This paper studies the judgement problem of full-period maps on Z(p^n) and proposes a novel congruential map with double modulus on Z(p^n). The full-period properties of the sequences generated by the novel map are st...This paper studies the judgement problem of full-period maps on Z(p^n) and proposes a novel congruential map with double modulus on Z(p^n). The full-period properties of the sequences generated by the novel map are studied completely. We prove some theorems including full-period judgement theorem on Z(p^n) and validate them by some numerical experiments. In the experiments, full-period sequences are generated by a full-period map on Z(p^n). By the binarization, full-period sequences are transformed into binary sequences. Then, we test the binary sequences with the NIST SP 800-22 software package and make the poker test. The passing rates of the statistical tests are high in NIST test and the sequences pass the poker test. So the randomness and statistic characteristics of the binary sequences are good. The analysis and experiments show that these full-period maps can be applied in the pseudo-random number generation(PRNG), cryptography, spread spectrum communications and so on.展开更多
To maximize the reliability index of a power system,this study modeled a generation maintenance scheduling problem that considers the network security constraints and rationality constraints of the generation maintena...To maximize the reliability index of a power system,this study modeled a generation maintenance scheduling problem that considers the network security constraints and rationality constraints of the generation maintenance practice in a power system.In view of the computational complexity of the generation maintenance scheduling model,a variable selection method based on a support vector machine(SVM)is proposed to solve the 0-1 mixed integer programming problem(MIP).The algorithm observes and collects data from the decisions made by strong branching(SB)and then learns a surrogate function that mimics the SB strategy using a support vector machine.The learned ranking function is then used for variable branching during the solution process of the model.The test case showed that the proposed variable selection algorithm-based on the features of the proposed generation maintenance scheduling problem during branch-and-bound-can increase the solution efficiency of the generation-scheduling model on the premise of guaranteed accuracy.展开更多
The conductive polymer poly(3,4-thylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)exhibits po-tential in the development of flexible devices due to its unique conjugated structure and water-solubility characteri...The conductive polymer poly(3,4-thylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)exhibits po-tential in the development of flexible devices due to its unique conjugated structure and water-solubility characteristics.To address the incompressibility of the original PEDOT:PSS aerogel without compromis-ing its high conductivity,a stable interpenetrating polymer network(IPN)was self-assembled by guiding the molecular motion within PEDOT:PSS and introducing multi-walled carbon nanotubes(MWCNTs).By combining critical surface removal,directional freeze-drying,and polydimethylsiloxane(PDMS)reinforce-ment processes,a hydrophobic PDMS@MWCNTs/PP aerogel with a highly oriented porous structure and high strength was prepared.Under the synergistic effect of MWCNTs/PEDOT:PSS electroactive scaffold,the composite aerogel exhibited a high sensitivity of up to 16.603 kPa^(-1) at 0-2 kPa,a fast response time of 74 ms,and excellent repeatability.Moreover,the sensor possessed hydrophobicity with a good water contact angle of 137°The sensor could serve as a wearable electronic monitoring device to achieve ac-curate and sensitive detection of human motion including large-scale human activities and tiny muscle movements.Therefore,our findings provide a new direction to fabricate high-performance piezoresistive sensors based on three-dimensional(3D)conductive polymer active scaffolds,demonstrating their great potential for flexible electronics,human-computer interaction,and a wide range of applications under special working conditions.展开更多
The insulation degradation in polymeric backsheets has been identified as a main cause of catastrophic accidents induced by short circuit or ground faults in photovoltaic module.To ensure quality,the photovoltaic indu...The insulation degradation in polymeric backsheets has been identified as a main cause of catastrophic accidents induced by short circuit or ground faults in photovoltaic module.To ensure quality,the photovoltaic industry is therefore faced with urgent demand in discovering degradation mechanisms.Moreover,the development of environmental-friendly backsheets and the establishment of backsheets recycling specifications are vital to fulfilling the requirements of a future reliable photovoltaic system with improved productivity.In this review,we innovatively summarize the detection methods of insulation deterioration from the viewpoints of spectroscopic,thermal and mechanical approaches.The corresponding ambient conditions in measurement and their accelerating effect on the degradation of photovoltaic backsheets are discussed.Subsequently,emerging novel materials and structures for enhancing insula-tion properties,antiaging performance and optical-electrical energy conversion efficiency of photovoltaic cell are summarized.It offers a comprehensive strategy to design materials with optimal structures in photovoltaic module for a future zero-carbon energy system.展开更多
