bluuebunny/crossref_metadata_2025 huggingface dataset:
Parental narratives on genetic testing for children with hearing loss: A qualitative inquiry
Authors: Steinberg Annie G. , Kaimal Girija , Bain Lisa , Krantz Ian , Li Yuelin
Published: May 2007

Studies on parental attitudes towards genetic testing for hearing loss have surveyed parents of newborns with hearing loss as well as deaf and hearing adults. Although research indicates that most people have positive attitudes about genetic testing, few studies examine parental narratives about the personal implications of genetic hearing loss in their children. In this qualitative study we conducted semi‐structured interviews with 24 parents whose children had been referred for, but had not yet undergone, genetic testing for hearing loss. The parents were recruited to represent a diverse range of racial, ethnic, and socioeconomic groups. Genetics and genetic testing for hearing loss were poorly understood topics. Beyond supporting or opposing genetic testing for hearing loss, parents' construction of meaning included struggles to locate responsibility (metaphysical attributions, ascription or alleviation of parental responsibility) as well as questions about the usefulness and implications of genetic testing for hearing loss in their child. Based on the themes that emerged from this study, we highlight the need for healthcare professionals to be aware and sensitized to parents' narratives, personal meanings and socio‐cultural context when referring them for genetic testing for hearing loss. Listening attentively to parental narratives can help minimize prevailing misconceptions among parents and enable appropriate medical care and education. © 2007 Wiley‐Liss, Inc.
A case for genetics education: Collaborating with speech‐language pathologists and audiologists
Authors: Harvey Erin K. , Stanton Susan , Garrett Jennifer , Neils‐Strunjas J. , Warren Nancy Steinberg
Published: May 2007

Because speech‐language pathologists (SLPs) and audiologists (AUDs) are among the first referrals for parents of children exhibiting feeding, speech, language, hearing, and balance difficulties, it is important for SLP and AUD professionals to recognize genetic causes of and contributions to complex and Mendelian communication disorders. We review genetics in the curricula of speech‐language pathology and audiology programs and obstacles to its integration throughout curricula. We present suggestions about how SLPs and AUDs can aid in diagnosis and contribute their clinical expertise in characterizing phenotypes, followed with a review of a new genetics‐education website developed by the National Coalition for Health Professional Education in Genetics (NCHPEG), the University of Cincinnati, and the National Society of Genetic Counselors. The need to integrate genetics content into curricula and continuing education across disciplines is clear, as is the need for and benefit of multidisciplinary collaboration in patient care. The NCHPEG site for speech‐language pathology and audiology begins to address those needs and may serve as a practical model for future multidisciplinary collaborations between genetics professionals and other health professions. © 2007 Wiley‐Liss, Inc.
A General Variational Criterion for Chemically Active Continuous Media
Authors: Lebon G. J. , Lambermont J. H.
Published: May 2007

A variational criterion describing the nonstationary flow of a mixture of chemically active compressible fluid components is presented. The problem considered constitutes a generalization of previous works [1, 2] of the authors.

It is shown that the Euler‐Lagrange equations corresponding to arbitrary variations of the chemical potentials, the velocity components, and the temperature are identical to the laws of conservation of mass of each component, of momentum, and of entropy, respectively.
One‐Particle Distribution Functions and Thermodynamics of Crystals with Many‐Body Forces. III. Perturbation Theory
Authors: Zubov V. I.
Published: May 2007

The theory of crystalline state described in preceding papers is considered as a zeroth‐order approximation. Statistical perturbation theory is used for the purpose of improving this approximation. The second‐order corrections to the Helmholtz free energy and thermodynamic properties of strongly anharmonic crystals are derived. The properties of solid Ar, Kr, and Xe are calculated using various pair‐potential functions in conjunction with the AXILROD‐TELLER‐MUTO three‐body potential. The first quantum corrections are taken into account in the quasi‐classical approximation. The result of computations are compared with the experimental data.
Widths of Decays of Intermediate Bosons of One‐Particle Exchange Models and Cross‐Section of Leptonic Weak Processes at Resonance
Authors: Guliyev N. A. , Jafarov I. G. , Khalil‐Zade F. T.
Published: May 2007

The widths of the intermediate bosons introduced in one‐particle exchange models of weak interactions are found. The cross‐sections of the leptonic processes are calculated and analyzed in the region of resonance.
Über die Existenz von Entropiefunktionen in Nichtgleichgewichtszuständen chemischer Reaktionssysteme II
Authors: West G.
Published: May 2007

Für solche chemischen Reaktionssysteme, welche unter Isolation von der Umwelt ins Gleichgewicht streben, kann die Existenz (mehrerer) Nichtgleichgewichtsentropiefunktionen mit Hilfe der Umkehrsätze zu den Ljapunovschen Sätzen bewiesen werden. Ein Vergleich mit der Thermodynamik irreversibler Prozesse zeigt, daß die Symmetrie der Onsagermatrix eine starke Einschränkung der nichtlinearen Reaktionskinetik zur Folge hat. Die Gültigkeit des Prinzips von Braun und Le Chatelier ist eine notwendige Voraussetzung dafür, daß es unter den Nichtgleichgewichtsentropiefunktionen eine gibt, welche die Potentialeigenschaft hat.
Calculation of the Hyperfinestructure and gJ‐Values of the 3d 4s 4p‐Configuration of Scandium
Authors: Siefart E.
Published: May 2007

Wave functions for the 3d 4s 4p, 3d2 4p and 4s2 4p configurations of ScI are calculated, taking into account departures from SL‐coupling and configuration interaction and on fitting the radial integrals to the experimental fine structure energies. Using these wave functions gJ‐values are derived.

The intermediate coupled hfs matrix elements of the 3d 4s 4p configuration are reduced to the unknown electron coupling constants as, ap and ad and calculated on estimating these constants from the spin‐orbit coupling constants and fitting them to some experimental A‐values.

By this way the absolute phases of the experimental A((1P)2D)‐ and A((1P)2F)‐values are obtained.

