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机动车排放车载实验及模型模拟研究 被引量:33
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作者 胡京南 郝吉明 +3 位作者 傅立新 吴烨 王志石 邓宇华 《环境科学》 EI CAS CSCD 北大核心 2004年第3期19-25,共7页
研究机动车的排放特征及获得排放因子 ,是建立机动车排放清单和制定相应控制策略的基础 ,而路上的机动车排放车载测试被认为是实验室台架测试的一个重要补充 .本研究利用AVLDiGas 4 0 0 0light五气分析仪 ,在澳门典型路段上对 7辆汽油... 研究机动车的排放特征及获得排放因子 ,是建立机动车排放清单和制定相应控制策略的基础 ,而路上的机动车排放车载测试被认为是实验室台架测试的一个重要补充 .本研究利用AVLDiGas 4 0 0 0light五气分析仪 ,在澳门典型路段上对 7辆汽油轿车样本开展了尾气排放车载实验 .研究发现安装电喷加三元催化转化系统的车辆 (以下称电喷车 )在气态污染物排放上比旧的化油器车有显著降低 ,化油器车HC、CO和NO排放的体积浓度平均值分别为 2 2 7× 10 -6、1 5 7%和 14 77× 10 -6,而电喷车则分别为 33× 10 -6、0 2 1%和 131× 10 -6,约是前者的 1/11~ 1/7.但电喷车在冷启动阶段会出现高排放 ;对电喷车的CO和NO排放浓度做算术平均 ,其绝对值主要由出现频率少的高浓度值所贡献 .研究进一步估算了汽油轿车的排放因子 ,同时利用MOBILE5模型计算了澳门 2 0 0 0年汽油轿车的平均排放因子 ,模型计算值和实验数据估算结果的比值在 5 9%~ 139%之间 ,如果仅比较年平均排放因子 ,这个比值则在 6 8%~ 132 %之间 .结果表明 ,车辆采用电喷加催化转化系统 ,对控制污染物排放的作用显著 ,但催化设备存在冷启动时起燃缓慢的问题 ;对电喷车的技术改进 ,减少其在行驶过程中出现高浓度的污染物排放 ,将能进一步大大降低平均排放水平 ; 展开更多
关键词 汽油轿车 车载实验 排放因子 mobile5 澳门
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广州市实施I/M简易瞬态工况检测方法的环境效果分析 被引量:9
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作者 李晓玲 吴烨 +3 位作者 姚欣灿 张少君 周昱 傅立新 《环境科学学报》 CAS CSCD 北大核心 2012年第1期101-108,共8页
采用简易瞬态工况法对在用车进行检测,能够更为有效地筛选高排放车辆.2007—2009年广州市轻型汽油车的简易瞬态工况法的初检数据表明,国Ⅰ排放标准实施以前(简称"国Ⅰ前")车辆和国Ⅰ及以后排放标准车辆排放超限值比例分别为20... 采用简易瞬态工况法对在用车进行检测,能够更为有效地筛选高排放车辆.2007—2009年广州市轻型汽油车的简易瞬态工况法的初检数据表明,国Ⅰ排放标准实施以前(简称"国Ⅰ前")车辆和国Ⅰ及以后排放标准车辆排放超限值比例分别为20.1%和17.6%.简易瞬态工况法复检数据得到的国Ⅰ前和国Ⅰ及以后车辆经维护后能够达标的比例分别为76.0%和64.7%,且经过有效维护后超标车辆的平均排放水平有较大比例的削减.同时,采用修正的MOBILE5模型对广州市轻型汽油车排放进行模拟.结果发现,广州市2009年轻型汽油车的CO、HC和NOx排放量分别为24.4×104、3.8×104和1.8×104t.如果考虑I/M制度实施及实际执行率,复检不达标车辆在全部淘汰情景下,2009年广州市轻型汽油车排放的CO、HC和NOx分别能削减4.20×104、0.58×104和0.15×104t,占全部轻型汽油车的削减比例分别为17.2%、15.3%和8.2%;而在全部置换为国Ⅳ新车情景下,3种污染物分别能削减4.12×104、0.57×104和0.14×104t,削减比例分别为16.9%、15.0%和8.0%.国Ⅰ前及国Ⅰ车辆对CO和HC削减量的贡献达到90%左右,对NOx削减量的贡献也在85%左右. 展开更多
关键词 检查/维护(I/M) 轻型汽油车 简易瞬态工况法 排放 mobile5模型
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机动车污染物排放量计算模型的应用 被引量:5
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作者 张泽生 张潞 韩晓东 《城市环境与城市生态》 CAS CSSCI CSCD 北大核心 2003年第6期142-143,共2页
概要介绍了MOBILE5b模型的组成、功能,介绍了该模型在世行贷款项目中的应用,并对该模型在公路交通改善项目环境影响评价的实用价值进行了分析。
关键词 机动车 污染物 排放量 计算 公路交通 mobile5b模型 贷款
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Modeling and Comprehensive Review of Signaling Storms in 3GPP-Based Mobile Broadband Networks:Causes,Solutions,and Countermeasures
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作者 Muhammad Qasim Khan Fazal Malik +1 位作者 Fahad Alturise Noor Rahman 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期123-153,共31页
Control signaling is mandatory for the operation and management of all types of communication networks,including the Third Generation Partnership Project(3GPP)mobile broadband networks.However,they consume important a... Control signaling is mandatory for the operation and management of all types of communication networks,including the Third Generation Partnership Project(3GPP)mobile broadband networks.However,they consume important and scarce network resources such as bandwidth and processing power.There have been several reports of these control signaling turning into signaling storms halting network operations and causing the respective Telecom companies big financial losses.This paper draws its motivation from such real network disaster incidents attributed to signaling storms.In this paper,we present a thorough survey of the causes,of the signaling storm problems in 3GPP-based mobile broadband networks and discuss in detail their possible solutions and countermeasures.We provide relevant analytical models to help quantify the effect of the potential causes and benefits of their corresponding solutions.Another important contribution of this paper is the comparison of the possible causes and solutions/countermeasures,concerning their effect on several important network aspects such as architecture,additional signaling,fidelity,etc.,in the form of a table.This paper presents an update and an extension of our earlier conference publication.To our knowledge,no similar survey study exists on the subject. 展开更多
