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Impact of Spectral Nudging on the Downscaling of Tropical Cyclones in Regional Climate Simulations

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Advances in Atmospheric Sciences 2016年第6期33卷 730-742页

作者： Suk-jin CHoI dong-Kyou LEE Atmospheric Sciences Program School of Earth and Environmental SciencesKorea-USA Weather and Climate Research Center Seoul National University

This study investigated the simulations of three months of seasonal tropical cyclone （TC） activity.over the western North Pacific using the Advanced Research WRF Model. In the control experiment （CTL）, the TC frequency was considerably.overestimated. Additionally, the tracks of some TCs tended to have larger radii of curvature and were shifted eastward. The large-scale environments of westerly monsoon flows and subtropical Pacific highs were unreasonably simulated. The overestimated frequency.of TC formation was attributed to a strengthened westerly wind field in the southern quadrants of the TC center. In comparison with the experiment with the spectral nudging method, the strengthened wind speed was mainly modulated by large-scale flow that was greater than approximately 1000 km in the model domain. The spurious formation and undesirable tracks of TCs in the CTL were considerably improved by reproducing realistic large-scale atmospheric monsoon circulation with substantial adjustment between large-scale flow in the model domain and large-scale boundary forcing modified by the spectral nudging method. The realistic monsoon circulation took a vital role in simulating realistic TCs. It revealed that, in the downscaling from large-scale fields for regional climate simulations, scale interaction between model-generated regional features and forced large-scale fields should be considered, and spectral nudging is a desirable method in the downscaling method.

关键词： tropical cyclone spectral nudging technique dynamic downscaling regional climate simulation

Moments of the maximum of normed partial sums of ρ^--mixing random variables

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Applied Mathematics(A Journal of Chinese Universities) 2009年第3期24卷 355-360页

作者： LIU Xiang-dong LIU jin-xia Dept. of Statist. Jinan Univ. Guangzhou 510630 China

Let {Xn,n ≥ 1} be a sequence of identically distributed ρ^--mixing random variables and set Sn =∑i^n=1 Xi,n ≥ 1,the suffcient and necessary conditions for the existence of moments of supn≥1 ｜Sn/n^1/r｜^p（0 〈 r... 详细信息

关键词： moment of supremum of normed partial sum ρ^--mixing random variable

The Decision of Prime and Primary Ideal

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Acta Mathematicae Applicatae Sinica 2011年第4期27卷 595-600页

作者： jin-wang LIU dong-mei LI School of Mathematics and Computing Sciences Hunan University of Science and Technology Xiangtan 411201 China School of Mathematical Science and Computing Technology Central South University Changsha 410083 China

We give more efficient criteria to characterise prime ideal or primary ideal. Further, we obtain the necessary and sufficient conditions that an ideal is prime or primary in real field from the Grobner bases directly.

关键词： Grobner basis prime ideal orimarv ideal

Azulene-based organic functional molecules for optoelectronics

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Chinese Chemical Letters 2016年第8期27卷 1097-1104,1464页

作者： jin-Xue dong Hao-Li Zhang State Key Laboratory.of Applied organic Chemistry(SKLAoC) Key Laboratory of Special Function Materials and Structure Design(MOE)College of Chemistry and Chemical EngineeringLanzhou University

Design and synthesis of new organic functional materials with improved performance or novel properties are of great importance in the field of ***,as a non-alternant aromatic hydrocarbon,has attracted rising attention in the last few *** from most common aromatic hydrocarbons,azulene has unique characteristics,including large dipole moment,small gap between the highest occupied molecular orbital（HoMo） and the lowest unoccupied molecular orbital（LUMo）.However,the design and synthesis of azulene-based functional materials are still facing several *** review focuses on the recent development of organic functional materials employing azulene *** synthesis of various functionalized azulene derivatives is summarized and their applications in optoelectronics are discussed,with particular attention to the fields including nonlinear optics（NLo）,organic field-effect transistors（oFETs）,solar cells,and molecular devices.

