Resonant PES at the Pr4d and Pr3d absorption edges is used to study the electronic properties at the interface of epitaxial grown Pr_2O_3 on Si(001). At the Si(001) interface in-situ prepared ...epitaxial layers (d < 5nm) enable us to study the contribution of the Pr4f electronic states in the valence band population as a function of layer thickness. We also find a silicate intermediate. In that range (1nm) the weak occupancy of the Pr4f states in the bulk phase of Pr_2O_3 is significantly enhanced. There is an additional 4f state which appears right at the VBM. On the other hand, in the XAS data we find the features of localized Pr4f states to be quenched. We conclude that the silicate causes an enhanced hybridization (covalent bonding) of the Pr4f states into the valence band. In our coverage dependent data the offset in the VB maxima is determined from the relative position of the valence band spectra. The offset of the conduction bands is deduced from the onset of the Si2p and Pr4d XAS data, it is of the order of 2eV again. Our data allow to derive a full description of the interface properties of that high K material, a prerequisite for its possible application in storage, logic, and power electronics.
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We report the results of lattice numerical studies of the S p ( 4 ) gauge theory coupled to fermions (hyperquarks) transforming in the fundamental and two-index antisymmetric representations of the ...gauge group. This strongly coupled theory is the minimal candidate for the ultraviolet completion of composite Higgs models that facilitate the mechanism of partial compositeness for generating the top-quark mass. We measure the spectrum of the low-lying, half-integer spin, bound states composed of two fundamental and one antisymmetric hyperquarks, dubbed chimera baryons, in the quenched approximation. In this first systematic, nonperturbative study, we focus on the three lightest parity-even chimera-baryon states, in analogy with QCD, denoted as Λ CB , Σ CB (both with spin 1 / 2 ), and Σ CB * (with spin 3 / 2 ). The spin- 1 / 2 such states are candidates of the top partners. The extrapolation of our results to the continuum and massless-hyperquark limit is performed using formulas inspired by QCD heavy-baryon Wilson chiral perturbation theory. Within the range of hyperquark masses in our simulations, we find that Σ CB is not heavier than Λ CB . Published by the American Physical Society 2024
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Juvenile steelhead Salmo gairdneri were subjected to three consecutive 2‐min disturbances, separated by 0.5‐h intervals, and then forced to swim at 0.5 body length/s for 1 h in a modified Blazka ...respirometer. Mean oxygen consumption (±SE) was 223 ± 19 mg˙kg−1˙h−1 in the stressed fish and 101 ± 9.7 in unstressed fish. There was no significant correlation between oxygen consumption and fish weight or water temperature within the ranges used (40–150 g and 8–11°C, respectively). Elevated plasma cortisol levels and oxygen consumption rates in stressed fish were positively correlated (r = 0.76). An acute physical stress may adversely affect fish by reducing, by about one‐quarter, the energy available for other activities within the scope for activity of the fish.
We explore a mechanism for generating the Yukawa hierarchies by displacing the left- and right-handed components of the standard model fermions in a higher-dimensional space. We find a unique ...configuration of displacements which fits all quark and lepton masses and mixing angles, with a prediction for the strange quark mass m{sub s}{sup MS}(2 GeV){approx_equal}(1.19)x(V{sub ub}V{sub cb}/V{sub us}){sup 1/2}xm{sub b}{sup MS}(m{sub b}){approx_equal}120 MeV. (c) 2000 The American Physical Society.
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碩士
國立高雄科技大學
化學工程與材料工程系
107
Polyphenylene oxide (PPO) was usually used in engineering plastics of IC tray, for this study, we use PPO's compatible property to blend with different carbon black, carbon ...fiber and glass fiber being a reinforcement material, and follow the standard of American Society for Testing Materials (ASTM) to test blending sample's physical properties. Sample pieces followed ASTM standard were injected from blending materials, and then study by tensile testing, bending test, percentage of elongation, shrinking, and used SEM to observe dispersibility of blending materials. The results show that CF/PPO is better than GF/PP and CB/PPO in rigidity, but the cost is higher than both of them and GF/PPO has good ductility and softness. CB/PPO is worse than both of CF/PPO and GF/PPO in physical properties, because it has a lower specific gravity, but its cost is lower than CF/PPO and GF/PPO, so CB/PPO is quite competitive in price.
The CLEO Collaboration has recently reported a (first) measurement of BR(B{yields}{pi}{sup +}{pi}{sup -})=(4.7{sub -1.5}{sup +1.8}{+-}0.6)x10{sup -6}. We study, using recent results on QCD improved ...factorization, the implications of this measurement for the determination of the Cabibbo-Kobayashi-Maskawa (CKM) phase {alpha} and also for the rate for B{yields}{pi}{sup 0}{pi}{sup 0}. If the B{yields}{pi}{sup -} form factor is large ((greater-or-similar sign)0.3), then we find that the CLEO measurement favors small |V{sub ub}/V{sub cb}| so that the expected error (due to neglecting the QCD penguin amplitude) in the measurement of {alpha} using only the time-dependent analysis of the decay B{yields}{pi}{sup +}{pi}{sup -} is large {approx}15 degree sign . However, if |V{sub ub}/V{sub cb}| is known, then it is possible to determine the correct value of sin2{alpha}. (c) 2000 The American Physical Society.
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