Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain sciences.In this article,we review the development of terahertz biot...Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain sciences.In this article,we review the development of terahertz biotechnology and its applications in the field of neuropsychiatry.Available evidence indicates promising prospects for the use of terahertz spectroscopy and terahertz imaging techniques in the diagnosis of amyloid disease,cerebrovascular disease,glioma,psychiatric disease,traumatic brain injury,and myelin deficit.In vitro and animal experiments have also demonstrated the potential therapeutic value of terahertz technology in some neuropsychiatric diseases.Although the precise underlying mechanism of the interactions between terahertz electromagnetic waves and the biosystem is not yet fully understood,the research progress in this field shows great potential for biomedical noninvasive diagnostic and therapeutic applications.However,the biosafety of terahertz radiation requires further exploration regarding its two-sided efficacy in practical applications.This review demonstrates that terahertz biotechnology has the potential to be a promising method in the field of neuropsychiatry based on its unique advantages.展开更多
The degradation of mechanical properties of overdischarge battery materials manifests as a significant effect on the energy density,safety,and cycle life of the batteries.However,establishing the correlation between d...The degradation of mechanical properties of overdischarge battery materials manifests as a significant effect on the energy density,safety,and cycle life of the batteries.However,establishing the correlation between depth of overdischarge and mechanical properties is still a significant challenge.Studying the correlation between depth of overdischarge and mechanical properties is of great significance to improving the energy density and the ability to resist abuse of the batteries.In this paper,the mechanical properties of the battery materials during the whole process of overdischarge from discharge to complete failure were studied.The effects of depth of overdischarge on the elastic modulus and hardness of the cathode of the battery,the tensile strength and the thermal shrinkage rate of the separator,and the performance of binder were investigated.The precipitation of Cu dendrites on the separator and cathode after dissolution of anode copper foil is a key factor affecting the performance of battery materials.The Cu dendrites attached to the cathode penetrate the separator,causing irreversible damage to the coating and base film of the separator,which leads to a sharp decline in the tensile strength,thermal shrinkage rate and other properties of the separator.In addition,the Cu dendrites wrapping the cathode active particles reduce the adhesion of the active particles binder.Meanwhile,the active particles are damaged,resulting in a significant decrease in the elastic modulus and hardness of the cathode.展开更多
Image fusion refers to extracting meaningful information from images of different sources or modalities,and then fusing them to generate more informative images that are beneficial for subsequent applications.In recen...Image fusion refers to extracting meaningful information from images of different sources or modalities,and then fusing them to generate more informative images that are beneficial for subsequent applications.In recent years,the growing data and computing resources have promoted the development of deep learning,and image fusion technology has continued to spawn new deep learning fusion methods based on traditional fusion methods.However,high-speed railroads,as an important part of life,have their unique industry characteristics of image data,which leads to different image fusion techniques with different fusion effects in high-speed railway scenes.This research work first introduces the mainstream technology classification of image fusion,further describes the downstream tasks that image fusion techniques may combine within high-speed railway scenes,and introduces the evaluation metrics of image fusion,followed by a series of subjective and objective experiments to completely evaluate the performance level of each image fusion method in different traffic scenes,and finally provides some possible future image fusion in the field of rail transportation of research.展开更多
1.A worldwide history of high-speed trains High-speed railway(HSR)is defined by the International Union of Railways(UIC)as new lines with design speeds above 250 kmh1 and upgraded existing lines with speeds of up to 2...1.A worldwide history of high-speed trains High-speed railway(HSR)is defined by the International Union of Railways(UIC)as new lines with design speeds above 250 kmh1 and upgraded existing lines with speeds of up to 200 kmh1[1].In China,HSR is defined as new passenger-dedicated lines designed for electric multiple unit(EMU)trains running at a speed of 250 kmh1 or above(actual or reserved),with an initial operation speed not lower than 200 kmh1[2].The worldwide development of HSRs and high-speed EMUs can be roughly divided into three stages:initial operation,line platform expansion,and rapid development.展开更多
