Field desorption mass spectra of involatile sulphonic acids,sulphonates and dyestuff materials

Abstract-Useful field desorption mass spectra can be obtained from involatile sulphonic acids and sulphonates, even when large dyestuff molecules are involved. Unusual cluster ions are commonly found, which can be singly or doubly charged. Most ions can be assigned, however, and the great potential of field desorption mass spectrometry in the identification of these involatile species is clearly established.     

207Pb(p,p') measurements at 135 and 61 MeV,the effective interaction and core polarization

Data at Einp = 61 and 135 MeV for neutron-hole transitions are used to study the proton-neutron part of the assumed NN force. Collective core-polarization strengths (A_L) from the present fits at 135 MeV are consistent with those extracted from the (e, e') reaction for two L = 2 transitions and one L = 4 transition. This is not the case at 61 MeV where the A_L values needed to fit the (p, p') data are much smaller for transitions to the $\text{f}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}\text{and}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$ hole states. A fully microscopic DWBA fit is successful for the L = 3 transition to the doublet at 2.64 MeV of excitation at E_p = 61 MeV, but fails at 135 MeV; a fully microscopic DWIA calculation provides a reasonable fit to the data at 135 MeV.     

Monotone scheme for finite difference equations concerning steady-state prey-predator interactions

In this article a system of semilinear elliptic partial differential equations is studied. This system determines the equilibria of the Volterra-Lotka equations describing prey-predator interactions with diffusion. To analyze the system, a new monotone scheme is presented. A rigorous foundation is given for numerical calculations by adapting a suitable finite difference method to the new monotone scheme. Earlier theories in finite differences are not successful in solving the system without this scheme.     

An entropy-theoretic proof of the Sucheston zero-one law

The purpose of this note is to provide a new proof to the following reformulation of the Sucheston zero-one law: An automorphism T of a Lebesgue space X is mixing if and only if, for every subsequence A of the sequence of natural numbers and every partition α of X having finite entropy, there exists a subsequence B = {b(j)} of A such that Λ_{r = 1}^∞ V_{j = r}^∞T^b(j)(α) is the trivial partition.     

Gluings of modular lattices

The notions of gluing, tolerance relations, and Mal'cev products of varieties have been used by various authors to investigate varieties of lattices. In this paper the authors introduce a general framework for all these concepts and apply it to varieties of modular and Arguesian lattices.     

A high sensitivity DC thermometric circuit using operational amplifiers and a hybrid combination of NTC and PTC thermistors

Equations predicting the response of thermometric circuits constructed from operational amplifiers with NTC and NTC—PTC hybrid thermistors are derived and tested. Sensitivities and time constants were determined experimentally and are compared with theoretical predictions. The circuit with the NTC—PTC hybrid is characterized by greater sensivity than a NTC circuit and greater linearity than a PTC circuit.