全文获取类型
收费全文 | 28029篇 |
免费 | 655篇 |
国内免费 | 37篇 |
专业分类
电工技术 | 205篇 |
综合类 | 30篇 |
化学工业 | 6679篇 |
金属工艺 | 522篇 |
机械仪表 | 516篇 |
建筑科学 | 973篇 |
矿业工程 | 61篇 |
能源动力 | 1175篇 |
轻工业 | 5090篇 |
水利工程 | 233篇 |
石油天然气 | 141篇 |
武器工业 | 4篇 |
无线电 | 1246篇 |
一般工业技术 | 3775篇 |
冶金工业 | 4068篇 |
原子能技术 | 218篇 |
自动化技术 | 3785篇 |
出版年
2024年 | 181篇 |
2023年 | 292篇 |
2022年 | 715篇 |
2021年 | 957篇 |
2020年 | 654篇 |
2019年 | 734篇 |
2018年 | 823篇 |
2017年 | 821篇 |
2016年 | 923篇 |
2015年 | 749篇 |
2014年 | 1040篇 |
2013年 | 1935篇 |
2012年 | 1490篇 |
2011年 | 1868篇 |
2010年 | 1430篇 |
2009年 | 1434篇 |
2008年 | 1237篇 |
2007年 | 1097篇 |
2006年 | 881篇 |
2005年 | 749篇 |
2004年 | 692篇 |
2003年 | 623篇 |
2002年 | 562篇 |
2001年 | 390篇 |
2000年 | 382篇 |
1999年 | 412篇 |
1998年 | 1429篇 |
1997年 | 916篇 |
1996年 | 675篇 |
1995年 | 370篇 |
1994年 | 325篇 |
1993年 | 324篇 |
1992年 | 124篇 |
1991年 | 120篇 |
1990年 | 85篇 |
1989年 | 114篇 |
1988年 | 92篇 |
1987年 | 84篇 |
1986年 | 67篇 |
1985年 | 105篇 |
1984年 | 66篇 |
1983年 | 52篇 |
1982年 | 55篇 |
1981年 | 59篇 |
1980年 | 58篇 |
1979年 | 36篇 |
1977年 | 97篇 |
1976年 | 186篇 |
1975年 | 31篇 |
1973年 | 30篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
R. Chaiyont C. Badoe C. Ponce de León J. L. Nava F. J. Recio I. Sirés P. Herrasti F. C. Walsh 《化学工程与技术》2013,36(1):123-129
A film of iridium and tin dioxides doped with antimony oxide (IrO2‐SnO2‐Sb2O5) was deposited onto Ti mesh and plate substrates by the Pechini method. The electrode surface morphology and composition were characterized by SEM‐EDS. The ternary oxide coating was used for the anodic oxidation of methyl orange (MO) azo dye. Linear sweep voltammetry was used to identify the electrode potentials that favour MO degradation. Batch electrolyses were then carried out at a constant electrode potential of 1.5, 1.75 and 2.0 V vs. SHE using either a three‐electrode batch cell or a flow reactor. The dye solutions were totally decolorized via reactive oxygen species, such as ?OH, H2O2 and O3 formed in situ from water oxidation at the Ti/IrO2‐SnO2‐Sb2O5 surface. 相似文献
103.
104.
105.
106.
CIE Division 1 entrusted TC 1–74 to investigate the possibility to develop a smooth curve version of the D illuminants. This article investigates the possibility to create such smoothed curves with minimal colorimetric error. Six different smoothing algorithms were investigated; the best method, using a locally weighted regression and smoothing algorithm, enabled a smooth function, where the worst colour difference for a 100 000 sample set was less than ΔEab* = 0.5, comparing calculations using the CIE standard daylight spectrum and the smoothed function. Thus, the smoothed function can be recommended for redefining the daylight spectra for colorimetry without loosing continuity to results using the current calculation tables and for designing daylight simulator spectra. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 316–321, 2013 相似文献
107.
108.
This paper deals with fault detection and identification in dynamic systems when the system dynamics can be modeled by smooth nonlinear differential equations including affine, bilinear or linear parameter varying (LPV) systems. Two basic approaches will be considered, these apply differential algebraic and differential geometric tools.In the differential algebraic approach the state elimination methods will be used to derive nonlinear parity relations. In the specific case when a reconstruction of the fault signal is needed the dynamic inversion based approach will be investigated. This approach will also be studied from geometric point of view. The geometric approach, as proposed by Isidori and De Persis, is suitable to extend the detection filter and unknown input observer design approaches (well elaborated for LTI systems) to affine nonlinear systems.Beyond the development of the theory of fault detection and identification it is equally important to offer computable methods and to analyze the robustness properties against uncertainties. Both the observer based and the inversion based approaches will be elaborated for LPV systems that may offer computational tools inherited from linear systems and also allow to design for robustness utilizing results from robust filtering and disturbance attenuation. 相似文献
109.
110.