The functional analysis of interruption is of great necessity in carrying out a smooth conversation.By exemplifying interruptions in specific conversational situations identified in Friends,the paper has explored the ...The functional analysis of interruption is of great necessity in carrying out a smooth conversation.By exemplifying interruptions in specific conversational situations identified in Friends,the paper has explored the relative,interactive,pluralistic and situational characteristics of functions of interruptions.展开更多
Reinforcement learning has been applied to air combat problems in recent years,and the idea of curriculum learning is often used for reinforcement learning,but traditional curriculum learning suffers from the problem ...Reinforcement learning has been applied to air combat problems in recent years,and the idea of curriculum learning is often used for reinforcement learning,but traditional curriculum learning suffers from the problem of plasticity loss in neural networks.Plasticity loss is the difficulty of learning new knowledge after the network has converged.To this end,we propose a motivational curriculum learning distributed proximal policy optimization(MCLDPPO)algorithm,through which trained agents can significantly outperform the predictive game tree and mainstream reinforcement learning methods.The motivational curriculum learning is designed to help the agent gradually improve its combat ability by observing the agent's unsatisfactory performance and providing appropriate rewards as a guide.Furthermore,a complete tactical maneuver is encapsulated based on the existing air combat knowledge,and through the flexible use of these maneuvers,some tactics beyond human knowledge can be realized.In addition,we designed an interruption mechanism for the agent to increase the frequency of decisionmaking when the agent faces an emergency.When the number of threats received by the agent changes,the current action is interrupted in order to reacquire observations and make decisions again.Using the interruption mechanism can significantly improve the performance of the agent.To simulate actual air combat better,we use digital twin technology to simulate real air battles and propose a parallel battlefield mechanism that can run multiple simulation environments simultaneously,effectively improving data throughput.The experimental results demonstrate that the agent can fully utilize the situational information to make reasonable decisions and provide tactical adaptation in the air combat,verifying the effectiveness of the algorithmic framework proposed in this paper.展开更多
The embedded data acquistition technology in vehicle electronic system was discussed. This technology adopts the parallel working mode, gets vehicle electronic system data by communication. This technology can provide...The embedded data acquistition technology in vehicle electronic system was discussed. This technology adopts the parallel working mode, gets vehicle electronic system data by communication. This technology can provide us a lot of information on the electronic control unit, is very useful for the development of the vehicle electronic system, and can be used in diagnosis. The key points to this technology are the timer interrupt, A/D interrupt, communication interrupt and real time operation. This technology has been validated by the application in the electronic control mechanism transmission shifting system of the tank.展开更多
Aim To achieve multitask data procssing in a wireless alarm system by computer. Methods The alarm system was composed of hardware and software. The hardware was composed of a master master computer and slave transmi...Aim To achieve multitask data procssing in a wireless alarm system by computer. Methods The alarm system was composed of hardware and software. The hardware was composed of a master master computer and slave transmitters. On urgent ugent occasion, one or more of the transmitters transmitted alarm signals and the master computer received the signals; interruption, residence, graph and word processing were utilized in software to achieve multitiask data processing . Results The main computer can conduct precise and quick multitask data procesing in any condition so long as alarm signals are received. The processing speed is higher than ordinary alarm System. Conclusion The master computer can conduct safe and quick multitask data processing by way of reliable design of software and hardware , so there is no need of special processor.展开更多
To determine the feasibility and practicability of interrupt continuous wave (CW) approach proposed for real time simulating radar intermediate frequency(IF) video signal, theoretical analysis and computer simulation...To determine the feasibility and practicability of interrupt continuous wave (CW) approach proposed for real time simulating radar intermediate frequency(IF) video signal, theoretical analysis and computer simulation were used. Phases at two linked points between the end and beginning of adjoined frames are always consistent; the bias Doppler frequency for the time delay of A/D sampling start responds to that for target acceleration. No digital phase compensation is required at continuous points, and the interrupt CW approach has apparently practical values.展开更多
In this paper, we present a new car-following model by taking into account the effects of the traffic interruption probability on the car-following behaviour of the following vehicle. The stability condition of the mo...In this paper, we present a new car-following model by taking into account the effects of the traffic interruption probability on the car-following behaviour of the following vehicle. The stability condition of the model is obtained by using the linear stability theory. The modified Korteweg-de Vries （KdV） equation is constructed and solved, and three types of traffic flows in the headway sensitivity space-stable, metastable, and unstable--are classified. Both the analytical and simulation results show that the traffic interruption probability indeed has an influence on driving behaviour, and the consideration of traffic interruption probability in the car-following model could stabilize traffic flow.展开更多
