In this paper, the authors present the transmission line (TL) realization of one-dimensional subwavelength resonator formed by a pair of conventional right-handed material (RHM) and left-handed material (LHM). In such...In this paper, the authors present the transmission line (TL) realization of one-dimensional subwavelength resonator formed by a pair of conventional right-handed material (RHM) and left-handed material (LHM). In such resonator, a novel reso- nant mode with the resonant frequency depending on the length ratio of the RH/LH TL sections occurs as a consequence of the full phase compensation due to the backward wave in the LH TL section. The theoretical circuit-model analyses are supported by simulation and experimental evidence on resonators with different RH/LH length ratios.展开更多
This article theoretically studies the influence of inhomogeneous abdominal walls on focused therapeutic ultrasound based on the phase screen model. An inhomogeneous tissue is considered as a combination of a homogene...This article theoretically studies the influence of inhomogeneous abdominal walls on focused therapeutic ultrasound based on the phase screen model. An inhomogeneous tissue is considered as a combination of a homogeneous medium and a phase aberration screen. Variations of acoustic parameters such as peak positive pressure, peak negative pressure, and acoustic intensity are discussed with respect to the phase screen statistics of human abdominal walls. Results indicate that the abdominal wall can result in energy loss of the sound in the focal plane. For a typical human abdominal wall with correlation length of 7.9 mm and variance of 0.36, the peak acoustic intensity radiated from a 1MHz transmitter with a radius of 30 mm can be reduced by about 14% at the focal plane.展开更多
Exploring new acoustic parameters is essential to develop a noninvasive imaging technique for the surgery of silicone oil tamponades. In this study, the acoustic nonlinearity parameters B/A of varied silicone oil samp...Exploring new acoustic parameters is essential to develop a noninvasive imaging technique for the surgery of silicone oil tamponades. In this study, the acoustic nonlinearity parameters B/A of varied silicone oil samples （e.g., linear or hyper-branched） are experimentally measured by using a modified thermodynamic method. The results show that： （i） when the concentration of the silicone oil with a molecular weight of 5 × 10^4 increases from 0.5 g/100 ml to 8 g/100 ml, the corresponding B/A value increases by about 18%, but the acoustic velocity only increases by about 0.1%; （ii） when the molecular weight of the hyper-branched silicone oil is enhanced from 2 × 10^5 to 1 × 10^6, the B/A value increases by about 22%, while the acoustic velocity is only raised by about 0.2%. This study suggests that the B/A parameter of the silicone oil is more sensitive to the change in its molecular structure than that of the acoustic velocity. Thus, the B/A parameter might be utilized as an effective index for the development and optimization of the noninvasive imaging of the surgery of silicone oil tamponades.展开更多
We investigate the photoinduced effects on the electronic structure for half-metallic ferromagnet CrO2 （Tc 390 K）, in which the conducting electrons are totally polarized, by using the LSDA＋U method. A significant ...We investigate the photoinduced effects on the electronic structure for half-metallic ferromagnet CrO2 （Tc 390 K）, in which the conducting electrons are totally polarized, by using the LSDA＋U method. A significant change is found for the band structure and the density of states （DOS） for CrO2 under photo-excitation, especially for the Cr 3dt2g band： disappearance of the spin-split band, suggesting collapse of the half-metallic state. We ascribe the change of electronic structure under photo-excitation to the wider one-electron band W via the strong hybridization of the down-spin Cr 3d and O 2p states. Furthermore we discuss the magnetic properties under photo-excitation.展开更多
Sub-harmonic contrast imaging promises to improve ultrasound imaging quality by taking advantage of increased contrast to tissue signal.The aim of this study is to examine the hysteretic nonlinearity of sub-harmonic c...Sub-harmonic contrast imaging promises to improve ultrasound imaging quality by taking advantage of increased contrast to tissue signal.The aim of this study is to examine the hysteretic nonlinearity of sub-harmonic component emitted from microbubbles.Two kinds of microbubble solutions,i.e.Sonovue■and a self-developed contrast agent,are utilized in the study.The hysteretic curves for increasing and decreasing acoustic pressure are theoretically predicted by the Marmottant model and confirmed by measurements.The results reveal that for both microbubble solutions,the development of the rising ramp undergoes three stages,i.e.occurrence,growth and saturation;while hysteresis effect appears in the descending ramp.Sono Vue■microbubbles exhibit better sub-harmonic performance over the self-developed UCAs microbubbles due to the difference of elastic properties of the shell.展开更多
