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(K_(0.5)Na_(0.5))Nb_(1-x)Ta_(x)O_(3)铁电性的第一性原理研究

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原子与分子物理学报 2025年第4期42卷 138-146页

作者：褚新建雷博程刘晨曦刘纪博新疆科技学院信息科学与工程学院库尔勒841000 新疆大学物理科学与技术学院新疆固体物理与器件重点实验室乌鲁木齐830046 西安工业大学光电工程学院西安710032

随着铅基陶瓷的大量使用,造成了严重的环境和健康问题,为了能够找寻替代铅基陶瓷的材料,人们开始了对无铅陶瓷材料的探索.(K_(0.5)Na_(0.5))NbO_(3)材料由于其优异的铁电压电性能,成为了无铅陶瓷材料的代表,但是碱性组分在高温下的高挥... 详细信息

随着铅基陶瓷的大量使用,造成了严重的环境和健康问题,为了能够找寻替代铅基陶瓷的材料,人们开始了对无铅陶瓷材料的探索.(K_(0.5)Na_(0.5))NbO_(3)材料由于其优异的铁电压电性能,成为了无铅陶瓷材料的代表,但是碱性组分在高温下的高挥发性使其应用范围受到了极大的限制.基于这样的考虑,本文基于密度泛函理论的第一性原理方法,探究了(K_(0.5)Na_(0.5))Nb_(1-x)TaxO_(3)(x=0.125,0.25,0.375,0.5,0.625,0.75,0.875,1)九种体系的铁电性能,结果表明:随着Ta浓度的增加,晶格常数发生了突变,由此猜测KNN材料随着Ta浓度的增加,发生了正交-单斜的相变;Ta的掺入能够降低KNN材料的烧结难度,且随着Ta浓度的增加,形成难度逐渐降低;掺杂体系中,Ta-4f轨道与Na-3p,K-4p以及O-2s轨道电子发生了杂化,使导带底Nb-4d与Na-3p电子的态密度峰向高能区移动,禁带宽度呈现增加的趋势;在分析KNN材料铁电性作用机理时发现KNN的铁电极化类型是离子位移型极化,且在[001]方向上不具有极化能力.分析掺杂后各个体系的极化强度,发现随着Ta浓度的增加,极化强度逐渐降低,但是在低浓度掺杂时极化有向上增加的趋势,这可能是体系在低浓存在着正交与单斜的准同型相界(Morphotropic phase boundary,MPB)导致的,由此可以判断,低浓度掺杂有利于提高KNN材料的铁电性能.

关键词：第一性原理钙钛矿结果 KNN 铁电性

Applying the maximum information principle to cell transmission model of traffic flow

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Journal of Hydrodynamics 2013年第5期25卷 725-730页

作者：刘喜敏卢守峰 Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Traffic and Transportation Engineering College and Key Laboratory of Road Structure and Material of Commu- nication ministry Changsha University of Science and Technology Traffic and Transportation Engineering College Changsha University of Science and Technology

This paper integrates the maximum information principle with the Cell Transmission Model （CTM） to formulate the velocity distribution evolution of vehicle traffic flow. The proposed discrete traffic kinetic model uses the cell transmission model to calculate the macroscopic variables of the vehicle transmission, and the maximum information principle to examine the velocity distribution in each cell. The velocity distribution based on maximum information principle is solved by the Lagrange multiplier method. The advantage of the proposed model is that it can simultaneously calculate the hydrodynamic variables and velocity distribution at the cell level. An example shows how the proposed model works. The proposed model is a hybrid traffic simulation model, which can be used to understand the self-organization phenomena in traffic flows and predict the traffic evolution.