关键词 Signaling storm problems control signaling load analytical modeling 3GPP networks smart devices diameter signaling mobile broadband data access data traffic mobility management signaling network architecture 5G mobile communication
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Research on the Practical Strategy of 5G Mobile Communication Technology in Power Communication
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作者 Wanshen Peng 《Journal of Electronic Research and Application》 2025年第3期119-124,共6页
With the acceleration of the intelligent transformation of power systems,the requirements for communication technology are increasingly stringent.The application of 5G mobile communication technology in power communic... With the acceleration of the intelligent transformation of power systems,the requirements for communication technology are increasingly stringent.The application of 5G mobile communication technology in power communication is analyzed.In this study,5G technology features,application principles,and practical strategies are discussed,and methods such as network slicing,customized deployment,edge computing collaborative application,communication equipment integration and upgrading,and multi-technology collaboration and complementation are proposed.It aims to effectively improve the efficiency,reliability,and security of power communication,solve the problem that traditional communication technology is difficult to meet the diversified needs of power business,and achieve the effect of optimizing the power communication network and supporting the intelligent development of the power system. 展开更多
关键词 5G mobile communication technology Electric power communication Network slicing Edge computing Multi-technology collaboration
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Secure and energy-efficient UAV-assisted maritime communication under multiple eavesdroppers with imperfect CSI and collusion
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作者 Fang MEI Yuqing LIU +4 位作者 Shuo GAO Jiahui LI Hui KANG Sujin HOU Geng SUN 《Chinese Journal of Aeronautics》 2025年第10期170-184,共15页
The maritime communication networks(MCNs)for industry require reliable,efficient,and wide coverage to deploy emerging intelligent marine applications.To this end,unmanned aerial vehicles(UAVs)can be integrated into MC... The maritime communication networks(MCNs)for industry require reliable,efficient,and wide coverage to deploy emerging intelligent marine applications.To this end,unmanned aerial vehicles(UAVs)can be integrated into MCNs to extend flexibility and mobility.However,harsh maritime environments and open line-of-sight(LoS)links increase the UAV onboard energy consumption and worsen communication security.In this work,we aim to propose a collaborative beamforming-based physical layer secure and energy-efficient communication method for UAV-assisted MCNs,in which the energy limitations of UAVs and the interference from both known and unknown eavesdroppers as well as the possible collusion among eavesdroppers are considered.Specifically,we formulate a multi-objective optimization problem(MOP)to improve the system confidentiality rate,reduce the level