In view of environmental and economic aspect, asphalt was modified with recycled packaging waste expended polystyrene （WEPS） instead of common polymer. The differential scanning calorimetry （DSC）, rotational visco...In view of environmental and economic aspect, asphalt was modified with recycled packaging waste expended polystyrene （WEPS） instead of common polymer. The differential scanning calorimetry （DSC）, rotational viscometer and dynamic shear rheology （DSR） were used to analyze and evaluate the viscoelasticity of modified asphalt. Results indicate that the sensitivity of modified asphalt to temperature is decreased while the rut resistance of asphalt is increased. In addition, the viscoelasticity of asphalt is improved after the modification with WEPS. Besides, the modified asphalt has high viscosity at low temperature and low viscosity at high temperature, which is favorable for construction.展开更多
In this work, waste-styrene-butadiene-rubber(WSBR)-modified petroleum-based mesophase asphalt was prepared through a co-carbonization process. The influence of contents of WSBR and carbonization temperature on the pro...In this work, waste-styrene-butadiene-rubber(WSBR)-modified petroleum-based mesophase asphalt was prepared through a co-carbonization process. The influence of contents of WSBR and carbonization temperature on the properties of mesophase asphalt was investigated. The chemical constituents,microstructure and thermal property of the samples were characterized. The results show that using WSBR as modifier can significantly promote the formation of mesophase. When the temperature is constant, the addition of WSBR results in more optically anisotropic crystal structure in the samples, and a better thermal stability. When the content of WSBR is invariable, with increasing temperature, the content of anisotropic structure in mesophase asphalt becomes higher and more uniform. The thermal stability of the samples is the best when WSBR content is 10 wt%.展开更多
Space-division multiplexing based on few-mode multi-core fiber(FM-MCF)technology is expected to break the Shannon limit of a single-mode fiber.However,an FM-MCF is compact,and it is difficult to couple the beam to eac...Space-division multiplexing based on few-mode multi-core fiber(FM-MCF)technology is expected to break the Shannon limit of a single-mode fiber.However,an FM-MCF is compact,and it is difficult to couple the beam to each fiber core.3D waveguide devices have the advantages of low insertion loss and low cross talk in separating various spatial paths of multi-core fibers.Designing a 3D waveguide device for an FM-MCF requires considering not only higher-order modes transmission,but also waveguide bending.We propose and demonstrate a 3D waveguide device fabricated by femtosecond laser direct writing for various spatial path separations in an FM-MCF.The 3D waveguide device couples the LP01 and LP11a modes to the FM-MCF with an insertion loss below 3 dB and cross talk between waveguides below-36 dB.To test the performance of the 3D waveguide device,we demonstrate four-channel multiplexing communication with two LP modes and two cores in a 1-km few-mode sevencore fiber.The bit error rate curves show that the different degrees of bending of the waveguides result in a difference of approximately 1 dB in the power penalty.Femtosecond laser direct writing fabrication enables 3D waveguide devices to support high-order LP modes transmission and further improves FM-MCF communication.展开更多
基金supported in part by the National Natural Science Foundation of China(NSFC)(Grant Nos.11365023)the Science and Technology Program of Shaanxi Province(Grant Nos.2018GY-050)+1 种基金the Key Scientific Research Program of Department of Education of Shaanxi Province(Grant No.16JS008)the Key Projects of Baoji University of Arts and Sciences(Grant Nos.ZK2017037)
文摘This paper studies the judgement problem of full-period maps on Z(p^n) and proposes a novel congruential map with double modulus on Z(p^n). The full-period properties of the sequences generated by the novel map are studied completely. We prove some theorems including full-period judgement theorem on Z(p^n) and validate them by some numerical experiments. In the experiments, full-period sequences are generated by a full-period map on Z(p^n). By the binarization, full-period sequences are transformed into binary sequences. Then, we test the binary sequences with the NIST SP 800-22 software package and make the poker test. The passing rates of the statistical tests are high in NIST test and the sequences pass the poker test. So the randomness and statistic characteristics of the binary sequences are good. The analysis and experiments show that these full-period maps can be applied in the pseudo-random number generation(PRNG), cryptography, spread spectrum communications and so on.
