基于PI系统的现代机床设计研究

我国机床工业设计与国际品牌相比较,机床品牌形象缺乏设计引导,产品外观不能充分反映其内在品质,需要塑造品牌形象,突出品牌基因,而现代机床PI系统的构建是重要的环节和系统工程。文章以研球机产品系列化设计为例,从产品识别系统的角度,初步研究了现代机床PI系统的构建,归纳机床设计基因特质的方法,并成功应用到产品系列其他型号机床中,总结了高效设计方法及流程。     

BAP31 is frequently overexpressed in patients with primary colorectal cancer and correlates with better prognosis

We previously showed that B cell receptor associated protein 31(BAP31) was significantly upregulated in colorectal cancer compared with normal mucosa epithelia. However, its expression pattern and pathological role in colorectal cancer are not clearly understood. In this study, we investigated whether the expression of BAP31 was associated with the clinicopathological parameters of colorectal cancer. The expression pattern of BAP31 was detected by immunohistochemistry on a tissue microarray in both primary ...     

导电聚酰亚胺及其复合材料的研究进展

聚酰亚胺(polyimide,PI)广泛应用于航空航天、微电子、纳米、液晶、分离膜、激光等高新领域,提升其导电性能,使之更好地应用于电子工业,是当前的研究热点。介绍了原位聚合法、溶液混合法、表面改性自金属化法、离子注入法等制备PI导电复合材料的原理及其研究进展;概述了纳米金属物质、含碳纳米物质、结构性导电聚合物等导电填料的性能及在导电PI中的研究现状;简述了导电PI复合材料在集成电路、电磁屏蔽、导电膜剂、涂料等方面的应用状况。     

磁控溅射在PI/石墨烯基体上制备氧化锌薄膜

聚酰亚胺(PI)/石墨烯复合薄膜兼备了可挠曲性及透明、导电性,可作为柔性透明导电电极用于柔性电子器件中。但附着于PI上的石墨烯易划伤,使其导电性变差。本文采用脉冲直流磁控溅射法,以PI/石墨烯为基体,镀制保护石墨烯的氧化锌薄膜。分别采用原子力显微镜、X射线衍射仪、台阶仪、霍尔效应仪及紫外-可见分光光度计检测PI/石墨烯/ZnO复合薄膜的表面形貌、晶体结构、薄膜厚度及导电、透光性能。结果表明,PI/石墨烯/ZnO复合薄膜结构致密,氧化锌以(002)为择优取向,最低方阻为1.9×104Ω/sq,略低于石墨烯的方阻,可见光区平均透光率达80%。     

基于电动转向的教练车副转向系统开发

本文设计了基于电动助力的副转向系统。建立了以副转向盘的转角为输入,车辆主转向柱的转角为输出的线性系统模型。设计完成了信号处理电路、电机驱动电路、控制系统反馈电路等。程序设计采用模块化设计的原则,选用PEC7000并应用PLC编写了信号检测程序、采样程序、主、副方向盘信号选择程序以及主控制程序等。对系统进行了试验验证。     

中心根扩张的一个推广

推广了Ｈｅｒｓｔｅｉｎ关于中心根扩张的一个重要结果。     

The role of apolipoprotein E in lipid metabolism in the central nervous system

The critical roles of apolipoprotein E (apoE) in regulating plasma lipid and lipoprotein levels have been extensively studied for over 2 decades. However, an understanding of the roles of apoE in the central nervous system (CNS) is less certain. This review will summarize the available experimental results on the role of apoE in CNS lipid homeostasis with respect to its modulation of sulfatide trafficking, alteration of CNS cholesterol homeostasis and apoE-induced changes in phospholipid molecular species in specialized subcellular membrane fractions. The results indicate that apoE mediates sulfatide trafficking and metabolism in the CNS. Moreover, although apoE does not affect the cholesterol mass content or the phospholipid mass levels and composition in the CNS as a whole, apoE modulates cholesterol and phospholipid homeostasis in selective subcellular membrane compartments. Through elucidating the roles of apoE in CNS lipid metabolism, new insights into overall functions of apoE in neurobiology can be accrued ultimately, leading to an increased understanding of CNS lipid metabolism and the identification of novel therapeutic targets for CNS diseases.Received 9 January 2004; received after revision 28 February 2004; accepted 10 March 2004     

一种新型聚酰亚胺的非等温热分解动力学

通过热重法、差示量热扫描法以及红外光谱法研究了由3,3',4,4'-benzophenone tetracarboxylicdianhydride(二苯酮四酸二酐,简称BTDA)和4,4'-(1,3-phenylenedioxy)-dianiline(CAS:2479-461)所形成的一种新型聚酰亚胺的非等温热分解过程,测得其失重5%温度为492℃,失重10%温度为530℃.用Kissinger-Akahira-Sunose(KAS)法和Ozawa法求取活化能Ea,用热分析动力学三因子求算的比较法判断出可能的机理函数.新型聚酰亚胺热分解的活化能为160.30kJ/mol,指前因子lnA为17.67.推断出可能的热反应机理函数为F2,其微分式和积分式分别为(1-α)2和(1-α)-1-1.     

AZ31镁合金在NaCl溶液中的电化学腐蚀行为研究

采用动电位极化曲线、电化学阻抗谱等方法研究了AZ31镁合金在3 5%NaCl溶液中的电化学腐蚀行为.结果表明,挤压加工成形的AZ31镁合金,由于合金内部组织沿水平方向发生了一定的层移,位错和缺陷增多,致使侧面和截面的耐腐蚀性能比表面稍差.阻抗测试结果显示,随着浸泡时间的延长,腐蚀产物在合金表面沉积,对基体金属具有一定的保护作用.