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1.
Summary The vertical differential and integral, muon spectra at super-high energies,viz. up to 10 TeV have been estimated from our predicted primary spectrum of the formN(E)dE=2.4E −2.7dE (cm2s sr GeV)−1. The accelerator data of Johnsonet al., Elbertet al. have been used for the evaluation of fractional hadronic energy moments. By using the conventional Feynman scaling hypothesis and the meson atmospheric diffusion equation after Bugaevet al., the differential and integral muon spectra have been estimated and the results are well in accord with the experimental data of Bakeret al., Allkoferet al., Ayreet al., Aminevaet al., Menon and Ramana Murthy, and Sheldonet al. in the spectral range (0.1÷10) TeV.  相似文献   

2.
C.R. Sarma 《Molecular physics》2013,111(3):857-859
The krypton potentials of Barker et al., Buck et al., Gough et al. (Maitland and Smith (n-6)) and Thakkar and Smith (MIST 2C and 6B) are compared as to their ability to predict dilute gas properties (second virial, viscosity, self-diffusion and thermal conductivity coefficients and thermal diffusion factors). The potentials of Barker et al. and Buck et al. and Gough et al. (MS) accurately predict these properties almost equally. The MIST potentials do not fare quite so well. The isotopic thermal diffusion factor, the dilute gas property most sensitive to the shape of the potential, is best described by the Buck et al. and MS potentials. An analysis of this property suggests the correctness of the slope of the repulsive wall of these potentials.  相似文献   

3.
Summary In a recent note by Shepherd it is claimed that the main conclusions discussed in a paper by Petroniet al. about certain instability mechanisms for steady equivalent barotropic flows are incorrect and, although no criticism is made regarding the analytical treatment, two counterexamples are presented to support this thesis. In addition to this it is asserted that the envisaged necessity for energy and enstrophy to be transferred in both spatial directions in a normal-mode instability is ?extremely well known?. Here we demonstrate that Shepherd's conclusions are without foundation and confirm the validity and originality of Petroniet al. results by showing that:a) the first counterexample describes a situation that is in fact provided for by Petroniet al.'s analysis;b) the second counterexample is not dynamically realizable and, even if it were, the related conclusions would not apply to flows defined in doubly periodic or bounded domains such as those considered by Petroniet al.; c) the mechanism cited above is not known at all in the specific context dealt with by Petroniet al. We emphasize this by pointing out that for steady equivalent barotropic flows the range of parameters for which such an instability mechanism is allowed complements exactly the range for which the steady states are stable according to Benziet al.  相似文献   

4.
Summary The prompt-muon flux generated directly from the decay of short-lived particles like D-mesons and Λc-hyperons produced during primary cosmic proton-air collisions has been estimated. The inclusive production cross-sections of charmed particles based on the recombination of quark parton model developed by Bugaevet al. and the primary-nucleon spectrum based on the latest JACEE balloon flight data have been used in this investigation. The derived direct muon spectrum has been compared with the earlier results of Elbertet al., Inazawaet al. Bugaevet al. and Allkofer and Bhattacharyya.  相似文献   

5.
The deuteronA(q 2 ) structure function is calculated up toq 2=20 fm–2 with the Paris potential including relativistic nucleonic and mesonic corrections. Different parametrizations (Iachello et al., Galster et al., Höhler et al., Gari and Krümpelmann (GK)) of the nucleon electromagnetic form factors (emff) are used. Unlike the data of Simon et al., those recently taken at Saclay are reasonably well reproduced by our full predictions for the first three emff considered. On the contrary, the predictions for the GK model fail to fit the Saclay data. The dependence ofA(q 2 ) on the cut-off masses of the hadronic form factors is also investigated.  相似文献   

6.
It was shown that N=1 super-symmetry algebra can be constructed in de Sitter space (Pahlavan et al. in Phys Lett. B 627:217–223, 2005), through calculation of charge conjugation in the ambient space notation (Moradi et al. in Phys. Lett. B 613:74, 2005; Phys. Lett. B 658:284, 2008). Calculation of N=2 super-symmetry algebra constitutes the main frame of this paper. N=2 super-symmetry algebra was presented in Pilch et al. (Commun. Math. Phys. 98:105, 1985). In this paper, we obtain an alternative N=2 super-symmetry algebra.  相似文献   

7.
For the problem of electron scattering on charged unscreened impurities, the scattering rate is calculated self-consistently. The resulting low-temperature mobility is only, slightly temperature dependent and differs from an analogous result of Fujita et al. (J. Phys. Chem. Sol.37 (1976), 227) and Zubarev et al. (Sol. State Commun.21 (1977), 565) by just a change of a numerical constant.  相似文献   

