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排序方式: 共有166条查询结果,搜索用时 16 毫秒
21.
Abstract A recent study discussing different ring-resonator- and fiber-based gyroscopes concluded that the performance of a single-loop resonant fiber-optical gyro exceeds that of more complex ring-resonator-based gyros. It is demonstrated here that this conclusion applies as well to a gyro that consists of a closed loop of coupled-ring resonators with internal feedback. While this device is more sensitive to rotation than other gyro structures with the same footprint and losses, a simpler alternative consisting of a resonant single ring with an area equal to complex gyro structures still displays a higher degree of sensitivity. 相似文献
22.
Fayed A. A. Alahmadi Y. M. Yousif M. N. M. Yousif N. M. Amer A. A. El-Farargy A. F. Ouf N. H. Gad F. A. 《Russian Journal of General Chemistry》2019,89(9):1887-1895
Russian Journal of General Chemistry - Synthesis of a new series of pyrimidinothienocinnoline derivatives involves the reaction of 9-aminodibenzo[f,... 相似文献
23.
The superconducting transition temperature T(c) of bilayers comprising underdoped La(2-x)Sr(x)CuO(4) films capped by a thin heavily overdoped metallic La(1.65)Sr(0.35)CuO(4) layer, is found to increase with respect to T(c) of the bare underdoped films. The highest T(c) is achieved for x=0.12, close to the "anomalous" 1/8 doping level, and exceeds that of the optimally doped bare film. Our data suggest that the enhanced superconductivity is confined to the interface between the layers. We attribute the effect to a combination of the high pairing scale in the underdoped layer with an enhanced phase stiffness induced by the overdoped film. 相似文献
24.
Maya Green Gad Marom Jing Li Jang‐Kyo Kim 《Macromolecular rapid communications》2008,29(14):1254-1258
The electrical conductivity of composites of exfoliated graphite nanoplatelets (GNPs), including bromine‐doped GNP, and conjugated polyacrylonitrile has been investigated. The focal point is the dual nature of the graphite nanoparticles, which exhibit both intrinsic electrical conductivity and doping capability of semi‐conductive polymers such as conjugated polyacrylonitrile to form charge‐transfer complexes. The conductivity is particularly enhanced in conjugated polyacrylonitrile composites (e.g., with 6 wt.‐% graphite nanoplatelets) where the value rises from 1 × 10−10 to 2 × 10−3 S · cm−1, which reflects jointly the conductivity of the doped semi‐conductive polymer together with the percolation‐based conductivity of the particles.
25.
26.
Kh. Gad 《Physics of Atomic Nuclei》2018,81(4):429-441
Thermal properties of symmetric nuclear matter and pure neutron matter are studied in a selfconsistent Green’s function and Brueckner–Hartree–Fock approaches with the inclusion of the contact interaction using CDBONN potential. Also we investigate the temperature dependence of the symmetry energy. The symmetry energy at fixed density is found to generally decrease with temperature. The temperature effects on the nuclear matter symmetry energy are found to be stronger at lower densities while become much weaker at higher densities. The results of several microscopic approaches are compared. Also the results are compared with recent experimental data. There is good agreement between the experimental symmetry energy and those calculated in the Brueckner–Hartree–Fock approach. 相似文献
27.
Man-Cheng Long Ting Wang Ping-Hui Duan You Gao Xiu-Li Wang Gang Wu Yu-Zhong Wang 《Journal of Energy Chemistry》2022,(2):9-18
Poly(ethylene oxide)(PEO)and its derivatives based gel polymer electrolytes(GPEs)are severely limited in advanced and safe lithium-ion batteries(LIBs)owing to the intrinsically high flammability of liquid electrolytes and PEO.Directly adding flame retardants to the GPEs can suppress their flammability and thus improve the safety of LIBs,but results in deteriorative electrochemical performance.Herein,a novel GPE with chemically bonded flame retardant(i.e.diethyl vinylphosphonate)in cross-linked polyethylene glycol diacrylate matrix,featuring both high-safety and high-performance,is designed.This as-prepared GPE storing the commercial 1 mol L-1 LiPF6 electrolyte resists high temperature of 200℃and cannot be ignited as well as possesses a high ionic conductivity(0.60 m S cm-1)and good compatibility with lithium.Notably,the LiFePO4/Li battery with this GPE delivers a satisfactory capacity of 142.2 m A h g-1 and a superior cycling performance with a capacity retention of 96.3%and a coulombic efficiency of close to 100%for 350 cycles at 0.2 C under ambient temperature.Furthermore,the battery can achieve steady charge–discharge for 100 cycles with a coulombic efficiency of 99.5%at 1 C under 80℃and run normally even at a high temperature of 150℃or under the exposure to butane flame.Differential scanning calorimetry manifests significantly improved battery safety compared to commercial battery systems.This work provides a new pathway for developing next-generation advanced LIBs with enhanced performance and high safety. 相似文献
28.
Ragab M. Gad 《International Journal of Theoretical Physics》2014,53(1):307-319
In this paper, we find the teleparallel version of the cylindrically symmetric stiff fluid space-time. The expressions for torsion vector and torsion axial-vector are obtained. We show that the value of torsion axial-vector depends on the choice of tetrad fields. Furthermore, we calculate the energy and momentum densities and show that these values do not depend on the choice of tetrad fields. Finally, we find the equation determining trajectory and spin precession of a Dirac equation in the space-time under consideration and show that the corresponding Hamiltonian depends on the choice of tetrad fields. 相似文献
29.
30.
F.X. Gadéa T. Leininger A.S. Dickinson 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,15(2):251-255
An improved ab initio calculation has been performed for the potential for the LiH a 3Σ+ state, using two very large basis sets. The Basis Set Superposition Error (BSSE) correction has been determined for both
basis sets and the non-Born-Oppenheimer correction estimated to be negligible. The best potential is approximately 10% deeper
than the previous estimate. Vibrational energies and scattering lengths have been calculated for 6,7LiH(D) with both potentials, with and without the BSSE correction, and also with an estimated potential expected to bracket
the true potential. The 7LiH scattering length is estimated to be (45 ± 4)a0 and hence the low-energy cross-section in the best a 3Σ+ potential is about half that calculated previously. Enhanced cooling by 7Li of trapped H atoms remains feasible.
Received 30 April 2001 相似文献