Influences of denucleation on contact force of facet joints under whole body vibration

To investigate the influence of the injured disc, frequency, load and damping on the facet contact forces of the low lumbar spine on the condition of whole body vibration, a detailed 3-D nonlinear finite element model was created based on the actual geometrical data of embalmed vertebrae of lumbar spine. The denucleation and facetectomy, together with removal of the capsular ligaments was employed to mimic the injury conditions of lumbar spine after surgery. The compression cyclic force was assumed to mimic the dynamic loads of transport vehicles. The results show that the high frequency vibration might increase both of the value and the vibration amplitude of facet contact forces of the lumbar spine under whole body vibration. The nucleus removal may increase significantly the facet contact forces. Although damping can decrease the vibration amplitude of facet contact forces for intact models, it has less effect on the vibration amplitude of facet contact force for the denucleated models. The denucleation of intervertebral discs is more harmful to the facet articulation on the condition of whole body vibration.     

一种新颖的半导体光放大器镀膜监控方法

本文介绍了一种在半导体光放大器镀膜过程中监测端面反射率的简单而有效的方法。理论模型的建立考虑了光放大器的漏电流和自发发射速率随载流于浓度的非线性变化，并且基于实验测量的ＰＩ（输出功率与注入电流）曲线，采用曲线拟合的方法来修正一些依赖于器件的参数，理论计算结果与有关文献的测量结果较好地吻合。     

Diffusion of clusters down (1 1 1) aluminum islands

The key factor determining nucleation processes and faceting in homoepitaxial growth as well as texture competition is the mobility of adatoms and small clusters across step edges and facets. Using a combination of molecular dynamics and ab initio calculations, we investigate the mechanisms of small clusters (dimer and trimer) diffusion down the aluminum (1 1 1) surface. In this paper we report results of molecular dynamics studies. Our study shows that the clusters dissociate at the step-edge of compact islands. As a result, the clusters diffuse down the step by an exchange mechanism with a small or medium Schwoebel barrier. The mechanism of this down-diffusion/dissociation is discussed and the corresponding energetics are calculated using the molecular statics method. We find a large anisotropy between the barriers at the two types of 1 1 0 oriented steps.     

CCM构件实现框架的分析与研究

CCM构件实现框架(CIF）为构造构件实现定义了的编程模型。作为编程抽象,CIF不但能与现存POA框架兼容,而且还能使编程人员与它的复杂性隔离。CIF使用CIDL描述创建编程框架自动化构件的基本行为。该文对CIF的架构和语义进行了剖析,描述了CCM构件的实现,然后CIF内部元素的关系进行了研究。     

面向领域的软件构件库系统初步研究

本文主要分析了面向领域应用的软件构件库系统总体框架,包括软件构件概念、软件构件库的总体结构及其相关内容。     

一种基于剖分的空间数据存储调度服务模型

随着空间数据应用领域深度和广度的扩展,空间数据在组织、存储、更新、应用等方面存在速度、效率等难题。针对上述问题,基于地球剖分组织理论,结合面向客户端聚合服务的G/S模式架构,研究并提出一种空间剖分数据存储调度服务模型。给出了该模型体系架构、数据访问流程,设计了模型的地址编码结构及地址解析过程,形成了一种有效的\"数据分散存储,客户端信息汇聚\"的空间剖分数据组织管理、按需整合、快捷调度的机制,实现并验证了服务原型系统,其具有一定的理论意义和应用价值。     

A Comparison between TGT and Cz Grown Nd：YAG

Large sized neodymium-doped Y3Al5O12 （Nd：YAG） laser crystals have been grown by temperature gradient technique （TGT） method and compared with Czochralski （Cz） method. The comparison of these two crystal growth methods has been listed. The results showed that the TGT method has many advantages over the Cz method. The concentration distribution of Nd ions in the crystals was determined and the absorption spectra of these crystals have been investigated and compared. The TGT grown highly doped Nd：YAG crystal has a larger absorption FWHM than that of Cz grown Nd：YAG crysral. Highly doped Nd：YAG （～2.8 at. pct） crystals could be obtained by TGT.     

相场法模拟凝固微观组织演化研究进展

相场法是凝固组织模拟中最有潜力的方法之一,近年来已成为凝固领域研究的热点.本文论述了相场法模拟凝固微观组织的原理,并分别介绍了无流动和流动条件下相场法模拟自由枝晶、定向凝固界面及小平面枝晶在国内外的研究进展,指出了进一步的研究方向.