Objectives:This study aimed to investigate the effect of motivational interviewing on the self-care behaviours in patients with chronic heart failure.Methods:Sixty-two hospitalized patients with chronic heart failure ...Objectives:This study aimed to investigate the effect of motivational interviewing on the self-care behaviours in patients with chronic heart failure.Methods:Sixty-two hospitalized patients with chronic heart failure were recruited in this study from April 2014 to April 2015 from a hospital.Twenty-nine patients were in the intervention group,and 33 patients were in the control group.Patients in the intervention group received four sessions of motivational interviewing,whereas those in the control group received traditional health education.At 2,4,and 8 weeks post-discharge,the intervention group underwent telephone follow-up based on motivational interviewing,whereas the control group underwent routine telephone follow-up.Primary outcome was measured using the Self-care of Heart Failure Index at baseline and at 2 months postdischarge.Results:Before intervention,the self-care behaviours scores were 79.00±48.80 in the intervention group and 88.68±29.26in the control group.No statistically significant differences were found between two groups in scores for each subscale and total scale(P>0.05).After intervention,the scores of self-care behaviours in the two groups were both improved at 155.13±35.65 for the intervention group and 115.44±22.82 for the control group with statistically significance(P<0.01).The score of self-care behaviours increased by 76.13 point in the intervention group on average,whereas 26.76 point in the control group.There was significant difference between increases in scores of self-care behaviours in two groups(P<0.01).Conclusions:The self-care behaviours of patients with chronic heart failure could be improved effectively through motivational interviewing.展开更多
The C (Cys) 2H (His) 2-type transcription factor is one of the most important transcription factors in plants and plays a regulatory role in the physiological responses of rice to abiotic stresses.A novel rice C2H2-ty...The C (Cys) 2H (His) 2-type transcription factor is one of the most important transcription factors in plants and plays a regulatory role in the physiological responses of rice to abiotic stresses.A novel rice C2H2-type zinc finger protein,abscisic acid (ABA)-drought-reactive oxygen species (ROS) 3 (OsADR3),was found to confer drought stress tolerance by enhancing antioxidant defense and regulating Os GPX1.Overexpression of OsADR3 in rice increased tolerance to drought stress by increasing ROS scavenging ability and ABA sensitivity.In contrast,CRISPR/Cas9-mediated knockout of osadr3 increased the sensitivity of rice to drought and oxidative stress.An exogenous ROS-scavenging reagent restored the droughtstress tolerance of osadr3-CRISPR plants.Global transcriptome analysis suggested that OsADR3 increased the expression of Os GPX1 under drought stress.Electrophoretic mobility shift,yeast one-hybrid,and dualluciferase reporter assays revealed that OsADR3 modified the expression of Os GPX1 by directly binding to its promoter.Knockdown of Os GPX1 repressed ROS scavenging ability under drought stress in OsADR3-overexpression plants.These findings suggest that OsADR3 plays a positive regulatory role in droughtstress tolerance by inducing antioxidant defense and associated with the ABA signaling pathway in rice.展开更多
Adaptive antenna arrays have been used to mitigate the interference on global navigation satellite system（GNSS） receivers. The performance of interference mitigation depends on the beamforming algorithms adopted by ...Adaptive antenna arrays have been used to mitigate the interference on global navigation satellite system（GNSS） receivers. The performance of interference mitigation depends on the beamforming algorithms adopted by the antenna array. However,the adaptive beamforming will change the array pattern in realtime, which has the potential to introduce phase center biases into the antenna array. For precise applications, these phase biases must be mitigated or compensated because they will bring errors in code phase and carrier phase measurements. A novel adaptive beamforming algorithm is proposed firstly, then the phase bias induced by the proposed algorithm is estimated, and finally a compensation strategy is addressed. Simulations demonstrate that the proposed beamforming algorithm suppresses effectively the strong interference and improves significantly the capturing performance of GNSS signals. Simultaneously, the bias compensation method avoids the loss of the carrier phase lock and reduces the phase measurement errors for GNSS receivers.展开更多
