Materials Literature
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。
The biosynthesis of vitamin B6 was studied in an Escherichia coli mutant, blocked between pyridoxol and pyridoxal. Specific incorporation of glycerol, pyruvate, serine, and glucose was shown by chemical degradation of labeled samples of pyridoxol isolated from the medium of cultures which had been incubated with vario…
The pair distribution function in amorphous deposited silicon monoxide has been measured at room temperature. The result is not in good agreement with expectations for a mixture of well-defined amorphous silicon and amorphous SiO2. Other possibilities, for which the average number of nearest-neighbor Si–O bonds per at…
Rate constants for collisional detachment of NO−, NO− + X → NO + X + e,have been measured from 193 to 506°K for X as He, Ne, H2, NO, CO, CO2, N2O, and NH3. The data fit Arrhenius plots kd=Ae−E/kT with both A and E showing large variations with X. From equilibrium constant considerations, electron attachment rates to N…
The spin density distributions in two alloys of iron and silicon (approximate compositions Fe3Si and Fe4Si) have been determined by polarized neutron diffraction. The observed data have been corrected for the effects of extinction and have been analysed by the standard Fourier method and also by expressing the density…
The structures of electroplated and vapor-deposited copper films have been studied by x-ray diffraction. While there was no evidence of stacking faults in any of these films, the electroplated films were characterized by presence of twins, large thickness-dependent microstrains, and small particle sizes. The vapor-dep…
Charge deposition on 2–25-μ m polyethylene terephthalate (PET), polyfluoroethylenepropylene (FEP), and polycarbonate (PC) foils by application of fields up to, and exceeding breakdown strength in the polymers is reported. The greatest negative or positive charge densities on PET foils metalized on one side are in exce…
Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation I. AITCHISON, B. COX; Interpretation of Fractographs of SCC in Hexagonal Metals. CORROSION 1 March 1972; 28…
Antimonic acid cannot be dehydrated by heating in air to give products of constant and reproducible weight without simultaneous reduction of some of the Sb V to Sb III . Neither anhydrous Sb 2 O 5 nor the hydroxy oxide Sb 3 O 6 OH postulated by Dihlström and Westgren can be obtained by this method. Two well-defined pr…
Two titanium centers (A–Ti–H and B–Ti–H) are formed in equal concentrations by reaction of hydrogen atoms with Ti4+ in the α-quartz lattice at 120°K. Above 150°K, B–Ti–H transforms into A–Ti–H. The spin Hamiltonians, including 47,49Ti hyperfine and nuclear quadrupole terms, have been determined by 9.850-GHz EPR at 20°…
Abstract In einem Durchfluß‐Kreislaufreaktor wurden bei der CO‐Oxidation an Platin unter isothermen Bedingungen sprunghafte Instabilitäten und periodisches Verhalten beobachtet. Die sprunghaften Instabilitäten lassen sich mit der gemessenen Formalkinetik deuten. Die Deutung des periodischen Reaktionsablaufes wird unte…
Abstract A phenomenological theory has been developed for explaining the anomalous dielectric and electro‐mechanical properties of some improper ferroelectrics. An ordering parameter 8, which plays the role of a trigger for the onset of the spontaneous polarization P is introduced into the thermodynamical potential fu…
We report herein the preparation of a form of noncrystalline Ge film by rf sputtering on to various substrates, which crystallizes with ``explosive'' velocities when triggered by a localized transient energy pulse. The films show this phenomenon only when they are thicker than about 10 μ. The crystallization wave appe…
Abstract Anisotropic growth of β‐form crystals of isotactic polypropylene in type III and type IV spherulites has made possible microanalysis of the unit cell structure, optical properties, and crystal arrangement within the spherulites. Micro x‐ray studies of the type III and type IV spherulites show that interspheru…
In view of recent x-ray experiments which detected a surprisingly strong diffuse scattering in the {100} reciprocal sheets of KTa${\mathrm{O}}_{3}$, a new neutron-scattering investigation was performed to determine the origin of this scattering. It was found that a strong anisotropy in the dispersion of the low-lying…
The electron spin relaxation processes for oblate and prolate symmetric top paramagnetic probes dissolved in liquid crystals are studied by solving the diffusion equation for molecules subjected to an orienting potential, expressed as a series expansion of Legendre polynomials. The line shape variations upon ordering…
Abstract High resolution electron microscope images showing the detailed distribution of metal atoms within the unit cells of complex oxide structures have been recorded recently and as a first approximation may be interpreted as amplitude-object images if obtained with the degree of defocus corresponding to the "opti…
The catalytic reaction between CO and O2 on a Pt (110) surface is investigated by residual gas analysis for different partial pressures of CO and O2 and various temperatures. The surface cleanliness of the Pt crystal is monitored by Auger electron spectroscopy. The results of the reaction study are generally in agreem…
Recent studies of the instantaneous magnetic correlations in ${(\mathrm{C}{\mathrm{D}}_{3})}_{4}$NMn${\mathrm{Cl}}_{3}$ using quasielastic-neutron-scattering techniques have shown that the Mn${\mathrm{Cl}}_{3}$ chains in this compound exhibit purely one-dimensional paramagnetic behavior down to 1.1 \ifmmode^\circ\else…
The electrochemical properties of the Alnico alloys are shown to be sensitive to their state of precipitation. These properties thus are used as an indirect means for evaluating the individual properties of the ferromagnetic phases in these alloys. Results are then compared with recent findings and are shown to agree…
This work investigates experimentally a recent model of magnetomechanical damping based on a distribution of internal stresses, verifies some predictions and extends the model. Damping results are reported for cast irons and iron alloyed with silicon or germanium. As predicted, the maximum magnetomechanical damping ψm…