全文获取类型
收费全文 | 1414篇 |
免费 | 41篇 |
国内免费 | 9篇 |
专业分类
电工技术 | 114篇 |
综合类 | 2篇 |
化学工业 | 316篇 |
金属工艺 | 54篇 |
机械仪表 | 46篇 |
建筑科学 | 26篇 |
矿业工程 | 1篇 |
能源动力 | 102篇 |
轻工业 | 85篇 |
水利工程 | 6篇 |
石油天然气 | 6篇 |
无线电 | 121篇 |
一般工业技术 | 315篇 |
冶金工业 | 95篇 |
原子能技术 | 66篇 |
自动化技术 | 109篇 |
出版年
2023年 | 4篇 |
2022年 | 13篇 |
2021年 | 12篇 |
2020年 | 7篇 |
2019年 | 20篇 |
2018年 | 18篇 |
2017年 | 13篇 |
2016年 | 31篇 |
2015年 | 15篇 |
2014年 | 33篇 |
2013年 | 67篇 |
2012年 | 60篇 |
2011年 | 66篇 |
2010年 | 61篇 |
2009年 | 67篇 |
2008年 | 60篇 |
2007年 | 60篇 |
2006年 | 49篇 |
2005年 | 44篇 |
2004年 | 55篇 |
2003年 | 48篇 |
2002年 | 49篇 |
2001年 | 37篇 |
2000年 | 47篇 |
1999年 | 34篇 |
1998年 | 50篇 |
1997年 | 36篇 |
1996年 | 39篇 |
1995年 | 30篇 |
1994年 | 29篇 |
1993年 | 22篇 |
1992年 | 14篇 |
1991年 | 11篇 |
1990年 | 13篇 |
1989年 | 13篇 |
1988年 | 16篇 |
1987年 | 16篇 |
1986年 | 12篇 |
1985年 | 19篇 |
1984年 | 22篇 |
1983年 | 19篇 |
1982年 | 20篇 |
1981年 | 21篇 |
1980年 | 17篇 |
1979年 | 15篇 |
1978年 | 17篇 |
1977年 | 11篇 |
1976年 | 5篇 |
1975年 | 14篇 |
1973年 | 4篇 |
排序方式: 共有1464条查询结果,搜索用时 15 毫秒
171.
The interdiffusion and reactions of zirconium/permalloy bilayer thin films annealed at 150 to 350 °C were investigated. Nickel atoms preferentially diffuse from the permalloy layer into the zirconium layer. This preferential diffusion results in the growth of an amorphous phase between the zirconium and permalloy thin films. Consequently, the magnetic properties of the permalloy thin layer in the bilayer thin films change. The starting temperature of interdiffusion between zirconium and permalloy films is higher than that of a titanium/permalloy system reported previously. 相似文献
172.
173.
Yoshinori Dobashi Kazufumi Kaneda Hideo Yamashita Tomoyuki Nishita† 《Computer Graphics Forum》1996,15(3):109-118
Recently, computer graphics are frequently used for both architectural design and visual environmental assessment. Using computer graphics, designers can easily compare the effect of the natural light on their architectural designs under various conditions, such as different times of day, seasons, atmospheric conditions (clear or overcast sky) or building wall materials. In traditional methods of calculating the luminance due to sky light, however, all calculation must be performed from scratch if such conditions undergo change. Therefore, to compare the architectural designs under different conditions, a great deal of time has to be spent on generating the images. This paper proposes a new method of quickly generating images of an outdoor scene, taking into account glossy specular reflection, even if such conditions change. In this method, luminance due to sky light is expressed by a series of basis functions, and basis luminances corresponding to each basis function are precalculated and stored in a compressed form in the preprocess. Once the basis luminances are calculated, the luminance due to sky light can be quickly calculated by the weighted sum of the basis luminances. Several examples of an architectural design demonstrate the usefulness of the proposed method. 相似文献
174.
Skylight for Interior Lighting Design 总被引:2,自引:0,他引:2
Yoshinori Dobashi Kazufumi Kaneda Takanobu Nakashima Hideo Yamashita Tomoyuki Nishita Kastumi Tadamura 《Computer Graphics Forum》1994,13(3):85-96
It is inevitable for indoor lighting design to render a room lit by natural light, especially for an atelier or an indoor pool where there are many windows. This paper proposes a method for calculating the illuminance due to natural light, i.e. direct sunlight and skylight, passing through transparent planes such as window glass. The proposed method makes it possible to efficiently calculate such illuminance accurately, because it takes into account both non-uniform luminous intensity distribution of skylight and the distribution of transparency of glass according to incident angles of light. Several examples including the lighting design in an indoor pool, are shown to demonstrate the usefulness of the proposed method. 相似文献
175.
K. Shigihara K. Kawasaki S. Yamamura A. Takemoto T. Yagi Y. Mitsui 《Photonics Technology Letters, IEEE》2003,15(5):640-642
The structure of an asymmetrically expanded optical field normal to the active layer was applied to 1020-nm ridge waveguide laser diodes in order to increase their maximum kink-free output power and reduce the aspect ratio of the output beams. As a result, a kink-free output power of more than 400 mW and an aspect ratio of less than 2.5 were achieved by this structure. Good reliability was also obtained at an output power of 300 mW at 50/spl deg/C. 相似文献
176.
177.
178.
179.
K. Mitsui 《Precision Engineering》1986,8(4):212-220
Potential non-contact optical methods for in-process surface roughness measurement are described, including reflected light position detection, focu 相似文献
180.