This paper introduces the high-speed electrical multiple unit （EMO） life cycle, including the design, manufacturing, testing, and maintenance stages. It also presents the train control and monitoring system （TCMS）...This paper introduces the high-speed electrical multiple unit （EMO） life cycle, including the design, manufacturing, testing, and maintenance stages. It also presents the train control and monitoring system （TCMS） software development platform, the TCMS testing and verification bench, the EMU driving simulation platform, and the EMU remote data transmittal and maintenance platform. All these platforms and benches combined together make up the EMU life cycle cost （LCC） system. Each platform facilitates EMU LCC management and is an important part of the system.展开更多
Objective Mechanisms of pulmonary vein isolation(PVI)for atrial fibrillation remain controversy.This study aimed to investigate the impact of PVI on vagal modulation to atria.Methods Eighteen adult mongrel dogs under ...Objective Mechanisms of pulmonary vein isolation(PVI)for atrial fibrillation remain controversy.This study aimed to investigate the impact of PVI on vagal modulation to atria.Methods Eighteen adult mongrel dogs under general anesthesia were randomly divided into two groups.Bilateral cervical sympathovagal trunks were decentralized and sympathetic effects was blocked by metoprolol administration.Atrial electrical remodeling(AER)was established by rapid right atrial pacing at the rate of 600 bpm for 30 minutes.PVI was performed in group A.Atrial effective refractory period(ERP),vulnerability window(VW)of atrial fibrillation,and sinus rhythm cycle length(SCL)were measured at baseline and during vagal stimulation before and after atrial rapid pacing with and without PVI at fight atrial appendage(RAA),left atrial appendage(LAA),distal coronary sinus(CSd)and proximal coronary sinus(CSp).Results(1)Effects of PVI on vagal modulation:Shortening of SCL during vagal stimulation decreased significantly after PVI compared with that before PVI in group A(P<0.001).Shortening of ERP during vagal stimulation decreaseed significantly after PVI compared with that before PVI(P<0.05).VW of atrial fibrillation during vagal stimulation decreased significantly after PVI compared with that before PVI(P<0.05).(2)Effects of PVI on AER:shortening of ERP before and after atrial rapid pacing increased significantly at baseline and vagal stimulation in group B compared with that in group A(P<0.05).VW during vagal stimulation increased significantly after atrial rapid pacing in group B(P<0.05).Conclusion PVI attenuates the vagal modulation to the atria,thereby decreases the susceptibility to atrial fibrillation mediated by vagal activity.PVI releases AER,which maybe contributes to the vagal denervation.Our study indicates that PVI not only can eradicate triggered foci but also modify substrates for AF.展开更多
Objective: To estimate the safety and efficacy of transcatheter arterial embolization(TAE) in the treatment of refractory hematuria of prostatic origin(RHPO).Methods: This retrospective study included 23 patients who ...Objective: To estimate the safety and efficacy of transcatheter arterial embolization(TAE) in the treatment of refractory hematuria of prostatic origin(RHPO).Methods: This retrospective study included 23 patients who underwent TAE for RHPO between May 2013 and August 2021. Technical and clinical success rates were calculated, and arteriogram findings and complications were detected.Results: Embolization was performed 24 times in 23 patients. Technical success was achieved in 24/24(100%)embolization procedures. Contrast agent extravasation was detected during 2 of the 24 angiographic procedures.Bilateral embolization was performed in 23(95.8%) of the 24 procedures. The clinical success rate was 21/23(91.3%), and hematuria stopped 1–4 days after TAE. No serious complications were observed.Conclusion: TAE is a safe and effective minimally invasive technique for treating patients with RHPO.展开更多
难熔高熵合金因其优异的高温屈服强度和抗软化性能而备受关注.然而,室温延展性差和较高的密度目前仍然是其加工以及应用需要面临的主要挑战.本文利用材料的固有特性作为合金设计原则,通过调控Mo浓度,制备了三种新型单相体心立方结构的Ti...难熔高熵合金因其优异的高温屈服强度和抗软化性能而备受关注.然而,室温延展性差和较高的密度目前仍然是其加工以及应用需要面临的主要挑战.本文利用材料的固有特性作为合金设计原则,通过调控Mo浓度,制备了三种新型单相体心立方结构的Ti3Zr1.5Nb((1-x))-MoxVAl_(0.25)(x=0.1,0.3,0.5,标记为Mo0.1,Mo0.3和Mo0.5)合金,这些合金都具有良好的拉伸延展性和低于6 g cm^(-3)的密度.高剪切模量Mo元素的引入促进了晶格畸变,从而提高了合金中的晶格摩擦应力以及屈服强度.铸态Mo0.3和Mo0.5合金均表现出超过1100 MPa的拉伸屈服强度,以及大于15%的断裂延伸率.Labusch模型计算结果表明,原子尺寸和剪切模量失配引起的固溶强化对屈服强度的影响最为显著.通过观察变形微观组织发现,由于存在高密度的位错界面,扭折带、位错壁以及泰勒晶格的形成能有效提高合金的应变硬化能力,使合金在展现高强度的同时保持足够的延展性.该研究为开发具有高强韧的单相难熔高熵合金提供了新的见解.展开更多
