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Optimal power allocation for multi-user OFDM and distributed antenna cognitive radio with RoF

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The Journal of China Universities of Posts and Telecommunications 2010年第6期17卷 41-46,71页

作者： GE Wen-dong JI Hong si peng-bo LI Yi School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China School of Electronics Information and Control Engineering Beijing University of Technology Beijing 100022 China

In cognitive radio （CR）,power allocation plays an important role in protecting primary user from disturbance of secondary user. Some existing studies about power allocation in CR utilize ＇interference temperature＇ to achieve this protection,which might not be suitable for the OFDM-based CR. Thus in this paper,power allocation problem in multi-user orthogonal frequency division multiplexing （OFDM） and distributed antenna cognitive radio with radio over fiber （RoF） is firstly modeled as an optimization problem,where the limitation on secondary user is not ＇interference temperature＇,but that total throughput of primary user in all the resource units （RUs） must be beyond the given threshold. Moreover,based on the theorem about maximizing the total throughput of secondary user,equal power allocation algorithm is introduced. Furthermore,as the optimization problem for power allocation is not convex,it is transformed to be a convex one with geometric programming,where the solution can be obtained using duality and Karush-Kuhn-Tucker （KKT） conditions to form the optimal power allocation algorithm. Finally,extensive simulation results illustrate the significant performance improvement of the optimal algorithm compared to the existing algorithm and equal power allocation algorithm.

关键词： cognitive radio power allocation OFDM distributed antenna convex optimization radio over fiber (RoF)

Resource allocation for cognitive WLAN over fiber

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Journal of Harbin Institute of Technology(New Series) 2011年第5期18卷 119-122页

作者：葛文栋纪红司鹏搏李曦 Key Laboratory of Universal Wireless Communication Ministry of EducationBeijing University of Posts and Telecommunications College of Electronics Information and Control Engineering Beijing University of Technology

In this paper,a novel WLAN system,Cognitive WLAN over Fiber (CWLANoF),is introduced in the first ***,when CWLANoF has more channels than STAs,a new channel allocation scheme is proposed using the Hungarian algorithm,which is demonstrated to be the optimal ***,when CWLANoF has fewer channels than STAs,it is possible for more than one STA to share the same channel simultaneously based on the new features of *** the power control scheme is proposed for this kind of sharing,considering efficiency and ***,extensive simulation results illustrate the significant performance improvement of the proposed channel allocation scheme and power control scheme.

关键词： WLANs cognitive radio channel allocation power control Hungarian algorithm

基于竞争限制的IEEE802.11最优省电模式

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北京邮电大学学报 2008年第2期31卷 113-117页

作者：司鹏搏纪红乐光新北京邮电大学泛网无线通信教育部重点实验室北京100876

在基于IEEE 802.11分布协调功能的无线局域网中,为解决每次beacon帧发送后竞争加剧的问题,提出了一种最优省电模式.该机制以成功竞争到信道的站点个数最大化为目标,通过修改beacon帧中的业务指示表域限制过度竞争.该机制定义了下行优先... 详细信息

在基于IEEE 802.11分布协调功能的无线局域网中,为解决每次beacon帧发送后竞争加剧的问题,提出了一种最优省电模式.该机制以成功竞争到信道的站点个数最大化为目标,通过修改beacon帧中的业务指示表域限制过度竞争.该机制定义了下行优先级区分度参数α,以刻画不同业务优先级的差距;建立了使用标准省电模式和最优省电模式时,下行固定速率业务的功耗模型.理论分析和仿真结果表明,该机制能显著改善无线局域网的吞吐量和功耗性能,并可区分优先级.

关键词： IEEE 802.11 媒体接入控制省电模式下行优先级区分度

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基于二维P2P的多环资源发现协议族

电子与信息学报 2009年第3期31卷 702-706页

作者：司鹏搏纪红乐光新北京邮电大学泛网无线通信教育部重点实验室北京100876

Chord中的所有节点可视作分布在一维空间中,形成单一的环。针对移动Ad hoc网络,该文提出二维P2P的概念,将所有节点视作分布在二维平面内,允许多个可灵活配置的环存在,并提供冗余查询路径。基于此概念,该文还提出多环二维P2P资源发现协议... 详细信息

