全文获取类型
收费全文 | 1887篇 |
免费 | 134篇 |
国内免费 | 25篇 |
专业分类
电工技术 | 46篇 |
综合类 | 11篇 |
化学工业 | 438篇 |
金属工艺 | 51篇 |
机械仪表 | 58篇 |
建筑科学 | 80篇 |
矿业工程 | 5篇 |
能源动力 | 112篇 |
轻工业 | 245篇 |
水利工程 | 35篇 |
石油天然气 | 57篇 |
武器工业 | 2篇 |
无线电 | 190篇 |
一般工业技术 | 314篇 |
冶金工业 | 112篇 |
原子能技术 | 5篇 |
自动化技术 | 285篇 |
出版年
2023年 | 30篇 |
2022年 | 74篇 |
2021年 | 124篇 |
2020年 | 115篇 |
2019年 | 115篇 |
2018年 | 137篇 |
2017年 | 105篇 |
2016年 | 128篇 |
2015年 | 72篇 |
2014年 | 103篇 |
2013年 | 171篇 |
2012年 | 134篇 |
2011年 | 107篇 |
2010年 | 90篇 |
2009年 | 71篇 |
2008年 | 45篇 |
2007年 | 49篇 |
2006年 | 35篇 |
2005年 | 31篇 |
2004年 | 20篇 |
2003年 | 10篇 |
2002年 | 13篇 |
2001年 | 10篇 |
2000年 | 14篇 |
1999年 | 18篇 |
1998年 | 41篇 |
1997年 | 27篇 |
1996年 | 13篇 |
1995年 | 19篇 |
1994年 | 11篇 |
1993年 | 11篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 14篇 |
1988年 | 10篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1973年 | 4篇 |
1972年 | 2篇 |
排序方式: 共有2046条查询结果,搜索用时 171 毫秒
21.
Mohammed A. Amin 《Journal of Applied Electrochemistry》2006,36(2):215-226
This work reports results of weight loss, potentiodynamic polarization and impedance measurements on the corrosion inhibition
of copper in aerated non-stirred 3% NaCl solutions in the temperature range 15–65 °C using sodium oleate (SO) as an anionic
surfactant inhibitor. These studies have shown that SO is a very good ”green”, mixed-type inhibitor. The inhibition process
was attributed to the formation of an adsorbed film on the metal surface that protects the metal against corrosive agents.
Scanning electron microscopy (SEM) and energy dispersion X-ray (EDX) observations of the electrode surface confirmed the existence
of such an adsorbed film. The inhibition efficiency increases with increasing surfactant concentration and time of immersion,
while it decreases with solution temperature. Maximum inhibition efficiency of the surfactant is observed at concentrations
around its critical micellar concentration (CMC). The potential of zero charge (pzc) of copper was studied by ac impedance,
and the mechanism of adsorption is discussed. The sigmoidal shape of the adsorption isotherm confirms the applicability of
Frumkin’s equation to describe the adsorption process. Thermodynamic functions for the adsorption process were determined. 相似文献
22.
Behzad Biglarbegian Mohammad‐Reza Nezhad‐Ahmadi Amin Enayati Guy A. E. Vandenbosch Walter De Raedt Safieddin Safavi‐Naeini 《国际射频与微波计算机辅助工程杂志》2014,24(2):155-160
A new millimeter‐wave antenna structure on a low‐cost, production platform integrated passive device technology is presented. The antenna consists of a 2‐by‐1 array of slot antennas at 60 GHz. An in‐house developed on‐chip antenna measurement setup was used to characterize the fabricated antenna. The measurement results show an antenna gain of more than 5 dBi with a return loss of 18 dB at 60 GHz. The better‐than‐10‐dB impedance bandwidth of the antenna covers the 60‐GHz unlicensed band from 57 to 64 GHz. The 3‐dB beamwidths of the antenna are 105° and 76° at E‐plane and H‐plane at 60 GHz, respectively. The size of the die of the antenna is 2 mm × 4.5 mm. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:155–160, 2014. 相似文献
23.
