Yury Gogotsi

Bio: Yury Gogotsi is an academic researcher from Drexel University. The author has contributed to research in topics: MXenes & Carbon. The author has an hindex of 171, co-authored 956 publications receiving 144520 citations. Previous affiliations of Yury Gogotsi include Qatar Airways & Clemson University.

Hydrothermal degradation of chemical vapour deposited SiC fibres

Abstract: The interaction of chemical vapour-deposited (CVD) SiC fibres with H2O at 200 MPa and 400–700°C (673–973K), was investigated. With increasing temperature and time, the smooth surface of the amorphous SiC fibre becomes rough and sponge-like. This modification can be controlled by adjusting temperature and duration of the hydrothermal treatment. CVD SiC dissolves in supercritical water in a first order reaction with Ea=150 kJ mol-1. According to thermodynamic calculations, the main products are SiO2, CH4 and H2. The formation of carbon is also predicted. Films of amorphous and graphitic carbon have been observed, but only small areas of the fibres were coated with carbon. Amorphous silica, quartz, cristobalite and keatite were deposited on the surface of fibres in larger quantities © 1998 Kluwer Academic Publishers

Investigation of chloride ion adsorption onto Ti2C MXene monolayers by first-principles calculations

Abstract: Chloride ion adsorption on Ti2C monolayers was theoretically investigated. Electrochemical parameters, including specific capacity, chloride ion (Cl−) diffusion barrier, and discharge voltage profile, were studied via first-principles calculations. The most favorable Cl− adsorption configuration was identified using a partial particle swarm optimization algorithm and the results showed that Cl− adsorption onto Ti2C monolayers achieved a large theoretical capacity (331 mA h g−1), high working voltage (4.0–3.5 V), and low diffusion barrier (0.22 eV). This resulted in excellent rate capability and a large specific energy of 1269 W h kg−1 at the material level. The effects of terminal O, F, and OH groups on Cl− adsorption onto Ti2C monolayer were also studied, which showed that Cl− could not be adsorbed onto O and F terminated Ti2C monolayers. In comparison, Cl− adsorption onto OH terminated Ti2C was allowed but generated a smaller specific capacity (126 mA h g−1) and lower working voltage (3.5–1.5 V) than a bare Ti2C monolayer.

Effect of Humidity on the Tribological Properties of Carbide-Derived Carbon (CDC) Films on Silicon Carbide

Abstract: The effect of humidity on the tribological behavior of carbide-derived carbon (CDC) films prepared by high-temperature chlorination of silicon carbide was examined. Pin-on-disk tribological tests indicate that CDC, unlike graphite or glassy carbon, performs better in dry nitrogen (less than 0.05 friction coefficient at 0% humidity) than in humid air. This versatility is explained by the onion-like structure of the nanoporous CDC coating.

I and i

Abstract: 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 …

Fast parallel algorithms for short-range molecular dynamics

Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

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

Abstract: 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。

Materials for electrochemical capacitors

Abstract: Electrochemical capacitors, also called supercapacitors, store energy using either ion adsorption (electrochemical double layer capacitors) or fast surface redox reactions (pseudo-capacitors). They can complement or replace batteries in electrical energy storage and harvesting applications, when high power delivery or uptake is needed. A notable improvement in performance has been achieved through recent advances in understanding charge storage mechanisms and the development of advanced nanostructured materials. The discovery that ion desolvation occurs in pores smaller than the solvated ions has led to higher capacitance for electrochemical double layer capacitors using carbon electrodes with subnanometre pores, and opened the door to designing high-energy density devices using a variety of electrolytes. Combination of pseudo-capacitive nanomaterials, including oxides, nitrides and polymers, with the latest generation of nanostructured lithium electrodes has brought the energy density of electrochemical capacitors closer to that of batteries. The use of carbon nanotubes has further advanced micro-electrochemical capacitors, enabling flexible and adaptable devices to be made. Mathematical modelling and simulation will be the key to success in designing tomorrow's high-energy and high-power devices.