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Calcium Carbonate and Ettringite Induced Efflorescence in CAC-Anhydrite Binary Systems

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1129-1137页

作者： SUN Zixuan chen Yuting XU Linglin LIU Siyu YU Long PAN Feng WANG Chaoqiang WU Kai YANG Zhenghong Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education School of Materials Science and EngineeringTongji UniversityShanghai 201804China Shanghai Construction No.5(Group)Co. Ltd.Shanghai 200063China School of Material Science and Engineering Chongqing Jiaotong UniversityChongqing 400074China

We focused on the efflorescence induced microstructural evolution of ettringite-rich systems prepared with calcium aluminate cement(CAC)and *** effects of anhydrite on the visible efflorescence,and the corresponding capillary absorption of CAC-anhydrite mortars were *** composition and microstructure of efflorescence-causing substances were investigated by optical microscope,in-situ Raman spectroscopy,scanning electron microscope,energy dispersive spectrometer,thermogravimetric analysis,and differential scanning calorimetry,at *** indicate that,besides the calcium carbonate,ettringite is another main component of efflorescence-causing *** with the neat CAC mortars,the addition of anhydrite has a significant effect on the degree of efflorescence by acting on the composition of hydration products and pore *** addition,methods are proposed for the prevention of efflorescence of CAC-anhydrite binary system.

关键词： calcium aluminate cement anhydrite efflorescence ettringite phase assemblage pore structure

Non-destructive electroluminescence inspection for LED epitaxial wafers based on soft single-contact operation

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Photonics Research 2024年第8期12卷 1776-1784页

作者： HAO SU JIAWEN QIU JUNLONG LI RONG chen JIANBI LE XIAOYANG LEI YONGAI ZHANG XIONGTU ZHOU TAILIANG GUO CHAOXING WU School of Physics and Information Engineering Fuzhou UniversityFuzhou 350000China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of china Fuzhou 350108China Fujian Inspection and Research Institute for Product Quality Fuzhou 350002China

Non-destructive and accurate inspection of gallium nitride light-emitting diode(Ga N-LED)epitaxial wafers is important to Ga N-LED ***,the conventional electroluminescence inspection,the photoluminescence inspection,and the automated optical inspection cannot fulfill the complex technical *** this work,an inspection method and an operation system based on soft single-contact operation,namely,single-contact electroluminescence(SC-EL)inspection,are *** key component of the SC-EL inspection system is a soft conductive probe with an optical fiber inside,and an AC voltage(70Vpp,100 k Hz)is applied between the probe and the ITO electrode under the LED epitaxial *** proposed SC-EL inspection can measure both the electrical and optical parameters of the LED epitaxial wafer at the same time,while not causing mechanical damage to the LED epitaxial ***,it is demonstrated that the SC-EL inspection has a higher electroluminescence wavelength accuracy than photoluminescence *** results show that the non-uniformity of SC-EL inspection is 444.64%,which is much lower than that of photoluminescence *** addition,the obtained electrical parameters from SC-EL can reflect the reverse leakage current(Is)level of the LED epitaxial *** proposed SC-EL inspection can ensure high inspection accuracy without causing damage to the LED epitaxial wafer,which holds promising application in LED technology.

关键词： electroluminescence operation epitaxial

3D nano-printed geometric phase metasurfaces for generating accelerating beams with complex amplitude manipulation

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Science china(Physics,Mechanics & Astronomy) 2024年第6期67卷 86-95页

作者： Tianchen Tang Saima Kanwal Yongzheng Lu Yuelong Li Shuangbao Wu Lei chen Ziheng Qian Zhouyu Xie Jing Wen Dawei Zhang Research Center of Optical Instrument and System Ministry of Education and Shanghai Key Lab of Modern Optical SystemUniversity of Shanghai for Science and TechnologyShanghai 200093China

Metasurface,a forefront in emerging optical devices,has demonstrated remarkable potential for complex amplitude manipulation of light ***,prevailing approaches face challenges in spatial resolution and complexities associated with integrating dynamic phases,impeding the simplified design and reproducible fabrication of ***,we introduce an innovative approach for complex amplitude modulation within 3D nano-printed geometric phase *** approach enables the generation of self-accelerating beams by encoding amplitude through phase-only manipulation,achieving high spatial ***,this method circumvents the conventional need to adjust the geometric parameters of metasurface unit structures for amplitude manipulation,offering a streamlined and efficient route for design and fabrication *** novel methodology holds promise for expedited and low-cost manufacturing of complex amplitude manipulation metasurfaces.

