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A frequency domain estimation and compensation method for system synchronization parameters of distributed-HFSWR
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作者 WANG Hongyong SUO Ying +3 位作者 DENG Weibo WU Xiaochuan BAI Yang ZHANG Xin 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第5期1084-1097,共14页
To analyze the influence of time synchronization error,phase synchronization error,frequency synchronization error,internal delay of the transceiver system,and range error and angle error between the unit radars on th... To analyze the influence of time synchronization error,phase synchronization error,frequency synchronization error,internal delay of the transceiver system,and range error and angle error between the unit radars on the target detection performance,firstly,a spatial detection model of distributed high-frequency surface wave radar(distributed-HFSWR)is established in this paper.In this model,a method for accurate extraction of direct wave spectrum based on curve fitting is proposed to obtain accurate system internal delay and frequency synchronization error under complex electromagnetic environment background and low signal to noise ratio(SNR),and to compensate for the shift of range and Doppler frequency caused by time-frequency synchronization error.The direct wave component is extracted from the spectrum,the range estimation error and Doppler estimation error are reduced by the method of curve fitting,and the fitting accuracy of the parameters is improved.Then,the influence of frequency synchronization error on target range and radial Doppler velocity is quantitatively analyzed.The relationship between frequency synchronization error and radial Doppler velocity shift and range shift is given.Finally,the system synchronization parameters of the trial distributed-HFSWR are obtained by the proposed spectrum extraction method based on curve fitting,the experimental data is compensated to correct the shift of the target,and finally the correct target parameter information is obtained.Simulations and experimental results demonstrate the superiority and correctness of the proposed method,theoretical derivation and detection model proposed in this paper. 展开更多
关键词 distributed high-frequency surface wave radar(distributed-HFSWR) direct wave synchronization error curve fitting system synchronization parameter compensation
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Effects of Mg-doping temperature on the structural and electrical properties of nonpolar a-plane p-type GaN films
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作者 陈凯 赵见国 +9 位作者 丁宇 胡文晓 刘斌 陶涛 庄喆 严羽 谢自力 常建华 张荣 郑有炓 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期631-636,共6页
Nonpolar(11–20) a-plane p-type GaN films were successfully grown on r-plane sapphire substrate with the metal–organic chemical vapor deposition(MOCVD) system. The effects of Mg-doping temperature on the structural a... Nonpolar(11–20) a-plane p-type GaN films were successfully grown on r-plane sapphire substrate with the metal–organic chemical vapor deposition(MOCVD) system. The effects of Mg-doping temperature on the structural and electrical properties of nonpolar p-type GaN films were investigated in detail. It is found that all the surface morphology, crystalline quality, strains, and electrical properties of nonpolar a-plane p-type GaN films are interconnected, and are closely related to the Mg-doping temperature. This means that a proper performance of nonpolar p-type GaN can be expected by optimizing the Mg-doping temperature. In fact, a hole concentration of 1.3×10^(18)cm^(-3), a high Mg activation efficiency of 6.5%,an activation energy of 114 me V for Mg acceptor, and a low anisotropy of 8.3% in crystalline quality were achieved with a growth temperature of 990℃. This approach to optimizing the Mg-doping temperature of the nonpolar a-plane p-type GaN film provides an effective way to fabricate high-efficiency optoelectronic devices in the future. 展开更多
关键词 nonpolar a-plane GaN film Mg-doping temperature strains activation efficiency
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Revealing the Role of Defect in 3D Graphene-Based Photocatalytic Composite for Efficient Elimination of Antibiotic and Heavy Metal Combined Pollution
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作者 Xin Wang Jingzhe Zhang +3 位作者 Hui Wang Mengjun Liang Qiang Wang Fuming Chen 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第3期164-174,共11页
Defect engineering can give birth to novel properties for adsorption and photocatalysis in the control of antibiotics and heavy metal combined pollution with photocatalytic composites.However,the role of defects and t... Defect engineering can give birth to novel properties for adsorption and photocatalysis in the control of antibiotics and heavy metal combined pollution with photocatalytic composites.However,the role of defects and the process mechanism are complicated and indefinable.Herein,TiO_(2)/CN/3DC was fabricated and defects were introduced into the tripartite structure with separate O_(2)plasma treatment for the single component.We find that defect engineering can improve the photocatalytic activity,attributing to the increase of the contribution from h^(+)and OH.In contrast to TiO_(2)/CN/3DC with a photocatalytic tetracycline removal rate of 75.2%,the removal rate of TC with D-TiO_(2)/CN/3DC has increased to 88.5%.Moreover,the reactive sites of tetracycline can be increased by adsorbing on the defective composites.The defect construction on TiO_(2)shows the advantages in tetracycline degradation and Cu^(2+)adsorption,but also suffers significant inhibition for the tetracycline degradation in a tetracycline/Cu^(2+)combined system.In contrast,the defect construction on graphene can achieve the cooperative removal of tetracycline and Cu^(2+).These findings can provide new insights into water treatment strategies with defect engineering. 展开更多
