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北斗三号仅用作追踪的机载设备适航要求分析

北京航空航天大学学报 2024年第4期50卷 1162-1175页

作者：马振洋周中华张帆王鹏柯炳清中国民航大学安全科学与工程学院天津300300 中国民航大学民航航空器适航审定技术重点实验室天津300300 航天恒星科技有限公司北京100094

随着北斗三号卫星导航系统服务正式开通,北斗二号相关适航标准已无法满足当前机载设备应用场景需求,严重制约了北斗在民航领域的应用进程,急需开展北斗三号相应标准的研究与制定。针对北斗在民用航空器中应用第1阶段“仅用作航空器追踪... 详细信息

随着北斗三号卫星导航系统服务正式开通,北斗二号相关适航标准已无法满足当前机载设备应用场景需求,严重制约了北斗在民航领域的应用进程,急需开展北斗三号相应标准的研究与制定。针对北斗在民用航空器中应用第1阶段“仅用作航空器追踪”,对北斗二号与北斗三号开展差异性分析,提出标准修订总体方案,综合考虑适航安全性、机载设备应用场景,结合工业实践,根据设备构型提出指标修订方案,形成审定要素及符合性方法建议,为设备研发与适航取证提供标准支持。仿真分析了设备天线增益、卫星可见性等关键参数,验证了所修订技术指标的正确性。

关键词：技术标准规定北斗三号航空器追踪定位短报文适航

Molecular Oxygen Abundance in Galactic Massive star Formation Regions Based on SWAS Observations

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Research in Astronomy and Astrophysics 2024年第9期24卷 83-98页

作者： Bing-Ru wang Di Li Paul F.Goldsmith Jingwen Wu Chao-Wei Tsai Donghui Quan Xia zhang Junzhi wang Gary J.Melnick Jin-Zeng Li Gary A.Fuller Jinjin Xie National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Tsinghua University Beijing 100084China University of Chinese Academy of Sciences Beijing 100049China Research Center for Astronomical computing Zhejiang LaboratoryHangzhou 311100China Jet Propulsion Laboratory California Institute of TechnologyPasadenaCA 91109USA Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Guangxi Key Laboratory for Relativistic Astrophysics School of Physical Science and TechnologyGuangxi UniversityNanning 530004China Center for Astrophysics Harvard&Smithsonian60 Garden StreetMS 66CambridgeMA 02138USA Jodrell Bank Center for Astrophysics Department of Physics&AstronomyUniversity of ManchesterOxford RoadManchesterM139PLUK I.Physikalisches Institut University of CologneZülpicher Str.7750937 KölnGermany

Molecular oxygen abundance is a key parameter in understanding the chemical network of the interstellar *** estimate the molecular oxygen column density and abundance for a sample of Galactic massive star formation regions based on observations from the Submillimiter Wave Astronomy Satellite(SWAS)*** obtained an averaged O_(2)spectrum based on this sample using the(SWAS)survey data(O_(2),487.249 GHz,N=3-1,J=3-2).No emission or absorption feature is seen around the supposed central velocity with a total integration time of t_(total)=8.67×10^(3)hr and an rms noise per channel of 1.45 m *** a kinetic temperature T_(kin)=30 K,we derive the 3σupper limit of the O_(2)column density to be 3.3×10^(15)cm^(-2),close to the lowest values reported in Galactic massive star formation regions in previous *** corresponding O_(2)abundance upper limit is6.7×10^(-8),lower than all previous results based on SWAS observations and is close to the lowest reported value in massive star formation *** a galactic scale,our statistical results confirm a generally low O_(2)abundance for Galactic massive star formation *** abundance is also lower than results reported in extragalactic sources.

关键词： ISM:molecules galaxies:abundances ISM:lines and bands Galaxy:abundances

Experimentation Research and Analysis of Application of Beidou Satellite Navigation System in Civil Aviation Aircraft

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Experimentation Research and Analysis of Application of Beid...

