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Enhanced electromagnetic wave absorption via optical fiber-like PMMA@Ti_(3)C_(2)T_(x)@SiO_(2) composites with improved impedance matching

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Nano Research 2024年第3期17卷 1676-1686页

作者： Huanhuan Niu xuewen jiang Wei Li Zhiyu Min Budi Riza Putra Wulan Tri Wahyuni Hailong Wang Rui Zhang Bingbing Fan School of Material Science and Engineering Zhengzhou UniversityZhengzhou 450001China School of Materials Science and Engineering Tongji UniversityShanghai 201804China Department of Materials and Earth Sciences Technical University of DarmstadtDarmstadt 64287Germany School of Material Science and Engineering Luoyang Institute of Science and TechnologyLuoyang 471023China Research Center for Metallurgy National Research and Innovation Agency(BRIN)PUSPIPTEK Gd.470South TangerangBanten 15315Indonesia Analytical Chemistry Division Department of ChemistryFaculty of Mathematics and Natural SciencesIPB UniversityWest Java 16680Indonesia

Ti_(3)C_(2)T_(x) nanosheets have attracted significant attention for their potential in electromagnetic wave absorption(EWA).However,their inherent self-stacking and exorbitant electrical conductivity inevitably lead to serious impedance mismatch,restricting their EWA ***,the optimization of impedance matching becomes *** this work,we developed polymethyl methacrylate(PMMA)@Ti_(3)C_(2)T_(x)@SiO_(2) composites with a sandwich-like core–shell structure by coating SiO_(2) on PMMA@Ti_(3)C_(2)T_(x).The results demonstrate that the superiority of the SiO_(2) layer in combination with PMMA@Ti_(3)C_(2)T_(x),outperforming other relative graded distribution structures and meeting the requirements of EWA *** resulting PMMA@Ti_(3)C_(2)T_(x)@SiO_(2) composites achieved a minimum reflection loss of-58.08 dB with a thickness of 1.9 mm,and an effective absorption bandwidth of 2.88 *** analysis revealed that the structural design of SiO_(2) layer not only optimized impedance matching,but also synergistically enhanced multiple loss mechanisms such as interfacial polarization and dipolar ***,this work provides valuable insights for the future preparation of high-performance electromagnetic wave absorbing Ti_(3)C_(2)T_(x)-based composites.

关键词： polymethyl methacrylate(PMMA)@Ti_(3)C_(2)T_(x)@SiO_(2)composites impedance match SiO_(2)layer optical fiber-like structure interfacial polarization and dipolar polarization

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Construction of hydrangea-like core-shell SiO_(2)@Ti_(3)C_(2)T_(x)@CoNi microspheres for tunable electromagnetic wave absorbers

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Journal of Advanced Ceramics 2023年第4期12卷 711-723页

作者： Huanhuan Niu xuewen jiang Yongde Xia Hailong Wang Rui Zhang Hongxia Li Bingbing Fan Yanchun Zhoua School of Material Science&Engineering Zhengzhou UniversityZhengzhou 450001China Department of Engineering University of ExeterExeter EX44SBUK School of Materials Science and Engineering Luoyang Institute of Science and TechnologyLuoyang 471023China Sinostel Luoyang Institute of Refractories Research Co. Ltd.Luoyang 471039China

Ti_(3)C_(2)T_(x)MXene shows great potential in the application as microwave absorbers due to its high attenuation ***,excessively high permittivity and self-stacking are the main obstacles that constrain its wide range of *** tackle these problems,herein,the microspheres of SiO_(2)@Ti_(3)C_(2)T_(x)@CoNi with the hydrangea-like core-shell structure were designed and prepared by a combinatorial electrostatic assembly and hydrothermal reaction *** microspheres are constructed by an outside layer of CoNi nanosheets and intermediate Ti_(3)C_(2)T_(x)MXene nanosheets wrapping on the core of modified SiO_(2),engendering both homogenous and heterogeneous *** trilayer SiO_(2)@Ti_(3)C_(2)T_(x)@CoNi microspheres are“magnetic microsize supercapacitors”that can not only induce dielectric loss and magnetic loss but also provide multilayer interfaces to enhance the interfacial *** optimized impedance matching and core-shell structure could boost the reflection loss(RL)by electromagnetic *** synthesized SiO_(2)@Ti_(3)C_(2)T_(x)@CoNi microspheres demonstrate outstanding microwave absorption(MA)performance benefited from these *** obtained RL value was-63.95 dB at an ultra-thin thickness of 1.2 mm,corresponding to an effective absorption bandwidth(EAB)of 4.56 *** work demonstrates that the trilayer core-shell structure designing strategy is highly efficient for tuning the MA performance of MXene-based microspheres.

