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Numerical Simulation of Rainfall-induced Xianchi Reservoir Landslide in Yunyang,Chongqing,China

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 505-517页

作者： yan Jinkai MA yan LIU Lei WANG Zhihui REN tianxiang Chinese Academy of Geological Sciences Beijing 100037China Urban Construction School Beijing City UniversityBeijing 100083China

A calamitous landslide happened at 22:00 on September 1,2014 in the Yunyang area of Chongqing City,southwest China,enforcing the evacuation of 508 people and damaging 23 *** landslide volume comprised 1.44 million m^(3) of material in the source area and 0.4 million m^(3) of shoveled *** debris flow runout extended 400 m vertically and 1600 m *** Xianchi reservoir landslide event has been investigated as follows:(1)samples collected from the main body of landslide were carried out using GCTS ring shear apparatus;(2)the parameters of shear and pore water pressure have been measured;and(3)the post-failure characteristics of landslide have been analyzed using the numerical simulation *** excess pore-water pressure and erosion in the motion path are considered to be the key reasons for the long-runout motion and the scale-up of landslides,such as that at Xianchi,were caused by the heavy *** aim of this paper is to acquired numerical parameters and the basic resistance model,which is beneficial to improve simulation accuracy for hazard assessment for similar to potentially dangerous hillslopes in China and elsewhere.

关键词： geohazards landslide post-failure rapid and long runout ring shear test

Self-supported ultrathin NiCo layered double hydroxides nanosheets electrode for efficient electrosynthesis of formate

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Journal of Energy Chemistry 2023年第10期85卷 267-275,I0008页

作者： Haoyuan Chi Jianlong Lin Siyu Kuang Minglu Li Hai Liu Qun Fan tianxiang yan Sheng Zhang Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Centre of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

Electrochemical CO_(2)reduction into energy-carrying compounds,such as formate,is of great importance for carbon neutrality,which however suffers from high electrical energy input and liquid products ***,we fabricated self-supported ultrathin NiCo layered double hydroxides(LDHs)electrodes as anode for methanol electrooxidation to achieve a high formate production rate(5.89 mmol h^(-1)cm^(-2))coupled with CO_(2)electro-reduction at the cathode.A total formate faradic efficiency of both anode for methanol oxidation and cathode for CO_(2)reduction can reach up to 188%driven by a low cell potential of only 2.06 V at 100 mA cm^(-2)in membrane-electrode assembly(MEA).Physical characterizations demonstrated that Ni^(3+)species,formed on the electrochemical oxidation of Ni-containing hydroxide,acted as catalytically active species for the oxidation of methanol to ***,DFT calculations revealed that ultrathin LDHs were beneficial for the formation of Ni^(3+)in hydroxides and introducing oxygen vacancy in NiCo-LDH could decrease the energy barrier of the rate-determining step for methanol *** work presents a promising approach for fabricating advanced electrodes towards electrocatalytic reactions.

关键词： CO_(2)reduction Methanol oxidation reaction Formate Layered double hydroxides Oxygen vacancies

Structure evolution,dielectric,and conductivity behavior of(K_(0.5)Na_(0.5))NbO_(3)-Bi(Zn_(2/3)Nb_(1/3))O_(3) ceramics

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Journal of Advanced Ceramics 2021年第4期10卷 809-819页

作者： tianxiang yan Kaiyuan CHEN Chengqi LI Min LIU Jie WANG Liang FANG Laijun LIU College of Mechanical and Control Engineering&College of Materials Science and Engineering Guilin University of TechnologyGuilin 541004China Institute of Fluid Engineering Equipment Jiangsu Industrial Technology Research InstituteJiangsu UniversityZhenjiang 212013China Key Laboratory for RF Circuits and Systems Ministry of Education&Key Laboratory of Large Scale Integrated DesignHangzhou Dianzi UniversityHangzhou 310018China

(1-x)K_(0.5)Na_(0.5)Nb0_(3-x)Bi(Zn_(2/3)Nb_(1/3))0_(3)((1-x)KNN-xBZN,x=0.010,0.015,0.020,0.025,and 0.030)lead-free ceramics were fabricated via a traditional solid-state *** crystal structure,microstructure,dielectric,and conductivity behavior of this system were *** with X-ray diffraction(XRD)patterns,Rietveld refinement,and dielectric spectroscopy,an orthorhombic phase was determined for x=0.010,an orthorhombic-tetragonal mixed phase was identified for x=0.015,and a rhombohedral symmetry appears in 0.020≤x≤*** 0.98KNN-0.02BZN and 0.975KNN-0.025BZN ceramics exhibit stable permittivity and low dielectric loss tangent(tan)in wide temperature ranges owing to the combination of rhombohedral-tetragonal step-like feature and the diffuse phase transition from tetragonal to *** activation energies of dielectric relaxation and conductivity behavior at high temperatures initially decrease slightly,then drop sharply,and finally decline slowly,which could be attributed to microstructure morphologies and the concentration of oxygen vacancies.

