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Multi-objective Optimization of Co-cured Composite Laminates with Embedded Viscoelastic Damping Layer

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Journal of Materials Science & Technology 2009年第5期25卷 708-712页

作者： lijian Pan Boming zhang Fuhong Dai Centre for Composite Materials and Structure Harbin Institute of Technology Harbin 150080 China

Presented herein is a methodology for the multi-objective optimization of damping and bending stiffness of cocoured composite laminates with embedded viscoelastic damping layer. The embedded viscoelastic damping layer is perforated with a series of small holes, and the ratio of the perforation area to the total damping area is the design variable of the methodology. The multi-objective optimization is converted into a single-objective problem by an evaluation function which is a liner weigh sum of the two sub-objective functions. The proposed methodology was carried out to determine the optimal perforation area ratios of two viscoelstic layers with different perforation distance embedded in two composite plates. Both the optimal perforation area ratios are approximate to 2.2%. However, the objective value of the plate with greater perforation distance in embedded viscoelatic layer is much greater.

关键词： Composite laminates Viscoelastic damping layer Co-cured Multi-objective optimization

Study on Robot Grasping System of SSVEP-BCI Based on Augmented Reality Stimulus

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Tsinghua Science and Technology 2023年第2期28卷 322-329页

作者： Shangen zhang Yuanfang Chen lijian zhang Xiaorong Gao Xiaogang Chen School of Computer and Communication Engineering University of Science and Technology BeijingBeijing 100083China Beijing Institute of Mechanical Equipment Beijing 100854China Department of Biomedical Engineering School of MedicineTsinghua UniversityBeijing100084China Institute of Biomedical Engineering Chinese Academy of Medical Sciences and Peking Union Medical CollegeTianjin 300192China

Although notable progress has been made in the study of Steady-State Visual Evoked Potential(SSVEP)-based Brain-Computer Interface(BCI),several factors that limit the practical applications of BCIs still *** of these factors is the importability of the *** this study,Augmented Reality(AR)technology was introduced to present the visual stimuli of SSVEP-BCI,while the robot grasping experiment was designed to verify the applicability of the AR-BCI *** offline experiment was designed to determine the best stimulus time,while the online experiment was used to complete the robot grasping *** offline experiment revealed that better information transfer rate performance could be achieved when the stimulation time is 2 *** of the online experiment indicate that all 12 subjects could control the robot to complete the robot grasping task,which indicates the applicability of the AR-SSVEP-humanoid robot(NAO)*** study verified the reliability of the AR-BCI system and indicated the applicability of the AR-SSVEP-NAO system in robot grasping tasks.

关键词： Steady-State Visual Evoked Potential(SSVEP) Brain-Computer Interface(BCI) Augmented Reality(AR) robot grasping system

Reduction Removal of Cr(Ⅵ)from Wastewater by COf Deriving from Formate Anion Based on Activated Carbon Catalyzed Persulfate

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Chemical Research in Chinese Universities 2020年第5期36卷 870-876页

作者： ZHOU Rui LI Tingting zhang lijian JIAO Xinqian Key Laboratory of Groundwater Resources and Environment Ministry of EducationJilin Provincial Key Laboratory of Water Resource and EnvironmentCollege of New Energy and EnvironmentJilin UniversityChangchun 130021P.R.China

As a strong reducing radical,carbon dioxide anion radical(CO·-2)can be generated by initiating sulfate radical(SO·-4)in the presence of tonnate anions(FA)for Cr(Ⅵ)***,activated carbon(AC)-catalyzed persultate(PS)oxidation is an economically justifiable,enⅥronmentally friendly,and easy-to-scalemethod to produce SO·-4 The complete removal of Cr(Ⅵ)was achieved within 280 min for an initial Cr(Ⅵ)concentration of 50 mg/L under the optional condition of c(AC)=1 g/L,[PS]0=1O mmol/L,[FA]0=10 mmol/L,T=30℃,and unadjusted *** the molar ratio of FA to PS was greater than or equal to 1,the system maintained a strong reduction *** mechanism investigation confirmed that FA was converted to carboxyl anion radical(CO2·-2)as the predominant radical tor Cr(Ⅵ)*** novel system may offer a potential plattbnn teclmology tor Cr(Ⅵ)wastewater treatment.

