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基于COSMIC掩星观测的顶部电离层标高特征分析

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电波科学学报 2024年第2期39卷 253-261页

作者：韩超庞岗靳睿敏甄卫民王丹丹马雪纯朱庆林陈龙江陈丽白培瑞山东科技大学电子信息工程学院青岛266590 中国电波传播研究所青岛266107

顶部电离层是指F2层电子密度最大值所在高度以上的电离层区域。掩星观测能够提供地面到低轨卫星轨道高度处的整个电离层电子密度剖面,对于顶部电离层的研究具有重要作用。标高是构建顶部以上电离层电子密度剖面模型的重要参数。本文使用... 详细信息

顶部电离层是指F2层电子密度最大值所在高度以上的电离层区域。掩星观测能够提供地面到低轨卫星轨道高度处的整个电离层电子密度剖面,对于顶部电离层的研究具有重要作用。标高是构建顶部以上电离层电子密度剖面模型的重要参数。本文使用2007—2020年的气象、电离层和气候星座观测系统(Constellation Observing System for Meteorology,Ionosphere and Climate,COSMIC)掩星观测数据,提取有效电子密度剖面数据的顶部标高,分析了其随地方时、季节、经纬度和太阳活动水平的变化特性。结果表明:顶部标高具有明显的日变化和季节变化规律,并且表现出强烈的太阳活动依赖性;顶部标高在纬度上的变化强烈依赖于地方时,同时在东西经向上表现出明显的波状结构,且这种经度波状结构在南北半球具有不同的形态;顶部标高在夏季半球具有显著的东西经向差异,南半球夏季更为明显。

关键词： COSMIC掩星顶部电离层电子密度剖面太阳活动标高

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低轨增强区域监测站覆盖性分析

现代导航 2024年第3期15卷 174-181页

作者：贺延伟麻军伟王彩霞田宇翟建勇中国电子科技集团公司第二十研究所西安710068 陕西省组合与智能导航重点实验室西安710068

监测站的分布和数量直接影响导航卫星的定轨精度、参数解算及状态监测。给出了监测站覆盖性评估方法,并利用真实的全球导航卫星系统(GNSS)轨道数据和仿真的低地球轨道(leo)星座,对不同数量区域增强监测站的覆盖范围及深度、跟踪平均值... 详细信息

监测站的分布和数量直接影响导航卫星的定轨精度、参数解算及状态监测。给出了监测站覆盖性评估方法,并利用真实的全球导航卫星系统(GNSS)轨道数据和仿真的低地球轨道(leo)星座,对不同数量区域增强监测站的覆盖范围及深度、跟踪平均值和可视弧段占比进行了仿真试验分析。得出的结论是:增加区域监测站的数量仅对GNSS卫星的覆盖性有一定提升,但无法有效改善leo卫星,需进行全球布站或结合星载接收机数据进一步分析。

关键词：低轨卫星监测站覆盖性跟踪平均值可视弧段占比

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低轨巨型星座体系架构设计与关键技术分析

天地一体化信息网络 2024年第2期5卷 43-52页

作者：高梓贺姚海鹏张磊石钰林王富陶滢中国空间技术研究院北京100094 北京邮电大学北京100876

巨型星座中海量网元对现有网络架构和技术体制提出了严峻挑战,如何设计和规划网络体系架构是巨型星座发展的关键问题之一。从星座架构的概念与特征出发,结合国内外卫星星座发展情况与技术预判,提出“四面”(感知平面、数据平面、控制平... 详细信息

巨型星座中海量网元对现有网络架构和技术体制提出了严峻挑战,如何设计和规划网络体系架构是巨型星座发展的关键问题之一。从星座架构的概念与特征出发,结合国内外卫星星座发展情况与技术预判,提出“四面”(感知平面、数据平面、控制平面、智能管理平面)和“三层”(资源层、传送层、业务层)的多层多域混合式智能协同组网体系架构,设计星座网络管控架构、技术参考模型与协议架构等。同时,针对星座建设与发展趋势,阐述并分析星座网络编址路由、网络鲁棒性敏捷保障、差异化业务承载、端到端可靠传送等关键技术的演化趋势,支撑我国低轨巨型星座网络发展与建设。