关键词： kinetic traffic model Cell Transmission Model (CTM) maximum information principle traffic flow velocity distribution

Cyclic Group Action of Composite Order on Indefinite 4-manifolds

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Communications in Mathematical Research 2011年第3期27卷 200-206页

作者： LI HONG-xiA liu xi-min Department of Applied Mathematics Shanghai Maritime University Shanghai 201306 Department of Mathematics South China University of Technology Guangzhou 510641

In this paper, we study the possibilities for several kinds of topological, locally linear cyclic group actions of non-prime order on some closed, simply connected 4-manifolds with indefinite intersection form. Especi... 详细信息

关键词： periodic map 4-manifold indefinite permutation representation

Recent advances in slippery liquid-infused surfaces with unique properties inspired by nature

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Bio-Design and Manufacturing 2021年第3期4卷 506-525页

作者： xi Zeng Zhiguang Guo Weimin liu MOE Key Laboratory of Green Preparation and Application for Functional Materials Hubei UniversityWuhan 430062China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

The slippery liquid-infused porous surface(s)(SLIPS)that imitates the Nepenthes pitcher plant has proven to be highly versatile and can be combined with various surface characteristics such as dynamic response,antifouling,selective adhesion,and optical/mechanical *** addition,the introduction of a lubricating fluid layer also gives it extremely low contact angle hysteresis and self-repairing properties,which further expands its application ***,SLIPS has been proven to be suitable for many frontier fields such as aerospace,communications,biomedicine,and microfluidic *** this review,we explain the theoretical background of SLIPS and the preparation methods currently available,including the choice of substrate materials and lubricants,and we discuss the design parameters of the liquid injection surface and how to deal with the consumption of lubricants in practical *** addition,the paper focuses on current and potential applications,such as preventing pathogen contamination of and blood adhesion of medical equipment,manipulation of tiny droplets,and directional transportation of ***,some weaknesses that appear when SLIPS is used in these applications are pointed out,which provides a new perspective for the development of SLIPS in the future.

关键词： SLIPS Lubricant-infused Slippery Repellent surface Preparation Application

NUMERICAL SIMULATION OF THE HYDRODYNAMIC PERFORMANCE OF AN UNSYMMETRICAL FLAPPING CAUDAL FIN

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Journal of Hydrodynamics 2012年第3期24卷 354-362页

作者： ZHANG xi SU Yu-min WANG Zhao-li State Key Laboratory of Autonomous Underwater Vehicle Harbin Engineering University Harbin 150001 China

A comprehensive numerical simulation of the hydrodynamic performance of a caudal fin with unsymmetric flapping motion is carried out. The unsymmetrical motion is induced by adding a pitch bias or a heave bias. A numerical simulation program based on the unsteady panel method is developed to simulate the hydrodynamics of an unsymmetrical flapping caudal fin. A CFD code based on Navier-Stokes equations is used to analyze the flow field. Computational results of both the panel method and the CFD method indicate that the hydrodynamics are greatly affected by the pitch bias and the heave bias. The mean lateral force coefficient is not zero as in contrast with the symmetrical flapping motion. By increasing the pitch bias angle, the mean thrust force coefficient is reduced rapidly. By adding a heave bias, the hydrodynamic coefficients are separated as two parts： in one part, the amplitude is the heave amplitude plus the bias and in the other part, it is the heave amplitude minus the bias. Analysis of the flow field shows that the vortex distribution is not symmetrical, which generates the non-zero mean lateral force coefficient.

关键词： flapping caudal fin caudal fin shape numerical simulations hydrodynamic experiments hydrodynamic performance

Multi-objective optimization of equipment capacity and heating network design for a centralized solar district heating system

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Building Simulation 2023年第1期16卷 51-67页

作者： Yanfeng liu Ting Mu xi Luo School of Building Services Science and Engineering Xi'an University of Architecture and TechnologyXi'an 710055China State Key Laboratory of Green Building in Western China Xi'an 710055China

Northwest China has abundant solar energy resources and a large demand for winter *** solar energy for centralized heating is a clean and effective way to solve local heating *** present studies usually decoupled solar heating stations and the heating network in the optimization design of centralized solar heating systems,this study developed a joint multi-objective optimization model for the equipment capacity and the diameters of the heating network pipes of a centralized solar district heating system,using minimum total life cycle cost and CO_(2)emission of the system as the optimization *** typical cities in northwest China with different solar resource conditions(Lhasa,xining,and xi'an)were selected as cases for *** to the results,the solar heating system designed using the method proposed in this study presents lower economic cost and higher environmental protection in comparison to separately optimizing the design of the solar heating station and the heating ***,the solar fraction of the optimal systems are 90%,70%,and 31%for Lhasa,xining,and xi'an,and the minimum water supply temperatures are 55℃,50℃,and 65℃for an optimal economy and 55℃,45℃,and 45℃for optimal environmental protection,*** was also established that the solar collector price has a greater impact on the equipment capacity of the solar heating station than the gas boiler price.

