全文获取类型
收费全文 | 1743篇 |
免费 | 21篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 45篇 |
金属工艺 | 4篇 |
机械仪表 | 10篇 |
建筑科学 | 7篇 |
矿业工程 | 1篇 |
能源动力 | 2篇 |
轻工业 | 43篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 37篇 |
一般工业技术 | 35篇 |
冶金工业 | 1536篇 |
原子能技术 | 1篇 |
自动化技术 | 37篇 |
出版年
2024年 | 3篇 |
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 13篇 |
2020年 | 7篇 |
2019年 | 11篇 |
2018年 | 13篇 |
2017年 | 10篇 |
2016年 | 13篇 |
2015年 | 7篇 |
2014年 | 8篇 |
2013年 | 16篇 |
2012年 | 12篇 |
2011年 | 22篇 |
2010年 | 20篇 |
2009年 | 15篇 |
2008年 | 8篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2000年 | 6篇 |
1999年 | 27篇 |
1998年 | 456篇 |
1997年 | 261篇 |
1996年 | 187篇 |
1995年 | 143篇 |
1994年 | 85篇 |
1993年 | 85篇 |
1992年 | 21篇 |
1991年 | 18篇 |
1990年 | 12篇 |
1989年 | 9篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 7篇 |
1985年 | 9篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 13篇 |
1980年 | 21篇 |
1978年 | 7篇 |
1977年 | 56篇 |
1976年 | 102篇 |
1975年 | 2篇 |
排序方式: 共有1764条查询结果,搜索用时 949 毫秒
51.
AV Kabashin Ph Delaporte A Pereira D Grojo R Torres Th Sarnet M Sentis 《Nanoscale research letters》2010,5(3):454-463
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.
Magalhaes KD Costa LS Fidelis GP Oliveira RM Nobre LT Dantas-Santos N Camara RB Albuquerque IR Cordeiro SL Sabry DA Costa MS Alves LG Rocha HA 《International journal of molecular sciences》2011,12(5):3352-3365
In the present study, six families of sulfated polysaccharides were obtained from seaweed Dictyopteris delicatula by proteolytic digestion, followed by acetone fractionation and molecular sieving on Sephadex G-100. Chemical analyses demonstrated that all polysaccharides contain heterofucans composed mainly of fucose, xylose, glucose, galactose, uronic acid, and sulfate. The fucans F0.5v and F0.7v at 1.0 mg/mL showed high ferric chelating activity (~45%), whereas fucans F1.3v (0.5 mg/mL) showed considerable reducing power, about 53.2% of the activity of vitamin C. The fucan F1.5v presented the most prominent anticoagulant activity. The best antiproliferative activity was found with fucans F1.3v and F0.7v. However, F1.3v activity was much higher than F0.7v inhibiting almost 100% of HeLa cell proliferation. These fucans have been selected for further studies on structural characterization as well as in vivo experiments, which are already in progress. 相似文献
53.
Cavalcanti OA Van den Mooter G Caramico-Soares I Kinget R 《Drug development and industrial pharmacy》2002,28(2):157-164
Oligosaccharides such as inulin (In) and polysaccharides such as galactomannans, combined with polymethacrylates on isolated films for film coatings, were obtained from aqueous-based solvents and investigated as potential vehicles for colonic drug delivery. These compositions, which are susceptible to fermentation by colonic microflora, constitute promising excipients for the development of new colon-specific therapeutic systems. The characteristics of several compositions have been demonstrated in permeability and swelling studies on isolated films composed of a polymethacrylate associated with In or galactomannans of mesquite seed gum (MSG). Results reported prove a dependency of the properties of mixed films on the polymethacrylate-polysaccharide concentration ratio and on the composition of the dissolution media. An increase in permeability through the mixed films was observed in a simulated colonic environment for the following compositions: Eudragit®RS30D-MSG 70 : 30 w/w; Eudragit® RS30D-In 90 : 10 w/w; Eudragit®RS30D-In 76 : 24 w/w. 相似文献
54.
55.
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
56.
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
57.
58.
59.
AV Demin AV Kolesnikov MA Olfer'ev PV Favorov KV Fegeding AG Gabibov NV Gnuchev 《Canadian Metallurgical Quarterly》1998,34(10):1333-1337
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
60.
AV Goriunova GV Kozlovskaia IA Kozlova NV Rimashevskaia NIu Savvateeva GN Shimonova 《Canadian Metallurgical Quarterly》1996,96(4):46-50
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