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

Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology.

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Self-assembled monolayers of thiolates on metals as a form of nanotechnology.

Department of Materials Science, University of Patras, 26504 Rio Patras, Greece, Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vass. Constantinou Avenue, 116 35 Athens, Greece, Institut de Biologie Moleculaire et Cellulaire, UPR9021 CNRS, Immunologie et Chimie Therapeutiques, 67084 Strasbourg, France, and Dipartimento di Scienze Farmaceutiche, Universita di Trieste, Piazzale Europa 1, 34127 Trieste, Italy

Chemistry of Carbon Nanotubes

The synthesis of well-defined porous carbon films involves four steps: (1) monomer-block copolymer film casting, (2) structure refining through solvent annealing, (3) polymerization of the carbon precursor, and (4) carbonization. The resulting films, such as that depicted, have potential as separation membranes, chemical sensors, and catalysts.

Synthesis of a Large‐Scale Highly Ordered Porous Carbon Film by Self‐Assembly of Block Copolymers

Macromolecular Architectures by Living and Controlled/Living Polymerizations

Polymer composites containing variable amounts of multiwalled carbon nanotubes (MWNTs) have been prepared using solution dispersion and melt-shear mixing Various polymer composites with 1 wt % MWNTs have been found to dissolve homogeneously in organic solvents The amount of polymer coated or wrapped MWNTs dissolved in the solution was quantified using UV−vis absorbance at 500 nm and the concentration ratio of [MWNTs]solution/[MWNTs]composite was close to 1 A nonspecific polymer adsorption through multiple-weak molecular interactions of CH groups with MWNTs in the composites has been identified through FTIR spectroscopy The composites of polybutadiene with different wt % of MWNTs showed slight changes in the CH bending vibrations, indicating the presence of intermolecular CH−π interactions The dissolution of various polymer composites containing low concentration of MWNTs in organic solvents was attributed to polymer coating on the MWNTs via noncovalent and nonspecific CH−π interactions The dissoluti

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Noncovalent and Nonspecific Molecular Interactions of Polymers with Multiwalled Carbon Nanotubes

Polymer-grafted multiwalled carbon nanotubes through surface-initiated polymerization.

The structure of thin films of a symmetric diblock copolymer, P(dS-b-MMA) (dS = perdeuterated styrene, MMA = methyl methacrylate), was investigated near preferential and nonpreferential (neutral) surfaces. Neutral surfaces were achieved at the substrate and air interfaces by localizing random copolymer, P(S-r-MMA), having a styrene fraction of 0.60, to each of these interfaces. This was performed by chemically grafting the random copolymer to the substrate and anchoring a surface active random copolymer having a perfluorinated end group to the air interface, respectively. Neutron reflectivity and small-angle neutron scattering were used to determine the orientation of the lamellar microdomains for films having various boundary conditions. Successive steps of CF4 reactive ion etching followed by field emission scanning electron microscopy were used to ascertain the orientation of the microdomains as a function of film depth. For films confined between two continuous neutral surfaces, the orientation of the...

Jimmy W. Mays

Papers

Synthesis of a Large‐Scale Highly Ordered Porous Carbon Film by Self‐Assembly of Block Copolymers

Macromolecular Architectures by Living and Controlled/Living Polymerizations

Noncovalent and Nonspecific Molecular Interactions of Polymers with Multiwalled Carbon Nanotubes

Polymer-grafted multiwalled carbon nanotubes through surface-initiated polymerization.

Using Surface Active Random Copolymers To Control the Domain Orientation in Diblock Copolymer Thin Films