关键词： metasurface complex amplitude manipulation geometric phase 3D nano-printing Airy beam accelerating parabolic beam

Pressure-induced magnetic phase and structural transition in SmSb2

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chinese Physics B 2024年第6期33卷 484-489页

作者：李涛王舒阳陈绪亮陈春华房勇杨昭荣 Science Island Branch of Graduate School University of Science and Technology of China Anhui Key Laboratory of Low-Energy Quantum Materials and Devices High Magnetic Field LaboratoryHFIPS Chinese Academy of Sciences Jiangsu Laboratory of Advanced Functional Materials Department of Physics Changshu Institute of Technology Institutes of Physical Science and Information Technology Anhui University Collaborative Innovation Center of Advanced Microstructures

Motivated by the recent discovery of unconventional superconductivity around a magnetic quantum critical point in pressurized CeSb2,here we present a high-pressure study of an isostructural antiferromagnetic（AFM） SmSb2through electrical transport and synchrotron x-ray diffraction *** PC～2.5 GPa,we found a pressure-induced magnetic phase transition accompanied by a Cmca→P4/nmm structural phase *** the pristine AFM phase below PC,the AFM transition temperature of SmSb2is insensitive to pressure;in the emergent magnetic phase above PC,however,the magnetic critical temperature increases rapidly with increasing *** addition,at ambient pressure,the magnetoresistivity（MR） of SmSb2increases suddenly upon cooling below the AFM transition temperature and presents linear nonsaturating behavior under high field at 2 *** increasing pressure above PC,the MR behavior remains similar to that observed at ambient pressure,both in terms of temperature-and field-dependent *** leads us to argue an AFM-like state for SmSb2above *** the investigated pressure of up to 45.3 GPa and the temperature of down to 1.8 K,we found no signature of superconductivity in SmSb2.

关键词： high pressure antiferromagnet magnetoresistivity structural transition

Synergistic effect of carbon nanotube and encapsulated carbon layer enabling high-performance SnS_2-based anode for lithium storage

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Journal of Energy Chemistry 2024年第10期97卷 700-709,I0015页

作者： Chunwei Dong Yongjin Xia Zhijiang Su Zhihua Han Yang Dong Jingyun chen Fei Hao Qiyao Yu Qing Jiang Jiaye Ye National Instituteof Clean-and-Low-Carbon Energy Beijing 102209China Key Laboratory of Automobile Materials Ministry of EducationSchool of Materials Science and EngineeringJilin UniversityChangchun 130022JilinChina State Key Laboratory of Explosion Science and Technology School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China School of Chemistry and Physics Faculty of ScienceQueensland University of Technology2 George StreetBrisbaneQLD 4000Australia Centre for Materials Science Queensland University of Technology2 George StreetBrisbaneQLD 4000Australia

Tin disulfide(SnS_(2)),due to large interlayer spacing and high theoretical capacity,is regarded as a prospective anode material for lithium-ion ***,the poor electron conductivity of SnS_(2) and huge volumetric change during the lithiation/delithiation process lead to a rapid capacity decay of the battery,hindering its *** address these issues,herein,SnS_(2) is in-situ grown on the surface of carbon nanotubes(CNT)and then encapsulated with a layer of porous amorphous carbon(CNT/SnS_(2)@C)by simple solvothermal and further carbonization *** synergistic effect of CNT and porous carbon layer not only enhances the electrical co nductivity of SnS_(2) but also limits the huge volumetric change to avoid the pulverization and detachment of SnS_(2).Density functional theo ry calculations show that CNT/SnS_(2)@C has high Li^(+)adsorption and lithium storage capacity achieving high reaction ***,cells with the CNT/SnS_(2)@C anode exhibit a high lithium storage capacity of 837mAh/g after 100 cycles at 0.1 A/g and retaining a capacity of 529.8 mAh/g under 1.0 A/g after 1000 *** study provides a fundamental understanding of the electrochemical processes and beneficial guidance to design high-performance SnS_(2)-based anodes for LIBs.

