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Policy iteration based Q-learning for linear nonzero-sum quadratic differential games

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Science China(Information Sciences) 2019年第5期62卷 195-213页

作者： xinxing LI Zhihong PENg Li LIANg Wenzhong zha School of Automation Beijing Institute of Technology State Key Laboratory of Intelligent Control and Decision of Complex System Information Science Academy China Electronics Technology Group Corporation

In this paper, a policy iteration-based Q-learning algorithm is proposed to solve infinite horizon linear nonzero-sum quadratic differential games with completely unknown dynamics. The Q-learning algorithm, which employs off-policy reinforcement learning(RL), can learn the Nash equilibrium and the corresponding value functions online, using the data sets generated by behavior policies. First, we prove equivalence between the proposed off-policy Q-learning algorithm and an offline PI algorithm by selecting specific initially admissible polices that can be learned online. Then, the convergence of the off-policy Qlearning algorithm is proved under a mild rank condition that can be easily met by injecting appropriate probing noises into behavior policies. The generated data sets can be repeatedly used during the learning process, which is computationally effective. The simulation results demonstrate the effectiveness of the proposed Q-learning algorithm.

关键词： adaptive dynamic programming ADP Q-learning reinforcement learning RL linear nonzerosum quadratic differential games policy iteration PI off-policy

IUKF neural network modeling for FOg temperature drift

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Journal of Systems Engineering and Electronics 2013年第5期24卷 838-844页

作者： Feng zha Jiangning Xu Jingshu Li Hongyang He Department of Navigation Engineering Naval University of Engineering

A novel neural network based on iterated unscented Kalman filter （IUKF） algorithm is established to model and com- pensate for the fiber optic gyro （FOg） bias drift caused by temperature. In the network, FOg temperature and its gradient are set as input and the FOg bias drift is set as the expected output. A 2-5-1 network trained with IUKF algorithm is established. The IUKF algorithm is developed on the basis of the unscented Kalman filter （UKF）. The weight and bias vectors of the hidden layer are set as the state of the UKF and its process and measurement equations are deduced according to the network architecture. To solve the unavoidable estimation deviation of the mean and covariance of the states in the UKF algorithm, iterative computation is introduced into the UKF after the measurement update. While the measure- ment noise R is extended into the state vectors before iteration in order to meet the statistic orthogonality of estimate and mea- surement noise. The IUKF algorithm can provide the optimized estimation for the neural network because of its state expansion and iteration. Temperature rise （-20-20℃） and drop （70-20℃） tests for FOg are carried out in an attemperator. The temperature drift model is built with neural network, and it is trained respectively with BP, UKF and IUKF algorithms. The results prove that the proposed model has higher precision compared with the back- propagation （BP） and UKF network models.

关键词： fiber optic gyro (FOg) temperature drift neural net- work iterated unscented Kalman filter (IUKF).

Scalable preparation and direct visualization of cyclic polymers via self-folding cyclization technique

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Science China Chemistry 2022年第12期65卷 2558-2566页

作者： Hualong zhang Hao zha Chao Liu Chunyan Hong CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei230026China

Cyclic polymers exhibit distinct properties compared with their linear counterparts due to the lack of chain ***,the scalable synthesis of cyclic polymers remains a major challenge,especially for ring-closure ***,we report a novel strategy for large-scale preparation of cyclic polymers,which relies on the prior self-folding of anthracene-telechelic amphiphilic random copolymers(poly((oligo(ethylene glycol)acrylate)-co-(dodecyl acrylate)),P(OEgA-co-DDA))into single-chain polymeric nanoparticles(SCPNs)in *** ultraviolet(UV)-induced cyclization occurs in the hydrophobic *** formation of SCPNs leads to a shortened distance between the end groups of the linear precursors and spatially separated cyclization loci,and significantly enhances the efficiency of UV-induced *** self-folding technique permits access to the synthesis of cyclic polymers not only with high molecular weights(M_(n)>10^(5) g/mol),but also in a decent scale(40 g/L),breaking through the limitations of ring-closure ***,the dense pendants of the copolymers can magnify the macromolecules by increasing the mass density along the backbones,thus making the polymers more readily detectable by the *** transmission electron microscopy(TEM)and atomic force microscopy(AFM)images allow us to observe the topological structures directly and provide crucial evidence to confirm the cyclization.

