四点弯曲试验条件下页岩的声发射特性

利用PXWAE型声发射系统进行了四点弯曲试验条件下页岩的声发射试验研究,试验中记录了岩样所受的最大弯曲应力、弯曲应变、声发射事件数、声发射能量等多个参数。研究发现,垂直页岩层理施加荷载时,在四点弯曲试验条件下其凯塞效应是存在的,凯塞点可以直接通过应力与累计声发射事件数曲线得出;但受自身水平层理结构及局部破坏的影响,应变在受载过程中会发生松弛现象,不易直接由应变-声发射试验曲线判断出岩石的凯塞点,必须结合其它试验数据以及岩样的最终破坏形态综合判断。弯曲应力状态下岩石的声发射特性研究对于利用声发射技术进行矿区顶板或隔层的稳定性监测具有一定的工程指导意义。     

直升机智能旋翼后缘小翼参数研究

介绍了用于直升机减振的后缘小翼型智能旋翼相关设计参数的研究。建立了后缘小翼型智能旋翼的气弹动力学分析模型。研究了小翼的关键设计参数:小翼展长、小翼弦长、小翼径向位置、小翼重心布置以及前进比等对后缘小翼偏转角度、驱动机构需用功率以及桨毂振动载荷的影响。参数分析结果用于指导模型的设计并为后续的模型试验提供理论依据。     

基于关系代数的数据立方体格的优化实现方法

多维数据立方体是数据仓库和OLAP服务器的主要数据组织模型，多维数据立方体格的实现占用大量的时间和空间资源。本文提出了一种基于关系代数的多维数据立方体格的实现算法，针对ROLAP和MOLAP的不同实现形式提供了一种综合的优化算法。     

邻菲啰啉体系测量Fe（Ⅲ）的双峰单波长分光光度法研究

本文采用双峰单波长分光光度法测定Ｆｅ（Ⅲ），具有较高的灵敏度（ε＝５．５４×１０４Ｌ·ｍｏｌ（－１）·ｃｍ（－１）），常见离子干扰少，重现性好。对固体饮料和辽河水中Ｆｅ（Ⅲ）进行测定，回收率分别在９７．３—１０４．０％和９７．７—１０２．０％。     

一种非化学计量钛氧化物的制备和表征

用钛粉和草酸反应制得前驱物 ,在氮气保护下 6 0 0℃热分解前驱物制备了一种非化学计量钛氧化物 .讨论了前驱物的组成和热分析结果 ,对其化学式进行了推断 ,并从组成、颜色、比表面积等方面对产物进行了表征 .认为前驱物的化学式可能是TiC2 O4·2H2 O .热分析的结果表明前驱物的热分解可分为三个过程 ,并且将热分解温度控制在 6 0 0℃可以保证前驱物的完全分解 .X射线粉末衍射分析 (XRD)结果显示产物中包含Ti2 O和TiO2两相 .本法制得的产物比表面积大 ,黑色度高 ,可以用作黑色颜料     

提高工程试验数据拟合精度的可行方法

利用泰勒级数展开的高斯迭代方法 ,高精度拟合工程实验数据。提出了修正估计因子矩阵方程的计算机求解和软件求法     

Management of Waste Electrical and Electronic Equipment in Brazilian Public Education Institutions: Implementation Through Action Research on a University Campus

One of the problems facing public education institutions in Brazil is the question of the correct handling and treatment of waste electrical and electronic equipment (WEEE). Being that these institutions are part of the public sector, they should adhere to Decree no. 99,658/1990 for the disposal of their goods. However, this decree is not completely in accordance with the Brazilian National Solid Waste Policy (PNRS), especially when considering the regulations for disposal of public goods. Thus, these institutions have no WEEE management model which encompasses not only the Decree but also the PNRS. An example of this situation can be found at the Federal University of Itajubá (UNIFEI) in Minas Gerais, Brazil. Due to the lack of such a management model, the university warehouse is at full capacity and unable to receive additional electronic equipment. Therefore, the objective of this study is to create a management model for WEEE to be used at public education institutions using the guidelines set forth in both the Decree and the PNRS. An action research investigation was performed at UNIFEI which relied upon two improvement and learning cycles to deal with all the WEEE found at the university. The first was undertaken at the university warehouse and the second at other sectors within the institution. In addition to the practical results obtained by properly disposing of 474 WEEE products, this study showed that action research is an adequate management tool for public institutions looking to deal with problems of this nature, being that these institutions are almost always subject to bureaucratic controls with respect to their public property, and expected to follow rigorous legislation that is often times controversial.     

Filamentous bodies in human glomerulonephritis

Summary Filamentous bodies have been identified in the glomerular cells of human kidney biopsies. These structures have a close morphological resemblance to ciliary rootlets, although the cells of the glomerular tuft only occasionally bear cilia. Their significance could be, as for cilia, of a cellular disdifferentiation of a pathological cellular proliferation.     

Effect of experimental chronic renal failure upon the production of urea,as measured by the liver arginase activity in rats

Summary A significant diminution in liver arginase activity of chronic renal failure uremic rats is described, thus implying that the experimental finding of an increased urea production is not due to a depressed arginase activity.This work was supported by the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico do Brasil's Grants. —Acknowledgments. We are indebted to Mr D'Arrochela Lobo for technical assistance, Mr Celso Chiarin for the statistical review and Dr C.E. Tosta and Dr Linda Caldas for helpful advice.     

Effect of actinomycin D onTrypanosoma cruzi

Summary Viable metacyclic forms ofT. cruzi, Y strain, treated with an adequate dose of actinomycin D (50 g Act-D/ml/10⁷ parasites/ml for 72 h at 28° C) showed the following properties: 1) they lost their ability to replicate in culture medium, in blood and in tissues of normal mice and were no longer able to incorporate tritiated thymidine; 2) they could no penetrate into Vero cells and could not replicate inside normal macrophages; 3) they retained their immunogenicity and the ability to protect mice against a virulent infection; 4) they did not induce histological lesions as described in chronic experimental Chagas' disease.