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1.
Spatial distributions of energetic charged particles, neutrons and gamma rays at altitude 500 km (below the radiation belts of the Earth), obtained by the measurements of two apparatuses on board the Intercosmos-17 satellite, are presented. The latitudinal dependences, [i.e. the variation of flux with vertical cut-off rigidity of the measurement point], for neutrons (E n = 1 –30 MeV), gamma rays (E =0·15–6 MeV), secondary electrons (E e > 100 MeV) and for primary protons coming from the west and the east, respectively, are given. The main characteristic, the ratioN p/N e of the counting rate of the particles in the polar regionN p(Rvert< <0·1 GeV/c) and on the equatorN e(Rvert > 16 GeV/c), is obtained for the various types of particles. This value is 10 for neutrons, 3.7 for gamma rays, 1·8 for electrons, 11 for protons in westward direction, 10 for protons in eastward direction. The latitude profile of neutrons and gamma rays is in a good agreement with calculations assuming their production by nuclear reactions of primary cosmic rays with nuclei of the atmosphere. The weakening of rigidity dependence of protons coming from east in comparison with those coming from the west, is interpreted as the cause of additional proton albedo flux. The equality of albedo electron fluxes (Ee = 100–3500 MeV) from these directions is observed. With the use of the shadowing effect the obtained data on electron-positron component are consistent with the flux of albedo positrons (Ee + > 3·5 GeV) of the value (0·5±0·2) m–2. s–1. ster–1. The possibility of abundance of albedo positrons above electrons at these altitudes for the energy intervalE=0·2÷0·3 GeV is indicated.  相似文献   

2.
金星日  张英俏  金哲  张寿 《中国物理》2005,14(10):1936-1941
We propose a scheme to realize the nonlocal quantum entanglement of three three-level particles by using a three-particle entangled state of three levels as a quantum channel with the aid of some local unitary transformations. This scheme can be directly generalized to the nonlocal quantum entanglement of N three-level particles.  相似文献   

3.
The group of rigid motions is considered to guide the search for a natural system of space-time coordinates in General Relativity. This search leads us to a natural extension of the space-times that support Painlevé–Gullstrand synchronization. As an interesting example, here we describe a system of rigid coordinates for the cross mode of gravitational linear plane waves.  相似文献   

4.
We define passive gravitational mass operator of a hydrogen atom in the post-Newtonian approximation of general relativity and show that it does not commute with energy operator, taken in the absence of gravitational field. Nevertheless, the equivalence between the expectation values of passive gravitational mass and energy is shown to survive for stationary quantum states. Inequivalence between passive gravitational mass and energy at a macroscopic level results in time dependent oscillations of the expectation values of passive gravitational mass for superpositions of stationary quantum states, where the equivalence restores after averaging over time. Inequivalence between gravitational mass and energy at a microscopic level reveals itself as unusual electromagnetic radiation, emitted by the atoms, supported and moved in the Earth gravitational field with constant velocity using spacecraft or satellite, which can be experimentally measured.  相似文献   

5.
A method of N×N sub-array crisscross insertion has been put forward. N×N holographic lens array is used for realizing PS-1 optical interconnection of the 2N×2N element array. The condition for the sub-array interlacing was analyzed. The formula of the PS-1 imaging magnifying power and the imaging distance have been given for both parallel light illumination and divergent light illumination. The results indicated that the formula of the PS-1 imaging magnifying power and imaging distance realized by N×N sub-array crisscross insertion are identical with the results of the PS realized by 2×2 holographic lens array. The experiments prove correctness of the formula.  相似文献   

6.
7.
A fully micro realistic, propensity version of quantum theory is proposed, according to which fundamental physical entities—neither particles nor fields—have physical characteristics which determine probabilistically how they interact with one another (rather than with measuring instruments). The version of quantum smearon theory proposed here does not modify the equations of orthodox quantum theory: rather it gives a radically new interpretation to these equations. It is argued that (i) there are strong general reasons for preferrring quantum smearon theory to orthodox quantum theory; (ii) the proposed change in physical interpretation leads quantum smearon theory to make experimental predictions subtly different from those of orthodox quantum theory. Some possible crucial experiments are considered.  相似文献   