关键词：巨型星座组网体系架构技术参考模型协议架构

基于流量预测的物联网卫星节点动态缓存分配路由策略

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通信学报 2020年第2期41卷 25-35页

作者：王卫东王程王慧文徐玭北京邮电大学电子工程学院

针对低轨物联网卫星系统的路由问题,提出了基于流量预测的物联网卫星节点动态缓存分配路由策略。首先,分析低轨卫星覆盖区域内业务分布的时空特性,提出了端到端流量预测方法。然后,根据流量预测结果,提出了动态缓存分配路由策略。卫星... 详细信息

针对低轨物联网卫星系统的路由问题,提出了基于流量预测的物联网卫星节点动态缓存分配路由策略。首先,分析低轨卫星覆盖区域内业务分布的时空特性,提出了端到端流量预测方法。然后,根据流量预测结果,提出了动态缓存分配路由策略。卫星节点通过对星间链路的流量负载进行周期性监测,动态分配与邻居节点间各条星间链路的缓存资源,分为初始化和系统运行2个阶段。同时,提出了节点拥塞时的业务分流及数据分组转发策略,通过比较排队时延和转发时延的大小,决定数据分组是否需要进行重路由。仿真结果表明,所提路由策略有效地降低了分组丢失率及平均端到端时延,改善了业务在全网的分布情况。

关键词：低轨卫星路由缓存分配物联网

基于leo/β-CD的长效芳香功能皮革的研究

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中国皮革 2024年第1期53卷 1-8,14页

作者：林可心刘琳聂子锐王拥昌牛泽温会涛福建省皮革绿色设计与制造重点实验室福建晋江362271 兴业皮革科技股份有限公司国家企业技术中心福建晋江362271

为提高芳香皮革的留香性能,以蓝湿革为原料皮,β-环糊精包合薰衣草香精(leo/β-CD)为香料,以加香后皮革的刺激性气味强度、香气浓度、香气舒适度、柔软度等为评价指标,采用正交设计法对复鞣、加脂、套色工序的加香工艺进行优化,并考察... 详细信息

为提高芳香皮革的留香性能,以蓝湿革为原料皮,β-环糊精包合薰衣草香精(leo/β-CD)为香料,以加香后皮革的刺激性气味强度、香气浓度、香气舒适度、柔软度等为评价指标,采用正交设计法对复鞣、加脂、套色工序的加香工艺进行优化,并考察在不同温度下的留香性能。结果表明,薰衣草芳香皮革的最佳制备工艺为:复鞣工序的leo/β-CD添加量为0.1%,加脂工序用量0.5%,套色工序用量0.2%;该芳香皮革的留香性能远高于普通芳香皮革,可在常温下存放6个月。利用β-环糊精包合香料制备的芳香皮革具有长效留香性能,这为制备芳香功能皮革提供了一种新思路。

关键词：制革工程芳香皮革功能皮革包合物

Design and test of HiSGR: a novel GNSS/INS ultra tight coupled receiver

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Journal of Communications and Information Networks 2016年第3期1卷 67-76页

作者： wang Xiaoliang wang Yanguang SU Zhe MENG Yansong GONG Deren Institute of Satellite Navigation and Intra-Satellite-Link Technology Academy of Space Electrical Information TechnologyXi'an 710100China School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200230China

With the support of the national nature science foundation,the Academy of Space Electronic Information Technology is developing a novel compact spaceborne GNSS receiver,referred to as the HiSGR(High Sensitivity GNSS Receiver).This receiver can operate effectively in the full range of Earth orbiting missions,from leo(Low Earth Orbit)to geostationary and *** signal detection algorithms are used in the signal process section of the HiSGR and an inertial sensor is used for GNSS/INS ultra tight coupled design,which makes the acquisition process fast and provides improved tracking performance for weaker GPS signals in the presence of high *** tests are performed using the HiSGR to demonstrate the good performance of some crucial specifications,by employing a real GNSS signal received in an open field and through hardware-in-the-loop *** performance is demonstrated for leo and GEO scenarios.A ground vehicle running test is performed for demonstration of fast acquisition and reacquisition capabilities under conditions of signal *** HiSGR showed good performance and it was stable during the simulations and tests,which proved its capability for future space applications.

