全文获取类型
收费全文 | 220篇 |
免费 | 34篇 |
国内免费 | 1篇 |
专业分类
林业 | 6篇 |
农学 | 11篇 |
18篇 | |
综合类 | 15篇 |
农作物 | 7篇 |
水产渔业 | 15篇 |
畜牧兽医 | 167篇 |
植物保护 | 16篇 |
出版年
2023年 | 6篇 |
2021年 | 5篇 |
2020年 | 9篇 |
2019年 | 4篇 |
2018年 | 11篇 |
2017年 | 8篇 |
2016年 | 14篇 |
2015年 | 9篇 |
2014年 | 8篇 |
2013年 | 17篇 |
2012年 | 8篇 |
2011年 | 7篇 |
2010年 | 6篇 |
2009年 | 11篇 |
2008年 | 1篇 |
2007年 | 12篇 |
2006年 | 7篇 |
2005年 | 6篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 10篇 |
2001年 | 3篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 8篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1969年 | 1篇 |
1967年 | 5篇 |
1966年 | 7篇 |
1965年 | 3篇 |
1953年 | 2篇 |
排序方式: 共有255条查询结果,搜索用时 78 毫秒
21.
AM Petrunkina A-R Günzel-Apel E Töpfer-Petersen 《Reproduction in domestic animals》2003,38(2):125-133
During the last decades, essential progresses in reproductive biotechnology were achieved, implying development of special spermatological techniques. The major problem was to set up simple, rapid, precise and adequate evaluation methods. The key aspect to be considered in all assays of sperm fertilizing function is capacitation. As not all spermatozoa respond to fertilizing conditions in a similar manner, it seems to be logical to assess samples via their response to these specific conditions. For the spermatological practice, the sensitivity of methodology for assessment and analysis of data with respect to differences in individual response, in heterogeneity of the population, and proper temporal characterization of the response is crucial for the improvement of evaluation procedures. Currently, most used statistical analytical tools in spermatology do not always fulfil these essential sensitivity requirements. We structured our paper concerning different fields of mathematical science (distribution analysis, fractal geometry, functional approximation and differentiation) related to the modern insights in sperm function analysis. The spectrum of methods we are going to review in this paper is restricted to basic ideas to illustrate how the accuracy and sensitivity of sperm evaluation assays may be improved by applying adequate elementary tools of the mathematical analysis. 相似文献
22.
A diagnosis of dicoumarol toxicity in a herd of Friesian cattle was made following investigation of the deaths of three mature cows and eleven yearling heifers. Affected stock had been fed wrapped, bailed silage containing approximately 90% sweet vernal grass ( Anthoxanthum odoratum ). Sweet vernal grass contains coumarin, which can be converted to dicoumarol, a vitamin K antagonist, through the action of moulds. Most deaths were preceded by lethargy, severe anaemia and subcutaneous and internal haemorrhage. Dicoumarol toxicosis was suspected based on clinical signs, necropsy findings and prolonged prothrombin and activated partial thromboplastin times. Dicoumarol analysis of blood from affected animals and silage confirmed the diagnosis. 相似文献
23.
24.
25.
Disomic wheat-barley addition lines carrying a full hexaploid set of chromosomes of the wheat cultivar Chinese Spring, plus a pair of either chromosome 1, 2, 3, 4, 6, or 7 from the barley cultivar Betzes, were assayed electrophoretically. Comparisons of zymograms of each addition line with the Chinese Spring wheat and Betzes barky parents of the addition lines gave direct (presumptive in the case of chromosome 5) evidence of the chromosomal locations of nine enzyme loci which have been useful genetic markers in studies of the population genetics, ecogeneties and breeding of barley. Previously reported chromosome locations of several loci were confirmed and evidence was presented for the existence and probable chromosome locations for additional enzyme loci. 相似文献
26.
27.
28.
1. Male broilers (0 to 35 d) were given foods with two types of yellow sorghum substituted for maize in isonutrient diets. Sorghum-based foods were also supplemented with extra phosphorus, to provide a total P of about 8 g/kg; the P being from either orthophosphoric acid or food grade dicalcium phosphate. 2. Both sorghums depressed growth and food:gain ratio and increased the incidence of locomotor disorder to about 0.50 (maize control = 0). Sorghum from Sudan, with higher concentrations of both tannin and phytate, caused more severe anti-nutritive effects than sorghum from Egypt. 3. Within the limits of statistical significance the growth depressing effect of sorghum was completely reversed by extra P. With the more toxic Sudanese sorghum this amelioration was numerically less than complete (growth = 0.94, maize control = 1). Locomotor disorders were also virtually, but not completely, eliminated by phosphorus treatment. 4. Treatment of sorghum by dry-mixing with dicalcium phosphate could form the basis of a simple and economic method for extending the use of high-tannin sorghum in poultry foods. The mode of action of the treatment remains to be determined. 相似文献
29.
Studies on the Physiological Chemistry of the Tibio-Tarsal Synovial Fluid of Healthy Bovines 下载免费PDF全文
S. El. Amrousi M. K. Soliman L. B. Youssef 《Canadian journal of veterinary research》1966,30(9):251-255
The physical properties, chemical composition and cytological content of the synovial fluid of healthy native breed cattle, obtained by tibio-tarsal arthrocentesis, was studied. 相似文献
30.