The self-excited DC air circuit breaker(SE-DCCB)has been widely used in urban rail transit due to its excellent stability.It can realize forward and reverse interruption,but has difficulty interrupting small currents ...The self-excited DC air circuit breaker(SE-DCCB)has been widely used in urban rail transit due to its excellent stability.It can realize forward and reverse interruption,but has difficulty interrupting small currents due to the phenomenon of arc root sticking at the entrance of the arc chamber in the splitting process,which is known as arc root stagnation.A coupling model of the self-excited magnetic field and magnetohydrodynamics is established for the SE-DCCB with the traditional structure.The magnetic field,temperature and airflow distribution in the arc chamber are investigated with an interrupting current of 150 A.The simulation results show that the direction and magnitude of the magnetic blowout force are the dominant factors in the arc root stagnation.The local high temperature of the arc chamber due to arc root stagnation increases the obstruction effect of the airflow vortex on the arc root movement,which significantly increases the arc duration time of small current interruption.Based on the research,the structure of the magnetic conductance plate of the actual product is improved,which can improve the direction and magnitude of the magnetic blowout force at the arc root so as to restrain the development of the airflow vortex effectively and solve the problem of arc root stagnation when the small current is interrupted.The simulation results show that the circuit breaker with improved structure has a better performance for a small current interruption range from 100 A to 350 A.展开更多
To improve the limiting current interruption capability and minimizing vacuum interrupter with axial magnetic field （AMF） electrodes, it is significant to investigate the vacuum arc behaviours between the contacts. ...To improve the limiting current interruption capability and minimizing vacuum interrupter with axial magnetic field （AMF） electrodes, it is significant to investigate the vacuum arc behaviours between the contacts. AMF distributions of the slot type electrodes were studied by both numerical analysis and experiments. Furthermore, the behaviours of vacuum arcs for different parameters of the slot type AMF electrodes were investigated by using high-speed CCD camera. The influences of gap distance, contact diameter and phase shift time between AMF and arc current on the vacuum arc were investigated. The results provide a reference for research and development of vacuum interrupters with slot type or other types of AMF electrode.展开更多
Influence of the shock wave on the turbulence in a supersonic nozzle was investigated for a SF6 puffer circuit breaker interruption process. Turbulence is enlarged through the shock wave. Baroclinic generation of vort...Influence of the shock wave on the turbulence in a supersonic nozzle was investigated for a SF6 puffer circuit breaker interruption process. Turbulence is enlarged through the shock wave. Baroclinic generation of vortex causes flow separation and broadening of the arc cross section. V-I characteristics are slightly modified due to the shock wave＇s influence.展开更多
The InGaAs/InAIAs/InP high electron mobility transistor （HEM：F） structures with lattice-matched and pseudo- morphic channels are grown by gas source molecular beam epitaxy. Effects of Si ^-doping condition and grow...The InGaAs/InAIAs/InP high electron mobility transistor （HEM：F） structures with lattice-matched and pseudo- morphic channels are grown by gas source molecular beam epitaxy. Effects of Si ^-doping condition and growth interruption on the electrical properties are investigated by changing the Si-cell temperature, doping time and growth process. It is found that the optimal Si ^-doping concentration （Nd） is about 5.0 x 1012 cm-2 and the use of growth interruption has a dramatic effect on the improvement of electrical properties. The material structure and crystal interface are analyzed by secondary ion mass spectroscopy and high resolution transmission elec- tron microscopy. An InGaAs/InAiAs/InP HEMT device with a gate length of lOOnm is fabricated. The device presents good pinch-off characteristics and the kink-effect of the device is trifling. In addition, the device exhibits fT = 249 GHa and fmax 〉 400 GHz.展开更多
OBJECTIVE To access the efficacy and safety of the double-ProGlide technique for the femoral vein access-site closure in cryoballoon ablation with uninterrupted oral anticoagulants(OAC),and its impact on the electroph...OBJECTIVE To access the efficacy and safety of the double-ProGlide technique for the femoral vein access-site closure in cryoballoon ablation with uninterrupted oral anticoagulants(OAC),and its impact on the electrophysiology laboratory time as well as hospital stay after the procedure in this observational study.METHODS Patients with atrial fibrillation undergoing cryoballoon ablation with uninterrupted OAC at Department of Cardiology,Beijing Anzhen Hospital,Capital Medical University,Beijing,China from May 2019 to May 2021 were enrolled in this study.From October 2020,double-ProGlide technique was consistently used for hemostasis(ProGlide group),and before that conventional manual compression was utilized(manual compression group).The occurrence of vascular and groin complications was accessed during the hospital stay and until the three-month follow-up.RESULTS A total of 140 participants(69.30%of male,mean age:59.21±10.29 years)were evaluated,70 participants being in each group.Immediate hemostasis was achieved in all the patients with ProGlide closure.No major vascular complications were found in the ProGlide group while two major vascular complications were occurred in the manual compression group.The incidence of any groin complication was obviously higher in subjects with manual compression than patients with ProGlide devices(15.71%vs.2.86%,P=0.009).In addition,compared with the manual compression group,the ProGlide group was associated with significantly shorter total time in the electrophysiology laboratory[112.0(93.3–128.8)min vs.123.5(107.3–158.3)min,P=0.006],time from sheath removal until venous site hemostasis[3.8(3.4–4.2)min vs.8.0(7.6–8.5)min,P<0.001],bed rest time[8.0(7.6–8.0)h vs.14.1(12.0–17.6)h,P<0.001]and hospital stay after the procedure[13.8(12.5–17.8)h vs.38.0(21.5–41.0)h,P<0.001].CONCLUSIONS Utilization of the double-ProGlide technique for hemostasis after cryoballoon ablation with uninterrupted OAC is feasible and safe,which has the clinical benefit in reducing the total electrophysiology laboratory time and the hospital stay length after the procedure.展开更多
