X-ray photoabsorption of solids by specular reflection
A method to obtain the X-ray photoabsorption spectra of a bulk sample based on the specular reflection of continuous radiation on its surface is proposed.
Materials Literature
文献浏览
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
LEED crystallography
LEED crystallography is reviewed by describing the four stages of a typical surface-structure analysis by LEED, namely (i) the experimental procedure, (ii) the identification of structural model, (iii) the calculation of LEED intensities expected from the chosen models, (iv) the evaluation of the agreement between cal…
Isolation and identification of yeast messenger ribonucleic acids coding for enolase, glyceraldehyde-3-phosphate dehydrogenase, and phosphoglycerate kinase
Yeast poly(adenylic acid)-containing messenger ribonucleic acid isolated from two strains of Saccharomyces cerevisiae was fractionated by preparative polyacrylamide gel electrophoresis in the presence of formamide. Three messenger ribonucleic acids, present at high intracellular concentration, were electrophoretically…
Observation of Edge Dislocations in Smectic Liquid Crystals
Isolated single-layer edge dislocations in smectic liquid crystals are observed by polarization microscopy. The modification of the smectic-$A$---smectic-$C$ transition temperature by the strain field of the dislocations is used to make them visible. Observations of periodic arrays in thin samples, by various polariza…
Core-Level Binding Energy and Density of States from the Surface Atoms of Gold
X-ray photoemission spectra of $4f$ and valence electrons in surface atoms of gold have been obtained. The surface-atom $4f$ level is shifted 0.40\ifmmode\pm\else\textpm\fi{}0.01 eV to lower binding energy relative to the bulk value. The surface density of states is narrowed by (7.6 \ifmmode\pm\else\textpm\fi{} 1.1)%…
Three-body attachment in oxygen
The three-body attachment coefficient in oxygen is calculated by a Boltzmann equation method using the electron collision cross section for this process which is proportional to the gas number density. The calculated values of the coefficient agree well with previous experimental values and represent well the gas pres…
Invertebrate Collagens
The collagens of all major invertebrate phyla have been studied, but characterization has been thorough in only a few classes and in no case in the detail (such as sequence analysis) known for vertebrate collagen. Biochemical data on insect collagen are particularly sparse. Invertebrate and vertebrate collagens are st…
Pressure-Induced Antiferroelectricity in Ferroelectric CsH2PO4
A new phase in Cs${\mathrm{H}}_{2}$P${\mathrm{O}}_{4}$ is induced by pressures above about 3.3 kbar; this phase is confirmed to be antiferroelectric by the observation of $P\ensuremath{-}E$ double hysteresis loops. The qualitative change from the paraelectric-ferroelectric to the paraelectric-antiferroelectric transit…
Dielectric Strength of Compressed Insulating Gases and their Mixtures
A method is developed for computing the discharge threshold voltages in SF6, N2 as well as their mixtures above atmopheric pressure. In electronegative gases, and for both uniform and nonuniform field gaps of positive polarity, there is a critical pressure above which field emission from the cathode surface has a sign…
The Ferroelectricity in the Mixtures of Chiral with Non-Chiral Smectic C
The spontaneous polarization was measured by means of the Sawyer-Tower method in mixtures of chiral smectic C liquid crystal with smectic C liquid crystal. Induced circular dichroism in the chiral smectic C phase was also measured on the same mixtures. It was found that the magnitude of spontaneous polarization was de…
Molecular distortion in the pyrazine triplet state. Analysis in terms of the MIDP experiments under polarized light
The distortion of the pyrazine molecule in its triplet excited state, as revealed by the appearance of the group theoretically forbidden bands in the sublevel phosphorescence, is analyzed in terms of the polarization of the originally forbidden bands in the sublevel phosphorescence. The experimental results together w…
Thermal shrinkage of drawn polystyrene
Abstract Many papers have reported on the thermal shrinkage mechanism of drawn polymers. The cause of the thermal shrinkage is very complex, because that relates to many factors. In this study, atactic polystyrene, a noncrystalline polymer, was used to eliminate factors related to the melting and crystallization effec…
Calculation of critical shapes and stresses of surface sources of dislocations
An iterative method of computation has been applied to determine the activation stress of emerging segments of dislocations, anchored beneath the free surface, in the case of a homogeneous applied stress field. The calculation has been performed for a series of orientations of the Burgers vector and of source lengths.…
Orotic acid excretion in some wild-type strains of Escherichia coli K-12
During rapid growth, the excretion of pyrimidines, predominantly uracil, is a common phenomenon in procaryotes and eucaryotes. In Escherichia coli, some K-12 strains excrete orotic acid and not uracil. This is caused by a mutation in the pyrF gene.
Lattice Vibration Spectra. XX. Infrared and Raman Spectra of BaCl 2 •2H 2 O and BaCl 2 •2D 2 O
The infrared absorption and laser Raman spectra of BaCl 2 ·2H 2 O powder and single crystals as well as BaCl 2 ·2D 2 O, partially deuterated, and isotopically dilute samples have been analyzed in the range from 30 to 4000 cm −1 . A revised interpretation of the observed water bands is given. The influence of the bond…
Unusual magnetic properties in two copper(II) chelates of Schiff bases derived from .alpha.-amino acids: a dimeric interaction in a structural linear chain
Ordinarily one expects the structural and magnetic properties of a given substance to be intimately related, with the dimensionality of the magnetic or electrical interactions that are present reflecting the lattice dimensionality. For example, a cluster of two interacting magnetic ions should obey a theoretical model…
Organo-substituted phosphazenes. 10. Reactions of hexafluorocyclotriphosphazene with propenyllithium reagents
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOrgano-substituted phosphazenes. 10. Reactions of hexafluorocyclotriphosphazene with propenyllithium reagentsJohn G. DuPont and Christopher W. AllenCite this: Inorg. Chem. 1978, 17, 11, 3093–3096Publication Date (Print):November 1, 1978Publication History Published online1 M…
A Raman Spectroscopic Investigation of Heteropolymolybdate Species in Aqueous Solution
Raman spectroscopy has been applied to the study of the pH-dependent decomposition of 12-molybdophosphoric acid, H 3 (PMo 12 O 40 ), and 12-molybdosilicic acid, H 4 (SiMo 12 O 40 ), in aqueous solution. The decomposition schemes involving several smaller polymeric molybdate species, proposed from indirect techniques s…
Lanthanide photochemistry initiated in f-f transitions
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLanthanide photochemistry initiated in f-f transitionsTerence DonohueCite this: J. Am. Chem. Soc. 1978, 100, 23, 7411–7413Publication Date (Print):November 1, 1978Publication History Published online1 May 2002Published inissue 1 November 1978https://pubs.acs.org/doi/10.1021/…
Flaw Growth in High Strength Al-Zn-Mg-Cu Alloys Exposed to Stress Corrosion Environments
Marine atmosphere and synthetic sea water stress corrosion tests on smooth and precracked specimens from 7075, 7050, and 7049 alloy plates (32 and 76 mm thick) show that for a given strength level, alloys 7050-T7X and 7049-T7X have superior short-transverse stress corrosion resistance (SCR) to 7075-T7X. At typical str…