全文获取类型
收费全文 | 204999篇 |
免费 | 16086篇 |
国内免费 | 7774篇 |
专业分类
电工技术 | 11227篇 |
技术理论 | 14篇 |
综合类 | 11213篇 |
化学工业 | 35696篇 |
金属工艺 | 10526篇 |
机械仪表 | 11997篇 |
建筑科学 | 16413篇 |
矿业工程 | 4942篇 |
能源动力 | 5849篇 |
轻工业 | 12681篇 |
水利工程 | 3211篇 |
石油天然气 | 11072篇 |
武器工业 | 1345篇 |
无线电 | 25479篇 |
一般工业技术 | 26699篇 |
冶金工业 | 10934篇 |
原子能技术 | 2114篇 |
自动化技术 | 27447篇 |
出版年
2024年 | 881篇 |
2023年 | 3260篇 |
2022年 | 5826篇 |
2021年 | 7877篇 |
2020年 | 5795篇 |
2019年 | 5007篇 |
2018年 | 5414篇 |
2017年 | 6199篇 |
2016年 | 5692篇 |
2015年 | 7290篇 |
2014年 | 9519篇 |
2013年 | 12269篇 |
2012年 | 12227篇 |
2011年 | 13875篇 |
2010年 | 11612篇 |
2009年 | 11460篇 |
2008年 | 10872篇 |
2007年 | 10467篇 |
2006年 | 10857篇 |
2005年 | 9629篇 |
2004年 | 6563篇 |
2003年 | 5776篇 |
2002年 | 5251篇 |
2001年 | 4723篇 |
2000年 | 4870篇 |
1999年 | 5637篇 |
1998年 | 5283篇 |
1997年 | 4351篇 |
1996年 | 3956篇 |
1995年 | 3310篇 |
1994年 | 2768篇 |
1993年 | 2187篇 |
1992年 | 1700篇 |
1991年 | 1277篇 |
1990年 | 1018篇 |
1989年 | 877篇 |
1988年 | 681篇 |
1987年 | 496篇 |
1986年 | 394篇 |
1985年 | 334篇 |
1984年 | 212篇 |
1983年 | 198篇 |
1982年 | 163篇 |
1981年 | 145篇 |
1980年 | 131篇 |
1979年 | 97篇 |
1978年 | 63篇 |
1977年 | 63篇 |
1976年 | 77篇 |
1975年 | 38篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Fluorescence‐Activated Cell Sorters: Standing Surface Acoustic Wave (SSAW)‐Based Fluorescence‐Activated Cell Sorter (Small 40/2018)
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
62.
Xueye Chen Yue Tian 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2020,95(3):806-812
Since the beginning of the 21st Century, the development of microfluidic chip technology has been very rapid and has attracted the attention of more and more scholars. As an important part of the microfluidic chip, the performance of the micromixer is critical. The fractal structure in the microchannels helps to improve the mixing performance of the micromixer and improve the mixing efficiency of the micromixer. The research results of other scholars are of great significance to the research of the present paper, which mainly studies the effect of changing the baffle state on the mixing efficiency of the micromixer based on the Koch fractal principle. Through simulation analysis, it was found that the mixing efficiency of the baffles distributed on both sides of the microchannel was higher than the mixing efficiency of the baffles distributed on the microchannel side. When the distance between adjacent baffles was divided into 0.15, 0.25 and 0.35 mm, simulated data suggested that the baffle distance of 0.15 mm was best. Increasing the number of baffles from six to eight groups increased the mixing path of the fluid in the microchannel and improved mixing efficiency. A comparison of mixing efficiencies of the 0°, 15° and 30° baffle angles revealed that very significant improvement in mixing efficiency was obtained at 30°. © 2019 Society of Chemical Industry 相似文献
63.
64.
World Wide Web - Infectious diseases such as Influenza and Ebola pose a serious threat to everyone but certain demographics and cohorts face a higher risk of infection than others. This research... 相似文献
65.
Wesley P. Chan Hiroto Mizohana Xiangyu Chen Yasuto Shiigi Yoshiyuki Yamanoue Masaki Nagatsuka Masayuki Inaba 《野外机器人技术杂志》2019,36(1):17-33
The use of field robots can greatly decrease the amount of time, effort, and associated risk compared to if human workers were to carryout certain tasks such as disaster response. However, transportability and reliability remain two main issues for most current robot systems. To address the issue of transportability, we have developed a lightweight modularizable platform named AeroArm. To address the issue of reliability, we utilize a multimodal sensing approach, combining the use of multiple sensors and sensor types, and the use of different detection algorithms, as well as active continuous closed‐loop feedback to accurately estimate the state of the robot with respect to the environment. We used Challenge 2 of the 2017 Mohammed Bin Zayed International Robotics Competition as an example outdoor manipulation task, demonstrating the capabilities of our robot system and approach in achieving reliable performance in the fields, and ranked fifth place internationally in the competition. 相似文献
66.
World Wide Web - The wide spread use of positioning and photographing devices gives rise to a deluge of traffic trajectory data (e.g., vehicle passage records and taxi trajectory data), with each... 相似文献
67.
68.
69.
Jie-Long He An-Te Chen Jyong-Huei Lee Shih-Kang Fan 《International journal of molecular sciences》2015,16(9):22319-22332
The basic structural and functional unit of a living organism is a single cell. To understand the variability and to improve the biomedical requirement of a single cell, its analysis has become a key technique in biological and biomedical research. With a physical boundary of microchannels and microstructures, single cells are efficiently captured and analyzed, whereas electric forces sort and position single cells. Various microfluidic techniques have been exploited to manipulate single cells through hydrodynamic and electric forces. Digital microfluidics (DMF), the manipulation of individual droplets holding minute reagents and cells of interest by electric forces, has received more attention recently. Because of ease of fabrication, compactness and prospective automation, DMF has become a powerful approach for biological application. We review recent developments of various microfluidic chips for analysis of a single cell and for efficient genetic screening. In addition, perspectives to develop analysis of single cells based on DMF and emerging functionality with high throughput are discussed. 相似文献
70.