全文获取类型
收费全文 | 61643篇 |
免费 | 5611篇 |
国内免费 | 3147篇 |
专业分类
电工技术 | 4433篇 |
技术理论 | 5篇 |
综合类 | 4330篇 |
化学工业 | 9585篇 |
金属工艺 | 3632篇 |
机械仪表 | 3590篇 |
建筑科学 | 5355篇 |
矿业工程 | 1581篇 |
能源动力 | 1857篇 |
轻工业 | 3898篇 |
水利工程 | 1114篇 |
石油天然气 | 3312篇 |
武器工业 | 517篇 |
无线电 | 7513篇 |
一般工业技术 | 7529篇 |
冶金工业 | 2631篇 |
原子能技术 | 784篇 |
自动化技术 | 8735篇 |
出版年
2024年 | 323篇 |
2023年 | 1121篇 |
2022年 | 1847篇 |
2021年 | 2720篇 |
2020年 | 1910篇 |
2019年 | 1587篇 |
2018年 | 1780篇 |
2017年 | 2001篇 |
2016年 | 1771篇 |
2015年 | 2436篇 |
2014年 | 2955篇 |
2013年 | 3616篇 |
2012年 | 3897篇 |
2011年 | 4136篇 |
2010年 | 3735篇 |
2009年 | 3447篇 |
2008年 | 3582篇 |
2007年 | 3423篇 |
2006年 | 3451篇 |
2005年 | 2895篇 |
2004年 | 2058篇 |
2003年 | 1870篇 |
2002年 | 1954篇 |
2001年 | 1743篇 |
2000年 | 1502篇 |
1999年 | 1627篇 |
1998年 | 1193篇 |
1997年 | 1046篇 |
1996年 | 1032篇 |
1995年 | 828篇 |
1994年 | 693篇 |
1993年 | 506篇 |
1992年 | 447篇 |
1991年 | 332篇 |
1990年 | 219篇 |
1989年 | 185篇 |
1988年 | 163篇 |
1987年 | 100篇 |
1986年 | 66篇 |
1985年 | 56篇 |
1984年 | 36篇 |
1983年 | 23篇 |
1982年 | 33篇 |
1981年 | 18篇 |
1980年 | 19篇 |
1979年 | 8篇 |
1978年 | 2篇 |
1959年 | 3篇 |
1951年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
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
72.
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
73.
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
74.
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
75.
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
76.
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
77.
Jinsheng?Xu Long?Han Jian?Zheng Xiong?ChenEmail author Changsheng?Zhou 《Mechanics of Time-Dependent Materials》2017,21(4):577-595
A thermo-damage-viscoelastic model for hydroxyl-terminated polybutadiene (HTPB) composite propellant with consideration for the effect of temperature was implemented in ABAQUS. The damage evolution law of the model has the same form as the crack growth equation for viscoelastic materials, and only a single damage variable \(S\) is considered. The HTPB propellant was considered as an isotropic material, and the deviatoric and volumetric strain-stress relations are decoupled and described by the bulk and shear relaxation moduli, respectively. The stress update equations were expressed by the principal stresses \(\sigma_{ii}^{R}\) and the rotation tensor \(M\), the Jacobian matrix in the global coordinate system \(J_{ijkl}\) was obtained according to the fourth-order tensor transformation rules. Two models having complex stress states were used to verify the accuracy of the constitutive model. The test results showed good agreement with the strain responses of characteristic points measured by a contactless optical deformation test system, which illustrates that the thermo-damage-viscoelastic model perform well at describing the mechanical properties of an HTPB propellant. 相似文献
78.
79.
Cancer Multidrug Resistance: Safe and Effective Reversal of Cancer Multidrug Resistance Using Sericin‐Coated Mesoporous Silica Nanoparticles for Lysosome‐Targeting Delivery in Mice (Small 9/2017) 下载免费PDF全文
80.
In this paper, a modified teaching–learning-based optimisation (mTLBO) algorithm is proposed to solve the re-entrant hybrid flowshop scheduling problem (RHFSP) with the makespan and the total tardiness criteria. Based on the simple job-based representation, a novel decoding method named equivalent due date-based permutation schedule is proposed to transfer an individual to a feasible schedule. At each generation, a number of superior individuals are selected as the teachers by the Pareto-based ranking phase. To enhance the exploitation ability in the promising area, the insertion-based local search is embedded in the search framework as the training phase for the TLBO. Due to the characteristics of the permutation-based discrete optimisation, the linear order crossover operator and the swap operator are adopted to imitate the interactions among the individuals in both the teaching phase and the learning phase. To store the non-dominated solutions explored during the search process, an external archive is used and updated when necessary. The influence of the parameter setting on the mTLBO in solving the RHFSP is investigated, and numerical tests with some benchmarking instances are carried out. The comparative results show that the proposed mTLBO outperforms the existing algorithms significantly. 相似文献