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   208篇
  免费   3篇
  国内免费   1篇
电工技术   9篇
化学工业   15篇
金属工艺   3篇
机械仪表   3篇
建筑科学   7篇
能源动力   2篇
轻工业   5篇
水利工程   2篇
无线电   21篇
一般工业技术   37篇
冶金工业   93篇
自动化技术   15篇
  2021年   2篇
  2018年   1篇
  2017年   1篇
  2016年   4篇
  2015年   2篇
  2014年   3篇
  2013年   16篇
  2012年   5篇
  2011年   5篇
  2010年   3篇
  2009年   4篇
  2008年   3篇
  2007年   4篇
  2006年   3篇
  2005年   2篇
  2004年   4篇
  2003年   6篇
  2002年   4篇
  2001年   3篇
  2000年   2篇
  1999年   10篇
  1998年   23篇
  1997年   15篇
  1996年   8篇
  1995年   5篇
  1994年   6篇
  1993年   5篇
  1992年   3篇
  1991年   4篇
  1990年   5篇
  1989年   6篇
  1988年   6篇
  1987年   4篇
  1986年   2篇
  1985年   1篇
  1984年   3篇
  1983年   2篇
  1982年   2篇
  1980年   5篇
  1979年   5篇
  1977年   1篇
  1976年   5篇
  1975年   1篇
  1972年   1篇
  1967年   1篇
  1965年   1篇
  1964年   1篇
  1961年   1篇
  1960年   1篇
  1959年   2篇
排序方式: 共有212条查询结果,搜索用时 115 毫秒
31.
The occurrence of a subdural hematoma caused by the rupture of an intracranial aneurysm is rare. In our case, the patient is a 43-year-old woman who suffered from sudden onset of severe headache. Computed tomographic (CT) scan disclosed a subdural hematoma associated with subarachnoid hemorrhage. CT angiography and digital subtraction angiography revealed an elongated aneurysm adhering to the dura in the left Sylvian fissure. The subdural hematoma was evacuated and the aneurysm clipped. The patient made a full recovery.  相似文献   
32.
In recent years, the separation of safety interlocks from regulatory control systems has emerged as an important safety issue within the process industries. Most modern control systems are large and complex and may be composed of many different types of programmable electronic system (PES) elements. The degree to which elements of the interlock system are shared with the regulatory control system and the resultant security and reliability risks and consequences are often over-looked in safety analyses of the design. The criteria for utilizing a programmable electronic PES in safety interlock applications, based on the degree of hazard and the potential severity of injury and damage, have been described in a previous paper. That paper presented an Interlock Guideline Matrix, which classified the levels of interlock protection required (based on these criteria) and defined the PES interlock system design to satisfy the safety requirements for each classification. This paper addresses the degree of separation required between interlock functions and regulatory control functions in the PES. These requirements are based primarily on the classification of the risk involved, the potential for injury, and environmental and/or property damage. The Interlock Guideline Matrix has been updated to include the requirements for this separation in the interlock system design criteria.  相似文献   
33.
The effects of the GABA antagonist picrotoxin and the glycine antagonist strychnine on the frequency components in sympathetic inferior cardiac nerve activity were observed. Picrotoxin (0.03-1.0 mg/kg) increased power in the 10-Hz component of sympathetic activity and produced a dramatic shift in the rhythm to higher frequencies. Only small changes were noted in the 2- to 6-Hz component. Strychnine produced a small generalized increase in power in both frequency bands in sympathetic activity. These data suggest that GABA may play an important role in the generation and maintenance of the 10-Hz rhythm in sympathetic activity while glycine likely inhibits activity at a site of convergence of the two rhythms in sympathetic activity.  相似文献   
34.
In this study, naturally-occurring, monoclonal IgM kappa anti-thymocyte autoantibodies from the neonatal inbred Balb/c mouse-derived hybridoma NMT-1 (NMT-1 mAb), previously reported to identify a restricted CD4+CD8+CD3/lo/int thymocyte subpopulation, have been shown to exhibit extensive polyspecificity. Using immunofluorescence, immunoblotting and antibody titration and competition ELISAs, NMT-1 mAbs exhibited polyspecific binding to 12 apparently structurally unrelated self and non-self antigens. The autoreactive component of the polyspecificity profile of NMT-1 mAbs encompassed reactivity to developmentally-related 14.5 and 18.3 kDa Thy-1 glycoforms expressed on a CD4+CD8+CD3-/lo/int thymocyte subpopulation. The autoreactivity profile of NMT-1 mAbs also included recognition of the heavy and light chains of mouse IgG1 and mouse cytokeratins within thymic medullary epithelium and basal epithelial cells of stratified squamous epithelium of mouse tongue, oesophagus, stomach, skin and vagina. Examination of the polyspecificity profile of NMT-1 mAbs was also undertaken using a panel of 23 antigens including heterologous proteins, phospholipids, haptens and bacterial antigens by antibody titration and competition ELISAs. Antibody titration ELISAs demonstrated that NMT-1 mAbs bound nine antigens including bovine carbonic anhydrase, ovalbumin, cardiolipin, phosphatidylserine, the haptens, DNP and FITC and the bacterial antigens including Escherichia coli beta-galactosidase and the toxoids from Corynebacterium tetani and Clostridium diphtheria. Competition ELISAs, based on the inhibition of NMT-1 mAb binding to antigens adsorbed to ELISA plate surfaces by inhibitor antigens in solution, demonstrated that NMT-1 mAb interactions were not dependent on multivalent binding. In these assays, NMT-1 mAbs recognized unmodified (native) epitopes on the solution phase forms of the protein antigens, including E. coli beta-galactosidase and toxoids from Corynebacterium tetani and Clostridium diphtheria, providing further evidence for the hypothesis that the binding of multiple, apparently unrelated, antigens by NMT-1 mAbs occurs via unique polyspecific antigen combining sites.  相似文献   
35.
