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   1627篇
  免费   3篇
电工技术   1篇
化学工业   8篇
金属工艺   1篇
机械仪表   2篇
建筑科学   4篇
轻工业   5篇
水利工程   1篇
无线电   3篇
一般工业技术   7篇
冶金工业   1592篇
自动化技术   6篇
  2022年   1篇
  2021年   2篇
  2018年   3篇
  2017年   2篇
  2016年   2篇
  2014年   2篇
  2012年   1篇
  2011年   3篇
  2010年   1篇
  2008年   3篇
  2006年   2篇
  2004年   2篇
  2003年   7篇
  1999年   43篇
  1998年   464篇
  1997年   273篇
  1996年   190篇
  1995年   109篇
  1994年   79篇
  1993年   87篇
  1992年   13篇
  1991年   14篇
  1990年   17篇
  1989年   29篇
  1988年   21篇
  1987年   17篇
  1986年   14篇
  1985年   15篇
  1982年   6篇
  1981年   17篇
  1980年   21篇
  1979年   2篇
  1978年   8篇
  1977年   46篇
  1976年   106篇
  1975年   4篇
  1974年   1篇
  1970年   1篇
  1955年   2篇
排序方式: 共有1630条查询结果,搜索用时 0 毫秒
71.
Emu antibody responses to avian influenza virus (AIV) infection were evaluated by the competitive enzyme-linked immunosorbent assay (C-ELISA), agar gel immunodiffusion (AGID) and hemagglutination inhibition (HI) tests. All birds infected with AIV H5N1, H5N3, or H7N7 developed antinucleoprotein (NP) antibodies as early as 7 days postinfection as detected by the C-ELISA. The responses lasted 49 days for the emus receiving H5N3 and at least 56 days for emus receiving the other two viruses. By evaluating 50 emu field serum samples, the C-ELISA was found more sensitive than the AGID test for the detection of anti-NP antibodies. This study indicates that emus experimentally infected with AIV developed antibody responses that can be detected by C-ELISA, AGID, and HI tests. The results from this and our previous studies demonstrate the use of the C-ELISA as a substitute for the AGID test in a routine serodiagnostic screening for detection of antibodies to AIV infection in multiple avian species.  相似文献   
72.
In the department of microsurgery of A.A. Vishnevsky Central Hospital the transplantation and transposition of the at the gunshot injuries of the extremities have begun to execute since 1990. For this time 94 surgical interventions have been conducted at 88 wounded: 57 transplantations and 37 transpositions of the bloody tissues. The transplantation and transposition of the vascularized complexes of tissues with application of microsurgical technique is the effective method of the treatment of the wounded in the extremities. In the conditions of the local armed conflicts it is necessary to provide deployment of the department of microsurgery at stages of the specialized medical care.  相似文献   
73.
74.
75.
76.
77.
78.
OBJECTIVE: The authors discuss obstacles and incentives associated with successful community-based public-academic liaison activities and illustrate their conclusions by describing their public-academic liaison program, which received the American College of Psychiatrists' first annual Award for Creativity in Psychiatric Education. METHOD: The first 8 years of a state/university collaboration are described in which the parties involved first developed a variety of innovative services designed to fill specific gaps in the public service delivery system and subsequently integrated academic research and training components. RESULTS: The carefully planned and monitored process resulted in the exponential growth of interest in public sector work, the realization of the university's primary goals of developing high quality training and research sites, a substantial increase in the number of graduates accepting positions in the public sector, several projects funded by the National Institute of Mental Health, and two national awards. CONCLUSIONS: These collaborations illustrate the highly complementary relationship of public-academic liaison activities and their potential capacity to improve access to services, substantially improve the quality of these services, generate extramural support for services research, and increase the number of well-trained professionals in the public sector.  相似文献   
79.
A retrospective study was carried out of patients from a single institution over a 30-year period. Thirty-one patients presented with 33 fistulas, four non-enteric and 27 enteric. In 25 of 27 patients with a prosthesis-related enteric fistula gastrointestinal bleeding was present. Angiography revealed the fistula in five patients endoscopy in three, and barium studies, echography and computed tomography each revealed one fistula. Six patients died before and five died during operation. In 20 patients various techniques were used for treatment. In-hospital mortality decreased from six of eight patients before 1970, to seven of ten between 1971 and 1980, and to four of 13 after 1981. In the long term, patients treated with an extra-anatomic reconstruction had a poorer prognosis than those treated by in situ reconstruction. This experience shows that diagnostic tests often fail to reveal a prosthesis-related fistula and that mortality can be substantially reduced by early exploration in patients with negative diagnostic studies.  相似文献   
80.
The laser-induced proton pulse technique [Gutman, M. (1986) Methods Enzymol. 127, 522-538] was applied on suspensions of submitochondrial vesicles, and the exchange of protons between the bulk and the mitochondrial membranes was measured in the time-resolved domain with a submicrosecond resolution. The protons were discharged by photoexcitation of pyranine (8-hydroxypyrene-1,3,6-trisulfonate) by a short laser pulse, and the reprotonation of the pyranine anion was monitored at 457.8 nm. In parallel, the protonation of the membrane was followed at 496.5 nm, looking at the transient absorbance of fluorescein, covalently attached to the M side of the membrane. The analysis of the relaxation dynamics was carried out by a simulation procedure that reconstructs the observed dynamics of the two chromophores. The analysis revealed the presence of the membrane indigenous buffering moieties. The low-pK buffer (pK 4.1) was present in a quantity of 100 +/- 20 nmol/mg of protein, and its kinetics indicate that it appears in multianionic clusters bearing a negative electric charge. The medium-pK buffer (pK 6.9) was present in a larger quantity (200 +/- 20 nmol/mg), and its kinetic parameter indicated clustering into positively charged domains. Both types of indigenous buffer reacted with the proton and pyranine anion in unhindered diffusion-controlled reactions. On the other hand, the exchange of protons between the indigenous buffer moieties was rather slow. No evidence was found for the presence of sites capable of retaining a proton, secluded from the bulk, for a time frame longer than 100 microseconds as required by the models of localized proton gradient.  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