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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

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Climate Change 2007: The Physical Science Basis.

Squid Ink-Assisted Fabricating MoS2 Nanosheets/Ultrafine Biocarbon Spheres Composites with an Enhanced Lithium Ion Storage Performance

Magnetic chitosan-based aerogel decorated with polydimethylsiloxane: A high-performance scavenger for oil in water

Controlling spintronic properties of ferromagnetic metal/organic interfaces in a reversible manner provides novel avenues in spin memory and logic operations. Until now, most previous work has been...

Reversible Control of Spintronic Properties of Ferromagnetic Metal/Organic Interfaces through Selective Molecular Switching

Ionic liquid-assisted two-phase synthesis of Lu7O6F9:Yb3+, Er3+ phosphors and their morphological control, color-tunable up-conversion luminescence and temperature sensing behavior

Ultrafine Ag–Cu nanoparticles (NPs) have been synthesized by a rapid one-step reduction within only 10 min. Effects of temperature and dispersants on the phases and morphology of Ag–Cu NPs were investigated. Results showed that citric acid exhibited an advantageous nature to avoid the formation of Cu2O and form uniform morphology over PVP. The average particle size of the Ag–Cu NPs synthesized simply in ice-cubes bath could be controlled in 8.6 nm about a quarter of that synthesized at room temperature. The synthesized Ag–Cu NPs presented alloy states near the eutectic composition of 72:28. Due to the lower Ostwald ripening rate and citric acid protection, smaller Ag–Cu NPs were achieved in ice-cube bath. Results also showed that the ultrafine Ag–Cu NPs could be expected to sinter at about 330 °C which was much lower than the eutectic temperature (779 °C) of bulk Ag–Cu alloy. The ultrafine Ag–Cu NPs could be applied as potential die attach materials for SiC power devices.

Wei Liu

Papers

Squid Ink-Assisted Fabricating MoS2 Nanosheets/Ultrafine Biocarbon Spheres Composites with an Enhanced Lithium Ion Storage Performance

Magnetic chitosan-based aerogel decorated with polydimethylsiloxane: A high-performance scavenger for oil in water

Reversible Control of Spintronic Properties of Ferromagnetic Metal/Organic Interfaces through Selective Molecular Switching

Ionic liquid-assisted two-phase synthesis of Lu7O6F9:Yb3+, Er3+ phosphors and their morphological control, color-tunable up-conversion luminescence and temperature sensing behavior

Effects of temperature and dispersants on the phases and morphology of Ag–Cu nanoparticles