The fast proliferation of edge devices for the Internet of Things(IoT)has led to massive volumes of data explosion.The generated data is collected and shared using edge-based IoT structures at a considerably high freq...The fast proliferation of edge devices for the Internet of Things(IoT)has led to massive volumes of data explosion.The generated data is collected and shared using edge-based IoT structures at a considerably high frequency.Thus,the data-sharing privacy exposure issue is increasingly intimidating when IoT devices make malicious requests for filching sensitive information from a cloud storage system through edge nodes.To address the identified issue,we present evolutionary privacy preservation learning strategies for an edge computing-based IoT data sharing scheme.In particular,we introduce evolutionary game theory and construct a payoff matrix to symbolize intercommunication between IoT devices and edge nodes,where IoT devices and edge nodes are two parties of the game.IoT devices may make malicious requests to achieve their goals of stealing privacy.Accordingly,edge nodes should deny malicious IoT device requests to prevent IoT data from being disclosed.They dynamically adjust their own strategies according to the opponent's strategy and finally maximize the payoffs.Built upon a developed application framework to illustrate the concrete data sharing architecture,a novel algorithm is proposed that can derive the optimal evolutionary learning strategy.Furthermore,we numerically simulate evolutionarily stable strategies,and the final results experimentally verify the correctness of the IoT data sharing privacy preservation scheme.Therefore,the proposed model can effectively defeat malicious invasion and protect sensitive information from leaking when IoT data is shared.展开更多
With a view of detecting the effects of macromolecular crowding on the phase transition of DNA compaction confined in spherical space,Monte Carlo simulations of DNA compaction in free space,in confined spherical space...With a view of detecting the effects of macromolecular crowding on the phase transition of DNA compaction confined in spherical space,Monte Carlo simulations of DNA compaction in free space,in confined spherical space without crowders and in confined spherical space with crowders were performed separately.The simulation results indicate that macromolecular crowding effects on DNA compaction are dominant over the roles of multivalent counterions.In addition,effects of temperature on the phase transition of DNA compaction have been identified in confined spherical space with different radii.In confined spherical space without crowders,the temperature corresponding to phase transition depends on the radius of the confined spherical space linearly.In contrast,with the addition of crowders to the confined spherical space,effects of temperature on the phase transition of DNA compaction become insignificant,whereas the phase transition at different temperatures strongly depends on the size of crowder,and the critical volume fraction of crowders pertains to the diameter of crowder linearly.展开更多
We present detailed investigations of structural and static/dynamic magnetic properties of hydrogenated hcp-Co_(80)^(57)Fe_(4)Ir_(16) soft magnetic thin films.Two different kinds of defects,i.e.,destructive and non-de...We present detailed investigations of structural and static/dynamic magnetic properties of hydrogenated hcp-Co_(80)^(57)Fe_(4)Ir_(16) soft magnetic thin films.Two different kinds of defects,i.e.,destructive and non-destructive,were demonstrated by controlling the negative bias voltage of the hydrogenation process.Our results show that the structure and magnetic properties of our sample can be tuned by the density of the induced defects.These results provide better understanding of the hydrogenation effect and thus can be used in the future for materials processing to meet the requirements of different devices.展开更多
Garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)is one of the most promising solid-state electrolytes(SSEs).However,the application of LLZO is limited by structural instability,low ionic conductivity,and poor lithium stabil...Garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)is one of the most promising solid-state electrolytes(SSEs).However,the application of LLZO is limited by structural instability,low ionic conductivity,and poor lithium stability.To obtain a garnet-type solid electrolyte with a stable structure and high ionic conductivity,a series of TaeCe co-doping cubic Li_(6.4)La_(3)Zr_(1.4-x)Ta_(0.6)Ce_(x)O_(12)(LLZTCO,x=,0.02,0.04,0.06,0.08,0.10,0.20,0.30)electrolytes were successfully synthesized through conventional solid-phase method.The Ta^(5+)doping can introduce more lithium vacancies and effectively maintain the stability of the cubic phase.The Ce^(4+)with a larger ionic radius is introduced into the lattice to widen the Lit migration bottleneck size,which significantly increased the ionic conductivity to 1.05×10^(-3)S/cm.It also shows excellent stability to lithium metal by the optimization of Lit transport channel.Li||LLZTCO||Li symmetric cells can cycle stably for more than 6000 h at a current density of 0.1 mA/cm^(2)without any surface modifications.The commercialization potential of LLZTCO samples in all solid-state lithium batteries(ASSLBs)is confirmed by the prepared LiFePO_(4)||LLZTCO||Li cells with a capacity retention rate of 98%after 100 cycles at 0.5C.This new co-doping method presents a practical solution for the realization of high-performance ASSLBs.展开更多
