다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

This article reviews the basic theoretical aspects of graphene, a one-atom-thick allotrope of carbon, with unusual two-dimensional Dirac-like electronic excitations. The Dirac electrons can be controlled by application of external electric and magnetic fields, or by altering sample geometry and/or topology. The Dirac electrons behave in unusual ways in tunneling, confinement, and the integer quantum Hall effect. The electronic properties of graphene stacks are discussed and vary with stacking order and number of layers. Edge (surface) states in graphene depend on the edge termination (zigzag or armchair) and affect the physical properties of nanoribbons. Different types of disorder modify the Dirac equation leading to unusual spectroscopic and transport properties. The effects of electron-electron and electron-phonon interactions in single layer and multilayer graphene are also presented.

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The electronic properties of graphene

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.

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Electronics and optoelectronics of two-dimensional transition metal dichalcogenides.

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

We report the first Hall effect measurements on K and Rb doped single crystals of C[sub 60]. The temperature dependence of the Hall coefficient [ital R][sub [ital H]] for each material and the variation in [ital R][sub [ital H]] [ital between] the two materials can be accounted for solely by the variations in lattice constant, yielding a universal relationship of [ital R][sub [ital H]] versus lattice constant for the alkali-doped C[sub 60] systems. The results are interpreted in the context of a strongly disordered system in which the Hall coefficient is sensitive to disorder broadening at the Fermi energy.

Universal form of Hall coefficient in K and Rb doped single crystal C60.

Topological materials host robust surface states, which could form the basis for future electronic devices. As such states have spins that are locked to the momentum, they are of particular interest for spintronic applications. Understanding spin textures of the surface states of topologically nontrivial materials, and being able to manipulate their polarization, is therefore essential if they are to be utilized in future technologies. Here we use first-principles calculations to show that pyrite-type crystals OsX2 (X= Se, Te) are a class of topological material that can host surface states with spin polarization that can be either in-plane or out-of-plane. We show that the formation of low-energy states with symmetry-protected energy- and direction-dependent spin textures on the (001) surface of these materials is a consequence of a transformation from a topologically trivial to nontrivial state, induced by spin orbit interactions. The unconventional spin textures of these surface states feature an in-plane to out-of-plane spin polarization transition in the momentum space protected by local symmetries. Moreover, the surface spin direction and magnitude can be selectively filtered in specific energy ranges. Our demonstration of a new class of topological material with controllable spin textures provide a platform for experimentalists to detect and exploit unconventional surface spin textures in future spin-based nanoelectronic devices.

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Selective Control of Surface Spin Current in Topological Materials based on Pyrite-type OsX2 (X = Se, Te) Crystals

https://iopscience.iop.org/article/10.1088/2053-1583/ab626a/pdf

Disentangling the effects of doping, strain and disorder in monolayer WS2 by optical spectroscopy

A full characterization of the electrical contact between conductive atomic force microscope (AFM) cantilevers and carbon nanotubes (CNTs) is presented. The dependence of current through the contact on loading force, geometric parameters, bias conditions, and time is studied in a two-terminal configuration, where a gold coated AFM cantilever serves as a movable electrode. We find that for an optimized placement of the cantilever relative to the CNT, the current through the contact becomes independent of the loading force beyond a certain limit, and this behavior is also independent of bias conditions. In that load-independent regime, the contact is stable in time to within the current fluctuations imposed by 1/f and telegraph noise in the CNT channel. Under certain conditions of tip placement, the current through the contact exhibits a non-monotonic behavior with loading, which is well explained by the parasitic planar motion of the cantilever.

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Characterization of the electrical contact between a conductive atomic force microscope cantilever and a carbon nanotube

We report on electronic transport in devices consisting of individual semiconducting singled-walled carbon nanotubes (SWNTs) grown by a chemical vapor deposition technique and contacted by metal electrodes. Low-temperature electronic transport at negative gate bias indicates the SWNTs act as single quantum dots with a length on order of the electrode spacing, indicating that the mean free path is greater than the contact spacing (∼1 μm). Upon increasing gate bias, an intermediate multiple quantum dot regime is observed, followed by a gapped region at positive gate bias. At room temperature and zero gate bias a mean free path of 700 nm is determined using electrostatic force microscopy to probe the local potential in the SWNT.

http://research.physics.berkeley.edu/zettl/pdf/264.AIP.591-Fuhrer.pdf

Michael S. Fuhrer

Papers

Universal form of Hall coefficient in K and Rb doped single crystal C60.

Selective Control of Surface Spin Current in Topological Materials based on Pyrite-type OsX2 (X = Se, Te) Crystals

Disentangling the effects of doping, strain and disorder in monolayer WS2 by optical spectroscopy

Characterization of the electrical contact between a conductive atomic force microscope cantilever and a carbon nanotube

Ballistic transport in semiconducting carbon nanotubes