Materials Literature
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The glass-transition temperatures of 34 liquids have been measured by differential thermal analysis, and the results compared with the values predicted from viscosity measurements by the equation lnη = A″+B″/(T—T0). In those liquids which have two non-Arrhenius viscosity regions, there is good agreement between observ…
A survey is made of all published data on self-diffusion in liquid metals and an examination is carried out on the temperature-dependence of D for studies covering a wide range of temperatures. Log D versus 1/T and D versus T represent the best data equally well, while D versus T 1/2 and D versus T 2 do not. The prope…
Experiments on the vacuum flashover of dielectric frusta subjected to 35 and 75 nsec pulses show the strong influence of cone angle on insulation strength. A theory is presented to explain the formative process leading to flashover for one polarity. It is proposed that positive surface charge grows by emission of hot…
The molybdates of Sm, Eu, Tb, and Dy are isotypic with ferroelectric Gd2(MoO4)3. Other compositions of this structure occur in the pseudoternary system Gd–La–Y-molybdate and in the pseudobinary system Gd2(MoO4)3–Gd2(WO4)3. A representative number of these compositions were grown as single crystals and tested for ferro…
Abstract Calcium carbonate samples containing known amounts of additives and impurities have been calcined in air at a series of temperatures for different lengths of time. Changes in specific surface and average crystallite size show the effect of the additives and impurities (accessory minerals in limestones and cha…
Rates of tail regeneration in the Madeira wall lizard (Lacerta dugesii) and the slow-worm (Anguis fragilis) were studied. L. dugesii regenerates very rapidly, the new tail sometimes attaining a maximum rate of growth of 2'6 mm a day during the fifth week after autotomy. By the twelfth week 90% of the original tail len…
The vaporization behavior of the titanium—oxygen system has been established by experimental measurements of the change in composition of the solid residue accompanying vaporization as determined by x-ray diffraction, chemical analysis, and color of sample. The solid phases studied were Ti2O, TiO, Ti2O3, Ti3O5, Ti4O7,…
The fluorescence quenching of the two phosphors Ba2Gd1−xEuxMe5+O6 (Me5+=Nb5+ or Ta5+) and Gd1−xEuxAl3B4O12 is reported. The shortest distance between the rare-earth sites in these materials is large and nearly equal, viz., 6.0 and 5.9 Å, respectively. The quenching behavior is different: In the materials Ba2Gd1−xEuxMe…
Observations on thermophilic algal communities during a three‐year period at Mount Rainier National Park and during January 1965 and 1966 in Yellowstone National Park have been analyzed to evaluate the distribution of species in thermal streams relative to temperature and competitive interaction. Although temperature…
Abstract A T‐x‐section of the phase diagram is proposed for the system CuMnO in air between 750 and 1,400°C. From X‐ray and chemical analyses on quenched samples and from high‐temperature X‐ray diffraction studies the occurrence of the following phases is deduced: a cubic phase α‐Mn 2 O 3 , a phase Cu x Mn 3−x O 4+γ…
A plot of the initial spreading pressures (F sub ba) or initial spreading coefficients (S sub ba) against the surface tensions of a homologous series of organic liquids b can be used to determine the critical surface tension for spreading on a second substrate liquid phase a. Straight-line relations are found for vari…
Abstract Activation energy E , pre‐exponential factor k 0 , and reaction order n for the pyrolysis of α‐cellulose and cellulose modified with dihydrogen ammonium phosphate were determined by means of TGA and DTA. The results obtained are E = 53.5 kcal./mole, k 0 = 10 18.8 min. −1 , n = 1 for α‐cellulose and E = 32 kca…
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…