MXenes are a group of recently discovered 2D materials and have attracted extensive attention since their first report in 2011;they have shown excellent prospects for energy storage applications owing to their unique ...MXenes are a group of recently discovered 2D materials and have attracted extensive attention since their first report in 2011;they have shown excellent prospects for energy storage applications owing to their unique layered microstructure and tunable electrical properties.One major feature of MXenes is their tailorable surface terminations(e.g.,-F,-O,-OH).Numerous studies have indicated that the composition of the surface terminations can significantly impact the electrochemical properties of MXenes.Nonetheless,the underlying mechanisms are still poorly understood,mainly because of the difficulties in quantitative analysis and characterization.This review summarizes the latest research progress on MXene terminations.First,a systematic introduction to the approaches for preparing MXenes is presented,which generally dominates the surface terminations.Then,theoretical and experimental efforts regarding the surface terminations are discussed,and the influence of surface terminations on the electronic and electrochemical properties of MXenes are generalized.Finally,we present the significance and research prospects of MXene terminations.We expect this review to encourage research on MXenes and provide guidance for usingthese materials for batteries and supercapacitors.展开更多
The Western Sichuan Foreland Basin(WSFB)in South China,a prolific hydrocarbon province,exhibits complex structural deformation influenced by Triassic salt tectonics.This paper integrates seismic data and well data to ...The Western Sichuan Foreland Basin(WSFB)in South China,a prolific hydrocarbon province,exhibits complex structural deformation influenced by Triassic salt tectonics.This paper integrates seismic data and well data to elucidate the role of Middle-Lower Triassic evaporite layers in shaping basin structures,focusing on Xinchang Tectonic Zone(XTZ).Salt layers facilitated decoupled deformation between supra-and sub-salt sequences,forming salt pillows and fault-related folds.Three distinct structural trends were identified in XTZ.Key findings reveal that salt thickness variations correlate with deformation styles:thicker salt promoted detachment folding,while thinner salt led to hard-linked fault systems.Sub-salt E-NE trending reverse faults formed horsetail terminations associated with the Pengzhou faults(PzF),deviating from the primary Longmenshan thrust belt(LmsTB)orientation.Structural evolution occurred in three stages:(1)Indosinian salt deposition and foreland basin initiation;(2)Yanshanian eastward propagation of thrust systems with salt-driven detachment folding;(3)Himalayan reactivation overprinting earlier structures with sub-NS trending folds.This work establishes a direct link between salt layers and structural traps,demonstrating how salt acted as a critical detachment layer during multi-stage compression.Results provide insights into the gas exploration of the Late Triassic Xujiahe Formation,emphasizing the importance of salt-influenced deformation in foreland basin systems.展开更多
This work presents a systematic analysis of proton-induced total ionizing dose(TID)effects in 1.2 k V silicon carbide(SiC)power devices with various edge termination structures.Three edge terminations including ring-a...This work presents a systematic analysis of proton-induced total ionizing dose(TID)effects in 1.2 k V silicon carbide(SiC)power devices with various edge termination structures.Three edge terminations including ring-assisted junction termination extension(RA-JTE),multiple floating zone JTE(MFZ-JTE),and field limiting rings(FLR)were fabricated and irradiated with45 Me V protons at fluences ranging from 1×10^(12) to 1×10^(14) cm^(-2).Experimental results,supported by TCAD simulations,show that the RA-JTE structure maintained stable breakdown performance with less than 1%variation due to its effective electric field redistribution by multiple P+rings.In contrast,MFZ-JTE and FLR exhibit breakdown voltage shifts of 6.1%and 15.2%,respectively,under the highest fluence.These results demonstrate the superior radiation tolerance of the RA-JTE structure under TID conditions and provide practical design guidance for radiation-hardened Si C power devices in space and other highradiation environments.展开更多
To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt b...To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt by physical property index,microscopic morphology,rheological testing,and infrared spectroscopy on multiple scales.The results show that the best preparation process for TB-modified asphalt is stirring at 260℃ for 4 h at 400 rpm,which significantly reduces the modification time of the asphalt.From a physical property viewpoint,the TB composite-modified asphalt sample with 5% styrene-butadiene-styrene(SBS)+1% aromatics+0.1% sulfur exhibits high-comprehensive,high-and low-temperature properties.More-over,its crosslinked mesh structure comprises black rubber particles uniformly interwoven in the middle,which further enhances the performance of the asphalt and results in an excellent performance formulation.In addition,the sample with 5%SBS content has a higher G*value and smaller δ value than that with 3%SBS content,indicating that its high-temperature resistance is improved.The effect of adding 3%SBS content on the viscoelastic ratio is,to some extent,less than that caused by 20% rubber powder.展开更多
With modern power utilities going green by utilising renewable energy technologies and the development of the smart power grid,high-voltage direct current(HVDC)technologies become more and more important in the energy...With modern power utilities going green by utilising renewable energy technologies and the development of the smart power grid,high-voltage direct current(HVDC)technologies become more and more important in the energy transmission.In particular,HVDC cable systems play a prominent role in undersea power transmission and offshore renewable energy integration.As an essential part of a complete HVDC cable system,the cable termination is one of the most critical components.The mathematical and physical background of HVDC cable systems is discussed and the development of various types of HVDC cable terminations is reviewed.Regarding the non-uniform field distribution,the influence of temperature on the non-linear conductivity is briefly discussed.Furthermore,faults of terminations caused by inappropriate installation and testing of cable systems are discussed.展开更多
