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   1569篇
  免费   1篇
电工技术   4篇
化学工业   13篇
金属工艺   15篇
机械仪表   2篇
矿业工程   1篇
轻工业   4篇
水利工程   6篇
石油天然气   2篇
无线电   2篇
一般工业技术   8篇
冶金工业   1509篇
原子能技术   4篇
  2022年   2篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2017年   6篇
  2016年   2篇
  2015年   1篇
  2013年   5篇
  2012年   1篇
  2011年   4篇
  2010年   2篇
  2009年   1篇
  2008年   3篇
  2005年   8篇
  2004年   2篇
  2003年   2篇
  2002年   1篇
  2000年   1篇
  1999年   27篇
  1998年   447篇
  1997年   257篇
  1996年   180篇
  1995年   143篇
  1994年   87篇
  1993年   80篇
  1992年   18篇
  1991年   17篇
  1990年   12篇
  1989年   8篇
  1988年   12篇
  1987年   9篇
  1986年   6篇
  1985年   9篇
  1984年   1篇
  1983年   5篇
  1982年   6篇
  1981年   12篇
  1980年   19篇
  1979年   1篇
  1978年   8篇
  1977年   58篇
  1976年   100篇
  1975年   2篇
  1974年   1篇
  1972年   1篇
排序方式: 共有1570条查询结果,搜索用时 15 毫秒
51.
An overview of pulsed laser-assisted methods for nanofabrication, which are currently developed in our Institute (LP3), is presented. The methods compass a variety of possibilities for material nanostructuring offered by laser–matter interactions and imply either the nanostructuring of the laser-illuminated surface itself, as in cases of direct laser ablation or laser plasma-assisted treatment of semiconductors to form light-absorbing and light-emitting nano-architectures, as well as periodic nanoarrays, or laser-assisted production of nanoclusters and their controlled growth in gaseous or liquid medium to form nanostructured films or colloidal nanoparticles. Nanomaterials synthesized by laser-assisted methods have a variety of unique properties, not reproducible by any other route, and are of importance for photovoltaics, optoelectronics, biological sensing, imaging and therapeutics.  相似文献   
52.
Methods of controlling the gas medium in diffusion welding are investigated. A method of control using film gas analysers is proposed. The method increases the accuracy, and can be used to detect the distribution of the composition of the gas medium in the cross section of the contact gap and determine the oxygen concentration in small gaps between the welded components.  相似文献   
53.
54.
This article takes lactose intolerance as a topic for exploring clashes of power, authority, and knowledge in clinical interactions and interpretations of laywomen. In clinics providing maternal and child care, staff and clients jointly produced authoritative knowledge, most often a version of biomedicine. The Euroamerican staff tended to give advice that was biologically appropriate for them but not for many of their patients, a process reflecting what we refer to as biocentrism. Resulting information given to pregnant and lactating women and diagnoses of children's growth patterns were inappropriate in some cases, with potentially serious legal and health implications. Clinic staff often unwittingly ignored the efforts of their clients to begin a discussion of discrepancies between their bodily knowledge and clinic advice. Some women created their own syntheses, which supported the ascendancy of biomedical knowledge but were not in the interests of their own health.  相似文献   
55.
The authors of the present article were the first to work out theoretical foundations and methods of physiological diagnosis of neurocirculatory dystonia. Criteria of tension of myocardial functional structures and central regulatory mechanisms have been identified both in healthy subjects and cardiological patients. It has been ascertained that degree and systematic character of tension cause the physiological risk factors for cardio-pathology to develop, 6 types were identified of loading adaptation of the heart caused by extent of its tension, in individuals with neurocirculatory dystonia. Each of the types disclosed is characterized by a dynamics of the functional volumes proportions as well as by peculiarities of the adaptation mechanisms. Physiological diagnosis of functioning of the heart is one of major methods of the primary prophylaxis of neurocirculatory dystonias as well as prevention of aggravation of their course.  相似文献   
56.
57.
58.
A new system for the expression of a catalytic light chain antibody to the vasoactive intestinal peptide is described. The system made possible the isolation the large amounts of a homogeneous protein without any additional peptide domains. The preparation obtained can be used in further experiments on light chain crystallization and in X-ray-structural analysis of its catalytic center.  相似文献   
59.
Computed tomography (CT) was performed in 189 individuals: in 44 children of schizophrenic parents (high risk group, HRG), in 39 parents with schizophrenia or with schizophrenic disturbance, in 56 children with schizophrenia, in 50 children with consequences of early organic damages of central nervous system (mental retardation syndrome and generalized tic syndrome). The frequency of CT changes was equal in the mentioned groups but their character was quite different. The widening of brain's liquor system (89.7%), the signs of frontal and temporal atrophia (31%), foci of decreased density of cerebral brain's matter, closer in subcortical ganglia and periventricular zone, and different anomalies of brain were observed in HRG children.  相似文献   
60.
Previously, we showed that truncated soluble forms of herpes simplex virus (HSV) glycoprotein D (gDt) bound directly to a truncated soluble form of the herpesvirus entry mediator (HveAt, formerly HVEMt), a cellular receptor for HSV. The purpose of the present study was to determine the affinity of gDt for HveAt by surface plasmon resonance and to compare and contrast the kinetics of an expanded panel of gDt variants in binding to HveAt in an effort to better understand the mechanism of receptor binding and virus entry. Both HveAt and gDt are dimers in solution and interact with a 2:1 stoichiometry. With HveAt, gD1(306t) (from the KOS strain of HSV-1) had a dissociation constant (KD) of 3.2 x 10(-6) M and gD2(306t) had a KD of 1.5 x 10(-6) M. The interaction between gDt and HveAt fits a 1:1 Langmuir binding model, i.e., two dimers of HveAt may act as one binding unit to interact with one dimer of gDt as the second binding unit. A gD variant lacking all signals for N-linked oligosaccharides had an affinity for HveAt similar to that of gD1(306t). A variant lacking the bond from cysteine 1 to cysteine 5 had an affinity for HveAt that did not differ from that of the wild type. However, variants with double cysteine mutations that eliminated either of the other two disulfide bonds showed decreased affinity for HveAt. This result suggests that two of the three disulfide bonds of gD are important for receptor binding. Four nonfunctional gDt variants, each representing one functional domain of gD, were also studied. Mutations in functional regions I and II drastically decreased the affinity of gDt for HveAt. Surprisingly, a variant with an insertion in functional region III had a wild-type level of affinity for HveAt, suggesting that this domain may function in virus entry at a step other than receptor binding. A variant with a deletion in functional region IV [gD1(Delta290-299t)] exhibited a 100-fold enhancement in affinity for HveAt (KD = 3.3 x 10(-8) M) due mainly to a 40-fold increase in its kinetic on rate. This agrees with the results of other studies showing the enhanced ability of gD1(Delta290-299t) to block infection. Interestingly, all the variants with decreased affinities for HveAt exhibited decreased kinetic on rates but only minor changes in their kinetic off rates. The results suggest that once the complex between gDt and HveAt forms, its stability is unaffected by a variety of changes in gD.  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