8.
We previously observed that an intrinsic staking fault shrunk through a glide of a Shockley partial dislocation terminating its lower end in a hard-sphere crystal under gravity coherently grown in ?001? by Monte Carlo simulations [Mori et al., Molec. Phys. 105, 1377 (2007)]; it was an answer to a one-decade long standing question why the stacking disorder in colloidal crystals reduced under gravity [Zhu et al., Nature 387, 883 (1997)]. Here, we present an elastic energy calculation; in addition to the self-energy of the partial dislocation [Mori et al., Prog. Theor. Phys. Suppl. 178, 33 (2009)] we calculate the cross-coupling term between elastic field due to gravity and that due to a Shockley partial dislocation. The cross-term is an increasing function of the linear dimension R over which the elastic field expands, showing that a driving force arises for the partial dislocation moving toward the upper boundary of a grain.  相似文献   

9.
Summary Final results of the experiment for the estimation of charge abundances using plastic emulsion chamber consisting of CR-39 (HCB) and Fuji ET-7B nuclear-emulsion sheet, launched from Alice Springs for 32 hours at an atmospheric depth of 9.8 g cm−2 is presented. The latest long hour etching technique was used for track detection in plastics. The estimated reduced etch rate distribution presented was based on 2968 measured track diameter data in CR-39 (HCB) stacks. The observed charge spectrum from the reduced etch rate distribution was duly corrected for the top of the atmosphere by adopting the conventional formulation for cosmic-ray propagation along with the latest modified partial cross-sections for A-A collisions after Tsaoet al. The average value of the observed energy of the 77 very heavy primaries was estimated from the opening angle measurements of alpha fragments in Fuji ET-7B nuclear emulsion and was found to be 5.01 GeV/n which comes out to be 8.2 GeV/n, when corrected for the top of the atmosphere due to propagation in the residual atmospheric depth. The measured integral fluxes for NeMgSi and Fe groups above 4 GeV/n have been compared with the global data surveyed by Ichimuraet al. Our results on element/Si and element/Fe have been compared with the HEAO-3-C2 data after Englemannet al. Using SSLB model, the source abundance is derived from the observed result and that was compared with the results of Juliusson,et al., Lezniak and Webber and Garcia-Munozet al.  相似文献   

10.
Summary In the recent years various and interesting superposition states of the quantized radiation field were investigated in the literature, such as that involving two number states by Wodkiewiczet al.; that involving two coherent states by Hillery and Gerryet al.; that involving two squeezed states by Xinet al., etc. Here we study a general one-parameter superposition state which unifies those states and others in the literature, all becoming a particularization of ours. General expressions characterizing the physical properties of the field are obtained. The role played by the present superposition state as an alternative interpolating state is also discussed. The authors of this paper have agreed to not receive the proofs for correction.  相似文献   

11.
Molecular reaction dynamics of Cl + H2 (D2) has been studied on the latest analytical potential energy surface called BW3 using the Monte Carlo quasi-classical trajectory method. Excitation functions, differential cross sections and angular distributions of HCl and DCl products have been calculated. The excitation functions of the Cl (2P3/2) + n-H2 and Cl(2P3/2) + n-D2 reactions are also studied. The results are compared with those of quasi-classical trajectory [M. Alagia et al.: Phys. Chem. Chem. Phys. 2 (2000); F. J. Aoiz et al.: J. Phys. Chem. 100 (1996)], quantum mechanical (QM) calculations [F. J. Aoiz et al.:J. Chem. Phys. 115 (2001)] and experimental data [S. H. Lee et al.: J. Chem. Phys. 110 (1999); F. Dong et al.: J. Chem. Phys. 115 (2001)]. Discussions are given to some new results.  相似文献   

12.
In April, 2010, after reading “An improved critical angle equation for ion channeling” (Zheng theory) proposed by Zheng et al. (1) in Nuclear Instruments and Methods in Physics Research Section B (NIM-B), we felt very strange, because the theory contradicts the well-known Lindhard theory (2) and many of the experimental results published during the last few decades (3). Therefore, we submitted our first comments (4) to NIM-B for publication on 15 April 2010. In September 2010, we had found a new paper published by Zheng et al. (5) in Radiation Effects and Defects in Solids. In the latter paper (5), Zheng et al. studied the isotopic mass effects for low-energy channeling in a silicon crystal by using Monte Carlo (MC) simulations. Immediately, we remembered that a similar work had been published by Zheng et al. two years before for low-energy ion channeling in single-wall carbon nanotubes (SWCNT) (6). The aim of the two papers (5, 6) is finding simulation evidence to support the Zheng theory (1) by studying isotopic ion channeling.  相似文献   

13.
This paper describes a rate equation model that has been formulated for an SF6 saturable absorber. The model includes three transitions in the 3 ladder and one hot band transition along with intramolecular V-V relaxation to the bath states. The coupled differential equations were solved using the Runge-Kutta method. The transmission characteristics have been calculated for several combinations of pulse length, cell length and SF6 pressure. Theoretical values of transmission are compared with the experimental data of Haglund et al., Taylor et al. and Daido et al., and it is found that the model explains the absorption behaviour more closely.  相似文献   