关键词 3D graphene Cu DEFECT photocatalytic composite TETRACYCLINE
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Intelligent Internet of Things with Reliable Communication and Collaboration Technologies
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作者 Zhao Junhui Wu Celimuge +4 位作者 Xu Wenjun Qi Chenhao Bu Shengrong Zhang Shuowen Zhang Qingmiao 《China Communications》 SCIE CSCD 2024年第8期I0002-I0006,共5页
The Internet of Things(IoT)connects objects to Internet through sensor devices,radio frequency identification devices and other information collection and processing devices to realize information interaction.IoT is w... The Internet of Things(IoT)connects objects to Internet through sensor devices,radio frequency identification devices and other information collection and processing devices to realize information interaction.IoT is widely used in many fields,including intelligent transportation,intelligent healthcare,intelligent home and industry.In these fields,IoT devices connected via high-speed internet for efficient and reliable communications and faster response times. 展开更多
关键词 INTERACTION INTERNET IOT
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Terahertz Spectroscopic Study of Standard Substances for Bituminous Coal and Anthracite
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作者 Dan Shao Yuanyuan Li Yu Wang 《Journal of Electronic Research and Application》 2024年第3期243-248,共6页
This study underscores the significance of online monitoring of standard substances for bituminous coal and anthracite,two commonly used fossil fuels.Terahertz technology emerges as a powerful non-destructive detectio... This study underscores the significance of online monitoring of standard substances for bituminous coal and anthracite,two commonly used fossil fuels.Terahertz technology emerges as a powerful non-destructive detection method capable of revealing the physical and chemical properties of measured objects.In this research,terahertz time-domain spectroscopy technology was employed to investigate the spectral characteristics of four distinct types of bituminous coal and anthracite samples.The refractive index and absorption coefficient spectra of these samples were calculated across a frequency range of 0.5 THz to 2.5 THz.Furthermore,principal component analysis was conducted using all refractive index and absorption coefficient data within this frequency band.Through the analysis and comparison with known parameters of coal standard materials,it was established that carbon content primarily influences the refractive index of bituminous coal and anthracite,while ash content predominantly affects the absorption effect.These findings underscore the potential of terahertz spectroscopy in conjunction with principal component analysis to qualitatively assess the similarities and differences between coal samples,thus offering novel insights for the online monitoring of diverse coal types and qualities. 展开更多
关键词 COAL Terahertz spectroscopy Optical parameters Principal component analysis
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Multiuser computational imaging encryption and authentication with OFDM-assisted key management
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作者 Hongran Zeng Ping Lu +7 位作者 Xiaowei Li Lingling Huang Chaoyun Song Dahai Li In-kwon Lee Seok-Tae Kim Qiong-Hua Wang Yiguang Liu 《Advanced Photonics Nexus》 2024年第5期162-173,共12页
Single-pixel imaging(SPI)enables an invisible target to be imaged onto a photosensitive surface without a lens,emerging as a promising way for indirect optical encryption.However,due to its linear and broadcast imagin... Single-pixel imaging(SPI)enables an invisible target to be imaged onto a photosensitive surface without a lens,emerging as a promising way for indirect optical encryption.However,due to its linear and broadcast imaging principles,SPI encryption has been confined to a single-user framework for the long term.We propose a multi-image SPI encryption method and combine it with orthogonal frequency division multiplexing-assisted key management,to achieve a multiuser SPI encryption and authentication framework.Multiple images are first encrypted as a composite intensity sequence containing the plaintexts and authentication information,simultaneously generating different sets of keys for users.Then,the SPI keys for encryption and authentication are asymmetrically isolated into independent frequency carriers and encapsulated into a Malus metasurface,so as to establish an individually private and content-independent channel for each user.Users can receive different plaintexts privately and verify the authenticity,eliminating the broadcast transparency of SPI encryption.The improved linear security is also verified by simulating attacks.By the combination of direct key management and indirect image encryption,our work achieves the encryption and authentication functionality under a multiuser computational imaging framework,facilitating its application in optical communication,imaging,and security. 展开更多
