We study the quark loop effects on the dressed gluon propagator and also on the quark propagator itself.We find that the gluon propagators are different in two phases.The quark mass effects on the gluon propagator are...We study the quark loop effects on the dressed gluon propagator and also on the quark propagator itself.We find that the gluon propagators are different in two phases.The quark mass effects on the gluon propagator aresmall but not negligible.We also study the current quark mass dependence on the bag constant.展开更多
Based on the global color symmetry mode/ （GCM）, a method for obtaining the quark loop effects on the dressed gluon propagator in GCM is developed. In the chiral limit, it is found that the dressed gluon propagator c...Based on the global color symmetry mode/ （GCM）, a method for obtaining the quark loop effects on the dressed gluon propagator in GCM is developed. In the chiral limit, it is found that the dressed gluon propagator containing the quark loop effects in the Nambu-Goldstone and Wigner phases are quite different. In solving the quark self-energy functions in the two different phases and subsequent study of bag constant one shouM use the above dressed gluon propagator as input. The above approach for obtaining the current quark mass effects on the dressed gluon propagator is quite general and can also be used to calculate the chemical potential dependence of the dressed gluon propagator.展开更多
The concept of unmanned weapon system-of-systems(UWSoS)involves a collection of various unmanned systems to achieve or accomplish a specific goal or mission.The mission reliability of UWSoS is represented by its abili...The concept of unmanned weapon system-of-systems(UWSoS)involves a collection of various unmanned systems to achieve or accomplish a specific goal or mission.The mission reliability of UWSoS is represented by its ability to finish a required mission above the baselines of a given mission.However,issues with heterogeneity,cooperation between systems,and the emergence of UWSoS cannot be effectively solved by traditional system reliability methods.This study proposes an effective operation-loop-based mission reliability evaluation method for UWSoS by analyzing dynamic reconfiguration.First,we present a new connotation of an effective operation loop by considering the allocation of operational entities and physical resource constraints.Then,we propose an effective operationloop-based mission reliability model for a heterogeneous UWSoS according to the mission baseline.Moreover,a mission reliability evaluation algorithm is proposed under random external shocks and topology reconfiguration,revealing the evolution law of the effective operation loop and mission reliability.Finally,a typical 60-unmanned-aerial-vehicle-swarm is taken as an example to demonstrate the proposed models and methods.The mission reliability is achieved by considering external shocks,which can serve as a reference for evaluating and improving the effectiveness of UWSoS.展开更多
We reexamine the simplified dark matter(DM) models with fermionic DM particle and spin-0 mediator.The DM-nucleon scattering cross sections in these models are low-momentum suppressed at tree-level,but receive sizable ...We reexamine the simplified dark matter(DM) models with fermionic DM particle and spin-0 mediator.The DM-nucleon scattering cross sections in these models are low-momentum suppressed at tree-level,but receive sizable loop-induced spin-independent contribution.We perform one-loop calculations for scalar-type and twist-2 DM-quark operators,and complete two-loop calculations for scalar-type DM-gluon operator.Analyzing the looplevel contribution from new operators,we find that future direct detection experiments could be sensitive to a fraction of the parameter space.The indirect detection and collider search also provide complementary constraints on these models.展开更多
Magnetic hysteresis and compensation behavior of a mixed spin-（1, 3/2） Ising model on a square lattice are investigated in the framework of effective field theory based on a probability distribution technique. The e...Magnetic hysteresis and compensation behavior of a mixed spin-（1, 3/2） Ising model on a square lattice are investigated in the framework of effective field theory based on a probability distribution technique. The effect of random crystal field, ferromagnetic and ferrimagnetic exchange interaction on hysteresis loops and compensation phenomenon are discussed. A number of characteristic phenomena have been reported such as the observation of triple hysteresis loops at low temperatures and for negative values of random crystal field. Critical and double compensation temperatures have been also found. The obtained results are also compared to some previous works.展开更多