Good agreement between calculated and most experimental data has been achieved.
On Caustics and Singularities in General Relativity
Authors: v. Borzeszkowski H.‐H. , Paul H.
Published: May 2007

Comparing gravitational converging effects with self‐focussing and lense effects in ordinary optics, we consider some physical properties of caustics in General Relativity. The resulting relations between geometrical and physical features of caustics are used to discuss the power asymptotes of homogeneous cosmological models in more detail.
Saturated Multi‐Photon‐Absorption of a Nonmonochromatic Quantized Field
Authors: Mohr Ulrike
Published: May 2007

By extending a previously developed method [9] to the case of saturation, the interaction of a nonmonochromatic light beam with a saturable m‐photon‐absorber (m = 1, 2,…) is theoretically investigated for frequency widths of the incident light being small compared to the bandwidth of the absorber. It turns out that by averaging the exact Heisenberg equation of motion of the operator for the slowly varying field amplitude with respect to the atomic relaxation time and by taking the expectation value over the absorbing atomic system a reduced single‐mode equation can be derived, which refers to a mode volume precisely defined in physical terms. The resulting reduced Heisenberg equation of motion for the radiation field is compared to the single‐mode density matrix equation following from the method of SCULLY and LAMB. For ideal laser light and for chaotic light it is used to study the change of photon statistics in dependence on the degree of saturation and on the ratio of inhomogeneous and homogeneous linewidth.
Resonances and Fluctuations in Nuclear Reaction Cross Sections
Authors: Rotter I.
Published: May 2007

On the basis of the continuum shell model, an expression for the S‐matrix is derived. The external mixing between shape resonances and resonance states of complicated nuclear structure is investigated. It is shown that the doorway properties of the shape resonances may lead to an l‐dependent transparency of the optical potential and, consequently, to an energy dependence of large back angle scattering if the unitarity of the S‐matrix is taken into account.
Negative Zeitentwicklung bei der kernmagnetischen Resonanz in Flüssigkristallen
Authors: Schmiedel H. , Hillner B. , Grande S.
Published: May 2007

In orientierten smektischen Flüssigkristallen ist es möglich, ohne Anwendung zusätzlicher Hochfrequenzimpulse durch eine sprunghafte mechanische Drehung der Probe ein magisches Echo der kernmagnetischen Protonenresonanz zu erzeugen. Dieses neuartige Zeitumkehrexperiment wird am Beispiel des NPOB beschrieben und im Zusammenhang mit dem Spintemperaturkonzept diskutiert.
Ionisierungspotentiale von Halbleiterkristallen und Abschätzung von Energiesprüngen an Heteroübergängen
Authors: Unger K. , Neumann H.
Published: May 2007

Ausgehend von lokalen empirischen Pseudopotentialen wird die Energie des oberen Valenzbandrandes bezogen auf das mittlere effektive Einelektronenpotential berechnet, um Ionisierungspotentiale für Si, Ge und neun III‐V‐Verbindungen zu bestimmen. Hierfür wird das auf das Vakuumniveau bezogene mittlere Einelektronenpotential unter Einschluß von Austausch und Korrelation in einem Bindungsladungsmodell ermittelt. Die Ergebnisse stimmen gut mit den experimentellen Werten überein, wenn zur Anpassung der berechneten Bandstrukturen nicht nur optische, sondern auch röntgenspektroskopische und Photoemissionsdaten herangezogen werden. Zum Vergleich werden auch Experimente an Heteroübergängen herangezogen, die Aufschlüsse über die auftretenden Energiesprünge liefern.
Landau‐Theorie zum Phasenübergang isotrop flüssig‐nematisch bei Flüssigkristallen
Authors: Kühnel A. , Schiele K. , Trimper S.
Published: May 2007

Im Rahmen der Landau‐Theorie wird das statische Verhalten am Phasenübergang isotrop flüssig‐nematisch berechnet. Zusätzlich zum üblichen Ordnungsparameter für die Orientierung der Rümpfe werden noch ein oder mehr Ordnungsparameter für die Orientierung der Ketten eingeführt, die miteinander verkoppelt sind. Die Temperaturabhängigkeit der Ordnungsparameter und die spezifische Wärme in der Nähe des Phasenübergangs werden erhalten und mit verschiedenen experimentellen Ergebnissen verglichen.
Über die Ankopplung des Gravitationsfeldes in der Quantenfeldtheorie
Authors: Kreisel Eckhard
Published: May 2007

Es werden Argumente dafür gegeben, daß die Ankopplung der Gravitation in der Quantenfeldtheorie zu verschiedenen Hilberträumen in den Punkten der Mannigfaltigkeit führt. Die Gleichung für die Zustände im Heisenberg‐Bild wird durch eine Vorschrift für den Paralleltransport von Zuständen ersetzt. Es wird ein Zusammenhang zwischen der Messung von vollständigen Observablensystemen an verschiedenen Orten und der Parallelität von Zuständen hergestellt.
Energy Levels of Doubly Excited States in Argon
Authors: El‐Sherbini Th. M. , Allam S. H.
Published: May 2007

Term energies of doubly excited states in argon and argon ions have been determined using single‐configuration Hartree‐Fock calculation.

The energies calculated for KL3s3p6nl and KL3s63p4nln1 states of Ar show a fairly good agreement with the experimental results obtained by various techniques. However, for Ar+, Ar2+, Ar2+ and Ar3+ states there are no experimental data available in the literature for comparison.
Synchronisationseffekte in einer linearen Anordnung aus N Josephson‐Verbindungen
Authors: Krech W.
Published: May 2007

Im Rahmen des RSJ‐Modells untersuchen wir die Synchronisation der Oszillationen in einer linearen. Anordnung von N identischen Josephsonverbinungen, die durch einen elektromagnetischen Resonator geshuntet sind. Mit Hilfe einer adiabatischen Approximation erster Ordnung in dem Parameter Ic/I werden verkürzte Gleichungen für die langsam variierenden Phasen hergeleitet. Diese Gleichungen gestatten die detaillierte Untersuchung aller stationären Zustände des Systems. Stabil erweisen sich nur der kohärente Zustand im induktiven Regime und der strahlungslose Zustand im kapazitiven Regime. Unter Einbeziehung von Rauscheffekten wird das Ordnungsparameterkonzept des Resonatorstroms für den Fall N ≫ 1 diskutiert.
Quantum Statistics of Multimode Optical Bistability with Trilinear interaction
Authors: Germey K. , Schütte F.‐J. , Tiebel R. , Worlitzer K.
Published: May 2007