8.
The last decade of research on κ-Minkowski noncommutative spacetime has been strongly characterized by a controversy concerning the speed of propagation of massless particles. Most arguments suggested that this speed should depend on the momentum of the particle strongly enough to be of interest for some ongoing experimental studies. But the only explicit derivations of worldlines in κ-Minkowski predicted no momentum dependence for the speed of massless particles. We return to this controversy equipped with the recent understanding that in some quantum spacetimes coincidences of events assessed by an observer who is distant from the events can be artifactual. We therefore set up our investigation in such a way that we never rely on the assessment of coincidences of events by distant observers. This allows us to verify explicitly that in κ-Minkowski simultaneously-emitted massless particles of different momentum are detected at different times, and establish a linear dependence of the detection times on momentum.  相似文献   

9.
PS(PerfectShuffle)opticalinterconnectioncancomposedvariousopticalinterconnectionnetworks,forexampleΩnetwork.However,itsconver...  相似文献   

10.
11.
The spatial dependence of K α emission generated from laser-produced hot electrons is investigated experimentally and theoretically. In addition, the conversion efficiency of K α production as a function of laser intensity is measured and compared with modeling results. We use the terawatt Ti:sapphire laser at MPQ and vary the peak intensity from 1015 to 1018 W/cm2 with a pulse duration of 200 fs. A solid Cu target is placed at various positions in the laser focus, which allows one to vary the intensity but keep the total energy on the target constant. When the target is near best focus, the FWHM of the K α emission, measured using a knife-edge, is considerably larger than the FWHM of the laser intensity. In measuring the efficiency of K α production using the fundamental wavelength of the laser, a clear maximum of K α emission is observed at a position away from best focus, where the peak intensity is down by more than an order of magnitude from the value at best focus. When the second harmonic of the laser is used, the K α emission is peaked near best focus. The K α emission from layer targets is used to obtain an estimate of the temperature of the hot electrons. Modeling of K α production, using a Monte Carlo electron/photon transport code, shows the relationship between incident electron energy and the emitted K α emission. Efficient K α generation from the low-intensity wings of the laser pulse contributes to the large spot size of the K α emission. The lower electron temperatures that are expected for the second harmonic explain the differences in the location of maximum K α emission for the two wavelengths. We discuss the use of K α emission in photoionizing inner-shell electrons with the goal of achieving X-ray lasing at short wavelengths. Received: 6 April 1999 / Revised version: 31 May 1999 / Published online: 11 August 1999  相似文献   

12.
Probability distributions that determine completely the bound state in the problem of a quantum particle in one or two delta-function wells are derived within the recently developed tomographic representation of quantum states, where a state is characterized by a positive probability distribution. The quantum propagator for the Schrödinger equation is obtained for the problem of two dispersing delta-function wells.  相似文献   

13.
The two-dimensional SU(N) quantum antiferromagnet, a generalization of the quantum Heisenberg model, is investigated by quantum Monte Carlo simulations. The ground state for Nor=5 with broken lattice translational invariance. Our computation of the magnetization and the dimerization order parameter shows the absence of the intermediate spin-liquid phase.  相似文献   

14.
宋斌  曹培林 《中国物理快报》2003,20(9):1488-1491
The structures and energies of a Ga4N4 cluster have been calculated using a full-potential linear-muffin-tin-orbital molecular-dynamics (FP-LMTO MD) method. We obtained twenty-four structures for a Ga4N4 cluster. The most stable structure we obtained is a C8 three-dimensional structure, the energy of which is lower than that of the C2v symmetry structure proposed by Kandalam et al. [J. Phys. Chem. B106 (2002) 1945] The calculated results show that the isomer with an N3 subunit is preferred, supporting the previous result made by Kandalam et al,We found that the most stable structure of Ga4N4 clusters presented semiconductor-like properties through the calculation of the density of states.  相似文献   

