Benchmark experiments are indispensable for the development of neutron nuclear data evaluation libraries.Given the lack of domestic benchmarking of nuclear data in the fission energy region,this study developed a neut...Benchmark experiments are indispensable for the development of neutron nuclear data evaluation libraries.Given the lack of domestic benchmarking of nuclear data in the fission energy region,this study developed a neutron leakage spectrum measurement system using a spherical sample based on the^(252)Cf spontaneous fission source.The EJ309 detector(for highenergy measurements)and CLYC detector(for low-energy measurements)were combined to measure the time-of-flight spectrum using theγtagging method.To assess the performance of the system,the time-of-flight spectrum without a sample was measured first.The experimental spectra were consistent with those simulated using the Monte Carlo method and the standard^(252)Cf spectrum from ISO:8529-1.This demonstrates that the system can effectively measure the neutron events in the 0.15-8.0 MeV range.Then,a spherical polyethylene sample was used as the standard to verify the accuracy of the system for the benchmark experiment.The simulation results were obtained using the Monte Carlo method with evaluated data from the ENDF/B-Ⅷ.0,CENDL-3.2,JEFF-3.3,and JENDL-5 libraries.The measured neutron leakage spectra were compared with the corresponding simulated results for the neutron spectrum shape and calculated C/E values.The results showed that the simulated spectra with different data libraries reproduced the experimental results well in the 0.15-8.0 MeV range.This study confirms that the leakage neutron spectrum measurement system based on the^(252)Cf source can perform benchmarking and provides a foundation for evaluating neutron nuclear data through benchmark experiments.展开更多
Existing vehicle experiment systems tend to focus on the research of vehicle dynamics by conducting performance tests on every system or some parts of the vehicle so as to improve the entire performance of the vehicle...Existing vehicle experiment systems tend to focus on the research of vehicle dynamics by conducting performance tests on every system or some parts of the vehicle so as to improve the entire performance of the vehicle.Virtual technology is widely utilized in various vehicle test-beds.These test-beds are mainly used to simulate the driving training,conduct the research on drivers'behaviors,or give virtual demonstrations of the transportation environment.However,the study on the active safety of the running vehicle in the virtual environment is still insufficient.A virtual scene including roads and vehicles is developed by using the software Creator and Vega,and radars and cameras are also simulated in the scene.Based on dSPACE's rapid prototyping simulation and its single board DS1103,a simulation model including vehicle control signals is set up in MATLAB/Simulink,the model is then built into C code,and the system defined file(SDF)is downloaded to the DS1103 board through the experiment debug software ControlDesk and is kept running.Programming is made by mixing Visual C++6.0,MATLAB API and Vega API.Control signals are read out by invoking library function MLIB/MTRACE of dSPACE.All the input,output,and system state values are acquired by arithmetic and are dynamically associated with the running status of the virtual vehicle.An intelligent vehicle experiment system is thus developed by virtue of program and integration.The system has not only the demonstration function,such as general driving,cruise control,active avoiding collision,but also the function of virtual experiment.Parameters of the system can be set according to needs,and the virtual test results can be analyzed and studied and used for the comparison with the existing models.The system reflects the running of the intelligent vehicle in the virtual traffic environment,at the same time,the system is a new attempt performed on the intelligent vehicle travel research and provides also a new research method for the development of intelligent vehicles.展开更多
This paper used the virtual reality modeling language （VRML） to establish the 3D virtual experiment instrument model, and by using the visual programming language VB to design and develop a interactive virtual reali...This paper used the virtual reality modeling language （VRML） to establish the 3D virtual experiment instrument model, and by using the visual programming language VB to design and develop a interactive virtual realization experiment platform, the interface has friendly interface, stable operation, strong practicability like with the Windows style, is a kind of reform for the traditional physics experiment teaching mode. The system has practical use value, also has reference value for the reform and modernization of other experimental courses.展开更多
Transitioning from outcrossing to self-fertilization is a widespread reproductive strategy in plants,especially in environments where pollination is limited.Despite its prevalence,this transition has rarely been exami...Transitioning from outcrossing to self-fertilization is a widespread reproductive strategy in plants,especially in environments where pollination is limited.Despite its prevalence,this transition has rarely been examined using transplant experiments,and previous studies have overlooked the contribution of the male parent in elucidating mating diversity.In this study,six transplanted populations were generated to investigate the relationship of the pollination environment with plant mating patterns and fecundity in Primula oreodoxa,a species that exhibits both distyly(predominantly outcrossing)and homostyly(predominantly selfing),based on data from 3582 individuals and 11 SSR markers.Homostylous plants had fruit and seed sets comparable to those of distylous plants at lower elevations but exhibited a clear reproductive advantage at higher elevations,particularly compared with the S morph.As elevation increased,the populational selfing rates increased,and the genetic diversity among the progeny was reduced.Furthermore,the visitation frequency of long-tongued pollinators was negatively and positively correlated with the selfing rate and number of mates,respectively,in the L and S morphs.In contrast,short-tongued pollinator visitation showed opposite correlations with the selfing rate and number of mates in homostylous morphs.In most populations,individuals functioned consistently as both female and male,and mating occurred randomly,suggesting a breakdown of the distyly polymorphism.Overall,our results provide experimental validation of the reproductive advantages of homostyly at high elevations by revealing that pollinator visitation shapes the selfing rate and mating diversity within populations,potentially driving the divergence of mating systems along environmental gradients.展开更多
The dynamic characteristics of the track system can directly affect its service performance and failure process.To explore the load characteristics and dynamic response of the track system under the dynamic loads from...The dynamic characteristics of the track system can directly affect its service performance and failure process.To explore the load characteristics and dynamic response of the track system under the dynamic loads from the rack vehicle in traction conditions,a systematic test of the track subsystem was carried out on a large-slope test line.In the test,the bending stress of the rack teeth,the wheel-rail forces,and the acceleration of crucial components in the track system were measured.Subsequently,a detailed analysis was conducted on the tested signals of the rack railway track system in the time domain and the time-frequency domains.The test results indicate that the traction force significantly affects the rack tooth bending stress and the wheel-rail forces.The vibrations of the track system under the traction conditions are mainly caused by the impacts generated from the gear-rack engagement,which are then transferred to the sleepers,the rails,and the ballast beds.Furthermore,both the maximum stress on the racks and the wheel-rail forces measured on the rails remain below their allowable values.This experimental study evaluates the load characteristics and reveals the vibration characteristics of the rack railway track system under the vehicle’s ultimate load,which is very important for the load-strengthening design of the key components such as racks and the vibration and noise reduction of the track system.展开更多