关键词： Lithium-ion batteries Porous amorphous carbon Carbon nanotubes SnS_(2)-based anode Density functional theory calculations

First wetland mapping at 10-m spatial resolution in South America using multi-source and multi-feature remote sensing data

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Science china Earth Sciences 2024年第10期67卷 3252-3269页

作者： Weiwei SUN Gang YANG Yuling HUANG Dehua MAO Ke HUANG Lin ZHU Xiangchao MENG Tian FENG Chao chen Yong GE Department of Geography and Spatial Information Techniques Ningbo UniversityNingbo 315211China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences&Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Natural Resources and Planning Bureau Shanghai Pudong New DistrictShanghai 200100China Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China Faculty of Electrical Engineering and Computer Science Ningbo UniversityNingbo 315211China School of Geography Science and Geomatics Engineering Suzhou University of Science and TechnologySuzhou 215009China

Wetland degradation has been accelerating in recent years globally. Accurate information on the geographic distribution and categories of wetlands is essential for their conservation and management. Despite being the world′s fourth largest continent, South America has limited research on wetland mapping, and there is currently no available map that provides comprehensive information on wetland distribution and categories in the region. To address this issue, we used Sentinel-1, Sentinel-2 and SRTM data, developed a sample collection method and a wetland mapping method with a collection of multi-source features such as optical features, polarization features and shape features for South American wetlands. We produced a 10-m resolution wetland map based on the Google Earth Engine(GEE) platform. Our Level-1 wetland cover map accurately captured six wetland sub-categories with an overall accuracy of 96.24% and a kappa coefficient of 0.8649, while our Level-2 water cover map included five sub-categories with an overall accuracy of 97.23% and a kappa coefficient of0.9368. The results show that the total area of existing wetlands in South America is approximately 1,737,000 km~2, which is6.8% of the total land area. Among the ten wetland categories, shallow sea had the largest area(960,527.4 km~2), while aquaculture ponds had the smallest area 1513.6 km~2. Swamp had the second largest area(306,240.1 km~2). Brazil, Argentina,Venezuela, Bolivia, and Colombia were found to have the largest wetland areas, with Brazil and Colombia having the most diverse wetland categories. This product can serve as baseline data for subsequent monitoring, management, and conservation of South American wetlands.

关键词： Wetland mapping Google Earth Engine Sentinel imagery South America

董事高管责任保险与真实盈余管理——基于凸显效应

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管理工程学报 2024年第4期38卷 88-103页

作者：屈伸陈朝龙陈宁陈璐电子科技大学经济与管理学院四川成都611731 南开大学中国公司治理研究院天津300071

过往文献较少考虑董事高管责任保险与真实盈余管理的关系。本文基于2009—2020年中国A股上市公司数据研究发现,处于发展期的董事高管责任保险(简称“董责险”)负向影响真实盈余管理,且上述关系经过一系列稳健性检验依旧存在。本文基于... 详细信息

过往文献较少考虑董事高管责任保险与真实盈余管理的关系。本文基于2009—2020年中国A股上市公司数据研究发现,处于发展期的董事高管责任保险(简称“董责险”)负向影响真实盈余管理,且上述关系经过一系列稳健性检验依旧存在。本文基于外部监督视角进一步分析发现:(1)认购董责险可以吸引媒体关注,进而负向影响真实盈余管理。(2)认购董责险可以减少分析师关注;分析师关注可以减少真实盈余管理;分析师关注在董责险与真实盈余管理的负向关系中起着正向遮掩效应。(3)在董责险与真实盈余管理的关系中,保险公司监督中介效应并不显著。公司的弱治理情境与董责险所处的发展阶段,使得中国的董责险治理在真实盈余管理层面“柳暗花明”。这给予了中国保险业与其他企业以发展启示,对于中国等发展中国家引进国外保险等治理举措具有借鉴意义。本文为董责险与盈余管理的研究提供了新的分析视角和经验证据,在一定程度上也体现了弱治理情境的优势。

关键词：董事高管责任保险盈余管理行为信号理论公司治理弱治理情境

Reliability Analysis of a Switched Reluctance Starter/Generator

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Protection and Control of Modern Power Systems 2024年第1期9卷 112-121页

