全文获取类型
收费全文 | 2266篇 |
免费 | 63篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 46篇 |
综合类 | 3篇 |
化学工业 | 509篇 |
金属工艺 | 65篇 |
机械仪表 | 42篇 |
建筑科学 | 96篇 |
矿业工程 | 9篇 |
能源动力 | 34篇 |
轻工业 | 266篇 |
水利工程 | 15篇 |
石油天然气 | 2篇 |
无线电 | 259篇 |
一般工业技术 | 371篇 |
冶金工业 | 353篇 |
原子能技术 | 9篇 |
自动化技术 | 255篇 |
出版年
2022年 | 27篇 |
2021年 | 48篇 |
2020年 | 38篇 |
2019年 | 36篇 |
2018年 | 46篇 |
2017年 | 32篇 |
2016年 | 52篇 |
2015年 | 45篇 |
2014年 | 61篇 |
2013年 | 92篇 |
2012年 | 68篇 |
2011年 | 92篇 |
2010年 | 69篇 |
2009年 | 73篇 |
2008年 | 93篇 |
2007年 | 97篇 |
2006年 | 62篇 |
2005年 | 57篇 |
2004年 | 50篇 |
2003年 | 58篇 |
2002年 | 55篇 |
2001年 | 27篇 |
2000年 | 46篇 |
1999年 | 38篇 |
1998年 | 72篇 |
1997年 | 62篇 |
1996年 | 51篇 |
1995年 | 33篇 |
1994年 | 39篇 |
1993年 | 44篇 |
1992年 | 43篇 |
1991年 | 23篇 |
1990年 | 38篇 |
1989年 | 30篇 |
1988年 | 19篇 |
1987年 | 28篇 |
1986年 | 20篇 |
1985年 | 35篇 |
1984年 | 27篇 |
1983年 | 27篇 |
1982年 | 17篇 |
1981年 | 28篇 |
1980年 | 17篇 |
1979年 | 15篇 |
1978年 | 26篇 |
1977年 | 21篇 |
1976年 | 23篇 |
1972年 | 15篇 |
1970年 | 14篇 |
1963年 | 13篇 |
排序方式: 共有2334条查询结果,搜索用时 31 毫秒
1.
Golam Haider Krishna Sampathkumar Tim Verhagen Lukáš Nádvorník Farjana J. Sonia Václav Valeš Jan Sýkora Peter Kapusta Petr Němec Martin Hof Otakar Frank Yang-Fang Chen Jana Vejpravová Martin Kalbáč 《Advanced functional materials》2021,31(29):2102196
Recent advancements in isolation and stacking of layered van der Waals materials have created an unprecedented paradigm for demonstrating varieties of 2D quantum materials. Rationally designed van der Waals heterostructures composed of monolayer transition-metal dichalcogenides (TMDs) and few-layer hBN show several unique optoelectronic features driven by correlations. However, entangled superradiant excitonic species in such systems have not been observed before. In this report, it is demonstrated that strong suppression of phonon population at low temperature results in a formation of a coherent excitonic-dipoles ensemble in the heterostructure, and the collective oscillation of those dipoles stimulates a robust phase synchronized ultra-narrow band superradiant emission even at extremely low pumping intensity. Such emitters are in high demand for a multitude of applications, including fundamental research on many-body correlations and other state-of-the-art technologies. This timely demonstration paves the way for further exploration of ultralow-threshold quantum-emitting devices with unmatched design freedom and spectral tunability. 相似文献
2.
Konstantinos Spyrou Matteo Calvaresi Evmorfia K. Diamanti Theodoros Tsoufis Dimitrios Gournis Petra Rudolf Francesco Zerbetto 《Advanced functional materials》2015,25(2):263-269
Experimental and theoretical studies are performed in order to illuminate, for first time, the intercalation mechanism of polycyclic aromatic molecules into graphite oxide. Two representative molecules of this family, aniline and naphthalene amine are investigated. After intercalation, aniline molecules prefer to covalently connect to the graphene oxide matrix via chemical grafting, while napthalene amine molecules bind with the graphene oxide surface through π–π interactions. The presence of intercalated aromatic molecules between the graphene oxide layers is demonstrated by X‐ray diffraction, while the type of interaction between graphene oxide and polycyclic organic molecules is elucidated by X‐ray photoelectron spectroscopy. Combined quantum mechanical and molecular mechanical calculations describe the intercalation mechanism and the aniline grafting, rationalizing the experimental data. The present work opens new perspectives for the interaction of various aromatic molecules with graphite oxide and the so‐called “intercalation chemistry”. 相似文献
3.
4.
5.
Rudolf Habison 《International Journal of Project Management》1985,3(3):178-181
Meeting time and cost objectives in complex projects involves specific problems and risks. An attempt is made to analyse the components of total cost increase of a project caused by time delay. An outline is given as to how these considerations can be used to estimate cost increases in investors' decision situations as well as to ascertain fair contractual penalties and claims for compensation and for the evaluation of justified project acceleration costs. 相似文献
6.
7.
Mariana Ušáková Jozef Lukáč Rastislav Dosoudil Vladimír Jančárik Anna Grusková Elemír Ušák Jozef Sláma Jan Šubrt 《Journal of Materials Science: Materials in Electronics》2007,18(12):1183-1189
The paper is devoted to the preparation of NiZn ferrite with small substitutions of copper by means of ceramic technology.
The influence of small Cu substitution on the microstructural and magnetic properties of NiZn ferrites have been analysed
by means of various experimental methods and interpreted from the point of view of preparation technology optimisation and
possible applications of such materials. A strong correlation between the substituent content and resulting properties has
been observed, thus allowing preparation of material with the properties tailored for any particular application. 相似文献
8.
9.
10.
A. A. Khrushchinskii S. A. Kuten’ N. M. Budevich V. F. Minenko O. M. Zhukova N. K. Luk’yanov 《Journal of Engineering Physics and Thermophysics》2007,80(6):1170-1177
Measurements of the beta-activity of milk, serving as the main source of information on the radioactive contamination of the
environment by the iodine isotope 131I, carried out on a DP-100 radiometer in the early post-Chernobyl period (1986) in Belarus, have been mathematically simulated.
The results obtained allow the conclusion that the indicated measurements should be analyzed again with consideration for
all of the nuclides present in milk.
__________
Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 80, No. 6, pp. 102–108, November–December, 2007. 相似文献