检索结果-内蒙古大学图书馆

Boosting ultra-wide temperature dielectric stability of multilayer ceramic capacitor through tailoring the combination types of polar nanoregions

引用

Journal of Materiomics 2024年第4期10卷 751-761页

作者： Jiacheng Liu Kaibiao Xi Beibei Song Huarong Cheng Xiaole Yu Mupeng Zheng Mankang Zhu Yudong Hou College of Materias Science and Engineering Key Laborutory of Advanced Functional Materials Education Ministry of China Beijing University of TechnologyBeijing100124China Materials R&D Department Beijing Yuanliu Hongyuan Eletronic Technology CompanyLtdBeijing102600China

With the rapid development of space exploration and new energy vehicles,it is urgent to build ultra-wide temperature multilayer ceramic capacitors(UWT MLCCs)to match electronic circuits that can withstand harsh environmental *** ferroelectrics with diffuse phase transition feature are potential dielectrics for the construction of UWT ***,how to ensure high dielectric constant together with low dielectric loss in the wide temperature region is still a big ***,the above difficulties are addressed by tailoring the combination types of polar nanoregions(PNrs)in the(1-x)(0.8Na_(0.5)Bi_(0.5)TiO_(3)-0.2K_(0.5)Bi_(0.5)TiO_(3))-xNaTaO3(NBT-KBT-xNT)*** with PNrS types of P4bm+r3c and P4bm+Pbnm,the combination type of P4bm+Pbnm+r3c PNrs in NBT-KBT-0.31NT is the most beneficial to obtain comprehensive excellent dielectric performance because it can balance the relationship between high dielectric constant and temperature stability over a wide temperature ***,by optimizing the laminating pressure and co-firing temperature to realize a tight interfacial structure between the dielectric layer and the Pt inner electrode,a record-high dielectric constant(er=(907%±15%))together with low dielectric loss(tan δ≤0.025)is achieved over an ultra-wide range from-61℃ to 306℃ for NBT-KBT-0.31 NT MLCC,demonstrating that tailoring the combination types of PNrs is a powerful strategy in designing UWT MLCC dielectrics.

关键词： Lead-free dielectrics Ultra-wide temperature Multilayer ceramic capacitor Polar nanoregion

来源：评论

学校读者我要写书评

暂无评论

Empirical Study on Heat Transfer Coefficients in Lumped Parameter Thermal Network of direct-Oil Cooled Permanent Magnet Synchronous Motor

Empirical Study on Heat Transfer Coefficients in Lumped Para...

引用

2024 International Conference on Electrical Machines, ICEM 2024

作者： Chin, Jun-Woo Park, Seojun Hwang, Jaeyeob Kim, deok-Jin Jung, Ho-Chang Korea Automotive Technology Institute Advanced Powertrain R&D Department Cheonan Korea Republic of

ISBN: (纸本)9798350370607

This paper presents an empirical study on heat transfer coefficients within a lumped parameter thermal network (LPTN) applied to a direct oil-cooled permanent magnet synchronous motor (PMSM). The study focuses on identifying unknown parameters within the LPTN, specifically the convection heat transfer coefficient (HTC) of automatic transmission fluid (ATF) oil, as well as the equivalent thermal conductivity and heat capacity of the coil. To improve the reliability of the LPTN, a proposed model for heat transfer by ATF oil is introduced. Additionally, the parameters influencing the convection HTC of ATF oil, including geometry, velocity, and temperature, are analyzed. These unknown parameters are crucial for accurate thermal analysis but those are challenging to determine due to the composite nature of the coil and the complex behavior of ATF oil. To address this challenge, a correlation process with temperature results is conducted, employing design of Experiment (dOE) with Latin Hypercube Sampling (LHS), surrogate modeling with the Kriging method, and optimization with a genetic algorithm (GA). Future work will involve expanding the scope of experimentation to include a wider range of operating points and flow rates, thus providing more comprehensive empirical data for correlation. © 2024 IEEE.

关键词： Lumped parameter networks

来源：评论

学校读者我要写书评

暂无评论

Viewing Angle Control through Electrically-Induced Effective Out-of-Plane retardation differences in Automotive displays

Viewing Angle Control through Electrically-Induced Effective...

引用

International Symposium, Seminar, and Exhibition, display Week 2024

作者： Choi, Tae-Hoon Wook Lee, Hyun Uk Ha, Jin Department of Advanced Materials R&D Korea Automotive Technology Institute Cheonan31214 Korea Republic of

We report a method for controlling the viewing angle using twisted nematic liquid crystal (TN-LC) materials for automotive display applications. We achieved switching between normal and privacy modes with the change in viewing-angle-dependent retardation through the reorientation of the TN-LC molecules under crossed polarizers by applying a vertical electric field. © 2024, John Wiley and Sons Inc. All rights reserved.

关键词： Nematic liquid crystals

来源：评论

学校读者我要写书评

暂无评论

Unidirectional Viewing Angle Control Using Liquid Crystal Film on the Automotive displays

Unidirectional Viewing Angle Control Using Liquid Crystal Fi...

