全文获取类型
收费全文 | 1266篇 |
免费 | 34篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 76篇 |
综合类 | 2篇 |
化学工业 | 333篇 |
金属工艺 | 54篇 |
机械仪表 | 19篇 |
建筑科学 | 22篇 |
能源动力 | 59篇 |
轻工业 | 116篇 |
水利工程 | 3篇 |
无线电 | 95篇 |
一般工业技术 | 214篇 |
冶金工业 | 103篇 |
原子能技术 | 31篇 |
自动化技术 | 179篇 |
出版年
2024年 | 2篇 |
2023年 | 6篇 |
2022年 | 17篇 |
2021年 | 27篇 |
2020年 | 19篇 |
2019年 | 16篇 |
2018年 | 36篇 |
2017年 | 32篇 |
2016年 | 32篇 |
2015年 | 21篇 |
2014年 | 44篇 |
2013年 | 80篇 |
2012年 | 66篇 |
2011年 | 87篇 |
2010年 | 53篇 |
2009年 | 75篇 |
2008年 | 82篇 |
2007年 | 53篇 |
2006年 | 42篇 |
2005年 | 48篇 |
2004年 | 46篇 |
2003年 | 44篇 |
2002年 | 37篇 |
2001年 | 29篇 |
2000年 | 14篇 |
1999年 | 29篇 |
1998年 | 48篇 |
1997年 | 25篇 |
1996年 | 26篇 |
1995年 | 25篇 |
1994年 | 16篇 |
1993年 | 15篇 |
1992年 | 13篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 12篇 |
1988年 | 8篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 10篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1977年 | 6篇 |
1976年 | 3篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 2篇 |
排序方式: 共有1306条查询结果,搜索用时 15 毫秒
121.
122.
Interactive and autonomous agents might be common in everyday life in the future; we expect that such agents will have the
ability to communicate with people naturally. For natural communication, the agents should speculate about the intentions
of the people they interact with. To enable agents to speculate about intentions like deception, we focused on unconscious
expressions when people tell a lie. However, there is no system that can meet the necessary conditions for measuring nonverbal
information in natural communication. Therefore, we made a real-time system for measuring gaze direction and facial features.
We conducted experiments for discriminating lies by using the system in a situation similar to actual communication. As a
result, we found that we could discriminate lies by using diverse nonverbal information in the same way people did. 相似文献
123.
Tshering Cigay Dorji El-sayed Atlam Susumu Yata Masao Fuketa Kazuhiro Morita Jun-ichi Aoe 《Knowledge and Information Systems》2011,27(1):141-161
Field Association (FA) Terms—words or phrases that serve to identify document fields are effective in document classification,
similar file retrieval and passage retrieval. But the problem lies in the lack of an effective method to extract and select
relevant FA Terms to build a comprehensive dictionary of FA Terms. This paper presents a new method to extract, select and
rank FA Terms from domain-specific corpora using part-of-speech (POS) pattern rules, corpora comparison and modified tf-idf weighting. Experimental evaluation on 21 fields using 306 MB of domain-specific corpora obtained from English Wikipedia dumps
selected up to 2,517 FA Terms (single and compound) per field at precision and recall of 74–97 and 65–98. This is better than
the traditional methods. The FA Terms dictionary constructed using this method achieved an average accuracy of 97.6% in identifying
the fields of 10,077 test documents collected from Wikipedia, Reuters RCV1 corpus and 20 Newsgroup data set. 相似文献
124.
125.
H. Fushimi N. Ohkawa S. Fujita 《Photonics Technology Letters, IEEE》1991,3(11):1015-1018
A FET-IC mixer that uses a Gilbert-cell multiplier with a single-to-balance conversion input buffer is proposed. The key point in the FET-IC mixer design is that a single-to-balance conversion input buffer is used to improve the amplitude and phase balance of signals output from the input buffer stage. Excellent squaring characteristics were achieved in the range from 0 to -25 dBm. The FET-IC mixer was successfully tested in a 2.5 Gb/s CPFSK demodulator for optical heterodyne reception. Compared to the best diode passive double-balanced diode mixers, receiver sensitivity was improved by 1 dB at +10 dBm electrical input power. Very small degradation in receiver sensitivity, less than 3 dB, was achieved at electrical input power levels ranging from +10 to -10 dBm.<> 相似文献
126.