关键词： ceramic crystal structure dielectric spectroscopy oxygen vacancies

Influence of interface point defect on the dielectric properties of Y doped CaCu_(3)Ti_(4)O_(12) ceramics

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Journal of Advanced Dielectrics 2016年第1期6卷 74-82页

作者： Jianming Deng Xiaojun Sun Saisai Liu Laijun Liu tianxiang yan Liang Fang Brahim Elouadi Key Laboratory of Nonferrous Materials and New Processing Technology Ministry of Education Guilin University of TechnologyGuilin 541004P.R.China College of Materials Science and Engineering Guangxi Universities Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and DevicesGuilin University of Technology Guilin 541004P.R.China Laboratory of Chemical Analysis Elaboration and Materials Engineering(LEACIM)Universite de La RochelleAvenue Michel Crepeau17042 La Rochelle Cedex 01France

CaCu_(3)Ti_(4-x)Y_(x)O_(12)(0≤x≤0.12)ceramics were fabricated with conventional solid-state reaction *** structure and microstructure of prepared ceramics were characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM),*** impedance and modulus tests both suggested the existence of two different relaxation behavior,which were attributed to bulk and grain boundary *** addition,the conductivity and dielectric permittivity showed a step-like behavior under 405 ***,frequency independence of dc conduction became dominant when above 405 *** CCTO ceramic,rare earth element Y^(3+)ions as an acceptor were used to substitute Ti sites,decreasing the concentration of oxygen vacancy around grainelectrode and grain *** reason to the reduction of dielectric behavior in low frequencies range was associated with the Y doping in CCTO ceramic.

关键词： CaCu_(3)Ti_(4)O_(12) grain boundary bulk conduction electrochemical techniques dispersion dielectric properties

Nonlinear photonic quasi-periodic spiral

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Chinese Optics Letters 2024年第3期22卷 112-117页

作者：曾静王森赵如薇刘永兴徐铁峰盛艳徐天翔 Laboratory of Infrared Materials and Devices Research Institute of Advanced TechnologiesNingbo UniversityNingbo 315211China Zhejiang Key Laboratory of Photoelectric Materials and Devices Ningbo UniversityNingbo 315211China Ningbo Institute of Oceanography Ningbo 315832China Department of Quantum Science and Technology Research School of PhysicsAustralian National UniversityCanberraACT 2601Australia

The design of nonlinear photonic Vogel's spiral based on quasi-crystal theory was *** main parameters of Vogel's spiral were arranged to obtain multi-reciprocal *** structure was fabricated by the near-infrared femtosecond laser poling technique,forming a nonlinear photonic structure,and multiple ring-like nonlinear Raman±Nath second-harmonic generation processes were realized and analyzed in *** structure for the cascaded thirdharmonic generation process was *** results could help deepen the understanding of Vogel's spiral and quasi-crystal and pave the way for the combination of quasi-crystal theory with more aperiodic structures.

关键词： nonlinear photonic quasi-crystal second-harmonic generation Vogel's spiral nonlinear Raman-Nath diffraction femtosecond laser poling

数字技术赋能市域社会治理的影响因素与优化策略——基于31个城市政务热线案例的组态分析

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西南民族大学学报（人文社会科学版） 2024年第1期45卷 181-191页

作者：杜天翔颜德如东北大学文法学院

政务热线是政民互动的重要渠道,也是大力推进市域社会治理现代化的技术治理平台。基于TOE理论框架,以我国31个城市政务热线为案例,运用模糊集定性比较分析方法探讨技术、组织与环境等条件对政务热线服务质量的组态效应及优化策略。研究... 详细信息

政务热线是政民互动的重要渠道,也是大力推进市域社会治理现代化的技术治理平台。基于TOE理论框架,以我国31个城市政务热线为案例,运用模糊集定性比较分析方法探讨技术、组织与环境等条件对政务热线服务质量的组态效应及优化策略。研究发现:1.地方政府政务热线服务质量受到技术、组织与环境因素的综合影响,单一要素并未构成高水平服务质量的必要条件。2.技术、组织和环境条件具有“多重并发”的特点,存在政务热线高水平服务质量的五条路径,可归纳为三种组态类型进行解读,分别为“技术-环境型”“组织-环境型”与“要素联动型”。地方政府应立足“市域”实际情况,在秉持因地制宜方针的基础上,加强技术管理能力,完善组织机构设计,促进公众积极参与,以实现政务热线服务质量优化,进一步推动数字技术赋能市域社会治理。

关键词：政务热线技术赋能数字治理市域社会治理组态分析

Second-harmonic generation in periodic fork-shaped χ^((2)) gratings at oblique incidence