In the scenario of a steam generator tube rupture accident in a lead-cooled fast reactor,secondary circuit subcooled water under high pressure is injected into an ordinary-pressure primary vessel,where a molten lead-b...In the scenario of a steam generator tube rupture accident in a lead-cooled fast reactor,secondary circuit subcooled water under high pressure is injected into an ordinary-pressure primary vessel,where a molten lead-based alloy(typically pure lead or lead-bismuth eutectic(LBE))is used as the coolant.To clarify the pressure build-up characteristics under water-jet injection,this study conducted several experiments by injecting pressurized water into a molten LBE pool at Sun Yat-sen University.To obtain a further understanding,several new experimental parameters were adopted,including the melt temperature,water subcooling,injection pressure,injection duration,and nozzle diameter.Through detailed analyses,it was found that the pressure and temperature during the water-melt interaction exhibited a consistent variation trend with our previous water-droplet injection mode LBE experiment.Similarly,the existence of a steam explosion was confirmed,which typically results in a much stronger pressure build-up.For the non-explosion cases,increasing the injection pressure,melt-pool temperature,nozzle diameter,and water subcooling promoted pressure build-up in the melt pool.However,a limited enhancement effect was observed when increasing the injection duration,which may be owing to the continually rising pressure in the interaction vessel or the isolation effect of the generated steam cavity.Regardless of whether a steam explosion occurred,the calculated mechanical and kinetic energy conversion efficiencies of the melt were relatively small(not exceeding 4.1%and 0.7%,respectively).Moreover,the range of the conversion efficiency was similar to that of previous water-droplet experiments,although the upper limit of the jet mode was slightly lower.展开更多
The hybrid CO_(2) thermal technique has achieved considerable success globally in extracting residual heavy oil from reserves following a long-term steam stimulation process.Using microscopic visualization experiments...The hybrid CO_(2) thermal technique has achieved considerable success globally in extracting residual heavy oil from reserves following a long-term steam stimulation process.Using microscopic visualization experiments and molecular dynamics(MD)simulations,this study investigates the microscopic enhanced oil recovery(EOR)mechanisms underlying residual oil removal using hybrid CO_(2) thermal systems.Based on the experimental models for the occurrence of heavy oil,this study evaluates the performance of hybrid CO_(2) thermal systems under various conditions using MD simulations.The results demonstrate that introducing CO_(2) molecules into heavy oil can effectively penetrate and decompose dense aggregates that are originally formed on hydrophobic surfaces.A stable miscible hybrid CO_(2) thermal system,with a high effective distribution ratio of CO_(2),proficiently reduces the interaction energies between heavy oil and rock surfaces,as well as within heavy oil.A visualization analysis of the interactions reveals that strong van der Waals(vdW)attractions occur between CO_(2) and heavy oil molecules,effectively promoting the decomposition and swelling of heavy oil.This unlocks the residual oil on the hydrophobic surfaces.Considering the impacts of temperature and CO_(2) concentration,an optimal gas-to-steam injection ratio(here,the CO_(2):steam ratio)ranging between 1:6 and 1:9 is recommended.This study examines the microscopic mechanisms underlying the hybrid CO_(2) thermal technique at a molecular scale,providing a significant theoretical guide for its expanded application in EOR.展开更多
As the commercialization of the fifth gen-eration communication(5G)is sped up,its system testing scheme is vital for the successful deployment of 5G.Especially,5G relies on the scale-increased multiple-input-multiple ...As the commercialization of the fifth gen-eration communication(5G)is sped up,its system testing scheme is vital for the successful deployment of 5G.Especially,5G relies on the scale-increased multiple-input-multiple output(MIMO)technique to improve its capacity and coverage.Thus,testing new functions of the 5G MIMO system accurately and ef-ficiently,including beamforming(beam-tracking with movement)and multiple-user(MU)multiplexing,is a challenging task.This paper tries to construct a lab-oratorial hardware and conduct equipment-controlled field testing.Firstly,the testing scheme is presented,which is composed of the framework,the channel models and the validation methods.Then,the channel model principles are explained in detail due to its di-rect influence on the testing accuracy.Specifically,we utilize the spatial consistency and the multi-link cor-relation properties to emulate the high-speed dynamic time-varying(HDT)and the multiple-cell(MC)-MU-MIMO channels.Finally,the above testing scheme is verified in a Shanghai 5G field experiment with the practical commercial equipment and the channel em-ulator.The results show that the 5G new functions are tested accurately and efficiently by switching the channel emulation configurations.展开更多
In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly effi...In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly efficacious approach to enhance the teaching level of experimental courses in medicinal botany.The implementation of a digital microscope mutual system in experimental teaching not only enhances students practical skills in laboratory operations but also increases classroom efficiency.Furthermore,it supports personalized development among students while fostering innovative thinking,independent learning capabilities,and analysis and problem-solving skills.Additionally,this approach contributes to the enhancement of students scientific literacy.展开更多
Background:QiShenYiQi(QSYQ)is commonly accepted to treat ischemic stroke(IS)in clinical settings,yet the underlying mechanism of action of QSYQ is largely unknown.Methods:By combining systems pharmacology with experim...Background:QiShenYiQi(QSYQ)is commonly accepted to treat ischemic stroke(IS)in clinical settings,yet the underlying mechanism of action of QSYQ is largely unknown.Methods:By combining systems pharmacology with experimental assessment,we examined the key targets,bioactive components,and mechanisms of QSYQ against IS.Results:Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform predicted a total number of 254 targets that were potentially related to QSYQ,whereas 699 targets associated with IS were gathered from Therapeutic Target Database,Comparative Toxicogenomics Database,Gene Cards,Online Mendelian Inheritance in Man,and National Center for Biotechnology Information databases,and 83 of these targets overlap with QSYQ-related targets.Importantly,through the analysis of Gene Ontology functional annotation,Kyoto Encyclopedia of Genes and Genomes pathway enrichment,and protein-protein interaction network,we identified 20 related signaling pathways along with 4 hub genes.Subsequently,our molecular docking results revealed that QSYQ might interact with PTGS2,PTGS1,SCN5A,and HSP90AB1.We observed dose-dependent beneficial effects of QSYQ in significantly improving neurological function and alleviating histopathological damage in middle cerebral artery occlusion model,while decreasing infarct volume.Notablely,QSYQ markedly downregulates tumor necrosis factor-α,interleukin-6,and interleukin-1 beta.Overall,this study demonstrates the synergetic effects of QSYQ on regulating multi-targets in IS through inhibiting inflammatory processes and neuronal apoptosis,these findings may expand the understanding of QSYQ and provide guidance for its clinical application in treating IS.Conclusion:Current study reveals the protective roles of QSYQ against IS through modulating PTGS2/PTGS1/SCN5A/HSP90AB1 and TNF signaling pathways.展开更多
