全文获取类型
收费全文 | 11565篇 |
免费 | 509篇 |
国内免费 | 894篇 |
专业分类
林业 | 1115篇 |
农学 | 958篇 |
基础科学 | 1250篇 |
1536篇 | |
综合类 | 5450篇 |
农作物 | 735篇 |
水产渔业 | 112篇 |
畜牧兽医 | 1012篇 |
园艺 | 302篇 |
植物保护 | 498篇 |
出版年
2024年 | 71篇 |
2023年 | 219篇 |
2022年 | 374篇 |
2021年 | 403篇 |
2020年 | 394篇 |
2019年 | 426篇 |
2018年 | 253篇 |
2017年 | 439篇 |
2016年 | 495篇 |
2015年 | 412篇 |
2014年 | 730篇 |
2013年 | 666篇 |
2012年 | 949篇 |
2011年 | 949篇 |
2010年 | 711篇 |
2009年 | 727篇 |
2008年 | 605篇 |
2007年 | 765篇 |
2006年 | 675篇 |
2005年 | 569篇 |
2004年 | 480篇 |
2003年 | 355篇 |
2002年 | 232篇 |
2001年 | 198篇 |
2000年 | 188篇 |
1999年 | 120篇 |
1998年 | 118篇 |
1997年 | 77篇 |
1996年 | 78篇 |
1995年 | 46篇 |
1994年 | 39篇 |
1993年 | 54篇 |
1992年 | 34篇 |
1991年 | 29篇 |
1990年 | 21篇 |
1989年 | 20篇 |
1988年 | 12篇 |
1987年 | 18篇 |
1986年 | 7篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1963年 | 1篇 |
1962年 | 3篇 |
1956年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
三氯蔗糖在食品加工中的应用及测定方法的研究概况 总被引:1,自引:0,他引:1
施雅梅 《农产品加工.学刊》2007,(12):80-82
介绍了三氯蔗糖的特性。阐述了三氯蔗糖在食品加工中的应用及测定方法的研究概况。 相似文献
113.
施肥对不同品种麦田CO2通量的影响 总被引:1,自引:0,他引:1
为探讨施肥对小麦田间CO2释放量的影响,本研究设计以4个不同施肥水平为主处理,以3个不同年代的主栽品种碧玛1号、烟农15号、山农11号为研究对象,采用封闭式静态暗箱技术,应用LI-6400型便携式光合仪(美国)在作物生长期测定土壤CO2释放量和光合速率。同时测定了环境影响因素土壤温度和水分等。研究结果表明,施肥有利于增加土壤CO2释放量,且中氮处理水平释放量最多;土壤温度和水分对土壤CO2释放量有一定的影响,土温越高,水分越大,CO2释放越多;麦田CO2交换量与小麦根系活性呈正相关。 相似文献
114.
红酵母的性质及其应用研究 总被引:10,自引:0,他引:10
红酵母是酵母菌的一个属,腐生,分布广泛,在医学、食品、化工和农业等方面都有一定的应用,但目前并没有引起人们足够的重视。综述了红酵母的种属特性、理化特性、培养及其应用。 相似文献
115.
HACCP体系在种植业应用的理论初探 总被引:2,自引:0,他引:2
王海啸 《农产品加工.学刊》2005,(3):53-55
重点介绍了HACCP体系的含义、起源、发展和原理,探讨了该体系在农产品生产等农业种植业领域中应用的可行性,对我国无公害农产品的生产、绿色食品的认证和发展农村经济、保障人们的身体健康具有重要的现实的意义。 相似文献
116.
In this paper,four models are selected as the representatives and applied to nonlinear dynamic analysis program for space frames which is based on the beam-column elements using the finite element flexibility method and the fiber model.Park's test on combined axial and bending columns under cyclic loading are taken as the calibrations,comparisons to material and structural member level are drawn and the analytical results of various models are discussed. 相似文献
117.
In this paper, the application of reinforced earth technique, principle and calculation method, new reinforced materials developed and produced are introduced. A few of key technical problems in reinforced earth application is discussed, such as reinforced earth behavior, calculation method, durability of reinforced material, amendment and complement of the current standards. Then, the reinforced earth technique development and advancement were introduced. 相似文献
118.
TAN Wen-an 《保鲜与加工》2004,(12):73-77
By analyzing the process of enterprise information engineering construction and intra relationship among information system requirement, business process modeling, application system constructing and project management, one of 4 meta model composed of requirement engineering, process engineering, application system engineering and support engineering is proposed for enterprise information engineering. The developments and applications of the business processes and its application systems are integrated into the same development space and application space. Basing on this, a prototype system composed of requirement modeling environment, business process modeling environment, application system modeling environment, and support engineering environment has been designed and built, which is used for supporting enterprise information engineering constructing. It is valued for the enterprise information engineering construction in our country. 相似文献
119.
The stimulation and the optimal design for bus ride comfort have played an importable roles in design and reform of automobile products. The new vibration comfort coefficient is applied to evaluate the ride comfort of automobile, and the software is developed. It is verified that the study has theoretical and practical value significantly. 相似文献
120.
The aerodynamic characteristic of wind turbine is calculated by applying the Blade Element Momentum(BEM) theory.Also finite element mode analysis is done for the tower and the rotor.Then the multi-dynamic model of the wind turbine is built in Adams.Also the drive chain is calculated by applying state space method and programmed in Matlab/ Simulink.With that the combined simulation of vibration characteristics is carried out on the base of MATLAB/Simulink and ADAMS,in which the transmission effects and aero-elasticity coupling is fully considered.The results show that the method is able to simulate the vibration characteristic almost the same as software Bladed,which is well-known for analyzing performance and loads for the design and certification of wind turbines. 相似文献