Woolf L. D. Figueroa T. L. Olstad R. A. Elsner F. E. Ohkawa T. 《Journal of Electronic Materials》1995,24(12):1797-1800
We have developed a continuous fabrication process for producing long lengths of Bi-2223 superconductor tapes. The process
involves sequentially electrophoretically depositing and sintering superconductor and then silver layers on a substrate, followed
by rolling and thermal processing. Both round and flat silver substrates have been used. Bi-2223 tapes made using flat silver
substrates require only a few processing steps. Transport critical current densities at 77K in zero applied magnetic field
exceeding 20000 A/cm2 have been obtained. 相似文献
127.
Morito Akiyama Hamid Reza Kokabi Kazuhiro Nonaka Kazuhisa Shobu Tadahiko Watanabe 《Journal of the American Ceramic Society》1995,78(12):3304-3308
c-axis-oriented aluminum nitride thin films were prepared on polycrystalline molybdenum disilicide substrates by rf magnetron sputtering at substrate temperatures of 50°–500°C. The films with the best orientation and crystallinity were prepared at 300°C. The dependence of film microstructure on substrate temperature was investigated by atomic force microscopy (AFM). Consequently, the microstructure changed in accordance with the model proposed by Thornton. It was found that the orientation and crystallinity of the films were optimal when the films consisted of dense fibrous grains. Further, it was confirmed that piezoelectric measurements could be made from the films during mechanical impacts. 相似文献
128.
Experimental investigations have been carried out for combined convective flows of air induced around uniformly heated, horizontal cylinders. Three cases of aiding, opposing, and cross flows were examined. The experiments covered the ranges of the Reynolds and modified Rayleigh numbers of Red=50 to 900 and Rad*=5×104 to 3×106. The flow fields around the cylinders were visualized with smoke. The results showed that separation points gradually shift from those of the forced convection to the top edge of the cylinder with increasing wall heat fluxes. The local heat transfer coefficients of the cylinders were also measured. Although the local coefficients show complex variations with the forced flow velocities and the wall heat fluxes, the overall coefficients become higher than those estimated from pure forced and natural convections throughout the cases of aiding, opposing, and cross flows. Moreover, it was confirmed that the overall Nusselt numbers as well as the separation points can be predicted with the non‐dimensional parameter (Grd*/NudRed2). © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(8): 474–488, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20180 相似文献
129.
Naotaka Kamijo Hideaki Saito Kazuhiro Kusama Osamu Kontani Robert Nigbor 《Nuclear Engineering and Design》2004,228(1-3):367
Extensive, large-amplitude vibration tests of a pile-supported structure in a liquefiable sand deposit have been performed at a large-scale mining site. Ground motions from large-scale blasting operations were used as excitation forces for vibration tests. A simple pile-supported structure was constructed in an excavated 3 m-deep pit. The test pit was backfilled with 100% water-saturated clean uniform sand. Accelerations were measured on the pile-supported structure, in the sand in the test pit, and in the adjacent free field. Excess pore water pressures in the test pit and strains of one pile were also measured.Vibration tests were performed with six different levels of input motions. The maximum horizontal acceleration recorded at the adjacent ground surface varied from 20 Gals to 1353 Gals. These alternations of acceleration provided different degrees of liquefaction in the test pit. Sand boiling phenomena were observed in the test pit with larger input motions. This paper outlines vibration tests and investigates the test results. 相似文献
130.
Nobuko Onozawa-Komatsuzaki Masatoshi Yanagida Takashi Funaki Kazuyuki Kasuga Kazuhiro Sayama Hideki Sugihara 《Inorganic chemistry communications》2009,12(12):1212-1215
A new ruthenium(II)–polypyridine complex (1) having a 2,6-bis(4-carboxyquinolin-2-yl)pyridine ligand was synthesized as a sensitizer for dye-sensitized solar cells (DSCs). This complex exhibited remarkable light-harvesting properties in the near-IR region. DSCs sensitized with 1 showed a 35% incident photon-to-current conversion efficiency (IPCE) at 900 nm. 相似文献