ratio of the UAV virtual antenna array,and decrease the energy consumption of the UAVs by jointly optimizing the UAV positions and synthesizing the UAV virtual antenna array.This MOP is non-convex and NP-hard,and thus we propose an enhanced non-dominated sorted whale optimization algorithm(ENSWOA)to solve the problem.In ENSWOA,the introduced chaotic solution initialization,adaptive weighting,and optimal position updating methods can increase the searching capability of the algorithm.Simulation results show that the proposed ENSWOA outperforms the baseline algorithms,and can effectively enhance the security and energy efficiency of the considered system. 展开更多
关键词 Channel state information Collaborative beamforming Eavesdropper collusion 5G mobile communication systems Unmanned aerial vehicles
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Circular RNA hsa_circRNA_101996 modulates gastric cancer cell proliferation and apoptosis through the miR-577/HMGN5 axis
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作者 Xiao-Lei Wang Lin Zhang Qing Shang 《World Journal of Gastrointestinal Oncology》 2025年第5期409-421,共13页
BACKGROUND Circular RNAs(circRNAs)are critical regulators in tumorigenesis,functioning as microRNA sponges or protein decoys.Although numerous circRNAs have been implicated in gastric cancer progression,the role of hs... BACKGROUND Circular RNAs(circRNAs)are critical regulators in tumorigenesis,functioning as microRNA sponges or protein decoys.Although numerous circRNAs have been implicated in gastric cancer progression,the role of hsa_circRNA_101996 remains unclear.This study hypothesizes that hsa_circRNA_101996 promotes gastric cancer cell proliferation and apoptosis via the microRNA-577(miR-577)/high mobility group nucleosome binding domain 5(HMGN5)axis.AIM To investigate the role of hsa_circRNA_101996 in gastric cancer proliferation and apoptosis through the miR-577/HMGN5 axis.METHODS Forty-one paired gastric cancer tissues and adjacent non-cancerous tissues were analyzed.Differential circRNA expression was identified using GSE83521 and GSE89143 datasets.miR-577 and HMGN5 were predicted via CircInteractome and TargetScan.Functional experiments(MTT,colony formation,Western blot)and dual-luciferase reporter assays were performed in gastric cancer cell lines(OCUM-1,HSC-39).In vivo tumorigenesis was validated in nude mice.Statistical analysis included Student’s t-test and one-way ANOVA(P<0.05).RESULTS Hsa_circRNA_101996 was significantly upregulated in gastric cancer tissues and cell lines compared to adjacent non-cancerous tissues(P<0.05).Dual-luciferase reporter assays validated the interactions among hsa_circRNA_101996,miR-577,and HMGN5.In vitro,gastric cancer cells overexpressing hsa_circRNA_101996 showed significantly increased proliferation and decreased apoptosis compared to controls(P<0.05).Cells transfected with miR-577 mimics exhibited reduced proliferation and increased apoptosis(P<0.05).Co-transfection with hsa_circRNA_101996 or HMGN5 reversed the effects of miR-577 mimics.In vivo,hsa_circRNA_101996-overexpressing tumors showed increased volume and HMGN5 expression(P<0.05).CONCLUSION Hsa_circRNA_101996 promotes gastric cancer progression by sponging miR-577 to upregulate HMGN5,suggesting a novel therapeutic target for gastric cancer. 展开更多
关键词 MicroRNA-577 Apoptosis PROLIFERATION High mobility group nucleosome binding domain 5 CircRNA_101996 Gastric cancer
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武汉市机动车排放因子的确定 被引量:10
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作者 刘恩栋 《环境与开发》 2000年第3期36-37,45,共3页
采用美国环保局 (EPA)的MOBILE5模式 ,结合武汉市的实际情况 ,对机动车的排放因子进行了计算 .
