摘要:
A method for producing a dichloropentafluoropropane, which comprises reacting dichlorofluoromethane (R21) with tetrafluoroethylene (4F) in the presence of a Lewis acid catalyst for addition reaction to obtain dichloropentafluoropropane, wherein a halide containing at least one element selected from the group consisting of Sb, Nb, Ta, B, Ga, In, Zr, Hf and Ti, or AlBr.sub.3, or AlI.sub.3, is used as the Lewis acid.
摘要:
An optically active compound having the formula: ##STR1## wherein each of Z and Z' is a single bond, --COO--, --OCO--, --CH.sub.2 CH.sub.2 --, --OCH.sub.2 -- or --CH.sub.2 O--, R is an alkyl group having from 1 to 12 carbon atoms, an alkoxyl group having from 1 to 12 carbon atoms, a cyano group or a halogen atom, each of rings A and B is a 1,4-di-substituted phenylene group or a trans-1,4-di-substituted cyclohexylene group, n is 0 or 1, X is ##STR2## wherein * indicates an optical center, and R' is an alkyl group having from 2 to 12 carbon atoms or ##STR3## where R" is a hydrogen atom, an alkyl or alkoxy group having from 1 to 12 carbon atoms, provided that when X is ##STR4## R is the alkyl group or the alkoxy group.
摘要:
New method to control the optical transmitter is disclosed. The optical transmitter provides both of the ATC feedback loop and the APC feedback loop. When a failure occurs in the ATC feedback loop and the temperature sensor is unable to output an adequate signal any longer, the optical transmitter cuts the APC loop and operates the LD in constant conditions. The output of the monitor PD is transferred to the ATC loop to control the TEC based on the optical output of the LD.
摘要:
A method for producing a dichloropentafluoropropane, which comprises reacting dichlorofluoromethane (R21) with tetrafluoroethylene (4F) in the presence of a Lewis acid catalyst for addition reaction to obtain dichloropentafluoropropane, wherein a halide containing at least one element selected from the group consisting of Sb, Nb, Ta, B, Ga, In, Zr, Hf and Ti, or AlBr.sub.3, or AlI.sub.3, is used as the Lewis acid.
摘要:
A compound represented by the general formula: ##STR1## where X is a halogen atom, an alkyl group having from 1 to 8 carbon atoms or a cyano group, and R is an alkyl group having from 1 to 8 carbon atoms.
摘要:
A method for producing a dichloropentafluoropropane, which comprises reacting dichlorofluoromethane (R21) with tetrafluoroethylene (4F) in the presence of a Lewis acid catalyst for addition reaction to obtain dichloropentafluoropropane, wherein a halide containing at least one element selected from the group consisting of Sb, Nb, Ta, B, Ga, In, Zr, Hf and Ti, or AlBr.sub.3, or AlI.sub.3, is used as the Lewis acid.
摘要:
New method to control the optical transmitter is disclosed. The optical transmitter provides both of the ATC feedback loop and the APC feedback loop. When a failure occurs in the ATC feedback loop and the temperature sensor is unable to output an adequate signal any longer, the optical transmitter cuts the APC loop and operates the LD in constant conditions. The output of the monitor PD is transferred to the ATC loop to control the TEC based on the optical output of the LD.