An externally driven light mode in a ring cavity may show multistable behaviour if linear losses and dispersive nonlinear coupling compete with each other. The paper considers the trilinear (sum frequency) system with two externally driven modes which shows bistability simultaneously in these two modes. It is described in a fully quantum manner. The master equation and the Fokker‐Planck equation for the Glanmber‐Sudarshan quasi‐probalbility are deduced with appropriate consideration of fluctuations. A closed steady solution of the Fokker‐Planck equation is given for one mode only under strong restrictive assumptions.
Nonequilibrium Sources of Hydrodynamic Fluctuations Mutual Influence of Hydrodynamic Motion and Nonequilibrium Fluctuations on the Kinetic Coefficients
Authors: Klimontovich Yu. L.
Published: May 2007

From generalized expressions for the entropy production the kinetic coefficients in the hydrodynamic equations are determined taking into account the mutual influence of the hydrodynamic motion and the fluctuations. Nonlinear effective and turbulent kinetic coefficients are obtained. The usefulness of the introduced coefficients is demonstrated for boundary layer and tube flows.
Thermodynamic Functions of Nonideal Alkali Plasmas
Authors: Richert W. , Insepov S. A. , Ebeling W.
Published: May 2007

The thermodynamic functions are analyzed on the basis of the present theoretical knowledge. Padé approximations are constructed which have the correct limiting behaviour: Debye law with quantum corrections in the high temperature limit, Gell‐Mann‐Brueckner law and Madelung law in the low‐temperature limit. The region of partial ionization (bound state valley in the n‐T‐plane) is studied by using the mass action law.
Rudolf Clausius. Ein Versuch, ihn zu verstehen
Authors: Schöpf Hans‐Georg
Published: May 2007

Es wird dargelegt, daß Clausius' Originalarbeiten über die Begründung des zweiten Hauptsatzes schwerlich vom Standpunkt konventioneller Lehrbücher verstanden werden können. Vielmehr erweist sich eine mit einem quasi‐ökonomischen Modell arbeitende Denkweise als Schlüssel zum Verständnis.
Ladungsträgerstreuung an polaren Grenzflächenphononen im 2‐dimensionalen Elektronengas einer Halbleitergrenzfläche: Anwendung auf die Inversionsschicht eines MOS‐FET
Authors: Bechstedt F. , Enderlein R.
Published: May 2007

Die Ladungsträger des 2‐dimensionalen Elektronengases einer Halbleitergrenzfläche unterliegen einer zusätzlichen Streuung an polaren Grenzflächenphononen. Das Energiespektrum dieser Phononen und die Raten für die Streuung an ihnen werden in der vorliegenden Arbeit auf einer einheitlichen Grundlage – der Selbstenergie des mit dem Gitter polar wechselwirkenden Elektronengases – berechnet. Für die Inversionsschicht eines MOS‐FET erweist sich die Streuung an den polaren Grenzflächenphononen des SiO2Si‐Übergangs bei hinreichend hohen Ladungsträgerenergien bzw.‐konzentrationen als effektiver Konkurrenzprozeß zu den bisher in der Literatur ausschließlich diskutierten Streuprozessen. Die Ergebnisse werden mit experimentellen Beweglichkeiten für den n‐Kanal eines MOS‐FET verglichen.
Theoretical Studies of the Configuration and Association Energies of Point Defect Aggregates in Alkali Halide Crystals
Authors: Berg G. , Fröhlich F. , Pippel A.
Published: May 2007

The aggregation of dipoles consisting of a divalent metal impurity and a cation vacancy in alkali halide crystals is determined mainly by the association energy connected with the formation of the special types of aggregates. It is shown that also larger aggregates (complexes of four and more dipoles) are important to characterize the equilibrium state. Therefore a simple computational method will be presented to estimate atomistically the association energy of such aggregates. A comparison with results from the literature valid for little aggregates (mainly dimers and trimers) confirms the applicability of the proposed procedure.
The Role of “Rotational Freezing” in the Polarisation‐Dependent Two‐Photon Excitation of Triply Degenerate Vibrations in Spherical‐Top‐Molecules
Authors: Ritze H.‐H.
Published: May 2007

Under certain circumstances at low rotational temperatures the multiphoton excitation probabilities of vibrational‐rotational levels in high‐symmetric molecules do not depend on the rotational quantum numbers J and M of the initially populated levels. Then the rotation of the molecule as a whole is “frozen”. This has the consequence that during the absorption process the photon spin is not transferred to the molecular rotation but to the molecular vibration. In more detail the two‐photon A1g(v = 0) → A1g(v = 2) transition in SF6 at 944.5 cm−1 is theoretically studied: If the “average lifetime” in the intermediate (v = 1)‐level is small compared with the effective molecular rotation period the considered transition is forbidden for circularly polarised light. Further the excitation process of the Eg(v = 2) and F2g(v = 2) vibrational levels is investigated; it is discussed under which conditions it is not necessary to consider the rotational degrees of freedom for a calculation of transition dipole moments.
Kovariantes Variationsprinzip in der Gravitationstheorie
Authors: Burghardt R.
Published: May 2007

Die Gravitationstheorie im Lorentzraum von H.‐J. Treder wird ergänzt durch ein koordinateninvariantes Variationsprinzip.
Entropy Decrease during Excitation of Sustained Oscillations
Authors: Engel‐Herbert H. , Schumann M.
Published: May 2007

The behaviour of the entropy is studied during a nonequilibrium phase transition. It is shown that for the generation of sustained oscillations the entropy decreases monotonously if the average oscillator energy remains fixed. This result is valid both for hard and soft excitation of oscillations.
Electric Dipole Oscillator Strengths and Radiative Lifetimes in the Boron Isoelectronic Sequence
Authors: El‐Sherbini Th. M. , Farrag A. A. , Mansour H. M. , Rahman A. A.
Published: May 2007

