全文获取类型
收费全文 | 1631篇 |
免费 | 158篇 |
国内免费 | 4篇 |
学科分类
工业技术 | 1793篇 |
出版年
2024年 | 10篇 |
2023年 | 27篇 |
2022年 | 81篇 |
2021年 | 112篇 |
2020年 | 64篇 |
2019年 | 80篇 |
2018年 | 89篇 |
2017年 | 89篇 |
2016年 | 109篇 |
2015年 | 67篇 |
2014年 | 91篇 |
2013年 | 148篇 |
2012年 | 109篇 |
2011年 | 144篇 |
2010年 | 77篇 |
2009年 | 73篇 |
2008年 | 75篇 |
2007年 | 66篇 |
2006年 | 56篇 |
2005年 | 39篇 |
2004年 | 27篇 |
2003年 | 21篇 |
2002年 | 32篇 |
2001年 | 10篇 |
2000年 | 11篇 |
1999年 | 13篇 |
1998年 | 18篇 |
1997年 | 13篇 |
1996年 | 13篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1985年 | 4篇 |
1981年 | 2篇 |
1978年 | 1篇 |
1976年 | 3篇 |
排序方式: 共有1793条查询结果,搜索用时 0 毫秒
1.
This paper presents a novel zero-voltage and zero-current switching (ZVZCS) three-level DC/DC converter. This converter overcomes the drawbacks presented by the conventional zero-voltage switching (ZVS) three-level converter, such as high circulating energy, severe parasitic ringing on the rectifier diodes, and limited ZVS load range for the inner switches. The converter presented in this paper uses a phase-shift control with a flying capacitor in the primary side to achieve ZVS for the outer switches. Additionally, the converter uses an auxiliary circuit to reset the primary current during the freewheeling stage to achieve zero-current switching (ZCS) for the inner switches. The principle of operation and the DC characteristics of the new converter are analyzed and verified on a 6 kW, 100 kHz experimental prototype. 相似文献
2.
Participating media with an inhomogeneous index of refraction make light follow curved paths. Simulating this in a global
illumination environment has usually been neglected due to the complexity of the calculations involved, sacrificing accurate
physical simulations for efficient visual results.
This paper aims to simulate non-linear media in a more reasonable time than previous works without losing physical correctness.
Accuracy is achieved by solving the Eikonal equation of geometrical optics, which describes the path followed by a light beam
that traverses a non-linear medium. This equation is used in the context of a photon mapping extension. 相似文献
3.
This study investigates the whole-body vibration exposure in kite surfing, alpine skiing, snowboarding and cycling. The vibration exposure was experimentally evaluated following the ISO 2631 guidelines. Results evidenced that the most critical axis is the vertical one. The weighted vibration levels are always larger than 2.5 m/s2 and the vibration dose values are larger than 25 m/s1.75. The exposure limit values of the EU directive are reached after 8–37 min depending on the sport. The vibration magnitude is influenced by the athletes’ speed, by their skill level and sometimes by the equipment. The large vibration values suggest that the practice of sport activities may be a confounding factor in the aetiology of vibration-related diseases. 相似文献
4.
5.
Pardo Diego Fichera Loris Caldwell Darwin Mattos Leonardo S. 《Neural Processing Letters》2015,41(1):55-69
Neural Processing Letters - This paper presents an approach to determine a model of superficial tissue temperature dynamics during continuous wave CO $$_2$$ laser irradiation. The main contribution... 相似文献
6.
7.
8.
Cáceres-Criado Irene García-Molina Diego Francisco Mesas-Carrascosa Francisco Javier Triviño-Tarradas Paula 《Virtual Reality》2023,27(2):967-983
Virtual Reality - Virtual reconstruction is defined as the visual recovery of a building or object through the creation of a three-dimensional model of the asset to be reconstructed, in a... 相似文献
9.
Journal of Intelligent Information Systems - Offline evaluation of recommender systems (RSs) mostly relies on historical data, which is often biased. The bias is a result of many confounders that... 相似文献