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ABSTRACT

The dielectric thermal and non-thermal properties of sodium chloride aqueous solution under the microwave region have been estimated. The dielectric properties, hydrogen bonding, transport properties, energy distribution and local structure have been evaluated by classical molecular dynamics method. In the process of microwave energy distribution, the direct coupling of rotational motion, vibration and redirection is revealed. Microwave energy is converted into kinetic energy and interaction energy between two molecules. A mechanism for exploring the effects of microwaves on the non-thermal effects of brine systems over a longer simulation time and a wider microwave range is proposed. The increase in field intensity is usually accompanied by local damage to the water structure near the hydrated ions. More specifically, above the field threshold, the residence time of water molecules near the ions significantly decreases.

Highlights
  1. Microwave energy is transferred to the kinetic energy and the energy between the molecules.

  2. The increase in field intensity is usually accompanied by local damage to the water structure near the hydrated ions.

  3. The larger electric field strength amplifies the effect of frequency.

  4. The residence time of water molecules near the ions significantly decreases.

  相似文献   

3.
While it is known that the charge-carrier mobility in organic semiconductors is only weakly dependent on the electric field at low fields, the experimental mobility in organic field-effect transistors using silylethynyl-substituted pentacene is found to be surprisingly field dependent at low source-drain fields. Corroborated by scanning Kelvin probe measurements, we explain this observation by the severe difference between local conductivities within grains and at grain boundaries. Redistribution of accumulated charges creates very strong local lateral fields in the latter regions. We further confirm this picture by verifying that the charge mobility in channels having no grain boundaries, made from the same organic semiconductor, is not significantly field dependent. We show that our model allows us to quantitatively model the source-drain field dependence of the mobility in polycrystalline organic transistors.  相似文献   

4.
The problem of cation self-diffusion in NaCl for a single vacancy mechanism is attempted using a reaction coordinate approach employing the phonons in the system. The vacancy is given an active role by estimating the displacements of its nearest neighbour Cl ions in the environment of the vacancy through the lattice Green's functions and the t matrix formalism. The jump frequency and the isotope effect estimated by this approach agree well with the experimentally deduced values.  相似文献   

5.
The emission of light due to rubbing or impact of two surfaces (Triboluminescence) has been traditionally studied under visible and ultraviolet spectrum. The current study provides an experimental insight into infrared emission occurring during low velocity impact on common salt crystals. The high speed IR imaging done using a whole field IR camera is first of its kind of measurement that provides experimental verification of IR emission occurring in these events. It was observed that the nature of impact surface and the crystalline structure of the material have a marked role in the IR emission. Of the existing theories that explain the origin of light emission in TL, the model provided by Chapman, that TL is a thermal radiation from high temperature regions, which propagate along with the crack, matches closely with the current experimental observations.  相似文献   

6.
The microwave spectrum of fluoroacetyl chloride has been studied in the 8–40 GHz region and transitions arising from one conformer have been assigned. This conformer has all the heavy atoms in a plane with the fluorine and chlorine atoms trans to one another. The rotational constants and nuclear quadrupole coupling constants for the ground vibrational state are (in MHz): H2FCCO35Cl: A = 9025.82, B = 2403.92, C = 1920.70, χaa = ?47.7, χbb = 23,7, χcc = 24.1; H2FCCO37Cl: A = 8994.95, B = 2342.24, C = 1879.75, χaa = ?38.0, χbb = 18.9, χcc = 19.1. The spectrum of the first excited torsional state has been assigned. Some lines possibly due to a second conformer have been observed but not yet assigned.  相似文献   

7.
The diffusion of Na22Cl in RbCl was measured in the temperature range 377–707°C by the tracer-sectioning technique. The activation energy is 2.06± 0.02 and 0.59 ± 0.01 eV in the intrinsic and extrinsic regions, respectively. The temperature dependence of the correlation factor, as deduced from isotope-effect measurements, is 0.19 eV in the intrinsic region and -0.05 eV in the extrinsic region. When a theoretical value for the Na+- vacancy binding energy is used, values of ½hf =1.22, eV and hm= 0.55 eV are obtained where hf is the energy of formation, and hm the energy of motion, of a cation vacancy. These values are not in agreement with the calculation by Tosi and Doyama.  相似文献   