This study aimed to evaluate the feasibility,safety,and efficacy of a noveltranscatheter suture closure system(HaloStitch^(®))for patent foramen ovale(PFO)closure in a swine model.Methods:Thirteen swine underwent...This study aimed to evaluate the feasibility,safety,and efficacy of a noveltranscatheter suture closure system(HaloStitch^(®))for patent foramen ovale(PFO)closure in a swine model.Methods:Thirteen swine underwentexperimental PF0 model creation.All animals received implantationof the transcatheter suture closure system to evaluate procedural success.Comprehensive follow-up over sixmonths included serial ultrasound imaging,histopathological analysis,and gross anatomical exaninationof cardiac specimens.Results:Successful HaloStitch^(®)device implantation was adhieved in 11 of 13 swine.Gross anatomical examination confirrned secure positioning of all sutures in the atrial septum,with noredundancy or thrombus formation.Postoperative ultrasound demonstrated stable suture and staplepositions throughout follow-up,with no evidence of suture breakage,displacement,or thrombus.Stapleswere clearly visualized under ultrasound imaging,Both the atrial septal defect orifice diameter and residualseptal shunt flow velocity decreased significantly during the observation period.Histopathological analysisrevealed partially organized thrombi at the implant head and fibrous connective tissue encapsulation withlocalized inflammatory cell infiltration surrounding the polymer material.Conclsions:The transcathetersuture closure system(HaloStitch^(®))demonstrated feasibility,safety,and biocompatib ility for PFO closure ina swine model,supporting its potential for clinical translation.展开更多
Pathological scarring,manifested in the form of hypertrophic scars(HTS)and keloid scars(KS),represents a major clinical challenge due to its aesthetic and functional implications for patients.Understanding the molecul...Pathological scarring,manifested in the form of hypertrophic scars(HTS)and keloid scars(KS),represents a major clinical challenge due to its aesthetic and functional implications for patients.Understanding the molecular mechanisms involved in these types of scars and developing effective treatments requires the use of controlled ex-perimental models,especially animals,to overcome the limitations of clinical studies.The aim of this sistematic review is to critically analyze the animal models used in the last five years(2020-2025)for the study of pathological scars,highlighting their advantages,limitations and applicability in the development of new therapeutic strat-egies.Murine,rabbit and porcine models,as well as alternative models,offer varied perspectives on the formation and treatment of HTS and KS,with an emphasis on histological and molecular correlations with human pathology.By synthesizing recent data,the paper highlights the essential role of preclinical research in optimizing an-tifibrotic treatments and in advancing the translation of data into the clinical sphere.Overall,animal models remain essential for bridging mechanistic insights with clinical translation,supporting the development of more effective and personalized anti-scar therapies.展开更多
Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study invest...Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study investigates their coupled effects using inclinedflume experiments and Discrete Element Method(DEM)simulations,covering three gravel sizes(2-5 mm,5-7 mm,7-10 mm)and four ice-content levels(0%,20%,40%,60%).Run-out distance,velocity,energy components,flow regime(Savage number),and segregation indexαwere quantified.Increasing ice content significantly enhances mobility,but with diminishing marginal effectiveness.From 0%to 40%ice content,run-out distance increases by 41%-86%,whereas the additional increase from 40%to 60%contributes only 12%-23%.Particle-size ratio strongly governs segregation intensity.Fine-gravel groups reach segregation indices ofα=0.92-0.98,indicating nearly complete upward migration of ice,whereas medium-gravel and coarse-gravel groups exhibit much weaker segregation,stabilizing atα=0.68-0.74 and 0.60-0.69.Savage number analyses reveal marked flow-regime transitions.At 0%ice content,Savage numbers reach 1.0-1.5,indicating a collisional regime.Increasing ice content suppresses collisionality,with Savage numbers decreasing to 0.03-0.07 at 60%ice content,consistent with dense-regime flow.DEM energy analyses confirm this regime shift:for finegravel mixtures,collision energy decreases by 14%,while sliding-friction energy increases by 33%as ice content increases from 0%to 60%,reflecting enhanced overburden effects imposed by upward-segregated ice layers.Medium and coarse mixtures exhibit weaker or opposite energy-shift patterns,demonstrating strong size dependence.Mechanistically,large particle-size contrasts promote strong segregation and form dense basal rock layers that increase basal friction and reduce mobility.When particle sizes are similar or ice content is high,segregation remains limited,allowing ice to mix into the basal layer,thereby reducing basal friction and enhancing mobility.This research quantitatively demonstrates how composition controls particle spatial distribution,flow regime,and energy dissipation,offering new mechanistic insights into the propagation and deposition behaviors of rock-ice avalanches and improving hazard assessment in vulnerable high-mountain regions.展开更多
Recovered samples of Jilin H5 chondrite experimentally shocked to 12-133 GPa were studied to explore the behavior of opaque minerals under shock loading using SEM-EDS,Raman spectroscopy,and TIMA.The following results ...Recovered samples of Jilin H5 chondrite experimentally shocked to 12-133 GPa were studied to explore the behavior of opaque minerals under shock loading using SEM-EDS,Raman spectroscopy,and TIMA.The following results were obtained.Firstly,at pressures lower than 53GPa,the opaque minerals still keep the unmelted state,while at 78 GPa and higher,FeNi metal and troilite form eutectic intergrowths occurring as disorderly fine veinlets filling the shock-induced fractures in silicate minerals.Secondly,single kamacite grains still maintain their contour at 12 GPa,but a part of brittle troilite grains was fragmented and squeezed into the shock-induced fractures within kamacite grains.At53 and 133 GPa,many more troilite fragments are poured in the kamacite interior to form disordered hybrid aggregates or to form squiggly strips,respectively.Similar phenomena are observed within single troilite grains,but the mineral squeezed into troilite grains is kamacite.Thirdly,chromite is a hard and refractory oxide mineral.When the shock pressure rises step by step from 12 to 133 GPa,the shock effect of chromite is only fragmentation.Its grain size decreases from tens of um at 53 GPa to a few um at 133 GPa.And,fourthly,native copper exhibits distinct redistribution behavior at high temperature.In Jilin samples shock-loaded to 12 GPa,copper initially located at troilite-kamacite interfaces partially transferred into small troilite grains containing fine FeNi particles.At 53 and 133 GPa,native copper preferentially transferred into larger troilite grains containing more particles of eutectic FeNi metal.展开更多
To meet the need for cultivating application-oriented talents in local universities,this study introduced a project-based learning approach into the reform of bioinformatics experimental teaching.The course was struct...To meet the need for cultivating application-oriented talents in local universities,this study introduced a project-based learning approach into the reform of bioinformatics experimental teaching.The course was structured around a project titled"Influenza Virus Analysis",comprising four progressive modules:database utilization and information retrieval,sequence alignment and phylogenetic analysis,functional and structural prediction,and omics data analysis.These modules were integrated into a coherent research workflow that connected fragmented knowledge and technical skills.During implementation,flipped classroom and group collaboration methods were employed,alongside the establishment of a diversified assessment system emphasizing process evaluation.Teaching practice indicates that the reform effectively enhances students professional application skills,learning experience,and scientific literacy,facilitating a shift from"tool operation"to"problem-solving"capabilities.This study provides a reference model for the reform of bioinformatics experimental teaching in local universities.展开更多