基金The authors thank the Key R&D Project of Zhejiang Province(No.2022C01056)the National Natural Science Foundation of China(No.62127803).
文摘To maximize the reliability index of a power system,this study modeled a generation maintenance scheduling problem that considers the network security constraints and rationality constraints of the generation maintenance practice in a power system.In view of the computational complexity of the generation maintenance scheduling model,a variable selection method based on a support vector machine(SVM)is proposed to solve the 0-1 mixed integer programming problem(MIP).The algorithm observes and collects data from the decisions made by strong branching(SB)and then learns a surrogate function that mimics the SB strategy using a support vector machine.The learned ranking function is then used for variable branching during the solution process of the model.The test case showed that the proposed variable selection algorithm-based on the features of the proposed generation maintenance scheduling problem during branch-and-bound-can increase the solution efficiency of the generation-scheduling model on the premise of guaranteed accuracy.
基金supported by the Xi’an Science and Technology Plan Project(Nos.GXYD14.27 and GX2338)the Key Scientific Research Program of Shaanxi Provincial Depart-ment of Education(Nos.22JY046 and 21JY032)+1 种基金the Opening Project of Shanxi Key Laboratory of Advanced Manufacturing Tech-nology of North University of China(No.XJZZ202104)the General Project of Natural Science Basic Research Program of Shaanxi Provincial Department of Science and Technology(No.2023-JC-YB-424)。
文摘The conductive polymer poly(3,4-thylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)exhibits po-tential in the development of flexible devices due to its unique conjugated structure and water-solubility characteristics.To address the incompressibility of the original PEDOT:PSS aerogel without compromis-ing its high conductivity,a stable interpenetrating polymer network(IPN)was self-assembled by guiding the molecular motion within PEDOT:PSS and introducing multi-walled carbon nanotubes(MWCNTs).By combining critical surface removal,directional freeze-drying,and polydimethylsiloxane(PDMS)reinforce-ment processes,a hydrophobic PDMS@MWCNTs/PP aerogel with a highly oriented porous structure and high strength was prepared.Under the synergistic effect of MWCNTs/PEDOT:PSS electroactive scaffold,the composite aerogel exhibited a high sensitivity of up to 16.603 kPa^(-1) at 0-2 kPa,a fast response time of 74 ms,and excellent repeatability.Moreover,the sensor possessed hydrophobicity with a good water contact angle of 137°The sensor could serve as a wearable electronic monitoring device to achieve ac-curate and sensitive detection of human motion including large-scale human activities and tiny muscle movements.Therefore,our findings provide a new direction to fabricate high-performance piezoresistive sensors based on three-dimensional(3D)conductive polymer active scaffolds,demonstrating their great potential for flexible electronics,human-computer interaction,and a wide range of applications under special working conditions.
基金supported by the National Natural Science Foundation of China (NSFC) (Nos.62061136009 and 51877031)the High-level Talents Plan of Shaanxi Province,the“Belt and Road Initiative”Overseas Expertise Introduction Center for Smart Energy and Reliability of Transmission and Distribution Equipment of Shaanxi Province,the State Key Laboratory of Engineering Dielectrics and Its Applications (Ministry of Education,China)+2 种基金the State Key Laboratory of Reliability and Intelligence Electrical Equipment (Hebei University of Technology,China,No.EERIKF2018010)Key R&D Program of Shaanxi Province (No.2022SF-168)Xi’an Programs for Science and Technology Plan (No.21XJZZ0045).
