摘要:
Novel calix[4]arene dibenzo crown ethers useful to selectively extract cesium are represented by the formula: wherein R is a C.sub.1 -C.sub.10 normal alkyl, a phenyl or a methoxyphenyl, R' is hydrogen, p-tert-butyl or a C.sub.1 -C.sub.10 normal alkyl, R" is a C.sub.1 -C.sub.10 normal alkyl, and n is an integer of 0-2. The novel compound is prepared at high yields by introduction of benzene rings into the crown ether ring of calix[4]arene crown-6-ether. The calix[4]arene dibenzo crown ethers are superior in selective absorptivity for cesium ions by virtue of their 1,3-alternate conformational structure and thus, can be used as selective extractants able to separate cesium ions at a high efficiency.
摘要:
Provided is a rehosting method for converting a mainframe system environment into an open system environment. The rehosting method rebuilds hardware (HAV) and software (SAV) of a company-data processing mainframe system environment to be appropriate for an open system environment, converts data included in a database or a general file to be appropriate for the open system environment, and reuses an application program. Thus, the rehosting method can be implemented at low cost within a short time and can significantly reduce maintenance cost.