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   179篇
  免费   49篇
  228篇
  2023年   2篇
  2022年   8篇
  2021年   4篇
  2020年   7篇
  2019年   5篇
  2018年   4篇
  2017年   4篇
  2016年   12篇
  2015年   7篇
  2014年   16篇
  2013年   17篇
  2012年   10篇
  2011年   21篇
  2010年   6篇
  2009年   10篇
  2008年   7篇
  2007年   5篇
  2006年   8篇
  2005年   1篇
  2004年   1篇
  2003年   1篇
  2002年   2篇
  2001年   4篇
  2000年   2篇
  1999年   5篇
  1998年   4篇
  1997年   2篇
  1996年   2篇
  1995年   4篇
  1994年   3篇
  1993年   2篇
  1992年   11篇
  1991年   6篇
  1990年   6篇
  1989年   3篇
  1988年   4篇
  1987年   1篇
  1986年   3篇
  1985年   2篇
  1984年   1篇
  1983年   3篇
  1981年   1篇
  1980年   1篇
排序方式: 共有228条查询结果,搜索用时 0 毫秒
221.
222.
In this paper an attempt has been made to reduce the computational complexities involved in estimation of several missing values. As a result it has been shown that one can estimate m missing values by developing only k (≤m) linear equations, where m and k are respectively the number of missing values and missing cells. The procedure is also illustrated with the help of a numerical example.  相似文献   
223.
Radiation resistance in Schizosaccharomyces pombe   总被引:2,自引:0,他引:2  
The fission yeast Schizosaccharomyces pombe serves as an excellent alternative and complementary model system for the analysis of genes and gene products involved in DNA repair. This brief review outlines the advantages of S. pombe and describes the radiation-sensitive mutants available for the analysis of DNA repair and recombination mechanisms in this organism. The progress in the cloning and characterization of representative genes is also described.  相似文献   
224.
The influence of Streptococcus phocae PI80 on the shelf life of Sardinella longiceps and Penaeus monodon was investigated by measurement of microbial and chemical analysis after appraising the safety of the protective probiotic culture in wistar rat’s model. The results of this safety assessment indicate that oral administration of protective culture does not demonstrate any toxicological effects. Consumption of this LAB strain had no adverse effects on animal’s general health status, hematology, blood biochemistry, histology parameters, or on the incidence of bacterial translocation. The effect of Streptococcus phocae is very evident with the reduction of Listeria monocytogenes, Vibrio parahemolyticus, and coliforms. During storage, a marked decline in total volatile base and peroxide value was observed in protective culture-treated samples than the control. This strain looks promising as a protective culture for the preservation of fish products.  相似文献   
225.
226.
In the present study an attempt has been made to esttimate several missing values in cross-over designs. When the observations are missing in a particular pattern, explicit expressions are given for the estimators of the missing values. This procedure is illustrated with the help of a numerical example.  相似文献   
227.
The present paper deals with an alternative and simple procedure to analyse the non-orthogonal data. The procedure is general in nature but has some advantages for the non-orthogonal data due to some missing observations. The procedure is applied to (i) two way classification with unequal number of observations per cell; (ii) randomized block designs with some missing observations and (iii) balanced incomplete block designs and also illustrated with the help of numerical examples.  相似文献   
228.
Abstract

6-Methyl-7H,8H,9H-[1,2,4]triazolo[4,3-b][1,2,4]triazepin-8-onehas been synthesized, characterized by spectroscopic techniques (FT-IR, 1H and 13C NMR) and finally the structure was confirmed by single crystal X-ray diffraction studies. In the title molecule, C6H7N5O, the 7-membered ring adopts a bowl-like conformation. In the crystal, the molecules form stacks along the c-axis direction through offset π-stacking interactions between the 5-membered rings and C–H···N hydrogen bonds. The stacks are associated via a combination of N–H···N, C–H···O and C–H···N hydrogen bonds. Further, the Hirshfeld surface analysis reveals the nature of molecular interactions and the fingerprint plot provides information about the percentage contribution from each individual molecular contact to the surface. In addition, due to its biological interest the target molecule adenosine A1 receptor was found based on Structural Activity Relationship (SAR) analysis and, further, subjected into molecular docking and molecular dynamics analysis to understand the binding interaction and stability of the molecule in adenosine A1 receptor system. Furthermore, the Density Functional Theory (DFT) calculations were carried for free compound and the compound in active site (single point DFT), to know the internal stability.

Communicated by Ramaswamy H. Sarma  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