关键词： SiO_(2)@Ti_(3)C_(2)T_(x)@CoNi hydrangea-like core-shell structure spherical capacitor high-performance microwave absorption(MA) interfacial polarization impedance match

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NaNbO_(3) modulated phase transition behavior and antiferroelectric stability evolution in 0.88(Bi_(0.5)Na_(0.5))TiO_(3)-0.12BaTiO_(3) lead-free ceramics

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Journal of Materiomics 2022年第5期8卷 1067-1076页

作者： Yi Zhang Jian Fu Aiwen Xie Tianyu Li xuewen jiang Ruzhong Zuo Dou Zhang Institute of Electro Ceramics&Devices School of Materials Science and EngineeringHefei University of TechnologyHefei230009China Center for Advanced Ceramics School of Materials Science and EngineeringAnhui Polytechnic UniversityWuhu241000China State Key Laboratory of Power Metallurgy Central South UniversityChangshaHunan410083China

Giant strains in(Bi_(0.5)Na_(0.5))TiO_(3) based ceramics are usually attributed to electric field induced nonpolar to polar phase *** it is an ergodic relaxor R3c/P4mm ferroelectric(FE)to long-range ordered FE phase transformation or a reversible P4bm antiferroelectric(AFE)to FE phase transition is still ***,lead-free(0.88-x)(Bi_(0.5)Na_(0.5))TiO_(3)-0.12BaTiO_(3-x)NaNbO_(3) ceramics exhibit a compositionmodulated FE tetragonal P4mm to relaxor AFE tetragonal P4bm phase transition,in which double hysteresis loop,sprout-shaped S-E curves,near-zero quasi-static d33 together with a large volume change suggest the AFE characteristics of P4bm *** interesting finding is that the reversibility of fieldinduced AFE P4bm phase to FE P4mm phase transition strongly depends on the NN content,from being completely irreversible at x=0.01e0.02,to partially reversible at x=0.03e0.05,and finally to completely reversible at x=*** is indicated that the variation of reversibility should be attributed to the change of relative free energy caused by decreasing the FE to AFE phase transition temperature with increasing the NN content.

关键词： Lead-free ceramic Sodium bismuth titanate Strains Antiferroelectric stability

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互联网+全程化管理在泌尿外科日间手术管理中的应用效果

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中国医药科学 2024年第12期14卷 82-85页

作者：蒋学文熊亚琴苏金英李汶泽黄宝仪广东省中山市中医院泌尿外科广东中山528400

目的探讨互联网+全程化管理在泌尿外科日间手术管理中的应用效果。方法选取2022年1月至2023年1月于中山市中医院泌尿外科住院的肾结石或输尿管结石手术后返院行输尿管支架管拔除术的患者160例,进行随机分组,其中接受互联网+日间行输尿... 详细信息

目的探讨互联网+全程化管理在泌尿外科日间手术管理中的应用效果。方法选取2022年1月至2023年1月于中山市中医院泌尿外科住院的肾结石或输尿管结石手术后返院行输尿管支架管拔除术的患者160例,进行随机分组,其中接受互联网+日间行输尿管支架管拔除术全程化管理为试验组(n=80),接受日间行输尿管支架管拔除术常规管理为对照组(n=80)。在护理干预前后分别对两组患者的疼痛、焦虑、抑郁情况进行评分,并对两组患者的护理满意度以及术后并发症的发生率进行比较。结果试验组疼痛评分较对照组低,差异有统计学意义(P<0.05)。试验组的焦虑及抑郁评分较对照组低,差异有统计学意义(P<0.05);试验组的整体护理满意度较对照组高(P<0.05),术后并发症总发生率低于对照组,差异有统计学意义(P<0.05)。结论泌尿外科日间行输尿管支架管拔除术采用互联网+全程化管理不仅可以改善患者的疼痛、焦虑抑郁情绪,还可以提高护理满意度,降低并发症发生情况。

关键词：互联网全程化管理泌尿外科日间手术

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Supersonic expansion and condensation characteristics of hydrogen gas under different temperature conditions

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Chinese Journal of Chemical Engineering 2024年第5期69卷 220-226页

作者： Xinyue Duan Zeyu Zhang Ziyuan Zhao Yang Liu Liang Gong xuewen Cao jiang Bian College of New Energy China University of Petroleum(East China)Qingdao 266580China College of Pipeline and Civil Engineering China University of Petroleum(East China)Qingdao 266580China

