Metallic lithium(Li)is considered the“Holy Grail”anode material for the nextgeneration of Li batteries with high energy density owing to the extraordinary theoretical specific capacity and the lowest negative electr...Metallic lithium(Li)is considered the“Holy Grail”anode material for the nextgeneration of Li batteries with high energy density owing to the extraordinary theoretical specific capacity and the lowest negative electrochemical potential.However,owing to inhomogeneous Li-ion flux,Li anodes undergo uncontrollable Li deposition,leading to limited power output and practical applications.Carbon materials and their composites with controllable structures and properties have received extensive attention to guide the homogeneous growth of Li to achieve high-performance Li anodes.In this review,the correlation between the behavior of Li anode and the properties of carbon materials is proposed.Subsequently,we review emerging strategies for rationally designing high-performance Li anodes with carbon materials,including interface engineering(stabilizing solid electrolyte interphase layer and other functionalized interfacial layer)and architecture design of host carbon(constructing three-dimension structure,preparing hollow structure,introducing lithiophilic sites,optimizing geometric effects,and compositing with Li).Based on the insights,some prospects on critical challenges and possible future research directions in this field are concluded.It is anticipated that further innovative works on the fundamental chemistry and theoretical research of Li anodes are needed.展开更多
Exploration of advanced gel polymer electrolytes(GPEs)represents a viable strategy for mitigating dendritic lithium(Li)growth,which is crucial in ensuring the safe operation of high energy density Li metal batteries(L...Exploration of advanced gel polymer electrolytes(GPEs)represents a viable strategy for mitigating dendritic lithium(Li)growth,which is crucial in ensuring the safe operation of high energy density Li metal batteries(LMBs).Despite this,the application of GPEs is still hindered by inadequate ionic conductivity,low Li^(+)transference number,and subpar physicochemical properties.Herein,Ti O_(2-x)nanofibers(NF)with oxygen vacancy defects were synthesized by a one-step process as inorganic fillers to enhance the thermal/mechanical/ionic-transportation performances of composite GPEs.Various characterizations and theoretical calculations reveal that the oxygen vacancies on the surface of Ti O_(2-x)NF accelerate the dissociation of Li PF_6,promote the rapid transfer of free Li^(+),and influence the formation of Li F-enriched solid electrolyte interphase.Consequently,the composite GPEs demonstrate enhanced ionic conductivity(1.90m S cm^(-1)at room temperature),higher lithium-ion transference number(0.70),wider electrochemical stability window(5.50 V),superior mechanical strength,excellent thermal stability(210℃),and improved compatibility with lithium,resulting in superior cycling stability and rate performance in both Li||Li,Li||Li Fe PO_(4),and Li||Li Ni_(0.8)Co_(0.1)Mn_(0.1)O_(2)cells.Overall,the synergistic influence of nanofiber morphology and enriched oxygen vacancy structure of fillers on electrochemical properties of composite GPEs is comprehensively investigated,thus,it is anticipated to shed new light on designing high-performance GPEs LMBs.展开更多
The population of non-alcoholic fatty liver disease(NAFLD)patients along with relevant advanced liver disease is projected to continue growing,because currently no medications are approved for treatment.Fecal microbio...The population of non-alcoholic fatty liver disease(NAFLD)patients along with relevant advanced liver disease is projected to continue growing,because currently no medications are approved for treatment.Fecal microbiota transplantation(FMT)is believed a novel and promising therapeutic approach based on the concept of the gut-liver axis in liver disease.There has been an increase in the number of pre-clinical and clinical studies evaluating FMT in NAFLD treatment,however,existing findings diverge on its effects.Herein,we briefly summarized the mechanism of FMT for NAFLD treatment,reviewed randomized controlled trials for evaluating its efficacy in NAFLD,and proposed the prospect of future trials on FMT.展开更多
The performance and reliability of ferroelectric thin films at temperatures around a few Kelvin are critical for their application in cryo-electronics.In this work,TiN/Hf_(0.5)Zr_(0.5)O_(2)/TiN capacitors that are fre...The performance and reliability of ferroelectric thin films at temperatures around a few Kelvin are critical for their application in cryo-electronics.In this work,TiN/Hf_(0.5)Zr_(0.5)O_(2)/TiN capacitors that are free from the wake-up effect are investigated systematically from room temperature(300 K)to cryogenic temperature(30 K).We observe a consistent decrease in permittivity(εr)and a progressive increase in coercive electric field(Ec)as temperatures decrease.Our investigation reveals exceptional stability in the double remnant polarization(2P_(r))of our ferroelectric thin films across a wide temperature range.Specifically,at 30 K,a 2P_(r)of 36μC/cm^(2)under an applied electric field of 3.0 MV/cm is achieved.Moreover,we observed a reduced fatigue effect at 30 K in comparison to 300 K.The stable ferroelectric properties and endurance characteristics demonstrate the feasibility of utilizing HfO_(2)based ferroelectric thin films for cryo-electronics applications.展开更多
