We present a new polymer quartz piezoelectric crystal sensor that takes a quartz piezoelectric crystal as the basal material and a nanometer nonmetallic polymer thin film as the surface coating based on the principle ...We present a new polymer quartz piezoelectric crystal sensor that takes a quartz piezoelectric crystal as the basal material and a nanometer nonmetallic polymer thin film as the surface coating based on the principle of quartz crystal microbalance(QCM). The new sensor can be used to detect the characteristic materials of a volatile liquid. A mechanical model of the new sensor was built, whose structure was a thin circle plate composing of polytef/quartz piezoelectric/polytef. The mechanical model had a diameter of 8 mm and a thickness of 170 μm. The vibration state of the model was simulated by software ANSYS after the physical parameters and the boundary condition of the new sensor were set. According to the results of experiments, we set up a frequency range from 9.995850 MHz to 9.997225 MHz, 17 kinds of frequencies and modes of vibration were obtained within this range. We found a special frequency fspof 9.996358 MHz. When the resonant frequency of the new sensor's mechanical model reached the special frequency, a special phenomenon occurred. In this case, the amplitude of the center point O on the mechanical model reached the maximum value. At the same time, the minimum absolute difference between the simulated frequency based on the ANSYS software and the experimental measured stable frequency was reached. The research showed that the design of the new polymer quartz piezoelectric crystal sensor perfectly conforms to the principle of QCM. A special frequency value fspwas found and subsequently became one of the most important parameters in the new sensor design.展开更多
Part II of this study detects the dominant decadal-centennial timescales in four SST indices up to the 2010/2011 winter and tries to relate them to the observed 11-yr and 88-yr solar activity with the sunspot number u...Part II of this study detects the dominant decadal-centennial timescales in four SST indices up to the 2010/2011 winter and tries to relate them to the observed 11-yr and 88-yr solar activity with the sunspot number up to Solar Cycle 24.To explore plausible solar origins of the observed decadal-centennial timescales in the SSTs and climate variability in general,we design a simple one-dimensional dynamical system forced by an annual cycle modulated by a small-amplitude single-or multi-scale"solar activity."Results suggest that nonlinear harmonic and subharmonic resonance of the system to the forcing and period-doubling bifurcations are responsible for the dominant timescales in the system,including the 60-yr timescale that dominates the Atlantic Multidecadal Oscillation.The dominant timescales in the forced system depend on the system's parameter setting.Scale enhancement among the dominant response timescales may result in dramatic amplifications over a few decades and extreme values of the time series on various timescales.Three possible energy sources for such amplifications and extremes are proposed.Dynamical model results suggest that solar activity may play an important yet not well recognized role in the observed decadal-centennial climate variability.The atmospheric dynamical amplifying mechanism shown in Part I and the nonlinear resonant and bifurcation mechanisms shown in Part II help us to understand the solar source of the multi-scale climate change in the 20th century and the fact that different solar influenced dominant timescales for recurrent climate extremes for a given region or a parameter setting.Part II also indicates that solar influences on climate cannot be linearly compared with non-cyclic or sporadic thermal forcings because they cannot exert their influences on climate in the same way as the sun does.展开更多
Internal resonance in nonlinear vibration of functionally graded （FG） circular cylin- drical shells in thermal environment is studied using the Hamiltonian dynamics formulation. The material properties are considere...Internal resonance in nonlinear vibration of functionally graded （FG） circular cylin- drical shells in thermal environment is studied using the Hamiltonian dynamics formulation. The material properties are considered to be temperature-dependent. Based on the Karman-Donnell＇s nonlinear shell theory, the kinetic and potential energy of FG cylindrical thin shells are formu- lated. The primary target is to investigate the two-mode internal resonance, which is triggered by geometric and material parameters of shells. Following a secular perturbation procedure, the underlying dynamic characteristics of the two-mode interactions in both exact and near resonance cases are fully discussed. It is revealed that the system will undergo a bifurcation in near resonance case, which induces the dynamic response at high energy level being distinct from the motion at low energy level. The effects of temperature and volume fractions of composition on the exact resonance condition and bifurcation characteristics of FG cylindrical shells are also investigated.展开更多
We report the experimental preparations of the absolute ground states of 87Rb and 40K atoms （｜F = 1, mF = 1 ） ＋ ｜F = 9/2, rnF ： -9/2）） by means of the radio-frequency and microwave adiabatic rapid passages, an...We report the experimental preparations of the absolute ground states of 87Rb and 40K atoms （｜F = 1, mF = 1 ） ＋ ｜F = 9/2, rnF ： -9/2）） by means of the radio-frequency and microwave adiabatic rapid passages, and the observation of magnetic Feshbach resonances in an ultracold mixture of bosonic STRb and fermionic 40K atoms between 0 T and 6.0 × 10^-2 T, including 7 homonuclear and 4 heteronuclear Feshbach resonances. The resonances are identified by the abrupt trap loss of atoms induced by the strong inelastic three-body collisions. These Feshbach resonances should enable the experimental control of interspecies interactions.展开更多
