Zur Theorie der dielektrischen Relaxation der amorphen Polymeren

Zusammenfassung In der Arbeit wird im Rahmen der theoretischen Deutung der dielektrischen Eigenschaften der amorphen Polymeren ein einfaches Modell diskutiert, das erstmalig auf zwei Relaxationsgebiete führt. Die berechneten Relaxationsspektren sind zwar gegenüber den experimentellen Gr?\en noch zu schmal, in bezug auf das Frequenz- und Intensit?tsverh?ltnis der beiden Relaxationsgebiete ergeben sich jedoch sinnvolle Werte. Das Modell gehorcht nicht dem Reduktionsverfahren vonTobolsky undFerry, es erm?glicht deshalb prinzipiell eine Deutung der Temperaturabh?ngigkeit des Frequenzverh?ltnisses.     

Ein neues statistisches Segmentmodell zur Deutung der dielektrischen Eigenschaften hochpolymerer Lösungen

Zusammenfassung Es wird ein neues statistisches Segmentmodell angegeben, das zur Deutung der dielektrischen Eigenschaften der Lösungen von Kettenmolekülen mit seitständigen Dipolgruppen herangezogen werden soll.Es wird zunächst die exakte Lösung für das Relaxationsspektrum angegeben. Anschlie\end wird eine Näherungslösung abgeleitet, die einen Vergleich mit den Me\ergebnissen vonBrouckère und Mitarb. gestattet. Dabei zeigt sich eine gute übereinstimmung zwischen Experiment und Theorie.     

Accurate calibration of TXRF using microdroplet samples

TXRF has been applied in combination with VPD to the analysis of trace impurities in the native oxide layer of Si wafer surfaces down to the range of 10(8) atoms. cm(-2). Proper quantification of VPD/TXRF data requires calibration with microdroplet standard reference wafers. The precision of calibration function has been evaluated and found to allow quantification at a high level of 3 sigma confidence with microdroplet standard reference.     

New tools: Expert systems for uncertainty budgets

An important part of quality assurance in any analytical laboratory is the production of comprehensive results integrating uncertainty measurements. Many testing laboratories face the problem that the expenditure required to evaluate small uncertainties (high precision and high accuracy) is often uneconomic. In most cases an uncertainty of high reliability has to be calculated from only a few data (one calibration, few replications, etc.). This problem can be solved by an expert system. To achieve this the analytical procedure has to be structured into a dialouge and divided into parts. The uncertainty has to be calculated for each part of the procedure. Addition of the individual uncertainties results in the combined and expanded uncertainty. During the dialouge the system should advise the analyst how to get an efficient and effective calculation of uncertainty. All calculations, mathematical and statistical procedures have to be surveyable but running the system should not be too time consuming for economic reasons. Within the scope of the EURECA-project initiated by the Eidgenössische Materialprüfungs- und Forschungsanstalt (EMPA), St. Gallen, Switzerland, expert system software is being developed in cooperation with other research institutes and manufacturers of analytical instruments. Using this software it will be possible to calculate the uncertainty for analytical procedures such as titration, atomic emission spectrometry (ICP-OES), atomic absorption spectrometry (AAS) and gas- and liquid chromatography (GC, HPLC).     

An integral representation for decomposable measures of measurable functions

Summary We start with a measurem on a measurable space (,A), decomposable with respect to an Archimedeant-conorm on a real interval [0,M], which generalizes an additive measure. Using the integral introduced by the second author, a Radon-Nikodym type theorem, needed in what follows, is given.The integral naturally leads to a -decomposable measurem on the space of all measurable functions from to [0, 1]. The main result of the present paper is the converse of this, namely that, under natural conditions, any -decomposable measurem on can be represented as an integral of a certain Markov-kernelK. We extend this representation to measures on which have values in a set of distribution functions.These results generalize the work done by the first author in the case of additive measures.     

Synthesis and Structure of Perfluorocongressane

Perfluorocongressane was synthesized using elemental fluorine and characterized by mass spectra, (19)F NMR, and X-ray crystallography.     

Dual-label autoradiographic analysis of human skin fibroblast and myoblast proteins by two-dimensional polyacrylamide gel electrophoresis using immobilised pH gradients in the first dimension

Horizontal two-dimensional polyacrylamide gel electrophoresis with immobilised pH gradients in the first dimension has been applied to the analysis of human skin fibroblast and muscle myoblast total cell proteins. Excellent two-dimensional separations of skin fibroblast proteins were obtained using pH 4-10 immobilised pH gradient gels with a long interelectrode distance (16 cm), but resolution was degraded, particularly of the more acidic proteins, by the use of shorter (10 cm) gels. Improved resolution of acidic and basic proteins was obtained using separate pH 4-7 and pH 7-10 immobilised pH gradient gels respectively in the first dimension. Two-dimensional protein maps of skin fibroblast proteins were visualised both by silver staining and by autoradiography of samples labelled synthetically with [35S]methionine. Horizontal two-dimensional electrophoresis, using pH 4-7 and pH 7-10 immobilised pH gradient gels in the first dimension, was applied to the analysis of protein samples from skin fibroblasts and muscle myoblasts dual-labelled synthetically with [35S]methionine and [75Se]selenomethionine in an attempt to identify sets of proteins specific to each cell type. In addition, two-dimensional maps or protein samples derived from normal individuals and patients with Duchenne muscular dystrophy were compared to search for protein changes associated with the disease state. Although sets of qualitative protein spot differences were observed by visual inspection of the two-dimensional gels, more rigorous qualitative and quantitative analysis of the patterns using a computerised analysis system will be required to obtain the maximum amount of information from these data.     

Riemannsche Arealstrukturen und multiquadratische Formen

It is well known (and rather trivial to prove) that the square F² of a Finsler norm F:TM on a differentiable manifold M is differentiable at the zero section if and only if F is the norm function of a Riemannian metric. However, the corresponding question for a general p-areal on M is far less trivial to settle and leads to interesting algebraic and combinatorial problems concerning multiquadratic forms. For p=2, the results are closely related to known properties of the curvature tensor of a Riemannian metric.     

The Radical Anions of N,N′-Dicyanoquinone Diimines,a New Class of Electron Acceptors

The radical anions of 12 N,N′-dicyanoquinone diimines, a new class of electron acceptors, hace been characterized by their hyperfine data with the use of ESR and ENDOR spectroscopy. The largest coupling constant (0.30–0.45 mT), due to the two ¹⁴N nuclei in the exocyclic positions, gives rise to a conspicuous broadening of the peripheral ESR lines by an incomplete averaging of the hyperfine anisotropy. The most plausible interpretation of the experimental results for the radical anions of N,N′-dicyano- 1,4-benzoquinone diimine ( 1 ) and N,N′-Dicyano-9,10-anthraquinone diimine ( 9 ) is in terms of both ‘syn’- and ‘anti’-configurations contributing to the ESR and ENDOR spectra and having equal proton- and ¹⁴N-coupling constants. The π-spin distribution in the radical anions of N,N′-dicyanoquinone diimines is compared with those in the analogous ions of tetracyanoquinodimethanes and quinones.