3 dB squeezing by single-pass parametric amplification in a periodically poled KTiOPO4 crystal.

We present the experimental observation of pulsed squeezed light from a degenerate optical parametric amplifier pumped by a second harmonic of a continuous-wave mode-locked Nd:YVO4 laser. With a single pass through a 10 mm long periodically poled KTiOPO4 crystal, the classical parametric gain of 11 is observed. The measured noise reduction in the quiet quadrature is 3.2 dB below the shot-noise level.

High-density trapping of cold ytterbium atoms by an optical dipole force.

We have succeeded in trapping a high density of rare-earth atom of ytterbium (Yb) in a crossed far-off resonance trap. The peak density reaches more than 10(14) cm(-3). With a new method of a delayed crossed far-off resonance trap, we have elucidated that the atoms became concentrated into the cross region by atom-atom collisions. We trap fermionic Yb atoms in the same way as bosonic ones.

Determination of germanium by graphite-furnace atomic-absorption spectrometry.

The premature loss of germanium as volatile GeO results in low sensitivity and poor reproducibility in the determination of germanium by graphite-furnace atomic-absorption spectrometry. This interference can be eliminated by suppressing the premature reduction of GeO(2) to GeO during the ashing step, and dissociating the germanium oxides into the atoms simultaneously with their vaporization during the atomization step. The premature reduction of GeO(2) to GeO has been successfully prevented by several approaches: (1) diminishing the reducing activity of the graphite furnace by (a) oxidizing the graphite surface and intercalating oxygen into the graphite lattice with oxidizing acids, such as nitric or perchloric, in the sample solution, or (b) using a tantalum-treated graphite furnace; (2) keeping the analyte as germanium (IV) by addition of sodium or potassium hydroxide to the sample solutions.

Fundamental investigation of thermal properties of rare-earth beta-diketonates.

The thermal properties of the rare-earth chelates of Htfa (trifluoroacetylacetone) and Hhfa (hexafluoroacetylacetone) have been investigated. Thermogravimetric curves were obtained by heating samples in the injection chamber of a gas chromatograph, both in an atmosphere of helium, and of helium containing ligand vapour. None of the chelates was completely vaporized in a helium atmosphere at temperatures up to about 240 degrees , but the tfa chelate of Lu and all the hfa chelates were completely vaporized in the atmosphere of helium containing ligand vapour. The vapour pressures and heats of vaporization of these chelates were also measured.

Gas chromatography of metal chelates with carrier gas containing ligand vapour.

The vapour of the ligand was used as carrier-gas additive in the gas chromatography of metal chelates. The effect of trifluoro-acetylacetone on non-symmetrical peaks was examined for Be(TFA)(2), Al(TPA)(3) Cr(TFA)(3), Pe(TFA)(3), U(TFA)(4) and Th(TFA)(4). All the chromatograms appeared quite normally especially those of Th(TFA)(4); Fe(TFA)(3) and Th(TFA)(4) were improved markedly by using the carrier gas containing ligand vapour.

Solid-liquid separation after liquid-liquid extraction.

A low-melting solid is used as organic solvent for liquid-liquid extraction at elevated temperatures followed by solidification and decantation of the aqueous phase.