理想量子气体高温条件下的相对论热容量

通过严格的理论推导,给出理想量子气体在高温条件下的相对论的状态方程、内能和热容量,并与高温条件下的非相对论结论对比,可看出相对论与非相对论两种理论的差异.     

Bayesian Analysis of Asymmetric Stochastic Conditional Duration Model

This paper proposes Markov chain Monte Carlo methods to estimate the parameters and log durations of the correlated or asymmetric stochastic conditional duration models. Following the literature, instead of fitting the models directly, the observation equation of the models is first subjected to a logarithmic transformation. A correlation is then introduced between the transformed innovation and the latent process in an attempt to improve the statistical fits of the models. In order to perform one‐step‐ahead in‐sample and out‐of‐sample duration forecasts, an auxiliary particle filter is used to approximate the filter distributions of the latent states. Simulation studies and application to the IBM transaction dataset illustrate that our proposed estimation methods work well in terms of parameter and log duration estimation. Copyright © 2014 John Wiley & Sons, Ltd.     

Regulation of neural circuit formation by protocadherins

The protocadherins (Pcdhs), which make up the most diverse group within the cadherin superfamily, were first discovered in the early 1990s. Data implicating the Pcdhs, including ~60 proteins encoded by the tandem Pcdha, Pcdhb, and Pcdhg gene clusters and another ~10 non-clustered Pcdhs, in the regulation of neural development have continually accumulated, with a significant expansion of the field over the past decade. Here, we review the many roles played by clustered and non-clustered Pcdhs in multiple steps important for the formation and function of neural circuits, including dendrite arborization, axon outgrowth and targeting, synaptogenesis, and synapse elimination. We further discuss studies implicating mutation or epigenetic dysregulation of Pcdh genes in a variety of human neurodevelopmental and neurological disorders. With recent structural modeling of Pcdh proteins, the prospects for uncovering molecular mechanisms of Pcdh extracellular and intracellular interactions, and their role in normal and disrupted neural circuit formation, are bright.     

A uniform numbering system for indole alkaloids

Résumé Nous proposons un mode uniforme de numérotation pour le squelette des alcaloïdes indoliques complexes. Il est basé sur le fait que tous ces composés sont susceptibles d'être coupés en éléments identiques.

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This is a precis of a suggestion discussed at the fifth annual meeting, American Society of Pharmacognosy, Symposium on the Chemistry and Biological Activity of Catharanthus, Vinca and Related Indole Alkaloids, Pittsburgh (Pennsylvania), June, 1964.     

时域谱和二甲基硅油的玻璃化转度

测量了聚合度由５０～８２４的二甲基硅油的频域和时域低温介电谱,其结果和聚合度几乎无关．在－１２０℃的玻璃化转变中频域损耗只有一个小峰,但时域慢介电常数却出现显著的强峰,由分子的螺旋结构解释了实验结果．     

单缸发动机消声器压力损失的CFD研究

测量了某单缸发动机消声器的入口气流脉冲压力信号.依据消声器的实际物理结构,建立了发动机消声器的仿真模型.考虑单缸发动机的排气特性,提出了使用脉冲压力有效值设置边界条件的方法,运用计算流体动力学(CFD)技术仿真计算了消声器内部压力损失的分布情况.根据仿真结果,分析得到消声器内部产生较大压力损失的环节,有针对性地对消声器内部结构进行了改进.在相同工况下,对改进后的消声器入口气流压力信号进行了测量,并再次进行了仿真计算.结果表明,改进后消声器压力损失明显降低,且在内部分布更加均匀.     

理想量子气体高温条件下相对论波长分析

从德布罗意波长的定义出发，通过严格的理论推导，给出理想量子气体高温条件下的各种层次的相对论统计波长，并进行分析比较，可看出这些统计理论的差异．     

理想量子气体的极端相对论统计态及其分析

本文给出理相量子气体在高温条件下极端相对论的状态方程、焓和热容量,并对其规律进行物理分析。     

数控凸轮磨削中三环控制系统设计

为验证数控凸轮磨削控制系统中三闭环的稳定性,根据矢量控制原理,将交流永磁同步电机（PMSM：Permanent Magnet Synchronous Motor)等效为直流电机系统模型,并应用机理分析法对凸轮旋转轴（C轴）和砂轮进给轴（X轴）进行深入剖析。利用三环（电流环-速度环-位置环）由内而外逐步推导传递函数的方法,建立了整个凸轮轴磨削控制系统的数学模型,并进行了Matlab仿真。结果表明,建立的三环控制系统稳定,为进一步研究凸轮高精度磨削提供了理论基础。     

Application of CAE technology for Geely car lightweight

In order to reduce energy consumption and protect the human survival environment,the lightweight has became the development trend of the world automobile industry.On the premise of ensuring the strength,safety and driving performance of the car,the major car enterprises try to reduce the curb weight of the car,fuel consumption and emissions.Not only a lot of new technologies and new products have been generated,but also joint vehicle development process and computer aided engineering(CAE) analysis technology have been developed.Since the entry into the "Automobile Lightweight Technology Innovation Strategic Alliance" in Dec.2007,Geely Group has been focusing on lightw eight construction of vehicle and key assemblies in every stage of the vehicle product development.Among vehicles appeared on the market and in research,it has presented continuously better performance.The paper describes application examples and successful experience of CAE simulation analysis and performance optimization during the lightweight design and development of a self-developed model of Geely,and looks forward to the prospects for the development of lightweight of Geely vehicle.