A semi‐parametric approach to fitting a nonlinear mixed PK/PD model with an effect compartment using SAS

Modelling of the relationship between concentration (PK) and response (PD) plays an important role in drug development. The modelling becomes complicated when the drug concentration and response measurements are not taken simultaneously and/or hysteresis occurs between the response and the concentration. A model‐based approach fits a joint pharmacokinetic (PK) and concentration–response (PK/PD) model, including an effect compartment if necessary, to concentration and response data. However, this approach relies on the PK data being well described by a common PK model. We propose an algorithm for a semi‐parametric approach to fitting nonlinear mixed PK/PD models including an effect compartment using linear interpolation and extrapolation for concentration data. This approach is independent of the PK model, and the algorithm can easily be implemented using SAS PROC NLMIXED. Practical issues in programming and computing are also discussed. The properties of this approach are examined using simulations. This approach is used to analyse data from a study of the PK/PD relationship between insulin and glucose levels. Copyright © 2005 John Wiley & Sons, Ltd.     

磁流变阻尼器半主动隔振系统试验研究

介绍了对磁流变阻尼器的特性试验和将阻尼器用于隔振系统的被动与半主动控制试验。试验结果表明，阻尼力与速度之间复杂滞后环与位移激励频率、幅值和励磁电流密切相关，并呈现出一定的变化规律；被动隔振效果随励磁电流变化规律类似线性阻尼的情形，并且有调节刚度的效应；半主动控制在系统共振点附近的隔振效果优于被动隔振，但在较高频段没有优势；半主动隔振数控采样频率越低，隔振效果越差，在高频段效果劣化较明显。     

滚动摩擦机理和滚动摩擦系数

指出古典滚动摩擦定律存在着一定的局限性,对滚动摩擦机理从摩擦学观点进行了探讨,分析了滚动阻力来自微观滑动和弹性滞后.通过一系列金属和非金属材料的摩擦试验,测得滚动摩擦系数值及其变化规律,从而指出了影响滚动摩擦系数的主要因素.最后认为,滚动摩擦系数还须靠实测来确定.     

УBa_2Cu_3O_(7-δ)超导体V—H测量中的电压台阶效应

在液氮温区首次观测到由外加静磁场引起的电压台阶与滞后效应,用颗粒和弱连接有效钉扎模型对其进行了分析。分析表明,这是一种类似I—V特性中具有回滞的直流约瑟夫森效应的新现象,与颗粒和弱连接对磁通流动产生的不同钉扎与陷获有关。     

Routes into activism in post-Soviet Russia: habitus,homology, hysteresis

This paper develops Bourdieusian notions of habitus, capital and field, along with the allied concepts of hysteresis and homology, to examine routes into public activism in post-Soviet Russia. Focusing on a neighbourhood campaign against construction projects in the Moscow district of Izmailovo, we argue that mobilization was driven by activists whose formative years took place during the Soviet period, and this resultant Soviet habitus enabled them to sustain their mobilization, despite the unpropitious circumstances. Our data shows that activists’ engagement was first triggered by perceived discrepancies between Soviet ideals and post-Soviet realities (hysteresis), and then supported by the mutual recognition of actors whose grievances echoed similarities in their structural positions (homologies). However, although mobilization gained momentum, it was unable to achieve definitive success in the face of negative social capital, or what Russians call administrativniy resurs: the arbitrary use of public office power that characterizes a number of social fields in post-Soviet Russia. We argue that understanding post-Soviet mobilization requires an understanding of the continued significance of Soviet ideals, as well of the role of the intergenerational transfer of civic ideals amid Bourdieusian ‘class struggle’.     

高校图书馆人力资源管理的滞后性及其原因分析

本文论述了高校图书馆人力资源管理的内涵、意义,并对高校图书馆人力资源管理发展滞后的主要表现及其原因进行了系统分析。     

齿式橡胶联轴器动力力学建模与分析

以一款齿式橡胶联轴器为研究对象,首先采用有限元软件对齿式橡胶联轴器的弹性元件进行动力分析,得到橡胶元件的恢复力 位移数据,其次运用拟合分解法建立了弹性联轴器恢复力的数学模型,其刚度系数和阻尼系数是关于位移振幅和频率的函数。最后分析了联轴器的幅频特性和扭矩传递系数,结果表明,弹性橡胶联轴器在有效传递扭矩的同时,表现出软弹簧的非线性特性。     

一种新型双稳态过温保护电路

提出了一种新型的双稳态过温保护电路及其雪崩式工作模式。从理论上对雪崩式状态转变及滞回的产生机理作了深入的分析。与传统过温保护电路相比,该工作模式使转换速度提高了3倍以上,同时由于双稳态系统固有的稳定性,电路的稳定性也得到一定的提高。