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 printer fabricates an object from a computerized model using a fused filament fabrication process and a metallic build material. The Seebeck effect can be employed to monitor a temperature difference between a build material and a nozzle that is extruding the build material based on voltage. The temperature difference can, in turn, be used to control operation of the printer or to determine an absolute temperature based on direct measurement of a temperature of the nozzle.

Monitoring temperature with seebeck effect

Role of grain constraint on the martensitic transformation in ceria-doped zirconia

The extension of nanoindentation techniques to elevated temperatures is a relatively recent development, with a set of best practices for testing up to 800 °C emerging in the past decade. As a result of these developments, high temperature nanoindentation is beginning to have an impact on engineering applications where components or devices are expected to see elevated temperatures in manufacture or in service, and on scientific investigations where thermally activated phenomena are of interest. This article summarizes the technique evolution, instrumentation, experimental challenges, applications, and future outlook of high-temperature nanoindentation.

Nanoindentation: High Temperature

Metal surface pretreatments using ionic liquids prior to electroplating are disclosed. The surface treatments include forming an activated metal substrate surface by removing any naturally formed metal oxide layers formed on the surfaces of the metal substrates. According to some embodiments, the surface treatments include exposing the metal substrate to a non-aqueous ionic liquid. In some embodiments, an electrical current is applied to the metal substrate to assist removal of the metal oxide layer. The electrical current can be a pulsed anodic current. After activating the surface, a metal layer can be deposited on the activated surface. In some embodiments, the metal layer is electrodeposited in the same ionic liquid used to form the activated surface. The resultant metal coating is resistant to scratching and peeling.

Preparation of metal substrate surfaces for electroplating in ionic liquids

Our recent progress in elevated temperature nanoindentation is reviewed, with an emphasis on the study of discrete events (i.e., pop-in phenomena) observed during nanoindentation. For crystalline materials the incipient plasticity problem is associated with the nucleation of dislocations, an effect which we show to be significantly temperature dependent. For metallic glasses it is the operation of individual shear bands beneath the indenter that gives rise to pop-in events; here we also show this to be a temperature dependent phenomenon. Approaches to extract the activation volume and energy of defects involved in plastic flow beneath the indenter are also briefly described.

Christopher A. Schuh

Papers

Monitoring temperature with seebeck effect

Role of grain constraint on the martensitic transformation in ceria-doped zirconia

Nanoindentation: High Temperature

Preparation of metal substrate surfaces for electroplating in ionic liquids

High Temperature Nanoindentation for the Study of Flow Defects