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

Polymer/layered silicate nanocomposites: a review from preparation to processing

Polydopamine and Its Derivative Materials: Synthesis and Promising Applications in Energy, Environmental, and Biomedical Fields

Rectorite powder modified by butadiene‐styrene‐vinyl pyridine rubber: Structure and its dispersion in styrene‐butadiene rubber

A facile method for enhancing the interaction between pristine graphene and nonpolar rubber matrices was developed by preparing a new solution-polymerized styrene-butadiene-p-(2,2,2-triphenylethyl)styrene (TPES) rubber (SBTR). SBTR macroradicals were formed by the thermal decomposition of a 1,1,1,2-tetraphenylethane pendant. The macroradicals were successfully trapped by graphene through the formation of covalent bonds. This was confirmed by rotorless rheometer and X-ray photoelectron spectroscopy measurements. The dispersion of graphene and interfacial interaction between graphene and the SBTR was significantly increased by increasing the TPES content in SBTR composites, as demonstrated by differential scanning calorimetry, scanning electron microscopy, rubber process analysis, and dynamic mechanical thermal analysis. The mechanical properties of the SBTR/GNS composites were significantly improved by the improved dispersion and the increased surface affinity of SBTR for graphene. The developed approach can be generally applied to the functionalization of other polymer matrices by copolymerizing TPES with other vinyl monomers for pristine graphene-based composite materials. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44923.

Covalent approach for in situ enhancement of interaction between pristine graphene and styrene-butadiene-p-(2,2,2-triphenylethyl)styrene rubber

Physical implications of activation energy derived from temperature dependent photoluminescence of InGaN-based materials*

Preparation and properties of a novel bio‐based and non‐crystalline engineering elastomer with high low‐temperature and oil resistance

In this work, by employing a coarse-grained molecular dynamics simulation, we have investigated the effect of the nanorod (NR) stiffness on the relationship between the NR microstructure and the conductive probability of NR filled polymer nanocomposites (PNCs) under the quiescent state and under the shear field. The conductive probability of PNCs is gradually enhanced with the increase of NR stiffness in the quiescent state; however, it first increases and then decreases under the shear field. As a result, the largest conductive probability appears at moderate NR stiffness, which results from the competition between the improved effective aspect ratio of the NR and the breakage of the conductive network. Meanwhile, compared with in the quiescent state, under the shear field the decrease or the increase of the conductive probability depends on the NR stiffness. At low NR stiffness, the increase of the effective aspect ratio of NR enhances the conductive probability, while at high NR stiffness, the breakage of the conductive network reduces the conductive probability. For flexible NRs, the conductive probability first increases and then decreases with increasing the shear rate. The maximum effective aspect ratio of NRs appears at the moderate shear rate, which is consistent with the conductive probability. In summary, this work presents some further understanding about how NR stiffness affects the electric conductive properties of PNCs under the shear field.

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Liqun Zhang

Papers

Rectorite powder modified by butadiene‐styrene‐vinyl pyridine rubber: Structure and its dispersion in styrene‐butadiene rubber

Covalent approach for in situ enhancement of interaction between pristine graphene and styrene-butadiene-p-(2,2,2-triphenylethyl)styrene rubber

Physical implications of activation energy derived from temperature dependent photoluminescence of InGaN-based materials*

Preparation and properties of a novel bio‐based and non‐crystalline engineering elastomer with high low‐temperature and oil resistance

Controlling the electrical conductive network formation in nanorod filled polymer nanocomposites by tuning nanorod stiffness