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Chinese Physics B 2014年第12期23卷 5-13页

作者： M.syed ali R.Saravanakumar Department of Mathematics Thiruvalluvar University

In this paper, the robust H∞control problem for a class of stochastic systems with interval time-varying and distributed delays is discussed. The system under study involves parameter uncertainty, stochastic disturbance, interval time-varying,and distributed delay. The aim is to design a delay-dependent robust H∞control which ensures the robust asymptotic stability of the given system and to express it in the form of linear matrix inequalities（LMIs）. Numerical examples are given to demonstrate the effectiveness of the proposed method. The results are also compared with the existing results to show its conservativeness.

关键词： distributed delay interval time-varying delay H∞control linear matrix inequality(LMI) stochastic systems

Robust H_∞ control of uncertain systems with two additive time-varying delays

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Chinese Physics B 2015年第9期24卷 25-34页

作者： M.syed ali R.Saravanakumar Department of Mathematics Thiruvalluvar University

This paper is concerned with the problem of delay-dependent robust H∞control for a class of uncertain systems with two additive time-varying delays. A new suitable Lyapunov–Krasovskii functional（LKF） with triple integral terms is constructed and a tighter upper bound of the derivative of the LKF is derived. By applying a convex optimization technique, new delay-dependent robust H∞stability criteria are derived in terms of linear matrix inequalities（LMI）. Based on the stability criteria, a state feedback controller is designed such that the closed-loop system is asymptotically ***, numerical examples are given to illustrate the effectiveness of the proposed method. Comparison results show that our results are less conservative than the existing methods.

关键词： additive time-varying delays Lyapunov method H∞ control linear matrix inequality

Augmented Lyapunov approach to H_∞ state estimation of static neural networks with discrete and distributed time-varying delays

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Chinese Physics B 2015年第5期24卷 140-147页

作者： M.syed ali R.Saravanakumar Department of Mathematics Thiruvalluvar University

This paper deals with H∞ state estimation problem of neural networks with discrete and distributed time-varying delays. A novel delay-dependent concept of H∞ state estimation is proposed to estimate the H∞ performance and global asymptotic stability of the concerned neural networks. By constructing the Lyapunov-Krasovskii functional and using the linear matrix inequality technique, sufficient conditions for delay-dependent H∞ performances are obtained, which can be easily solved by some standard numerical algorithms. Finally, numerical examples are given to illustrate the usefulness and effectiveness of the proposed theoretical results.

关键词： distributed delay H∞ state estimation neural networks stability analysis

Phase Time for the Tunneling of Ultracold V-Type Atoms Through a Mazer Cavity

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Communications in Theoretical Physics 2019年第5期71卷 610-616页

作者： Fazal Badshah Abdul basit Hamad ali Qing He Guo-Qin Ge School of Physics Huazhong University of Science and Technology Quantum Optics Lab.Department of Physics COMSATS University Islamabad College of Science Zhongyuan University of Technology

We study the tunneling time of ultracold V-type atoms interacting a high quality microwave cavity. Here atomic coherence is introduced in the system by a strong driving field which couples the two lower states of the three-level atom. It is found that in the presence of coherence, mazer action or the scattering like nature of the interaction may be examined for extended energies of the incident cold atoms. Our results show that position and amplitudes of the peak values of the phase time(traversal time) may be very effectively controlled by the coherent driving field. Further, here we obtained superclassical values of the phase time corresponding to much higher values of the transmission amplitudes of the tunneling atoms which may be advantageous in the possible experimental realization of the superclassical tunneling time of the traversing cold atoms. In addition, we examine a mirror reflection type symmetry in the phase time curve for a judicious choice of the external driving field.

