首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7098篇
  免费   227篇
  国内免费   29篇
电工技术   105篇
综合类   2篇
化学工业   1339篇
金属工艺   305篇
机械仪表   187篇
建筑科学   113篇
矿业工程   12篇
能源动力   346篇
轻工业   292篇
水利工程   59篇
石油天然气   14篇
无线电   1013篇
一般工业技术   1575篇
冶金工业   883篇
原子能技术   80篇
自动化技术   1029篇
  2023年   67篇
  2022年   131篇
  2021年   181篇
  2020年   160篇
  2019年   158篇
  2018年   250篇
  2017年   201篇
  2016年   216篇
  2015年   118篇
  2014年   224篇
  2013年   436篇
  2012年   239篇
  2011年   325篇
  2010年   251篇
  2009年   299篇
  2008年   257篇
  2007年   213篇
  2006年   231篇
  2005年   168篇
  2004年   135篇
  2003年   139篇
  2002年   133篇
  2001年   122篇
  2000年   109篇
  1999年   102篇
  1998年   235篇
  1997年   176篇
  1996年   121篇
  1995年   137篇
  1994年   107篇
  1993年   135篇
  1992年   109篇
  1991年   101篇
  1990年   87篇
  1989年   74篇
  1988年   74篇
  1987年   76篇
  1986年   87篇
  1985年   108篇
  1984年   98篇
  1983年   100篇
  1982年   81篇
  1981年   65篇
  1980年   51篇
  1979年   47篇
  1978年   48篇
  1977年   62篇
  1976年   82篇
  1975年   43篇
  1973年   37篇
排序方式: 共有7354条查询结果,搜索用时 15 毫秒
1.
Gupta  Aishwarya  Trivedi  Aditya  Prasad  Binod 《Wireless Networks》2022,28(7):3199-3211
Wireless Networks - Unmanned Aerial Vehicles (UAVs) deployed as flying base stations is a promising technology for enhancing the quality of service (QoS) and quick recovery from unexpected damages...  相似文献   
2.

Explosive growth of big data demands efficient and fast algorithms for nearest neighbor search. Deep learning-based hashing methods have proved their efficacy to learn advanced hash functions that suit the desired goal of nearest neighbor search in large image-based data-sets. In this work, we present a comprehensive review of different deep learning-based supervised hashing methods particularly for image data-sets suggested by various researchers till date to generate advanced hash functions. We categorize prior works into a five-tier taxonomy based on: (i) the design of network architecture, (ii) training strategy based on nature of data-set, (iii) the type of loss function, (iv) the similarity measure and, (v) the nature of quantization. Further, different data-sets used in prior works are reported and compared based on various challenges in the characteristics of images that are part of the data-sets. Lastly, different future directions such as incremental hashing, cross-modality hashing and guidelines to improve design of hash functions are discussed. Based on our comparative review, it has been observed that generative adversarial networks-based hashing models outperform other methods. This is due to the fact that they leverage more data in the form of both real world and synthetically generated data. Furthermore, it has been perceived that triplet-loss-based loss functions learn better discriminative representations by pushing similar patterns together and dis-similar patterns away from each other. This study and its observations shall be useful for the researchers and practitioners working in this emerging research field.

  相似文献   
3.
(Ta2O5)1-x- (TiO2)x (TTOx) thin films, with x = 0, 0.03, 0.06, 0.08, and 0.11, were deposited using magnetron direct current (DC) sputtering method onto the P/boron-silicon (1 0 0) substrates by varying areas of Tantalum and Titanium metallic targets, in oxygen environment at ambient temperature. The as-deposited thin films were annealed at temperatures ranging from 500 to 800 °C. Generally, the formation of the Ta2O5 structure was observed from the X-ray diffraction measurements of the annealed films. The capacitance of prepared metal– oxide– semiconductor (MOS) structures of Ag/TTOx/p-Si was measured at 1 MHz. The dielectric constant of the deposited films was observed altering with varying composition and annealing temperature, showing the highest value 71, at 1 MHz, for the TTOx films, x = 0.06, annealed at 700 °C. With increasing annealing temperature, from 700 to 800 °C, the leakage current density was observed, generally decreasing, from 10?5 to 10?8 A cm?2, for the prepared compositions. Among the prepared compositions, films with x = 0.06, annealed at 800 °C, having the observed value of dielectric constant 48, at 1 MHz; and the leakage current density 2.7 × 10?8 A cm?2, at the electric field of 3.5 × 105 V cm?1, show preferred potential as a dielectric for high-density silicon memory devices.  相似文献   
4.
Wireless Personal Communications - The orthogonal frequency division multiplexing (OFDM) is the most encouraging multi-carrier modulation system chosen for the high data rates but the objective is...  相似文献   
5.
Wireless Personal Communications - The efficient management of resource sharing plays a crucial role in the cloud execution environment. The constraints such as heterogeneity and dynamic nature of...  相似文献   
6.
ABSTRACT

Wireless Interoperability for Multiple Access (WiMAX) is one of the emerging fields of high-speed wireless communication that has enormous capabilities due to its range and the connection speed. Like wireless local area networks (LANs), WiMAX networks implement multiple quality of service (QoS) frameworks at the Media Access Control (MAC) level for assured data, voice, and video services. The question of ensuring QoS is basically how to distribute available resources to users in order to satisfy QoS parameters such as latency, jitter and throughput requirements. IEEE 802.16 standard does not have any particular guidelines on scheduling of incoming and outgoing data. This has caught the attention of researchers working on WiMAX. This article discusses the various issues in WiMAX along with a classification of various scheduling approaches based upon the type of scheduler for the sake of better understanding the scheduling problem and analyzing various available theories.  相似文献   
7.
Multimedia Tools and Applications - The automatic binary classification of normal and abnormal subjects using magnetic resonance (MR) brain images has made remarkable progress in recent years. This...  相似文献   
8.
Protection of Metals and Physical Chemistry of Surfaces - Single NbSi2 and duplex NbSi2/Nb5Si3 coatings were successfully applied on Nb substrates using halide activated pack cementation (HAPC)...  相似文献   
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号