Human mobility prediction is important for many applications.However,training an accurate mobility prediction model requires a large scale of human trajectories,where privacy issues become an important problem.The ris...Human mobility prediction is important for many applications.However,training an accurate mobility prediction model requires a large scale of human trajectories,where privacy issues become an important problem.The rising federated learning provides us with a promising solution to this problem,which enables mobile devices to collaboratively learn a shared prediction model while keeping all the training data on the device,decoupling the ability to do machine learning from the need to store the data in the cloud.However,existing federated learningbased methods either do not provide privacy guarantees or have vulnerability in terms of privacy leakage.In this paper,we combine the techniques of data perturbation and model perturbation mechanisms and propose a privacy-preserving mobility prediction algorithm,where we add noise to the transmitted model and the raw data collaboratively to protect user privacy and keep the mobility prediction performance.Extensive experimental results show that our proposed method significantly outperforms the existing stateof-the-art mobility prediction method in terms of defensive performance against practical attacks while having comparable mobility prediction performance,demonstrating its effectiveness.展开更多
With the rapid development ofmobile Internet,spatial crowdsourcing has becomemore andmore popular.Spatial crowdsourcing consists of many different types of applications,such as spatial crowd-sensing services.In terms ...With the rapid development ofmobile Internet,spatial crowdsourcing has becomemore andmore popular.Spatial crowdsourcing consists of many different types of applications,such as spatial crowd-sensing services.In terms of spatial crowd-sensing,it collects and analyzes traffic sensing data from clients like vehicles and traffic lights to construct intelligent traffic prediction models.Besides collecting sensing data,spatial crowdsourcing also includes spatial delivery services like DiDi and Uber.Appropriate task assignment and worker selection dominate the service quality for spatial crowdsourcing applications.Previous research conducted task assignments via traditional matching approaches or using simple network models.However,advanced mining methods are lacking to explore the relationship between workers,task publishers,and the spatio-temporal attributes in tasks.Therefore,in this paper,we propose a Deep Double Dueling Spatial-temporal Q Network(D3SQN)to adaptively learn the spatialtemporal relationship between task,task publishers,and workers in a dynamic environment to achieve optimal allocation.Specifically,D3SQNis revised through reinforcement learning by adding a spatial-temporal transformer that can estimate the expected state values and action advantages so as to improve the accuracy of task assignments.Extensive experiments are conducted over real data collected fromDiDi and ELM,and the simulation results verify the effectiveness of our proposed models.展开更多
The 2022 M_(S)6.8 Luding earthquake is the strongest earthquake in Sichuan Province, Western China, since the 2017 M_(S)7.0 Jiuzhaigou earthquake. It occurred on the Moxi fault in the southeastern segment of the Xians...The 2022 M_(S)6.8 Luding earthquake is the strongest earthquake in Sichuan Province, Western China, since the 2017 M_(S)7.0 Jiuzhaigou earthquake. It occurred on the Moxi fault in the southeastern segment of the Xianshuihe fault, a tectonically active and mountainous region with severe secondary earthquake disasters. To better understand the seismogenic mechanism and provide scientific support for future hazard mitigation, we summarize the preliminary results of the Luding earthquake, including seismotectonic background, seismicity and mainshock source characteristics and aftershock properties, and direct and secondary damage associated with the mainshock.The peak ground displacements in the NS and EW directions observed by the nearest GNSS station SCCM are ~35 mm and ~55 mm, respectively, resulting in the maximum coseismic dislocation of 20 mm along the NWW direction, which is consistent with the sinistral slip on the Xianshuihe fault. Back-projection of teleseismic P waves suggest that the mainshock rupture propagated toward south-southeast. The seismic intensity of the mainshock estimated from the back-projection results indicates a Mercalli scale of Ⅷ or above near the ruptured area,consistent with the results from instrumental measurements and field surveys. Numerous aftershocks were reported, with the largest being M_(S)4.5. Aftershock locations(up to September 18, 2022) exhibit 3 clusters spanning an area of 100 km long and 30 km wide. The magnitude and rate of aftershocks decreased as expected, and the depths became shallower with time. The mainshock and two aftershocks show left-lateral strike-slip focal mechanisms. For the aftershock sequence, the b-value from the Gutenberg-Richter frequency-magnitude relationship, h-value, and p-value for Omori’s law for aftershock decay are 0.81, 1.4, and 1.21, respectively, indicating that this is a typical mainshock-aftershock sequence. The low b-value implies high background stress in the hypocenter region. Analysis from remote sensing satellite images and UAV data shows that the distribution of earthquake-triggered landslides was consistent with the aftershock area. Numerous small-size landslides with limited volumes were revealed, which damaged or buried the roads and severely hindered the rescue process.展开更多