The thermal deformation behavior of a novel CrFeNiSi_(0.15)medium entropy alloy(MEA)was studied via isothermal compression experiments,with the processing parameter range of 900–1200℃and 0.001–1 s^(−1).According to...The thermal deformation behavior of a novel CrFeNiSi_(0.15)medium entropy alloy(MEA)was studied via isothermal compression experiments,with the processing parameter range of 900–1200℃and 0.001–1 s^(−1).According to experimental data,the modified constitutive equation had been obtained,which precisely predicted the flow behavior of CrFeNiSi_(0.15)MEA during thermal deformation.At the same time,the processing map was established on the basis of the dynamic material model(DMM)theory.According to the map,the optimal processing parameters were determined at 1130–1200℃/0.06–1 s−1,under which the power dissipation efficiency could reach above 34%.The peak efficiency was above 38%,which occurred at 1200℃/1 s^(−1).In such parameter,complete dynamic recrystallization(DRX)also occurred.The flow instability of CrFeNiSi_(0.15)MEA was estimated to occur at 900–985℃/0.12–1 s^(−1),which was shown as grain boundaries cracking.Furthermore,both the continuous DRX(CDRX)and discontinuous DRX(DDRX)occurred simultaneously during thermal deformation.Meanwhile,some twins were also newly formed during DRX process,most of which were primary twins.The occurrence of twinning was beneficial to promote the development of DRX behavior.展开更多
The California Department of Transportation(Caltrans) has been using scrap tire rubber in asphalt pavements since the 1970 s in chip seals and the 1980 s in rubberized hot mix asphalt(RHMA).Both the wet(field blend) a...The California Department of Transportation(Caltrans) has been using scrap tire rubber in asphalt pavements since the 1970 s in chip seals and the 1980 s in rubberized hot mix asphalt(RHMA).Both the wet(field blend) and dry processes were used in early trials.Caltrans has also used rubber modified binders containing both crumb rubber modifier and polymer modifier that could be manufactured at a refinery facility,a terminal blend wet process.Since the beginning of this century,Caltrans increased the use of scrap tire rubber in paving projects and invested considerable resources in developing technically sound,cost effective,and environmentally friendly strategies for using scrap tire rubber in roadway applications.By the end of year 2010,approximately 31%of all hot mix asphalt(HMA) placed by Caltrans was rubberized HMA,roughly 1.2 million tons.Caltrans efforts in using asphalt rubber products were also demonstrated in its research and technology development.These included the construction of two full-scale field experiments,five warranty projects,and an accelerated pavement study using a heavy vehicle simulator.Additionally,terminal blend asphalt rubber and rubberized warm mix asphalts began to be experimented on trial basis.This paper provides a comprehensive review of Caltrans experience over four decades with asphalt rubber products.Current practices and future outlook are also discussed.展开更多
Hydrogenation of transition metal oxides offers a powerful platform to tailor physical functionalities as well as for potential applications in modern electronic technologies.An ideal nondestructive and efficient hydr...Hydrogenation of transition metal oxides offers a powerful platform to tailor physical functionalities as well as for potential applications in modern electronic technologies.An ideal nondestructive and efficient hydrogen incorporation approach is important for the realistic technological applications.We demonstrate the proton injection on SrCro3 thin films via an efficient low-energy hydrogen plasma implantation experiments,without destroying the original lattice framework.Hydrogen ions accumu-late largely at the interfacial regions with amorphous character which extend about one-third of the total thickness.The Hx.SrCro3(HSCO)thin films appear like exfoliated layers which however retain the fully strained state with distorted perovskite structure.Proton doping induces the change of Cr oxidation state from Cr^4+to Cr^3+in HSCO thin films and a transition from metallic to insulat-ing phase.Our investigations suggest an attractive platform in manipulating the electronic phases in proton-based approaches and may offer a potential peeling off strategy for nanoscale devices through low-energy hydrogen plasma implantation approaches.展开更多
