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The effect of pseudorabies (Aujeszky''s) virus infection on young mature boars and boar fertility. 总被引:1,自引:0,他引:1 下载免费PDF全文
L B Hall Jr J P Kluge L E Evans H T Hill 《Canadian journal of veterinary research》1984,48(2):192-197
This study was designed to determine the effects of experimental inoculation with pseudorabies virus on the reproductive tracts of young adult boars. Pseudorabies virus was inoculated intranasally into 12 boars and intrapreputially into four boars. All animals seroconverted after nasal or preputial inoculation. Semen abnormalities were observed 21 days postinoculation with partial recovery by 50 days postinoculation. Virus was isolated from the preputial sheath of two intrapreputially inoculated boars 12 days postinoculation. It was concluded that pseudorabies virus infection can be established via preputial inoculation and that decreased spermatogenesis and infertility can result. 相似文献
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Tryptophan requirement of growing pigs at various body weights 总被引:3,自引:0,他引:3
Eder K Nonn H Kluge H Peganova S 《Journal of animal physiology and animal nutrition》2003,87(9-10):336-346
The purpose of this study was to determine the tryptophan (Trp) requirement of growing pigs at different body weight (BW) ranges. Three performance experiments were conducted with female pigs in the BW ranges of 25-50, 50-80 and 80-115 kg. In addition to the performance experiments, nitrogen balance experiments were carried out in which pigs weighing 56, 66 and 86 kg were used. Trp-deficient basal diets were formulated to which varying amounts of l-Trp were added. The amino acid concentrations of the diets were analysed; concentrations of standardized digestible amino acids were calculated on the basis of tabular values. The calculated concentrations of standardized ileal digestible tryptophan were 0.81, 1.11, 1.41, 1.71, 2.01 g/kg diet in the lower BW range (25-50 kg), 0.71, 0.96, 1.21, 1.46, 1.71 g/kg diet in the middle BW range (50-80 kg), and 0.49, 0.69, 0.89, 1.09, 1.29 g/kg diet in the upper BW range (80-115 kg). Dose-response relationships were evaluated by means of an exponential regression model. In all three age ranges, performance parameters as well as nitrogen retention were strongly influenced by the dietary concentration of standardized ileal digestible tryptophan. According to the exponential model, in the 25-50 kg BW range, 95% of the maximum feed consumption, BW gain and nitrogen retention were achieved at concentrations between 1.96 and 2.00 g of standardized ileal digestible Trp per kilogram diet, corresponding to 3.32-3.39 g/day. In the BW range of 50-80 kg, 95% of the maximum of these parameters occurred at concentrations of standardized ileal digestible tryptophan in excess of the highest concentration of 1.71 g/kg diet, corresponding to 3.71 g/day. In the BW range of 80-115 kg, 95% of the maximum of BW gain and nitrogen retention were recorded at concentrations of 1.22 and 0.84 g standardized ileal digestible Trp per kilogram diet, corresponding to 3.77 and 2.25 g/day, respectively. Related to the energy value of the diets, the optimal concentration of standardized ileal digestible tryptophan are between 140 and 143 mg/MJ metabolizable energy (ME) in the BW range of 25-50 kg, in excess of 127 mg/MJ ME in the BW range of 50-80 kg and between 62 and 90 mg/MJ ME in the BW range of 80-115 kg. In conclusion, it is suggested that the requirement of standardized ileal digestible tryptophan for growing pigs might be higher than currently assumed. 相似文献
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The nitrogen pool of piglets weighing 19.4 +/- 1.4 kg at the beginning of the experiment was labeled with an oral application of ([15N]H4)2SO4 (1.26 [15N]-atom percent excess of dietary N) over a period of 7 d. The labeling period was followed by an equilibration period of 7 d without feeding the labeling compound. The two experimental diets were based on wheat (53%) and rye (25%) and were fed either with or without a xylanase containing enzyme preparation over both experimental periods. Additionally, diets were supplemented with an indigestible marker during the 2nd period of the experiment to allow the calculation of endogenous N-losses in subsequent segments of the digestive tract of the pigs. These endogenous N-losses were estimated at the end of the experiment by analyzing feces, ingesta and urine for [15N]-enrichment assuming that [15N]-enrichment of urine represents the [15N]-enrichment of the precursor pool. Endogenous N-losses were not significantly affected by xylanase addition at any measurement site (stomach, 3 sections of the small intestine, total digestive tract). Endogenous N-proportions of total nitrogen amounted on average for the six pigs to 42 +/- 11% and 56 +/- 5% at the last section of the small intestine and over the whole digestive tract, respectively, which corresponded to endogenous N-losses of 2.8 +/- 1.3 g N/kg DM and 2.0 +/- 0.3 g N/kg DM, respectively. 相似文献
