We report the first result of measurements of the lateral distribution of Cerenkov light associated with cosmic ray extensive air showers with size between 10^(5.0)and 10^(6.6)observed in the Liangwang Mountain Observ...We report the first result of measurements of the lateral distribution of Cerenkov light associated with cosmic ray extensive air showers with size between 10^(5.0)and 10^(6.6)observed in the Liangwang Mountain Observatory,90 km east of Kunming City in China.The change trend towards heavy nucleus dominance of the primary cosmic ray composition in the“Knee”region is deduced with the aid of a Monte Carlo simulation.展开更多
Objective The end-Triassic mass extinction was one of the five most profound Phanerozoic extinction events.This event was accompanied by a series of significant environmental changes,of which the most notable is the e...Objective The end-Triassic mass extinction was one of the five most profound Phanerozoic extinction events.This event was accompanied by a series of significant environmental changes,of which the most notable is the emergence of warm climate and the world-wide disappearance of carbonate platform.展开更多
The in-plane dynamic crushing behavior of re-entrant honeycomb is analyzed and compared with the conventional hexagon topology.Detailed deformation modes along two orthogonal directions are examined,where a parametric...The in-plane dynamic crushing behavior of re-entrant honeycomb is analyzed and compared with the conventional hexagon topology.Detailed deformation modes along two orthogonal directions are examined,where a parametric study of the effect of impact velocity and cell wall aspect ratio is performed.An analytical formula of the dynamic crushing strength is then deduced based on the periodic collapse mechanism of cell structures.Comparisons with the finite element results validate the effectiveness of the proposed analytical method.Numerical results also reveal higher plateau stress of re-entrant honeycomb over conventional hexagon topology,implying better energy absorption properties.The underlying physical understanding of the results is emphasized,where the auxetic effect（negative Poisson＇s ratio） induced in the re-entrant topology is believed to be responsible for this superior impact resistance.展开更多
In this paper, the decade data of meteorological satellite and surface meteorological observation of China have been analysed. The relationship between cloud and radiation has been studied. A set of empirical formulae...In this paper, the decade data of meteorological satellite and surface meteorological observation of China have been analysed. The relationship between cloud and radiation has been studied. A set of empirical formulae of the ralationships between the albedo and cloud amount, the outgoing longwave radiation and cloud amount in Chinese different districts and different seasons has been deduced. They express simply the response of both planet reflectivity and earth-atmosphere outgoing longwave radiation to the change of cloud amount. So that the sensitivity of net radiation of the earth-atmosphere system to the change of cloud amount and the ratio of cloud reflective effect to greenhouse effect can be estimated. In this paper, the radiative process of the earth-atmosphere system, cloud and radiative balance and its effect on climate have been synthetically studied.展开更多
With a heralded single photon source(HSPS), a measurement-device-independent quantum key distribution(MDIQKD) protocol is proposed, combined with a three-intensity decoy-state method. HSPS has the two-mode characteris...With a heralded single photon source(HSPS), a measurement-device-independent quantum key distribution(MDIQKD) protocol is proposed, combined with a three-intensity decoy-state method. HSPS has the two-mode characteristic, one mode is used as signal mode, and the other is used as heralded mode to reduce the influence of the dark count. The lower bound of the yield and the upper bound of the error rate are deduced and the performance of the MDI-QKD protocol with an HSPS is analyzed. The simulation results show that the MDI-QKD protocol with an HSPS can achieve a key generation rate and a secure transmission distance which are close to the theoretical limits of the protocol with a single photon source(SPS). Moreover, the key generation rate will improve with the raise of the senders' detection efficiency. The key generation rate of the MDI-QKD protocol with an HSPS is a little less than that of the MDI-QKD protocol with a weak coherent source(WCS) in the close range, but will exceed the latter in the far range. Furthermore, a farther transmission distance is obtained due to the two-mode characteristic of HSPS.展开更多