文摘The insulation degradation in polymeric backsheets has been identified as a main cause of catastrophic accidents induced by short circuit or ground faults in photovoltaic module.To ensure quality,the photovoltaic industry is therefore faced with urgent demand in discovering degradation mechanisms.Moreover,the development of environmental-friendly backsheets and the establishment of backsheets recycling specifications are vital to fulfilling the requirements of a future reliable photovoltaic system with improved productivity.In this review,we innovatively summarize the detection methods of insulation deterioration from the viewpoints of spectroscopic,thermal and mechanical approaches.The corresponding ambient conditions in measurement and their accelerating effect on the degradation of photovoltaic backsheets are discussed.Subsequently,emerging novel materials and structures for enhancing insula-tion properties,antiaging performance and optical-electrical energy conversion efficiency of photovoltaic cell are summarized.It offers a comprehensive strategy to design materials with optimal structures in photovoltaic module for a future zero-carbon energy system.
基金the financial support provided by the National Natural Science Foundation of China(Grant Nos.51002118,51172180)Program for New Century Excellent Talents in University of Ministry of Education of China(Grant No.NCET-12-1045)Shaanxi Programs for Outstanding Youth Project(2011)
文摘In view of environmental and economic aspect, asphalt was modified with recycled packaging waste expended polystyrene （WEPS） instead of common polymer. The differential scanning calorimetry （DSC）, rotational viscometer and dynamic shear rheology （DSR） were used to analyze and evaluate the viscoelasticity of modified asphalt. Results indicate that the sensitivity of modified asphalt to temperature is decreased while the rut resistance of asphalt is increased. In addition, the viscoelasticity of asphalt is improved after the modification with WEPS. Besides, the modified asphalt has high viscosity at low temperature and low viscosity at high temperature, which is favorable for construction.
基金financially support provided by the National Natural Science Foundation of China (Grant No. 51772243)the Innovation Team Plan of Shaanxi Province (Grant No. 2017KCT-17)+1 种基金the China Postdoctoral Science Foundation Funded Project (Grant No. 2016M592824)the fund of the State Key Laboratory of Solidfication Processing in NWPU SKLSP201625
文摘In this work, waste-styrene-butadiene-rubber(WSBR)-modified petroleum-based mesophase asphalt was prepared through a co-carbonization process. The influence of contents of WSBR and carbonization temperature on the properties of mesophase asphalt was investigated. The chemical constituents,microstructure and thermal property of the samples were characterized. The results show that using WSBR as modifier can significantly promote the formation of mesophase. When the temperature is constant, the addition of WSBR results in more optically anisotropic crystal structure in the samples, and a better thermal stability. When the content of WSBR is invariable, with increasing temperature, the content of anisotropic structure in mesophase asphalt becomes higher and more uniform. The thermal stability of the samples is the best when WSBR content is 10 wt%.
基金Guangdong Major Project of Basic Research(2020B0301030009)National Key Research and Development Program of China(2018YFB1801801,2018YFB1800901)+4 种基金National Natural Science Foundation of China(61935013,61975133,62075139,61705135,12047540,61835005,62175162,62105215)Natural Science Foundation of Guangdong Province(2020A1515011185)Science,Technology and Innovation Commission of Shenzhen Municipality(RCJC20200714114435063,KQJSCX20170727100838364,JCYJ20180507182035270,JCYJ20200109114018750)Shenzhen Peacock Plan(KQTD20170330110444030)Shenzhen University(2019075)。
文摘Space-division multiplexing based on few-mode multi-core fiber(FM-MCF)technology is expected to break the Shannon limit of a single-mode fiber.However,an FM-MCF is compact,and it is difficult to couple the beam to each fiber core.3D waveguide devices have the advantages of low insertion loss and low cross talk in separating various spatial paths of multi-core fibers.Designing a 3D waveguide device for an FM-MCF requires considering not only higher-order modes transmission,but also waveguide bending.We propose and demonstrate a 3D waveguide device fabricated by femtosecond laser direct writing for various spatial path separations in an FM-MCF.The 3D waveguide device couples the LP01 and LP11a modes to the FM-MCF with an insertion loss below 3 dB and cross talk between waveguides below-36 dB.To test the performance of the 3D waveguide device,we demonstrate four-channel multiplexing communication with two LP modes and two cores in a 1-km few-mode sevencore fiber.The bit error rate curves show that the different degrees of bending of the waveguides result in a difference of approximately 1 dB in the power penalty.Femtosecond laser direct writing fabrication enables 3D waveguide devices to support high-order LP modes transmission and further improves FM-MCF communication.
