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   560篇
  免费   10篇
  2021年   9篇
  2019年   8篇
  2018年   4篇
  2017年   11篇
  2016年   8篇
  2015年   12篇
  2014年   14篇
  2013年   13篇
  2012年   13篇
  2011年   13篇
  2010年   14篇
  2009年   7篇
  2008年   22篇
  2007年   21篇
  2006年   6篇
  2005年   10篇
  2004年   12篇
  2003年   20篇
  2002年   11篇
  2001年   17篇
  2000年   17篇
  1999年   17篇
  1998年   7篇
  1995年   3篇
  1992年   13篇
  1991年   20篇
  1990年   24篇
  1989年   20篇
  1988年   19篇
  1987年   16篇
  1986年   8篇
  1985年   13篇
  1984年   11篇
  1983年   8篇
  1982年   5篇
  1981年   6篇
  1980年   5篇
  1979年   18篇
  1978年   10篇
  1977年   13篇
  1976年   3篇
  1974年   5篇
  1973年   9篇
  1972年   11篇
  1971年   9篇
  1970年   4篇
  1969年   3篇
  1968年   5篇
  1967年   4篇
  1966年   6篇
排序方式: 共有570条查询结果,搜索用时 15 毫秒
561.
562.
The wavenumber-resolved radar backscattering diagnostics in the upper hybrid resonance (UHR) region was used to study low-frequency short-scale turbulence in the FT-1 tokamak. The scattered spectra were measured for different delay times of the scattered signals. It is shown that the width of the spectrum of enhanced scattering by spontaneous fluctuations is proportional to the delay time. Possible mechanisms for the formation of the scattered spectra are proposed and discussed. The results of simulations and additional experiments were used to determine the dominant mechanisms governing the formation of the scattered spectra in the FT-1 tokamak. These mechanisms are related to the effect of multiple small-angle scattering of both the probing wave and the waves backscattered in the UHR region by long-scale density fluctuations and to the Doppler effect caused by the entrainment of short-scale fluctuations by the long-scale turbulent flow.  相似文献   
563.
The review considers the results of genome research on the Russian program Human Genome carried out in the Institute of Medical Genetics (Tomsk) since 1990. The three major fields were molecular cytogenetics and chromosomal disorders, genomics of Mendelian and common diseases, and ethnogenomics of the North Asian population. Several human genes were cytogenetically mapped, and numerical and structural abnormalities associated with human diseases were studied by fluorescence hybridization. Procedures of DNA diagnosis were developed for 15 hereditary diseases. New data were obtained on the genetic heterogeneity of idiopathic hypertrophic cardiomyopathy. The genetic bases of multifactorial (atopic bronchial asthma) and infectious (tuberculosis) diseases were analyzed. The North Eurasian population (41 local populations of 21 ethnic groups) was tested for genetic diversity with numerous genetic markers, including Y-chromosomal haplotypes, autosomal microsatellites, and polymorphic Alu insertions.  相似文献   
564.
565.
The effect of sulfated polysaccharides on the efficiency of the infection of mouse transplantable fibroblast SC-1 and NIH-3T3 cell lines by replication-competent recombinant Moloney murine leukemia virus (Mo-MuLV), which carries the eGFP gene, was investigated. It was found that sulfated polysaccharides have no cytostatic and cytotoxic effects on SC-1 and NIH-3T3 cells in the concentration range of 0.01–100 μg/mL and have virucidal activity against Mo-MuLV. Polysaccharides in the indicated concentrations inhibit Mo-MuLV infection that prevents the further development of viral infection. It was shown that sulfated polysaccharides are also effective inhibitors of other retroviruses, including lentiviruses, which use sulfated polysaccharides as primary cell receptors.  相似文献   
566.
567.
Biochemical, morphological and biomechanic study of various veins which were taken from 54 patients without trophic disorders during phlebectomy and kept for 7 days was made. 2% solution of neutral formalin and isotonic buffer solution (Henx solution) was used; results of the study show, that conserved veins can be used for grafting in arterial reconstructive surgery in cases of absence of autogenous vein material. Optimal period of conservation is 1 day.  相似文献   
568.
Some serine proteases and leucine aminopeptidases were detected inside and outside the cells during the analysis of three crystalline and two acrystalline strains of Bac. thuringiensis var. galleriae. The data obtained on the protease formation during growth and sporulation and the level of their activity are indicative of intracellular proteases involvement in spore- and crystal formation. The enzymes isolated from the culture medium do not probably take part in these processes. The intracellular enzymes may account for the different crystal protein composition of various strains due to limited proteolysis of crystal proteins in the course of biosynthesis.  相似文献   
569.
The crystals of entomopathogenic protein from Bac. thuringiensis contain admixtures of proteinases adhering to their surfaces. A newly developed technique of protease inactivation allowed to estimate the true protein composition of the crystals of various strains of Bac. thuringiensis. It was shown that the crystals of all strains (with the exception of V and VIII) are composed of only one protein with molecular weights of 145,000, 135,000 and 130,000, depending on the strain. The crystals of serotype VIII and the majority of the V serotype strains have two proteins with molecular weights of 135,000 and 130,000. A method for estimation of the protein composition of crystal without their preliminary isolation from a crystal--spore mixture is proposed.  相似文献   
570.
In 30 patients with myasthenia the authors studied the dynamic of changes of subfraction content of the blood serum using the method of laser correlation spectroscopy. Significant changes of the blood serum homeostasis have been revealed in the process of hemosorption. The obtained results make it possible to develop objective criteria for indications to hemosorption as well as for the assessment of the efficacy of therapy.  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