Peer-to-peer(P2P)spectrum sharing and energy trading are promising solutions to locally satisfy spectrum and energy demands in power Internet of Things(IoT).However,implementation of largescale P2P spectrum sharing an...Peer-to-peer(P2P)spectrum sharing and energy trading are promising solutions to locally satisfy spectrum and energy demands in power Internet of Things(IoT).However,implementation of largescale P2P spectrum sharing and energy trading confronts security and privacy challenges.In this paper,we exploit consortium blockchain and Directed Acyclic Graph(DAG)to propose a new secure and distributed spectrum sharing and energy trading framework in power IoT,named spectrum-energy chain,where a set of local aggregators(LAGs)cooperatively confirm the identity of the power devices by utilizing consortium blockchain,so as to form a main chain.Then,the local power devices verify spectrum and energy micro-transactions simultaneously but asynchronously to form local spectrum tangle and local energy tangle,respectively.Moreover,an iterative double auction based micro transactions scheme is designed to solve the spectrum and energy pricing and the amount of shared spectrum and energy among power devices.Security analysis and numerical results illustrate that the developed spectrum-energy chain and the designed iterative double auction based microtransactions scheme are secure and efficient for spectrum sharing and energy trading in power IoT.展开更多
Commercial application of lithium-sulfur(Li-S) batteries is hindered by the insulating nature of sulfur and the dissolution of polysulfides. Here, a bioinspired 3D urchin-like N-doped Murray's carbon nanostructure...Commercial application of lithium-sulfur(Li-S) batteries is hindered by the insulating nature of sulfur and the dissolution of polysulfides. Here, a bioinspired 3D urchin-like N-doped Murray's carbon nanostructure(N-MCN) with interconnected micro-meso-macroporous structure and a polydopamine protection shell has been designed as an effective sulfur host for high-performance Li-S batteries. The advanced 3D hierarchically porous framework with the characteristics of the generalized Murray's law largely improves electrolyte diffusion, facilitates electrons/ions transfer and provides strong chemisorption for active species, leading to the synergistic structural and chemical confinement of polysulfides. As a result,the obtained P@S/N-MCN electrode with high areal sulfur loading demonstrates high capacity at high current densities after long cycles. This work reveals that following the generalized Murray's law is feasible to design high-performance sulfur cathode materials for potentially practical Li-S battery applications.展开更多
As typical quarternary copper-based chalcogenides,Cu–Zn–Sn–S nanocrystals(CZTS NCs)have emerged as a newfashioned electrocatalyst in hydrogen evolution reactions(HERs).Oleylamine(OM),a reducing surfactant and solve...As typical quarternary copper-based chalcogenides,Cu–Zn–Sn–S nanocrystals(CZTS NCs)have emerged as a newfashioned electrocatalyst in hydrogen evolution reactions(HERs).Oleylamine(OM),a reducing surfactant and solvent,plays a significant role in the assisting synthesis of CZTS NCs due to the ligand effect.Herein,we adopted a facile one-pot colloidal method for achieving the structure evolution of CZTS NCs from 2D nanosheets to 1D nanorods assisted through the continuous addition of OM.During the process,the mechanism of OM-induced morphology evolution was further discussed.When merely adding pure 1-dodecanethiol(DDT)as the solvent,the CZTS nanosheets were obtained.As OM was gradually added to the reaction,the CZTS NCs began to grow along the sides of the nanosheets and gradually shrink at the top,followed by the formation of stable nanorods.In acidic electrolytic conditions,the CZTS NCs with 1.0 OM addition display the optimal HER activity with a low overpotential of 561 m V at 10 m A/cm^(2) and a small Tafel slope of 157.6 m V/dec compared with other CZTS samples.The enhancement of HER activity could be attributed to the contribution of the synergistic effect of the diverse crystal facets to the reaction.展开更多
Developing effective strategies to improve the initial Coulombic efficiency(ICE)and cycling stability of hard carbon(HC)anodes for sodium-ion batteries is the key to promoting the commercial application of HC.In this ...Developing effective strategies to improve the initial Coulombic efficiency(ICE)and cycling stability of hard carbon(HC)anodes for sodium-ion batteries is the key to promoting the commercial application of HC.In this paper,homotype heterojunctions are designed on HC to induce the generation of stable solid electrolyte interfaces,which can effectively increase the ICE of HC from 64.7%to 81.1%.The results show that using a simple surface engineering strategy to construct a homotypic amorphous Al_(2)O_(3) layer on the HC could shield the active sites,and further inhibit electrolyte decomposition and side effects occurrence.Particularly,due to the suppression of continuous decomposition of NaPF 6 in ester-based electrolytes,the accumulation of NaF could be reduced,leading to the formation of thinner and denser solid electrolyte interface films and a decrease in the interface resistance.The HC anode can not only improve the ICE but elevate its sodium storage performance based on this homotype heterojunction composed of HC and Al_(2)O_(3).The optimized HC anode exhibits an outstanding reversible capacity of 321.5mAhg^(−1) at 50mAg^(−1).The cycling stability is also improved effectively,and the capacity retention rate is 86.9%after 2000 cycles at 1Ag^(−1) while that of the untreated HC is only 52.6%.More importantly,the improved sodium storage behaviors are explained by electrochemical kinetic analysis.展开更多
