Tailoring the structure of water at a metal surface: a structural analysis of the water bilayer formed on an alloy template

Recent studies show that structures based on the traditional "icelike" water bilayer are not stable on flat transition metal surfaces and, instead, more complex wetting layers are formed. Here we show that an ordered bilayer can be formed on a SnPt(111) alloy template and determine the structure of the water layer by low energy electron diffraction. Close agreement is found between experiment and the structure calculated by density functional theory. Corrugation of the alloy surface allows only alternate water molecules to chemisorb, stabilizing the H-down water bilayer by reducing the metal-hydrogen repulsion compared to a flat surface.     

Plug‐Based Microfluidics with Defined Surface Chemistry to Miniaturize and Control Aggregation of Amyloidogenic Peptides

Small with control : For miniaturization of protein aggregation experiments the interfacial chemistry must be controlled to avoid protein aggregation caused by interfacial adsorption. Plug‐based microfluidics with defined surface chemistry (see schematic picture) can then be used to perform hundreds of aggregation experiments with volume‐limited samples, such as cerebrospinal fluid from mice.

     

Stochastic flows on a countable set: Convergence in distribution

Consider a sequenceF ₁,F ₂,... of i.i.d. random transformations from a countable setV toV. Such a sequence describes a discrete-time stochastic flow onV, in which the position at timen of a particle that started at sitex isM _n(x), whereM _n =F _n F _n–1 F ₁. We give conditions on the law ofF ₁ for the sequence (M _n) to be tight, and describe the possible limiting law. an example called the block charge model is introduced. The results can be formulated as a statement about the convergence in distribution of products of infinite-dimensional random stochastic matrices. In practical terms, they describe the possible equilibria for random motions of systems of particles on a countable set, without births or deaths, where each site may be occupied by any number of particles, and all particles at a particular site move together.     

Enolate alkylations with diethylbutadiene phosphonat-I

Enolates of various cyclic ketones undergo Michael addition to 1-diethyl-phosphinyl-1,3-butadiene to yield ketophosphonates.     

Enephosphinilation

A general method is described for the formation of vinylphosphines from arylsulfonylhydrazones. Oxidation of the resulting vinylphosphines yields phosphine oxides.     

Smart pixels with smart illumination

Smart pixels with smart illumination is a new concept in sensor array technology based on structured built-in illumination and optoelectronic feedback. It offers many new possibilities and potential advantages over more-traditional sensor arrays. We discuss an edge-detection system as an example of how smart illumination can advantageously be used to achieve a variety of functions. We also present initial experimental results from a fabricated chip based on this concept. The chip includes an integrated array of photodetectors and LED's. The output of each pixel can be controlled based on the feedback received by its dual detectors.     

Living polymerization: Rationale for uniform terminology

Polymer chemistry textbooks (e.g., B. Vollmert, Polymer Chemistry, Springer‐Verlag: New York, 1973, p 37; G. Odian, Principles of Polymerization, 3rd ed., Wiley: New York, 1991, p 8; H. G. Elias, An Introduction to Polymer Science, VCH: Weinheim, 1997, p 51) classify polymerization reactions as chain, step, and living according to the dependence of their degree of polymerization (DP ) or molecular weight (M̄) on conversion. This article discusses the rationale for uniform terminology in living polymerization. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1706–1708, 2000