引用

2024 Conference on Lasers and Electro-Optics/Pacific rim, CLEO-Pr 2024

作者： Choi, Tae-Hoon Lee, Hyun Wook Ha, Jin Uk Department of Advanced Materials R&D Korea Automotive Technology Institute Cheonan31214 Korea Republic of

We report a method for controlling unidirectional viewing angle in automotive displays using a liquid crystal (LC) film. By electrically controlling the refractive index distribution of the LC film, the light is emitted toward the left side, which indicates that the display panel can be effectively controlled in the direction of the driver between transmission and blocking. © 2024 The Author(s)

关键词： Liquid crystal displays

来源：评论

学校读者我要写书评

暂无评论

role of solute elements in Mg-Mg_(2)Ni hydrogen storage alloys:A first-principles calculation study

引用

Journal of Magnesium and Alloys 2024年第11期12卷 4574-4593页

作者： Min-Seok Yoon Jae Hur Seo-Hui Park Ui-Jong Lee Guanglong Xu Hyung-Ki Park Byeong-Chan Suh Young Min Kim Won-Seok Ko Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea College of Materials Science and Engineering Nanjing Tech UniversityNanjing 211816China Functional Materials and Components R&D Group Korea Institute of Industrial TechnologyGangneung 25440Republic of Korea Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea Advanced Materials Engineering University of Science and TechnologyDaejeon 34113Republic of Korea

The effects of various alloying elements on the performance of Mg-Mg_(2)Ni hydrogen storage alloys were investigated by performing firstprinciples density functional theory *** examined the important characteristics of hydrogen storage alloys by considering both Mg-based solid solution and Mg_(2)Ni-based intermetallic compound phases,where the hydride forms are Mg H2and Mg_(2)NiH4,*** particular,qualitatively valid information for predicting changes in plateau pressures in the pressure-composition-temperature(PCT)curve was provided by calculating changes in the energy of related hydrogenation *** effects of alloying elements on volume changes due to hydrogenation reactions were also obtained to provide additional criteria for the practical use of hydrogen storage *** the Mg_(2)Ni-based intermetallic compound,we examined the site preference of each alloying element,considering the designated stoichiometry of the base *** on the revealed site preferences,the effects of various possible alloying elements on the properties of Mg_(2)Ni-based hydrides were also *** structure analyses were further conducted to elucidate the detailed mechanisms underlying the role of the additional solute elements.

关键词： Mg-Mg_(2)Ni alloys density functional theory Hydrogen storage alloys Metal hydrides

来源：评论

学校读者我要写书评

暂无评论

Systematic analysis of an unreliable batch service retrial queueing system with two sort of vacation

引用

International Journal of Applied Systemic Studies 2023年第3期10卷 243-264页

作者： Niranjan, S.P. Indhira, K. Chandrasekaran, V.M. Department of Mathematics Vel Tech Rangarajan Dr. Sagunthala R&D Institute of Science and Technology Chennai India Department of Mathematics School of Advanced Sciences VIT Vellore India

This paper concentrates on bulk arrival and batch service retrial queueing system with server failure, two types of vacation and constant retrial rate. If an arrival of customers finds a server is free then batch service will be provided with minimum of one customers and maximum of ‘b’ customers. On the contrary, if the arrival of customers finds the server is busy then entire customers will join in the orbit to explore service again. After service completion, if there are no customers in the orbit then the server leaves for working vacation. during working vacation, the server provides service in lower service rate compared to regular service rate. In the working vacation completion, if the orbit size is zero then the server leaves for non-working vacation. The server may get failure in working period. If the server got failure with probability (φ) then the renewal of service station will be considered. On the other hand, if there is no breakdown and orbit is empty then the server leaves for working vacation with probability (1 – φ). For this designed queueing model probability generating function of the orbit size will be obtained. Various performance measures are also be derived with suitable numerical illustrations. Copyright © 2023 Inderscience Enterprises Ltd.

关键词： Sales

来源：评论

学校读者我要写书评

暂无评论

Cell architecture designs towards high-energy-density microscale energy storage devices

引用

Nano research Energy 2024年第2期3卷 69-82页

作者： Kwon-Hyung Lee Sang-Young Lee Ulsan Advanced Energy Technology R&D Center Korea Institute of Energy Research(KIER)Ulsan44776Republic of Korea Department of Chemical and Biomolecular Engineering Yonsei UniversitySeoul03722Republic of Korea

The rapid growth of miniaturized electronics has led to an urgent demand for microscale energy storage devices(MESds)to sustainably power the micro electronic ***,most MESds reported to date have suffered from the limited energy densities and shape versatility compared to conventional large-scale counterparts because of the architectural constraints inherent in microfabrication-based cell manufacturing and cell dimension/*** review addresses the cell architecture design for MESds that can achieve both miniaturization and high energy *** provide a comprehensive overview of five types of cell architectures of MESds and their fabrication *** addition,to enable practical applications of MESds,several cell design approaches are presented with the aim of minimizing the inactive parts of the cell and maximizing the performance metrics of ***,we discuss development direction and outlook of MESds with a focus on materials chemistry,energy-dense electrochemical systems,and cell performance normalization,which will help to expand their applications and manufacturing scalability.

