检索结果-南通市图书馆

Performance Study of MIMO-OSTBC Parallel Relay FSO System Based on GFDM

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年第2期33卷 564-572页

作者： Rui ZHOU yong WANG Yi WANG Key Laboratory of Electromagnetic Wave Information Technology and Metrology of Zhejiang Province College of Information Engineering China Jiliang University State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University

This paper investigates the performance of a new generalized frequency division multiplexing(GFDM)parallel relay free space optical(FSO) communication system using multi-input multi-output(MIMO) orthogonal space-time block codes(OSTBC) scheme. Under the M distribution atmospheric turbulence, taking into account the triple effects of irradiance, pointing errors and path loss, the mathematical expression of system symbol error rate is derived with the help of Meijer G-function. The symbol error performance of GFDM is compared with on-off keying,Gaussian minimum shift keying, polarization shift keying and orthogonal frequency division multiplexing(OFDM)modulation methods. The effects of the MIMO-OSTBC parallel relay scheme on the GFDM system including filter roll down coefficient, the number of transmitting and receiving antennas, the number of relays, normalized beamwidth and jitter variance are analyzed, and the numerical results are verified by Monte Carlo simulation. This work provides a good foundation for engineering applications.

关键词： Monte Carlo methods Transmitting antennas Symbols Receiving antennas Modulation Jitter Transceivers

B cell development and antibody responses in human immune system mice:current status and future perspective

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2024年第4期67卷 645-652页

作者： Tao Zhang Wentao Liu yong-Guang Yang Key Laboratory of Organ Regeneration&Transplantation of the Ministry of Education The First Hospital of Jilin UniversityChangchun 130061China National-Local Joint Engineering Laboratory of Animal Models for Human Diseases Jilin UniversityChangchun 130061China International Center of Future Science Jilin UniversityChangchun 130061China

Humanized immune system(HIS)mice have been developed and used as a small surrogate model to study human immune function under normal or disease *** variations are found between models,most HIS mice show robust human T cell ***,there has been unsuccessful in constructing HIS mice that produce high-affinity human antibodies,primarily due to defects in terminal B cell differentiation,antibody affinity maturation,and development of primary follicles and germinal *** this review,we elaborate on the current knowledge about and previous attempts to improve human B cell development in HIS mice,and propose a potential strategy for constructing HIS mice with improved humoral immunity by transplantation of human follicular dendritic cells(FDCs)to facilitate the development of secondary follicles.

关键词： humanized immune system mouse humoral immunity germinal center B cell follicular dendritic cell

Non-symmetric differentially subordinate martingales and sharp weak-type bounds for Fourier multipliers

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第8期67卷 1807-1826页

作者： Meryem Akboudj yong Jiao Adam Osękowski School of Mathematics and Statistics Hunan Key Laboratory of Analytical Mathematics and ApplicationsCentral South UniversityChangsha 410075China Faculty of Mathematics Informatics and MechanicsUniversity of WarsawWarsaw 02-097Poland

Let p>2 be a given *** this paper,we prove,with the best constant,the weak-type(p,p)inequality■for a large class of non-symmetric Fourier multipliers T_(m) obtained via modulation of jumps of certain Lévy *** particular,the estimate holds for appropriate linear combinations of second-order Riesz transforms and skew versions of the Beurling-Ahlfors operator on the complex *** proof rests on a novel probabilistic bound for Hilbert-space-valued martingales satisfying a certain non-symmetric subordination *** applications to harmonic functions and Riesz systems on Euclidean domains are indicated.