Modeling of permanent magnet（PM） is very important in the process of electromagnetic system calculation of aerospace electromagnetic relay（AEMR）. In traditional analytical calculation, PM is often equivalent to a ...Modeling of permanent magnet（PM） is very important in the process of electromagnetic system calculation of aerospace electromagnetic relay（AEMR）. In traditional analytical calculation, PM is often equivalent to a lumped parameter model of one magnetic resistance and one magnetic potential, but great error is often caused for the inner differences of PM; based on the conception of flux tube, a type of 2D magnetic equivalent circuit framework of permanent magnet model（2D MECF） is established; the element is defined, the relationship between elements is deduced, and solution procedure as well as verification condition of this model is given; by a case study of the electromagnetic system of a certain type of AEMR, the electromagnetic system calculation model is established based on 2D MECF and the attractive force at different rotation angles is calculated; the proposed method is compared with the traditional lumped parameter model and finite element method（FEM）; for some types of electromagnetic systems with symmetrical structure, 2D MECF proves to be of acceptable accuracy and high calculation speed which fit the requirement of robust design for AEMR.展开更多
By installing an X-mode polarized Q-band（32-56 GHz） reflectometry at the low field side on EAST,the zero density cutoff layer was determined and the edge density profile was measured in normally operating plasmas.A ...By installing an X-mode polarized Q-band（32-56 GHz） reflectometry at the low field side on EAST,the zero density cutoff layer was determined and the edge density profile was measured in normally operating plasmas.A Monte Carlo procedure has been developed to analyze the density profiles by considering the error of time delay measured by reflectometry.By combining this Q-band and previously developed V- and W-band reflectometries,the density profiles from edge to core can be measured in most EAST experiments.The line integrated densities deduced from density profiles measured by reflectometry are consistent with those directly measured by a horizontal interferometer.The density pedestal measured by reflectometry shows a clear crash during an ELM（edge localized mode） event,after which the pedestal gradually increases and recovers in 10 ms and then remains little changed up to the next ELM.展开更多
The ordinary multidimensional reductive perturbation method is generalized so as to apply to the general case including the dissipative factor. With this the corresponding Cubic-Schrbdinger equation is deduced, and by...The ordinary multidimensional reductive perturbation method is generalized so as to apply to the general case including the dissipative factor. With this the corresponding Cubic-Schrbdinger equation is deduced, and by the preliminary study of its solution, it shows that it is more admissible to consider atmospheric meso-scale systems as the nonlinear Cubic-Schrbdinger waves.With suitable boundary and initial conditions, the Cubic-Schrodinger equation is numerically integrated so as to investigate the possible dynamic mechanism as well as the impacts of the nonlinear action, turbulent friction and topogrphy to the formation of the LLJ. The results indicate that the downward transfer of the momentum and the effect of the surface friction are responsible for the concentration of the momentum in the layer between 850 and 700 hPa. The location of the horizontal concentration of momentum depends on the propagation of momentum, in the process the inertia-gravity internal wave is very important, whereas turbulent friction is unfavourable for or delays the formation of the low level jet.展开更多
Heat transfer characteristics of a small heated device have been investigated in a liquid bath with gas jetimpingement as function of gas flow rate,coolant temperature,liquid phsicochemical properties,heat flux,heat s...Heat transfer characteristics of a small heated device have been investigated in a liquid bath with gas jetimpingement as function of gas flow rate,coolant temperature,liquid phsicochemical properties,heat flux,heat source size,ambient pressure and the distance between jet and heated wall.The experimental results show that the agitation of liquid caused by gas jet bubbles increases greatly therate of heat transfer,and the evaporation of coolant near the wall,which was due to the concentration differencebetween gas-liquid interface and bulk gas phase,gives additional enhancement of heat transfer.The rate ofevaporation related to the bubble growth was mathematically formulated.By using the simultaneous heat and mass transfer model,the convective heat transfer coefficient and masstransfer coefficient can be deduced from the experimental results.In addition,the local heat transfer coefficient and the distribution of evaporation heat flux on the smallheated surface are investigated mathematically and experimentally.展开更多
Scattering neutrons are one of the key factors which may affect the images of fast neutron radiography(FNR).We develop a math model of FNR physical process and deduce an image contrast formula that is further confirme...Scattering neutrons are one of the key factors which may affect the images of fast neutron radiography(FNR).We develop a math model of FNR physical process and deduce an image contrast formula that is further confirmed by comparing the results obtained by the formula with the results given by Monte Carlo simulation and experimental results.We provide a simple method to predict the image contrast in the FNR experiment.展开更多