Considering the effects that the probability of traffic interruption and the friction between two lanes have on the car-following behaviour, this paper establishes a new two-lane microscopic car-following model. Based...Considering the effects that the probability of traffic interruption and the friction between two lanes have on the car-following behaviour, this paper establishes a new two-lane microscopic car-following model. Based on this microscopic model, a new macroscopic model was deduced by the relevance relation of microscopic and macroscopic scale parameters for the two-lane traffic flow. Terms related to lane change are added into the continuity equations and velocity dynamic equations to investigate the lane change rate. Numerical results verify that the proposed model can be efficiently used to reflect the effect of the probability of traffic interruption on the shock, rarefaction wave and lane change behaviour on two-lane freeways. The model has also been applied in reproducing some complex traffic phenomena caused by traffic accident interruption.展开更多
On the assumption that random interruptions in the observation process are modeled by a sequence of independent Bernoulli random variables, we firstly generalize two kinds of nonlinear filtering methods with random in...On the assumption that random interruptions in the observation process are modeled by a sequence of independent Bernoulli random variables, we firstly generalize two kinds of nonlinear filtering methods with random interruption failures in the observation based on the extended Kalman filtering （EKF） and the unscented Kalman filtering （UKF）, which were shortened as GEKF and CUKF in this paper, respectively. Then the nonlinear filtering model is established by using the radial basis function neural network （RBFNN） prototypes and the network weights as state equation and the output of RBFNN to present the observation equation. Finally, we take the filtering problem under missing observed data as a special case of nonlinear filtering with random intermittent failures by setting each missing data to be zero without needing to pre-estimate the missing data, and use the GEKF-based RBFNN and the GUKF-based RBFNN to predict the ground radioactivity time series with missing data. Experimental results demonstrate that the prediction results of GUKF-based RBFNN accord well with the real ground radioactivity time series while the prediction results of GEKF-based RBFNN are divergent.展开更多
The greenhouse effect of SFe is a great concern today. The development of high voltage vacuum circuit breakers becomes more important. The vacuum circuit breaker has minimum pollution to the environment. The vacuum in...The greenhouse effect of SFe is a great concern today. The development of high voltage vacuum circuit breakers becomes more important. The vacuum circuit breaker has minimum pollution to the environment. The vacuum interrupter is the key part of a vacuum circuit breaker. The interrupting characteristics in vacuum and arc-controlling techniue are the main problems to be solved for a longer gap distance in developing high voltage vacuum interrupters. To understand the vacuum arc characteristics and provide effective technique to control vacuum arc in a long gap distance, the arc mode transition of a cup-type axial magnetic field electrode is observed by a high-speed charge coupled device （CGD） video camera under different gap distances while the arc voltage and arc current are recorded. The controlling ability of the axial magnetic field on vacuum arc obviously decreases when the gap distance is longer than 40 ram. The noise components and mean value of the arc voltage significantly increase. The effective method for controlling the vacuum arc characteristics is provided by long gap distances based on the test results. The test results can be used as a reference to develop high voltage and large capacity vacuum interrupters.展开更多
When subjected to high voltages between opened contacts, vacuum interrupters may emit X-rays. In order to ensure that these are of an acceptable level, vacuum interrupters should comply with the limits for X-ray emiss...When subjected to high voltages between opened contacts, vacuum interrupters may emit X-rays. In order to ensure that these are of an acceptable level, vacuum interrupters should comply with the limits for X-ray emission and the test procedures to be carried out to verify this based on relevant standards and specifications. In this paper, a comprehensive experimental study has been performed for 126 kV vacuum interrupters used in a transmission system to understand the X-radiation level and its influence by three main parameters, namely applied power-frequency voltage, contact gap and power=frequency voltage conditioning. The radiation instrument is an FJ347 radiometer and the X-radiation dose was measured at the power-frequency test voltage. These tests demonstrated that the X-radiation emission level for a 126 kV vacuum interrupter did not exceed the following： 5 μSv per hour at a rated voltage of 126 kV and 150 μSv per hour at a power-frequency voltage of 230 kV at 1 m distance. The X-radiation dose increased with the applied power-frequency voltage increasing and decreased with the contact gap increasing. The X- radiation dose for 126 kV vacuum interrupters decreased by 57% after the conditioning procedure with a certain power-frequency voltage. During the conditioning procedure, the average value of the X-radiation dose was 4.49 mSv, which means if a professional conditions 180 interrupters per year, it will be safe at the 6.4 m distance.展开更多
This paper begins with a brief introduction of the embedded real-time operating system VxWorks and CompactPCI standard, then gives the programming interfaces of Peripheral Controller Interface （PCI） configuring, int...This paper begins with a brief introduction of the embedded real-time operating system VxWorks and CompactPCI standard, then gives the programming interfaces of Peripheral Controller Interface （PCI） configuring, interrupts handling and multi-tasks programming interface under VxWorks, and then emphasis is placed on the software frameworks of CPCI interrupt management based on multi-tasks. This method is sound in design and easy to adapt, ensures that all possible interrupts are handled in time, which makes it suitable for data acquisition systems with multi-channels, a high data rate, and hard real-time high energy physics.展开更多
Traffic interruption phenomena frequently occur with the number of vehicles increasing.To investigate the effect of the traffic interruption probability on traffic flow,a new optimal velocity model is constructed by c...Traffic interruption phenomena frequently occur with the number of vehicles increasing.To investigate the effect of the traffic interruption probability on traffic flow,a new optimal velocity model is constructed by considering the driver anticipation term in the interruption case for car-following theory.Furthermore,the effect of driver anticipation in the interruption case is investigated via linear stability analysis.Also,the MKdV equation is obtained concerning the effect of driver anticipation in the interruption case.Moreover,numerical simulation states that the driver anticipation term in the interruption case contributes to the stability of traffic flow.展开更多
