Materials Literature
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The Debye equation gives the spherically averaged diffracted intensity from a group of atoms and is exact under the first Born, or kinematic, approximation. Algebraic simplifications are developed for calculating multiplicities in the double summation and are used in a new algorithm for implementing this equation. The…
Abstract Sb‐doped ZnO nanocrystallites of average grain size about 10 nm were made by using the citrate method. Raman spectra of the Sb‐doped ZnO nanocrystallites at room temperature are reported. Shifts and broadening of the Raman peak with Sb increasing content were observed and it was found that the intensity of a…
Abstract Hot‐stage optical microscopy was used to study the crystal morphology, nucleation, and spherulitic growth rates of poly( p ‐dioxanone) (PDS) homopolymer and an 89/11 PDS/glycolide segmented block copolymer. A wide range of crystallization conditions were experimentally accessible, allowing the inspection of v…
Highly aligned carbon nanotubes (NTs) have been directly grown on metallic surfaces and in the channels of anodic aluminum oxide (AAO) templates at a low temperature by bias-enhanced microwave plasma chemical vapor deposition. Microwave plasma generated nanoparticles of various sizes (10−100 nm) on metallic surfaces,…
Although a commonly neglected fact, the physical properties of chiral carbon nanotubes may differ significantly from those of the usually considered, simpler achiral tubes. We show that the phonon eigenvectors, e.g., of the high-energy eigenmodes no longer fall into axial and circumferential modes as in armchair and z…
We have determined the crystal structure of MTH938 (Fig. 1), a hypothetical protein encoded by the Methanobacterium thermoautotrophicum (Mthe) genome (DNA bases 843,263–862,747),1 at 2.2 Å resolution by Se-Met multiwavelength anomalous diffraction (MAD) techniques. Se-Met labeled MTH938 crystallized with the symmetry…
The compounds A(1+x)M'(3-2x)Bi(7+x)Se(14) and A(1-x)M'(3-x)Bi(11+x)Se(20) (A = K, Rb, Cs; M' = Sn, Pb) were discovered from reactions involving A(2)Se, Bi(2)Se(3), M', and Se at 760 degrees C. The single-crystal structures reveal that A(1+x)M'(3-2x)Bi(7+x)Se(14) are isostructural to K(2.5)Bi(8.5)Se(14) whereas A(1-x)M…
Sodium may be topotactically inserted into the perovskite layers (under thermodynamic control) or the rock-salt layers (under kinetic control) of the cation-deficient n = 2 Ruddlesden-Popper oxysulfides Ln2Ti2O5S2 with concomitant reduction of TiIV.
Abstract The Raman spectra of the isomorphous series descloizite [PbZn(VO 4 )(OH)] and mottramite [PbCu(VO 4 ) (OH)] were obtained at 298 and 77 K. The Raman band at 844 cm −1 , assigned to the ν 1 symmetric (VO 4 − ) stretching mode for descloizite, is shifted to 814 cm −1 for mottramite. The ν 3 mode of descloizite…
Abstract This work validated a SERS probe able to compare adenyl reactivity in DNA and RNA. A Creighton silver colloid including adenine (A) [or 2 ′ ‐deoxyadenosine 5 ′ ‐phosphate (pdA)] from 2 × 10 −3 to 2 × 10 −8 M is stabilized in the absence or presence of chloride. Concentration‐dependent SER spectral profiles re…
The interpretation of Opechowski-Guccione symbols for magnetic space-group types is based on coordinate triplets given in the now superceded International Tables for X-ray Crystallography [(1952), Vol. 1, edited by N. F. M. Henry & K. Lonsdale. Birmingham: Kynoch Press]. Changes to coordinate triplets in International…
Abstract We introduce the concept of low‐resolution surface enhanced Raman spectroscopy (SERS) for cyanide as a potentially highly useful, cost‐effective approach to detection and analysis for monitoring water contamination. We present high‐sensitivity, low‐resolution measurements of cyanide in water using a solid‐sta…
Abstract The Raman spectra of liquid ethylene glycol (EG) and EG confined to series of nanoporous silica glasses with pores ranging from 30.7 to 68.5 Å were recorded at 303 K. Using vibrational assignments of specific Raman bands to the trans and gauche conformers of EG allowed us to follow the effect of confinement o…
gamma-Hexachlorocyclohexane dehydrochlorinase (LinA) is a unique dehydrochlorinase that has no homologous sequence at the amino acid-sequence level and for which the evolutionary origin is unknown. We here propose that LinA is a member of a novel structural superfamily of proteins containing scytalone dehydratase, 3-o…
High-resolution X-ray photoelectron spectroscopy (XPS) has been applied to a series of free-base and Zn-porphyrin polymers in which the macrocycles are separated by oligo(phenylene vinylene) units (OPV) of different, controllable lengths. Neat films of all the Zn-porphyrin polymers unexpectedly reveal two peaks in the…
The electron-density distribution of the high-pressure polymorph of SiO2, stishovite [a = 4.177 (1), c = 2.6655 (5) A, space group P4(2)/mnm, Z = 2], has been redetermined by single-crystal diffractometry using synchrotron radiation of 100.42 and 30.99 keV, respectively, in order to obtain essentially absorption- and…
The reaction of 2,2‘-methylenebis(4-chloro-6-isopropyl-3-methylphenol) (MCIMP-H 2 ) with 1.2 molar equiv of AlMe 3 in THF yields [(MCIMP)AlMe(THF)] ( 1 ), which further reacts with a stoichiometric amount of 2-propanol (IPA), affording the isopropoxy-bridged dimer [(MCIMP)Al(μ-O i Pr)] 2 ( 2 ). Compound 2 can also be…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTIsotope Labeling of Carbon Nanotubes and Formation of 12C−13C Nanotube JunctionsLiang Liu and Shoushan FanView Author Information Department of Physics and Tsinghua-Foxconn Nanotechnology Laboratory Tsinghua University, Beijing, 100084, China Cite this: J. Am. Chem. So…
The distribution of the final base damage was determined within isolated DNA exposed to pulses of 266 nm laser light. Studied lesions included oxidation products arising from biphotonic ionization of DNA bases and pyrimidine dimeric photoproducts arising from monophotonic processes. The distribution of the latter clas…
Abstract Surface‐enhanced Raman spectra of 2‐mercaptobenzoxazole (MBO) adsorbed on silver hydrosol were obtained. From the comparison of the SER and normal Raman spectra, both in the solid state and in NaOH solution, it can be deduced that the molecule is dissociatively adsorbed on the silver sol. The similarity betwe…