[en] A generalized BSC Hamiltonian, in which the interaction strengths (V₁₁, V₁₂, V₂₂) among and between 'electron' (1) and 'hole' (2) Cooper pairs are differentiated, is proposed. The ground state energy W of the Hamiltonian with respect to that of the non-interacting system W₀ is found by variational calculations W₀ - W = 1/4[N₁(O)Δ²₁ + N₂(O)Δ²₂], where N₁(0) and N₂(0) represent the 'electron' and 'hole' densities of states at the Fermi energy ε_F, and Δ₁ and Δ₂ are the solutions of the simultaneous equations, Δ_j = 1/2 V_j1N₁(0)Δ₁ sinh^-1 (ℎω_D/Δ₁) + 1/2 V_j2N₂(0)Δ₂ sinh^-1 (ℎω_D/Δ₂), with ω_D denoting the Debye frequency. The usual BCS results are obtained in the limits: (all)V_jt = V₀, N₁(o) = N₂(0). The supercondensate is composed of zero momentum 'electron' and 'hole' Cooper pairs, which are neither bosons nor fermions. Any excitations generated through the BCS interaction Hamiltonian containing V_jl must involve Cooper pairs of antiparallel spins and nearly opposite momenta. Non-zero momentum or excited Cooper pairs above the critical temperature T_c move like free bosons with the energy-momentum relation ε^(j) = ω^(j)₀ + 1/2 υ^(j)_Fq, where υ^(j)_F is the Fermi velocity and ω^(j)(<0) is the band edge, which is lower than that of free-electron pairs (ε = 0). They undergo a Bose-Einstein condensation at T_c = 1.00856ℎυF^n1/3/k_B, where n = N(0)ℎω_D is the density of Cooper pairs

[en] We employ a di rence-in-di rence regression model to analyse the effciency of carbon taxation policy and its interaction with an Emission Trading System (ETS). We provide evidence for 26 of the most developed countries in the world in the period 1980-2014. Following the work of Dynarski [2004], Cameron et al. [2008, 2012] and Hoechle [2007], we compare the results under three methods of regression analysis. We con m that carbon taxation has preformed well in the 35 years under observation in that they e iently control CO2 emissions. We and that the longer the duration a country uses carbon taxation, the greater the reduction in CO2 emissions. For the countries that use both an ETS and carbon taxation, we and an even more effcient CO2 emission reduction. The results are robust to heteroskedasticity, autocorrelation and cross-sectional dependence.

[en] Purpose: To investigate if the selection of gantry and table angle has an impact on the calculated proton range (defined at the 90% distal falloff of the spread out Bragg peak) in XiO treatment planning system (TPS). Methods: A homogenous water phantom (40x40x40 cm³) was constructed in XiO TPS. Ten treatment plans were generated using identical beam conditions (proton range = 25cm, modulation = 10cm) and device (10 cm diameter aperture) for various combinations of gantry (G) and table (T) angles (G0T90, G90T90, G180T90, G270T90, G90T0, G90T180, G90T270, G270T0, G270T180, and G270T270). The isocenter in each plan was selected at the center of the cubic target volume (5x5x5 cm³) inside the phantom. All ten plans were calculated with pencil beam algorithm using a grid size of 3mm. The calculated proton ranges in all 10 plans were then compared against the prescribed (or expected) proton range, which was 25 cm in this study. Results: For all 10 treatment plans, calculated proton range was smaller when compared to the expected value (25cm), with XiO predicting the proton range from 24.62cm to 24.92cm. The difference between the prescribed and calculated proton range was highest (3.8mm) for plans with G90T270 and G270T90. Conclusion: Treatment plans generated in XiO TPS using G90T270 and G270T90 could produce a difference of more than 3 mm between the prescribed and calculated proton ranges. Further study using smaller dose calculation grid size (e.g., 1mm) is under progress to determine if the dose calculation grid size has any impact on the proton range. What causes the angle dependence of proton range calculation with the XiO TPS is also under investigation

No abstract available

[en] Relative differential cross sections for the asymmetric coplanar (e,2e) reaction have been measured in three energy-sharing regions, for two of which the ionisation peak is about 1 a.u. off the Bethe ridge. Momentum transfer is intermediate between large (binary) and small (dipole) values, where the distorted-wave impulse and second Born approximations respectively give a good account of the experimental data. In addition to these approximations the distorted-wave Born approximation is calculated. It is somewhat superior to the distorted-wave impulse approximation and very much better than the second Born approximation