关键词： ultracold atoms mazer cavity phase time superclassicality

TiC-Maraging stainless steel composite:microstructure, mechanical and wear properties

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Rare Metals 2006年第6期25卷 630-635页

作者： Akhtar Farid Khadijah ali Shah syed Javid Askari School of Material Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Particulate TiC reinforced 17-4PH and 465 maraging stainless steel matrix composites were processed by conventional powder metallurgy （P/M）. TiC-maraging stainless steel composites with theoretical density 〉97% were produced using conventional P/M. The microstructure, and mechanical and wear properties of the composites were evaluated. The microstructure of the composites consisted of （core-rim structure） spherical and semi-spherical TiC particles depending on the wettability of the matrix with TiC particles. In TiC-maraging stainless steel composites, 465 stainless steel binder phase showed good wettability with TiC particles. Some microcracks appeared in the composites, indicating the presence of tensile stresses in the composites produced during sintering. The typical properties, hardness, and bend strength were reported for the composites. After heat treatment and aging, an increase in hardness was observed. The increase in hardness was at- tributed to the aging reaction in maraging stainless steel. The specific wear behavior of the composites strongly depends on the content of TiC particles and their interparticle spacing, and on the heat treatment of the maraging stainless steel.

关键词： TiC-maraging stainless steel composites aging wear powder metallurgy microcracks

Fingerprint matching,spoof and liveness detection:classification and literature review

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Frontiers of Computer Science 2021年第1期15卷 179-196页

作者： syed Farooq ali Muhammad Aamir KHAN Ahmed Sohail ASLAM Department of Software Engineering University of Management and TechnologyLahore 54770Pakistan Department of Informatics and Systems University of Management and TechnologyLahore 54770Pakistan Department of Computer Science University of Management and TechnologyLahore 54770Pakistan

Fingerprint matching,spoof mitigation and liveness detection are the trendiest biometric techniques,mostly because of their stability through life,uniqueness and their least risk of *** recent decade,several techniques are presented to address these challenges over well-known *** study provides a comprehensive review on the fingerprint algorithms and techniques which have been published in the last few *** divides the research on fingerprint into nine different approaches including feature based,fuzzy logic,holistic,image enhancement,latent,conventional machine learning,deep learning,template matching and miscellaneous *** these,deep learning approach has outperformed other approaches and gained significant attention for future *** reviewing fingerprint literature,it is historically divided into four eras based on 106 referred papers and their cumulative citations.

关键词： computer society template matching fingerprint recognition survey deep learning machine learning

MgO(001) barrier based magnetic tunnel junctions and their device applications

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Science China(Physics,Mechanics & Astronomy) 2013年第1期56卷 29-60页

作者： HAN XiuFeng ali syed Shahbaz LIANG ShiHeng State Key Laboratory of Magnetism Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of Sciences

Spintronics has received a great attention and significant interest within the past decades,and provided considerable and remarked applications in industry and electronic information *** spintronics,the MgO based magnetic tunnel junction(MTJ) is an important research advancement because of its physical properties and excellent performance,such as the high TMR ratio in MgO based *** present an overview of more than a decade development in MgO based *** review contains three main sections.(1) Research of several types of MgO based MTJs,including single-crystal MgO barrier based-MTJs,double barrier MTJs,MgO based MTJs with interlayer,novel electrode material MTJs based on MgO,novel barrier based MTJs,novel barrier MTJs based on MgO,and perpendicular MTJs.(2) Some typical physical effects in MgO based MTJs,which include six observed physical effects in MgO based MTJs,namely spin transfer torque(STT) effect,Coulomb blockade magnetoresistance(CBMR) effect,oscillatory magnetoresistance,quantum-well resonance tunneling effect,electric field assisted magnetization switching effect,and spincaloric effect.(3) In the last section,a brief introduction of some important device applications of MgO based MTJs,such as GMR & TMR read heads and magneto-sensitive sensors,both field and current switching MRAM,spin nano oscillators,and spin logic devices,have been provided.