Graphene(Gr)reinforced high-entropy alloy(HEA)matrix composites are expected as potential candidates for next-generation structural applications in light of outstanding mechanical properties.A deep comprehension of th...Graphene(Gr)reinforced high-entropy alloy(HEA)matrix composites are expected as potential candidates for next-generation structural applications in light of outstanding mechanical properties.A deep comprehension of the underlying deformation mechanisms under extreme shock loading is of paramount importance,however,remains lacking due to experimentally technical limitations in existence.In the present study,by means of nonequilibrium molecular dynamics simulations,dynamic deformation behaviors and corresponding mechanisms in equiatomic FeNiCrCoCu HEA/Gr composite systems were investigated in terms of various shock velocities.The resistance to dislocation propagation imparted by Gr was corroborated to encourage the elevated local stress level by increasing the likelihood of dislocation interplays,which facilitated the onset of twins and hexagonal close-packed(HCP)martensite laths.Meanwhile,the advent of Gr was demonstrated to endow the HEA with an additional twinning pathway that induced a structural conversion from HCP to parent face-centered cubic(FCC)inside HCP martensite laths,different from the classical one that necessitated undergoing the intermediate procedure of extrinsic stacking fault(ESF)evolution.More than that,by virtue of an increase in flow stress,the transformation-induced plasticity(TRIP)effect was validated to be additionally evoked as the predominant strain accommodation mechanism at higher strains on the one hand,but which only assisted plasticity in pure systems,and on the other hand,can also act as an auxiliary regulation mode together with the twinning-induced plasticity(TWIP)effect under intermediate strains,but with enhanced contributions relative to pure systems.One may expect that TRIP and TWIP effects promoted by introducing Gr would considerably inspire a synergistic effect between strength and ductility,contributing to the exceptional shock-resistant performance of FeNiCrCoCu HEAs under extreme regimes.展开更多
High-entropy alloys(HEAs)possess immense potential for structural applications due to their excellent mechanical properties.Deeply understanding underlying deformation mechanisms under extreme regimes is crucial but s...High-entropy alloys(HEAs)possess immense potential for structural applications due to their excellent mechanical properties.Deeply understanding underlying deformation mechanisms under extreme regimes is crucial but still limited,due to the restrictions of existing experimental techniques.In the present study,dynamic deformation behaviors in equiatomic FeNiCrCoCu HEAs were investigated in terms of various shock velocities through nonequilibrium molecular dynamics simulations.The amorphous atoms by amorphization transformation were corroborated to be conducive to dislocation nucleation and propagation.Also,the dominant plasticity pattern was confirmed to be taken over by amorphization under higher velocities,while dislocation slips merely prevailed for lower shock ones.More importantly,for a shock velocity of 1.4 km/s,multi-level deformation modes appearing in deformation,first amorphization and then a combination of amorphization and dislocation slip,was demonstrated to substantially contribute to the shock wave attenuation.These interesting findings provide important implications for the dynamic deformation behaviors and corresponding mechanisms of the FeNiCrCoCu HEA system.展开更多
At present,the existing piezoelectric stick-slip actuators have an inherent back-slip problem,which greatly limits the development and application of stick-slip actuators.In order to inhibit the regression phenomenon,...At present,the existing piezoelectric stick-slip actuators have an inherent back-slip problem,which greatly limits the development and application of stick-slip actuators.In order to inhibit the regression phenomenon,a new bionic lemongrass stickslip actuator was prepared by using polymer PDMS to replicate natural biological surface.The surface microstructure of the grass was copied by PDMS,and the PDMS film was prepared.The rigid and flexible bionic friction pair was further prepared,and the flexible anisotropic PDMS stick slip actuator was developed.It was found that the anisotropic friction characteristics of the surface microstructure of the grass inhibited the anti-sliding motion,and the elastic potential energy of the PDMS film improved the output characteristics of the driver.By adjusting the input voltage to control the contact between the drive foot and the rotor,the rigid and flexible hybrid drive can be realized and the backsliding phenomenon can be suppressed.The actuator is compact,lightweight and can achieve high speed and high resolution output without preloading force,which has important application value in the field of fast and accurate positioning with load limitation.展开更多
基金supported by grants from the National Key R&D Program of China,No.2017YFC0909200(to DC)the National Natural Science Foundation of China,No.62075225(to HZ)+1 种基金Zhejiang Provincial Medical Health Science and Technology Project,No.2023XY053(to ZP)Zhejiang Provincial Traditional Chinese Medical Science and Technology Project,No.2023ZL703(to ZP).
