全文获取类型
收费全文 | 13479篇 |
免费 | 1212篇 |
国内免费 | 546篇 |
专业分类
电工技术 | 967篇 |
综合类 | 1081篇 |
化学工业 | 785篇 |
金属工艺 | 340篇 |
机械仪表 | 921篇 |
建筑科学 | 615篇 |
矿业工程 | 929篇 |
能源动力 | 165篇 |
轻工业 | 726篇 |
水利工程 | 138篇 |
石油天然气 | 753篇 |
武器工业 | 128篇 |
无线电 | 3137篇 |
一般工业技术 | 977篇 |
冶金工业 | 437篇 |
原子能技术 | 114篇 |
自动化技术 | 3024篇 |
出版年
2024年 | 41篇 |
2023年 | 132篇 |
2022年 | 233篇 |
2021年 | 352篇 |
2020年 | 363篇 |
2019年 | 308篇 |
2018年 | 282篇 |
2017年 | 358篇 |
2016年 | 428篇 |
2015年 | 470篇 |
2014年 | 894篇 |
2013年 | 651篇 |
2012年 | 1142篇 |
2011年 | 1031篇 |
2010年 | 804篇 |
2009年 | 725篇 |
2008年 | 775篇 |
2007年 | 886篇 |
2006年 | 878篇 |
2005年 | 716篇 |
2004年 | 649篇 |
2003年 | 540篇 |
2002年 | 437篇 |
2001年 | 345篇 |
2000年 | 349篇 |
1999年 | 251篇 |
1998年 | 192篇 |
1997年 | 183篇 |
1996年 | 167篇 |
1995年 | 137篇 |
1994年 | 95篇 |
1993年 | 83篇 |
1992年 | 57篇 |
1991年 | 49篇 |
1990年 | 29篇 |
1989年 | 36篇 |
1988年 | 17篇 |
1987年 | 13篇 |
1986年 | 6篇 |
1985年 | 19篇 |
1984年 | 31篇 |
1983年 | 31篇 |
1982年 | 16篇 |
1981年 | 4篇 |
1976年 | 3篇 |
1964年 | 4篇 |
1960年 | 2篇 |
1959年 | 3篇 |
1957年 | 3篇 |
1956年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
71.
With the increasing popularity of touch screen mobile devices, improving the usability and the user experience while inputting text on these devices is becoming increasingly important. Most conventional touch screen keyboards on mobile devices rely heavily on visual feedback, while auditory feedback seldom includes any useful information about what is being inputted by the user. The auditory feedback usually simply replicates the sounds produced by a physical keyboard. This paper describes the development of an enhanced auditory feedback mechanism for a Korean touch screen keyboard called the enhanced auditory feedback (EAF) mechanism. EAF has subtle phonetic auditory feedback generated using the acoustic phonetic features of human speech. While typing with EAF, users can acquire non-invasive auditory clues about the keys pressed. In this work, we compare conventional auditory feedback for a touch screen keyboard used in touch screen mobile devices with that of EAF and explore the possibility of using enhanced auditory feedback for touch screen keyboards. 相似文献
72.
Michael E. Becker 《Journal of the Society for Information Display》2015,23(10):472-485
Four years after introduction of the first instrument for measurement of sparkle, the foundations have been reconsidered, and the pool of practical experience has been analyzed to provide a more detailed and complete picture of the subject matter. The following aspects are introduced and discussed: observation conditions and resulting requirements for imaging (sampling) and filtering, analysis of spatial periods and frequencies as a basis for filtering, spatial filtering concepts, sparkle in the frequency domain, sparkle evaluation based on analysis of single images and difference images, origins of unwanted sparkle components, scaling and offset in sparkle evaluation, and verification of the method. 相似文献
73.
74.
Guo‐Zhen Wang Yi‐Pai Huang Tian‐Sheuan Chang 《Journal of the Society for Information Display》2013,21(9):381-388
A camera‐free 3D air‐touch system was proposed. Hovering, air swiping, and 3D gestures for further interaction with the floated 3D images on the mobile display were demonstrated. By embedding multiwavelength optical sensors into the display pixels and adding angular‐scanning illuminators with multiwavelength on the edge of the display, the flat panel can sense images reflected by a bare finger from different heights. In addition, three axis (x, y, z) information of the reflected image of the fingertip can be calculated. Finally, the proposed 3D air‐touch system was successfully demonstrated on a 4‐inch mobile 3D display. 相似文献
75.
