Materials Literature
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The common tetragonal form of KH 2 PO 4 undergoes two high-temperature transformations that have been studied extensively by vibrational spectroscopy. But, because these changes are strikingly heterogeneous, the previously reported spectra, averages over polycrystalline and single crystal domains, have remained ill-de…
Das kovalente Verankern von 1,4-Dimethyl-1,4,7-triazacyclononan an Kieselgel ist der erste Schritt bei der Herstellung eines heterogenisierten Mn-Katalysators. Wird H2O2 als Oxidationsmittel eingesetzt, so kann das Material die vicinale cis-Dihydroxylierung von disubstituierten Olefinen katalysieren, wie hier schemati…
Durch Umsetzung der Sesquioxide M2O3 der schweren Lanthanoide (M = Dy–Lu) mit SiO2 und CsCl als Flußmittel (molares Verhältnis 1 : 1 : 4; 700 °C, 7 d) in evakuierten Quarzglasampullen läßt sich die Reihe der Lanthanid-Oxidsilicate M2O[SiO4] im A-Typ (bisher bekannt mit M = La–Tb) bis hin zum Lutetium erweitern. Wichti…
Rare earth ions are widely used in lasers and amplifiers. Depending on the device, there are different demands on the properties of the active ions and on the host glass. Thus, an extensive characterization and comparison of both host matrix properties and spectroscopic properties of rare earth ions for various glass…
Flexure creep and creep‐recovery behavior were investigated for monolithic Al 2 O 3 and 10‐vol%‐SiC‐particle‐reinforced Al 2 O 3 ‐matrix composites in an air atmosphere at temperatures of 1160°‐1400°C. Two types of SiC particles were used: one has an average size of 2.7 µm and has an amount of SiO 2 impurities per uni…
Lead alloys, such as lead‐calcium‐tin and lead‐silver, are the primary insoluble anodes used in the electrowinning of metals. While some difficulties are encountered in their use, there is no obvious replacement that is economically and technically competitive. Two of the specific problems with lead include decreased…
Thermal stresses leading to fracture during rapid freezing of a biomaterial are studied using potato tissues as an example. The thermal model includes the gradual freezing of the tissue, that is, the presence of a mushy zone. Water in the biomaterial expands almost 9% during freezing and develops transient stresses wh…
Abstract Detailed analysis of the crystal structures of minerals and inorganic compounds containing oxocentred [OCu 4 ] tetrahedra reveals the following principle for relationships between oxocentred tetrahedra and tetrahedral oxyanions (T n + O 4 ) −(8− n ) with T = S 6+ or V 5+ , or triangular pyramidal oxyanions (S…
Raman excitation profiles of several normal vibrations of 2- and 4-benzylpyridine were measured and analyzed. On the basis of the results, possible structures and other interesting properties of the two molecules in the excited electronic states are discussed. Normal mode characteristics are also described. It seems l…
Models of thermally activated linear and high-field nonlinear conductivity of a dielectric phase in granular metals (nanocomposites), i.e., aggregates of small metallic grains in a dielectric matrix, have been suggested. Given a sufficiently large spread of grain sizes, the temperature dependence of the nanocomposite…
I. Introduction 2 a. Bacterial Endospores 2 b.Terbium Dipicolinate 4 II.Bacterial Endospore Detection Method 10 III.Interferents 13 a.Reduced Emission Intensity of Terbium Dipicolinate 14 b.Overlapping Emission Spectra of Interferent 15 c.Other Terbium Complexes 16 IV.Conclusions 18 V.
The synthesis, spectroscopic characterization, and electrochemical study of eleven heteroleptic and their corresponding homoleptic lanthanide sandwiches are reported. Studies in solution have been carried out in solvents of different basicity, in order to elucidate the equilibrium between the protonated and deprotonat…
A new objective method for evaluating fabric wrinkles involves a 3-D projecting grid technique based on image processing. The uniform grid is projected on the AATCC replica surface, and then the gridded image of each replica is captured by the image capturing system. Noise reduction and extraction of the horizontal fe…
Anisotropic strain broadening in X-ray or neutron powder diffraction can cause severe difficulties in whole powder-pattern fitting and Rietveld structure refinement. Several phenomenological models have been proposed to deal with this problem. These, however, lack physically sound bases. In the present work the disloc…
The compound β-LaSc3(BO3)4 crystallizes in the rhombohedral with space group R32 and cell parameters a=9.819(3), c=7.987(1) Å, Z=3, V=666.5(3) Å3, Dc=3.80 g/cm3, λ(MoKβ)=0.71067 Å, F(000)=708, final R=0.053. RW=0.072 for 512 observed reflection with I≥3σ(I). The La atoms, Sc atoms and B atoms occupy trigonal prisms, o…
Cyano groups have been introduced into alkoxytriphenylene-based mesogens by bromination followed by treatment with copper(I) cyanide. The introduction of cyano substitutents enhances the mesophases ranges.
This article considers the ways in which humankind has made use of charcoal down the ages, as a fuel, as an artistic material, and as an adsorbent. The scientific study of charcoal's structure is discussed, and the role played by Rosalind Franklin highlighted. Current ideas on the structure of charcoal are summarised.
Clay mineralogical X-ray diffraction and electron microprobe studies have been carried out on separated <2 μm fractions from cutting and core material from three wells in the Chipilapa geothermal system in El Salvador. The data indicate that the smectite to chlorite transition is prevalent, but a secondary smectite…
This paper presents a new algorithm to remove the Cu K α 2 profile in X-ray powder diffraction patterns. Previous algorithms for α 2 elimination can be divided into two categories. The first category assumes the shape identity of the α 1 and α 2 components. The second category uses parameters by fitting experimental d…
Poly(3-hydroxyalkanoates) (PHAs) are biodegradable thermoplastics which are accumulated by many bacterial species in the form of intracellular granules and which are thought to serve as reserves of carbon and energy. Pseudomonas putida accumulates a polyester, composed of medium-side-chain 3-hydroxyalkanoic acids, whi…