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Design and Analysis of Spatial Modulation Based Orthogonal Time Frequency Space System 被引量:4
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作者 Yingchao Yang Zhiquan Bai +4 位作者 Ke Pang Piming Ma Haixia Zhang Xinghai Yang Dongfeng Yuan 《China Communications》 SCIE CSCD 2021年第8期209-223,共15页
In this paper,we design a spatial modulation based orthogonal time frequency space(SMOTFS)system to achieve improved transmission reliability and meet the high transmission rate and highspeed demands of future mobile ... In this paper,we design a spatial modulation based orthogonal time frequency space(SMOTFS)system to achieve improved transmission reliability and meet the high transmission rate and highspeed demands of future mobile communications,which fully utilizes the characteristics of spatial modulation(SM)and orthogonal time frequency space(OTFS)transmission.The detailed system design and signal processing of the SM-OTFS system have been presented.The closed-form expressions of the average symbol error rate(ASER)and average bit error rate(ABER)of the SM-OTFS system have been derived over the delay-Doppler channel with the help of the union bounding technique and moment-generating function(MGF).Meanwhile,the system complexity has been evaluated.Numerical results verify the correctness of the theoretical ASER and ABER analysis of the SM-OTFS system in the high signal-to-noise ratio(SNR)regions and also show that the SM-OTFS system outperforms the traditional SM based orthogonal frequency division multiplexing(SM-OFDM)system with limited complexity increase under mobile conditions,especially in high mobility scenarios. 展开更多
关键词 orthogonal time frequency space(OTFS) spatial modulation based OTFS(SM-OTFS) delay-Doppler domain average symbol error rate(ASER) average bit error rate(ABER)
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Deep Reinforcement Learning Based Joint Partial Computation Offloading and Resource Allocation in Mobility-Aware MEC System 被引量:3
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作者 Luyao Wang Guanglin Zhang 《China Communications》 SCIE CSCD 2022年第8期85-99,共15页
Mobile edge computing(MEC)emerges as a paradigm to free mobile devices(MDs)from increasingly dense computing workloads in 6G networks.The quality of computing experience can be greatly improved by offloading computing... Mobile edge computing(MEC)emerges as a paradigm to free mobile devices(MDs)from increasingly dense computing workloads in 6G networks.The quality of computing experience can be greatly improved by offloading computing tasks from MDs to MEC servers.Renewable energy harvested by energy harvesting equipments(EHQs)is considered as a promising power supply for users to process and offload tasks.In this paper,we apply the uniform mobility model of MDs to derive a more realistic wireless channel model in a multi-user MEC system with batteries as EHQs to harvest and storage energy.We investigate an optimization problem of the weighted sum of delay cost and energy cost of MDs in the MEC system.We propose an effective joint partial computation offloading and resource allocation(CORA)algorithm which is based on deep reinforcement learning(DRL)to obtain the optimal scheduling without prior knowledge of task arrival,renewable energy arrival as well as channel condition.The simulation results verify the efficiency of the proposed algorithm,which undoubtedly minimizes the cost of MDs compared with other benchmarks. 展开更多
关键词 mobile edge computing energy harvesting device-mobility partial computation offloading resource allocation deep reinforcement learning
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Genome-wide identification and characterization of WUSCHEL-related homeobox(WOX) genes in Salix suchowensis 被引量:3
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作者 Xuelin Wang Changwei Bi +3 位作者 Chunyan Wang Qiaolin Ye Tongming Yin Ning Ye 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第5期1811-1822,共12页
Members of the WUSCHEL-related homeobox(WOX)transcription factor family are essential for determining cell fate and regulating diverse developmental processes in plants.Many WOX genes have been systematically investig... Members of the WUSCHEL-related homeobox(WOX)transcription factor family are essential for determining cell fate and regulating diverse developmental processes in plants.Many WOX genes have been systematically investigated in woody plants such as Populus trichocarpa,but not in Salix suchowensis.Whole-genome sequence data for S.suchowensis is now available for comprehensive study of WOX genes in S.suchowensis.We thus surveyed the genome of S.suchowensis and demonstrated active expression of 15 WOX genes.In a phylogenetic analysis of WOX genes,the 15 SsWOX genes clustered among the