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Theoretical study on the 1s^22s-1s^2np transitions for Ni25^＋ion

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Frontiers of physics 2012年第2期7卷 252-255页

作者： zhi-wen wang (1) Yang Guo (1) College of Physics and Electronic Technology Liaoning Normal University Dalian China

The transition energies, wavelengths and oscillator strengths for the ls22s-ls2np （n≤9） transitions of Ni25＋ ion are calculated. In calculation of the energies, we not only take account of the first- order corrections from relativistic and mass-polarization effects, but also estimate the higher-order relativistic contribution and QED correction by introducing the effective nuclear charge. The results agree with experimental data available in literature satisfactorily. Grotrian diagram showing these transitions is given.

关键词： Ni^25+ ion higher-order relativistic contribution and QED corrections Grotrian dia-gram oscillator strength

Vertex Distinguishing Equitable Total Chromatic Number of Join Graph

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Acta Mathematicae Applicatae Sinica 2007年第3期23卷 433-438页

作者： zhi-wen wang Li-hong Yan Zhong-fuZhang Department of Mathematics of Yeungnam University Daedong Kyongsan Kyongbuk 712-749 Korea Department of Mathematics of Xianyang Normal University Xianyang 712000 China School of Mathematics of Lanzhou Jiaotong University Lanzhou 730070 China

A vertex distinguishing equitable total coloring of graph G is a proper total coloring of graph G such that any two distinct vertices＇ coloring sets are not identical and the difference of the elements colored by any two colors is not more than 1. In this paper we shall give vertex distinguishing equitable total chromatic number of join graphs Pn VPn, Cn VCn and prove that they satisfy conjecture 3, namely, the chromatic numbers of vertex distinguishing total and vertex distinguishing equitable total are the same for join graphs Pn V Pn and Cn ∨ Cn.

关键词： Path cycle join graph vertex distinguishing equitable total chromatic number

Adaptive modulation for SVD-based MIMO systems with outdated CSI

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The Journal of China Universities of Posts and Telecommunications 2009年第4期16卷 78-83页

作者： YAN zhi wang wen-bo wang Xiao-ting ZHENG Kan Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

The performance of singular value decomposition （SVD）-based multiple-input multiple-output （MIMO） with adaptive modulation （AM） is dependent on the accuracy of the channel state information （CSI） at the transmitter and the receiver. However, for a time-varying channel, the CSI obtained at the transmitter or the receiver is incorrect owing to an inherent delay or error. A typical system employing SVD suffers degradation in capacity when outdated CSI is used to transmit data. This article first addresses the adaptive modulation MIMO system designed under perfect CSI assumption. Based on that, two scenarios of outdated CSI are investigated and analyzed. The effect of imperfect CSI on the system performance is focused on and a simple post processing SNR （pSNR） adjustment design is proposed on AM system in the two scenarios for reducing degradation in average spectral efficiency （ASE）. Simulation results show that these designs provide good performance in an adaptive way, and enable the adaptive MIMO system considerably more to be robust against CSI imperfection.

关键词： MIMO SVD adaptive modulation ohtdated CSI

Joint linear precoder and power allocation design for uplink MIMO systems with limited feedback

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The Journal of China Universities of Posts and Telecommunications 2009年第3期16卷 14-18页

作者： YAN zhi wang wen-bo wang Jian-feng ZHENG Kan Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing 100876 China

In this article, the authors consider joint design of a linear precoder and power allocation for uplink multiuser multiple input multiple output （MIMO） communication systems with limited feedback to improve the bit error rate （BER） performance for all users. Precoder selection from the codebook set is directly based on the exact BER performance, instead of other suboptimal criteria, to achieve the optimal precoder matrix, but closed-form expressions may not exist in the view of power allocation based directly on the BER criterion. From this perspective, the authors propose the joint transmitter optimization algorithm for the consideration of precoder design, with total power constraint for asymptotic MBER （AMBER） criterion. In this AMBER criterion, a closed-form solution has been derived for power allocation with an optimal precoder. The simulation results show that the proposed joint design algorithm can achieve a much better performance than precoding with uniform power allocation and only consideration of power allocation.

关键词： MIMO linear precoder power allocation spatial multiplexing multiuser

Numerical analysis of the hydraulic fracture communication modes in fracture-cavity reservoirs

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Petroleum Science 2022年第5期19卷 2227-2239页

作者： Jia-Wei Kao Shi-Ming Wei wen-zhi wang Yan Jin State Key Laboratory Petroleum Resources and Prospecting China University of PetroleumBeijing102249China Sinopec Research Institute of Petroleum Engineering Beijing102206China CNPC Engineering Technology R&D Company Limited Beijing102206China

The fracture-cavity carbonate reservoirs in the Tahe Oilfield in China are mainly exploited by *** need the hydraulic fractures to communicate with caves to create a flow ***,due to the existence of the fracture-cavity systems,the hydraulic fracture propagation morphology is complicated,while the propagation characteristics are not *** analyze the hydraulic fracture propagation in fracture-cavity carbonate formations,based on the discontinuous discrete fracture model,we developed a solid-seepage-freeflow coupled fracturing model for fracture-cavity formations,which can simulate the complex interaction behavior of fractures and *** on the simulation results,we found the interaction rule between hydraulic fractures and fracture-cavity systems:the stress concentration around caves is the main factor that determines the fracture propagation *** due to stress concentration is usually not conducive to communication,while natural fractures distributed around caves could break the rejection *** the hydraulic energy in the hydraulic fracture can make fracture propagate directly and reduce the influence of *** steering fracture formed by temporary plugging is beneficial to the communication of fracture-cavity systems in the non-principal stress *** to the simulation results of different fracture-cavity characteristics,we raised four optimization communication modes for fracture-cavity carbonate formation to provide references for fracturing optimization design and parameter optimization.

