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201.
During the clinical phase of bovine spongiform encephalopathy (BSE), a significant decrease was observed in the ratio of muscle glycogen to plasma L-lactic acid concentrations in BSE infected field case and experimentally infected dairy cattle compared with healthy control cattle (P<0.001), this being due to changes in the concentration of both metabolites in the BSE infected cattle compared with the control group. Furthermore, the concentration of plasma alanine was significantly increased (P<0.05) in the infected animals. No significant difference was detected between these two groups in the ratio of hepatic glycogen to plasma lactate. We infer that BSE infected cattle exhibit signs of altered energy metabolism and when applied in conjunction with changes in other metabolite biomarkers these changes may be useful for discriminating BSE infected cattle from healthy cattle or those suffering with other disorders or diseases.  相似文献   
202.
A mail survey of 1889 pig producers in Great Britain with more than 100 sows or more than 1000 pigs was carried out to investigate their use of antimicrobials and other health-related management practices. The response rate was 25.5 per cent. Antimicrobials were most commonly administered in feed. Depending on the production system, between 60 and 75 per cent of the farms had used antimicrobials in their weaner rations and 20 to 62 per cent had used them in their grower rations. Antimicrobial injections had been used on 59 per cent of the farms. The use of antimicrobials in pigs of different age groups was variously associated with the scale of production, membership of a quality assurance scheme, the use of vaccination and whether the farmer thought the farm environment could be improved. Half the respondents (49 per cent) indicated that they used growth promoters in their weaners, but fewer used these in their growers (45 per cent) and finishers (34 per cent). Although 63 per cent of the farmers felt that the continued use of antimicrobials for disease prevention was justified, only 21 per cent felt that their continued use as growth promoters was justified.  相似文献   
203.
Hyperthyroidism is a common endocrinopathy of older cats and is associated with an increased glomerular filtration rate (gfr). Renal dysfunction is also common in older cats and may develop after they have been treated for hyperthyroidism. This paper describes the changes in the gfr of 27 hyperthyroid cats in the six months after their treatment with radioactive iodine ((131)I), and evaluates whether any commonly measured pretreatment parameters (serum biochemistry, systolic blood pressure, urine specific gravity) could predict a clinically significant decline in renal function. The gfr of all the cats had decreased one month after treatment, and the mean gfr was significantly lower. There was no further significant change in gfr between one and six months. The only independent variable associated with the final gfr was the pretreatment plasma glucose concentration (P=0.003).  相似文献   
204.

Background

Sugar beet is threatened by virus yellows, a disease complex vectored by aphids that reduces sugar content. We present an analysis of Myzus persicae population dynamics with and without neonicotinoid seed treatment. We use 6 years' yellow water trap and field-collected aphid data and two decades of 12.2 m suction-trap aphid migration data. We investigate both spatial synchrony and forecasting error to understand the structure and spatial scale of field counts and why forecasting aphid migrants lacks accuracy. Our aim is to derive statistical parameters to inform regionwide pest management strategies.

Results

Spatial synchrony, indicating the coincident change in counts across the region over time, is rarely present and is best described as stochastic. Uniquely, early season field populations in 2019 did show spatial synchrony to 90 km compared to the overall average weekly correlation length of 23 km. However, 70% of the time series were spatially heterogenous, indicating patchy between-field dynamics. Field counts lacked the same seasonal trend and did not peak in the same week. Forecasts tended to under-predict mid-season log10 counts. A strongly negative correlation between forecasting error and the proportion of zeros was shown.

Conclusion

Field populations are unpredictable and stochastic, regardless of neonicotinoid seed treatment. This outcome presents a problem for decision-support that cannot usefully provide a single regionwide solution. Weighted permutation entropy inferred that M. persicae 12.2 m suction-trap time series had moderate to low intrinsic predictability. Early warning using a migration model tended to predict counts at lower levels than observed. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   
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The heterogeneity of the spatial distribution of soil organic carbon (SOC) at the landscape scale is generally not considered in regional or national SOC dynamics models. In cropland this heterogeneity is controlled largely by topography, which influences the distribution of water, energy and sediments, and thus the SOC dynamics. Sediment redistribution rates have increased strongly since the mechanization of agriculture. The over‐simplification of landscape processes in regional models of C dynamics may add to the uncertainty in C balances. Therefore, a better characterization of the importance of landscape‐scale effects on the SOC distribution throughout a region is needed. This study characterized the relative importance of geomorphology in the SOC horizontal and vertical variability across croplands in the Belgian loess belt region. A large legacy dataset of soil horizons was exploited together with 147 recently sampled profiles. Mean SOC depth profiles for different soil types were compared. Various topographic attributes were computed from a digital elevation model, and their influence on SOC was quantified through simple linear models. Finally, SOC content was mapped at three depth layers through multiple linear models, and results were cross‐validated. The legacy dataset allowed identification of significant differences in the mean SOC profile according to texture, drainage or profile development classes. A clear relationship between SOC content and topographic attributes was demonstrated, but only for the recently sampled profiles. This may be explained by a substantial error in the location of the profiles of the legacy dataset. This study thus shows evidence that the major control of the vertical distribution of SOC is related to topography in a region where observed heterogeneities for other commonly involved factors are limited. However, the large amount of unexplained variability still limits the usefulness of the spatial prediction of SOC content, and suggests the importance of additional influencing factors.  相似文献   
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208.
Duodenal mucosa obtained from two patients with Menkes' syndrome contained abnormally large amounts of copper. The defect in copper absorption in this disease must lie in the process of intracellular handling or of transport across the serosal cell membrane. Fibroblastic cells cultured from the skin of patients and of heterozygous females show intense metachromasia in primary culture which disappears in subculture. These cells may be useful for the study of copper transport in vitro and for the identification of heterozygotes in affected families.  相似文献   
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210.
Low doses of hormetic (n. hormesis) ultraviolet light-C (UV-C) seed treatments were used to elicit host resistance to black rot, and improve the quality and growth response of cabbages in greenhouse studies. Different UV-C doses (1.3 to 7.5 kJ m−2) were tested to determine their ability to induce resistance to black rot. The optimum UV-C dose of 3.6 kJ m−2 was effective in reducing black rot and the population density of Xanthomonas campestris pv. campestris in infected cabbage leaves. Seeds treated with UV-C at 3.6 kJ m−2 produced plants with the most desirable color, highest weight, largest head diameter and delayed maturity. The effect of storage time at room temperature on disease incidence of black rot of cabbage from seeds treated with a low hormetic UV-C dose of 3.6 kJ m−2, was 90%, 40%, 60% and 60% reduction of black rot in plants from UV-C treated seeds stored for 2 days, 1, 5, and 8 months, respectively, 8 weeks after transplanting cabbage plants.  相似文献   
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