Objective Delayed graft function(DGF)and early graft loss of renal grafts are determined by the quality of the kidneys from the deceased donor.As“non-traditional”risk factors,serum biomarkers of donors,such as lipid...Objective Delayed graft function(DGF)and early graft loss of renal grafts are determined by the quality of the kidneys from the deceased donor.As“non-traditional”risk factors,serum biomarkers of donors,such as lipids and electrolytes,have drawn increasing attention due to their effects on the postoperative outcomes of renal grafts.This study aimed to examine the value of these serum biomarkers for prediction of renal graft function.Methods The present study consecutively collected 306 patients who underwent their first single kidney transplantation(KT)from adult deceased donors in our center from January 1,2018 to December 31,2019.The correlation between postoperative outcomes[DGF and abnormal serum creatinine(SCr)after 6 and 12 months]and risk factors of donors,including gender,age,body mass index(BMI),past histories,serum lipid biomarkers[cholesterol,triglyceride,high-density lipoprotein(HDL)and low-density lipoprotein(DL)],and serum electrolytes(calcium and sodium)were analyzed and evaluated.Results(1)Donor age and pre-existing hypertension were significantly correlated with the incidence rate of DGF and high SCr level(≥2 mg/dL)at 6 and 12 months after KT(P<0.05);(2)The donor’s BMI was significantly correlated with the incidence rate of DGF after KT(P<0.05);(3)For serum lipids,merely the low level of serum HDL of the donor was correlated with the reduced incidence rate of high SCr level at 12 months after KT[P<0.05,OR(95%CI):0.425(0.202–0.97)];(4)The serum calcium of the donor was associated with the reduced incidence rate of high SCr level at 6 and 12 months after KT[P<0.05,OR(95%CI):0.184(0.045–0.747)and P<0.05,OR(95%CI):0.114(0.014–0.948),respectively].Conclusion The serum HDL and calcium of the donor may serve as predictive factors for the postoperative outcomes of renal grafts after KT,in addition to the donor’s age,BMI and pre-existing hypertension.展开更多
Lithium primary batteries are widely used in various fields where high energy densities and long storage times are in demand.However,studies on lithium primary batteries are currently focused on the gravimetric energy...Lithium primary batteries are widely used in various fields where high energy densities and long storage times are in demand.However,studies on lithium primary batteries are currently focused on the gravimetric energy densities of active materials and rarely account for the volumetric energy requirements of unmanned devices.Herein,CuF_(2)/CF_(x) composites are prepared via planetary ball milling(PBM)to improve the volumetric energy densities of lithium primary batteries using the high mass density of CuF_(2),achieving a maximum volumetric energy density of 4163.40 Wh L^(-1).The CuF_(2)/CF_(x) hybrid cathodes exhibit three distinct discharge plateaus rather than simple combinations of the discharge curves of their components.This phenomenon is caused by charge redistribution and lattice modulation on the contact surfaces of CuF_(2) and CF_(x) during PBM,which change the valence state of Cu and modify the electronic structures of the composites.As a result,CuF_(2)/CF_(x) hybrid cathodes exhibit unique discharge behaviors and improved rate capabilities,delivering a maximum power density of 11.16 kW kg^(-1)(25.56 kW L^(-1)).Therefore,it is a promising strategy to further improve the comprehensive performance of lithium primary batteries through the use of interfacial optimization among different fluoride cathodes.展开更多
Pepper(Capsicum annuum L.)is frequently challenged by various pathogens,among which Phytophthora capsici is the most devastating to pepper production.Red light signal acts as a positive induction of plant resistance a...Pepper(Capsicum annuum L.)is frequently challenged by various pathogens,among which Phytophthora capsici is the most devastating to pepper production.Red light signal acts as a positive induction of plant resistance against multiple pathogens.However,little is known about how the red light signal affects pepper resistance to P.capsici infection(PCI).Here,we report that red light regulates salicylic acid(SA)accumulation by activating elongated hypocotyl5(CaHY5),a basic leucine zipper(bZIP)transcription factor,thereby decreasing pepper susceptibility to PCI.Exogenous SA treatment reduced pepper susceptibility to PCI,while silencing of CaPHYB(a red light photoreceptor)increased its susceptibility.PCI significantly induced CaHY5 expression,and silencing of CaHY5 reduced SA accumulation,accompanied by decreases in the expression levels of phenylalanine ammonia-lyase 3(CaPAL3),CaPAL7,pathogenesis-related 1(CaPR1),and CaPR1L,which finally resulted in higher susceptibility of pepper to PCI.Moreover,CaHY5 was found to activate the expression of CaPAL3 and CaPAL7,which are essential for SA biosynthesis,by directly binding to their promoters.Further analysis revealed that exogenous SA treatment could restore the resistance of CaHY5-silenced pepper plants to PCI.Collectively,this study reveals a critical mechanism through which red light induces SA accumulation by regulating CaHY5-mediated CaPAL3 and CaPAL7 expression,leading to enhanced resistance to PCI.Moreover,red light-induced CaHY5 regulates pepper resistance to PCI,which may have implications for PCI control in protected vegetable production.展开更多
基金supported by the China Petrochemical Corporation(222260).