关键词： weak-type bound Fourier multiplier martingale differential subordination laminate

Engineering the Interface Between Au Nanoparticles and CoO-Ov to Enhance the Catalytic Performance of 5-Hydroxymethylfurfural(HMF)to 2,5-Dimethylfuran(DMF)

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2024年第1期40卷 47-54页

作者： XIANG Shuang GUO yong LIU Xiaohui WANG Yanqin Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterResearch Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237P.R.China

The interface between Au and support has attracted extensive interest because of its unique catalytic ability for hydrogen activation in catalytic hydrogenation/hydrogenolysis ***,we create the Au-CoO-OV interface in the 1.0%Au/Co3O4-Rod-250 catalyst,which could dissociate H2 via the heterolytic way to yield rich hydride species and achieve excellent catalytic performance in the hydrogenolysis of biomass-derived 5-hydroxymethylfurfural(HMF)to 2,5-dimethylfuran(DMF).The XRD and HRTEM analyses show that Au nanoparticles are uniformly dispersed on CoO-OV surface and in situ DRIFTS spectra show the enhancement of heterolytic dissociation of hydrogen(signals of Au-D and O-D vibration)compared with bare CoO(Co3O4-Rod-250).This work provides insights for fabricating highly active Au-support catalysts for catalytic hydrogenation/hydrogenolysis reactions.

关键词： Au-CoO-OV interface Hydride species Heterolytic dissociation 5-Hydroxymethylfurfural(HMF) 2 5-Dimethylfuran(DMF)

Air purifier or fresh air system?A comparison of energy consumption and cost in urban China residential buildings

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第9期67卷 2637-2647页

作者： GUO yong SUN ZhiWei WESCHLER Louise B ZHANG YinPing Department of Building Science Tsinghua UniversityBeijing 100084China Beijing Key Laboratory of Indoor Air Quality Evaluation and Control Beijing 100084China Independent Researcher Colts Neck 07722NJUSA

Chinese urban residential buildings face serious indoor air quality *** purification systems(e.g.,air purifiers,fresh air systems)that supply fresh air or purify indoor air are widely used in residential buildings to improve indoor air *** the challenges of energy conservation and emission reduction,it is urgent to guide residents on choosing appropriate air purification *** key problem is how to identify the best air purification system with the lowest energy consumption or operating *** of air purification systems have rarely been conducted on the premise that they should deliver air such that the main indoor pollutant concentrations all meet air quality *** ignored in comparisons are the increased filtration resistance caused by dust accumulation on the filter and the cost of filter *** this study,we propose a method to compare residential air purification systems based on energy consumption and total cost,and we provide methods to select air purification systems in China's different climatic *** used a standard two-person bedroom as the example,and determined the most suitable(minimum cost or energy consumption)air purification systems for the capital cities of the provinces in Chinese mainland.

关键词： IAQ fresh air system air purifier energy consumption cost

Evolutionary Multi/Many-Objective Optimisation via Bilevel Decomposition

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 1973-1986页

作者： Shouyong Jiang Jinglei Guo yong Wang Shengxiang Yang School of Automation Central South UniversityChangsha 410083China Department of Computing Science University of AberdeenAberdeen AB243FXUK School of Computer Science Central China Normal UniversityWuhan 430079China School of Computer Science and Informatics De Montfort UniversityLeicester LE19BHUK

Decomposition of a complex multi-objective optimisation problem(MOP)to multiple simple subMOPs,known as M2M for short,is an effective approach to multi-objective ***,M2M facilitates little communication/collaboration between subMOPs,which limits its use in complex optimisation *** paper extends the M2M framework to develop a unified algorithm for both multi-objective and manyobjective *** bilevel decomposition,an MOP is divided into multiple subMOPs at upper level,each of which is further divided into a number of single-objective subproblems at lower *** subMOPs are allowed to share some subproblems so that the knowledge gained from solving one subMOP can be transferred to another,and eventually to all the *** bilevel decomposition is readily combined with some new mating selection and population update strategies,leading to a high-performance algorithm that competes effectively against a number of state-of-the-arts studied in this paper for both multiand many-objective *** analysis and component analysis have been also carried out to further justify the proposed algorithm.