The influence of the nonlinearity of electrodynamic loudspeakers on the performance of thermoacoustic refrigerators with the loudspeakers as acoustic sources is studied by nonlinear equivalent circuit models of electr...The influence of the nonlinearity of electrodynamic loudspeakers on the performance of thermoacoustic refrigerators with the loudspeakers as acoustic sources is studied by nonlinear equivalent circuit models of electrodynamic loudspeakers driven by current and voltage. The simulated results demonstrate that there are different nonlinear effects between current-drive and voltage-drive refrigerators, and the differences are mainly induced by the motional electromotive force caused by the coil moving in the magnetic field. With voltage driving, the influence of the nonlinearity of the loudspeaker on the diaphragm displacement and acoustic output power is much smaller than that with current driving. Therefore, considering the nonlinearity of the loudspeakers, a proper driving method must be chosen according to the practical applications although little difference is found with the linear models.展开更多
We present a systematic study on the extraordinary resonant scattering in imperfect acoustic cloak by means of acoustic scattering theory. Analysis results demonstrate that the resonances are inevitable due to the per...We present a systematic study on the extraordinary resonant scattering in imperfect acoustic cloak by means of acoustic scattering theory. Analysis results demonstrate that the resonances are inevitable due to the perturbation to the ideal clo^k, and specific resonance modes are excited by specific order waves. The strength of resonance is determined by the magnitude of perturbation and each order wave＇s sensitivity to the perturbation. Further studies reveal the unique scattering characters of different resonance modes.展开更多
We found an error in our previous report [Chin. Phys. Lett. 26（2009）077809] concerning the JCPDS data which was used to compare with our data. It should read as JCPDS No 21-1272 （α = 3.7850A, c = 9.5140A, c/α = 2...We found an error in our previous report [Chin. Phys. Lett. 26（2009）077809] concerning the JCPDS data which was used to compare with our data. It should read as JCPDS No 21-1272 （α = 3.7850A, c = 9.5140A, c/α = 2.5140, and V = 136.30A^3）,展开更多
A confocally and coaxially arranged pair of focused transmitter and receiver represents one of the best geometries for medical ultrasonic imaging and non-invasive detection. We develop a simple theoretical model for d...A confocally and coaxially arranged pair of focused transmitter and receiver represents one of the best geometries for medical ultrasonic imaging and non-invasive detection. We develop a simple theoretical model for describing the nonlinear propagation of a confocal ultrasonic beam in biological tissues. On the basis of the parabolic approximation and quasi-linear approximation, the nonlinear Khokhlov-Zabolotskaya-Kuznetsov （KZK） equation is solved by using the angular spectrum approach. Gaussian superposition technique is applied to simplify the solution, and an analytical solution for the second harmonics in the confocal ultrasonic beam is presented. Measurements are performed to examine the validity of the theoretical model. This model provides a preliminary model for acoustic nonlinear microscopy.展开更多
The Ag-doping effects on Ti02 nanoparticles are investigated by means of x-ray diffraction （XRD） and Raman scattering spectroscopy. XRD and Raman results indicate that Ag-doping stabilizes the rutile phase in TiO2. ...The Ag-doping effects on Ti02 nanoparticles are investigated by means of x-ray diffraction （XRD） and Raman scattering spectroscopy. XRD and Raman results indicate that Ag-doping stabilizes the rutile phase in TiO2. We find an Ag-doping induced lattice expansion in both anatase and rutile phases. The Ag-doping has different influences on the lattice distortion for anatase and rutile phases, that is, the e/a-value for the anatase phase decreases with 0.5% Ag-doping and then increases with 1~ Ag-doping while that for the rutile phase shows a gradual increase with increasing Ag-doping. We have ascribed the different variations of lattice distortion due to Ag-doping to the change of interracial interaction between the anatase and rutile phases induced by different Ag concentrations.展开更多
Subharmonics or ultraharmonics provides better contrast-to-tissue ratio (CTR) than the fundamental or the second harmonics, having prospective application in medical diagnosis. In this paper, subharmonic and ultra-har...Subharmonics or ultraharmonics provides better contrast-to-tissue ratio (CTR) than the fundamental or the second harmonics, having prospective application in medical diagnosis. In this paper, subharmonic and ultra-harmonic emissions are theoretically studied through nonlinear oscillation of encapsulated bubbles. The optimized frequencies for emissions of the subharmonics and ultra-harmonics are discussed. In addition, sound pressure de-pendences of the subharmonics and ultraharmonics are studied in theory as well as in measurement. Results reveal that the developments of both subharmonics and ultrahar-monics have the same trend, i.e. occurrence, growth and saturation, but the generation of ultraharmonic is a little earlier than that of subharmonic.展开更多
The nonlinearity has significant effect on the ultrasonic therapy using phased ar- rays. A numerical approach is developed to calculate the nonlinear sound field generated from a phased array based on the Gaussian sup...The nonlinearity has significant effect on the ultrasonic therapy using phased ar- rays. A numerical approach is developed to calculate the nonlinear sound field generated from a phased array based on the Gaussian superposition technique. The parameters of the phased array elements are first estimated from the focal parameters using the inverse matrix algorithm; Then the elements are expressed as a set of Gaussian functions; Finally, the nonlinear sound field can be calculated using the Gaussian superposition technique. In the numerical simulation, a 64~ 1 phased array is used as the transmitter. In the linear case, the difference between the results of the Gaussian superposition technique and the Fresnel integral is less than 0.5%, which verifies the feasibility of the approach. In the nonlinear case, the nonlinear fields of single-focus modes and double-focus modes are calculated. The results reveal that the nonlinear effects can improve the focusing performance, and the nonlinear effects are related with the source pressures and the excitation frequencies.展开更多
