Quantum relativistic action at a distance

A well-known relativistic action at a distance interaction of two unequal masses is altered so as to yield purely Newtonian radial forces with fixed particle rest masses in the system center-of-momentum inertial frame. Although particle masses experience no kinematic mass increase in this frame, speeds are naturally restricted to less than the speed of light. We derive a relation between the center-of-momentum frame total Newtonian energy and the composite rest mass. In a new proper time quantum formalism, we obtain an L²(R⁴ R⁴, C) Hilbert space by varying individual particle rest masses. We propose the use of density operators, recognizing that the auxiliary proper time parameter is not an observable. The quantum formalism is applied to our altered version of the relativistic harmonic oscillator. Our generalized coherent states yield four-dimensional wave packets which follow the correct classical world lines. Appendices contain reviews of classical Hamiltonian reparametrization (incorporating our notion of manifest covariance), and a comparison of this work with the literature.     

Electronic properties of polyoxometalates: a DFT study of alpha/beta-[XM(12)O(40)](n-) relative stability (M=W, Mo and X a main group element)

Keggin heteropolyanions [XM(12)O(40)](n-) have various isomeric structures, alpha and beta being the most common. Conventionally, the alpha structure appears to be the most stable, but calculations carried out at the DFT level for X = P(V), Si(IV), Al(III), As(V), Ge(IV), and Ga(III) and M = W(VI) and Mo(VI) show that this stability depends on several factors, particularly on the nature of the heteroatom (X) and the total charge of the cluster. In this paper, we apply the clathrate model to the Keggin molecule to carry out a fragment-interaction study to elucidate when and why the traditional relative stability of various isomers can be inverted. The fully oxidized anions that have inverted the traditional stability trend in this series are [AlW(12)O(40)](5-) and [GaW(12)O(40)](5-), both of which contain a third-group heteroatom and an overall charge of -5. beta-isomers are always more easily reduced than alpha-isomers. This experimental observation suggests that reduction favors the stability of beta-isomers and one of the most important results of this study is that the alpha/beta inversion is achieved in most cases after the second reduction. The alpha- and beta-isomers may have different properties because the energy of the LUMO, a symmetry-adapted d(xy)-metal orbital, is different.     

Zur Katalysierten Verflüchtigung von rotem Phosphor und von Claudetit

The Catalysed Volatilization of Red Phosphorus and of Claudetite The catalysis of the volatilization of P_red (as P₄) by AlCl_3,g, and of the volatilization of claudetite (as As₄O₆) by I_2,g is observed by mass spectrometry.     

CHEMILUMINESCENCE FROM THE OXIDATION OF AUXIN DERIVATIVES

Abstract— The thiophenyl ester of indole-3-acetic acid and indole-3-acetonitrile produce chemiluminescence in aerated dimethylsulfoxide in the presence of potassium t -butoxide. The emitter is the aromatic aldehyde. In the case of acetonitrile, the other product expected from the cleavage of an intermediate dioxetane, cyanate/isocyanate, has also been identified. Other auxins also chemiluminesce under similar conditions, but the emitters have not been properly identified.
These systems are models for the peroxidase catalyzed oxidation of indole-3-acetic acid to indole-3-carboxaldehyde and as such support the earlier inference (Vidigal et al , 1975) that the excited aldehyde is generated in the enzymic process.
An additional result is the observation of an exciplex between excited indole-3-carboxaldehyde and the thiophenylester of indole-3-acetic acid. This appears to be the first case of chemical generation of an exciplex by a route other than radical ion reaction, presumably by the dioxetane route.     

A study of thin surface layers by multilayer Mössbauer spectroscopy /MMS/

A stacking Mössbauer technique, MMS has been applied for studying thin surface layers. The surface layers formed on the⁵⁷Fe film in aqueous solutions of corrosion inhibitors, such as zinc phosphate and barium metaborate, and in distilled water was studied by this method. It has been found that the corrosion is much slower in the presence of zinc phosphate and barium metaborate. XPS analysis suggests the formation of a mixed iron zinc phosphate on the surface of the⁵⁷Fe film after corrosion in a zinc phosphate solution.     

Über die Reproduzierbarkeit der turbidimetrischen Bestimmung von Phosphorspuren mit Strychninmolybdostickstoff(V)säure

Microchimica Acta - Mit der turbidimetrischen Strychninnitrat-Methode für Phosphorspurenbestimmung nach der Version von Hegedüs und Dvorszky kann man nur dann ausgezeichnete...     

Controlled vesicle self-assembly in microfluidic channels with hydrodynamic focusing

Traditional liposome preparation methods are based on mixing of bulk phases, leading to inhomogeneous chemical and/or mechanical conditions during formation; hence liposomes are often polydisperse in size and lamellarity. Here we show the formation of liposomes that encapsulate reagents in a continuous two-phase flow microfluidic network with precision control of size from 100 to 300 nm by manipulation of liquid flow rates. We demonstrate that by creating a solvent-aqueous interfacial region in a microfluidic format that is homogeneous and controllable on the length scale of a liposome, we can facilitate the fine control of liposome size and polydispersity.