第三届中国卫星导航学术年会

作者： Hong Sun,Nengjie Yu,fengshan zhang,Hong Liang space star technology co.China''s Academy of space technology,Beijing,China,100086

With the development of airborne avionics,satellite navigation capabilities and other advanced technology,the concept of PBN（Performance Based Navigation）is proposed by ***,in the 36th General Assembly of ICAO,states parties are required to ensure that by 2016,a coordinated approach to the global transition to PBN ***,China’s civil aviation has developed a PBN implementation decision and *** will play an important role in PBN implementation *** its development,applied experimentation of Beidou Satellite Navigation System in CAAC is researched in the ***,both exploring static and flight experimentations of testing aircraft carrying Beidou navigation receivers on board cooperating with Flight Inspection Center of CAAC is conducted and *** experimentations provide a reference for the development of Beidou Satellite Navigation System standards in the aviation sector,and can be considered as a support to promote the Beidou Satellite Navigation System into the framework of the ICAO standard system.

关键词： Beidou Satellite Navigation System Beidou satellite navigation receiver Civil Aviation flight experimentation

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集成非互易光学器件(特邀)

光学学报 2024年第15期44卷 341-358页

作者：张子健严巍秦俊毕磊国家电磁辐射控制材料工程技术研究中心四川成都611731 多频谱吸波材料与结构教育部重点实验室(B类) 四川成都611731

光隔离器、光环行器等非互易光学器件广泛应用于信息光子系统,在光纤通信、光纤传感等技术中发挥了不可替代的作用。面向集成光学系统,研制平面化、可集成的非互易光学器件是该领域的关键难题之一,被称为“缺失的一环”。介绍了在集成... 详细信息

光隔离器、光环行器等非互易光学器件广泛应用于信息光子系统,在光纤通信、光纤传感等技术中发挥了不可替代的作用。面向集成光学系统,研制平面化、可集成的非互易光学器件是该领域的关键难题之一,被称为“缺失的一环”。介绍了在集成光波导器件中实现光学非互易性的主要原理,总结了近年来基于磁光效应、非线性光学效应和时空调制机理研制集成非互易光学器件的部分代表性工作。最后分析了该领域面临的挑战,并对未来发展趋势进行了展望。

关键词：非互易光学磁光效应非线性光学时空调制硅基光电子

基于深度学习的Android恶意软件动态检测

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计算机工程与设计 2024年第1期45卷 10-16页

作者：张雪芹王逸璇赵敏华东理工大学信息科学与工程学院上海200237

为提高Android恶意软件的检测精度,提出一种基于改进DenseNet网络的Android恶意软件动态检测方法。以应用软件运行特定阶段的网络通信流量为分析对象,根据会话五元组信息切分原始网络流量并转换为灰度图,提出一种基于DenseNet网络改进... 详细信息

为提高Android恶意软件的检测精度,提出一种基于改进DenseNet网络的Android恶意软件动态检测方法。以应用软件运行特定阶段的网络通信流量为分析对象,根据会话五元组信息切分原始网络流量并转换为灰度图,提出一种基于DenseNet网络改进的分类检测网络DenseNet_IS。通过添加具有不同大小卷积核的卷积分支获取不同感受野的特征,通过引入SimAM注意力模块,从空间和通道两个维度实现对重要特征的关注。结合应用软件判决机制,实现最终分类。在CICAndMal2017数据集上的实验结果表明,所提方法可以达到99.06%的良恶性检测精度和96.51%的多分类精度,验证了该方法的有效性。

关键词： Android系统恶意软件异常检测网络流量 DenseNet 注意力机制流量灰度图

Winter wheat identification by integrating spectral and temporal information derived from multi-resolution remote sensing data

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Journal of Integrative Agriculture 2019年第11期18卷 2628-2643页

作者： zhang Xi-wang liu Jian-feng Zhenyue qin qin Fen Key Laboratory of Geospatial technology for Middle and Lower Yellow River Regions Ministry of EducationKaifeng 475004P.R.China Research School of computer Science The Australian National UniversityCanberra 2601Australia college of Environment and Planning Henan UniversityKaifeng 475004P.R.China Yellow River conservancy Technical Institute Kaifeng 475004P.R.China Institute of Urban Big Data Henan UniversityKaifeng 475004P.R.China

