全文获取类型
收费全文 | 2857篇 |
免费 | 529篇 |
国内免费 | 236篇 |
专业分类
电工技术 | 226篇 |
技术理论 | 2篇 |
综合类 | 101篇 |
化学工业 | 230篇 |
金属工艺 | 108篇 |
机械仪表 | 127篇 |
建筑科学 | 79篇 |
矿业工程 | 22篇 |
能源动力 | 168篇 |
轻工业 | 988篇 |
水利工程 | 42篇 |
石油天然气 | 39篇 |
武器工业 | 2篇 |
无线电 | 211篇 |
一般工业技术 | 381篇 |
冶金工业 | 30篇 |
原子能技术 | 7篇 |
自动化技术 | 859篇 |
出版年
2024年 | 32篇 |
2023年 | 131篇 |
2022年 | 272篇 |
2021年 | 290篇 |
2020年 | 274篇 |
2019年 | 250篇 |
2018年 | 221篇 |
2017年 | 191篇 |
2016年 | 185篇 |
2015年 | 191篇 |
2014年 | 282篇 |
2013年 | 242篇 |
2012年 | 389篇 |
2011年 | 230篇 |
2010年 | 132篇 |
2009年 | 57篇 |
2008年 | 12篇 |
2007年 | 17篇 |
2006年 | 21篇 |
2005年 | 23篇 |
2004年 | 9篇 |
2003年 | 16篇 |
2002年 | 20篇 |
2001年 | 19篇 |
2000年 | 7篇 |
1999年 | 10篇 |
1998年 | 7篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 7篇 |
1987年 | 16篇 |
1986年 | 16篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1951年 | 1篇 |
排序方式: 共有3622条查询结果,搜索用时 0 毫秒
1.
《Sensors and actuators. B, Chemical》2006,113(1):106-111
A stable film made from hydroxyethylcellulose (HEC) on pyrolytic graphite (PG) electrode was employed for incorporating hemoglobin (Hb), myoglobin (Mb) and horseradish peroxidase (HRP), and the electrochemical characteristics of the proteins were studied correspondingly. Experimental results revealed that HEC film could greatly accelerate electron transfer between the proteins and electrode, and the proteins showed a thin layer electrochemical behavior in the film. Moreover, all the proteins in the film exhibited good catalytic activity towards the reduction of hydrogen peroxide (H2O2) in the low H2O2 concentration range. In the high concentration range, H2O2 would exhibit toxicity effect on the proteins. The electrochemical properties and electrocatalytic abilities of the three heme proteins in HEC film have been compared, and the optimal conditions for H2O2 biosensor fabrication have been obtained. 相似文献
2.
《Fuel》2006,85(10-11):1509-1517
FT-IR/Raman spectroscopies have been used to identify the structural features of Victorian brown coal chars during the gasification in air at 400 °C. The deconvolution of the Raman spectra has allowed us to identify the main structural sites in char where preferential reaction with O2 takes place. The presence of Na and Ca catalysts is shown to alter the reaction pathways between char and O2. In the absence of a catalyst, the O-containing functional groups formed in char during gasification were closely associated with the aromatic structure and thus tended to loosen the aromatic structure. The non-catalysed gasification was slow and took place on some specific (especially sp3-rich or sp2–sp3 mixture) sites distributed throughout the char. In the presence of a catalyst (Na or Ca), the O-containing functional groups were not closely associated with the main aromatic structure throughout the char. The catalytic gasification reactions were localised on the sites associated with the catalysts. The preferential removal of smaller aromatic ring systems and the persistence of cross-linking structures in the presence of a catalyst mean that the large aromatic ring systems were increasingly concentrated with little flexibility, affecting the dispersion of catalyst. 相似文献
3.
4.
Mobile Networks and Applications - 相似文献
5.
Jeremiah D. Still Veronica J. Dark 《International journal of human-computer studies》2010,68(9):561-571
Although there is a debate about whether designers should draw a distinction between perceptual affordances and cultural conventions, there are few behavioral studies. We examined the impact of working memory load and expected button-to-action mapping congruency on affordances and conventions. The findings suggest both sides of the debate are correct. Learned conventions were found to structure responses towards expected actions, just like affordances, but affordance-based interactions were not affected by memory load while convention-based actions were. Therefore, designers ought to employ perceptual affordances when possible and when not feasible they ought to reuse established conventions. Additionally, evidence is presented that violating expected affordance-based and convention-based button-to-action mappings caused a similar performance cost. We believe that after the initial learning period, conventions play a critical role in the perception of a design’s available actions just as perceptual affordances do. 相似文献
6.
7.
介绍了云计算与物联网的主要技术特点,阐述了两种技术在供应链管理中的应用,最后指出了应用该技术需要注意的问题及实现技术带来的价值。 相似文献
8.
《Engineering Analysis with Boundary Elements》2005,29(7):713-724
This paper presents the application of a Trefftz type method for partial differential equations (PDEs) of the elliptic type with inhomogeneous term given by a set of scattered data. The method of particular solutions is used. Basis functions of a new type were introduced to approximate the scattered data. Using these basis functions, we get the approximation in the form of series over some orthogonal system of eigenfunctions. The particular case of the trigonometric eigenfunctions is considered. The corresponding approximation of the inhomogeneous term allows to get a particular solution for PDEs with constant coefficients or for the systems of such PDEs easily. We test our basis functions on recovering well-known Franke's and PEAKS functions given by scattered data. We also present results of solution Helnholtz PDE, PDE with differential operator of 4th order and system of PDEs arising in shell deflection problems. A comparison of the numerical solutions with analytic solutions is performed for all the problems. 相似文献
9.
10.
针对真实环境中由于复杂背景和物体遮挡、角度变换、行人姿态变化带来的行人重识别(person re-identification,person re-ID) 问题,设计了基于通道注意力(efficient channel attention,ECA) 机制和多尺度卷积(poly-scale convolution,PSConv) 的行人重识别模型。首先利用残差网络提取全局特征,在网络末端加入基于ECA机制及PSConv的特征融合模块,将全局特征和该模块提取的全局特征进行融合,之后将新的全局特征进行分割得到局部特征,最后将新的全局特征和分割得到的局部特征融合得到最终特征,并计算损失函数。模型在Market1501和DukeMTMC-reID 数据集上进行实验验证。在Market1501数据集中,Rank-1和平均精度均值分别达到94.3%和85.2%,在DukeMTMC-reID数据集中,上述两参数分别达到86.3%和75.4%。实验结果可知,该模型可应对实际环境中的复杂情况,增强行人特征的辨别力,有效提高行人重识别的准确率和精度。 相似文献