Dr.Feng Chen is a chief medical doctor and the vice chairman of the Department of Radiology in Zhong Da Hospital at Southeast University,Nanjing,China and a senior researcher in the Department of Radiology at the Cath...Dr.Feng Chen is a chief medical doctor and the vice chairman of the Department of Radiology in Zhong Da Hospital at Southeast University,Nanjing,China and a senior researcher in the Department of Radiology at the Catholic University of Leuven,Belgium.His main areas of interest are translational imaging research including stroke,tumor angiogenesis,assessment of therapeutic response in solid tumors,and magnetic resonance contrast media.Dr.Feng Chen has published 44 scientific papers in peer-reviewed international journals.He and his colleagues have developed an imaging platform which includes animal models,animal preparations and multiparametric magnetic resonance imaging(MRI)protocols for translational animal imaging research using clinical machines.His MRI findings on rodent stroke are considered to"serve as a model for future laboratory investigations of treatment of acutestroke and unify the approaches developed for clinical studies".He and his colleagues have introduced a novel liver tumor model in rodents,in which a series of studies concerning the antitumor activity of vascular disrupting agents have been successively conducted and assessed by in vivo MRI,especially by diffusion weighted imaging as an imaging biomarker.His goal is to provide valuable references for clinical practice and to contribute to the translation of animal imaging research into patient applications.展开更多
Dense coding using superpositions of Bell-states is proposed. The generalized Grover's algorithm is used to prepare the initial entangled states, and the reverse process of the quantum algorithm is used to determi...Dense coding using superpositions of Bell-states is proposed. The generalized Grover's algorithm is used to prepare the initial entangled states, and the reverse process of the quantum algorithm is used to determine the entangled state in the decoding measurement. Compared with the previous schemes, the superpositions of two Bell-states are exploited. Our scheme is demonstrated using a nuclear magnetic resonance (NMR)quantum computer. The corresponding manipulations are obtained. Experimental results show a good agreement between theory and experiment. We also generalize the scheme to transmit eight messages by introducing an additional two-state system.展开更多
基金Project supported by the National High Technology Research and Developmem Program of China ~Grant No. 2013AA030901）.
文摘We present a new polymer quartz piezoelectric crystal sensor that takes a quartz piezoelectric crystal as the basal material and a nanometer nonmetallic polymer thin film as the surface coating based on the principle of quartz crystal microbalance(QCM). The new sensor can be used to detect the characteristic materials of a volatile liquid. A mechanical model of the new sensor was built, whose structure was a thin circle plate composing of polytef/quartz piezoelectric/polytef. The mechanical model had a diameter of 8 mm and a thickness of 170 μm. The vibration state of the model was simulated by software ANSYS after the physical parameters and the boundary condition of the new sensor were set. According to the results of experiments, we set up a frequency range from 9.995850 MHz to 9.997225 MHz, 17 kinds of frequencies and modes of vibration were obtained within this range. We found a special frequency fspof 9.996358 MHz. When the resonant frequency of the new sensor's mechanical model reached the special frequency, a special phenomenon occurred. In this case, the amplitude of the center point O on the mechanical model reached the maximum value. At the same time, the minimum absolute difference between the simulated frequency based on the ANSYS software and the experimental measured stable frequency was reached. The research showed that the design of the new polymer quartz piezoelectric crystal sensor perfectly conforms to the principle of QCM. A special frequency value fspwas found and subsequently became one of the most important parameters in the new sensor design.
基金provided by the LASG State Key Laboratory Special Fund for this research project
文摘Part II of this study detects the dominant decadal-centennial timescales in four SST indices up to the 2010/2011 winter and tries to relate them to the observed 11-yr and 88-yr solar activity with the sunspot number up to Solar Cycle 24.To explore plausible solar origins of the observed decadal-centennial timescales in the SSTs and climate variability in general,we design a simple one-dimensional dynamical system forced by an annual cycle modulated by a small-amplitude single-or multi-scale"solar activity."Results suggest that nonlinear harmonic and subharmonic resonance of the system to the forcing and period-doubling bifurcations are responsible for the dominant timescales in the system,including the 60-yr timescale that dominates the Atlantic Multidecadal Oscillation.The dominant timescales in the forced system depend on the system's parameter setting.Scale enhancement among the dominant response timescales may result in dramatic amplifications over a few decades and extreme values of the time series on various timescales.Three possible energy sources for such amplifications and extremes are proposed.Dynamical model results suggest that solar activity may play an important yet not well recognized role in the observed decadal-centennial climate variability.The atmospheric dynamical amplifying mechanism shown in Part I and the nonlinear resonant and bifurcation mechanisms shown in Part II help us to understand the solar source of the multi-scale climate change in the 20th century and the fact that different solar influenced dominant timescales for recurrent climate extremes for a given region or a parameter setting.Part II also indicates that solar influences on climate cannot be linearly compared with non-cyclic or sporadic thermal forcings because they cannot exert their influences on climate in the same way as the sun does.
