Materials Literature
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Central to the concept of seed-mediated growth of nanoparticles is that small nanoparticle seeds serve as nucleation centers to grow nanoparticles to a desired size. We have examined this common assumption in a model system, the wet chemical synthesis of gold nanoparticles via reduction of a gold salt, by transmission…
The structure of the free-acid form of the coenzyme NAD(+) was determined at 100 K from a single-crystal neutron experiment. NAD(+) is the oxidized form of the coenzyme redox pair NAD(+)/NADH and plays an important role in the catalysis of biological processes. The molecule crystallizes in space group P1 with one NAD(…
The potassium salt of poly(trimethylene-1,1-dicarboxylic acid), the first member of a new polyelectrolyte family where the carbon backbone is substituted on every third carbon by two carboxylate anions, was obtained by hydrolysis of a monodisperse di- n -propyl ester polymer (CH 2 CH 2 C(COO n Pr) 2 ) n . This precurs…
Two poly(pyridinium salt)s containing tosylate as a counterion were synthesized by the ring-transmutation polymerization reaction of bis(pyrylium tosylate) with the corresponding aromatic diamines and characterized for their lyotropic liquid-crystalline as well as fluorescence properties in both polar protic and aprot…
The preparation of derivatives by the traditional methods of soaking is one of the most time-consuming steps in protein crystal structure solution by X-ray diffraction techniques. The 'quick cryosoaking' procedure for derivatization with halides (monovalent anions) offers the possibility of significantly speeding up t…
We have examined the forces of interaction between opposing polystyrene brushes of various molecular weights in cyclohexane near the ϑ temperature. The force−distance profiles and structural information obtained from surface forces experiments are compared to those of brushes in the good solvent, toluene. In both solv…
Rare-earth alloys $R{\mathrm{Ag}}_{1\ensuremath{-}x}{\mathrm{In}}_{x}$ (where $R=\mathrm{La},$ Ce, and Pr) are improper ferroelastic materials with the CsCl structure. A weakly first-order phase transition occurs with the softening of a zone-edge ${\mathrm{M}}_{5}^{\ensuremath{-}}$ mode that drives the material from a…
Summary Using four different wood species, the wetting behaviour of sanded wood surfaces was compared with that of microtomed surfaces. Sanding caused lower contact angles and lower total surface free energies. Electron donor components were considered to be responsible for the observed changes according to the applie…
We examine the demixing transition in star-polymer-colloid mixtures for star arm numbers f=2,6,16,32 and different star-polymer-colloid size ratios 0.18< or =q< or =0.50. Theoretically, we solve the thermodynamically self-consistent Rogers-Young integral equations for binary mixtures using three effective pair potenti…
A systematic measurement of thermal conductivity $\ensuremath{\kappa}(T)$ below room temperature has been carried out on a series of single-crystal samples of ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{MnO}}_{3}$ that were chosen to probe changes on crossing several crystallographic phases and electron…
The ferromagnetic Kondo lattice model with an antiferromagnetic interaction between localized spins is a minimal description of the competing kinetic (t) and magnetic (K) energy terms which generate the rich physics of manganite systems. Motivated by the discovery in one dimension of homogeneous ``island phases,'' we…
4-Methyl-2-nitroacetanilide ( 1 ) crystallizes in white ( 1 W), amber ( 1 A), and yellow ( 1 Y) modifications. The isomorphic molecules 4-chloro-2-nitroacetanilide ( 2 ) and 2-nitro-4-trifluoromethylacetanilide ( 3 ) were synthesized, and their effects on the crystallization of 1 were studied. The percentages of an ad…
The magnetic structure of the series $({\mathrm{La}}_{1\ensuremath{-}y}{\mathrm{Pr}}_{y}{)}_{0.7}{\mathrm{Ca}}_{0.3}{\mathrm{MnO}}_{3}$ for y from 0.5 to 1.0 has been studied by neutron powder diffraction in the temperature range from 10 to 293 K and in external magnetic fields up to 4 T. The phase diagram has a borde…
The classical approach to building the amino-acid residues into the initial electron-density map requires days to weeks of a skilled investigator's time. Automating this procedure should not only save time, but has the potential to provide a more accurate starting model for input to refinement programs. The new softwa…
When three grain boundaries having misorientations generating coincidence site lattices (CSLs) meet at a triple junction, a common (triple-junction) CSL is formed. A theory is developed as a set of theorems establishing the relationships between the geometrical parameters of the grain-boundary and triple-junction CSLs…
Photographic artists will gravitate to this full-color, comprehensive technical resource which explores every aspect of alternative photography. Written in a user-friendly, conversational style, each chapter introduces the history of a technique, presents an overview of the relevant alternative or non-silver photograp…
A study has been made of the deformation and recrystallization textures of 99.99% pure copper sheets which were cross rolled by 82 and 96% reduction in thickness and recrystallized in a salt bath at 450°C for 1h. The deformation texture was approximated by the {011}〈755〉 orientation as the major component and {001}〈10…
Understanding direct salt effects on protein crystal polymorphism is addressed by comparing different crystal forms (triclinic, monoclinic, tetragonal and orthorhombic) for hen, turkey, bob white quail and human lysozymes. Four new structures of hen egg-white lysozyme are reported: crystals grown in the presence of Na…
The ${\mathrm{TA}}_{2}$ phonon dispersion curves of Ni-Mn-Ga alloys with different compositions which transform to different martensitic structures have been measured over a broad temperature range covering both paramagnetic and ferromagnetic phases. The branches show an anomaly (dip) at a wave number that depends on…
This paper describes self-assembly of millimeter-sized, magnetized disks floating on a liquid-air interface, and rotating under the influence of a rotating external magnetic field. Spinning of the disks results in hydrodynamic repulsion between them, while the rotating magnetic field produces an average confining pote…