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Low complexity bit loading algorithm for OFDM system

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Journal of systems Engineering and Electronics 2006年第1期17卷 71-74页

作者： Yang Yu sha xuejun Zhang Zhonghua national Key Laboratory of Tunable Laser Technology Harbin Inst. of Technology Harbin 150001 P. R. China Communication Research Center Harbin Inst. of Technology Harbin 150001 P. R. China

A new approach to loading for orthogonal frequency division multiplexing （OFDM） system is proposed, this bit-loading algorithm assigns bits to different subchannels in order to minimize the transmit energy. In the algorithm, first most bit are allocated to each subchannels according to channel condition, shannon formula and Qos require of the user, then the residual bit are allocated to the subchannels bit by bit. In this way the algorithm is efficient while calculation is less complex. This is the first time to load bits with the scale following shannon formula and the algorithm is of O （4 n） complexity.

关键词： OFDM bit loading shannon formula Qos

GLEAs.n's PROBLEM On THE sPACE F^(p,q,s)(B) In C^(n)

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Acta Mathematica scientia 2022年第5期42卷 1971-1980页

作者： Pengcheng TAnG xuejun ZHAnG College of Mathematics and statistics Hunan Normal UniversityChangsha 410081China

Let Ω be a domain in C^(n) and let Y be a function space on Ω.If a∈Ω and g∈Y with g(a)=0,do there exist functions f_(1),f_(2),…,f_(n)∈Y such that g(z)=∑_(l=1)^(n)(z_(l)−a_(l))f_(l)(z)for all z=(z_(1),z_(2),…,z_(n))∈Ω?This is Gleas.n’s *** this paper,we prove that Gleas.n’s problem is solvable on the boundary general function space F^(p,q,s)(B)in the unit ball B of C^(n).

关键词： oundary general function space Gleas.n's problem solvability unit ball

Green ionic metal-organic frameworks as.nanocatalysts for CO_(2)fixation

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nano Research 2025年第1期18卷 260-269页

作者： nuria Martín Miguel Maireles-Porcar Julián s.nchez Velandia Belén Altava Francisco G.Cirujano Eduardo García-Verdugo Departamento de Química Inorgánica y Orgánica Universidad Jaume IAv.Sos Baynats/nCastellóde la PlanaCastellón 12071Spain

Co,ni,and Zn iso-reticular coordination polymers of 2,5-dihydroxyterphthalic acid(H_(2)dot)can be rapidly obtained under room temperature and aqueous conditions us.ng either sodium or ammonium hydroxide as the bases to deprotonate the *** use of metal bromides and tetrabutylammonium hydroxide(TBAOH)as the base allows the green s.nthesis of ionic metal-organic frameworks(MOFs),characterized by X-ray diffraction(XRD),Fourier transform infrared(FTIR),scanning electron microscopy(sEM),thermo gravimetric analysis(TGA),H-nuclear magnetic res.nance(nMR),elemental analysis,and X-ray photoelectron spectroscopy(XPs),and employed in the pressure,solvent,and additive-free CO_(2)fixation to epoxides by its cycloaddition to epichlorohydrin,exhibiting a cooperative behavior between the MOF and the ionic liquid formed within the framework,achieving TOns of the confined tetrabutylammonium bromide(TBABr)up to 700.

关键词： metal-organic frameworks(MOFs) ionic liquids heterogeneous catalysis CO_(2)conversion

Us.ng the EMD Method to Determine Fault Criterion for Medium-low Pressure Gas Regulators

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Journal of Thermal science 2015年第6期24卷 557-561页

作者： HAO xuejun LIU Qiang YAnG Guobin DU Yi Beijing University of Civil Engineering and Architecture

By extracting the outlet pressure data of gas regulators,this paper uses the EMD toolbox of the MATLAB software,which can perform data decomposition and the Hilbert-Huang Transform to find the rules with fault ***,the... 详细信息

关键词： medium-low pressure gas regulator EMD decomposition fault criterion

The Coupling Relationships and Influence Mechanisms of Green Credit and Energy-Environment-Economy Under China’s Goal of Carbon neutrality

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Journal of systems science & Complexity 2023年第1期36卷 360-374页

作者： CHAI Jian WAnG Yabo HU Yi ZHAnG xuejun ZHAnG Xiaokong school of Economics and Management Xidian UniversityXi’an 710126China school of Economics and Management University of Chinese Academy of SciencesBeijing 100190China

Under the goal of carbon neutrality,it is critical for China to give full play to the role of green credit,and promote the coordinated development of energy-environment-economy(3E)*** on the data of China from 2000 to 2020,the authors build the environmental pollution index,energy transformation index and high-quality economic development *** us.ng Bayesian network model(Bn),the authors investigate the coupling relationships and influence mechanisms of green credit and 3E *** results show that the main cause of environmental pollution is the annual increase of carbon dioxide *** credit can reduce carbon emissions to a certain extent,and alleviate environmental pollution through energy structure,technological progress and per capita *** energy utilization and per capita GDP growth also help to control environmental *** credit can stimulate technological progress and accelerate energy transformation together with technological *** energy utilization can facilitate the upgrading of industrial structure,industrial structure upgrading and green credit can restrict the level of opening *** progress promotes per capita GDP *** capita GDP growth can reduce energy intensity and improve urbanization and per capita energy consumption.