The influence of selective laser melting(SLM)process parameters on the microstructure and mechanical properties of a typical Ni-based superalloy was researched.The optimum parameters of P=170 W,V=0.8 m/s were determin...The influence of selective laser melting(SLM)process parameters on the microstructure and mechanical properties of a typical Ni-based superalloy was researched.The optimum parameters of P=170 W,V=0.8 m/s were determined,under which the SLMed samples exhibited both the largest relative density of 99.57%and the best mechanical properties,including the microhardness(329.3±3.8 HV),yield strength(726±8.1 MPa),ultimate tensile strength(900±5.9 MPa)and elongation((31.9±0.24)%).The average grain size ranges of SLMed samples are from 15.2 to 17.4μm,with a typical mixed grain structure.Owing to the high cooling rate and remelting during SLM process,a large number of low-angle grain boundaries(LAGBs),dislocations and sub-grains were formed,and the fraction of LAGBs reached above 65%.At the same time,the content of low-Σcoincidence site lattice(CSL)boundaries was mostly less than 1%,while there was almost noγ′phase precipitated in the matrix.The texture of SLMed samples was weak,and there was no obvious preferred growth direction.Combining with the microstructure characterization,both grain refinement strengthening and dislocation strengthening were considered as the main strengthening mechanisms.Moreover,the fracture mechanism of the optimum sample belonged to ductile fracture.展开更多
基金supported in part by Zhejiang Provincial Natural Science Foundation of China under Grant nos.LZ22F020002 and LY22F020003National Natural Science Foundation of China under Grant nos.61772018 and 62002226the key project of Humanities and Social Sciences in Colleges and Universities of Zhejiang Province under Grant no.2021GH017.
文摘The fast proliferation of edge devices for the Internet of Things(IoT)has led to massive volumes of data explosion.The generated data is collected and shared using edge-based IoT structures at a considerably high frequency.Thus,the data-sharing privacy exposure issue is increasingly intimidating when IoT devices make malicious requests for filching sensitive information from a cloud storage system through edge nodes.To address the identified issue,we present evolutionary privacy preservation learning strategies for an edge computing-based IoT data sharing scheme.In particular,we introduce evolutionary game theory and construct a payoff matrix to symbolize intercommunication between IoT devices and edge nodes,where IoT devices and edge nodes are two parties of the game.IoT devices may make malicious requests to achieve their goals of stealing privacy.Accordingly,edge nodes should deny malicious IoT device requests to prevent IoT data from being disclosed.They dynamically adjust their own strategies according to the opponent's strategy and finally maximize the payoffs.Built upon a developed application framework to illustrate the concrete data sharing architecture,a novel algorithm is proposed that can derive the optimal evolutionary learning strategy.Furthermore,we numerically simulate evolutionarily stable strategies,and the final results experimentally verify the correctness of the IoT data sharing privacy preservation scheme.Therefore,the proposed model can effectively defeat malicious invasion and protect sensitive information from leaking when IoT data is shared.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11464004 and 11864006)the State Scholarship Fund,China(Grant No.20173015)Guizhou Scientific and Technological Program,China(Grant No.20185781)
文摘With a view of detecting the effects of macromolecular crowding on the phase transition of DNA compaction confined in spherical space,Monte Carlo simulations of DNA compaction in free space,in confined spherical space without crowders and in confined spherical space with crowders were performed separately.The simulation results indicate that macromolecular crowding effects on DNA compaction are dominant over the roles of multivalent counterions.In addition,effects of temperature on the phase transition of DNA compaction have been identified in confined spherical space with different radii.In confined spherical space without crowders,the temperature corresponding to phase transition depends on the radius of the confined spherical space linearly.In contrast,with the addition of crowders to the confined spherical space,effects of temperature on the phase transition of DNA compaction become insignificant,whereas the phase transition at different temperatures strongly depends on the size of crowder,and the critical volume fraction of crowders pertains to the diameter of crowder linearly.