modern/WUS,intermediate and ancient clades similar to the WOX genes of Arabidopsis thaliana.Based on the conserved intron/exon structure,SsWOX genes in the same subgroup had similar conserved exon–intron structures and motif domains.Furthermore,among several SsWOX subgroups,WUS(Wuschel)-box and EAR(the ERF-associated amphiphilic repression)-like motifs were conserved.Expression profiles of WOX genes in roots,stems and leaves indicate that SsWOX genes have various conserved roles in the tissues.Comparative analysis of the expression patterns in Salix suchowensis with that of Arabidopsis suggests that different shoot regeneration abilities are controlled by different WOX genes in plants.The analysis provide an overview of differentially expressed SsWOX genes during shoot regeneration,but also contribute to understanding the evolution of WOX genes in Salicaceae and the interrelations of WOX genes and other transcription factors,providing targets for further study. 展开更多
关键词 WOX family SALICACEAE Expression Evolution DUPLICATION
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An Algorithm of the Adaptive Grid and Fuzzy Interacting Multiple Model 被引量:3
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作者 Yuan Zhang Chen Guo +2 位作者 Hai Hu Shubo Liu Junbo Chu 《Journal of Marine Science and Application》 2014年第3期340-345,共6页
This paper studies the algorithm of the adaptive grid and fuzzy interacting multiple model (AGFIMM) for maneuvering target tracking, while focusing on the problems of the fixed structure multiple model (FSMM) algo... This paper studies the algorithm of the adaptive grid and fuzzy interacting multiple model (AGFIMM) for maneuvering target tracking, while focusing on the problems of the fixed structure multiple model (FSMM) algorithm's cost-efficiency ratio being not high and the Markov transition probability of the interacting multiple model (IMM) algorithm being difficult to determine exactly. This algorithm realizes the adaptive model set by adaptive grid adjustment, and obtains each model matching degree in the model set by fuzzy logic inference. The simulation results show that the AGFIMM algorithm can effectively improve the accuracy and cost-efficiency ratio of the multiple model algorithm, and as a result is suitable for enineering apolications. 展开更多
关键词 maneuvering target tracking adaptive grid fuzzy logicinference variable structure multiple model adaptive grid andfuzzy interacting multiple model (AGFIMM) interacting multiplemodel (IMM)
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GLOBAL EXISTENCE AND EXPONENTIAL STABILITY OF SOLUTIONS TO THE QUASILINEAR THERMO-DIFFUSION EQUATIONS WITH SECOND SOUND 被引量:2
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作者 秦玉明 李海燕 《Acta Mathematica Scientia》 SCIE CSCD 2014年第3期759-778,共20页
This article is devoted to the study of global existence and exponential stability of solutions to an initial-boundary value problem of the quasilinear thermo-diffusion equations with second sound by means of multipli... This article is devoted to the study of global existence and exponential stability of solutions to an initial-boundary value problem of the quasilinear thermo-diffusion equations with second sound by means of multiplicative techniques and energy method provided that the initial data are close to the equilibrium and the relaxation kernel is strongly positive definite and decays exponentially. 展开更多
关键词 Thermo-diffusion equations global existence exponential stability second sound multiplicative techniques
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Optimal capacity planning of combined renewable energy source-pumped storage and seawater desalination systems 被引量:4
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作者 Boyu Liu Bowen Zhou +2 位作者 Dongsheng Yang Zhile Yang Mingjian Cui 《Global Energy Interconnection》 2019年第4期310-317,共8页
As water scarcity is becoming a growing threat to human development, finding effective solutions has become an urgent need. To make better use of water resources, seawater desalination and storage systems using renewa... As water scarcity is becoming a growing threat to human development, finding effective solutions has become an urgent need. To make better use of water resources, seawater desalination and storage systems using renewable energy sources(RES) are designed and implemented around the world. In this paper, an optimal capacity planning method for RES-pumped storage-seawater desalination(RES-PS-D) system is introduced. The configuration of the RES-PS-D system is clarified first, after which a cost-benefit analysis is performed using all cost and benefit components. A function for determining maximum economic benefits of the RES-PS-D system is then established, and the constraints are proposed based on various limitations. The mixed-integer linear programming algorithm is applied to solve the optimal function. A case study is introduced to validate the feasibility and effectiveness of the method. The conclusion shows that the strategy is suitable for solving the configuration optimization problem, and finally both merits and defects of the method are discussed. 展开更多
