No abstract available

[en] The element lithium has strong absorption lines near 6707.84 A and 3232.61 A and possesses specific isotope shifts at the respective absorption lines. With the aid of a laser capable of controlling the oscillation spectral width accurately to 0.01 A, the isotopes of this element are separated from each other by irradiating lithium atomic beam with a laser beam tuned to the absorption line of either of the isotopes, ⁶Li and ⁷Li, for thereby selectively exciting the isotope, ionizing the excited isotope along by irradiation with a laser beam having one photon energy enough to pump it from the excited state to the ionized state and separating the ionized isotope from the un-ionized isotope by means of a mass-filter

[en] A method of changing the energy of charged particles contained in a gas comprises allowing the gas to flow into a region of reduced pressure through a tube like member so that viscous forces exerted on the charged particles by the flowing gas molecules determine the kinetic energy of the charged particles. A potential gradient is maintained along the length of the tube so that the potential energy of the charged particles is changed as they pass through the tube. At the end of the tube a free jet expansion occurs so that the kinetic energy of the charged particles is no longer determined by the flowing gas, so that they can be accelerated to any desired kinetic energy by means of another potential gradient. The invention can be used to interface any high pressure ion source to a magnetic sector mass spectrometer, or to permit the operation of an electrospray ion source with an earthed inlet capillary with either a quadrupole or a magnetic sector mass spectrometer

[en] Disclosed is a III-V Group compound semiconductor light-emitting element having a III-V Group compound semiconductor body with a p-n junction and including a p-type layer involved in forming the p-n junction; and a multi-layer electrode mounted on the p-type layer of the semiconductor body. The electrode comprises a first layer of gold alloy containing a small amount of beryllium or zinc and formed in direct contact with the p-type layer of the semiconductor body and an uppermost layer formed of gold or aluminum. A tantalum layer doped with carbon, nitrogen and/or oxygen is formed between the first layer and the uppermost layer by means of vacuum vapor deposition

[en] Solutions passed through a small capillary at 2-10 kV relative to ground are electrosprayed into a bath gas to form a gaseous dispersion of ions that is expanded into vacuum in a small supersonic free jet. A portion of the jet is passed through a skimmer to form a molecular beam that contains a variety of ionic species. Mass spectrometric analysis reveals that these species include solute cations in aggregation with solvent molecules and/or nonionized solute species. The nature of the product ions depends upon the composition and feed rate of the original solution, the temperature and composition of the bath gas, and the voltage applied to the capillary. The exploratory experiments reported here suggest that this novel ion source may be useful for producing in vacuo a wide variety of cluster ions for examination by various spectroscopic techniques. Also inviting is the prospect of extending the applicability of mass spectrometric analysis to large organic molecules that are too complex, too fragile, or too nonvolatile for ionization by more conventional methods. Another intriguing possibility is to use the technique on probing the microscopic structure and properties of solutions

[en] Solution passed through a small capillary tube at several kilovolts relative to its surroundings is electrosprayed into a bath gas at slightly above atmospheric pressure to form a dispersion of ions that expands into vacuum through a small sonic orifice. A portion of the resulting supersonic free jet passes through a skimmer carrying ions into a quadrupole mass spectrometer. Previously reported results were obtained with positive ions formed when the capillary was at a positive potential. The present report concerns operation with the capillary at a negative potential to produce negative ions. As in the case of operation in the positive mode ions with varying degrees of solvation can be obtained from a variety of solute species including complex and nonvolatile organic molecules. No fragmentation of parent species is observed as long as electrical discharge is avoided in the gas phase. The presence of electron scavengers in the bath gas raises the potential at which discharge phenomena begin. Differences and similarities relative to operation in the positive mode are discussed

No abstract available

[en] A hysteresis effect in gain variations with count rate is observed in two of four examined photomultiplier tubes of the same type under certain operational conditions. A phenomenological aspect of the effect is briefly reported to show that the effect explains reasonably some puzzling phenomena ever known in connection with rate-dependent photomultiplier gain variations in scintillation detectors. (Auth.)

[en] The phase diagram of κ-(BEDT-TTF)₂Cu[N(CN)₂]Br around the metal-insulator (MI) boundary controlled by partially deuteration and by cooling rate through the 80 K anomaly has been investigated by resistivity measurements under magnetic fields. The humps of resistance were observed at 33.5 K corresponding to the T* anomaly and at 9.5 K with the hysteresis of resistance in the partially deuterated sample for slowly cooled. According to approach to the critical region of MI transition from the metallic side by the increase of cooling rate: (a) the hump of resistance at the T* anomaly is shifted towards a lower temperature and (b) the temperature of the resistance hump with the hysteresis increases. Our results suggest that these anomalies are related to the phase separation of the metallic and insulator phase around the MI boundary

[en] Mercaptotropone was synthesized from tropone, and its acid dissociation constant (K_a) and distribution coefficient (K_D) between benzene and aqueous solution were spectrophotometrically determined as 5.75 (pK_a) and 2.46 (log K_D). The extraction behaviour of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Y(III), Zr(IV) and Pb(II) with mercaptotropone is studied using the corresponding radioisotopes. Cu(II) and Fe(III) were completely extracted from acidic solution, Y(III) was not extracted at all, the rest of studied compounds was extracted from intermediate pH region. (author) 20 refs.; 5 figs