[en] Two succinato-pillared coordination polymers Mn₅(OH)₂L₄ 1 and Cd₃(OH)₂L₂₂ were prepared by hydrothermal reactions of succinic acid (H₂L-HOOC(CH₂)₂COOH) and KOH with the corresponding metal chlorides at 180 deg. C. Within 1, the adjacent MnO₆ octahedra are edge shared to generate Mn₅O₂₂ pentamers, which are interconnected to form 2D manganese oxide layers stabilized by the intralayer gauche succinato groups within the aperture. The manganese oxide layers are pillared by the interlayer trans succinato groups to complete 3D framework. The magnetic behavior of 1 obeys Curie-Weiss law χ m(T-Θ)=4.46(2) cm³ mol^-1 K with the Weiss constant Θ=-67.3(3) K over the temperature range 5-300 K. Compound 2 contains CdO₆ octahedra and edge-shared Cd₂O₁₀ bi-octahedra. The former CdO₆ octahedra are each surrounded by four Cd₂O₁₀ bi-octahedra which in turn are each surrounded by four former CdO₆ octahedra and four neighboring Cd₂O₁₀ bi-octahedra, thus resulting in the corrugated cadmium oxide layers. The formed 2D layers are pillared by trans succinato groups to constitute 3D coordination polymer. Additionally, thermal decomposition of both title coordination polymers upon heating in a flowing nitrogen atmosphere from room temperature to 800 deg. C is discussed. Crystal data: (1) monoclinic, P2 1/c, Z=2, a=9.575(2) A, b=9.611(2) A, c=12.526(3) A, β=97.04(2) deg., V=1144.0(4) A³, R 1=0.0289 and wR 2=0.0815 for 2411 observed reflections (I≥2σ(I)) out of 2629 unique reflections; (2) orthorhombic, Pbca, Z=4, a=10.679(1) A, b=6.873(1) A, c=16.996(2) A, V=1247.5(3) A³, R 1=0.0234 and wR 2=0.0585 for 1213 observed reflections (I≥2σ(I)) out of 1437 unique reflections

[en] In this study, laser cleaning efficiencies to remove 2.5 μm particles have been investigated with different incident angles ranging from 0 degree to 60 degree. It is found that when the laser light irradiated normally to the substrate surface, the particle could be removed most efficiently. In this direction, the cleaning efficiency was also most sensitive to the light intensity. A sharp drop of cleaning efficiency occurred with a small change of the incident angle. Theoretical calculations based on the Lorentz - Mie theory and an accurate solution of the boundary problem, indicate that the light intensity near the contacting point is sensitive to the incident angle even though the incident light is uniform. [copyright] 2001 American Institute of Physics

[en] In this paper, we discuss the problem of the local energy content in gravitational fields. A new total energy-momentum density pseudo-tensor of the gravitational field is given in this paper. The energy content in any part of a gravitational field given by the new pseudo-tensor is an invariant under arbitrary purely spatial transformation, hence the local energy content in the gravitational field has a well-defined physical meaning. For the energy and momentum of a Schwarzschild gravitational field, the results given by the new pseudo-tensor are more reasonable than those given by other pseudo-tensors proposed in the literatures of the general theory of relativity. The relation between mass and energy in the theory of gravitation is also discussed

[en] This paper describes a rapid procedure that allows precise analysis of Mo, Cd, U and Th in sediment samples as small as 10 mg by using a novel approach that utilizes a 'pseudo' isotope dilution for Th and conventional isotope dilution for Mo, Cd and U by ICP-MS. Long-term reproducibility of the method is between 2.5 and 5% with an advantage of rapid analysis on a single digestion of sediment sample and the potential of adding other elements of interest if so desired. Application of this method to two piston cores collected near the mouth of the Patuxent River in Chesapeake Bay showed that the accumulation of authigenic Mo and Cd varied in response to the changing bottom water redox conditions, with anoxia showing consistent oscillations throughout both pre-industrial and industrial times. Accumulation of authigenic U shows consistent oscillations as well, without any apparent increase in productivity related to anoxic trends. Degrees of Mo and Cd enrichment also inversely correlate to halophilic microfaunal assemblages already established as paleoclimate proxies within the bay indicating that bottom water anoxia is driven in part by the amount of freshwater discharge that the area receives

[en] The active material of secondary alkaline zinc electrode with barium additives was prepared by a chemical reaction method and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The electrochemical performance of various pasted Zn electrodes was investigated by cyclic voltammetry, charge/discharge method and electrochemical impedance spectroscopy (EIS). The addition of barium can synthesize a compound barium zincate with the molecular structure of BaZn(OH)₄·xH₂O, which turns into another molecular structure of BaZnO₂ after heat treatment, and improve the discharge performance. The EIS of the various Zn electrodes show two time constants besides diffusion impedance including a state variable representing the covering degree of ZnO on the electrode surface