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Secrecy outage analysis on underlay cognitive radio using selection combining

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The Journal of China Universities of Posts and Telecommunications 2016年第3期23卷 51-56页

作者： Tan Youyu pan gaofeng Zhao Hui School of Electronic and Information Engineering Southwest University

Secure data transmission in future high-capacity high-coverage multi-tier hierarchical networks, for which cognitive radio （CR） has emerged as an essential recipe, is of utmost importance. This paper investigates the secrecy outage performance of selection combining （SC） in CR networks （CRNs） over Rayleigh fading channels. In a single-input multiple-output （SIMO） wiretap channel, a secondary user transmits confidential messages to another secondary user, which is equipped with n B （nB ≥1） antennas. Meanwhile, a passive eavesdropper, which is equipped with nE （n E ≥1） antennas, intends to overhear the messages. Both the legal receiver and the eavesdropper adopt SC scheme to process the received multiple signals. The secondary transmitter uses the underlay strategy to guarantee the quality of service of the primary user without spectrum sensing. Compared to the work proposed by Maged Elkashlan et al. in Ref. [ 1 ], we present an alternative method to derive the closed-form expression for the secrecy outage probability （SOP） and develop a simplified SOP when the maximal transmit power at the secondary user is sufficiently high. Our results reveal the impact of the primary network on the secondary network with a multi-antenna wiretap channel and simulations are conducted to validate the accuracy of our proposed analytical models.

关键词： secrecy outage probability cognitive radio selection combining underlay

Diagenesis of the Triassic Yanchang Formation Tight Sandstone Reservoir in the Xifeng–Ansai Area of Ordos Basin and its Porosity Evolution

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Acta Geologica Sinica(English Edition) 2016年第3期90卷 956-970页

作者： LIU Mingjie LIU Zhen WANG Peng pan gaofeng School of Geoscience and Technology Southwest Petroleum University State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing) Changqing Branch of Geophysical Research Institute BGP Inc.CNPC

This work aims to reveal the evolution of the porosity in the Triassic Yanchang Formation tight sandstone reservoir of the Xifeng-Ansai area of Ordos Basin. Based on destructive diagenesis （compaction and cementation） and constructive diagenesis （dissolution） of sandstone reservoirs, this study analyzed the diagenesis characteristics of the tight sandstone reservoirs in this area, and discussed the relationship between sandstone diagenesis and porosity evolution in combination with present porosity profile characteristics of sandstone reservoir. The effect simulation principle was employed for the mathematical derivation and simulation of the evolution of porosity in the Yanchang Formation tight sandstone reservoirs. The result shows that compaction always occurs in tight sandstone reservoirs in the Yanchang Formation, and cementation occurs when the burial depth increases to a certain value and remains ever since. Dissolution occurs only at a certain stage of the evolution with window features. In the corresponding present porosity profile, diagenesis is characterized by segmentation. From the shallow to the deep, compaction, compaction, cementation and dissolution, compaction and cementation occur successively. Therefore, the evolution of sandstone porosity can be divided into normal compaction section, acidification and incremental porosity section, and normal compaction section after dissolution. The results show that the evolution of sandstone porosity can be decomposed into porosity reduction model and porosity increase model. The superposition of the two models at the same depth in the three stages or in the same geological time can constitute the evolution simulation of the total porosity in sandstone reservoirs. By simulating the evolution of sandstone reservoir porosity of the eighth member in Xifeng area and the sixth member in Ansai area, it shows that they are similar in the evolution process and trend. The difference is caused by the regional uplift or

关键词： tight sandstone diagenesis porosity evolution effect simulation Yanchang Formation Ordos Basin

Secure analysis over generalized-K channels

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Science China(Information Sciences) 2020年第4期63卷 242-244页

作者： Luyao ZHANG Hui ZHAO gaofeng pan Liang YANG Jiawei CHEN School of Mathematics and Statistics Southwest University Computer Electrical and Mathematical Science and Engineering DivisionKing Abdullah University of Science and Technology School of Information and Electronics Beijing Institute of Technology College of Computer Science and Electronic Engineering Hunan University

Dear editor,The secrecy outage probability (SOP) is used to estimate the secrecy outage performance when the transmitter has no state information about potential wiretap channels [1], i.e., silent eavesdropping. Most previous work, such as [2, 3], has focused on the SOP defined in [1], which we call the conventional SOP in this study, where both un-