In this study, the effects of high-energy proton radiation on the effectiveness of edge terminations using field limiting rings(FLRs) in 4 H–SiC junction barrier Schottky(JBS) diodes were examined in detail. The devi...In this study, the effects of high-energy proton radiation on the effectiveness of edge terminations using field limiting rings(FLRs) in 4 H–SiC junction barrier Schottky(JBS) diodes were examined in detail. The devices were irradiated using 5-MeV protons at fluences ranging from 5×10^12 cm^-2 to 5×10^14 cm^-2. Further, the reverse breakdown performances of the investigated devices were measured both before and after irradiation. Proton irradiation initially decreased the breakdown voltage(BV);subsequently, the BV was increased as the proton fluence increased. At a fluence of 5×10^13 cm^-2, the BV was reduced by approximately 18%, whereas it was reduced by approximately 5% at a higher proton fluence of 5×10^14 cm^-2. The related degradation mechanism that was associated with this phenomenon was also investigated using the numerical simulations of the current-voltage(I-V) and capacitance-voltage(C-V) characteristics of the device. The main contribution to the radiation-induced changes in BV originates from the variations of charge distribution at the SiO2/4 H–SiC interface and the reduction of the net carrier density in the drift region. Both the aforementioned variations affect the spread of the electric field in the FLR edge termination regions.展开更多
Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene g...Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene glycol(PEG),to immediately fuse closely apposed open ends of severed proximal and distal axons in rat sciatic nerves.We have previously reported that sciatic nerve axons repaired by PEG-fusion do not undergo Wallerian degeneration,and PEG-fused animals exhibit rapid(within 2–6 weeks)and extensive locomotor recovery.Furthermore,our previous report showed that PEG-fusion of severed sciatic motor axons was non-specific,i.e.,spinal motoneurons in PEG-fused animals were found to project to appropriate as well as inappropriate target muscles.In this study,we examined the consequences of PEG-fusion for sensory axons of the sciatic nerve.Young adult male and female rats(Sprague–Dawley)received either a unilateral single cut or ablation injury to the sciatic nerve and subsequent repair with or without(Negative Control)the application of PEG.Compound action potentials recorded immediately after PEG-fusion repair confirmed conduction across the injury site.The success of PEG-fusion was confirmed through Sciatic Functional Index testing with PEG-fused animals showing improvement in locomotor function beginning at 35 days postoperatively.At 2–42 days postoperatively,we anterogradely labeled sensory afferents from the dorsal aspect of the hindpaw following bilateral intradermal injection of wheat germ agglutinin conjugated horseradish peroxidase.PEG-fusion repair reestablished axonal continuity.Compared to unoperated animals,labeled sensory afferents ipsilateral to the injury in PEG-fused animals were found in the appropriate area of the dorsal horn,as well as inappropriate mediolateral and rostrocaudal areas.Unexpectedly,despite having intact peripheral nerves,similar reorganizations of labeled sensory afferents were also observed contralateral to the injury and repair.This central reorganization may contribute to the improved behavioral recovery seen after PEG-fusion repair,supporting the use of this novel repair methodology over currently available treatments.展开更多
This article investigates the anti-disturbance and stabilization problems for the nonlinear uncertain permanent magnet synchronous motor(PMSM)with stator voltage saturation and unknown load.A smooth switching mechanis...This article investigates the anti-disturbance and stabilization problems for the nonlinear uncertain permanent magnet synchronous motor(PMSM)with stator voltage saturation and unknown load.A smooth switching mechanism is presented to structure the adaptive integral terminal sliding mode control(SMC)strategy.The control design consists of compensation control and nominal control,which improves the rapidity and accuracy of trajectory tracking.The smooth saturation model based on the error function is applied to approximate the voltage saturation phenomenon.Additionally,to deal with the adverse effects of various unknown disturbances,including model parameter uncertainties and unknown external load disturbances,an improved disturbance observer(DO)is proposed.This observer effectively suppresses the fluctuations caused by fixed gain during the starting period of the system.Finally,the experimental results under different conditions show that the proposed strategy has good tracking and disturbance suppression performances.展开更多
This paper presents a robust finite-time visual servo control strategy for the tracking problem of omni-directional mobile manipulators(OMMs)subject to mismatched disturbances.First,the nonlinear kinematic model of vi...This paper presents a robust finite-time visual servo control strategy for the tracking problem of omni-directional mobile manipulators(OMMs)subject to mismatched disturbances.First,the nonlinear kinematic model of visual servoing for OMMs with mismatched disturbances is explicitly presented to solve the whole-body inverse kinematic problem.Second,a sliding mode observer augmented with an integral terminal sliding mode controller is proposed to handle these uncertainties and ensure that the system converges to a small region around the equilibrium point.The boundary layer technique is employed to mitigate the chattering phenomenon.Furthermore,a strict finite-time Lyapunov stability analysis is conducted.An experimental comparison between the proposed algorithm and a traditional position-based visual servo controller is carried out,and the results demonstrate the superiority of the proposed control algorithm.展开更多
Construction of LNG receiving terminals The scale of receiving terminals is expanding rapidly At the end of 1999,the state approved the Guangdong LNG Pilot Project,which opened the prelude to the construction of LNG r...Construction of LNG receiving terminals The scale of receiving terminals is expanding rapidly At the end of 1999,the state approved the Guangdong LNG Pilot Project,which opened the prelude to the construction of LNG receiving terminals.In 2006,China's first LNG receiving terminal,namely Dapeng LNG Receiving Terminal in Shenzhen,Guangdong Province,was put into operation,marking the beginning of the use of overseas natural gas in China.展开更多
