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81.
Emma Jane Dillon Thia Hennessy Peter Howley John Cullinan Kevin Heanue Anthony Cawley 《Agriculture and Human Values》2018,35(1):207-221
Animal health is a key factor affecting the economic efficiency of the dairy industry. Improvements in animal health are also of relevance to society more broadly, given important implications for animal welfare, food safety and quality. Although the economic gains of best practice with regard to animal health have been well documented, many farmers are not adopting optimal herd management techniques. This paper utilises nationally representative farm-level data from Ireland for 2013 to identify drivers and barriers to the adoption of best practice with regard to on-farm mastitis management. Exploratory factor analysis is used to derive measures of farmers’ attitudes towards animal health and mastitis and econometric techniques are employed to empirically assess the influence of these on the uptake of beneficial herd health management practices. A number of focus groups were also undertaken to complement the analysis. This paper concludes that farmers’ attitudes towards animal health are not a key driver in the uptake of best practice, although perceived disease risk is of relevance. A number of interesting issues arise in identifying barriers to the uptake of best practice, these include the possibility of routine inertia, i.e., farmers do not deviate from the routine developed around mastitis prevention until there is an indication of infection, as well as constraints around the availability of labour and time. Farmer behaviour with respect to mastitis management can thus be considered as reactionary as opposed to precautionary. This research highlights the valuable role of the extension agent but concludes that engagement around knowledge transfer and technology adoption is particularly complex. 相似文献
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83.
Wendel Keller Peter Dillon Jocelyne Heneberry Michael Malette John Gunn 《Water, air, and soil pollution》2001,130(1-4):793-798
Sulphur emissions from the Sudbury, Ontario, metal smelting industry have affected thousands of lakes in Ontario, Canada. Reductions in these emissions during the 1970's resulted in reduced lakewater SO4 concentrations and other water quality changes in the 1970's and 1980's. Further declines in lakewater SO4 concentrations have accompanied additional recent S emission reductions achieved by 1994. Recent (1997) SO4 concentrations are still related to distance from the Sudbury smelters. A strong inverse relationship with distance is evident to about 45 km, and is most pronounced in lakes within about 20 km. In lakes beyond 45 km, dissolved organic carbon (DOC), which was correlated with hydrological response time and total phosphorus concentrations, was the best correlate with recent SO4 concentrations, indicating that some slowly-flushing, oligotrophic lakes still exhibit a "Sudbury" effect. Most lakes beyond 45 km, however, showed SO4 declines and recent SO4 concentrations comparable to lakes around Dorset, ~200 km from Sudbury, suggesting that these lakes are now most affected by the long-range atmospheric transport of S. 相似文献
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85.
OBJECTIVE: To evaluate effect of alternate-day oral administration of prednisolone on endogenous plasma ACTH concentration and adrenocortical response to exogenous ACTH in dogs. ANIMALS: 12 Beagles. PROCEDURE: Dogs were allotted to 2 groups (group 1, 8 dogs treated with 1 mg of prednisolone/kg of body weight; group 2, 4 dogs given excipient only). During a 30-day period, blood samples were collected for determination of plasma ACTH and cortisol concentrations before, during, and after treatment with prednisolone. From day 7 to 23, prednisolone or excipient was given on alternate days. Sample collection (48-hour period with 6-hour intervals) was performed on days 1, 7, 15, 21, and 28; on other days, sample collection was performed at 24-hour intervals. Pre- and post-ACTH plasma cortisol concentrations were determined on days 3, 9, 17, 23, and 30. RESULTS: A significant difference was detected between treatment and time for group 1. Plasma ACTH concentrations significantly decreased for 18 to 24 hours after prednisolone treatment in group-1 dogs. At 24 to 48 hours, ACTH concentrations were numerically higher but not significantly different in group-1 dogs. Post-ACTH plasma cortisol concentration significantly decreased after 1 dose of prednisolone and became more profound during the treatment period. However, post-ACTH cortisol concentration returned to the reference range 1 week after prednisolone administration was discontinued. CONCLUSIONS AND CLINICAL RELEVANCE: Single oral administration of 1 mg of prednisolone/kg significantly suppressed plasma ACTH concentration in dogs for 18 to 24 hours after treatment. Alternate-day treatment did not prevent suppression, as documented by the response to ACTH. 相似文献
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Emissions of SO2 in the Sudbury area declined from an estimated average of 1.41 × 106 tonne yr?1 in 1973–78 to 0.68 × 106 tonne yr?1 in 1979–85. As a result, SO4 concentrations of lakes in the area have decreased, and the pH of each of the acidic lakes that was studied has increased. Aluminum, Cu, Ni and Zn concentrations have also decreased; however, the latter three metals have probably declined because of reductions in emissions of metals from the smelters rather than because of the pH changes in the lakes. 相似文献
88.
