摘要:
An improved process for the preparation of pyrimidine derivatives is provided comprising reacting a Wittig reagent of the general formula wherein R is an alkyl of from 1 to 10 carbon atoms, aryl or arylalkyl, R1 is a substituted or unsubstituted hydrocarbon group, R2 and R3 are the same or different and are hydrogen or a substituted or unsubstituted hydrocarbon group; Z is sulfur, oxygen, sulfonyl, or imino which may be substituted by formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, amino substituted by sulfonyl or alkylsulfonyl, and sulfonyl substituted by alkyl, amino or alkylamino and X is a halogen; with an aldehyde of the general formula wherein R4 is hydrogen, a lower alkyl or a cation capable of forming a non-toxic pharmaceutically acceptable salt and each R5 are the same or different and are hydrogen or a hydrolyzable protecting group, or each R5, together with the oxygen atom to which each is bonded, form a hydrolyzable cyclic protecting group, or each R5 is bonded to the same substituent which is bonded to each oxygen atom to form a hydrolyzable protecting group; in the presence of a base.
摘要:
Information storage devices are permanently deployed on individual components of turbine engines to permanently record operating, repair, and maintenance data on the parts that comprise the individual components. Ensuring that such data will not be lost when individual components or their parts are replaced in an engine, allows the use of life limited parts in turbine engines and improves their reliability. The information storage devices can be accessed to record maintenance or to record changes when repairs are done. They can also be attached to external circuitry for the purpose of analyzing, downloading or recording data remotely, allowing analysis of component operating, repair, and maintenance information.
摘要:
A gas turbine engine combustor can downstream of a pre-mixer has a pre-mixer flowpath therein and circumferentially spaced apart swirling vanes disposed across the pre-mixer flowpath. A primary fuel injector is positioned for injecting fuel into the pre-mixer flowpath. A combustion chamber surrounded by an annular combustor liner disposed in supply flow communication with the pre-mixer. An annular trapped dual vortex cavity located at an upstream end of the combustor liner is defined between an annular aft wall, an annular forward wall, and a circular radially outer wall formed therebetween. A cavity opening at a radially inner end of the cavity is spaced apart from the radially outer wall. Air injection first holes are disposed through the forward wall and air injection second holes are disposed through the aft wall. Fuel injection holes are disposed through at least one of the forward and aft walls.