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Squeezing microwaves by magnetostriction

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National Science Review 2023年第5期10卷 208-214页

作者： Jie Li yi-Pu Wang jian-qiang You Shi-Yao Zhu Interdisciplinary Center of Quantum Information Zhejiang Province Key Laboratory of Quantum Technology and Deviceand State Key Laboratory of Modern Optical InstrumentationSchool of PhysicsZhejiang University

Squeezed light finds many important applications in quantum information science and quantum metrology,and has been produced in a variety of physical systems involving optical non-linear ***,we show how a non-linear magnetostrictive interaction in a ferrimagnet in cavity magnomechanics can be used to reduce quantum noise of the electromagnetic *** show optimal parameter regimes where a substantial and stationary squeezing of the microwave output field can be *** of the scheme is within reach of current technology in cavity electromagnonics and *** work provides a new and practicable approach for producing s queezed vacuum states of electromagnetic fields,and may find promising applications in quantum information processing and quantum metrology.

关键词： squeezing of quantum noise cavity magnonics magnomechanics

Protecting lithium metal anode in all-solid-state batteries with a composite electrolyte

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Rare Metals 2021年第2期40卷 409-416页

作者： Wen-Qing Wei Bing-qiang Liu yi-qiang Gan Hai-jian Ma Da-Wei Cui School of Mechanical-electronic and Vehicle Engineering Weifang UniversityWeifang261061China Department of Chemical and Materials Engineering the University of AucklandAuckland1142New Zealand College of Mechanical and Electronic Engineering Shandong University of Science and TechnologyQingdao266590China

The volume of the metallic lithium anode in allsolid-state Li metal batteries increases significantly due to the lithium dendrite formation during the battery cycling,and the rough surface of lithium metal also reduces Li-ion transport in Li/electrolyte *** this work,we developed a solid polymer composite by adding the lowcost Si_(3)N_(4)particles to protect the lithium anode in allsolid-state *** Fourier transform infrared spectroscopy(FTIR)data show that the surface of 10 wt%Si_(3)N_(4)particles interacts with the polyethylene oxide(PEO)and lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)salt;the interaction restricts the anion mobility and improves the ionic conductivity(1×10^(-4)S·cm^(-1))and lithium-ion transference number(0.28)of the composite *** lithium metal anode is well protected by the composite electrolyte in all-solid-state cells,including symmetric and Li/LiFePO_(4)*** lithium dendrite growth suppression by this composite electrolyte indicates the possible application of these low-cost composite electrolytes for lithium metal protection.

关键词： Lithium metal anode Lithium dendrite growth Composite electrolyte Symmetric cell

STYRENE POLYMERIZATION MEDIATED BY CYCLIC TRITHIOCARBONATE AS RAFT AGENT

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Chinese Journal of Polymer Science 2006年第6期24卷 593-597页

作者： Qi Wang yi-xian Li jian Hong Zhi-qiang Fan Department of Polymer Science ＆ Engineering Zhejiang University Hangzhou 310027 China

The novel cyclic trithiocarbonate was synthesized by dialkylation of trithiocarbonate anion with 2,2＇- bis（bromomethyl）biphenyl in a two-phase system using an onium salt as a phase-transfer agent. Styrene polymerization was carried out in the presence of cyclic trithiocarbonate （CTTC）. CTTC undergoes ring opening-polymerization and the incorporated trithiocarbonate moiety derived from CTTC performs as the reversible addition-fragmentation chain transfer （RAFT） agent. Through this mechanism, multiblock polys-tyrenes containing various narrow polydispersity blocks can be prepared.

关键词： Cyclic trithiocarbonate Multiblock polymer RAFT polymerization Styrene.

Experiment-based identification of time delays in linear systems

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Acta Mechanica Sinica 2017年第2期33卷 429-439页

作者： Meng-Shi Jin yi-qiang Sun Han-Wen Song jian Xu School of Aerospace Engineering and Applied Mechanics Tongji University Shanghai 200092 China Shanghai Engineering Center for Microsatellites Shanghai 201210 China

This paper presents an identification approach to time delays in single-degree-of-freedom (SDOF) and multiple-degree-of-freedom (MDOF) systems. In an SDOF system, the impedance function of the delayed system is expressed by the system parameters, the feedback gain, and the time delay. The time delay can be treated as the 'frequency' of the difference between the impedance function of the delayed system and that of the corresponding uncontrolled system. Thus, it can be identified from the Fourier transform of the difference between the two impedance functions. In an MDOF system, the pseudo-impedance functions are defined. The relationships between the time delay and the pseudo-impedance functions of the delayed system and uncontrolled system are deduced. Similarly, the time delay can be identified from the Fourier transform of the difference between the two pseudo-impedance functions. The results of numerical examples and experimental tests show that the identification approach to keeps a relatively high accuracy.

关键词： Time-delay identification Impedance function Feedback controlled system

Time-delay identification for vibration systems with multiple feedback

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Acta Mechanica Sinica 2016年第6期32卷 1138-1148页

作者： yi-qiang Sun Meng-Shi Jin Han-Wen Song jian Xu School of Aerospace Engineering and Applied Mechanics Tongji University

An approach for time-delay identification is proposed in multiple-degree-of-freedom (MDOF) linear systems with multiple feedback. The applicability of the approach is discussed in detail. Based on the characteristics of frequency domain in feedback controlled system with multiple time-delays, this paper proposes a time-delay identification approach, which is based on the pseudo impedance function of reference point. Treating feedback time-delays as the 'frequencies' of the oscillation curve, the time-delays can be obtained from the 'frequencies' of the curve. Numerical simulation is conducted to validate the proposed approach. The application scope of the approach is discussed with regard to different forms of feedback.