This paper introduced supersonic expansion liquefaction technology into the field of hydrogen *** mathematical model for supersonic condensation of hydrogen gas in a Laval nozzle model was *** supersonic expansion and condensation characteristics of hydrogen gas under different temperature conditions were *** simulation results show that the droplet number rises rapidly from 0 at the nozzle throat as the inlet temperature increases,and the maximum droplet number generated is 1.339×10^(18)kg^(-1)at inlet temperature of 36.0 *** hydrogen nucleation occurs,the droplet radius increases significantly and shows a positive correlation with the increase in the inlet temperature,and the maximum droplet radii are 6.667×10^(-8)m,1.043×10^(-7)m,and 1.099×10^(-7)m when the inlet temperature is 36.0 K,36.5 K,and 37.0 K,*** maximum nucleation rate decreases with increasing inlet temperature,and the nucleation region of the Laval nozzle becomes *** liquefaction efficiency can be effectively improved by lowering the inlet *** is because a lower inlet temperature provides more subcooling,which allows the hydrogen to reach the thermodynamic conditions required for large-scale condensation more quickly.

关键词： Hydrogen Liquefaction Supersonic Condensation Laval nozzle Computational fluid dynamics

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Efficient Dynamic Locomotion of Quadruped Robot via Adaptive Diagonal Gait

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Journal of Bionic Engineering 2024年第1期21卷 126-136页

作者： Jian Bi Teng Chen xuewen Rong Guoteng Zhang Guanglin Lu Jingxuan Cao Han jiang Yibin Li The Center for Robotics School of Control Science and EngineeringShandong UniversityJi Nan 250000China

Quadruped animals in the nature realize high energy efficiency locomotion by automatically changing their gait at different *** by this character,an efficient adaptive diagonal gait locomotion controller is designed for quadruped robot.A unique gait planning method is proposed in this *** the speed of robot varies,the gait cycle time and the proportion of stance and swing phase of each leg are adjusted to form a variety of *** optimal joint torque is calculated by the controller combined with Virtual Model Control(VMC)and Whole-Body Control(WBC)to realize the desired *** gait and step frequency of the robot can automatically adapt to the change of *** experiments are done with a quadruped robot made by our laboratory to verify that the gait can change automatically from slow-trotting to flying-trot during the period when speed is from 0 to 4 m/*** ratio of swing phase is from less than 0.5 to more than 0.5 to realize the running motion with four feet off the *** have shown that the controller can indeed consume less energy when robot runs at a wide range of speeds comparing to the basic controller.

关键词： Quadruped robot Gait transition Adaptive gait Energy efficiency

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Optimal combination of the correction model and parameters for the precision geometric correction of UAV hyperspectral images

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INTERNATIONAL JOURNAL OF AGRICULTURAL AND BIOLOGICAL ENGINEERING 2024年第3期17卷 173-184页

作者： Tian, Wenzhong Kan, Za Zhao, Qingzhan jiang, Ping Wang, xuewen Liu, Hanqing Shihezi Univ Coll Mech & Elect Engn Shihezi 832000 Xinjiang Peoples R China Res Ctr Space Informat Engn Technol Shihezi 832000 Xinjiang Peoples R China XPCC Div Natl Remote Sensing Ctr China Shihezi 832000 Xinjiang Peoples R China Shihezi Univ Coll Informat Sci & Technol Shihezi 832000 Xinjiang Peoples R China

Nowadays, with the rapid development of quantitative remote sensing represented by high-resolution UAV hyperspectral remote sensing observation technology, people have put forward higher requirements for the rapid preprocessing and geometric correction accuracy of hyperspectral images. The optimal geometric correction model and parameter combination of UAV hyperspectral images need to be determined to reduce unnecessary waste of time in the preprocessing and provide high-precision data support for the application of UAV hyperspectral images. In this study, the geometric correction accuracy under various geometric correction models (including affine transformation model, local triangulation model, polynomial model, direct linear transformation model, and rational function model) and resampling methods (including nearest neighbor resampling method, bilinear interpolation resampling method, and cubic convolution resampling method) were analyzed. Furthermore, the distribution, number, and accuracy of control points were analyzed based on the control variable method, and precise ground control points (GCPs) were analyzed. The results showed that the average geometric positioning error of UAV hyperspectral images (at 80 m altitude AGL) without geometric correction was as high as 3.4041 m (about 65 pixels). The optimal geometric correction model and parameter combination of the UAV hyperspectral image (at 80 m altitude AGL) used a local triangulation model, adopted a bilinear interpolation resampling method, and selected 12 edgemiddle distributed GCPs. The correction accuracy could reach 0.0493 m (less than one pixel). This study provides a reference for the geometric correction of UAV hyperspectral images.