文摘Metallic lithium(Li)is considered the“Holy Grail”anode material for the nextgeneration of Li batteries with high energy density owing to the extraordinary theoretical specific capacity and the lowest negative electrochemical potential.However,owing to inhomogeneous Li-ion flux,Li anodes undergo uncontrollable Li deposition,leading to limited power output and practical applications.Carbon materials and their composites with controllable structures and properties have received extensive attention to guide the homogeneous growth of Li to achieve high-performance Li anodes.In this review,the correlation between the behavior of Li anode and the properties of carbon materials is proposed.Subsequently,we review emerging strategies for rationally designing high-performance Li anodes with carbon materials,including interface engineering(stabilizing solid electrolyte interphase layer and other functionalized interfacial layer)and architecture design of host carbon(constructing three-dimension structure,preparing hollow structure,introducing lithiophilic sites,optimizing geometric effects,and compositing with Li).Based on the insights,some prospects on critical challenges and possible future research directions in this field are concluded.It is anticipated that further innovative works on the fundamental chemistry and theoretical research of Li anodes are needed.
基金supported by the National Natural Science Foundation of China(52122702,52277215)the Natural Science Foundation of Heilongjiang Province of China(JQ2021E005)。
文摘Exploration of advanced gel polymer electrolytes(GPEs)represents a viable strategy for mitigating dendritic lithium(Li)growth,which is crucial in ensuring the safe operation of high energy density Li metal batteries(LMBs).Despite this,the application of GPEs is still hindered by inadequate ionic conductivity,low Li^(+)transference number,and subpar physicochemical properties.Herein,Ti O_(2-x)nanofibers(NF)with oxygen vacancy defects were synthesized by a one-step process as inorganic fillers to enhance the thermal/mechanical/ionic-transportation performances of composite GPEs.Various characterizations and theoretical calculations reveal that the oxygen vacancies on the surface of Ti O_(2-x)NF accelerate the dissociation of Li PF_6,promote the rapid transfer of free Li^(+),and influence the formation of Li F-enriched solid electrolyte interphase.Consequently,the composite GPEs demonstrate enhanced ionic conductivity(1.90m S cm^(-1)at room temperature),higher lithium-ion transference number(0.70),wider electrochemical stability window(5.50 V),superior mechanical strength,excellent thermal stability(210℃),and improved compatibility with lithium,resulting in superior cycling stability and rate performance in both Li||Li,Li||Li Fe PO_(4),and Li||Li Ni_(0.8)Co_(0.1)Mn_(0.1)O_(2)cells.Overall,the synergistic influence of nanofiber morphology and enriched oxygen vacancy structure of fillers on electrochemical properties of composite GPEs is comprehensively investigated,thus,it is anticipated to shed new light on designing high-performance GPEs LMBs.
基金the National Natural Science Foundation of China,No.82104525the Natural Science Foundation of the Jiangsu Higher Education Institutions of China,No.21KJB360009Health Commission of Zhejiang Province Scientific Research Foundation,No.2024KY247.
文摘The population of non-alcoholic fatty liver disease(NAFLD)patients along with relevant advanced liver disease is projected to continue growing,because currently no medications are approved for treatment.Fecal microbiota transplantation(FMT)is believed a novel and promising therapeutic approach based on the concept of the gut-liver axis in liver disease.There has been an increase in the number of pre-clinical and clinical studies evaluating FMT in NAFLD treatment,however,existing findings diverge on its effects.Herein,we briefly summarized the mechanism of FMT for NAFLD treatment,reviewed randomized controlled trials for evaluating its efficacy in NAFLD,and proposed the prospect of future trials on FMT.
基金supported by the National Key R&D Program of China under Grant No.2022YFB3608400National Natural Science Foundation of China under Grant Nos.61825404,61888102,and 62104044the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No.XDB44000000 and the project of MOE innovation platform.
文摘The performance and reliability of ferroelectric thin films at temperatures around a few Kelvin are critical for their application in cryo-electronics.In this work,TiN/Hf_(0.5)Zr_(0.5)O_(2)/TiN capacitors that are free from the wake-up effect are investigated systematically from room temperature(300 K)to cryogenic temperature(30 K).We observe a consistent decrease in permittivity(εr)and a progressive increase in coercive electric field(Ec)as temperatures decrease.Our investigation reveals exceptional stability in the double remnant polarization(2P_(r))of our ferroelectric thin films across a wide temperature range.Specifically,at 30 K,a 2P_(r)of 36μC/cm^(2)under an applied electric field of 3.0 MV/cm is achieved.Moreover,we observed a reduced fatigue effect at 30 K in comparison to 300 K.The stable ferroelectric properties and endurance characteristics demonstrate the feasibility of utilizing HfO_(2)based ferroelectric thin films for cryo-electronics applications.
基金supported in part by the National Key Research and Development Program of China under 2020AAA0106000the National Natural Science Foundation of China under U20B2060 and U21B2036supported by a grant from the Guoqiang Institute, Tsinghua University under 2021GQG1005
文摘Human mobility prediction is important for many applications.However,training an accurate mobility prediction model requires a large scale of human trajectories,where privacy issues become an important problem.The rising federated learning provides us with a promising solution to this problem,which enables mobile devices to collaboratively learn a shared prediction model while keeping all the training data on the device,decoupling the ability to do machine learning from the need to store the data in the cloud.However,existing federated learningbased methods either do not provide privacy guarantees or have vulnerability in terms of privacy leakage.In this paper,we combine the techniques of data perturbation and model perturbation mechanisms and propose a privacy-preserving mobility prediction algorithm,where we add noise to the transmitted model and the raw data collaboratively to protect user privacy and keep the mobility prediction performance.Extensive experimental results show that our proposed method significantly outperforms the existing stateof-the-art mobility prediction method in terms of defensive performance against practical attacks while having comparable mobility prediction performance,demonstrating its effectiveness.