Objectives To evaluate the effect of hydrogen sulfide(H2S) postconditioning on myocardial ischemia-reperfusion (I/R) by pressure-volume loop(P-V loop). Methods The I/R model of rat in vivo was established by ligating ...Objectives To evaluate the effect of hydrogen sulfide(H2S) postconditioning on myocardial ischemia-reperfusion (I/R) by pressure-volume loop(P-V loop). Methods The I/R model of rat in vivo was established by ligating the left anterior descending coronary artery for 30min and reperfusing for 120 min.Wistar rats(n=32) were ran- domly divided into 4 groups;Sham operation,ischemia-reperfusion (I/R),Ischemic postconditioning(IPO) and H2S postconditioning.In sham operation,there was no ligation.In IPO,at the start of reperfusion,three cycles of 30s reperfusion and 30s LAD reocclusion preceded the 3h of reperfusion. In H2S postconditioning,NaHS(15μmol/kg,Sodium hydrosulfide)was administrated before coronary artery reperfusion. The heart rate(HR),I/R arrhythmia,the left ventricular end-systolic pressure(LVESP),left ventricular enddiastolic pressure(LVEDP),the slope of the end- systolic P-V relation(ESPVR) and the slope of the end-diastolic P-V relation(EDPVR) were detected.Infarct size was determined by scanning the images of the rat heart ventricular sections stained with Evans blue and TTC.Results Compared with I/R group,the I/R arrhythmia and the infarct size were decreased significantly(PPP2S postconditioning group.Conclusions Myocardial I/R injury was decreased by H2S post-conditioning, and it was sensitive and accurate to evaluate the heart function by P-V loop.展开更多
In this paper, a new strategy of switchable CMOS phase-locked loop frequency synthesizer is proposed to increase its tuning range. The switchable PLL which integrates two phase-locked loops with different tuning frequ...In this paper, a new strategy of switchable CMOS phase-locked loop frequency synthesizer is proposed to increase its tuning range. The switchable PLL which integrates two phase-locked loops with different tuning frequencies are designed and fabricated in 0.5 μm n-well CMOS process. Cadence/Spectre simulations show that the frequency range of the switchable phased-locked loop is between 320 MHz to 1.15 GHz. The experimental results show that the RMS jitter of the phase-locked loop changes from 26 ps to 123 ps as output frequency varies. For 700 MHz carrier frequency, the phase noise of the phase-locked loop reaches as low as ?81 dBc/Hz at 10 kHz offset frequency and ?104 dBc/Hz at 1 MHz offset frequency. A device degradation model due to hot carrier effects has been used to analyze the jitter and phase noise performance in an open loop voltage-controlled oscillator. The oscillation frequency of the voltage-controlled oscillator decreases by approximately 100 to 200 MHz versus the bias voltage and the RMS jitter increases by 40 ps under different phase-locked loop output frequencies after 4 hours of stress time.展开更多
文摘We study the quark loop effects on the dressed gluon propagator and also on the quark propagator itself.We find that the gluon propagators are different in two phases.The quark mass effects on the gluon propagator aresmall but not negligible.We also study the current quark mass dependence on the bag constant.
基金The project supported in part by National Natural Science Foundation of China under Grant Nos. 10575050 and 10135030 and the Research Fund for the Doctoral Program of Higher Education under Grant No. 20030284009.
文摘Based on the global color symmetry mode/ （GCM）, a method for obtaining the quark loop effects on the dressed gluon propagator in GCM is developed. In the chiral limit, it is found that the dressed gluon propagator containing the quark loop effects in the Nambu-Goldstone and Wigner phases are quite different. In solving the quark self-energy functions in the two different phases and subsequent study of bag constant one shouM use the above dressed gluon propagator as input. The above approach for obtaining the current quark mass effects on the dressed gluon propagator is quite general and can also be used to calculate the chemical potential dependence of the dressed gluon propagator.
基金supported by the National Natural Science Foundation of China(72101270,72001213).
