Materials Literature
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The crystal structure of trehalose dihydrate has been solved by direct methods and refined to an R index of 0-057 using anisotropic refinement. The space group is P212121 and four formula units of C12HzzOz~.2HzO are contained in the unit cell of dimensions a= 17.90, b= 12.21 and c= 7.586 A. The two glucopyranose resid…
We have used the second harmonic of a Nd: glass laser and a continuously tunable dye laser to measure the variation of the third-order nonlinear susceptibility ${|{\ensuremath{\chi}}^{(3)}(\ensuremath{-}2{\ensuremath{\omega}}_{1}+{\ensuremath{\omega}}_{2}, {\ensuremath{\omega}}_{1}, {\ensuremath{\omega}}_{1}, \ensurem…
The thermal conductivities $\ensuremath{\kappa}$ of over twenty different single crystals of synthetic ZnO, ZnS, ZnSe, ZnTe, CdTe, and of natural, cubic ZnS have been measured from temperatures of 3 to 300 K. The results for the undoped crystals above 30 K can be scaled using the parameter $\overline{M}\ensuremath{\de…
The lowest conduction bands of a number of perovskites are determined principally by the ($\mathrm{pd}\ensuremath{\pi}$) interaction which mixes the ${t}_{2g} d$ orbitals of the transition-metal ion with the $p$ orbitals of the oxygen. Because of the planar character of the ($\mathrm{pd}\ensuremath{\pi}$) interaction,…
We present a method for the conversion of x-ray diffraction data into an electron density which reflects the antisymmetry of the N-electron wave function.Received 24 January 1972DOI:https://doi.org/10.1103/PhysRevLett.29.1363©1972 American Physical Society
Accurate birefringence measurements on monodomain SrTi${\mathrm{O}}_{3}$ platelets give important information about the fluctuations associated with the second-order structural phase transition. Above the transition, the monodomain character is announced by a birefringence tail caused by anisotropic fluctuations. Beca…
The adsorption of elemental mercury vapor on a thin (several hundred angstroms) gold film produces resistance changes in the film. An instrument for the detection of mercury based on this phenomenon is simple and rapid and requires no chemical separations other than passage of the vapor sample through a few standard d…
Abstract The height of a sessile drop first increases as the drop size increases and then diminishes to a limiting value for very large drops. The variation of sessile drop height with drop size has been calculated and is given in graphical form for a very wide range of drop size and of contact angle. These data are t…
The author criticizes the shortcomings of the usual text book explanations of surface tension and capillary rise which are two quite different types of phenomena.
Abstract The thermal degradation of saturated chlorinated polyethylene in powder and fiber form has been studied. Direct observations of fiber length variations have enabled us to prove the reactional mechanisms proposed. In the temperature range of 200°–300°C, the material exhibits some fluidity. Its degradation is e…
Abstract An activation energy theory of yielding in glassy polymers has been proposed by Starita and Keaton. It predicts a linear relation between energy to yield and test temperature. This concept was tested and found valid for five amorphous polymers; poly(methyl methacrylate), polycarbonate, polyarylsulfone, polysu…
Stacking faults nucleated at an annealing twin boundary in pure nickel are analysed by electron microscopy. The formation of the stacking faults is qualitatively explained in terms of the forces acting on the partial dislocations in the annealing twin boundary and in the matrix. The critical factors are found to be th…
Abstract Zusammenfassung . Es wird die Synthese der im Titel genannten 3‐Amino‐cardenolide beschrieben.
The phase diagram of water at moderate pressures is studied by a dielectric measurement for solid-solid transitions and further by a volume change method for liquid-ice VI transition. The metastable phase ice IV can be made from ice VI on decreasing the pressure at temperatures from -13.6 to -14.6°C. The growth and th…
Abstract It is shown by ESR‐measurements on differently treated single crystals of MoO 3 that in these crystals the localisation of molybdenum 4d 1 electrons is always connected with the presence of protons. We determine the parameters of the transferred hyperfine interaction tensor.
Abstract Polyethylenimine (PEI) has been oxidized with aqueous hydrogen peroxide to yield a hygroscopic, water‐soluble, slightly basic, yellow polymeric solid (OPEI) containing about 25% oxygen. Some chain degradation accompanies oxidation. The nature of the product varies somewhat with preparative conditions. OPEI, i…
The temperature dependence of the direction of the easy axis of magnetization in the ferromagnetic compound Cr 1- x Te ( x =0.077, T c =342 K) is determined by single crystal magnetic and neutron diffraction measurements in the temperature range from 80 K to 350 K. Below about 200 K the spin direction lies in the c -p…
In this article, we derive the balance laws and constitutive equations of polarized elastic solids with electronic spin by use of a relativistic (special) variational principle. The theory is fully dynamical and nonlinear. It is shown that this approach encompasses several previous works in micromagnetism (magnetoelas…
The ionic strength, concentration, and temperature effects on the association‐dissociation properties of lysozyme in aqueous solution have been studied by gel chromatography. The following results were obtained: Increasing ionic strength leads to an increase in inter‐conversion rate between the monomeric and associate…
Nearly stoichiometric MgAl2O4 spinel single crystals can be grown by a gradient furnace technique in molybdenum crucibles with an inert-gas atmosphere of industrial-grade argon, high-purity argon, or technical-grade helium. There is a reaction between MgO in the melt and the molybdenum crucibles which results in bands…