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.

Disaggregation of aggregated nanodiamond clusters

Abstract: The present invention is directed to methods of disaggregating nanodiamond clusters, especially those clusters typically produced from detonation syntheses, the nanodiamond particles and dispersions produced from these disaggregation processes, and compositions derived from these nanodiamond particles and dispersions.

Carbon Nanotubes Containing Confined Copper Azide

Abstract: The invention concerns copper azide containing carbon nanotubes. The invention also concerns methods of producing such nanotubes by placing CuO nanoparticles within carbon nanotubes to produce CuO-containing carbon nanotubes, contacting CuO-containing carbon nanotubes with hydrogen to produce reduced nanotubes; and contacting the reduced nanotubes with hydrazoic acid to produce copper azide containing carbon nanotubes.

Is there a link between very high strain and metastable phases in semiconductors: cases of Si and GaAs?

Abstract: Silicon and gallium arsenide indentations have been investigated by using Raman spectroscopy. This perfect tool permits the study of the strain field within and around the indentation with 3D-micrometric resolution. By mapping both indented materials, we show that the strain varies strongly in GaAs and is constant in Si within indentations. With the selected orientation of GaAs, the two observed phonons provide a way to determine the local symmetry of the strain in all the area of the fingerprint. In Si, the quite constant value within the indentation, always reported in the literature with low laser power, seems to be correlated with the metastable phases created. To provide evidence for this fact, we have selected samples which favour metastable phases over amorphous, allowing the study of the correlation of the Raman peaks associated with metastable crystalline Si phases (Si-XII) and associated with diamond Si-I. The frequency shift plot of the 355 cm -1 band as a function of the Si-I Raman band frequency at 522 cm -1 exhibits a negative slope. The strains in both phases have an opposite sign. This accurate observation provides an insight into the origin of the surprising high strain in silicon.

Confined water controls capacitance.

Abstract: By using a battery of experimental and theoretical methods, it is shown that ion intercalation into the electrode material birnessite is mediated by structural water.

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.