BACKGROUND Children with critical acute abdominal conditions often undergo intestinal stoma surgery.AIM To explore the impact of a visual mobile terminal-based extended care model on caregiver competence for children ...BACKGROUND Children with critical acute abdominal conditions often undergo intestinal stoma surgery.AIM To explore the impact of a visual mobile terminal-based extended care model on caregiver competence for children with enterostomies.METHODS One hundred twenty children with enterostomies and their caregivers in a children's hospital in Beijing were divided into a control group and a study group.The control group(60 cases)received traditional telephone follow-up for continuity of care,while the study group(60 cases)used a visualization mobile terminal-based care model.The incidence of stoma-related complications,caregiver burden scale,and competence scores of children with stoma were compared between the two groups.RESULTS The primary caregiver burden score in the study group(37.22±3.17)was significantly lower than that in the control group(80.00±4.47),and the difference was statistically significant(P<0.05).Additionally,the caregiving ability score of the study group(172.08±3.49)was significantly higher than that of the control group(117.55±4.28;P<0.05).The total incidence of complications in the study group(11.7%,7/60)was significantly lower compared to the control group(33.3%,20/60;χ2=8.086,P=0.004).CONCLUSION The visual mobile terminal-based care model reduces caregiver burden,improves home care ability,lowers the incidence of complications and readmission rates,and supports successful second-stage reduction surgery for children with enterostomies.展开更多
In this paper,an improved error-rate sliding window decoder is proposed for spatially coupled low-density parity-check(SC-LDPC)codes.For the conventional sliding window decoder,the message retention mechanism causes u...In this paper,an improved error-rate sliding window decoder is proposed for spatially coupled low-density parity-check(SC-LDPC)codes.For the conventional sliding window decoder,the message retention mechanism causes unreliable messages along the edges of belief propagation(BP)decoding in the current window to be kept for subsequent window decoding.To improve the reliability of the retained messages during the window transition,a reliable termination method is embedded,where the retained messages undergo more reliable parity checks.Additionally,decoding failure is unavoidable and even causes error propagation when the number of errors exceeds the error-correcting capability of the window.To mitigate this problem,a channel value reuse mechanism is designed,where the received channel values are utilized to reinitialize the window.Furthermore,considering the complexity and performance of decoding,a feasible sliding optimized window decoding(SOWD)scheme is introduced.Finally,simulation results confirm the superior performance of the proposed SOWD scheme in both the waterfall and error floor regions.This work has great potential in the applications of wireless optical communication and fiber optic communication.展开更多
The approximately 3000 km long Tan-Lu fault zone(TLFZ)in East Asia is the longest continental strike-slip fault zone in the world and exemplifies how such a fault zone forms and propagates on a continental scale.Struc...The approximately 3000 km long Tan-Lu fault zone(TLFZ)in East Asia is the longest continental strike-slip fault zone in the world and exemplifies how such a fault zone forms and propagates on a continental scale.Structural and geochronological data from the TLFZ and surrounding regions indicate that the fault zone originated as NE/SW-striking sinistral ductile shear zones along an oblique continental convergence margin during the Triassic indentation collision between the North China Craton and the Yangtze Block.The Triassic fault zone,with a total length of about 720 km between the Dabie and Sulu orogens,exhibited an apparent sinistral offset of approximately 300 km along the TLFZ.The second stage of sinistral movement occurred in the earliest Late Jurassic,reactivating the pre-existing southern segment and propagating northwards to the southern coastline of present-day Bohai Bay,as well as forming a significant portion of the Dunhua-Mishan fault zone.The third stage of sinistral movement,in the earliest Early Cretaceous,was the most intense strike-slip movement of the Mesozoic,leading to the complete linkage of the TLFZ.This stage included further northward propagation of the southern-middle segment,both southward and northward propagation of the Dunhua-Mishan fault zone,as well as the formation of the entire Yilan-Yitong fault zone.The fourth stage,in the earliest Late Cretaceous,involved the reactivation of the entire TLFZ.Following its Triassic origin due to the indentation collision,the subduction of the Paleo-Pacific Plate and the subduction and closure of the Mongol-Okhotsk Ocean were responsible for the multi-stage sinistral movements from the Late Jurassic to the Cretaceous.The evolution of the TLFZ demonstrates that a continental-scale strike-slip fault zone(>1000 km long)forms through multiple stages of propagation and linkage in dynamic settings of plate convergence.展开更多
Mitochondria are semi-autonomous organelles present in eukaryotic cells,containing their own genome and transcriptional machinery.However,their functions are intricately linked to proteins encoded by the nuclear genom...Mitochondria are semi-autonomous organelles present in eukaryotic cells,containing their own genome and transcriptional machinery.However,their functions are intricately linked to proteins encoded by the nuclear genome.Mitochondrial transcription termination factors(mTERFs)are nucleic acid-binding proteins involved in RNA splicing and transcription termination within plant mitochondria and chloroplasts.Despite their recognized importance,the specific roles of mTERF proteins in maize remain largely unexplored.Here,we clone and functionally characterize the maize mTERF18 gene.Our findings reveal that mTERF18 mutations lead to severely undifferentiated embryos,resulting in abortive phenotypes.Early kernel exhibits abnormal basal endosperm transfer layer and a significant reduction in both starch and protein accumulation in mterf18.We identify the mTERF18 gene through mapping-based cloning and validate this gene through allelic tests.mTERF18 is widely expressed across various maize tissues and encodes a highly conserved mitochondrial protein.Transcriptome data reveal that mTERF18 mutations disrupt transcriptional termination of the nad6 gene,leading to undetectable levels of Nad6 protein and reduced complex I assembly and activity.Furthermore,transmission electron microscopy observation of mterf18 endosperm uncover severe mitochondrial defects.Collectively,these findings highlight the critical role of mTERF18 in mitochondrial gene transcription termination and its pivotal impact on maize kernel development.展开更多
