全文获取类型
收费全文 | 1730篇 |
免费 | 30篇 |
国内免费 | 17篇 |
专业分类
电工技术 | 103篇 |
综合类 | 8篇 |
化学工业 | 600篇 |
金属工艺 | 99篇 |
机械仪表 | 38篇 |
建筑科学 | 24篇 |
矿业工程 | 2篇 |
能源动力 | 76篇 |
轻工业 | 94篇 |
水利工程 | 3篇 |
石油天然气 | 9篇 |
武器工业 | 1篇 |
无线电 | 134篇 |
一般工业技术 | 295篇 |
冶金工业 | 101篇 |
原子能技术 | 49篇 |
自动化技术 | 141篇 |
出版年
2021年 | 16篇 |
2019年 | 17篇 |
2018年 | 11篇 |
2017年 | 13篇 |
2016年 | 21篇 |
2015年 | 14篇 |
2014年 | 24篇 |
2013年 | 84篇 |
2012年 | 48篇 |
2011年 | 59篇 |
2010年 | 55篇 |
2009年 | 79篇 |
2008年 | 77篇 |
2007年 | 70篇 |
2006年 | 66篇 |
2005年 | 61篇 |
2004年 | 51篇 |
2003年 | 66篇 |
2002年 | 60篇 |
2001年 | 55篇 |
2000年 | 39篇 |
1999年 | 33篇 |
1998年 | 81篇 |
1997年 | 55篇 |
1996年 | 35篇 |
1995年 | 41篇 |
1994年 | 40篇 |
1993年 | 39篇 |
1992年 | 21篇 |
1991年 | 40篇 |
1990年 | 18篇 |
1989年 | 30篇 |
1988年 | 24篇 |
1987年 | 32篇 |
1986年 | 27篇 |
1985年 | 15篇 |
1984年 | 25篇 |
1983年 | 28篇 |
1982年 | 24篇 |
1981年 | 24篇 |
1980年 | 17篇 |
1979年 | 21篇 |
1978年 | 8篇 |
1977年 | 16篇 |
1976年 | 16篇 |
1975年 | 10篇 |
1974年 | 8篇 |
1973年 | 14篇 |
1972年 | 9篇 |
1971年 | 7篇 |
排序方式: 共有1777条查询结果,搜索用时 15 毫秒
91.
模态综合法是对复杂的机械进行振动解析的有效方法之一。本文将该法用于带换气扇马达的振动解析。整个马达系统分成四个子结构,用锤击试验法获得各子结构的传递函数。模态参数用曲线拟合法求得。然后用模态综合法进行综合,得到全系统的动特性。比较计算值和实验值,从而证明了这个方法的有效性。 相似文献
92.
Nagase Hiroshi Matsuda Yasuo Ohnishi Kazuo Ninomiya Hisakazu Koike Toshio 《Industry Applications, IEEE Transactions on》1984,(6):1482-1489
A high-performance speed control system for cage induction motors is described which utilizes a PWM inverter. The effects of primary current coincidence and machine constant variation on system characteristics such as response time, torque precision, and operating noise were investigated. Based on the results obtained, new control methods have been devised; one varies the gain of the current controller in proportion to the primary frequency, and a second compensates for the slip frequency by using the deviation between the flux reference value and the actual value. Effectiveness of the compensation methods was confirmed in tests. 相似文献
93.
Hiroshi Kageyama Mitsuhide Miyamoto Hajime Akimoto Shigeyuki Nishitani Toshihiro Sato Toshio Miyazawa 《Journal of the Society for Information Display》2006,14(4):345-351
Abstract— A common‐decoder architecture for a data‐driver circuit fabricated by using a polysilicon process has been developed. The architecture achieves a compact circuit and low‐power consumption. In application to an integrated polysilicon data driver for small‐sized displays, this architecture reduces the area of the data driver by removing the vertical bus lines that occupy a large area. It also suppresses the power consumption of the data bus by reducing the number of driven lines in the data bus during word‐to‐word transitions from six to two. By using a conventional 4‐μm design rule, we fabricated an active‐matrix OLED (AMOLED) panel with an integrated six‐bit data‐driver circuit with 384 outputs. The driver circuit had a height of 2.6 mm and a pitch between output lines of 84 μm. The maximum power consumption of the driver was only 5 mW, i.e., 3.8 mW for logic‐data transfer and 1.2 mW for reference‐voltage source. Furthermore, we also fabricated an active‐matrix LCD (AMLCD) panel including driver circuits of the same type as the integrated elements. Six‐bit full‐color images were successfully displayed on both panels. 相似文献
94.
