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991.
甘肃农业地域分异及其生态农业产业化模式设计   总被引:7,自引:0,他引:7  
通过定性与定量分析,认为甘肃自然环境、农业生产条件都具有明显的地域分异特征。甘肃农业地域分异是设计生态农业产业化模式的主要依据,根据甘肃农业地域分异特征,设计了6种不同的生态农业产业化模式,体现了农业因地制宜的基本发展原则,对指导甘肃各地生态农业的发展具有一定的意义。  相似文献   
992.
我国是拖拉机生产大国,在技术、产量不断提高的同时,质量安全问题日益突出,主要表现在驾驶室无足够的安全强度、危害部位安全防护不足、照明信号装置失效、噪声危害大、部分零部件可靠性差等方面,由此导致的拖拉机道路外事故和交通事故经常发生。从产品质量分析入手,提出了规范企业、加强管理以降低安全事故的建议。  相似文献   
993.
针对套袋后的葡萄体积增加和葡萄叶片表面积大容易出现重叠遮挡,及人工拍摄视频的速度不稳定可能导致套袋葡萄目标丢失的问题,该研究提出一种基于自纠正NMS(non-maximum suppression)-ByteTrack的套袋葡萄估产方法。该方法首先通过目标检测方法YOLOv5s检测视频中的套袋葡萄,将检测阶段的NMS操作后置到追踪阶段,保留因遮挡而被过滤的果实检测框;其次在ByteTrack的基础上加入相机运动补偿和改进的卡尔曼滤波算法,以自动纠正果实预测框的位置并进行追踪;最后提出一种划线计数策略对套袋葡萄自动计数。试验结果表明,该方法的多目标追踪准确率、多目标追踪精度和ID调和平均数分别为64.6%、82.4%和80.8%,相比ByteTrack分别提高了1.7个百分点、1.0个百分点和4.1个百分点,平均计数精度达到82.8%。因此,基于自纠正NMS-ByteTrack的估产方法能有效解决套袋葡萄的追踪计数问题,实现对套袋葡萄更精确地估产。  相似文献   
994.
随着农业大数据时代的到来,如何开展直观的有效信息挖掘成为数据利用的一大难题。作为一种能够帮助人们高效地管理现实世界中事物及其关系的异构语义网络,知识图谱应用在近年来备受关注。在农业数据不断增加、结构越来越复杂的背景下,将知识图谱应用于农业领域有助于农业大数据分析,促进智慧农业发展。该文首先分析了知识图谱构建的模式,即自顶向下、自底向上及两种模式结合等3种模式的特点,然后从本体构建、知识抽取、知识融合、知识推理、知识图谱存储及可视化5个方面综述了农业知识图谱构建的关键技术应用进展与难点,接着对当前知识图谱在农业领域的应用进行了梳理,主要有农业专题文献计量研究、农业信息检索、农业知识问答和农业信息资源推荐等4个方面,最后对知识图谱技术在农业领域的应用研究方向进行了展望,认为未来应关注基于知识图谱的农产品电商推荐、动态农业知识图谱的构建、跨领域知识图谱的构建与关联等方面。  相似文献   
995.
The increasing demand for biomass for food, animal feed, fibre and bioenergy requires optimization of soil productivity, while at the same time, protecting other soil functions such as nutrient cycling and buffering, carbon storage, habitat for biological activity and water filter and storage. Therefore, one of the main challenges for sustainable agriculture is to produce high yields while maintaining all the other soil functions. Mechanistic simulation models are an essential tool to fully understand and predict the complex interactions between physical, biological and chemical processes of soils that generate those functions. We developed a soil model to simulate the impact of various agricultural management options and climate change on soil functions by integrating the relevant processes mechanistically and in a systemic way. As a special feature, we include the dynamics of soil structure induced by tillage and biological activity, which is especially relevant in arable soils. The model operates on a 1D soil profile consisting of a number of discrete layers with dynamic thickness. We demonstrate the model performance by simulating crop growth, root growth, nutrient and water uptake, nitrogen cycling, soil organic matter turnover, microbial activity, water distribution and soil structure dynamics in a long-term field experiment including different crops and different types and levels of fertilization. The model is able to capture essential features that are measured regularly including crop yield, soil organic carbon, and soil nitrogen. In this way, the plausibility of the implemented processes and their interactions is confirmed. Furthermore, we present the results of explorative simulations comparing scenarios with and without tillage events to analyse the effect of soil structure on soil functions. Since the model is process-based, we are confident that the model can also be used to predict quantities that have not been measured or to estimate the effect of management measures and climate states not yet been observed. The model thus has the potential to predict the site-specific impact of management decisions on soil functions, which is of great importance for the development of a sustainable agriculture that is currently also on the agenda of the ‘Green Deal’ at the European level.  相似文献   
996.