15.
We analytically compute the orbital effects induced on the motion of a spinning particle geodesically traveling around a central rotating body by the general relativistic two-body spin–spin and spin-orbit leading-order interactions. Concerning the spin-orbit term, we compute the long-term variations due to the particle’s spin by finding secular precessions for the inclination I of the particle’s orbit, its longitude of the ascending node Ω and the longitude of pericenter v{\varpi} . Moreover, we generalize the well-known Lense-Thirring precessions to a generic orientation of the source’s angular momentum by obtaining an entirely new effect represented by a secular precession of I, and additional secular precessions of Ω and v{\varpi} as well. The spin–spin interaction is responsible of gravitational effects à la Stern-Gerlach consisting of secular precessions of I, W, v{I, \Omega, \varpi} and the mean anomaly M{\mathcal{M}} . Such results are obtained without resorting to any approximations either in the particle’s eccentricity e or in its inclination I; moreover, no preferred orientations of both the system’s angular momenta are adopted. Their generality allows them to be applied to a variety of astronomical and astrophysical scenarios like, e.g., the Sun and its planets and the double pulsar PSR J0737-3039A/B. It turns out that the orbital precessions caused by the spin–spin and the spin-orbit perturbations due to the less massive body are below the current measurability level, especially for the solar system and the Stern-Gerlach effects. Concerning the solar Lense-Thirring precessions, the slight misalignment of the solar equator with respect to the ecliptic reduces the gravitomagnetic node precession of Mercury down to a 0.08 mas per century level with respect to the standard value of 1 mas per century obtained by aligning the z axis with the Sun’s angular momentum. The new inclination precession is as large as 0.06 mas per century, while the perihelion’s rate remains substantially unchanged, amounting to −2 mas per century. Further studies may be devoted to the extrasolar planets which exhibit a rich variety of orbital and rotational configurations.  相似文献   

16.
杨树政  林理彬 《中国物理》2002,11(6):619-623
We have found that the nonthermal radiation of a nonstationary Kerr-Newman black hole is affected by interstellar materials. In particular, the interstellar gas deeply influences the average range of nonthermal radiation particles, while the average range depends on the maximum energy of the radiation and the energy extent of the radiation.  相似文献   

17.
18.
《Annals of Physics》1986,172(2):451-482
A method for calculating the one-loop effective potential for matter fields in Kaluza-Klein theories with the structure M4 × SN for both even and odd N is presented. The cases M4 × SN (N = 1, 2, 3, 4, 5, 6, and 8) have been examined. The method leads to finite results when N = odd and divergent results when N = even as expected.  相似文献   

19.
We compute the mass spectrum of the fermionic sector of the Dirac–Kähler extension of the SM (DK-SM) by showing that there exists a Bogoliubov transformation that transforms the DK-SM into a flavor U(4)U(4) extension of the SM (SM-4) with a particular choice of masses and mixing textures. Mass relations of the model allow determination of masses of the 4th generation. Tree level prediction for the mass of the 4th charged lepton is 370 GeV. The model selects the normal hierarchy for neutrino masses and reproduces naturally the near tri-bimaximal and quark mixing textures. The electron neutrino and the 4th neutrino masses are related via a see-saw-like mechanism.  相似文献   

20.
Vector quantization (VQ) is an important data compression method. The key of the encoding of VQ is to find the closest vector among N vectors for a feature vector. Many classical linear search algorithms take $O(N)$ steps of distance computing between two vectors. The quantum VQ iteration and corresponding quantum VQ encoding algorithm that takes $O(\sqrt N )$ steps are presented in this paper. The unitary operation of distance computing can be performed on a number of vectors simultaneously because the quantum state exists in a superposition of states. The quantum VQ iteration comprises three oracles, by contrast many quantum algorithms have only one oracle, such as Shor's factorization algorithm and Grover's algorithm. Entanglement state is generated and used, by contrast the state in Grover's algorithm is not an entanglement state. The quantum VQ iteration is a rotation over subspace, by contrast the Grover iteration is a rotation over global space. The quantum VQ iteration extends the Grover iteration to the more complex search that requires more oracles. The method of the quantum VQ iteration is universal.  相似文献   

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