桐庐县分水江流域面源污染评价及防治对策   总被引：4，自引：0，他引：4  

王亦宁  毛明海 《科技通报》2008,24(5)

介绍了桐庐县分水江流域农业面源污染基本状况.从面源污染对水环境影响的角度人手,在考察桐庐县分水江流域土地类型的基础上,通过SCS径流曲线方程计算各种土地类型的产流能力和产流情况,进而计算各土地类型所产生的面源污染物量和污染负荷,分析了各行政区的面源污染状况.并与调查资料作了实证对比分析,结果较为吻合.最后以污染负荷为依据进行面源污染的整体评价,得出了各行政区的面源污染等级.提出若干污染治理对策.  相似文献   

Stretching the Imagination     

ANNE S. HAWKINS 《Teaching Statistics》1985,7(1):6-10

  相似文献   

试析我国市场经济中的寻租问题     

景芳 《青海师专学报》2003,23(4):54-55

所谓寻租，即租金的寻求，通常是指经济主体寻求非生产性利润的行为，它是我国改革开放以来经济中出现的一种泛滥最广、危害最大的新现象，由此引发的一系列腐败行为也引起了理论界的广泛关注。本文试图分析寻租的形成机制以及对设租、寻租行为的治理与防范。  相似文献   

浅谈如何用逻辑以求词义     

侯占香 《宜宾学院学报》2006,6(4):106-108

本文一反传统训诂的方法,针对王力在《古代汉语》中的注解,从逻辑方面探求和诠释了“三”在不同语境中的具体意义。  相似文献   

Revising the ISSN Standard: The Challenge of Change     

Regina Romano Reynolds 《期刊图书馆员》2017,72(1-4):172-176

ABSTRACT

The International Standard Serial Number (ISSN) has been the standard, eight-digit code used to identify newspapers, journals, magazines, and periodicals on all kinds of media—print and electronic—for the past 40 years. Periodically, the standard must be revised to allow it to accommodate new formats, changes in the publishing industry and information supply chain, and other developments in the information field. Regina Romano Reynolds, director of the U.S. ISSN Center at the Library of Congress, describes the issues that the ISSN International Centre perceives as necessitating a revision of the standard and the likely next steps in the International Organization for Standardization standards revision process.  相似文献   

一个新的数论函数及它的渐近公式   总被引：1，自引：0，他引：1  

张文鹏  刘红艳 《咸阳师范学院学报》2002,17(4):5-9,12

研究了一个新的数论函数的渐近性质，并给出一个较为精确的渐近公式。  相似文献   

高校扩招的现状、问题及对策研究   总被引：5，自引：0，他引：5  

张静 《贵州教育学院学报》2004,20(3):7-9

1999年高校扩招政策的出台启动了我国高等教育大众化发展的进程，这是政府顺应历史潮流，适应社会经济发展、满足人民群众教育需求所做出的重大举措。在高校扩招的进程中，教育质量下滑和毕业生就业难是教育界争论得最多的两大问题，在分析现状的基础上，找出问题产生的根源，并探讨行之有效的对策来加以解决。  相似文献   

在VFP环境下实现随机编号的一种实用方法     

张山清 《三明学院学报》2003,20(4):119-123

主要介绍了在设计开发"三明市中职招生管理系统"过程中,学生准考证号随机生成的一种实用方法。  相似文献   

析学术期刊页码的编排     

陈道斌 《襄樊学院学报》2008,29(11):84-85

页码是期刊的一个重要组成部分.目前学术期刊页码的编排形式多种多样.要高度重视和规范学术期刊页码的编排.在页码编排这一细节中要引入CIS中的VI(视觉识别),页码应是VI的一个重要组成.  相似文献   

Four and twenty blackbirds: how transcoding ability mediates the relationship between visuospatial working memory and math in a language with inversion     

Sanne H.G. van der Ven  Jonathan D. Klaiber  Han L.J. van der Maas 《教育心理学》2017,37(4):487-505

Writing down spoken number words (transcoding) is an ability that is predictive of math performance and related to working memory ability. We analysed these relationships in a large sample of over 25,000 children, from kindergarten to the end of primary school, who solved transcoding items with a computer adaptive system. Furthermore, we investigated the nature of transcoding difficulty of over 300 two- and three-digit numbers. All data come from a Dutch sample, meaning that transcoding is complicated by decade-unit inversion: 24 is pronounced as ‘four-and-twenty’. Omission to invert the digits of a spoken number when writing it down is an inversion error: the incidence of these declined but did not disappear in later elementary school. Furthermore, transcoding ability mediated the relationship between visuospatial working memory and mathematics performance, a strong effect that declined with age. Inversion error making mediated this same relationship in an inverted U-shaped curve, peaking around grade 2 (8 years old). At the item level, structural characteristics related to inversion and irregular pronunciation of units and decades explained a large part of the variance in item difficulty. We conclude that number transcoding is an important ability to develop mathematical proficiency and discuss the implications of these findings.  相似文献