全文获取类型
收费全文 | 17624篇 |
免费 | 1331篇 |
国内免费 | 619篇 |
专业分类
电工技术 | 1044篇 |
综合类 | 2047篇 |
化学工业 | 418篇 |
金属工艺 | 935篇 |
机械仪表 | 4490篇 |
建筑科学 | 5243篇 |
矿业工程 | 848篇 |
能源动力 | 413篇 |
轻工业 | 153篇 |
水利工程 | 652篇 |
石油天然气 | 502篇 |
武器工业 | 125篇 |
无线电 | 250篇 |
一般工业技术 | 957篇 |
冶金工业 | 979篇 |
原子能技术 | 48篇 |
自动化技术 | 470篇 |
出版年
2024年 | 83篇 |
2023年 | 206篇 |
2022年 | 476篇 |
2021年 | 547篇 |
2020年 | 581篇 |
2019年 | 379篇 |
2018年 | 377篇 |
2017年 | 462篇 |
2016年 | 569篇 |
2015年 | 632篇 |
2014年 | 1102篇 |
2013年 | 749篇 |
2012年 | 1276篇 |
2011年 | 1322篇 |
2010年 | 959篇 |
2009年 | 1048篇 |
2008年 | 874篇 |
2007年 | 1260篇 |
2006年 | 1148篇 |
2005年 | 1003篇 |
2004年 | 734篇 |
2003年 | 666篇 |
2002年 | 626篇 |
2001年 | 512篇 |
2000年 | 431篇 |
1999年 | 334篇 |
1998年 | 291篇 |
1997年 | 219篇 |
1996年 | 203篇 |
1995年 | 130篇 |
1994年 | 113篇 |
1993年 | 64篇 |
1992年 | 45篇 |
1991年 | 30篇 |
1990年 | 24篇 |
1989年 | 20篇 |
1988年 | 13篇 |
1987年 | 17篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 12篇 |
1980年 | 9篇 |
1979年 | 7篇 |
1959年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
In actual engineering scenarios, limited fault data leads to insufficient model training and over-fitting, which negatively affects the diagnostic performance of intelligent diagnostic models. To solve the problem, this paper proposes a variational information constrained generative adversarial network (VICGAN) for effective machine fault diagnosis. Firstly, by incorporating the encoder into the discriminator to map the deep features, an improved generative adversarial network with stronger data synthesis capability is established. Secondly, to promote the stable training of the model and guarantee better convergence, a variational information constraint technique is utilized, which constrains the input signals and deep features of the discriminator using the information bottleneck method. In addition, a representation matching module is added to impose restrictions on the generator, avoiding the mode collapse problem and boosting the sample diversity. Two rolling bearing datasets are utilized to verify the effectiveness and stability of the presented network, which demonstrates that the presented network has an admirable ability in processing fault diagnosis with few samples, and performs better than state-of-the-art approaches. 相似文献
2.
This paper introduces the potential feasibility that ELID (electrolytic in-process dressing) grinding replaces superfinishing in bearing manufacturing, but ELID grinding will bring new challenges. Different regions present distinguish surface profile due to the non-uniform contact in ELID groove grinding. However, few reports explaining the non-uniform contact are available. This article explores the mechanisms of the non-uniform contact during ELID groove grinding. Experiments on the non-uniform contact between bearing raceway and grinding wheel have been carried out under different conditions. The results show that non-uniform contact exists in ELID groove grinding process and it exerts influence on the profile of the raceway surface. Non-uniform contact influences the Rsk and Rku value all the time, but it influences the Ra value occasionally. Improvement strategies of eliminating the non-uniform contact are also discussed based on the experimental study. 相似文献
3.
With increasing consumption of natural gas (NG), small NG reservoirs, such as coalbed methane and oil field associated gas, have recently drawn significant attention. Owing to their special characteristics (e.g., scattered distribution and small output), small-scale NG liquefiers are highly required. Similarly, the mixed refrigerant cycle (MRC) is suitable for small-scale liquefaction systems due to its moderate complexity and power consumption. In consideration of the above, this paper reviews the development of mobile miniature NG liquefiers in Technical Institute of Physics and Chemistry (TIPC), China. To effectively liquefy the scattered NG and overcome the drawbacks of existing technologies, three main improvements, i.e., low-pressure MRC process driven by oil-lubricated screw compressor, compact cold box with the new designed heat exchangers, and standardized equipment manufacturing and integrated process technology have been made. The development pattern of “rapid cluster application and flexible liquefaction center” has been eventually proposed. The small-scale NG liquefier developed by TIPC has reached a minimum liquefaction power consumption of about 0.35 kW·h/Nm3. It is suitable to exploit small remote gas reserves which can also be used in boil-off gas reliquefaction and distributed peak-shaving of pipe networks. 相似文献
4.
5.
6.
7.
8.
文中对万家寨引黄工程北干线1号隧洞Ⅳ标使用的155—274型TBM主轴承总成各部件组装过程及其相应的技术要求进行了概要的描述,目的是进一步熟悉155—274型TBM主轴承总成的各个部件并加深对主轴承工作原理的理解。 相似文献
9.
10.