Purpose： One of the main indicators of scientific production is the number of papers published in scholarly journals. Turkey ranks 18th place in the world based on the number of scholarly publications. The objective ...Purpose： One of the main indicators of scientific production is the number of papers published in scholarly journals. Turkey ranks 18th place in the world based on the number of scholarly publications. The objective of this paper is to find out if the monetary support program initiated in 1993 by the Turkish Scientific and Technological Research Council （TUBITAK） to incentivize researchers and increase the number, impact, and quality of international publications has been effective in doing so.Design/methodology/approach： We analyzed some 390,000 publications with Turkish affiliations listed in the Web of Science （WoS） database between 1976 and 2015 along with about 157,000 supported ones between 1997 and 2015. We used the interrupted time series （ITS） analysis technique （also known as ＂quasi-experimental time series analysis＂ or ＂intervention analysis＂） to test if TOBITAK＇s support program helped increase the number of publications. We defined ARIMA （1,1,0） model for ITS data and observed the impact of TOBiTAK＇s support program in 1994, 1997, and 2003 （after one, four and 10 years of its start, respectively）. The majority of publications （93%） were full papers （articles）, which were used as the experimental group while other types of contributions functioned as the control group. We also carried out a multiple regression analysis.Findings： TUBITAK＇s support program has had negligible effect on the increase of the number of papers with Turkish affiliations. Yet, the number of other types of contributions continued to increase even though they were not well supported, suggesting that TUBITAK＇s support program is probably not the main factor causing the increase in the number of papers with Turkish affiliations. Research limitations： Interrupted time series analysis shows if the ＂intervention＂ has had any significant effect on the dependent variable but it does not explain what caused the increase in the number of papers if it was not the intervention. Moreover, except the＂intervention＂, other ＂event（s）＂ that might affect the time series data （e.g., increase in the number of research personnel over the years） should not occur during the period of analysis, a prerequisite that is beyond the control of the researcher. Practical implications： TUBITAK＇s ＂cash-for-publication＂ program did not seem to have direct impact on the increase of the number of papers published by Turkish authors, suggesting that small amounts of payments are not much of an incentive for authors to publish more. It might perhaps be a better strategy to concentrate limited resources on a few high impact projects rather than to disperse them to thousands of authors as ＂micropayments.＂ Originality/value： Based on 25 years＇ worth of payments data, this is perhaps one of the first large-scale studies showing that ＂cash-for-publication＂ policies or ＂piece rates＂ paid to researchers tend to have little or no effect on the increase of researchers＇ productivity. The main finding of this paper has some implications for countries wherein publication subsidies are used as an incentive to increase the number and quality of papers published in international journals. They should be prepared to consider reviewing their existing support programs （based usually on bibliometric measures such as journal impact factors） and revising their reward policies.展开更多
Interruption,as a linguistic phenomenon,can be see everywhere.And talk show programs are common setting for interruptions.So in this thesis three questions are addressed as followed:What function does the interruption...Interruption,as a linguistic phenomenon,can be see everywhere.And talk show programs are common setting for interruptions.So in this thesis three questions are addressed as followed:What function does the interruption have in these two kinds of talk shows(relatively formal and informal) respectively;what are the similarities of relatively formal and informal talk show programs;what are the differences between relatively formal and informal talk shows.展开更多
Vacuum gaps have rapid dynamic dielectric recovery speed while SF6 gaps have high insulation strength. The series-connected vacuum and SF6 gaps are used as the main switch(MS), which combines their advantages. The wor...Vacuum gaps have rapid dynamic dielectric recovery speed while SF6 gaps have high insulation strength. The series-connected vacuum and SF6 gaps are used as the main switch(MS), which combines their advantages. The work aims to verify the feasibility of serial vacuum and SF6 gaps in mechanical HVDC interruption. The test circuit of the dynamic dielectric recovery performance(DDRP) is set up. The DDRP is tested under free recovery condition by the high voltage pulse source. The DDRP of the vacuum circuit breaker(VCB) and SF6 gas circuit breaker(GCB) in DC interruption with active current injection is analyzed and compared. The test results indicate that the dielectric recovery duration of the VCB is below 30 μs while that of the GCB is above 100 μs. In order to achieve the cooperation between the VCB and GCB, a novel hybrid HVDC circuit breaker(CB) based on series-connected vacuum and SF6 gaps is proposed. The ‘voltage-zero’ duration is created by introducing the follow current loop and there more recovery time for the dielectric recovery of the MS. The voltage distribution is controlled by the voltage dividing method so that the VCB undertakes the initial transient recovery voltage(TRV) and the later TRV is took by the GCB. The theoretical synergy characteristic of the novel HVDC CB is obtained. The paper supplies a new method to improve the custom mechanical HVDC CB, which is useful to achieve the HVDC CB with less serial breaks.展开更多
文摘The functional analysis of interruption is of great necessity in carrying out a smooth conversation.By exemplifying interruptions in specific conversational situations identified in Friends,the paper has explored the relative,interactive,pluralistic and situational characteristics of functions of interruptions.