关键词 RENEWABLE energy source Seawater DESALINATION PUMPED storage MAXIMUM ECONOMIC BENEFIT
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Finite-difference time-domain studies of low-frequency stop band in superconductor-dielectric superlattice 被引量:1
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作者 王身云 刘少斌 Le-Wei Joshua Li 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第8期374-378,共5页
The transmission coefficients of electromagnetic (EM) waves due to a superconductor-dielectric superlattice are numerically calculated. Shift operator finite difference time domain (SO-FDTD) method is used in the ... The transmission coefficients of electromagnetic (EM) waves due to a superconductor-dielectric superlattice are numerically calculated. Shift operator finite difference time domain (SO-FDTD) method is used in the analysis. By using the SO-FDTD method, the transmission spectrum is obtained and its characteristics are investigated for different thicknesses of superconductor layers and dielectric layers, from which a stop band starting from zero frequency can be apparently observed. The relation between this low-frequency stop band and relative temperature, and also the London penetration depth at a superconductor temperature of zero degree are discussed, separately. The low-frequency stop band properties of superconductor-dielectric superlattice thus are well disclosed. 展开更多
关键词 shift operator finite difference time domain method SUPERCONDUCTOR superconductor- dielectric superlattice high-pass filter
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Review on engineering two-dimensional nanomaterials for promoting efficiency and stability of perovskite solar cells 被引量:1
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作者 Qingwei Zhou Jialong Duan +1 位作者 Yanyan Duan Qunwei Tang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第5期154-175,共22页
Perovskite solar cell(PSC) has gradually shown its great superiority in photovoltaic filed to compete commercial solar cells owing to its great advantages, such as high efficiency and low fabrication cost. On the way ... Perovskite solar cell(PSC) has gradually shown its great superiority in photovoltaic filed to compete commercial solar cells owing to its great advantages, such as high efficiency and low fabrication cost. On the way towards commercialization, great efforts have been achieved by accelerating charge extraction and reducing carrier recombination. Recently, two-dimensional(2 D) layered materials have attracted increasing interests for application in PSCs due to their distinctive chemical and physical properties, such as high carrier mobility and tunable bandgap, which greatly determines the perovskite film growth kinetics, carrier transfer and stability of PSCs. Therefore, with the aim to better understand their recent development and application in PSC, in this review, the emerging 2D materials beyond graphene as charge transport layers, buffer layers and additives in perovskite film for enhancing the efficiency and stability of PSCs are summarized. However, there are still some crucial challenges to be addressed for commercialization. Finally, the challenges and prospects of these 2D nanomaterials for application in PSCs are further proposed for future development. 展开更多
关键词 Perovskite solar cells 2D materials Interface engineering Charge transfer STABILITY
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A Remark on Global Existence,Uniqueness and Exponential Stability of Solutions for the 1D Navier-Stokes-Korteweg Equations 被引量:1
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作者 ZHANG Jian-lin CAO Jie SU Xing 《Chinese Quarterly Journal of Mathematics》 2016年第1期27-38,共12页
In this paper, we investigate non-isothermal one-dimensional model of capillary compressible fluids as derived by M Slemrod(1984) and J E Dunn and J Serrin(1985). We establish the existence, uniqueness and exponential... In this paper, we investigate non-isothermal one-dimensional model of capillary compressible fluids as derived by M Slemrod(1984) and J E Dunn and J Serrin(1985). We establish the existence, uniqueness and exponential stability of global solutions in H^2×H^1× H^1 for the one-dimensional Navier-Stokes-Korteweg equations by a priori estimates,which implies the existence and exponential stability of the nonlinear C_0-semigroups S(t) on H^2× H^1× H^1. 展开更多
关键词 Navier-Stokes equations CAPILLARITY Korteweg stress tensor