文摘Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain sciences.In this article,we review the development of terahertz biotechnology and its applications in the field of neuropsychiatry.Available evidence indicates promising prospects for the use of terahertz spectroscopy and terahertz imaging techniques in the diagnosis of amyloid disease,cerebrovascular disease,glioma,psychiatric disease,traumatic brain injury,and myelin deficit.In vitro and animal experiments have also demonstrated the potential therapeutic value of terahertz technology in some neuropsychiatric diseases.Although the precise underlying mechanism of the interactions between terahertz electromagnetic waves and the biosystem is not yet fully understood,the research progress in this field shows great potential for biomedical noninvasive diagnostic and therapeutic applications.However,the biosafety of terahertz radiation requires further exploration regarding its two-sided efficacy in practical applications.This review demonstrates that terahertz biotechnology has the potential to be a promising method in the field of neuropsychiatry based on its unique advantages.
基金supported by the National Natural Science Foundation of China(92266206,52227810)the Jilin Province Science and Technology Development Plan(YDZJ202101ZYTS129)the Fundamental Research Funds for the Central Universities(2022-JCXK-11)。
文摘The degradation of mechanical properties of overdischarge battery materials manifests as a significant effect on the energy density,safety,and cycle life of the batteries.However,establishing the correlation between depth of overdischarge and mechanical properties is still a significant challenge.Studying the correlation between depth of overdischarge and mechanical properties is of great significance to improving the energy density and the ability to resist abuse of the batteries.In this paper,the mechanical properties of the battery materials during the whole process of overdischarge from discharge to complete failure were studied.The effects of depth of overdischarge on the elastic modulus and hardness of the cathode of the battery,the tensile strength and the thermal shrinkage rate of the separator,and the performance of binder were investigated.The precipitation of Cu dendrites on the separator and cathode after dissolution of anode copper foil is a key factor affecting the performance of battery materials.The Cu dendrites attached to the cathode penetrate the separator,causing irreversible damage to the coating and base film of the separator,which leads to a sharp decline in the tensile strength,thermal shrinkage rate and other properties of the separator.In addition,the Cu dendrites wrapping the cathode active particles reduce the adhesion of the active particles binder.Meanwhile,the active particles are damaged,resulting in a significant decrease in the elastic modulus and hardness of the cathode.
基金supported in part by the National Key Research and Development Program of China,under Grant 2020YFB2103800.
文摘Image fusion refers to extracting meaningful information from images of different sources or modalities,and then fusing them to generate more informative images that are beneficial for subsequent applications.In recent years,the growing data and computing resources have promoted the development of deep learning,and image fusion technology has continued to spawn new deep learning fusion methods based on traditional fusion methods.However,high-speed railroads,as an important part of life,have their unique industry characteristics of image data,which leads to different image fusion techniques with different fusion effects in high-speed railway scenes.This research work first introduces the mainstream technology classification of image fusion,further describes the downstream tasks that image fusion techniques may combine within high-speed railway scenes,and introduces the evaluation metrics of image fusion,followed by a series of subjective and objective experiments to completely evaluate the performance level of each image fusion method in different traffic scenes,and finally provides some possible future image fusion in the field of rail transportation of research.
文摘1.A worldwide history of high-speed trains High-speed railway(HSR)is defined by the International Union of Railways(UIC)as new lines with design speeds above 250 kmh1 and upgraded existing lines with speeds of up to 200 kmh1[1].In China,HSR is defined as new passenger-dedicated lines designed for electric multiple unit(EMU)trains running at a speed of 250 kmh1 or above(actual or reserved),with an initial operation speed not lower than 200 kmh1[2].The worldwide development of HSRs and high-speed EMUs can be roughly divided into three stages:initial operation,line platform expansion,and rapid development.