基金Project supported by the National Natural Science Foundation of China(Nos.11072204 and 11372257)
文摘Internal resonance in nonlinear vibration of functionally graded （FG） circular cylin- drical shells in thermal environment is studied using the Hamiltonian dynamics formulation. The material properties are considered to be temperature-dependent. Based on the Karman-Donnell＇s nonlinear shell theory, the kinetic and potential energy of FG cylindrical thin shells are formu- lated. The primary target is to investigate the two-mode internal resonance, which is triggered by geometric and material parameters of shells. Following a secular perturbation procedure, the underlying dynamic characteristics of the two-mode interactions in both exact and near resonance cases are fully discussed. It is revealed that the system will undergo a bifurcation in near resonance case, which induces the dynamic response at high energy level being distinct from the motion at low energy level. The effects of temperature and volume fractions of composition on the exact resonance condition and bifurcation characteristics of FG cylindrical shells are also investigated.
基金supported by the National Natural Science Foundation for Distinguished Young Scholars of China (Grant No. 10725416)the National Basic Research Program of China (Grant No. 2006CB921101)the National Natural Science Foundation of China for Excellent Research Team, China (Grant No. 60821004)
文摘We report the experimental preparations of the absolute ground states of 87Rb and 40K atoms （｜F = 1, mF = 1 ） ＋ ｜F = 9/2, rnF ： -9/2）） by means of the radio-frequency and microwave adiabatic rapid passages, and the observation of magnetic Feshbach resonances in an ultracold mixture of bosonic STRb and fermionic 40K atoms between 0 T and 6.0 × 10^-2 T, including 7 homonuclear and 4 heteronuclear Feshbach resonances. The resonances are identified by the abrupt trap loss of atoms induced by the strong inelastic three-body collisions. These Feshbach resonances should enable the experimental control of interspecies interactions.
基金Supported by Health Bureau of Jiangsu Province,ChinaChinese Scholarship Council+2 种基金National Natural Science Foundation of ChinaEuropean Congress of Radiology 2000,EAR-ECR Research and Education Fund Fellowship GrantEuropean Union Asia-Link Project
文摘Dr.Feng Chen is a chief medical doctor and the vice chairman of the Department of Radiology in Zhong Da Hospital at Southeast University,Nanjing,China and a senior researcher in the Department of Radiology at the Catholic University of Leuven,Belgium.His main areas of interest are translational imaging research including stroke,tumor angiogenesis,assessment of therapeutic response in solid tumors,and magnetic resonance contrast media.Dr.Feng Chen has published 44 scientific papers in peer-reviewed international journals.He and his colleagues have developed an imaging platform which includes animal models,animal preparations and multiparametric magnetic resonance imaging(MRI)protocols for translational animal imaging research using clinical machines.His MRI findings on rodent stroke are considered to"serve as a model for future laboratory investigations of treatment of acutestroke and unify the approaches developed for clinical studies".He and his colleagues have introduced a novel liver tumor model in rodents,in which a series of studies concerning the antitumor activity of vascular disrupting agents have been successively conducted and assessed by in vivo MRI,especially by diffusion weighted imaging as an imaging biomarker.His goal is to provide valuable references for clinical practice and to contribute to the translation of animal imaging research into patient applications.
基金We are grateful to Professor Long Guilu and Mr.Liu Xiaoshu for helpful discussions.This work was supported by the National Natural Science Foundation of China(Grant No.10374010)the China Postdoctoral Science Foundation.
文摘Dense coding using superpositions of Bell-states is proposed. The generalized Grover's algorithm is used to prepare the initial entangled states, and the reverse process of the quantum algorithm is used to determine the entangled state in the decoding measurement. Compared with the previous schemes, the superpositions of two Bell-states are exploited. Our scheme is demonstrated using a nuclear magnetic resonance (NMR)quantum computer. The corresponding manipulations are obtained. Experimental results show a good agreement between theory and experiment. We also generalize the scheme to transmit eight messages by introducing an additional two-state system.
