2,052 research outputs found
Semi-Annual Report: October 15, 1961
Investigations are proposed involving an experimental and theoretical program designed to investigate various properties of the structure of helium both in its atomic form and in the aggregates of the liquid and solid states. The key to the possibilities of performing the experiments lies in the relatively weak electric fields existing in liquid and solid helium and the possibility of producing external fields almost comparable with the internal fields. It is proposed to examine a) the melting pressure curve for helium as a function of electric field b) the dielectric constant of helium as a function of pressure and electric field c) in future, the effect of electric fields on the lambda transition. From the results of these experiments one would expect to be able to gather at least corroborative evidence on a) the crystal structure of solid helium on b) the effect of the Van der Waal interaction of the electric polarizability of helium, c) the possibility of producing helium molecules d) the effective volume available to helium atoms in the liquid and possibly e) the effect of particle interactions on the Bose-Einstein condensation
Saturation in ânonmagneticâ stainless steel
Scientific equipment often uses ânonmagneticâ stainless steel, relying on the steelâs nonmagnetic behavior to leave external magnetic fields unaltered. However, stainless steelâs permeability can rise significantly when it is welded or machined, possibly perturbing an external field. Such perturbations will diminish well above the stainless steelâs saturation point. The authors measured the permeability of both welded and machined 304 stainless steel as a function of an external magnetic field, and found that both saturate at fields of approximately 0.25 T
Electronic Structure and Stability of Hydrogen Halides and of Complex Ions XO4
(1) It is shown that in the hydrogen halide molecules (internuclear distance r0) the proton penetrates the electronic shell of the anion to a depth which for the simplified case of spherical symmetry can be characterized by the condition: The amount of negative charge beyond the sphere of radius r0 equals â1e. (2) From the dipole moments ÎŒ=xer0 of the hydrogen halide molecules it can be concluded: The wave mechanical distribution of the negative charge of the free halide ions is changed by the introduction of the proton in such a way that the center of gravity of an amount of charge equal to â(1âx)e is shifted from the halogen nucleus to the proton. The fraction (1âx) increases with the electronic polarizability of the anion, and would be equal to 1 for an ion of infinitely large polarizability, leading to a completely unpolar type of binding in this case. (3) It is shown that for the complex ions SiO44â, PO43â, SO4=, and ClO4â, the gradation of the XâO distances and of the molar dispersion can be easily understood from the point of view used in 1924 for the case of the molar refraction: These ions represent the result of the polarization of O= by Si4+, P5+, S6+, and Cl7+, and the XâO binding in them shows gradual changes toward the unpolar type. (4) It is pointed out that the relatively unstable HI and ClO4â approach the unpolar type of binding more closely than any other of the compounds considered here. The generalization of this connection between instability and the degree of deformation of electronic shells explains why compounds like FO4â and BrO4â are unknown.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70366/2/JCPSA6-10-7-410-1.pd
Discontinuous Change of Binding Type in the Series of Monohydrides. III. Regularities and Irregularities of Internuclear Distances and Force Constants
The recently attempted correlation of internuclear distances of the monohydrides of all elements by linear plots of logr vs logZ (atomic number) for each of the two octaves and of the three long periods is not satisfactory. The equations re=2.2240 nâ0.426 and r0=2.7793 nâ0.371 (n is the total number of valence electrons in the hydride) apply merely from HF to BH and from HCl to AlH, respectively. The marked deviations from these equations shown by the hydrides M (I) H and M (II) H are related to a discontinuous change of binding type. In the long periods, r increases for the hydrides of the heavy metals from M (I) H to M (III) H, due to the decrease of polarizability and penetrability of the cations with an 18âelectron (s2p6d10) outer shell, e.g., from AgH to InH. It is emphasized that the knowledge of spectroscopic data for molecule ions of the hydrides of long period elements is necessary in order to decide at which places discontinuous changes of binding type occur.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70893/2/JCPSA6-43-7-2159-1.pd
Molar Volume, Refraction and Interionic Forces
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70588/2/JCPSA6-9-3-282-1.pd
Erratum: Discontinuous Change of Binding Type in the Series of Monohydrides. II. Place of Discontinuity
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69666/2/JCPSA6-42-10-3742-3.pd
Difficulties in the Valence Bond Theory
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70689/2/JCPSA6-10-12-760-1.pd
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