To improve the accuracy of rockburst risk evaluation in mining and tunnelling engineering,the influence of intermediate principal stress σ_(2) deserves further consideration,which has been neglected in general predic...To improve the accuracy of rockburst risk evaluation in mining and tunnelling engineering,the influence of intermediate principal stress σ_(2) deserves further consideration,which has been neglected in general prediction frameworks.This study employs an integrated approach that combines true-triaxial unloading experiments with three-dimensional grain-based discrete element modeling(PFC3D-GBM)to examine the effects of σ_(2) on strain systematically burst and elucidate the underlying mechanisms.Through this dual experimental–numerical methodology,the strainburst characteristics under varying σ_(2) are analyzed in detail regarding mechanical responses,failure evolution and patterns,microscope fracture mechanisms,and energy partitioning.The results indicate that elevated σ_(2) can enhance the bearing capacity of rock,thereby necessitating a higher stress condition required for strainburst.However,it also enlarges the potential strainburst intensity,manifesting as deeper rockburst pits and more violent ejection of rock fragments.An increasing σ_(2) facilitates the microscope transgranular fractures,inhibits intergranular tensile fractures,and raises the kinetic energy conversion ratio slightly.It affects the intensity of strainburst through the following mechanisms,including the increase of energy storage limit,the intensification of Poisson effect for lateral expansion,and the enhancement of the transgranular fracturing mechanism.In practical engineering,the depth and range of support needs to be ensured under high σ_(2) conditions,and it is recommended to use prestressing techniques to control the development of significant slabbing.展开更多
Experimental therapies targeting immune and stromal cells,such as mast cells,cancer-associated fibroblasts,dendritic cells,and tumor endothelial cells,in the treatment of gastrointestinal solid tumors pose new and com...Experimental therapies targeting immune and stromal cells,such as mast cells,cancer-associated fibroblasts,dendritic cells,and tumor endothelial cells,in the treatment of gastrointestinal solid tumors pose new and complex surgical and medico-legal challenges.These innovative treatments require that informed consent not be limited to simple acceptance of the medical procedure,but instead reflect a true relational and cognitive process grounded in understanding,free choice,and the ability to revoke consent at any time.In particular,it is essential that the patient understands the experimental nature of the therapy,its development stage,potential benefits and risks,as well as the implications for their health and personal dignity.In the case of stromal cell-based treatments,which may exert complex immunomodulatory effects or activate angiogenic pathways that are not yet fully understood,patients must be made fully aware that they are participating in a non-standardized therapy whose outcomes,whether beneficial or harmful,cannot yet be predicted with certainty.This requires particularly careful medical communication,using simple yet scientifically accurate explanations delivered in appropriate language,along with a final verification of the patient’s actual understanding.展开更多
Effective partitioning is crucial for enabling parallel restoration of power systems after blackouts.This paper proposes a novel partitioning method based on deep reinforcement learning.First,the partitioning decision...Effective partitioning is crucial for enabling parallel restoration of power systems after blackouts.This paper proposes a novel partitioning method based on deep reinforcement learning.First,the partitioning decision process is formulated as a Markov decision process(MDP)model to maximize the modularity.Corresponding key partitioning constraints on parallel restoration are considered.Second,based on the partitioning objective and constraints,the reward function of the partitioning MDP model is set by adopting a relative deviation normalization scheme to reduce mutual interference between the reward and penalty in the reward function.The soft bonus scaling mechanism is introduced to mitigate overestimation caused by abrupt jumps in the reward.Then,the deep Q network method is applied to solve the partitioning MDP model and generate partitioning schemes.Two experience replay buffers are employed to speed up the training process of the method.Finally,case studies on the IEEE 39-bus test system demonstrate that the proposed method can generate a high-modularity partitioning result that meets all key partitioning constraints,thereby improving the parallelism and reliability of the restoration process.Moreover,simulation results demonstrate that an appropriate discount factor is crucial for ensuring both the convergence speed and the stability of the partitioning training.展开更多
Time-delayed blasting is widely utilized in engineering to mitigate induced vibration hazards and enhance fragmentation.The underlying vibration reduction principle is the decrease of the charge weight per delay,while...Time-delayed blasting is widely utilized in engineering to mitigate induced vibration hazards and enhance fragmentation.The underlying vibration reduction principle is the decrease of the charge weight per delay,while the potential for further vibration reduction remains debated,largely due to unclear underlying mechanisms.In light of the popularization of electronic detonators and the representativeness of double-hole configurationsfor multiple blastholes,it is essential to investigate the vibration characteristics induced by time-delayed double blastholes.Therefore,a series of doubleborehole experimental blasts was conducted in an underground roadway to clarify the variation in vibration from single-hole to dual-hole conditions.Based on the experimental data and inherent limitations,an exact full-fieldtheoretical model was further employed to systematically analyze the effects of delay time,charge length,and borehole inclination angle on vibrations induced by various doublehole configurations.The experimental data and theoretical analysis reveal that the general scaled distance effectively predicts vibrations in delayed blasting but does not reflectvibration reduction.Increasing delay time causes fluctuatingPPVs,which stabilize slightly above single-hole PPVs as delay times exceed a certain value.The delayed blasting primarily reduces near-fieldfrequencies.Longer charge lengths in double boreholes increase PPV levels and attenuation rates within a certain length,and the vibration behavior of combined long and short charge lengths is governed by the long blasthole.Larger blasthole inclination angles enhance vibration amplitude and reduce PPV attenuation rates.Optimizing inclination angles is more critical than adjusting delay times,and parallel boreholes offer the best vibration control.展开更多
Vehicular ad hoc networks(VANets) experiment system is studied.Configuration,characteristics and research fields of VANets are introduced briefly.According to the characteristics of VANets,key modules that multi-vehic...Vehicular ad hoc networks(VANets) experiment system is studied.Configuration,characteristics and research fields of VANets are introduced briefly.According to the characteristics of VANets,key modules that multi-vehicle ad hoc experiment system needs are designed,and each module's function and practice requirement is analyzed.The reliability of experiment system is tested primarily using three experiment scenes of multi-vehicle ad hoc network,car following and wireless positioning.The experiment result shows that multi-vehicle ad hoc experiment system has the capability of the correlated experiment of VANets.展开更多
基金supported by the National Natural Science Foundation of China(No.U2067205)。
文摘Benchmark experiments are indispensable for the development of neutron nuclear data evaluation libraries.Given the lack of domestic benchmarking of nuclear data in the fission energy region,this study developed a neutron leakage spectrum measurement system using a spherical sample based on the^(252)Cf spontaneous fission source.The EJ309 detector(for highenergy measurements)and CLYC detector(for low-energy measurements)were combined to measure the time-of-flight spectrum using theγtagging method.To assess the performance of the system,the time-of-flight spectrum without a sample was measured first.The experimental spectra were consistent with those simulated using the Monte Carlo method and the standard^(252)Cf spectrum from ISO:8529-1.This demonstrates that the system can effectively measure the neutron events in the 0.15-8.0 MeV range.Then,a spherical polyethylene sample was used as the standard to verify the accuracy of the system for the benchmark experiment.The simulation results were obtained using the Monte Carlo method with evaluated data from the ENDF/B-Ⅷ.0,CENDL-3.2,JEFF-3.3,and JENDL-5 libraries.The measured neutron leakage spectra were compared with the corresponding simulated results for the neutron spectrum shape and calculated C/E values.The results showed that the simulated spectra with different data libraries reproduced the experimental results well in the 0.15-8.0 MeV range.This study confirms that the leakage neutron spectrum measurement system based on the^(252)Cf source can perform benchmarking and provides a foundation for evaluating neutron nuclear data through benchmark experiments.