关键词： Cr(Ⅵ) Activated carbon Carboxyl anion radical Persulfate:Reduction

Robust secure transmission for multiuser MISO systems with probabilistic QoS constraints

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Science China(Information Sciences) 2016年第2期59卷 126-138页

作者： lijian zhang Liang JIN Wenyu LUO Chunming WANG Yanqun TANG National Digital Switching System Engineering & Technological Research Center School of Information Systems Engineering Zhengzhou Information Science and Technology Institute

This paper considers a unicast multiuser multiple-input single-output(MISO) downlink system overheard by multiple single-antenna eavesdroppers. The objective is to jointly design the beamforming vectors and the artificial noise(AN) covariance matrix with imperfect channel state information(CSI) at the transmitter,such that the total transmit power is minimized while satisfying probabilistic quality of service(Qo S) constraints at legitimate users and the eavesdroppers. Using Bernstein-type inequalities and the S-procedure, we recast the non-convex power minimization problem as two different convex semidefinite programs(SDPs) which can be solved using interior-point methods. Simulation results show that the proposed methods outperform a nonrobust method and the ones using the isotropic AN.

关键词： physical layer security artificial noise imperfect CSI robust beamforming semidefinite program outage probability

External Dependent Economy and Structural Real Estate Bubbles in China

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China & World Economy 2008年第1期16卷 34-50页

作者： lijian Sun Shengxing zhang Economics School

This study explores the relationship between external dependent economic structure, surplus monetary liquidity and real estate bubbles in China. Employing monthly data from 28 Chinese provinces over the period 2004-2005, we test whether real estate bubbles are caused by structural surplus monetary liquidity, ccontrolling other possible factors. Our empirical findings show that the growth of private savings in the banking sector, as an index of surplus monetary liquidity, ferments real estate bubbles regardless of the different development level across the 28 provinces.

关键词： private saving real estate bubble ripple effect surplus monetary liquidity

Quantum verification of NP problems with single photons and linear optics

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Light(Science & Applications) 2021年第9期10卷 1750-1760页

作者： Aonan zhang Hao Zhan Junjie Liao Kaimin Zheng Tao Jiang Minghao Mi Penghui Yao lijian zhang National Laboratory of Solid State Microstructures Key Laboratory of Intelligent Optical Sensing and Manipulation(Ministry of Education)and College of Engineering and Applied SciencesNanjing University210093NanjingChina Collaborative Innovation Center of Advanced Microstructures Nanjing University210093NanjingChina State Key Laboratory for Novel Software Technology Nanjing University210093NanjingChina

Quantum computing is seeking to realize hardware-optimized algorithms for application-related computational ***(nondeterministic-polynomial-time)is a complexity class containing many important but intractable problems like the satisfiability of potentially conflict constraints(SAT).According to the well-founded exponential time hypothesis,verifying an SAT instance of size n requires generally the complete solution in an O(n)-bit *** contrast,quantum verification algorithms,which encode the solution into quantum bits rather than classical bit strings,can perform the verification task with quadratically reduced information about the solution in O~(Õ−−√n)*** we realize the quantum verification machine of SAT with single photons and linear *** using tunable optical setups,we efficiently verify satisfiable and unsatisfiable SAT instances and achieve a clear completeness-soundness gap even in the presence of experimental *** protocol requires only unentangled photons,linear operations on multiple modes and at most two-photon joint *** features make the protocol suitable for photonic realization and scalable to large problem sizes with the advances in high-dimensional quantum information manipulation and large scale linear-optical *** results open an essentially new route toward quantum advantages and extend the computational capability of optical quantum computing.