Based on the main physical processes,we deduce the relationships among the incident energy Wp0 of the primary electron,the number of released secondary electrons(i.e.δ_(PEθ))per primary electron entering the metal a...Based on the main physical processes,we deduce the relationships among the incident energy Wp0 of the primary electron,the number of released secondary electrons(i.e.δ_(PEθ))per primary electron entering the metal at incident angleθand the angleθitself.In addition,the relationship ofδPEθatθ=0°,i.e.δ_(PE0),with Wp0 is determined.From the experimental results,the relationship of the ratio atθ=0°,i.e.β_(0) which is the ratio of the average number of released secondary electrons generated by a single primary electron backscattered at the metal surface to that generated by a single primary electron entering the metal,with Wp0 is determined.Moreover,the relationships among the ratioβθ,Wp0 andθare obtained.Based on the relationships among the secondary electron yield atθ(i.e.δθ),the yield atθ=0°(i.e.δ_(0)),the backscattering coefficient atθ(i.e.η_(θ)),the coefficient atθ=0°(i.e.η0),δ_(PEθ)andδ_(PE0),we deduce the universal formula forδ_(θ),δ_(0),η_(θ),η_(0),and W_(p0) for the primary electrons at an incident energy of 2–10 keV.The secondary electron yields calculated from the universal formula and the experimental yields of some metals are compared,and the results suggest that the proposed formula is universal for estimation of secondary electron yields atθ=0°−80°.展开更多
Based on a simple classical model that primary electrons at high electron energy interact with the electrons of lattice by the Coulomb force,we deduce the energy of secondary electrons.In addition,the number of second...Based on a simple classical model that primary electrons at high electron energy interact with the electrons of lattice by the Coulomb force,we deduce the energy of secondary electrons.In addition,the number of secondary electrons in the direction of velocity of primary electrons per unit path length,n,is obtained.According to the energy band of the insulator,n,the definition of the probability B of secondary electrons passing over the surface barrier of insulator into the vacuum and the assumption that lattice scattering is ignored,we deduce the expression of B related to the width of the forbidden band(E_(g))and the electron affinityχ.As a whole,the B values calculated with the formula agree well with the experimental data.The calculated B values lie between zero and unity and are discussed theoretically.Finally,we conclude that the deduced formula and the theory that explains the relationships among B,χand E_(g) are correct.展开更多
The concept effective jump length is proposed.Due to the joint probability density function of jump length and waiting time,it is complicated to distinguish the diffusion types.However,we calculate the probability den...The concept effective jump length is proposed.Due to the joint probability density function of jump length and waiting time,it is complicated to distinguish the diffusion types.However,we calculate the probability density function of effective jump length for the coupled continuous time random walk model we proposed previously.The mean square displacements deduced are coincident with the known results.More importantly,we find that the anomalous diffusion induced by the coupled model is equivalent to the competition between long jump length and long waiting time.展开更多
Total reaction cross sections σR for some proton-rich isotones (N = 10) near ^(23)Al on a carbon target have been measured at intermediate energies in the experiment performed at the Radioactive Ion Beam Line of the ...Total reaction cross sections σR for some proton-rich isotones (N = 10) near ^(23)Al on a carbon target have been measured at intermediate energies in the experiment performed at the Radioactive Ion Beam Line of the Heavy Ion Research Facility in Lanzhou. The Z-dependence of σR shows a remarkable enhancement for ^(23)Al relative to its neighbours. The difference factor d has been deduced from the measured σR by using the Glauber or Boltzmann-Uehling-Uhlenbeck models. From the above analysis, a possible one-proton halo structure is suggested for ^(23)Al.展开更多
The reduced sputtering yield (y_(n)^(R)) of materials induced by fast neutron is presented. Based on the experimental (y_(n)^(R)) results for (n, 2n), (n, p), (n, α) and (n, np) reactions, the value of (y_(n)^(R)) fo...The reduced sputtering yield (y_(n)^(R)) of materials induced by fast neutron is presented. Based on the experimental (y_(n)^(R)) results for (n, 2n), (n, p), (n, α) and (n, np) reactions, the value of (y_(n)^(R)) for (n, non-elastic) reaction is deduced by using data of cross sections in JENDL-3.2 and ENDF/B-VI. The value of (y_(n)^(R)) for (n, n) reaction is predicted by relation between (y_(n)^(R)) and the mean projected ranges of recoil nuclides. Combining both (y_(n)^(R)) for (n, n) and (n, non-elastic) reactions, the total (y_(n)^(R)) is obtained. Systematics of (y_(n)^(R)) for (n, non-elastic), (n, n) and (n, total) reactions have been demonstrated.展开更多