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Chinese Optics Letters 2024年第4期22卷 101-105页

作者：盛艳刘山胡效康陈鑫徐天翔赵如薇 Wieslaw Kroli kowski Laboratory of Infrared Materials and Devices Research Institute of Advanced TechnologiesNingbo UniversityNingbo 315211China Engineering Research Center for Advanced Infrared Photoelectric Materials and Devices of Zhejiang Province Ningbo UniversityNingbo 315211China Department of Quantum Science and Technology Research School of PhysicsAustralian National UniversityCanberra ACT 2601Australia School of Physics and Optoelectronics Engineering Xidian UniversityXi’an 710071China

Three-dimensional(3D) nonlinear photonic crystals have received intensive interest as an ideal platform to study nonlinear wave interactions and explore their applications. Periodic fork-shaped gratings are extremely important in this context because they are capable of generating second-harmonic vortex beams from a fundamental Gaussian wave, which has versatile applications in optical trapping and materials engineering. However, previous studies mainly focused on the normal incidence of the fundamental Gaussian beam, resulting in symmetric emissions of the second-harmonic vortices. Here we present an experimental study on second-harmonic vortex generation in periodic fork-shaped gratings at oblique incidence, in comparison with the case of normal incidence. More quasi-phase-matching resonant wavelengths have been observed at oblique incidence, and the second-harmonic emissions become asymmetric against the incident *** results agree well with theoretic explanations. The oblique incidence of the fundamental wave is also used for the generation of second-harmonic Bessel beams with uniform azimuthal intensity distributions. Our study is important for a deeper understanding of nonlinear interactions in a 3D periodic medium. It also paves the way toward achieving highquality structured beams at new frequencies, which is important for manipulation of the orbital angular momentum of light.

关键词： second-harmonic generation nonlinear photonic crystal periodically poled ferroelectric crystal quasi-phase matching nonlinear wavefront shaping

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基于混合强化学习的主动配电网故障恢复方法

电力系统及其自动化学报 2024年第4期36卷 50-58页

作者：徐岩陈嘉岳马天祥华北电力大学电气与电子工程学院保定071003 国网河北省电力有限公司电力科学研究院石家庄050021

针对高比例新能源接入的配电网故障恢复问题,提出一种基于混合强化学习的主动配电网故障恢复方法。首先,以故障损失最小为恢复目标、配电网安全运行要求为约束条件,构造主动配电网的故障恢复模型;其次,建立用于故障恢复的强化学习环境,... 详细信息

针对高比例新能源接入的配电网故障恢复问题,提出一种基于混合强化学习的主动配电网故障恢复方法。首先,以故障损失最小为恢复目标、配电网安全运行要求为约束条件,构造主动配电网的故障恢复模型;其次,建立用于故障恢复的强化学习环境,根据状态空间和动作空间特点,提出一种混合强化学习方法,该方法使用竞争架构双深度Q网络算法处理离散动作空间,进行开关动作;然后,使用深度确定性策略梯度算法处理连续动作空间,调节电源出力;最后,通过IEEE33节点系统仿真实验验证所提方法的可行性和优越性。

关键词：主动配电网故障恢复混合强化学习状态空间动作空间

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半圆柱阻流体锥形腔无阀压电泵

压电与声光 2023年第6期45卷 839-844页

作者：严天祥龙志文李成其陈虎城秦建华桂林理工大学机械与控制工程学院高校先进制造与自动化技术重点实验室广西桂林541006 桂林电子科技大学机电工程学院广西桂林541004

为了提高半圆柱阻流体无阀压电泵的流量,结合锥形腔的流阻不等特性,该文设计了一种半圆柱阻流体锥形腔无阀压电泵,并建立了其流量的理论公式。数值模拟了该泵的泵腔流速分布,对比分析了其与半圆柱阻流体无阀压电泵的阻力特性。模拟结果... 详细信息

为了提高半圆柱阻流体无阀压电泵的流量,结合锥形腔的流阻不等特性,该文设计了一种半圆柱阻流体锥形腔无阀压电泵,并建立了其流量的理论公式。数值模拟了该泵的泵腔流速分布,对比分析了其与半圆柱阻流体无阀压电泵的阻力特性。模拟结果表明,半圆柱阻流体锥形腔无阀压电泵能实现流体的单向输送,且其输送能力优于半圆柱阻流体无阀压电泵。制作了两种泵的样机并进行了流量和压力差试验。试验结果表明,在驱动电压220 V下,半圆柱阻流体锥形腔无阀压电泵的最高流量和压力差分别为30.96 g/min和394 Pa,与半圆柱阻流体无阀压电泵相比,其流量和压力差均得到提高。

关键词：半圆柱锥形腔无阀压电泵流量压力差