The direct synthesis process of dimethyl ether (DME) from syngas in slurry reactors is considered to be promising because of its advantages in caloric transfer. In this paper, the influences of operating conditions (temperature, pressure and weight hourly space velocity) on the conversion of CO, selectivity of DME and methanol were studied in a stirred autoclave over Cu-Zn-Al-Zr slurry catalyst...

External flavone aglycones in the overground parts of Veronica chamaedrys L. (Scrophulariaceae) have been analysed by isocratic reversed-phase high performance liquid chromatography. Luteolin, apigenin, luteolin-3'-methyl ether and scuterallein-6,4'-dimethyl ether have been identified. The latter compound is a new flavonoid identified in Veronica genus.

The title compound, C(31)H(34)N(2)O(9), is a product of the Michael addition of the cyclic secondary amine subunit of the (bis-pidino)aza-14-crown-4 ether to dimethyl acetyl-ene-dicarboxyl-ate. The mol-ecule comprises a tricyclic system containing the aza-14-crown-3 ether macrocycle and two six-membered piperidinone rings. The aza-14-crown-3-ether ring adopts a bowl conformation with a dihedral...

Statistical rate theory calculations, in particular formulations of the chemical master equation, are widely used to calculate rate coefficients of interest in combustion environments as a function of temperature and pressure. However, despite the increasing accuracy of electronic structure calculations, small uncertainties in the input parameters for these master equation models can lead to re...

The third-order nonlinear-optical susceptibility of dimethyl ether, (CH3)2O, has been measured in the gas phase over the wavelength range 488 nm < λ < 1064 nm using the technique of gas-phase electric-field-induced second-harmonic generation with periodic phase matching and with N2 as the reference gas. Measurements span a range of temperature, which allows for separation of the temperature-ind...

The viscosities of dimethyl ether (DME, C2H6O) and of the fluorinated propene isomers 2,3,3,3-tetrafluoroprop-1-ene (R1234yf, C3H2F4) and trans-1,3,3,3-tetrafluoropropene (R1234ze(E)) were measured in a combined temperature range from 242 K to 350 K at saturated liquid conditions. The instrument was a sealed gravitational capillary viscometer developed at NIST for volatile liquids. Calibration ...

In view of the problems caused by conventional means energy, it is necessary to promote cleaner and more environmentally friendly ways produce energy. Therefore, study ammonia combustion can be providential for progressive substitution fuels such as oil or natural gas.

A synthesis of ±-cherylline dimethyl ether is reported. The key steps involved are Michael-type addition, radical azidonation of an aldehyde, Curtius rearrangement, and reduction of an isocyanate intermediate followed by Pictet-Spengler cyclization.