关键词 mobile5模式 排放因子 机动车 废气 污染控制
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应用模式计算机动车排放因子 被引量:57
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作者 何东全 郝吉明 +1 位作者 贺克斌 傅立新 《环境科学》 CAS CSSCI CSCD 北大核心 1998年第3期7-10,共4页
以澳门地区机动车污染物排放因子计算为例,介绍了根据当地实际情况,进行模式参数修正,并采用修正的模式确定排放因子的基本方法.结果表明,采用修正模式计算的方法能够比较方便地确定不同时空研究范围内机动车的排放因子.澳门地区... 以澳门地区机动车污染物排放因子计算为例,介绍了根据当地实际情况,进行模式参数修正,并采用修正的模式确定排放因子的基本方法.结果表明,采用修正模式计算的方法能够比较方便地确定不同时空研究范围内机动车的排放因子.澳门地区机动车的排放水平较高,需要采取更先进的技术以控制机动车的污染. 展开更多
关键词 排放因子 环境污染控制 机动车 模式计算机
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盘锦冬季城区机动车污染物排放模拟研究 被引量:1
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作者 李冬梅 刘冲 +1 位作者 李朝旭 车宏宇 《气象与环境学报》 2006年第3期20-23,共4页
采用美国环境保护局开发的机动车排放因子模型Mobile5,计算了2005年盘锦冬季机动车单车排放因子在不同车型条件下的排放情况。结果表明:不同车型的机动车其单车排放因子随着车速的增加而呈不同趋势的变化,HC和CO逐渐降低,而NOx随车型的... 采用美国环境保护局开发的机动车排放因子模型Mobile5,计算了2005年盘锦冬季机动车单车排放因子在不同车型条件下的排放情况。结果表明:不同车型的机动车其单车排放因子随着车速的增加而呈不同趋势的变化,HC和CO逐渐降低,而NOx随车型的变化而变化。 展开更多
关键词 机动车排放因子 mobile5 污染物 车型 排放模拟
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Structure and performance analysis of fusion positioning system with a single 5G station and a single GNSS satellite 被引量:2
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作者 Chi Guo Shufeng Qi +2 位作者 Wenfei Guo Chenlong Deng Jingnan Liu 《Geo-Spatial Information Science》 SCIE EI CSCD 2023年第1期94-106,共13页
NaGlobal vigation Satellite System(GNSS)positioning technology is widely used for its high precision,global,and all-weather service.However,in complex environments such as urban canyons,GNSS performance is often degra... NaGlobal vigation Satellite System(GNSS)positioning technology is widely used for its high precision,global,and all-weather service.However,in complex environments such as urban canyons,GNSS performance is often degraded due to signal occlusion and even fails to achieve positioning due to the insufficient visible satellites.Because of the characteristics of large band-width,low latency,and high Base Station(BS)density,the fifth-Generation mobile communication(5G)technology has gradually become a trend for positioning in cities while offering traditional communication service.To supply the communication demands of the User Equipment(UE),only one BS is usually considered to establish a connection with the UE during the BS construction.However,the positioning accuracy with a single BS in urban canyons will be significantly reduced.To further improve the positioning accuracy in such extreme scenarios,this paper proposes a simplified 5G/GNSS fusion positioning system architecture using observations from only a 5G BS and a GNSS satellite.In this system,the GNSS receiver is mounted on the 5G BS,and the measurements provided by the receiver are used to form the differential code and complete the position estimation.The positioning mathematical models of the system based on the original code and differential code are derived.Then,the impacts of the measurements noise and the time synchronization error on the positioning accuracy are analyzed theoretically.Finally,the positioning performance is investigated by a set of simulation experiments.Numerical results show that under the existing 5G measurement noise and 2 m’s code measurement noise,the improvement of the differential code based fusion positioning compared with the 5G-only positioning is more than 32%,which is also about 6%higher than the original code based fusion positioning.Besides,this improvement is not affected by the time synchronization error between the BS and the GNSS satellite. 展开更多
关键词 The fifth-generation mobile communication(5G)positioning 5G/Global navigation satellite system(GNSS)fusion positioning differential code error analysis
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FedRec:Trusted rank-based recommender scheme for service provisioning in federated cloud environment 被引量:1
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作者 Ashwin Verma Pronaya Bhattacharya +3 位作者 Umesh Bodkhe Deepti Saraswat Sudeep Tanwar Kapal Dev 《Digital Communications and Networks》 SCIE CSCD 2023年第1期33-46,共14页
