Hydrogen evolution reaction(HER)plays a crucial role in developing clean and renewable hydrogen energy technologies.However,conventional HER catalysts rely on expensive and scarce noble metals,which is a significant c...Hydrogen evolution reaction(HER)plays a crucial role in developing clean and renewable hydrogen energy technologies.However,conventional HER catalysts rely on expensive and scarce noble metals,which is a significant challenge for practical application.Recently,twodimensional transition metal dichalcogenides(2D-TMDs)have emerged as attractive and cost-effective alternatives for efficient electrocatalysis in the HER.Substantial efforts have been dedicated to advancing the synthesis and application of 2D-TMDs.This review highlights the design and synthesis of high-performance 2D-TMDs-based HER electrocatalysts by combining theoretical calculations with experimental methods.Subsequently,recent advances in synthesizing different types of 2D TMDs with enhanced HER activity are summarized.Finally,the conclusion and perspectives of the 2D TMDs-based HER electrocatalysts are discussed.We expect that this review will provide new insights into the design and development of highly efficient 2D TMDs-based HER electrocatalysts for industrial applications.展开更多
We study the two-dimensional traffic of cellular automata using computer simulation. We propose two type of decentralized cooperation strategies, which are called stepping aside (CS-SA) and choosing alternative routes...We study the two-dimensional traffic of cellular automata using computer simulation. We propose two type of decentralized cooperation strategies, which are called stepping aside (CS-SA) and choosing alternative routes (CS-CAR) respectively. We introduce them into an existing two-dimensional cellular automata (CA) model. CS-SA is designed to prohibit a kind of ping-pong jump when two objects standing together try to move in opposite directions. CS-CAR is designed to change the solution of conflict in parallel update. CS-CAR encourages the objects involved in parallel conflicts choose their alternative routes instead of waiting. We also combine the two cooperation strategies (CS-SA-CAR) to test their combined effects. It is found that the system keeps on a partial jam phase with nonzero velocity and flow until the density reaches one. The ratios of the ping-pong jump and the waiting objects involved in conflict are decreased obviously, especially at the free phase. And the average flow is improved by the three cooperation strategies. Although the average travel time is lengthened a bit by CS-CAR, it is shorten by CS-SA and CS-SA-CAR. In addition, we discuss the advantage and applicability of decentralized cooperation modeling.展开更多
Quantum error correction is a crucial technology for realizing quantum computers.These computers achieve faulttolerant quantum computing by detecting and correcting errors using decoding algorithms.Quantum error corre...Quantum error correction is a crucial technology for realizing quantum computers.These computers achieve faulttolerant quantum computing by detecting and correcting errors using decoding algorithms.Quantum error correction using neural network-based machine learning methods is a promising approach that is adapted to physical systems without the need to build noise models.In this paper,we use a distributed decoding strategy,which effectively alleviates the problem of exponential growth of the training set required for neural networks as the code distance of quantum error-correcting codes increases.Our decoding algorithm is based on renormalization group decoding and recurrent neural network decoder.The recurrent neural network is trained through the ResNet architecture to improve its decoding accuracy.Then we test the decoding performance of our distributed strategy decoder,recurrent neural network decoder,and the classic minimum weight perfect matching(MWPM)decoder for rotated surface codes with different code distances under the circuit noise model,the thresholds of these three decoders are about 0.0052,0.0051,and 0.0049,respectively.Our results demonstrate that the distributed strategy decoder outperforms the other two decoders,achieving approximately a 5%improvement in decoding efficiency compared to the MWPM decoder and approximately a 2%improvement compared to the recurrent neural network decoder.展开更多
Inherent complexity of plant metabolites necessitates the use of multi-dimensional information to accomplish comprehensive profiling and confirmative identification.A dimension-enhanced strategy,by offline two-dimensi...Inherent complexity of plant metabolites necessitates the use of multi-dimensional information to accomplish comprehensive profiling and confirmative identification.A dimension-enhanced strategy,by offline two-dimensional liquid chromatography/ion mobility-quadrupole time-of-flight mass spectrometry(2 D-LC/IM-QTOF-MS)enabling four-dimensional separations(2 D-LC,IM,and MS),is proposed.In combination with in-house database-driven automated peak annotation,this strategy was utilized to characterize ginsenosides simultaneously from white ginseng(WG)and red ginseng(RG).An offline 2 DLC system configuring an Xbridge Amide column and an HSS T3 column showed orthogonality 0.76 in the resolution of ginsenosides.Ginsenoside analysis was performed by data-independent high-definition MSE(HDMSE)in the negative ESI mode on a Vion?IMS-QTOF hybrid high-resolution mass spectrometer,which could better resolve ginsenosides than MSEand directly give the CCS information.An in-house ginsenoside database recording 504 known ginsenosides and 58 reference compounds,was established to assist the identification of ginsenosides.Streamlined workflows,by applying UNIFI?to automatedly annotate the HDMSEdata,were proposed.We could separate and characterize 323 ginsenosides(including 286 from WG and 306 from RG),and 125 thereof may have not been isolated from the Panax genus.The established 2 D-LC/IM-QTOF-HDMSEapproach could also act as a magnifier to probe differentiated components between WG and RG.Compared with conventional approaches,this dimensionenhanced strategy could better resolve coeluting herbal components and more efficiently,more reliably identify the multicomponents,which,we believe,offers more possibilities for the systematic exposure and confirmative identification of plant metabolites.展开更多