Oscillator strengths for the 2s2ns(2S) −2s2mp(2P), (n = 3–6, m = 2–6) and 2s2np(2P) −2s2md(2D), (n = 4–6, m = 3–5) transitions in B I sequence are calculated in LS‐coupling scheme. The Coulomb approximation is used in calculating the radial part of the wave functions, while the angular part is determined using the Racah technique. Lifetimes of the ns(2S) and np(2P), (n = 3–6) excited states are evaluated and compared with previous results from beamfoil experiments.
On the Theory of Gravitational Field in Finsler Spaces
Authors: Ikeda Satoshi
Published: May 2007

Some structural considerations are made on the Finslerian gravitational field: A Finslerian metrical structure such as gλχ(x, y) = γλχ(x) + hλχ(x, y) is proposed, where γλχ denotes the Riemann metric of Einstein's gravitational field, while hλχ the Finsler metric induced by the Riemann metric hij(y) of the internal field; The intrinsic behaviour of the internal variable y, which is expressed as ȳi = K(x, y) yj in the internal field, is grasped by the Finslerian parallelism δyi (=0), which is reflected in the spatial structure of the external gravitational field by the mapping relation δyχ = e(x) δyi. The whole metrical Finsler connection D for gλχ(i.e., Dgλχ = 0) is determined by taking account of the intrinsic behaviour δyχ.
Photodetachment of Electrons Compounded to Excited Hydrogen Atoms as Source of Absorption Features in Magnetic Stars?
Authors: Oetken L.
Published: May 2007

Scattering of thermal electrons at excited hydrogen atoms forms resonances, from which absorption features may arise, if the resonances donot decay by electron emission before; these absorption features agree in wavelengths with those observed in normal early type stars (Teff ∼ 104 K) and predominantly in magnetic stars. It is shown that the conditions for the formation of the resonances, the quasistable states of H−, are just most convenient for the stars in question.
Oscillations in the Determination of Renyi Dimension
Authors: Thümmel Ottfried
Published: May 2007

To describe the degree of chaos of a strange attractor created by a nonlinear map, GRASSBERGER [1] revived Renyi Dimension Dq which is a common generalization of both metric capacity D0 and information dimension D1. But often, the numerical determination of Dq is complicated by an oscillating effect first investigated by BADII and PUOLITI [5] for a dimension similar to D0. This effect is studied in the present paper. We consider the conditions for the appearance of oscillations and the dependence on q, and we give some numerical examples.
Dependence of the Three‐Nucleon Binding Energy on Some Different Effects
Authors: Osman Ahmed , Ramadan S.
Published: May 2007

The bound state of three‐nucleon system is studied as a three‐body problem which is solved following the different approaches of the Faddeev formalism as well as the unitary pole approximation. The three‐body problem is reduced to a set of coupled integral equations by using separable approximations. Numerical calculations are carried out for the resulting integral equations and the separable expansion. In the present work, we calculate the ground‐state binding energy of the bound three‐nucleon system 3H. The main interest of the present work is to investigate the sensitivity of the three‐nucleon binding energy to different effects. For this reason, we study the dependence of this energy on different forms of local and separable nucleon‐nucleon potentials, the effective range of the nucleon‐nucleon interaction, and on the percent of the D state in the deuteron wave function. Also we test the sensitivity of the three‐nucleon binding energy to the considered number of terms from the separable expansion.
Einstein's Materialism and Modern Tests of Quantum Mechanics
Authors: Vigier J. P.
Published: May 2007

After a presentation of Einstein's and Bohr's antagonistic point of view on the interpretation of Quantum Mechanics an illustration of their conflicting positions in the particular case of Young's double slit experiment is presented. It is then shown that in their most recent form (i. e. time dependent neutron interferometry) these experiments suggest (if one accepts absolute energymomentum conservation in all individual microprocesses) that Einstein was right in the Bohr‐Einstein controversy.
Modellierung des Energieaustausches in den Gleichungen des turbulenten Spannungstensors
Authors: Szablewski W.
Published: May 2007

Aus der Ähnlichkeitsstruktur der Reynoldsspannungen in homogener Scherströmung wird die Formulierung des Energieaustausches hergeleitet.
Stochastic Quantization of Einstein‐Cartan Gravitational Theory
Authors: Ivanenko D. , Budylin S. , Pronin P.
Published: May 2007

We apply the stochastic quantization method to Einstein‐Cartan gravitational theory. The stochastic propagators are calculated and the cooperation of modes in such a theory is investigated. It was shown that in equilibrium limit our result is equivalent to the propagator for the symmetric part of tetrads.
Purely Affine Theories
Authors: Liebscher Dierck‐Ekkerhard
Published: May 2007

The problems of constructing purely affine theories for non‐gravitational fields are demonstrated and compared with these of unitary affine theories and formal mechanics.
Entropy of a Two‐phase Mixture
Authors: Schulz H. , Reinhardt H. , Kämpfer B.
Published: May 2007

The isentropic expansion of a blob of nuclear matter towards the two‐phase instability region is studied by considering two extreme conditions: the instantaneous development of the phase transition and the spinodal decomposition. We show that the experimentally observed entropy values of light clusters give evidence for the onset of a liquid‐gas phase transition in heavy ion and proton induced reactions, but to be more conclusive the disassembly of relatively cold nuclear systems has experimentally to be investigated in more detail.
Sum Rules in the Quark Model
Authors: Abbas Afsar
Published: May 2007

With the help of various sum rules we look into the spin‐isospin excitations in nuclei within a framework of the quark model. The effect of Pauli correlations is explicitly taken care of. In agreement with the experiments we find negligible amount of M1 strength in heavy nuclei. This is explained in terms of the Fermi gas model.
Translation Gauge Fields and Space‐Time Dislocations
Authors: Sardanashvily G. , Gogberashvily M.
Published: May 2007

