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

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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Two-dimensional crystals have emerged as a class of materials that may impact future electronic technologies. Experimentally identifying and characterizing new functional two-dimensional materials is challenging, but also potentially rewarding. Here, we fabricate field-effect transistors based on few-layer black phosphorus crystals with thickness down to a few nanometres. Reliable transistor performance is achieved at room temperature in samples thinner than 7.5 nm, with drain current modulation on the order of 10(5) and well-developed current saturation in the I-V characteristics. The charge-carrier mobility is found to be thickness-dependent, with the highest values up to ∼ 1,000 cm(2) V(-1) s(-1) obtained for a thickness of ∼ 10 nm. Our results demonstrate the potential of black phosphorus thin crystals as a new two-dimensional material for applications in nanoelectronic devices.

Black phosphorus field-effect transistors

We introduce the 2D counterpart of layered black phosphorus, which we call phosphorene, as an unexplored p-type semiconducting material. Same as graphene and MoS2, single-layer phosphorene is flexible and can be mechanically exfoliated. We find phosphorene to be stable and, unlike graphene, to have an inherent, direct, and appreciable band gap. Our ab initio calculations indicate that the band gap is direct, depends on the number of layers and the in-layer strain, and is significantly larger than the bulk value of 0.31–0.36 eV. The observed photoluminescence peak of single-layer phosphorene in the visible optical range confirms that the band gap is larger than that of the bulk system. Our transport studies indicate a hole mobility that reflects the structural anisotropy of phosphorene and complements n-type MoS2. At room temperature, our few-layer phosphorene field-effect transistors with 1.0 μm channel length display a high on-current of 194 mA/mm, a high hole field-effect mobility of 286 cm2/V·s, and an...

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Phosphorene: An Unexplored 2D Semiconductor with a High Hole Mobility

In this paper, we report a top gate SWNT-FET with reduced hysteresis in the IV characteristics and extremely low 1/f noise. We have also investigated the source of 1/f noise in these devices and attributed the low noise property to low trap charges near the carbon nanotube substrate interface. The SWNT-FET devices reported here and shown schematically in Fig. 1(a), are fabricated on high resistivity Si substrate (rhoap10 KOmega) with a 500 nm thermal SiO2. Catalyst patterns are defined by UV photolithography with a 10 mum spacing and subsequent iron deposition and lift-off. Single-walled carbon nanotubes (SWNTs) are then synthesized by chemical vapor deposition (CVD) of methane on the substrate using iron catalyst.

The study of low frequency noise of single-walled carbon nanotube transistors

The interface between III–V and gate dielectrics is a key challenge in developing high performance III–V MOSFETs such as GaAs and InGaAs. The high density of interface states (D it ) makes it very difficult to modulate surface Fermi level and inversion carrier concentration. By growing an epitaxial layer (ALE) of La 2 O 3 dielectric on GaAs(111)A, D it can be effectively reduced and Fermi levels movement efficiency is greatly improved. In this paper, we studied systematically the carrier transport including IV, CV and conductance method at temperatures ranging from 300 K to low temperatures down to 4.3 K.

Low temperature study of GaAs MOSFETs with atomic layer epitaxial La 2 O 3

Recently, β-Ga 2 O 3 has shown its great promise for next generation high power device applications due to its ultra-wide bandgap of 4.6–4.9 eV [1]-[5]. Despite the very early development stage, β-Ga 2 O 3 metal-oxide-semiconductor field-effect transistors (MOSFETs) have demonstrated a high blocking voltage of 0.75 kV and a breakdown field of 3.8 MV/cm [2][4]. However, a crucial disadvantage of this material is its low thermal conductivity of 0.1–0.3 W/cm-K. One of the approaches to solve this issue is to introduce a high thermal conductivity substrate with β-Ga 2 O 3 on insulator (GOOI) structure rather than the β-Ga 2 O 3 native substrate. It is questionable whether β-Ga 2 O 3 based FETs can compete with existing GaN or SiC technologies in terms of drain current (I dmax ) and on-resistance (R on ). Meanwhile, whether β-Ga 2 O 3 can also be applied in large-signal RF power devices remains to be answered, although β-Ga 2 O 3 suffers from relatively low electron mobility (μ). In this abstract, we have fully explored the device potentials and demonstrated that depletion/enhancement (D/E)-mode GOOI FETs can achieve a record high I DMAX of 1.5/1.0 A/mm and high estimated virtual source velocity v=7.3 × 106 cm/s.

Depletion/enhancement-mode β-Ga 2 O 3 on insulator field-effect transistors with drain currents exceeding 1.5/1.0 A/mm

Phosphorus is one of the most abundant elements preserved in earth, constructing with a fraction of 0.1% of the earth crust. In general, phosphorus has several allotropes including white, red, and black phosphorus. Black phosphorus, though rarely mentioned, is a layered semiconductor as shown in Figure 1 and have great potentials in optical and electronic applications. Remarkably, this layered material can be reduced to one single atomic layer as shown in Figure 2 in the vertical direction owing to the van der Waals structure, dubbed phosphorene, where the physical properties can be tremendously different from its bulk counterpart and needed to be further explored. In this talk, we trace back to the 100 years research history on black phosphorus from the synthesis to material properties, and extend the topic from black phosphorus to phosphorene. The physical and transport properties are highlighted, aiming at further applications in electronic and optoelectronics devices.

Phosphorene as a new 2D material for device applications

Electromigration (EM) is a phenomenon whereby the flow of current in metal wires moves the underlying atoms, potentially inducing electronic interconnect failures. The continued decrease in commercial lithographically defined feature sizes means that EM presents an increasing risk to the reliability of modern electronics. To mitigate these risks, it is important to look for novel mechanisms to extend lifetime without forfeiting miniaturization. Typically, only the overall increase in the interconnect resistance and failure voltage are characterized. However, if the current flows non-uniformly, spatially resolving the resulting hot spots during electromigration aging experiments may provide better insights into the fundamental mechanisms of this process. In this study, we focus on aluminum interconnects containing asymmetric reservoir and void pairs with contact pads on each end. Such reservoirs are potential candidates for self-healing. Thermoreflectance imaging was used to detect hot spots in electrical ...

Peide D. Ye

Papers

The study of low frequency noise of single-walled carbon nanotube transistors

Low temperature study of GaAs MOSFETs with atomic layer epitaxial La 2 O 3

Depletion/enhancement-mode β-Ga 2 O 3 on insulator field-effect transistors with drain currents exceeding 1.5/1.0 A/mm

Phosphorene as a new 2D material for device applications

Thermoreflectance imaging of electromigration evolution in asymmetric aluminum constrictions