Multiple-point statistics(MPS)is a useful approach to reconstruct three-dimensional models in the macroscopic or microscopic field.Extracting spatial features for three-dimensional reconstruction from two-dimensional ...Multiple-point statistics(MPS)is a useful approach to reconstruct three-dimensional models in the macroscopic or microscopic field.Extracting spatial features for three-dimensional reconstruction from two-dimensional training images(TIs),and characterizing non-stationary features with directional ductility are two key issues in MPS simulation.This study presents a step-wise MPS-based three-dimensional structures reconstruction algorithm with the sequential process and hierarchical strategy based on two-dimensional images.An extension method is proposed to construct three-dimensional TIs.With a sequential simulation process,an initial guess at the coarsest scale is simulated,in which hierarchical strategy is used according to the characteristics of TIs.To obtain a more refined realization,an expectation-maximization like iterative process with global optimization is implemented.A concrete example of chondrite micro-structure simulation,in which one scanning electron microscopy(SEM)image of the Heyetang meteorite is used as TI,shows that the presented algorithm can simulate complex non-stationary structures.展开更多
Let Ф（u ×v, k, Aa, Ac） be the largest possible number of codewords among all two- dimensional （u ×v, k, λa, λc） optical orthogonal codes. A 2-D （u× v, k, λa, λ）-OOC with Ф（u× v, k, λ...Let Ф（u ×v, k, Aa, Ac） be the largest possible number of codewords among all two- dimensional （u ×v, k, λa, λc） optical orthogonal codes. A 2-D （u× v, k, λa, λ）-OOC with Ф（u× v, k, λa, λc） codewords is said to be maximum. In this paper, the number of codewords of a maximum 2-D （u × v, 4, 1, 3）-OOC has been determined.展开更多
Orthogonal variable spreading factor channelization codes are widely used to provide variable data rates for supporting different bandwidth requirements in wideband code division multiple access (WCDMA) systems. A new...Orthogonal variable spreading factor channelization codes are widely used to provide variable data rates for supporting different bandwidth requirements in wideband code division multiple access (WCDMA) systems. A new code match scheme for WCDMA code tree management was proposed. The code match scheme is similar to the existing crowed-first scheme. When choosing a code for a user, the code match scheme only compares the one up layer of the allocated codes, unlike the crowed-first scheme which perhaps compares all up layers. So the operation of code match scheme is simple, and the average time delay is decreased by 5.1%. The simulation results also show that the code match strategy can decrease the average code blocking probability by 8.4%.展开更多
To improve the error correction performance, an innovative encoding structure with tail-biting for spinal codes is designed. Furthermore, an adaptive forward stack decoding(A-FSD) algorithm with lower complexity for s...To improve the error correction performance, an innovative encoding structure with tail-biting for spinal codes is designed. Furthermore, an adaptive forward stack decoding(A-FSD) algorithm with lower complexity for spinal codes is proposed. In the A-FSD algorithm, a flexible threshold parameter is set by a variable channel state to narrow the scale of nodes accessed. On this basis, a new decoding method of AFSD with early termination(AFSD-ET) is further proposed. The AFSD-ET decoder not only has the ability of dynamically modifying the number of stored nodes, but also adopts the early termination criterion to curtail complexity. The complexity and related parameters are verified through a series of simulations. The simulation results show that the proposed spinal codes with tail-biting and the AFSD-ET decoding algorithms can reduce the complexity and improve the decoding rate without sacrificing correct decoding performance.展开更多
By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is b...By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is based on the cyclic redundancy check( CRC) of the messages in the subframes 2 and 3. The simulation results show that average number of iterations of the proposed strategy is less than that of the standard ET strategy,with nearly no degradation in decoding performance. Besides,the proposed ET strategy can be efficiently implemented in a sequential or parallel manner. Thus,the proposed ET strategy is attractive for practical purposes.展开更多