基金supported in part by the Pioneer and Leading Goose R&D Program of Zhejiang Province under Grant 2022C01083 (Dr.Yu Li,https://zjnsf.kjt.zj.gov.cn/)Pioneer and Leading Goose R&D Program of Zhejiang Province under Grant 2023C01217 (Dr.Yu Li,https://zjnsf.kjt.zj.gov.cn/).
文摘With the rapid development ofmobile Internet,spatial crowdsourcing has becomemore andmore popular.Spatial crowdsourcing consists of many different types of applications,such as spatial crowd-sensing services.In terms of spatial crowd-sensing,it collects and analyzes traffic sensing data from clients like vehicles and traffic lights to construct intelligent traffic prediction models.Besides collecting sensing data,spatial crowdsourcing also includes spatial delivery services like DiDi and Uber.Appropriate task assignment and worker selection dominate the service quality for spatial crowdsourcing applications.Previous research conducted task assignments via traditional matching approaches or using simple network models.However,advanced mining methods are lacking to explore the relationship between workers,task publishers,and the spatio-temporal attributes in tasks.Therefore,in this paper,we propose a Deep Double Dueling Spatial-temporal Q Network(D3SQN)to adaptively learn the spatialtemporal relationship between task,task publishers,and workers in a dynamic environment to achieve optimal allocation.Specifically,D3SQNis revised through reinforcement learning by adding a spatial-temporal transformer that can estimate the expected state values and action advantages so as to improve the accuracy of task assignments.Extensive experiments are conducted over real data collected fromDiDi and ELM,and the simulation results verify the effectiveness of our proposed models.
基金the National Key R&D Program of China(No.2021YFC3000702-05)the Natural Science Foundation of China(41922025,41874062 and 42072248).
文摘The 2022 M_(S)6.8 Luding earthquake is the strongest earthquake in Sichuan Province, Western China, since the 2017 M_(S)7.0 Jiuzhaigou earthquake. It occurred on the Moxi fault in the southeastern segment of the Xianshuihe fault, a tectonically active and mountainous region with severe secondary earthquake disasters. To better understand the seismogenic mechanism and provide scientific support for future hazard mitigation, we summarize the preliminary results of the Luding earthquake, including seismotectonic background, seismicity and mainshock source characteristics and aftershock properties, and direct and secondary damage associated with the mainshock.The peak ground displacements in the NS and EW directions observed by the nearest GNSS station SCCM are ~35 mm and ~55 mm, respectively, resulting in the maximum coseismic dislocation of 20 mm along the NWW direction, which is consistent with the sinistral slip on the Xianshuihe fault. Back-projection of teleseismic P waves suggest that the mainshock rupture propagated toward south-southeast. The seismic intensity of the mainshock estimated from the back-projection results indicates a Mercalli scale of Ⅷ or above near the ruptured area,consistent with the results from instrumental measurements and field surveys. Numerous aftershocks were reported, with the largest being M_(S)4.5. Aftershock locations(up to September 18, 2022) exhibit 3 clusters spanning an area of 100 km long and 30 km wide. The magnitude and rate of aftershocks decreased as expected, and the depths became shallower with time. The mainshock and two aftershocks show left-lateral strike-slip focal mechanisms. For the aftershock sequence, the b-value from the Gutenberg-Richter frequency-magnitude relationship, h-value, and p-value for Omori’s law for aftershock decay are 0.81, 1.4, and 1.21, respectively, indicating that this is a typical mainshock-aftershock sequence. The low b-value implies high background stress in the hypocenter region. Analysis from remote sensing satellite images and UAV data shows that the distribution of earthquake-triggered landslides was consistent with the aftershock area. Numerous small-size landslides with limited volumes were revealed, which damaged or buried the roads and severely hindered the rescue process.
基金supported by the National Key R&D Program of China(2020YFB1807801,2020YFB1807800)in part by Project Supported by Engineering Research Center of Mobile Communications,Ministry of Education(cqupt-mct-202003)+2 种基金in part by Key Lab of Information Network Security,Ministry of Public Security under Grant C19603in part by National Natural Science Foundation of China(Grant No.61901067 and 61901013)in part by Chongqing Municipal Natural Science Foundation(Grant No.cstc2020jcyj-msxmX0339).
文摘Peer-to-peer(P2P)spectrum sharing and energy trading are promising solutions to locally satisfy spectrum and energy demands in power Internet of Things(IoT).However,implementation of largescale P2P spectrum sharing and energy trading confronts security and privacy challenges.In this paper,we exploit consortium blockchain and Directed Acyclic Graph(DAG)to propose a new secure and distributed spectrum sharing and energy trading framework in power IoT,named spectrum-energy chain,where a set of local aggregators(LAGs)cooperatively confirm the identity of the power devices by utilizing consortium blockchain,so as to form a main chain.Then,the local power devices verify spectrum and energy micro-transactions simultaneously but asynchronously to form local spectrum tangle and local energy tangle,respectively.Moreover,an iterative double auction based micro transactions scheme is designed to solve the spectrum and energy pricing and the amount of shared spectrum and energy among power devices.Security analysis and numerical results illustrate that the developed spectrum-energy chain and the designed iterative double auction based microtransactions scheme are secure and efficient for spectrum sharing and energy trading in power IoT.
