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   59469篇
  免费   5424篇
  国内免费   3070篇
电工技术   4206篇
技术理论   5篇
综合类   4157篇
化学工业   9182篇
金属工艺   3520篇
机械仪表   3477篇
建筑科学   5212篇
矿业工程   1522篇
能源动力   1797篇
轻工业   3759篇
水利工程   1058篇
石油天然气   3145篇
武器工业   500篇
无线电   7302篇
一般工业技术   7317篇
冶金工业   2544篇
原子能技术   779篇
自动化技术   8481篇
  2024年   313篇
  2023年   1090篇
  2022年   1758篇
  2021年   2567篇
  2020年   1828篇
  2019年   1517篇
  2018年   1723篇
  2017年   1937篇
  2016年   1708篇
  2015年   2332篇
  2014年   2823篇
  2013年   3472篇
  2012年   3755篇
  2011年   3982篇
  2010年   3606篇
  2009年   3341篇
  2008年   3465篇
  2007年   3314篇
  2006年   3340篇
  2005年   2810篇
  2004年   1998篇
  2003年   1804篇
  2002年   1903篇
  2001年   1690篇
  2000年   1476篇
  1999年   1571篇
  1998年   1155篇
  1997年   1023篇
  1996年   1003篇
  1995年   815篇
  1994年   669篇
  1993年   493篇
  1992年   438篇
  1991年   323篇
  1990年   216篇
  1989年   181篇
  1988年   157篇
  1987年   100篇
  1986年   66篇
  1985年   56篇
  1984年   35篇
  1983年   23篇
  1982年   32篇
  1981年   18篇
  1980年   19篇
  1979年   8篇
  1978年   2篇
  1959年   2篇
  1951年   6篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
101.
由于水的选择性吸收特性,辐射换热中水份波长匹配一直是一个有分歧的问题。文章通过理论与计算论证了这个问题,得出的结论否定了波长匹配的重要性。  相似文献   
102.
Lithium metal batteries (LMBs), due to their ultra-high energy density, are attracting tremendous attentions. However, their commercial application is severely impeded by poor safety and unsatisfactory cycling stability, which are induced by lithium dendrites, side reactions, and inferior anodic stability. Electrolytes, as the indispensable and necessary components in lithium metal batteries, play a crucial role in regulating the electrochemical performance of LMBs. Recently, the fluorinated electrolytes are widely investigated in high-performance LMBs. Thus, the design strategies of fluorinated electrolytes are thoroughly summarized, including fluorinated salts, fluorinated solvents, and fluorinated additives in LMBs, and insights of the fluorinated components in suppressing lithium dendrites, improving anodic stability and cycling stability. Finally, an outlook with several design strategies and challenges will be proposed for novel fluorinated electrolytes.  相似文献   
103.
Wang  Lin  Wang  Xin  Li  Tao  Zheng  Ruijuan  Zhu  Junlong  Zhang  Mingchuan 《Neural computing & applications》2023,35(11):8051-8063
Neural Computing and Applications - Adaptive (sub)gradient methods have received wide applications such as the training of deep networks. The square-root regret bounds are achieved in convex...  相似文献   
104.
Ferromagnetic materials with a strong spin-orbit coupling (SOC) have attracted much attention in recent years because of their exotic properties and potential applications in energy-efficient spintronics. However, such materials are scarce in nature. Here, a proximity-induced paramagnetic to ferromagnetic transition for the heavy transition metal oxide CaRuO3 in (001)-(LaMnO3/CaRuO3) superlattices is reported. Anomalous Hall effect is observed in the temperature range up to 180 K. Maximal anomalous Hall conductivity and anomalous Hall angle are as large as ∼15 Ω−1 cm−1 and ∼0.93%, respectively, by one to two orders of magnitude larger than those of the typical 3d ferromagnetic oxides such as La0.67Sr0.33MnO3. Density functional theory calculations indicate the existence of avoid band crossings in the electronic band structure of the ferromagnetic CRO layer, which enhances Berry curvature thus strong anomalous Hall effects. Further evidences from polarized neutron reflectometry show that the CaRuO3 layers are in a fully ferromagnetic state (∼0.8 μB/Ru), in sharp contrast to the proximity-induced canted antiferromagnetic state in 5d oxides SrIrO3 and CaIrO3 (∼0.1 μB/Ir). More than that, the magnetic anisotropy of the (001)-(LaMnO3/CaRuO3) superlattices is eightfold symmetric, showing potential applications in the technology of multistate data storage.  相似文献   
105.
Hu  Zhigang  Huang  Yuhang  Zheng  Hao  Zheng  Meiguang  Liu  JianJun 《Pattern Analysis & Applications》2023,26(3):1481-1492
Pattern Analysis and Applications - The prosperity of datasets and model architectures has led to the development of pretrained source models, which simplified the learning process in multi-domain...  相似文献   
106.
This paper is concerned with the heading tracking control problem for a network-based unmanned surface vessel (USV) under wave-induced disturbances. Considering the characteristics of the wave-induced disturbances, the unknown-but-bounded (UBB) noise model is adopted. Meanwhile, signal quantization is taken into account due to the limited capacity of the communication channel. Based on these considerations, a novel set-membership based control scheme is proposed, which consists of a set-membership filter (SMF) and a set-membership controller (SMC). In the proposed control scheme, the SMF is designed for providing an ellipsoidal estimation set for the USV at each sampling step, and then the SMC uses the estimation set for producing control input for the USV in order to track the reference. Sufficient conditions are derived for the considered USV system to be asymptotically stable and satisfy the modified set-membership performance constraint. Simulation results verifies the effectiveness of the proposed control scheme.  相似文献   
107.
The formation control for multiple quadrotors subject to maintaining the formation configuration and collision avoidance in the situation of stochastic links failure is investigated in this paper. First, the distributed formation controller is designed, the position controller is developed to manage the desired formation of position, and the attitude controller is developed to control the translation and rotation movements of the quadrotor. Then, in order to avoid the collisions between multiple quadrotors and the obstacles, a potential energy function method is introduced into the quadrotor formation control combined with the nest adaptive control. Inspired by the design of event trigger controller, a communication compensation controller is designed to ensure the stability of quadrotor formation under the condition of random communication interruption and recovery. Moreover, a prescribed time function is designed, which means the convergence time of the formation system can be set in advance. The prescribed time stability of the formation control system is proved by Lyapunov theory. Finally, the simulation results verify the effectiveness and superiority of this method.  相似文献   
108.
Zheng  Jianbing  Gao  Ming  Lim  Ee-Peng  Lo  David  Jin  Cheqing  Zhou  Aoying 《Knowledge and Information Systems》2022,64(7):1967-1996
Knowledge and Information Systems - Network robustness measures how well network structure is strong and healthy when it is under attack, such as vertices joining and leaving. It has been widely...  相似文献   
109.
Xu  Junwei  Zheng  Ruijuan  Yang  Lei  Liu  Muhua  Song  Jianqiang  Zhang  Mingchuan  Wu  Qingtao 《The Journal of supercomputing》2022,78(12):14504-14529
The Journal of Supercomputing - In the edge computing, service placement refers to the process of installing service platforms, databases, and configuration files corresponding to computing tasks...  相似文献   
110.
Zhang  Kai  Zheng  Jing  Wang  Ying-Ming 《Applied Intelligence》2022,52(13):15177-15192
Applied Intelligence - Heterogeneous multi-attribute case retrieval is a crucial step in generating emergency alternatives during the course of emergency decision making (EDM) by referring to...  相似文献   
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