Gauge fields of Poincaré translations define particular nongravitation structure on a space‐time, which can be treated as sui generis space‐time dislocations. Their source is the canonical energy‐momentum tensor of matter, and these dislocations can introduce some corrections to standard values of gravitation effects, e. g. the Yukawa type corrections to the Newtonian gravitation potential.
Definition of the Degree of Order in Selforganization Processes
Authors: Klimontovich Yu. L. , Bonitz M.
Published: May 2007

Selforganization processes controlled by two pumping parameters are studied. The question of thermodynamic equilibrium in nonlinear pumped systems is investigated. Using the entropy statement formulated in a recent paper the degree of order of steady states is defined. It is shown that those systems can be optimated following various principles. For illustration, selfoscillations of nonlinear oscillators with two pumping parameters are studied.
Generalized Heat Kernel Method with Local Mass Scale
Authors: Reinhardt H.
Published: May 2007

A generalized heat kernel method which includes space‐time dependent scalar fields as mass scale already in zero order is presented. The approach is illustrated by calculating the vacuum polarization of a coupled meson‐fermion theory exhibiting soliton type of solutions.
Rearrangement Collisions between Four Identical Particles as a Four‐Body Problem
Authors: Osman Ahmed
Published: May 2007

Nuclear reactions between composite particles with rearrangement processes are considered. The cluster model is used in describing the structure of the nuclei. With this structure we have in the initial channel as well as in the final channel, four interacting particles. These reactions are studied as a four‐body problem. The scattering amplitudes are approximated by using a separable expansion for the separable potential model. The four‐body equations are reduced to integral equations in the form of exact effective two‐particle Lippmann‐Schwinger equations. These equations are solved by standard methods in a form suitable for numerical calculations. The present four‐body treatment is applied calculating the differential cross‐sections for different scattering and transfer nuclear reactions. Distorted wave Born approximation calculations are used in calculating the angular distributions. The present theoretical calculations are in good agreement with the experimental angular distributions.
Pade‐Approximants for the Electron Gas and for Symmetrical Plasmas
Authors: Ebeling W. , Lehmann H.
Published: May 2007

The range of validity for several Pade‐formulae for thermodynamic functions is checked in comparison with most recently available numerical data. Landscapes of maximum deviation are plotted. Application to symmetrical electron‐positron and electron‐hole plasmas is performed. An evaluation of the critical data for the droplet transition in semiconductors is given.
The Feynman integrand for the perturbed harmonic oscillator as a Hida distribution
Authors: Cunha Mário , Drumond Custódia , Leukert Peter , Silva José Luís , Westerkamp Werner
Published: May 2007

We review some basic notions and results of White Noise Analysis that are used in the construction of the Feynman integrand as a generalized White Noise functional. We show that the Feynman integrand for the harmonic oscillator in an external potential is a Hida distribution.
Determination of transition curves of high‐Tc superconductors by phase contrast microscopy
Authors: Kriebel Cl. , Hoffels O. , Borowski R. , Gottschalk H. , Alexander H. , Wohlleben D.
Published: May 2007

A new method which allows the detection of the superconducting phase transition of high‐Tc superconductors (HTSC) on a microscopic scale is reported. Micro‐size holes in thin foils of superconducting material are examined in a transmission electron microscope at varying temperatures. The superconducting transition induces small changes in the image intensity within the holes, which can be detected by using electronic image analysis. Superconducting transition curves are then obtained for various types of high‐Tc superconductors and for given values of the applied magnetic field.
Kapitza phonon transmission from clean H‐silicon(111) surfaces into liquid helium
Authors: Wichert K. H. , Reimann C. , Blahusch G. , Kinder H.
Published: May 2007

We have studied the phonon transmission from ultraclean Si(111) surfaces into liquid helium by the phonon pulse technique. Reflection experiments and angular resolving transmission experiments were performed to measure the absolute value of the transmission coefficient and its dependence on the phonon emission angle into the solid. Clean samples etched conventionally in dilute HF show a significant anomalous transmission. An additional etch step in highly buffered HF (i.e., NH4F) with a pH‐value of 7.8 reduces the transmission coefficient drastically. Local inhomogeneities of the transmission coefficient caused by the deposition of water molecules on the surface could be visualized by the enhanced transmission. We found that the observed anomalous transmission is caused by mass defects.
Experiments with narrow movable beams of pulsed sound waves at 35 GHz
Authors: Knöll Th. , Weis O.
Published: May 2007

Only the study of absorption and angular dependent scattering of GHz and THz sound can give us detailed information about interaction processes of acoustical phonons. Therefore, the necessary techniques of sound generation, detection and undisturbed transmission to the target must be improved or to a large extent must still be developed. Corresponding attempts at 35 GHz are described. Sound‐beam topography allowed to study crystal defects and also showed us where transmission without scattering occurred. For the piezoelectric generation a reflex klystron was used feeding a planar Hertzian resonator. The needle‐like sound beams appeared as a double beam, each showing a minimum diameter of 35 μm for longitudinal polarized sound at an acoustic wavelength of 165 nm in X‐cut quartz and 320 nm in a‐cut sapphire. To obtain the smallest possible beam diameter for high resolution work, model calculations are presented for an excited fundamental Gaussian sound beam in an isotropic medium.
Transition from SU(2)L × SU(2)R × U(1)B‐L representation to SU(2)L × U(1)Y by q‐deformation and the corresponding classical breaking term of chiral U(2)
Authors: Bönisch R.
Published: May 2007

The minimal Standard Model exhibits a nontrivial chiral U(2) symmetry if the VEV and the hypercharge splitting Δ = (y‐y)/2 of right‐handed leptons (quarks) in a family vanish and Q = T0 + Y independently in each helicity sector. As a generalization, we start with SU(2)L × SU(2)R × U(1)(B‐L) and introduce Δ as a continuous parameter which is a measure of explicit symmetry breakdown. Values 0 ⩽ Δ ⩽ 1/2 take the neutral generator of the isospin ½ representation to the singlet representation, i.e. ‘deformes’ the LR representation into the minimal Standard one. The corresponding classical O(3)‐breaking term is a magnetic field perpendicular to the x3‐axis. A simple mapping on the fundamental Drinfeld‐Jimbo q‐deformed SU(2) representation is given.
Solution of the Eliashberg equations for a very strong electron‐phonon coupling with a low‐energy cutoff
Authors: Weger M. , Barbiellini B. , Jarlborg T. , Peter M. , Santi G.
Published: May 2007