关键词： SOP Secure analysis over generalized-K channels

Physical-layer secrecy outage of spectrum sharing CR systems over fading channels

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Science China(Information Sciences) 2016年第10期59卷 112-120页

作者： Hequn LIU Hui ZHAO Hong JIANG Chaoqing TANG gaofeng pan Tingting LI Yunfei CHEN Chongqing Key Laboratory of Nonlinear Circuits and Intelligent Information Processing Southwest University School of Mathematics and Statistics Southwest University School of Engineering University of Warwick

In this paper, we investigate the physical-layer secrecy outage performance of underlay spectrum sharing systems over Rayleigh and log-normal fading channels in the presence of one eavesdropper. In particular, the secondary transmitter sends data to the legitimate receiver under the constraints of the interference temperature at the primary receiver, while suffering the wiretap from the eavesdropper. Closed-form and approximated expressions are derived for the secrecy outage probability over Rayleigh and log-normal fading channels,respectively. The accuracy of our performance analysis is verified by simulation results.

关键词： spectrum sharing cognitive radio secrecy outage probability Rayleigh fading channels log-normal fading channels

A throughput aware with collision-free MAC for wireless LANs

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Science China(Information Sciences) 2016年第2期59卷 240-242页

作者： Tingrui PEI Yafeng DENG Zhetao LI Gengming ZHU gaofeng pan Youngjune CHOI Hiroo SEKIYA College of Information Engineering Xiangtan University Key Laboratory of Intelligent Computing & Information Processing of Ministry of Education Xiangtan University School of Computer Science & Engineering Hunan University of Science and Technology School of Electronic and Information Engineering Southwest University Department of Information and Computer Engineering Ajou University Graduate School of Advanced Integration Science Chiba University

Dear editor,The Carrier Sense Multiple Access with Collision Avoidance(CSMA/CA)hybrid with the resource reservation approach from Time Division Multiple Address(TDMA)has been emerged as a promising method to solve collision problems in wireless LANs[1–6].In the hybrid method,a TDMA circle contains multiple slots for nodes to contend for the ***,it allows a

关键词： MAC CSCF free TDMA A throughput aware with collision-free MAC for wireless LANs

Schisandrin B protects PC12 cells by decreasing the expression of amyloid precursor protein and vacuolar protein sorting 35

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Neural Regeneration Research 2012年第9期7卷 652-658页

作者： Mingmin Yan Shanping Mao Huimin Dong Baohui Liu Qian Zhang gaofeng pan Zhiping Fu Department of Neurology Renmin Hospital Wuhan University Wuhan 430060 Hubei Province China Department of Neurosurgery Renmin Hospital Wuhan University Wuhan 430060 Hubei Province China

PC12 cell injury was induced using 20 μM amyloid β-protein 25-35 to establish a model of Alzheimer＇s disease. The cells were then treated with 5, 10, and 25 μM Schisandrin B. Methylthiazolyldiphenyl-tetrazolium bromide assays and Hoechst 33342 staining results showed that with increasing Schisandrin B concentration, the survival rate of PC12 cells injured by amyloid β-protein 25-35 gradually increased and the rate of apoptosis gradually decreased. Reverse transcription-PCR, immunocytochemical staining and western blot results showed that with increasing Schisandrin B concentration, the mRNA and protein expression of vacuolar protein sorting 35 and amyloid precursor protein were gradually decreased. Vacuolar protein sorting 35 and amyloid precursor protein showed a consistent trend for change. These findings suggest that 5, 10, and 25 μM Schisandrin B antagonizes the cellular injury induced by amyloid β-protein 25-35 in a dose-dependent manner. This may be caused by decreasing the expression of vacuolar protein sorting 35 and amyloid precursor protein.

