文献浏览

Referate/Abstracts

Titelei

Impressum/Masthead

Ticker/Ticker

Die nichtlinearen rheologischen Eigenschaften von viskoelastischen Tensidlösungen und ihre quantitative Beschreibung durch das Giesekus Modell / The Nonlinear Rheological Response of Viscoelastic Surfactant Solutions and its Quantitative Description by the Giesekus Model

Zürich ist immer eine Reise wert / Zürich is always worth the trip

Experimentelle Untersuchung von ER-Suspensionen im Squeeze-mode / Experimental Investigation of ER-Suspensions in the Squeeze Mode

Magneto-optical effect in the weak ferromagnetsLaMO3(M= Cr, Mn, and Fe)

It is shown that antiferromagnetic spin order coupled through the spin-orbit interaction with the lattice distortion can lead to a nonvanishing ferromagnetic component of the orbital magnetization and strong optical nonreciprocity in transition-metal perovskite oxides with orthorhombic structure. This magneto-optical…

Effects of Adding Copper(II) Salt to Organosulfur Cathodes for Rechargeable Lithium Batteries

We report the preliminary analysis of a new cathode material and the performance of secondary lithium cells which contain it. The material is comprised of an organosulfur compound, 2,5‐dimercapto‐1,3,4‐thiadiazole (DMcT), doped with a copper(II) salt in a poly(aniline) matrix. Secondary lithium cells which use this ma…

Refined Relationships between Chemical Composition of Dioctahedral Fine-Grained Mica Minerals and Their Infrared Spectra within the OH Stretching Region. Part I: Identification of the OH Stretching Bands

Abstract A large and representative collection of clay-size dioctahedral mica minerals differing in their chemical compositions has been studied by infrared (IR) spectroscopy in the OH stretching vibration region. Decomposition of the IR spectra in the individual OH bands has provided unambiguous identification of the…

Slip energy barriers in aluminium and implications for ductile-brittle behaviour

We consider the ductile-brittle behaviour of aluminium in the framework of the Peierls-model analysis of dislocation emission from a crack tip. To this end, we perform first-principles quantum mechanical calculations for the unstable stacking energy γus of aluminium along the Shockley partial slip route. Our calculati…

Self-diffusion of adatoms, dimers, and vacancies on Cu(100)

We use ab initio static relaxation methods and semi-empirical molecular-dynamics simulations to investigate the energetics and dynamics of the diffusion of adatoms, dimers, and vacancies on Cu(100). It is found that the dynamical energy barriers for diffusion are well approximated by the static, 0 K barriers and that…

Young's Modulus, Flexural Strength, and Fracture of Yttria‐Stabilized Zirconia versus Temperature

The flexural strength and elastic modulus of cubic zirconia that was stabilized with 6.5 mol% yttria was determined in the temperature range of 25°–1500°C in air. Specimens were diamond machined from both hot‐pressed and sintered billets that were prepared from alkoxy‐derived powders. The flexural strength of the hot‐…

Semiempirical Correlation between Optical Band Gap Values of Oxides and the Difference of Electronegativity of the Elements. Its Importance for a Quantitative Use of Photocurrent Spectroscopy in Corrosion Studies

A semiempirical correlation between the optical band gap of binary oxides and the difference of electronegativity between the oxygen and metallic elements (Pauling's extraionic energy) is proposed. In the frame of the proposed correlation an estimate of the repulsive term in the total lattice energy of ionic oxides is…

Exfoliated−Restacked Phase of WS2

A modified method for obtaining large quantities of exfoliated single layers of WS2 is reported. The restacked WS2 obtained from the precipitation of the single layers is metastable with respect to 2H-WS2 with an apparent activation energy of 82.4 kJ/mol, and a conversion temperature of 207 °C at 5 °C/min. Pressed pel…

Thermoplastic nanocomposites filled with wheat straw cellulose whiskers. Part II: Effect of processing and modeling

Abstract The reinforcing effect of cellulose microcrystals, or whiskers, dispersed in a thermoplastic matrix is analyzed. In Part I [ Polym. Compos. , 17, 604 (1996)], the preparation and the characterization of cellulose whiskers obtained from wheat straw were detailed. Composite films were processed by freeze‐drying…

Nonaqueous Electrolytes for Electrochemical Capacitors: Imidazolium Cations and Inorganic Fluorides with Organic Carbonates

Electrolytes based on 1‐ethyl‐3‐methylimidazolium cation ( EMI + ) and either the hexafluorophosphate ( EMIPF 6 ) or tetrafluorborate ( EMIBF 4 ) anion in organic alkyl carbonate solvents have been evaluated for use in electrochemical capacitors The conductivity capacitance, limiting oxidation and reduction potentials…

Mass Spectrometric Identification of Si–O–H( g ) Species from the Reaction of Silica with Water Vapor at Atmospheric Pressure

A high‐pressure sampling mass spectrometer was used to detect the volatile species formed from SiO 2 at temperatures between 1200° and 1400°C in a flowing water vapor/oxygen gas mixture at 1 bar total pressure. The primary vapor species identified was Si(OH) 4 . The fragment ion Si(OH) 3 + was observed in quantities 3…

Oxozirconium Methacrylate Clusters: Zr6(OH)4O4(OMc)12 and Zr4O2(OMc)12 (OMc = Methacrylate)

Abstract The crystalline oxozirconium methacrylate clusters Zr 6 (O‐H) 4 O 4 (OMc) 12 and Zr 4 O 2 (OMc) 12 were obtained by reaction of Zr(O n Pr) 4 with an excess of methacrylic acid and analysed by X‐ray diffraction. The oxide and hydroxide groups are in a μ 3 ‐ bridging mode in both structures, and the methacrylat…

One-Dimensional Thermomechanical Constitutive Relations for Shape Memory Materials

The use of the thermoelastic martensitic transformation and its reverse transformation has recently been proposed and demonstrated for several active control applications. However. the present constitutive models have lacked several important fundamental concepts that are essential for many of the proposed intelligent…