关键词： cyclic polymer scalable preparation direct visualization self-folding cyclization technique

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Continuous Quantum Nondemolition Measurements of a Particle in Electromagnetic and gravitational Fields

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Communications in Theoretical Physics 2005年第3X期44卷 455-458页

作者： ZHU Chun-Hua zha Chao-Zheng Department of Physics Xinjiang University Wulumuqi 830046 China CCAST (World Laboratory) P.O. Box 8730 Beijing 100080 China

The detection of a particle in electromagnetic plus gravitational fields is investigated. We obtain a set of quantum nondemolition variables. The continuous measurements of these nondemolition parameters are analyzed in the framework of restricted path integral formalism. We manipulate the corresponding propagators, and deduce the probabilities associated with the possible measurement outputs.

关键词： continuous quantum nondemolition measurements restricted path integral

Testing the nonlocality of entangled states by a new Bell-like inequality

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Science China(Physics,Mechanics & Astronomy) 2013年第11期56卷 2236-2238页

作者： QI Jianxia zha xinWei SUN xinMei School of Science Xi'an University of Posts and Telecommunications

We test a new four-qubit entangled state by the former Bell-like inequalities and find that it violates these inequalities,but not *** to this entangled state,we build a new Bell-like inequality,which is violated by this new state *** also determine the nonlocality of some other four-qubit states by the new *** is found that the new inequality acts as a strong entanglement witness for the new *** can be used to test new entangled states experimentally.

关键词： entangled states entanglement witness Bell inequality

Magnetic property recovery in Nd-Fe-B bonded magnet wastes with chemical reaction and physical dissolution

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Journal of Rare Earths 2021年第11期39卷 1396-1401,I0003页

作者： Min Liu Haiyuan Cui Qingyan Li Peihong Zhu Weiqiang Liu Qingmei Lu Dongtao zhang Zaisheng Pang xi Yu Chunhui Yu Shanshun zha Youhao Liu xiaofei Yi Ming Yue Laboratory of Advanced Functional Materials Ministry of EducationFaculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China ganzhou Fortune Electronic Co. Ltd.Canzhou 341000China Earth-Panda Advanced Magnetic Materials Co. Ltd.Hefei 231500China

The main difficulty for the recovery of Nd-Fe-B bonded magnet wastes is how to completely remove the epoxy *** this study,chemical reaction and physical dissolution were combined to remove the epoxy resins by adding ammonia-water and mixed organic ***-water can react with the epoxy functional group of epoxy resin to generate *** organic solvents of alcohol,dimethyl formamide(DMF),and tetrahydrofuran(THF) can dissolve the generated polyols and residual epoxy *** the optimum processing conditions,the epoxy resins in the waste magnetic powders are substantially *** oxygen and carbon contents in the recycled magnetic powder are reduced from 13500 × 10^(-6) to 1600 × 10^(-6) and from 19500 × 10^(-6) to 2100 × 10^(-6) with the reduction ratio of88.1% and 89.2%,*** recycled magnetic powder presents improved magnetic properties with MS of 1.306 × 10^(-1) A·m^(2)/g,Mr of 0.926 × 10^(-1) A·m^(2)/g,Hcj of 1.170 T,and(BH)max of 125.732 kJ/m^(3),which reach 99.8%,99.4%,95.9%,and 96.9% of the original magnetic powders,respectively.

