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   3850篇
  免费   213篇
  国内免费   286篇
林业   155篇
农学   149篇
基础科学   75篇
  325篇
综合类   1503篇
农作物   88篇
水产渔业   114篇
畜牧兽医   1744篇
园艺   52篇
植物保护   144篇
  2024年   9篇
  2023年   72篇
  2022年   117篇
  2021年   168篇
  2020年   124篇
  2019年   150篇
  2018年   90篇
  2017年   162篇
  2016年   172篇
  2015年   153篇
  2014年   205篇
  2013年   195篇
  2012年   308篇
  2011年   282篇
  2010年   235篇
  2009年   255篇
  2008年   222篇
  2007年   264篇
  2006年   214篇
  2005年   165篇
  2004年   164篇
  2003年   124篇
  2002年   87篇
  2001年   78篇
  2000年   67篇
  1999年   50篇
  1998年   47篇
  1997年   23篇
  1996年   19篇
  1995年   15篇
  1994年   22篇
  1993年   16篇
  1992年   12篇
  1991年   18篇
  1990年   6篇
  1989年   4篇
  1988年   5篇
  1987年   3篇
  1986年   2篇
  1985年   3篇
  1984年   3篇
  1983年   3篇
  1982年   4篇
  1981年   1篇
  1979年   3篇
  1977年   2篇
  1975年   2篇
  1974年   1篇
  1973年   2篇
  1956年   1篇
排序方式: 共有4349条查询结果,搜索用时 21 毫秒
71.
Under the background of the new rural construction in China, it is an important scientific question and an urgent social task to construct the harmonious society and to achieve the sustainable regional development on how to construct concentrative residence and manage the human habitat environment in the fast industrializing and typically urbanizing area. This paper analyzed the problems in the construction of the human habitat envi- ronment in the rural area of southern Jiangsu, discussed the methodologies of planning and design for rural con- centrative residence, researched the human habitat environment improvement technologies, and put forward the resolution of the recycling community for the rural inhabitation, which aimed at demonstrating the practicing in rapidly urbanizing regions.  相似文献   
72.
73.
The design of multi-controller and multi-mode control law is presented for the three-link Acrobot on horizontal bar by employing Human simulated intelligent control method based on sensory-motor Schema.Imitated the characteristics of gymnast's swing-up and handstand movement,the control process of robot is divided by six sequence phase.Then the sensory cell and motor cell and the group of sensory-motor schema is designed based on the analysis of quality-quantity combination.The simulation results show that the controller ensures the gesture and the energy to the desired goal,farther more the motion control of giant swing backword is realized in the simulation.  相似文献   
74.
The biological effects of ELFMES including proliferation and apoptosis of cells as well as the damage of DNA are initially evaluated with the treatment of plant cells and human pulmonary fibroblasts in low frequency magnetic fields with certain intensity and different time intervals in vitro. Cell culture, counting in vitro, fluorescent dyeing analysis and single cell gel electrophoresis are adopted. The results demonstrate that the electromagnetic field with the intensity of 3mT can affect the proliferation and apoptosis of cells significantly.  相似文献   
75.
In accordance with the special characteristics of state medium-sized construction enterprises and their reform objects of "having a free hand and enlivening", the suitable objective model, the stock cooperative system for state medium-sized construction enterprises has been put forward in this paper by analyzing the system mechanism of stock cooperative system enterprises. Then the causes for it were expounded.  相似文献   
76.
Based on the model of Human Simulation Intelligent Controller (HSIC) presented briefly, a detailed algorithm was described for the servo system control by using the method of HSIC. Simulation results obtained proves the good performance of the control algorithm.  相似文献   
77.
The externality of surrounding is introduced into the 2-capital of economical increasing models, which includes human factors, to explore the influences of circumstances contradiction on the human capital formation. The normal and special nash equilibrium of environmental and human capital is presented through a limited boundary model of overlapping generations. The character of equilibrium trail and its economical meaning are examined. The study on the model shows that laissez faire economy will be either stagnant,growing,or collapsing in the long-run,depending on the returns of the learning technology with respect to the two kinds of capital,the initial state of economy,and the relative price of the environmental and consumption goods.  相似文献   
78.
Analyses the thermal environment parameters from physiological aspect and from psychological aspect respectively. Introduces the conception of thermal comfort of human body from heat balance aspect. Presents some measures to improve indoor thermal environment and advance thermal comfort of human body. Analyses the influence of indoor thermal environment on thermal comfort of human body and some questions on the aspect of this research, also puts forward some advices.  相似文献   
79.
农村人力资源开发的核心--加强农村教育   总被引:3,自引:0,他引:3  
张艳 《农机化研究》2004,(3):268-270
农村人力资源开发的根本目的是充分发掘和利用农村人力资源,为农村社会经济的发展服务。我国农村人力资源从数量和质量两个方面来衡量,其现状是数量过大、质量供给不足。农村人力资源开发重点在于提高农村人力资源的质量,核心是加强农村教育。即以提高新增劳动力素质为核心,加强农村基础教育;以就业为导向,大力发展农村职业技术教育;以农民培训为重点,大力开展农村成人教育。  相似文献   
80.
邓伟艳 《湖南农机》2007,(1):121-122
自诉权源于个体的一种自我保护,它的理论基础在于权利保护和程序正义。本对对自诉权的构成要素、属性进行了分析。本文认为,自诉权的构成要素有三个方面:自诉权主体、自诉权的行为对象与效力以及自诉权的内容。自诉权的主要属性有三个方面:自诉权是一种自然之权也是法定之权、自诉权是一种诉权、自诉权是一种相对权也是一种非强制性权利。  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