A laser ultrasonics method is used to surface wave traveling on the surface of materials characterize the propagation properties of with sub-surface defect in 2D. Linear and nonlinear propagation properties of ultraso...A laser ultrasonics method is used to surface wave traveling on the surface of materials characterize the propagation properties of with sub-surface defect in 2D. Linear and nonlinear propagation properties of ultrasonics caused by the defects have been detected in experiment. A theoretical model is proposed and used to study the linear and nonlinear properties of ultrasonics caused by the defect. The numerical results indicate that the nonlinear ultrasonic wave will be excited when a finite amplitude ultrasonics propagates on the surface of materials with sub-surface defect. The theoretical analysis confirms that the nonlinear wave is caused by the ＂clapping＂ of the interface of defect instead of the mode conversions of ultrasonics.展开更多
Under combined irradiation of laser and ultrasound, cavitary bubbles are generated on the surface of gold nanoparticle. The laser-induced thermal effect, ultrasonic cavitation el- fect and the synergistic effect of la...Under combined irradiation of laser and ultrasound, cavitary bubbles are generated on the surface of gold nanoparticle. The laser-induced thermal effect, ultrasonic cavitation el- fect and the synergistic effect of laser and ultrasound are studied by means of the investigation of the dynamical process for the vibration of the cavitation bubble, with different external con- ditions such as laser power, ultrasound intensity, etc. It is found that dynamical process of the cavitation bubble can be modified by the irradiation of laser or ultrasound. The enhancement of laser power can increase the critical radius of the cavitation bubble, while that of ultrasound may intensify the vibration. Cavitation bubble may become more stable due to the synergistic effect of laser and ultrasound. It is also found that variation of the coupling between laser and ultrasound can affect synergistic effect.展开更多
Iodine release in potassium iodide solution has been investigated under the irradiations of ultrasound and visible light respectively and simultaneously. We have observed that the amount of iodine liberated under the ...Iodine release in potassium iodide solution has been investigated under the irradiations of ultrasound and visible light respectively and simultaneously. We have observed that the amount of iodine liberated under the combined irradiation of ultrasound and visible light is larger than the sum of that under the respective irradiations of ultrasound and visible light, indicating a synergistic effect of ultrasound and visible light irradiations. Based on the investigation of the reaction kinetics of iodine liberated, we have ascribed the synergistic effect to the perfect stirring of the photochemical reactor induced by the applying simultaneous ultrasound. The ideal stirring can result in the homogenization of the primary light effect in the whole reaction medium, which induces the acceleration of the photochemical reaction. On behavior of our knowledge, there are few reports on the investigations of utilizing the combination of ultrasonic energy and light energy to accelerate the reaction yield and rate as well as the kinetics of the reaction.展开更多
The interactions between solitary waves and impurities have been studied experimentally in a 1D nonlinear coupled pendulum chain under vertical excitation. The mass and the coupling are unique, except a single pendulu...The interactions between solitary waves and impurities have been studied experimentally in a 1D nonlinear coupled pendulum chain under vertical excitation. The mass and the coupling are unique, except a single pendulum with length impurity in the chain. The experiment reveals: the long impurity repels breather and attracts kink while the short one attracts breather and repels kink under higher frequency driving, and the long impurity attracts breather and repels kink while the short one repels breather and attracts kink under the lower frequency driving. These results prove the current theoretical prediction based on continuum-limit approximation.展开更多
基金Project supported by the National Basic Research Program (973) of China (No. 2004CB719800) and the Specialized Research Fund for the Doctoral Program of Higher Education (No. 20030284024)
文摘In this paper, the authors present the transmission line (TL) realization of one-dimensional subwavelength resonator formed by a pair of conventional right-handed material (RHM) and left-handed material (LHM). In such resonator, a novel reso- nant mode with the resonant frequency depending on the length ratio of the RH/LH TL sections occurs as a consequence of the full phase compensation due to the backward wave in the LH TL section. The theoretical circuit-model analyses are supported by simulation and experimental evidence on resonators with different RH/LH length ratios.