基金supported by Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20070006011)
文摘Existing vehicle experiment systems tend to focus on the research of vehicle dynamics by conducting performance tests on every system or some parts of the vehicle so as to improve the entire performance of the vehicle.Virtual technology is widely utilized in various vehicle test-beds.These test-beds are mainly used to simulate the driving training,conduct the research on drivers'behaviors,or give virtual demonstrations of the transportation environment.However,the study on the active safety of the running vehicle in the virtual environment is still insufficient.A virtual scene including roads and vehicles is developed by using the software Creator and Vega,and radars and cameras are also simulated in the scene.Based on dSPACE's rapid prototyping simulation and its single board DS1103,a simulation model including vehicle control signals is set up in MATLAB/Simulink,the model is then built into C code,and the system defined file(SDF)is downloaded to the DS1103 board through the experiment debug software ControlDesk and is kept running.Programming is made by mixing Visual C++6.0,MATLAB API and Vega API.Control signals are read out by invoking library function MLIB/MTRACE of dSPACE.All the input,output,and system state values are acquired by arithmetic and are dynamically associated with the running status of the virtual vehicle.An intelligent vehicle experiment system is thus developed by virtue of program and integration.The system has not only the demonstration function,such as general driving,cruise control,active avoiding collision,but also the function of virtual experiment.Parameters of the system can be set according to needs,and the virtual test results can be analyzed and studied and used for the comparison with the existing models.The system reflects the running of the intelligent vehicle in the virtual traffic environment,at the same time,the system is a new attempt performed on the intelligent vehicle travel research and provides also a new research method for the development of intelligent vehicles.
文摘This paper used the virtual reality modeling language （VRML） to establish the 3D virtual experiment instrument model, and by using the visual programming language VB to design and develop a interactive virtual realization experiment platform, the interface has friendly interface, stable operation, strong practicability like with the Windows style, is a kind of reform for the traditional physics experiment teaching mode. The system has practical use value, also has reference value for the reform and modernization of other experimental courses.
基金funded by grants from the National Natural Science Foundation of China(31800314,32370239,U160323)the foundation of South China Botanical Garden,Chinese Academy of Sciences(QNXM-06)to SY and the Doctoral Research Foundation of China West Normal University(412994).
文摘Transitioning from outcrossing to self-fertilization is a widespread reproductive strategy in plants,especially in environments where pollination is limited.Despite its prevalence,this transition has rarely been examined using transplant experiments,and previous studies have overlooked the contribution of the male parent in elucidating mating diversity.In this study,six transplanted populations were generated to investigate the relationship of the pollination environment with plant mating patterns and fecundity in Primula oreodoxa,a species that exhibits both distyly(predominantly outcrossing)and homostyly(predominantly selfing),based on data from 3582 individuals and 11 SSR markers.Homostylous plants had fruit and seed sets comparable to those of distylous plants at lower elevations but exhibited a clear reproductive advantage at higher elevations,particularly compared with the S morph.As elevation increased,the populational selfing rates increased,and the genetic diversity among the progeny was reduced.Furthermore,the visitation frequency of long-tongued pollinators was negatively and positively correlated with the selfing rate and number of mates,respectively,in the L and S morphs.In contrast,short-tongued pollinator visitation showed opposite correlations with the selfing rate and number of mates in homostylous morphs.In most populations,individuals functioned consistently as both female and male,and mating occurred randomly,suggesting a breakdown of the distyly polymorphism.Overall,our results provide experimental validation of the reproductive advantages of homostyly at high elevations by revealing that pollinator visitation shapes the selfing rate and mating diversity within populations,potentially driving the divergence of mating systems along environmental gradients.
基金supported by the National Natural Science Foundation of China(No.52388102)the Sichuan Science and Technology Program(No.2024NSFTD0011)the Fundamental Research Funds for the State Key Laboratory of Rail Transit Vehicle System of Southwest Jiaotong University(No.2023TPL-T11).
文摘The dynamic characteristics of the track system can directly affect its service performance and failure process.To explore the load characteristics and dynamic response of the track system under the dynamic loads from the rack vehicle in traction conditions,a systematic test of the track subsystem was carried out on a large-slope test line.In the test,the bending stress of the rack teeth,the wheel-rail forces,and the acceleration of crucial components in the track system were measured.Subsequently,a detailed analysis was conducted on the tested signals of the rack railway track system in the time domain and the time-frequency domains.The test results indicate that the traction force significantly affects the rack tooth bending stress and the wheel-rail forces.The vibrations of the track system under the traction conditions are mainly caused by the impacts generated from the gear-rack engagement,which are then transferred to the sleepers,the rails,and the ballast beds.Furthermore,both the maximum stress on the racks and the wheel-rail forces measured on the rails remain below their allowable values.This experimental study evaluates the load characteristics and reveals the vibration characteristics of the rack railway track system under the vehicle’s ultimate load,which is very important for the load-strengthening design of the key components such as racks and the vibration and noise reduction of the track system.
基金supported by Basic and Applied Basic research foundation of Guangdong province(Nos.2021A1515010343 and 2022A1515011582)the Science and Technology Program of Guangdong Province(Nos.2021A0505030026 and 2022A0505050029).