It has been observed that the alkalinity concentrations in the hypolimnia of many thermally stratified lakes increase over the duration of the summer. We have quantified the processes, both redox and exchange, that contributed to the alkalinity increases measured in two lakes that are situated on the Precambrian Shield of Ontario, Canada by measuring hypolimnetic mass balances for all substances involved in alkalinity-generating or -consuming reactions. These include nitrate, ammonium base cations, iron, manganese, sulphate, organic anions, as well as alkalinity itself. In one lake, iron reduction was the dominant source of alkalinity; since this process is probably reversed at fall overturn when hypolimnetic waters mix with oxygenated surface waters, the alkalinity generated by this mechanism is likely temporary in nature. In the second lake, iron reduction and sulphate reduction were both important the latter should provide more permanent alkalinity. 相似文献
89.
Reproductive Performance of Gilts with Similar Age but with Different Growth Rate at the Onset of Puberty Stimulation 总被引:1,自引:0,他引:1
R Kummer ML Bernardi AC Schenkel WS Amaral Filha I Wentz FP Bortolozzo 《Reproduction in domestic animals》2009,44(2):255-259
The aim of this study was to evaluate the reproductive performance of gilts that had a similar age but different weights at the onset of puberty stimulation by boar exposure at 144 days. Gilts were divided into two groups according to their lifetime growth rate from birth to approximately 144 days of age. Mean growth rates at this moment were 577 and 724 g/day for group 1 (G1; n = 58) and group 2 (G2; n = 58), respectively. After selection, gilts were weighed at approximately 155, 165 and 175 days of age, on the insemination day and at slaughter. Gilts were inseminated, on average, at 193 days of age and were slaughtered 32 days after insemination, when the number of corpora lutea and embryos were recorded. Higher growth rate gilts (G2) reached puberty earlier (155.3 vs 164.1 days; p < 0.01). More gilts of G2 group attained puberty by 190 days of age (p = 0.004) than G1 gilts (95%; 55/58 vs 76%; 44/58). The anoestrous rate, until 60 days after the onset of boar exposure was higher (p < 0.01) in G1 (19.0%; 11/58) than in G2 (3.4%; 2/58) group. However, there were no differences in the pregnancy rate (90.7 vs 94.5), ovulation rate (15.9 vs 16.5), total embryos (12.9 vs 11.7), viable embryos (12.0 vs 11.1) and embryo survival (73.7% vs 68.5%), between G1 gilts and G2 gilts, respectively (p > 0.05). High growth rate gilts attain puberty earlier and have a lower anoestrous rate than low growth rate gilts. 相似文献
90.
Jordan Shockley Carl R. Dillon Tim Stombaugh Scott Shearer 《Precision Agriculture》2012,13(4):411-420
Automatic section control was analyzed in a whole farm decision-making framework when implemented on an agricultural sprayer and/or planter. In addition, various field types and navigational scenarios were examined to determine their impact on profitability. It was determined that automatic section control increased net returns under all scenarios; up to $36/ha. This investigation highlighted the importance of considering field size in addition to field shape as well as initial navigational scenarios when determining the profitability of automatic section control. 相似文献