全文获取类型
收费全文 | 6699篇 |
免费 | 447篇 |
国内免费 | 18篇 |
专业分类
电工技术 | 128篇 |
综合类 | 9篇 |
化学工业 | 1469篇 |
金属工艺 | 244篇 |
机械仪表 | 409篇 |
建筑科学 | 126篇 |
矿业工程 | 2篇 |
能源动力 | 236篇 |
轻工业 | 627篇 |
水利工程 | 22篇 |
石油天然气 | 6篇 |
无线电 | 1159篇 |
一般工业技术 | 1416篇 |
冶金工业 | 429篇 |
原子能技术 | 75篇 |
自动化技术 | 807篇 |
出版年
2024年 | 8篇 |
2023年 | 86篇 |
2022年 | 124篇 |
2021年 | 219篇 |
2020年 | 153篇 |
2019年 | 178篇 |
2018年 | 219篇 |
2017年 | 219篇 |
2016年 | 248篇 |
2015年 | 226篇 |
2014年 | 321篇 |
2013年 | 439篇 |
2012年 | 449篇 |
2011年 | 529篇 |
2010年 | 348篇 |
2009年 | 395篇 |
2008年 | 350篇 |
2007年 | 264篇 |
2006年 | 279篇 |
2005年 | 226篇 |
2004年 | 211篇 |
2003年 | 183篇 |
2002年 | 178篇 |
2001年 | 146篇 |
2000年 | 123篇 |
1999年 | 132篇 |
1998年 | 210篇 |
1997年 | 139篇 |
1996年 | 83篇 |
1995年 | 84篇 |
1994年 | 67篇 |
1993年 | 60篇 |
1992年 | 45篇 |
1991年 | 38篇 |
1990年 | 31篇 |
1989年 | 23篇 |
1988年 | 11篇 |
1987年 | 17篇 |
1986年 | 16篇 |
1985年 | 12篇 |
1984年 | 15篇 |
1983年 | 10篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 7篇 |
1978年 | 3篇 |
1977年 | 7篇 |
1976年 | 10篇 |
1975年 | 4篇 |
排序方式: 共有7164条查询结果,搜索用时 15 毫秒
111.
Takeo Uchida Keita Abe Yuma Endo Shosei Ichiseki Satoru Akita Shiyun Liu Sho Aradachi Masataka Saito Akihiko Fukuchi Taiyo Kikkawa Theo Dammaretz Ibuki Kawamata Yuki Suzuki Shin‐ichiro M. Nomura Satoshi Murata 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(41)
A new kind of the Vernier mechanism that is able to control the size of linear assembly of DNA origami nanostructures is proposed. The mechanism is realized by mechanical design of DNA origami, which consists of a hollow cylinder and a rotatable shaft in it connected through the same scaffold. This nanostructure stacks with each other by the shape complementarity at its top and bottom surfaces of the cylinder, while the number of stacking is limited by twisting angle of the shaft. Experiments have shown that the size distribution of multimeric assembly of the origami depends on the twisting angle of the shaft; the average lengths of the multimer are decamer, hexamer, and tetramer for 0°, 10°, and 20° twist, respectively. In summary, it is possible to affect the number of polymerization by adjusting the precise shape and movability of a molecular structure. 相似文献
112.
Ji Chan Park Shin Wook Kang Jeong-Chul Kim Jae In Kwon Sanha Jang Geun Bae Rhim Mijong Kim Dong Hyun Chun Ho-Tae Lee Heon Jung Hyunjoon Song Jung-II Yang 《Nano Research》2017,(3):1044-1055
A cobalt-silica hybrid nanocatalyst bearing small cobalt particles of diameter ~5 nm was prepared through a hydrothermal reaction and hydrogen reduction.The resulting material showed very high CO conversion (>82%) and high hydrocarbon productivity (~1.0 gHc·g-1cat,·h-11) with high activity (~8.5 x 10-5 molco·g-1Co·S-1) in the Fischer-Tropsch synthesis reaction. 相似文献
113.
Seung-Jun Shin Duck Bong Kim Senthilkumaran Kumaraguru Sudarsan Rachuri 《国际生产研究杂志》2016,54(15):4487-4505
The ability to predict performance of manufacturing equipment during early stages of process planning is vital for improving efficiency of manufacturing processes. In the metal cutting industry, measurement of machining performance is usually carried out by collecting machine-monitoring data that record the machine tool’s actions (e.g. coordinates of axis location and power consumption). Understanding the impacts of process planning decisions is central to the enhancement of the machining performance. However, current methodologies lack the necessary models and tools to predict impacts of process planning decisions on the machining performance. This paper presents the development of a virtual machining model (called STEP2M model) that generates machine-monitoring data from process planning data. The STEP2M model builds upon a physical model-based analysis for the sources of energy on a machine tool, and adopts STEP-NC and MTConnect standardised interfaces to represent process planning and machine-monitoring data. We have developed a prototype system for 2-axis turning operation and validated the system by conducting an experiment using a Computer Numerical Control lathe. The virtual machining model presented in this paper enables process planners to analyse machining performance through virtual measurement and to perform interoperable data communication through standardised interfaces. 相似文献
114.
115.
Dong-Jun Kwon Jin-Yeong Choi Pyeong-Su Shin K. Lawrence DeVries 《Advanced Composite Materials》2016,25(6):515-524
Dispersion and shape of nanoparticles, as well as interfacial conditions, add significantly to difficulties in composite manufacture. In the work reported here, an innovative method of recycling composites using out-of-date prepreg was investigated in which the carbon nanotube (CNT) on the prepreg was optimally coated. Nanocomposites utilizing the out-of-date prepreg were coated with CNT and fabricated by a sheet molding method. CNT nanofillers were observed to be uniformly dispersed on epoxy prepreg by spray coating. The mechanical and interfacial properties of these CNT coated nanocomposites were improved over those of more conventionally manufactured carbon fiber/epoxy composites. The CNT nanofillers were embedded at the epoxy and fiber interface, as a result of etching of the epoxy prepreg surface by a CNT dispersion solution which enhanced interfacial reactivity. 相似文献
116.
117.
118.
119.
An efficient microfluidic sorter: implementation of double meandering micro striplines for magnetic particles switching 总被引:1,自引:1,他引:0
Tian Fook Kong Huan Shin E Hendrik Santoso Sugiarto Hwi Fen Liew Xinghua Wang Wen Siang Lew Nam-Trung Nguyen Yong Chen 《Microfluidics and nanofluidics》2011,10(5):1069-1078
The ability to trap, manipulate, and separate magnetic beads has become one of the key requirements in realizing an integrated
magnetic lab-on-chip biosensing system. In this article, we present the design and fabrication of an integrated magneto-fluidic
device for sorting magnetic particles with a sorting efficiency of up to 95%. The actuation and manipulation of magnetic beads
are realized using microfabricated square meandering current-carrying micro striplines. The current is alternated between
two neighboring micro striplines to switch the magnetic beads to either one of the two outlets. We performed a series of parametric
study to investigate the effect of applied current, flow rate, and switching frequency on the sorting efficiency. Experimental
results reveal that the sorting efficiency is proportional to the square of current applied to the stripline, and decreases
with increasing buffer flow rate and switching frequency. Such phenomena agree well with our theoretical analysis and simulation
result. The fastest switching rate, which is limited by the microchannel geometry and bead velocity, is 2 Hz. 相似文献
120.