关键词： Schisandrin B PC12 cells amyloid β-protein 25-35 amyloid precursor protein vacuolar protein sorting 35 neural protection

Impact of anthropogenic heat emissions on meteorological parameters and air quality in Beijing using a high-resolution model simulation

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Frontiers of Environmental Science & Engineering 2022年第4期16卷 47-57页

作者： Hengrui Tao Jia Xing gaofeng pan Jonathan Pleim Limei Ran Shuxiao Wang Xing Chang Guojing Li Fei Chen Junhua Li Aviation University of Air Force Changchun 130022China School of Environment and State Key Joint Laboratory of Environment Simulation and Pollution Control Tsinghua UniversityBeijing 100084China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084China Research Triangle Park Environmental Protection AgencyNC 27711USA East Remote Sensing Laboratory United States Department of AgricultureNC 20250USA Unit No.96941 of Chinese People's Liberation Army Beijing 100041China Unit No.31010 of Chinese People's Liberation Army Beijing 100081China

Anthropogenic heat emissions(AHE)play an important role in modulating the atmospheric thermodynamic and kinetic properties within the urban planetary boundary layer,particularly in densely populated megacities like *** this study,we estimate the AHE by using a Large-scale Urban Consumption of energY(LUCY)model and further couple LUCY with a high-resolution regional chemical transport model to evaluate the impact of AHE on atmospheric environment in *** areas with high AHE,the 2-m temperature(T_(2))increased to varying degrees and showed distinct diurnal and seasonal variations with maxima in night and *** increase in 10-m wind speed(WS_(10))and planetary boundary layer height(PBLH)exhibited slight diurnal variations but showed significant seasonal ***,the systematic continuous precipitation increased by 2.1 mm due to the increase in PBLH and water vapor in upper *** contrast,the precipitation in local thermal convective showers increased little because of the limited water ***,the PM_(2.5) reduced in areas with high AHE because of the increase in WS_(10) and PBLH and continued to reduce as the pollution levels *** contrast,in areas where prevailing wind direction was opposite to that of thermal circulation caused by AHE,the WS_(10) reduced,leading to increased PM_(2.5).The changes of PM_(2.5) illustrated that a reasonable AHE scheme might be an effective means to improve the performance of PM_(2.5) ***,high AHE aggravated the O_(3) pollution in urban areas due to the reduction in NO_(x).

关键词： Anthropogenic heat emissions LUCY High-resolution Meteorological parameters Air quality

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改性活性炭纤维吸附二甲胺水溶液的研究

离子交换与吸附 2008年第6期24卷 544-550页

作者：潘高峰崔鹏合肥工业大学化学工程学院安徽省可控化学与材料化工重点实验室

采用气相氧化法制备改性ACF,以二甲胺水溶液为吸附对象,在静态吸附条件下研究了吸附时间、温度、ACF用量对吸附效果的影响,获得了吸附等温线;在动态吸附条件下测定了动态穿透曲线,并研究了ACF的再生方法。在ACF优化用量0.6g/100mL溶液... 详细信息

采用气相氧化法制备改性ACF,以二甲胺水溶液为吸附对象,在静态吸附条件下研究了吸附时间、温度、ACF用量对吸附效果的影响,获得了吸附等温线;在动态吸附条件下测定了动态穿透曲线,并研究了ACF的再生方法。在ACF优化用量0.6g/100mL溶液条件下,对初始浓度256mg/L二甲胺溶液的吸附率为85%;吸附饱和的ACF用5%盐酸溶液进行再生时,再生率接近100%。

关键词：活性炭纤维吸附二甲胺水溶液

聚乙烯炭黑复合材料导电逾渗的蒙脱卡罗法研究

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高分子学报 2000年第4期10卷 510-513页

作者：周啸潘高峰清华大学化工系北京100084 清华大学材料科学与工程研究院北京100084

A group of polyethylene\|carbon black (PE\|CB) composites was prepared with different CB volume fraction and the dependence of conductivity on the CB volume fraction was measured. The conductive percolation phenomenon of those composites was studied by Monte Carlo method. It was supposed that the conduction of those composites was not only dependent on the contact pathway formation but also on the quantum mechanical tunnel formation. The put in particle number dependence of “the conductive conjunction” number and “the partial conducting pathway” number and “the average particle number” in the partial conducting pathway was showed in three figures, respectively. The typical CB particle conjunct states obtained by Monte Carlo method were illustrated with “the conductive conjunction”, “the partial conducting pathway”, and “the conducting pathway” in different marks. Thus it vividly demonstrates the internal reason for the conductive percolation of the PE\|CB composites. It is worth notice that only more than 50% CB particles are connected together to form the conducting pathway when the conductive percolation takes place, and that in the system there still exist some partial conducting pathways. The later does not make contribution for the conductivity of the PE\|CB composites.

关键词：聚乙烯炭黑导电复合材料逾渗蒙特卡罗模拟