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Chinese Journal of Electronics 2016年第3期25卷 577-582页

作者： zhang jinling YANG Jinsheng zhang Hongxin School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing Vacuum Electronics Research Institute

Based on the principle of phase velocity tapering or stepping output circuit, using the phase velocity variation of the output circuit, four kinds of nonuniform output circuit models have been presented in broadband helix Traveling-wave tubes(TWTs). Taking an example of6–18GHz, 100 W broadband helix TWT and using the improved one-dimensional large signal program, second harmonic suppression performances have been studied by calculating the quantitative relationship between fundamental efficiency, second harmonic output power, and the stepping(tapering) position and strength of phase velocity variation for the four kinds of nonuniform output circuits. From the research results of backward wave and second harmonic suppression feature in two kinds of nonuniform output circuits, we obtained the design principle of phase velocity stepping or tapering, which could suppress the Backward wave oscillation(BWO) and reduce the output power of second harmonic for broadband high-power helix TWTs.

关键词： Backward wave suppression Fundamental efficiency Nonuniform circuits Second harmonic suppression Traveling-wave tube(TWT)

Integrated Trojan detecting model based on period feature statistics

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The Journal of China Universities of Posts and Telecommunications 2019年第1期26卷 32-39页

作者： zhang jinling Lü Lei School of Information Renmin University of China School of Information Sciences and Engineering Shandong Normal University

Aiming at the problem that more popular network application and more complicated network traffic bring big challenge to current Trojan detecting technique, communication behavior of remote access Trojan(RAT) is analyzed, traffic features' different performance in different communication sub-periods is discussed, and an integrated Trojan detecting model based on period feature statistics is presented. Feature statistics based on sub-periods and whole session(WS) respectively can increase the gap and classification ability of traffic features. The weighted integrated classifier can take full use of each base classifier's advantage and compensate for each other's weaknesses, therefore can strong system's detecting and generalization capability. Experiment result shows that this system can recognize Trojan traffics from many kinds of normal traffic effectively.

关键词： Trojan detecting RAT weighted voting integrated system

Research of the terahertz dual-band notch filter based on FSS structures

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Chinese Science Bulletin 2013年第36期58卷 4687-4691页

作者： zhang jinling zhang Yu GAO Ke ZHAO GuoZhong School of Electronic Engineering Beijing University of Posts and Telecommunications School of Physics Capital Normal University

In this paper,a dual-band notch filter for two-layer frequency selective surface(FSS)at terahertz(THz)frequency with high filtering performance has been realized on high-resistivity silicon *** periodic metallic resonators patterned on the silicon wafer,the designed filter can provide two tunable resonant frequencies for terahertz *** transmission response was improved by introducing an extra surrounding pattern around the T-shaped structure,and the location of transmission drop was tuned independently with geometric *** by finite-integral time-domain method,the filter is designed to operate between 0.2 and 0.6 THz with dual-band band-stop performance,a salient feature of this design is making the low sensitivity of its frequency response to the incident angles,which allows to place the filter close to the radiation source with spherical wave *** proposed structures were fabricated using photolithography and tested by THz time-domain spectroscopy *** results show that the transmission response has more than 12 and 32 dB rejections near 285 and 460 GHz respectively,which is in good agreement with the simulation result.

关键词：陷波滤波器太赫兹波 T形结构双频段 FSS 太赫兹时域光谱频率选择表面谐振频率

Analysis on the effectiveness of decoupling capacitor on mitigating radiated emission from power ground planes by BEM

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The Journal of China Universities of Posts and Telecommunications 2015年第1期22卷 77-82页

作者： Wen Shuhua zhang jinling Hu Yusheng School of Electronic Engineering Beijing University of Posts and Telecommunications College of Mechanical and Energy Engineering Jimei University

The radiation emission （RE） of multilayer primed circuit board （PCB） will cause electromagnetic compatibility problem. An efficient numerical method for evaluating the effectiveness of decoupling capacitors in reducing RE from power ground （P/G） planes in PCB was presented. A two-dimensional boundary-element method （BEM） was used to establish the radiation model. Then, the RE was calculated by equivalent magnetic current of edge field around P/G planes. Furthermore, the radiation and input impedance of P/G planes mounted decoupling capacitors were calculated for frequency up to 5 GHz The results were compared to those of the case without decoupling capacitors. It shows that the decoupling capacitors can effectively decrease RE except for anti-resonant frequency. At higher frequencies, the decoupling effectiveness mainly depends on the parasitic inductance of capacitor pin rather than the value.