14.
This talk is a survey of the question of joint measurability of coexistent observables and it is based on the monograph Operational Quantum Physics (Busch et al., Springer-Verlag, Berlin, 1997) and on the papers (Lahti et al., Journal of Mathematical Physics 39, 6364–6371, 1998; Lahti and Pulmannova, Reports on Mathematical Physics 39, 339–351, 1997; 47, 199–212, 2001).  相似文献   

15.
M2 is now widely used to characterize the quality of laser radiation. In the paraxial approach the inequality M21 holds, if M2 is defined by the second moments. Nevertheless, in some publications M2<1 is presented, either theoretically or experimentally (Wang et al., Optik 1995;100(1):8; Lu et al., Optik 1995;100(2):91; Wang et al., Optics and Laser Technology 1999;31:151). In particular, it is stated that for a superposition of axially shifted Gaussian spherical beams, M2 can become smaller than one (Wang et al., Optics and Laser Technology 1999;31:151). These problems with M2 are briefly summarized.  相似文献   

16.
We provide a new class of entanglement witnesses for dd systems (two qudits). Our construction generalizes the one proposed recently by Jafarizadeh et al. for d = 3 and d = 4 on the basis of semidefinite linear programming. Moreover, we provide a new class of PPT entangled states detected by our witnesses which generalizes well known family of states constructed by Horodecki et al. for d = 3.  相似文献   

17.
Using the recently derived primary cosmic ray nucleon spectrum from JACEE and GSFC balloon flight data and Fermilab results for pp → π± + X anything inclusive reaction data in the light of Feynman scaling the depth-intensity spectrum under standard rock has been estimated. A precisely constructed range-energy relation has been applied in this analysis. The derived spectrum when corrected for range fluctuation agrees approximately with the experimental data under standard rocks measured by MIYAZAKI , BARTON , CASTAGNOLI et al., MEYER et al., BERGAMASCO et al., SHELDON et al. and BASCHIERA et al.  相似文献   

18.
In constructing a theory of thermal diffusiophoresis of volatile aerosol particles it is necessary to have boundary conditions for the tangential velocity component which allow for the presence of heterogeneous chemical reactions. Conditions of this sort have been obtained by a number of authors [R. N. Gupta et al., Technical Papers, AIAA 22nd Aerospace Science Meeting, AIAA 19th Thermophysics Conference, New York (1985), pp. 465–490; D. V. Kul’ginov, Tech. Phys. 63, 940 (1993); A. V. Bogdanov et al., Preprint No. 1051, Fiz-Tekh. Inst. Akad. Nauk. SSSR, Leningrad (1986)]. The results of Gupta et al. are in the form of analytical expressions, but their computations actually used Maxwell’s method, which is of low accuracy. Kul’ginov et al. and Bogdanov et al. used the method of matched asymptotic expansions, which did not permit them to get simple analytical expressions. In the present paper the slip velocity is calculated by the Loyalka method. Analytical expressions are obtained for the slip coefficients, and the results of numerical calculations are presented. It is shown that in the presence of concentration gradients of the components of the gaseous mixture along the surface of an aerosol particle, the slip velocity can acquire new terms due to the change in the sticking coefficient along the catalytic surface. Expressions in final form are given for these terms. Zh. Tekh. Fiz. 67, 29–33 (May 1997)  相似文献   

19.
Experimental results on the current-voltage characteristics of polydiacetylene (PDA) single crystals reported by Aleshin et al [Phys. Rev. Vol. B 69, (2004) art. 214203] are reinterpreted in terms of the phonon-assisted electron tunnelling model. It is shown that the experimental results, measured in the temperature range from 1.8 K to 300 K are consistent with the tunnelling rate dependence on field strength, computed for the same range of temperatures. An advantage of this model over that of Aleshin et al, using the variable range hopping (VRH) model, is the possibility of describing the behaviour of I — V data measured at both high and low temperatures with the same set of parameters characterizing this material. This assertion is confirmed by comparison of the temperature-dependent current-voltage data extracted from Aleshin et al’s work with tunnelling rate dependence on temperature, computed using two different expressions of the phonon-assisted tunnelling theory. The temperature dependence of the conductivity of an ion implanted PDA crystals [B. S. Elman et al, Appl. Phys. Lett., Vol. 46, (1985) p. 100] and polypyrrole [P. Dutta et al, Synth. Met., Vol. 139 (2003) p. 201] are also explained on the basis of this model.   相似文献   

20.
The study of the electrical resistivity of alkali K-based liquid binaries, viz, K 1−x Na x, K 1−x Rb x, and K 1−x Cs x have been made by well recognized model potential. The most recent local field correction functions due to Farid et al. (F) and Sarkar et al. (S) are used for the first time in the study of electrical resistivity of liquid binary mixtures and found suitable for such study. The results due to the inclusion of Sarkar et al.’s local field correction function are found superior to those obtained due to Farid et al.’s local field correction function. The present results compare well the experimental data. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 40–44, August, 2006.  相似文献   

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