Concerning measurements in quantum theory: A critique of a recent proposal

Conclusion Jauch's theory of measurement, if satisfactory, would have provided an elegant and very simple solution to all of the standard difficulties found in other versions of the measurement process in quantum theory. We have examined this theory and found it to contain an important element of obscurity (that concerned with just exactly under what conditions the reductions may be performed) and ambiguity (namely concerning which reductions are to be performed), but most importantly we have concluded that it was both inconsistent and lacking in physical plausibility.I wish to acknowledge Dr. J. Bub and members of my graduate seminar, stimulating conversations with whom served to clarify many of the issues in this paper.     

Gas-phase deprotonation of arylalkylamines. A collision-induced dissociation study

The collision-induced dissociation (CID) of deprotonated arylalkylamines of general formula R(1)C(6)H(4)CHR(2)CH(2)NR(3)(2) (where R(1) = H, OH, F or NO(2); R(2) = H or OH; R(3) = H or CH(3)) generated by negative chemical ionization with H(2)O and D(2)O as ionizing reagents, is discussed. The negative chemical ionization mass spectra show that, in the absence of a hydroxy group in the aromatic ring, deprotonation takes place at the benzylic position whereas the proton is lost from the OH group when present. The nitro compound forms only M(-.) ions. The CID spectra of the deprotonated molecules show that fragmentations are strongly dependent on the structural features of the molecules, namely the presence or absence of substituents in the aromatic ring or aliphatic chain. Copyright 1999 John Wiley & Sons, Ltd.     

Influence of cavity configuration on the pulse energy of a high-pressure molecular fluorine laser

We report an investigation of a high-pressure molecular fluorine laser operating at 158 nm. Several cavity configurations were studied, including one employing a roof prism as the high reflector. A maximum VUV pulse energy of 237 mJ, corresponding to a specific output of 3.3 J/1 was obtained when the laser was operated as a double-ended device. With single-ended operation the largest output energy was 176 mJ at a specific output of 2.5 J/1.     

The reversible decarbonylation of methyl- and acetyldicarbonyl(η5-cyclopentadienyl)iron complexes in polyvinyl-chloride film matrices at 12–200 K

Infrared spectroscopic experiments using polyvinyl chloride film matrices at 12–200 K have shown for the first time that the photoinduced decarbonylation of Fe(η⁵-C₅H₅)(CO)₂(COCH₃) is thermally reversible, and that the photolysis of Fe(η⁵-C₅H₅)(CO)₂(CH₃) leads to the reversible formation of the new species Fe(η⁵-C₅H₅)(CO)(CH₃).     

Oxygen KLL Auger spectra from O2 and CO adsorbed on Ni

High resolution oxygen KLL Auger spectra from O₂ and CO adsorbed on clean Ni (110) have been measured and compared. These Auger spectra are quite different from one another and are compared with spectra of the free molecules. Similarities between the oxygen spectra from adsorbed and gaseous CO are noted and interpreted as due to the weak bonding of CO to Ni with the O atom furthest from the surface. These Auger studies also characterize the change in bonding of adsorbed CO due to electron beam interaction.     

Generalized resolution and cutting planes

This paper illustrates how the application of integer programming to logic can reveal parallels between logic and mathematics and lead to new algorithms for inference in knowledge-based systems. If logical clauses (stating that at least one of a set of literals is true) are written as inequalities, then the resolvent of two clauses corresponds to a certain cutting plane in integer programming. By properly enlarging the class of cutting planes to cover clauses that state that at least a specified number of literals are true, we obtain a generalization of resolution that involves both cancellation-type and circulant-type sums. We show its completeness by proving that it generates all prime implications, generalizing an early result by Quine. This leads to a cutting-plane algorithm as well as a generalized resolution algorithm for checking whether a set of propositions, perhaps representing a knowledge base, logically implies a given proposition. The paper is intended to be readable by persons with either an operations research or an artificial intelligence background.This report was prepared as part of the activities of the Management Sciences Research Group, Carnegie-Mellon University. Reproduction in whole or in part is permitted for any purpose of the U.S. Government.     

Interior surface modification of bacteriophage MS2

An efficient strategy for the interior surface functionalization of MS2 viral capsids is reported, featuring a new hetero-Diels-Alder bioconjugation reaction. After virus isolation, the RNA genome was removed from the spherical particles by exposure to pH 11.8 conditions for a period of 4 h. Following this, 180 tyrosine residues on the interior surface of each "empty" capsid shell were modified by using a site-selective diazonium-coupling reaction. To attach additional functionality, the azo conjugate was reduced with Na2S2O4 to afford an ortho-amino tyrosine derivative. Oxidation of this moiety with NaIO4 produced an o-iminoquinone on the protein surface, which was found to undergo an efficient hetero-Diels-Alder reaction with N-(4-aminophenyl)acrylamide. This four-step procedure can be carried out in under 4 h, reaches high levels of conversion, and yields the desired conjugates in >60% overall yield.     

Targeted Fluorination with the Fluoride Ion by Manganese‐Catalyzed Decarboxylation

We describe the first catalytic decarboxylative fluorination reaction based on the nucleophilic fluoride ion. The reported method allows the facile replacement of various aliphatic carboxylic acid groups with fluorine. Moreover, the potential of this method for PET imaging has been demonstrated by the successful ¹⁸F labeling of a variety of carboxylic acids with radiochemical conversions up to 50 %, representing a targeted decarboxylative ¹⁸F labeling method with no‐carrier‐added [¹⁸F]fluoride. Mechanistic probes suggest that the reaction proceeds through the interaction of the manganese catalyst with iodine(III) carboxylates formed in situ from iodosylbenzene and the carboxylic acid substrates.