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   239篇
  免费   14篇
林业   14篇
农学   2篇
基础科学   1篇
  42篇
综合类   9篇
农作物   9篇
水产渔业   30篇
畜牧兽医   130篇
园艺   1篇
植物保护   15篇
  2023年   1篇
  2022年   1篇
  2021年   5篇
  2020年   4篇
  2019年   3篇
  2018年   3篇
  2017年   4篇
  2016年   5篇
  2015年   6篇
  2014年   4篇
  2013年   22篇
  2012年   8篇
  2011年   16篇
  2010年   8篇
  2009年   3篇
  2008年   10篇
  2007年   18篇
  2006年   11篇
  2005年   16篇
  2004年   14篇
  2003年   17篇
  2002年   15篇
  2001年   5篇
  2000年   9篇
  1999年   9篇
  1998年   2篇
  1997年   2篇
  1993年   1篇
  1992年   3篇
  1991年   4篇
  1989年   1篇
  1988年   1篇
  1986年   1篇
  1985年   2篇
  1983年   1篇
  1981年   1篇
  1975年   1篇
  1973年   5篇
  1972年   1篇
  1971年   3篇
  1970年   1篇
  1968年   3篇
  1967年   1篇
  1966年   2篇
排序方式: 共有253条查询结果,搜索用时 125 毫秒
141.
Djungarian (Phodopus sungorus) and Chinese (Cricetulus griseus) hamster IFN-gamma genes were cloned and sequenced. The Djungarian and Chinese hamster genes were both 525bp nucleotides, resulting in 174 amino acids in full length with a predicted molecular weight (MW) of 19,560 dal and 19,775 dal, respectively. The first 23 amino terminal amino acids consisted of a hydrophobic signal sequence when cleavaged, which would result in a mature 151 amino acid polypeptide with a predicted MW of 17,115 dal in the Djungarian hamster IFN-gamma and 17,255 dal in the Chinese hamster one.  相似文献   
142.
Bisphenol A (BPA), a candidate endocrine disruptor (ED), is considered to bind to estrogen receptors and to regulate expressions of estrogen responsive genes. It has also shown evidence of affecting the reproductive, immunological and nervous systems of mammalian embryos. However, the effects of BPA on placentae, a central organ of feto-maternal interlocution, are still unclear. To reveal the mechanisms of BPA effects on placentae in mammals, we compared the mRNA expression of 20 nuclear receptors between placentae of vehicle controls and those of orally BPA exposed pregnant mice by a DNA microarray technique. In murine placentae, mRNAs of 11 nuclear receptors were not detected. However, greater than 1.5 fold changes in mRNA expression of nine nuclear receptors between vehicle control and BPA treated mice were noted. Moreover, remarkable changes in mRNA expression of six non-nuclear receptor proteins were induced by BPA exposure. There were various differences in the effects of BPA on the expression of these mRNAs between the placentae with male embryos and those with female embryos. Such embryo-sex dependent differences are interesting and important pointers to understanding of the endocrine disrupting effect of BPA. The present data indicate that BPA affects the expression of nuclear receptor mRNAs in placentae and may disrupt the physiological functions of placentae.  相似文献   
143.
144.
145.
The first case of human babesiosis was reported in Japan. The epidemiology of this disease in Japanese nature remains unclear. In this study, 97 common field mice captured in Hokkaido, Japan, were examined. Blood specimens absorbed onto filter papers were eluted and tested by nested PCR using specific primers for the B. microti nuclear small subunit rRNA genome. Twenty-three percent (11/47) of Apodemus speciosus and four percent (2/50) of Clethrionomys rufocanus were positive. The 159-bp primary sequences of PCR products tested exhibited 97.5% and 96.8% homology with those of the human isolate in Japan and of U.S. strains of B. microti, respectively.  相似文献   
146.
147.
148.
149.
Flour qualities of polished wheat flours of three fractions, C‐1 (100–90%), C‐5 (60–50%), and C‐8 (30–0%), obtained from hard‐type wheat grain were used for the evaluation of four kinds of baking methods: optimized straight (OSM), long fermentation (LFM), sponge‐dough (SDM) and no‐time (NTM) methods. The dough stability of C‐5 in farinograph mixing was excellent and the maturity of polished flour doughs during storage in extensigraph was more improved than those of the commercial wheat flour (CW). There were no significant differences in the viscoelastic properties of CW dough after mixing, regardless of the baking method, while those of polished flour doughs were changed by the baking method; this tendency became clear after fermentation. The polished flours could make a better gluten structure in the dough samples after mixing or fermentation using LFM and SDM, as compared with other baking methods. Baking qualities such as specific volume and storage properties of breads from all polished flours made with SDM increased more than with other methods. In addition, viscoelastic properties of C‐5 and C‐8 doughs fermented by SDM were similar to those of CW, and the C‐5 breadcrumb showed softness similar to that of the CW. Also, SDM could make C‐5 bread with significantly higher elasticity and cohesiveness after storage for five days when compared with CW bread. Therefore, SDM with long fermentation, as compared with other baking methods, was considered suitable for use with polished flours to give better effects on dough properties during fermentation, resulting in more favorable bread qualities.  相似文献   
150.
We examined the effects of cultivar (Taporuri, Mohretsu, Tachiaoba, and Hinohikari) on estimated total digestible nutrient (TDN) yield of forage rice in double harvesting. The total estimated whole-plant TDN yield (i.e., of the first crop plus second crop) of Taporuri was the highest in double harvesting. In the first crop, the estimated whole-plant TDN yield of Taporuri was the highest. In the second crop, the estimated whole-plant TDN yield of Taporuri was almost the same as those of Mohretsu and Tachiaoba but higher than that of Hinohikari. We also examined the effects of cultivation method (double harvesting or single harvesting) on estimated TDN yield of forage rice. In Taporuri and Mohretsu, the total estimated whole-plant TDN yield was similar in double harvesting and single harvesting. However, in Tachiaoba and Hinohikari, it was lower in double harvesting than in single harvesting. It is important to maximize the amount of nutrition in leaf and stem rather than panicle because the grain is not digested well by cattle. In the double harvesting, the total estimated leaf blade (leaf) TDN yield of Taporuri was higher than that of Hinohikari and almost the same as those of Tachiaoba and Mohretsu. The total estimated leaf sheath plus stem (stem) TDN yield of Taporuri was the highest. In comparison of the total TDN yield of double harvesting with that of single harvesting, the total estimated leaf and stem TDN yields were higher in double harvesting than in single harvesting in all cultivars except for Hinohikari. Thus, double harvesting of Taporuri is an effective way of reducing the overall loss of nutrition from the crop.  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