文摘The concept of unmanned weapon system-of-systems(UWSoS)involves a collection of various unmanned systems to achieve or accomplish a specific goal or mission.The mission reliability of UWSoS is represented by its ability to finish a required mission above the baselines of a given mission.However,issues with heterogeneity,cooperation between systems,and the emergence of UWSoS cannot be effectively solved by traditional system reliability methods.This study proposes an effective operation-loop-based mission reliability evaluation method for UWSoS by analyzing dynamic reconfiguration.First,we present a new connotation of an effective operation loop by considering the allocation of operational entities and physical resource constraints.Then,we propose an effective operationloop-based mission reliability model for a heterogeneous UWSoS according to the mission baseline.Moreover,a mission reliability evaluation algorithm is proposed under random external shocks and topology reconfiguration,revealing the evolution law of the effective operation loop and mission reliability.Finally,a typical 60-unmanned-aerial-vehicle-swarm is taken as an example to demonstrate the proposed models and methods.The mission reliability is achieved by considering external shocks,which can serve as a reference for evaluating and improving the effectiveness of UWSoS.
基金supported by the Fundamental Research Funds for the Central Universities,Nankai University(63196013,63191522)
文摘We reexamine the simplified dark matter(DM) models with fermionic DM particle and spin-0 mediator.The DM-nucleon scattering cross sections in these models are low-momentum suppressed at tree-level,but receive sizable loop-induced spin-independent contribution.We perform one-loop calculations for scalar-type and twist-2 DM-quark operators,and complete two-loop calculations for scalar-type DM-gluon operator.Analyzing the looplevel contribution from new operators,we find that future direct detection experiments could be sensitive to a fraction of the parameter space.The indirect detection and collider search also provide complementary constraints on these models.
文摘Magnetic hysteresis and compensation behavior of a mixed spin-（1, 3/2） Ising model on a square lattice are investigated in the framework of effective field theory based on a probability distribution technique. The effect of random crystal field, ferromagnetic and ferrimagnetic exchange interaction on hysteresis loops and compensation phenomenon are discussed. A number of characteristic phenomena have been reported such as the observation of triple hysteresis loops at low temperatures and for negative values of random crystal field. Critical and double compensation temperatures have been also found. The obtained results are also compared to some previous works.
文摘Objectives To evaluate the effect of hydrogen sulfide(H2S) postconditioning on myocardial ischemia-reperfusion (I/R) by pressure-volume loop(P-V loop). Methods The I/R model of rat in vivo was established by ligating the left anterior descending coronary artery for 30min and reperfusing for 120 min.Wistar rats(n=32) were ran- domly divided into 4 groups;Sham operation,ischemia-reperfusion (I/R),Ischemic postconditioning(IPO) and H2S postconditioning.In sham operation,there was no ligation.In IPO,at the start of reperfusion,three cycles of 30s reperfusion and 30s LAD reocclusion preceded the 3h of reperfusion. In H2S postconditioning,NaHS(15μmol/kg,Sodium hydrosulfide)was administrated before coronary artery reperfusion. The heart rate(HR),I/R arrhythmia,the left ventricular end-systolic pressure(LVESP),left ventricular enddiastolic pressure(LVEDP),the slope of the end- systolic P-V relation(ESPVR) and the slope of the end-diastolic P-V relation(EDPVR) were detected.Infarct size was determined by scanning the images of the rat heart ventricular sections stained with Evans blue and TTC.Results Compared with I/R group,the I/R arrhythmia and the infarct size were decreased significantly(PPP2S postconditioning group.Conclusions Myocardial I/R injury was decreased by H2S post-conditioning, and it was sensitive and accurate to evaluate the heart function by P-V loop.
文摘In this paper, a new strategy of switchable CMOS phase-locked loop frequency synthesizer is proposed to increase its tuning range. The switchable PLL which integrates two phase-locked loops with different tuning frequencies are designed and fabricated in 0.5 μm n-well CMOS process. Cadence/Spectre simulations show that the frequency range of the switchable phased-locked loop is between 320 MHz to 1.15 GHz. The experimental results show that the RMS jitter of the phase-locked loop changes from 26 ps to 123 ps as output frequency varies. For 700 MHz carrier frequency, the phase noise of the phase-locked loop reaches as low as ?81 dBc/Hz at 10 kHz offset frequency and ?104 dBc/Hz at 1 MHz offset frequency. A device degradation model due to hot carrier effects has been used to analyze the jitter and phase noise performance in an open loop voltage-controlled oscillator. The oscillation frequency of the voltage-controlled oscillator decreases by approximately 100 to 200 MHz versus the bias voltage and the RMS jitter increases by 40 ps under different phase-locked loop output frequencies after 4 hours of stress time.