文摘In the scenario of a steam generator tube rupture accident in a lead-cooled fast reactor,secondary circuit subcooled water under high pressure is injected into an ordinary-pressure primary vessel,where a molten lead-based alloy(typically pure lead or lead-bismuth eutectic(LBE))is used as the coolant.To clarify the pressure build-up characteristics under water-jet injection,this study conducted several experiments by injecting pressurized water into a molten LBE pool at Sun Yat-sen University.To obtain a further understanding,several new experimental parameters were adopted,including the melt temperature,water subcooling,injection pressure,injection duration,and nozzle diameter.Through detailed analyses,it was found that the pressure and temperature during the water-melt interaction exhibited a consistent variation trend with our previous water-droplet injection mode LBE experiment.Similarly,the existence of a steam explosion was confirmed,which typically results in a much stronger pressure build-up.For the non-explosion cases,increasing the injection pressure,melt-pool temperature,nozzle diameter,and water subcooling promoted pressure build-up in the melt pool.However,a limited enhancement effect was observed when increasing the injection duration,which may be owing to the continually rising pressure in the interaction vessel or the isolation effect of the generated steam cavity.Regardless of whether a steam explosion occurred,the calculated mechanical and kinetic energy conversion efficiencies of the melt were relatively small(not exceeding 4.1%and 0.7%,respectively).Moreover,the range of the conversion efficiency was similar to that of previous water-droplet experiments,although the upper limit of the jet mode was slightly lower.
基金financially supported by the National Natural Science Foundation of China(No.U20B6003)the China Scholarship Council(No.202306440015)a project of the China Petroleum&Chemical Corporation(No.P22174)。
文摘The hybrid CO_(2) thermal technique has achieved considerable success globally in extracting residual heavy oil from reserves following a long-term steam stimulation process.Using microscopic visualization experiments and molecular dynamics(MD)simulations,this study investigates the microscopic enhanced oil recovery(EOR)mechanisms underlying residual oil removal using hybrid CO_(2) thermal systems.Based on the experimental models for the occurrence of heavy oil,this study evaluates the performance of hybrid CO_(2) thermal systems under various conditions using MD simulations.The results demonstrate that introducing CO_(2) molecules into heavy oil can effectively penetrate and decompose dense aggregates that are originally formed on hydrophobic surfaces.A stable miscible hybrid CO_(2) thermal system,with a high effective distribution ratio of CO_(2),proficiently reduces the interaction energies between heavy oil and rock surfaces,as well as within heavy oil.A visualization analysis of the interactions reveals that strong van der Waals(vdW)attractions occur between CO_(2) and heavy oil molecules,effectively promoting the decomposition and swelling of heavy oil.This unlocks the residual oil on the hydrophobic surfaces.Considering the impacts of temperature and CO_(2) concentration,an optimal gas-to-steam injection ratio(here,the CO_(2):steam ratio)ranging between 1:6 and 1:9 is recommended.This study examines the microscopic mechanisms underlying the hybrid CO_(2) thermal technique at a molecular scale,providing a significant theoretical guide for its expanded application in EOR.
基金supported in part by National Natural Science Foundation of China under Grant 62201087,Grant 62525101,in part by the National Key R&D Program of China under Grant 2023YFB2904803in part by the Guangdong Major Project of Basic and Applied Basic Research under Grant 2023B0303000001+1 种基金in part by the Natural Science Foundation of Beijing-Xiaomi Innovation Joint Foundation under Grant L243002in part by the Beijing University of Posts and Telecommunications-China Mobile Research Institute Joint Institute.
文摘As the commercialization of the fifth gen-eration communication(5G)is sped up,its system testing scheme is vital for the successful deployment of 5G.Especially,5G relies on the scale-increased multiple-input-multiple output(MIMO)technique to improve its capacity and coverage.Thus,testing new functions of the 5G MIMO system accurately and ef-ficiently,including beamforming(beam-tracking with movement)and multiple-user(MU)multiplexing,is a challenging task.This paper tries to construct a lab-oratorial hardware and conduct equipment-controlled field testing.Firstly,the testing scheme is presented,which is composed of the framework,the channel models and the validation methods.Then,the channel model principles are explained in detail due to its di-rect influence on the testing accuracy.Specifically,we utilize the spatial consistency and the multi-link cor-relation properties to emulate the high-speed dynamic time-varying(HDT)and the multiple-cell(MC)-MU-MIMO channels.Finally,the above testing scheme is verified in a Shanghai 5G field experiment with the practical commercial equipment and the channel em-ulator.The results show that the 5G new functions are tested accurately and efficiently by switching the channel emulation configurations.
基金Supported by Major Project of School-level Teaching Reform and Research of Guangxi University of Chinese Medicine(2022A006)。
文摘In comparison with conventional experimental teaching methods,the implementation of the Motic digital microscope mutual system in the experimental teaching of medicinal botany has been demonstrated to be a highly efficacious approach to enhance the teaching level of experimental courses in medicinal botany.The implementation of a digital microscope mutual system in experimental teaching not only enhances students practical skills in laboratory operations but also increases classroom efficiency.Furthermore,it supports personalized development among students while fostering innovative thinking,independent learning capabilities,and analysis and problem-solving skills.Additionally,this approach contributes to the enhancement of students scientific literacy.
基金supported by the National Natural Science Foundation of China(No.82274313)Projects of Shaanxi Administration of Traditional Chinese Medicine(2022-SLRH-YQ-010)Key Laboratory of Traditional Chinese Medicine and Pharmacology.
文摘Background:QiShenYiQi(QSYQ)is commonly accepted to treat ischemic stroke(IS)in clinical settings,yet the underlying mechanism of action of QSYQ is largely unknown.Methods:By combining systems pharmacology with experimental assessment,we examined the key targets,bioactive components,and mechanisms of QSYQ against IS.Results:Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform predicted a total number of 254 targets that were potentially related to QSYQ,whereas 699 targets associated with IS were gathered from Therapeutic Target Database,Comparative Toxicogenomics Database,Gene Cards,Online Mendelian Inheritance in Man,and National Center for Biotechnology Information databases,and 83 of these targets overlap with QSYQ-related targets.Importantly,through the analysis of Gene Ontology functional annotation,Kyoto Encyclopedia of Genes and Genomes pathway enrichment,and protein-protein interaction network,we identified 20 related signaling pathways along with 4 hub genes.Subsequently,our molecular docking results revealed that QSYQ might interact with PTGS2,PTGS1,SCN5A,and HSP90AB1.We observed dose-dependent beneficial effects of QSYQ in significantly improving neurological function and alleviating histopathological damage in middle cerebral artery occlusion model,while decreasing infarct volume.Notablely,QSYQ markedly downregulates tumor necrosis factor-α,interleukin-6,and interleukin-1 beta.Overall,this study demonstrates the synergetic effects of QSYQ on regulating multi-targets in IS through inhibiting inflammatory processes and neuronal apoptosis,these findings may expand the understanding of QSYQ and provide guidance for its clinical application in treating IS.Conclusion:Current study reveals the protective roles of QSYQ against IS through modulating PTGS2/PTGS1/SCN5A/HSP90AB1 and TNF signaling pathways.
基金supported by grants from National High-Level Hospital Clinical Research Funding(2023-GSP-RC-04).
