全文获取类型
收费全文 | 2938篇 |
免费 | 23篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 42篇 |
综合类 | 8篇 |
化学工业 | 562篇 |
金属工艺 | 162篇 |
机械仪表 | 70篇 |
建筑科学 | 149篇 |
矿业工程 | 10篇 |
能源动力 | 101篇 |
轻工业 | 232篇 |
水利工程 | 26篇 |
石油天然气 | 68篇 |
武器工业 | 1篇 |
无线电 | 266篇 |
一般工业技术 | 693篇 |
冶金工业 | 204篇 |
原子能技术 | 88篇 |
自动化技术 | 287篇 |
出版年
2021年 | 33篇 |
2020年 | 23篇 |
2019年 | 23篇 |
2018年 | 70篇 |
2017年 | 56篇 |
2016年 | 70篇 |
2015年 | 50篇 |
2014年 | 62篇 |
2013年 | 116篇 |
2012年 | 108篇 |
2011年 | 166篇 |
2010年 | 138篇 |
2009年 | 135篇 |
2008年 | 96篇 |
2007年 | 111篇 |
2006年 | 113篇 |
2005年 | 69篇 |
2004年 | 66篇 |
2003年 | 89篇 |
2002年 | 85篇 |
2001年 | 93篇 |
2000年 | 63篇 |
1999年 | 51篇 |
1998年 | 90篇 |
1997年 | 88篇 |
1996年 | 60篇 |
1995年 | 49篇 |
1994年 | 49篇 |
1993年 | 54篇 |
1992年 | 40篇 |
1991年 | 42篇 |
1990年 | 30篇 |
1989年 | 35篇 |
1988年 | 34篇 |
1987年 | 39篇 |
1986年 | 44篇 |
1985年 | 33篇 |
1984年 | 36篇 |
1983年 | 17篇 |
1982年 | 19篇 |
1981年 | 26篇 |
1980年 | 15篇 |
1979年 | 21篇 |
1978年 | 14篇 |
1977年 | 21篇 |
1976年 | 31篇 |
1975年 | 15篇 |
1974年 | 18篇 |
1973年 | 16篇 |
1971年 | 13篇 |
排序方式: 共有2969条查询结果,搜索用时 0 毫秒
1.
Nomograms are given for claculating the dielectric constant and dielectric loss of polar liquids by measuring the standing
wave ratio for an infinitely thick layer of fluid and the layer thickness at which wave reflection is minimum.
Translated from Izmeritel'naya Tekhnika, No. 2, pp. 46–47, February, 1996. 相似文献
2.
Der elektrische Antriebsstrang in Nahverkehrsystemen 总被引:1,自引:1,他引:0
Ch. Vana 《e & i Elektrotechnik und Informationstechnik》2006,123(10):419-423
3.
Ohne Zusammenfassung 相似文献
4.
5.
6.
Current efficiency losses in indirect electrochemical processing 总被引:3,自引:0,他引:3
7.
Ch. Vasavi G. Suresh Kumar M. S. N. Murty 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2016,20(3):1093-1104
This paper deals with the fuzzy set-valued functions of real variables on time scale whose values are normal, convex, upper semicontinuous and compactly supported fuzzy sets in \(\mathbb {R}^{n}\). We introduce and study the fundamental properties of new class of derivative called generalized delta derivative (\(\Delta _{g}\)-derivative) and generalized delta integral (\(\Delta _{g}\)-integral) for such fuzzy functions. 相似文献
8.
I. Maggio-Aprile Ch. Renner A. Erb E. Walker Ø. Fischer 《Journal of Low Temperature Physics》1996,105(5-6):1129-1134
Scanning Tunneling Spectroscopy (STS) measurements have been carried out on the high Tc superconductor (HTS) YBa2Cu3O7– (YBCO). Using very high quality single crystals as well as hard tips, we obtained differential conductance spectra which showed various conductance features in agreement with other spectroscopic techniques. The reproducibility of our spectra allowed us to map for the first time the vortex lattice on a HTS using a STS technique1. The vortices are arranged in a short range order oblique lattice, while the cores of the flux lines show an anisotropic shape. These observations can be related to the in-plane anisotropy of YBCO. 相似文献
9.
L. E. Evseeva V. Ch. Kruplevich A. I. Lesnikovich G. V. Printsev V. R. Sobol' S. A. Tanaeva 《Journal of Engineering Physics and Thermophysics》1991,61(3):1113-1116
Measurements have been made on the thermal conductivity and specific heat of the powder product from quenching in nitrogen applied to the gas-liquid flame formed by the combustion of a tetrazole-sodium tetrazolate mixture in weight proportion 31. The thermal conductivity on the whole is a nonmonotone function of temperature in the range 100–450 K and has some local turning points associated with the multicomponent structure and the phase transitions associated with chemical and structural transformations.Translated from Inzhenrno-fizicheskii Zhurnal, Vol. 61, No. 3, pp. 422–426, September, 1991. 相似文献
10.
Bovine immunoglobulins (IgG1 type) have been isolated from colostral whey. Hydrolysis by pronase, trypsin and (or) chymotrypsin yield several glycopeptides structural studies of which lead to the following results. 1. IgG1 colostral immunoglobulins possess two glycan moieties which are linked to the peptidic chain by an N-(beta-aspartyl)-N-acetylglucosaminylamine bound. 2. The peptidic sequence around the linkage region has been determined by classical methods and is as follows: Thr-Lys-Pro-Arg-Glu-Glu-Gln-Phe-Asn(Glycan)-Ser-Thr-Tyr-Arg. 3. The following procedures: partial acidic hydrolysis, periodic oxidation, hydrazinolysis-nitrous deamination, methylation and use of specific glycosidases allowed us to determine the structure of the glycan moieties which fit with the general following scheme: (see article) Thus they could be related to the general glycan structure so-called of "N-acetyllactosamine type" because they possess the pentasaccharidic core common to numerous glycoproteins Man alpha 1 leads to [Man alpha 1 leads to 6] Man beta 1 leads to 4 GlcNAc beta 1 leads to 4 GlcNAc beta 1 leads to Asn on which are conjugated 2 N-acetyllactosamine residues. Besides they present a microheterogeneity which is due to the varying number of additional N-acetylneuraminic acid and fucose residues. 4. These structures are compared to various immunoglobulin structures proposed by others: bovine serum IgG and human serum IgG, IgE and IgA. 相似文献