1 Among many of my favorite books,the one that is called Tuesdays with Morrie has touched me the most.The book is a memoir by Mitch Albom that recounts the author's conversations with his former college professor,...1 Among many of my favorite books,the one that is called Tuesdays with Morrie has touched me the most.The book is a memoir by Mitch Albom that recounts the author's conversations with his former college professor,Morrie Schwartz.2 After learning that Morrie is terminally ill with amyotrophic lateral sclerosis(ALS),Mitch reconnects with him and begins visiting him every Tuesday.Through these meetings,Morrie shares his insights into life,love,work,family,aging and death.展开更多
Benzotriazole(BTA)-based A_(2)-A_1-D-A_1-A_(2)type wide-bandgap(WBG)non-fullerene acceptors(NFAs)have shown promising potential in indoor photovoltaic,and in-depth investigation of their structure-property relationshi...Benzotriazole(BTA)-based A_(2)-A_1-D-A_1-A_(2)type wide-bandgap(WBG)non-fullerene acceptors(NFAs)have shown promising potential in indoor photovoltaic,and in-depth investigation of their structure-property relationship is of great significance.Herein,we explored the chlorination effect of the side chain on the terminals.We introduced Cl atoms into the benzyl side chains in parent BTA5 to synthesize two NFAs,BTA5-Cl with mono-chlorinated benzyl groups and BTA5-2Cl containing bi-chlorinated benzyl groups.We chose D18-Cl with deep-energy levels and strong crystallinity to pair with these three acceptors,affording high photovoltage and photocurrent.With the stepwise chlorination,the open-circuit voltage(V_(OC))values decrease from 1.28,1.22,to 1.20 V,while the corresponding power conversion efficiencies(PCEs)improve from 5.07%,9.15%,to 10.96%.Compared with BTA5-based OSCs,introducing Cl atoms downshifts the energy levels and slightly increases the non-radiative energy loss(0.14<0.17<0.19 e V),resulting in a sequential decrease in VO C.However,more chlorine atom replacements produce more effective exciton dissociation,higher charge transfer,and balanced carrier mobility in the blend films,ultimately achieving better PCEs.This work indicates that chlorination of the benzyl group on the terminals can improve the device's performance,implying good application potential in indoor photovoltaics.展开更多
In the context of the diversity of smart terminals,the unity of the root of trust becomes complicated,which not only affects the efficiency of trust propagation,but also poses a challenge to the security of the whole ...In the context of the diversity of smart terminals,the unity of the root of trust becomes complicated,which not only affects the efficiency of trust propagation,but also poses a challenge to the security of the whole system.In particular,the solidification of the root of trust in non-volatile memory(NVM)restricts the system’s dynamic updating capability,which is an obvious disadvantage in a rapidly changing security environment.To address this issue,this study proposes a novel approach to generate root security parameters using static random access memory(SRAM)physical unclonable functions(PUFs).SRAM PUFs,as a security primitive,show great potential in lightweight security solutions due to their inherent physical properties,low cost and scalability.However,the stability of SRAM PUFs in harsh environments is a key issue.These environmental conditions include extreme temperatures,high humidity,and strong electromagnetic radiation,all of which can affect the performance of SRAM PUFs.In order to ensure the stability of root safety parameters under these conditions,this study proposes an integrated approach that covers not only the acquisition of entropy sources,but also the implementation of algorithms and configuration management.In addition,this study develops a series of reliability-enhancing algorithms,including adaptive parameter selection,data preprocessing,auxiliary data generation,and error correction,which are essential for improving the performance of SRAM PUFs in harsh environments.Based on these techniques,this study establishes six types of secure parameter generation mechanisms,which not only improve the security of the system,but also enhance its adaptability in variable environments.Through a series of experiments,we verify the effectiveness of the proposed method.Under 10 different environmental conditions,our method is able to achieve full recovery of security data with an error rate of less than 25%,which proves the robustness and reliability of our method.These results not only provide strong evidence for the stability of SRAM PUFs in practical applications,but also provide a new direction for future research in the field of smart terminal security.展开更多
基金funded by the National Natural Science Foundation of China(Nos.51731004 and 51902051)Natural Science Foundation of Jiangsu Province(No.BK20200386)。
文摘MXenes are a group of recently discovered 2D materials and have attracted extensive attention since their first report in 2011;they have shown excellent prospects for energy storage applications owing to their unique layered microstructure and tunable electrical properties.One major feature of MXenes is their tailorable surface terminations(e.g.,-F,-O,-OH).Numerous studies have indicated that the composition of the surface terminations can significantly impact the electrochemical properties of MXenes.Nonetheless,the underlying mechanisms are still poorly understood,mainly because of the difficulties in quantitative analysis and characterization.This review summarizes the latest research progress on MXene terminations.First,a systematic introduction to the approaches for preparing MXenes is presented,which generally dominates the surface terminations.Then,theoretical and experimental efforts regarding the surface terminations are discussed,and the influence of surface terminations on the electronic and electrochemical properties of MXenes are generalized.Finally,we present the significance and research prospects of MXene terminations.We expect this review to encourage research on MXenes and provide guidance for usingthese materials for batteries and supercapacitors.
