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Activation Distance and Capacity Analysis for Ambient Backscatter Communications with Sensitivity Constraint and Beamforming

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China Communications 2024年第11期21卷 257-266页

作者： Mu Yunping Fan Dian Wang Gongpu Xu Yongjun kuang lei Engineering Research Center of Network Management Technology for High Speed Railway of Ministry of Education School of Computer and Information TechnologyBeijing Jiaotong UniversityBeijing 100044China China Academy of Information and Communications Technology Beijing 100191China School of Communication and Information Engineering Chongqing University of Posts and TelemcommunicationsChongqing 400065China Shanghai Key Laboratory of Multidimensional Information Processing Engineering Center of SHMEC for Space Information and GNSSSchool of Information Science and TechnologyEast China Normal UniversityShanghai 200241China

Circuit sensitivity of sensors or tags without battery is one practical constraint for ambient backscatter communication *** letter considers using beamforming to reduce the sensitivity constraint and evaluates the corresponding performance in terms of the tag activation distance and the system ***,we derive the activation probabilities of the tag in the case of single-antenna and multi-antenna ***,we obtain the capacity expressions for the ambient backscatter communication system with beamforming and illustrate the power allocation that maximizes the system capacity when the tag is ***,simulation results are provided to corroborate our proposed studies.

关键词： activation distance ambient backscatter communications beamforming channel capacity power allocation sensitivity

Synthesis and optical properties of turquoise-and green-colored brownmilleritetype Ba_2In_(2-x-y)Mn_xAl_yO_(5+x) codoped with manganese and aluminum

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International Journal of Minerals,Metallurgy and Materials 2016年第11期23卷 1346-1351页

作者： Peng Jiang Wen-hui Yang Yun-cheng Zhou Jian-lei kuang Yong Li Ting Xiao School of Materials Science and Engineering University of Science and Technology Beijing

Brownmillerite-type oxides Ba_2In_（2-x-y）Mn_xAl_yO_（5＋x）（0 ≤ x ≤ 0.6, 0 ≤ y ≤ 0.5） were prepared at 1300°C through solid-state reaction. X-ray diffraction（XRD） analysis showed that the structure symmetry evolved from orthorhombic to cubic with increasing Mn and Al contents. When y was greater than 0.3, peaks associated with small amounts of BaAl_2O_4 and Ba_2InAlO_5 impurities were observed in the XRD patterns. When substituted with a small amount of Mn（x ≤ 0.3）, the Ba_2In_（2-x-y）Mn_xAl_yO_（5＋x） samples exhibited an intense turquoise color. The color changed to green and dark-green with increasing Mn concentration. UV–vis absorbance spectra revealed that the color changed only slightly upon Al doping. The valence state of Mn ions in Ba_2In_（2-x-y）Mn_xAl_yO_（5＋x） was confirmed to be ＋5 on the basis of X-ray photoelectron spectroscopic analysis. According to this analysis, the intense turquoise color of the Ba_2In_（2-x-y）Mn_xAl_yO_（5＋x） samples is rooted in the existence of Mn^（5＋）; thus, the introduction of Al does not affect the optical properties of the compounds.

关键词： oxides doping pigments optical properties solid state reaction

Enhanced photocatalytic activity of quantum-dot-sensitized one-dimensionally-ordered ZnO nanorod photocatalyst

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Journal of Environmental Sciences 2013年第12期25卷 2487-2491页

作者： Jinzhao Huang Song Liu lei kuang Yongdan Zhao Tao Jiang Shiyou Liu Xijin Xu School of Physics and Technology University of Jinan

An efficient photocatalyst was fabricated by assembling quantum dots （QDs） onto one-dimensionally-ordered ZnO nanorods, and the photocatalytic properties for Methyl Orange degradation were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV-Vis-NIR absorption spectroscopy and photoluminescence. The results indicate that the catalyst with assembled QDs is more favorable for the degradation than the pristine ZnO nanorods. The QDs with core-shell structure lower the photocatalytic ability due to the higher carder transport barrier of the ZnS shell layer. Besides its degradation efficiency, the photocatalyst has several advantages given that the one-dimensionally-ordered ZnO nanorods have been grown directly on indium tin oxide substrates. The article provides a new method to design an effective and easily recyclable photocatalyst.

