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1.
Mohammed Harunor Rashid 《计算数学(英文版)》2022,40(1):44-69
In the present paper,we study the restricted inexact Newton-type method for solving the generalized equation 0∈f(x)+F(x),where X and Y are Banach spaces,f:X→Y is a Frechet differentiable function and F:X■Y is a set-valued mapping with closed graph.We establish the convergence criteria of the restricted inexact Newton-type method,which guarantees the existence of any sequence generated by this method and show this generated sequence is convergent linearly and quadratically according to the particular assumptions on the Frechet derivative of f.Indeed,we obtain semilocal and local convergence results of restricted inexact Newton-type method for solving the above generalized equation when the Frechet derivative of f is continuous and Lipschitz continuous as well as f+F is metrically regular.An application of this method to variational inequality is given.In addition,a numerical experiment is given which illustrates the theoretical result. 相似文献
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3.
We study the local stability near the maximum figure of merit for the low-dissipation cyclic refrigerator,where the irreversible dissipation occurs not only in the thermal contacts but also the adiabatic strokes.We find that the bounds of the coefficient of performance at a maximum figure of merit or maximum cooling rate in the presence of internal dissipation are identical to those in the corresponding absence of internal dissipation.Using two different scenarios,we prove the existence of a single stable steady state for the refrigerator,and clarify the role of internal dissipation on the stability of the thermodynamic steady state,showing that the speed of system evolution to the steady state decreases due to internal dissipation. 相似文献
4.
精准扶贫是习近平总书记为彻底解决贫困问题而提出一项战略要求。精准扶贫是一项复杂性较高、涉及范畴较广的系统工作,其工作的展开需要由地方政府共同协作完成。地方政府合作周期长短对精准扶贫有着巨大的影响,基于博弈论的基本思想方法,针对地方政府精准扶贫合作机制进行研究。首先,针对精准扶贫过程中完全信息静态博弈的情况,构建地方政府合作与非合作的无限次重复博弈模型,并分析双方政府均采取冷酷战略时,彼此合作的临界贴现因子;然后,针对精准扶贫过程中地方政府合作周期长短对精准扶贫成效的问题,探讨了有限重复博弈模型的临界贴现因子与地方政府合作周期的关系。分析表明:在精准扶贫过程中,双方政府合作周期越长,临界贴现因子越小,精准扶贫合作的稳定性越强。最后,针对精准扶贫过程中地方政府合作周期和合作机制等提出对策和建议。 相似文献
5.
本文研究了数值求解非自治随机微分方程的正则Euler-Maruyama分裂(CEMS)方法,该方程的漂移项系数带有刚性且允许超线性增长,扩散项系数满足全局Lipschitz条件.首先,证明了CEMS方法的强收敛性及收敛速度.其次,证明了在适当条件下CEMS方法是均方稳定的.进一步,利用离散半鞅收敛定理,研究了CEMS方法的几乎必然指数稳定性.结果表明,CEMS方法在漂移系数的刚性部分满足单边Lipschitz条件下可保持几乎必然指数稳定性.最后通过数值实验,检验了CEMS方法的有效性并证实了我们的理论结果. 相似文献
6.
A general framework for describing photofission observables of actinides at an average excitation energy below 30 MeV 下载免费PDF全文
Guan-Lin Wang Hao-Yang Lan Xiao-Ming Shi Zhi-Chao Zhu Wen Luo 《中国物理C(英文版)》2022,46(8):084102-084102-14
A reasonable prediction of photofission observables plays a paramount role in understanding the photofission process and guiding various photofission-induced applications, such as short-lived isotope production, nuclear waste disposal, and nuclear safeguards. However, the available experimental data for photofission observables are limited, and the existing models and programs have mainly been developed for neutron-induced fission processes. In this study, a general framework is proposed for characterizing the photofission observables of actinides, including the mass yield distributions (MYD) and isobaric charge distributions (ICD) of fission fragments and the multiplicity and energy distributions of prompt neutrons (np) and prompt γ rays (γp). The framework encompasses various systematic neutron models and empirical models considering the Bohr hypothesis and does not rely on the experimental data as input. These models are then validated individually against experimental data at an average excitation energy below 30 MeV, which shows the reliability and robustness of the general framework. Finally, we employ this framework to predict the characteristics of photofission fragments and the emissions of prompt particles for typical actinides including 232Th, 235, 238U and 240Pu. It is found that the 238U(γ, f) reaction is more suitable for producing neutron-rich nuclei compared to the 232Th(γ, f) reaction. In addition, the average multiplicity number of both np and γp increases with the average excitation energy. 相似文献
7.
A buckling model of Timoshenko micro-beam with local thickness defects is established based on a modified gradient elasticity. By introducing the local thickness defects function of the micro-beam, the variable coe-cient differential equations of the buckling problem are obtained with the variational principle. Combining the eigensolution series of the complete micro-beam with the Galerkin method, we obtain the critical load and buckling modes of the micro-beam with defects. The results show that the depth and location of the defect are the main factors affecting the critical load, and the combined effect of boundary conditions and defects can significantly change the buckling mode of the micro-beam. The effect of defect location on buckling is related to the axial gradient of the rotation angle, and defects should be avoided at the maximum axial gradient of the rotation angle. The model and method are also applicable to the static deformation and vibration of the micro-beam. 相似文献
8.
We report a facile phase conversion method that can locally convert n-type SnSe2 into p-type SnSe by direct laser irradiation. Raman spectra of SnSe2 flakes before and after laser irradiation confirm the phase conversion of SnSe2 to SnSe. By performing the laser irradiation on SnSe2 flakes at different temperatures, it is found that laser heating effect induces the removal of Se atoms from SnSe2 and results in the phase conversion of SnSe2 to SnSe. Lattice-revolved transmission electron microscope images of SnSe2 flakes before and after laser irradiation further confirm such conversion. By selective laser irradiation on SnSe2 flakes, a pattern with SnSe2/SnSe heteostructures is created. This indicates that the laser induced phase conversion technique has relatively high spatial resolution and enables the creation of micron-sized in-plane p-n junction at predefined region. 相似文献
9.
Based on the primal mixed variational formulation, a stabilized nonconforming mixed finite element method is proposed for the linear elasticity on rectangular and cubic meshes. Two kinds of penalty terms are introduced in the stabilized mixed formulation, which are the jump penalty term for the displacement and the divergence penalty term for the stress. We use the classical nonconforming rectangular and cubic elements for the displacement and the discontinuous piecewise polynomial space for the stress, where the discrete space for stress are carefully chosen to guarantee the well-posedness of discrete formulation. The stabilized mixed method is locking-free. The optimal convergence order is derived in the $L^2$-norm for stress and in the broken $H^1$-norm and $L^2$-norm for displacement. A numerical test is carried out to verify the optimal convergence of the stabilized method. 相似文献
10.
Ram Manohar & Rajen Kumar Sinha 《计算数学(英文版)》2022,40(2):147-176
This article studies a posteriori error analysis of fully discrete finite element approximations for semilinear parabolic optimal control problems. Based on elliptic reconstruction approach introduced earlier by Makridakis and Nochetto [25], a residual based a posteriori error estimators for the state, co-state and control variables are derived. The space discretization of the state and co-state variables is done by using the piecewise linear and continuous finite elements, whereas the piecewise constant functions are employed for the control variable. The temporal discretization is based on the backward Euler method. We derive a posteriori error estimates for the state, co-state and control variables in the $L^\infty(0,T;L^2(\Omega))$-norm. Finally, a numerical experiment is performed to illustrate the performance of the derived estimators. 相似文献