Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Double-zeta functions 1 are very useful because of their relative simplicity connected with good accuracy as compared with the Hartree-Fock functions 2 . These two advantages make them an obvious choice even for semiempirical type of calculations. To test the doublezeta function we have calculated one-and two-center i…
The crystal structure of the rubidium salt of an octadecahydroeicosaborate(2-) photoisomer, Rb 2 B 20 H 18 , has been determined by X-ray diffraction vnth a single crystal specimen.The orthorhombic unit cell, space group Pn2 1 a, vnth ~ = 12.334 A, £ = 19.014A, £ = 7.260 A, contains four formula units.The structur.e w…
not available
It was possible to drive plastically blunted cleavage cracks through double cantilever beam specimens of impure MgO monocrystals in a series of small propagations. The forces required to propagate the cracks often defined a fairly constant apparent surface energy and provided an environment‐sensitive measure of toughn…
The crystal structure of ferrites including garnets and their methods of preparation are first reviewed. This is followed by an examination of microwave ferrite devices and their application to actual systems. Sufficient theoretical details as well as an extensive though not exhaustive list of references are included…
By a general theorem connecting the steady-state electrical potential function for the region surrounding a system of long, parallel homogeneous conductors carrying steady currents to the solutions for the electrostatic potential in the given geometry, it is shown that the density of the surface charges on the conduct…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSolvent and temperature effects in the determination of pyrrolizidine alkaloids with 4-(dimethylamino)benzaldehydeJ. B. BingleyCite this: Anal. Chem. 1968, 40, 7, 1166–1167Publication Date (Print):June 1, 1968Publication History Published online1 May 2002Published inissue 1…
Permanent magnets are finding ever-increasing uses as magnet technology develops and materials improve. Permanent magnet materials are evaluated in terms of the geometry and configuration of the application for which they are intended. The origin of the properties of most modern permanent magnet materials is interpret…
Abstract The melt viscosity, the glass transition, and the effect of pressure on these are analyzed for polystyrene on the basis of the Tammann‐Hesse viscosity equation: log η = log A + B /( T − T 0 ). Evidence that the glass transition is an isoviscosity state (log η g ≃ 13) for lower molecular weight fractions ( M &…
Three clay minerals, a kaolinite, an illite and a montmorillonite, were saturated with different cations (Li + , Na + , K + , Mg ++ , Ca ++ , Sr ++ , and Ba ++ ) before equilibration with dilute phosphorus solutions. The phosphorus adsorption data conformed to the Langmuir adsorption isotherm. The relative magnitude o…
Ester cross linkages in cotton cellulose have been investigated for mobility (trans esterification) at elevated temperature. Cotton cellulose polycarboxylates were prepared by reaction of cotton print cloth with polycarboxylic acids having 3-6 carboxyl groups per molecule, at least two of the carboxyl groups being on…
Stacking faults and dislocation dissociations on {011} and {121} planes in body-centred cubic lattices are examined. The effect of stress on the threefold dissociation of screw dislocations on {121} planes is studied in detail. A change in configuration occurs on reversal of stress, as in tension and compression exper…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPotential functions and the bonding in the XCO free radicalsJames S. Shirk and George C. PimentelCite this: J. Am. Chem. Soc. 1968, 90, 13, 3349–3351Publication Date (Print):June 1, 1968Publication History Published online1 May 2002Published inissue 1 June 1968https://pubs.a…
The deformation microstructures associated with aluminium after shock loading and cold rolling at room temperature and at liquid nitrogen temperature are presented and discussed. A high density of point defects is produced by shock loading aluminium and it is observed that vacancy-produced dislocation loops are more n…
Steady-state and time-transient measurements of the decay of oxygen atoms in a cylinder with catalytic walls have been used to determine the diffusion coefficient of atomic oxygen in O2, He, Ar, and Kr. The relative change in atom density as a function of distance (under steady-state conditions) and time (after the at…
Electrical conductivities of binary alkali and thallous silicate glasses have been measured as a function of composition, temperature, and frequency. The best approximation to the activation energy for dc conduction can probably be obtained by extrapolating its frequency dependence to zero frequency, although values o…
Abstract The thermodynamic properties of crystalline and amorphous poly(2,6‐dimethyl‐1,4‐phenylene ether) (PPO Registered trademark of General Electric Company. polymer, General Electric Co.) have been studied calorimetrically between 80 and 570°K. The calculated configurational entropy of this polymer, of similar mag…
Abstract The submicroscopic morphology of uniaxially deformed isotactic polypropylene films has been examined by small‐angle light scattering (SALS), electron microscopy, optical microscopy, small‐angle x‐ray scattering (SAXS), wide‐angle x‐ray diffraction, birefringence, sonic modulus, and density methods. Several ne…
The dyebanding and tattooed patch techniques of estimating wool production were compared in three experiments, and in two of these, mean diameters of wool fibres taken from the tattooed patches and from the dyebands were also determined. There were significant differences at some times of the year between the two esti…
It is shown that a free-volume treatment of the relaxational behavior of a polymer can be extended into the glassy region. A modified form of the WLF equation is derived in which the temperature is replaced by Te, a parameter related to the “frozen” free volume in the glass and defined such that Te = T at equilibrium.…