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101.
We present transport measurements of ferromagnetically contacted carbon nanotubes. In both single- and multi-walled nanotube devices, a spin valve effect is observed due to spin-polarized transport. In one single-walled nanotube device, the spin-valve effect is suppressed as the influence of Coulomb charging is observed at around 10 K. To help understand the interplay between the Coulomb charging and the spin-polarized transport we investigated the temperature dependence of the carbon nanotube magnetoresistance. 相似文献
102.
Xiaoyi Xie Yi Zhang Dong Li Yuxiu Fan Bin Huang Xiupei Yang 《Particle & Particle Systems Characterization》2023,40(10):2300039
Nanozymes can be used as favorable substitutes for natural enzymes because of their strong catalytic activity and good stability. At the same time, research on single-atom catalysts (SACs) with isolated metal atoms as active centers is also in full swing, showing excellent performance in a variety of catalytic reactions. With the in-depth study of SACs, people have a comprehensive understanding of them and put forward the concept of single-atom nanozymes (SAzymes) by combining nanozymes with SACs. As a new type of nanomaterial, SAzymes have attracted great interest due to their remarkable catalytic activity and rapid energy conversion. However, most applications of SAzymes are mainly in the fields of biomedicine and biosensing, and less research has been done in the field of the environment. Based on the amazing ability of nanozymes to detect and degrade pollutants, SAzymes are also used in the environmental field, and even they will show better capabilities. This review mainly analyses common transition metal-based SAzymes and describes their applications in the field of environmental pollutants. 相似文献
103.
G.G.M. Coppa A. D'Angola 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,6(4):533-539
The paper deals with the stationary distribution of charged particles moving in a material medium, having scattering and absorption
properties, in which a uniform electric field is present. The purpose of the work is finding analytical solutions in simplified
but physically significant situations and comparing different approximations based on a spherical-harmonics expansion of the
velocity distribution.
Received: 28 July 1998 相似文献
104.
《Physics letters. A》2020,384(28):126732
In this work, we investigate the electronic transport properties of M/SiC Schottky junctions (M=Ag, Au and Pd). The results show that the band structures of hydrogenated zigzag SiC nanoribbons (ZSiCNRs) and hydrogenated armchair SiC nanoribbons (ASiCNRs) are almost unaffected by their width changes. When the hydrogenated 7-ASiCNR is directly connected to the Ag, Au and Pd electrode, the transmission spectra of three metal-semiconductor junctions show that the Fermi level of metal is pinned to a fixed position in the semiconductor band gap of hydrogenated 7-ASiCNR. The nearly same rectifying current-voltage characteristics are found in three metal-semiconductor junctions. The average rectification ratios of three M/SiC Schottky junctions are all in the neighborhood of 106. In other word, the M/SiC Schottky junction has remarkable application prospect as the candidate for Schottky Diode. 相似文献
105.
S. Harris 《Journal of statistical physics》1970,2(4):379-385
A model Liouville equation is proposed for a system composed of an ion moving in a solvent fluid. Using this model, explicit results are obtained for the Ohmic conductivityL and the Hall conductivityh. These results are then used to calculate the Hall coefficientR = ehL–2, which is a measure of the effect of non-Brownian motion, for several charge carriers of interest. Our results are in agreement with earlier findings based on a stochastic model which predictR > 1 for H+(aq). Our results also indicate thatR 1 for charge carriers such as Na+, Cl–, and K+ which have a mass greater than that of a solvent molecule (here taken as 18 amu).This research was supported in part by grants from the National Science Foundation and by the Research Foundation of the State University of New York. 相似文献
106.
107.
This paper is concerned with the limit relations from the Euler equations of one‐dimensional compressible fluid flow and the magnetohydrodynamics equations to the simplified transport equations, where the δ‐shock waves occur in their Riemann solutions of the latter two equations. The objective is to prove that the Riemann solutions of the perturbed equations coming from the one‐dimensional simplified Euler equations and the magnetohydrodynamics equations converge to the corresponding Riemann solutions of the simplified transport equations as the perturbation parameterx ε tends to zero. Furthermore, the result can also be generalized to more general situations. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
108.
Using Green's function method, we investigate the spin transport properties of armchair graphene nanoribbons (AG- NRs) under magnetic field and uniaxial strain. Our results show that it is very difficult to transform narrow AGNRs directly from semiconductor to spin gapless semiconductors (SGS) by applying magnetic fields. However, as a uniaxial strain is exerted on the nanoribbons, the AGNRs can transform to SGS by a small magnetic field. The combination mode be- tween magnetic field and uniaxial strain displays a nonmonotonic arch-pattern relationship. In addition, we find that the combination mode is associated with the widths of nanoribbons, which exhibits group behaviors. 相似文献
109.
甲状腺内^(131)I放射性活度与辐射探测结果的比例关系与甲状腺几何尺寸、探测距离等因素相关,是估算甲状腺内^(131)I含量与其可能造成的辐照损伤的关键参数。基于MCPT辐射输运数值模拟算法器库开发了用于开展NaI探测器伽马辐射测量模拟的应用程序,进而建立了多组具有不同容积的甲状腺型容器和不同探测距离的物理模型,最终通过蒙特卡罗数值计算得到了不同测量状态下探测器的探测效率。在甲状腺型容器与探测器距离较远时,数值模拟给出的结果与理论计算结果一致,证明此应用程序可用于定量分析NaI的探测效率。数值模拟结果表明,小距离模型的结果受甲状腺样容器的大小和距离的显著影响,模拟给出的探测效率表为开展深入细致的实验研究奠定了基础。 相似文献
110.
Abstract Conductivity of chalcogenide glasses was measured as a function of temperature (290–340 K) and frequency (10?4–10?1 Hz). Frequency dependence of conductivity can be approximated by a power law G~ωs (S < 1). The relaxation maximum of dielectric losses was found. The dielectric constant ? decreases with frequency rise. The obtained results are discussed in terms of the defect structure model. 相似文献