文摘Reinforcement learning has been applied to air combat problems in recent years,and the idea of curriculum learning is often used for reinforcement learning,but traditional curriculum learning suffers from the problem of plasticity loss in neural networks.Plasticity loss is the difficulty of learning new knowledge after the network has converged.To this end,we propose a motivational curriculum learning distributed proximal policy optimization(MCLDPPO)algorithm,through which trained agents can significantly outperform the predictive game tree and mainstream reinforcement learning methods.The motivational curriculum learning is designed to help the agent gradually improve its combat ability by observing the agent's unsatisfactory performance and providing appropriate rewards as a guide.Furthermore,a complete tactical maneuver is encapsulated based on the existing air combat knowledge,and through the flexible use of these maneuvers,some tactics beyond human knowledge can be realized.In addition,we designed an interruption mechanism for the agent to increase the frequency of decisionmaking when the agent faces an emergency.When the number of threats received by the agent changes,the current action is interrupted in order to reacquire observations and make decisions again.Using the interruption mechanism can significantly improve the performance of the agent.To simulate actual air combat better,we use digital twin technology to simulate real air battles and propose a parallel battlefield mechanism that can run multiple simulation environments simultaneously,effectively improving data throughput.The experimental results demonstrate that the agent can fully utilize the situational information to make reasonable decisions and provide tactical adaptation in the air combat,verifying the effectiveness of the algorithmic framework proposed in this paper.
文摘The embedded data acquistition technology in vehicle electronic system was discussed. This technology adopts the parallel working mode, gets vehicle electronic system data by communication. This technology can provide us a lot of information on the electronic control unit, is very useful for the development of the vehicle electronic system, and can be used in diagnosis. The key points to this technology are the timer interrupt, A/D interrupt, communication interrupt and real time operation. This technology has been validated by the application in the electronic control mechanism transmission shifting system of the tank.
文摘Aim To achieve multitask data procssing in a wireless alarm system by computer. Methods The alarm system was composed of hardware and software. The hardware was composed of a master master computer and slave transmitters. On urgent ugent occasion, one or more of the transmitters transmitted alarm signals and the master computer received the signals; interruption, residence, graph and word processing were utilized in software to achieve multitiask data processing . Results The main computer can conduct precise and quick multitask data procesing in any condition so long as alarm signals are received. The processing speed is higher than ordinary alarm System. Conclusion The master computer can conduct safe and quick multitask data processing by way of reliable design of software and hardware , so there is no need of special processor.
文摘To determine the feasibility and practicability of interrupt continuous wave (CW) approach proposed for real time simulating radar intermediate frequency(IF) video signal, theoretical analysis and computer simulation were used. Phases at two linked points between the end and beginning of adjoined frames are always consistent; the bias Doppler frequency for the time delay of A/D sampling start responds to that for target acceleration. No digital phase compensation is required at continuous points, and the interrupt CW approach has apparently practical values.
基金supported by the National Natural Science Foundation of China (Grant Nos 70701002 and 70521001)the National Basic Research Program of China (Grant No 2006CB705503)the Research Grants Council of the Hong Kong Special Administrative Region of China (Grant No HKU7187/05E)
文摘In this paper, we present a new car-following model by taking into account the effects of the traffic interruption probability on the car-following behaviour of the following vehicle. The stability condition of the model is obtained by using the linear stability theory. The modified Korteweg-de Vries （KdV） equation is constructed and solved, and three types of traffic flows in the headway sensitivity space-stable, metastable, and unstable--are classified. Both the analytical and simulation results show that the traffic interruption probability indeed has an influence on driving behaviour, and the consideration of traffic interruption probability in the car-following model could stabilize traffic flow.
基金supported by National Natural Science Foundation of China(No.51977132)the Key Special Science and Technology Project of Liaoning Province(No.2020JH1/10100012)the General Program of the Education Department of Liaoning Province(No.LJKZ0126).