The emergence of on-demand service provisioning by Federated Cloud Providers(FCPs)to Cloud Users(CU)has fuelled significant innovations in cloud provisioning models.Owing to the massive traffic,massive CU resource req... The emergence of on-demand service provisioning by Federated Cloud Providers(FCPs)to Cloud Users(CU)has fuelled significant innovations in cloud provisioning models.Owing to the massive traffic,massive CU resource requests are sent to FCPs,and appropriate service recommendations are sent by FCPs.Currently,the FourthGeneration(4G)-Long Term Evolution(LTE)network faces bottlenecks that affect end-user throughput and latency.Moreover,the data is exchanged among heterogeneous stakeholders,and thus trust is a prime concern.To address these limitations,the paper proposes a Blockchain(BC)-leveraged rank-based recommender scheme,FedRec,to expedite secure and trusted Cloud Service Provisioning(CSP)to the CU through the FCP at the backdrop of base 5G communication service.The scheme operates in three phases.In the first phase,a BCintegrated request-response broker model is formulated between the CU,Cloud Brokers(BR),and the FCP,where a CU service request is forwarded through the BR to different FCPs.For service requests,Anything-as-aService(XaaS)is supported by 5G-enhanced Mobile Broadband(eMBB)service.In the next phase,a weighted matching recommender model is proposed at the FCP sites based on a novel Ranking-Based Recommender(RBR)model based on the CU requests.In the final phase,based on the matching recommendations between the CU and the FCP,Smart Contracts(SC)are executed,and resource provisioning data is stored in the Interplanetary File Systems(IPFS)that expedite the block validations.The proposed scheme FedRec is compared in terms of SC evaluation and formal verification.In simulation,FedRec achieves a reduction of 27.55%in chain storage and a transaction throughput of 43.5074 Mbps at 150 blocks.For the IPFS,we have achieved a bandwidth improvement of 17.91%.In the RBR models,the maximum obtained hit ratio is 0.9314 at 200 million CU requests,showing an improvement of 1.2%in average servicing latency over non-RBR models and a maximization trade-off of QoE index of 2.7688 at the flow request 1.088 and at granted service price of USD 1.559 million to FCP for provided services.The obtained results indicate the viability of the proposed scheme against traditional approaches. 展开更多
关键词 Blockchain 5G-enhanced mobile broadband Federated clouds Rank-based recommender model Smart contracts
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A Novel 28 GHz Phased Array Antenna for 5G Mobile Communications 被引量:3
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作者 LI Yezhen REN Yongli +2 位作者 YANG Fan XU Shenheng ZHANG Jiannian 《ZTE Communications》 2020年第3期20-25,共6页
A novel phased array antenna consisting of 256 elements is presented and experimentally verified for 5G millimeter-wave wireless communications.The antenna integrated with a wave control circuit can perform real-time ... A novel phased array antenna consisting of 256 elements is presented and experimentally verified for 5G millimeter-wave wireless communications.The antenna integrated with a wave control circuit can perform real-time beam scanning by reconfiguring the phase of an antenna unit.The unit,designed at 28 GHz using a simple patch structure with one PIN diode,can be electronically controlled to generate 1 bit phase quantization.A prototype of the antenna is fabricated and measured to demonstrate the feasibility of this approach.The measurement results indicate that the antenna achieves high gain and fast beam-steering,with the scan beams within±60°range and the maximum gain up to 21.7 dBi.Furthermore,it is also tested for wireless video transmission.In ZTE Shanghai,the antenna was used for the 5G New Radio(NR)test.The error vector magnitude(EVM)is less than 3%and the adjacent channel leakage ratio(ACLR)less than−35 dBc,which can meet 5G system requirements.Compared with the conventional phased array antenna,the proposed phased array has the advantages of low power consumption,low cost and conformal geometry.Due to these characteristics,the antenna is promising for wide applications in 5G millimeter-wave communication systems. 展开更多