关键词： Bilevel decomposition evolutionary algorithm many-objective optimisation multi-objective optimisation

Resource Allocation for Cognitive Network Slicing in PD-SCMA System Based on Two-Way Deep Reinforcement Learning

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第6期21卷 53-68页

作者： Zhang Zhenyu Zhang yong Yuan Siyu Cheng Zhenjie School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Beijing Key Laboratory of Work Safety Intelligent Monitoring(Beijing University of Posts and Telecommunications) Beijing 100876China

In this paper,we propose the Two-way Deep Reinforcement Learning(DRL)-Based resource allocation algorithm,which solves the problem of resource allocation in the cognitive downlink network based on the underlay *** users(SUs)in the cognitive network are multiplexed by a new Power Domain Sparse Code Multiple Access(PD-SCMA)scheme,and the physical resources of the cognitive base station are virtualized into two types of slices:enhanced mobile broadband(eMBB)slice and ultrareliable low latency communication(URLLC)*** design the Double Deep Q Network(DDQN)network output the optimal codebook assignment scheme and simultaneously use the Deep Deterministic Policy Gradient(DDPG)network output the optimal power allocation *** objective is to jointly optimize the spectral efficiency of the system and the Quality of Service(QoS)of *** results show that the proposed algorithm outperforms the CNDDQN algorithm and modified JEERA algorithm in terms of spectral efficiency and QoS ***,compared with the Power Domain Non-orthogonal Multiple Access(PD-NOMA)slices and the Sparse Code Multiple Access(SCMA)slices,the PD-SCMA slices can dramatically enhance spectral efficiency and increase the number of accessible users.

关键词： cognitive radio deep reinforcement learning network slicing power-domain non-orthogonal multiple access resource allocation

In situ crosslink polymerization induced long-lived multicolor supramolecular hydrogel based on modifiedβ-cyclodextrin

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第2期35卷 374-379页

作者： yonghui Sun Linnan Jiang yong Chen Yu Liu College of Chemistry State Key Laboratory of Elemento-Organic Chemistry Nankai UniversityTianjin 300071China

The construction of hydrogels with good mechanical properties and phosphorescent properties is full of ***,we report a supramolecular phosphorescent hydrogel with long lifetime,high tensile strength and self-healing property,which can be easily constructed through in-situ thermalinitiated polymerization of isocyanatoethyl acrylate-modifiedβ-cyclodextrin(β-CD-DA)and acrylatemodified adamantane(Ad-DA),acrylic acid(AA),followed by the non-covalent association with carbon dots(CNDs).The lifetime of phosphorescent hydrogel can reach 1261 ms at room temperature,and the quantum yield is 11%.Importantly,through the efficient triplet to singlet Förster resonance energy transfer(TS-FRET),the phosphorescent hydrogel shows the good phosphorescence energy transfer property for organic dyes Rhodamine B and Eosin Y with the delayed fluorescence lifetime up to 730 ms and 585 ms as well as the energy transfer efficiency(Φ_(ET))up to 99.9%and 99.3%,***,owing to the host-guest interactions betweenβ-CD-DA and Ad-DA,the three-dimensional cross-linked network phosphorescent hydrogel can be easily stretched to 18 times of its original length,and can achieve self-healing of the cut surfaces within 30 *** results will expand the scope of phosphorescent materials and provide new ideas and opportunities for materials science.

关键词： Room temperature phosphorescence Hydrogel Phosphorescence energy transfer Cyclodextrin Supramolecular interaction

Empirical likelihood for spatial cross-sectional data models with matrix exponential spatial specification

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 125-139页

作者： LIU Yan RONG Jian-rong QIN yong-song Nanning University Nanning 530200China Center for Applied Mathematics of Guangxi and College of Mathematics and Statistics Guangxi Normal UniversityGuilin 541004China

In this paper,we study spatial cross-sectional data models in the form of matrix exponential spatial specification(MESS),where MESS appears in both dependent and error *** empirical likelihood(EL)ratio statistics are established for the parameters of the MESS *** is shown that the limiting distributions of EL ratio statistics follow chi-square distributions,which are used to construct the confidence regions of model *** experiments are conducted to compare the performances of confidence regions based on EL method and normal approximation method.

关键词： MESS empirical likelihood con dence region