The alloying behaviour, including solid solubilities of rare-earths as well as the formation and stability of various intermediate phases in palladium-rich Pd-RE systems were studied by means of the atomic size factor...The alloying behaviour, including solid solubilities of rare-earths as well as the formation and stability of various intermediate phases in palladium-rich Pd-RE systems were studied by means of the atomic size factor and the reduced transition temperatures. A strong analogy is observed in the plots of the reduced transition temperatures of various intermediate phases against the atomic numbers of rare-earths, and the law proposed by Hume-Rothery and Raynor for dependence of liquidus temperature on atomic radius in simple alloy systems has been extended to more complicated alloy systems.展开更多
Five homologous series of bifurcate systems of aliphatic and aromatic polyenic cyano andcarboxylic compounds have been prepared and studied. The electronic absorption spectra forthe series and the NMR chemical shifts ...Five homologous series of bifurcate systems of aliphatic and aromatic polyenic cyano andcarboxylic compounds have been prepared and studied. The electronic absorption spectra forthe series and the NMR chemical shifts for the methyl-, methylene- and beta-protons havebeen found to conform very well to the rule of homologous linearity. The mass spectra forthe α-cyano polyenic ester series show strong peaks for the fragments of M-COOEt but noneof M-CN, indicating that the CN group seems to be in stronger conjugation with the poly-enic chain than the COOEt group does. In all the forked series studided, a red shift in electronic spectra is brought about upon theintroduction of an electron-attractive branching group, just like the case of introducing anelectron-repelling substituent. This has been taken as an indication of the predominance of themolecular integrality over the group characteristics. By means of the method of similar triangles between a homologous line for a linearseries and that for the展开更多
文摘The alloying behaviour, including solid solubilities of rare-earths as well as the formation and stability of various intermediate phases in palladium-rich Pd-RE systems were studied by means of the atomic size factor and the reduced transition temperatures. A strong analogy is observed in the plots of the reduced transition temperatures of various intermediate phases against the atomic numbers of rare-earths, and the law proposed by Hume-Rothery and Raynor for dependence of liquidus temperature on atomic radius in simple alloy systems has been extended to more complicated alloy systems.
文摘Five homologous series of bifurcate systems of aliphatic and aromatic polyenic cyano andcarboxylic compounds have been prepared and studied. The electronic absorption spectra forthe series and the NMR chemical shifts for the methyl-, methylene- and beta-protons havebeen found to conform very well to the rule of homologous linearity. The mass spectra forthe α-cyano polyenic ester series show strong peaks for the fragments of M-COOEt but noneof M-CN, indicating that the CN group seems to be in stronger conjugation with the poly-enic chain than the COOEt group does. In all the forked series studided, a red shift in electronic spectra is brought about upon theintroduction of an electron-attractive branching group, just like the case of introducing anelectron-repelling substituent. This has been taken as an indication of the predominance of themolecular integrality over the group characteristics. By means of the method of similar triangles between a homologous line for a linearseries and that for the