关键词 computational imaging optical encryption optical authentication key management
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Object detection based on combination of local and spatial information
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作者 Qinkun Xiao Nan Zhang +1 位作者 Fei Li Yue Gao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第4期715-720,共6页
A method of object detection based on combination of local and spatial information is proposed. Firstly, the categorygiven representative images are chosen through clustering to be templates, and the local and spatial... A method of object detection based on combination of local and spatial information is proposed. Firstly, the categorygiven representative images are chosen through clustering to be templates, and the local and spatial information of template are ex- tracted and generalized as the template feature. At the same time, the codebook dictionary of local contour is also built up. Secondly, based on the codebook dictionary, sliding-window mechanism and the vote algorithm are used to select initial candidate object win- dows. Lastly, the final object windows are got from initial candidate windows based on local and spatial structure feature matching. Experimental results demonstrate that the proposed approach is able to consistently identify and accurately detect the objects with better performance than the existing methods. 展开更多
关键词 object detection codebook dictionary spatial matching local contour matching.
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Design and Implementation of Agricultural Information Data-Delivery System Based on Web
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作者 TANG Xinzhong SUN Hongmin HU Xinyi 《Journal of Northeast Agricultural University(English Edition)》 CAS 2009年第3期52-56,共5页
Data-delivery of agricultural information is a very tedious work, traditional data-delivery patterns and methods can not meet the requirements of the practical work. This paper provided the design idea and implement m... Data-delivery of agricultural information is a very tedious work, traditional data-delivery patterns and methods can not meet the requirements of the practical work. This paper provided the design idea and implement method for data-delivery system of agricultural information based on Web. Report and data will be separated in this system, and the person can change template and data at any time on demand. The problem that report template and data fixed together would be solved. The agricultural information resources sharing would be also implemented. 展开更多
关键词 data-delivery WEB pattern REPORT
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A Survey of Web Information Technology and Application 被引量:1
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作者 MENG Xiao-feng XU Bao-wen +4 位作者 LIU Qing YU Ge SHEN Jun-yi LU Zheng-ding HE Yan-xiang 《Wuhan University Journal of Natural Sciences》 CAS 2006年第1期1-5,共5页
0 Introduction The surprising growth of the Internet, coupled with the rapid development of Web technique and more and more emergence of web information system and application, is bring great opportunities and big cha... 0 Introduction The surprising growth of the Internet, coupled with the rapid development of Web technique and more and more emergence of web information system and application, is bring great opportunities and big challenges to us. Since the Web provides cross-platform universal access to resources for the massive user population, even greater demand is requested to manage data and services effectively. 展开更多
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Accuracy improvement of GPS/MEMS-INS integrated navigation system during GPS signal outage for land vehicle navigation 被引量:15
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作者 Honglei Qin Li Cong Xingli Sun 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第2期256-264,共9页
To improve the reliability and accuracy of the global po- sitioning system (GPS)/micro electromechanical system (MEMS)- inertial navigation system (INS) integrated navigation system, this paper proposes two diff... To improve the reliability and accuracy of the global po- sitioning system (GPS)/micro electromechanical system (MEMS)- inertial navigation system (INS) integrated navigation system, this paper proposes two different methods. Based on wavelet threshold denoising and functional coefficient autoregressive (FAR) model- ing, a combined data processing method is presented for MEMS inertial sensor, and GPS attitude information is also introduced to improve the estimation accuracy of MEMS inertial sensor errors. Then the positioning accuracy during GPS signal short outage is enhanced. To improve the positioning accuracy when a GPS signal is blocked for long time and solve the problem of the tra- ditional adaptive neuro-fuzzy inference system (ANFIS) method with poor dynamic adaptation and large calculation amount, a self-constructive ANFIS (SCANFIS) combined with the extended Kalman filter (EKF) is proposed for MEMS-INS errors modeling and predicting. Experimental road test results validate the effi- ciency of the proposed methods. 展开更多
关键词 functional coefficient autoregressive (FAR) global po- sitioning system (GPS) micro electromechanical system (MEMS) inertial navigation system (INS) self-constructive adaptive neuro- fuzzy inference system (SCANFIS).
