I. Introduction. Background. Focus of the review. Review procedure and results. The NEA-TDB data base system. Presentation of the selected data. II. Standards and Conventions. Symbols, terminology and nomenclature. Units and conversion factors. Standard and reference conditions. Fundamental physical constants. III. Selected Uranium Data. IV. Selected Auxiliary Data. V. Discussion of Data Selection. Elemental uranium. Aqua ions. Oxide, hydride and hydroxide species. VI. Discussion of Auxiliary Data Selection. Reference list. Authors list. Formula list. Discussion of selected references. Ionic strength corrections. Assigned uncertainties. The estimation of entropies.

Chemical thermodynamics of uranium

This is a review and analysis of the optical properties of quantum crystallites, with principal emphasis on the electro-optic Stark effect and all optical third order nonlinearity. There are also introductory discussions on physical size regimes, crystallite synthesis, quantum confinement theory, and linear optical properties. The experiments describe CdSe crystallites, exhibiting strong confinement of electrons and holes, and CuCl crystallites, exhibiting weak confinement of the exciton center of mass. In the CdSe system, neither the Stark effect nor the third order nonlinearity is well understood. The Stark shifts appear to be smaller than calculated, and field inducted broadening also occurs. The third order nonlinearity is only modestly stronger than in bulk material, despite theoretical prediction. Unexpectedly large homogeneous widths, due to surface carrier trapping, in the nominally discrete crystallite excited states appear to be involved. The CuCl system shows far narrower spectroscopic homogeneous widths, and corresponds more closely to an ideal quantum dot in the weak confinement limit. CuCl also exhibits exciton superradiance at low temperature. Surface chemistry and crystallite encapsulation are critical in achieving the predicted large Stark and third order optical effects in II-VI and III-V crystallites.

Quantum crystallites and nonlinear optics

A substantial amount of work has been carried out in the area of nanocomposite materials for optical applications. Composites are typically constructed by embedding an optically functional phase into a processable, transparent matrix material. By doing so, the optical properties can be utilized in more technologically important forms such as films and fibers. This review covers many areas of optical composite research to date. Composites with second- and third-order nonlinearities and laser amplification properties are discussed with examples from the recent literature. Other composites, including transparent magnets, may be made using similar structures. The principles used to construct these composites may have important technological applications soon and are therefore summarized in this review.

Nanocomposite Materials for Optical Applications

The science describing semiconductor−liquid interfaces is highly interdisciplinary, broad in scope, interesting, and of importance to various emerging technologies. We present a review of the basic physicochemical principles of semiconductor−liquid interfaces, including their historical development, and describe the major technological applications that are based on these scientific principles.

Physical Chemistry of Semiconductor−Liquid Interfaces

The aqueous geochemistry of the rare-earth elements and yttrium

The growth of small CdS colloidal particles has been initiated by pulse radiolytic release of sulfide from thiol (3-mercapto-1,2-propanediol, RSH) in the presence of Cd{sup 2+} ions. The kinetics and stoichiometry of the ensuring reactions were followed by conductivity, absorption spectroscopy, and light-scattering techniques. The final CdS product has been identified by electron diffraction. The formation of Cd-thiolate complexes at the surface of the particles is indicated by conductivity and by energy dispersive analysis of X-ray (EDAX) results. The rate of formation of CdS clusters is strongly pH dependent due to the pH effect on the stability of Dd{sup 2+}/HS{sup {minus}} complexes. At low pHs (4.0-5.3) the growth mechanism is proposed to be primarily a cluster-molecule process. At this pH range Cd{sup 2+} ions at the CdS particle surface complex with thiolate ions stronger than in the bulk of the solution. The size control of the particles by thiols is proposed to result from a competition of thiolate ions with HS{sup {minus}} ions for cadmium ions at the surface of the growing particles.

Thiol surface complexation on growing CdS clusters

Absorption spectrum of eaq- in the temperature range -4 to 390.deg.

The transient change in conductivity in diluted barium hydroxide solutions during and immediately after irradiation with single pulses of electrons from a 15-million-electron-volt linear accelerator was measured. Ionic mobility of the radiation-produced hydrated electrons was 1.84 x 10-3cm-2 volt-1 sec-1 ± 10 percent. This value corresponds to a diffusion constant of 4.75 x 10-5 cm2 sec-1.

https://science.sciencemag.org/content/sci/151/3706/70.full.pdf

Mobility of the hydrated electron.

A pulse radiolysis study of aqueous benzene solutions

Obtention par radiolyse pulsee des radicaux suivants: benzhydryle et dihydro-10,11 dibenzo(a,d] cycloheptenyle-5 (groupe 1), trityle, α-cyclopropylbenzydryle et diphenyl-1,1 ethyle (groupe 2). Ils sont excites par photolyse Laser eclair (λ=347 nm). Etude de la fluorescence et de la photoreactivite. La distinction des deux ensembles de radicaux caracterise la difference de comportement qui s'interprete par le degre de torsion des groupes phenyles a l'exterieur du plan moleculaire. Mecanisme

Klaus H. Schmidt

Papers

Thiol surface complexation on growing CdS clusters

Absorption spectrum of eaq- in the temperature range -4 to 390.deg.

Mobility of the hydrated electron.

A pulse radiolysis study of aqueous benzene solutions

Photophysics and photochemistry of arylmethyl radicals in liquids