Current widespread and intensive soil degradation in India has been driven by unprecedented levels of population growth, large-scale industrialization, high-yield agriculture, urban sprawl and the spread of human infrastructure. The damage caused to managed and natural systems by soil degradation threatens livelihoods and local services and leads to national socio-economic disruption. Human-induced soil degradation results from land clearing and deforestation, inappropriate agricultural practices, improper management of industrial effluents and wastes, careless management of forests, surface mining, urban sprawl, and ill-planned commercial and industrial development. Of these, inappropriate agricultural practices, including excessive tillage and use of heavy machinery, over-grazing, excessive and unbalanced use of inorganic fertilizers, poor irrigation and water management techniques, pesticide overuse, inadequate crop residue and/or organic carbon inputs, and poor crop cycle planning, account for nearly 40% (121 Mha) of land degradation across India. Globally, human activities related to agriculture contribute to the transgression of four of the nine Planetary Boundaries proposed by Rockström et al. (2009): Climate Change, Biodiversity Integrity, Land-system Change, and altered Phosphorus and Nitrogen Biogeochemical Flows. This review focuses on how knowledge of soil processes in agriculture has developed in India over the past 10 years, and the potential of soil science to meet the objectives of the United Nations' Sustainable Development Goal 2: Zero Hunger (End hunger, achieve food security, improved nutrition and promote sustainable agriculture), using the context of the four most relevant Planetary Boundaries as a framework. Solutions to mitigate soil degradation and improve soil health in different regions using conservation agricultural approaches have been proposed. Thus, in this review we (1) summarize the outputs of recent innovative research in India that has explored the impacts of soil degradation on four Planetary Boundaries (Climate Change, Biodiversity Loss, Land-system Change, and altered Biogeochemical Flows of Phosphorus and Nitrogen) and vice-versa; and (2) identify the knowledge gaps that require urgent attention to inform developing soil science research agendas in India, to advise policy makers, and to support those whose livelihoods rely on the land.  相似文献   
997.
发展精品农业是立足于寒旱地区实际的现实选择,是实施乡村振兴的重要手段和途径。以天水市为例,从寒旱地区的区位特点和精品农业的资源禀赋出发,阐述了精品农业的含义和特征,提出了寒旱地区精品农业发展建议:加强组织领导,提高精品农业思路认识;强化项目支撑,夯实精品农业驱动基础;创新经营方式,提升精品农业产业化水平;推进科技创新,提高精品农业“芯片”含量。为给寒旱地区构建精品农业产业体系和助推乡村振兴战略实施提供参考。  相似文献   
998.
Stability and reliability of yield and quality for 15 durum wheat genotypes (old and modern) were evaluated in a 5‐year experiment (southern Italy) in organic farming. Genotypes were grown at two N levels (0 and 80 kg/ha), with the aim of evaluating ‘genotype × environment’ (GE) interactions and their role on genotype selection in N‐limited environments. Several approaches to stability were used, within the frame of mixed models and additive main effects and multiplicative interaction analysis, and their validity in stressful conditions and organic farming was discussed. Especially for protein and gluten content, results indicate high environmental variability and the presence of crossover ‘N × environment’ interactions, which supports the need for specific breeding programmes in N‐deficient environments. The average response was strongly affected by N availability (on average, yield was 2.95 and 3.42 t/ha, protein content was 11.6% and 12.85%, gluten content was 8.55% and 9.92%, respectively, at 0 and 80 kg N/ha), and few genotypes gave high yield and quality at both fertilization levels. Only ‘Gargano’ and ‘Fortore’ showed a good inter‐year stability at both N levels. The old cultivars gave minimal responsiveness to increased N input, but gave good results in limiting conditions, indicating that they may play a role in organic farming.  相似文献   
999.
Many white-faced whistling ducks (Dendrocygna viduata) have responded to European colonization by overwintering on irrigation and stock-watering ponds in the semi-arid interior of South Africa. I studied the body condition, diet, behaviour and moult intensity of whitefaced whistling ducks prior to departure for breeding areas during spring 1995. Other than higher protein levels in immature males than immature females, there were no sexual differences in body mass or levels of lipid, protein, or ash in adults or immatures. Adults were heavier than immatures and had higher levels of ash. There were no sex- or age-related differences in the proportion of individual food items consumed, 96.6% of which was maize. By foraging on neighbouring agricultural fields, birds were able to spend large portions (80%) of the day/night in comfort-related activities (preen, loaf, sleep) and little time foraging (8.8%) while on ponds. There were no sex- or age-related differences in overall moult intensity score or intensity of moult in 20 feather areas. With exception of primaries and secondaries, birds were moulting moderately to heavily in all feather regions. Agricultural ponds permit whitefaced whistling ducks to overwinter close to breeding areas, while the high availability and energy content of maize enables them to attain higher spring fat levels than birds that overwinter on traditional sites closer to the coast. Intensive agriculture has probably contributed to the population increase and range expansion of white-faced whistling ducks in South Africa.  相似文献   
1000.
张掖市生态循环农业与经济发展模式   总被引:2,自引:0,他引:2  
王艺林  贾玉琴  赵维俊 《草业科学》2013,30(9):1488-1492
本文立足张掖市生态优势,着眼循环农业发展,总结了张掖市发展生态循环农业的生态整合、减量化生产、生态链连接与转换、产业纵向拉长、产业横向延伸及庭院微循环等模式。分析表明,认识创新是发展生态循环农业的前提条件,理清基本思路是发展生态循环农业的关键所在,政府推动是发展生态循环农业的重要基础,市场化运作是发展生态循环农业的重要途径,科技创新是发展生态循环农业的核心手段,政策法规是发展循环经济型生态农业的重要保证。  相似文献   
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