Electrocatalytic CO_(2) reduction reaction(eCO_(2) RR)has significant relevance to settle the global energy crisis and abnormal climate problem via mitigating the excess emission of waste CO_(2) and producing high-val...Electrocatalytic CO_(2) reduction reaction(eCO_(2) RR)has significant relevance to settle the global energy crisis and abnormal climate problem via mitigating the excess emission of waste CO_(2) and producing high-value-added chemicals.Currently,eCO_(2) RR to formic acid or formate is one of the most technologically and economically viable approaches to realize high-efficiency CO_(2) utilization,and the development of efficient electrocatalysts is very urgent to achieve efficient and stable catalytic performance.In this review,the recent advances for two-dimensional bismuth-based nanosheets(2D Bi-based NSs)electrocatalysts are concluded from both theoretical and experimental perspectives.Firstly,the preparation strategies of 2D Bi-based NSs in aspects to precisely control the thickness and uniformity are summarized.In addition,the electronic regulation strategies of 2D Bi-based NSs are highlighted to gain insight into the effects of the structure-property relationship on facilitating CO_(2) activation,improving product selectivity,and optimizing carrier transport dynamics.Finally,the considerable challenges and opportunities of 2D Bi-based NSs are discussed to lighten new directions for future research of eCO_(2) RR.展开更多
Test points selection for integer-coded fault wise table is a discrete optimization problem. The global minimum set of test points can only be guaranteed by an exhaustive search which is eompurationally expensive. In ...Test points selection for integer-coded fault wise table is a discrete optimization problem. The global minimum set of test points can only be guaranteed by an exhaustive search which is eompurationally expensive. In this paper, this problem is formulated as a heuristic depth-first graph search problem at first. The graph node expanding method and rules are given. Then, rollout strategies are applied, which can be combined with the heuristic graph search algorithms, in a computationally more efficient manner than the optimal strategies, to obtain solutions superior to those using the greedy heuristic algorithms. The proposed rollout-based test points selection algorithm is illustrated and tested using an analog circuit and a set of simulated integer-coded fault wise tables. Computa- tional results are shown, which suggest that the rollout strategy policies are significantly better than other strategies.展开更多
The rapid screening of bioactive constituents within traditional Chinese medicine(TCM)presents a significant challenge to researchers.Prevailing strategies for the screening of active components in TCM often overlook ...The rapid screening of bioactive constituents within traditional Chinese medicine(TCM)presents a significant challenge to researchers.Prevailing strategies for the screening of active components in TCM often overlook trace components owing to their concealment by more abundant constituents.To address this limitation,a fishing strategy based on offline two-dimensional liquid chromatography(2D-LC)combined with surface plasmon resonance(SPR)was utilized to screen bioactive trace components targeting peroxiredoxin 3(PRDX3),using Uncaria alkaloids(UAs)as a case study.Initially,an orthogonal preparative offline 2D-LC system combining a positively charged C18 column and a conventional C18 column under disparate mobile phase conditions was constructed.To fully reveal the trace alkaloids,132D fractions of UAs were prepared,and their components were characterized using mass spectrometry(MS).Subsequently,employing PRDX3 as the targeting protein,a SPR-based screening approach was established and rigorously validated with geissoschizine methyl ether(GSM)serving as a positive control for binding.Employing this refined strategy,29 candidate binding alkaloids were fished from the 132D fractions.Notably,combining offline 2D-LC with SPR increased the yield of candidate binding components from 10 to 29 when compared to SPR-based screening alone.Subsequent binding affinity assays confirmed that PRDX3 was a direct binding target for the 12 fished alkaloids,with isovallesiachotamine(IV),corynoxeine N-oxide(CO-N),and cadambine(CAD)demonstrating the highest affinity for PRDX3.Their interactions were further validated through molecular docking analysis.Subsequent intracellular H_(2)O_(2)measurement assays and transfection experiments confirmed that these three trace alkaloids enhanced PRDX3-mediated H_(2)O_(2)clearance.In conclusion,this study introduced an innovative strategy for the identification of active trace components in TCM.This approach holds promise for accelerating research on medicinal components within this field.展开更多
Phase transformation of two-dimensional(2D)nanomaterials can lead to significant changes in electronic and optical properties,which enables the development of novel applications.Effective strategies for phase engineer...Phase transformation of two-dimensional(2D)nanomaterials can lead to significant changes in electronic and optical properties,which enables the development of novel applications.Effective strategies for phase engineering of 2D nanomaterials have drawn considerable attention in recent years.This review focuses on the state-of-the-art progress in the phase transformation of 2D nanomaterials and their catalytic applications.First,the basic concepts of phase transformation and the outstanding electronic and optical properties induced by phase transformation are briefly introduced.Second,different strategies for achieving phase transformation are discussed in detail and classified into several types based on their characteristics,including(i)doping,(ii)external fields,(iii)optical irradiation,(iv)strain effect,(v)high-energy particle excitation,and(vi)thermal post-processing.The applications of 2D nanomaterials in catalysis based on phase transformation have also been discussed.Finally,a summary of the technical challenges to phase control in 2D nanomaterials and potential opportunities for developing novel applications is presented.展开更多