关键词： Azulene Nonlinear optics organic field-effect transistors Solar cells Molecular devices

基于离散元的钢渣透水沥青混合料疲劳损伤数值仿真

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江苏大学学报（自然科学版） 2025年第1期46卷 98-104页

作者：刘振辉陈雪琴董侨姚波范进南京理工大学理学院江苏南京210094 南京理工大学安全科学与工程学院江苏南京210094 东南大学交通学院江苏南京211189 东南大学道路交通工程国家级实验教学示范中心江苏南京211189

采用钢渣替换透水沥青混合料中部分玄武岩粗集料,开展室内疲劳试验及数值仿真,研究钢渣透水沥青混合料的疲劳性能.基于CT扫描获取图像,通过阈值分割将混合料中钢渣、玄武岩、沥青砂浆和孔隙进行区分,导入颗粒流程序(PFC),建立颗粒直径为... 详细信息

采用钢渣替换透水沥青混合料中部分玄武岩粗集料,开展室内疲劳试验及数值仿真,研究钢渣透水沥青混合料的疲劳性能.基于CT扫描获取图像,通过阈值分割将混合料中钢渣、玄武岩、沥青砂浆和孔隙进行区分,导入颗粒流程序(PFC),建立颗粒直径为0.4 mm的钢渣透水沥青混合料离散元模型,基于宏观和细观力学参数转换及虚拟强度试验进一步校正细观力学参数,开展虚拟疲劳损伤数值模拟,得到重复荷载作用下试件微裂纹扩展路径及疲劳寿命.结果表明:虚拟强度试验能够较好地模拟钢渣透水沥青混合料试件荷载与位移关系曲线,试件裂纹扩展路径符合实际断裂情况,裂纹的分布主要沿着模型内部孔隙处扩展;虚拟疲劳损伤模型能够较好地描绘平行黏结模型的黏结直径随荷载作用次数的增加而减小、随着平行黏结接触颗粒间的拉应力增大而加速减小的趋势,虚拟疲劳损伤模型计算结果和室内疲劳损伤试验结果较为接近,误差不到10%,可有效预测高应力比下钢渣透水沥青混合料的疲劳寿命.

关键词：钢渣透水沥青混合料疲劳损伤离散元方法裂纹扩展

A double transition metal Ti_(2)NbC_(2)T_(x) MXene for enhanced lithium-ion storage

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Rare Metals 2023年第1期42卷 100-110页

作者： Wei Liu jin Cao Feng Song dong-dong Zhang Manunya okhawilai jin yi Jia-Qian Qin Xin-yu Zhang State Key Laboratory.of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao066004China International Graduate Program of Nanoscience&Technology Chulalongkorn UniversityBangkok10330Thailand Metallurgy and Materials Science Research Institute Chulalongkorn UniversityBangkok10330Thailand Center of Excellence in Responsive Wearable Materials Chulalongkorn UniversityBangkok10330Thailand Institute for Sustainable Energy College of SciencesShanghai UniversityShanghai200444China

MXene,an emerging two-dimensional(2D)layered material,has received worldwide attention in various energy storage systems because of its excellent ***,the low capacity.of pristine MXene restricts its application in energy storage devices especially for the lithium-ion batteries(LIBs).To address the above issue,herein,a stable and highly conductive double transition metal MXene(Ti_(2)NbC_(2)T_(x)) is successfully fabricated,which provides enlarged interlayer spacing and excellent conductivity for fast ion diffusion and charge *** the Ti_(2)NbC_(2)T_(x)s anode for LIBs,a superior specific capacity.of 196.2 mAh·g-1and an excellent long-term cycling stability.of~100%after 400cycles under 0.1 A·g^(-1) are achieved for *** particular,Ti_(2)NbC_(2)T_(x) delivers an impressive capacity retention of 81%over 4000 cycle under 1 A·g^(-1),outperforming the Ti_(3)C_(2)T_(x) and various previously reported MXene-based *** results offer an attractive strategy for the future application of MXene-based materials.