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Electromagnetism and Absorptivity of the Modified Micro-coiled Chiral Carbon Fibers 被引量:10
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作者 Zheng Tianliang Wang Yuehong +2 位作者 Zheng Kuangyu Li Qian Tao Ye 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2007年第6期559-563,共5页
Micro-coiled chiral carbon fibers are modified by nano-Ni. X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used to compare the composition and morphology of the unmodified and the modified fiber... Micro-coiled chiral carbon fibers are modified by nano-Ni. X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used to compare the composition and morphology of the unmodified and the modified fibers. The results show that electromagnetism parameters of the modified are different from those of the unmodified. After modification by nano-Ni, the micro-coiled chiral carbon fibers have decreased permittivity and electrical loss. The permeability and magnetic loss of the modified carbon fibers become larger than those of the unmodified ones. Moreover, the modification of unmodified chiral carbon fibers into the modified is much like changing hollow electric windings into those with magnetic cores inside. The modifier intensifies the cross polarization of the chiral carbon fibers and makes the permittivity and the permeability get closer to each other which improves the matching performance and enhances absorbability of coatings. In the range of 6-18 GHz, the reflectivity of the coating is 6-8dB and the bandwidth is 12 GHz. The area density of the coating is below 3 kg/m^2. 展开更多
关键词 absorbing coating micro-coiled chiral carbon fiber modify electromagnetism parameters
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On the Probability Density Function of the Real and Imaginary Parts in WFRFT Signals 被引量:7
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作者 Xiaolu Wang Lin Mei +1 位作者 Zhenduo Wang Naitong Zhang 《China Communications》 SCIE CSCD 2016年第9期44-52,共9页
Recently a Hybrid Carrier (HC) scheme based on Weighted-type Fractional Fourier Transform (WFRFT) was proposed and developed, which contains Single Carrier (SC) and Multi-Carrier (MC) synergetie transmission. ... Recently a Hybrid Carrier (HC) scheme based on Weighted-type Fractional Fourier Transform (WFRFT) was proposed and developed, which contains Single Carrier (SC) and Multi-Carrier (MC) synergetie transmission. The wide interest is primarily due to its appealing characteristics, such as the robust performances in different types of selective fading channels and a great deal of potential for secure communications. According to the literatures, the HC signal and SC or MC signal probability distributions are different. In particular, some benefits of this HC scheme are brought by the quasi-Gaussian distribution of WFRFT signals. However, until now researchers have only presented statistic properties through computer simulations, and the accurate expressions of signals are not derived yet. In this paper, we derive the accu- rate and rigorously established closed-form expressions of Probability Density Function (PDF) of WFRFT signal real and imaginary parts with a large number of QPSK subcarriers, and this PDF can describe the behavior of data modulated by WFRFT, avoiding the complex computation for extensive computer simulations. Furthermore, the components of PDF expression are described and analyzed, and it is revealed that the tendency of signal quasi-Gaussian changes with the increasing of the parameter a (a in (0,1]). To validate the analytical results, extensive simulations have been conducted, showing a very good match between the analytical results and the real situations. The contribution of this paper may be useful to deduce the closed form expressions of Bit Error Ratio (BER), the Complementary Cumulative Distribution Function (CCDF) of Peak to Average Power Ratio (PAPR), and other analytical studies which adopt the PDF. 展开更多
关键词 weighted-type fractional Fourier transform probability density function single carrier MULTI-CARRIER hybrid carrier
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Ultrathin nanosheets of cobalt-nickel hydroxides hetero-structure via electrodeposition and precursor adjustment with excellent performance for supercapacitor 被引量:4