The rapid expansion of two-dimensional(2D)van der Waals semiconductors has enabled new possibilities for next-generation electronic and optoelectronic technologies.However,the absence of robust,scalable,and CMOS-compa...The rapid expansion of two-dimensional(2D)van der Waals semiconductors has enabled new possibilities for next-generation electronic and optoelectronic technologies.However,the absence of robust,scalable,and CMOS-compatible doping strategies remains a key bottleneck for their circuit-level integration.Conventional doping techniques,such as ion implantation and substitutional doping,are fundamentally incompatible with atomically thin crystals due to lattice damage,poor dopant activation,and limited spatial precision.In this context,photodoping has emerged as a promising alternative,offering noninvasive,reversible,and highly tunable modulation of carrier density through light–matter interactions without compromising structural integrity.By precisely controlling illumination parameters and employing optical patterning techniques,photodoping offers nanometer-scale spatial resolution and enables programmable modulation of doping polarity and carrier concentration.Moreover,specific mechanisms allow for nonvolatile doping states through longlived charge trapping effects.This review provides a comprehensive overview of recent advancements in photodoping strategies for 2D materials,encompassing device configurations,physical mechanisms,and state-of-the-art characterization methods.We further highlight emerging applications in multifunctional transistors,photodetectors,memory,neuromorphic,and reconfigurable devices,and discuss the challenges and future prospects of integrating photodoping into large-scale 2D material platforms.展开更多
本文以The Da Vinci Code大陆和台湾的两个中译本的描述研究为例,来验证译者的翻译策略是否遵循或违背规范。从描述研究中得出结论,翻译过程是一个极为动态多变的过程。对翻译规范与译者思维互动的研究,正是为了更动态的还原多变的翻译...本文以The Da Vinci Code大陆和台湾的两个中译本的描述研究为例,来验证译者的翻译策略是否遵循或违背规范。从描述研究中得出结论,翻译过程是一个极为动态多变的过程。对翻译规范与译者思维互动的研究,正是为了更动态的还原多变的翻译过程,从而对翻译实践提供借鉴与帮助。展开更多
This paper combines improved Hamming codes and parity codes to assure the reliability of memory in presence of multiple bit upsets with low cost overhead.The redundancy bits of improved Hamming codes will be appended ...This paper combines improved Hamming codes and parity codes to assure the reliability of memory in presence of multiple bit upsets with low cost overhead.The redundancy bits of improved Hamming codes will be appended at the end of data bits,which eliminates the overhead of interspersing the redundancy bits at the encoder and decoder.The reliability of memory is further enhanced by the layout architecture of redundancy bits and data bits.The proposed scheme has been implemented in Verilog and synthesized using the Synopsys tools.The results reveal that the proposed method has about 19% less area penalties and 13% less power consumption comparing with the current two-dimensional error codes,and its latency of encoder and decoder is 63% less than that of Hamming codes.展开更多
In this article,we introduce a new bi-directional dual-relay selection strategy with its bit error rate(BER)performance analysis.During the first step of the proposed strategy,two relays out of a set of N relay-nodes ...In this article,we introduce a new bi-directional dual-relay selection strategy with its bit error rate(BER)performance analysis.During the first step of the proposed strategy,two relays out of a set of N relay-nodes are selected in a way to optimize the system performance in terms of BER,based on the suggested algorithm which checks if the selected relays using the maxmin criterion are the best ones.In the second step,the chosen relay-nodes perform an orthogonal space-time coding scheme using the two-phase relaying protocol to establish a bi-directional communication between the communicating terminals,leading to a significant improvement in the achievable coding and diversity gain.To further improve the overall system performance,the selected relay-nodes apply also a digital network coding scheme.Furthermore,this paper discusses the analytical approximation of the BER performance of the proposed strategy,where we prove that the analytical results match almost perfectly the simulated ones.Finally,our simulation results show that the proposed strategy outperforms the current state-of-the-art ones.展开更多
基金supported by the National Key Projects for Fundamental Research and Development of China(2021YFA1500803)the National Natural Science Foundation of China(51825205,52120105002,22088102,22279150,22209186)+1 种基金the Beijing Natural Science Foundation(2222080)the Youth Innovation Promotion Association of the CAS(Y2021011)。
文摘Hydrogen evolution reaction(HER)plays a crucial role in developing clean and renewable hydrogen energy technologies.However,conventional HER catalysts rely on expensive and scarce noble metals,which is a significant challenge for practical application.Recently,twodimensional transition metal dichalcogenides(2D-TMDs)have emerged as attractive and cost-effective alternatives for efficient electrocatalysis in the HER.Substantial efforts have been dedicated to advancing the synthesis and application of 2D-TMDs.This review highlights the design and synthesis of high-performance 2D-TMDs-based HER electrocatalysts by combining theoretical calculations with experimental methods.Subsequently,recent advances in synthesizing different types of 2D TMDs with enhanced HER activity are summarized.Finally,the conclusion and perspectives of the 2D TMDs-based HER electrocatalysts are discussed.We expect that this review will provide new insights into the design and development of highly efficient 2D TMDs-based HER electrocatalysts for industrial applications.
