The measured energy loss of high energy electrons in aluminum

The energy distributions of electrons of about 54, 75 and 97 Mev have been measured before and after passing through aluminum absorbers of thicknesses ranging from 0.730 to 5.574 gm/cm². The electrons were accelerated by the LINAC of the Naval Postgraduate School. The most probable energy losses agree with the theory ofBlunck andWestphal for all thicknesses; the half widths of the distributions agree with theory except for large thicknesses, where they exceed the theoretical values. These results are in contrast to those ofBreuer, which indicate systematically large half widths and most probable energy losses which are greater than theory for thicknesses greater than about 2 gm/cm². Since our data agree with those ofBreuer, the difference occurs in the treatment of the theory.     

Crystal and molecular structure of 17-β-methyllupanine perchlorate

The formula of the title compound is C₁₆H₂₇ClN₂O₅,MW = 362.9 orthorhombic,P2₁2₁2₁,a = 8.403(1),b= 13.133(1),c= 15.972(2) Å,Z = 4,D _x = 1.37 g cm^–3, (CuK) = 2.2 mm^-1. The lupanine skeleton has atrans-trans configuration. The ringA has a half-chair conformation, theB andD rings adopt a chair form, and theC ring forms a boat. The lupanine cations are linked together by the intermolecular hydrogen bonds forming infinite chains alongb. The N(16) ... O(C2) distance is 2.763(7) Å.     

Generation of basis states via variational methods

A systematic means of generating an optimal set of basis states via variational methods is presented. A calculation for ²⁰Ne has been performed and compared with the exact shell model diagonalization. Very good agreement for the lower-lying states in the eigenvalue spectrum has been obtained with relatively few basis states.     

Graph with given achromatic number

An irreducible (point-determining) graph is one in which distinct vertices have distinct neighbourhoods. Every graph X can be reduced to an irreducible graph X¹ by identifying all vertices with the same neighbourhood; the colourability properties of X¹ carry over to X. Hence irreducible graphs are instrumental in the study of achromatic number. We prove that there are only finitely many irreducible graphs with a given achromatic number, and describe all graphs with achromatic number less than four. We deduce certain bounds on the achromatic number X in terms of the number of vertices of X¹. In the course of the proofs we calculate the achromatic numbers of paths and cycles. Generalizations of the main theorem to homomorphisms other than colourings are discussed.     

Electrical conductivity of N-methyl phenazinium tetracyanoquinodimethanide, (NMP) (TCNQ)

New conductivity, σ, vs. temperature, T, measurements on numerous (NMP)-(TCNQ) samples, as well as older data, can all be fit, in the range 65K<T<400K, by the simple expression σ = σ_oT^-αexp(-900/T). σ_o and α(3<α<4) are sample-dependent constants. We interpret this as representing an activated carrier concentration and strongly T-dependent mobility, μ. We can account for the magnitude and T-dependence of μ by a model involving interaction with the molecular vibrations through the known electron-phonon coupling constants of TCNQ^-.     

Zur Kenntnis des Phosphatstoffwechsels der Hefe, 5. Mitt.: Weitere Untersuchungen über freie Nucleotide in Säureextrakten aus verschiedenen Stoffwechselbedingungen unterworfener Hefe

Zusammenfassung In Fortsetzung früherer Arbeiten wurden die freien Nucleotide in Säureextrakten aus anaerob phosphat-angereicherter Hefe, aus wachsender Hefe, aus sporulierter Hefe und aus Hefe, die ohne Kohlenstoffquelle auf einer Pufferlösung gezogen wurde, bestimmt. Es zeigte sich, daß die seinerzeit unter aeroben Bedingungen beobachtete Abnahme der Nucleotidkonzentration bei Phosphat-anreicherung anaerob nicht eintritt. Die Suche nach reduzierten Pyrimidinnucleotiden in den Säureextrakten aus anaerob phosphat-angereicherter Hefe gab ein negatives Ergebnis.Bei Vergleich der freien Nucleotide aus wachsender, sporulierender und im Hungerzustand gehaltener Hefe zeigte sich deutlich, daß während der Sporulierung der pool der freien Nucleotide fast völlig erschöpft wird, während zwischen dem Nucleotidgehalt wachsender Hefe und solcher im Hungerzustand keine sehr markanten Unterschiede zu beobachten sind. Dieses Ergebnis unterstreicht wiederum die Besonderheit des Sporulierungsvorgangs, dessen morphologische Phänomene in den biochemischen Verhältnissen ein deutliches Korrelat finden.Mit 4 Abbildungen     

Band absorption in nonhomogeneous,isotropically-scattering planetary atmospheres: theory and experiment

A computer program is developed which predicts the vertical distribution of an absorbing species in an isotropically-scattering, finite planetary atmosphere from measurements of the upwelling band radiance determined by a vertically traversing 2-channel radiometer. Comparison is made with experiment.     

Theoretical computations of spontaneous vibration-rotation raman scattering from OH(X 2Φ) and NO(X 2Φ)

Absolute values of Q-branch line intensities for OH(X² Φ) and NO(X² Φ) has been calculated, primarily for use in making measurements in flames. The effects of spin-orbit interaction, spin uncoupling, vibration-rotation interaction, and anharmonicity has been included in the calculations simultaneously in a self-consistent fashion. A-doubling is neglected. Multiconfigurational self-consistent field calculations of static polarizabilities are used to approximate the required electronic matrix elements. Complete derivations and discussion of the wave functions and matrix elements are included for clarity and to point out restrictions and approximations. Results of the calculations for NO agree well with room temperature measurements of Raman cross sections. No experimental data are available for OH.     

Polymers containing polyhedral borane rings I. Condensation polymers

The preparation and properties of a unique new class of polymers containing polyhedral borane cages as part of the backbone polymer chain are described. The synthesis of polyamides, polyesters, polyureas, and polyurethanes proceeds from suitably chosen B₁₀ and B₁₂ polyhedral borane dicarbonyls, diols, and diisocyanates by typical condensation polymer techniques. Each complementary monomer may be a borane compound, but more often higher molecular weight products are provided when one monomer is a conventional organic reagent such as an aromatic diisocyanate. The polyamides prepared from 1, 12-B₁₂H₁₀(CO)₂ and organic diamines were crystalline and soluble, but molecular weight were limited because the amidation reaction was reversible and/or the amide linkage could be split by nucleophilic attack by some solvents. The polyurethanes prepared from Na₂B₁₂H₁₀(OH)₂ and aromatic diisocyanates were high molecular weight and relatively more stable. Clear, colorless, tough films were prepared. These polymers were soluble in many polar solvents and exhibited typical polyelectrolyte behavior.