Cosmic Ray Composition in the“Knee”Region Deduced from the Lateral Distribution of Cerenkov Light Emitted in Extensive Air Showers

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.

Atmospheric Carbon Dioxide Reconstruction and Ocean Acidification Deduced from Carbon Isotope Variations across the Triassic–Jurassic Boundary in the Qiangtang Area, Tibetan Plateau

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.

Study on Cloud-Radiation Effect on Climate in Eastern Asia

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.

The Dynamic Mechanism of the Formation of the Low Level Jet

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.

CONVECTIVE HEAT TRANSFER CHARACTERISTICS OF GAS IMPINGEMENT ON SMALL HEATED DEVICE IN LIQUID COOLANT BATH

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.

A Universal Formula for the Secondary Electron Yield of Metals at an Incident Angle of θ

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°.

Analysis of Imaging Contrast of Small Cracks in FNR Specimens

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.

Formula for the Probability of Secondary Electrons Passing over the Surface Barrier into a Vacuum

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.

Effective Jump Length of Coupled Continuous Time Random Walk

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.

Total Reaction Cross Section Measurements at Intermediate Energy for the Proton Halo Candidate ^(23)Al and Its Neighbours

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.

Reduced Sputtering Yields Induced by Fast Neutrons

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.

Evidence for Different Fission Behavior of Hot Nuclei Formed in Central and Peripheral Collisions of ^(40)Ar+^(209)Bi Reaction at 25 MeV/u

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.

Yuan Brand Common Eel Tonic Syrup Capsules

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

表示“推断”、“推测”意义的动词

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。

An optimized ion trap geometry to measure quadrupole shifts of ^(171)Yb~＋ clocks

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.

The Laplace Transform L_+ and L_-

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

Quantum-mathematical model of edge and peak point in Fresnel diffraction through a slit

The intensity distribution in Fresnel diffraction through a slit includes numerous small fluctuations referred to as ripples. These ripples make the modelling of the intensity distribution complicated. In this study, we examine the characteristics of the Fresnel diffraction intensity distribution to deduce the rule for the peak position and then propose two types of quantum-mathematical models to obtain the distance between the edge and the peak point. The analysis and simulation indicate that the error in the models is below 0.50 μm. The models can also be used to detect the edges of a diffraction object, and we conduct several experiments to measure the slit width. The experimental results reveal that the repetition accuracy of the method can reach 0.23 μm.

γ-ray Anisotropy Measurement in Coincidence Mode

The method of ADO ratios deduced from coincidence data has been described.Based on this method,γ-ray multipolarities could be assigned.For two cascade transitions,γ1 and γ2,the ADO ratio ofγ1 is defined

Determination of Proton Drip-line Nucleus of P Isotopes

Researches have been made in recent years in the search of the proton drip-line and halo nuclei of P isotopes both in theory^([1～3])and in experimerit~[4].We have deduced the matter,proton,neutron and halo density distribution of^(25)P with the theory of relativistic-mean-field(RMF)by using the parameter set of

Some Results on Halo Research at RIBLL

Last years,several experiments about halo nuclei were performed at RIBLL.On the analyzing and fitting the data by using Glauber theory with some assumptions,following some results were deduced.1.~8B shows a proton halo structure.The reaction cross section σR of 54 MeV/u^8B on Si was measured as 1634±49 mb.The density distribution of ~8B was studied through a fitting procedure on the enhancement of the σR at low energies including the high energy data by using Glauber theory.The result shows a long tail ...