Analysis of a combat problem: The turret game

The turret game is defined and solved to illustrate the nature of games of combat. This game represents a highly simplified version of air combat, yet it is sufficiently complex so as to exhibit a rich variety of combat phenomena. A review of the formulation of -combat games is included in this paper.on sabbatical leave from Technion, Israel Institute of Technology, Haifa, Israel.     

Production and characterization of monoclonal antibodies against urea derivatives

A panel of monoclonal antibodies was generated against the ureabased haptenN-(2-N-chloroacetylaminobenzyl)-N′-4-chlorophenylurea as a tool for building up sensitive immune assays to detect urea derivatives and to screen them for catalytic antibodies (Abs). Eleven hybridomas were obtained that produced Abs reactive to the hapten. All Abs were of IgG class. Crossreactivities of the Abs to different haptens were examined, especially to a possible transition-state analog. Only four of the hybridomas (R2-DA10/F7, R2-GE7/H2, R2-HC2/A5, R2-HD6/F7) produced Abs crossreactive with the transition-state analog. From the 11 hybridomas, hybridoma B76-BF5 was chosen for further characterization. Compared to the other Abs, B76-BF5 showed the strongest binding and had a rather restricted specificity. These Abs could be used to build up a sensitive enzyme immunoassay for the detection of the hapten. All Abs were screened for crossreactivity with the pesticides monuron and diuron. No reactivity could be detected. In addition, the nucleotide sequences of the variable light and heavy chain genes of the similarly reactive Abs B76-BF5, B76-BB3, R2-DA10/F7, and R2-GA6/G3 were determined to clarify whether structure and binding specificity of these Abs showed any correlation.     

Reversible dimerization of [5,6]-C60O

The recently discovered [5,6]-open isomer of C(60)O has been found to undergo facile dimerization to form a new C(2) symmetry isomer of C(120)O(2), which can be photodissociated with relatively high efficiency to regenerate monomeric [5,6]-C(60)O. High yield dimerization of [5,6]-C(60)O proceeds spontaneously in toluene solution near room temperature. On the basis of (13)C NMR spectroscopy, ab initio quantum computations, and HPLC retention patterns, the resulting C(120)O(2) product has been deduced to be a nonpolar dimer of C(2) symmetry in which the C(60)O moieties are linked by two single bonds between sp(3)-hybridized carbon atoms adjacent to oxygen atoms. Photophysical properties of this dimer have also been measured and compared to those of C(120), the [2 + 2]-dimer of C(60). The ground-state absorption spectrum of C(120)O(2) in toluene is slightly red-shifted relative to that of C(120), with a distinctive peak at 329 nm and an S(1)-S(0) origin band at 704 nm. Its fluorescence spectrum shows two major peaks at 718 and 793 nm. In room-temperature toluene, the measured triplet state intrinsic lifetime of this C(120)O(2) isomer is 34 +/- 2 micros, a value somewhat shorter than that of C(120) (44 micros). C(120)O(2) undergoes photodissociation from its triplet state to regenerate monomeric [5,6]-C(60)O with quantum yields of 2.5% at 24 degrees C and 43% at 70 degrees C. It can therefore serve as a stable reactant for photolytic production of [5,6]-C(60)O. As a simple fullerene adduct that reacts under mild conditions, [5,6]-C(60)O may prove useful in special synthetic applications. Solutions of [5,6]-C(60)O are also unique because they can provide mixtures of a fullerene monomer and its dimer in a dynamic balance controllable by adjustment of concentration, temperature, and optical irradiation.     

Radikalanionen des Bis(diphenylphosphino)maleinsäureanhydrid und seiner Derivate Polarographische und ESR-Messungen Präparative Anwendungen

