There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

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

Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

Fully exploiting the properties of graphene will require a method for the mass production of this remarkable material. Two main routes are possible: large-scale growth or large-scale exfoliation. Here, we demonstrate graphene dispersions with concentrations up to approximately 0.01 mg ml(-1), produced by dispersion and exfoliation of graphite in organic solvents such as N-methyl-pyrrolidone. This is possible because the energy required to exfoliate graphene is balanced by the solvent-graphene interaction for solvents whose surface energies match that of graphene. We confirm the presence of individual graphene sheets by Raman spectroscopy, transmission electron microscopy and electron diffraction. Our method results in a monolayer yield of approximately 1 wt%, which could potentially be improved to 7-12 wt% with further processing. The absence of defects or oxides is confirmed by X-ray photoelectron, infrared and Raman spectroscopies. We are able to produce semi-transparent conducting films and conducting composites. Solution processing of graphene opens up a range of potential large-area applications, from device and sensor fabrication to liquid-phase chemistry.

/pdf/high-yield-production-of-graphene-by-liquid-phase-z66xsivrg7.pdf

High-yield production of graphene by liquid-phase exfoliation of graphite

Crystalline carbon nitride films have been synthesized on Si(100) substrates by a microwave plasma chemical vapour deposition technique, using a gas mixture containing nitrogen and methane at various ratios as precursors. Scanning electron microscopy shows that the films consisted of hexagonal crystalline rods, which are about 1-2 µm long and about 0.4 µm wide. X-ray diffraction and transition electron microscopy indicate that the films are mainly composed of α- and β-C3N4, and these results match more closely with the α-C3N4 than with the β-C3N4 phase. Fourier transform infrared absorption spectra of carbon nitride films support the existence of α- and β-C3N4.} \fnm{3}{Author to whom correspondence should be addressed.

https://iopscience.iop.org/article/10.1088/0022-3727/34/3/308/pdf

Structure studies of C3N4 thin films prepared by microwave plasma chemical vapour deposition

Boron carbide and silicon oxide (BCSiO) hetero-nanonecklaces have been successfully synthesized via temperature modulation. This kind of nanostructure was formed by coating 100-500 nm silicon oxide nanoballs onto 20-30 nm boron carbide nanowires. Synthetic analysis shows that a two-step model at different temperatures and the poor wettability between boron carbide and silicon oxide play important roles in the growth of hetero-nanonecklaces. Photoluminescence of the synthesized BCSiO hetero-nanonecklaces shows enhanced visible light emissions at 637.6 nm, which is attributed to the small size of the boron carbide nanowires and defects induced by silicon oxide sheaths.

Boron carbide and silicon oxide hetero-nanonecklaces via temperature modulation

https://pubs.rsc.org/en/Content/ArticlePDF/2015/CC/C5CC03130C

Stereoselective formation of coordination polymers with 1,4-diaminonaphthalene on various Cu substrates

We report on temperature-programmed growth of graphene islands on Ru (0001) at annealing temperatures of 700 °C, 800 °C, and 900 °C. The sizes of the islands each show a nonlinear increase with the annealing temperature. In 700 °C and 800 °C annealings, the islands have nearly the same sizes and their ascending edges are embedded in the upper steps of the ruthenium substrate, which is in accordance with the etching growth mode. In 900 °C annealing, the islands are much larger and of lower quality, which represents the early stage of Smoluchowski ripening. A longer time annealing at 900 °C brings the islands to final equilibrium with an ordered moire pattern. Our work provides new details about graphene early growth stages that could facilitate the better control of such a growth to obtain graphene with ideal size and high quality.

https://iopscience.iop.org/article/10.1088/1674-1056/21/8/088102/pdf

The influence of annealing temperature on the morphology of graphene islands

We modelled the adsorption of benzene, fluorobenzene and meta-di-fluorobenzene on Cu(110) by Density Functional Theory. We found that the adsorption configuration depends on the coverage. At high coverage, benzene assumes a tilted position, while at low coverage a horizontal slightly distorted geometry is favoured. Functionalizing the benzene ring with one or two fluorine atoms weakens the bonding to the Surface. A rotation is induced, which decreases the distance of the fluorine atom from the surface. STM simulations reveal that details about both, benzene adsorption geometry and fluorine position, can be only detected at short tip-surface distances. (C) Crown copyright 2008.

Hong-Jun Gao

Papers

Structure studies of C3N4 thin films prepared by microwave plasma chemical vapour deposition

Boron carbide and silicon oxide hetero-nanonecklaces via temperature modulation

Stereoselective formation of coordination polymers with 1,4-diaminonaphthalene on various Cu substrates

The influence of annealing temperature on the morphology of graphene islands

Adsorption of benzene, fluorobenzene and meta-di-fluorobenzene on Cu(110): a computational study.