关键词： high sensitivity GNSS/INS ultra tight coupled spaceborne receiver

Performance Analysis of MAC Protocol for leo Satellite Networks

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International Journal of Communications, Network and System Sciences 2009年第8期2卷 786-791页

作者： Mingxiang GUAN Ruichun wang Department of Electronic Communication Technology Shenzhen Institute of Information Technology

Considering that weak channel collision detection ability, long propagation delay and heavy load in leo satellite communications, a valid adaptive APRMA MAC protocol was proposed. Different access probability functions for different services were obtained and appropriate access probabilities for voice and data users were updated slot by slot based on the estimation of the voice traffic and the channel status. In the proposed MAC protocol limited wireless resource is allocated reasonably by multiple users and high capacity was achieved. Three performance parameters: voice packet loss probability, average delay of data packets and throughput of data packets were considered in simulation. Finally simulation results demonstrated that the performance of system was improved by the APRMA compared with the conventional PRMA, with an acceptable trade-off between QoS of voice and delay of data.

关键词： leo Satellites Adaptive Packet Reservation Multiple Access MAC Protocol

Keggin Structure and Surface Acidity of 12-Phosphotungstic Acid Grafted Zr-MCM-48 Mesoporous Molecular Sieves

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World Journal of Nano Science and Engineering 2012年第3期2卷 134-141页

作者： Zhiqi wang Juan Navarrete Dirección de Investigación y Posgrado Instituto Mexicano del Petróleo Eje Lázaro Cárdenas Norte No. 152 México D.F. Mexico The American School Foundation Bondojito No. 21 Col. Las Americas México D.F. Mexico

A zirconium modified MCM-48 mesoporous material was synthesized by surfactant-templated method. Surface grafting Zr-MCM-48 with tungstophosphoric acid led to a great enhancement of both the number of the Br?nsted acid sites and acidity strength in comparison with the bare support. At 100°C, the 30 wt% H3PW12O40/Zr-MCM-48 contained 174 μmol/g Br?nsted acid sites which were 14.5 times greater than that of Zr-MCM-48. The Keggin structure of the grafted heteropolyacid was rather stable after calcination at 400°C for 2 h, approximately 93.3% of Keggin structure in the dispersed heteropolyacid were remained without destruction but slightly distorted in some degree, as evidenced by FTIR characterization and 31P NMR-MAS analysis. This H3PW12O40/Zr-MCM-48 solid with three dimensional mesoporous system, large surface area and very strong Br?nsted acidity will be a promising catalyst for acid catalytic reactions.

关键词： Zr-MCM-48 Surface Acidity Heteropolyacid Spectroscopic Characterization

Production of Carbon Nanotubes and Hydrogen Catalyzed with Ni/MCM-41 Catalysts

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Green and Sustainable Chemistry 2012年第3期2卷 91-96页

作者： Zhiqi wang Juan Navarrete Dirección de Investigación y Posgrado Instituto Mexicano del Petróleo México City México The American School Foundation México City Mexico

Methane catalytic decomposition (MCD) over Ni/MCM-41 catalysts was tested in a microreactor to simultaneously produce hydrogen and carbon nanotubes (CNTs). The methane conversion reached 30% to 47% at a moderate temperature range from 400°C to 600°C and the catalytic activity of the catalysts remains stable during 500 min steam on time. CNTs were chiefly formed through tip-growth mode, due to the weak interaction between the metallic Ni and the support. Most of the Ni particles are located on the tip of the produced CNTs, which avoids rapid deactivation of the catalyst resulted from carbon encapsulation. Large Ni particles usually lead to the formation of CNTs with big diameter. During the reaction, the shape of Ni particles changed from pseudo-sphere to diamond-like. All the CNTs consist of multiple layer walls and are curved in certain degree.

关键词： Methane Catalytic Decomposition Hydrogen Carbon Nanotubes Catalysts Ni/MCM-41