Materials Literature
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Abstract Polyethyleneimine and its acyl derivatives have been thiolated with thiobutyrolactone and the SH groups introduced have been crosslinked in the presence of and in the absence of methyl orange, respectively. After crosslinking of the polymers, the bound methyl orange was removed. The resultant two kinds of cro…
Abstract Transition temperatures by thermo‐optical analysis (TOA) and by DSC were measured on films of polystyrene (PS), poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO resin) and nine homogeneous blends of these polymers. The TOA procedure consists of automatically monitoring light transmission through birefringent scrat…
We wish to report on a simple method for measuring the birefringence and indices of refraction of nematic liquids with an accuracy comparable with or superior to previously reported means.(1–3) The method is exemplified in measurement of the temperature dependences of the indices of refraction of p-methoxybenzylidene…
The electrical and optical properties of EuO are studied in order to help determine conduction mechanisms. A strong relationship between growth parameters and electrical behavior is noted. Free-carrier absorption below the band edge in energy is observed in moderately conducting crystals. By comparing optical and elec…
Electron conduction in single crystals of Nb${\mathrm{Se}}_{2}$ has been measured at 4.2\ifmmode^\circ\else\textdegree\fi{}K in magnetic fields up to 150 kOe. The upper critical field ${H}_{c2}$ has been measured as a function of the angle between the applied field and the layers of the crystal for currents flowing bo…
The temperature dependence of paramagnetic resonance frequencies in a short range ordered spin state is studied theoretically and experimentally for two typical one-dimensional Heisenberg antiferromagnets, CsMnCl 3 2H 2 O and (CH 3 ) 4 NMnCl 3 . The present theory with the classical nearest-neighbor Heisenberg model p…
The theory of the homogeneous interacting electron gas is used to derive a functional of the density for the form factor for incoherent scattering of x rays by a statistical atom. The results show a dramatic improvement over an early calculation of Heisenberg who used the Thomas-Fermi model. Detailed calculations of f…
ADVERTISEMENT RETURN TO ISSUEPREVArticleDetailed nature of the six-coordinate polyhedra in tris(bidentate ligand) complexesEdward I. Stiefel and Gary F. BrownCite this: Inorg. Chem. 1972, 11, 2, 434–436Publication Date (Print):February 1, 1972Publication History Published online1 May 2002Published inissue 1 February 1…
Equilibrium H,O pressure (POH.O) was fixed at values less than total pressure (PT) in melting experiments on mixtures of 1921 Kilauea tholeiite, H,O, and CO, (58-5 mole per cent H,O, 41-5 mole per cent CO,), buffered by Ni+NiO. New determinations of the beginning of melting of mixtures of 1921 Kilauea tholeiite and H,…
A method of comparing the kinetics of isothermal solid‐state reactions based on the classical equation for analysis of nucleation‐and‐growth processes is described. In this method, plots of In In (1‐α) vs In (time), where α is the fraction reacted, are used to distinguish reaction mechanisms. Even nonintegral slopes o…
Abstract A novel and general synthesis of δ‐lactones from glutaraldehyde is described. The dialdehyde is first reacted with an alkyl or substituted alkyl Grignard reagent to afford a δ‐hydroxyaldehyde in good yield. These aldehydes exist preferentially in the cyclic hemiacetal form (δ‐lactols). Oxidation of the latter…
The superconducting resistive transition of the layer compound Nb${\mathrm{Se}}_{2}$ has been observed for crystals a few layers thick. The ${T}_{c}$ decreases as the crystal thickness is reduced below six Nb${\mathrm{Se}}_{2}$ layers, and a ${T}_{c}$ of 3.8\ifmmode^\circ\else\textdegree\fi{}K is predicted for a singl…
The book is devoted to a systematic description of physical phenomena in ferroelectrics and antiferroelectrics. Serious attention is given to thermodynamic, dynamic and model theories of ferroelectricity, which are set forth in a form understandable to a wide range of readers. Results of experimental studies and their…
The directions of the easy magnetization in the ${\mathrm{Ho}}_{x}{\mathrm{Tb}}_{1\ensuremath{-}x}{\mathrm{Fe}}_{2}$ system have been determined by means of the M\"ossbauer effect in $^{57}\mathrm{Fe}$. If the direction of magnetization of the system is described by an ($x,T$) spin-orientation diagram, it is found tha…
Abstract Copolymers of ethylene with relatively small amount of nine species of α‐olefins, i.e. , propylene, butene‐1, pentene‐1, hexene‐1, octene‐1, dodecene‐1, octadecene‐1, 4‐methylpentene‐1, and 4.6‐dimethylheptene‐1 were prepared with the use of ZIEGLER‐NATTA catalyst and their melt properties, crystalline behavi…
The thermoluminescence spectrum and phosphorescence decays of Harshaw KCl samples gamma irradiated at room temperature have been studied up to 400 degrees C. For the six peaks found, the order of the kinetics of recombination, the pre-exponential factor and the activation energy have been obtained. It has been observe…
For pt. III see ibid, vol. 4, 2611 (1971). Electron-phonon interaction effects in tunnelling junctions are considered in the framework of the formalism proposed in Pt. I (see abstr. A52955 of 1971). This formalism is simplified and then used to study electron-phonon interaction in metal-insulator-metal junctions. The…
NiMnSb and CoMnSb alloys were studied using neutron diffraction, X-ray diffraction, and magnetometric techniques. The distribution of the constituent atoms over the four sublattices was found and at 77 °K the magnetic structure of the alloys was determined. In NiMnSb a magnetic moment of (3.85 ± 0.05) μB was found onl…
Measurements of the high-field transverse electrical and thermal conductivities ${\ensuremath{\sigma}}_{\mathrm{xx}}$ and ${\ensuremath{\kappa}}_{\mathrm{xx}}$ of a high-purity tungsten single crystal are presented for the temperature range 1.5-6 K. The magnetic field dependences of the conductivities conform excellen…
A differential parallel-plate capacitance dilatometer has been used to measure the linear thermal-expansion coefficients of free-standing samples of solid argon (1-35 K), krypton (1-45 K), and xenon (1-105 K). The present data for argon and krypton are systematically larger than existing x-ray lattice-parameter data a…