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

THE large-scale use of photovoltaic devices for electricity generation is prohibitively expensive at present: generation from existing commercial devices costs about ten times more than conventional methods1. Here we describe a photovoltaic cell, created from low-to medium-purity materials through low-cost processes, which exhibits a commercially realistic energy-conversion efficiency. The device is based on a 10-µm-thick, optically transparent film of titanium dioxide particles a few nanometres in size, coated with a monolayer of a charge-transfer dye to sensitize the film for light harvesting. Because of the high surface area of the semiconductor film and the ideal spectral characteristics of the dye, the device harvests a high proportion of the incident solar energy flux (46%) and shows exceptionally high efficiencies for the conversion of incident photons to electrical current (more than 80%). The overall light-to-electric energy conversion yield is 7.1-7.9% in simulated solar light and 12% in diffuse daylight. The large current densities (greater than 12 mA cm-2) and exceptional stability (sustaining at least five million turnovers without decomposition), as well as the low cost, make practical applications feasible.

A low-cost, high-efficiency solar cell based on dye-sensitized colloidal TiO2 films

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

The civilian, commercial, and defense sectors of most advanced industrialized nations are faced with a tremendous set of environmental problems related to the remediation of hazardous wastes, contaminated groundwaters, and the control of toxic air contaminants. For example, the slow pace of hazardous waste remediation at military installations around the world is causing a serious delay in conversion of many of these facilities to civilian uses. Over the last 10 years problems related to hazardous waste remediation have emerged as a high national and international priority.

Environmental Applications of Semiconductor Photocatalysis

We have developed a reusable piezoelectric immunosensor for human granulocytes. Three different methods for immobilization of the anti-CD 18 antibody on the gold electrode of the immunosensor were tested. The methods showed some differences in terms of stability and sensitivity. Applying an anti-CD 18 antibody layer onto a 10-MHz AT-cut crystal resulted for 2 × 103 to 3 × 105 cells on the surface in a linear frequency change. The modified crystal was stable for eight weeks when stored desiccated at room temperature.

Human Granulocytes Detected with a Piezoimmunosensor

Site of dopamine D1 receptor binding to Gs protein mapped with synthetic peptides.

We designed and synthesized a metal-free organic sensitizer based on phenothiazine as the core moiety for application in dye-sensitized solar cells (DSCs). The structure of the donor–π–bridge–acceptor (D–π–A) dye 3-(5-(7-((E)-3,4,5-trimethoxystyryl)-10-octyl-10H-phenothiazin-3-yl)thiophen-2-yl)-2-cyanoacrylic acid (TMPTZT) has tri-methoxy phenyl as a donor segment on a phenothiazine core and cyanoacrylic acid as an acceptor group. In this study, we investigated the influence of iodide/triiodide and Co(bpy)32+/3+ complexes as redox electrolytes on the DSC device performance. The maximal monochromatic incident photon to current conversion efficiency (IPCE) reached a value of 70%. The solar light to electrical energy conversion efficiency of the devices with a volatile solvent based iodide/triiodide electrolyte reached up to 5.1% at AM 1.5G illumination, whereas the devices with Co(bpy)32+/3+ and ionic liquid electrolytes showed efficiencies of 4.9% and 4.5%, respectively. The DSC devices were characterized using charge extraction and Voc decay techniques to understand the difference in the photovoltaic performance of this metal free organic dye with these three types of redox electrolytes.

Influence of redox electrolyte on the device performance of phenothiazine based dye sensitized solar cells

Reference LPI-CHAPTER-1997-017View record in Web of Science Record created on 2006-02-21, modified on 2017-05-12

Nanocrystalline electronic junctions

This invention concerns a lithium rechargeable electrochemical cell containing electrochemical redox active compounds in the electrolyte. The cell is composed of two compartments, where the cathodic compartment comprises a cathodic lithium insertion material and one or more of p-type redox active compound(s) in the electrolyte; the anodic compartment comprises an anodic lithium insertion material and one or more of n-type redox active compound(s) in the electrolyte. These two compartments are separated by a separator and the redox active compounds are confined only in each compartment. Such a rechargeable electrochemical cell is suitable for high energy density applications. The present invention also concerns the general use of redox active compounds and electrochemically addressable electrode systems containing similar components which are suitable for use in the electrochemical cell.

Michael Grätzel

Papers

Human Granulocytes Detected with a Piezoimmunosensor

Site of dopamine D1 receptor binding to Gs protein mapped with synthetic peptides.

Influence of redox electrolyte on the device performance of phenothiazine based dye sensitized solar cells

Nanocrystalline electronic junctions

Lithium rechargeable electrochemical cell