首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   39篇
  免费   6篇
农学   1篇
  7篇
综合类   2篇
农作物   1篇
水产渔业   16篇
畜牧兽医   15篇
植物保护   3篇
  2023年   2篇
  2022年   1篇
  2021年   1篇
  2020年   6篇
  2019年   2篇
  2018年   4篇
  2017年   3篇
  2016年   1篇
  2014年   1篇
  2013年   3篇
  2012年   2篇
  2011年   2篇
  2010年   2篇
  2008年   5篇
  2006年   3篇
  2004年   1篇
  2002年   1篇
  2001年   1篇
  1992年   1篇
  1980年   1篇
  1974年   1篇
  1972年   1篇
排序方式: 共有45条查询结果,搜索用时 93 毫秒
1.
The efficacy of an oral formulation of the newly developed parasiticide, moxidectin, was tested against benzimidazole-resistant Haemonchus contortus, Trichostrongylus colubriformis, and Nematodirus spathiger, levamisole-resistant Ostertagia circumcincta, and susceptible Cooperia curticei infections in weaned lambs. Thirty-two lambs were experimentally infected with mixed doses of the above strains of nematodes. They were allocated into four treatment groups by stratified randomisation using liveweights and faecal egg counts 28 days later. One group received moxidectin at 0.2 mg/kg liveweight, one group oxfendazole at 4.5 mg/kg liveweight, one group levamisole at 7.5 mg/kg liveweight and the last group remained untreated as the control. Worm burdens in the lambs at slaughter 10 days after oral treatment confirmed the resistance status of the nematode strains used, and showed that moxidectin had a greater than 99.9% efficacy (p<0.01) against all of them. No adverse effects due to treatment with moxidectin were observed in any of the animals.  相似文献   
2.
3.
4.
The incorporation of brewer's spent grain (BSG) into baked snacks (crispy-slices) was investigated in terms of nutritional, sensory and aromatic properties. Wheat flour was replaced with BSG at the levels of 10, 15 and 25%. Snacks containing 10% BSG exhibited high Crispiness index (Ci), low Crispiness work (Wc) and a high number of peaks during texture analysis, indicating that the crispiness of the samples was not negatively affected. However higher levels of BSG affected the texture and the crumb structure of snacks and the results were significantly different to the 100% wheat control. Addition of BSG altered the odour profile of the snacks as shown by the volatile profiles, however sensory results indicated that BSG-containing snacks at a level of 10% were highly acceptable and highlighted the possibility of using BSG as a baking ingredient in the formulation of enhanced fibre baked snacks.  相似文献   
5.
6.
  • 1. An experiment was conducted in Australia's pelagic longline fishery to establish a scientific basis for the introduction of line weighting to reduce seabird mortality. The experiment examined the effects of different bait species (blue mackerel, yellow‐tail mackerel and squid), bait life status (dead or alive), weight of leaded swivels (60 g, 100 g and 160 g) and leader length (distance between leaded swivel and hooks: 2 m, 3 m and 4 m) on the sink rates of baited hooks from 0–6 m deep.
  • 2. On average, live bait sank much more slowly than dead bait. The sink rates of individual live bait were highly variable: many were <2 m underwater 18 s after deployment, including some on the heaviest swivels, and some were <10 m deep after 120 s.
  • 3. Within the dead bait group, all three swivel weights on 3 m and 4 m leaders sank at similar rates. Initial sink rates (e.g. 0–2 m) were 2–3 times slower than final rates (e.g. 4–6 m) for all combinations of swivel weight and leader length. The fastest initial and final sink rates were associated with heavy swivels placed close to hooks.
  • 4. The results show that (a) compared with dead bait, live bait greatly increases the exposure of baited hooks to seabirds; (b) initial sink rates of dead bait are increased by placing leaded swivels close to hooks and final rates by increasing the weight of the swivels; (c) adding weight to long leaders makes little difference to sink rates; and (d) the small (incremental) changes to swivel weights and leader lengths typically preferred by industry will be difficult to detect at sea and unlikely to substantially reduce seabird mortality.
