首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1228篇
  免费   58篇
  国内免费   51篇
林业   114篇
农学   89篇
基础科学   89篇
  174篇
综合类   715篇
农作物   16篇
水产渔业   40篇
畜牧兽医   63篇
园艺   12篇
植物保护   25篇
  2024年   7篇
  2023年   37篇
  2022年   38篇
  2021年   49篇
  2020年   54篇
  2019年   52篇
  2018年   17篇
  2017年   31篇
  2016年   36篇
  2015年   21篇
  2014年   53篇
  2013年   54篇
  2012年   87篇
  2011年   112篇
  2010年   90篇
  2009年   79篇
  2008年   67篇
  2007年   74篇
  2006年   71篇
  2005年   80篇
  2004年   54篇
  2003年   30篇
  2002年   32篇
  2001年   27篇
  2000年   35篇
  1999年   13篇
  1998年   11篇
  1997年   3篇
  1996年   5篇
  1995年   3篇
  1994年   3篇
  1993年   1篇
  1992年   3篇
  1991年   3篇
  1990年   2篇
  1989年   3篇
排序方式: 共有1337条查询结果,搜索用时 15 毫秒
121.
This study critiques the idea of a Western science -- indigenous knowledge dichotomy in agricultural knowledge by examining the hybrid nature of knowledge use and incorporation by villagers in Madhya Pradesh, India. By analyzing knowledge systems as multi-leveled structures consisting of concrete practices linked to more abstract, explanatory concepts, this paper illustrates how information from multiple sources is integrated into local bodies of knowledge about tree management. Practices such as urea fertilization from formal global science might be explained by concepts such as that of a hot/cold duality from informal folk science. Similarly, other pieces of knowledge stemming from diverse knowledge systems are shown to become mixed and matched on practical and conceptual levels. Additionally, several knowledge elements used locally appear to be held in common by many knowledge systems around the world, rendering the determination of their origins in one system or another nearly impossible. These observations lead to the conclusion that local knowledge systems of tree management are better characterized as open systems rather than distinct, closed systems. Furthermore, the constant exchange of material between formal and informal, local and global systems renders untenable any strict dichotomy of knowledge systems.  相似文献   
122.
This article analyzes learning in context through the prism of a sustainable dairy-farming project. The research was performed within a nutrient management project that involved the participation of farmers and scientists. Differences between heterogeneous forms of farmers knowledge and scientific knowledge were discursively constructed during conflict and subsequent alignment over the validity and relevance of knowledge. Both conflict and alignment appeared to be essential for learning in context. Conflict spurred learning when disagreeing groups of actors developed their knowledge in order to strengthen their arguments. Conflict caused self-referentiality when the actors no longer listened to each other. This inhibited self-reflection, thus blocking ongoing learning. Nevertheless, after a period of alignment, scientific models and knowledge of farmers were reevaluated and recontextualized. Through determining how to use scientific models and farmers knowledge for further learning, aimed at a shared goal, the participating actors also learned how to learn.Jasper Eshuis is a PhD candidate in the Department of Communication Management at Wageningen University, The Netherlands. His research deals with multiple land use, governance processes, and farmers decision-making. He is currently interested in monitoring and trust.Marian Stuiver is a PhD candidate in the Department of Rural Sociology of Wageningen University, The Netherlands. Her current research focuses on nutrient management, farmers innovation, and co-production of knowledge within the agricultural sciences.  相似文献   
123.
从阐述研究型大学图书馆的意义入手,强调从图书馆的藏书布局、馆员素质、服务理念、网络技术应用四个角度进行创新,构建符合知识经济时代的研究型图书馆。  相似文献   
124.
用DC元数据扩展集构建园林数据库   总被引:3,自引:0,他引:3  
本文研究了有关DC元数据及其扩展元素在园林数据库的应用,探索了网络信息资源的组织方法,提出了若干建议。  相似文献   
125.
基于现代系统理论基础上的作物模拟模型方法概述   总被引:1,自引:0,他引:1       下载免费PDF全文
从基本概念、基础理论、研究内容、组织结构、系统内容及特征、研究展望等方面阐述了基于现代理论基础上的作物模拟模型的研究方法概况。  相似文献   
126.
A focus group study using four groups of food shoppers provides insights into consumers’ knowledge, beliefs, and behaviors regarding organic foods. Two focus groups consisted of shoppers who regularly bought organic foods and two focus groups of shoppers who predominantly purchased conventional foods. Participants in one of the conventional groups were all Caucasian; in the other they were all African-American. While familiarity with organic foods was much lower in the African-American group, its members were more receptive and positive towards organic foods. Likewise, the African-American shoppers were more accepting of price premiums for organics foods. In comparing the two organic shopper groups with the two conventional shopper groups, it was found that the former were generally more knowledgeable about organic foods. They were also more likely to follow a special diet than conventional Caucasian shoppers. However, the behavior of organic shoppers varied widely. The research supports examining social justice and access as motivations for changing policies to support organic agriculture. Lydia Zepeda is a Professor of Consumer Science at University of Wisconsin and Senior Fellow of the Center for World Affairs and the Global Economy. Her research focuses on agricultural technology adoption, farm household decision making, and consumer perceptions and behavior towards agricultural technology and food. Hui-Shung Chang is a Senior Lecturer in the School of Economics at the University of New England, Armidale, New South Wales, Australia. Her research focuses on demand analysis and agribusiness marketing. Catherine Leviten-Reid is a research assistant and graduate student in the Department of Consumer Science at the University of Wisconsin–Madison. She is interested in household behavior and sustainable community development.  相似文献   
127.
编辑的知识更新与农业科技期刊的可持续发展   总被引:2,自引:0,他引:2  
知识经济时代是以人为本的时代,人是生产力中最活跃的因素。科技期刊编辑的知识更新是科技期刊可持续发展的关键因素,农业科技期刊的知识更新是多方面、全方位的。主要包括:掌握现代思想观念,现代农业科技知识和编辑技能。知识更新的途径有:强化培训,循序渐进。  相似文献   
128.
本文认为讲道德时应讲理性,愚昧无知与道德不相容,要注重利益的比较与权衡,关爱他人也应注意其后果。文章还对法律与道德关系、义利之辩、知其不可而为之等经典命题作出自己的分析。  相似文献   
129.
基于“3S”技术的环境质量评价及其研究展望   总被引:17,自引:0,他引:17       下载免费PDF全文
论述了环境质量评价的基本内容和基本类型、"3S"技术在环境质量评价中的应用及其局限性,明确了今后基于"3S"技术的环境质量评价应用发展方向和研究领域,特别关注了近年来数据挖掘技术、数据融合技术、高光谱遥感技术给环境质量评价带来的应用前景.  相似文献   
130.
信息技术的发展贯穿于从纸质图书馆、缩微图书馆、虚拟图书馆又到数字图书馆的历史发展过程。因特网代替了小型局域网,掀起了第一次互联网技术浪潮;万维网实现了网页之间的互联,掀起了第二次浪潮,并为因特网赢得了更为广泛的发展空间。因特网和万维网之后是什么?计算机专家认为:网格将掀起因特网和万维网之后的又一次技术浪潮,其标志将是以全球大网格GGG替代万维网。讨论了网格技术在图书馆领域的应用。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号