Chord中的所有节点可视作分布在一维空间中,形成单一的环。针对移动Ad hoc网络,该文提出二维P2P的概念,将所有节点视作分布在二维平面内,允许多个可灵活配置的环存在,并提供冗余查询路径。基于此概念,该文还提出多环二维P2P资源发现协议族,并给出协议族中可行的环配置方案,证明其在网络直径和度性能上的改善。仿真结果表明,合理的配置环能明显改善基于移动Ad hoc网络的P2P查询性能。

关键词：移动Ad hoc网络 P2P 资源发现协议 Chord环二维P2P

Well-controlled Organocatalytic Ring-opening Polymerization of Seven-membered Cyclic Carbonates with Cyclohexyl Fusion

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CHEMICAL RESEARCH IN CHINESE UNIVERsiTIES 2024年第5期40卷 856-862页

作者： Zhang, Wei Shan, si-Yi Dai, Jiang Cai, Zhongzheng Zhu, Jian-bo Tianjin Univ Sci & Technol Coll Chem Engn & Mat Sci Tianjin Key Lab Brine Chem Engn & Resource Ecoutil Tianjin 300457 Peoples R China sichuan Univ Coll Chem Natl Engn Lab Ecofriendly Polymer Mat Sichuan Chengdu 610064 Peoples R China

Developing green and well-controlled polymerization methods is of great significance for the preparation of biomedical polymer materials. In this contribution, an efficient organocatalytic ring-opening polymerization (ROP) of a class of seven-membered cyclic carbonates (T6DO, T6HDO, C6DO, C6HDO) containing cis- or trans-cyclohexane structure was established. Organic catalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) promoted living polymerization of these cyclic carbonates to deliver polycarbonate and block copolymer products with predictable molecular weights and narrow dispersity. The robust TBD-mediated ROP at 90 degrees C showcased turnover frequency (TOF) up to 10(3) h(-1). The resulting amorphous polycarbonates displayed good thermal stability.

关键词： CO2 Organic catalyst Living ring-opening polymerization Aliphatic polycarbonate KINETIC RESOLUTION POLYMERIZATION RAC-LACTIDE

Development of a high-repetition-rate lumped-inductance kicker magnet prototype for the beam switchyard of SHINE

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Nuclear Science and Techniques 2024年第2期35卷 20-31页

作者： Yong-Fang Liu Rui-Ping Wang Jin Tong bo Zhang si Chen Qi-Bing Yuan Hai-Xiao Deng Ming Gu bo Liu Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201412People’s Republic of China

The Shanghai high-repetition-rate X-ray free-electron laser and extreme light facility(SHINE)operates at a maximum repetition rate of 1 *** magnets are key components that distribute electron bunches into three different undulator lines in a bunch-by-bunch *** kicker field width must be less than the time interval between bunches.A lumpedinductance kicker prototype was developed using a vacuum chamber with a single-turn *** full magnetic field strength was 0.005 *** paper presents the requirements,design considerations,design parameters,magnetic field calculations,and measurements of the kicker *** relevant experimental results are also *** pulse width of the magnetic field was approximately 600 ns,and the maximum operation repetition rate was 1 *** developed kicker satisfies the requirements for the SHINE ***,numerous recommendations for the future optimization of kicker magnets are provided.

关键词： X-ray free-electron laser Kicker magnet Beam switchyard High repetition rate Ni-Zn ferrites

HIV encephalopathy is contributed by macrophages and microglia

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Science China(Life Sciences) 2024年第4期67卷 836-838页

作者： si-Meng Liu Man Li Chunhui Ma Chunying Liu An Lv Qing Li Yamei Niu peng Wang bo Huang Wei-Min Tong Department of Pathology China Medical UniversityShenyang 110122China Department of Pathology Institute of Basic Medical Sciences Chinese Academy of Medical SciencesSchool of Basic Medicine Peking Union Medical CollegeNeuroscience CenterChinese Academy of Medical SciencesBeijing 100005China Department of Pathology Beijing Ditan HospitalCapital Medical UniversityBeijing 100015China Molecular Pathology Research Center Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100730China Center For Experimental Animal Research Institute of Basic Medical SciencesChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100005China Department of Immunology and National Key Laboratory of Medical Molecular Biology Institute of Basic Medical SciencesChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100010China Department of Biochemistry and Molecular Biology Tongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