Correlated fission fragments from the reaction of 25MeV/u ^(40)Ar+^(209)Bi and their further correlation with a par-tides have been studied for peripheral and central collisions simultaneously.The excitation energy at...Correlated fission fragments from the reaction of 25MeV/u ^(40)Ar+^(209)Bi and their further correlation with a par-tides have been studied for peripheral and central collisions simultaneously.The excitation energy at scission deduced from postscission multiplicity is about 1725 MeV.The fission timescale deduced from prescission multiplicity is about 4×10^(21)s.Systematic analysis of the mass and energy distributions of Hssion fragments as a function of the initial temperature of hot fissioning nuclei reveals the existence of different fission behavior of hot nuclei formed in central and peripheral collisions.Experimental data demonstrate the change of Hssion behavior at T~4MeV.展开更多
For the same reason, the average intelligence quotient of Japanese is claimed to be higher than that of many people who like to eat meat. These facts have been deduced from studies made by scientists. Fish has rich un...For the same reason, the average intelligence quotient of Japanese is claimed to be higher than that of many people who like to eat meat. These facts have been deduced from studies made by scientists. Fish has rich unsaturated fatty acid necessary for man. This material, called DHA, can help improve the memory, delay mental decline and decrease the content of cholesterol in the blood展开更多
infer,conjecture,guess,surmise,conclude,deduce 1.infer:指根据已知的事实或信念,用推理的方法得出结论。如: We inferred from the principal’s announcement that he alreadyknew who had broken his window。我们从校长宣布的话...infer,conjecture,guess,surmise,conclude,deduce 1.infer:指根据已知的事实或信念,用推理的方法得出结论。如: We inferred from the principal’s announcement that he alreadyknew who had broken his window。我们从校长宣布的话中推断出他已知道是谁打破他的窗户。 The fossil remains of ape—man can help us infer how they lived。猿人化石可以帮助我们推测猿人的生活情况。展开更多
We propose a new ion-trap geometry to carry out accurate measurements of the quadrupole shifts in the （171）Yb ion.This trap will minimize the quadrupole shift due to the harmonic component of the confining potential...We propose a new ion-trap geometry to carry out accurate measurements of the quadrupole shifts in the （171）Yb ion.This trap will minimize the quadrupole shift due to the harmonic component of the confining potential by an order of magnitude.This will be useful to reduce the uncertainties in the clock frequency measurements of the 6s 2S（1/2）→4f（13）6s2 2F（7/2）and 6s 2S（1/2）→5d2D（3/2） transitions,from which we can deduce the precise values of the quadrupole moments（0s） of the 4f（13）6s2 2F（7/2） and 5d2D（3/2） states.Moreover,it may be able to affirm the validity of the measured 0 value of the4f（13）6s22F（7/2） state,for which three independent theoretical studies defer almost by one order of magnitude from the measurement.We also calculate 0s using the relativistic coupled-cluster（RCC） method.We use these 0 values to estimate the quadrupole shift that can be measured in our proposed ion trap experiment.展开更多
If the bounded function f(t)is considered,which is near the point t=0,the value f(0)does not have relationship to laplace transform of f(t)discnssed,because the values of f(t)at some points have not in fluence upon
文摘We report the first result of measurements of the lateral distribution of Cerenkov light associated with cosmic ray extensive air showers with size between 10^(5.0)and 10^(6.6)observed in the Liangwang Mountain Observatory,90 km east of Kunming City in China.The change trend towards heavy nucleus dominance of the primary cosmic ray composition in the“Knee”region is deduced with the aid of a Monte Carlo simulation.
基金financially supported by the National Science Foundation of China(grant No.41572089)
文摘Objective The end-Triassic mass extinction was one of the five most profound Phanerozoic extinction events.This event was accompanied by a series of significant environmental changes,of which the most notable is the emergence of warm climate and the world-wide disappearance of carbonate platform.
基金Project supported by the National Natural Science Foundation of China(Nos.11372252 and 11402035)
文摘The in-plane dynamic crushing behavior of re-entrant honeycomb is analyzed and compared with the conventional hexagon topology.Detailed deformation modes along two orthogonal directions are examined,where a parametric study of the effect of impact velocity and cell wall aspect ratio is performed.An analytical formula of the dynamic crushing strength is then deduced based on the periodic collapse mechanism of cell structures.Comparisons with the finite element results validate the effectiveness of the proposed analytical method.Numerical results also reveal higher plateau stress of re-entrant honeycomb over conventional hexagon topology,implying better energy absorption properties.The underlying physical understanding of the results is emphasized,where the auxetic effect（negative Poisson＇s ratio） induced in the re-entrant topology is believed to be responsible for this superior impact resistance.