关键词： solar energy solar energy system district heating optimization design genetic algorithm

Effects of fluid recirculation on mass transfer from the arterial surface to flowing blood

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Acta Mechanica Sinica 2012年第3期28卷 904-910页

作者： Zhi-Guo Zhang xi-Wen Zhang Ying-xi liu Department of Engineering Mechanics Faculty of Vehicle Engineering and MechanicsState Key Laboratory of Structural Analysisfor Industrial EquipmentDalian University of Technology116024 DalianChina School of Aerospace Tsinghua University100084 BeijingChina

The effect of disturbed flow on the mass trans- fer from arterial surface to flowing blood was studied nu- merically, and the results were compared with that of our previous work. The arterial wall was assumed to be vis- coelastic and the blood was assumed to be incompressible and non-Newtonian fluid, which is more close to human arte- rial system. Numerical results indicated that the mass trans- fer from the arterial surface to flowing blood in regions of disturbed flow is positively related with the wall shear rates and it is significantly enhanced in regions of disturbed flow with a local minimum around the reattachment point which is higher than the average value of the downstream. There- fore, it may be implied that the accumulation of cholesterol or lipids within atheromatous plaques is not caused by the reduced efflux of cholesterol or lipids, but by the infiltration of the LDL （low-density lipoprotein） from the flowing blood to the arterial wall.

关键词： Disturbed flow Arterial wall Mass transfer Atherosclerosis Wall shear rates

Attention and Intervention of Oncologists on Oxaliplatin-induced Adverse Reactions in China' Mainland:A Cross-sectional Internet-based Survey

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Current Medical Science 2022年第6期42卷 1319-1324页

作者： Wei LI Lu xiAO Zao-qin YU min LI xi-min WANG Dong liu Cheng-liang ZHANG Department of Pharmacy Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China Rehabilitation Division Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China

Objective This cross-sectional study aimed to investigate the current attention and intervention of oncologists on oxaliplatin(OXA)-induced adverse reactions(ADRs).Methods In 31 provinces or administrative regions across China,401 oncologists were surveyed through a self-designed *** survey queried the basic information of respondents,clinical use of OXA,OXA-induced ADRs,and relative ***-square tests and multiple logistic regression were used to explore the sociodemographic factors influencing the safety perception of OXA and the relevant *** The survey showed that the age of respondents was mainly distributed between 30 and 40 years and the working period for most oncologists was no more than 5 *** with long working years were more willing to conduct patient education and inquire about ADRs than those with short working *** rate of ADRs reported by oncologists with intermediate professional titles was significantly higher than that reported by oncologists with junior and senior professional *** Our findings indicate that oncologists in China's Mainland are concerned about OXA-induced ADRs,but the reporting of ADRs still needs to be ***,training and educational programs are urgently needed to improve the risk management of OXA-induced ADRs among oncologists.

关键词： oxaliplatin adverse reaction intervention cross-sectional survey

Penetration Depth of Torpedo Anchor in Two-Layered Cohesive Soil Bed by Free Fall

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China Ocean Engineering 2018年第6期32卷 706-717页

作者： WANG Cheng ZHANG min-xi YU Guo-liang SKLOE CISSE School of Naval Architecture Ocean & Civil Engineering Shanghai Jiao Tong University

The penetration depth of torpedo anchor in two-layered soil bed was experimentally investigated. A total of 177 experimental data were obtained in laboratory by varying the undrained shear strength of the two-layered soil and the thickness of the top soil layer. The geometric parameters of the anchor and the soil properties(the liquid limit, plastic limit, specific gravity, undrained shear strength, density, and water content) were measured. Based on the energy analysis and present test data, an empirical formula to predict the penetration depth of torpedo anchor in two-layered soil bed was proposed. The proposed formula was extensively validated by laboratory and field data of previous researchers. The results were in good agreement with those obtained for two-layered and single-layered soil ***, a sensitivity analysis on the parameters in the formula was performed.

关键词： torpedo anchor penetration depth two-layered soil bed