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Björn Kluge Arvid Markert Michael Facklam Harald Sommer Mathias Kaiser Matthias Pallasch Gerd Wessolek 《Journal of Soils and Sediments》2018,18(2):431-441
Purpose
Stormwater bioretention systems are widely used to treat diffuse infiltration of runoff from paved surfaces and roofs. Substantial questions remain about the hydraulic performance and the accumulation of pollutants in systems over the long term. Data of metal accumulation of systems with operational times >10 years currently is limited. This study deals with the accumulation of metals in a variety of long-term operational bioretention systems (11–22 years) to derive further operation recommendations for the water authorities.Materials and methods
The hydraulic conductivity of the bioretention systems in field was measured using a double ring infiltrometer. Media soil samples from 22 diverse designed systems were collected across the surface and at intervals up to a depth of 65 cm to determine the spatial accumulation of Zn, Cu, Pb and Cd. Leaching experiments of selected bioretention media soils were derived to assess the metal leachability by water.Results and discussion
The hydraulic performance of most bioretention systems still met the technical guidelines of Germany even after long-term operation. Considerable metal accumulation occurred in the topsoil (0–20 cm). Median concentrations of all metals are highest at the soil surface (0–10 cm), decreasing with increasing depth. High concentrations were determined at the inflow points of the runoff waters, whereas concentrations at more than 1.5 m distance from the inflow were only slightly increased compared to the initial soil concentrations. Leachability tests have shown that most of the metals deposited in bioretention soils are only slightly water soluble. No concentrations exceeding the threshold values of the German Soil Contamination Ordinance for the pathway soil to groundwater could be determined.Conclusions
The hydraulic conductivity of the bioretention systems is given even well after long-term operation. Most of the metal accumulation is concentrated in the top 20 cm; concentrations decrease rapidly and mostly reach background/initial concentrations after depths of 30 cm. The water-soluble metals are all below the trigger values of the German Soil Act. This underlines the strong retention capacity of long-term bioretention systems after long-term operational times.8.
Boldo (Peumus boldus Mol.) is a medicinal plant native to the central zone of Chile and part of the sclerophyll forest. More than 2000 tons of dried leaves exported annually are wild collected. To develop a cultivation system that supports sustainable production of boldo leaves, we have studied growth and harvest of boldo under different light and soil water conditions. The leaf yield per plant as well as the alkaloid and essential oil content were the same for plants grown under shade and for plants exposed to full sun. The only difference between the shaded and the full sun plants was a higher percentage of stem in the harvested product of shade grown plants. This result would permit the intercropping of boldo in forest plantations without affecting the leaf yield and medicinal quality. The excellent adaptation to dry conditions was confirmed, as the different treatments of soil water led to similar leaf yields and plant heights. Plants submitted to water stress produced fewer but longer shoots and contained less essential oil. None of the treatments except water stress affected the medicinal quality requirements of alkaloid or essential oil concentration in the leaves. Wild collected leaves are inexpensive because of low production costs. To be able to compete with wild supplied leaves in the international market, we have evaluated high density plantings as a way to lower costs of a cultivated product by mechanizing harvest. High planting densities led to loweryielding individuals, but leaf yield per area increased. Plant height and the percentage of leaves in the harvested product was the same for densities of 8- and 16 plants m−2. The leaves produced by cultivated boldo generally fulfill the requirements described in the European Pharmacopoeia. We conclude that boldo can be successfully cultivated under the described cultivation conditions. 相似文献
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Summary Potato virus S was eliminated from systemically infected stem cuttings of five potato cultivars after three passages in nutrient
media containing 0.003% of the synthetic riboside ribavirin (Virazole). Treatment effects could be detected after only two
passages which also revealed differences in cultivar response. Treated plants transferred to ribavirin-free culture media
and to soil remained PVS-free.
This simple method is less time-consuming than the usual meristem (axillary) tip culture procedures combined with chemotherapy
or heat treatment. 相似文献
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