关键词： magnetic tunnel junction (MTJ) tunneling magnetoresistance (TMR) MgO spin transfer torque (STT) Coulombblockade magnetoresistance (CBMR)

Debating the magnesium-selenium battery technology

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Journal of Magnesium and Alloys 2020年第4期8卷 980-988页

作者： Muhammad Rashada syed Danish ali Zaidi Muhammad Asif School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003JiangsuChina Advanced Rechargeable Batteries Laboratory Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Department of Chemical Sciences School of Natural SciencesUniversity of LimerickLimerick V94 T9PXIreland

Magnesium ion batteries(MIBs)have received tremendous research attention owing to their low cost,dendrite free electroplating,and high theoretical capacities compared with lithium ion batteries(LIBs).Despite these advantages,the launching of MIBs is hindered by sluggish kinetics of the magnesium ions inside the host ***,several magnesium-selenium batteries have been developed to achieve the fast kinetics of magnesium ions inside the selenium-based ***,we have critically reviewed the five-year advancements made in the field of selenium cathode design,selenium loadings,compatible organic and inorganic electrolytes,their resultant reversible capacities,working voltages,cycle life,and specific *** selenium-based cathodes were critically debated in terms of their electrochemical performance and *** the end of this review article,several irmovative directions are proposed to shed light on future research.c 2020 Published by Elsevier *** behalf of Chongqing University.

关键词： Magnesium-selenium batteries Energy storage Selenium cathodes Electrolytes Electrochemical properties

Perpendicular magnetic tunnel junction and its application in magnetic random access memory

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Chinese Physics B 2014年第7期23卷 13-21页

作者：刘厚方 syed Shahbaz ali 韩秀峰 Beijing National Laboratory of Condensed Matter Physics Institute of Physics Chinese Academy of Sciences

Recent progresses in magnetic tunnel junctions with perpendicular magnetic anisotropy （PMA） are reviewed and summarized. At first, the concept and source of perpendicular magnetic anisotropy （PMA） are introduced. Next, a historical overview of PMA materials as magnetic electrodes, such as the RE-TM alloys TbFeCo and GdFeCo, novel tetragonal manganese alloys Mn-Ga, L10-ordered （Co, Fe）/Pt alloy, multilayer film [Co, Fe, CoFe/Pt, Pd, Ni, AU]N, and ultra-thin magnetic metal/oxidized barrier is offered. The other part of the article focuses on the optimization and fabrication of CoFeB/MgO/CoFeB p-MTJs, which is thought to have high potential to meet the main demands for non-volatile magnetic random access memory.

关键词： magnetic random access memory perpendicular magnetic anisotropy spin transfer torque effect,magnetic tunnel junction

Three new anthraquinone derivatives isolated from Symplocos racemosa and their antibiofilm activity

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Chinese Journal of Natural Medicines 2017年第12期15卷 944-949页

作者： Umar Farooq Sara Khan Sadia Naz Ajmal Khan Afsar Khan Ayaz Ahmed Abdur Rauf syed Majid bukhari Shujaat ali Khan Arfa Kamil Nadia Riaz Abdur Rahman Khan Department of Chemistry COMSATS Institute of Information Technology Abbottabad-22060 Pakistan Dr. Panjwani Center for Molecular Medicine and Drug Research International Center for Chemical and Biological Sciences University of Karachi- 752 70 Pakistan Department of Geology University of Swabi Anbar-23430 KPK Pakistan Institute of Chemical Sciences University of Peshawar Peshawar 25120 Pakistan Department of Pharmaceutical Chemistry Faculty of Pharmacy Federal Urdu University of Arts Science and Technology Karachi Karachi 75300 Pakistan Department of Environmental Sciences COMSATS Institute of lnformation Technology Abbottabad-22060 Pakistan

Three new alkyl substituted anthraquinone derivatives, trivially named as symploquinones A-C(Compounds 1-3) were isolated from Symplocos racemosa. The structures of these compounds were determined on the basis of extensive spectroscopic analyses(UV, IR, Mass, ~1 H-and ^(13)C-NMR, and two-dimensional(2D) NMR techniques). The resulting data were also compared with the reported literature. These compounds were then subjected to antibacterial or antibiofilm testing. Compounds 1 and 3 exhibited good antibacterial activity in the concentration range of 160-83 μg·m L^(-1) against Streptococcus mutans, methicillin resistant Staphylococcus aureus and Proteus mirabilis. Both compounds were further screened for anti-biofilm activity, which revealed promising activities at sub-MIC concentrations. None of the compounds were found to be active against Klebsiella pneumoniae.

关键词： Symplocos racemosa Substituted anthraquinone Antibiofilm activity