Zheng J.,Ludong University
Journal of Mathematical Analysis and Applications | Year: 2017
This paper deals with a fully parabolic chemotaxis system with nonlinear logistic source. (0.1)(ut=δu-χ∇(u∇v)+u(1-μur-1),vt=δv-v+u, under homogeneous Neumann boundary conditions in a smooth bounded convex domain RN, with parameters μ,χ>0,r≥2. It is shown that if r>2 or r=2 and μ>Nχ4, then for all sufficiently smooth initial data, the associated initial-boundary-value problem (0.1) possesses a unique global-in-time classical solution that is bounded in Ω×(0,∞), which satisfies. limsupt→∞(norm of matrix)u(,t)(norm of matrix)L∞(Ω)≤μ(maxt≥0 (Nχ4μt2+rμt-tr))min (r-1,2). Moreover, with the assumption u0≢0 and appropriate growth assumptions, the globally asymptotical stability of ((1μ)1r-1,(1μ)1r-1) is established. © 2017 Elsevier Inc.
News Article | November 14, 2016
New Rochelle, NY, November 14, 2016--Use of the instant messaging service WeChat, developed in China and used globally, may enhance peoples' feelings of overall satisfaction with life if they use it for fun and to pursue their interests. WeChat use will not necessarily bring happiness or unhappiness, though--that depends on how you use it, according to a study published in Cyberpsychology, Behavior, and Social Networking, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. The article is available free on the Cyberpsychology, Behavior, and Social Networking website until December 16, 2016. The study entitled "Does the Use of WeChat Lead to Subjective Well-Being?: The Effect of Use Intensity and Motivations" was conducted by Zhengbao Wen, Hangzhou Normal University, Yinghua Ye, Zhejiang University, Hangzhou, China, and Xiaowei Geng, Ludong University, Yantai, China. The researchers examined the motivations for and intensity of WeChat use by university students as they related to the users' emotional experience and feelings of well-being. "According to its parent company Tencent, as of the second quarter of 2016, WeChat reported over 806 million active monthly users, a 34% rise from the same period in 2015," says Editor-in-Chief Brenda K. Wiederhold, PhD, MBA, BCB, BCN, Interactive Media Institute, San Diego, California and Virtual Reality Medical Institute, Brussels, Belgium. "With its multifaceted functionalities, research into the psychological impacts of this lifestyle app are only just beginning to be understood." Cyberpsychology, Behavior, and Social Networking is an authoritative peer-reviewed journal published monthly online with Open Access options and in print that explores the psychological and social issues surrounding the Internet and interactive technologies. Complete tables of contents and a sample issue may be viewed on the Cyberpsychology, Behavior, and Social Networking website. Mary Ann Liebert, Inc., publishers is a privately held, fully integrated media company known for establishing authoritative peer-reviewed journals in many promising areas of science and biomedical research, including Games for Health Journal, Telemedicine and e-Health, and Journal of Child and Adolescent Psychopharmacology. Its biotechnology trade magazine, GEN (Genetic Engineering & Biotechnology News), was the first in its field and is today the industry's most widely read publication worldwide. A complete list of the firm's 80 journals, books, and newsmagazines is available on the Mary Ann Liebert, Inc., publishers website.
Wei X.,Ludong University |
Guo L.,Beihang University
International Journal of Robust and Nonlinear Control | Year: 2010
A novel type of control scheme combining the disturbance-observer-based control (DOBC) with H∞ control is proposed for a class of complex continuous models with disturbances. The disturbances are supposed to include two parts. One part in the input channel is generated by an exogenous system with uncertainty, which can represent the harmonic signals with modeling perturbations. The other part is supposed to have the bounded H 2-norm. Parametric uncertainties exist both in concerned plant and in exogenous subsystem. The disturbance observers based on regional pole placement and D-stability theory are designed and integrated with conventional H∞ control laws. The new composite DOBC and H∞ control scheme is applied to complex continuous models for the case with known and unknown nonlinearity, respectively. Then the first type of disturbances can be estimated and rejected, and the second type can be attenuated; simultaneously, the desired dynamic performances can be guaranteed. Simulations for a flight control system are given to demonstrate the effectiveness of the results and compare the proposed results with the previous schemes. Copyright © 2009 John Wiley & Sons, Ltd.
Li W.,Ludong University |
Liu X.,Ludong University |
Zhang S.,Northeastern University China
Automatica | Year: 2012
This paper aims to relax the results in Xie and Tian (2009) from the following two aspects: completely removing the power order restriction and largely relaxing the growth conditions of nonlinear functions. By using the backstepping design method and homogeneous domination technique, this paper investigates the problem of adaptive state-feedback stabilization for a class of stochastic high-order nonlinear systems with nonlinear parameterization. The closed-loop system can be proved to be globally stable in probability and the states can be regulated to the origin almost surely. The efficiency of the adaptive state-feedback controller is demonstrated by a simulation example. © 2012 Elsevier Ltd. All rights reserved.
