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排序方式: 共有458条查询结果,搜索用时 46 毫秒
41.
刘福成 《安徽农业大学学报》2006,(2):16-19
本文通过对农村居民人力资本投资制约因素的详尽分析,提出了增强农民人力资本投资动力的若干对策。 相似文献
42.
三种增菌液对食品沙门氏菌检验结果比较试验 总被引:3,自引:0,他引:3
本试验以三种增菌液,对300份鲜猪肉和120份鲜鸡肉检样进行沙门氏菌增菌培养,比较三种增菌液的增菌检出效果。结果表明:MM液对鲜猪肉和鲜鸡肉检样中沙门氏菌捡出率最高,分别为22.7%、53.3%,平均捡出率31.4%,敏感指数88.0%;SM液次之,检出率20.3%、47.5%,平均检出率28.1%,敏感指数78.7%;SBG液最低,检出率分别为19.3%、40%,平均检出率25.2%,敏感指数70.7%。MM液和SM液检出沙门氏菌菌株符合率均高于SBG液,分别为88.0%和78.7%。 相似文献
43.
建筑施工属于高危行业,各种各样的事故频频发生,给我国造成了严重的人身伤害和财产损失,本文分析了当前我国建筑施工中主要存在的安全问题,并根据这些问题提出了相应的解决方案,可以为建筑施工安全管理提供重要参考价值。 相似文献
44.
45.
陈玥 《四川畜牧兽医学院学报》2008,(4):172-174
目前高校家庭经济困难学生的问题日益突出,国家和高校都采取了积极的助学措施,但在实施过程中也暴露出问题和矛盾。文中分析了高校家庭经济困难学生资助育人工作的现状和问题,并提出了相关的对策和建议。 相似文献
46.
GONG Xian sheng 《保鲜与加工》1999,(5):6-12
A method,stroboscopic harmonicbalance method which is used to solve strong nonlinear system, is proposed. The method is used to find the solution of strong nonlinear system. In investigation,the existence conditions of primary resonance solution and subharmonic resonance solutions are obtained. The results which are obtained by the stroboscopic harmonicbalance method are compared with those by computer numerical simulation. The results show that the stroboscopic harmonicbalance method is correct in qualitative analysis and it can meet the demands in engineering. 相似文献
47.
Wang Changliang 《保鲜与加工》1998,(1):116-119
Following the rapid development of the revolutions in housing system,reconstruction of old buildings is rising.In order to make the reconstruction proceed smoothly,in this paper the author studies the secondary parts,reinforcing foundation,dismantlement of some parts of an old building,linkage of new and old frames,solutions for the four relationships,and others. 相似文献
48.
Physically based equations for unsaturated groundwater flow and solute transport have been coupled with kinetic rate laws for mineral dissolution–precipitation, and mass balance/mass action equations for aqueous species, in a numerical model that is capable of simulating rock–water interactions in a weathering profile subjected to fluctuating boundary conditions. A numerical experiment was conducted to demonstrate how incipient soil development may proceed in a warm subhumid environment. The simulation involved a hypothetical coarse-textured parent material that was subjected to frequent wetting and drying during an annual water cycle. The hypothetical weathering profile evolved rapidly; dissolution of primary minerals (enstatite, forsterite, and diopside) and precipitation of secondary clay–minerals (kaolinite and Ca-montmorillonite) occurred monotonically despite the abrupt fluctuations in soil-moisture content. In contrast, the activities of aqueous species and dissolution–precipitation rates of calcite were very sensitive to the changing moisture conditions in the upper part of the profile. Although the simulation involved numerous simplifying assumptions, reasonable results were achieved and the calculated (from the model) rate of chemical denudation fell within the range of contemporary denudation rates determined from the dissolved loads of rivers. 相似文献
49.
一类多分子生化反应系统模型的定性分析 总被引:1,自引:1,他引:0
对一类生化反应系统模型进行定性分析,得到了系统解的有界性与极限环不存在的充分条件。 相似文献
50.
Urban green spaces play essential roles in regulating the global carbon cycle and reducing carbon dioxide (CO2) emissions. However, research on the carbon sequestration efficiency of urban public green spaces, which is closely related to the human settlement environment, has not received enough attention. Thus, we systematically analyzed the existing literature in the Web of Science core database using bibliometrics and network analysis combined with the CiteSpace visualization tool. The aim of this review was to elucidate the focus and development trend of research conducted between 2007 and 2022 on carbon sinks in urban public green spaces. Our results demonstrated that: 1) Numbers of related publications are increasing annually, indicating that the subject is receiving increasing global attention. Related research topics primarily focus on two aspects: carbon sink measurement methods and sustainable carbon sink design for urban public green spaces. 2) Methods for measuring and monitoring carbon sinks in the urban public green spaces include sample plot measurement, the assimilation method, the micrometeorological method, the remote sensing (RS) estimation method, and laboratory work. Most methods follow the forestry system approach and lack the methods and techniques to directly assess the carbon sink effectiveness of urban public green spaces. 3) Key factors affecting the carbon sink capacity of urban public green spaces are: plant species selection, plant community structure, green space characteristics, and maintenance management. 4) Future research should focus on encouraging public participation in the design of sustainable carbon sinks in urban public green spaces, advancing biodiversity research on carbon sinks in urban public green spaces, and enhancing the precision of measurements while addressing regional differences. This study contributes to the integration of research on the effectiveness of carbon sinks in urban public green spaces and provides a theoretical reference and guidance reduces prospective urban emission and achieves climate goals. 相似文献