Scientists and journalists have traditionally viewed each other warily, but recently scientists from all disciplines have been urged to be more cooperative with reporters. Psychologists, in particular, have more contact with the press than other scientists, and the American Psychological Association has increased its public communications activities substantially in recent years. But if relations are to improve, both scientists and journalists must understand the purposes, values, and procedures of the other. This article reviews the research literature pertinent to the difference in emphases between these two disciplines, the accuracy of scientific reports, and the possibility that the social and behavioral sciences are treated differently by the press than other scientific disciplines. Finally, suggestions for both scientists and journalists are offered to improve cooperation for the betterment of both enterprises and of society. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
36.
This study used workers' compensation data from Oregon from 1990 to 1997 to examine workers' compensation claims from vehicular accidents by truck drivers, and to calculate claim rate estimates using baseline data derived from the US Bureau of Census' Current Population Surveys. During this period, 1168 valid injury claims due to vehicular accidents were filed representing an accident claim rate of 50.3 (95% CI: 45.1-55.5) per 10,000 truck drivers annually. There were 19 work-related vehicular accident fatalities recorded in the data over the 8-year period. Of all claimants, males constituted the majority (80.7%), most were 35 years of age or younger (51.4%) and had less than 1 year of job tenure (51.0%). Truck driver claim rates due to vehicular accidents were lowest during the 6 a.m. to 12 p.m. period. The average amount of compensable lost work days per injury claim was 57.8 days (S.D.=124.7) and the median claim time was 16.0 days with the inter-quartile range being 53.5 days. The amount of lost work reported increased with the claimant's age. A total of US$ 11,642,635 was paid in claims for vehicular accidents of truck drivers in Oregon over the time examined, which averaged US$ 9966 per claim, with a median claim amount of US$ 2590 and inter-quartile range of US$ 7670. Claims citing sprains were the most frequently recorded injury experienced from vehicular accidents.  相似文献   
37.
Rates and methods of suicide during 1961-70 migrants in Australia were compared with native born Australians. Large differences in both rates and methods of suicide were found in individual migrant groups. The rates were more akin to those in the country of origin than of the Australian-born, no matter how long the migrants had lived in Australia. By contrast, methods of suicide use by migrants approached more closely those of the Australian-born the longer they had lived in Australia. The change in methods used was greater in those migrant groups coming from countries with a language and culture more akin to those in Australia. A discussion follows of various possible sociological and cultural factors, both within the countries of origin and within Australia, which could have contributed to these results.  相似文献   
38.
A hemostatic survey was done on 14 Bedlington terriers, 13 of which have the recently discovered copper toxicosis. Their hepatic copper ranged from 109 to 9,888 microgram/g dry weight and their ages from 8 months to 8 years. Despite histologic evidence of hepatitis in younger dogs and cirrhosis in older ones, plasmatic coagulation factors were not depressed. In fact, the hemophilic factors VIII, IX and XI were above normal, more closely related to the age of the dog than to the hepatic copper. Furthermore, their platelet were unusually sensitive to adenosine diphosphate exposure. Offsprings of matings between Bedlington terriers and Beagles seem to be normal.  相似文献   
39.
The synthesis and biological activity in the rat passive cutaneous anaphylaxis (PCA) test of a new class of compounds, 1-[(ethoxyamino)methyl]-1,3,4,5-tetrahydro-7,8-dimethoxy-2-benzoxepins, are reported. These compounds are synthesized from the adduct of 1-(bromomethyl)-1,3,4,5-tetrahydro-7,8-dimethoxy-2-benzoxepins, are reported. These compounds are synthesized from the adduct of 1-(bromomethyl)-1,3,4,5-tetrahydro-7,8-dimethoxy-2-benzoxepin and ethylene glycol or chloroethanol. The influence of the amine function on activity in the rat PCA is discussed. Aryl- or heteroarylpiperazines favor activity with this class of compounds.  相似文献   
40.
The ability of oral tetracycline to inhibit the development of third-stage infective larvae (L3) of Brugia pahangi to adult worms in jirds was studied using 2 experimental protocols. Jirds treated with 1.4% tetracycline in drinking water for a period beginning 30 days before inoculation of L3 until 30 days post-inoculation (DPI) had 97% reduction in adult worm recovery compared to untreated controls. Jirds that received 1.2% tetracycline in drinking water beginning 1 day before until either 12 or 26 DPI had adult worm recoveries of 11% and < 1%, respectively. Untreated jirds and those given tetracycline beginning at or later than 13 DPI had similar adult worm recovery (27-29%). Prepatent periods were prolonged, and circulating microfilariae were reduced in jirds given tetracycline from 27 to 54 DPI compared to controls. These data indicate that tetracycline administered to jirds in drinking water inhibits B. pahangi development from L3 to adult worms and suggest that this effect occurs during early larval development. Tetracycline administered to infected jirds prior to and continuing through the onset of patency can also affect development of microfilaremia.  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