关键词： Bayesian network carbon neutrality coupling nexus energy-environment-economy green credit

Ultras.nsitive detection of methamphetamine by antibody-modified transistor assay

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Journal of semiconductors 2023年第2期44卷 77-83页

作者： Banpeng Cao Changhao Dai xuejun Wang Dacheng Wei Jiangxi Key Laboratory of Organic Chemistry Jiangxi Science and Technology Normal UniversityNanchang 330013China state Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200433China

Effective detection of methamphetamine(Met)requires a fast,s.nsitive,and cheap testing ***,commercially available methods require expensive instruments and highly trained operators,which are time-consuming and ***,an antibody-modified graphene transistor assay is developed for s.nsitive and minute-level detection of Met in complex *** anti-Met probe captured charged targets within 120 s,leading to a p-doping effect near the graphene *** limit of detection reaches 50 aM(5.0×10^(-17)M)Met in *** graphene transistor would be a valuable tool for Met detection effective prevention of drug abuse.

关键词： graphene field effect transistor bios.nsor methamphetamine antibody immobilization

Linear network Coding Based Fast Data s.nchronization for Wireless Ad Hoc networks with Controlled Topology

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China Communications 2022年第5期19卷 46-53页

作者： Die Hu xuejun Zhu Min Gong shaoshi Yang school of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China China Academy of Launch Vehicle Technology Beijing 100076China Key Laboratory of Universal Wireless Communications Ministry of EducationBeijing 100876China

Fast data s.nchronization in wireless ad hoc networks is a challenging and critical *** is fundamental for efficient information fusion,control and decision in distributed ***,distributed data s.nchronization was mainly studied in the latency-tolerant distributed databases,or assuming the general model of wireless ad hoc *** this paper,we propose a pair of linear network coding(nC)and all-to-all broadcast based fast data s.nchronization algorithms for wireless ad hoc networks whose topology is under operator’s *** consider both data block selection and transmitting node selection for exploiting the benefits of *** of us.ng the store-and-forward protocol as in the conventional uncoded approach,a compute-and-forward protocol is used in our scheme,which improves the transmission *** performance of the proposed algorithms is studied under different values of network size,network connection degree,and per-hop packet error *** results demonstrate that our algorithms significantly reduce the times slots used for data s.nchronization compared with the baseline that does.not use nC.

关键词： all-to-all broadcast data s.nchronization distributed system network coding wireless ad hoc network UAV

Analysis on the Mutation and Time-Varying Characteristics of Coal Price system Evolution from the Perspective of Finance

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Journal of systems science & Complexity 2021年第4期34卷 1501-1521页

作者： CHAI Jian LEI Junchan sHI Huiting ZHAnG xuejun LAnG Meiling school of Economics and Management Xidian UniversityXi'an 710126China

Coal is ess.ntial to ensure China’s energy *** sudden or gradual change of coal price reflects the degree of disequilibrium or expected disequilibrium of coal supply and demand,which will not be conducive to energy ***,it is important to analyze the change points of coal price and explore the reas.n of the price *** paper analyses the coal price from January2008 to June 2019 as the perspective of the financial ***,the PPM-DBsCAn model is used to identify the mutation point of coal price ***,path analysis is used to extract the core driving factors that affect coal ***,the authors construct a time-varying and time-lag effect analysis model for structural changes of coal price based on the TVP-VAR *** results show that there are 11 mutation points of coal price *** market factors,coal supply and demand and alternative factors are the reas.ns of coal price *** authors find that the imbalance of coal supply and demand in traditional view cannot fully explain the fluctuation of coal *** impact of the financial market and non-thermal power generation have more influence on the coal price.

关键词： Coal price financial market mutation

Direct model reference adaptive control us.ng K_p = LDU factorization for multivariable discrete-time plants

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控制理论与应用（英文版） 2008年第4期6卷 392-398页

作者： Junling LI xuejun XIE Wei CHEn Institute of Automation Qufu Normal University Qufu Shandong 273165 China

For a large class of discrete-time multivariable plants with arbitrary relative degrees, the design and analysis of the direct model reference adaptive control scheme are investigated under less restrictive assumptions. The algorithm is based on a new parametrization derived from the high frequency gain matrix factorization Kp=LDU under the condition that the signs of the leading principal minors of/fp are known. By reproving the discrete-time Lp and L2σ norm relationship between inputs and outputs, establishing the properties of discrete-time adaptive law, defining the normalizing signal, and relating the signal with all signals in the closed-loop system, the stability and convergence of the discrete-time multivariable model reference adaptive control scheme are analyzed rigorously in a systematic fashion as in the continuous-time case.

关键词： Discrete-time systems swapping lemma L2σ-nonn normalizing signal Model reference adaptive control