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941.
毛竹周年采伐及经营管理配套技术研究   总被引:1,自引:0,他引:1  
为满足现代竹材加工业生产周年供竹的需要,开展毛竹周年采伐及经营管理配套技术的研究。结果表明,在毛竹1个生理周期中,除每年3~5月和白露前后半个月外,其余16个月可伐第4度毛竹,这对竹笋和竹材产量的影响不明显,可提高未来第2度竹竹笋的产量,实施周年采伐后,对竹材的抗拉、抗压强度最大下降7%,对竹制品的性能无明显影响;施尿素可提高经济产量,以每公顷施300kg以上为好。实行周年采伐还必需加强林政管理,以杜绝乱砍乱伐现象发生。  相似文献   
942.
长白落叶松丰产林造林密度及其经济效益初探   总被引:4,自引:0,他引:4  
本文以长白山落叶松人工林的造林初植密度为研究对象,在5种不同初植密度下,优选出适于黑龙江省利用世界银行贷款集约经营人工林项目合理密度。建筑材林分的合理初植密度为3000株/ha,纤维材林分为3300株/ha。  相似文献   
943.
实行森林分类经营需要处理好的六个关系   总被引:1,自引:0,他引:1  
林业分类经营改革是实行林业可持续发展的关键,为了推进林业分类经营改革,笔者以六个方面分析阐述了在分类经营改革中需处理好的六个关系。即:分类经营与综合经营的关系;分类经营与市场经济的关系;分类经营与传统林业的关系;商品林与公益林的关系;分类经营与林业企业转机建制的关系;分类经营与可持续发展的关系。  相似文献   
944.
The subject of risk management is attracting more and more attention around the world. The risk of forest fire disasters should be faced and dealt with for forest fires cannot be avoided. Treating forest fire disasters as a risk management issue promotes important measures and methods for fire fighters to prevent, reduce and control the risks of forest fires. In this paper, the risk concept and risk connotation as well as the management risks for forest fire suppression are discussed clearly. Issues such as risk judgments, risk analysis, risk control and the assessment of risk, including their contents and corresponding methods are clarified. Translated from Forest Resources Management, 2006, 2: 24–27 [译自: 林业资源맜理]  相似文献   
945.
The Regional Forest Agreement process has dominated Australian forest policy for the past decade. The RFA process set in place a mechanism by which benchmark conservation values were established for forest ecosystems, whilst addressing the needs of the timber industry. The outcomes of a number of RFA's have been fraught with controversy. Key stakeholder groups have shown disagreement with processes and outcomes of methods employed by government both in establishing conservation reserves and areas allocated to timber harvesting. This research uses non-linear techniques to examine the dynamical behavior in stakeholder responses and to identify patterns of behavior that may lead to prediction of stakeholder responses. The method developed in this research provides a bridge between social sciences and Chaos theory.1  相似文献   
946.
947.
We investigated the initial effects of strip wise soil loosening (0–35 cm depth) on soil chemical and physical parameters by using a deeply working rotary cultivator in combination with liming and mixing of the dolomite with the soil material of acidic forests. The investigations took place 8 months after the treatment. pH values and contents of exchangeable Ca and Mg increased significantly at the tilled depth whereas the content of exchangeable Al and easily soluble P decreased. The rate of mineralisation increased at this depth which was shown by a loss of Corg, Ntot and short-term loss of NO3-N. The treatment led to a mobilisation of Mn at the tilled depth. However, the content of exchangeable Pb decreased due to an increased pH value. Below the tillage depth of 35 cm only partly significant changes of exchangeable Mn and NO3-N were found. The total porosity and bulk density at 10–15 and 40–45 cm depths were not significantly different from those in the control plot, but the rate of infiltration increased significantly.  相似文献   
948.
Phenological transects were employed to assess monthly leaf, flower, unripe fruit and ripe fruit abundance for a total of 1732 individual plants within five tropical forest habitats at the ‘Lago Caiman Research Camp’, Noel Kempff Mercado National Park, northeastern Santa Cruz Department, Bolivia. Fruit surveys along trails were conducted concomitantly to assess fruit availability for the resident terrestrial frugivore community. The results of the two methodologies are compared and discussed with respect to wildlife and forest management in the region. Phenological transects revealed that Cerrado forest, tall forest, low vine forest, Sartenejal (swamp) forest, and pied mont (premontane) forest, showed seasonal variations in flower, unripe fruit and ripe fruit abundance, however, the broad temporal patterns were significantly different across habitats. Seasonal variation in overall foliage abundance was only marked for Cerrado forest. Ripe fruit production within the study site was not significantly different across months, with different habitats peaking asynchronously in abundance. From a frugivory perspective, overall ripe fleshy fruit abundance also varied considerably between habitats, and again showed asynchronous peaks in habitat production. However, both methodologies revealed the early dry season (June–July) as a period of ripe fleshy fruit scarcity throughout the study area. This period represents a resource ‘bottleneck’ for the resident frugivore community and phenological results allowed the identification of a number of keystone fruit resources for the region. Furthermore, fruit resources which are super-abundant in the early–mid wet season (November–February) might also be considered keystone resources for the region, given that they are available in an otherwise fruit scarce forest. The dynamic spatial patterning of fruit availability at Lago Caiman suggests that certain habitats might be considered keystone habitats, since they provide the majority of fruit resources on a seasonal basis. Finally, the potential of phenological information in tropical forest management plans is discussed and underlined by the observation that rainfall in itself fails to predict fruit availability in the dominant habitats at Lago Caiman.  相似文献   
949.
Trade-offs among wood production, wood quality and ecological characteristics in the management of harvested forest stands are explored through model simulation of various silvicultural regimes. Long-term production of merchantable wood, production of various types of high-quality wood, and the level of certain quantitative ecological indicators are projected for coniferous forests of Pacific Northwestern USA. The set of ecological indicators used is based on the species composition and physical structure of old, unlogged forest stands. Simulations are performed with an ecological model of forest stand dynamics that tracks the fate of live and dead trees. Short rotations (<50 years) produce the least amount of high-quality wood over the multi-century simulation period. They also fail to generate ecological attributes resembling those of old forest stands. Production of high-quality wood is moderate to high under all rotations of 80 years or more; however, most ecological indicators require longer rotations unless alternatives to clearcutting are applied. Alternatives examined include retention of 15% cover of live tree canopy at each harvest in combination with artificial thinning between harvests. Thinning from below can expedite the development of large live and dead trees, and canopy height diversity without greatly diminishing wood quantity or quality. Proportional thinning retains understory stems, thereby expediting the recruitment of shade-tolerant trees. A possible drawback to thinning, particularly proportional thinning, is the diminished production of clean-bole wood at rotations of 150 and 260 years. It is concluded that most wood quantity, wood quality and ecological objectives can be met with long rotations (ca. 260 years). Certain objectives can be met with shorter rotations (80–150 years) when treatments of thinning and canopy tree retention are applied.  相似文献   
950.
1998-2000年期间对白云山风景区主要森林植物病害进行了调查,发现病害共计59种,分布于44种寄主植物中,病害类型比较丰富,其中以叶部病害为主,病原涉及真菌、细菌、植物菌原体等多种寄生物及非侵染性病原,其中又以真菌为主,病害发生普遍,但为害较轻,没有发现严重的危害性病害。  相似文献   
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