作者： Hao chen Fan Yang Lijun Xu Qiwei Lu Xiqiang Chang Xing Wang Lijiang Dong Yi Wen Jiang chen Gang Miao Jianmin Hu Guanjun Wang Wei Li Xiaohua Bao School of Electrical Engineering China University of Mining and TechnologyXuzhou 221116China Xinjiang Institute of Engineering Urumqi 830000China International Joint Research Center of Central and Eastern European Countries on New Energy Electric Vehicle Technology and Equipment Xuzhou 221008China International Cooperation Joint Laboratory of New Energy Power Generation and Electric Vehicles of Jiangsu Province Colleges and Universities Xuzhou 221008China School of Information and Electrical Engineering China University of Mining and TechnologyXuzhouChina china University of Mining and Technology(Beijing) BeijingChina State Grid Xingjiang Electric Power Co. Ltd.UrumqiXinjiangChina china University of Mining and Technology XuzhouChina State Grid Xinjiang Company Limited Electric Power Research Institute UrumqiXinjiangChina Xinjiang Fukang Pumped Storage Power Company Limited UrumqiXinjiangChina State Grid Urumqi Electric Power Supply Company UrumqiXinjiangChina Wuxi Inspection and Testing Certification Research Institute WuxiJiangsuChina Anhui Wannan Electric Machine Co. Ltd.WannanAnhuiChina Hefei University of Technology in Electrical and Automation Engineering

In this paper,the combined k-out-of-n:G model and reliability block diagram model is used to analyze the reliability of a switched reluctance starter/generator ***,the different operational modes of a switched reluctance motor starter/generator are analyzed,and the fault states of the system are briefly *** the fault criteria of the system in different operational states are put ***,a relia-bility block diagram model is established to calculate the system-level reliability,and the k-out-of-n:G model is adopted to analyze the reliability of each part of the switched reluctance starter/generator *** verify effectiveness,the first-order Markov model is also used to analyze the reliability of each part of the switched reluc-tance starter/generator *** the compu-tational complexity and accuracy of the system,the k-out-of-n:G model is more suitable for system component level reliability ***,a 6/4 switched reluctance motor is used as the simulated and experimental platform *** final results verify the effectiveness of the reliability analysis model.

关键词： system switched generator

Hollow FeCoNiAl microspheres with stabilized magnetic properties for microwave absorption

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Nano Research 2024年第3期17卷 2079-2087页

作者： Linhe Yu Gangjie Lian Guozhen Zhu Sue Ren Yanfang Du Xuhui Xiong Rui chen Jincang Zhang Wenbin You Renchao Che Institute of Advanced Materials College of Chemistry and Chemical EngineeringJiangxi Normal UniversityNanchang 330022China Laboratory of Advanced Materials Shanghai Key Lab of Molecular Catalysis and Innovative MaterialsAcademy for Engineering&TechnologyFudan UniversityShanghai 200438China Zhejiang Laboratory Hangzhou 311100China Capital Aerospace Machinery Corporation Limited Beijing 100000China AECC Beijing Institute of Aeronautical Materials Beijing 100095China International Center for Quantum and Molecular Structures Materials Genome InstitutePhysics DepartmentShanghai UniversityShanghai 200444China

Development of high-performance microwave absorption materials(MAM)with stabilized magnetic properties at high temperatures is specifically essential but remains ***,the Snoke's limitation restrains the microwave absorption(MA)property of magnetic *** alloy components is considered an effective way to solve the aforementioned ***,a hollow medium-entropy FeCoNiAl alloy with a stable magnetic property is prepared via simple spray-drying and two-step annealing for efficient *** exhibited an ultrabroad effective absorption band(EAB)of 5.84 GHz(12.16–18 GHz)at a thickness of just 1.6 mm,revealing an excellent absorption ***,the MA mechanism of FeCoNiAl is comprehensively investigated via off-axis ***,the electromagnetic properties,antioxidant properties,and residual magnetism at high temperatures of FeCoNiAl alloys are summarized in detail,providing new insights into the preparation of MAM operating at elevated temperatures.

关键词： microwave absorption hollow structure magnetic stability multiple microwave absorption mechanism