关键词： quantum optics verify

Treatment of osteoporotic vertebral compressive fractures with percutaneous kyphoplasty and oral Zishengukang

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Journal of Traditional Chinese Medicine 2012年第4期32卷 561-564页

作者： Zhenjun Huang lijian zhang Rehabilitation Centre of the 309th Hospital of the People's Liberation Army of China

OBJECTIVE:To observe the therapeutic effect of percutaneous kyphoplasty(PKP) and oral Zishengukang(ZSGK) for the treatment of osteoporotic vertebral compression fractures(OVCFs).METHODS:Seventy patients were randomly divided into a control group(PKP group) and an experimental group(PKP plus ZSGK group).The 35 patients in the experimental group were prescribed 6 g oral ZSGK three times a day for 90 days after *** analog pain scale(VAS),Oswestry functional score,vertebral height and Cobb's angle were recorded and compared before treatment and at one week,one month and three months after ***:Vertebral height and Cobb's angle significantly improved and VAS and Oswestry functional score were significantly lower in both groups after PKP than pre-operatively(P0.05).CONCLUSION:PKP combined with oral ZSGK provide superior short-term and long-term symptom control after OVCF than PKP alone.

关键词： Osteoporosis Fractures, Compression Kyphoplasty Zishengukang pill

Development of Transient Electric Field Radiation Simulation Device during Gas Insulation Switch Operation

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Energy Engineering 2022年第1期119卷 371-385页

作者： Wei Shen Sen Wang Xuanxiang Zhao Haotian zhang Shuo Cao lijian zhang Hao Yang Xixiang Wang Lei Lei Electric Power Research Institute State Grid Shaanxi Electric Power CompanyXi’an710100China School of Electronics and Information Xi’an Polytechnic UniversityXi’an710048China Yulin Power Supply Company State Grid Shaanxi Electric Power CompanyYulin719000China Shaanxi Pilot Power Technology Co. Ltd.Xi’an710000China

In gas insulation switch(GIS)substation,secondary devices such as linemonitoring devices are placed in the switching field,and these electronic devices are vulnerable to transient electromagnetic interference caused by switching *** order to facilitate the measurement and research of electromagnetic disturbance data under different working conditions,a simulation test device is developed in this paper,which can be used to simulate electromagnetic disturbance of GIS substation sensor and secondary device port under switch operation.A four-channel parallel gas switch was designed,and the main characteristic parameters of electromagnetic disturbance generated by the simulation device were measured by using high-frequency pulse power supply as the excitation *** comparison between the measured waveform and the measured disturbance characteristic parameters of GIS substation shows that it is in good agreement with the measured waveform characteristics,conforms to the basic characteristics of damped oscillation wave,and can be used in the secondary equipment port disturbance voltage coupling characteristics,protection measures evaluation and assessment method research.

关键词： GIS transient electric field radiation time-frequency characteristic TEM horn antenna

Entirety of Quantum Uncertainty and Its Experimental Verification

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Chinese Physics Letters 2021年第7期38卷 11-16页

作者： Jie Xie Li Zhou Aonan zhang Huichao Xu Man-Hong Yung Ping Xu Nengkun Yu lijian zhang National Laboratory of Solid State Microstructures College of Engineering and Applied Sciences and School of PhysicsNanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and TechnologyShenzhen 518055China Shenzhen Key Laboratory of Quantum Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Institute for Quantum Information&State Key Laboratory of High Performance Computing College of ComputerNational University of Defense TechnologyChangsha 410073China Centre for Quantum Software and Information School of SoftwareFaculty of Engineering and Information TechnologyUniversity of Technology SydneyNSWAustralia

As a foundation of quantum physics,uncertainty relations describe ultimate limit for the measurement uncertainty of incompatible ***,uncertainty relations are formulated by mathematical bounds for a specific *** we present a method for geometrically characterizing uncertainty relations as an entire area of variances of the observables,ranging over all possible input *** find that for the pair of position and momentum operators,Heisenberg's uncertainty principle points exactly to the attainable area of the variances of position and ***,for finite-dimensional systems,we prove that the corresponding area is necessarily semialgebraic;in other words,this set can be represented via finite polynomial equations and inequalities,or any finite union of such *** particular,we give the analytical characterization of the areas of variances of(a)a pair of one-qubit observables and(b)a pair of projective observables for arbitrary dimension,and give the first experimental observation of such areas in a photonic system.

关键词： observable union operators