基金financially supported by National Key Research and Development Program of China [2016YFA0202602, 2021YFE0115800]National Natural Science Foundation of China [22275142, U22B6011, U20A20122, 21671155]+4 种基金Program of Introducing Talents of Discipline to Universities-Plan 111 from the Ministry of Science and Technology and the Ministry of Education of China [Grant No. B20002]Sinopec Ministry of Science and Technology Basic Prospective Research Project [218025-9]Natural Science Foundation of Hubei Province [2021CFB082]Scientific Research Foundation of Wuhan Institute of Technology [K2021042]the Open Key Fund Project of State Key Laboratory of Advanced Technology for Materials Synthesis and Processing [Wuhan University of Technology, 2022-KF-10]。
文摘Commercial application of lithium-sulfur(Li-S) batteries is hindered by the insulating nature of sulfur and the dissolution of polysulfides. Here, a bioinspired 3D urchin-like N-doped Murray's carbon nanostructure(N-MCN) with interconnected micro-meso-macroporous structure and a polydopamine protection shell has been designed as an effective sulfur host for high-performance Li-S batteries. The advanced 3D hierarchically porous framework with the characteristics of the generalized Murray's law largely improves electrolyte diffusion, facilitates electrons/ions transfer and provides strong chemisorption for active species, leading to the synergistic structural and chemical confinement of polysulfides. As a result,the obtained P@S/N-MCN electrode with high areal sulfur loading demonstrates high capacity at high current densities after long cycles. This work reveals that following the generalized Murray's law is feasible to design high-performance sulfur cathode materials for potentially practical Li-S battery applications.
基金partially supported by National Natural Science Foundation of China (12274021 and 62075005)。
文摘As typical quarternary copper-based chalcogenides,Cu–Zn–Sn–S nanocrystals(CZTS NCs)have emerged as a newfashioned electrocatalyst in hydrogen evolution reactions(HERs).Oleylamine(OM),a reducing surfactant and solvent,plays a significant role in the assisting synthesis of CZTS NCs due to the ligand effect.Herein,we adopted a facile one-pot colloidal method for achieving the structure evolution of CZTS NCs from 2D nanosheets to 1D nanorods assisted through the continuous addition of OM.During the process,the mechanism of OM-induced morphology evolution was further discussed.When merely adding pure 1-dodecanethiol(DDT)as the solvent,the CZTS nanosheets were obtained.As OM was gradually added to the reaction,the CZTS NCs began to grow along the sides of the nanosheets and gradually shrink at the top,followed by the formation of stable nanorods.In acidic electrolytic conditions,the CZTS NCs with 1.0 OM addition display the optimal HER activity with a low overpotential of 561 m V at 10 m A/cm^(2) and a small Tafel slope of 157.6 m V/dec compared with other CZTS samples.The enhancement of HER activity could be attributed to the contribution of the synergistic effect of the diverse crystal facets to the reaction.
基金supported by the National Natural Science Foundation of China(grant nos.21975026 and 22005033)the National Postdoctoral Program of China(no.BX20180037)+1 种基金China Postdoctoral Science Foundation(no.2018M640077)the Beijing Institute of Technology Research Fund Program for Young Scholars(no.XSQD-202108005).
文摘Developing effective strategies to improve the initial Coulombic efficiency(ICE)and cycling stability of hard carbon(HC)anodes for sodium-ion batteries is the key to promoting the commercial application of HC.In this paper,homotype heterojunctions are designed on HC to induce the generation of stable solid electrolyte interfaces,which can effectively increase the ICE of HC from 64.7%to 81.1%.The results show that using a simple surface engineering strategy to construct a homotypic amorphous Al_(2)O_(3) layer on the HC could shield the active sites,and further inhibit electrolyte decomposition and side effects occurrence.Particularly,due to the suppression of continuous decomposition of NaPF 6 in ester-based electrolytes,the accumulation of NaF could be reduced,leading to the formation of thinner and denser solid electrolyte interface films and a decrease in the interface resistance.The HC anode can not only improve the ICE but elevate its sodium storage performance based on this homotype heterojunction composed of HC and Al_(2)O_(3).The optimized HC anode exhibits an outstanding reversible capacity of 321.5mAhg^(−1) at 50mAg^(−1).The cycling stability is also improved effectively,and the capacity retention rate is 86.9%after 2000 cycles at 1Ag^(−1) while that of the untreated HC is only 52.6%.More importantly,the improved sodium storage behaviors are explained by electrochemical kinetic analysis.
基金The study was supported by the Innovation Team Fund Project of Hubei Province(No.WJ2021C001)the Key Research and Development Plan of Hubei Province(No.2022BCA015).