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作者 Min Wei Qingsong Huang +2 位作者 Yanping Zhou Zhu Peng Wei Chu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2018年第2期591-599,共9页
A homogeneous better-dispersed ultrathin nanosheets(ca. 5 nm) of cobalt-nickel layered double hydroxides(LDH) supported on nickel foam scaffold was synthesized using controllable electrodeposition approach for hig... A homogeneous better-dispersed ultrathin nanosheets(ca. 5 nm) of cobalt-nickel layered double hydroxides(LDH) supported on nickel foam scaffold was synthesized using controllable electrodeposition approach for high efficiency electrode materials of new supercapacitor. The morphology and electrochemical performances of the samples can be controlled by adjusting the precursor ratio, i.e., Ni(OAc)2/Co(NO3)2 molar ratio in the electrodeposition approach. With the increase of this molar ratio, the electrochemical performances give a volcano trend. When the optimized molar ratio is 0.64/0.36, the hybrid delivered a high specific capacitance of 1587.5 F g-1 at a current density of 0.5 A g-1, with good rate capability(1155 F g-1 was retained even at 10 A g-1) and a robust recycle stability(remaining 91.5% after 1000 cycles at 5 A g-1). The good performance could be attributed to the enlarged interlayer spacing, ultrathin nanosheets and synergistic effects between Co(OH)2 and Ni(OH)2. Furthermore, an asymmetric supercapacitor with a high energy density of 34.5 Wh kg-1 at 425 W kg-1 and excellent cycling stability of 85.4% after 5000 charge-discharge cycles at 2 A g-1 was fabricated. We believe that this fantabulous new electrode material would have encouraging applications in electrochemical energy storage and a wide readership. 展开更多
关键词 Ultrathin nanosheets CoNi layered double hydroxides (LDH) electrode Ni(OAc)2/Co(NO3)2 precursors High performance ELECTRODEPOSITION Asymmetric supercapacitor
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Application of Road Information in Ground Moving Target Tracking 被引量:3
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作者 Zhen Xinyan Zhao Wei 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2007年第6期529-538,共10页
A new algorithm is developed to achieve accurate state estimation in ground moving target tracking by means of using road information. It is an adaptive variable structure interacting multiple model estimator with dyn... A new algorithm is developed to achieve accurate state estimation in ground moving target tracking by means of using road information. It is an adaptive variable structure interacting multiple model estimator with dynamic models modification (DMM VS-IMM for short). Firstly, road information is employed to modify the target dynamic models used by filter, including modification of state transition matrix and process noise. Secondly, road information is applied to update the model set of a VS-IMM estimator. Predicted state estimation and road information are used to locate the target in the road network on which the model set is updated and finally IMM filtering is implemented. As compared with traditional methods, the accuracy of state estimation is improved for target moving not only on a single road, but also through an intersection. Monte Carlo simulation demonstrates the efficiency and robustness of the proposed algorithm with moderate computational loads. 展开更多
关键词 ground moving target tracking state estimation road information models modification variable structure interacting multiple model (VS-IMM)
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Epitaxial Growth and Characteristics of Nonpolar a-Plane InGaN Films with Blue-Green-Red Emission and Entire In Content Range 被引量:6
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作者 Jianguo Zhao Kai Chen +12 位作者 Maogao Gong Wenxiao Hu Bin Liu Tao Tao Yu Yan Zili Xie Yuanyuan Li Jianhua Chang Xiaoxuan Wang Qiannan Cui Chunxiang Xu Rong Zhang Youdou Zheng 《Chinese Physics Letters》 SCIE EI CAS CSCD 2022年第4期83-87,共5页
