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161.
Abstract— A review of the problems arising from cross-infection of helminth parasites in children derived from dogs and cats. The particular danger of visceral larvae migrans is outlined.
Résumé— Examen des problemès soulevés par la parasitose intestinale croisée entre des enfants d'une part, des chiens et des chats de l'autre. Le danger des migrations de larves dans les viscères est particulièrement souligné.
Zusammenfassung— Ein Überblick über die Probleme, die sich aus der infektiösen Übertragung der von Hunden und Katzen herrührenden Wurmparasiten auf Kinder ergeben. Auf die besondere Gefahrlichkeit der wandernden Eingeweidelarven wird hingewiesen.  相似文献   
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Wild potato germplasm represents a unique, diverse and accessible resource for disease and pest resistance, along with useful agronomic traits that may be introgressed into the cultivated potato (Solanum tuberosum L.). Hybridization of diploid wild Solanum species with haploids (2×) of cultivated potato (4×) is generally an effective technique for introducing genetic diversity and desirable traits into potato. However, in this study, hybridization barriers were found in crosses between S. tuberosum haploids and the wild species S. raphanifolium. Male sterility, likely due to nuclear-cytoplasmic interactions, was observed in some haploid tbr?×?S. raphanifolium hybrids. In addition, pollen-pistil incompatibilities were observed in backcross, F2, and reciprocal cross hybridization attempts that failed to produce seed. More crosses were successful when F1 clones were crossed as females to wild clones than to cultivated clones. When crosses were made in the other direction, with F1 hybrids used as male parents, seeds were almost never produced.  相似文献   
165.
Detailed chemical studies and RAPD analysis were done in different populations of Podophyllum hexandrum collected from high altitude regions of North Western Himalayas. Random amplified polymorphic DNA (RAPD) analysis revealed a high degree of genetic diversity among the 12 collected accessions, attributed to their geographical and climatic conditions. HPLC analysis also revealed variation in the concentration of two major marker compounds which lead to the identification of a chemotype. The study demonstrated that RAPD and chemical markers are very useful tools to compare the genetic relationship and pattern of variation among such prioritized and endangered medicinal plants.  相似文献   
166.
Summary Colchicine induced tetraploid jute plants were shorter than their diploid counterparts. C2 tetraploid plants became taller than C1 plants. Leaves were larger in size and with higher breadth/length ratios compared to those of diploids. Stomata were bigger than those in diploid leaves but their frequency was less in tetraploid leaves. Tetraploid flowers were bigger than the diploids and bore a reduced number of stamens. Tetraploid pollen grains were larger but the percentage of sterility in them was more than that of the diploids. Fewer fruits with a reduced number of seeds were formed in tetraploid plants. They usually were shorter but wider than diploid fruits. Tetraploid seeds were larger and heavier. C2 tetraploid plants bore more fruits with an increased number of seeds than C1 plants. Breadth of individual fibres increased but length remained unchanged.The paper was read at the Eighth Pakistan Science Conference held at Dacca, 1956.  相似文献   
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Summary Experiments conducted in the greenhouse and in the field indicated that plants produced from seedlings of Cucumis sativus L. which displayed their cotyledons in an upward position grew faster than plants which displayed their cotyledons in a downward position. Cotyledon angle was not a function of seed size nor seedling weight at 10 days after planting. An increase in plant height, node number, and fresh weight at later growth stages was associated with an upward cotyledon angle and persisted until time of harvest. Anthesis tended to occur later in plants having a downward cotyledon angle. The number of pistillate flowers was greater in plants with an upward cotyledon angle compared to those with a downward cotyledon angle. Differences in yield (fruit number) were not associated with cotyledon angle.Paper No. 5432 of the Journal Series of the North Carolina Agricultural Experiment Station, Raleigh, NC. The use of trade names in this publication does not imply endorsement by the North Carolina Agricultural Experiment Station of products named, nor criticism of similar ones not mentioned.  相似文献   
169.
Spirulina fusiformis was tested for its possible in vivo protective effects against cyclophosphamide (CP) and mitomycin-C (MMC) induced genotoxicity and oxidative stress in mice. Pre-treatment with S. fusiformis (250, 500 and 1000 mg kg(-1), p.o., daily for 5 days) significantly reduced the chromosomal damage and lipid peroxidation with concomitant changes in antioxidants and detoxification systems. All the three tested doses were effective in exerting a protective effect against CP and MMC.  相似文献   
170.
A mail survey was conducted to gain understanding of the agroforestry practices of non-industrial private forest landowners (NIPF) in Washington State, located in the north-western USA. Although NIPF owners control 1.5 million hectares of the state's commercial forestland base, their diversity of forestland uses, land management practices and objectives as land managers are not well understood. Past NIPF surveys and anecdotal information suggest agroforestry is a major use of NIPF lands. We defined agroforestry as a potentially sustainable land use practice combining the deliberate growing of woody perennials with agricultural crops and/or animals. Objectives of this study were to:
  1. determine the extent that agroforestry is used by Washington's NIPF owners,
  2. develop insight into NIPF owners' motivations for practicing agroforestry,
  3. describe the agroforestry practices within three distinct physiographic and agroecological zones in Washington, and
  4. determine the agroforestry information needs of NIPF owners.
The target population consisted of NIPF owners in 4 counties within each of the three regions. Response to the August 1990 mail survey was 63.5%, yielding 296 useable questionnaires. Fifty-seven percent of all respondents practice agroforestry. Forestland grazing is the most common agroforestry practice (39% of all respondents), followed by windbreaks (34%), harvest of special forest products (12%), livestock enrichment plantings for forage or shelter (7%), orchard grazing (5%), orchard intercropping (2%), and Christmas tree grazing (0.34%). The most frequent motives for owning land were passing land on to children (80%), keeping it natural and income from timber (both 72%). Respondents saw aesthetics (77%), increasing land unit income (74%), and water conservation (70%) as possible advantages of practicing agroforestry. High establishment costs (66%) and livestock damage to trees or crops (64%) were the most frequently selected potential disadvantages to practicing agroforestry. Lack of technical and educational support (67%) and lack of access to livestock/livestock facilities (58%) were disincentives to practicing agroforestry. Landowners are interested in learning more about agroforestry and how agroforestry techniques might be incorporated in their land management tool kit. A significant number of non-industrial private forest land owners in Washington believe that management of forestland, balancing conservation and production goals, can be furthered by suitable agroforestry practices.  相似文献   
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