Naoyuki Kubota Yusuke Nojima Fumio Kojima Toshio Fukuda 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2006,10(10):891-901
The purpose of this study is to develop partner robots that can obtain and accumulate human-friendly behaviors. To achieve this purpose, the entire architecture of the robot is designed, based on a concept of structured learning which emphasizes the importance of interactive learning of several modules through interaction with its environment. This paper deals with a trajectory planning method for generating hand-to-hand behaviors of a partner robot by using multiple fuzzy state-value functions, a self-organizing map, and an interactive genetic algorithm. A trajectory for the behavior is generated by an interactive genetic algorithm using human evaluation. In order to reduce human load, human evaluation is estimated by using the fuzzy state-value function. Furthermore, to cope with various situations, a self-organizing map is used for clustering a given task dependent on a human hand position. And then, a fuzzy state-value function is assigned to each output unit of the self-organizing map. The robot can easily obtain and accumulate human-friendly trajectories using a fuzzy state-value function and a knowledge database corresponding to the unit selected in the self-organizing map. Finally, multiple fuzzy state-value functions can estimate a human evaluation model for the hand-to-hand behaviors. Several experimental results show the effectiveness of the proposed method. 相似文献
95.
唐新峰 《武汉理工大学学报(材料科学英文版)》2002,17(3)
1 IntroductionTheelectricaltransportproperties (conductiontype ,carrierconcentration ,carriermobility ,carriereffectivemass)andthethermaltransportproperties (atomdis placementparameter ,meanfreepathofphonon ,latticethermalconductivity)offilledskutteruditecomp… 相似文献
96.
Miyuki Hayashi Masahiro Susa Toshio Maruyama Kazuhiro Nagata 《Journal of Electronic Materials》1995,24(8):983-989
The annealing of 20CaO·20SiO2·7Fe2O3·6FeO glasses at 973K in vacuo produced clusters of iron oxide, the shape of which was nearly spherical and the diameter distributed in the narrow range 25–115Å. The phase of clusters was identified to be Fe3+(Fe3+ poststagger|1.30Fe2+ poststagger|0.55V0.15)·O4 in the inverse spinel structure based upon the Mössbauer spectra and x-ray diffraction profiles. The clusters exhibited superparamagnetism and their effective anisotropy energy constant was inversely proportional to the cluster diameter. The magnetization of the glasses measured by a vibrating sample magnetometer was 7.2 × 10-6 Wbmkg-1 at 10 kOe at room temperature and smaller than the value calculated assuming that the whole clusters have superparamagnetism. These results suggest the pinning of spins near the cluster surface. 相似文献
97.
Masahiro Sugaya Masakazu Takeshi Tomoji Yamashiki Toshio Oikawa Kan-Ichi Fujii 《Electromagnetic Compatibility, IEEE Transactions on》1982,(1):20-25
Correlation of light emission, discharge structure, waveform of the discharge current, electrode configuration, and electromagnetic radiation is examined with the intent of obtaining an effective means for preventing electromagnetic interference (EMI) due to a short-gap discharge. The electromagnetic radiation (EMR) level resulting from a current step which, in turn, was formed by a discrete movement of a cathode spot was clearly recognized. A combination of needle rotor and needle post gave the smallest electromagnetic radiation level in the experiments. 相似文献
98.
99.
A survey was performed of the mold flora in the air and on the surfaces inside twelve homes throughout four seasons. There were significant variations of the mold flora in homes associated with the outdoor spore count, various rooms, carpeting, central air-conditioning and pets. We conclude that homes may be a source of perennial mold exposure. 相似文献
100.
Yields and properties of products on hydrogenation of Japanese and Australian coals have been studied using an autoclave equipped with a magnedrive device at temperatures of 500–600 °C and hydrogen pressure 4.9–14.7 MPa (gauge) in the absence of solvent. Optimum contact time, at which maximum extraction yield was observed, shifted from 15 s to a few seconds with increasing reaction temperature and hydrogen pressure. The extracts derived from both coals reveal similar structural parameters. 相似文献