文摘This study aimed to evaluate the feasibility,safety,and efficacy of a noveltranscatheter suture closure system(HaloStitch^(®))for patent foramen ovale(PFO)closure in a swine model.Methods:Thirteen swine underwentexperimental PF0 model creation.All animals received implantationof the transcatheter suture closure system to evaluate procedural success.Comprehensive follow-up over sixmonths included serial ultrasound imaging,histopathological analysis,and gross anatomical exaninationof cardiac specimens.Results:Successful HaloStitch^(®)device implantation was adhieved in 11 of 13 swine.Gross anatomical examination confirrned secure positioning of all sutures in the atrial septum,with noredundancy or thrombus formation.Postoperative ultrasound demonstrated stable suture and staplepositions throughout follow-up,with no evidence of suture breakage,displacement,or thrombus.Stapleswere clearly visualized under ultrasound imaging,Both the atrial septal defect orifice diameter and residualseptal shunt flow velocity decreased significantly during the observation period.Histopathological analysisrevealed partially organized thrombi at the implant head and fibrous connective tissue encapsulation withlocalized inflammatory cell infiltration surrounding the polymer material.Conclsions:The transcathetersuture closure system(HaloStitch^(®))demonstrated feasibility,safety,and biocompatib ility for PFO closure ina swine model,supporting its potential for clinical translation.
基金Ministry of Research,Innovation and Digitization,CCCDI-UEFISCDI,Grant/Award Number:PN-IV-P7-7.1-PED-2024-1578,within PNCDI Ⅳ.
文摘Pathological scarring,manifested in the form of hypertrophic scars(HTS)and keloid scars(KS),represents a major clinical challenge due to its aesthetic and functional implications for patients.Understanding the molecular mechanisms involved in these types of scars and developing effective treatments requires the use of controlled ex-perimental models,especially animals,to overcome the limitations of clinical studies.The aim of this sistematic review is to critically analyze the animal models used in the last five years(2020-2025)for the study of pathological scars,highlighting their advantages,limitations and applicability in the development of new therapeutic strat-egies.Murine,rabbit and porcine models,as well as alternative models,offer varied perspectives on the formation and treatment of HTS and KS,with an emphasis on histological and molecular correlations with human pathology.By synthesizing recent data,the paper highlights the essential role of preclinical research in optimizing an-tifibrotic treatments and in advancing the translation of data into the clinical sphere.Overall,animal models remain essential for bridging mechanistic insights with clinical translation,supporting the development of more effective and personalized anti-scar therapies.
基金funded by the Natural Science Foundation of China(Grants No 42277127)。
文摘Rock-ice avalanches in cold high-mountain regions pose severe hazards due to their high mobility,yet the quantitative controls of particle-size ratio and ice content remain insufficiently constrained.This study investigates their coupled effects using inclinedflume experiments and Discrete Element Method(DEM)simulations,covering three gravel sizes(2-5 mm,5-7 mm,7-10 mm)and four ice-content levels(0%,20%,40%,60%).Run-out distance,velocity,energy components,flow regime(Savage number),and segregation indexαwere quantified.Increasing ice content significantly enhances mobility,but with diminishing marginal effectiveness.From 0%to 40%ice content,run-out distance increases by 41%-86%,whereas the additional increase from 40%to 60%contributes only 12%-23%.Particle-size ratio strongly governs segregation intensity.Fine-gravel groups reach segregation indices ofα=0.92-0.98,indicating nearly complete upward migration of ice,whereas medium-gravel and coarse-gravel groups exhibit much weaker segregation,stabilizing atα=0.68-0.74 and 0.60-0.69.Savage number analyses reveal marked flow-regime transitions.At 0%ice content,Savage numbers reach 1.0-1.5,indicating a collisional regime.Increasing ice content suppresses collisionality,with Savage numbers decreasing to 0.03-0.07 at 60%ice content,consistent with dense-regime flow.DEM energy analyses confirm this regime shift:for finegravel mixtures,collision energy decreases by 14%,while sliding-friction energy increases by 33%as ice content increases from 0%to 60%,reflecting enhanced overburden effects imposed by upward-segregated ice layers.Medium and coarse mixtures exhibit weaker or opposite energy-shift patterns,demonstrating strong size dependence.Mechanistically,large particle-size contrasts promote strong segregation and form dense basal rock layers that increase basal friction and reduce mobility.When particle sizes are similar or ice content is high,segregation remains limited,allowing ice to mix into the basal layer,thereby reducing basal friction and enhancing mobility.This research quantitatively demonstrates how composition controls particle spatial distribution,flow regime,and energy dissipation,offering new mechanistic insights into the propagation and deposition behaviors of rock-ice avalanches and improving hazard assessment in vulnerable high-mountain regions.
基金Science and Technology Planning Project of Guangdong Province,2023B1212060048,Xiande Xie。
文摘Recovered samples of Jilin H5 chondrite experimentally shocked to 12-133 GPa were studied to explore the behavior of opaque minerals under shock loading using SEM-EDS,Raman spectroscopy,and TIMA.The following results were obtained.Firstly,at pressures lower than 53GPa,the opaque minerals still keep the unmelted state,while at 78 GPa and higher,FeNi metal and troilite form eutectic intergrowths occurring as disorderly fine veinlets filling the shock-induced fractures in silicate minerals.Secondly,single kamacite grains still maintain their contour at 12 GPa,but a part of brittle troilite grains was fragmented and squeezed into the shock-induced fractures within kamacite grains.At53 and 133 GPa,many more troilite fragments are poured in the kamacite interior to form disordered hybrid aggregates or to form squiggly strips,respectively.Similar phenomena are observed within single troilite grains,but the mineral squeezed into troilite grains is kamacite.Thirdly,chromite is a hard and refractory oxide mineral.When the shock pressure rises step by step from 12 to 133 GPa,the shock effect of chromite is only fragmentation.Its grain size decreases from tens of um at 53 GPa to a few um at 133 GPa.And,fourthly,native copper exhibits distinct redistribution behavior at high temperature.In Jilin samples shock-loaded to 12 GPa,copper initially located at troilite-kamacite interfaces partially transferred into small troilite grains containing fine FeNi particles.At 53 and 133 GPa,native copper preferentially transferred into larger troilite grains containing more particles of eutectic FeNi metal.
基金Supported by Undergraduate Higher Education Teaching Quality and Reform Projects of Guangdong Province(Yuejiao Gao Han[2024]No.9,Yuejiao Gao Han[2024]No.30)Guangdong Basic and Applied Basic Research Foundation(2023A1515110973)+1 种基金Guangdong Provincial Young Innovative Talents Project of General Colleges and Universities(2023KQNCX089)Quality Engineering and Teaching Reform Projects of Zhaoqing University(zlgc202239,zlgc202207,zlgc2024005,zlgc2024038).