基金Supported by the National Natural Science Foundation of China under Grant No. 61103093the National High-Tech Research and Development Plan of China (863) under Grant No. 2011AA010502
文摘We study the two-dimensional traffic of cellular automata using computer simulation. We propose two type of decentralized cooperation strategies, which are called stepping aside (CS-SA) and choosing alternative routes (CS-CAR) respectively. We introduce them into an existing two-dimensional cellular automata (CA) model. CS-SA is designed to prohibit a kind of ping-pong jump when two objects standing together try to move in opposite directions. CS-CAR is designed to change the solution of conflict in parallel update. CS-CAR encourages the objects involved in parallel conflicts choose their alternative routes instead of waiting. We also combine the two cooperation strategies (CS-SA-CAR) to test their combined effects. It is found that the system keeps on a partial jam phase with nonzero velocity and flow until the density reaches one. The ratios of the ping-pong jump and the waiting objects involved in conflict are decreased obviously, especially at the free phase. And the average flow is improved by the three cooperation strategies. Although the average travel time is lengthened a bit by CS-CAR, it is shorten by CS-SA and CS-SA-CAR. In addition, we discuss the advantage and applicability of decentralized cooperation modeling.
基金Project supported by Natural Science Foundation of Shandong Province,China (Grant Nos.ZR2021MF049,ZR2022LLZ012,and ZR2021LLZ001)。
文摘Quantum error correction is a crucial technology for realizing quantum computers.These computers achieve faulttolerant quantum computing by detecting and correcting errors using decoding algorithms.Quantum error correction using neural network-based machine learning methods is a promising approach that is adapted to physical systems without the need to build noise models.In this paper,we use a distributed decoding strategy,which effectively alleviates the problem of exponential growth of the training set required for neural networks as the code distance of quantum error-correcting codes increases.Our decoding algorithm is based on renormalization group decoding and recurrent neural network decoder.The recurrent neural network is trained through the ResNet architecture to improve its decoding accuracy.Then we test the decoding performance of our distributed strategy decoder,recurrent neural network decoder,and the classic minimum weight perfect matching(MWPM)decoder for rotated surface codes with different code distances under the circuit noise model,the thresholds of these three decoders are about 0.0052,0.0051,and 0.0049,respectively.Our results demonstrate that the distributed strategy decoder outperforms the other two decoders,achieving approximately a 5%improvement in decoding efficiency compared to the MWPM decoder and approximately a 2%improvement compared to the recurrent neural network decoder.
基金the National Natural Science Foundation of China(Grant No.81872996)the State Key Research and Development Project(Grant No.2017YFC1702104)+1 种基金the State Key Project for the Creation of Major New Drugs(2018ZX09711001-009-010)the Tianjin Municipal Education Commission Research Project(Grant No.2017ZD07)。
文摘Inherent complexity of plant metabolites necessitates the use of multi-dimensional information to accomplish comprehensive profiling and confirmative identification.A dimension-enhanced strategy,by offline two-dimensional liquid chromatography/ion mobility-quadrupole time-of-flight mass spectrometry(2 D-LC/IM-QTOF-MS)enabling four-dimensional separations(2 D-LC,IM,and MS),is proposed.In combination with in-house database-driven automated peak annotation,this strategy was utilized to characterize ginsenosides simultaneously from white ginseng(WG)and red ginseng(RG).An offline 2 DLC system configuring an Xbridge Amide column and an HSS T3 column showed orthogonality 0.76 in the resolution of ginsenosides.Ginsenoside analysis was performed by data-independent high-definition MSE(HDMSE)in the negative ESI mode on a Vion?IMS-QTOF hybrid high-resolution mass spectrometer,which could better resolve ginsenosides than MSEand directly give the CCS information.An in-house ginsenoside database recording 504 known ginsenosides and 58 reference compounds,was established to assist the identification of ginsenosides.Streamlined workflows,by applying UNIFI?to automatedly annotate the HDMSEdata,were proposed.We could separate and characterize 323 ginsenosides(including 286 from WG and 306 from RG),and 125 thereof may have not been isolated from the Panax genus.The established 2 D-LC/IM-QTOF-HDMSEapproach could also act as a magnifier to probe differentiated components between WG and RG.Compared with conventional approaches,this dimensionenhanced strategy could better resolve coeluting herbal components and more efficiently,more reliably identify the multicomponents,which,we believe,offers more possibilities for the systematic exposure and confirmative identification of plant metabolites.
