全文获取类型
收费全文 | 225篇 |
免费 | 21篇 |
国内免费 | 73篇 |
专业分类
林业 | 10篇 |
农学 | 7篇 |
基础科学 | 8篇 |
24篇 | |
综合类 | 87篇 |
农作物 | 10篇 |
水产渔业 | 29篇 |
畜牧兽医 | 101篇 |
园艺 | 27篇 |
植物保护 | 16篇 |
出版年
2023年 | 14篇 |
2022年 | 33篇 |
2021年 | 44篇 |
2020年 | 30篇 |
2019年 | 37篇 |
2018年 | 11篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 4篇 |
2014年 | 8篇 |
2013年 | 19篇 |
2012年 | 9篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 8篇 |
2008年 | 8篇 |
2007年 | 5篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2003年 | 3篇 |
2001年 | 1篇 |
2000年 | 5篇 |
1999年 | 1篇 |
1997年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 5篇 |
1971年 | 3篇 |
1970年 | 3篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1956年 | 1篇 |
1930年 | 1篇 |
1927年 | 1篇 |
1916年 | 1篇 |
排序方式: 共有319条查询结果,搜索用时 15 毫秒
61.
62.
Suna Kalender Yusuf Kalender Ayse Ogutcu Bekir Sitki Cevrimli 《Pesticide biochemistry and physiology》2007,88(2):213-218
Methyl parathion is an organophosphate insecticide that has been used in agriculture and domestic for several years. Vitamin C (200 mg/kg bw per day) + vitamin E (200 mg/kg bw per day), methyl parathion (0.28 mg/kg bw per day) and vitamin C (200 mg/kg bw per day) + vitamin E (200 mg/kg bw per day) + methyl parathion (0.28 mg/kg bw per day) combination were given to rats orally via gavage for 7 weeks. Body and kidney weights, malondialdehyde (MDA) levels and histopathological changes were investigated at the end of 4th and 7th weeks comparatively with control group. When methyl parathion-treated group and vitamins C and E + methyl parathion-treated group were compared to control group body and kidney weights decreased significantly at the end of 4th and 7th weeks. MDA levels increased in kidney tissues of the methyl parathion- and vitamins C and E + methyl parathion-treated groups compared to control group. MDA levels decreased significantly in vitamins C and E + methyl parathion treated group compared with methyl parathion treated group at the end of 4th and 7th weeks. In our light microscopic investigations, after 4 weeks of methyl parathion exposure, glomerular atrophy and vascular dilatation, and after 7 weeks, necrosis and edema were observed in the kidney tissues. After 4 weeks of vitamins C and E + methyl parathion exposure, mononuclear cell infiltrations, and after 7 weeks, calcification were detected in the kidney tissues. 相似文献
63.
J Wünsche T Zebrowska U Hennig F Kreienbring M Meinl K Krawielitzki E Borgmann T V?lker B Idzior H D Bock S Buraczewski 《Archives of Animal Nutrition》1979,29(3):151-164
Re-entrance cannulae were applied by way of operations at the end of the small intestine of a larger number of growing pigs. After a post-operative phase these animals were fed with various rations (N-free diet, fattening feed for pigs, rations with dried skim milk resp. wheat gluten + lysine and wheat + wheat gluten + lysine). During the main experiment periods the ileum digesta (24 hour-periods of collecting) and the feces were quantitatively registered. The protein and amino acid content ascertained in the feed rations, the digesta and feces samples are reported, comparatively evaluated and discussed. The amount of amino acids (in mg per kg intake of dry matter) contained in the ileum digesta after N-free feeding were statistically calculated with regard to differences occuring between the animals and days. For most amino acids a significant decrease in the ileum digesta could be detected during the course of the N-free feeding period. Moreover, the amount of amino acids in the ileum digesta was compared with the metabolic fecal amino acids, from which conclusions could be drawn concerning the disappearance rate of the individual amino acids in large intestine. 相似文献
64.
65.
A method is described for estimation of 2.6-diaminopimelic acid (DAP) using an automated amino acid analyzer and MOORE and STEIN ninhydrin reagent. Investigations were made concerning the influence of sample treatment on DAP content of faeces and ileal digesta of pigs and isolated bacteria. Oxidation before hydrolysis did not change DAP content of faeces and bacterial samples, but increased DAP of digesta. Since analytical reasons were excluded, different accessibility of DAP in faeces and digesta for hydrolysis is suggested. Lyophilization or preservation of fresh samples with formaldehyde and phenolic solution, resp., resulted in no significant influence on DAP content. 相似文献
66.
The concentration of ascorbic acid in the cerebrum and in the brain stem of bovine fetuses decreased with increasing body weight; in the cerebellum there was no change. The decrease of the concentration in the lungs, in the heart, in the kidneys, in the M. longissimus and in the M. semimembranosus in the course of the fetal growth was different. In the liver and in the adrenals the concentration in the 3 groups of fetuses with a body weight of 4.18 +/- 2.01, of 9.72 +/- 0.97 and of 17.12 +/- 2.61 kg was similar. The highest concentrations were found in the adrenals, in the testes and in the cerebrum. The functional significance of the changes in the concentration in the tissues of the bovine fetuses is discussed and compared with the results in human fetuses and in adult cattle. 相似文献
67.
68.
69.
Berendzen K Searle I Ravenscroft D Koncz C Batschauer A Coupland G Somssich IE Ulker B 《Plant methods》2005,1(1):4
Background
Many established PCR-based approaches in plant molecular biology rely on lengthy and expensive methods for isolation of nucleic acids. Although several rapid DNA isolation protocols are available, they have not been tested for simultaneous RNA isolation for RT-PCR applications. In addition, traditional map-based cloning technologies often use ill-proportioned marker regions even when working with the model plant Arabidopsis thaliana, where the availability of the full genome sequence can now be exploited for the creation of a high-density marker systems. 相似文献70.
Oral supply of 100 mg iron as bivalent cations per day effectively prevented clinical and subclinical symptoms of anaemia in calves. Additionally, male and female calves reached optimal growth values. The supplementation of iron to alleviate neonatal masked anaemia ("physiological anaemia") should start on the first day of life. This measure can be terminated at the end of the praeruminal stage of the development, as young calves are able to take up all ferric ions contained in the diet. The real extend of the iron deficiency of calves could not be determined by clinical symptoms. As a practical measure it is recommended to use the packed cell volume test. 相似文献