Fir laser emissions from population inversion transition by TEA-CO2 laser pumping

In this paper, the numerical analysis is given which is applicable for a TEA-CO₂ laser pumping in search of effective pumping method.The analysis also can estimate the optimum pressure for a given molecule and a given pulse laser.Also we report in this work many FIR laser emissions from population inversion transition which have never observed before using a TEA-CO₂ laser.     

Conformations of the triplet state of aromatic olefins. Observation of the transoid triplet states of 3,3-dimethyl-1-(2-naphthyl)-1-butene and 3,4-dihydrophenanthrene as a rigid planar triplet model

The observed triplet—triplet absorption of 3,3-dimethyl-1-(2-naphthyl)-1-butene is assigned to the planar transoid geometry (³t*) from its spectral similarity to the 3,4-dihydrophenanthrene triplet, a rigid planar model, as well as from the measured rate constants for its quenching by azulene and oxygen. The results are in contrast the 1,2-diarylethylene triplets which favor the perpendicularly twisted geometry (³p*).     

Ptychanolide, a sesquiterpenoid with a new type skeleton from the liverwort ptychanthus striatus (lehm. et lindenb.) nees

The structure of ptychanolide, isolated from the liverwort Ptychanthus striatus, has been determined by spectroscopic analysis and chemical transformation.     

Thermal rearrangement of dienolesters. Sequential [1.3] sigmatropic rearrangement and intramolecular diels-alder cycloaddition of 1-methylene-2-methyl-2-propenyl hex-5-enoate

The high temperature thermal rearrangement of the title dienol ester is reported. Its reactions entail a [1.3] acyl shift followed by intramolecular Diels-Alder cyclo-addition of the resulting β-diketone.     

Evaporation of VC and TiC in floating zone melting

The evaporation of vanadium carbide during floating zone systems was examined. The evaporation composition and rate were measured as a function of the melt composition. At a composition of C/V = 0.72, the dependence of evaporation rate on ambient gas pressure (P) was measured at the range of 3.5–40 atm of helium and argon. The evaporation rate was proportional to P^-0.70 in helium and P^-0.31 in argon. The same results were obtained with TiC. These pressure dependences are shown to be expected for laminar and turbulent free convective mass transport.     

Preparation and synthetic use of the zerovalent nickel complex by electrochemical reduction

The generation of Ni(PPh₃)₄ by electrochemical reduction was carried out in a divided cell containing NiCl₂(PPh₃)₄, PPh₃ and n-Bu₄NBr in DMF with a lead plate as cathode and a platinum plate as anode under the stream of argon at 60°. Using this Ni(PPh₃)₄, biphenyls and the heterocyclic compounds were synthesized in fairly good yields.