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TESTING OF CORRELATION AND HETEROSCEDASTICITY IN NONLINEAR REGRESSION MODELS WITH DBL(p,q,1) RANDOM ERRORS
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作者 刘应安 韦博成 《Acta Mathematica Scientia》 SCIE CSCD 2008年第3期613-632,共20页
Chaos theory has taught us that a system which has both nonlinearity and random input will most likely produce irregular data. If random errors are irregular data, then random error process will raise nonlinearity (K... Chaos theory has taught us that a system which has both nonlinearity and random input will most likely produce irregular data. If random errors are irregular data, then random error process will raise nonlinearity (Kantz and Schreiber (1997)). Tsai (1986) introduced a composite test for autocorrelation and heteroscedasticity in linear models with AR(1) errors. Liu (2003) introduced a composite test for correlation and heteroscedasticity in nonlinear models with DBL(p, 0, 1) errors. Therefore, the important problems in regression model axe detections of bilinearity, correlation and heteroscedasticity. In this article, the authors discuss more general case of nonlinear models with DBL(p, q, 1) random errors by score test. Several statistics for the test of bilinearity, correlation, and heteroscedasticity are obtained, and expressed in simple matrix formulas. The results of regression models with linear errors are extended to those with bilinear errors. The simulation study is carried out to investigate the powers of the test statistics. All results of this article extend and develop results of Tsai (1986), Wei, et al (1995), and Liu, et al (2003). 展开更多
关键词 DBL(p Q 1) random errors nonlinear regression models score test HETEROSCEDASTICITY CORRELATION
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Homogenizing the sulfonic acid distribution of DMF-modified PEDOT:PSS films and perovskite solar cells
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作者 Hongliang Li Cuiling Zhang +3 位作者 Yunping Ma Zhiqiang Li Ying Xu Yaohua Mai 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第5期71-77,共7页
Inverted perovskite solar cells using pristine PEDOT:PSS as the hole-transporting layer (HTL) have been widely studied for its less hysteresis and low-temperature preparation technologies. However, this device suffers... Inverted perovskite solar cells using pristine PEDOT:PSS as the hole-transporting layer (HTL) have been widely studied for its less hysteresis and low-temperature preparation technologies. However, this device suffers from an inferior open-circuit voltage (VOC) and stability problems. Several attempts have made on film formation and interface engineering to improve the efficiency. Modification proved beneficial to decrease energy offset at the interface between the HTL layer and the adjacent perovskite layer. In this paper, modification PEDOT:PSS layers were realized with a dimethyl formamide (DMF) solvent. The sulfonic acid distribution was homogenized in the normal directi on after modification. The work function of the modified PEDOT:PSS layers increased from 4.71 to 5.07eV, and the conductivity of modified PEDOT:PSS increased from 3×10^-4 to 0.45 S/cm. The as-deposited perovskite films were more uniform with larger grain sizes and less pinholes, resulting in an improved VOC from 0.93 to 1.048 V, while the efficiency was increased from 11.5% to 16.8%. Solar cells without encapsulation under the 50 h and 50% humidity aging test showed 7% degradation of fill factor (FF) with 50 v/v% PEDOT:PSS layer, while the fill factor decreased 11.2% in the 0 v/v% PEDOT:PSS layer, respectively. 展开更多
关键词 MODIFICATION HYSTERESIS INVERTED PEROVSKITE solar cells (PSCs)
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Assembly and analysis of the Populus deltoides mitochondrial genome:the first report of a multicircular mitochondrial conformation for the genus Populus
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作者 Yanshu Qu Pengyan Zhou +2 位作者 Chunfa Tong Changwei Bi Li’an Xu 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第3期717-733,共17页
Genomics research of Populus deltoides,an important timber species that is widely planted worldwide,is an important part of poplar breeding.Currently,the nuclear and chloroplast genome of P.deltoides have been sequenc... Genomics research of Populus deltoides,an important timber species that is widely planted worldwide,is an important part of poplar breeding.Currently,the nuclear and chloroplast genome of P.deltoides have been sequenced,but its mitochondrial genome(mitogenome)has not been reported.To further explore the evolution and phylogeny of P.deltoides,the mitogenome of P.deltoides I-69 was assembled using reads from Nanopore and Illumina sequencing platforms and found to consist of 802,637 bp and three circular chromosomes(336,205,280,841,and 