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81.
Summary Genetic transformation is vital to the transfer of novel genes into crop plants as well as to the emerging area of functional genomics. However, the successful genetic transformation of wheat still remains time consuming and genotype dependent. This paper updates the progress made in last 3 years towards developing a robust genetic transformation system for wheat. Agrobacterium-mediated wheat transformation offers advantages such as single-copy gene insertion, minimal rearrangement of DNA, low cost and comparatively high efficiency. The reported recent developments in wheat transformation will lead to increased efficiency of wheat breeding programs. The most promising recent progress is in the development of drought-tolerant wheat, since water stress continues to be a major limiting factor hindering world wheat productivity under adverse hot and dry weather conditions. 相似文献
82.
Martina Kasper Bernhard Freyer Kurt‐Jürgen Hülsbergen Harald Schmid Jürgen Kurt Friedel 《植物养料与土壤学杂志》2015,178(1):25-34
The importance of the soil humus content is indisputable. Soil humus plays an important role in preserving soil fertility and exerts great influence on plant production and yield potential. However, proofing that management‐related changes in the stock of soil organic matter (SOM) have taken place against the background of spatial and temporal variation is a difficult task. In most cases, sampling over a long period of time is needed to verify these changes. Alternatively, potential changes in the SOM stock can be estimated using humus balancing models, which help to identify the need for humus reproduction on a farm. In general, a humus balance is the difference between the humus demand of cultivated crops and humus supply through crops and organic fertilizers. In this study, the ‘Dynamic Humus Unit Method' within the modelling program REPRO was applied to calculate the humus balance for 29 model‐farms that are representative of most of the agricultural production in Austria. Each model‐farm represents a specific production type (PT) and farming system in a defined region or main production area (MPA). This approach gives an overview of the humus balances at a large scale and allows a general trend in Austria to be estimated. Besides differing between conventional and organic farming systems, specific site conditions can also be selected in the model. The constructed model‐farms belong to different PTs such as “forage production”, “cash crops”, “refinement”, and “permanent crops”. The PT “permanent crops” refers to the cultivation of wine. The cropping system of each PT was analyzed in detail, while livestock keeping was considered only when applicable. Positive humus balances were found for all PTs except for permanent crops. The results ranged from –122 to 890 kg C ha?1 y?1. Regions and farm structure, e.g., forage production compared to cash crop, were found to have a greater influence than the kind of farming system (i.e., organic vs. conventional farming). Comparing the different PTs, forage production had the highest positive humus balances (219 to 890 kg C ha?1 y?1), followed by cash crop (24 to 239 kg C ha?1 y?1), refinement (–64 to 402 kg C ha?1 y?1) and permanent crops (–122 to –38 kg C ha?1 y?1). Regarding the farming system, organic farming led to more humus accumulation than conventional farming due to a higher share of fodder legumes and catch crops and more diverse crop rotations. The results were within the range of available empirical data on SOM change, and it was therefore concluded that the results are reasonable. In general, humus reproduction can be regarded as sufficient for agricultural production. 相似文献
83.
Kristin Hamre Brit Hjeltnes Harald Kryvi Sverre Sandberg Mette Lorentzen Øyvind Lie 《Fish physiology and biochemistry》1994,12(5):421-429
Atlantic salmon (Salmo salar) fry, initial weight 0.16 g, were fed a semipurified diet with 0, 15, 30, 60 or 120 mg dl-α-tocopheryl acetate/kg. After
24 weeks, the first two of these groups were extinct, and the fish receiving 30 mg/kg were clearly vitamin E deficient. Vitamin
E deficient fish had low hemoglobin levels, characterized by a combination of reduced cellular hemoglobin concentration, red
cell volume and red cell number, and an increased number and fraction of immature red blood cells. The hemoglobin concentration
decreased over the decreasing range of experimental dl-ga-tocopheryl acetate levels. Therefore, even if 60 mg dl-α-tocopheryl
acetate/kg gave good survival, this level was clearly physiologically suboptimal. Ceroid accumulated in the liver of fish
fed 30 mg vitamin E/kg, and autofluorescent inclusions were found in the red blood cells of fish fed 30 and 60 mg vitamin
E/kg. Degeneration of skeletal muscle was not observed in the present study. 相似文献
84.
Tagging of juvenile lobsters (Homarus gammarus (L.)) with visible implant fluorescent elastomer tags
Ingebrigt Uglem Harald Nœss Eva Farestveit Knut Eirik Jørstad 《Aquacultural Engineering》1996,15(6):499-501
Visible implant fluorescent elastomer (VIFE) tags were implanted beneath the epidermal layer within the abdomen of 25 juvenile lobsters. After three molts the tag retention was 100% and the total survival 92%. The results suggest that VIFE tags could be an effective tool when assessing the feasibility of enhancing natural lobster stocks. 相似文献
85.