关键词： printed circuit board radiation emission decoupling capacitors boundary-element method equivalent magnetic current

The Dual-Polarized Staggered Stacked Patches Antenna

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China Communications 2021年第12期18卷 208-218页

作者： Xinyu Cao jinling zhang Hongzhen Yang Hourong Li School of Electrical and Control Engineering North China Institute of Aerospace EngineeringLangfang Hebei 065000China School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

A new dual-polarized staggered and stacked patches antenna with wide impedance band-width and high isolation is *** antenna consists of two groups of radiation patches,in 7 layers,and uses the orthogonal adjacent coupling structure on staggered layer to excite a pair of linear polarization *** to the staggered feeder mode,it has increased the isolation performance be-tween ports and compressed the transverse size of the *** a result of the combination of staggered stack-up between the patches and the stepped gradient shape of the main radiating patches,it has effectively expanded the impedance bandwidth of the *** proposed antenna is simulated,fabricated and *** staggered feeding structure effectively reduces the cross-sectional area of the antenna,and greatly improves the isolation between feeding *** measurement results show that the impedance bandwidths for vertical and horizontal polarization modes are 40.2%(638-960 MHz)and 40.0%(645-968 MHz)respectively when the return loss is lower than-10 dB,and the isolation between feeding ports is better than-30 ***,the antenna has a stable and symmetrical radiation pattern across the working band,therefore making it suitable to be used as antenna and antenna array element of mobile wireless communication base stations.

关键词： staggered stacked patches wide impedance bandwidth high isolation

Mechanical Properties and Fracture Behavior of Mg-Al/AlN Composites with Different Particle Contents

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Journal of Materials Science & Technology 2017年第7期33卷 668-674页

作者： Jie Chen Chonggao Bao Wenhui Chen Li zhang jinling Liu State Key Laboratory of Traction Power School of Mechanics and Engineering SouthwestJiaotong University Chengdu 610031 China

In this study, magnesium matrix composites reinforced with different loading of AlN particles were fabricated by the powder metallurgy technique. The microstructure, bending strength and fracture behavior of the resulting Mg-Al/Al N composites were investigated. It showed that the 5 wt% AlN reinforcements led to the highest densification and bending strength. The total strengthening effect of AlN particles was predicted by considering the contributions of CTE mismatch between the matrix and the particles,load bearing and Hall-Petch mechanism. The results revealed that the increase of dislocation density,the change of Mg17Al12 phase morphology, and the effective load transfer were the major strengthening contributors to the composites. The fracture of the composites altered from plastic to brittle mode with increasing reinforcement content. The regions of clustered particles in the composites were easy to be damaged under external load, and the fracture occurred mainly along grain boundaries.

关键词： Magnesium matrix composite AlN particle Bending strength Fracture behavior Microstructure Powder metallurgy

Kinetics of steam regeneration of SAPO-34 zeolite catalyst in methanol-to-olefins(MTO) process

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Chinese Journal of Chemical Engineering 2021年第7期34卷 231-238页

作者： Huaiqing An Hua Li Jibin Zhou jinling zhang Tao zhang Mao Ye Zhongmin Liu National Engineering Laboratory for Methanol to Olefins Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China

Methanol-to-olefins(MTO)is industrially applied to produce ethylene and propylene using methanol converted from coal,synthetic gas,and ***-34 zeolites,as the most efficient catalyst in MTO process,are subject to the rapid deactivation due to coke *** work shows that steam regeneration can provide advantages such as low carbon dioxide emission and enhanced light olefins yield in MTO process,compared to that by air regeneration.A kinetic study on the steam regeneration of spent SAPO-34 catalyst has been carried out in this *** doing so,we first investigated the effect of temperature on the regeneration performance by monitoring the crystal structure,acidity,residual coke properties and other structural *** results show that with the increase of regeneration temperature,the compositions of residual coke on the catalyst change from pyrene and phenanthrene to naphthalene,which are normally considered as active hydrocarbon pool species in MTO ***,when the regeneration temperature is too high,nitrogen oxides can be found in the residual ***,as the regeneration temperature increases,the quantity of residual coke reduces and the acidity,BET surface area and pore structure of the regenerated samples can be better recovered,resulting in prolonging catalyst *** have further derived the kinetics of steam regeneration,and obtained an activation energy of about 177.8 kJ·mol^(-1).Compared that with air regeneration,the activation energy of steam regeneration is higher,indicating that the steam regeneration process is more difficult to occur.