185,591 bp)containing 58 genes(34 protein-coding genes,21 tRNA genes,and 3 rRNA genes).RNA analysis in combination with several species showed signifi cantly fewer RNA editingsites in the mitogenomes of poplar and other angiosperms than in gymnosperms.Sequence transfer analysis showed extensive mitogenome rearrangements in Populus species,and with evolution from lower to higher plants,tRNA transfer from chloroplasts to mitochondria became increasingly frequent.In a phylogenetic analysis,the evolutionary status of P.deltoides was determined,and the section Populus was supported.Our results based on the fi rst report of a multicircular conformation of the Populus mitogenome provide a basis for further study of the evolution and genetics of P.deltoides and other Populus species and for breeding programs. 展开更多
关键词 Mitochondrial genome Multi-circular Populus deltoids Comparative genomics PHYLOGENY
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Transparent and Ultra-lightweight Design for Ultra-Broadband Asymmetric Transmission of Airborne Sound 被引量:1
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作者 Jie Hu Bin Liang Xiao-Jun Qiu 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第2期34-37,共4页
Acoustic one-way manipulations have recently attracted significant attention due to the deep implications in many diverse fields such as biomedical imaging and treatment.However,the previous mechanisms of asymmetric m... Acoustic one-way manipulations have recently attracted significant attention due to the deep implications in many diverse fields such as biomedical imaging and treatment.However,the previous mechanisms of asymmetric manipulation of airborne sound need to use elaborate heavyweight structures and only work in certain frequency ranges.We propose a mechanism for designing an ultra-lightweight and optically transparent structure with asymmetric transmission property for normally incident plane waves.Instead of fabricating solids into complicated artificial structures with limited bandwidth and heavy asymmetric shape which allows the incident plane wave weight,we simply use xenon to fill a spatial region of to pass along one direction while reflecting the reversed wave regardless of frequency.We demonstrate both analytically and numerically its effectiveness of producing highly-asymmetric transmission within an ultra-broad band.Our design offers new possibility for the design of one-way devices and may have far-reaching impact on various scenarios such as noise control. 展开更多
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Robust Synchronization in an E/I Network with Medium Synaptic Delay and High Level of Heterogeneity
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作者 韩芳 王直杰 +1 位作者 范宏 龚涛 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第4期25-28,共4页
It is known that both excitatory and inhibitory neuronal networks can achieve robust synchronization only under certain conditions, such as long synaptic delay or low level of heterogeneity. In this work, robust synch... It is known that both excitatory and inhibitory neuronal networks can achieve robust synchronization only under certain conditions, such as long synaptic delay or low level of heterogeneity. In this work, robust synchronization can be found in an excitatory/inhibitory (E/I) neuronal network with medium synaptie delay and high level of heterogeneity, which often occurs in real neuronal networks. Two effects of post-synaptic potentials (PSP) to network synchronization are presented, and the synaptic contribution of excitatory and inhibitory neurons to robust synchronization in this E/I network is investigated. It is found that both excitatory and inhibitory neurons may contribute to robust synchronization in E/I networks, especially the excitatory PSP has a more positive effect on synchronization in E/I networks than that in excitatory networks. This may explain the strong robustness of synchronization in Eli neuronal networks. 展开更多
关键词 PSP Robust Synchronization in an E/I Network with Medium Synaptic Delay and High Level of Heterogeneity
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Bifurcation Analysis and Transition Mechanism in a Modified Model of Ca^(2+) Oscillations
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作者 季全宝 杨卓琴 韩芳 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第8期29-32,共4页
Some new elements are introduced into a mathematical model of intracellular calcium oscillations, which make it particularly suitable for the study of bifurcation. In addition to generating regular oscillations, such ... Some new elements are introduced into a mathematical model of intracellular calcium oscillations, which make it particularly suitable for the study of bifurcation. In addition to generating regular oscillations, such a modified model can be used to reproduce the burst discharges similar to those recorded in experiments and to describe two new types of oscillatory phenomena. By means of a fast/slow dynamical analysis, we explore the bifurcation and transition mechanisms associated with two types of bursters due to changes in the interaction of two slow variables with different timescales. 展开更多
