全文获取类型
收费全文 | 85篇 |
免费 | 0篇 |
国内免费 | 20篇 |
专业分类
电工技术 | 3篇 |
综合类 | 2篇 |
化学工业 | 8篇 |
金属工艺 | 2篇 |
机械仪表 | 1篇 |
建筑科学 | 14篇 |
矿业工程 | 1篇 |
轻工业 | 2篇 |
水利工程 | 1篇 |
无线电 | 5篇 |
一般工业技术 | 6篇 |
原子能技术 | 44篇 |
自动化技术 | 16篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 6篇 |
2015年 | 2篇 |
2014年 | 7篇 |
2013年 | 18篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2009年 | 9篇 |
2008年 | 9篇 |
2007年 | 3篇 |
2006年 | 1篇 |
2005年 | 3篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1998年 | 1篇 |
1996年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1982年 | 2篇 |
排序方式: 共有105条查询结果,搜索用时 265 毫秒
1.
We consider the minimization over probability measures of the expected value of a random variable, regularized by relative entropy with respect to a given probability distribution. In the general setting we provide a complete characterization of the situations in which a finite optimal value exists and the situations in which a minimizing probability distribution exists. Specializing to the case where the underlying probability distribution is Wiener measure, we characterize finite relative entropy changes of measure in terms of square integrability of the corresponding change of drift. For the optimal change of measure for the relative entropy weighted optimization, an expression involving the Malliavin derivative of the cost random variable is derived. The theory is illustrated by its application to several examples, including the case where the cost variable is the maximum of a standard Brownian motion over a finite time horizon. For this example we obtain an exact optimal drift, as well as an approximation of the optimal drift through a Monte-Carlo algorithm. 相似文献
2.
This paper deals with a class of fuzzy stochastic differential equations (FSDEs) driven by a continuous local martingale under the Lipschitzian condition. Such equations can be useful in modeling hybrid systems, where the phenomena are simultaneously subjected to two kinds of uncertainties: randomness and fuzziness. The solutions of the FSDEs are the fuzzy stochastic processes, and their uniqueness is considered to be in a strong sense. Thus, the existence and uniqueness of solutions to the FSDEs under the Lipschitzian condition is first proven. Moreover, some asymptotic properties of the solutions to the FSDEs are investigated. Finally, an illustrating example on the interest term model is provided. 相似文献
3.
Megaprojects are complex projects which impact millions of people, involve public and private stakeholders, and present challenges related to decision making and performance shortfalls. They are relevant cases for studying faulty management thinking as well as performance evolutions and self-organizing dynamics. Our paper builds on the theory of Complex Adaptive Systems (CAS) to understand and model processes of evolution in the Hinkley Point C nuclear power plant megaproject. The results show that CAS properties apply to megaproject changes and provide a theoretical and practical framework for examining and modeling megaproject management dynamics. We designed a research methodology combining content analysis and historical research for its relevance in conducting organizational research in conditions of complexity and non-linearity. This original research design makes it possible to conduct causal analyses of relations between key megaproject events and thus build models of evolution dynamics in stakeholder success expectations, change mechanisms in the implementation of project outputs, and self-organizing patterns. 相似文献
4.
5.
6.
N.P. Barradas A.R. Ramos E. Alves 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2008,266(8):1180-1184
Analysis of RBS and ERDA data relies first and foremost on knowledge of the relevant stopping power and scattering cross-sections. Scattering cross-sections in the non-Rutherford region are often used for enhanced sensitivity to light elements, or for instance in 4He-ERDA measurement of hydrogen. Accurate experimental cross-section values in the energy and scattering angle regions of interest to IBA are thus essential to much analysis work. We developed a new method to determine scattering cross-sections experimentally, which consists in collecting many RBS spectra at different energies, and analysing them taking the cross-sections as fitting parameter. High quality simulations of resonances is essential. A Bayesian inference analysis leads not only to the cross-section curve that best fits the data, but also leads to confidence limits on the results obtained. We apply the method to several (p,p) resonances, and compare them to the literature experimental and evaluated values. 相似文献
7.
水溶液中Np、Pu、Am和Cm同时电沉积制备α测量源 总被引:1,自引:0,他引:1
为制备高分辨率Np、Pu、Am和Cm的α混合测量源,研究了电沉积液介质浓度、pH值、电流密度、电沉积时间等条件对电沉积效率及沉积源质量的影响。结果表明,在pH为2.0~2.5的0.2mol/L硫酸铵介质中,电流密度为0.40~0.50A/cm2,室温条件下电沉积60min,~(237)Np、~(238)Pu、~(243)Am和~(244)Cm在阴极不锈钢片上的电沉积效率均大于96%,制备的α测量源能量分辨率较好。 相似文献
8.
随着汽车工业的迅速发展,汽车智能化成为大势所趋.电机驱动模块是智能车的重要组成部分.基于探索不同频率PWM控制电机输出的目的,采用Multisim12仿真软件以B车模为研究对象,对电路的工作波形进行了仿真实验测试,给出了仿真实验方案,分析了PWM选取不同频率时电路工作波形.通过实际测试,该电机驱动模块能很好完成智能车电机驱动. 相似文献
9.
ABSTRACT This study examines the finite time annular domain stability (FTADS) and stabilisation of a class of Itô stochastic impulsive systems with asynchronous switching controller. The asynchronous switching means that the controller switching does not accurately coincide with system switching in delayed time interval. The design of the controller depends on the observed jumping parameters, which cannot be precisely measured in real-time because of switching delay. Our results apply to cases where some subsystems of the switched systems are not necessarily stable under the influence of input delay. When the subsystem is stable in the synchronous switching interval and unstable in the asynchronous case, a compromise among the average impulsive interval, the upper bound of delay, and the decay/increasing rate of Lyapunov function in the synchronous/asynchronous switching interval respectively is given. By the mode-dependent parameter approach (MDPA) and allowing the increase of the impulses on all the switching times, the extended FTADS criteria for Itô stochastic impulsive systems in generally nonlinear setting are derived first. Then, we focus on the case when the system in both synchronous and asynchronous switching intervals are unstable. By reaching a tradeoff among average impulsive interval, the upper bound of delay, the magnitude of impulses and the difference between the increasing rate of Lyapunov function in the synchronous and asynchronous switching interval, new sufficient conditions for existence of the state feedback controller are also developed by MDPA. In addition, we consider the effect of different impulsive strengths (harmful and beneficial impulses) and obtained less conservative results because the Lyapunov function may be non-decreasing during switching interval. Moreover, we extend the conclusion from nonlinear stochastic impulsive switching systems to linear case. Finally, we present two examples to illustrate the effectiveness of the results obtained in this study. 相似文献
10.
Guangying Lv Jinqiao Duan Hongjun Gao 《Computers & Mathematics with Applications》2019,77(7):1945-1962
After introducing an entropy formulation for stochastic nonlocal conservation laws via an integral formula, we develop a uniqueness theory by using a doubling variables technique and an existence theory by using a vanishing viscosity method. We further consider the continuous dependence of the entropy solution on initial data. 相似文献