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81.
82.
Jean-Philippe Roy Luc DesC?teaux Denis DuTremblay Francis Beaudry Johanne Elsener 《The Canadian veterinary journal. La revue veterinaire canadienne》2009,50(12):1257-1262
This study determined the efficacy of a 5-day extended therapy with cephapirin sodium in dairy cows chronically infected with Staphylococcus aureus. Chronically infected cows selected from 14 dairy herds in the St-Hyacinthe region, Québec were randomly allocated to a group of 31 cows treated for 5 consecutive days with 200 mg of cephapirin per quarter BID or a group of 30 untreated control cows. Bacteriological cure was determined by 3 negative bacterial cultures at 10, 24, and 31 days after treatment. The cow cure rates were 25.8% (8/31) in the treated cows and 3.3% (1/30) in the control group (P = 0.013). The quarter cure rates at first sampling post-treatment were 77.6% (38/49) and 18% (9/50) in the treated and the control groups, respectively (P < 0.0001). A 5-day extended therapy with cephapirin is effective in treating cows chronically infected with S. aureus. 相似文献
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84.
Alvarez J de Juan L Bezos J Romero B Sáez JL Marqués S Domínguez C Mínguez O Fernández-Mardomingo B Mateos A Domínguez L Aranaz A 《Veterinary microbiology》2009,135(3-4):389-393
Interferon-gamma (IFN-gamma) detection assay is being applied as an ancillary test to tuberculin tests in the diagnosis of bovine tuberculosis to detect the maximum number of infected animals. Among possible factors influencing the performance of tuberculosis-diagnostic tests, paratuberculosis, a widespread disease in Spain and other European countries, has been pointed out as a cause of false positive reactions. Still, its effect on the sensitivity of these tests in cattle has yet to be fully characterized. The impact of paratuberculosis in the apparent sensitivity of IFN-gamma assay was studied in a bullfighting cattle herd with a mixed tuberculosis-paratuberculosis infection, using culture of Mycobacterium bovis and Mycobacterium avium paratuberculosis as the gold standard to determine the infection status of every animal. A total of 218 animals were slaughtered and sampled for bacteriology after blood sampling. IFN-gamma assay showed a lower apparent sensitivity in animals with a mixed infection (50%) compared to all animals suffering tuberculosis (78.3%). This finding indicates that the presence of paratuberculosis in tuberculosis-infected herds could imply a serious impairment in the sensitivity of IFN-gamma detection test. 相似文献
85.
Vasquez-Caicedo AL Heller A Neidhart S Carle R 《Journal of agricultural and food chemistry》2006,54(16):5769-5776
Accumulation of beta-carotene and trans-cis isomerization of ripening mango mesocarp were investigated as to concomitant ultrastructural changes. Proceeding postharvest ripening was shown by relevant starch degradation, tissue softening, and a rising sugar/acid ratio, resulting in a linear decrease (R (2) = 0.89) of a ripening index (RPI(KS)) with increasing ripening time. A modest accumulation of all-trans-beta-carotene and its cis isomers resulted in a slight pigmentation of the mango chromoplasts, because ambient temperatures of 18.2-19.5 degrees C provided suboptimal ripening conditions, affecting color development and beta-carotene biosynthesis. The ultrastructures of chromoplasts from mango mesocarp and carrot roots were comparatively studied by means of light and transmission electron microscopy. Irrespective of the ripening stage, mango chromoplasts showed numerous plastoglobuli varying in size and electron density. They comprised the main part of carotenoids, thus supporting the partial solubilization of the pigments in lipid droplets. However, because different pigment-carrying tubular membrane structures were also observed, mango chromoplasts were assigned to the globular and reticulotubular types, whereas the crystalline type was confirmed for carrot chromoplasts. The large portions of naturally occurring cis-beta-carotene in mango fruits contrasted with the predominance of the all-trans isomer characteristic of carrots, indicating that the nature of the structure where carotenoids are deposited and the physical state of the pigments are crucial for the stability of the all-trans configuration. 相似文献
86.
