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Generation of hyperentangled photon pairs based on lithium niobate waveguide

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Chinese Physics B 2023年第9期32卷 172-176页

作者：陈洋河姜震何广强 SJTU Pinghu Institute of Intelligent Optoelectronics Department of Electronic EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Advanced Optical Communication Systems and Networks Department of Electronic EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Generation of hyperentangled photon pairs is investigated based on the lithium niobate straight *** propose to use the nonlinear optical process of spontaneous parametric down-conversion(SPDC)and a well-designed lithium niobate waveguide structure to generate a hyperentangled(in the polarization dimension and the energy-time dimension)two-photon *** performing numerical simulations of the waveguide structure and calculating the possible polarization states,joint spectral amplitudes(JSA),and joint temporal amplitudes(JTA)of the generated photon pair,we show that the generated photon pair is indeed hyperentangled in both the polarization dimension and the energy-time dimension.

关键词： hyperentanglement nonlinear photonic crystal lithium niobate waveguide

MEinVR:Multimodal interaction techniques in immersive exploration

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Visual Informatics 2023年第3期7卷 37-48页

作者： Ziyue Yuan Shuqi he Yu Liu Lingyun Yu School of Advanced Technology Xi’an Jiaotong-Liverpool UniversitySuzhouChina

Immersive environments have become increasingly popular for visualizing and exploring large-scale,complex scientific data because of their key features:immersion,engagement,and *** reality offers numerous new interaction possibilities,including tactile and tangible interactions,gestures,and voice ***,it is crucial to determine the most effective combination of these techniques for a more natural interaction *** this paper,we present MEinVR,a novel multimodal interaction technique for exploring 3D molecular data in virtual *** combines VR controller and voice input to provide a more intuitive way for users to manipulate data in immersive *** using the VR controller to select locations and regions of interest and voice commands to perform tasks,users can efficiently perform complex data exploration *** findings provide suggestions for the design of multimodal interaction techniques in 3D data exploration in virtual reality.

关键词： Multimodal interaction Virtual reality Scientific visualization

Seismic response of the Lengzhuguan slope during Kangding Ms5.8 earthquake

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Journal of Mountain Science 2017年第11期14卷 2337-2347页

作者： WANG Yun-sheng he Jian-xian LUO Yong-hong State Key Laboratory of Geohazard Prevention and Geoenvironmental Protection Chengdu University of Technology Key Laboratory of Shale Gas and Geoengineering Institute of Geology and Geophysics Chinese Academy of Sciences University of Chinese Academy of Sciences

In order to investigate the role of the amplification of peak ground acceleration(PGA) in seismic landslide formation mechanisms and study how earthquake waves interact with rock structures, a few strong-motion seismometers are installed at various locations on both sides of the Lengzhuguan gully. Five strong-motion seismometers were triggered at different depths in a tunnel at the same altitude during the Kangding Ms 5.8 earthquake on November 25 th, 2014. The data reveal that the horizontal peak acceleration(PGA_H) at each site decreased with increasing site depths. The PGAH at the deepest monitoring site(99 m from the tunnel entrance) was approximately half that of the outermost site. The amplitude of the acceleration response spectrum was also attenuated from the entrance inwards, the dynamic magnification factor(β) of the standard acceleration spectrum was less than 3.5, and rate of change was the same as that for the amplitude acceleration response. The Fourier spectra of each monitoring site also decreased from the outside inwards, and the components of the Fourier spectra were more complex at the surface.

关键词： Earthquake Tunnel Ground motionattenuation Topographic effects Lengzhuguan Horizontal peak acceleration

Jigsaw-Sketch: a fast and accurate algorithm for finding top-k elephant flows in high-speed networks

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Science China(Information Sciences) 2024年第4期67卷 113-130页

作者： Boyu ZHANG he HUANG Yu-E SUN Yang DU Dan WANG School of Computer Science and Technology Soochow University School of Rail Transportation Soochow University

Finding top-k elephant flows in high-speed networks is one of the most fundamental network measurement tasks. It is more challenging than per-flow size estimation since the IDs and sizes of top-k flows must be tracked simultaneously. Most existing studies only record the IDs of a small number of elephant flows to fit their estimators in the extremely limited high-speed on-chip memory. However, these solutions need too many memory accesses when a packet arrives to track the elephant flows with high accuracy, which limits their practicability. Therefore, this paper proposes Jigsaw-Sketch, a new algorithm to find the top-k elephant flows with much fewer memory accesses while achieving high memory efficiency and accuracy. In this design, we propose a novel two-stage jigsaw storage scheme, which can capture the candidate top-k flows from massive network steams efficiently, and further find the top-k elephant flows with high memory efficiency and only a few memory accesses for each packet. Extensive experimental results based on real network traces show that Jigsaw-Sketch improves the packet processing throughput by at least 86%, while achieving smaller memory footprints and higher accuracy compared to the SOTA.

