We would like to propose a new in-line multi-channel power level monitor, which is applicable as tap-monitor for multi-channel WDM signals. Its ribbon fiber structure has far exceeded PLC performance and realized comp...We would like to propose a new in-line multi-channel power level monitor, which is applicable as tap-monitor for multi-channel WDM signals. Its ribbon fiber structure has far exceeded PLC performance and realized compact-size and lower insertion/polarization dependent loss.展开更多
Substituted polyglycolides having two asymmetric centers are attractive alternatives to materials derived from petroleum because of their biocompatibility and biodegradability. The conformational behavior of various s...Substituted polyglycolides having two asymmetric centers are attractive alternatives to materials derived from petroleum because of their biocompatibility and biodegradability. The conformational behavior of various substituted polyglycolides has been investigated by both quantum mechanical and molecular dynamics approaches. Polymethylglycolide (polylactide) and polyphenylmethylglycolide in RS or SR forms are predicted to adopt 27 ribbon type structures with φ, ψ values of ±30, ±50 or +30 or +50 respectively stabilised by carbonyl-carbonyl interactions. Isopropylglycolide and isobutyl-glycolide having branching at β & γ positions respectively in their side chains can be realized in all SS form with φ, ψ values lying in right handed helical region. In addition to carbonyl-carbonyl interactions, the hydrophobic interactions between the side chains in isopropylgly-colide the C-H-O interactions also contributes to the stability. With cyclic side chains directly attached to Cα of backbone, polyphenylglycolide (polymandelide) and polycyclohexylglycolide are found to adopt left handed helical structure without hydrogen bonds in RR form, stabilised by stacking interactions and hydrophobic interactions respectively. In all the forms of polyphenylglycolide & polycyclohexylglycolide, the cyclic side chains are found to be locked into unfavourable gauche plus conformation. The stability of substituted polyglycolides has been analyzed in terms of various interactions. The carbonyl-carbonyl interactions in all the conformations of all forms of substituted polyglycolides are found to be of highly shielded parallel motif with only one short carbon-oxygen interaction. Simulation studies of substituted polyglycolides in water give a good insight of the approach of water molecules to the backbone.展开更多
文摘We would like to propose a new in-line multi-channel power level monitor, which is applicable as tap-monitor for multi-channel WDM signals. Its ribbon fiber structure has far exceeded PLC performance and realized compact-size and lower insertion/polarization dependent loss.
文摘Substituted polyglycolides having two asymmetric centers are attractive alternatives to materials derived from petroleum because of their biocompatibility and biodegradability. The conformational behavior of various substituted polyglycolides has been investigated by both quantum mechanical and molecular dynamics approaches. Polymethylglycolide (polylactide) and polyphenylmethylglycolide in RS or SR forms are predicted to adopt 27 ribbon type structures with φ, ψ values of ±30, ±50 or +30 or +50 respectively stabilised by carbonyl-carbonyl interactions. Isopropylglycolide and isobutyl-glycolide having branching at β & γ positions respectively in their side chains can be realized in all SS form with φ, ψ values lying in right handed helical region. In addition to carbonyl-carbonyl interactions, the hydrophobic interactions between the side chains in isopropylgly-colide the C-H-O interactions also contributes to the stability. With cyclic side chains directly attached to Cα of backbone, polyphenylglycolide (polymandelide) and polycyclohexylglycolide are found to adopt left handed helical structure without hydrogen bonds in RR form, stabilised by stacking interactions and hydrophobic interactions respectively. In all the forms of polyphenylglycolide & polycyclohexylglycolide, the cyclic side chains are found to be locked into unfavourable gauche plus conformation. The stability of substituted polyglycolides has been analyzed in terms of various interactions. The carbonyl-carbonyl interactions in all the conformations of all forms of substituted polyglycolides are found to be of highly shielded parallel motif with only one short carbon-oxygen interaction. Simulation studies of substituted polyglycolides in water give a good insight of the approach of water molecules to the backbone.
