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1.
It has been argued theoretically that the recently proposed vacuum fieldB (3) is not accompanied by a real electric fieldE (3) . Experimental evidence for this interence is available in the data reported by Deschampset al. [10], using microwave magnetization of an electron plasma set up in helium gas. Faraday induction due toB (3) does not occur in the inert gas and is not observed experimentally in the absence of free electrons. WheneverB (3) interacts with free electrons, however, Faraday induction occurs through a pulse of induced magnetization (i.e., induced orbital electronic angular momentum).  相似文献   

2.
Based on ab initio   electronic structure calculations by self-interaction-corrected local-density-approximation (SIC-LDA) with the Korringa–Kohn–Rostoker coherent potential approximation (KKR-CPA), we propose a materials design for high efficiency photovoltaic solar cells (PVSCs). It is shown that (i) the concentration dependence of the mixing energy of CuIn1−xGaxSe2CuIn1xGaxSe2 shows upward convexity, thus this system favors phase separation. Due to the type II band alignment between CuInSe2CuInSe2 and CuGaSe2CuGaSe2, efficient electron–hole separation is realized in decomposed phase of this system. (ii) CuIn1−xZn0.5xSn0.5xSe2CuIn1xZn0.5xSn0.5xSe2 has a direct band gap and no impurity state appears in the gap. Therefore, cost reduction is possible by using Zn and Sn instead of In. (iii) n-type CuAl1−xSnxS2CuAl1xSnxS2 and p-type Cu1−xVCuxAlS2Cu1xVCuxAlS2 have negative activation energy for doped impurities and are expected to be low-resistive transparent conducting sulfides, which should be useful for CuInSe2CuInSe2-based PVSCs.  相似文献   

3.
All existing "positive" results on two-neutrino double-beta decay in different nuclei were analyzed. Using procedure recommended by Particle Data Group weighted average values for half-lives of 48Ca, 76Ge, 82Se, 96Zr, 100Mo, 100Mo-100Ru (0+ 1), 116Cd, 150Nd and 238U were obtained. Existing geochemical data were analyzed and recommended values for half-lives of 128Te and 130Te are proposed. We recommend to use these results as the most precise and reliable values for half-lives at this moment.  相似文献   

4.
T1ρ imaging is useful in a number of clinical applications. T1ρ preparation methods, however, are sensitive to non-uniformities of the B0 magnetic field and the B1 RF field. These common system imperfections can result in image artifacts and quantification errors in T1ρ imaging. We report on a phase-cycling method which can eliminate B1 RF inhomogeneity effects in T1ρ imaging. This method does not only correct for image artifacts but also for T2ρ contamination caused by B1 RF inhomogeneity. The presence of B0 magnetic field inhomogeneity can compromise the effectiveness of this method for B1 RF inhomogeneity correction. We demonstrate that, by combining the spin-locking scheme reported by Dixon et al. (Myocardial suppression in vivo by spin locking with composite pulses. Magn Reson Med 1996; 36:90-94) with phase cycling, we can simultaneously correct B0 magnetic field inhomogeneity effects and B1 RF inhomogeneity effects in T1ρ imaging. Phantom and in vivo data sets are used to demonstrate the proposed methods and to compare them with other existing T1ρ preparation methods.  相似文献   

5.
It is shown that the longitudinal, magnetic flux density,B (3) , of vacuum electromagnetic radiation can be accommodated rigorously within Noether's theorem, which relates fundamental spacetime symmetries to fundamental conservation laws. This demonstration linksB (3) to the canonical energy-momentum tensorT µv that appears in Einstein's field equations of general relativity. Thus,B (3) provides a link between electromagnetism and gravitation which might eventually lead to an unified understanding of field theory.  相似文献   