8.
The high-resolution microwave spectrum of the axial conformer of cyclohexyl chloride has been assigned for both the Cl(35) and Cl(37) isotopic species, in natural abundance. Moreover, the high-resolution microwave spectrum of the equatorial conformer, previously assigned in the ground state [Chem. Phys. Lett.21, 592–594 (1973)], has been further investigated. Several low-energy vibrational satellites have been studied for the Cl(35) isotopic species of both the axial and the equatorial isomers. The ground state centrifugal distortion constants for both the isotopic species of the two rotamers, and the quadrupole coupling constants of Cl(35) and Cl(37) axial isomer and of Cl(37) equatorial isomer (not reported previously) have been determined. From line relative intensity measurements the energy difference between the two conformers has been calculated to be 0.51 ± 0.15 kcal/mol, the equatorial isomer being more stable. In the same way, the vibrational energies of the investigated vibrational satellites have been computed. A structural model for axial cyclohexyl chloride is proposed on the basis of the available experimental data.  相似文献   

9.
ZnO nanocrystals were synthesized by hydrolysis in methanol. X-ray diffraction and photoluminescence spectra confirm that good crystallized ZnO nanoparticles were formed. Utilizing those ZnO nanoparticles and poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV), light emitting devices with indium tin oxide (ITO)/poly(3,4-oxyethyleneoxy-thiophene):poly(styrene sulfonate) (PEDOT:PSS)/ZnO:MDMO-PPV/Al and ITO/PEDOT:PSS/MDMO-PPV/Al structures were fabricated. Electroluminescence (EL) spectra reveal that EL yield of hybrid MDMO-PPV and ZnO nanocrystals devices increased greatly as compared with pristine MDMO-PPV devices. The current-voltage characteristics indicate that addition of ZnO nanocrystals can facilitate electrical injection and charge transport. The decreased energy barrier to electron injection is responsible for the increased efficiency of electron injection.  相似文献   

10.
It is demonstrated that the vertical charge transport in a superlattice is influenced uniquely by the difference in the effective mass of the electron between its adjacent layers. The mass difference produces a coupling between the parallel and vertical motions of the electron. As a consequence, the vertical velocity of an electron depends not only on its wavevector in the vertical direction but also on the wavevector in the direction parallel to the layers. As an illustration of the effect, a qualitative analysis is made to show that the vertical motion of the electron wavepacket can be altered by the application of a magnetic field whose direction is normal to the layers.  相似文献   

11.
The first global quantum simulation of semiconductor-based quantum-cascade lasers is presented. Our three-dimensional approach allows us to study in a purely microscopic way the current-voltage characteristics of state-of-the-art unipolar nanostructures, and therefore to answer the long-standing controversial question: Is charge transport in quantum-cascade lasers mainly coherent or incoherent? Our analysis shows that (i) quantum corrections to the semiclassical scenario are minor and (ii) inclusion of carrier-phonon and carrier-carrier scattering gives excellent agreement with experimental results.  相似文献   

12.
The repulsive energy in sodium chloride and potassium chloride crystals has been evaluated and related to the lattice constant. The accuracy aimed at was ±0·2 kcal mole-1 but owing to some unidentified experimental error the accuracy claimed is only ±0·6 kcal mole-1 as compared with previous analyses in which the uncertainty is about ±2 kcal mole-1. The improvement has been achieved by critical evaluation of the experimental data, by the elimination of inaccuracies from the thermodynamic formulae and by carrying out the analysis at several specified temperatures.  相似文献   

13.
By combined studies of electron spin resonance and optical absorption at low temperatures, the charge-transfer bands of Rh5+ and Rh4+ are identified to be peaked near 1.6 and 1.9 eV, respectively. On this basis, the light-induced charge-transfer processes in BaTiO3:Rh are unraveled at room temperature. It is shown that three charge states of Rh are involved, leading to two levels: the shallow Rh4+/5+ and the deeper Rh3+/4+ level. The optical behaviour of these two levels corresponds to those expected from a two-center model. The present paper represents the first atomic-scale identification of three charge states of one element leading to optical two-level response.  相似文献   

14.
The possibility of the existence of localized charged distribution giving rise to a special axially symmetric electrostatic field has been explored in Einstein's unified field theory [2]. The field equations have been studied in two particular cases. In one case the field equations have a solution representing flat space-time along with an electrostatic field which is constant in the direction of the axis of symmetry. For the other case the solution is non-existent.  相似文献   

15.
The microwave spectrum has been investigated for the molecule of Benzenesulphonyl chloride within the 8–18 Ghz frequency region. Several a and b type bands corresponding to the Cl35 and Cl37 Isotopes were observed and assigned.