基金the National Natural Science Foundation of China(Grant Nos.11704167,11704317,and 11574122).
文摘We present detailed investigations of structural and static/dynamic magnetic properties of hydrogenated hcp-Co_(80)^(57)Fe_(4)Ir_(16) soft magnetic thin films.Two different kinds of defects,i.e.,destructive and non-destructive,were demonstrated by controlling the negative bias voltage of the hydrogenation process.Our results show that the structure and magnetic properties of our sample can be tuned by the density of the induced defects.These results provide better understanding of the hydrogenation effect and thus can be used in the future for materials processing to meet the requirements of different devices.
基金Acknowledgments This work was supported by the National Natural Science Foundation of China （Grant No. 10647005） and Science and Technology Foundation of Guizhou Province, China （Grant No. 20090060）.
基金the National Natural Science Foundation of China(Grant No.52102123)Natural Science Foundation of Sichuan Province(Grant No.2022NSFSC2008,and Grant No.2023NSFSC0442)the China Postdoctoral Science Foundation(2022M710619).
文摘Garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)is one of the most promising solid-state electrolytes(SSEs).However,the application of LLZO is limited by structural instability,low ionic conductivity,and poor lithium stability.To obtain a garnet-type solid electrolyte with a stable structure and high ionic conductivity,a series of TaeCe co-doping cubic Li_(6.4)La_(3)Zr_(1.4-x)Ta_(0.6)Ce_(x)O_(12)(LLZTCO,x=,0.02,0.04,0.06,0.08,0.10,0.20,0.30)electrolytes were successfully synthesized through conventional solid-phase method.The Ta^(5+)doping can introduce more lithium vacancies and effectively maintain the stability of the cubic phase.The Ce^(4+)with a larger ionic radius is introduced into the lattice to widen the Lit migration bottleneck size,which significantly increased the ionic conductivity to 1.05×10^(-3)S/cm.It also shows excellent stability to lithium metal by the optimization of Lit transport channel.Li||LLZTCO||Li symmetric cells can cycle stably for more than 6000 h at a current density of 0.1 mA/cm^(2)without any surface modifications.The commercialization potential of LLZTCO samples in all solid-state lithium batteries(ASSLBs)is confirmed by the prepared LiFePO_(4)||LLZTCO||Li cells with a capacity retention rate of 98%after 100 cycles at 0.5C.This new co-doping method presents a practical solution for the realization of high-performance ASSLBs.
基金the Project of Natural Science Foundation of Shandong Province(No.ZR2021ME234).
文摘The thermal deformation behavior of a novel CrFeNiSi_(0.15)medium entropy alloy(MEA)was studied via isothermal compression experiments,with the processing parameter range of 900–1200℃and 0.001–1 s^(−1).According to experimental data,the modified constitutive equation had been obtained,which precisely predicted the flow behavior of CrFeNiSi_(0.15)MEA during thermal deformation.At the same time,the processing map was established on the basis of the dynamic material model(DMM)theory.According to the map,the optimal processing parameters were determined at 1130–1200℃/0.06–1 s−1,under which the power dissipation efficiency could reach above 34%.The peak efficiency was above 38%,which occurred at 1200℃/1 s^(−1).In such parameter,complete dynamic recrystallization(DRX)also occurred.The flow instability of CrFeNiSi_(0.15)MEA was estimated to occur at 900–985℃/0.12–1 s^(−1),which was shown as grain boundaries cracking.Furthermore,both the continuous DRX(CDRX)and discontinuous DRX(DDRX)occurred simultaneously during thermal deformation.Meanwhile,some twins were also newly formed during DRX process,most of which were primary twins.The occurrence of twinning was beneficial to promote the development of DRX behavior.