关键词 5G mobile communications millimeter wave phased array antenna
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SDN-Based Data Offloading for 5G Mobile Networks 被引量:1
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作者 Mojdeh Amani Toktam Mahmoodi +1 位作者 Mallikarjun Tatipamula Hamid Aghvami 《ZTE Communications》 2014年第2期34-40,共7页
The rapid growth of 3G/4G enabled devices such as smartphones and tablets in large numbers has created increased demand for mobile data services. Wi-Fi offloading helps satisfy the requirements of data-rich applicatio... The rapid growth of 3G/4G enabled devices such as smartphones and tablets in large numbers has created increased demand for mobile data services. Wi-Fi offloading helps satisfy the requirements of data-rich applications and terminals with improved multi- media. Wi-Fi is an essential approach to alleviating mobile data traffic load on a cellular network because it provides extra capacity and improves overall performance. In this paper, we propose an integrated LTE/Wi-Fi architecture with software-defined networking (SDN) abstraction in mobile baekhaul and enhanced components that facilitate the move towards next-generation 5G mo- bile networks. Our proposed architecture enables programmable offloading policies that take into account real-time network conditions as well as the status of devices and applications. This mechanism improves overall network performance by deriving real- time policies and steering traffic between cellular and Wi-Fi networks more efficiently. 展开更多
关键词 mobile data offloading LTE/Wi-Fi interworking policy derivation network selection software-defined networking dynamic policies 5G mobile networks
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Addressing the Issues and Developments Correlated with Envisaged 5G Mobile Technologies: Comprehensive Solutions
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作者 Idrees Sarhan Kocher 《Computers, Materials & Continua》 SCIE EI 2023年第11期2205-2223,共19页
Fifth Generation(5G)communications are regarded as the cornerstone to household consumer experience improvements and smart manufacturing revolution from the standpoint of industries’objectives.It is anticipated that ... Fifth Generation(5G)communications are regarded as the cornerstone to household consumer experience improvements and smart manufacturing revolution from the standpoint of industries’objectives.It is anticipated that Envisaged 5G(E5G)mobile technology would be operational in certain developed countries by 2023.The Internet of Things(IoTs)will transform how humans live when combined with smart and integrated sensing devices,such as in-home sensing devices.Recent research is being carried out all over the world to produce a new technique that can be crucial in the success of the anticipated 5G mobile technology.High output,reduced latency,highly reliable,greater scalability,high performance,capacity,bandwidth efficiency,virtual open-air transmission,and efficient energy mobile wireless communications are all being investigated currently.In this work,a comprehensive path for addressing the difficulties and developments associated with 5G mobile technology is provided.The debate and description of a complete analysis of current situations,certain characteristics and prospective scenarios,important technologies,problems and advances,and spectrum allocation of envisioned 5G mobile technologies are provided.Furthermore,this paper analyzes the most notable elements of 5G mobile technology,such as Cognitive Radio(CR),flexibility,accessibility,and cloud-based service offers,which will assure 5G mobile technology’s dominance as the main protocol for international communication.Eventually,this paper provides a method for integrating CR with current wireless communication systems,the necessity for further evolution of the E5G network,and the need for comprehensive consideration of architecture evolution and function enhancement to enhance the E5G mobile technologies. 展开更多