关键词： Double transition metal MXene Ti_(2)NbC_(2)T_(x) Ti_(3)C_(2)T_(x) Lithium-ion batteries(LIBs) Anode

Viewpoint optimization Method for Flying Robot Inspecting Transmission Towers Based on Point Cloud Model

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Chinese Journal of Electronics 2018年第5期27卷 976-984页

作者： LIU Chang'an dong Ruifang jin Lu WU Hua School of Control and Computer Engineering North China Electric Power University

This paper presents a method to derive optimal viewpoints for flying robot based transmission tower inspection, which applies point cloud model. A safe envelope is established according to safe transmission tower inspection rules. Essential inspection factors are proposed to evaluate the quality.of candidate viewpoints, which includes visibility, dimensionality feature of point cloud as well as the distance between viewpoint and transmission power. A score function is constructed to quantify candidate viewpoints, while multiple attribute decision theory is applied to calculate the weight of each factor. Particle swarm optimization(PSo) is used to find the optimal viewpoints set. Both simulation experiment and practical observations are carried out. The results prove that optimal viewpoints have a great contribution for accurate transmission tower inspection. Final results are compared to patch-based method and proved to be feasible.

关键词： Transmission tower inspection Viewpoint optimization Point cloud model Particle swarm optimization(PSo) Flying robot

Adaptive observer Based Backstepping Controller Design for Dynamic Ship Positioning

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China ocean Engineering 2017年第5期31卷 639-645页

作者： DENG Fang WANG Long-jin JIAo dong-mei College of Mechanical & Electrical Engineering Qingdao University of Science & Technology

Modified adaptive observer based backstepping control system for dynamic positioning of ship is proposed. As an improvement, the adaptive observer takes the first-order wave frequency model and the bias term which represent the slowly varying environmental disturbances and the unmodeled dynamics. Thus, the wave-frequency motions are filtered out, and only the reconstructed low-frequency motions are sent as inputs of the controller. Furthermore, as the ship dynamics parameters are unknown, the adaptive estimation law is designed for both the unknown ship dynamics and the unmeasured state variables. Based on the estimated states and parameters, backstepping controller considering the integral action is designed. Global exponential stability （GES） for the total system is proved using Lyapunov direct method. Simulation results show a good performance of the observer and control system.

关键词： Dynamic positioning backstepping control adaptive observer parameter estimation

Material Characterization of Ni Base Alloy for Very High Temperature Reactor

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Journal of Materials Science & Technology 2013年第12期29卷 1184-1190页

作者： dong-jin Kim Gy.ong-Geun Lee Dae Jong Kim Su jin Jeong Nuclear Materials Division Korea Atomic Energy Research Institute

The generation of highly efficient electricity and the production of massive hydrogen are possible using a very high temperature reactor （VHTR） among generation IV nuclear power plants. The structural material for an intermediate heat exchanger （IHX） among numerous components should be endurable at high temperature of up to 950 °C during long-term operation. Impurities inevitably introduced in helium as a coolant facilitate the material degradation by corrosion at high temperature. In the present work, the surface reactions available under controlled impure helium at 950 °C were investigated based on the thermodynamics and the corrosion tests were performed in a temperature range of 850-950 °C during 10-250 h for commercial Alloy 617 as a candidate material for an IHX. Moreover, the mechanical property and microstructure for nickel-based alloys fabricated in laboratory were evaluated as a function of the processing parameters such as hot rolling and heat treatment conditions. From the reaction rate constant obtained from an impure helium control system for a material evaluation, it was predicted that the outer oxide layer thickness, internal oxide depth, and carbide- depleted zone depth reach about 116, 600 and 1000 μm, respectively when Alloy 617 is exposed to an impure helium environment at 950 ~C for 20 years. For Ni-Cr-Co-Mo alloy, subsequent annealing and a combination of cold working and subsequent annealing following solution annealing caused increases in the grain boundary carbide coverage and size. The angular distribution of the grain boundary as well as the carbide distribution was also changed leading to a consequent improvement of the mechanical property at 950 °C in air.

关键词： Nickel base alloy Intermediate heat exchanger High temperature reactor Corrosion Mechanical property