全文获取类型
收费全文 | 141篇 |
免费 | 12篇 |
国内免费 | 12篇 |
专业分类
林业 | 2篇 |
农学 | 3篇 |
7篇 | |
综合类 | 33篇 |
农作物 | 16篇 |
水产渔业 | 80篇 |
畜牧兽医 | 21篇 |
园艺 | 3篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 2篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 6篇 |
2013年 | 14篇 |
2012年 | 6篇 |
2011年 | 12篇 |
2010年 | 6篇 |
2009年 | 6篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 9篇 |
2005年 | 3篇 |
2004年 | 6篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 5篇 |
2000年 | 8篇 |
1998年 | 4篇 |
1997年 | 9篇 |
1996年 | 3篇 |
1992年 | 2篇 |
1987年 | 1篇 |
排序方式: 共有165条查询结果,搜索用时 125 毫秒
11.
M.C. Leal C. Nunes S. Kempf A. Reis T.L. da Silva J. Serdio D.F.R. Cleary R. Calado 《Aquaculture Nutrition》2013,19(5):818-826
Sea anemones of the genus Aiptasia are used as biological models for research and as a prey for the culture of the highly priced ornamental nudibranch Aeolidiella stephanieae. Symbiotic Aiptasia display a remarkable trophic plasticity, being able to fulfil their energetic demands heterotrophically and autotrophically. Consequently, they display a highly variable fatty acid (FA) profile. The objective of the present study was to analyse how light regime (12 h light : 12 h dark versus 24 h darkness), water temperature (22 versus 26 °C) and diet (Artemia nauplii versus enriched Artemia metanauplii) affect the FA composition of A. pallida. The FA profile of wild specimens was also analysed. The dominant FAs of cultured A. pallida were 16:0, 18:1n‐9 and 22:6n‐3. Higher FA levels were recorded when anemones were exposed to light, with this factor explaining the largest amount of variation in the composition of FA profiles. Cultured A. pallida that best mimicked wild anemones were obtained when using a regular light regime, Artemia metanauplii and 22 °C water temperature. Higher FA levels were obtained at a higher temperature and by providing nauplii to cultured anemones. The present study also indicated that A. pallida has the potential to recycle nutrients in marine aquacultures. 相似文献
12.
13.
14.
DHA对小鼠脂肪生成基因的时序表达影响 总被引:1,自引:1,他引:0
研究二十二碳六烯酸(docosahexaenoic acid,DHA)对小鼠脂肪组织与肝脏中生脂基因转录表达水平变化规律的影响。用两种浓度DHA(6.25 g/kg体重和12.5 g/kg体重)灌胃小鼠,分别于0、1、2、4、8、16和24 h处死,取肝脏和脂肪组织,提取总RNA,半定量(semi-quantitative,SQ)RT-PCR方法检测生脂基因(PPARγ、SREBP-1c、FAS)的时序表达规律。结果表明:脂肪组织中DHA可上调PPARγ和FAS的转录表达,8h达到峰值,其后表达量下降,SREBP-1c表达规律与这两种基因相反;肝脏中DHA能下调PPARγ、SREBP-1c、FAS的转录表达,8h达到最低,其后表达量上升。推测DHA可通过促进脂肪组织中脂肪合成以及抑制肝脏中脂肪合成来调节体脂沉积。 相似文献
15.
饲料中添加鱼油对肥育猪脂肪酸组成的影响 总被引:3,自引:0,他引:3
在肥育猪饲料中添加鱼油生产富含DHA(docosahexaenoic acid),EPA(eicosapentaenoic acid)的猪肉.结果表明:在肥育猪饲料中添加2.5鱼油,可以极显著提高脂肪、肌肉中的DHA,EPA含量.100 g肌肉中EPA对照组为4.7 mg,鱼油组为30.4 mg,是对照组的6.5倍;DHA对照组为13.5 mg,鱼油组为53.8 mg,是对照组的4倍,证明在饲料中添加鱼油生产富含DHA,EPA的猪肉可行.在肥育猪饲料中添加鱼油对猪生产性能、肉质均没有影响. 相似文献
16.
17.