关键词 E5G mobile technologies spectrum allocation pseudo outdoor communication key performance indicators cloudbased services efficient energy CR
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Zebrafish Cdh5 negatively regulates mobilization of aorta-gonad-mesonephros-derived hematopoietic stem cells
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作者 Ping Meng Yongxiang Liu +2 位作者 Xiaohui Chen Wenqing Zhang Yiyue Zhang 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2016年第10期613-616,共4页
Establishment of a hematopoietic stem cell(HSC)pool depends on the appropriate formation,maturation and mobilization of HSCs in vertebrates.In mice,the aorta-gonad-mesonephros(AGM)is a prominent site for the forma... Establishment of a hematopoietic stem cell(HSC)pool depends on the appropriate formation,maturation and mobilization of HSCs in vertebrates.In mice,the aorta-gonad-mesonephros(AGM)is a prominent site for the formation of definitive HSCs from endothelial cells,although the placenta and yolk sac also give rise to HSCs(Mikkola and Orkin,2006;Chen et al.,2009).After formation,AGM-derived HSCs migrate to the fetal liver(FL),and ultimately to the bone marrow (BM), two definitive hematopoietic organs (Cumano and Godin, 2007). 展开更多
关键词 AGM HSC Zebrafish Cdh5 negatively regulates mobilization of aorta-gonad-mesonephros-derived hematopoietic stem cells stem
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Research on Online Education Consumer Choice Behavior Path Based on Informatization
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作者 Yongrui Su Ling Zhao 《China Communications》 SCIE CSCD 2021年第10期233-252,共20页
The application of information and communications technology(ICT)in the education industry is becoming more and more extensive,and online education realized through ICT is developing in full swing.The influence of ICT... The application of information and communications technology(ICT)in the education industry is becoming more and more extensive,and online education realized through ICT is developing in full swing.The influence of ICT on online education consumer's choice behavior is the core issue of online education industry development research.The research on the interactive path and methods of information and online education consumer choice behavior is worth exploring and revealing.This study introduces the word-of-mouth factor as a new research variable under the framework of the Rational Choice Theory model(RCT)and the structural equation method to conduct empirical research and theoretical analysis to verify the validity of the hypothesis and model.The fifthGeneration mobile communication system(5 G)analyses the factors affecting online education consumer behavior choices based on the premise of ICT.Research on the path between ICT and choice behavior provides new ideas for online education consumer choice behavior research and ICT and content and provides a new scenario.This article is a cross-disciplinary research content in theory,and its innovation opens up a new path for the management of ICT research.The research results have innovative significance and value at both the theoretical and practical levels. 展开更多
关键词 information and communications technology(ICT) consumer choice behavior rational choice theory the fifth-Generation mobile communication system(5G) online education
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Compact 5G Vivaldi Tapered Slot Filtering Antenna with Enhanced Bandwidth
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作者 Sahar Saleh Mohd Haizal Jamaluddin +1 位作者 Bader Alali Ayman A.Althuwayb 《Computers, Materials & Continua》 SCIE EI 2023年第3期5983-5999,共17页
