网络中路由选择算法的计算机模拟

结合互联网络中路由选择的问题,通过计算机模拟寻找一条最佳的通信路径,从而提高通信的效率.     

祁东矿副井井筒过特厚粘土层施工

祁东矿表土２４０ ～２８０ ｍ ，为一特厚粘土层段。本文详细地叙述了过这层厚粘土层所采取的各项有力措施，为今后类似工程的施工提供了这一方面的经验     

阻尼振子的起伏频谱及扩散系数

本文讨论一个最简单的耗散系统，即一个谐振子与热库耦合的系统。给出Ｌａｎｇｅｖｉｎ力Ｇ（ｔ）及算符ａ（ｔ），ａ￣＋（ｔ）的定义，由此算出阻尼振子的起伏频谱及扩散系数。其结果与Ｗｉｇｎｅｒ－ｗｅｉｓｓｋｏｐｆ近似下求得结果完全一致。     

Sexual reproduction selects for robustness and negative epistasis in artificial gene networks

The mutational deterministic hypothesis for the origin and maintenance of sexual reproduction posits that sex enhances the ability of natural selection to purge deleterious mutations after recombination brings them together into single genomes. This explanation requires negative epistasis, a type of genetic interaction where mutations are more harmful in combination than expected from their separate effects. The conceptual appeal of the mutational deterministic hypothesis has been offset by our inability to identify the mechanistic and evolutionary bases of negative epistasis. Here we show that negative epistasis can evolve as a consequence of sexual reproduction itself. Using an artificial gene network model, we find that recombination between gene networks imposes selection for genetic robustness, and that negative epistasis evolves as a by-product of this selection. Our results suggest that sexual reproduction selects for conditions that favour its own maintenance, a case of evolution forging its own path.     

中小型河道纳污能力计算方法研究

在对河段污染源进行概化的基础上提出纳污能力的计算方法及计算公式。结合水资源保护的实际需要，给出不同功能区组合情况下的纳污能力的计算方法，为水资源保护与规划提供了一种简捷有效的方法。     

Lib2.0环境下高校图书馆设立“读者互动部”的探究

分析了Lib2.0环境下读者互动工作面临的瓶颈,阐述了读者互动部的组织架构、关系模型与职能,探讨了设立读者互动部带来的体制创新之处以及通过创新提高馆读互动质量的问题,指出服务理念变革和体制创新是解决读者互动瓶颈的关键。