基金substantially supported by the National Natural Science Foundation of China(NSFC)Program(Nos.41972302,41772345)。
文摘Multiple-point statistics(MPS)is a useful approach to reconstruct three-dimensional models in the macroscopic or microscopic field.Extracting spatial features for three-dimensional reconstruction from two-dimensional training images(TIs),and characterizing non-stationary features with directional ductility are two key issues in MPS simulation.This study presents a step-wise MPS-based three-dimensional structures reconstruction algorithm with the sequential process and hierarchical strategy based on two-dimensional images.An extension method is proposed to construct three-dimensional TIs.With a sequential simulation process,an initial guess at the coarsest scale is simulated,in which hierarchical strategy is used according to the characteristics of TIs.To obtain a more refined realization,an expectation-maximization like iterative process with global optimization is implemented.A concrete example of chondrite micro-structure simulation,in which one scanning electron microscopy(SEM)image of the Heyetang meteorite is used as TI,shows that the presented algorithm can simulate complex non-stationary structures.
基金Supported by the National Natural Science Foundation of China(61071221,10831002)
文摘Let Ф（u ×v, k, Aa, Ac） be the largest possible number of codewords among all two- dimensional （u ×v, k, λa, λc） optical orthogonal codes. A 2-D （u× v, k, λa, λ）-OOC with Ф（u× v, k, λa, λc） codewords is said to be maximum. In this paper, the number of codewords of a maximum 2-D （u × v, 4, 1, 3）-OOC has been determined.
基金Project(60202005) supported by the National Natural Science Foundation of China
文摘Orthogonal variable spreading factor channelization codes are widely used to provide variable data rates for supporting different bandwidth requirements in wideband code division multiple access (WCDMA) systems. A new code match scheme for WCDMA code tree management was proposed. The code match scheme is similar to the existing crowed-first scheme. When choosing a code for a user, the code match scheme only compares the one up layer of the allocated codes, unlike the crowed-first scheme which perhaps compares all up layers. So the operation of code match scheme is simple, and the average time delay is decreased by 5.1%. The simulation results also show that the code match strategy can decrease the average code blocking probability by 8.4%.
基金supported by the National Natural Science Foundation of China (61701020)the Scientific and Technological Innovation Foundation of Shunde Graduate School,USTB (BK19BF009)。
文摘To improve the error correction performance, an innovative encoding structure with tail-biting for spinal codes is designed. Furthermore, an adaptive forward stack decoding(A-FSD) algorithm with lower complexity for spinal codes is proposed. In the A-FSD algorithm, a flexible threshold parameter is set by a variable channel state to narrow the scale of nodes accessed. On this basis, a new decoding method of AFSD with early termination(AFSD-ET) is further proposed. The AFSD-ET decoder not only has the ability of dynamically modifying the number of stored nodes, but also adopts the early termination criterion to curtail complexity. The complexity and related parameters are verified through a series of simulations. The simulation results show that the proposed spinal codes with tail-biting and the AFSD-ET decoding algorithms can reduce the complexity and improve the decoding rate without sacrificing correct decoding performance.
基金Sponsored by the National Natural Science Foundation of China(Grant No.61271423)
文摘By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is based on the cyclic redundancy check( CRC) of the messages in the subframes 2 and 3. The simulation results show that average number of iterations of the proposed strategy is less than that of the standard ET strategy,with nearly no degradation in decoding performance. Besides,the proposed ET strategy can be efficiently implemented in a sequential or parallel manner. Thus,the proposed ET strategy is attractive for practical purposes.
基金supported by the Hainan Provincial Natural Science Foundation of China(222RC548)the National Natural Science Foun-dation of China(22109034,22109035,52164028,62105083,21805104)+3 种基金the Opening Project of Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan Province(KFKT2021007)the Start-up Research Foundation of Hainan University(KYQD(ZR)-20008,20082,20083,20084,21065,21124,21125)the Innovative Research Projects for Graduate Students of Hainan Province(Qhyb2022-89,Qhys2022-174)the State Key Laboratory of Powder Metallurgy,Central South University,Changsha,China and the Specific Research Fund of the Innovation Platform for Academicians of Hainan Province.