We solve the Eliashberg equations for the case of an explicit k dependence of the interactions, and of the resulting self‐energies Σ1(k,ω), Σ2(k,ω). We consider a strong energy‐dependence of the electron‐electron scattering‐rate τ, which is associated with a strong energy‐dependence of the electron‐phonon matrix element g(k,k′). We characterize this energy‐dependence by a cutoff ζ1, which is of the order of the phonon frequency ωph. We find that we can account for a large number of unexpected features of the superconductivity of the cuprates by the BCS electron‐phonon theory, if we consider very large values of the McMillan coupling constant λph, and small values of the cutoff ζ1. Specifically, the Coulomb interaction is found not to depress Tc; the isotope effect is strongly reduced when ζ1 < ωph. We find solutions in which the gap function Δ(k, ω) has extended s‐wave symmetry but is very anisotropic. These large anisotropies are in good agreement with various experiments. We suggest that the underlying cause of the strong energy‐dependence is a very small electronic screening parameter at the Fermi surface; the electron‐phonon matrix element g is abnormally large, and this accounts for the high transition temperatures of the cuprates. An order of magnitude estimate suggests that the electron‐phonon mechanism can account for transition temperatures up to about 200 K. We thus propose a very‐strong‐coupling theory, in which the renormalization functions, in particular the energy‐renormalization X, depend very strongly on the superconducting gap Δ, and thus display a very strong temperature‐dependence between Tc and T = 0. An experimental manifestation of the very strong coupling with a small cutoff is a zero bias anomaly sometimes observed in tunneling experiments.
Reflection time as an eigenvalue problem
Authors: Bracher C. , Kleber M.
Published: May 2007

Starting with wave packets, an eigenvalue equation is derived for the amount of time a particle needs for reflection from an impermeable potential barrier. The corresponding Hermitian operator TR is linear and diagonal in energy space. The eigenvalues are given by τ2(E) = ℏ \documentclass{article}\pagestyle{empty}\begin{document}$ \left\{ {\frac{{\partial \rho (E)}}{{\partial E}} + \frac{{\sin \rho (E)}}{{2E}}} \right\} $\end{document}, where ρ(E) is the phase shift for stationary reflection at fixed scattering energy E. The quantum mechanical reflection time τR(E) has a well defined WKB‐limit. For low scattering energies τR(E) is proportional to \documentclass{article}\pagestyle{empty}\begin{document}$ \sqrt E $\end{document} if weakly bound states are absent in the reflection region. However, if there is an empty weakly bound state it will transiently trap a slowly moving particle, causing a \documentclass{article}\pagestyle{empty}\begin{document}$ 1/\sqrt E $\end{document} divergence of the reflection time for E→0. We work out and illustrate the theory for various reflecting potentials. The method allows for a consistent treatment of the quantum mechanical Goos‐Hänchen time delay.
Mott‐Hubbard transition in a magnetic field
Authors: van Dongen P. G. J. , Leinung C.
Published: May 2007

We study the density of states (DOS) as a function of the interaction U in the half‐filled simplified Hubbard model in a magnetic field. This model is considered on the Bethe lattice in the limit of high dimensions. We show that the DOS can be calculated exactly, and that many of its properties have an astonishingly simple form. In particular, the DOS can be investigated explicitly in the limits of weak and strong coupling and near the metal‐insulator transition. E.g., we find an explicit result for the critical value Uc, at which the metal‐insulator transition occurs, as a function of the magnetization. The relation between the magnetization and the magnetic field is calculated numerically. An important result is that the metal‐insulator transition, occurring in the model with B = 0, is continuously connected to the metal‐insulator transition in the subspace of single spin flips.
On the interbasis expansion for the Kaluza‐Klein monopole system
Authors: Grosche C. , Pogosyan G. S. , Sissakian A. N.
Published: May 2007

We study the interbasis expansion of the wave‐functions of the Kaluza‐Klein monopole system in the parabolic coordinate system with respect to the spherical coordinate system, and vice versa. We show that the coefficients of the expansion are proportional to Clebsch‐Gordan coefficients. We analyse the discrete and continuous spectrum as well, briefly discuss the feature that the (reduced) Kaluza‐Klein monopole system is separable in three coordinate systems, and the fact that there are five functionally independent integrals of motion, respectively observables, a property which characterizes this system as super‐integrable.
Anisotropy of the mixed‐state resistance of Tl2Ba2CaCu2O8 single crystals
Authors: Weidinger A. , Seng P. , Tidecks R. , Samwer K. , Yu. Logvenov G. , Kolesnikov N. N.
Published: May 2007

The electrical resistance of single crystals of the high‐temperature superconductor Tl2Ba2CaCu2O8 has been measured as a function of the angle θ between the direction of the magnetic field and the current‐carrying CuO2‐planes. The resistance is maximal for θ = 90° (B⟂CuO2‐planes) and decreases to a minimum at θ = 0°. For small angles an anomalous enhancement of the resistance is found. While the general shape of the resistance is generated by the motion of “pancake vortices” in the CuO2‐planes, the anomaly is due to “Josephson vortices” moving perpendicular to the planes.
A unified treatment of Ising model magnetizations
Authors: Davies Brian , Peschel Ingo
Published: May 2007

We show how the spontaneous bulk, surface and corner magnetizations in the square lattice Ising model can all be obtained within one approach. The method is based on functional equations which follow from the properties of corner transfer matrices and vertex operators and which can be derived graphically. In all cases, exact analytical expressions for general anisotropy are obtained. Known results, including several for which only numerical computation was previously possible, are verified and new results related to general anisotropy and corner angles are obtained.
Encapsulation of magnetic particles via miniemulsion polymerization of styrene. II. Effect of some parameters on the polymerization of styrene
Authors: Zhang Qiuyu , Xie Gang , Zhang Hepeng , Zhang Junping , He Min
Published: May 2007