关键词： Fracture-cavity carbonate formation Hydraulic fracture propagation Numerical simulation Fracture-cave communication Discontinuous discrete fracture model

A brief overview on secure control of networked systems

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Advances in Manufacturing 2017年第3期5卷 243-250页

作者： Hong-Tao Sun Chen Peng Peng Zhou zhi-wen wang Department of Automation School of MechatronicEngineering and Automation Shanghai UniversityShanghai 200240 People's Republic of China College of Electrical and Information Engineering LanzhouUniversity of Technology Lanzhou 730050 Gansu People'sRepublic of China

This paper focuses on the issues of the security of networked control systems by summarizing recent progress in secure control of this research and application area. We mainly discuss existing results, especially in modeling issues, of three aspects：（1） attack mechanisms and their impacts on control systems, （2） the identification and design of attacks, and （3） secure estimation and control strategies. A conclusion is drawn at the end of this paper. In addition, several promising research tendencies of the development for secure control in networked control system are presented.

关键词： Networked control system Security Attack·Estimation and control

The level and influencing factors of quality of life in patients with brachial plexus injury

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International Journal of Nursing Sciences 2014年第2期1卷 171-175页

作者： Jie Shen zhi-wen wang Department of Hand Surgery Beijing Jishuitan HospitalBeijingChina School of Nursing Peking UniversityBeijingChina

Purpose:To investigate the overall quality of life level and identify influencing factors in patients with traumatic brachial plexus ***:One hundred three patients with brachial plexus injury were assessed using the World Health Organization Quality of Life-BREF(WHOQOL-BREF)and Family Adaptability and Cohesion Evaluation Scale(FACESII-CV)***:The overall quality of life score from patients with brachial plexus injury was 65.78*** scores for the physical,psychological and environmental factors were significantly lower than the norm(Ps<0.05).Regression analysis showed that age,injury located ipsilateral to the dominant hand,upper limb function score,score of family intimacy and family income were all factors influencing the of quality of ***:A brachial plexus injury significantly compromises an individual’s quality of *** factors influence this quality,which should be targeted to augment the physical and psychological care provided.

关键词： Brachial plexus injury Family intimacy Influencing factors Quality of life

On the Relations of Graph Parameters and Its Total Parameters

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Acta Mathematicae Applicatae Sinica 2010年第3期26卷 525-528页

作者： Jing-wen Li zhi-wen wang Jaeun Lee Moo Young Sohn Zhong-fu Zhang En-qiang Zhu Institute of Applied Mathematics Lanzhou Jiaotong University Lanzhou 730070 China School of Mathematics and Computer Science Ningxia University Yinchuan 750021 China Department of Mathematics Yeungnam University Kyongsan 712-749 Korea Department of Applied Mathematics Changwon University Changwon 641 773 Korea

In this paper we get some relations between α（G）, α＇（G）, β（G）, β＇（G） and αT（G）, βT（G）. And all bounds in these relations are best possible, where α（G）, α＇（G）,/3（G）, β（G）, αT（G） and βT（G） are the covering number, edge-covering number, independent number, edge-independent number （or matching number）, total covering number and total independent number, respectively.

关键词： Graph covering number edge covering number independent number edge independent number,total covering number total independent number

Modification and refinement effects of Sb and Sr on Mg_(17)Al_(12) and Mg_2Si phases in Mg-12Al-0.7Si alloy

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China Foundry 2016年第5期13卷 310-315页

作者： zhi-wen wang Hong-xia wang Jia-lin Gong Ming Li Wei-li Cheng Wei Liang Key Laboratory of lnterface Science and Engineering in Advanced Materials Taiyuan University of Technology Ministry of Education Taiyuan 030024 Shanxi China

The effects of Sb and Sr on the modification and refinement of Mg17Al12 and Mg2Si phases in Mg- 12Al-0.7Si alloy were investigated and compared. The microstructure and mechanical properties of Mg-12Al0.7Si alloy and its modification mechanism by Sb and Sr were investigated using a scanning electron microscope （SEM）, an energy dispersive spectrometer （EDS）, X-ray diffraction （XRD） and differential thermal analysis （DTA）. The results indicate that by adding 0.5wt.% Sb to the Mg-12Al-0.7Si alloy, the Mg17Al12 phase was refined and broken into some discontinuous island structures. However, some network Mg17Al12 phases still can be detected in Mg-12Al-0.7Si-0.09Sr alloy. Therefore, Sb performs better in modification and refinement of Mg17Al12 phase than does Sr. Small amounts of fine polygonal shaped Mg2Si phases were found in Mg-12AI-0.7Si-0.5Sb alloy, while the morphology of Mg2Si phases in Mg-12Al-0.7Si-0.09Sr alloy changed from the coarse Chinese script shapes to fine granule and irregular polygonal shapes, indicating that the effects of modification and refinement on Mg2Si phase are more significant by adding 0.09wt.% Sr than 0.5wt.% Sb. The ultimate tensile strengths of the Sb and Sr modified Mg-12Al-0.7Si alloys were considerably increased both at room temperature and at 200 ℃.

关键词： magnesium alloy Sb Sr Mg17Al12 phase Mg2Si phase