全文获取类型
收费全文 | 9068篇 |
免费 | 176篇 |
国内免费 | 51篇 |
专业分类
电工技术 | 396篇 |
综合类 | 42篇 |
化学工业 | 1777篇 |
金属工艺 | 246篇 |
机械仪表 | 272篇 |
建筑科学 | 199篇 |
矿业工程 | 23篇 |
能源动力 | 243篇 |
轻工业 | 669篇 |
水利工程 | 56篇 |
石油天然气 | 16篇 |
武器工业 | 2篇 |
无线电 | 857篇 |
一般工业技术 | 1460篇 |
冶金工业 | 2023篇 |
原子能技术 | 160篇 |
自动化技术 | 854篇 |
出版年
2023年 | 32篇 |
2022年 | 96篇 |
2021年 | 150篇 |
2020年 | 69篇 |
2019年 | 94篇 |
2018年 | 122篇 |
2017年 | 99篇 |
2016年 | 114篇 |
2015年 | 123篇 |
2014年 | 158篇 |
2013年 | 350篇 |
2012年 | 305篇 |
2011年 | 433篇 |
2010年 | 343篇 |
2009年 | 380篇 |
2008年 | 398篇 |
2007年 | 379篇 |
2006年 | 336篇 |
2005年 | 336篇 |
2004年 | 259篇 |
2003年 | 257篇 |
2002年 | 264篇 |
2001年 | 214篇 |
2000年 | 183篇 |
1999年 | 198篇 |
1998年 | 713篇 |
1997年 | 457篇 |
1996年 | 342篇 |
1995年 | 242篇 |
1994年 | 237篇 |
1993年 | 210篇 |
1992年 | 121篇 |
1991年 | 113篇 |
1990年 | 113篇 |
1989年 | 91篇 |
1988年 | 94篇 |
1987年 | 76篇 |
1986年 | 79篇 |
1985年 | 104篇 |
1984年 | 68篇 |
1983年 | 77篇 |
1982年 | 51篇 |
1981年 | 70篇 |
1980年 | 62篇 |
1979年 | 36篇 |
1978年 | 25篇 |
1977年 | 59篇 |
1976年 | 60篇 |
1975年 | 32篇 |
1973年 | 26篇 |
排序方式: 共有9295条查询结果,搜索用时 15 毫秒
991.
992.
993.
Regularization of hypersingular and nearly singular integrals in the potential theory and elasticity
V. Sladek J. Sladek M. Tanaka 《International journal for numerical methods in engineering》1993,36(10):1609-1628
Both the hypersingular and nearly singular integrals, which appear in the hypersingular boundary integralequations and integral representations of the secondary fields, respectively, are regularized by the application of the superposition principle. Two kinds of the non-singular formulations, namely, those with the strongly singular and weakly singular kernels, are presented in this paper. The formulations are given in terms of the relevant boundary quantities and the collocation at element junctions is possible. Two- and three-dimensional problems are analysed simultaneously in a unique way for either internal or external problems of the potential theory and elasticity. 相似文献
994.
Behaviormetrika - A questionnaire on interpersonal attitudes was administered to university students majoring engineering in Singapore, Thailand, and Japan. Examination of responses to individual... 相似文献
995.
H Niiyama K Yamaguchi S Shimizu K Yokohata K Chijiiwa H Yonemasu M Tanaka 《Canadian Metallurgical Quarterly》1998,10(8):703-707
We report an unusual case of laryngomucocele occurring after subtotal laryngectomy. Laryngoceles generally have a congenital origin in a long-preexisting saccule, and their association with laryngeal carcinoma is well known. Laryngocele is usually favored by the increase of intraglottic pressure caused by the laryngeal carcinoma. However, an iatrogenic secondary laryngomucocele occurring after a surgical procedure is uncommon. We report in detail the physiopathologic conditions leading to the creation of this lesion. 相似文献
996.
997.
998.
T Tanaka T Morimoto Y Kinouchi T Iritani Y Monden 《Canadian Metallurgical Quarterly》1995,195(5):255-264
With hyperthermia for treatment of superficial tumors in mind, a prototype applicator with two electrodes arranged concentrically on a disk was designed for efficient local heating, and a basic heating test was carried out. Frequencies as low as 200 kHz were used in order to simplify the configuration of the power device. The applicator consists of two electrodes, a circular inner electrode and another looped outer electrode, arranged concentrically. Water was passed through the applicator as a cooling mechanism; it was placed in direct contact with the target tissue to be heated and then charged with electricity. In the heating test using a phantom, oval hot spots were noted below the inner electrode. Using cooling water at 3 degrees C and 8.2 W, an isothermal line of 45 degrees C was located at a 5-mm radius circle around the central axis with 9 mm depth. A similar temperature distribution map was obtained in heating tests on the thigh muscle of a mongrel adult dog. The temperature distribution maps obtained from these tests corresponded closely with the results of theoretical analysis carried out according to the finite-element method. Since a comparatively low frequency was employed for this applicator the power device was simplified, which made adequate heating possible with low electric power. The temperature distribution map indicated that efficient local heating of superficial tumors could be achieved. 相似文献
999.
The electric field distribution in an automobile body must be known when developing an antenna system mounted inside the car body for mobile communication. A microwave simulation experiment was carried out in an electromagnetic anechoic chamber using 4 GHz band signals and a miniaturized automobile. The automobile model used in this simulation experiment was about 1/15 of the size of the actual automobile under consideration. A simpler box-type model with large apertures was also studied. The internal electric field distribution measured in the box model was estimated to be a combination of the resonant TEPmn modes excited in the box. which acted as a resonant cavity. The spatial and frequency dependence of the internal automobile's electromagnetic field for each model is plotted for the frequency range 3-5 GHz 相似文献
1000.
Yokokawa S. Ueki Y. Tanaka H. Doi H. Ueda K. Taniguchi N. 《Energy Conversion, IEEE Transaction on》1988,3(3):479-486
A digital control system using the optimal control has been developed for a thermal power generator. In order to increase the generator control performance for improving the power system stability, this system supplies the excitation system directly with control signals and provides the governor system with control signals and supplemental control signals for a conventional governor. The system utilizes adaptive control for changes in generator nonlinear characteristics, as well as in power system characteristics. The principles and application of this system are described and results of simulation tests using a 1000 MVA thermal power plant model on a high-reliability AC/DC electric power system simulator are presented. The results verify the performance of this system, as well as the applicability of the system to actual plants 相似文献