Jeremy Gustin Brian Freeman James Stone Mohammad Mahinfalah Amin Salehi‐Khojin 《应用聚合物科学杂志》2005,96(6):2309-2315
Nanocomposites are more widely studied today because of higher stiffness, decreased permeability, thermal stability, and many other properties superior to those of regular polymers. However, manufacturers are concerned about implementing nanocomposites because of their lower impact properties with respect to the base polymer. This study focused on low‐velocity impact tests of a thermoplastic olefin by itself and with 5 wt % nanoclay. The impact tests were conducted at ?40, 23.9, and 65.6°C until the polymer and nanocomposite plates experienced complete striker penetration. The force–time and force–deflection responses obtained from the impact testing provided a means of comparing the impact performances of the two materials. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2309–2315, 2005 相似文献
24.
Muhammad Asfand-e-yar Amin Anjomsho Edgar R. Weippl A Min Tjoa 《International Journal of Software and Informatics》2010,4(1):89-100
Software end-users need to sign licenses to seal an agreement with the product
providers. Habitually, users agree with the license (i.e. terms and conditions) without fully
understanding the agreement. To address this issue, an ontological model is developed to
formulate the user requirements and license agreements formally. This paper, introduces
ontological model that includes the abstract license ontology of common features found in
di?erent license agreements. The abstract license ontology is then extended to a few real
world license agreements. The resulting model can be used for di?erent purposes such as
querying the appropriate licenses for a speciˉc requirement or checking the license terms and
conditions with user requirements. 相似文献
25.
Khaksar Pour Amin Chaw Seng Woo Palaiahnakote Shivakumara Tahaei Hamid Anuar Nor Badrul 《Multimedia Tools and Applications》2021,80(16):24121-24145
Multimedia Tools and Applications - Rating a video based on its content is one of the most important solutions to classify videos for audience age groups. In this regard, Film content rating and TV... 相似文献
26.
Mohammad-Ali Saeimi-Sadigh Amin Paykani Amir Afkar Dehghan Aminollah 《中南工业大学学报(英文版)》2014,(4):1307-1312
V-shape hulls are widely used in peacekeeping efforts such as demining vehicles in order to deflect the blast energy and reduce the effects of mine blast. Blast resistant design and energy absorption enhancement of V-shape plates were carried out using finite element analysis package ABAQUS. Various geometries of V-shape plates with and without interlayer of materials like Al-foams and honeycomb were employed to analyze their effects on the deformation of the plate and applied stresses and strains. The results obtained show that application of metallic foams leads to better response of the plate and consequently results in more energy dissipation, less dame to vehicle and enhances crew survivability. 相似文献
27.
28.
Majid Alizadeh Moghadam Reza Mohammadi Ehsan Sadeghi Mohammad Amin Mohammadifar Mohammad Nejatian Maryam Fallah Milad Rouhi 《应用聚合物科学杂志》2021,138(28):50672
The effects of gum tragacanth obtained from two species of Astragalus Gossypinus (GT-G) and A. Parrowianus (GT-P) at two levels of 10% and 30% combined with cellulose nanofibers (CNF; 5%) on the physico-mechanical and structural properties of polyvinyl alcohol (PVA) nanocomposite film were investigated in this study. The water solubility and water vapor permeability of the films decreased with increasing the content of both gums, especially in the film containing 30% GT-P. The highest values of the tensile strength (39.3 MPa) and elongation at break (445%) belonged to the treatment containing 10% GT-P (90/10P/0). The FTIR and DSC analyses confirmed good interactions between GT and PVA in the 90/10P/0 treatment. SEM images indicated the dense structure of this film as the optimum treatment. Although the presence of CNF in the films containing GT-G improved some properties, especially the Young modulus, it impaired all the functional properties of nanocomposite GT-P film. 相似文献
29.
30.
Mohammad H. S. Amin Neil G. Dickson Peter Smith 《Quantum Information Processing》2013,12(4):1819-1829
Most realistic solid state devices considered as qubits are not true two-state systems. If the energy separation of the upper energy levels from the lowest two levels is not large, then these upper states may affect the evolution of the ground state over time and therefore cannot be neglected. In this work, we study the effect of energy levels beyond the lowest two energy levels on adiabatic quantum optimization in a device with a double-well potential as the basic logical element. We show that the extra levels can be modeled by adding additional ancilla qubits coupled to the original logical qubits, and that the presence of upper levels has no effect on the final ground state. We also study the influence of upper energy levels on the minimum gap for a set of 8-qubit spin glass instances. 相似文献