全文获取类型
收费全文 | 1653篇 |
免费 | 88篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 23篇 |
综合类 | 1篇 |
化学工业 | 484篇 |
金属工艺 | 22篇 |
机械仪表 | 32篇 |
建筑科学 | 50篇 |
矿业工程 | 3篇 |
能源动力 | 58篇 |
轻工业 | 132篇 |
水利工程 | 15篇 |
石油天然气 | 10篇 |
无线电 | 126篇 |
一般工业技术 | 298篇 |
冶金工业 | 192篇 |
原子能技术 | 23篇 |
自动化技术 | 275篇 |
出版年
2023年 | 24篇 |
2022年 | 71篇 |
2021年 | 59篇 |
2020年 | 40篇 |
2019年 | 51篇 |
2018年 | 51篇 |
2017年 | 53篇 |
2016年 | 65篇 |
2015年 | 48篇 |
2014年 | 58篇 |
2013年 | 121篇 |
2012年 | 92篇 |
2011年 | 101篇 |
2010年 | 63篇 |
2009年 | 82篇 |
2008年 | 75篇 |
2007年 | 58篇 |
2006年 | 52篇 |
2005年 | 52篇 |
2004年 | 40篇 |
2003年 | 35篇 |
2002年 | 38篇 |
2001年 | 26篇 |
2000年 | 14篇 |
1999年 | 14篇 |
1998年 | 35篇 |
1997年 | 19篇 |
1996年 | 23篇 |
1995年 | 18篇 |
1994年 | 19篇 |
1993年 | 12篇 |
1992年 | 11篇 |
1989年 | 9篇 |
1988年 | 10篇 |
1987年 | 9篇 |
1984年 | 9篇 |
1982年 | 11篇 |
1981年 | 7篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 12篇 |
1975年 | 9篇 |
1974年 | 11篇 |
1973年 | 6篇 |
1971年 | 10篇 |
1970年 | 11篇 |
1969年 | 6篇 |
1968年 | 7篇 |
1967年 | 6篇 |
1966年 | 15篇 |
排序方式: 共有1744条查询结果,搜索用时 15 毫秒
101.
Mingming Tong Gregory Duggan Jun Liu Yu Xie Mike Dodge Lee Aucott Hongbiao Dong Ruslan L. Davidchack Jon Dantzig Olga Barrera Alan C.F. Cocks Hiroto Kitaguchi Sergio Lozano-Perez Chuangxin Zhao Ian Richardson Anton Kidess Chris R. Kleijn Shuwen Wen Roger Barnett David J. Browne 《JOM Journal of the Minerals, Metals and Materials Society》2013,65(1):99-106
Various physical interfacial phenomena occur during the process of welding and influence the final properties of welded structures. As the features of such interfaces depend on physics that resolve at different spatial scales, a multiscale and multiphysics numerical modeling approach is necessary. In a collaborative research project Modeling of Interface Evolution in Advanced Welding, a novel strategy of model linking is employed in a multiscale, multiphysics computational framework for fusion welding. We only directly link numerical models that are on neighboring spatial scales instead of trying to link all submodels directly together through all available spatial scales. This strategy ensures that the numerical models assist one another via smooth data transfer, avoiding the huge difficulty raised by forcing models to attempt communication over many spatial scales. Experimental activities contribute to the modeling work by providing valuable input parameters and validation data. Representative examples of the results of modeling, linking and characterization are presented. 相似文献
102.
103.
Viktoriya Rumyantceva Valeriya Rumyantceva Yulia Andreeva Sofia Tsvetikova Anton Radaev Maria Vishnevskaya Vladimir Vinogradov Andrey S. Drozdov Elena Koshel 《International journal of molecular sciences》2021,22(12)
Biofilms are the reason for a vast majority of chronic inflammation cases and most acute inflammation. The treatment of biofilms still is a complicated task due to the low efficiency of drug delivery and high resistivity of the involved bacteria to harmful factors. Here we describe a magnetically controlled nanocomposite with a stimuli-responsive release profile based on calcium carbonate and magnetite with an encapsulated antibiotic (ciprofloxacin) that can be used to solve this problem. The material magnetic properties allowed targeted delivery, accumulation, and penetration of the composite in the biofilm, as well as the rapid triggered release of the entrapped antibiotic. Under the influence of an RF magnetic field with a frequency of 210 kHz, the composite underwent a phase transition from vaterite into calcite and promoted the release of ciprofloxacin. The effectiveness of the composite was tested against formed biofilms of E. coli and S. aureus and showed a 71% reduction in E. coli biofilm biomass and an 85% reduction in S. aureus biofilms. The efficiency of the composite with entrapped ciprofloxacin was higher than for the free antibiotic in the same concentration, up to 72%. The developed composite is a promising material for the treatment of biofilm-associated inflammations. 相似文献
104.
