全文获取类型
收费全文 | 9130篇 |
免费 | 388篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 95篇 |
综合类 | 4篇 |
化学工业 | 1724篇 |
金属工艺 | 181篇 |
机械仪表 | 171篇 |
建筑科学 | 463篇 |
矿业工程 | 16篇 |
能源动力 | 191篇 |
轻工业 | 1040篇 |
水利工程 | 70篇 |
石油天然气 | 21篇 |
武器工业 | 2篇 |
无线电 | 514篇 |
一般工业技术 | 1449篇 |
冶金工业 | 2047篇 |
原子能技术 | 53篇 |
自动化技术 | 1485篇 |
出版年
2021年 | 119篇 |
2020年 | 109篇 |
2019年 | 138篇 |
2018年 | 179篇 |
2017年 | 184篇 |
2016年 | 206篇 |
2015年 | 189篇 |
2014年 | 245篇 |
2013年 | 576篇 |
2012年 | 438篇 |
2011年 | 515篇 |
2010年 | 420篇 |
2009年 | 370篇 |
2008年 | 471篇 |
2007年 | 418篇 |
2006年 | 338篇 |
2005年 | 266篇 |
2004年 | 268篇 |
2003年 | 236篇 |
2002年 | 247篇 |
2001年 | 141篇 |
2000年 | 110篇 |
1999年 | 128篇 |
1998年 | 379篇 |
1997年 | 261篇 |
1996年 | 211篇 |
1995年 | 182篇 |
1994年 | 159篇 |
1993年 | 151篇 |
1992年 | 114篇 |
1991年 | 88篇 |
1990年 | 96篇 |
1989年 | 104篇 |
1988年 | 75篇 |
1987年 | 70篇 |
1986年 | 87篇 |
1985年 | 103篇 |
1984年 | 81篇 |
1983年 | 100篇 |
1982年 | 92篇 |
1981年 | 91篇 |
1980年 | 75篇 |
1979年 | 78篇 |
1978年 | 59篇 |
1977年 | 74篇 |
1976年 | 83篇 |
1975年 | 69篇 |
1974年 | 48篇 |
1973年 | 55篇 |
1972年 | 37篇 |
排序方式: 共有9526条查询结果,搜索用时 15 毫秒
1.
2.
María Carrascal Pablo Sendra Antonio Alanís Plácido González Martínez Alfonso Guajardo-Fajardo 《Journal of Urbanism》2019,12(1):60-82
The creative city approach is going through a redefinition after the 2008 global financial crisis. In the specific case of South-European cities, in the context of austerity and cuts in public investment, creativity is becoming a strategy for achieving maximum social benefit and improvement of the built environment with minimum economic expenditure. This paper looks at this redefinition of creativity through the case study of Seville, in southern Spain. Through research methods that include video-recorded testimonies of the actors involved, mapping at the online platform “Laboratorio Q”, and public engagement activities, this paper explores how the civic society, professional, and public authorities have reinvented how to produce collective spaces. The paper concludes that bottom-up creative processes for producing collective spaces have become more visible since the 2008 crisis, when architects, planners, public authorities and policy-makers have been “learning” from them. 相似文献
3.
Fernández-Godino M. Giselle Dubreuil Sylvain Bartoli Nathalie Gogu Christian Balachandar S. Haftka Raphael T. 《Structural and Multidisciplinary Optimization》2019,60(6):2205-2220
Structural and Multidisciplinary Optimization - When simulations are very expensive and many are required, as for optimization or uncertainty quantification, a way to reduce cost is using... 相似文献
4.
Federico Martín Bergero Francesco Casella Ernesto Kofman Joaquín Fernández 《Building Simulation》2018,11(2):405-418
Models describing energy consumption, heating, and cooling of buildings usually impose difficulties to the numerical integration algorithms used to simulate them. Stiffness and the presence of frequent discontinuities are among the main causes of those difficulties, that become critical when the models grow in size. Quantized State Systems (QSS) methods are a family of numerical integration algorithms that can efficiently handle discontinuities and stiffness in large models. For this reason, they are promising candidates for overcoming the mentioned problems. Based on this observation, this article studies the performance of QSS methods in some systems that are relevant to the field of building simulation. The study includes a performance comparison of different QSS algorithms against state-of-the-art classic numerical solvers, showing that the former can be more than one order of magnitude faster. 相似文献
5.