文摘The California Department of Transportation(Caltrans) has been using scrap tire rubber in asphalt pavements since the 1970 s in chip seals and the 1980 s in rubberized hot mix asphalt(RHMA).Both the wet(field blend) and dry processes were used in early trials.Caltrans has also used rubber modified binders containing both crumb rubber modifier and polymer modifier that could be manufactured at a refinery facility,a terminal blend wet process.Since the beginning of this century,Caltrans increased the use of scrap tire rubber in paving projects and invested considerable resources in developing technically sound,cost effective,and environmentally friendly strategies for using scrap tire rubber in roadway applications.By the end of year 2010,approximately 31%of all hot mix asphalt(HMA) placed by Caltrans was rubberized HMA,roughly 1.2 million tons.Caltrans efforts in using asphalt rubber products were also demonstrated in its research and technology development.These included the construction of two full-scale field experiments,five warranty projects,and an accelerated pavement study using a heavy vehicle simulator.Additionally,terminal blend asphalt rubber and rubberized warm mix asphalts began to be experimented on trial basis.This paper provides a comprehensive review of Caltrans experience over four decades with asphalt rubber products.Current practices and future outlook are also discussed.
基金the valuable discussion with X.P.Yang and the provision of synchrotron radiation at NSRL.This project was funded by National Natural Science foundation of China(Grant No.11704317)China Postdoctoral Science Foundation(Grant No.2016M602064)We also acknowledge the supports by the Natural Science Foundation of Shenzhen University(Grant No.827-000198)。
文摘Hydrogenation of transition metal oxides offers a powerful platform to tailor physical functionalities as well as for potential applications in modern electronic technologies.An ideal nondestructive and efficient hydrogen incorporation approach is important for the realistic technological applications.We demonstrate the proton injection on SrCro3 thin films via an efficient low-energy hydrogen plasma implantation experiments,without destroying the original lattice framework.Hydrogen ions accumu-late largely at the interfacial regions with amorphous character which extend about one-third of the total thickness.The Hx.SrCro3(HSCO)thin films appear like exfoliated layers which however retain the fully strained state with distorted perovskite structure.Proton doping induces the change of Cr oxidation state from Cr^4+to Cr^3+in HSCO thin films and a transition from metallic to insulat-ing phase.Our investigations suggest an attractive platform in manipulating the electronic phases in proton-based approaches and may offer a potential peeling off strategy for nanoscale devices through low-energy hydrogen plasma implantation approaches.
基金financially supported by the National Nature Science Foundation of China(No.52175297)the Project of Shandong Province Higher Educational Young Innovative Talent Introduction and Cultivation Team(Performance Enhancement of Deep Coal Mining Equipment).
文摘The influence of selective laser melting(SLM)process parameters on the microstructure and mechanical properties of a typical Ni-based superalloy was researched.The optimum parameters of P=170 W,V=0.8 m/s were determined,under which the SLMed samples exhibited both the largest relative density of 99.57%and the best mechanical properties,including the microhardness(329.3±3.8 HV),yield strength(726±8.1 MPa),ultimate tensile strength(900±5.9 MPa)and elongation((31.9±0.24)%).The average grain size ranges of SLMed samples are from 15.2 to 17.4μm,with a typical mixed grain structure.Owing to the high cooling rate and remelting during SLM process,a large number of low-angle grain boundaries(LAGBs),dislocations and sub-grains were formed,and the fraction of LAGBs reached above 65%.At the same time,the content of low-Σcoincidence site lattice(CSL)boundaries was mostly less than 1%,while there was almost noγ′phase precipitated in the matrix.The texture of SLMed samples was weak,and there was no obvious preferred growth direction.Combining with the microstructure characterization,both grain refinement strengthening and dislocation strengthening were considered as the main strengthening mechanisms.Moreover,the fracture mechanism of the optimum sample belonged to ductile fracture.