6.
13C and 2H spin–lattice relaxation times have been determined by inversion recovery in a range of site-specific 13C- and 2H-labeled saccharides under identical solution conditions, and the data were used to calculate deuterium nuclear quadrupolar coupling constants (2H NQCC) at specific sites within cyclic and acyclic forms in solution. 13C T1 values ranged from 0.6 to 8.2 s, and 2H T1 values ranged from 79 to 450 ms, depending on molecular structure (0.4 M sugar in 5 mM EDTA (disodium salt) in 2H2O-depleted H2O, pH 4.8, 30°C). In addition to providing new information on 13C and 2H relaxation behavior of saccharides in solution, the resulting 2H1 NQCC values reveal a dependency on anomeric configuration within aldopyranose rings, whereas 2H NQCC values at other ring sites appear less sensitive to configuration at C1. In contrast, 2H NQCC values at both anomeric and nonanomeric sites within aldofuranose rings appear to be influenced by anomeric configuration. These experimental observations were confirmed by density functional theory (DFT) calculations of 2H NQCC values in model aldopyranosyl and aldofuranosyl rings.  相似文献   

7.
Abstract

Three new bands of the B 2Σ+X 2Σ+ system of 12C17O+ have been investigated using conventional spectroscopic techniques. The spectra were observed in a graphite hollow‐cathode lamp by discharging molecular oxygen (enriched in about 45% of the 17O2 isotope) under 1.0 Torr pressure. The rotational analysis of the 2–4, 2–5, and 2–6 bands was performed with the effective Hamiltonian of Brown (Brown et al., J. Mol. Spectrosc. 1979; 74: 294–318). Molecular constants were derived from a merge calculation, including both the current wavenumbers and the spectroscopic data published by the authors previously. The principal equilibrium constants for the ground state of 12C17O+ are ωe=2185.9658(84), ωe x e = 14.7674(11), B e=1.927001(38), αe=1.8236(22)×10?2, γe=?0.331(28)×10?4, D e=6.041(12)×10?6, βe=0.100(31)×10?7 cm?1, and the equilibrium constants for the excited state are σe=45876.499(15), ωe=1712.201(12), ωe x e=27.3528(39), B e=1.754109(35), αe=2.8706(57)×10?2, γe = ?1.15(19)×10?4, D e=7.491(20)×10?6, βe=2.13(12)×10?7, γe = 2.0953(97)×10?2, and αγe=?9.46(59)×10?4 cm?1, respectively. Rydberg–Klein–Rees potential energy curves were constructed for the B 2Σ+ and X 2Σ+ states of this molecule, and Franck–Condon factors were calculated for the vibrational bands of the BX system.  相似文献   

8.
A. Mehta 《Pramana》2003,61(5):819-826
In this paper recent measurements of structure functions from the HERA Collaborations are presented.  相似文献   

9.
The infrared spectrum of DNO3 (deuterated nitric acid) was recorded at high resolution (0.0027 cm−1) in the 700-1400 cm−1 region on a Bruker IFS 120 HR Fourier transform spectrometer. The analysis of the ν5 band of DNO3 centred at 887.657 cm-1 which is mostly an A-type band, was performed making use of the ground state parameters achieved by Drouin et al. [Drouin BJ, Miller CE, Fry JL, Petkie DT, Helminger P, Medvedev IR. J Mol Spectrosc 2006;236:29-34]. The ν5 fundamental band is strongly perturbed because of the existence of the ν7+ν9 dark combination band at 882.21  cm-1. The 51 and 7191 energy levels of DNO3 are coupled through A and B type Coriolis resonances, and as a consequence, numerous lines from the ν7+ν9 dark combination band could be identified also. In this way about 1070 and 75 energy levels of the 51 and 7191 vibrational states, respectively, were satisfactorily reproduced by the energy levels calculation which account for the observed resonances. A reasonable estimation of the absolute line intensities for the ν5 band of DNO3 was performed using the ν5 transition operator from H14NO3. The spectrum also features the ν5+ν6ν6, ν5+ν7ν7 and ν5+ν9−ν9 hot bands located at 881.03, 882.61 and 884.45 cm−1, respectively.  相似文献   

10.
The longitudinal vacuum fieldB (3) is an experimental observable which produces by magnetization a well-defined square-root beam power density dependence. Its longitudinal polarization implies that the helicities of the photon are +1, 0, and –1, and that the little group of the Poincaré group is the rotation group 0(3) of a massive boson. The mass of the photon (m) is therefore related directly toB (3) through the Proca equation, and it is concluded that experimental evidence forB (3) is also evidence for finitem.  相似文献   

