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.     

浅谈钻井冲洗液在钻探施工中的重要性

介绍了常用钻井冲洗液的类型及适用地层，通过亲自实践总结出钻井冲洗液在钻探施工中的重要性。为今后相关钻探施工工作提供借鉴。     

高校社会主义核心价值体系宣传教育思路探析

开展社会主义核心价值体系宣传教育是高校宣传思想工作当前和今后的一项重要课题和主线,推进高校社会主义核心价值体系建设,必须联系高校实际,发挥宣传舆论作用,坚持正面教育引导,大力唱响主旋律;必须坚持"三贴近",增强针对性和吸引力,把握主动权,切实做好引领工作;要健全体制机制,形成宣传教育合力.     

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.     

具有Sturm-Liouville边界条件的四阶奇异微分方程正解的存在性

利用极值原理和上下解方法给出了具有Sturm-Liouville边界条件的四阶奇异微分方程C2[0,1]和C3[0,1]正解的存在性,允许非线性项f(t,u)在u=0和t=0,1处可以是奇异的。     

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.     

老子“不尚贤”与墨子“尚贤”的比较及其意义

老子"不尚贤"的人才思想与墨子的"尚贤"观相比,其实质上是一致的,比起墨子,老子的思维显示了更高的道德水准,更加具有哲学思维的深度与智慧。其中所蕴含的辩证法思想与自然、无为、不争等美德,对于当代建设与完善科学合理的人才制度,构建社会主义和谐社会,有着积极的启示意义,值得我们在社会实践中借鉴。