Materials Literature
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The scanning electron microscope has provided much information about the structure of the valves of centric diatoms that supplements or, at times, corrects the accounts based on transmission electron microscopy. In particular, the morphology of the special features that have been called processes, spines, ocelli, tubu…
In order to determine quantitative information about chemical bonding in metallocenes, we investigated the electronic structure of the cobaltocene molecule by EPR and magnetic susceptibility measurements at 4.2°K and by optical spectroscopy at 77°K. Diamagnetic ruthenocene, weakly paramagnetic nickelocene, and paramag…
The relative emission per ion and the lifetime have been obtained as a function of Tb concentration for the $^{5}D_{4}$ to $^{7}F_{J}$ transitions in ${({\mathrm{Y}}_{1\ensuremath{-}x}{\mathrm{Tb}}_{x})}_{3}{\mathrm{Al}}_{5}{\mathrm{O}}_{12}$ crystals. At 297 \ifmmode^\circ\else\textdegree\fi{}K both are concentration…
${\mathrm{Cd}}_{2}$Sn${\mathrm{O}}_{4}$ has been found to be an $n$-type defect semiconductor in which oxygen vacancies provide the donor states. Crystalline powders and amorphous films with a wide range of conductivities have been prepared. Large Burstein shifts have been observed in the visible reflection and transm…
The photoelectron spectra of some 40 transition metal compounds have been measured using AlKα(1487 eV) and MgKα(1254 eV) x-rays. The compounds included both simple salts (halides and chalcogenides) and hexacoordinated complexes (cyano- and fluoro-) of Cr(III), Mn(II, III), Fe(II, III), and Co(III). From these data we…
Abstract La synthèse de spiropyrannes photochromes substitués en position 3 montre que la méthode de cyclisation classique est limitée dans certains cas, notamment pour les composés multifonctionnels ou lorsque les anhydrobases intermeAdiaires sont peu réactives; elle constitue en mêmo temps une généralisation de la s…
Abstract An X‐ray crystal structure investigation of the macrotetrolide antibiotic nonactin is reported. The shape of the molecule is discussed with special reference to the conformational changes involved in passing from free nonactin to the K + ‐complex.
Results on the temperature dependence of orientational order at constant molar volume in the nematic liquid crystal $p$-azoxyanisole are reported for the first time. These results clearly indicate the failure of theories of the nematic phase which do not include both energetic and steric intermolecular interactions.
Abstract The ‘observed’ π‐orbital energies ϵ v,j = −I v,j derived from the vertical ionization potentials obtained by a photoelectron spectroscopic investigation of the acenes benzene A(1), naphthalene A(2), anthracene A(3), naphthacene A(4) and pentacene A(5) have been compared with π‐orbital energies calculated by t…
This paper treats the derivation of a two-dimensional differential equation, which describes the phenomenon of combined refraction — diffraction for simple harmonic waves, and a method of solving this equation. The equation is derived with the aid of a small parameter development, and the method of solution is based o…
It is shown that the photoionization process of inner-shell electrons by unpolarized radiation leads to an alignment of the ionized atoms. From the nonisotropic angular distribution of the following Auger electrons the relative partial photoionization cross sections can be determined.
Abstract On the basis of several observations of laminated Raney nickel catalysts with an electron microprobe X-ray analyzer, it is concluded that the activity of the catalysts is seemingly correlated to the composition of Raney nickel alloys, and that the active centers are distributed probably at random on the surfa…
Abstract By an extension of the Callaway ansatz for the solution of the Boltzmann equation it is possible to calculate the phonon thermal conductivity of thin layers and plates for all values of combined relaxation time to thickness, in particular also for the region of Poiseuille flow of phonons. The integral equatio…
Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text R. A. Buchroeder and A. S. Leonard, "Wide-Field Tilted-Component Telescope: a Leonard Extended Yolo All-Reflecting System," Appl. Opt. 11, 1649-1651 (1…
Abstract Crystallite sizes have been obtained from the breadth of equatorial x‐ray reflections from polypropylene samples subjected to a draw ratio of 6 at 21°C and then annealed at 155°C, 140°C, and 120°C, respectively. For all samples it was found that the ratio of the dimension of the crystallite perpendicular to t…
Numerical calculations are presented for the impedance per square of metallic films. We consider in detail the case in which the mean free path of the conduction electrons is comparable to or greater than the film thickness (thin films at low temperatures), with particular attention to the transition between the dc li…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIntermolecular exchange in methylphosphonic difluoride-amine complexes via a fluorine bridged dimerR. L. Wintermyer, L. L. Szafraniec, and H. R. BradfordCite this: J. Org. Chem. 1972, 37, 14, 2355–2357Publication Date (Print):July 1, 1972Publication History Published online1…
A single crystal structure refinement of Cr 3 P shows that the compound crystallizes with the Fe 3 P type structure. Atomic positional parameters and interatomic distances are reported and discussed. An examination by X-ray diffraction methods shows that Zr 3 P can dissolve hydrogen in solid solution. Some evidence is…
By the use of the resonance method, the electrostrictive coefficient Q 33 and the elastic compliance coefficients s 33 D , s 33 E have been determined from -70°C to 50°C. In the ferroelectric phase, Q 33 was obtained from the piezoelectric coefficient and spontaneous polarization, while in the paraelectric phase it wa…
The problems involved in making a mechanical analysis of bending deformations in textile fabrics are discussed. It is suggested that progress can be made by making simplifying assumptions concerning the geometry of fabric structure and deformation and using energy considerations to calculate forces and moments. Certai…