Timely crop acreage and distribution information are the basic data which drive many agriculture related *** identifying crop types based on remote sensing,methods using only a single image type have significant *** research that integrates fine and coarser spatial resolution images,using techniques such as unmixing methods,regression models,and others,usually results in coarse resolution abundance without sufficient detail within pixels,and limited attention has been paid to the spatial relationship between the pixels from these two kinds of *** we propose a new solution to identify winter wheat by integrating spectral and temporal information derived from multi-resolution remote sensing data and determine the spatial distribution of sub-pixels within the coarse resolution ***,the membership of pixels which belong to winter wheat is calculated using a 25-m resolution resampled Landsat Thematic Mapper(TM)image based on the Bayesian ***,the winter wheat abundance(acreage fraction in a pixel)is assessed by using a multiple regression model based on the unique temporal change features from moderate resolution imaging spectroradiometer(MODIS)time series ***,winter wheat is identified by the proposed Abundance-Membership(AM)model based on the spatial relationship between the two types of ***,winter wheat is identified by comparing the spatially corresponding 10×10 membership pixels of each abundance *** other words,this method takes advantage of the relative size of membership in a local space,rather than the absolute size in the entire study *** method is tested in the major agricultural area of Yiluo Basin,China,and the results show that acreage accuracy(Aa)is 93.01%and sampling accuracy(As)is 91.40%.confusion matrix shows that overall accuracy(OA)is 91.4%and the kappa coefficient(Kappa)is *** values are significantly improved compared to the traditional Maximum Likeli

关键词： temporal change characteristics membership abundance winter wheat multi-resolution remote sensing

长期碳酸盐碱度胁迫对脊尾白虾生长及卵巢发育的影响

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水产学报 2024年第4期48卷 257-267页

作者：张秀红李吉涛王佳佳王成伟秦桢葛倩倩刘萍李健上海海洋大学水产科学国家级实验教学示范中心中国水产科学研究院黄海水产研究所海水养殖生物育种与可持续产出全国重点实验室青岛海洋科技中心海洋渔业科学与食物产出过程功能实验室

为探讨碳酸盐碱度对脊尾白虾生长及卵巢发育的影响。本研究设置3 mmol/L （对照组）、5 mmol/L和8 mmol/L三种碳酸盐碱度梯度养殖脊尾白虾60 d，比较不同碳酸盐碱度胁迫对脊尾白虾生长性能、组织结构、酶活性以及卵巢发育的影响，结果... 详细信息

为探讨碳酸盐碱度对脊尾白虾生长及卵巢发育的影响。本研究设置3 mmol/L （对照组）、5 mmol/L和8 mmol/L三种碳酸盐碱度梯度养殖脊尾白虾60 d，比较不同碳酸盐碱度胁迫对脊尾白虾生长性能、组织结构、酶活性以及卵巢发育的影响，结果显示，5 mmol/L组与对照组体长增长率、体重增长率以及成活率差异不显著，8 mmol/L组体长增长率、体重增长率以及成活率显著低于对照组。肝胰腺组织切片显示，5 mmol/L组中部分B细胞体积增大，部分转运泡内出现颗粒物质，8 mmol/L组管腔的形态结构严重变形。鳃组织切片显示，5 mmol/L组出现轻微鳃丝肿大现象，角质层略有变形，且角质层下间隙扩张变长，上皮细胞与支柱细胞排列紊乱；8 mmol/L组鳃丝肿大，排列不规则，出现血细胞肿胀现象，鳃丝上皮细胞严重破坏，毛细血管网结构形态改变，角质层下间隙变形。肌肉组织酶活性测定结果显示，5 mmol/L组的碳酸酐酶活性显著高于对照组，Na+/K+-ATP酶活性在肌肉中差异不显著；肝胰腺组织酶活性测定结果显示，碳酸酐酶在肝胰腺组织中差异不显著，8 mmol/L组Na+/K+-ATP酶活性显著低于其他组，鳃组织中，5和8 mmol/L组鳃组织中和Na+/K+-ATP酶活性均显著高于对照组，且两组间差异显著。卵巢发育统计结果显示，三组脊尾白虾卵巢均能发育，其发育至Ⅱ期的百分比分别为20.51%、10.52%和6.25%，其中5mmol/L组与对照组间无显著差异，8 mmol/L组显著低于对照组；3 mmol/L组和5 mmol/L组均有卵巢发育至Ⅲ期的脊尾白虾，但两组差异不显著，8 mmol/L组未见有卵巢发育至Ⅲ期的脊尾白虾。卵巢组织切片显示，8 mmol/L组卵原细胞细胞排列疏松，周围滤泡细胞排列疏松且数量较少。研究表明，脊尾白虾可以在低于8 mmol/L的碳酸盐碱度中生长发育，但高碳酸盐碱度可能会造成脊尾白虾鳃和肝胰腺组织损伤，导致其生长受到影响，同时猜测高碳酸盐碱度可能也会影响卵巢的发育速率。本研究可为开展脊尾白虾在盐碱水中的增养殖提供基础数据和参考信息。