We have also used the CNDO/2 method in order to estimate some molecular parameters and the dipole moment. The theoretical calculation and the experimental data have been joined to derive a reliable structure of the molecule concluding that the Cl is located on the plane of the benzene ring.  相似文献   

16.
17.
A model is proposed that treats electrons at surfaces as a combination of two-dimensional and three-dimensional degrees of freedom. This yields a simple formula for the surface state induced resonant enhancement of the transfer of electrons through a surface. The model also yields analytic approximations for the transition between two-dimensional and three-dimensional distance laws in the correlations between electrons in surface states. Received 6 August 2002 Published online 31 October 2002 RID="a" ID="a"e-mail: rainer@sask.usask.ca  相似文献   

18.
The behavior of saturated aqueous Na Cl solutions under a constant external electric field(E) was studied by molecular dynamics(MD) simulation. Our dynamic MD simulations indicated that the irreversible nucleation process towards crystallization is accelerated by a moderate E but retarded or even prohibited under a stronger E, which can be understood by the competition between self-diffusion and drift motion. The former increases with E, thereby accelerating the nucleation process, whereas the latter pulls oppositely charged ions apart under a stronger E, thereby decelerating nucleation.Additionally, our steady-state MD simulations indicated that a first-order phase transition occurs in saturated solutions at a certain threshold Ec. The magnitude of Ec increases with concentration because larger clusters form more easily when the solution is more concentrated and require a stronger E to dissociate.  相似文献   

19.
The galvanomagnetic properties of single-crystal samples with various isotopic boron compositions have been investigated for the first time for the normal state of superconductor LuB12 (T c ≈ 0.44 K). Precision measurements of the resistivity, Hall coefficient, and magnetic susceptibility have been performed over a wide temperature range of 2–300 K in magnetic fields up to 80 kOe. A change of the charge transport regime in this nonmagnetic compound with metallic conduction is shown to occur near T* ≈ 50−70 K. As a result, a sharp peak with significantly different amplitudes for Lu10B12 and Lu11B12 is recorded in the temperature dependences of the Hall coefficient R H(T) near T*. A significant (about 10%) difference (in absolute value) of the Hall coefficients R H for the Lu10B12 and Lu11B12 compounds at helium and intermediate temperatures has been found and the patterns of behavior of the dependence R H(H) for T < T* in an external magnetic field H ≤ 80 kOe for Lu10B12 and Lu11B12 are shown to differ significantly. Analysis of the Curie-Weiss contribution to the magnetic susceptibility χ(T) leads to the conclusion about the formation of magnetic moments μeff ≈ (0.13−0.19)μB in each unit cell of the fcc structure of LuB12 compounds with various isotopic compositions. The possibility of the realization of an electronic topological 2.5-order transition near T* and the influence of correlation effects in the 5d-band on the formation of a spin polarization near the rare-earth ions in LuB12 is discussed.  相似文献   

20.
We present measurements of the normalized charge transport or Nusselt number Nu as a function of the aspect ratio Gamma for turbulent convection in an electrically driven film. In analogy with turbulent Rayleigh-Bénard convection, we develop the relevant theoretical framework in which we discuss the local power-law scaling of Nu with a dimensionless electrical forcing parameter R. For these experiments where 10(4) less, similar R less, similar 2 x 10(5) we find that Nu approximately F(Gamma)Rgamma with either gamma=0.26 (+/-0.02) or gamma=0.20 (+/-0.03), in excellent agreement with the theoretical predictions of gamma=1/4 and 1/5. Our measurements of the aspect-ratio dependence of Nu for 0.3相似文献   

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