水栖性的棘胸蛙身体大小不随环境水热梯度及净初级生产力梯度而分化

之前的研究发现不同地理种群棘胸蛙(Quasipaa spinosa)的身体大小随着环境生产力以及年最低温的降低而增大,因为更大的身体利于在生产力水平较低的环境中耐受饥饿并利于在寒冷的环境条件下保存热量.然而在种间水平上进行的相关研究发现:由于大部分时间生活在水体这种相对稳定的环境中,水栖性无尾类的身体大小并不受宏观水热波动的影响.为了更好地探究这个问题,我们以棘胸蛙为研究对象,在之前的基础上选择更多的研究地点及更多的环境因子,研究其身体大小的地理分化格局并探究潜在机制.与之前的发现不同,作为一种水栖性无尾类,棘胸蛙的身体大小并不受环境水热梯度以及净初级生产力梯度的影响.导致这种现象的原因可能是水栖性的生境偏好缓和了棘胸蛙受到的来自宏观环境水热波动的影响,所以它们并不通过改变身体大小来适应宏观环境梯度.此外由于棘胸蛙的肉食性,环境初级生产力并不能有效地衡量其食物供给,其身体大小是否受到食物供给量的影响仍有待深入探究.     

头盘微小间隙动态浮动理论研究

本文对微小浮动间隙的磁头浮动块的动态浮动性能进行了仿真计算。在考虑头盘碰撞的基础上,分析了磁头浮动块对冲击的响应。分析结果表明:在微小浮动间隙的头盘系统中,盘片表面粗糙度和外界干扰冲击对浮动块的浮动性能影响较大。新的动态浮动理论中,必须包含头盘磁撞的研究。     

图像编码技术的发展

本文回顾了常规的图像编码技术及其进展，介绍了近年来迅猛发展起来的新的图像编码技术，并讨论了这些技术的发展前景。     

Some synchronization criteria for general complex networks with coupling delays

A general complex delayed dynamical network model with asymmetric coupling matrix is considered in this paper. For reducing the conservativeness of synchronization criteria, several novel synchronization stability conditions are presented by using delay decomposition methods. Numerical examples which are widely used to study delay-dependent synchronization stability are given to illustrate the effectiveness of the proposed methods.     

<Emphasis Type="Italic">H</Emphasis><Subscript>∞</Subscript> control for stochastic systems with Poisson jumps

This paper discusses the H _∞ control problem for a class of linear stochastic systems driven by both Brownian motion and Poisson jumps. The authors give the basic theory about stabilities for such systems, including internal stability and external stability, which enables to prove the bounded real lemma for the systems. By means of Riccati equations, infinite horizon linear stochastic state-feedback H _∞ control design is also extended to such systems.     

Optimal combinational of quota-share and stop-loss reinsurance contracts under VaR and CTE with a constrained reinsurance premium

This paper considers the problem of minimizing the VaR and CTE of an insurer’s retained risk by controlling the combinational quota-share and stop-loss reinsurance strategy. With a constrained reinsurance premium, the authors give the explicit reinsurance forms and the minimal VaR and CTE of retained risk in the case of quota-share after stop-loss reinsurance and the case of stop-loss after-quota-share reinsurance respectively. Finally, the authors conclude that the quota-share after stop-loss is a better reinsurance strategy than stop-loss after quota-share to minimize the VaR and CTE with a same constrained reinsurance premium. And the pure stop-loss reinsurance is preferred for an insurer with a high level regulatory requirement.     

β转化生长因子（TGF—βs）与骨代谢

β转化生长因子是一族具有多种生理功能的生长因子,它分布广泛,通过自／旁分泌对各组织细胞的增殖,分化的各环节起促进和抑制作用。本文对ＴＧＦ－βｓ在骨,软骨中的分布,合成,分泌,以及其对骨,软骨的增殖,分化的调控作用,作了全面的回顾与总结,介绍了国内外ＴＧＦ－βｓ研究领域的最新动态,有助于进一步探讨ＴＧＦ－βｓ与骨组织的关系,进一步揭示骨代谢的机理,为临床诊治提供新思路,新方法。     

强化高速公路工程质量管理浅议

高速公路的设计标准和工程质量要求高,必须重视和加强高速公路工程质量的管理.本文从提高工程人员质量意识、重视现场施工质量管理、重视工地实验室建设等多个环节对如何加强高速公路工程质量管理提出建议.