关键词：脊尾白虾碳酸盐碱度胁迫生长组织切片酶活性卵巢发育

北斗星座设计虚拟仿真实验教学系统建设与实践

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测绘地理信息 2024年第3期49卷 145-150页

作者：黄观文王乐王利张勤李晓菲长安大学地质工程与测绘学院陕西西安710054 长安大学马克思主义学院陕西西安710054

北斗卫星导航系统(Beidou navigation satellite sys⁃tem,BDS)星座在太空中的空间部署及运行轨迹不可见,地面星座设计及模拟系统昂贵或不公开,导致星座设计内容只能通过课堂进行理论讲授,无法实习实践,影响了测绘学科教学质量,亟待建设... 详细信息

北斗卫星导航系统(Beidou navigation satellite sys⁃tem,BDS)星座在太空中的空间部署及运行轨迹不可见,地面星座设计及模拟系统昂贵或不公开,导致星座设计内容只能通过课堂进行理论讲授,无法实习实践,影响了测绘学科教学质量,亟待建设北斗星座设计虚拟仿真实验教学系统。针对此问题,设计了一种BDS星座设计虚拟仿真实验教学系统,并介绍了其设计思路、总体框架、实验原理和建设成效。该系统采用Unity3D前端开发平台,利用C#、JavaS⁃cript、HTML5语言开发,包括星座模拟、地面数据模拟和效果评估3大模块,还原了BDS独具特色的混合星座和BDS地面跟踪站设计,并能对星座及地面站的设计效果进行初步评价,提升了教学效果,同时使学生能够从中体验到BDS设计中蕴含的中国智慧。系统已向社会共享,为学科教育和行业发展提供教学实践支撑。

关键词：北斗卫星导航系统虚拟仿真星座模拟地面数据模拟效果评估

Antenna Design for Modern Mobile Phones: A Review

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Electromagnetic Science 2024年第2期2卷 55-90页

作者： Yan wang Libin Sun Zhengwei Du Zhijun zhang Key Laboratory for Information Science of Electromagnetic Waves(MoE) School of Information Science and TechnologyFudan UniversityShanghai 200433China Shanghai Huawei Technologies Ltd.Shanghai 201206China Beijing National Research Center for Information Science and technology Department of Electronic EngineeringTsinghua UniversityBeijing 100084China

Due to limited antenna space,high communication requirements,and strict regulatory constraints,the design of antennas for modern mobile phones has become an exceedingly challenging *** recent years,numerous studies have been conducted in this area,leading to significant *** review paper comprehensively summarizes recent progress made in antenna design for modern mobile ***,the challenges faced in antenna design for modern mobile phones are described,including bandwidth enhancement,integration and decoupling techniques,mm-wave array antennas,satellite communication antennas,as well as interactions between mobile antennas and the human ***,the basic antenna types(such as inverted-F,slot,loop,and planar inverted-F antennas)commonly used in modern metal-bezel mobile phones along with their key characteristics are briefly ***,the commonly exployed methods used in practical applications for designing wideband antennas within compact sizes and achieving decoupling among multiple antennas with wide bandwidths are ***,recent advances in the design of compact,wideband,and wide-angle scanning mm-wave arrays for modern mobile phones are ***,recent progress made in satellite communication antenna designs for modern mobile phones,including broadside and end-fire radiation patterns,is ***,recent studies on the interaction between mobile antennas and the human body are briefly ***,the future challenge of antenna design for mobile phones is briefly *** is our hope that this comprehensive review will provide readers with a systematic understanding of antenna design principles applicable to modern mobile phones.

关键词： Mobile antenna Bandwidth Decoupling mm-wave antenna Satellite communication antenna Specific absorption rate