A series of compounds were discovered which have the generalized formula R22+R4+R25+Og.Examination of single crystals of Pb~ZrP209 showed it to have hexagonal symmetry with aH ~ 10.08fl~ and CH ~ 23.29A. Five of the seven compounds studied (Ba2ZrP,209, Sr2ZrP209, Pb2TiP209, Ba2ZrAs2Og, and PbuZrAs2Og) were isostructural with PbuZrP2Og, and the seventh, Sr2ZrAs2Og, had optical properties closely related to the group. With the exception of Pb2TiP2Og, all of the compounds exhibited a broad band blue fluorescence, with an intensity maximum near 4800A, when excited by 25377~ radiation. By contrast, Pb2TiP.209 showed a weak orange fluorescence, more easily excited by 3650A radiation. Emission, absorption, and excitation data are presented.

TIN-STEEL COUPLE IN AIR-FREE SOLUTION 491anodic effects. The corroding potential thus serves to give a direct indication of the corrosion rate. Unfortunately, it must be cautioned that this relationship cannot be generally extended to corrosion relationships in fruits or fruit juices. ACKNOWLEDGMENTResults presented in this paper were obtained in connection with a project on the corrosion of tin plate sponsored by the Inland Steel Co. The author wishes to thank this organization, and in particular Dr. E. D. Martin, for their support and for permitting publication of these results. He further wishes to acknowledge the help of Dr.

The effects of sodium dodecyl sulfate (SDS) concentration (≤ 10 mass %), temperature (35 and 50 °C), and pressure (0.1 to 100 MPa) on the cooperative diffusion coefficient and static correlation length of micelles in solutions in 1 M NaCl were studied using static and dynamic light scattering. These data are interpreted in terms of models of dilute and semidilute solutions of rod-like polymers. The results indicate that the effects of pressure are most significant near the crossover concentration between dilute and semidilute solution behavior. This concentration is a function of temperature and pressure because both of these thermodynamic parameters affect the mean micellar size.

The existence of two zirconium phosphate compounds has been established. The “normal” phosphate, ZrP2O7, has a reversible inversion at 300 °C. and dissociates to the zirconyl compound, (ZrO)2P2O7, at 1550°C., with the simultaneous loss of P2O5 as vapor. The room‐temperature form of ZrP2O7 is cubic with refractive index 1.657 ± 0.003. The zirconyl compound has a stable existence to temperatures around 1600°C. and is characterized by a very low linear thermal‐expansion coefficient.