基于Pro/E的车用CNG气瓶装卸机械设计

针对车用CNG气瓶定检时人工装卸气瓶效率低、安全性差等问题,提出设计一种CNG气瓶装卸机械.该装置包括升降小车和机械抓手两部分,可实现对气瓶的抓取、旋转、升降、进退等动作.基于Pro/Engineer的三维建模功能,建立该机械装置、气瓶及车厢的3D模型,进行模拟装卸的结构干涉分析.结果表明该机械结构简单、操作方便,具有...     

浅论煤矿安全文化建设

煤矿安全工作应首先从职工的需要出发,制订目标,形成工作机制,逐步形成以"安全第一"为灵魂的战略格局.     

在企业文化建设中面临的问题及对策

加强企业思想政治工作,提高职工素质,是目前新形势下企业管理工作的重要内容,具有相当重要的地位。文章就思想政治工作在企业和谐文化建设中面临的问题及对策谈一些粗浅的认识。     

Wiener-Hopf factorization of a class of matrix functions and Corona theorem

By using Riemann-Hilbert method and Corona theorem, Wiener-Hopf factorization for a class of matrix functions is studied. Under appropriate assumption, a sufficient and necessary condition for the existence of the matrix function admitting canonical factorization is obtained and the solution to a class of non-linear Riemann-Hilbert problem is also given. Furthermore, by means of non-standard Corona theorem partial estimation of the general factorization can be obtained. Foundation item: Supported by the National Natural Science Foundation of China(10471107) and the Specialized Research Fund for the Doctoral Program of Higher Education of China (20060486001)     

Molecular phylogenetic evidence that the Chinese viviparid genus Margarya (Gastropoda: Viviparidae) is polyphyletic

We investigated the phylogeny of the viviparid genus Margarya,endemic to Yunnan,China,using two mitochondrial gene fragments(COI and 16S rRNA).The molecular phylogeny based on the combined dataset indicates that Margarya is polyphyletic,as two of the three well-supported clades containing species of Margarya also comprise species from other viviparid genera.In one clade,sequences of four species of Margarya even cluster indiscriminately with those of two species of Cipangopaludina,indicating that the current state of Asian viviparid taxonomy needs to be revised.Additionally,these data suggest that shell evolution in viviparids is complex,as even the large and strongly sculptured shells of Margarya,which are outstanding among Asian viviparids,can apparently be easily converted to simple smooth shells.The molecular data also indicate that the species status of the six extant species of Margarya should be re-assessed.     

基于KQGIS平台的城镇地籍更新调查数据库建设与关键技术研究

以北京苍穹KQGIS为建库平台,建立河南省罗山县城镇地籍更新调查数据库.介绍了其主要环节和关键技术.首先阐述了城镇地籍更新调查数据库建设工作,包括建库前数据的准备、数据格式转换、数据整理入库及成果提交等方面.之后研究分析建库过程中出现的关键技术问题,实现了地籍成果科学的存储与管理,达到快速查询、更新、统计、空间分析以及数据发布和资源共享等目的.     

复杂工况下连轧过程数值仿真系统研究

针对板、管、棒材连轧过程中出现的工艺制度难以确定、实验研究理论性不强等问题,以非线性有限元为内核,通过机型选择、系统仿真、工艺决策等措施,提出了确定最佳工艺制度的理论和方法.     

Joint Funds of National Natural Science Foundation of China： Strategy, Practice and Development

Joint Funds of National Natural Science Foundation of China(NSFC) are initiated by different stakeholders,which aim to play a better guiding role to support basic research in specific areas and directions.They have formed an important part of the national natural science funding system,which is responsible for advancing science and technology in an expanding frontier.The article would briefly summarize the joint funds strategic goals,programs implementation and achievements in the past decade, and provide a perspective on their future development.     

基于SWOT分析的攀钢通信网运维管理发展研究

随着攀钢信息化建设的进一步推进,通信已成为人们生活中必不可少的一部分,而网络质量的好与坏将直接影响着工厂的生产与人们的生活。运用SWOT分析法对当前环境下攀钢通信网运维管理发展的优势、劣势、机遇、威胁进行了综合分析。在分析的基础上探讨了几种发展策略。     

Robust Sensor Bias Estimation for Ill-Conditioned Scenarios

Sensor bias estimation is an inherent problem in multi-sensor data fusion systems. Classical methods such as the Generalized Least Squares (GLS) method can have numerical problems with ill-conditioned sets which are common in practical applications. This paper describes an azimuth-GLS method that provides a solution to the ill-conditioning problem while maintaining reasonable accuracy compared with the classical GLS method. The mean square error is given for both methods as a criterion to determine when to use this azimuth-GLS method. Furthermore, the separation boundary between the azimuth-GLS favorable region and that of the GLS method is explicitly plotted. Extensive simulations show that the azimuth-GLS approach is preferable in most scenarios.