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

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

J. Appl. Cryst.の発刊に際して

/pdf/convex-analysisnoer-san-nojin-zhan-nituite-5dl2rbmoyr.pdf

Convex Analysisの二,三の進展について

A combined program of experiments and simulations is used to study the problem of cyclic indentation loading on metallic glasses. The experiments use a spherical nanoindenter tip to study shear band formation in three glasses (two based on Pd and one on Fe), after subjecting the glass to cycles of load in the nominal elastic range. In all three glasses, such elastic cycles lead to significant increases in the load required to subsequently trigger the first shear band. This cyclic hardening occurs progressively over several cycles, but eventually saturates. The effect requires cycles of sufficient amplitude and is not induced by sustained loading alone. The simulations employed a new shear transformation zone (STZ) dynamics code to reveal the local STZ operations that occur beneath an indenter during cycling. These results reveal a plausible mechanism for the observed cyclic hardening: local regions of confined microplasticity can develop progressively over several cycles, without being detectable in the g...

Cyclic Hardening of Metallic Glasses under Hertzian Contacts: Experiments and STZ Dynamics Simulations

There is provided a shape memory ceramic structure including an aggregate population of crystalline particles. Each crystalline particle in the population, of crystalline particles comprises a shape memory ceramic particle material. Each crystalline particle in the population of crystalline particles has a crystalline particle extent that is between about 0.5 microns and about fifty microns. At least a portion of the population of crystalline particles has a crystalline structure that is either oligocrystalline or monocrystalline.

Shape memory ceramic particles and structures formed thereof

Verfahren zur herstellung von legierungsabscheidungen und steuerung ihrer nanostruktur mittels galvanischer abscheidung mit negativstrompulsierung

Procede de production de depots d'alliage et de controle de leur nanostructure par electrodeposition par impulsions de courant negatif, et articles incorporant lesdits depots

Grain boundary networks differ from randomly assembled networks due to a requirement for crystallographic consistency at grain boundary junctions. The effects of crystallographic constraint are observed at all length scales, from preferential coordination at individual triple junctions to nonrandom percolation thresholds for large networks.Copyright © 2004 by ASME

Christopher A. Schuh

Papers

Cyclic Hardening of Metallic Glasses under Hertzian Contacts: Experiments and STZ Dynamics Simulations

Shape memory ceramic particles and structures formed thereof

Verfahren zur herstellung von legierungsabscheidungen und steuerung ihrer nanostruktur mittels galvanischer abscheidung mit negativstrompulsierung

Procede de production de depots d'alliage et de controle de leur nanostructure par electrodeposition par impulsions de courant negatif, et articles incorporant lesdits depots

Applications of Percolation Theory to Grain Boundary Engineering