Nonpolar(1120)plane In_(x)Ga_(1-x)N epilayers comprising the entire In content(x)range were successfully grown on nanoscale Ga N islands by metal-organic chemical vapor deposition.The structural and optical properties... Nonpolar(1120)plane In_(x)Ga_(1-x)N epilayers comprising the entire In content(x)range were successfully grown on nanoscale Ga N islands by metal-organic chemical vapor deposition.The structural and optical properties were studied intensively.It was found that the surface morphology was gradually smoothed when x increased from 0.06 to 0.33,even though the crystalline quality was gradually declined,which was accompanied by the appearance of phase separation in the In_(x)Ga_(1-x)N layer.Photoluminescence wavelengths of 478 and 674 nm for blue and red light were achieved for x varied from 0.06 to 0.33.Furthermore,the corresponding average lifetime(τ_(1/e))of carriers for the nonpolar In Ga N film was decreased from 406 ps to 267 ps,indicating that a high-speed modulation bandwidth can be expected for nonpolar In Ga N-based light-emitting diodes.Moreover,the bowing coefficient(b)of the(1120)plane In Ga N was determined to be 1.91 e V for the bandgap energy as a function of x. 展开更多
关键词 POLAR LIFETIME separation
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Density functional theory study of NO_2 -sensing mechanisms of pure and Ti-doped WO_3 (002) surfaces 被引量:3
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作者 胡明 王巍丹 +1 位作者 曾晶 秦玉香 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第10期177-184,共8页
Density functional theory (DFT) calculations are employed to explore the NO2-sensing mechanisms of pure and Ti-doped WO3 (002) surfaces. When Ti is doped into the WO3 surface, two substitution models are considere... Density functional theory (DFT) calculations are employed to explore the NO2-sensing mechanisms of pure and Ti-doped WO3 (002) surfaces. When Ti is doped into the WO3 surface, two substitution models are considered: substitution of Ti for W6c and substitution of Ti for Wsc. The results reveal that substitution of Ti for 5-fold W forms a stable doping structure, and doping induces some new electronic states in the band gap, which may lead to changes in the surface properties. Four top adsorption models of NO2 on pure and Ti-doped WO3 (002) surfaces are investigated: adsorptions on 5-fold W (Ti), on 6-fold W, on bridging oxygen, and on plane oxygen. The most stable and likely NO2 adsorption structures are both N-end oriented to the surface bridge oxygen Olc site. By comparing the adsorption energy and the electronic population, it is found that Ti doping can enhance the adsorption of NO2, which theoretically proves the experimental observation that Ti doping can greatly increase the WO3 gas sensor sensitivity to NO2 gas. 展开更多
关键词 adsorption Ti doping NO2-sensing density functional theory
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Sparse Transform Matrices and Their Application in the Calculation of Electromagnetic Scattering Problems 被引量:4
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作者 CAO Xin-Yuan CHEN Ming-Sheng WU Xian-Liang 《Chinese Physics Letters》 SCIE CAS CSCD 2013年第2期231-234,共4页
When compressed sensing is introduced into the moment method,a 3D electromagnetic scattering problem over a wide angle can be solved rapidly,and the selection of sparse basis has a direct influence on the performance ... When compressed sensing is introduced into the moment method,a 3D electromagnetic scattering problem over a wide angle can be solved rapidly,and the selection of sparse basis has a direct influence on the performance of this algorithm,especially the number of measurements.We set up five sparse transform matrices by discretization of five types of classical orthogonal polynomials,i.e.,Legendre,Chebyshev,the second kind of Chebyshev,Laguerre,and Hermite polynomials.Performances of the algorithm using these matrices are compared via numerical experiments,and the results show that some of them obviously work excellently and can accelerate wide angle scattering analysis greatly. 展开更多
关键词 MATRICES ANGLE SCATTERING
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An approach of motion compensation and ISAR imaging for micro-motion targets 被引量:4
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作者 WANG Yong ZHOU Xingyu +1 位作者 LU Xiaofei LI Yajun 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2021年第1期68-80,共13页
