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

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.

Fast parallel algorithms for short-range molecular dynamics

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

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.

https://hal.archives-ouvertes.fr/hal-02417326/document

Materials for electrochemical capacitors

Ultrafast assembly and healing of nanomaterial networks on polymer substrates for flexible hybrid electronics

Carbon Nanotube Science: Synthesis, Properties and Applications, Peter J.F. Harris. Cambridge University Press (2009). Hardback, Price 45 GBP (US$81), ISBN: 978-0-521-82895-6

Silicon oxide (SiOx) nanowire assemblies have been synthesized using anhydrous ferric chloride (FeCl3) as a catalyst precursor and silicon wafers as both the silicon source and substrate by means of floating catalyst chemical vapor deposition (CVD) in order to produce different morphologies. It is found that the growth and morphology of SiOx is strongly temperature-dependent, as tested within the temperature range 1000-1200 degrees C. The sublimation of FeCl3 and its subsequent reduction in the gas phase to produce Fe nanoparticles with high catalytic activity allows for the efficient growth of SiOx nanowires via vapor liquid solid (VLS) mechanism. The prepared amorphous SiOx nanowires show photoluminescence and emit blue light. This floating catalyst method offers a simple and comprehensive approach for the large-scale production of SiOx nanostructures with tunable assemblies.

SiO x Nanowire Assemblies Grown by Floating Catalyst Method

Nanotechnology has been recognized as an emerging technology of the new century. Control over the structure of materials on nanoscale can open opportunities for the development of nanostructured materials with controlled properties, if the structure/property relations are known. This paper describes a technique that can produce a broad range of potentially important carbon nanostructures that may be used in future technologies. Nanostructured carbon coatings can be obtained either by deposition from the gas phase onto a substrate, or by surface treatment of a carbon-containing substrate. The method presented in this paper is accomplished through the extraction of metals from carbides (SiC and TiC) using chlorine or chlorine-hydrogen mixtures. This is a versatile technology because a variety of carbon structures can be obtained on the surface of carbides in the same reactor. Not only simple shapes, but also fibers, powders and components with complex shapes and surface morphologies can be coated. This technology allows the control of coating growth on the atomic level, monolayer by monolayer, with high accuracy and controlled structures.

Nanostructured Carbon Coatings on Silicon Carbide: Experimental and Theoretical Study

The present disclosure is directed to compositions comprising at least one layer having first and second surfaces, each layer comprising: a substantially two-dimensional array of crystal cells, each crystal cell having an empirical formula of M′ 2 M″ n X n+1 , such that each X is positioned within an octahedral array of M′ and M″; wherein M′ and M″ each comprise different Group IIIB, IVB, VB, or VIB metals; each X is C, N, or a combination thereof; n=1 or 2; and wherein the M′ atoms are substantially present as two-dimensional outer arrays of atoms within the two-dimensional array of crystal cells; the M″ atoms are substantially present as two-dimensional inner arrays of atoms within the two-dimensional array of crystal cells; and the two dimensional inner arrays of M″ atoms are sandwiched between the two-dimensional outer arrays of M′ atoms within the two-dimensional array of crystal cells.

Yury Gogotsi

Papers

Ultrafast assembly and healing of nanomaterial networks on polymer substrates for flexible hybrid electronics

Carbon Nanotube Science: Synthesis, Properties and Applications, Peter J.F. Harris. Cambridge University Press (2009). Hardback, Price 45 GBP (US$81), ISBN: 978-0-521-82895-6

SiO x Nanowire Assemblies Grown by Floating Catalyst Method

Nanostructured Carbon Coatings on Silicon Carbide: Experimental and Theoretical Study

Two-Dimensional, Ordered, Double Transition Metals Carbides Having A Nominal Unit Cell Composition M'2M"NXN+1