Lauryna Sinusaite Anton Popov Eva Raudonyte-Svirbutaviciene Jen-Chang Yang Aivaras Kareiva Aleksej Zarkov 《Ceramics International》2021,47(9):12078-12083
In the present work, effect of Mn doping on hydrolysis rate of low-temperature synthesized metastable α-tricalcium phosphate (α-TCP) was investigated. α-TCP powders containing different amount of Mn2+ ions (0, 0.5 and 1 mol%) were synthesized by wet co-precipitation process, followed by annealing and crystallization of as-precipitated amorphous calcium phosphate at 700 °C. It was demonstrated that the presence of Mn2+ ions significantly retards hydrolysis rate of α-TCP. While pristine α-TCP fully hydrolyzed with a conversion to calcium-deficient hydroxyapatite in 10 h, complete hydrolysis of α-TCP doped with 0.5 and 1 mol% of Mn occurred only after 20 and 35 h, respectively. Initial and final products were characterized by X-ray diffraction (XRD) analysis, infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Chemical composition of starting and fully hydrolyzed α-TCP powders was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). 相似文献
105.
106.
Anton Trník Igor Štubňa Jana Moravčíková 《International Journal of Thermophysics》2009,30(4):1323-1328
The sound velocity of Sedlec kaolin during heating from 20 °C to 1100 °C was investigated by modulated force thermomechanical
analysis (mf-TMA). In the interval from 20 °C to 250 °C, the sound velocity increases which can be explained by liberation
of the water molecules from pores and micropores. Dehydroxylation (450 °C to 650 °C) presents itself with a decrease of the
sound velocity. After dehydroxylation, a two-step increase of the sound velocity was observed. The first step of the increase
of the sound velocity is due to solid-state sintering at low temperatures. The second step starts at 950 °C as a consequence
of the collapse of the metakaolinite structure. After the maximum, a steep increase of the sound velocity follows as a result
of solid-state sintering. 相似文献
107.
Miks A 《Journal of the Optical Society of America. A, Optics, image science, and vision》2002,19(9):1867-1871
New parameters for calculation of third-order aberration coefficients (Seidel aberration coefficients) are introduced. The formulas for Seidel aberration coefficients are linear in these new variables. With these new variables it is possible to calculate the shape and the refractive index of the glass of the individual lenses of the optical system, which was not possible before. 相似文献
108.
The optical constants of thin films of CsI, KI, and KBr and the quantum efficiency (QE) of planar photocathodes made with these alkali halides in the 53.6-174.4-nm spectral range are presented. The optical constants were obtained from measurements of the reflectance as a function of incidence angle. The effect of film heating and exposure to UV irradiation on the optical properties and on the QE of the three alkali halides was investigated. KBr was found to be the most stable material for both heating and UV irradiation. KI appeared to be close to temperature stable, whereas UV exposure affected its optical constants. CsI optical constants changed after 420 K heating and after UV exposure. The changes in the optical constants were related to the QE changes, and a certain correlation between both variations was determined. However, it was also demonstrated that the QE changes cannot be explained solely by the changes in optical constants. 相似文献
109.
Back JW Notenboom V de Koning LJ Muijsers AO Sixma TK de Koster CG de Jong L 《Analytical chemistry》2002,74(17):4417-4422
A new method is presented to screen proteolytic mass maps of cross-linked protein complexes for the presence of cross-linked peptides and for the verification of proposed structures. On the basis of the incorporation of 18O from isotopically enriched water into the C-termini of proteolytic peptides, cross-linked peptides are readily distinguished in mass spectra by a characteristic 8 amu shift. This is due to the incorporation of two 18O atoms in each C-terminus, so that normal and surface-labeled peptides shift 4 amu and cross-linked peptides containing two C-termini will shift 8 amu compared with their unlabeled counterparts. The method is fast, sensitive, and reliable and can be combined with any available cross-linking reagent and a wide range of proteolytic agents. As proof of principle, we successfully applied the method to a complex of two DNA repair proteins (Rad18-Rad6) and identified the interaction domain. 相似文献
110.
Kaspirzhny AV Gogan P Horcholle-Bossavit G Tyc-Dumont S 《Network (Bristol, England)》2002,13(3):357-380
For technical, instrumental and operator-related reasons, three-dimensional reconstructions of neurons obtained from intracellularly stained neuronal pieces scattered in serial sections are blurred by some morphological noise. This noise may strongly invalidate conclusions drawn from models built using the three-dimensional reconstructions and it must be taken into account when retrieving digitized neurons from available databases. We analyse the main generating sources of the noise and its consequences for the 'quality' of the data. We provide tools for detecting and evaluating the noise in any database providing sufficient information is given in the database. We propose a unified format for submitting data and a new neuron viewer/editor to analyse the digitized neurons with our tools. 相似文献