Compact fifth-generation(5G)low-frequency band filtering antennas(filtennas)with stable directive radiation patterns,improved bandwidth(BW),and gain are designed,fabricated,and tested in this research.The proposed fil... Compact fifth-generation(5G)low-frequency band filtering antennas(filtennas)with stable directive radiation patterns,improved bandwidth(BW),and gain are designed,fabricated,and tested in this research.The proposed filtennas are achieved by combining the predesigned compact 5G(5.975–7.125 GHz)third-order uniform and non-uniform transmission line hairpin bandpass filters(UTL and NTL HPBFs)with the compact ultrawide band Vivaldi tapered slot antenna(UWB VTSA)in one module.The objective of this integration is to enhance the performance of 5.975–7.125GHz filtennas which will be suitable for modern mobile communication applications by exploiting the benefits of UWB VTSA.Based on NTL HPBF,more space is provided to add the direct current(DC)biassing circuits in cognitive radio networks(CRNs)for frequency reconfigurable applications.To overcome the mismatch between HPBFs and VTSA,detailed parametric studies are presented.Computer simulation technology(CST)software is used for the simulation in this study.Good measured S11 appeared to be<−13 and<−10.54 dB at 5.48–7.73 and 5.9–7.98GHz with peak realized gains of 6.37 and 6.27 dBi,for VTSA with UTL and NTL HPBFs,respectively which outperforms the predesigned filters.Validation is carried out by comparing the measured and simulated results. 展开更多
关键词 Filtering antenna(filtenna) hairpin bandpass filters(HBPFs) vivaldi tapered slot filtering antenna(VTSFA) fifth generation(5G)mobile communication
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Application of 5G Mobile Communication Technology in Communication Engineering
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作者 TANG Qiwei 《外文科技期刊数据库(文摘版)工程技术》 2021年第9期555-558,共6页
With the rapid growth of mobile data traffic and the continuous expansion of various new services, 5G mobile communication technology aiming at meeting the wide application requirements of ultra-high service throughpu... With the rapid growth of mobile data traffic and the continuous expansion of various new services, 5G mobile communication technology aiming at meeting the wide application requirements of ultra-high service throughput has become a research hotspot. Full duplex communication technology can double the spectral efficiency. With the emergence of effective self-interference cancellation technology, full duplex technology is widely used. Non orthogonal multiple access technology allows multiple users to transmit information in the same time-frequency resources. Noma technology can simplify the access process and meet the low delay requirements of 5G network.5G technology has become the core technology of communication engineering construction, which can improve the transmission quality of communication engineering and provide strong support for intelligent communication. Affected by many factors, 5G technology is not ideal in communication engineering. In recent years, the expansion of domestic science and technology has continued to accelerate, and the world's development is moving towards intelligence. The application of 5G technology has effectively improved the speed of information and data transmission. 展开更多
关键词 5G mobile communication technology communication engineering APPLICATION
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澳门机动车排放清单 被引量:50
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作者 吴烨 郝吉明 +3 位作者 傅立新 胡京南 王志石 邓宇华 《清华大学学报(自然科学版)》 EI CAS CSCD 北大核心 2002年第12期1601-1604,共4页
建立机动车排放清单是实行机动车污染控制的基础。通过对澳门机动车保有量及其构成、车辆登记分布和累积里程分布的调查分析,获得了澳门机动车基本的运营特征参数。采用修正的MOBILE5模式和PART5模式,计算了澳门机动车排放的气态污染物... 建立机动车排放清单是实行机动车污染控制的基础。通过对澳门机动车保有量及其构成、车辆登记分布和累积里程分布的调查分析,获得了澳门机动车基本的运营特征参数。采用修正的MOBILE5模式和PART5模式,计算了澳门机动车排放的气态污染物和颗粒污染物的排放系数,并确定了澳门机动车污染物的排放总量和分车型的排放分担率。1999年澳门机动车CO,NOx,HC,PM10和PM2.5的总排放量分别为15852t,2416t,2449t,141t和128t。研究结果表明,控制摩托车和汽油轿车可以有效削减HC和CO的排放;而对于NOx和颗粒物,公共汽车和重型柴油车应是主要的控制车型。 展开更多
关键词 澳门 机动车 排放清单 空气污染物 排放系数 mobile5模式 PART5模式 排放总量
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