文摘The self-excited DC air circuit breaker(SE-DCCB)has been widely used in urban rail transit due to its excellent stability.It can realize forward and reverse interruption,but has difficulty interrupting small currents due to the phenomenon of arc root sticking at the entrance of the arc chamber in the splitting process,which is known as arc root stagnation.A coupling model of the self-excited magnetic field and magnetohydrodynamics is established for the SE-DCCB with the traditional structure.The magnetic field,temperature and airflow distribution in the arc chamber are investigated with an interrupting current of 150 A.The simulation results show that the direction and magnitude of the magnetic blowout force are the dominant factors in the arc root stagnation.The local high temperature of the arc chamber due to arc root stagnation increases the obstruction effect of the airflow vortex on the arc root movement,which significantly increases the arc duration time of small current interruption.Based on the research,the structure of the magnetic conductance plate of the actual product is improved,which can improve the direction and magnitude of the magnetic blowout force at the arc root so as to restrain the development of the airflow vortex effectively and solve the problem of arc root stagnation when the small current is interrupted.The simulation results show that the circuit breaker with improved structure has a better performance for a small current interruption range from 100 A to 350 A.
文摘To improve the limiting current interruption capability and minimizing vacuum interrupter with axial magnetic field （AMF） electrodes, it is significant to investigate the vacuum arc behaviours between the contacts. AMF distributions of the slot type electrodes were studied by both numerical analysis and experiments. Furthermore, the behaviours of vacuum arcs for different parameters of the slot type AMF electrodes were investigated by using high-speed CCD camera. The influences of gap distance, contact diameter and phase shift time between AMF and arc current on the vacuum arc were investigated. The results provide a reference for research and development of vacuum interrupters with slot type or other types of AMF electrode.
文摘Influence of the shock wave on the turbulence in a supersonic nozzle was investigated for a SF6 puffer circuit breaker interruption process. Turbulence is enlarged through the shock wave. Baroclinic generation of vortex causes flow separation and broadening of the arc cross section. V-I characteristics are slightly modified due to the shock wave＇s influence.
基金Supported by the National Natural Science Foundation of China under Grant No 61434006
文摘The InGaAs/InAIAs/InP high electron mobility transistor （HEM：F） structures with lattice-matched and pseudo- morphic channels are grown by gas source molecular beam epitaxy. Effects of Si ^-doping condition and growth interruption on the electrical properties are investigated by changing the Si-cell temperature, doping time and growth process. It is found that the optimal Si ^-doping concentration （Nd） is about 5.0 x 1012 cm-2 and the use of growth interruption has a dramatic effect on the improvement of electrical properties. The material structure and crystal interface are analyzed by secondary ion mass spectroscopy and high resolution transmission elec- tron microscopy. An InGaAs/InAiAs/InP HEMT device with a gate length of lOOnm is fabricated. The device presents good pinch-off characteristics and the kink-effect of the device is trifling. In addition, the device exhibits fT = 249 GHa and fmax 〉 400 GHz.
基金supported by the National Natural Science Foundation of China(No.81100143)the Beijing Nova Program(Z121107002512053)+4 种基金the Beijing Health System High Level Health Technology Talent Cultivation Plan(No.2013-3-013)the Beijing Outstanding Talent Training Program(No.2014000021223ZK32)the Beijing National Science Foundation(No.7212100)the Beijing Municipal Administration of Hospitals Clinical Medicine Development of Special Funding Support(ZYLX201303)the National Key Clinical Speciality Construction Project。
文摘OBJECTIVE To access the efficacy and safety of the double-ProGlide technique for the femoral vein access-site closure in cryoballoon ablation with uninterrupted oral anticoagulants(OAC),and its impact on the electrophysiology laboratory time as well as hospital stay after the procedure in this observational study.METHODS Patients with atrial fibrillation undergoing cryoballoon ablation with uninterrupted OAC at Department of Cardiology,Beijing Anzhen Hospital,Capital Medical University,Beijing,China from May 2019 to May 2021 were enrolled in this study.From October 2020,double-ProGlide technique was consistently used for hemostasis(ProGlide group),and before that conventional manual compression was utilized(manual compression group).The occurrence of vascular and groin complications was accessed during the hospital stay and until the three-month follow-up.RESULTS A total of 140 participants(69.30%of male,mean age:59.21±10.29 years)were evaluated,70 participants being in each group.Immediate hemostasis was achieved in all the patients with ProGlide closure.No major vascular complications were found in the ProGlide group while two major vascular complications were occurred in the manual compression group.The incidence of any groin complication was obviously higher in subjects with manual compression than patients with ProGlide devices(15.71%vs.2.86%,P=0.009).In addition,compared with the manual compression group,the ProGlide group was associated with significantly shorter total time in the electrophysiology laboratory[112.0(93.3–128.8)min vs.123.5(107.3–158.3)min,P=0.006],time from sheath removal until venous site hemostasis[3.8(3.4–4.2)min vs.8.0(7.6–8.5)min,P<0.001],bed rest time[8.0(7.6–8.0)h vs.14.1(12.0–17.6)h,P<0.001]and hospital stay after the procedure[13.8(12.5–17.8)h vs.38.0(21.5–41.0)h,P<0.001].CONCLUSIONS Utilization of the double-ProGlide technique for hemostasis after cryoballoon ablation with uninterrupted OAC is feasible and safe,which has the clinical benefit in reducing the total electrophysiology laboratory time and the hospital stay length after the procedure.
