Die Synthese und Kristallstruktur von Caesium-Praseodymsulfat Über Salze und Doppelsalze der Seltenen Erden, 4. Mitt.

Crystals of the title compound were prepared by heating Cs[Pr(SO₄)₂(H₂O)₃]·H₂O with H₂SO₄ at 300°C. CsPr(SO₄)₂ crystallizes in the orthorhombic space group Pnna witha=9.497(3),b=14.106(5),c=5.457(1) Å,p ₀=4.20,p _c=4.236 gcm^-3,Z=4. The structure, solved by the heavy-atom method from X-ray diffractometer data, was refined by least-squares techniques to R=0.023. The praseodymium atom is eight coordinated by eight oxygen atoms in the form of a distortedArchimedian antiprism. The antiprisms together with sulphur atoms form a layer-like structure parallel to thexz plane. The caesium atoms, which lie between the layers, have a coordination number of fourteen.

---

---

3. Mitt.: Mh. Chem.108, 997 (1977).     

Characterization of poly(ethylene oxide) modified with different phenyl hepta isobutyl polyhedral oligomeric silsesquioxanes

Journal of Thermal Analysis and Calorimetry - Poly(ethylene oxide)/polyhedral oligomeric silsesquioxanes (PEO/POSSs) composites were prepared by the melting method. The investigation of their...     

A Lower Bound on Blowup Rates for the 3D Incompressible Euler Equation and a Single Exponential Beale-Kato-Majda Type Estimate

We prove a Beale-Kato-Majda type criterion for the loss of regularity for solutions of the incompressible Euler equations in , for . Instead of double exponential estimates of Beale-Kato-Majda type, we obtain a single exponential bound on involving the length parameter introduced by Constantin in (SIAM Rev. 36(1):73–98, 1994). In particular, we derive lower bounds on the blowup rate of such solutions.     

Four algorithms to solve symmetric multi-type non-negative matrix tri-factorization problem

Journal of Global Optimization - In this paper, we consider the symmetric multi-type non-negative matrix tri-factorization problem (SNMTF), which attempts to factorize several symmetric...     

Perturbations of the Dushman Reaction with Piroxicam: Experimental and Model Calculations

Perturbation of the Bray? Liebhafsky non‐oscillating subsystem (mixture of KIO₃ and H₂SO₄), i.e., Dushman reaction (DR), by piroxicam (PX), was observed in an open reactor, i.e., in the continuously fed well‐stirred tank reactor (CSTR). Monitoring the response of DR to perturbations by different concentrations of PX allows developing a simple procedure for quantitative determination of this analyte in both bulk drug and pharmaceutical preparation (injection). A tentative perturbation mechanism of PX action on the DR matrix, based on a kinetic scheme that was suggested by Agreda et al., is proposed. The PX reactivity in DR has been generally related to the reaction of PX with hypoiodous acid (HIO) present in the matrix.