Larval pigmentation, survival and growth of Penaeus indicus fed the nematode Panagrellus redivivus enriched with astaxanthin and various lipids 总被引:1,自引:0,他引:1
The highly unsaturated fatty acid (HUFA) content of the free-living nematode Panagrellus redivivus was successfully increased when three different lipid sources (cod-liver oil, marilla oil and capelin oil) from marine animals were used in the nematode culture medium. The lipid enrichment significantly increased the ω3 HUFA content, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), of the nematodes compared with lipid non-enriched nematodes. Penaeus indicus larvae fed the lipid-enriched nematodes had significantly ( P < 0.05) greater larval survival (69–77%) until metamorphosis than those fed non-enriched nematodes (54%).
This nematode species was also enriched with astaxanthin to determine the effects of this carotenoid on pigmentation, survival and growth during the larval development of P. indicus . The pigment, delivered via nematodes, significantly ( P < 0.05) improved larval coloration and survival (88%) compared with that of placebo-pigmented nematodes (78%). However, there was no strong evidence to show the benefit of either pigment and/or lipid enrichment on larval growth and development of P. indicus .
This study has shown that the nutritional value of the nematodes can be enhanced by the addition of fish oil into the culture medium. Supplementation of EPA and DHA, together with synthetic astaxanthin, allow the nematodes to be used as a sole diet for the larval culture of P. indicus . 相似文献
This nematode species was also enriched with astaxanthin to determine the effects of this carotenoid on pigmentation, survival and growth during the larval development of P. indicus . The pigment, delivered via nematodes, significantly ( P < 0.05) improved larval coloration and survival (88%) compared with that of placebo-pigmented nematodes (78%). However, there was no strong evidence to show the benefit of either pigment and/or lipid enrichment on larval growth and development of P. indicus .
This study has shown that the nutritional value of the nematodes can be enhanced by the addition of fish oil into the culture medium. Supplementation of EPA and DHA, together with synthetic astaxanthin, allow the nematodes to be used as a sole diet for the larval culture of P. indicus . 相似文献
18.
A 28-day feeding trial was conducted for comparing the effect of different dietary phospholipid (PL) classes on the growth of post-larval turbot and on the incorporation of dietary neutral lipid fatty acids into their body lipids. Prior to the experiment the turbot were weaned for one week on a PL-free diet. The nine experimental diets were isolipidic and contained an equal amount of highly unsaturated fatty acids in the form of ethyl esters. They differed by their PL content (0, 1 or 2%) and by the PL class composition of the added soybean PL fractions.Compared to the PL-free diet, diets enriched with phosphatidylcholine (PC) resulted in a better growth, a higher triglyceride content (% body dry matter) and increased levels of docosahexaenoic acid (% total fatty acids) in each of the examined body lipid classes (neutral lipid, phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol). The effects of the other soybean PL fractions were less explicit than those noted for soybean PC.The results support the idea that dietary PC plays a role in the intestinal absorption of neutral lipid fatty acids. This might, at least partially, explain the superiority of PC for enhancing growth. Abbreviations: DHA – docosahexaenoic acid (22:6n-3); EPA – eicosapentaenoic acid (20:5n-3); HUFA – highly unsaturated fatty acid; PA – phosphatidic acid; PC – phosphatidylcholine; PE – phosphatidylethanolamine; PI – phosphatidylinositol; PL – phospholipid; PS – phosphatidylserine; PUFA – polyunsaturated fatty acid. 相似文献
19.
J. P. Narain Rai 《Biology and Fertility of Soils》1992,13(3):187-191
Summary The effects of 15 years of field applications of 2,4-dichlorophenoxy acetate (2,4-D) on soil microbial population and biochemical processes were studied in a field cropped with maize followed by potatoes. Amine or ester formulations at the rate of 0.95 kg 2,4-D per hectare applied in May and October every year. Fungal, bacterial, and actinomycete populations, and microbial biomass C and N were reduced by the 2,4-D treatment, the reduction being more marked where the ester was used. N mineralization, nitrification, and potentially mineralizable N were reduced by the 2,4-D ester only, while urease activity was depressed by both formulations. Dehydrogenase activity and soil microbial respiration tended to be temporarily increased by the amine, but were reduced substantially by the ester, indicating that the ester probably interfered with nutrient cycling. 相似文献
20.