关键词： Multiple time-delays Parameter identification Feedback Frequency response functions

Molecular simulation study of the microstructures and properties of pyridinium ionic liquid[HPy][BF_(4)]mixed with acetonitrile

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原子与分子物理学报 2025年第4期42卷 27-32页

作者： XU jian-qiang MA Zhao-Peng CHENG Si LIU Zhi-Cong ZHU Guang-Lai Department of Physics School of Physics and Electronic InformationAnhui Normal UniversityWuhu 241002China

The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this *** following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution *** results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient ***,the excess molar volume initially decreases,reaches a minimum,and then *** rules of radial distribution functions(RDFs)of characteristic atoms are *** increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then *** indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.

关键词： Pyridinium ionic liquids Thermodynamic properties Molecular dynamics simulation Radial distribution functions

Microstructure and mechanical properties of Mg–Zn–(Nd)–Zr alloys with different extrusion processes

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Rare Metals 2016年第11期35卷 841-849页

作者： Xin Qiu qiang Yang Zhan-yi Cao Yong-Bing Liu jian Meng Key Laboratory of Automobile Materials of Ministry of Education Department of Materials Science and EngineeringJilin University State Key Laboratory of Rare Earth Resources Utilization Changchun Institute of Applied ChemistryChinese Academy of Sciences

The effect of Nd addition and the influence of extrusion processes on the microstructure and mechanical properties of Mg-6Zn-0.5Zr（ZK60） and Mg-6Zn-1.5Nd-0.5Zr（ZKNd602） alloys were investigated. Nd element can obviously refine the microstructure of both as-cast and asextruded Mg-Zn-Nd-Zr alloy. All of the extruded alloys exhibit a bimodal grain structure composed of equiaxedfine recrystallized（DRXed） grains and elongated coarse un DRXed grains. It is necessary to achieve high strength,particularly the yield strength, for ZKNd602 alloy, when it is extruded with a lower extrusion temperature, a suitable extrusion ratio and a relatively lower extrusion ram speed. In this study, the ultimate tensile strength（UTS）,yield strength（YS） and elongation（El） of the extruded ZKNd602 alloy were 421 MPa, 402 MPa and 6.7 %,respectively, with extrusion temperature of 290 °C, extrusion ratio of 18：1 and a ram speed of approximate0.4 mm·s^（-1）. Meanwhile, the extrusion process has obvious effects on the room-temperature properties but weak effects on the high-temperature properties.

关键词： Magnesium alloy Rare earth element Extrusion process Microstructure Mechanical property

Landslide susceptibility mapping of mountain roads based on machine learning combined model

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Journal of Mountain Science 2023年第5期20卷 1232-1248页

作者： DOU Hong-qiang HUANG Si-yi jian Wen-bin WANG Hao Zijin School of Geology and Mining Fuzhou UniversityFuzhou 350116China Fujian Key Laboratory of Geohazard Prevention Fuzhou 350002China

Landslide susceptibility mapping of mountain roads is frequently confronted by insufficient historical landslide sample data,multicollinearity of existing evaluation index factors,and inconsistency of evaluation factors due to regional environmental ***,a single machine learning model can easily become overfitting,thus reducing the accuracy and robustness of the evaluation *** paper proposes a combined machine-learning model to address the *** landslide susceptibility in mountain roads were mapped by using factor analysis to normalize and reduce the dimensionality of the initial condition factor and generating six new combination factors as evaluation *** mountain roads in the Youxi County,Fujian Province,China were used for the landslide susceptibility *** most frequently used machine learning techniques,support vector machine(SVM),random forest(RF),and artificial neural network(ANN)models,were used to model the landslide susceptibility of the study area and validate the accuracy of this evaluation index *** global minimum variance portfolio was utilized to construct a machine learning combined model.5-fold cross-validation,statistical indexes,and AUC(Area Under Curve)values were implemented to evaluate the predictive accuracy of the landslide susceptibility *** mean AUC values for the SVM,RF,and ANN models in the training stage were 89.2%,88.5%,and 87.9%,respectively,and 78.0%,73.7%,and 76.7%,respectively,in the validating *** the training and validation stages,the mean AUC values of the combined model were 92.4% and 87.1%,*** combined model provides greater prediction accuracy and model robustness than one single model.

关键词： Landslide susceptibility mapping Factor analysis Machinelearning Combinedmodel Mountain roads

Nonlinear dynamic analysis of a rotor/bearing/seal system

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第1期12卷 46-55页

作者： Wei LI yi YANG De-ren SHENG jian-hong CHEN Yong-qiang CHE Department of Energy Engineering Zhejiang University Hangzhou 310027 China

In this study a new dynamic model of a rotor system is established based on the Hamilton principle and the finite element method (FEM). We analyze the dynamic behavior of the rotor system with the coupled effects of the nonlinear oil film force, the nonlinear seal force, and the mass eccentricity of the disk. The equations of the motion are solved effectively using the fourth order Runge-Kutta method in MATLAB. The dynamic behavior of the system is illustrated by bifurcation diagrams, largest Lyapunov exponents, phase trajectory diagrams, and Poincaré maps. The numerical results show that the rotational speed of the rotor, the pressure drop in the seal, the seal length, the seal clearance, and the mass eccentricity of the disk are the key parameters that significantly affect the dynamic characteristics of the rotor system. The motion of the rotor system exhibits complex types of periodic, quasi-periodic, double-periodic, multi-periodic, and chaotic vibrations. This analysis can be used to guide the design of seal parameters and to diagnose the vibration of rotor/bearing/seal systems.

关键词： Nonlinear Rotor system Hamilton principle Dynamic Finite element method (FEM)