关键词： Nd-Fe-B bonded magnet wastes Epoxy resin Open-loop reaction Physical dissolution Recycled magnetic powders Rare earths

Surrounding rock control of gob-side entry driving with narrow coal pillar and roadway side sealing technology in Yangliu Coal Mine

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International Journal of Mining Science and Technology 2017年第5期27卷 819-823页

作者： zha Wenhua Shi Hao Liu San Kang Changhao Key Laboratory of Safe and Effective Coal Mining School of Mining and Safety EngineeringAnhui University of Science&TechnologyMinistry of EducationHuainan 232001China

gob-side entry driving can increase coal recovery ratio, and it is implied in many coal mines. Based on geological condition of 10416 working face tailentry in Yangliu Coal Mine, the surrounding rock deformation characteristics of gob-side entry driving with narrow coal pillar is analysed, reasonable size of coal pillar and reasonable roadway excavation time after mining are achieved. Surrounding rock control technology and effective roadway side sealing technology are proposed and are taken into field practice. The results showed that a safer and more efficient mining of working face can be achieved. In addition, results of this paper also have important theoretical significance and valuable reference for surrounding rock control technology of gob-side entry driving with narrow coal pillar under special geological condition.

关键词： Narrow coal pillar gob-side entry driving Surrounding rock control Roadway side sealing technology

Structural Stability and Half Metallic Features of Zn_(0.5)Cr_(0.5)S under Pressure

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Journal of Materials Science & Technology 2014年第3期30卷 234-238页

作者： Yuhong Huang Wanqi Jie Yan Zhou gangqiang zha State Key Laboratory of Solidification Processing School of Materials Science and Engineering Northwestern Polytechnical University

Spin-polarized first-principle was performed to study the structural stability and the electronic states of Cr doped ZnS with the Cr component of 50% in zincblende （ZB）, wurtzite （W） and rocksalt （RS） structures under pressure. The results show that the zincblende and wurtzite structures become unstable under low pressures of about 4.68 and 9.61 gPa, respectively, but the rocksalt structure can be maintained up to an extremely high pressure of about 32.92 gPa. Both zincblende and wurtzite ***.5S display half metallic features under pressure, while rocksalt *** exhibits metallic feature. The half metallic features can be ascribed to the stronger interactions between S-3p and Cr-3d states and the metallic feature is due to the higher crystal symmetry of rocksalt Zn0.5Cr0.5S. These results can provide helpful guidance for Cr doped ZnS to be used in spintronic devices.

关键词： Structural stability Half metallic features Electronic properties Zn0.5Cr0.5S Pressure

Particle breakage evolution of coral sand using triaxial compression tests

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Journal of Rock Mechanics and geotechnical Engineering 2021年第2期13卷 321-334页

作者： gang Wang zhaonan Wang Qinguo Ye Jingjing zha Key Laboratory of New Technology for Construction of Cities in Mountain Area Chongqing UniversityChongqing400045China School of Civil Engineering Chongqing UniversityChongqing400045China National Joint Engineering Research Center for geohazards Prevention in the Reservoir Areas Chongqing400045China

Particle breakage continuously changes the grading of granular materials and has a significant effect on their mechanical *** the evolution pattern of particle breakage is valuable for development and validation of constitutive models for crushable materials.A series of parallel triaxial compression tests along the same loading paths but stopped at different axial strains were conducted on two coral sands with different particle sizes under drained and undrained *** tested specimens were carefully sieved to investigate the intermediate accumulation of particle breakage during the loading *** test results showed that under both drained and undrained conditions,particle breakage increases continuously with increasing axial strain but exhibits different accumulating patterns,and higher confining pressures lead to greater particle *** on the test results,the correlations between particle breakage and the stress state as well as the input energy were *** results demonstrated that either the stress state or input energy alone is inadequate for describing the intermediate process of particle breakage ***,based on experimental observation,a path-dependent model was proposed for particle breakage evolution,which was formulated in an incremental form and reasonably considers the effects of the past breakage history and current stress state on the breakage *** path-dependent model successfully reproduced the development of particle breakage during undrained triaxial compression using the parameters calibrated from the drained tests,preliminarily demonstrating its effectiveness for different stress paths.

关键词： Particle breakage Coral sand Triaxial compression Relative breakage Breakage model