Inverse synthetic aperture radar(ISAR)imaging of the target with the non-rigid body is very important in the field of radar signal processing.In this paper,a motion compensation method combined with the preprocessing ... Inverse synthetic aperture radar(ISAR)imaging of the target with the non-rigid body is very important in the field of radar signal processing.In this paper,a motion compensation method combined with the preprocessing and global technique is proposed to reduce the influence of micro-motion components in the fast time domain,and the micro-Doppler(m-D)signal in the slow time domain is separated by the improved complex-valued empirical-mode decomposition(CEMD)algorithm,which makes the m-D signal more effectively distinguishable from the signal for the main body by translating the target to the Doppler center.Then,a better focused ISAR image of the target with the non-rigid body can be obtained consequently.Results of the simulated and raw data demonstrate the effectiveness of the algorithm. 展开更多
关键词 inverse synthetic aperture radar(ISAR) micro-Doppler(m-D) motion compensation complex-valued empiricalmode decomposition(CEMD)
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Maneuvering target state estimation based on separate model-ing of target trajectory shape and dynamic characteristics 被引量:2
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作者 ZHANG Zhuanhua ZHOU Gongjian 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2022年第5期1195-1209,共15页
The state estimation of a maneuvering target,of which the trajectory shape is independent on dynamic characteristics,is studied.The conventional motion models in Cartesian coordinates imply that the trajectory of a ta... The state estimation of a maneuvering target,of which the trajectory shape is independent on dynamic characteristics,is studied.The conventional motion models in Cartesian coordinates imply that the trajectory of a target is completely determined by its dynamic characteristics.However,this is not true in the applications of road-target,sea-route-target or flight route-target tracking,where target trajectory shape is uncoupled with target velocity properties.In this paper,a new estimation algorithm based on separate modeling of target trajectory shape and dynamic characteristics is proposed.The trajectory of a target over a sliding window is described by a linear function of the arc length.To determine the unknown target trajectory,an augmented system is derived by denoting the unknown coefficients of the function as states in mileage coordinates.At every estimation cycle except the first one,the interaction(mixing)stage of the proposed algorithm starts from the latest estimated base state and a recalculated parameter vector,which is determined by the least squares(LS).Numerical experiments are conducted to assess the performance of the proposed algorithm.Simulation results show that the proposed algorithm can achieve better performance than the conventional coupled model-based algorithms in the presence of target maneuvers. 展开更多
关键词 maneuvering target tracking separate modeling natural parametric function interacting multiple model(IMM)filter data fitting state augmentation
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Formation mechanism of asymmetric breather and rogue waves in pair-transition-coupled nonlinear Schr?dinger equations 被引量:2
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作者 Zai-Dong Li Yang-yang Wang Peng-Bin He 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第1期283-289,共7页
Based on the developed Darboux transformation, we investigate the exact asymmetric solutions of breather and rogue waves in pair-transition-coupled nonlinear Schr?dinger equations. As an example, some types of exact b... Based on the developed Darboux transformation, we investigate the exact asymmetric solutions of breather and rogue waves in pair-transition-coupled nonlinear Schr?dinger equations. As an example, some types of exact breather solutions are given analytically by adjusting the parameters. Moreover, the interesting fundamental problem is to clarify the formation mechanism of asymmetry breather solutions and how the particle number and energy exchange between the background and soliton ultimately form the breather solutions. Our results also show that the formation mechanism from breather to rogue wave arises from the transformation from the periodic total exchange into the temporal local property. 展开更多
关键词 Akhmediev BREATHER SOLUTION Kuznetsov–Ma BREATHER SOLUTION rogue wave NONUNIFORM exchange
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