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   3330篇
  免费   245篇
  国内免费   245篇
  2023年   68篇
  2022年   51篇
  2021年   97篇
  2020年   111篇
  2019年   138篇
  2018年   97篇
  2017年   155篇
  2016年   144篇
  2015年   110篇
  2014年   140篇
  2013年   288篇
  2012年   120篇
  2011年   192篇
  2010年   117篇
  2009年   163篇
  2008年   171篇
  2007年   197篇
  2006年   166篇
  2005年   157篇
  2004年   93篇
  2003年   99篇
  2002年   106篇
  2001年   80篇
  2000年   73篇
  1999年   58篇
  1998年   52篇
  1997年   53篇
  1996年   45篇
  1995年   46篇
  1994年   42篇
  1993年   34篇
  1992年   44篇
  1991年   35篇
  1990年   33篇
  1989年   23篇
  1988年   19篇
  1987年   18篇
  1986年   23篇
  1985年   20篇
  1984年   24篇
  1982年   10篇
  1981年   15篇
  1980年   14篇
  1979年   12篇
  1978年   7篇
  1977年   15篇
  1976年   7篇
  1975年   10篇
  1974年   12篇
  1973年   6篇
排序方式: 共有3820条查询结果,搜索用时 15 毫秒
21.
Thirty components were identified in Lavandula latifolia essential oil (spike oil). One of the compounds, espliegol (δ-terpineol), is a new natural product.  相似文献   
22.
The short- to medium-term viability and growth of Metarhizium anisopliae var. acridum conidia were investigated when combined with six insecticides, at three different concentrations. All of the insecticides used in this study were suitable for immediate spraying with M. anisopliae var. acridum conidia except for fenitrothion. Fipronil, teflubenzuron, and fenitrothion formulations significantly reduced conidial viability over time. The 10% teflubenzuron treatment caused loss of viability relatively quickly with 9.9% germination after 28 days. Mycelial growth was affected by all the treatments except fenitrothion.  相似文献   
23.
Mono- and sesqui-terpenes of individual oil glands of Citrus latipes fruits were analyzed for their homogeneity. The effect of oleocellosis, desiccation, Penicillium and Phytophthora infection upon the individual terpene components was investigated and expressed in a discriminant analysis and in canonical variables. Each oil gland contained the entire spectrum of terpenes specific for each species, and the biggest difference in affected glands was due to Penicillium infection.  相似文献   
24.
25.
26.
27.
Malathion (MAL) is an organophosphate insecticide that disrupts the body's antioxidant system; it is one of the earliest organophosphate insecticides extensively used as dust, emulsion, and vapor control a wide variety of insect pests under different conditions. This experimentation aims to evaluate the influence of Arabica coffee oil and olive oil on MAL-induced nephrotoxicity in male rat. 6 sets bearing the same number of animals were applied to this experiment. Each set comprised 10 rats. The first set of rats was used as the control group; rats in the second set were exposed to MAL measured at 100 mg/kg body weight for 7 weeks. Animals in the third and fourth set were treated with 400 mg/kg body weight of Arabica coffee oil and olive oil, and 100 mg/kg body weight of MAL. The fifth, together with the sixth set, were fed with a similar proportion of Arabica coffee oil and olive oil as administered to the third set of rats. After the experimental duration, rats of group 2 showed severe biochemical alterations, including significant increases of creatinine, uric acids, and urea nitrogen (BUN), resulting in marked decreases in serum albumin values and total protein (TP). Severe histopathological and immunohistochemical alterations of kidney tissues were observed in exposed MAL-intoxicated rats. Administration of these oils reduced the detected biochemical, histopathological modifications caused by MAL intoxication. Two active ingredients in Arabica coffee oil (oleic acid) and olive oil (hydroxytyrosol) showed good cyclooxygenase-2 (COX 2) interaction. Moreover, oleic acid from coffee oil and olive oil exhibited impressive association with xanthine oxidase (XO). The current finding showed that coffee oil and olive oil could be appraised as possible and a likely deterrence component against nephrotoxicity brought about by MAL.  相似文献   
28.
The present study explored the possibility that aroma components generated by the oxidation of olive oil may enhance the palatability of olive oil. Using a mouse behavioral model, we found that olive oil oxidized at room temperature for 3 weeks after opening the package, and heated olive oil were both significantly preferred over non-oxidized olive oil. Furthermore, this preference was enhanced with an additive of oxidized refined olive oil flavoring preparation at a certain concentration. These results suggest that the aroma of oxidized fat might be present in most fats, and might act as a signal that makes possible the detection of fats or fatty acid sources.  相似文献   
29.
Oil bodies of liverworts are intracellular organelles bounded by a single unit membrane containing lipophilic globules suspended in a proteinaceous matrix. They are a prominent and highly distinctive organelle uniquely found in liverworts. Although they have been widely used in taxonomy and chemosystematics, and many of their secondary metabolites are known to be bioactive and are considered as potential sources of medicines, their origin, development and function still remain poorly understood. Recently, biochemical studies have indicated that the isoprenoid biosynthetic pathways in liverworts are similar to those of the seed plants and that oil bodies of Marchantia polymorpha contain a protein complex immunologically related to plastid and cytosolic enzymes of isoprenoid synthesis. Cytoplasmic lipid droplets lacking a bounding membrane have recently been recognized as important dynamic organelles playing active roles in cell physiology. Structural proteins, covering the surface of the lipid droplets and preventing them coalescing during desiccation, have been found in seed plants and also in the moss Physcomitrella patens. However, whether liverwort oil bodies play a dynamic role in cell metabolism, in addition to their role as sites of essential oil accumulation and sequestration, has not been formally tested. In this review, we present current knowledge on the oil bodies of liverworts on their origin and development, their role in taxonomy, chemosystematics and potential pharmaceutical applications leading to their functional significance, and we also identify avenues for future studies on this important but long-overlooked organelle.  相似文献   
30.
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