全文获取类型
收费全文 | 89380篇 |
免费 | 6840篇 |
国内免费 | 3472篇 |
专业分类
电工技术 | 4940篇 |
技术理论 | 5篇 |
综合类 | 5705篇 |
化学工业 | 15706篇 |
金属工艺 | 5407篇 |
机械仪表 | 5486篇 |
建筑科学 | 7862篇 |
矿业工程 | 2579篇 |
能源动力 | 2375篇 |
轻工业 | 5365篇 |
水利工程 | 1565篇 |
石油天然气 | 5266篇 |
武器工业 | 683篇 |
无线电 | 9344篇 |
一般工业技术 | 10635篇 |
冶金工业 | 4504篇 |
原子能技术 | 1068篇 |
自动化技术 | 11197篇 |
出版年
2024年 | 359篇 |
2023年 | 1493篇 |
2022年 | 2419篇 |
2021年 | 3364篇 |
2020年 | 2622篇 |
2019年 | 2184篇 |
2018年 | 2536篇 |
2017年 | 2874篇 |
2016年 | 2455篇 |
2015年 | 3263篇 |
2014年 | 4125篇 |
2013年 | 5060篇 |
2012年 | 5545篇 |
2011年 | 5929篇 |
2010年 | 5034篇 |
2009年 | 4965篇 |
2008年 | 4761篇 |
2007年 | 4579篇 |
2006年 | 4883篇 |
2005年 | 4339篇 |
2004年 | 2897篇 |
2003年 | 2501篇 |
2002年 | 2296篇 |
2001年 | 2025篇 |
2000年 | 2301篇 |
1999年 | 2683篇 |
1998年 | 2185篇 |
1997年 | 1778篇 |
1996年 | 1825篇 |
1995年 | 1486篇 |
1994年 | 1211篇 |
1993年 | 858篇 |
1992年 | 700篇 |
1991年 | 554篇 |
1990年 | 402篇 |
1989年 | 333篇 |
1988年 | 271篇 |
1987年 | 184篇 |
1986年 | 123篇 |
1985年 | 89篇 |
1984年 | 57篇 |
1983年 | 36篇 |
1982年 | 40篇 |
1981年 | 35篇 |
1980年 | 23篇 |
1979年 | 6篇 |
1978年 | 2篇 |
1965年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
131.
Chuanming Tian Bin Li Yichuan Rui Hao Xiong Yu Zhao Xuefei Han Xinliang Zhou Yu Qiu Wei An Kerui Li Chengyi Hou Yaogang Li Hongzhi Wang Qinghong Zhang 《Advanced functional materials》2023,33(41):2302270
Despite the outstanding power conversion efficiency (PCE) of perovskite solar cells (PSCs) achieved over the years, unsatisfactory stability and lead toxicity remain obstacles that limit their competitiveness and large-scale practical deployment. In this study, in situ polymerizing internal encapsulation (IPIE) is developed as a holistic approach to overcome these challenges. The uniform polymer internal package layer constructed by thermally triggered cross-linkable monomers not only solidifies the ionic perovskite crystalline by strong electron-withdrawing/donating chemical sites, but also acts as a water penetration and ion migration barrier to prolong shelf life under harsh environments. The optimized MAPbI3 and FAPbI3 devices with IPIE treatment yield impressive efficiencies of 22.29% and 24.12%, respectively, accompanied by remarkably enhanced environmental and mechanical stabilities. In addition, toxic water-soluble lead leakage is minimized by the synergetic effect of the physical encapsulation wall and chemical chelation conferred by the IPIE. Hence, this strategy provides a feasible route for preparing efficient, stable, and eco-friendly PSCs. 相似文献
132.
Ding Chun Wang Meimin Zhou Zhili Huang Teng Wang Xiaoliang Li Jin 《Neural computing & applications》2023,35(11):8125-8142
Neural Computing and Applications - As a fundamental technique for mining and analysis of remote sensing (RS) big data, content-based remote sensing image retrieval (CBRSIR) has received a lot of... 相似文献
133.
Zhang Man Zhou Yong Liu Bing Zhao Jiaqi Yao Rui Shao Zhiwen Zhu Hancheng Chen Hao 《Pattern Analysis & Applications》2023,26(2):669-677
Pattern Analysis and Applications - The designed method aims to perform image classification tasks efficiently and accurately. Different from the traditional CNN-based image classification methods,... 相似文献
134.
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
135.
Wei Shang Guohao Jing Yulin Wang Tianlong Chen Zhou Liu Zhongzhong Zheng 《Asian journal of control》2023,25(4):2699-2719
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
136.
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
137.
The Journal of Supercomputing - We argue the agent’s low generalization problem for searching target object in challenging visual navigation could be solved by "how" and... 相似文献
138.
Neural Computing and Applications - A new iterative method based on the event-triggered strategy for finding a solution to a mixed equilibrium problem (MEP) is introduced in this paper. The target... 相似文献
139.
Computational Economics - The study aims to analyze and forecast Internet financial risks based on the model based on deep learning and the Back Propagation Neural Network (BPNN). First, the theory... 相似文献
140.