全文获取类型
收费全文 | 2003篇 |
免费 | 138篇 |
国内免费 | 93篇 |
专业分类
电工技术 | 25篇 |
综合类 | 424篇 |
化学工业 | 327篇 |
金属工艺 | 20篇 |
机械仪表 | 78篇 |
建筑科学 | 80篇 |
矿业工程 | 11篇 |
能源动力 | 31篇 |
轻工业 | 194篇 |
水利工程 | 8篇 |
石油天然气 | 6篇 |
武器工业 | 6篇 |
无线电 | 241篇 |
一般工业技术 | 255篇 |
冶金工业 | 135篇 |
原子能技术 | 26篇 |
自动化技术 | 367篇 |
出版年
2024年 | 2篇 |
2023年 | 49篇 |
2022年 | 42篇 |
2021年 | 76篇 |
2020年 | 44篇 |
2019年 | 63篇 |
2018年 | 46篇 |
2017年 | 42篇 |
2016年 | 37篇 |
2015年 | 49篇 |
2014年 | 93篇 |
2013年 | 139篇 |
2012年 | 114篇 |
2011年 | 135篇 |
2010年 | 108篇 |
2009年 | 104篇 |
2008年 | 117篇 |
2007年 | 120篇 |
2006年 | 142篇 |
2005年 | 93篇 |
2004年 | 122篇 |
2003年 | 78篇 |
2002年 | 78篇 |
2001年 | 62篇 |
2000年 | 36篇 |
1999年 | 38篇 |
1998年 | 24篇 |
1997年 | 18篇 |
1996年 | 38篇 |
1995年 | 26篇 |
1994年 | 23篇 |
1993年 | 9篇 |
1992年 | 10篇 |
1991年 | 2篇 |
1990年 | 9篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 2篇 |
1977年 | 2篇 |
1970年 | 1篇 |
1964年 | 1篇 |
1962年 | 3篇 |
1959年 | 4篇 |
1957年 | 1篇 |
1956年 | 2篇 |
1954年 | 1篇 |
排序方式: 共有2234条查询结果,搜索用时 31 毫秒
1.
2.
《Journal of the European Ceramic Society》2022,42(13):5893-5903
Technical ceramics exhibit exceptional high-temperature properties, but unfortunately their extreme crack sensitivity and high melting point make it challenging to manufacture geometrically complex structures with sufficient strength and toughness. Emerging additive manufacturing technologies enable the fabrication of large-scale complex-shape artifacts with architected internal topology; when such topology can be arranged at the microscale, the defect population can be controlled, thus improving the strength of the material. Here, ceramic micro-architected materials are fabricated using direct ink writing (DIW) of an alumina nanoparticle-loaded ink, followed by sintering. After characterizing the rheology of the ink and extracting optimal processing parameters, the microstructure of the sintered structures is investigated to assess composition, density, grain size and defect population. Mechanical experiments reveal that woodpile architected materials with relative densities of 0.38–0.73 exhibit higher strength and damage tolerance than fully dense ceramics printed under identical conditions, an intriguing feature that can be attributed to topological toughening. 相似文献
3.
4.
We model developable surfaces by wrapping a planar figure around cones and cylinders. Complicated developables can be constructed by successive mappings using cones and cylinders of different sizes and shapes. We also propose an intuitive control mechanism, which allows a user to select an arbitrary point on the planar figure and move it to a new position. Numerical techniques are then used to find a cone or cylinder that produces the required mapping. Several examples demonstrate the effectiveness of our technique. 相似文献
5.
6.
7.
在双光束激光直写系统中,衍射光变图像的光刻是逐像素点进行的.本文提出在该系统中采用狭缝获得光栅线来进行衍射图形的直写,利用一种改进的矢量文件格式,使平台沿着垂直光栅线的方向运动,获得连续的多光点同时直写,直写后的衍射光栅线是连续的,系统的运行效率是逐点光刻的几十倍.编写了与DXF文件的接口直写控制程序,给出了实验结果. 相似文献
8.
J. Pujara M. A. Siddiqui Z. Liu P. Bjegovic S. S. Takagaki P. Y. Li S. Ramaswamy 《Drying Technology》2008,26(3):341-348
This is part II of a study reported earlier on a method to characterize the air flow and water removal characteristics during vacuum dewatering. This article presents experimental data and analysis of results from the use of a cyclically actuated vacuum dewatering device for removing moisture from wetted porous materials such as paper with the intermittent application of vacuum and accompanying air flow though the material. Results presented include sheet moisture content as a function of residence time and hence water removal rate under a variety of process conditions. Also, experimental results on air flow through the wet porous structure and hence the role and importance of air flow during vacuum dewatering are presented. Vacuum dewatering process conditions include exit solids content between 11 and 20% solid under applied vacuum conditions of 13.5 to 67.7 kPa (4 to 20 in. Hg). Regression analysis indicated that the exit sheet moisture content exhibited a nonlinear relationship with residence time with exit solids reaching a plateau after a certain residence time. Final moisture content correlated linearly with the average overall flow rate of air through the paper sample and the basis weight of the material. 相似文献
9.
10.
Aseel Berglund Erik Berglund Anders Larsson Magnus Bang 《Universal Access in the Information Society》2006,4(4):300-327
The television (TV) is one of the most common entertainment devices in homes. Searching and finding TV programs is a common task and using TV guides is one way of performing this. This paper presents three studies that are focused on examining audiences’ TV habits and TV guide usage, evaluating a new concept based on linking paper and pen with TV technology, and studying the audiences’ attitudes toward and anticipated interest in the future guide. The results of our first study emphasize the value of using paper based TV guides and also identify the deficiencies. We also found indications that the advantages and disadvantages of paper-based TV guides are related to the physical properties of paper. Thus, we suggest a solution that uses digital pen and paper technology to offer a new interaction method for TV. A research system “Paper Remote”, is developed and used in the two subsequent studies. Viewers tick designated areas on the paper-based guide to perform actions such as channel switching. However, this solution is not a substitute for the remote control device. We argue that these user studies on linking digital paper to the TV for everyday information navigation illuminate the possibilities of providing innovative solutions also for home information systems also. 相似文献