关键词： microscale energy storage device cell architecture microfabrication miniaturization high-energy-density

来源：评论

学校读者我要写书评

暂无评论

Polyethylene Oxide-Based Composite Solid Electrolytes for Lithium Batteries:Current Progress,Low-Temperature and High-Voltage Limitations,and Prospects

引用

Electrochemical Energy reviews 2024年第1期7卷 53-90页

作者： Xin Su Xiao-Pei Xu Zhao-Qi Ji Ji Wu Fei Ma Li-Zhen Fan Advanced Battery Technology Center School of New EnergyHarbin Institute of TechnologyWeihai 264209ShandongChina Advanced Battery Technology Center School of Marine Science and TechnologyHarbin Institute of TechnologyWeihai 264209ShandongChina Advanced Battery Technology Center School of Automotive EngineeringHarbin Institute of TechnologyWeihai 264209ShandongChina R&D Center Shanghai Shanshan Technology Co.Ltd.Shanghai 201209China Department of Chemistry and Biochemistry Georgia Southern UniversityStatesboro GA30460USA Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China

Lithium-ion batteries(LIBs)are considered to be one of the most promising power sources for mobile electronic products,portable power devices and vehicles due to their superior environmental friendliness,excellent energy density,negligible memory effect,good charge/discharge rates,stable cycling life,and efficient electrochemical energy conversion,which distinguish it from other power ***,the flammable and volatile organic solvents in carbonate-containing liquid electrolytes can leach,resulting in thermal runaway and interface reactions,thus significantly limiting its *** use of polymer solid electrolytes is an effective way to solve this safety issues,among which poly(ethylene oxide)(PEO)-based solid polymer electrolytes(SPEs)have attracted much attention because of their stable mechanical properties,ease of fabrication,excellent electrochemical and thermal ***,PEO-SPEs with their low room-temperature ionic conductivity,narrow electrochemical windows,poor interface stability,and uncontrollable growth of lithium dendrites cannot meet the demand for high energy density in future ***,this review firstly describes the ion transport mechanisms and challenges that are crucial for PEO-SPEs,and then provides a comprehensive review of current approaches to address the challenges,including novel and efficient lithium salts,additives,composite electrolytes,stable solid electrolyte interfaces,3-d lithium metals and alloys,cathode protection layers and multi-layer ***,future research directions are proposed for the stable operation of PEO-SPEs at room temperature and high voltage,which is imperative for the commercialization of safe and high energy density LIBs.

关键词： Solid polymer electrolytes Polyethylene oxide Ionic conductivity Electrochemical window Lithium-ions batteries Additives

来源：评论

学校读者我要写书评

暂无评论

Low Switching Frequency Motor drive Using All Switching Patterns Search based direct Torque Control 50

Low Switching Frequency Motor Drive Using All Switching Patt...

引用

50th Annual Conference of the IEEE Industrial Electronics Society, IECON 2024

作者： Hayashi, Haru Yokokura, Yuki Ohishi, Kiyoshi Kobayashi, Yuto Hiwatari, Tenjiro Satake, Akira Department of Electrical Electronics and Information Engineering Nagaoka University of Technology Nagaoka Japan Advanced Technology R&D Center Mitubishi Electric Corporation Amagasaki Japan

ISBN: (纸本)9781665464543

This paper focuses on voltage-integral-based reference tracking modulation (VIrTM) and direct torque control (dTC), proposing the control strategy that minimizes switching frequency while achieving excellent dynamic performance. In the proposed scheme, the optimal voltage integral trajectory calculated by exhaustively searching all switching patterns in an offline process is applied to the dTC. One of the advantages of the proposed scheme is its superior versatility and robustness, as it does not rely on motor parameters. Secondly, it significantly reduces the switching frequency at all operating points while preserving the dynamic characteristics of dTC. The effectiveness of the proposed scheme has been validated through experiments, demonstrating up to a 28% reduction in switching frequency compared to conventional standard dTC. © 2024 IEEE.

关键词： Switching frequency

来源：评论

学校读者我要写书评

暂无评论

discussion on Instability of Current-controlled Inverter with df/dt-type Virtual Inertia Control

Discussion on Instability of Current-controlled Inverter wit...

引用

2024 IEEE Energy Conversion Congress and Exposition, ECCE 2024

作者： Ueda, Takumi Sano, Kenichiro Terazono, daisuke Nada, Kaho Institute of Science Tokyo Department of Electrical and Electronic Engineering Tokyo Japan Mitsubishi Electric Advanced Technology R&d Center Hyogo Japan

ISBN: (纸本)9798350376067

This paper focuses on the stability of a current-controlled inverter (GFL type) with df/dt-type virtual inertia control. The authors analyze the dynamic characteristics compared to those of synchronous generators and demonstrate the existence of a second-order delay between the electrical frequency and the rotor's rotational frequency in synchronous generators. Then, this second-order delay is implemented into the df/dt-type virtual inertia control as a second-order low-pass filter (LPF), and the influence of the LPF is investigated by EMT simulation. © 2024 IEEE.

关键词： Synchronous generators

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：