关键词： quantum dots one-dimensionally-ordered ZnO nanorods photocatalyst

Effects of Si/Al,Na/Al and H_(2)O/Na_(2)O molar ratios on formaldehyde barrier properties of inorganic aluminosilicate coatings

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International Journal of Minerals,Metallurgy and Materials 2021年第11期28卷 1868-1874页

作者： Shan-xia Xiong Jian-lei kuang Qian-fang Zheng Ting Xiao Wen-xiu Liu Qi Wang Peng Jiang Wen-bin Cao Department of Inorganic Nonmetallic Materials School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

Wood-based panels containing urea-formaldehyde resin result in the long-term release of formaldehyde and threaten human *** this study,inorganic aluminosilicate coatings prepared by combining metakaolin,silica fume,NaOH,and H_(2)O were applied to the surfaces of wood-based panels to obstruct formaldehyde *** Si/Al,Na/Al,and H_(2)O/Na_(2)O molar ratios of the coatings were regulated to investigate their effects on the structure and formaldehyde-resistant barrier properties of *** showed that the cracks in the coatings gradually disappeared and the formaldehyde resistance rates of the barrier increased as the Si/Al molar ratio was increased from 1.6 to *** value also increased as the Na/Al molar ratio was increased from 0.9 to 1.2 because of the improvement of the degree of *** the H_(2)O/Na_(2)O molar ratio was increased from 12 to 15,the thickness of the dry film decreased gradually and led to the reduction in the formaldehyde resistance *** the Si/Al,Na/Al,and H_(2)O/Na_(2)O molar ratios were 2.2,1.2,and 12,respectively,the inorganic aluminosilicate coating showed good performance as a formaldehyde-resistant barrier and its formaldehyde resistance rate could reach up to 83.2%.

关键词： aluminosilicate coating chemical composition formaldehyde barrier properties

Construction of Business English Negotiation Practice Teaching Mode Based on PBGS Project Method

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校园英语 2020年第24期 46-47页

作者： lei kuang Nanchang Institute of Technology

Project Based Group Study(PBGS) teaching, as a kind of education mode reflecting individual oriented ability, has been widely used in modern higher education. This paper analyzes the current situation of business English Negotiation teaching, and focuses on the reform and practice of business English Negotiation teaching based on *** the four aspects of the introduction of PBGS teaching mode, the current situation and orientation of business English Negotiation training course, the application of PBGS teaching in Business English Negotiation training and its key points for attention, this paper expounds the application of PBGS teaching mode in Business English Negotiation training course.

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三维随机粗糙面与目标复合电磁散射的FDTD方法

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计算物理 2007年第5期24卷 550-560页

作者：匡磊金亚秋复旦大学波散射与遥感信息教育部重点实验室上海200433

用时域有限差分方法(FDTD)研究三维周期性延拓的随机粗糙面与上方目标复合电磁散射.用周期性延拓消除数值计算中截取有限大小粗糙面产生的边缘效应,讨论一个周期单元粗糙面的边长与其相关长度之间的关系.给出在FDTD方法中向粗糙面加载... 详细信息

用时域有限差分方法(FDTD)研究三维周期性延拓的随机粗糙面与上方目标复合电磁散射.用周期性延拓消除数值计算中截取有限大小粗糙面产生的边缘效应,讨论一个周期单元粗糙面的边长与其相关长度之间的关系.给出在FDTD方法中向粗糙面加载入射波的方法,建立了粗糙面上单个三维目标的复合散射FDTD计算模型.数值结果给出粗糙面与目标散射的近场分布,应用近远场变换得到全方位散射角的双站散射系数.比较了三维与二维散射模型的区别.结果显示当粗糙面上放置目标时,其后向散射显著增强.

