Field-dependence of carrier screening in non-linear transport theory

Modifications to the high-field Boltzmann transport equation are obtained to include ab initio self-consistent non-equilibrium free-carrier screening of the scattering rates. For quasi-static homogeneous fields the screening involves a Lindhard-like dielectric function which is field-dependent via the carrier distribution function and the carrier energetics.     

The post-post-Newtonian problem in classical electromagnetic theory

We find the Lagrangian to order c^?4 for two charged bodies (with $\text{e}{}_1\text{m}{}_1\text{=}\text{e}{}_2\text{m}{}_2$) in electromagnetic theory. This Lagrangian contains acceleration terms in its final form and we show why it is incorrect to eliminate these terms by using the equationsof motion in the Lagrangian as was done by Golubenkov and Smorodinskii, and by Landau and Lifshitz. We find the center of inertia and show that the potential energy term does not split equally between particles 1 and 2 as it does in the Darwin Lagrangian (Lagrangian to order c^?2). In addition to the infinite self-energy terms in the electromagnetic energy-momentum tensor, which are eliminated using Gupta's method, some new type of divergent terms are found in the moment of electromagnetic field energy and in the electromagnetic field momentum which cancel in the final conservation law for the center of inertia.     

Square wave polarography and some related techniques

The theory of square wave polarography is reviewed, and methods for obtaining increased sensitivity in A.C. polarography are outlined, including a new technique which makes use of an amplitude-modulated radio-frequency polarizing current. This R.F. technique can also be used to study the kinetics of very rapid electrode processes.     

Time-dependent-thermal-lensing (TDTL) studies on gas-phase azulene

Several aspects of the time-dependent-thermal-lensing (TDTL) technique were explored experimentally, including pressure effects, risetime behavior and falltime behavior. The experiments were performed using azulene vapor excited to high vibrational energies (≈ 17000 cm^?1). It was found that the energy appears in translational degrees of freedom at very early times, but the intrinsic limitations of the technique permitted only an estimate of the V-T rate constant for excited azulene deactivation by krypton. The result is discussed in terms of other recent experiments, and it is tentatively concluded that deactivation of excited azulene by unexcited azulene molecules may proceed primarily by a V-V process.     

Zizaane sesquiterpenes. Synthesis of the coates-sowerby tricyclic ketone

The cycloadduct (5) , which is conveniently prepared by irradiation of (4), is converted $\text{via}$ a 4-step sequence, into the tricyclic ketone (2$\text{a}$) and its epimer (2$\text{b}$); the sequence formally completes a new total synthesis of (±)-zizaene (1) and its Me-epimer.     

Observation of muon neutrino disappearance with the MINOS detectors in the NuMI neutrino beam

This Letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rates and energy spectra of charged current nu(mu) interactions are compared in two detectors located along the beam axis at distances of 1 and 735 km. With 1.27 x 10(20) 120 GeV protons incident on the NuMI target, 215 events with energies below 30 GeV are observed at the Far Detector, compared to an expectation of 336+/-14 events. The data are consistent with nu(mu) disappearance via oscillations with |Delta(m)2/32|=2.74 +0.44/-0.26 x10(-3)eV(2) and sin(2)(2theta(23))>0.87 (68% C.L.).     

Search for lepton-flavor-violating decays of the neutral kaon

The Fermilab KTeV experiment has searched for lepton-flavor-violating decays of the K(L) meson in three decay modes. We observe no events in the signal region for any of the modes studied, and we set the following upper limits for their branching ratios at the 90% C.L.: BR(K(L) --> pi(0) micro(+/-) e(-/+)) <7.6 x 10(-11); BR(K(L) --> pi(0)pi(0) micro(+/-) e(-/+)) <1.7 x 10(-10); BR(pi(0) --> micro(+/-) e(-/+)) <3.6 x 10(-10). This result represents a factor of 82 improvement in the branching ratio limit for K(L) --> pi(0) micro(+/-) e(-/+) and is the first reported limit for K(L) --> pi(0)pi(0) micro(+/-) e(-/+).     

Influence in kinetic studies by competitive photocurrent methods of a post-competition link between parallel reactions chains: Part II. OH radical addition to phenol and aniline

The rate constants for the homogeneous reaction of OH radicals of O^? ions with phenol and aniline have been determined by a photoelectrochemical method involving studies of the suppressive effect of mixtures of aniline and of phenol with methanol on the nitrous oxide photocurrent at a DME. Fairly good agreement with absolute rate constants obtained by conventional radiation chemical methods is obtained if use is made of the theory developed in Part I of this paper which takes account of the possibility of interaction between the photocurrent reaction chains following competition between the two organic solutes for OH radicals. The present work points to a value of 1.75±0.6 10¹⁰M^?1 s^?1 for the capture of OH by phenol at pH 9.5. The reaction product, the cyclohexadienyl radical Φ (OH)₂, is able to extract H atoms from methanol with a rate constant of the order of 10⁷M^?1 s^?1, this reaction tending to lessen the suppressive effect of a phenol + methanol mixture on the nitrous oxide photocurrent. Similar complications are observed at higher pH, and also when using aniline + methanol mixtures.     

Diruthenium(II,III) bis(tetramethyl-1,3-benzenedipropionate) as a novel catalyst for tert-butyl hydroperoxide oxygenation

The reaction of Ru2(OAc)4Cl with 2.2 equiv of H2esp (esp = alpha,alpha,alpha',alpha'-tetramethyl-1,3-benzenedipropionate) resulted in a new compound, Ru2(esp)2Cl (1), that is soluble in organic media. 1 is an active catalyst for the oxygenation of organic sulfides by tert-butyl hydroperoxide (TBHP) in both an acetonitrile solution or neat (solvent-free) conditions. Solvent-free reactions display the quantitative utility of TBHP and hence excellent chemical selectivity for sulfoxide formation.