全文获取类型
收费全文 | 344902篇 |
免费 | 6156篇 |
国内免费 | 2418篇 |
专业分类
电工技术 | 7816篇 |
技术理论 | 6篇 |
综合类 | 2298篇 |
化学工业 | 53124篇 |
金属工艺 | 18228篇 |
机械仪表 | 14036篇 |
建筑科学 | 9012篇 |
矿业工程 | 2907篇 |
能源动力 | 6665篇 |
轻工业 | 27681篇 |
水利工程 | 4159篇 |
石油天然气 | 8324篇 |
武器工业 | 369篇 |
无线电 | 35838篇 |
一般工业技术 | 69174篇 |
冶金工业 | 53379篇 |
原子能技术 | 6744篇 |
自动化技术 | 33716篇 |
出版年
2021年 | 3139篇 |
2020年 | 2181篇 |
2019年 | 2502篇 |
2018年 | 11968篇 |
2017年 | 12501篇 |
2016年 | 8628篇 |
2015年 | 3887篇 |
2014年 | 5363篇 |
2013年 | 12252篇 |
2012年 | 11101篇 |
2011年 | 19049篇 |
2010年 | 16505篇 |
2009年 | 15856篇 |
2008年 | 16447篇 |
2007年 | 18424篇 |
2006年 | 9292篇 |
2005年 | 11485篇 |
2004年 | 9006篇 |
2003年 | 8240篇 |
2002年 | 7323篇 |
2001年 | 6807篇 |
2000年 | 6390篇 |
1999年 | 6283篇 |
1998年 | 13171篇 |
1997年 | 9790篇 |
1996年 | 7522篇 |
1995年 | 5745篇 |
1994年 | 5260篇 |
1993年 | 5068篇 |
1992年 | 4055篇 |
1991年 | 3838篇 |
1990年 | 3880篇 |
1989年 | 3819篇 |
1988年 | 3574篇 |
1987年 | 3043篇 |
1986年 | 3062篇 |
1985年 | 3423篇 |
1984年 | 3341篇 |
1983年 | 3076篇 |
1982年 | 2714篇 |
1981年 | 2908篇 |
1980年 | 2651篇 |
1979年 | 2843篇 |
1978年 | 2736篇 |
1977年 | 2843篇 |
1976年 | 3694篇 |
1975年 | 2458篇 |
1974年 | 2290篇 |
1973年 | 2321篇 |
1972年 | 1981篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
The Raman spectrum of water adsorbed on a metallic silver surface reveals an anomalously large shift of the vibrational frequency as compared to that in the bulk. The results are compared to data reported by other researchers, and possible interpretations of the observed phenomenon are discussed. 相似文献
122.
S. A. Pul’nev A. I. Pryadko A. V. Chikiryaka V. I. Nikolaev 《Technical Physics Letters》2018,44(11):992-994
The behavior of a superelastic Cu?14.2% Al?4%Ni single crystal in the case of high reversible strains under a longitudinal bending force was investigated. The effect of strain confinement along the crystal length was revealed and studied. The highest reversible strains (up to 10%) were shown to be confined within the central part of the bent crystal. 相似文献
123.
David L. Wood Jeffrey D. Quass Jianlin Li Shabbir Ahmed David Ventola Claus Daniel 《Drying Technology》2018,36(2):234-244
Processing lithium-ion battery (LIB) electrode dispersions with water as the solvent during primary drying offers many advantages over N-methylpyrrolidone (NMP). An in-depth analysis of the comparative drying costs of LIB electrodes is discussed for both NMP- and water-based dispersion processing in terms of battery pack $/kWh. Electrode coating manufacturing and capital equipment cost savings are compared for water vs. conventional NMP organic solvent processing. A major finding of this work is that the total electrode manufacturing costs, whether water- or NMP-based, contribute about 8–9% of the total pack cost. However, it was found that up to a 2?×?reduction in electrode processing (drying and solvent recovery) cost can be expected along with a $3–6?M savings in associated plant capital equipment (for a plant producing 100,000 10-kWh Plug-in Hybrid Electric Vehicle (PHEV) batteries) using water as the electrode solvent. This paper shows a different perspective in that the most important benefits of aqueous electrode processing actually revolve around capital equipment savings and environmental stewardship and not processing cost savings. 相似文献
124.
X-ray diffraction analysis has been used to study the structure of the α-Zr matrix phase and the precipitation of β-Nb particles upon the annealing of a Zr–2.5% Nb deformed alloy. It has been found that the process of the precipitation of the strengthening β-Nb particles in the alloy is accompanied by the appearance of fields of elastic interphase deformations in the matrix α phase of the alloy due to the difference in the specific atomic volumes of the crystal structures of the matrix and precipitated phases. It has been shown experimentally that, as a result of the presence of interphase deformations in the alloy, the bcc crystal structure of the precipitating β-Nb particles undergoes monoclinic distortions. 相似文献
125.
126.
The cracks in the workpiece specimens can reduce the fatigue life of any machine components. Since the residual stress has a considerable amount of influence on determining crack formation over the machined surface, it is very essential to analyze the residual stress developed in any machining process. However, it is a very tedious process to compute the residual stress over the machined surface. In the present study, an endeavor has been made to measure and analyze the residual stress of machined silicon steel as a workpiece using the EDM process with different energy distribution. The nano-indentation method was used to compute the residual stress produced over the machined surface. From the experimental results, it was found that the uniform energy distribution has produced higher compressive residual stress owing to the tiny and uniform spark energy distribution. It has also been observed that the tool electrode has a considerable amount of influence on determining development of residual stress in the EDM process. 相似文献
127.
128.
Application of high‐temperature Fenton oxidation for the treatment of sulfonation plant wastewater
下载免费PDF全文
![点击此处可从《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
129.
Crespo Juan-José Sánchez José L. Alfaro-Cortés Francisco J. Flich José Duato José 《The Journal of supercomputing》2021,77(11):12826-12856
The Journal of Supercomputing - Deadlock-free dynamic network reconfiguration process is usually studied from the routing algorithm restrictions and resource reservation perspective. The dynamic... 相似文献
130.