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81.
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
82.
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
83.
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
84.
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
85.
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
86.
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
87.
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
88.
Simulated long-term effects of different soil management regimes on the water balance in the Loess Plateau, China 总被引:1,自引:0,他引:1
Shulan Zhang Elisabeth Simelton Lars Lvdahl Harald Grip Deliang Chen 《Field Crops Research》2007,100(2-3):311-319
A soil management regime that improves water use efficiency (WUE) is urgently required to increase the sustainability of the winter wheat-summer fallow system in the Loess Plateau, China. However, the long-term partitioning of the water balance must be understood in order to evaluate the viability of possible soil management regimes. Therefore, an ecosystem model (CoupModel) was used to explore the effects on components of the water balance of five types of soil management regimes: conventional practice, wheat straw mulching, incorporation of high organic matter contents, compaction, and use of a harvested fallow crop. Three variants of the fallow crop approach were also considered, in which the crop was harvested 15, 30 and 45 days before sowing the wheat (designated Fallow-15d, Fallow-30d and Fallow-45d, respectively). Simulations were used to identify the relative magnitude of soil evaporation, wheat transpiration and deep percolation and to elucidate the temporal variability in these components for a selected location using climate records spanning 45 years. However, the soil management regime significantly influenced the magnitude of every component of the water balance (in terms of minimum, maximum and mean values) over the long periods considered. Consequently, wheat yield and WUE differed significantly among the simulated treatments. Mulching led to significantly lower soil evaporation, higher transpiration, and more frequent and extensive deep percolation than other regimes, thereby improving fallow efficiency (percentage of rainfall stored in the soil during the fallow period at the end of the fallow period), wheat yields and WUE. In contrast, soil compaction gave the opposite results, leading to the most unfavourable partitioning of the water balance reflected in the lowest wheat yield and WUE values of all the regimes. In 90% of the years no deep percolation occurred in the soil compaction simulations. Use of a fallow crop with optimal harvest timing (Fallow-30d) improved partitioning of the water balance (decreased soil evaporation) and did not significantly reduce wheat yield compared with conventional practice. High organic matter contents in the soil also had a positive influence on the water balance and improved wheat yield and WUE relative to conventional practice. Therefore, mulching appears to be the best management practice for the winter wheat-summer fallow system in the Loess Plateau, according to the simulations. Increasing soil organic matter may be the best option if mulching cannot be implemented. The ideal time for harvesting a fallow crop for use as green manure or fodder appears to be ca. 30 days before sowing the winter wheat. 相似文献
89.
At the inaugural conference of SedNet WG 4 in April 2002 in Venice it was decided that a survey of existing sediment management guidelines was an important pre-requisite to elaborate on the opportunities for river basin planning of sediment management. This article discusses the existing programmes, decision support system, and conventions and concludes that there is presently no comprehensive river basin sediment management guideline at an international (European) or national level. Management guidelines which are of high relevance for sediment management exist mostly for the purpose of environmentally sound handling for navigation. For the maintenance of waterways and harbours sediments have to be handled in an environmentally sound and economical way. There are some special international and national regulations for dredged material which have different legal and technical backgrounds, purposes and limited competence. The way to find the appropriate regulation within legislation is to ask the question: What will happen with the sediment/dredged material? 相似文献
90.
Land use and nitrate-nitrogen in the vadose zone of loess deposits in the southern part of the Lower Rhenish Embayment Mean annual nitrogen-leaching was studied at seven experimental sites with grain-sugar beet crop rotation. Soil water simulation models and determination of the nitrogen content in the vadose zone below the rooting zone were combined to quantify the annual leaching rates. Leaching amounts to 11–18 kg NO3? N/ha · a at sites where only mineral fertilizer was applied, whereas sites with additional organic fertilizers show higher leaching rates of 30–36 kg NO3? N/ha · a. 相似文献