基金The project is supported by National Natural Sciences Fundation of China (NNSFC)
文摘In this paper, the decade data of meteorological satellite and surface meteorological observation of China have been analysed. The relationship between cloud and radiation has been studied. A set of empirical formulae of the ralationships between the albedo and cloud amount, the outgoing longwave radiation and cloud amount in Chinese different districts and different seasons has been deduced. They express simply the response of both planet reflectivity and earth-atmosphere outgoing longwave radiation to the change of cloud amount. So that the sensitivity of net radiation of the earth-atmosphere system to the change of cloud amount and the ratio of cloud reflective effect to greenhouse effect can be estimated. In this paper, the radiative process of the earth-atmosphere system, cloud and radiative balance and its effect on climate have been synthetically studied.
基金supported by the National Natural Science Foundation of China(No.61302099)
文摘With a heralded single photon source(HSPS), a measurement-device-independent quantum key distribution(MDIQKD) protocol is proposed, combined with a three-intensity decoy-state method. HSPS has the two-mode characteristic, one mode is used as signal mode, and the other is used as heralded mode to reduce the influence of the dark count. The lower bound of the yield and the upper bound of the error rate are deduced and the performance of the MDI-QKD protocol with an HSPS is analyzed. The simulation results show that the MDI-QKD protocol with an HSPS can achieve a key generation rate and a secure transmission distance which are close to the theoretical limits of the protocol with a single photon source(SPS). Moreover, the key generation rate will improve with the raise of the senders' detection efficiency. The key generation rate of the MDI-QKD protocol with an HSPS is a little less than that of the MDI-QKD protocol with a weak coherent source(WCS) in the close range, but will exceed the latter in the far range. Furthermore, a farther transmission distance is obtained due to the two-mode characteristic of HSPS.
基金support of National Natural Science Foundation of China(Nos.51177021,51207028)
文摘Modeling of permanent magnet（PM） is very important in the process of electromagnetic system calculation of aerospace electromagnetic relay（AEMR）. In traditional analytical calculation, PM is often equivalent to a lumped parameter model of one magnetic resistance and one magnetic potential, but great error is often caused for the inner differences of PM; based on the conception of flux tube, a type of 2D magnetic equivalent circuit framework of permanent magnet model（2D MECF） is established; the element is defined, the relationship between elements is deduced, and solution procedure as well as verification condition of this model is given; by a case study of the electromagnetic system of a certain type of AEMR, the electromagnetic system calculation model is established based on 2D MECF and the attractive force at different rotation angles is calculated; the proposed method is compared with the traditional lumped parameter model and finite element method（FEM）; for some types of electromagnetic systems with symmetrical structure, 2D MECF proves to be of acceptable accuracy and high calculation speed which fit the requirement of robust design for AEMR.
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2014GB106000 and 2014GB106003)National Natural Science Foundation of China(Nos.11275234,11305215,11305208)
文摘By installing an X-mode polarized Q-band（32-56 GHz） reflectometry at the low field side on EAST,the zero density cutoff layer was determined and the edge density profile was measured in normally operating plasmas.A Monte Carlo procedure has been developed to analyze the density profiles by considering the error of time delay measured by reflectometry.By combining this Q-band and previously developed V- and W-band reflectometries,the density profiles from edge to core can be measured in most EAST experiments.The line integrated densities deduced from density profiles measured by reflectometry are consistent with those directly measured by a horizontal interferometer.The density pedestal measured by reflectometry shows a clear crash during an ELM（edge localized mode） event,after which the pedestal gradually increases and recovers in 10 ms and then remains little changed up to the next ELM.
