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   470篇
  免费   0篇
化学工业   15篇
轻工业   1篇
无线电   1篇
一般工业技术   7篇
冶金工业   445篇
自动化技术   1篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2017年   1篇
  2015年   1篇
  2013年   1篇
  2005年   1篇
  2004年   1篇
  1999年   8篇
  1998年   106篇
  1997年   56篇
  1996年   43篇
  1995年   27篇
  1994年   23篇
  1993年   36篇
  1992年   4篇
  1991年   8篇
  1990年   8篇
  1989年   13篇
  1988年   6篇
  1987年   4篇
  1986年   9篇
  1985年   6篇
  1984年   1篇
  1982年   4篇
  1981年   3篇
  1980年   7篇
  1979年   1篇
  1978年   5篇
  1977年   19篇
  1976年   50篇
  1975年   3篇
  1968年   1篇
  1965年   1篇
  1961年   2篇
  1958年   1篇
  1957年   2篇
  1947年   1篇
  1945年   2篇
  1944年   1篇
  1940年   1篇
排序方式: 共有470条查询结果,搜索用时 0 毫秒
61.
Mechanisms of formalin--induced luminescence of protein-lipid complexes have been studied. Free radical reactions of lipid oxidation were shown to be necessary for generating luminescence quanta. The luminescence intensity was mostly promoted by fluorescing products formed in the reoxidized system protein-lipid. Formalin-induced flash of luminescence in these systems may evidently serve as an express-method for analysing protein sample contamination with unsaturated lipids.  相似文献   
62.
An analysis of reovirus-specific polypeptides in cells infected with temperature-sensitive mutants under permissive and nonpermissive conditions revealed the presence of (i) all the known viral polypeptides and (ii) aberrant migration of the mu 1 and mu 2 polypeptides in four groups of mutants.  相似文献   
63.
64.
65.
OBJECTIVE: To examine the effect of gender on the relationship between obesity measures and lipids/lipoproteins. DESIGN: Cross-sectional, matched observational study of adult men and women. SUBJECTS: 225 spousal pairs from Cincinnati, Ohio (age range, 28-66 years; mean +/- SD (yr), 44.0 +/- 6.7 (men), 42.1 +/- 5.9 (women). MEASUREMENTS: Body mass measures, lipids, lipoproteins, apolipoproteins, physical activity levels, cigarette use and dietary variables. RESULTS: Correlations between the lipids/lipoproteins and body mass index (BMI) were stronger in women than in men for cholesterol (r = 0.24 vs 0.10), LDL-c (r = 0.27 vs 0.12), triglycerides (TG) (r = 0.48 vs 0.23) and the ratio cholesterol/HDL-c (r = 0.47 vs 0.28). Utilizing statistical regression models which included potentially confounding environmental factors, BMI and WHR both contributed significant information to describe cholesterol, HDL-c, TG and cholesterol/HDL-c values in women, whereas WHR alone provided information for these lipids/lipoproteins in men. CONCLUSION: The association between BMI and lipids/lipoproteins appears to be stronger in women than in men. In women, in contrast to men, BMI and WHR, measures which are easily attainable in the clinical setting, provide separate, independent information in the explanation of these lipid/lipoprotein levels.  相似文献   
66.
OBJECTIVE: Changes in the health care environment have placed a greater responsibility on psychiatrists to deliver basic primary care services. The study assessed baseline knowledge and attitudes about clinical preventive medical services among psychiatric faculty and psychiatric residents at a tertiary care medical center. METHODS: Residents and faculty in psychiatry and general internal medicine completed a structured questionnaire, including 20 case scenarios, that assessed their baseline knowledge of clinical preventive medical services, their attitudes concerning delivery of those services, and their beliefs about the effectiveness of those services in changing patients' behavior. The case scenarios and knowledge questions were based on the clinical preventive medical services recommendations outlined by the U. S. Preventive Services Task Force. RESULTS: Psychiatrists reported more frequent assessment of and counseling about the use of illicit drugs and weapons, and internists were more likely to query about measures related to physical health such as cancer screening and immunizations. The two groups reported similar attitudes toward the need for and the efficacy of preventive medical services. Commonly cited barriers to the delivery of preventive care included lack of time and education. Psychiatrists scored reasonably well on baseline knowledge about guidelines for preventive medical services, particularly given their recent lack of specific education in these matters. CONCLUSIONS: Psychiatrists believe clinical preventive services are important and express interest in their delivery. Additional educational interventions are needed to train psychiatrists in clinical preventive services to avoid missed clinical opportunities for intervention in psychiatric populations that may have poor access to other medical care.  相似文献   
67.
68.
Mycobacterium avium complex-serotype 6 was isolated in pure culture on blood agar plates from inocula taken from the heart blood, lungs, liver, kidneys, and spleen of a naturally infected captive female opossum (Didelphis marsupialis virginiana). Repeat cultures from stored tissues and transfer of colonies from original blood agar plates revealed that the mycobacterium grew on tryptose, brilliant green, eosin-methylene blue. Sabouraud glucose, and mycobiotic agar plates and in Fletcher leptospira medium. The cultural, biochemical, and serological characteristics of the test isolate were compared with other mycobacteria. This is the first report to describe the primary isolation of a serotype from the M. avium complex from an animal species on blood agar or in Fletcher broth. In addition, this is the second documented report describing the isolation and identification of a mycobacterial species from the American opossum.  相似文献   
69.
70.
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