文摘Objective Delayed graft function(DGF)and early graft loss of renal grafts are determined by the quality of the kidneys from the deceased donor.As“non-traditional”risk factors,serum biomarkers of donors,such as lipids and electrolytes,have drawn increasing attention due to their effects on the postoperative outcomes of renal grafts.This study aimed to examine the value of these serum biomarkers for prediction of renal graft function.Methods The present study consecutively collected 306 patients who underwent their first single kidney transplantation(KT)from adult deceased donors in our center from January 1,2018 to December 31,2019.The correlation between postoperative outcomes[DGF and abnormal serum creatinine(SCr)after 6 and 12 months]and risk factors of donors,including gender,age,body mass index(BMI),past histories,serum lipid biomarkers[cholesterol,triglyceride,high-density lipoprotein(HDL)and low-density lipoprotein(DL)],and serum electrolytes(calcium and sodium)were analyzed and evaluated.Results(1)Donor age and pre-existing hypertension were significantly correlated with the incidence rate of DGF and high SCr level(≥2 mg/dL)at 6 and 12 months after KT(P<0.05);(2)The donor’s BMI was significantly correlated with the incidence rate of DGF after KT(P<0.05);(3)For serum lipids,merely the low level of serum HDL of the donor was correlated with the reduced incidence rate of high SCr level at 12 months after KT[P<0.05,OR(95%CI):0.425(0.202–0.97)];(4)The serum calcium of the donor was associated with the reduced incidence rate of high SCr level at 6 and 12 months after KT[P<0.05,OR(95%CI):0.184(0.045–0.747)and P<0.05,OR(95%CI):0.114(0.014–0.948),respectively].Conclusion The serum HDL and calcium of the donor may serve as predictive factors for the postoperative outcomes of renal grafts after KT,in addition to the donor’s age,BMI and pre-existing hypertension.
基金financially supported by the National Key R&D Program of China(No.2016YFA0202302)the State Key Program of National Natural Science Foundation of China(Nos.51633007 and 52130303)the National Natural Science Foundation of China(Nos.51773147 and 51973151).
文摘Lithium primary batteries are widely used in various fields where high energy densities and long storage times are in demand.However,studies on lithium primary batteries are currently focused on the gravimetric energy densities of active materials and rarely account for the volumetric energy requirements of unmanned devices.Herein,CuF_(2)/CF_(x) composites are prepared via planetary ball milling(PBM)to improve the volumetric energy densities of lithium primary batteries using the high mass density of CuF_(2),achieving a maximum volumetric energy density of 4163.40 Wh L^(-1).The CuF_(2)/CF_(x) hybrid cathodes exhibit three distinct discharge plateaus rather than simple combinations of the discharge curves of their components.This phenomenon is caused by charge redistribution and lattice modulation on the contact surfaces of CuF_(2) and CF_(x) during PBM,which change the valence state of Cu and modify the electronic structures of the composites.As a result,CuF_(2)/CF_(x) hybrid cathodes exhibit unique discharge behaviors and improved rate capabilities,delivering a maximum power density of 11.16 kW kg^(-1)(25.56 kW L^(-1)).Therefore,it is a promising strategy to further improve the comprehensive performance of lithium primary batteries through the use of interfacial optimization among different fluoride cathodes.
基金supported by grants from the National Natural Science Foundation of China(32002030)Major Discipline Academic and Technical Leaders Training Program of Jiangxi Province,China-Young Talents Project(20204BCJL23044)+3 种基金the China Postdoctoral Science Foundation(2020 M682732)the Yan’an University Doctoral Research Initiation Project(YAU202313800)China Agriculture Research System of MOF and MARA(CARS-24-B-01)the earmarked fund for Jiangxi Agriculture Research System(JXARS-06).
文摘Pepper(Capsicum annuum L.)is frequently challenged by various pathogens,among which Phytophthora capsici is the most devastating to pepper production.Red light signal acts as a positive induction of plant resistance against multiple pathogens.However,little is known about how the red light signal affects pepper resistance to P.capsici infection(PCI).Here,we report that red light regulates salicylic acid(SA)accumulation by activating elongated hypocotyl5(CaHY5),a basic leucine zipper(bZIP)transcription factor,thereby decreasing pepper susceptibility to PCI.Exogenous SA treatment reduced pepper susceptibility to PCI,while silencing of CaPHYB(a red light photoreceptor)increased its susceptibility.PCI significantly induced CaHY5 expression,and silencing of CaHY5 reduced SA accumulation,accompanied by decreases in the expression levels of phenylalanine ammonia-lyase 3(CaPAL3),CaPAL7,pathogenesis-related 1(CaPR1),and CaPR1L,which finally resulted in higher susceptibility of pepper to PCI.Moreover,CaHY5 was found to activate the expression of CaPAL3 and CaPAL7,which are essential for SA biosynthesis,by directly binding to their promoters.Further analysis revealed that exogenous SA treatment could restore the resistance of CaHY5-silenced pepper plants to PCI.Collectively,this study reveals a critical mechanism through which red light induces SA accumulation by regulating CaHY5-mediated CaPAL3 and CaPAL7 expression,leading to enhanced resistance to PCI.Moreover,red light-induced CaHY5 regulates pepper resistance to PCI,which may have implications for PCI control in protected vegetable production.