关键词 CYCLE OSCILLATIONS
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Entanglement polygon inequalities for a class of mixed states
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作者 Xian Shi 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第11期218-222,共5页
The study on the entanglement polygon inequality of multipartite systems has attracted much attention.However,most of the results are on pure states.Here we consider the property for a class of mixed states,which are ... The study on the entanglement polygon inequality of multipartite systems has attracted much attention.However,most of the results are on pure states.Here we consider the property for a class of mixed states,which are the reduced density matrices of generalizedW-class states in multipartite higher dimensional systems.First we show the class of mixed states satisfies the entanglement polygon inequalities in terms of Tsallis-q entanglement,then we propose a class of tighter inequalities for mixed states in terms of Tsallis-q entanglement.At last,we get an inequality for the mixed states,which can be regarded as a relation for bipartite entanglement. 展开更多
关键词 entanglement polygon INEQUALITY W-class states Tsallis-q entanglement
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Reconcile the contradictory wettability requirements for the reduction and oxidation half-reactions in overall CO_(2) photoreduction via alternately hydrophobic surfaces
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作者 Hailing Huo Ting Hu +9 位作者 Chengxi Huang Fang Wu Tongyu Wang Xuan Liu Liang Zhang Qiang Ju Zhiqing Zhong Hongbin Xing Erjun Kan Ang Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第6期202-212,I0006,共12页
The overall photocatalytic CO_(2) reduction reaction(OPCRR)that can directly convert CO_(2) and H_(2)O into fuels represents a promising renewable energy conversion technology.As a typical redox reaction,the OPCRR inv... The overall photocatalytic CO_(2) reduction reaction(OPCRR)that can directly convert CO_(2) and H_(2)O into fuels represents a promising renewable energy conversion technology.As a typical redox reaction,the OPCRR involves two half-reactions:the CO_(2) reduction half-reaction(CRHR)and the water oxidation half-reaction(WOHR).Generally,both half-reactions can be promoted by adjusting the wettability of catalysts.However,there is a contradiction in wettability requirements for the two half-reactions.Specifically,CRHR prefers a hydrophobic surface that can accumulate more CO_(2) molecules on the active sites,ensuring the appropriate ratio of gas-phase(CO_(2))to liquid-phase(H_(2)O)reactants.Conversely,the WOHR prefers a hydrophilic surface that can promote the departure of the gaseous product(O_(2))from the catalyst surface,preventing isolation between active sites and the reactant(H_(2)O).Here,we successfully reconciled the contradictory wettability requirements for the CRHR and WOHR by creating an alternately hydrophobic catalyst.This was achieved through a selectively hydrophobic modification method and a charge-transfer-control strategy.Consequently,the collaboratively promoted CRHR and WOHR led to a significantly enhanced OPCRR with a solar-to-fuel conversion efficiency of 0.186%.Notably,in ethanol production,the catalyst exhibited a 10.64-fold increase in generation rate(271.44μmol g^(-1)h~(-1))and a 4-fold increase in selectivity(55.77%)compared to the benchmark catalyst.This innovative approach holds great potential for application in universal overall reactions involving gas participation. 展开更多
关键词 HYDROPHOBIC HYDROPHILIC Gas transport Overall CO_(2)photoreduction Z-scheme
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Cross-efficiency DEA model-based evaluation of allocative efficiency of rural information resources in Jiangsu Province, China
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作者 Jiannong ZHOU Aidong PENG +1 位作者 Jing CUI Shuiqing HUANG 《Chinese Journal of Library and Information Science》 2012年第2期33-44,共12页
