全文获取类型
收费全文 | 3526篇 |
免费 | 383篇 |
国内免费 | 373篇 |
专业分类
电工技术 | 177篇 |
综合类 | 365篇 |
化学工业 | 342篇 |
金属工艺 | 70篇 |
机械仪表 | 139篇 |
建筑科学 | 73篇 |
矿业工程 | 34篇 |
能源动力 | 130篇 |
轻工业 | 68篇 |
水利工程 | 46篇 |
石油天然气 | 51篇 |
武器工业 | 27篇 |
无线电 | 463篇 |
一般工业技术 | 417篇 |
冶金工业 | 22篇 |
原子能技术 | 35篇 |
自动化技术 | 1823篇 |
出版年
2024年 | 16篇 |
2023年 | 40篇 |
2022年 | 58篇 |
2021年 | 87篇 |
2020年 | 125篇 |
2019年 | 115篇 |
2018年 | 99篇 |
2017年 | 157篇 |
2016年 | 145篇 |
2015年 | 156篇 |
2014年 | 198篇 |
2013年 | 304篇 |
2012年 | 277篇 |
2011年 | 266篇 |
2010年 | 204篇 |
2009年 | 255篇 |
2008年 | 233篇 |
2007年 | 206篇 |
2006年 | 188篇 |
2005年 | 162篇 |
2004年 | 117篇 |
2003年 | 115篇 |
2002年 | 95篇 |
2001年 | 89篇 |
2000年 | 72篇 |
1999年 | 68篇 |
1998年 | 61篇 |
1997年 | 71篇 |
1996年 | 42篇 |
1995年 | 49篇 |
1994年 | 35篇 |
1993年 | 30篇 |
1992年 | 17篇 |
1991年 | 12篇 |
1990年 | 13篇 |
1989年 | 12篇 |
1988年 | 9篇 |
1987年 | 6篇 |
1986年 | 10篇 |
1985年 | 12篇 |
1984年 | 5篇 |
1983年 | 9篇 |
1982年 | 5篇 |
1981年 | 9篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1978年 | 3篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1973年 | 4篇 |
排序方式: 共有4282条查询结果,搜索用时 62 毫秒
111.
Optimal assembly plan generation: a simplifying approach 总被引:3,自引:0,他引:3
The main difficulty in the overall process of optimal assembly plan generation is the great number of different ways to assemble
a product (typically thousands of solutions). This problem confines the application of most existing automated planning methods
to products composed of only a limited number of components. The presented method of assembly plan generation belongs to the
approach called “disassembly” and is founded on a new representation of the assembly process, with introduction of a new concept,
the equivalence of binary trees. This representation allows to generate the minimal list of all non-redundant (really different) assembly plans. Plan generation is directed by assembly operation constraints and plan-level performance
criteria. The method was tested for various assembly applications and compared to other generation approaches. Results show
a great reduction in the combinatorial explosion of the number of plans. Therefore, this simplifying approach of assembly
sequence modeling allows to handle more complex products with a large number of parts. 相似文献
112.
113.
114.
针对一类不确定切换中立型系统, 设计相应的积分型滑模面. 基于平均驻留时间方法和线性矩阵不等式技术, 给出滑模动力学系统鲁棒指数渐近稳定的时滞相关性判据. 通过设计滑模控制器, 使闭环系统的状态满足到达条件. 数值仿真表明, 所提出的方法是有效可行的.
相似文献115.
Global output‐feedback stabilization for a class of stochastic nonlinear systems via sampled‐data control
下载免费PDF全文
![点击此处可从《国际强度与非线性控制杂志<br>》网站下载免费的PDF全文](/ch/ext_images/free.gif)
In this paper, the global sampled‐data output‐feedback stabilization problem is considered for a class of stochastic nonlinear systems. First, based on output‐feedback domination technique and emulation approach, a systematic design procedure for sampled‐data output‐feedback controller is proposed for a class of stochastic lower‐triangular nonlinear systems. It is proved that the proposed sampled‐data output‐feedback controller will stabilize the given stochastic nonlinear system in the sense of mean square exponential stability. Because of the domination nature of the proposed control approach, it is shown that the proposed control approach can also be used to handle the global sampled‐data output‐feedback stabilization problems for a more general class of stochastic non‐triangular nonlinear systems. Finally, simulation examples are given to demonstrate the effectiveness of the proposed method. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
116.