Dr. Jürgen Schultze-Motel Reinhard Fritsch Karl Hammer Peter Hanelt Joachim Kruse Harald Ohle Helga I. Maass 《Genetic Resources and Crop Evolution》1979,27(2):247-264
Summary Important papers on taxonomy and evolution of cultivated plants published in 1977 and 1978 were put together and briefly discussed.
Taxonomie und Evolution der Kulturpflanzen: Literaturübersicht 1977/1978
Zusammenfassung Wichtige Arbeiten über Taxonomie und Evolution der Kulturpflanzen aus den Jahren 1977–1978 wurden zusammengestellt und kurz kommentiert.
: 1977 1978
, 1977–1978 . .相似文献
86.
The accumulation of heavy metals in soils and crops by practical sewage sludge application An accumulation of cadmium, lead, zinc and copper was found in some soils and crops after sewage sludge application as compared with same soils and plants not fertilized with sewage sludge. In the soils the heavy metals mainly were accumulated in the Ap-horizons. The displacement into subsoils was small, in spite of the good permeability of the sandy soils investigated. Relatively the mobility of zinc and cadmium in soils was most distinct. Within the plants the accumulation of the heavy metals was strongest in the roots, however also evident in the shoots of rye, barley and oats. Zinc and copper was concentrated in the grains, too. On the meadow-land an accumulation of the elements investigated was found in the blades of rye grass (Lolium perenne L.). 相似文献
87.
Salim Belyazid Harald Sverdrup Daniel Kurz Sabine Braun 《Water, air, and soil pollution》2011,216(1-4):289-317
The ForSAFE-VEG model was used to investigate the impacts of climate change and air pollution scenarios on soil chemistry and ground vegetations composition. In particular, the model involves a ground vegetation model incorporating plant changes to ambient site conditions in terms of climate and chemistry, but the model also incorporate competition between the different plant groups. The model was validated against observed values and reproduced observations of tree growth, soil chemistry, and ground vegetation compositions to satisfaction. The results show that the ground vegetation reacts strongly to changes in air pollution, in particular nitrogen as well as to climate change with major shifts in plant composition. A procedure for estimating critical loads for nitrogen, using ground vegetation biodiversity as criterion, was tested and the method seems operable. It suggests that if we want to protect the present biodiversity of the ground vegetation, this will face significant difficulties because of permanent climate change that induced changes in the ecosystem. We conclude that the reference state for ground vegetation biodiversity is rather to be sought for in the future, hopefully using models, than in the past or present. 相似文献
88.
The Apple mealybug Phenacoccus aceris was verified as the vector of the Little Cherry Virus-2 (LChV-2) in Baden-Württemberg. However, this does not exclude the participation of even more different vectors. Because the Apple mealybug is more spread than presumed as of yet, this vector should be specifically controlled as well as fought in cherry orchards. If planting new cherry orchards it must be strictly adhered to virus-free, certificated plant matter, so that in areas free from Little cherry an epidemic as in the ??Altes Land?? can be avoided. 相似文献
89.
Twenty-four flocks comprising 2370 breeding goats were examined. Three hundred-and-sixty-nine (15.6%) of the goats either aborted or delivered dead kids at full term, or were barren. In 23 of the herds the rate of reproductive loss ranged from 2% to 36%, whereas in one herd all of 54 mated goats had live kids. A loss of greater than or equal to 20% was found in 9 herds comprising 799 goats. In 11 herds comprising 946 goats the rate of reproductive failure was less than or equal to 10%. The incidence of reproductive failure was higher in older goats than in those in their first or second pregnancy. The causes were identified in only about 3% of the goats that aborted. It is concluded that reproductive failure in many flocks probably is associated with non-infectious causes such as nutritional and environmental factors. 相似文献
90.
Mayr B Korb H Oppeneiger T Demetz F Egger J 《Veterinary journal (London, England : 1997)》2007,174(3):677-680
A combined primed in situ labelling (PRINS)/4',6-diamino-2-phenylindole (DAPI)/propidium iodide (PI)-fluorescence-banding method was used to characterise telomeres, identify their specific chromosomes and visualise neighbouring heterochromatin in 25 artificial insemination (AI) bulls. A highly heterogeneous telomere length pattern was found in cattle. Each bull possessed his own characteristic, specific telomere length pattern. 相似文献