Dear Editor,Acquired immunodeficiency syndrome(AIDS),characterized by a significant decrease in the number of CD4^(+)T cells,causes a defective T cell immune response,which subsequently leads to various conditional pathogenic infections and tumors(Calmy et al.,2018;Seligmann et al.,1987).Neurological disorders have been reported in 70%–80%of patients with AIDS(Saylor et al.,2016)。

关键词： encephalopathy immunodeficiency

Manganese oxide and derivative-modified materials in advanced oxidation processes:A review of modification enhancement and activation mechanisms

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Chinese Chemical Letters 2024年第3期35卷 40-51页

作者： si Sun Shuang Song Shuai Yang Yong-Li He Yang Shi peng Zhou Zhao-kun Xiong Yang Liu Heng Zhang Ye Du Chuan-Shu He bo Lai State Key Laboratory of Hydraulics and Mountain River Engineering College of Architecture and EnvironmentSichuan UniversityChengdu 610065China sino-German Centre for Water and Health Research Sichuan UniversityChengdu 610065China Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaSichuanChengdu 610054China

Manganese oxides(MNO_(x)),as low-toxicity and high-abundance catalysts,have been demonstrated to hold great promise for application in advanced oxidation processes(AOPs).However,further application of this material is restricted due to its unsatisfactory oxidant activation ***,recently remarkable research on deep activation mechanisms and modification of MNO_(x)have been undertaken to improve its ***,modification enhancement mechanisms of MNO_(x)to efficiently degrade various organic contaminants were discussed and highlighted,including metal doping,coupling with other metal oxides,composite with carbonaceous material,and compounding with other *** activation mechanisms of different MNO_(x)and derivative-modified material(such as doped MNO_(x),metal oxide-MNO_(x)hybrids,and MNO_(x)-carbonaceous material hybrids)were summarized in great details,which was specifically categorized into both radical and non-radical *** effects of pH,inorganic ions,and natural organic matter on degradation reactions are also ***,future research directions and perspectives are presented to provide a clear interpretation on the MNO_(x)initiated AOPs.

关键词： Manganese oxide Derivative-modified materials Modification enhancement mechanisms Advanced oxidation process Activation mechanism

Prediction and quantification of effective gas source rocks in a lacustrine basin: Western Depression in the Liaohe Subbasin, China

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Petroleum Science 2024年第4期21卷 2218-2239页

作者： si-bo Yang Mei-Jun Li Hong Xiao Fang-Zheng Wang Guo-Gang Cai Shuang-Quan Huang State Key Laboratory of Petroleum Resources and Prospecting College of Geosciences China University of Petroleum China University of Petroleum-Beijing at Karamay College of Petroleum Research Institute of Petroleum Exploration and Development Liaohe Oilfield Company PetroChina

Due to limited data on the geochemical properties of natural gas, estimations are needed for the effective gas source rock in evaluating gas potential. However, the pronounced heterogeneity of mudstones in lacustrine successions complicates the prediction of the presence and geochemical characteristics of gas source rocks. In this paper, the Liaohe Subbasin of Northeast China is used as an example to construct a practical methodology for locating effective gas source rocks in typical lacustrine basins. Three types of gas source rocks, microbial, oil-type, and coal-type, were distinguished according to the different genetic types of their natural gas. A practical three-dimensional geological model was developed, refined, and applied to determine the spatial distribution of the mudstones in the Western Depression of the Liaohe Subbasin and to describe the geochemical characteristics(the abundance, type, and maturation levels of the organic matter). Application of the model in the subbasin indicates that the sedimentary facies have led to heterogeneity in the mudstones, particularly with respect to organic matter types. The effective gas source rock model constructed for the Western Depression shows that the upper sequence(SQ2) of the Fourth member(Mbr 4) of the Eocene Shahejie Formation(Fm) and the lower and middle sequences(SQ3 and SQ4) of the Third member(Mbr 3) form the principal gas-generating interval. The total volume of effective gas source rocks is estimated to be 586 km3. The effective microbial, oil-type, and coal-type gas source rocks are primarily found in the shallow western slope, the central sags, and the eastern slope of the Western Depression, respectively. This study provides a practical approach for more accurately identifying the occurrence and geochemical characteristics of effective natural gas source rocks, enabling a precise quantitative estimation of natural gas reserves.

关键词： Effective gas source rock 3D geological modeling Spatial distribution Geochemical characteristics Lacustrine rift basin