11.
We present results on the production of bound states of Θ+ in nuclei using the (K+,π+) reaction. By taking into account the states obtained within a wide range of strength of the Θ+ nucleus optical potential, plus the possibility to replace different nucleons of the nucleus, we obtain an excitation spectra with clearly differentiated peaks. The magnitude of the calculated cross sections is well within reachable range.  相似文献   

12.
Spin relaxation is a sensitive probe of molecular structure and dynamics. Correlation of relaxation time constants, such as T1 and T2, conceptually similar to the conventional multidimensional spectroscopy, have been difficult to determine primarily due to the absense of an efficient multidimensional Laplace inversion program. We demonstrate the use of a novel computer algorithm for fast two-dimensional inverse Laplace transformation to obtain T1T2 correlation functions. The algorithm efficiently performs a least-squares fit on two-dimensional data with a nonnegativity constraint. We use a regularization method to find a balance between the residual fitting errors and the known noise amplitude, thus producing a result that is found to be stable in the presence of noise. This algorithm can be extended to include functional forms other than exponential kernels. We demonstrate the performance of the algorithm at different signal-to-noise ratios and with different T1T2 spectral characteristics using several brine-saturated rock samples.  相似文献   

13.
The densities ρ, speed of sound u, data of o-toluidine (i) + tetrahydropyran (j) + N,N-dimethylformamide (k) and its {tetrahydropyran (j) + N,N-dimethylformamide (k); o-toluidine (i) + N,N-dimethylformamide (k)} binaries have been measured as a function of composition at 298.15, 303.15 and 308.15 K. The excess molar enthalpies, HE data of same set of binary mixtures have also been measured over entire composition at 308.15 K. The densities and speeds of sound data of binary and ternary mixtures have been utilized to determine their excess molar volumes, VE and excess isentropic compressibilities, κSE. The observed thermodynamic properties of binary and ternary mixtures have been analyzed in terms of Graph theory. It has been observed that Graph theory correctly predicts the sign as well as magnitude of thermodynamic properties.  相似文献   

14.
ABSTRACT

High-resolution emission spectrum of the 1–4 band of the B 2Σ+X 2Σ+ transition of 14C16O+ was observed for the first time by conventional emission spectroscopy. The band spectrum was excited in a water-cooled Geissler lamp filled with commercial gaseous carbon monoxide enriched in about 80% of the radiocarbon 14C. A rotational analysis has been carried out and obtained molecular constants have been merged with previously published data for the B 2Σ+A 2Πi and A 2ΠiX 2Σ+ transitions. The principal equilibrium constants for the ground X 2Σ+ state obtained from this work are ωe = 2121.7726(98), ωe x e = 13.9055(27), B e = 1.815290(30), αe = 1.6594(33) × 10?2, and γe = ? 0.377(73) × 10?4 cm?1. Also, presently known experimental equilibrium molecular constants of the X 2Σ+ states of the CO+ isotopic molecules are summarized and isotopic dependence of the B e and ω e constants is discussed.  相似文献   

15.
The effect of continuous layer on CoCrPt–SiO2 granular layer is studied in coupled granular continuous (CGC) perpendicular recording media. In the cross-section transmission electron microscope (TEM) observation, magnetic grain in the granular layer shows columnar structure, while Co/Pd multilayer shows continuous layer. The plane-view TEM image of the granular layer shows well-isolated grain structure with average grain size of around 6 nm, and grain-to-grain separation width of around 2 nm. Therefore, the interactions among the grains are negligible (J∼0). By depositing a continuous layer on a CoCrPt–SiO2 granular layer, the grains in the granular layer are magnetically coupled through capping layer that leads to the suppression of magnetic anisotropy dispersion. This CGC structure reduces the coercivity dispersion (ΔHc/HcΔHc/Hc) from 0.26 to 0.15 and saturation field (Hs) from 10.4 to 6.7 kOe. The reduction of Hs and ΔHc/HcΔHc/Hc improves the OW by 21.3 dB. The small ΔHc/HcΔHc/Hc also maintains SNR of CGC media with strong magnetic exchange coupling. Furthermore, the coupling of grains through continuous layer enlarges the magnetic nucleation field (Hn) from 0.4 to −1.7 kOe. Consequently, CGC media shows better thermal stability compared to non-CGC media.  相似文献   

