全文获取类型
收费全文 | 397篇 |
免费 | 18篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 86篇 |
金属工艺 | 33篇 |
机械仪表 | 5篇 |
建筑科学 | 10篇 |
能源动力 | 14篇 |
轻工业 | 30篇 |
水利工程 | 6篇 |
无线电 | 11篇 |
一般工业技术 | 104篇 |
冶金工业 | 83篇 |
原子能技术 | 1篇 |
自动化技术 | 30篇 |
出版年
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 4篇 |
2017年 | 9篇 |
2015年 | 9篇 |
2014年 | 5篇 |
2013年 | 12篇 |
2012年 | 9篇 |
2011年 | 29篇 |
2010年 | 24篇 |
2009年 | 25篇 |
2008年 | 22篇 |
2007年 | 17篇 |
2006年 | 18篇 |
2005年 | 7篇 |
2004年 | 11篇 |
2003年 | 19篇 |
2002年 | 9篇 |
2001年 | 6篇 |
2000年 | 10篇 |
1999年 | 7篇 |
1998年 | 18篇 |
1997年 | 17篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 6篇 |
1982年 | 3篇 |
1981年 | 10篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1971年 | 2篇 |
1970年 | 3篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1963年 | 1篇 |
1956年 | 2篇 |
排序方式: 共有415条查询结果,搜索用时 0 毫秒
411.
Ulrich Weber Georg Greuel Ulrich Boettger Sophie Weber Detlev Hennings Rainer Waser 《Journal of the American Ceramic Society》2001,84(4):759-766
The purpose of the present investigation is to describe the influence of the processing parameters on the dielectric behavior of manganese-doped Ba(Ti1− x Zr x )O3 ceramics, particularly variations in the small-signal aging rate, temperature characteristic, and hysteresis. In this paper, the aging behavior of base-metal electrode materials above the temperature of the permittivity maximum ( T M ), including the influence of the zirconium content and annealing conditions, is described for the first time. The aging rate at temperatures greater than T M decreases as the oxygen partial pressure increases during annealing and the zirconium content increases, whereas the aging rate exhibits a maximum at temperatures much less than T M . The behavior is explained in terms of a diffuse phase transition. Hysteresis-loop deformation is observed during aging. 相似文献
412.
Flöhr K Liebmann M Sladek K Günel HY Frielinghaus R Haas F Meyer C Hardtdegen H Schäpers T Grützmacher D Morgenstern M 《The Review of scientific instruments》2011,82(11):113705
InAs nanowires are grown epitaxially by catalyst-free metal organic vapor phase epitaxy and are subsequently positioned with a lateral accuracy of less than 1 μm using simple adhesion forces between the nanowires and an indium tip. The technique, requiring only an optical microscope, is used to place individual nanowires onto the corner of a cleaved-edge wafer as well as across predefined holes in Si(3)N(4) membranes. The precision of the method is limited by the stability of the micromanipulators and the precision of the optical microscope. 相似文献
413.
Gudrun Ratzinger Simone Mitteregger Barbara Wolf Regina Berger Bernhard Zelger Georg Weinlich Peter Fritsch Georg Goebel Heidelinde Fiegl 《International journal of molecular sciences》2014,15(7):11984-11995
In this retrospective pilot study, the DNA-methylation status of genes that have been demonstrated to be involved in melanoma carcinogenesis was analyzed in order to identify novel biomarkers for the risk assessment of melanoma patients. We analyzed DNA extracted from punch-biopsies from 68 formalin-fixed paraffin-embedded (FFPE) melanoma specimens. Using MethyLight PCR, we examined 20 genes in specimens from a training set comprising 36 melanoma patients. Selected candidate genes were validated in a test set using FFPE tissue samples from 32 melanoma patients. First, we identified the TNFRSF10D DNA-methylation status (TNFRSF10D methylated vs. unmethylated) as a prognostic marker for overall (p = 0.001) and for relapse-free survival (p = 0.008) in the training set. This finding was confirmed in the independent test set (n = 32; overall survival p = 0.041; relapse-free survival p = 0.012). In a multivariate Cox-regression analysis including all patients, the TNFRSF10D DNA-methylation status remained as the most significant prognostic parameter for overall and relapse-free survival (relative-risk (RR) of death, 4.6 (95% CI: 2.0–11.0; p < 0.001), RR of relapse, 7.2 (95% CI: 2.8–18.3; p < 0.001)). In this study, we demonstrate that TNFRSF10D DNA-methylation analysis of a small tissue-punch from archival FFPE melanoma tissue is a promising approach to provide prognostic information in patients with melanoma. 相似文献
414.
Spörhase Stefanie Brombach Falk Marian Eckhardt Felix Krause Tim Markus Detlev Küstner Bernd Walch Otto 《Forschung im Ingenieurwesen》2023,87(2):605-616
Forschung im Ingenieurwesen - Der Einsatz von elektrischen Geräten in explosionsgefährdeten Bereichen erfordert besondere Schutzmaßnahmen, um eine Zündung der... 相似文献
415.
Quinones. XIII. Synthesis of 4,5,9,10-Tetrahydropyrene-2,7-dione and Attempted Preparation of Pyrene-2,7-dione The titel quinones 7 and 9 are of interest as electron acceptors for organic conductors. The synthesis of their conjugate hydroquinones 6 and 8 via the metacyclophane derivative 3 is described. The tetrahydropyrene-2,7-dione 7 – obtained by oxidation of 6 – possesses only a limited stability, whereas pyrene-2,7-dion ( 9 ) proved to unstable to be isolated. 相似文献