全文获取类型
收费全文 | 545篇 |
免费 | 12篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 67篇 |
金属工艺 | 6篇 |
机械仪表 | 5篇 |
建筑科学 | 34篇 |
矿业工程 | 1篇 |
能源动力 | 5篇 |
轻工业 | 166篇 |
水利工程 | 9篇 |
无线电 | 37篇 |
一般工业技术 | 89篇 |
冶金工业 | 98篇 |
原子能技术 | 6篇 |
自动化技术 | 27篇 |
出版年
2021年 | 8篇 |
2019年 | 8篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 5篇 |
2014年 | 6篇 |
2013年 | 15篇 |
2012年 | 7篇 |
2011年 | 20篇 |
2010年 | 10篇 |
2009年 | 13篇 |
2008年 | 19篇 |
2007年 | 24篇 |
2006年 | 16篇 |
2005年 | 11篇 |
2004年 | 21篇 |
2003年 | 8篇 |
2002年 | 8篇 |
2001年 | 15篇 |
2000年 | 8篇 |
1999年 | 15篇 |
1998年 | 32篇 |
1997年 | 19篇 |
1996年 | 12篇 |
1995年 | 10篇 |
1993年 | 6篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1985年 | 7篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 8篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1977年 | 9篇 |
1976年 | 11篇 |
1975年 | 6篇 |
1970年 | 4篇 |
1967年 | 4篇 |
1966年 | 7篇 |
1965年 | 4篇 |
1964年 | 7篇 |
1963年 | 10篇 |
1961年 | 4篇 |
1960年 | 4篇 |
1959年 | 6篇 |
1943年 | 11篇 |
1942年 | 11篇 |
1941年 | 7篇 |
排序方式: 共有557条查询结果,搜索用时 906 毫秒
1.
LE Lindner 《Canadian Metallurgical Quarterly》1993,41(3):439-445
The silver-staining technique for nucleolar organizer regions (AgNOR) of Ploton et al., as popularized by Crocker, is being widely used for evaluation of nucleolar function, especially in neoplasia. It suffers from limited reliability, background staining, precipitates, and fading of the sections. Factors were identified that affect these problems. The oxidation-reduction level and gelatin used are particularly important. An improved procedure is presented which incorporates pre-reduction of the sections, selection of an optimal gelatin, and post-treatment of the sections to produce a permanent preparation. It is compatible with many fixatives and with other stains used before or after the silver stain. 相似文献
2.
R. Breil T. Fries J. Garnaes J. Haycocks D. Hüser J. Joergensen W. Kautek L. Koenders N. Kofod K. R. Koops R. Korntner B. Lindner W. Mirand A. Neubauer J. Peltonen G. B. Picotto M. Pisani H. Rothe M. Sahre M. Stedman G. Wilkening 《Precision Engineering》2002,26(3)
Comparison measurements on reference standards are reported in which 13 partners with different instruments took part. A set of prototype standards which had been produced and calibrated within a European project were used for the measurements. Here, results of measurements on a 240 nm step height standard and a two-dimensional lateral standard with a nominal pitch of 1 μm are reported. 相似文献
3.
4.
5.
6.
Insights into the assessment of myocardial perfusion offered by different cardiac imaging modalities
Myocardial perfusion may be very broadly defined as the tightly regulated nutrient delivery to cardiac tissue. The different components of perfusion are myocardial blood flow, oxygen delivery, myocardial oxygen consumption, and myocardial blood volume. Historically, focus has been placed mostly on the assessment of blood flow. In many instances, knowledge of flow without information about these other aspects is inadequate. This review discusses the various cardiac imaging techniques used for the assessment of myocardial perfusion that represent diverse physiologic measures of "perfusion." Their strengths and limitations are discussed as is their relevance to specific clinicopathologic conditions. Significant work still needs to be performed before all the aspects of myocardial perfusion can be precisely measured in human beings. 相似文献
7.
Qi Jia Xin Ou Manuel Langer Benjamin Schreiber Jörg Grenzer Pablo F. Siles Raul D. Rodriguez Kai Huang Ye Yuan Alireza Heidarian René Hübner Tiangui You Wenjie Yu Kilian Lenz Jürgen Lindner Xi Wang Stefan Facsko 《Nano Research》2018,11(7):3519-3528
A nanofabrication method for the production of ultra-dense planar metallic nanowire arrays scalable to wafer-size is presented. The method is based on an efficient template deposition process to grow diverse metallic nanowire arrays with extreme regularity in only two steps. First, III–V semiconductor substrates are irradiated by a low-energy ion beam at an elevated temperature, forming a highly ordered nanogroove pattern by a “reverse epitaxy” process due to self-assembly of surface vacancies. Second, diverse metallic nanowire arrays (Au, Fe, Ni, Co, FeAl alloy) are fabricated on these III–V templates by deposition at a glancing incidence angle. This method allows for the fabrication of metallic nanowire arrays with periodicities down to 45 nm scaled up to wafer-size fabrication. As typical noble and magnetic metals, the Au and Fe nanowire arrays produced here exhibited large anisotropic optical and magnetic properties, respectively. The excitation of localized surface plasmon resonances (LSPRs) of the Au nanowire arrays resulted in a high electric field enhancement, which was used to detect phthalocyanine (CoPc) in surface-enhanced Raman scattering (SERS). Furthermore, the Fe nanowire arrays showed a very high in-plane magnetic anisotropy of approximately 412 mT, which may be the largest in-plane magnetic anisotropy field yet reported that is solely induced via shape anisotropy within the plane of a thin film. 相似文献
8.
We consider the resource-bounded measure of polynomial-time learnable subclasses of polynomial-size circuits. We show that
if EXP ≠ MA, then every PAC-learnable subclass of P/poly has EXP-measure zero. We introduce a nonuniformly computable variant
of resource-bounded measure and show that, for every fixed polynomial q , any polynomial-time learnable subclass of circuits of size q has measure zero with respect to P/poly. We relate our results to the question of whether the class of Boolean circuits
is polynomial-time learnable.
Received July 15, 1998, and in final form September 9, 1999. 相似文献
9.
Applications of sol-gel-processed interphase catalysts 总被引:2,自引:0,他引:2
10.
对于3D互连、圆片级封装(WLP)和先进的MEMS器件的圆片键合,精密对准是一项关键技术,不同的MEMS,常常包含双面加工处理,而IC和CMOS制造业则只利用单面加工处理步骤,因此,圆片到圆片的对准必须使用设置在键合界面(也就是面对面)中的对准标记。论述了面对面对准方法的主要步骤,最新结果报导,用一种特殊开发的对准系统获得了≤1μm的对准精度。设备主要是为圆片对圆片的对准和键合而设计。 相似文献