基金Project supported by the National High Tech Research and Development Program of China (Grant No. 511-0910-1031)
文摘Considering the effects that the probability of traffic interruption and the friction between two lanes have on the car-following behaviour, this paper establishes a new two-lane microscopic car-following model. Based on this microscopic model, a new macroscopic model was deduced by the relevance relation of microscopic and macroscopic scale parameters for the two-lane traffic flow. Terms related to lane change are added into the continuity equations and velocity dynamic equations to investigate the lane change rate. Numerical results verify that the proposed model can be efficiently used to reflect the effect of the probability of traffic interruption on the shock, rarefaction wave and lane change behaviour on two-lane freeways. The model has also been applied in reproducing some complex traffic phenomena caused by traffic accident interruption.
基金Project supported by the State Key Program of the National Natural Science of China (Grant No. 60835004)the Natural Science Foundation of Jiangsu Province of China (Grant No. BK2009727)+1 种基金the Natural Science Foundation of Higher Education Institutions of Jiangsu Province of China (Grant No. 10KJB510004)the National Natural Science Foundation of China (Grant No. 61075028)
文摘On the assumption that random interruptions in the observation process are modeled by a sequence of independent Bernoulli random variables, we firstly generalize two kinds of nonlinear filtering methods with random interruption failures in the observation based on the extended Kalman filtering （EKF） and the unscented Kalman filtering （UKF）, which were shortened as GEKF and CUKF in this paper, respectively. Then the nonlinear filtering model is established by using the radial basis function neural network （RBFNN） prototypes and the network weights as state equation and the output of RBFNN to present the observation equation. Finally, we take the filtering problem under missing observed data as a special case of nonlinear filtering with random intermittent failures by setting each missing data to be zero without needing to pre-estimate the missing data, and use the GEKF-based RBFNN and the GUKF-based RBFNN to predict the ground radioactivity time series with missing data. Experimental results demonstrate that the prediction results of GUKF-based RBFNN accord well with the real ground radioactivity time series while the prediction results of GEKF-based RBFNN are divergent.
基金supported by National Natural Science Foundation of China(No.50477024)
文摘The greenhouse effect of SFe is a great concern today. The development of high voltage vacuum circuit breakers becomes more important. The vacuum circuit breaker has minimum pollution to the environment. The vacuum interrupter is the key part of a vacuum circuit breaker. The interrupting characteristics in vacuum and arc-controlling techniue are the main problems to be solved for a longer gap distance in developing high voltage vacuum interrupters. To understand the vacuum arc characteristics and provide effective technique to control vacuum arc in a long gap distance, the arc mode transition of a cup-type axial magnetic field electrode is observed by a high-speed charge coupled device （CGD） video camera under different gap distances while the arc voltage and arc current are recorded. The controlling ability of the axial magnetic field on vacuum arc obviously decreases when the gap distance is longer than 40 ram. The noise components and mean value of the arc voltage significantly increase. The effective method for controlling the vacuum arc characteristics is provided by long gap distances based on the test results. The test results can be used as a reference to develop high voltage and large capacity vacuum interrupters.
基金supported by National Key Basic Research Program of China(973 Program)(No.2015CB251002)
文摘When subjected to high voltages between opened contacts, vacuum interrupters may emit X-rays. In order to ensure that these are of an acceptable level, vacuum interrupters should comply with the limits for X-ray emission and the test procedures to be carried out to verify this based on relevant standards and specifications. In this paper, a comprehensive experimental study has been performed for 126 kV vacuum interrupters used in a transmission system to understand the X-radiation level and its influence by three main parameters, namely applied power-frequency voltage, contact gap and power=frequency voltage conditioning. The radiation instrument is an FJ347 radiometer and the X-radiation dose was measured at the power-frequency test voltage. These tests demonstrated that the X-radiation emission level for a 126 kV vacuum interrupter did not exceed the following： 5 μSv per hour at a rated voltage of 126 kV and 150 μSv per hour at a power-frequency voltage of 230 kV at 1 m distance. The X-radiation dose increased with the applied power-frequency voltage increasing and decreased with the contact gap increasing. The X- radiation dose for 126 kV vacuum interrupters decreased by 57% after the conditioning procedure with a certain power-frequency voltage. During the conditioning procedure, the average value of the X-radiation dose was 4.49 mSv, which means if a professional conditions 180 interrupters per year, it will be safe at the 6.4 m distance.
基金supported by the National Hi-Tech Research and Development Program (863) of China (No. 2001AA602011-1)
文摘This paper begins with a brief introduction of the embedded real-time operating system VxWorks and CompactPCI standard, then gives the programming interfaces of Peripheral Controller Interface （PCI） configuring, interrupts handling and multi-tasks programming interface under VxWorks, and then emphasis is placed on the software frameworks of CPCI interrupt management based on multi-tasks. This method is sound in design and easy to adapt, ensures that all possible interrupts are handled in time, which makes it suitable for data acquisition systems with multi-channels, a high data rate, and hard real-time high energy physics.
基金the National Natural Science Foundation of China(Grant Nos.61963008 and 61673168)the Natural Science Foundation of Guangxi Zhuang Autonomous Region,China(Grant No.2018GXNSFAA281274)+1 种基金the Doctor Scientific Research Startup Project Foundation of Guangxi Normal University,China(Grant No.2018BQ007)the Innovation-Driven Development Special Fund Project of Guangxi Zhuang Autonomous Region,China(Grant No.GUIKEAA19254034).