文摘Objectives:This study aimed to investigate the effect of motivational interviewing on the self-care behaviours in patients with chronic heart failure.Methods:Sixty-two hospitalized patients with chronic heart failure were recruited in this study from April 2014 to April 2015 from a hospital.Twenty-nine patients were in the intervention group,and 33 patients were in the control group.Patients in the intervention group received four sessions of motivational interviewing,whereas those in the control group received traditional health education.At 2,4,and 8 weeks post-discharge,the intervention group underwent telephone follow-up based on motivational interviewing,whereas the control group underwent routine telephone follow-up.Primary outcome was measured using the Self-care of Heart Failure Index at baseline and at 2 months postdischarge.Results:Before intervention,the self-care behaviours scores were 79.00±48.80 in the intervention group and 88.68±29.26in the control group.No statistically significant differences were found between two groups in scores for each subscale and total scale(P>0.05).After intervention,the scores of self-care behaviours in the two groups were both improved at 155.13±35.65 for the intervention group and 115.44±22.82 for the control group with statistically significance(P<0.01).The score of self-care behaviours increased by 76.13 point in the intervention group on average,whereas 26.76 point in the control group.There was significant difference between increases in scores of self-care behaviours in two groups(P<0.01).Conclusions:The self-care behaviours of patients with chronic heart failure could be improved effectively through motivational interviewing.
基金supported by the National Key Research and Development Program of China (2017YFD0300501)National Science and Technology Major Project (2018ZX0800912B-002)+1 种基金National Natural Science Foundation of China (31701507)China National Novel Transgenic Organisms Breeding Project (2016ZX08004002)。
文摘The C (Cys) 2H (His) 2-type transcription factor is one of the most important transcription factors in plants and plays a regulatory role in the physiological responses of rice to abiotic stresses.A novel rice C2H2-type zinc finger protein,abscisic acid (ABA)-drought-reactive oxygen species (ROS) 3 (OsADR3),was found to confer drought stress tolerance by enhancing antioxidant defense and regulating Os GPX1.Overexpression of OsADR3 in rice increased tolerance to drought stress by increasing ROS scavenging ability and ABA sensitivity.In contrast,CRISPR/Cas9-mediated knockout of osadr3 increased the sensitivity of rice to drought and oxidative stress.An exogenous ROS-scavenging reagent restored the droughtstress tolerance of osadr3-CRISPR plants.Global transcriptome analysis suggested that OsADR3 increased the expression of Os GPX1 under drought stress.Electrophoretic mobility shift,yeast one-hybrid,and dualluciferase reporter assays revealed that OsADR3 modified the expression of Os GPX1 by directly binding to its promoter.Knockdown of Os GPX1 repressed ROS scavenging ability under drought stress in OsADR3-overexpression plants.These findings suggest that OsADR3 plays a positive regulatory role in droughtstress tolerance by inducing antioxidant defense and associated with the ABA signaling pathway in rice.
基金supported by the National Natural Science Foundation of China(61301094)the Postdoctoral Science Foundation of China(2014M552490)
文摘Adaptive antenna arrays have been used to mitigate the interference on global navigation satellite system（GNSS） receivers. The performance of interference mitigation depends on the beamforming algorithms adopted by the antenna array. However,the adaptive beamforming will change the array pattern in realtime, which has the potential to introduce phase center biases into the antenna array. For precise applications, these phase biases must be mitigated or compensated because they will bring errors in code phase and carrier phase measurements. A novel adaptive beamforming algorithm is proposed firstly, then the phase bias induced by the proposed algorithm is estimated, and finally a compensation strategy is addressed. Simulations demonstrate that the proposed beamforming algorithm suppresses effectively the strong interference and improves significantly the capturing performance of GNSS signals. Simultaneously, the bias compensation method avoids the loss of the carrier phase lock and reduces the phase measurement errors for GNSS receivers.
文摘This paper introduces the high-speed electrical multiple unit （EMO） life cycle, including the design, manufacturing, testing, and maintenance stages. It also presents the train control and monitoring system （TCMS） software development platform, the TCMS testing and verification bench, the EMU driving simulation platform, and the EMU remote data transmittal and maintenance platform. All these platforms and benches combined together make up the EMU life cycle cost （LCC） system. Each platform facilitates EMU LCC management and is an important part of the system.