  • 5. We suggest that experiments designed to reduce seabird mortality from that associated with 60 g swivels and ~3.5 m leaders (the preferred option by industry) should aim to expedite the initial sink rates as well as rates to deeper depths. This objective could be achieved by including branch lines with ≥120 g swivels ≤2 m in comparative assessments of the effectiveness of line weighting regimes in reducing seabird mortality. Copyright © 2010 John Wiley & Sons, Ltd.
  相似文献   
7.
Fish are increasingly exposed to anthropogenic stressors from human developments and activities such as agriculture, urbanization, pollution and fishing. Lethal impacts of these stressors have been studied but the potential sublethal impacts, such as behavioural changes or reduced growth and reproduction, have often been overlooked. Unlike mortality, sublethal impacts are broad and difficult to quantify experimentally. As a result, sublethal impacts are often ignored in regulatory frameworks and management decisions. Building on established fish bioenergetic models, we present a general method for using the population consequences of disturbance framework to investigate how stressors influence ecologically relevant life processes of fish. We partition impact into the initial energetic cost of attempts to escape from the stressor, followed by the energetic impacts of any injury or behavioural change, and their consequent effects on life processes. As a case study, we assess the sublethal effects of catch and release angling for the European sea bass (Dicentrachus labrax, Moronidae), a popular target species for recreational fishers. The energy budget model described is not intended to replace existing experimental approaches but does provide a simple way to account for sublethal impacts in assessment of the impact of recreational fisheries and aid development of robust management approaches. There is potential to apply our energy budget approach to investigate a broad range of stressors and cumulative impacts for many fish species while also using individual‐based models to estimate population‐level impacts.  相似文献   
8.
BACKGROUND: Captan is an important fungicide for controlling diseases in horticultural crops. Predicting its dissipation is important for estimating dietary risks and optimising pesticide application. Experiments were conducted to determine the relationship of captan loss on apple leaves with temperature, humidity and rainfall, and to investigate captan loss on fruit in dry conditions. RESULTS: There was large unit-to-unit variability in captan residues in spite of the controlled application. Temperature and humidity had negligible effects on captan loss. Captan loss is predominately due to washoff by rain, although a certain proportion of captan may bind to the plant surface tightly and hence may not be readily removed by rain. About 50% of captan can be washed off by as little as 1 mm of rain after an application, and the loss appeared not to relate to the amount of rain. Under dry conditions, daily loss of captan is estimated to be around 1% on both fruit and leaves, giving a half-life of ca 70 days. CONCLUSIONS: Captan loss on leaf and fruit surfaces is primarily due to rain washoff.  相似文献   
9.
Whole plant foods, including fruit, vegetables, and whole grain cereals, protect against chronic human diseases such as heart disease and cancer, with fiber and polyphenols thought to contribute significantly. These bioactive food components interact with the gut microbiota, with gut bacteria modifying polyphenol bioavailability and activity, and with fiber, constituting the main energy source for colonic fermentation. This paper discusses the consequences of increasing the consumption of whole plant foods on the gut microbiota and subsequent implications for human health. In humans, whole grain cereals can modify fecal bacterial profiles, increasing relative numbers of bifidobacteria and lactobacilli. Polyphenol-rich chocolate and certain fruits have also been shown to increase fecal bifidobacteria. The recent FLAVURS study provides novel information on the impact of high fruit and vegetable diets on the gut microbiota. Increasing whole plant food consumption appears to up-regulate beneficial commensal bacteria and may contribute toward the health effects of these foods.  相似文献   
10.
The slash-and-burn system is a subsistence agronomical practice widespread in tropical areas worldwide. This system has been extensively studied,especially for its impacts on agronomical aspects and soil physicochemical properties; however, knowledge of soil microbial diversity under slash and bum is scarce. In this study, for the first time, soil bacterial diversity of three locations from Central Mozambique, where slash and burn has been practiced for different durations of the forest fallow p...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号