关键词： sketch top-k network measurement elephant flow high-speed networks

Orderly adaptation to climate change： A roadmap for the post-Paris Agreement Era

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Science China Earth Sciences 2018年第1期61卷 119-122页

作者： WU ShaoHong PAN Tao LIU YanHua GAO JiangBo he XiaoJia Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China College of Resources and Environment University of Chinese Academy of Sciences Beijing 100190 China The Administrative Center for China's Agenda 21 Beijing 100038 China

Mitigation and adaptation are two complementary strategies for addressing climate ***,adaptation has received far less attention than *** response to observed and future climate change,the currently adopted measures for adaptation are ***,constraints,costs and other limitations to adaptation have not been fully recognized(Field et al.,2014).

关键词： adaptation mitigation currently constraints addressing limitations warming costs sector insufficient

Preparation of nanocrystalline palladium on p-Si by electroless deposition and its photo-electrochemical hydrogen evolution property

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Rare Metals 2006年第3期25卷 241-245页

作者： YAO Suwei LI he ZHANG Weiguo WANG Hongzhi BEN Yuheng SUGIYAMA Laboratory of Surface Technology School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China

The Pd-modified p-Si electrode was prepared by means of electroless deposition. The average diameter of Pd nanoparticles was about 80 nm from SEM observations. XRD results showed that the structure of Pd coatings was nanocrystalline. The catalyzing properties of the Pd-modified p-Si electrode for hydrogen evolution under illumination and in dark were studied with the constant current polarization method. The polarization potential for hydrogen evolution reac- tion （heR） of the Pd/p-Si electrode under illumination was 250 mV lower than that in dark, and was 450 mV lower than that of p-Si in dark at the current density of 2.5 mA·cm^-2. The results of electrochemistry impedance spectra （EIS） showed that electrochemistry heR resistance of the modified electrode under illumination decreased from 593.12 to 442.20 Ω·cm^2, and the heR rate increased evidently.

关键词： electrochemistry Pd-modified p-Si electrode electroless hydrogen evolution reaction

Stability Control and Mode Shift of Ramp Compensation in V2 Controlled Buck Converter

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Chinese Journal of Electronics 2015年第2期24卷 295-299页

作者： he Shengzhong XU Jianping ZHOU Guohua BAO Bocheng YAN Tiesheng School of Electrical Engineering Southwest Jiaotong University School of Information Science and Engineering Changzhou University

V2 controlled buck converter with ramp compensation is studied, its two border voltages are derived and one-dimensional discrete-time model is established, upon which the dynamical effect of V2 control technique on stability control and mode shift of V2 controlled buck converter with ramp compensation is studied by using the bifurcation diagram, Lyapunov exponent spectrum,and parameter space map. The research results verified by simulation and experimental measurements indicate that by utilizing ramp compensation, V2 controlled buck converter can not only shift its operation mode from discontinuous conduction mode to continuous conduction mode, but also effectively stabilize its operation state from unstable subharmonic oscillation to stable periodic state.

关键词： Bifurcation Parameter space Ramp compensation V2control

Characteristics of the dynamic distribution of suspended particles in the flocculation process

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第9期10卷 1350-1358页

作者： Jun NAN Wei-peng he Juan-juan SONG Gui-bai LI State Key Laboratory of Urban Water Resource and Environment School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China

Polyaluminium chloride (PAC) synthetic water was selected as a coagulant and kaolin suspension particles as objects to be removed. Online instruments such as the turbidimeter and particle counter were employed to monitor the flocculation process online and collect test data. The aim of the experiments was to study the dynamic distribution characteristics of suspension particles in the flocculation process. The 3D flow field in the reacting vessel was also simulated at different slow stirring speeds. The experiments showed that particle collision and aggregation in the flocculation process is in compliance with the Sutherland cluster aggregation model. This study further indicated that under appropriate hydrodynamic conditions, the distribution of turbulent flow in the reactor could be improved to increase the odds of effective particle collision and restrain the breakup of formed flocs by vortex shearing force. A good flocculation effect could therefore be produced.

关键词： Suspension particle Particle counter Flocculation process Dynamic distribution

NUMERICAL APPROACH TO DETERMINING INSTANTANEOUS CONTACT REGION FOR CONJUGATE SURFACES

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Chinese Journal of Mechanical Engineering 2008年第4期21卷 15-17页

作者： WANG Taiyong LI Jingcai he Gaiyun FAN Shengbo HAO Yongjiang Key Laboratory of AdvancedManufacturing Technologies and Equipments Tianjin University Tianjin 300072 China

According to the defect of traditional method of determining instantaneous contact regions for conjugate surfaces, a numerical approach to the determination is proposed. A local coordinate system is built by using the surface unit tangent and unit normal at the contact point. Considering that the gap forming the boundary of instantaneous contact region in the direction of the common normal vectors is given, a system of nonlinear equations is built to find the instantaneous contact boundary in local coordinate system, a modified Powell＇s hybrid algorithm of finite-difference approximation to the Jacobian used to solve the system. The new method simplifies the task of determining instantaneous contact regions without calculating curvatm＇e and relative curvature. The validity of the proposed approach is verified by an example of hypoid gears.

关键词： Tooth contact analysis Conjugate surfaces Numerical solutions