Wang D.-H.,Ludong University
Current Applied Physics | Year: 2011
It is a well-known fact that the surfaces can affect the photodetachment of negative ion. In this paper, we focus on how the photodetachment cross-section of H- is altered when it is placed near two perpendicular metal surfaces. We begin by briefly presenting the electrostatic image potential of the detached electron caused by the metal surfaces, then we study the classical motion of the photo-detached electron near two perpendicular metal surfaces. The photodetachment cross-section of this system has been derived and calculated based on the closed orbit theory. The results show that the cross-section depends on the photon energy and the ion-surface distances sensitively. Compared to the case of the photodetachment of H- near one metal surface, the oscillatory structure in the cross-section of our system becomes much more complicated. This study provides a new understanding on the photodetachment process of negative ion or atoms in the vicinity of surfaces or cavities. © 2011 Elsevier B.V. All rights reserved.
Gong Y.,Ludong University
Physica A: Statistical Mechanics and its Applications | Year: 2011
In this paper, by introducing a particular kind of parametric non-Gaussian noise (NGN) via the inositol triphosphate (IP 3), we study the effect of the NGN's deviation q from the Gaussian noise and its correlation time τ, as well as the cell number N on the intercellular Ca 2+ oscillations in an array of bi-directionally coupled cells. It is found that Ca 2+ oscillations may become the most ordered in time when q, τ or N is varied, which characterize the phenomenon of coherence resonance and system size resonance. These results show that the temporal coherence of the Ca 2+ oscillation can be enhanced when the NGN or the cell number is optimal. This work extends the study of the NGN in calcium systems and provides new insight into the roles of the NGN in the intercellular Ca 2+ oscillations in the coupled cells. © 2011 Elsevier B.V. All rights reserved.
Wang D.-H.,Ludong University
Journal of Electromagnetic Waves and Applications | Year: 2014
During photodetachment in external electric and magnetic fields, the detached electron wave propagated from the negative ion in different directions may intersect again at a large distance from the negative ion, thus creating an interference pattern in the detached electrons current density distributions on a detector plane placed at a certain distance from the negative ion. In this work, we calculate the photodetached electrons current density distributions in perpendicular electric and magnetic fields on the basis of the semi-classical theory. Our results suggest that the electron current density distributions on the detector plane are not only related to the electric and magnetic fields strength, but also related to the electron energy. Under certain conditions, the interference pattern could reach macroscopic dimensions and could be observed in a direct photodetachment microscopy experiment. Our studies may guide the future researches in the wave propagation theory and the photodetachment microscopy of negative ion in the presence of external fields. © 2014 Taylor & Francis.
Yu X.,Ludong University |
Qu H.,Ludong University
Renewable and Sustainable Energy Reviews | Year: 2013
Climate change has become the most globally concerned environmental issue. As the world's largest carbon dioxide emitter and primary energy consumer, China has strong incentives to change its coal-dominated electricity structure. Various renewable powers such as wind and solar are suitable and necessary options for carbon emission reduction. The 12th Five-Year (2011-2015) and the mid-term until 2020 are critical periods for the development of Chinese renewable powers. In this paper individual renewable electricity sources were introduced based on their characteristics. Based on the introduction, the targets as well as their effects in the medium and long-term were presented and explained; challenges China has to face in the periods were discussed in detail, and emphasis was put on hydro, solar and wind power, which is highlighted in the plans. Also solutions against these challenges were recommended. © 2013 Elsevier Ltd.
Chen J.,Ludong University
Plasmonics | Year: 2013
We design and fabricate a nonplanar two-stage surface plasmonic lens composed of concentric circular slits for exciting propagating surface plasmonic wave and a center-positioned cone-like nanoparticle for generating localized surface plasmonic waves. The numerical investigation based on the finite difference in time domain method is performed. It is found that, when a radially polarized beam illumination is applied, a highly confined electric field with full width half maximum of as small as 6 nm and the transmission enhancement factor of six orders higher than the incident beam is achievable. The optimization design is conducted through comparison of different conic angles and different materials of the cone-like nanoparticles. © 2013 Springer Science+Business Media New York.
Li W.,Ludong University |
Wu Z.,Yantai University
IEEE Transactions on Automatic Control | Year: 2013
This technical note poses and solves the output tracking problem for a class of stochastic high-order nonlinear systems with stationary Markovian switching. By introducing a II-operator and using Dynkin formula for Markovian switching systems, a switching controller is constructed to ensure that the closed-loop system has a unique solution and is bounded in probability. Also, the tracking error converges to an arbitrarily small neighborhood of zero. The efficiency of the tracking controller is demonstrated by a simulation example. © 1963-2012 IEEE.