The Peierls structural transition in quasi-one-dimensional organic crystals of TTF-TCNQ is investigated in the frame of a more complete physical model. The two most important electron-phonon interaction mechanisms are...The Peierls structural transition in quasi-one-dimensional organic crystals of TTF-TCNQ is investigated in the frame of a more complete physical model. The two most important electron-phonon interaction mechanisms are taken into account simultaneously. One is similar of that of deformation potential and the other is of polaron type. For simplicity, the 2D crystal model is considered. The renormalized phonon spectrum and the phonon polarization operator are calculated in the random phase approximation for different temperatures. The effects of interchain interaction on renormalized acoustic phonons and on the Peierls critical temperature are analyzed.展开更多
The Peierls structural transition in the TTT<sub>2</sub>I<sub>3</sub> (tetrathiotetracene-iodide) crystal, for different values of carrier concentration is studied in 3D approximation. A crysta...The Peierls structural transition in the TTT<sub>2</sub>I<sub>3</sub> (tetrathiotetracene-iodide) crystal, for different values of carrier concentration is studied in 3D approximation. A crystal physical model is applied that considers two of the most important hole-phonon interactions. The first interaction describes the deformation potential and the second one is of polaron type. In the presented physical model, the interaction of carriers with the structural defects is taken into account. This is crucial for the explanation of the transition. The renormalized phonon spectrum is calculated in the random phase approximation for different temperatures applying the method of Green functions. The renormalized phonon frequencies for different temperatures are presented in two cases. In the first case the interaction between TTT chains is neglected. In the second one, this interaction is taken into account. Computer simulations for the 3D physical model of the TTT<sub>2</sub>I<sub>3</sub> crystal are performed for different values of dimensionless Fermi momentum <em>k</em><sub>F</sub>, that is determined by variation of carrier concentration. It is shown that the transition is of Peierls type and strongly depends on iodine concentration. Finally, the Peierls critical temperature was determined.展开更多
Hydrogels are promising candidates for mimicking native extracellular matrix(ECM)and are therefore widely adopted as scaffolds in tissue engineering.However,conventional hydrogels composed of static networks are prone...Hydrogels are promising candidates for mimicking native extracellular matrix(ECM)and are therefore widely adopted as scaffolds in tissue engineering.However,conventional hydrogels composed of static networks are prone to permanent structural damages and lack the ability to provide the time-dependent mechanical cues,which are essential for cell development,ECM remodeling,and tissue regeneration.The recent substantial development in the structurally dynamic hydrogels with energy-dissipative ability has demonstrated the unique capability of such viscoelastic hydrogels to withstand extreme biomechanical loads and regulate cellular behaviors not present in classical hydrogels.This review starts with the general design principles for energy-dissipative hydrogels,followed by recent advancements in fabrication approaches for energy-dissipative hydrogels.We then highlight some applications of energy-dissipative hydrogels in tissue engineering,including bone and cartilage regeneration,vessel regeneration,nerve regeneration,and wound healing.Finally,we discuss about the key current challenges and future development of energy-dissipative hydrogels for biomedical applications.展开更多
文摘The Peierls structural transition in quasi-one-dimensional organic crystals of TTF-TCNQ is investigated in the frame of a more complete physical model. The two most important electron-phonon interaction mechanisms are taken into account simultaneously. One is similar of that of deformation potential and the other is of polaron type. For simplicity, the 2D crystal model is considered. The renormalized phonon spectrum and the phonon polarization operator are calculated in the random phase approximation for different temperatures. The effects of interchain interaction on renormalized acoustic phonons and on the Peierls critical temperature are analyzed.
文摘The Peierls structural transition in the TTT<sub>2</sub>I<sub>3</sub> (tetrathiotetracene-iodide) crystal, for different values of carrier concentration is studied in 3D approximation. A crystal physical model is applied that considers two of the most important hole-phonon interactions. The first interaction describes the deformation potential and the second one is of polaron type. In the presented physical model, the interaction of carriers with the structural defects is taken into account. This is crucial for the explanation of the transition. The renormalized phonon spectrum is calculated in the random phase approximation for different temperatures applying the method of Green functions. The renormalized phonon frequencies for different temperatures are presented in two cases. In the first case the interaction between TTT chains is neglected. In the second one, this interaction is taken into account. Computer simulations for the 3D physical model of the TTT<sub>2</sub>I<sub>3</sub> crystal are performed for different values of dimensionless Fermi momentum <em>k</em><sub>F</sub>, that is determined by variation of carrier concentration. It is shown that the transition is of Peierls type and strongly depends on iodine concentration. Finally, the Peierls critical temperature was determined.
基金This work was supported by the National Key R&D Program of China(2022YFB380440003)the National Natural Science Foundation of China(32271385).
文摘Hydrogels are promising candidates for mimicking native extracellular matrix(ECM)and are therefore widely adopted as scaffolds in tissue engineering.However,conventional hydrogels composed of static networks are prone to permanent structural damages and lack the ability to provide the time-dependent mechanical cues,which are essential for cell development,ECM remodeling,and tissue regeneration.The recent substantial development in the structurally dynamic hydrogels with energy-dissipative ability has demonstrated the unique capability of such viscoelastic hydrogels to withstand extreme biomechanical loads and regulate cellular behaviors not present in classical hydrogels.This review starts with the general design principles for energy-dissipative hydrogels,followed by recent advancements in fabrication approaches for energy-dissipative hydrogels.We then highlight some applications of energy-dissipative hydrogels in tissue engineering,including bone and cartilage regeneration,vessel regeneration,nerve regeneration,and wound healing.Finally,we discuss about the key current challenges and future development of energy-dissipative hydrogels for biomedical applications.
