全文获取类型
收费全文 | 2287篇 |
免费 | 423篇 |
国内免费 | 211篇 |
专业分类
电工技术 | 349篇 |
技术理论 | 1篇 |
综合类 | 363篇 |
化学工业 | 67篇 |
金属工艺 | 19篇 |
机械仪表 | 92篇 |
建筑科学 | 226篇 |
矿业工程 | 37篇 |
能源动力 | 81篇 |
轻工业 | 55篇 |
水利工程 | 39篇 |
石油天然气 | 31篇 |
武器工业 | 6篇 |
无线电 | 407篇 |
一般工业技术 | 218篇 |
冶金工业 | 18篇 |
原子能技术 | 11篇 |
自动化技术 | 901篇 |
出版年
2024年 | 17篇 |
2023年 | 57篇 |
2022年 | 69篇 |
2021年 | 75篇 |
2020年 | 124篇 |
2019年 | 84篇 |
2018年 | 87篇 |
2017年 | 99篇 |
2016年 | 133篇 |
2015年 | 134篇 |
2014年 | 164篇 |
2013年 | 171篇 |
2012年 | 207篇 |
2011年 | 200篇 |
2010年 | 149篇 |
2009年 | 133篇 |
2008年 | 117篇 |
2007年 | 151篇 |
2006年 | 112篇 |
2005年 | 94篇 |
2004年 | 78篇 |
2003年 | 77篇 |
2002年 | 52篇 |
2001年 | 60篇 |
2000年 | 32篇 |
1999年 | 34篇 |
1998年 | 26篇 |
1997年 | 32篇 |
1996年 | 21篇 |
1995年 | 27篇 |
1994年 | 16篇 |
1993年 | 19篇 |
1992年 | 17篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 8篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有2921条查询结果,搜索用时 15 毫秒
81.
以往的分布式故障诊断系统只有当故障发生后才进行故障诊断,不具有实时性,不能监测网络的运行并根据网络的运行情况适时地启动故障诊断模块。给出了一种新的分布式故障诊断系统,既克服了网络频繁进行故障诊断代价太高的缺点又使网络的故障得到及时发现。 相似文献
82.
83.
84.
Synchronization analysis of coupled connected neural networks with mixed time delays 总被引:2,自引:0,他引:2
In this paper, the global exponential synchronization of coupled connected neural networks with both discrete and distributed delays is investigated under mild condition, assuming neither the differentiability and strict monotonicity for the activation functions nor the diagonal for the inner coupling matrices. By employing a new Lyapunov–Krasovskii functional, applying the theory of Kronecker product of matrices and the linear matrix inequality (LMI) technique, several delay-dependent sufficient conditions in LMI form are obtained for global exponential synchronization of such systems. Moreover, the decay rate is estimated. The proposed LMI approach has the advantage of considering the difference of neuronal excitatory and inhibitory efforts, which is also computationally efficient as it can be solved numerically using efficient Matlab LMI toolbox, and no tuning of parameters is required. In addition, the proposed results generalize and improve the earlier publications. An example with simulation is given to show the effectiveness of the obtained results. 相似文献
85.
Heuristics and metaheuristics are inevitable ingredients of most of the general purpose ILP solvers today, because of their contribution to the significant boost of the performance of exact methods. In the field of bi/multi-objective optimization, to the best of our knowledge, it is still not very common to integrate ILP heuristics into exact solution frameworks. This paper aims to bring a stronger attention of both the exact and metaheuristic communities to still unexplored possibilities for performance improvements of exact and heuristic multi-objective optimization algorithms.We focus on bi-objective optimization problems whose feasible solutions can be described as 0/1 integer linear programs and propose two ILP heuristics, boundary induced neighborhood search (BINS) and directional local branching. Their main idea is to combine the features and explore the neighborhoods of solutions that are relatively close in the objective space. A two-phase ILP-based heuristic framework relying on BINS and directional local branching is introduced. Moreover, a new exact method called adaptive search in objective space (ASOS) is also proposed. ASOS combines features of the ϵ-constraint method with the binary search in the objective space and uses heuristic solutions produced by BINS for guidance. Our new methods are computationally evaluated on two problems of particular relevance for the design of FTTx-networks. Comparison with other known exact methods (relying on the exploration of the objective space) is conducted on a set of realistic benchmark instances representing telecommunication access networks from Germany. 相似文献
86.
针对港口监控摄像机与船舶目标距离远,船舶目标成像小,海面噪声干扰大等特点,采用一种基于多结构元素形态学滤波的背景抑制算法.根据船舶的几何特征,采用多组结构元素的加权形态学滤波,将船舶目标与海面背景分离,然后利用基于邻域的自适应快速中值滤波滤除脉冲噪声,最后根据海面杂波在帧间运动不连续且面积较小等特点,利用连通域计算建立船舶的形态特征模型,来排除海面杂波对船舶检测的干扰.实验结果证明,该检测方法在实际港口获取的视频中,可以有效的抑制背景噪声和海面杂波,快速的检测出船舶目标. 相似文献
87.
In this paper, controller design for discrete‐time bilinear systems is investigated by using sum of squares programming methods and quadratic Lyapunov functions. The class of rational polynomial controllers is considered, and necessary conditions on the degree of controller polynomials for quadratic stability are derived. Next, a scalarized version of the Schur complement is proposed. For controller design, the Lyapunov difference inequality is converted to a sum of squares problem, and an optimization problem is proposed to design a controller, which maximizes the region of quadratic stability of the bilinear system. Input constraints can also be accounted for. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
88.
图连通性的判定对于路径规划中任意两点间路径相通性判断以及连通块的划分都具有重要意义。从节点的边连通关系着手分析图的结构层次,通过构建图的分层递阶商空间链,分析不同层次商空间链中各节点分布情况,得出新的图连通性判定方法。与以往各判定方法相比,该方法具有易实现、效率高的优点,不仅能有效地判定图是否连通,还能确定图的连通分支数以及哪些节点位于同一连通分支中。 相似文献
89.
针对传统视觉传感器信号处理能力差、模拟信号输出易受干扰等问题,设计了基于ARM 6410处理器的智能化数字视觉传感器,应用于白车身在线视觉检测系统,完成数据采集、像素级二维定位和通讯控制工作。在Linux平台上,研究了一种快速稳定的像素级模板匹配算法,以去均值归一化灰度互相关法为相似性测度,多分辨率金字塔匹配法为搜索策略,使用“滚动相加补全像素法冶的二维求和新方法来优化计算过程,并进行了全局冗错设计,确保传感器工作稳定性。现场实验表明:采用该匹配算法和冗错机制使得视觉传感器定位功能速度快、精度高、鲁棒性好,能较好完成白车身视觉检测系统前端数据采集和处理任务。 相似文献
90.
Suppose a graph G is given with two vertex-disjoint sets of vertices Z1 and Z2. Can we partition the remaining vertices of G such that we obtain two connected vertex-disjoint subgraphs of G that contain Z1 and Z2, respectively? This problem is known as the 2-Disjoint Connected Subgraphs problem. It is already NP-complete for the class of n-vertex graphs G=(V,E) in which Z1 and Z2 each contain a connected set that dominates all vertices in V?(Z1∪Z2). We present an O∗(1.2051n) time algorithm that solves it for this graph class. As a consequence, we can also solve this problem in O∗(1.2051n) time for the classes of n-vertex P6-free graphs and split graphs. This is an improvement upon a recent O∗(1.5790n) time algorithm for these two classes. Our approach translates the problem to a generalized version of hypergraph 2-coloring and combines inclusion/exclusion with measure and conquer. 相似文献