关键词： geometric correction hyperspectral images unmanned aerial vehicle (UAV) ground control point (GCP)

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Structure and enhanced dielectric temperature stability of BaTiO3- based ceramics by Ca ion B site-doping

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Journal of Materiomics 2021年第2期7卷 295-301页

作者： xuewen jiang Hua Hao Yang Yang Enhao Zhou Shujun Zhang Ping Wei Minghe Cao Zhonghua Yao Hanxing Liu Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory Xianhu Hydrogen ValleyFoshan528200China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and EngineeringWuhan University of TechnologyWuhan430070China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing International School of Material Science and EngineeringWuhan University of TechnologyWuhan430070China Institute for Superconducting and Electronic Materials Australian Institute of Innovative MaterialsUniversity of WollongongWollongongNSW2500Australia Nanostructure Research Centre Wuhan University of TechnologyWuhan430070China

Capacitor is an important part of many electronic devices,so the temperature stability as one key parameter of capacitor needs to be improved constantly for meeting the requirements of various application ***,combined with the X-ray diffraction(XRD),selected area electron diffraction(SAED)and Vienna Ab-initio Simulation Package(VASP)calculation,it was confirmed that Ca ion can substitute the Ti site in the BaTi1-xCaxO3-x[BTC100](0≤x≤0.05)ceramics synthesized by solid-phase method which greatly improved the low-temperature stability of dielectric ***,introducing Bi3þand Zn^(2+) into BTC4 to form(1-y)BaTi0.6Ca0.04O2.96-yBi(Zn_(0.5)Ti_(0.5))O_(3)[(1-y)BTC4-yBZT](0.1≤y≤0.2)ceramics can further improve the dielectric-temperature stability by means of diffused phase transition and core-shell *** importantly,the 0.85BTC4-0.15BZT ceramics with a pseudocubic perovskite structure possessed a temperature coefficient of capacitance at 25℃(TCC25℃)being less than±15%over a wide temperature range of 55℃-200℃and a temperate dielectric constant(ε=1060)and low dielectric loss(tanδ=1.5%),which measure up to the higher standard in the current capacitor industry such as X9R requirements.

关键词： BaTiO3 Ca substituted X9R capacitors Dielectric properties

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An improved initial rotor position estimation method using high-frequency pulsating voltage injection for PMSM

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Defence Technology（防务技术） 2024年第3期33卷 19-29页

作者： Yang jiang Ming Cheng School of Electrical Engineering Southeast UniversityNanjing 210096China

High frequency pulsating voltage injection method is a good candidate for detecting the initial rotor position of permanent magnet synchronous ***,traditional methods require a large number of filters,which leads to the deterioration of system stability and dynamic *** order to solve these problems,a new signal demodulation method is proposed in this *** proposed new method can directly obtain the amplitude of high-frequency current,thus eliminating the use of filters,improving system stability and dynamic performance and saving the work of adjusting filter *** addition,a new magnetic polarity detection method is proposed,which is robust to current measurement ***,experiments verify the effectiveness of the method.

关键词： Initial position detection Signal demodulation algorithm Magnetic polarity detection Filter elimination

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建筑企业推进数字化转型的路径与实践研究

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铁道工程学报 2024年第1期41卷 88-92页

作者：江文化谢学文杨向歌中铁云网信息科技有限公司北京100039

研究目的:全球数字经济进入高速发展期,由于数字化转型起点较低、启动较晚,建筑企业在数字化转型过程中缺乏统一的顶层设计、技术路径、实施路径和有效的应用场景,无法适应数字化转型升级的发展要求。为提高建筑企业数字化转型水平,本... 详细信息

研究目的:全球数字经济进入高速发展期,由于数字化转型起点较低、启动较晚,建筑企业在数字化转型过程中缺乏统一的顶层设计、技术路径、实施路径和有效的应用场景,无法适应数字化转型升级的发展要求。为提高建筑企业数字化转型水平,本文结合某建筑央企数字化转型实践,对建筑企业推进数字化转型的路径和实践进行研究。研究结论:(1)建筑业数字化存在数字化应用年限底、应用程度不高、应用不够全面等现状,分析其原因为BIM正向设计推广难度大、缺少专业数字化人才、工程项目全生命期存在数据孤岛、信息化基础设施难以满足数字化转型要求;(2)提出了建筑企业数字化转型的技术路径和实施路径;(3)提出了应用BIM技术打造建筑业数据资产、信息化技术打通数据孤岛、数字化技术赋能智能建造、新一代信息技术助力智能运营等数字化转型的应用场景;(4)本文研究可为建筑企业数字化转型升级提供借鉴或参考。

关键词：建筑企业数字化转型实施路径实践研究

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