New occurrences of xenolithic alkaline rocks from three East African volcanoes are described. Micro-ijolites and alkali pyroxenites occur in the carbonate-rich tufts and lavas of Mount Elgon; kaersutite-rich pyroxenites and a suite of fenitized basement rocks in the caldera flows of Mount Meru, and apparently unique melanocratic hortonolite nepheline syenites in the central foyaite plug of Moun...

We describe a simple strontium vapor cell for laser spectroscopy experiments. Strontium vapor is produced using an electrically heated commercial dispenser source. The sealed cell operates at room temperature, and without a buffer gas or vacuum pump. The cell was characterized using laser spectroscopy, and was found to offer stable and robust operation, with an estimated lifetime of >10 000 h. ...

[structure: see text] A new type of donor-spacer-acceptor podand system has been synthesized and proved as an efficient dual channel fluorosensor for Li+, Mg2+, and Ca2+. The known ability for the N-oxide function to bind Lewis acids is the key step in the appearance of a new emitting charge-transfer (CT) excited state. The occurrence of this CT state for alkaline earth (Mg2+ and Ca2+) and not ...

The structures of two derivatives of the bisdioxine diisocyanate 1, the bisurea 4 and the biscarbamate 5, are established by X-ray crystallography and DFT calculations. These compounds possess endo,endo structures, in the case of the bisurea 4 with two nearly parallel pendant chains. The X-ray structures are reproduced very well by DFT calculations. Similar endo,endo conformations are calculate...

in this study, a temperature-dependent of the dispersion coefficients is calculated from equation state.the lennard-jones lj (12-6-3) effective pair potential function and simple thermodynamic argumentwith the input pvt data of liquid metals are used to calculate the dispersion coefficients. the dispersioncoefficients ( , , ) 3 6 12 c c c are found to be a linear function of 1/t1+α , where t is...

Abstract The development of efficient thermal energy management devices such as thermoelectrics and barrier coatings often relies on compounds having low lattice conductivity ( ? l ). Here, we present the computational discovery a large family 628 thermodynamically stable quaternary chalcogenides, AMM?Q 3 (A = alkali/alkaline earth/post-transition metals; M/M? transition metals, lanthanides; Q ...