Moschetti Michael Xu Alan Schuh Benjamin Hohenwarter Anton Couzinié Jean-Philippe Kruzic Jamie J. Bhattacharyya Dhriti Gludovatz Bernd 《JOM Journal of the Minerals, Metals and Materials Society》2020,72(1):130-138
JOM - Refractory high-entropy alloys (RHEAs) are potential candidate materials for use in next-generation nuclear reactors due to their excellent mechanical performance at high temperatures. Here,... 相似文献
6.
7.
Similarities and differences between male and female novice designers on color‐concept associations for warnings,action required,and signs and equipment status messages 下载免费PDF全文
This research examined the male and female novice designers toward color associations for the concepts used for ‘warnings’, ‘action required’, and ‘signs and equipment status’ through a questionnaire‐based study. A total of 178 Hong Kong Chinese final year undergraduate design students (89 males and 89 females) participated in the study. The test used required the participants to indicate their choice of one of nine colors to associations with each of 38 concepts in a color‐concept table, so that any one color could be associated with any one of the concepts. For both male and female groups of novice designers, chi‐square tests revealed a strong color association for each concept tested in this study (P < .05). The results showed males and females agreed on some color‐concept association stereotypes which were therefore gender neutral. The male and female novice designers had the same color associations and similar levels of stereotype strengths for 21 concepts. The nine strongest and therefore most useful color‐concept association stereotypes for both male and female novice designers were: red‐danger, red‐fire, red‐hot, red‐stop, red‐emergency, red‐error, blue‐cold, blue‐male, and green‐exit. However, the male and female novice designers had different color association stereotypes for the standby (green vs. yellow), emergency exit (green vs. red), and toxic (purple vs. black) concepts, and the strengths of the 14 remaining associations for both groups were not at equivalent levels. Overall, it is anticipated that the findings of this study will act as a useful reference for novice designers and other design practitioners to optimize color coding in the design of ‘warnings’, ‘action required’, and ‘signs and equipment status’ messages. 相似文献
8.
Hierarchical micro-nanostructured albite-based glass-ceramic for high dielectric strength insulators
V. Fuertes M.J. Cabrera J. Seores D. Muñoz J.F. Fernández E. Enríquez 《Journal of the European Ceramic Society》2018,38(7):2759-2766
A novel glass-ceramic material based on albite type Na-rich feldspar has been synthesized by conventional ceramic process. High crystallinity, >94%?Vol.% is obtained by fast sintering which allows energy saving processing. Albite is the main crystalline phase and tetragonal SiO2 is a secondary phase. Electrical properties were examined by complex impedance, DC measurements, and dielectric breakdown test. Dielectric characterization shows a non-Debye type dielectric behavior with low dielectric constant, 4.6 at 1?MHz, low dielectric losses, (~10?3 at 1?MHz, and a large dielectric strength, ~60?kV/mm), that it is the largest value reported in ceramic insulators. Those dielectric properties are attained by the low glassy phase content in the samples and their unique micro-nanostructure. All these properties make this novel material a very promising candidate in the market of ceramic electrical insulator, highlighting for high-voltage applications. 相似文献
9.
10.
Microbial Fuel Cell Application for Azoic Dye Decolorization with Simultaneous Bioenergy Production Using Stenotrophomonas sp. 下载免费PDF全文
Said Galai Antonia Pérez de los Ríos Francisco José Hernández‐Fernández Sihem Haj Kacem Francisco Mateo Ramírez Joaquín Quesada‐Medina 《化学工程与技术》2015,38(9):1511-1518
A single‐chamber air‐cathode microbial fuel cell (MFC) was successfully applied for decolorization of the diazoic dye Reactive Black 5 (RB5) with simultaneous production of electricity. An innovative low‐cost medium, the marine water‐glucose‐yeast extract medium (MWGY), was developed which appears as a textile marine effluent in terms of salinity. The anode compartment containing a single bacterial strain of Stenotrophomonas sp. showed almost complete dye decolorization with different RB5 concentrations after seven days of treatment. For the four dye concentrations used, a correlation between dye removal and production of electrical energy was found. The comparison of the decolorization process in the MFC with that in a batch reactor as control experiment highlights the efficiency of the single‐chamber air‐cathode MFC technology which improved the dye removal by the same bacterial strain. 相似文献