文摘The ordinary multidimensional reductive perturbation method is generalized so as to apply to the general case including the dissipative factor. With this the corresponding Cubic-Schrbdinger equation is deduced, and by the preliminary study of its solution, it shows that it is more admissible to consider atmospheric meso-scale systems as the nonlinear Cubic-Schrbdinger waves.With suitable boundary and initial conditions, the Cubic-Schrodinger equation is numerically integrated so as to investigate the possible dynamic mechanism as well as the impacts of the nonlinear action, turbulent friction and topogrphy to the formation of the LLJ. The results indicate that the downward transfer of the momentum and the effect of the surface friction are responsible for the concentration of the momentum in the layer between 850 and 700 hPa. The location of the horizontal concentration of momentum depends on the propagation of momentum, in the process the inertia-gravity internal wave is very important, whereas turbulent friction is unfavourable for or delays the formation of the low level jet.
基金The project supported by National Natural Science Foundation of China.
文摘Heat transfer characteristics of a small heated device have been investigated in a liquid bath with gas jetimpingement as function of gas flow rate,coolant temperature,liquid phsicochemical properties,heat flux,heat source size,ambient pressure and the distance between jet and heated wall.The experimental results show that the agitation of liquid caused by gas jet bubbles increases greatly therate of heat transfer,and the evaporation of coolant near the wall,which was due to the concentration differencebetween gas-liquid interface and bulk gas phase,gives additional enhancement of heat transfer.The rate ofevaporation related to the bubble growth was mathematically formulated.By using the simultaneous heat and mass transfer model,the convective heat transfer coefficient and masstransfer coefficient can be deduced from the experimental results.In addition,the local heat transfer coefficient and the distribution of evaporation heat flux on the smallheated surface are investigated mathematically and experimentally.
基金Supported by the Science and Technology Development Foundation of China Academy of Engineering Physics(2008B0103002).
文摘Scattering neutrons are one of the key factors which may affect the images of fast neutron radiography(FNR).We develop a math model of FNR physical process and deduce an image contrast formula that is further confirmed by comparing the results obtained by the formula with the results given by Monte Carlo simulation and experimental results.We provide a simple method to predict the image contrast in the FNR experiment.
基金by Scientific Research Fund of Nanjing University of Information Science and Technology(No S8108197001)the Natural Science Foundation of Jiangsu Provincial Universities(No 10KJB180004).
文摘Based on the main physical processes,we deduce the relationships among the incident energy Wp0 of the primary electron,the number of released secondary electrons(i.e.δ_(PEθ))per primary electron entering the metal at incident angleθand the angleθitself.In addition,the relationship ofδPEθatθ=0°,i.e.δ_(PE0),with Wp0 is determined.From the experimental results,the relationship of the ratio atθ=0°,i.e.β_(0) which is the ratio of the average number of released secondary electrons generated by a single primary electron backscattered at the metal surface to that generated by a single primary electron entering the metal,with Wp0 is determined.Moreover,the relationships among the ratioβθ,Wp0 andθare obtained.Based on the relationships among the secondary electron yield atθ(i.e.δθ),the yield atθ=0°(i.e.δ_(0)),the backscattering coefficient atθ(i.e.η_(θ)),the coefficient atθ=0°(i.e.η0),δ_(PEθ)andδ_(PE0),we deduce the universal formula forδ_(θ),δ_(0),η_(θ),η_(0),and W_(p0) for the primary electrons at an incident energy of 2–10 keV.The secondary electron yields calculated from the universal formula and the experimental yields of some metals are compared,and the results suggest that the proposed formula is universal for estimation of secondary electron yields atθ=0°−80°.
基金Supported by the Natural Science Foundation of Jiangsu Provincial Universities under Grant No 10KJB180004.
文摘Based on a simple classical model that primary electrons at high electron energy interact with the electrons of lattice by the Coulomb force,we deduce the energy of secondary electrons.In addition,the number of secondary electrons in the direction of velocity of primary electrons per unit path length,n,is obtained.According to the energy band of the insulator,n,the definition of the probability B of secondary electrons passing over the surface barrier of insulator into the vacuum and the assumption that lattice scattering is ignored,we deduce the expression of B related to the width of the forbidden band(E_(g))and the electron affinityχ.As a whole,the B values calculated with the formula agree well with the experimental data.The calculated B values lie between zero and unity and are discussed theoretically.Finally,we conclude that the deduced formula and the theory that explains the relationships among B,χand E_(g) are correct.
基金Supported by the National Natural Science Foundation of China under Grant No 11175021.
文摘The concept effective jump length is proposed.Due to the joint probability density function of jump length and waiting time,it is complicated to distinguish the diffusion types.However,we calculate the probability density function of effective jump length for the coupled continuous time random walk model we proposed previously.The mean square displacements deduced are coincident with the known results.More importantly,we find that the anomalous diffusion induced by the coupled model is equivalent to the competition between long jump length and long waiting time.