文摘Electrocatalytic CO_(2) reduction reaction(eCO_(2) RR)has significant relevance to settle the global energy crisis and abnormal climate problem via mitigating the excess emission of waste CO_(2) and producing high-value-added chemicals.Currently,eCO_(2) RR to formic acid or formate is one of the most technologically and economically viable approaches to realize high-efficiency CO_(2) utilization,and the development of efficient electrocatalysts is very urgent to achieve efficient and stable catalytic performance.In this review,the recent advances for two-dimensional bismuth-based nanosheets(2D Bi-based NSs)electrocatalysts are concluded from both theoretical and experimental perspectives.Firstly,the preparation strategies of 2D Bi-based NSs in aspects to precisely control the thickness and uniformity are summarized.In addition,the electronic regulation strategies of 2D Bi-based NSs are highlighted to gain insight into the effects of the structure-property relationship on facilitating CO_(2) activation,improving product selectivity,and optimizing carrier transport dynamics.Finally,the considerable challenges and opportunities of 2D Bi-based NSs are discussed to lighten new directions for future research of eCO_(2) RR.
基金supported by Commission of Science Technology and Industry for National Defence of China under Grant No.A1420061264National Natural Science Foundation of China under Grant No.60934002General Armament Department under Grand No.51317040102)
文摘Test points selection for integer-coded fault wise table is a discrete optimization problem. The global minimum set of test points can only be guaranteed by an exhaustive search which is eompurationally expensive. In this paper, this problem is formulated as a heuristic depth-first graph search problem at first. The graph node expanding method and rules are given. Then, rollout strategies are applied, which can be combined with the heuristic graph search algorithms, in a computationally more efficient manner than the optimal strategies, to obtain solutions superior to those using the greedy heuristic algorithms. The proposed rollout-based test points selection algorithm is illustrated and tested using an analog circuit and a set of simulated integer-coded fault wise tables. Computa- tional results are shown, which suggest that the rollout strategy policies are significantly better than other strategies.
基金supported by Shanghai Institute of Materia Medica-Shanghai University of Traditional Chinese Medicine(SIMM-SHUTCM)Traditional Chinese Medicine Innovation Joint Research Program,China(Grant No.:2022,E2G808H096)the National Key Research and Development Program of China(Grant Nos.:2022YFC3501704 and 2023YFC3504205)Sanming Project of Medicine in Shenzhen,China(Grant No.:ZZYSM202106004).
文摘The rapid screening of bioactive constituents within traditional Chinese medicine(TCM)presents a significant challenge to researchers.Prevailing strategies for the screening of active components in TCM often overlook trace components owing to their concealment by more abundant constituents.To address this limitation,a fishing strategy based on offline two-dimensional liquid chromatography(2D-LC)combined with surface plasmon resonance(SPR)was utilized to screen bioactive trace components targeting peroxiredoxin 3(PRDX3),using Uncaria alkaloids(UAs)as a case study.Initially,an orthogonal preparative offline 2D-LC system combining a positively charged C18 column and a conventional C18 column under disparate mobile phase conditions was constructed.To fully reveal the trace alkaloids,132D fractions of UAs were prepared,and their components were characterized using mass spectrometry(MS).Subsequently,employing PRDX3 as the targeting protein,a SPR-based screening approach was established and rigorously validated with geissoschizine methyl ether(GSM)serving as a positive control for binding.Employing this refined strategy,29 candidate binding alkaloids were fished from the 132D fractions.Notably,combining offline 2D-LC with SPR increased the yield of candidate binding components from 10 to 29 when compared to SPR-based screening alone.Subsequent binding affinity assays confirmed that PRDX3 was a direct binding target for the 12 fished alkaloids,with isovallesiachotamine(IV),corynoxeine N-oxide(CO-N),and cadambine(CAD)demonstrating the highest affinity for PRDX3.Their interactions were further validated through molecular docking analysis.Subsequent intracellular H_(2)O_(2)measurement assays and transfection experiments confirmed that these three trace alkaloids enhanced PRDX3-mediated H_(2)O_(2)clearance.In conclusion,this study introduced an innovative strategy for the identification of active trace components in TCM.This approach holds promise for accelerating research on medicinal components within this field.