基金supported by the National Science Foundation of China(Grant No.41602161,92255302)the National Science and Technology Major Project of China(Project No.2016ZX05033)Sinopec Science and Technology Development Project(Project No.P18089-1,P22085).
文摘The Western Sichuan Foreland Basin(WSFB)in South China,a prolific hydrocarbon province,exhibits complex structural deformation influenced by Triassic salt tectonics.This paper integrates seismic data and well data to elucidate the role of Middle-Lower Triassic evaporite layers in shaping basin structures,focusing on Xinchang Tectonic Zone(XTZ).Salt layers facilitated decoupled deformation between supra-and sub-salt sequences,forming salt pillows and fault-related folds.Three distinct structural trends were identified in XTZ.Key findings reveal that salt thickness variations correlate with deformation styles:thicker salt promoted detachment folding,while thinner salt led to hard-linked fault systems.Sub-salt E-NE trending reverse faults formed horsetail terminations associated with the Pengzhou faults(PzF),deviating from the primary Longmenshan thrust belt(LmsTB)orientation.Structural evolution occurred in three stages:(1)Indosinian salt deposition and foreland basin initiation;(2)Yanshanian eastward propagation of thrust systems with salt-driven detachment folding;(3)Himalayan reactivation overprinting earlier structures with sub-NS trending folds.This work establishes a direct link between salt layers and structural traps,demonstrating how salt acted as a critical detachment layer during multi-stage compression.Results provide insights into the gas exploration of the Late Triassic Xujiahe Formation,emphasizing the importance of salt-influenced deformation in foreland basin systems.
基金supported by the IITP(Institute for Information&Communications Technology Planning&Evaluation)under the ITRC(Information Technology Research Center)support program(IITP-2025-RS-2024-00438288)grant funded by the Korea government(MSIT)+1 种基金National Research Council of Science&Technology(NST)grant by the MSIT(Aerospace Semiconductor Strategy Research Project No.GTL25051-000)supported by the IC Design Education Center(IDEC),Korea。
文摘This work presents a systematic analysis of proton-induced total ionizing dose(TID)effects in 1.2 k V silicon carbide(SiC)power devices with various edge termination structures.Three edge terminations including ring-assisted junction termination extension(RA-JTE),multiple floating zone JTE(MFZ-JTE),and field limiting rings(FLR)were fabricated and irradiated with45 Me V protons at fluences ranging from 1×10^(12) to 1×10^(14) cm^(-2).Experimental results,supported by TCAD simulations,show that the RA-JTE structure maintained stable breakdown performance with less than 1%variation due to its effective electric field redistribution by multiple P+rings.In contrast,MFZ-JTE and FLR exhibit breakdown voltage shifts of 6.1%and 15.2%,respectively,under the highest fluence.These results demonstrate the superior radiation tolerance of the RA-JTE structure under TID conditions and provide practical design guidance for radiation-hardened Si C power devices in space and other highradiation environments.
基金Funded by the National Natural Science Foundation of China(No.52278446)。
文摘To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt by physical property index,microscopic morphology,rheological testing,and infrared spectroscopy on multiple scales.The results show that the best preparation process for TB-modified asphalt is stirring at 260℃ for 4 h at 400 rpm,which significantly reduces the modification time of the asphalt.From a physical property viewpoint,the TB composite-modified asphalt sample with 5% styrene-butadiene-styrene(SBS)+1% aromatics+0.1% sulfur exhibits high-comprehensive,high-and low-temperature properties.More-over,its crosslinked mesh structure comprises black rubber particles uniformly interwoven in the middle,which further enhances the performance of the asphalt and results in an excellent performance formulation.In addition,the sample with 5%SBS content has a higher G*value and smaller δ value than that with 3%SBS content,indicating that its high-temperature resistance is improved.The effect of adding 3%SBS content on the viscoelastic ratio is,to some extent,less than that caused by 20% rubber powder.
基金the National Key Research and Development Program of China in its project entitle‘Critical Technologies for Designing and Manufacturing±500 kV DC Cables and their Accessories’(grant no.2016YFB0900703).