基金Supported by the Major State Basic Research Development Program under contract No.G200077400。
文摘Total reaction cross sections σR for some proton-rich isotones (N = 10) near ^(23)Al on a carbon target have been measured at intermediate energies in the experiment performed at the Radioactive Ion Beam Line of the Heavy Ion Research Facility in Lanzhou. The Z-dependence of σR shows a remarkable enhancement for ^(23)Al relative to its neighbours. The difference factor d has been deduced from the measured σR by using the Glauber or Boltzmann-Uehling-Uhlenbeck models. From the above analysis, a possible one-proton halo structure is suggested for ^(23)Al.
基金the Returned Scientists1 Foundation of Chinese Academy of Sciences。
文摘The reduced sputtering yield (y_(n)^(R)) of materials induced by fast neutron is presented. Based on the experimental (y_(n)^(R)) results for (n, 2n), (n, p), (n, α) and (n, np) reactions, the value of (y_(n)^(R)) for (n, non-elastic) reaction is deduced by using data of cross sections in JENDL-3.2 and ENDF/B-VI. The value of (y_(n)^(R)) for (n, n) reaction is predicted by relation between (y_(n)^(R)) and the mean projected ranges of recoil nuclides. Combining both (y_(n)^(R)) for (n, n) and (n, non-elastic) reactions, the total (y_(n)^(R)) is obtained. Systematics of (y_(n)^(R)) for (n, non-elastic), (n, n) and (n, total) reactions have been demonstrated.
基金Supported by the National Natural Science Foundation of China under Grant No.19235011.
文摘Correlated fission fragments from the reaction of 25MeV/u ^(40)Ar+^(209)Bi and their further correlation with a par-tides have been studied for peripheral and central collisions simultaneously.The excitation energy at scission deduced from postscission multiplicity is about 1725 MeV.The fission timescale deduced from prescission multiplicity is about 4×10^(21)s.Systematic analysis of the mass and energy distributions of Hssion fragments as a function of the initial temperature of hot fissioning nuclei reveals the existence of different fission behavior of hot nuclei formed in central and peripheral collisions.Experimental data demonstrate the change of Hssion behavior at T~4MeV.
文摘For the same reason, the average intelligence quotient of Japanese is claimed to be higher than that of many people who like to eat meat. These facts have been deduced from studies made by scientists. Fish has rich unsaturated fatty acid necessary for man. This material, called DHA, can help improve the memory, delay mental decline and decrease the content of cholesterol in the blood
文摘infer,conjecture,guess,surmise,conclude,deduce 1.infer:指根据已知的事实或信念,用推理的方法得出结论。如: We inferred from the principal’s announcement that he alreadyknew who had broken his window。我们从校长宣布的话中推断出他已知道是谁打破他的窗户。 The fossil remains of ape—man can help us infer how they lived。猿人化石可以帮助我们推测猿人的生活情况。
基金CSIR-National Physical Laboratory,Depaitment of Science and Technology(Grant No.SB/S2/LOP/033/2013)the Board of Research in Nuclear Sciences(Grant No. 34/14/ 19/2014-BRNS/0309) for supporting
文摘We propose a new ion-trap geometry to carry out accurate measurements of the quadrupole shifts in the （171）Yb ion.This trap will minimize the quadrupole shift due to the harmonic component of the confining potential by an order of magnitude.This will be useful to reduce the uncertainties in the clock frequency measurements of the 6s 2S（1/2）→4f（13）6s2 2F（7/2）and 6s 2S（1/2）→5d2D（3/2） transitions,from which we can deduce the precise values of the quadrupole moments（0s） of the 4f（13）6s2 2F（7/2） and 5d2D（3/2） states.Moreover,it may be able to affirm the validity of the measured 0 value of the4f（13）6s22F（7/2） state,for which three independent theoretical studies defer almost by one order of magnitude from the measurement.We also calculate 0s using the relativistic coupled-cluster（RCC） method.We use these 0 values to estimate the quadrupole shift that can be measured in our proposed ion trap experiment.
文摘If the bounded function f(t)is considered,which is near the point t=0,the value f(0)does not have relationship to laplace transform of f(t)discnssed,because the values of f(t)at some points have not in fluence upon