文摘Traffic interruption phenomena frequently occur with the number of vehicles increasing.To investigate the effect of the traffic interruption probability on traffic flow,a new optimal velocity model is constructed by considering the driver anticipation term in the interruption case for car-following theory.Furthermore,the effect of driver anticipation in the interruption case is investigated via linear stability analysis.Also,the MKdV equation is obtained concerning the effect of driver anticipation in the interruption case.Moreover,numerical simulation states that the driver anticipation term in the interruption case contributes to the stability of traffic flow.
文摘Purpose： One of the main indicators of scientific production is the number of papers published in scholarly journals. Turkey ranks 18th place in the world based on the number of scholarly publications. The objective of this paper is to find out if the monetary support program initiated in 1993 by the Turkish Scientific and Technological Research Council （TUBITAK） to incentivize researchers and increase the number, impact, and quality of international publications has been effective in doing so.Design/methodology/approach： We analyzed some 390,000 publications with Turkish affiliations listed in the Web of Science （WoS） database between 1976 and 2015 along with about 157,000 supported ones between 1997 and 2015. We used the interrupted time series （ITS） analysis technique （also known as ＂quasi-experimental time series analysis＂ or ＂intervention analysis＂） to test if TOBITAK＇s support program helped increase the number of publications. We defined ARIMA （1,1,0） model for ITS data and observed the impact of TOBiTAK＇s support program in 1994, 1997, and 2003 （after one, four and 10 years of its start, respectively）. The majority of publications （93%） were full papers （articles）, which were used as the experimental group while other types of contributions functioned as the control group. We also carried out a multiple regression analysis.Findings： TUBITAK＇s support program has had negligible effect on the increase of the number of papers with Turkish affiliations. Yet, the number of other types of contributions continued to increase even though they were not well supported, suggesting that TUBITAK＇s support program is probably not the main factor causing the increase in the number of papers with Turkish affiliations. Research limitations： Interrupted time series analysis shows if the ＂intervention＂ has had any significant effect on the dependent variable but it does not explain what caused the increase in the number of papers if it was not the intervention. Moreover, except the＂intervention＂, other ＂event（s）＂ that might affect the time series data （e.g., increase in the number of research personnel over the years） should not occur during the period of analysis, a prerequisite that is beyond the control of the researcher. Practical implications： TUBITAK＇s ＂cash-for-publication＂ program did not seem to have direct impact on the increase of the number of papers published by Turkish authors, suggesting that small amounts of payments are not much of an incentive for authors to publish more. It might perhaps be a better strategy to concentrate limited resources on a few high impact projects rather than to disperse them to thousands of authors as ＂micropayments.＂ Originality/value： Based on 25 years＇ worth of payments data, this is perhaps one of the first large-scale studies showing that ＂cash-for-publication＂ policies or ＂piece rates＂ paid to researchers tend to have little or no effect on the increase of researchers＇ productivity. The main finding of this paper has some implications for countries wherein publication subsidies are used as an incentive to increase the number and quality of papers published in international journals. They should be prepared to consider reviewing their existing support programs （based usually on bibliometric measures such as journal impact factors） and revising their reward policies.
文摘Interruption,as a linguistic phenomenon,can be see everywhere.And talk show programs are common setting for interruptions.So in this thesis three questions are addressed as followed:What function does the interruption have in these two kinds of talk shows(relatively formal and informal) respectively;what are the similarities of relatively formal and informal talk show programs;what are the differences between relatively formal and informal talk shows.
基金supported by National Natural Science Foundation of China (Nos. 51407163, 51777025)National Rail Transportation Electrification and Automation Engineering Technology Research Center (No. NEEC-2017B07)+1 种基金China Postdoctoral Science Foundation (No. 2017M622370)Key scientific research projects of colleges and universities in Henan(16A470014, 19A470008)
文摘Vacuum gaps have rapid dynamic dielectric recovery speed while SF6 gaps have high insulation strength. The series-connected vacuum and SF6 gaps are used as the main switch(MS), which combines their advantages. The work aims to verify the feasibility of serial vacuum and SF6 gaps in mechanical HVDC interruption. The test circuit of the dynamic dielectric recovery performance(DDRP) is set up. The DDRP is tested under free recovery condition by the high voltage pulse source. The DDRP of the vacuum circuit breaker(VCB) and SF6 gas circuit breaker(GCB) in DC interruption with active current injection is analyzed and compared. The test results indicate that the dielectric recovery duration of the VCB is below 30 μs while that of the GCB is above 100 μs. In order to achieve the cooperation between the VCB and GCB, a novel hybrid HVDC circuit breaker(CB) based on series-connected vacuum and SF6 gaps is proposed. The ‘voltage-zero’ duration is created by introducing the follow current loop and there more recovery time for the dielectric recovery of the MS. The voltage distribution is controlled by the voltage dividing method so that the VCB undertakes the initial transient recovery voltage(TRV) and the later TRV is took by the GCB. The theoretical synergy characteristic of the novel HVDC CB is obtained. The paper supplies a new method to improve the custom mechanical HVDC CB, which is useful to achieve the HVDC CB with less serial breaks.