文摘With modern power utilities going green by utilising renewable energy technologies and the development of the smart power grid,high-voltage direct current(HVDC)technologies become more and more important in the energy transmission.In particular,HVDC cable systems play a prominent role in undersea power transmission and offshore renewable energy integration.As an essential part of a complete HVDC cable system,the cable termination is one of the most critical components.The mathematical and physical background of HVDC cable systems is discussed and the development of various types of HVDC cable terminations is reviewed.Regarding the non-uniform field distribution,the influence of temperature on the non-linear conductivity is briefly discussed.Furthermore,faults of terminations caused by inappropriate installation and testing of cable systems are discussed.
基金supported by the National Natural Science Foundation of China (Grant No. 61774117)the National Key Basic Research Program of China (Grant No. 2015CB759600)+2 种基金Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2017JM6003)the Fundamental Research Funds for the Central Universities (Grant No. 20101185935)the Shaanxi Key Research and Development Program of China (No. 2018ZDXM-GY-008)
文摘In this study, the effects of high-energy proton radiation on the effectiveness of edge terminations using field limiting rings(FLRs) in 4 H–SiC junction barrier Schottky(JBS) diodes were examined in detail. The devices were irradiated using 5-MeV protons at fluences ranging from 5×10^12 cm^-2 to 5×10^14 cm^-2. Further, the reverse breakdown performances of the investigated devices were measured both before and after irradiation. Proton irradiation initially decreased the breakdown voltage(BV);subsequently, the BV was increased as the proton fluence increased. At a fluence of 5×10^13 cm^-2, the BV was reduced by approximately 18%, whereas it was reduced by approximately 5% at a higher proton fluence of 5×10^14 cm^-2. The related degradation mechanism that was associated with this phenomenon was also investigated using the numerical simulations of the current-voltage(I-V) and capacitance-voltage(C-V) characteristics of the device. The main contribution to the radiation-induced changes in BV originates from the variations of charge distribution at the SiO2/4 H–SiC interface and the reduction of the net carrier density in the drift region. Both the aforementioned variations affect the spread of the electric field in the FLR edge termination regions.
基金supported by the Department of Defense AFIRMⅢW81XWH-20-2-0029 grant subcontractLone Star Paralysis gift,UT POC19-1774-13 grant+1 种基金Neuraptive Therapeutics Inc.26-7724-56 grantNational Institutes of Health R01-NS128086(all to GDB)。
文摘Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene glycol(PEG),to immediately fuse closely apposed open ends of severed proximal and distal axons in rat sciatic nerves.We have previously reported that sciatic nerve axons repaired by PEG-fusion do not undergo Wallerian degeneration,and PEG-fused animals exhibit rapid(within 2–6 weeks)and extensive locomotor recovery.Furthermore,our previous report showed that PEG-fusion of severed sciatic motor axons was non-specific,i.e.,spinal motoneurons in PEG-fused animals were found to project to appropriate as well as inappropriate target muscles.In this study,we examined the consequences of PEG-fusion for sensory axons of the sciatic nerve.Young adult male and female rats(Sprague–Dawley)received either a unilateral single cut or ablation injury to the sciatic nerve and subsequent repair with or without(Negative Control)the application of PEG.Compound action potentials recorded immediately after PEG-fusion repair confirmed conduction across the injury site.The success of PEG-fusion was confirmed through Sciatic Functional Index testing with PEG-fused animals showing improvement in locomotor function beginning at 35 days postoperatively.At 2–42 days postoperatively,we anterogradely labeled sensory afferents from the dorsal aspect of the hindpaw following bilateral intradermal injection of wheat germ agglutinin conjugated horseradish peroxidase.PEG-fusion repair reestablished axonal continuity.Compared to unoperated animals,labeled sensory afferents ipsilateral to the injury in PEG-fused animals were found in the appropriate area of the dorsal horn,as well as inappropriate mediolateral and rostrocaudal areas.Unexpectedly,despite having intact peripheral nerves,similar reorganizations of labeled sensory afferents were also observed contralateral to the injury and repair.This central reorganization may contribute to the improved behavioral recovery seen after PEG-fusion repair,supporting the use of this novel repair methodology over currently available treatments.
基金supported by the National Natural Science Foundation under Grant 62273189the Shandong Province Natural Science Foundation under Grant ZR2021MF005Systems Science Plus Joint Research Program of Qingdao University under Grant XT2024201 of China supporting this research work.
文摘This article investigates the anti-disturbance and stabilization problems for the nonlinear uncertain permanent magnet synchronous motor(PMSM)with stator voltage saturation and unknown load.A smooth switching mechanism is presented to structure the adaptive integral terminal sliding mode control(SMC)strategy.The control design consists of compensation control and nominal control,which improves the rapidity and accuracy of trajectory tracking.The smooth saturation model based on the error function is applied to approximate the voltage saturation phenomenon.Additionally,to deal with the adverse effects of various unknown disturbances,including model parameter uncertainties and unknown external load disturbances,an improved disturbance observer(DO)is proposed.This observer effectively suppresses the fluctuations caused by fixed gain during the starting period of the system.Finally,the experimental results under different conditions show that the proposed strategy has good tracking and disturbance suppression performances.
基金supported by the Artificial Intelligence Innovation and Development Special Fund of Shanghai(No.2019RGZN01041)the National Natural Science Foundation of China(No.92048205).
