Nd（OH）3 particles sized of nanometer have been prepared using the different methods. The obtained neodymium hydroxide samples were investigated using the enhanced electronic Raman spectroscopy, Xray diffraction, tra...Nd（OH）3 particles sized of nanometer have been prepared using the different methods. The obtained neodymium hydroxide samples were investigated using the enhanced electronic Raman spectroscopy, Xray diffraction, transmission electron microscopy, as well as field emission electron microscopy. Observable changes in electronic Raman bands were found among the electronic Raman spectra of Nd （OH）3 particles which formed under different physical-chemical conditions. Compared to the difference of the X-ray diffraction paterns, it suggests that the change of size and morphology of Nd （OH）3 particles occurs with subtle variation on dae coordination environment around the neodymium ions,展开更多
Recently we have successfully produced fine denier PA6 fibers by using additives containing lanthanide compounds.Meanwhile,crystallization and phase transition of PA6 fibers during spinning and drawing processes were ...Recently we have successfully produced fine denier PA6 fibers by using additives containing lanthanide compounds.Meanwhile,crystallization and phase transition of PA6 fibers during spinning and drawing processes were investigated.During the spinning process,β phase crystal could be obtained in as-spun PA6 fibers which were produced with relatively high melt draw ratio,while γ phase crystal predominated when the melt draw ratio was relatively low.β phase crystal,whose behaviors are similar with those of γ phase by FT-IR and XRD characterization,could be transformed to α form easily when PA6 fibers are immersed in boiling water.However,γ phase crystal of PA6 remains unchanged in boiling water.Thus,β and γ phase crystals of PA6 can be differentiated by the crystalline behaviors of PA6 fibers after treatment in boiling water.Further experiments demonstrate that the β phase can also be produced during a drawing process where a phase transformation from γ to α occurs.In other words,β phase may act as an intermediate state during the phase transformation.展开更多
文摘Nd（OH）3 particles sized of nanometer have been prepared using the different methods. The obtained neodymium hydroxide samples were investigated using the enhanced electronic Raman spectroscopy, Xray diffraction, transmission electron microscopy, as well as field emission electron microscopy. Observable changes in electronic Raman bands were found among the electronic Raman spectra of Nd （OH）3 particles which formed under different physical-chemical conditions. Compared to the difference of the X-ray diffraction paterns, it suggests that the change of size and morphology of Nd （OH）3 particles occurs with subtle variation on dae coordination environment around the neodymium ions,
基金Supported by the National Natural Science Foundation of China (Grant Nos. 50673005, 50973003 & 20671007)a program of Advanced Technology Institute, Peking University
文摘Recently we have successfully produced fine denier PA6 fibers by using additives containing lanthanide compounds.Meanwhile,crystallization and phase transition of PA6 fibers during spinning and drawing processes were investigated.During the spinning process,β phase crystal could be obtained in as-spun PA6 fibers which were produced with relatively high melt draw ratio,while γ phase crystal predominated when the melt draw ratio was relatively low.β phase crystal,whose behaviors are similar with those of γ phase by FT-IR and XRD characterization,could be transformed to α form easily when PA6 fibers are immersed in boiling water.However,γ phase crystal of PA6 remains unchanged in boiling water.Thus,β and γ phase crystals of PA6 can be differentiated by the crystalline behaviors of PA6 fibers after treatment in boiling water.Further experiments demonstrate that the β phase can also be produced during a drawing process where a phase transformation from γ to α occurs.In other words,β phase may act as an intermediate state during the phase transformation.
