Materials Literature
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Growth of Escherichia coli in medium containing glucose, at a concentration insufficient to support full growth, and containing lactose, is diauxic. A mutation in the gene, CR, which determines catabolite repression specific to the lac operon, was found to relieve glucose-lactose but not glucose-maltose diauxie. Furth…
Certain general features of the second-order reduced density matrix, or 2 matrix, for configuration-interaction (CI) wavefunctions are reviewed, with special reference to the simplifying features of spin singlet states. A restricted form of CI in which all spatial orbitals are doubly occupied (DOCI) is proposed for si…
Phase relations for the systems ZrO 2 –WO 2 –WO 3 and HfO 2 –WO 2 –WO 3 from 1000° to 1700° C were determined by the quenching technique using sealed sample containers. In the system ZrO 2 –WO 3 , 1:2 compound, ZrW 2 O 8 forms, having a cubic structure with a = 9.159 A. The ZrW 2 O 8 melts incongruently at 1257°± 3°C…
Metastable solid solutions with the β‐quartz structure can be crystallized from most glasses in the system SiO 2 ‐Mg(AlO 2 ) 2 ‐LiAlO 2 as well as from many containing the additional components Zn(AlO 2 ) 2 Al(AlO 2 ) 3 , Li 2 ZnO 2 , and Li 2 BeO 2 . Internal nucleation is afforded by additions of ZrO 2 or TiO 2 . Ei…
The absorption spectrum of crystalline horse-heart ferricytochrome-c was investigated. Measurements were made on single crystals at room temperature from 3700 to 7600 Å using a microspectrophotometer. Molar extinction coefficients for light parallel and perpendicular to the fourfold c crystallographic axis are given.…
In this work, the structural, electronic and absorption properties of crystalline 3′-Amino-3′-deoxyadenosine (3′-AD) under hydrostatic compression of 0–300 GPa have been studied by using density functional theory with dispersion correction. The crystal structure of 3′-AD was relaxed using three types of exchange corre…
Samples of beech litter were taken from a site in Lambridge Wood, near Henley‐on‐Thames, Oxon. during the period May 1963 to November 1964. Peaks and trends in the densities of each of the stages of C. ischnocheles clarify the earlier work of Gabbutt & Vachon (1963) especially for the postwinter period. Most of th…
Computationally convenient formulas are derived for the matrix elements of the identity and of one- and two-electron operators, for open-shell spin-projected wavefunctions built from orthogonal spatial orbitals. These formulas explicitly show the coefficients of the one- and two-electron integrals involved, and are no…
I. Introduction 332 II. Excitation of Electrons Due to the Internal Energy of the Atomic Particle-plus-solid System and Potential Ejection of Electrons 332 III. Kinetic Ejection of Electrons in Vacuum 342 IV. Radiative (Induced) Conductivity of Semiconductors Bombarded with Ions 353 V. Excitation of Luminescence by Io…
CONTENTS I. Introduction 156 II. Complex halides in vapour form 156 III. Increase in the thermal stability of complex halides on vaporisation 159 IV. Connection between complex formation and dimerisation of compounds in the vapour state 161
Abstract Silica fibres and flame polished rods having strengths around 600 Kg/mm2 were prepared and the preparation conditions studied. The effects on fibre strengths of atmospheric and temperature changes, and of variations in rate of stressing and previous heat treatment, were extensively investigated. From the resu…
The temperature-modulated reflectance, $\frac{\ensuremath{\Delta}R}{R}$, of gold films has been measured from 2 to 10 eV. The range of modulated reflectance experiments is thus extended into the vacuum ultraviolet. The observed structure, which is much more complex than the conventional reflectance spectra, is of cons…
The infrared spectra of 9,10-anthraquinone and 9,10-anthraquinone-d8 of high isotopic purity have been measured in the 4000–33 cm−1 region both in solution and in the solid. Polarized spectra have been taken on thin layers of oriented crystals grown between KBr plates. Group-theoretical analyses were made for the free…
Lattice response functions, such as the thermal conductivity and dielectric susceptibility of an imperfect crystal with rocksalt structure, are evaluated in terms of the irreducible $T$ matrix accounting for the phonon scattering. It is shown that the effect of defects on thermal conductivity and dielectric susceptibi…
A study of electrostriction in strontium titanate provides evidence that SrTi${\mathrm{O}}_{3}$ is not perfectly cubic. It exhibits a small but noticeable piezoelectric effect whose temperature and field dependence is $\frac{E}{(T\ensuremath{-}{T}_{a})}$, whereas the electrostrictive effect was found to vary as $\frac…
For equivalent values of plastic strain, the dislocation density and point-defect concentration following deformation by the propagation of high-amplitude shock waves (70 to 330 kbar) through high-purity polycrystalline nickel are appreciably larger than as a result of cold rolling near 0°C. Based on the electrical-re…
Evidence is presented for the existence of two overlapping dispersions at 20°C in toluene. Resolution of the two dispersions was in terms of separate Debye relaxation processes, with dispersion parameters ε01=2.384, ε∞1=2.269, and τ1=5.80×10−12 sec for the low-frequency process and ε02=2.269, ε∞2=2.222, and τ2=2.0×10−…
An analysis of the experimental evidence in Part I of this paper clearly indicates that for the case of copper crystals, striations in low-amplitude fatigue are suppressed by strong slip on intersecting slip planes, including the cross slip system, but are formed by interactions between dislocations on the primary gli…
The lattice parameter of La 2 Ce 2 O 7 fired at 1 400 °C was found to be 5.5700 ± 7 Å (at 20 ± 2 °C). Its crystal structure was of the disordered fluorite rather than the pyrochlore type. The degree of order in the structure could not be established from the neutron powder diffraction pattern, but it is likely that th…
Reactions between cation vacancies and Cr3+ impurity ions in single crystals of magnesium oxide are studied using optical techniques to determine the concentrations of the reaction components. Several new features of the Cr3+-ion luminescence spectrum are reported. The spectrum of these impurity ions is very sensitive…