关键词：三维粗糙面与目标双站电磁散射时域有限差分法周期边界条件

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一种新型空调系统优化指标的计算模型

中山大学学报（自然科学版） 2008年第Z1期47卷 25-28页

作者：邝小磊佛山科学技术学院机电与信息工程学院广东佛山528000

制冷量和能耗是中央空调系统最优化的两个整体系统指标,现有的制冷量和能耗两种模型均不适合计算机控制之用。将现有这两种模型中不可测的内部变量转换为外部可测的温度变量,在近似处理之后,得到制冷量,输入电功率为回水温度、出水温度... 详细信息

制冷量和能耗是中央空调系统最优化的两个整体系统指标,现有的制冷量和能耗两种模型均不适合计算机控制之用。将现有这两种模型中不可测的内部变量转换为外部可测的温度变量,在近似处理之后,得到制冷量,输入电功率为回水温度、出水温度、进水温度等易检测和控制的物理量参数的计算模型,特别适合于工程实际的优化控制,并通过实例表明其计算方法简易、可行。

关键词：中央空调系统制冷量能耗模型

Nano high-entropy oxide cathode with enhanced stability for direct borohydride fuel cells

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Journal of Energy Chemistry 2025年第1期100卷 309-316页

作者： lei Zhang Lingfeng kuang Lianke Zhang Wen Chu Haiying Qin Jing Zhang Junjing He Hualiang Ni Hongzhong Chi New Energy Materials Research Center College of Materials and Environmental Engineering Hangzhou Dianzi University School of Materials Science and Engineering Zhejiang University Key Laboratory of MEMS of Ministry of Education School of Integrated Circuits Southeast University

High-entropy materials have become high-activity electrocatalysis owing to their high-entropy effect and multiple active ***,we synthesize a series of carbon-supported nano high-entropy oxides（HEOs/C）,specifically （PtFeCoNiCu）O/C,using a carbothermal shock （CTS） method for application as a cathode catalyst in direct borohydride fuel cells （DBFCs）.The microstructure of the prepared catalysts was characterized by X-ray photoelectron spectroscopy,X-ray absorption fine structure,and transmission electron *** prepared （PtFeCoNiCu）O/C,with particle sizes ranging from 2 to 4 nm,demonstrates 3.94 transferred electrons towards the oxygen reduction reaction in an alkaline environment,resulting in a minimal H2O2yield of 2.6%.Additionally,it exhibits a Tafel slope of 61 mV dec-1,surpassing that of commercial Pt/C (82 mV dec-1).Furthermore,after 40,000 cycles of cyclic voltammetry（CV） testing,the half-wave potential of （PtFeCoNiCu）O/C shows a positive shift of 3 mV,with no notable decline in the limiting current *** （PtFeCoNiCu）O/C is used as a cathode catalyst in DBFCs,the DBFC achieves a maximum power density of 441 mW cm-2at 60°C and sustains a cell voltage of approximately 0.73 V after 52 h at 30°*** findings confirm that HEO/C is a promising cathode catalyst for DBFCs.

关键词： Direct borohydride fuel cells (DBFC)

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紫外像增强器用于电力安全检测的研究

红外技术 2015年第11期37卷 986-990页

作者：匡蕾顾燕江苏省安全生产科学研究院江苏南京210042 北方夜视技术股份有限公司江苏南京211106

随着日盲紫外探测技术的快速发展,紫外电晕探测成为电力设备安全检测的主要手段之一。测试了国产碲铯阴极紫外像增强器的光谱响应特性曲线,并计算了太阳辐射照射下,配备有深截止日盲紫外滤光片的紫外像增强器所产生的光电子数,验证了国... 详细信息

随着日盲紫外探测技术的快速发展,紫外电晕探测成为电力设备安全检测的主要手段之一。测试了国产碲铯阴极紫外像增强器的光谱响应特性曲线,并计算了太阳辐射照射下,配备有深截止日盲紫外滤光片的紫外像增强器所产生的光电子数,验证了国产碲铯阴极紫外像增强器在深截止日盲紫外滤光片的滤光作用下,可以满足强烈阳光背景下电晕检测的需求。

关键词：日盲紫外像增强器电晕探测紫外滤光片