关键词： Methanol to olefins(MTO) SAPO-34 zeolite catalyst Steam regeneration Regeneration kinetics

Design of terahertz band-stop filter based on a metallic resonator on high-resistivity silicon wafer

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Science China(Technological Sciences) 2013年第9期56卷 2238-2242页

作者： zhang jinling zhang Yu GAO Ke Du YuLei zhang Nan LU YingHua School of Electronic Engineering Beijing University of Posts and Telecommunications

In this paper, we present a terahertz (THz) band-stop filter realized by fabricating a metallic T-shaped resonator pattern on the high-resistivity silicon wafer. The filter exhibits two typical band-stop response characteristics depending on the incident direction of electric field with respect to the T-shaped resonator. When the long and the short arms of the T-shaped resonator were electrically polarized by changing the incident THz wave transmission directions, the corresponding central frequencies of the band-stop filter were found to be 0.436 THz at 42dB and 0.610 THz at 28 dB, respectively. Using three-dimensional (3D) finite-integral time-domain simulations, the band-stop filter was designed, which can operate in the wavelength between 0.2 and 0.8 THz. Experimental verification was also performed using a free space THz time-domain spectroscopy system. The band-stop response characteristics are in good agreement with the simulation results. The interesting THz band-stop filtering properties suggest a promising application in the modern THz communication systems, THz time-domain spectroscopic imaging and THz continuous wave imaging.

关键词： band-stop filter finite-integral time-domain terahertz filter T-shaped resonator terahertz time-domain spectroscopy

A Posteriori Error Estimates for hp Spectral Element Approximation of Elliptic Control Problems with Integral Control and State Constraints

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Advances in Applied Mathematics and Mechanics 2022年第2期14卷 469-493页

作者： jinling zhang Yanping Chen Yunqing Huang Fenglin Huang Hunan Key Laboratory for Computation and Simulation in Science and Engineering School of Mathematics and Computational ScienceXiangtan UniversityXiangtanHunan 411105China School of Mathematical Sciences South China Normal UniversityGuangzhouGuangdong 510631China School of Mathematics and Statistics Xinyang Normal UniversityNo.237 Nanhu RoadShihe DistrictXinyangHenan 464000China

This paper investigates an optimal control problem governed by an elliptic equation with integral control and state *** control problem is approxi-mated by the hp spectral element method with high accuracy and geometricﬂ*** conditions of the continuous and discrete optimal control problems are presented,*** a posteriori error estimates both for the control and state variables are established in *** addition,illustrative numerical examples are carried out to demonstrate the accuracy of theoretical results and the validity of the proposed method.

关键词： Elliptic equations optimal control control-state constraints a posteriori error esti-mates hp spectral element method.

Quantitative Relationship Between Land Use and Phosphorus Discharge in Subtropical Hilly Regions of China

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Pedosphere 2003年第1期13卷 67-74页

作者： YANG jinling and zhang GANLINInstitute of Soil Science, the Chinese Academy of Sciences, Nanjing 210008 (China) Institute of Soil Science the Chinese Academy of Sciences Nanjing 210008 (China)

The increase of phosphorus concentration is a crucial factor causing the eutrophication of water body,while land use has an important impact on agricultural non-point sources (NPS) phosphorus discharge. Sevensites controlling the water in four sub-watersheds and the main exit of the Meicun Watershed of XuanchengCounty, Anhui Province, were investigated by dynamic monitoring of stream water and nutrient discharge,integrating interpretation of aerial image and GIS analysis to find out how the land use affects phosphorusloss with stream water in typical agriculture-forest watershed in subtropical China. These monitored sitesare different in structure of land use. Phosphorus concentration of the stream water was analyzed everyweek and at the next day of rainfall. The velocity of flow was measured by kinemometer to calculatethe runoff flux and phosphorus discharge. The results showed that the runoff flux and the discharges ofdissolved phosphorus (DP), particle-associated phosphorus (PAP) and total phosphorus (TP) had significantexponential relationships with the area percentages of forest, pond and paddy field. There existed a significantlinear relationship between the TP and PAP concentrations in stream water and the area percentages of forest,pond and paddy field, and the discharge of PAP was also significantly linearly correlated with the dischargeof suspended soil particles. There was a logarithmic linear relationship between DP and PAP discharges. Thestudy indicated that the adjustment of land use patterns and construction of ecologically sound landscapewould be an important measure to reduce the runoff discharge of phosphorus. The results would be veryuseful in building the best management practices (BMPs) of agricultural watershed in subtropics.

关键词： land use phosphorus runoff watershed