基金the National NaturalScience Foundation of China(No.30770866)
文摘Objective Mechanisms of pulmonary vein isolation(PVI)for atrial fibrillation remain controversy.This study aimed to investigate the impact of PVI on vagal modulation to atria.Methods Eighteen adult mongrel dogs under general anesthesia were randomly divided into two groups.Bilateral cervical sympathovagal trunks were decentralized and sympathetic effects was blocked by metoprolol administration.Atrial electrical remodeling(AER)was established by rapid right atrial pacing at the rate of 600 bpm for 30 minutes.PVI was performed in group A.Atrial effective refractory period(ERP),vulnerability window(VW)of atrial fibrillation,and sinus rhythm cycle length(SCL)were measured at baseline and during vagal stimulation before and after atrial rapid pacing with and without PVI at fight atrial appendage(RAA),left atrial appendage(LAA),distal coronary sinus(CSd)and proximal coronary sinus(CSp).Results(1)Effects of PVI on vagal modulation:Shortening of SCL during vagal stimulation decreased significantly after PVI compared with that before PVI in group A(P<0.001).Shortening of ERP during vagal stimulation decreaseed significantly after PVI compared with that before PVI(P<0.05).VW of atrial fibrillation during vagal stimulation decreased significantly after PVI compared with that before PVI(P<0.05).(2)Effects of PVI on AER:shortening of ERP before and after atrial rapid pacing increased significantly at baseline and vagal stimulation in group B compared with that in group A(P<0.05).VW during vagal stimulation increased significantly after atrial rapid pacing in group B(P<0.05).Conclusion PVI attenuates the vagal modulation to the atria,thereby decreases the susceptibility to atrial fibrillation mediated by vagal activity.PVI releases AER,which maybe contributes to the vagal denervation.Our study indicates that PVI not only can eradicate triggered foci but also modify substrates for AF.
基金the National Natural Science Foundation of China (82072023)the Fujian Province Natural Science Fund Project (2020J011096 and 2020J011064)。
文摘Objective: To estimate the safety and efficacy of transcatheter arterial embolization(TAE) in the treatment of refractory hematuria of prostatic origin(RHPO).Methods: This retrospective study included 23 patients who underwent TAE for RHPO between May 2013 and August 2021. Technical and clinical success rates were calculated, and arteriogram findings and complications were detected.Results: Embolization was performed 24 times in 23 patients. Technical success was achieved in 24/24(100%)embolization procedures. Contrast agent extravasation was detected during 2 of the 24 angiographic procedures.Bilateral embolization was performed in 23(95.8%) of the 24 procedures. The clinical success rate was 21/23(91.3%), and hematuria stopped 1–4 days after TAE. No serious complications were observed.Conclusion: TAE is a safe and effective minimally invasive technique for treating patients with RHPO.
基金the National Natural Science Foundation of China(Grant Nos.11932008 and 12172357)the Key Projects of Guangdong Basic and Applied Basic Research Fund Joint Fund(Grant No.2022B1515120051)+2 种基金the Key Projects of Natural Science Fund of Gansu Province(Grant No.22JR5RA127)the Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2022-kb06)Gansu Science and Technology Program.
基金supported by the National Natural Science Foundation of China (52074257)Chinese Academy of Sciences (ZDBS-LY-JSC023)。
文摘难熔高熵合金因其优异的高温屈服强度和抗软化性能而备受关注.然而,室温延展性差和较高的密度目前仍然是其加工以及应用需要面临的主要挑战.本文利用材料的固有特性作为合金设计原则,通过调控Mo浓度,制备了三种新型单相体心立方结构的Ti3Zr1.5Nb((1-x))-MoxVAl_(0.25)(x=0.1,0.3,0.5,标记为Mo0.1,Mo0.3和Mo0.5)合金,这些合金都具有良好的拉伸延展性和低于6 g cm^(-3)的密度.高剪切模量Mo元素的引入促进了晶格畸变,从而提高了合金中的晶格摩擦应力以及屈服强度.铸态Mo0.3和Mo0.5合金均表现出超过1100 MPa的拉伸屈服强度,以及大于15%的断裂延伸率.Labusch模型计算结果表明,原子尺寸和剪切模量失配引起的固溶强化对屈服强度的影响最为显著.通过观察变形微观组织发现,由于存在高密度的位错界面,扭折带、位错壁以及泰勒晶格的形成能有效提高合金的应变硬化能力,使合金在展现高强度的同时保持足够的延展性.该研究为开发具有高强韧的单相难熔高熵合金提供了新的见解.
