全文获取类型
收费全文 | 48016篇 |
免费 | 4469篇 |
国内免费 | 2033篇 |
专业分类
电工技术 | 2538篇 |
技术理论 | 2篇 |
综合类 | 2529篇 |
化学工业 | 8543篇 |
金属工艺 | 2767篇 |
机械仪表 | 3208篇 |
建筑科学 | 3083篇 |
矿业工程 | 1302篇 |
能源动力 | 1454篇 |
轻工业 | 3173篇 |
水利工程 | 675篇 |
石油天然气 | 2484篇 |
武器工业 | 338篇 |
无线电 | 6211篇 |
一般工业技术 | 6996篇 |
冶金工业 | 2640篇 |
原子能技术 | 526篇 |
自动化技术 | 6049篇 |
出版年
2024年 | 250篇 |
2023年 | 943篇 |
2022年 | 1607篇 |
2021年 | 2319篇 |
2020年 | 1684篇 |
2019年 | 1579篇 |
2018年 | 1639篇 |
2017年 | 1700篇 |
2016年 | 1616篇 |
2015年 | 2047篇 |
2014年 | 2470篇 |
2013年 | 2992篇 |
2012年 | 3069篇 |
2011年 | 3498篇 |
2010年 | 2732篇 |
2009年 | 2677篇 |
2008年 | 2677篇 |
2007年 | 2366篇 |
2006年 | 2456篇 |
2005年 | 1977篇 |
2004年 | 1429篇 |
2003年 | 1304篇 |
2002年 | 1222篇 |
2001年 | 1065篇 |
2000年 | 1024篇 |
1999年 | 1064篇 |
1998年 | 920篇 |
1997年 | 777篇 |
1996年 | 686篇 |
1995年 | 563篇 |
1994年 | 433篇 |
1993年 | 299篇 |
1992年 | 250篇 |
1991年 | 222篇 |
1990年 | 188篇 |
1989年 | 177篇 |
1988年 | 106篇 |
1987年 | 97篇 |
1986年 | 62篇 |
1985年 | 58篇 |
1984年 | 40篇 |
1983年 | 38篇 |
1982年 | 32篇 |
1981年 | 25篇 |
1980年 | 26篇 |
1979年 | 18篇 |
1978年 | 15篇 |
1976年 | 18篇 |
1975年 | 11篇 |
1973年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
931.
Electrocatalysis: Morphology and Structure Engineering in Nanofiber Reactor: Tubular Hierarchical Integrated Networks Composed of Dual Phase Octahedral CoMn2O4/Carbon Nanofibers for Water Oxidation (Small 26/2017)
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
932.
Dominance of Plasmonic Resonant Energy Transfer over Direct Electron Transfer in Substantially Enhanced Water Oxidation Activity of BiVO4 by Shape‐Controlled Au Nanoparticles
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mi Gyoung Lee Cheon Woo Moon Hoonkee Park Woonbae Sohn Sung Bum Kang Sanghan Lee Kyoung Jin Choi Ho Won Jang 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(37)
The performance of plasmonic Au nanostructure/metal oxide heterointerface shows great promise in enhancing photoactivity, due to its ability to confine light to the small volume inside the semiconductor and modify the interfacial electronic band structure. While the shape control of Au nanoparticles (NPs) is crucial for moderate bandgap semiconductors, because plasmonic resonance by interband excitations overlaps above the absorption edge of semiconductors, its critical role in water splitting is still not fully understood. Here, first, the plasmonic effects of shape‐controlled Au NPs on bismuth vanadate (BiVO4) are studied, and a largely enhanced photoactivity of BiVO4 is reported by introducing the octahedral Au NPs. The octahedral Au NP/BiVO4 achieves 2.4 mA cm?2 at the 1.23 V versus reversible hydrogen electrode, which is the threefold enhancement compared to BiVO4. It is the highest value among the previously reported plasmonic Au NPs/BiVO4. Improved photoactivity is attributed to the localized surface plasmon resonance; direct electron transfer (DET), plasmonic resonant energy transfer (PRET). The PRET can be stressed over DET when considering the moderate bandgap semiconductor. Enhanced water oxidation induced by the shape‐controlled Au NPs is applicable to moderate semiconductors, and shows a systematic study to explore new efficient plasmonic solar water splitting cells. 相似文献
933.
Biomolecular regulatory networks are organised around hubs, which can interact with a large number of targets. These targets compete with each other for access to their common hubs, but whether the effect of this competition would be significant in magnitude and in function is not clear. In this review, the authors discuss recent in vivo studies that analysed the system level retroactive effects induced by target competition in microRNA and mitogen‐activated protein kinase regulatory networks. The results of these studies suggest that downstream targets can regulate the overall state of their upstream regulators, and thus cannot be ignored in analysing biomolecular networks.Inspec keywords: reviews, RNA, molecular biophysics, enzymesOther keywords: target‐mediated reverse signalling, mitogen‐activated protein kinase regulatory networks, biomolecular regulatory networks, microRNA regulatory networks, review, in vivo study 相似文献
934.
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
935.
X Y Long C Jiang X Han W Gao X G Wang M Z Hou 《Fatigue & Fracture of Engineering Materials & Structures》2017,40(1):12-26
This paper proposes a novel analysis method of stochastic crack trajectory based on a dimension reduction approach. The developed method allows efficiently estimating the statistical moments, probability density function and cumulative distribution function of the crack trajectory for cracked elastic structures considering the randomness of the loads, material properties and crack geometries. First, the traditional dimension reduction method is extended to calculate the first four moments of the crack trajectory, in which the responses are eigenvectors rather than scalars. Then the probability density function and cumulative distribution function of the crack trajectory can be obtained using the maximum entropy principle constrained by the calculated moments. Finally, the simulation of the crack propagation paths is realized by using the scaled boundary finite element method. The proposed method is well validated by four numerical examples performed on varied cracked structures. It is demonstrated that this method outperforms the Monte Carlo simulation in terms of computational efficiency, and in the meanwhile, it has an acceptable computational accuracy. 相似文献
936.
In the response analysis of uncertain structural models with limited information, parameterized p-boxes are used to quantify the uncertain variables. In this study, a new technique is developed to compute the probability bounds of the structural response. Monotonicity analysis is performed on probability transformations of the random variables, revealing the relations between the interval distribution parameters and probability bounds of the structural response. Based on the monotonicity analysis, an algorithm for parameterized p-boxes is developed for computing the structural response. Three numerical examples are investigated to demonstrate the effectiveness of the proposed method. 相似文献
937.
938.
939.
940.