文摘This paper presents a robust finite-time visual servo control strategy for the tracking problem of omni-directional mobile manipulators(OMMs)subject to mismatched disturbances.First,the nonlinear kinematic model of visual servoing for OMMs with mismatched disturbances is explicitly presented to solve the whole-body inverse kinematic problem.Second,a sliding mode observer augmented with an integral terminal sliding mode controller is proposed to handle these uncertainties and ensure that the system converges to a small region around the equilibrium point.The boundary layer technique is employed to mitigate the chattering phenomenon.Furthermore,a strict finite-time Lyapunov stability analysis is conducted.An experimental comparison between the proposed algorithm and a traditional position-based visual servo controller is carried out,and the results demonstrate the superiority of the proposed control algorithm.
文摘Construction of LNG receiving terminals The scale of receiving terminals is expanding rapidly At the end of 1999,the state approved the Guangdong LNG Pilot Project,which opened the prelude to the construction of LNG receiving terminals.In 2006,China's first LNG receiving terminal,namely Dapeng LNG Receiving Terminal in Shenzhen,Guangdong Province,was put into operation,marking the beginning of the use of overseas natural gas in China.
基金Supported by Project of the Health Bureau of the Logistics and Security Department of the Central Military Commission,No.145BHQ090003076XMilitary Family Planning Special Fund,No.21JSZ18.
文摘BACKGROUND Children with critical acute abdominal conditions often undergo intestinal stoma surgery.AIM To explore the impact of a visual mobile terminal-based extended care model on caregiver competence for children with enterostomies.METHODS One hundred twenty children with enterostomies and their caregivers in a children's hospital in Beijing were divided into a control group and a study group.The control group(60 cases)received traditional telephone follow-up for continuity of care,while the study group(60 cases)used a visualization mobile terminal-based care model.The incidence of stoma-related complications,caregiver burden scale,and competence scores of children with stoma were compared between the two groups.RESULTS The primary caregiver burden score in the study group(37.22±3.17)was significantly lower than that in the control group(80.00±4.47),and the difference was statistically significant(P<0.05).Additionally,the caregiving ability score of the study group(172.08±3.49)was significantly higher than that of the control group(117.55±4.28;P<0.05).The total incidence of complications in the study group(11.7%,7/60)was significantly lower compared to the control group(33.3%,20/60;χ2=8.086,P=0.004).CONCLUSION The visual mobile terminal-based care model reduces caregiver burden,improves home care ability,lowers the incidence of complications and readmission rates,and supports successful second-stage reduction surgery for children with enterostomies.
基金supported by the National Natural Science Foundation of China (No.62275193)。
文摘In this paper,an improved error-rate sliding window decoder is proposed for spatially coupled low-density parity-check(SC-LDPC)codes.For the conventional sliding window decoder,the message retention mechanism causes unreliable messages along the edges of belief propagation(BP)decoding in the current window to be kept for subsequent window decoding.To improve the reliability of the retained messages during the window transition,a reliable termination method is embedded,where the retained messages undergo more reliable parity checks.Additionally,decoding failure is unavoidable and even causes error propagation when the number of errors exceeds the error-correcting capability of the window.To mitigate this problem,a channel value reuse mechanism is designed,where the received channel values are utilized to reinitialize the window.Furthermore,considering the complexity and performance of decoding,a feasible sliding optimized window decoding(SOWD)scheme is introduced.Finally,simulation results confirm the superior performance of the proposed SOWD scheme in both the waterfall and error floor regions.This work has great potential in the applications of wireless optical communication and fiber optic communication.
基金funded by the Ministry of Science and Technology of the People's Republic of China(Grant 2024ZD1001301)the National Natural Science Foundation of China(Grants 42272241,42102254 and 41830213)the Fundamental Research Funds for the Central Universities(Grant JZ2023HGTB0238).
文摘The approximately 3000 km long Tan-Lu fault zone(TLFZ)in East Asia is the longest continental strike-slip fault zone in the world and exemplifies how such a fault zone forms and propagates on a continental scale.Structural and geochronological data from the TLFZ and surrounding regions indicate that the fault zone originated as NE/SW-striking sinistral ductile shear zones along an oblique continental convergence margin during the Triassic indentation collision between the North China Craton and the Yangtze Block.The Triassic fault zone,with a total length of about 720 km between the Dabie and Sulu orogens,exhibited an apparent sinistral offset of approximately 300 km along the TLFZ.The second stage of sinistral movement occurred in the earliest Late Jurassic,reactivating the pre-existing southern segment and propagating northwards to the southern coastline of present-day Bohai Bay,as well as forming a significant portion of the Dunhua-Mishan fault zone.The third stage of sinistral movement,in the earliest Early Cretaceous,was the most intense strike-slip movement of the Mesozoic,leading to the complete linkage of the TLFZ.This stage included further northward propagation of the southern-middle segment,both southward and northward propagation of the Dunhua-Mishan fault zone,as well as the formation of the entire Yilan-Yitong fault zone.The fourth stage,in the earliest Late Cretaceous,involved the reactivation of the entire TLFZ.Following its Triassic origin due to the indentation collision,the subduction of the Paleo-Pacific Plate and the subduction and closure of the Mongol-Okhotsk Ocean were responsible for the multi-stage sinistral movements from the Late Jurassic to the Cretaceous.The evolution of the TLFZ demonstrates that a continental-scale strike-slip fault zone(>1000 km long)forms through multiple stages of propagation and linkage in dynamic settings of plate convergence.