Die Halbstufenpotentiale der Reduktion der Titelverbindung und einiger ihrer Derivate werden polarographisch gemessen. Die gefundenen, bemerkenswert niedrigen Reduktionspotentiale werden vergleichend diskutiert. Ihre Abstufung kann nur z. T. durch induktive Substituenteneffekte erklärt werden. Zusätzlich muß eine Ausweitung der π-Elektronenzustände unter Einschluß der Phosphoratome diskutiert werden, was auch aus den Kopplungskonstanten in den ESR-Spektren der gebildeten Radikalanionen zu schließen ist. Die Kaliumsalze der Radikalanionen sind äußerst luftempfindlich. Dagegen ist das aus Cobaltocen und Bis(diphenylphosphino)-maleinsäure-thioanhydrid ( 2 ) entstehende [CoCp₂]⁺[ 2 ]^? an der Luft beständig. Aus solchen ?Salzen”? der Radikalanionen können durch Umsetzung mit Metallhalogeniden Metall(0)-Komplexe der ditertiären Phosphane erhalten werden. Radical Anions of Bis(diphenylphosphino)maleic Anhydride and its Derivatives. Polarographic and ESR Measurements. Preparative Applications Half-wave potentials of the title compound and some of its derivatives have been measured by polarography. The observed reduction potentials are remarkably low. The changes within this series cannot be explained by inductive effects only. A contribution of extended π-states has to be regarded likewise, including the phosphorus atoms. This is confirmed by the coupling constants derived from ESR spectra of the radical anions formed by the reduction. The potassium salts of the radical anions are extremly air sensitive. However the salt of the cation [CoCp₂]⁺ with the radical anion of bis(diphenylphosphino)maleic thioanhydride is stable at the air. It is prepared in excellent yields from CoCp₂ and the diphosphine in toluene. The salts of the radical anions can be used to synthesize metal(0) complexes of the corresponding ditertiary phosphines by their reaction with metal halides.     

Configurable NOR gate arrays from Belousov-Zhabotinsky micro-droplets

We investigate the Belousov–Zhabotinsky (BZ) reaction in an attempt to establish a basis for computation using chemical oscillators coupled via inhibition. The system consists of BZ droplets suspended in oil. Interdrop coupling is governed by the non-polar communicator of inhibition, Br₂. We consider a linear arrangement of three droplets to be a NOR gate, where the center droplet is the output and the other two are inputs. Oxidation spikes in the inputs, which we define to be TRUE, cause a delay in the next spike of the output, which we read to be FALSE. Conversely, when the inputs do not spike (FALSE) there is no delay in the output (TRUE), thus producing the behavior of a NOR gate. We are able to reliably produce NOR gates with this behavior in microfluidic experiment.     

Crystal structures, phase-transition, and photoluminescence of rare earth carbodiimides

Rare earth carbodiimides with the general formula RE 2(CN 2) 3 crystallize with two modifications. A monoclinic( C2/m) modification is obtained for RE = Y, Ce-Tm and a rhombohedral ( R3 c) modification for RE = Tm-Lu. The space group R3 c is confirmed by single-crystal structure determination on Lu 2(CN 2) 3 and indexed powder patterns of RE = Tm, Yb and Lu. The use of diverse chemical syntheses conditions for Tm 2(CN 2) 3 revealed the dimorphic character of this compound. In addition, pressure experiments on Tm 2(CN 2) 3 have induced a phase-transition from rhombohedral to monoclinic. This transformation comprises an increase of the coordination number of Tm from 6 to 7, and a unit-cell volume reduction in the order of 20 %. The photoluminescence behavior of lanthanide doped Gd 2(CN 2) 3:Ln samples is presented with different activators (Ln = Ce, Tb) revealing a broad band emission of Gd 2(CN 2) 3:Ce, quite similar to that of the well-known YAG:Ce.     

Pr3Mo4B6O24(OH)3: High-Pressure/High-Temperature Synthesis of an Acentric Rare Earth Molybdenum Borate

We report on the synthesis of a new praseodymium molybdenum borate under high-pressure/high-temperature conditions. The new compound with the sum formula Pr₃Mo₄B₆O₂₄(OH)₃ crystallizes acentrically in the monoclinic space group Cm displaying a new structure type. The structure was solved via single-crystal structure determination. Additionally, the proposed structural model was confirmed by powder X-ray diffraction, second harmonic generation measurement, and single-crystal infrared and Raman spectroscopic investigation.     

A test of financial time-series data to discriminate among lognormal,Gaussian and square-root random walks

This paper aims to offer a testing framework for the structural properties of the Brownian motion of the underlying stochastic process of a time series. In particular, the test can be applied to financial time-series data and discriminate among the lognormal random walk used in the Black-Scholes-Merton model, the Gaussian random walk used in the Ornstein-Uhlenbeck stochastic process, and the square-root random walk used in the Cox, Ingersoll and Ross process. Alpha-level hypothesis testing is provided. This testing framework is helpful for selecting the best stochastic processes for pricing contingent claims and risk management.