Stability of neutral stochastic switched time delay systems: An average dwell time approach
下载免费PDF全文
![点击此处可从《国际强度与非线性控制杂志<br>》网站下载免费的PDF全文](/ch/ext_images/free.gif)
This paper considers a class of stochastic systems referred to as stochastic switched systems of neutral type with time‐varying delay, which combines switched systems with neutral stochastic systems. The systems consist of subsystems of two forms: (i) only stable subsystems and (ii) both stable subsystems and unstable subsystems. By establishing an integral inequality, the exponential stability in pth(p≥1)‐moment for such systems with only stable subsystems is first considered. Then, by using an average dwell time approach, the exponential stability in pth(p≥1)‐moment for the second form is addressed. An important finding of this study is that when the average dwell time is chosen to be sufficiently large and the total activation time of unstable subsystems is relatively small compared with that of stable subsystems, the exponential stability in pth(p≥1)‐moment for such systems can be guaranteed. Two major advantages of these new results are that the differentiability or continuity of the delay function is not required compared with the existing results in the literature, and the proposed approaches can be used to consider the case when the neutral item and the stochastic perturbation are simultaneously presented. An example is provided to verify the effectiveness and potential of the theoretic results obtained. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
117.
主要研究了基于多变量特征模型的黄金分割自适应控制器的闭环系统稳定性.对从特定区间取值的双输入输出特征模型,通过计算离散系统的矩阵导出1范数,一个充分条件被用来证明闭环系统是指数稳定的.结果不仅表现了系统稳定性,还同时给出了一个黄金分割自适应控制器中可调参数数值的选取方法.最后对中继星的数学仿真验证了系统的稳定性. 相似文献
118.
Matthias Jungmann Margarete Kopal Christoph ClauserThomas Berlage 《Computers & Geosciences》2011,37(4):541-553
Electrical borehole wall images represent micro-resistivity measurements at the borehole wall. The lithology reconstruction is often based on visual interpretation done by geologists. This analysis is very time-consuming and subjective. Different geologists may interpret the data differently. In this work, linear discriminant analysis (LDA) in combination with texture features is used for an automated lithology reconstruction of ODP (Ocean Drilling Program) borehole 1203A drilled during Leg 197. Six rock groups are identified by their textural properties in resistivity data obtained by a Formation MircoScanner (FMS). Although discriminant analysis can be used for multi-class classification, non-optimal decision criteria for certain groups could emerge. For this reason, we use a combination of 2-class (binary) classifiers to increase the overall classification accuracy. The generalization ability of the combined classifiers is evaluated and optimized on a testing dataset where a classification rate of more than 80% for each of the six rock groups is achieved. The combined, trained classifiers are then applied on the whole dataset obtaining a statistical reconstruction of the logged formation. Compared to a single multi-class classifier the combined binary classifiers show better classification results for certain rock groups and more stable results in larger intervals of equal rock type. 相似文献
119.
This paper is concerned with the sliding mode control (SMC) of a continuous-time switched stochastic system. A sufficient condition for the existence of reduced-order sliding mode dynamics is derived and an explicit parametrization of the desired sliding surface is also given. Then, a sliding mode controller is then synthesized for reaching motion. Moreover, the observer-based SMC problem is also investigated. Some sufficient conditions are established for the existence and the solvability of the desired observer and the observer-based sliding mode controller is synthesized. Finally, numerical examples are provided to illustrate the effectiveness of the proposed theory. 相似文献
120.