Mariela Fuentes Bram Govaerts Fernando De León Claudia Hidalgo Luc Dendooven Ken D. Sayre Jorge Etchevers 《European Journal of Agronomy》2009,30(3):228-237
Soil management systems may negatively affect the quality of the soil. Policymakers and farmers need scientific information to make appropriate land management decisions. Conventional (CT) and zero tillage (ZT) are two common soil management systems. Comparative field studies under controlled conditions are required to determine the impact of these systems on soil quality and yields. The research presented studied plant and soil physical and chemical characteristics as affected by different agricultural management practices, i.e. ZT and CT, cropped with continuous wheat or maize in monoculture (M) or in a yearly rotation (R) of these two crops, either with residue retention (+r) or without residues retention (?r), in an experimental field in the Transvolcanic Belt of Mexico after 14 years. The dominant factors defining soil quality were organic C, total N, moisture, aggregate stability, mechanical resistance, pH and EC. The principal component combining the variables organic C, total N, aggregate stability and moisture content showed the highest correlations with final yield (R = 0.85 for wheat and 0.87 for maize).After 14 years of continuous practice, ZTM + r and ZTR + r had the best soil quality and produced the highest wheat and maize yields of average 2001–2004 (6683 and 7672 kg ha?1 and 5085 and 5667 kg ha?1, respectively). Removing the residues, i.e. treatments ZTM ? r with maize (average 2001–2004: 1388 kg ha?1) and ZTR ? r and CTR ? r with wheat (average 2001–2004: 3949 and 5121 kg ha?1), gave the lowest yields and less favourable soil physical and chemical characteristics compared to the other practices. It was found that zero tillage with residue retention is a feasible management technology for farmers producing maize and wheat in the agro-ecological zone studied, resulting in a better soil quality and higher yields than with the conventional farmer practice (maize monoculture, conventional tillage and residue removal). 相似文献
87.
88.
Steven Van Pottelberge Kristof Van Amermaet Luc Tirry 《Pesticide biochemistry and physiology》2008,91(2):128-133
Detoxification by cytochrome P450 monooxygenases is an important mechanism involved in pesticide resistance in insects and mites. The activity of these enzymes can be induced by a variety of chemicals. The aim of this study was to evaluate the effect of six P450 inducers (phenobarbital, barbital, 3-methylcholanthrene, geraniol, isosafrole, pentamethylbenzene), known to have an inducing activity in insects and mammals, on the O-deethylation activity in the two-spotted spider mite Tetranychus urticae. Treatment with barbital, phenobarbital and geraniol resulted in a dose-dependent increase in activity. Neither 3-methylcholanthrene, isosafrole nor pentamethylbenzene were effective inducers. Time course studies showed that induction by geraniol and barbital started rapidly within a period of 1-4 h after initiation of the treatment, while maximal activity was reached within 4 and 48 h, respectively. In addition, it was shown that induction with xenobiotic compounds can alter the monooxygenase-mediated acaricide tolerance in a susceptible strain of T. urticae. Although barbital induced higher levels of P450 activity, geraniol proved to be a better compound to decrease toxicity of the tested acaricides. 相似文献
89.
Moerkens Rob Berckmoes Els Van Damme Veerle Wittemans Lieve Tirry Luc Casteels Hans De Clercq Patrick De Vis Raf 《植物病害和植物保护杂志》2017,124(3):295-303
Journal of Plant Diseases and Protection - Macrolophus pygmaeus Rambur (Hemiptera: Miridae) is a key biological control agent in greenhouse tomato crops. In the present study, we describe the... 相似文献
90.
土壤添加沼渣对温室气体排放及小麦生长的影响 总被引:1,自引:1,他引:0
Liliana PAMPILLÓN-GONZÁLEZ Marco LUNA-GUIDO Victor Manuel RUÍZ-VALDIVIEZO Olivia FRANCO-HERNÁNDEZ Fabián FERNÁNDEZ-LUQUE NO Octavio PAREDES-LÓPEZ Gerardo HERNÁNDEZ Luc DENDOOVEN 《土壤圈》2017,27(2):318-327
Digestate, the product obtained after anaerobic digestion of organic waste for biogas production, is rich in plant nutrients and might be used to fertilize crops. Wheat(Triticum spp. L.) was fertilized with digestate, urea, or left unfertilized and cultivated in the greenhouse for 120 d. Emissions of greenhouse gasses(carbon dioxide(CO_2), methane(CH_4), and nitrous oxide(N_2O)) were monitored and plant growth characteristics were determined at harvest. The digestate was characterized for heavy metals, pathogens, and C and N mineralization potential in an aerobic incubation experiment. No Salmonella spp., Shigella spp., or viable eggs of helminths were detected in the digested pig slurry, but the number of faecal coliforms was as high as 3.6 × 10~4colony-forming units(CFU) g-~(1)dry digestate. The concentrations of heavy metals did not surpass the upper limits established by US Environmental Protection Agency(EPA). After 28 d, 17% of the organic C(436 g kg~(-1)dry digestate) and 8% of the organic N(6.92 g kg~(-1)dry digestate)were mineralized. Emissions of CO_2 and CH_4 were not significantly affected by fertilization in the wheat-cultivated soil, but digestate significantly increased the cumulative N_2O emission by 5 times compared to the urea-amended soil and 63 times compared to the uncultivated unfertilized soil. It could be concluded that digestate was nutrient rich and low in heavy metals and pathogens, and did not affect emissions of CH_4 and CO_2 when applied to a soil cultivated with wheat, but increased emission of N_2O. 相似文献