16.
Der Anionenaustausch unter Verwendung von Salpetersäure-Methanol-Gemischen ist in den letzten Jahren von einer Anzahl von Autoren untersucht worden [1, 2, 3, 4]. In einer früheren Arbeit hatten wir bereits auf seine praktisehc Anwendbarkeit für die Trennung der SK hingewiescn [5]. In der vorliegenden Arbeit werden von uns die Verteilungs-koeffizienten von Ag, In, Re, Au, Hg, Tl, Pb und Bi angegeben und Beispiele für mögliche Trennungen angeführt.  相似文献   

17.
A search for double β decay of dysprosium was realized for the first time with the help of an ultra-low background HP Ge γ detector. After 2512 h of data taking with a 322 g sample of dysprosium oxide limits on double beta processes in 156Dy and 158Dy have been established on the level of T1/2?10141016 yrT1/2?10141016 yr. Possible resonant double electron captures in 156Dy and 158Dy were restricted on a similar level. As a by-product of the experiment we have measured the radioactive contamination of the Dy2O3 sample and set limits on the α   decay of dysprosium isotopes to the excited levels of daughter nuclei as T1/2?10151017 yrT1/2?10151017 yr.  相似文献   

18.
This paper reports for the first time both, an experimental observation and theoretical calculations of the K2 43Δg state. For the experiment we used cw perturbation-facilitated optical-optical double resonance (PFOODR) spectroscopy. A single mode Ti-sapphire laser and a dye laser served as the pump and probe lasers, respectively. A total of 55 PFOODR signals have been assigned to the 43Δg ← b3Πu transitions. Absolute vibrational numbering was determined by using quantum defect analysis combined with comparing observed intensities with calculated Franck-Condon factors (FCF). For the former we used known parameters from the 23Δg state since the 23Δg and the 43Δg states belong to the same Rydberg series. We report here our experimental and calculated spectroscopic constants, the corresponding RKR potential energy curve, the Franck-Condon table for the 43Δg ↔ b3 Πu system, as well as a comparison with the theoretical potential energy curve. The Te value is found to be 28408.938(52) cm−1.  相似文献   

19.
The influence of the sample orientation on the effective value of the hydrostatic piezoelectric coefficients d h (i) of Sn2P2S6 crystals has been studied. The hydrostatic piezoelectric coefficients d h (1) and d′ h (3) , were measured, d h (1) =(244±3) pC/N and d′ h (3) =(92±1) pC/N. The hydrostatic piezoelectric coefficient d h (3) for orthogonal axis system was calculated to be d h (3) =(87±2) pC/N. The, optimal orientation of the sample has been found as (Xy l)−20°-cut. Maximal value of the effective hydrostatic piezoelectric coefficient d h (1) equals 260 pC/N. Double rotated samples were also studied. The orientation of the samples insensitive to the pressure has been found. The theoretical mean value of hydrostatic piezoelectric coefficient (d h ) mean corresponding to randomly oriented Sn2P2S6 grains in a poled composite has been calculated to be (d h ) mean =136 pC/N.  相似文献   

20.
S Kailas  M K Mehta 《Pramana》1976,7(1):6-16
Thermonuclear reaction rates for the temperature range 1≤T 9≤5 have been extracted from experimentally measured (p, n) cross sections for45Sc50Ti,51V,54Cr,55Mn and59Co nuclides below 5 MeV bombarding energy. These reaction rates are important in the build-up of medium and heavy nuclides in the stellar evolution process and nucleosynthesis. To enhance the usefulness of these reaction rates in astrophysical calculations, they have been fitted to an analytic function of temperature, valid throughout the temperature range considered here.  相似文献   

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