基金supported by the National Key Research and Development Program of China(2021YFF1000304)the National Natural Science Foundation of China(32222060)Anhui Agricultural University(RC422404)to J.Y.
文摘Mitochondria are semi-autonomous organelles present in eukaryotic cells,containing their own genome and transcriptional machinery.However,their functions are intricately linked to proteins encoded by the nuclear genome.Mitochondrial transcription termination factors(mTERFs)are nucleic acid-binding proteins involved in RNA splicing and transcription termination within plant mitochondria and chloroplasts.Despite their recognized importance,the specific roles of mTERF proteins in maize remain largely unexplored.Here,we clone and functionally characterize the maize mTERF18 gene.Our findings reveal that mTERF18 mutations lead to severely undifferentiated embryos,resulting in abortive phenotypes.Early kernel exhibits abnormal basal endosperm transfer layer and a significant reduction in both starch and protein accumulation in mterf18.We identify the mTERF18 gene through mapping-based cloning and validate this gene through allelic tests.mTERF18 is widely expressed across various maize tissues and encodes a highly conserved mitochondrial protein.Transcriptome data reveal that mTERF18 mutations disrupt transcriptional termination of the nad6 gene,leading to undetectable levels of Nad6 protein and reduced complex I assembly and activity.Furthermore,transmission electron microscopy observation of mterf18 endosperm uncover severe mitochondrial defects.Collectively,these findings highlight the critical role of mTERF18 in mitochondrial gene transcription termination and its pivotal impact on maize kernel development.
文摘1 Among many of my favorite books,the one that is called Tuesdays with Morrie has touched me the most.The book is a memoir by Mitch Albom that recounts the author's conversations with his former college professor,Morrie Schwartz.2 After learning that Morrie is terminally ill with amyotrophic lateral sclerosis(ALS),Mitch reconnects with him and begins visiting him every Tuesday.Through these meetings,Morrie shares his insights into life,love,work,family,aging and death.
基金support from the National Natural Science Foundation of China(Nos.52373176,52073067)。
文摘Benzotriazole(BTA)-based A_(2)-A_1-D-A_1-A_(2)type wide-bandgap(WBG)non-fullerene acceptors(NFAs)have shown promising potential in indoor photovoltaic,and in-depth investigation of their structure-property relationship is of great significance.Herein,we explored the chlorination effect of the side chain on the terminals.We introduced Cl atoms into the benzyl side chains in parent BTA5 to synthesize two NFAs,BTA5-Cl with mono-chlorinated benzyl groups and BTA5-2Cl containing bi-chlorinated benzyl groups.We chose D18-Cl with deep-energy levels and strong crystallinity to pair with these three acceptors,affording high photovoltage and photocurrent.With the stepwise chlorination,the open-circuit voltage(V_(OC))values decrease from 1.28,1.22,to 1.20 V,while the corresponding power conversion efficiencies(PCEs)improve from 5.07%,9.15%,to 10.96%.Compared with BTA5-based OSCs,introducing Cl atoms downshifts the energy levels and slightly increases the non-radiative energy loss(0.14<0.17<0.19 e V),resulting in a sequential decrease in VO C.However,more chlorine atom replacements produce more effective exciton dissociation,higher charge transfer,and balanced carrier mobility in the blend films,ultimately achieving better PCEs.This work indicates that chlorination of the benzyl group on the terminals can improve the device's performance,implying good application potential in indoor photovoltaics.
基金supported by National key Research and Development Program“Security Protection Technology for Critical Information Infrastructure of Distribution Network”(2022YFB3105100).
文摘In the context of the diversity of smart terminals,the unity of the root of trust becomes complicated,which not only affects the efficiency of trust propagation,but also poses a challenge to the security of the whole system.In particular,the solidification of the root of trust in non-volatile memory(NVM)restricts the system’s dynamic updating capability,which is an obvious disadvantage in a rapidly changing security environment.To address this issue,this study proposes a novel approach to generate root security parameters using static random access memory(SRAM)physical unclonable functions(PUFs).SRAM PUFs,as a security primitive,show great potential in lightweight security solutions due to their inherent physical properties,low cost and scalability.However,the stability of SRAM PUFs in harsh environments is a key issue.These environmental conditions include extreme temperatures,high humidity,and strong electromagnetic radiation,all of which can affect the performance of SRAM PUFs.In order to ensure the stability of root safety parameters under these conditions,this study proposes an integrated approach that covers not only the acquisition of entropy sources,but also the implementation of algorithms and configuration management.In addition,this study develops a series of reliability-enhancing algorithms,including adaptive parameter selection,data preprocessing,auxiliary data generation,and error correction,which are essential for improving the performance of SRAM PUFs in harsh environments.Based on these techniques,this study establishes six types of secure parameter generation mechanisms,which not only improve the security of the system,but also enhance its adaptability in variable environments.Through a series of experiments,we verify the effectiveness of the proposed method.Under 10 different environmental conditions,our method is able to achieve full recovery of security data with an error rate of less than 25%,which proves the robustness and reliability of our method.These results not only provide strong evidence for the stability of SRAM PUFs in practical applications,but also provide a new direction for future research in the field of smart terminal security.