文摘To meet the need for cultivating application-oriented talents in local universities,this study introduced a project-based learning approach into the reform of bioinformatics experimental teaching.The course was structured around a project titled"Influenza Virus Analysis",comprising four progressive modules:database utilization and information retrieval,sequence alignment and phylogenetic analysis,functional and structural prediction,and omics data analysis.These modules were integrated into a coherent research workflow that connected fragmented knowledge and technical skills.During implementation,flipped classroom and group collaboration methods were employed,alongside the establishment of a diversified assessment system emphasizing process evaluation.Teaching practice indicates that the reform effectively enhances students professional application skills,learning experience,and scientific literacy,facilitating a shift from"tool operation"to"problem-solving"capabilities.This study provides a reference model for the reform of bioinformatics experimental teaching in local universities.
基金supported by the National Natural Science Foundation of China(No.42507210)the Fundamental Research Funds for the Central Universities(No.2025XJSB01)+1 种基金the State Key Laboratory for Tunnel Engineering(No.SKLTEK202421)the Foundation of Key Laboratory of Deep Coal Resource Mining(China University of Mining and Technology),Ministry of Education(No.KLDCRMMOE24KF11).
文摘To improve the accuracy of rockburst risk evaluation in mining and tunnelling engineering,the influence of intermediate principal stress σ_(2) deserves further consideration,which has been neglected in general prediction frameworks.This study employs an integrated approach that combines true-triaxial unloading experiments with three-dimensional grain-based discrete element modeling(PFC3D-GBM)to examine the effects of σ_(2) on strain systematically burst and elucidate the underlying mechanisms.Through this dual experimental–numerical methodology,the strainburst characteristics under varying σ_(2) are analyzed in detail regarding mechanical responses,failure evolution and patterns,microscope fracture mechanisms,and energy partitioning.The results indicate that elevated σ_(2) can enhance the bearing capacity of rock,thereby necessitating a higher stress condition required for strainburst.However,it also enlarges the potential strainburst intensity,manifesting as deeper rockburst pits and more violent ejection of rock fragments.An increasing σ_(2) facilitates the microscope transgranular fractures,inhibits intergranular tensile fractures,and raises the kinetic energy conversion ratio slightly.It affects the intensity of strainburst through the following mechanisms,including the increase of energy storage limit,the intensification of Poisson effect for lateral expansion,and the enhancement of the transgranular fracturing mechanism.In practical engineering,the depth and range of support needs to be ensured under high σ_(2) conditions,and it is recommended to use prestressing techniques to control the development of significant slabbing.
文摘Experimental therapies targeting immune and stromal cells,such as mast cells,cancer-associated fibroblasts,dendritic cells,and tumor endothelial cells,in the treatment of gastrointestinal solid tumors pose new and complex surgical and medico-legal challenges.These innovative treatments require that informed consent not be limited to simple acceptance of the medical procedure,but instead reflect a true relational and cognitive process grounded in understanding,free choice,and the ability to revoke consent at any time.In particular,it is essential that the patient understands the experimental nature of the therapy,its development stage,potential benefits and risks,as well as the implications for their health and personal dignity.In the case of stromal cell-based treatments,which may exert complex immunomodulatory effects or activate angiogenic pathways that are not yet fully understood,patients must be made fully aware that they are participating in a non-standardized therapy whose outcomes,whether beneficial or harmful,cannot yet be predicted with certainty.This requires particularly careful medical communication,using simple yet scientifically accurate explanations delivered in appropriate language,along with a final verification of the patient’s actual understanding.
基金funded by the Beijing Engineering Research Center of Electric Rail Transportation.
文摘Effective partitioning is crucial for enabling parallel restoration of power systems after blackouts.This paper proposes a novel partitioning method based on deep reinforcement learning.First,the partitioning decision process is formulated as a Markov decision process(MDP)model to maximize the modularity.Corresponding key partitioning constraints on parallel restoration are considered.Second,based on the partitioning objective and constraints,the reward function of the partitioning MDP model is set by adopting a relative deviation normalization scheme to reduce mutual interference between the reward and penalty in the reward function.The soft bonus scaling mechanism is introduced to mitigate overestimation caused by abrupt jumps in the reward.Then,the deep Q network method is applied to solve the partitioning MDP model and generate partitioning schemes.Two experience replay buffers are employed to speed up the training process of the method.Finally,case studies on the IEEE 39-bus test system demonstrate that the proposed method can generate a high-modularity partitioning result that meets all key partitioning constraints,thereby improving the parallelism and reliability of the restoration process.Moreover,simulation results demonstrate that an appropriate discount factor is crucial for ensuring both the convergence speed and the stability of the partitioning training.
基金supported by the National Natural Science Foundation of China(Grant Nos.42407267 and 52374152)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20220975).
文摘Time-delayed blasting is widely utilized in engineering to mitigate induced vibration hazards and enhance fragmentation.The underlying vibration reduction principle is the decrease of the charge weight per delay,while the potential for further vibration reduction remains debated,largely due to unclear underlying mechanisms.In light of the popularization of electronic detonators and the representativeness of double-hole configurationsfor multiple blastholes,it is essential to investigate the vibration characteristics induced by time-delayed double blastholes.Therefore,a series of doubleborehole experimental blasts was conducted in an underground roadway to clarify the variation in vibration from single-hole to dual-hole conditions.Based on the experimental data and inherent limitations,an exact full-fieldtheoretical model was further employed to systematically analyze the effects of delay time,charge length,and borehole inclination angle on vibrations induced by various doublehole configurations.The experimental data and theoretical analysis reveal that the general scaled distance effectively predicts vibrations in delayed blasting but does not reflectvibration reduction.Increasing delay time causes fluctuatingPPVs,which stabilize slightly above single-hole PPVs as delay times exceed a certain value.The delayed blasting primarily reduces near-fieldfrequencies.Longer charge lengths in double boreholes increase PPV levels and attenuation rates within a certain length,and the vibration behavior of combined long and short charge lengths is governed by the long blasthole.Larger blasthole inclination angles enhance vibration amplitude and reduce PPV attenuation rates.Optimizing inclination angles is more critical than adjusting delay times,and parallel boreholes offer the best vibration control.
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 2006CB705500)the Fundamental Research Funds for the Central Universities (Grant No. 2009JBM055)
文摘Vehicular ad hoc networks(VANets) experiment system is studied.Configuration,characteristics and research fields of VANets are introduced briefly.According to the characteristics of VANets,key modules that multi-vehicle ad hoc experiment system needs are designed,and each module's function and practice requirement is analyzed.The reliability of experiment system is tested primarily using three experiment scenes of multi-vehicle ad hoc network,car following and wireless positioning.The experiment result shows that multi-vehicle ad hoc experiment system has the capability of the correlated experiment of VANets.
