Standardization of cement. Notes and explanations about the reelaboration of the German Cement Standards DIN 1164; June 1970 edition
Not available
Materials Literature
文献浏览
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。
Bibliografía
xxxx
Identification of phase α —C4AH13 in the accelerated hydratation of a Portland type and clase of clinker
Not available
Structure and Thermomechanical Properties of Partially Stabilized Zirconia in the CaO‐ZrO 2 System
Partially stabilized zirconia (PSZ) ceramics in the system CaO‐ZrO 2 were characterized. The microstructure, as revealed by optical microscopy, consisted of grains of pure ZrO 2 distributed in a matrix of fully stabilized material. Electron microscopy showed that the matrix grains have a complex substructure of 1000‐Å…
Fabrication and properties of microwave lithium ferrites
Lithium ferrites are low-cost materials which are attractive for microwave device applications. For a number of years these materials have been prominent in the computer core industry because of excellent temperature performance and the squareness of their hysteresis loops. Previous attempts at exploiting lithium ferr…
Thermal polymerization of styrene at high conversions and temperatures. An experimental study
Abstract An experimental study of thermal polymerization of styrene in the temperature range 100–200°C and conversion range 0–100% is reported. Conversions, molecular weight averages, and molecular weight distributions were measured. A kinetic model with third‐order initiation gives a satisfactory fit of conversion an…
Pressure-Induced Electronic Changes in Compounds of Iron
We analyze a series of recent experiments in which it has been found that pressure induces changes in charge or spin of iron [i.e., Fe(III) reduces to Fe(II) and in Fe(II) there are spin changes involving either decrease or increase of multiplicity]. In addition to considering the volume difference of the two states a…
Infrared Spectra of Tetrakis(tropolonato) Lanthanide(III) Chelates: Evidence for Crystal Field Effects
The infrared spectra of the fourteen complex ions [LnT4]- (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb, Lu; T = tropolonate anion) have been determined. One band within the range 480 to 510 cm-1 is found to be significantly metal-sensitive and is accordingly assigned to the metal-oxygen stretching frequenc…
ON THE CORRECTNESS OF BOUNDARY VALUE PROBLEMS IN THE MECHANICS OF CONTINUOUS MEDIA
The paper considers the properties of vector analogs of the Sobolev spaces, , which appear in the study of various models of continuous media. Korn's inequality, proved in the paper, makes it possible to reduce the problem of compactness of the imbedding operators in these spaces to the scalar case and, consequently,…
Photoelectron spectra of carbonyl halides and related compounds
Abstract Photoelectron spectra in the region 6 to 21 eV have been measured for carbonyl halides (fluoride, chloride and bromide) and carbonyl cyanide. In a number of cases, vibrational structure coupled with the ionization process has been resolved and correlated with the known frequencies of the parent molecule. Ioni…
Synthèse et caractérisation de quelques poly‐ε‐caprolactones
Abstract Pour polymériser l'ε‐caprolactone, on a opéré en solution dans le benzène, le toluène ou le tétrahydrofuranne, sous atmosphère inerte, à 55°C, avec le méthanolate ou l'éthanolate de sodium comme amorceur de polymérisation. Les échantillons ont été fractionnés à 34°C par addition d'isooctane à leur solution da…
A study of intramolecular reaction during linear polyurethane formation
Abstract The numbers of rings formed in the reactions of hexamethylene diisocyanate with two polyethylene glycols have been determined as a function of dilution and ratios of reactants. In this work the cryoscopic apparatus developed in the preceding paper has been utilised. It is found that more rings are formed (a)…
Biosynthesis of cardenolides, bufadienolides and steroid sapogenins
Abstract It has been known for several years that pregnenolone is the biogenetic precursor of hormones of the adrenal cortex and of progesterone in the animal kingdom. The route to the androgenous and oestrogenous hormones also goes via this intermediate. However, in the plant kingdom it was only later that the role o…
Coating, Mechanical Constraints, and Pressure Effects on Electromigration
The effect of the mechanical constraints exerted by coatings upon electromigration in thin films is evaluated on the basis of known pressure effects upon diffusion.
Use of an Electron Flood Gun to Reduce Surface Charging in X-Ray Photoelectron Spectroscopy
A flood-gun arrangement is shown to be useful in alleviating the sample-charging problem in x-ray photoelectron spectroscopy. Modest currents (<10−8 A) of low-energy electrons result in the shifting of photoelectron energy peaks to the proper positions and the reduction of the peak widths.
Dielectric Properties of Some Nematic Liquid Crystals with Strong Positive Dielectric Anisotropy
Measurements of the temperature dependence of the dielectric constants ε‖, ε⊥, and εis of some nematic liquid crystals with strong positive dielectric anisotropy (ε‖ ≃ 3 ε ⊥) are reported. The low frequency dispersion regions of the dielectric constants parallel to the unique axes were measured to be in the range from…
Piezoelectricity
It is shown that piezoelectric effects can be easily derived from bulk properties and are expressible in terms of linear and quadrupole moments of variations in charge density induced by atomic displacements. The linear-moment contribution is determined by optic macroscopic effective charges and internal-strain parame…
Luminescence Quantum Efficiency of Gd and Tb in Borate Glasses and the Mechanism of Energy Transfer between Them
A study of the quantum efficiency of the luminescence of gadolinium and terbium in borate glasses and of the energy transfer between these ions is presented. From our measurements of fluorescence decay times, absorption, fluorescence, and excitation spectra, we calculated the fluorescence quantum yield of the 6P7/2 ga…
Optical intensities of trivalent erbium in various host lattices
The electric-dipole intensities of Er 3+ spectra in six different host lattices have been calculated on the basis of Judd-Ofelt theory, which takes into account the effect of a mixing of higher configurations of opposite parity into the f n configuration through odd parity spherical harmonics in the ligand field inter…
The Biosynthesis of Collagen
Micro-Heterogeneity in the Biosynthesis of CollagenDetailed analyses of the structure of the polypeptide chains of collagen has revealed a "micro-heterogeneity" of the amino acid sequences. Sequencing of the first 50 amino acid residues from the NH2-terminal end of the α1 chain of rat skin and tendon collagen indicate…