Effects of some parameters on the polymerization of Styrene (St) during encapsulation of iron oxide particles via miniemulsion polymerization have been investigated. At the early stage of reaction, polymerization rate increased slightly with the increase of sonicating time, and then it leveled off. The polymerization rate increased with the increase of KPS at the early stage of polymerization, which tendency is analogous to the result of polymerization of St in miniemulsion without the presence of iron oxide particles. The increase of iron oxide not only decreased the polymerization rate but also resulted in poorer monodisperse of the particles when keeping the amount of dispersant constant. The dispersant played an important role in the encapsulation of magnetic particles via miniemulsion polymerization of St. It not only made the iron oxide disperse well in monomer droplets but also led to a much faster polymerization than that of no dispersant in system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Über N‐Glykoside, VIII. Mitteil.Überführung von 1‐Arylamino‐1‐desoxy‐hexiten und ‐pentiten in Zucker
Authors: Weygand Friedrich , Schaefer Gerhard
Published: May 2007

Bei der Behandlung von d‐Mannityl‐p‐toluidin mit Brom in wäßriger Lösung wird es zunächst in 3.5‐Stellung im Kern bromiert. Bei der Weiteren Einwirkung von Brom entsteht d‐Mannose und d‐Fructose neben 3.5‐Dibrom‐p‐toluidin. Andere 1‐Arylamino‐1‐desoxy‐hexite bzw. ‐pentite zeigen ähnliches Verhalten. East immer bildet sich neben der zu erwartenden Aldose die Ketose, deren Entstehungsweise noch unklar ist.
Die Umwandlung des Colchicins durch Sonnenlicht
Authors: Grewe Rudolf , Wulf Wilhelm
Published: May 2007

Colchicin wird in wäßriger Lösung durch Sonnenlicht fast quantitativ in ein Gemisch aus α‐, β‐ und γ‐Lumicolchicin verwandelt.
Synthese der Adenylthiomethylpentose
Authors: Weygand Friedrich , Trauth Otto
Published: May 2007

Es wird die Synthese der Adenylthiomethylpentose ausgehend von Adenosin beschrieben. Dadurch wird die β‐Konfiguration und die Haftstelle der 5‐Methylthio‐d‐ribose in 9‐Stellung des Adenins bewiesen.
Darstellung eines neuen Ringsystems mit Urotropin‐Struktur
Authors: Stetter Hermann , Böckmann Walter
Published: May 2007

Ausgehend von Pentaglycerin wurde das 1.1.1‐Tri‐[aminomethyl]‐äthan dargestellt. Durch seine Kondensation mit Formaldehyd wurde das 1‐Methyl‐3.5.7‐triaza‐tricyclo‐[3.3.1.13,7]‐decan erhalten. Das dieser Verbindung zugrunde liegende Ringsystem besitzt Urotropin‐Struktur und leitet sich vom Urotropin durch Ersatz eines Ringstickstoffatoms durch Kohlenstoff ab. Das neue Ringsystem zeigt eine wesentlich höhere Stabilität als das Urotropin.
6‐Acetyl‐salicylsäure
Authors: Kuhn Richard , Dury Karl
Published: May 2007

Terramycin liefert bei alkalischem Abbau unter anderem eine Phenol‐keto‐carbonsäure, die mit Diazomethan eine Verbindung C11H12O4 vom Schmp. 119° liefert. Durch eine vom 1.5‐Dioxy‐naphthalin ausgehende Synthese wird bewiesen, daß es sich um den Methyläther‐methylester der 6‐Oxy‐2‐acetyl‐benzoesäure (6‐Acetyl‐salicylsäure) handelt.
Notiz über die Dismutation von 5‐Chlor‐7‐jod‐8‐oxy‐chinolin
Authors: Nógrádi Tamás
Published: May 2007

Es wird gezeigt, daß beim Kochen von 5‐Chlor‐7‐jod‐8‐oxy‐8‐chinolin („Vioform”︁) in dioxanlösung eine Dismutation in 5.7‐Dijod‐8‐oxy‐chinolin und 5.7‐Dichlor‐8‐oxy‐chinolin eintritt. Analog gebaute Brom‐Substitutionsprodukte zeigen bei gleicher Behandlung diese Dismutation nicht.
Die Konstitution der Hydrierungsprodukte des N‐Methyl‐isopseudostrychnins und des Desoxy‐N‐methyl‐ isopseudostrychnins. (VI. Mitteil. über Strychnos‐Alkaloide
Authors: Boit Hans‐G.
Published: May 2007

Die aus N‐Methyl‐isopseudostrychnin (I) bzw. Desoxy‐N‐methyl‐isopseudostrychnin (II) durch Hydrierung erhaltenen Basen C22H30O2N2 bzw. C22H30ON2 entstehen auch bei der Hydrierung von Isostrychnin‐chlormethylat bzw. Desoxy ‐isostrychnin‐chlormethylat, wodurch ihre Konstitution als Verbindung III bzw. IV bewiesen wird.
Über Ionitrilkomplexe, II. Mitteil.: Darstellung und Eigenschaften einiger Isonitrilkomplexe des Nickels, Kupfers, Silbers und Quecksilbers (Z. TI. mitbearbeitet von Rudolf Heinle
Authors: Klages Friedrich , Mönkemeyer Karl
Published: May 2007

Es wurden eine Reihe von Isonitrilkomplexen des Nickels, Kupfer‐(I)‐ phenylacetylenids, Kupfer (I)‐chlorids, Kupfer(I)‐cyanids, Silbernitrats und Quecksilber(II)‐chlorids hergestellt und die z. Tl. neuartigen Reaktionen des organischen Molekülteiles untersucht.
Die präparative Bedeutung der Zersetzung von Diazo‐carbonylverbindungen im UV‐Licht
Authors: Horner Leopold , Spietschka Ernst
Published: May 2007

