有缺陷的一维三元光子晶体透射谱特性的研究

运用光学传输矩阵理论,研究了有缺陷的一维三元光子晶体的透射谱特性。数值模拟结果表明:光子晶体透射谱特性将受到缺陷层折射率和光学厚度的影响。     

基于VPC3+C的Profibus-DP智能从站设计

从开发的角度介绍了VPC3+C芯片的主要功能和单片机C8051F020以及软硬件设计的主要思想,分析了Profibus-DP从站的状态机,并介绍了从站与主站通讯所需的GSD文件.     

Heat shock protein 90 protects rat mesenchymal stem cells against hypoxia and serum deprivation-induced apoptosis via the PI3K/Akt and ERK1/2 pathways

Mesenchymal stem cell(MSC)transplantation has shown a therapeutic potential to repair the ischemic and infracted myocardium,but the effects are limited by the apoptosis and loss of donor cells in host cardiac microenvironment.The aim of this study is to explore the cytoprotection of heat shock protein 90(Hsp90)against hypoxia and serum deprivation-induced apoptosis and the possible mechanisms in rat MSCs.Cell viability was determined by3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.Apoptosis was assessed by Hoechst 33258nuclear staining and flow cytometric analysis with annexin V/PI staining.The gene expression of Toll-like receptor-4(TLR-4)and V-erb-b2 erythroblastic leukemia viral oncogene homolog 2(ErbB2)was detected by real-time polymerase chain reaction(PCR).The protein levels of cleaved caspase-3,Bcl-2,Bcl-xL,Bax,total-ERK,phospho-ERK,totaI-Akt,phospho-Akt,and Hsp90 were detected by Western blot.The production of nitric oxide was measured by spectrophotometric assay.Hsp90 improves MSC viability and protects MSCs against apoptosis induced by serum deprivation and hypoxia.The protective role of Hsp90 not only elevates Bcl-2/Bax and Bcl-xL/Bax expression and attenuates cleaved caspase-3 expression via down-regulating membrane TLR-4 and ErbB2 receptors and then activating their downstream PI3K/Akt and ERK1/2 pathways,but also enhances the paracrine effect of MSCs.These findings demonstrated a novel and effective treatment strategy against MSC apoptosis in cell transplantation.     

淋巴管生成在食管鳞癌进展中的意义

目的:探讨食管鳞状细胞癌组织中淋巴管生成的临床病理意义.方法:应用单克隆抗体D2-40检测食管癌周围和中心区以及正常食管组织中微淋巴管密度(lymphatic micro vessel density,LMVD),分析其与食管癌患者年龄、性别、食管癌分化程度、淋巴结转移的关系.结果:肿瘤周围区LMVD明显高于中心区和正常组织.肿瘤周围区LMVD和淋巴结转移密切相关,而与肿瘤的分化程度无关.结论:食管癌在肿瘤周围区存在着明显的淋巴管形成,检测肿瘤周围淋巴管密度可以预测肿瘤淋巴结转移,因此具有良好的临床病理应用价值.     

车辆工程本科应用型人才“3＋1”人才培养模式研究与实践

从汽车工业发展对车辆工程应用型本科人才的基本素质要求出发,论述了车辆工程本科专业应用型人才的特征,重点探讨＂3＋1＂模式下,车辆工程专业本科应用型人才培养课程体系的设置,通过优化课程,使学生具备一定的应用能力和创新能力。     

Effect of the geometric shapes of specimens on impact tensile tests

The geometric shapes of specimens are important in impact tensile tests because geometric shapes determine the stress states of the specimens, and precise geometric shapes can obtain proper material properties without non-material factors. The aim of this study was to investigate the 1D form of the stress by changing the length-to-diameter （L/D） ratios of specimens. The experiments were carried out on a split Hopkinson tensile bar （SHTB）-rotating disk indirect bar-bar tensile impact apparatus. The L/D ratios of the LY12CZ specimens used in the test ranged from 1 to 5. Results show that the specimens can be used to obtain exact parameters of materials under the proposed conditions when the L/D ratio is greater than 2. This is because the longer length will reduce or eliminate the effects of the interfaces.     

Green’s functions for infinite planes and half-planes consisting of quasicrystal bi-materials

This paper deals with the combination of point phonon and phason forces applied in the interior of infinite planes and half-planes of 1D quasicrystal bi-materials. Based on the general solution of quasicrystals, a series of displacement functions are adopted to obtain Green＇s functions for infinite planes and bi-material planes composed of two half-planes in the closed form, when the two half-planes are supposed to be ideally bonded or to be in smooth contact. Since the physical quantities can be readily calculated without the need of performing any transform operations, Green＇s functions are very convenient to be used in the study of point defects and inhomogeneities in the quasicrystal materials.     

DAEMON下光盘镜像文件的自动加载

本文介绍了光盘镜像文件和虚拟光驱,并详述了在虚拟光驱DAEMON下光盘镜像文件自动加载的方法。     

英语专业教学模式对学生就业思维的影响

近年来,我国社会经济格局发生了急剧的深刻变化,就业市场对大学毕业生的要求也发生了深刻变化。英语专业以纯文学为专长的毕业生面临的就业困难越加严重。学校为提高学生就业竞争能力想方设法调整课程设置;学生为满足就业需要学习了各种与英语语言文学专业相关或不相关的知识。但是,他们的就业前景仍然不乐观。笔者根据这些现象,分析目前学校的教学管理方式和教师的教学方法能否对学生就业能力产生的作用。论述了改变目前英语教学管理方式,改变教师的教学理念和教学方法的可行性,以利于培养学生的主动思考意识、知识扩展能力,为学生在今后的现实生活中实现自我发展奠定基础。     

论教学理念的认识与计算机基础课程教学模式的改革

基于对计算机基础教学理念的认识和计算机教学模式的改革的一些看法和认识,认为应从教师专业化角度去看待教育过程,通过对目前计算机基础教学过程中存在问题的分析,特别是对重视课堂教学而忽视实践教学和项目设计训练的现状,探讨启发式教学和研究性学习的教学模式应用,通过改变考核方式作为惟一的学业评价手段,突出专题讨论作为一种比考试更重要的学生学业水平的鉴定形式.