基金funded by the National Natural Science Foundation of China(Nos.92266206,52227810)Jilin Province Science and Technology Development Plan(No.YDZJ202101ZYTS129)the Fundamental Research Funds for the Central Universities(No.2022-JCXK-11).
文摘Graphene(Gr)reinforced high-entropy alloy(HEA)matrix composites are expected as potential candidates for next-generation structural applications in light of outstanding mechanical properties.A deep comprehension of the underlying deformation mechanisms under extreme shock loading is of paramount importance,however,remains lacking due to experimentally technical limitations in existence.In the present study,by means of nonequilibrium molecular dynamics simulations,dynamic deformation behaviors and corresponding mechanisms in equiatomic FeNiCrCoCu HEA/Gr composite systems were investigated in terms of various shock velocities.The resistance to dislocation propagation imparted by Gr was corroborated to encourage the elevated local stress level by increasing the likelihood of dislocation interplays,which facilitated the onset of twins and hexagonal close-packed(HCP)martensite laths.Meanwhile,the advent of Gr was demonstrated to endow the HEA with an additional twinning pathway that induced a structural conversion from HCP to parent face-centered cubic(FCC)inside HCP martensite laths,different from the classical one that necessitated undergoing the intermediate procedure of extrinsic stacking fault(ESF)evolution.More than that,by virtue of an increase in flow stress,the transformation-induced plasticity(TRIP)effect was validated to be additionally evoked as the predominant strain accommodation mechanism at higher strains on the one hand,but which only assisted plasticity in pure systems,and on the other hand,can also act as an auxiliary regulation mode together with the twinning-induced plasticity(TWIP)effect under intermediate strains,but with enhanced contributions relative to pure systems.One may expect that TRIP and TWIP effects promoted by introducing Gr would considerably inspire a synergistic effect between strength and ductility,contributing to the exceptional shock-resistant performance of FeNiCrCoCu HEAs under extreme regimes.
基金funded by the National Natural Science Foundation of China(Nos.92266206,52350039,52227810)Jilin Province Science and Technology Development Plan(No.YDZJ202101ZYTS129)+1 种基金Jilin Province Creative and Innovative Talents Funding Project(No.2023RY01)Graduate Innovation Fund of Jilin University(No.2022032).
文摘High-entropy alloys(HEAs)possess immense potential for structural applications due to their excellent mechanical properties.Deeply understanding underlying deformation mechanisms under extreme regimes is crucial but still limited,due to the restrictions of existing experimental techniques.In the present study,dynamic deformation behaviors in equiatomic FeNiCrCoCu HEAs were investigated in terms of various shock velocities through nonequilibrium molecular dynamics simulations.The amorphous atoms by amorphization transformation were corroborated to be conducive to dislocation nucleation and propagation.Also,the dominant plasticity pattern was confirmed to be taken over by amorphization under higher velocities,while dislocation slips merely prevailed for lower shock ones.More importantly,for a shock velocity of 1.4 km/s,multi-level deformation modes appearing in deformation,first amorphization and then a combination of amorphization and dislocation slip,was demonstrated to substantially contribute to the shock wave attenuation.These interesting findings provide important implications for the dynamic deformation behaviors and corresponding mechanisms of the FeNiCrCoCu HEA system.
基金supported by the National Science Fund for Distinguished Young Scholars(51925504)National major research instrument development projects(52227810)+1 种基金the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(52021003)the National Natural Science Foundation of China(52175271,52021003,52375287).
文摘At present,the existing piezoelectric stick-slip actuators have an inherent back-slip problem,which greatly limits the development and application of stick-slip actuators.In order to inhibit the regression phenomenon,a new bionic lemongrass stickslip actuator was prepared by using polymer PDMS to replicate natural biological surface.The surface microstructure of the grass was copied by PDMS,and the PDMS film was prepared.The rigid and flexible bionic friction pair was further prepared,and the flexible anisotropic PDMS stick slip actuator was developed.It was found that the anisotropic friction characteristics of the surface microstructure of the grass inhibited the anti-sliding motion,and the elastic potential energy of the PDMS film improved the output characteristics of the driver.By adjusting the input voltage to control the contact between the drive foot and the rotor,the rigid and flexible hybrid drive can be realized and the backsliding phenomenon can be suppressed.The actuator is compact,lightweight and can achieve high speed and high resolution output without preloading force,which has important application value in the field of fast and accurate positioning with load limitation.