基金National Natural Science Foundation of China (22308343, 51972294,22275088, 52101260 and 52202306)Zhejiang Provincial Natural Science Foundation of China (LQ24B030003)+3 种基金Program from Guangdong Introducing Innovative and Entrepreneurial Teams (2019ZT08L101 and RCTDPT-2020-001)Shenzhen Key Laboratory of Eco-materials and Renewable Energy (ZDSYS20200922160400001)Shenzhen Natural Science Foundation(GXWD20201231105722002-20200824163747001)Provincial Talent Plan of Guangdong (2023TB0012)。
文摘Phase transformation of two-dimensional(2D)nanomaterials can lead to significant changes in electronic and optical properties,which enables the development of novel applications.Effective strategies for phase engineering of 2D nanomaterials have drawn considerable attention in recent years.This review focuses on the state-of-the-art progress in the phase transformation of 2D nanomaterials and their catalytic applications.First,the basic concepts of phase transformation and the outstanding electronic and optical properties induced by phase transformation are briefly introduced.Second,different strategies for achieving phase transformation are discussed in detail and classified into several types based on their characteristics,including(i)doping,(ii)external fields,(iii)optical irradiation,(iv)strain effect,(v)high-energy particle excitation,and(vi)thermal post-processing.The applications of 2D nanomaterials in catalysis based on phase transformation have also been discussed.Finally,a summary of the technical challenges to phase control in 2D nanomaterials and potential opportunities for developing novel applications is presented.
基金supported by the open research of Songshan Lake Materials Laboratory(Grant No.2023SLABFK07)the National Science Foundation of China(Grant No.62304151,No.62204170,and No.62474124)+2 种基金the Natural Science Foundation of Tianjin(Grant No.24JCQNJC00520)the China Postdoctoral Science Foundation(No.2023M742585)the State Key Laboratory of Fluid Power and Mechatronic Systems under Grant(No.GZKF-202327).
文摘The rapid expansion of two-dimensional(2D)van der Waals semiconductors has enabled new possibilities for next-generation electronic and optoelectronic technologies.However,the absence of robust,scalable,and CMOS-compatible doping strategies remains a key bottleneck for their circuit-level integration.Conventional doping techniques,such as ion implantation and substitutional doping,are fundamentally incompatible with atomically thin crystals due to lattice damage,poor dopant activation,and limited spatial precision.In this context,photodoping has emerged as a promising alternative,offering noninvasive,reversible,and highly tunable modulation of carrier density through light–matter interactions without compromising structural integrity.By precisely controlling illumination parameters and employing optical patterning techniques,photodoping offers nanometer-scale spatial resolution and enables programmable modulation of doping polarity and carrier concentration.Moreover,specific mechanisms allow for nonvolatile doping states through longlived charge trapping effects.This review provides a comprehensive overview of recent advancements in photodoping strategies for 2D materials,encompassing device configurations,physical mechanisms,and state-of-the-art characterization methods.We further highlight emerging applications in multifunctional transistors,photodetectors,memory,neuromorphic,and reconfigurable devices,and discuss the challenges and future prospects of integrating photodoping into large-scale 2D material platforms.
基金Sponsored by the Opening Project of National Key Laboratory of Science and Technology on Reliability PhysicsApplication Technology of Electrical Component(Grant No.ZHD200903)
文摘This paper combines improved Hamming codes and parity codes to assure the reliability of memory in presence of multiple bit upsets with low cost overhead.The redundancy bits of improved Hamming codes will be appended at the end of data bits,which eliminates the overhead of interspersing the redundancy bits at the encoder and decoder.The reliability of memory is further enhanced by the layout architecture of redundancy bits and data bits.The proposed scheme has been implemented in Verilog and synthesized using the Synopsys tools.The results reveal that the proposed method has about 19% less area penalties and 13% less power consumption comparing with the current two-dimensional error codes,and its latency of encoder and decoder is 63% less than that of Hamming codes.
基金This work was supported by College of Engineering and Technology,the American University of the Middle East,Kuwait.Homepage:https://www.aum.edu.kw.
文摘In this article,we introduce a new bi-directional dual-relay selection strategy with its bit error rate(BER)performance analysis.During the first step of the proposed strategy,two relays out of a set of N relay-nodes are selected in a way to optimize the system performance in terms of BER,based on the suggested algorithm which checks if the selected relays using the maxmin criterion are the best ones.In the second step,the chosen relay-nodes perform an orthogonal space-time coding scheme using the two-phase relaying protocol to establish a bi-directional communication between the communicating terminals,leading to a significant improvement in the achievable coding and diversity gain.To further improve the overall system performance,the selected relay-nodes apply also a digital network coding scheme.Furthermore,this paper discusses the analytical approximation of the BER performance of the proposed strategy,where we prove that the analytical results match almost perfectly the simulated ones.Finally,our simulation results show that the proposed strategy outperforms the current state-of-the-art ones.
