全文获取类型
| 收费全文 | 1011篇 |
| 免费 | 73篇 |
| 国内免费 | 20篇 |
专业分类
| 化学 | 50篇 |
| 晶体学 | 2篇 |
| 力学 | 18篇 |
| 综合类 | 16篇 |
| 数学 | 898篇 |
| 物理学 | 120篇 |
出版年
| 2024年 | 6篇 |
| 2023年 | 5篇 |
| 2022年 | 33篇 |
| 2021年 | 35篇 |
| 2020年 | 22篇 |
| 2019年 | 26篇 |
| 2018年 | 19篇 |
| 2017年 | 41篇 |
| 2016年 | 47篇 |
| 2015年 | 28篇 |
| 2014年 | 56篇 |
| 2013年 | 63篇 |
| 2012年 | 48篇 |
| 2011年 | 42篇 |
| 2010年 | 43篇 |
| 2009年 | 74篇 |
| 2008年 | 68篇 |
| 2007年 | 58篇 |
| 2006年 | 54篇 |
| 2005年 | 50篇 |
| 2004年 | 36篇 |
| 2003年 | 27篇 |
| 2002年 | 33篇 |
| 2001年 | 19篇 |
| 2000年 | 11篇 |
| 1999年 | 12篇 |
| 1998年 | 19篇 |
| 1997年 | 25篇 |
| 1996年 | 18篇 |
| 1995年 | 15篇 |
| 1994年 | 6篇 |
| 1993年 | 8篇 |
| 1992年 | 6篇 |
| 1991年 | 5篇 |
| 1990年 | 3篇 |
| 1989年 | 4篇 |
| 1988年 | 1篇 |
| 1987年 | 1篇 |
| 1986年 | 2篇 |
| 1985年 | 6篇 |
| 1984年 | 4篇 |
| 1983年 | 1篇 |
| 1982年 | 4篇 |
| 1981年 | 4篇 |
| 1980年 | 6篇 |
| 1979年 | 2篇 |
| 1978年 | 3篇 |
| 1977年 | 2篇 |
| 1976年 | 1篇 |
| 1973年 | 2篇 |
排序方式： 共有1104条查询结果，搜索用时 15 毫秒
41.
Modularity is a natural instrument and a ubiquitous practice for the engineering of human‐made systems. However, modularization remains more of an art than a science; to the extent that the notion of optimal modularity is rarely used in engineering design. We prove that optimal modularity exists (at least for construction)—and is achieved through balanced modularization as structural symmetry in the distribution of the sizes of modules. We show that system construction cost is highly sensitive to both the number of modules and the modularization structure. However, this sensitivity has an inverse relationship with process capability and is minimal for highly capable construction processes with small process uncertainties. Conclusions are reached by a Bayesian estimation technique for a relatively simple construction model originally introduced by Herbert Simon for the hypothetical production of a linear structure, taking into account errors that may occur in the work associated with the production of the links between the nodes in the structure for varied numbers of modules. © 2015 Wiley Periodicals, Inc. Complexity 21: 176–189, 2016 相似文献
42.
Balasubramaniam Pagavathigounder Nishanthi Dhanasekaran Jarina Banu Liyakath Ali 《Complexity》2016,21(Z2):113-122
In this article, a partially delay‐dependent controller is designed to analyze the guaranteed performance analysis of a class of uncertain discrete‐time systems with time‐varying delays. By constructing suitable Lyapunov–Krasovskii Functional (LKF), sufficient conditions are derived to ensure the system to be robustly stochastically stable in mean square sense by using Wirtinger‐based inequality and convex reciprocal lemma. The proper cost function is chosen to guarantee an adequate level of performance. The derived conditions are expressed in terms of linear matrix inequalities (LMIs) which can be easily solved by LMI Toolbox in MATLAB. Further, the advantage of employing the obtained results is illustrated via numerical examples. © 2016 Wiley Periodicals, Inc. Complexity 21: 113–122, 2016 相似文献
43.
Julián Costa 《Optimization》2016,65(4):797-809
The class of maintenance cost games was introduced in 2000 to deal with a cost allocation problem arising in the reorganization of the railway system in Europe. The main application of maintenance cost games regards the allocation of the maintenance costs of a facility among the agents using it. To that aim it was first proposed to utilize the Shapley value, whose computation for maintenance cost games can be made in polynomial time. In this paper, we propose to model this cost allocation problem as a maintenance cost game with a priori unions and to use the Owen value as a cost allocation rule. Although the computation of the Owen value has exponential complexity in general, we provide an expression for the Owen value of a maintenance cost game with cubic polynomial complexity. We finish the paper with an illustrative example using data taken from the literature of railways management. 相似文献
44.