Substituierte Diazo‐ketone spalten unter der Einwirkung von UV‐Licht Stickstoff ab und lagern sich in Ketene um. Diese können–wenn beständig ‐‐ in Substanz isoliert, immer aber durch geeignete Reaktionspartner als funktionelles Derivat abgefangen werden. Die Ausbeuten sind vorzüglich.
Bärlapp‐Alkaloide, I. Mitteil.: Zur Kenntnis der Alkaloide aus Lycopodium annotinum L
Authors: Bertho Alfred , Stoll Alois
Published: May 2007

In einheimischen Lycopodium annotinum L. wurden sieben Alkaloide aufgefunden und durch Salze, UV‐Absorptionsspektren usw. charakterisiert. Acrofolin C16H23O2N, Annotinin C16H21O3N und Lycopodin C16H25ON sind bereits bekannt; Annotin C16H23O4N, Annotoxin C31H42O5N2, eine weitere mit Lycopodin isomere Base C16H25ON und eine Base C10H19(21)ON sind bisher nicht beobachtet worden. Es werden verschiedene Umsetzungen beschrieben, u.a. ein Abbau eines Umwandlugsproduktes des Acrifolins.
Über die Kondensation von Orthoestern mit aktivierten Methylengruppen, VI. Mitteil.: Die Reaktion zwischen Orthoessigsäuremethylester und Benzoylacetonitril
Authors: Pascual José , Serratosa Félix
Published: May 2007

Läßt man Orthoessigsäuremethylester mit Benzoylacetonitril reagieren, so entsteht β‐Methoxy‐α‐benzoyl‐crotonsäurenitril (I), das mit Phenylhydrazin analog wie der aus Benzoylacetessigsäureester mit Diazomethan erhaltene β‐Methoxy‐α‐benzoyl‐ crotonsäuremethylester reagiert.
Über die Ähnlichkeit des Absorptionsspektrums einfacher organischer Moleküle und Farbstoffe mit dem Spektrum des Wasserstoffatoms
Authors: Scheibe Günter , Brück Dora , Dörr Fritz
Published: May 2007

An Hand einiger Beispiele wird gezeigt, daß der Energieabstand zwischen erstem angeregtem Zustand und Ionisierung nicht nur bei einfacheren Atomen, sondern auch bei organischen Farbstoff‐Molekülen und‐Ionen nahezu gleich der entsprechenden Differenz (3.39 eV) beim Wasserstoffatom ist. Diese Erscheinung wird als „Wasserstoffähnlichkeit”︁ bezeichnet. Die wesentlichen Unterschiede in den Termhöhen ganz verschiedenartiger Atome und Moleküle liegen in der Höhe des Grundzustandes, die stark von der Resonanzenergie abhängt. Zu einem ähnlichen Schluß hatten schon frühere Beobachtungen an substituierten Monomethincyaninen geführt.

Zur Deutung wird angenommen, daß sich im angeregten Zustand das Leuchtelektron schon in so großem Abstand vom Rumpf befindet, daß es sich praktisch in einem Coulomb‐Feld bewegt. Bei manchen Molekülen treten langwellige Vorbanden auf, die nicht in diese Regel passen. Beim äthylen gehört dieser übergang zu einem bindungslockernden Elektronenzustand, wie mittels des Franck‐Condon‐Prinzips aus der Feinstruktur zu entnehmen ist. Solche Zustände sollen deshalb außer acht gelassen werden. Dann erlaubt die gefundene Gesetzmäßigkeit eine näherungsweise Berechnung der Ionisierungsenergie aus der Lichtabsorption für Moleküle, bei denen eine direkte Messung nicht möglich ist. In gelöstem oder adsorbiertem Zustand kann die Ionisierungsenergie unter dem Einfluß äußerer Felder noch erniedrigt werden, wofür ein Beispiel angegeben ist.
Über den Einfluß der Substituenten auf die chemische Reaktivität, IV. Mitteil.: Über das Verhalten der Diazoniumsalze gegen UV‐Licht
Authors: Horner Leopold , Stöhr Helmut
Published: May 2007

Diazoniumsalze werden in alkoholischer Lösung bei Bestrahlung mit UV‐Licht im Gegensatz zur thermischen Zersetzung (Ätherbildung) bevorzugt reduktiv desaminiert. In Isopropanol ist die Ätherbildung im UV‐Licht praktisch völlig unterdrückt; die reduktive Desaminierung wird zur Hauptreaktion. Ein übersichtlicher Substituenteneinfluß ist bei der Photolyse nicht zu erkennen. Durch Auslösung der Polymerisation von Acrylnitril sowie durch die völlige Unterdrückung der reduktiven Desaminierung durch typische Radikalfänger wie molekularen Sauerstoff und p‐Chinon wird auf präparativem Wege der Beweis für den radikalischen Chemismus des reduktiven Austausches von NH2 gegen H erbracht. Die Ätherbildung verläuft über polare Zwischenstufen.
Synthese und Eigenschaften des monomeren 1.2‐Dihydro‐chinolins und einiger substituierter 1.2‐Dihydro‐chinoline
Authors: Rosenmund Karl W. , Zymalkowski Felix
Published: May 2007

Es wird über Synthese und Eigenschaften des 1.2‐Dihydro‐chinolins, des 8‐Methoxy‐1.2‐dihydro‐chinolins und des 4‐Oxymethyl‐2‐phenyl‐1.2‐dihydro‐chinolins berichtet. Die Verbindungen sind höchst instabil und verändern sich innerhalb kurzer Zeit sowohl durch Sauerstoffaufnahme als auch durch innermolekulare Umlagerungen.
Hochvakuum‐Destillation acetylierter Zucker
Authors: Bredereck Hellmut , Höschele Günther
Published: May 2007

Es wird das Verhalten von voll‐ und partiell acetylierten Zuckern sowie von acetylierten Zucker‐Derivaten bei der Destillation im Hochvakuum beschrieben. Hierauf basiert eine präparative Trennung von Mono‐und Disacchariden durch fraktionierte Destillation ihrer Acetate.