We report on the heterobimetallic system, Eu[Ag(x)Au(1-x)(CN)(2)](3) (x = 0-1) in which sensitization of europium luminescence occurs by energy transfer from [Ag(x)Au(1-x)(CN)(2)](-) donor excited states. The donor states have energies which are tunable and dependent on the Ag/Au stoichiometric ratio. These layered systems exhibit interesting properties, one of which is their emission energy tunability when excited at different excitation wavelengths. In this paper, we report on their use as donor systems with Eu(III) ions as acceptor ions in energy transfer studies. Luminescence results show that the mixed metal dicyanides with the higher silver loading have a better energy transfer efficiency than the pure Ag(CN)(2)(-) and Au(CN)(2)(-) donors. The better energy transfer efficiency is due to the greater overlap between the donor emission and acceptor excitation. Additionally, more acceptor states are available in the high silver loading mixed metal Eu(III) complexes. The results from a crystal structure determination and Raman experiments are also presented in this paper and provide information about metallophilic interactions in the closed-shell d(10) metal-metal [Ag(x)Au(1-x)(CN(2)](-) dicyanide clusters.

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a-, DTIC S ELECTE OCT231992 U 1 039227801The dielectric properties of wet and dry natural snow were studied In the frequency range of 50 Hz to 100 kHz to deterrnlne wfether measurements made In this frequency range might prove useful in evaluating the water content of snow. Dielectric heating at 20 kHz proved a very useful means of modifying the water content from 0 to 30% by weight. Six different natural snows were used in these experiments. Meltwater was analyzed for conductivity, pH, and Impurity content. In addition to developing Information on the dielectric properties of wet and dry snow, we measured the changes produced in dry snow by altering Its density overthe range of 0. 11 to 0.66 g/cm 3 . Details of the experimental technique and the data obtained are fully reported. Our results do not lead to optimism about the usefulness of measurements In this frequency range alone for the determination of water content.For conversion of SI metric units to U.SJBrltlsh customary units of measurement consult ASTM Standard E380, Mfr Ptce Gukde, published by the American Society for Testing and Materials, 1916 Race St., PhIladelphia, Pa. 19103. This report Is printed on paper that contains a minimum of 50% recycled material. The authos thank Kurt Knuth and Gary Koh of CRREL for technically reviewing the manuscript of this report. They also express their appreciation to Ronald Atkins of CRREL for many hours of technical discussion during the progress of this work as well as for review of the manuscript.The contents of this report are not to be used for advertising or promotional purposes. Citation of brand names does not constitute an official endorsement or approval of the use of such commercial produ'ts. ..................................................................................................................... show n ................................................................................... 1, 2 and 3 .............................................................. I through V ......................................................... water for sample 3 ........................................................ 13 14. Dielectric spectra for sample 1 for indicated water contents ....................................... for dry snow samples ............................................................. 32 40. Log 1 0 K vs logl 0 density for samples 10-16 having water contents between I and 3% .... 32 Sam ple data ......................................................................................................................... 12 3. Polynomial fit to data for samples 10-16 .................................................................. Figure 1 shows the approximate dielectric constant for ice at 0°C as a function of frequency (solid line). The Knowledge of the free water content of snowfields is dielectric constant of water is also shown (dashed line). important in snow mechanics, hydrology, avalanche It would appear that one might easily determine the control and in satellite imagery int...

We demonstrated that the use of high-frequency QIGs can extend the operational lower m/z range for both external EI- and ESI-FTICR mass spectrometers. By considering both ICR and Mathieu equations of motions to describe ion trajectories, theoretical ion ejection thresholds (consistent with our experimental findings) could be predicted.