C. Zălinescu 《Optimization》2016,65(3):651-670
It is known that, in finite dimensions, the support function of a compact convex set with nonempty interior is differentiable excepting the origin if and only if the set is strictly convex. In this paper, we realize a thorough study of the relations between the differentiability of the support function on the interior of its domain and the convexity of the set, mainly for unbounded sets. Then, we revisit some results related to the differentiability of the cost function associated to a production function. 相似文献
45.
考察内生网络环境下局中人之间的局部策略互动, 网络中的局中人只与直接邻居进行协同对策. 网络生成的过程中, 建立连接的费用是异质的~(具有两种水平), 与采取有效行动的局中人建立连接时执行高水平费用, 与采取风险占优行动的局中人建立连接时执行低水平费用. 在异质连接费用的情形下, 首次较为完整地给出了均衡网络的结构特性和局中人的行动选择, 并分析了费用参数对均衡结果的影响. 相似文献
46.
In this article, we investigate robust optimization equilibria with two players, in which each player can neither evaluate his opponent's strategy nor his own cost matrix accurately while may estimate a bounded set of the strategy or cost matrix. We obtain a result that solving this equilibria can be formulated as solving a second-order cone complementarity problem under an ellipsoid uncertainty set or a mixed complementarity problem under a box uncertainty set. We present some numerical results to illustrate the behaviour of robust optimization equilibria. 相似文献
47.
Ruiyue Lin 《Applied mathematics and computation》2011,218(7):3680-3688
An issue of considerable importance involves the allocation of fixed costs or common revenue among a set of competing entities in an equitable way. Based on the data envelopment analysis (DEA) theory, this paper proposes new methods for (i) allocating fixed costs to decision making units (DMUs) and (ii) distributing common revenue among DMUs, in such a way that the relative efficiencies of all DMUs remain unchanged and the allocations should reflect the relative efficiencies and the input-output scales of individual DMUs. To illustrate our methods, numerical results for an example are described in this paper. 相似文献
48.
This article reports on an investigation into robust guaranteed cost control (GCC) for uncertain switched neutral systems (USNSs) with interval time‐varying mixed delays and nonlinear perturbations via dynamic output feedback. Delay‐dependent sufficient conditions are suggested to guarantee the robust exponential stability and to obtain robust GCC for USNSs using the average dwell time approach and the piecewise Lyapunov function technique in terms of a set of linear matrix inequalities. The problem of uncertainty in the system model is solved by deploying the Yakubovich lemma. Lastly, two examples (i.e., a numerical example and the water‐quality dynamic model for the Nile River) are given to verify the efficiency of the propounded theories. © 2016 Wiley Periodicals, Inc. Complexity 21: 555–578, 2016 相似文献
49.
F. Dufour M. Horiguchi A. B. Piunovskiy 《Stochastics An International Journal of Probability and Stochastic Processes》2016,88(7):1073-1098
In this paper, we study the infinite-horizon expected discounted continuous-time optimal control problem for Piecewise Deterministic Markov Processes with both impulsive and gradual (also called continuous) controls. The set of admissible control strategies is supposed to be formed by policies possibly randomized and depending on the past-history of the process. We assume that the gradual control acts on the jump intensity and on the transition measure, but not on the flow. The so-called Hamilton–Jacobi–Bellman (HJB) equation associated to this optimization problem is analyzed. We provide sufficient conditions for the existence of a solution to the HJB equation and show that the solution is in fact unique and coincides with the value function of the control problem. Moreover, the existence of an optimal control strategy is proven having the property to be stationary and non-randomized. 相似文献
50.
温度/应变/扭曲三参量同时测量低成本传感系统 总被引：6，自引：3，他引：6
提出了一种利用布喇格光纤光栅反射光作信号源、高频CO2激光脉冲写入的长周期光纤光栅和超周期光纤光栅作传感器实现温度、应变和扭曲同时测量的全光栅型低成本强度解调传感方案.文中利用长周期光纤光栅边缘滤波效应实现了温度、应变和扭曲传感信号的实时解调.实验结果表明,其温度和应变的测量灵敏度分别为－0.211 dB/℃和－0.012 dB/10με;而扭曲率的测量灵敏度为0.4394 dB/(rad·m－1),是该法写入普通LPFG的4倍以上. 相似文献