Purpose: This paper aims to compare and rank the allocative efficiency of information resources in rural areas by taking 13 rural areas in Jiangsu Province, China as the research sample.Design/methodology/approach: We... Purpose: This paper aims to compare and rank the allocative efficiency of information resources in rural areas by taking 13 rural areas in Jiangsu Province, China as the research sample.Design/methodology/approach: We designed input and output indicators for allocation of rural information resources and conducted the quantitative evaluation of allocative efficiency of rural information resources based on cross-efficiency model in combination with the classical CCR model in data envelopment analysis(DEA).Findings: Cross-efficiency DEA model can be used for our research with the objective to evaluate quantitatively and objectively whether the allocation of information resources in various rural areas is reasonable and whether the output is commensurate with the input.Research limitations: We have to give up using some indicators because of limited data availability. There is a need to further improve the cross-efficiency DEA model because it cannot identify the specific factors influencing the efficiency of decision-making units(DMUs).Practical implications: The evaluation results will help us understand the present allocative efficiency levels of information resources in various rural areas so as to provide a decisionmaking basis for formulation of the policies aimed at promoting the circulation of information resources in rural areas.Originality/value: Little or no research has been published about the allocative efficiency of rural information resources. The value of this research lies in its focus on studying rural informatization from the perspective of allocative efficiency of rural information resources and in the application of cross-efficiency DEA model to evaluate allocative efficiency of rural information resources as well. 展开更多
关键词 Rural information resources Data envelopment analysis(DEA) Cross-efficiency Allocation of information resources Allocative efficiency
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THE LONG TIME BEHAVIOR OF THE FRACTIONAL ORNSTEIN-UHLENBECK PROCESS WITH LINEAR SELF-REPELLING DRIFT
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作者 夏晓宇 闫理坦 杨晴 《Acta Mathematica Scientia》 SCIE CSCD 2024年第2期671-685,共15页
Let B^(H) be a fractional Brownian motion with Hurst index 1/2≤H<1.In this paper,we consider the equation(called the Ornstein-Uhlenbeck process with a linear self-repelling drift)dX_(t)^(H)=dB_(t)^(H)+σ X_(t)^(H)... Let B^(H) be a fractional Brownian motion with Hurst index 1/2≤H<1.In this paper,we consider the equation(called the Ornstein-Uhlenbeck process with a linear self-repelling drift)dX_(t)^(H)=dB_(t)^(H)+σ X_(t)^(H)dt+vdt-θ(∫_(0)^(t)(X_(t)^(H)-X_(s)^(H))ds)dt,whereθ<0,σ,v∈ℝ.The process is an analogue of self-attracting diffusion(Cranston,Le Jan.Math Ann,1995,303:87–93).Our main aim is to study the large time behaviors of the process.We show that the solution X^(H)diverges to infinity as t tends to infinity,and obtain the speed at which the process X^(H)diverges to infinity. 展开更多
关键词 fractional Brownian motion stochastic difference equations rate of convergence ASYMPTOTIC
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OFDM with Generalized Cascade Index Modulation for Secure Communications
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作者 Hu Zeng Jin Xiaopin +3 位作者 Yao Yudong Chen Fangjiong Wan Dehuan Liu Yun 《China Communications》 SCIE CSCD 2024年第10期210-225,共16页
Cascade index modulation(CIM) is a recently proposed improvement of orthogonal frequency division multiplexing with index modulation(OFDM-IM) and achieves better error performance.In CIM, at least two different IM ope... Cascade index modulation(CIM) is a recently proposed improvement of orthogonal frequency division multiplexing with index modulation(OFDM-IM) and achieves better error performance.In CIM, at least two different IM operations construct a super IM operation or achieve new functionality. First, we propose a OFDM with generalized CIM(OFDM-GCIM) scheme to achieve a joint IM of subcarrier selection and multiple-mode(MM)permutations by using a multilevel digital algorithm.Then, two schemes, called double CIM(D-CIM) and multiple-layer CIM(M-CIM), are proposed for secure communication, which combine new IM operation for disrupting the original order of bits and symbols with conventional OFDM-IM, to protect the legitimate users from eavesdropping in the wireless communications. A subcarrier-wise maximum likelihood(ML) detector and a low complexity log-likelihood ratio(LLR) detector are proposed for the legitimate users. A tight upper bound on the bit error rate(BER) of the proposed OFDM-GCIM, D-CIM and MCIM at the legitimate users are derived in closed form by employing the ML criteria detection. Computer simulations and numerical results show that the proposed OFDM-GCIM achieves superior error performance than OFDM-IM, and the error performance at the eavesdroppers demonstrates the security of D-CIM and M-CIM. 展开更多
关键词 cascade index modulation low-complexity detector maximum likelihood OFDM physical layer security
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