Kuo‐Chung Huang Yi‐Heng Chou Lang‐chin Lin Hoang Yan Lin Fu‐Hao Chen Ching‐Chiu Liao Yi‐Han Chen Kuen Lee Wan‐Hsuan Hsu 《Journal of the Society for Information Display》2013,21(6):263-270
The optimal viewing distance was proposed as a parameter for designing a parallax barrier 3D display. It can be designed based on simple geometric method and by considering the pitches of image display pixels and parallax barrier, or even including the aperture ratios of the image display pixels and parallax barrier. It can be analyzed by using ray tracing method. By considering the optical refraction index of the cover glass, the angular behavior of the system becomes more realistic; however, the geometric method is difficult to be used. We propose a revised method for estimating the view distance and angular behavior. In this paper, we have demonstrated a designated eye position (DEP) for each view and shown that multiple DEPs make a circular curve around the center of the display. We prove the new concept by comparing the optical ray tracing calculations and optical measurement. 相似文献
76.
Joe Miseli 《Journal of the Society for Information Display》2013,21(6):214-224
On June 1, 2012, the Information Display Measurement Standard version 1 was released. This is the first standard from the worldwide standard group, the International Committee for Display Metrology, a standards committee within SID, and it culminates several years worth of development from many contributors at various levels. It has 26 top‐level chapters and a total over 450 sections of all parts, including over 200 measurement sections and 8 appendices that cover 133 topics of display metrology, tutorials, technical discussions, and references. Herein is an overview of the Information Display Measurement Standard version 1, including the structure of the document, tips, tricks, and hidden features, how it is maintained, support material, a breakdown of its contents, and finally, a sampling of four of the over 200 measurements. The standard is available as a free download and can be found on the International Committee for Display Metrology home page — http://www.icdm‐sid.org . 相似文献
77.
78.
基于AT89C51单片机的蔬菜大棚控制系统 总被引:3,自引:1,他引:2
主要介绍以AT89C51单片机为主控制器,以温度、湿度等传感器为主要外围元件的蔬菜大棚控制系统。该系统采用AT89C51单片机采集处理、监测控制以及输出显示环境值,为蔬菜的生长提供稳定的环境场所。在系统设计过程中充分考虑性价比,选用价格低,性能稳定的元器件。 相似文献
79.
The influence of wall charge distribution on the time lag of address discharge in an AC plasma display panel is investigated using two different reset waveforms: one (typical reset) induces both face and surface discharges and the other (TR reset) induces face discharges only. The measured formative time lag and statistical time lag of address discharge for TR were 21–31 ns and 31–74 ns shorter than the one for the typical reset, respectively. The TR reset resulted in much less increase of statistical time lag than the typical reset when the reset-to-address time interval was increased, and 70 ns smaller deviation of the statistical time lag among different color cells. Calculations show that the TR reset forms a much smoother wall charge profile, which is less susceptible to cell parameter variations, than the typical reset. The observed differences in the time lags of address discharge between different scan lines and color cells are strongly correlated to the differences of the wall charge profile, indicating that a smooth wall charge profile formed by the reset using face discharges only reduces the time lag of address discharge and minimizes the susceptibility of address discharge to cell parameter variation. 相似文献
80.
Multilayer hybrid visualizations to support 3D GIS 总被引:3,自引:0,他引:3
In this paper, we present a unique hybrid visualization system for spatial data. Although some existing 3D GIS systems offer 2D views they are typically isolated from the 3D view in that they are presented in a separate window. Our system is a novel hybrid 2D/3D approach that seamlessly integrates 2D and 3D views of the same data. In our interface, multiple layers of information are continuously transformed between the 2D and 3D modes under the control of the user, directly over a base terrain. In this way, our prototype system is able to depict 2D and 3D views within the same window. This has advantages, since 2D and 3D visualizations can each be easier to interpret in different contexts.In this work we develop this concept of a hybrid visualization by presenting a comprehensive set of capabilities within our distinctive system. These include new facilities such as: hybrid landmark, 3D point, and chart layers, the grouping of multiple hybrid layers, layer painting, the merging of layer controls and consistent zooming functionality. 相似文献