基金Project supported by the Program for New Century Excellent Talents in University of China (Grant No 06-0450)the National Natural Science Foundation of China (Grant No 10774071)the Natural Science Foundation of Jiangsu Province, China (Grant No BK2007518)
文摘This article theoretically studies the influence of inhomogeneous abdominal walls on focused therapeutic ultrasound based on the phase screen model. An inhomogeneous tissue is considered as a combination of a homogeneous medium and a phase aberration screen. Variations of acoustic parameters such as peak positive pressure, peak negative pressure, and acoustic intensity are discussed with respect to the phase screen statistics of human abdominal walls. Results indicate that the abdominal wall can result in energy loss of the sound in the focal plane. For a typical human abdominal wall with correlation length of 7.9 mm and variance of 0.36, the peak acoustic intensity radiated from a 1MHz transmitter with a radius of 30 mm can be reduced by about 14% at the focal plane.
基金Project supported by the National Basic Research Program of China(Grant No.2011CB707900)the National Natural Science Foundation of China(Grant Nos.81127901,11174141,61072027,and 11374155)the Natural Science Foundation of Jiangsu Province,China(Grant No.BE2011110)
文摘Exploring new acoustic parameters is essential to develop a noninvasive imaging technique for the surgery of silicone oil tamponades. In this study, the acoustic nonlinearity parameters B/A of varied silicone oil samples （e.g., linear or hyper-branched） are experimentally measured by using a modified thermodynamic method. The results show that： （i） when the concentration of the silicone oil with a molecular weight of 5 × 10^4 increases from 0.5 g/100 ml to 8 g/100 ml, the corresponding B/A value increases by about 18%, but the acoustic velocity only increases by about 0.1%; （ii） when the molecular weight of the hyper-branched silicone oil is enhanced from 2 × 10^5 to 1 × 10^6, the B/A value increases by about 22%, while the acoustic velocity is only raised by about 0.2%. This study suggests that the B/A parameter of the silicone oil is more sensitive to the change in its molecular structure than that of the acoustic velocity. Thus, the B/A parameter might be utilized as an effective index for the development and optimization of the noninvasive imaging of the surgery of silicone oil tamponades.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10574071 and 10374041, the Key Project of Chinese Ministry of Education under Grant No 107051, and the Program for New Century Excellent Talents in Chinese University under Grant No NECT-04-045.
文摘We investigate the photoinduced effects on the electronic structure for half-metallic ferromagnet CrO2 （Tc 390 K）, in which the conducting electrons are totally polarized, by using the LSDA＋U method. A significant change is found for the band structure and the density of states （DOS） for CrO2 under photo-excitation, especially for the Cr 3dt2g band： disappearance of the spin-split band, suggesting collapse of the half-metallic state. We ascribe the change of electronic structure under photo-excitation to the wider one-electron band W via the strong hybridization of the down-spin Cr 3d and O 2p states. Furthermore we discuss the magnetic properties under photo-excitation.
基金Supported by the National Basic Research Program of China under Grant No 2010CB732600 andNational Natural Science Foundation of China under Grant Nos 10974093,11011130201 and 10904094 and Key Lab of Acoustics。
文摘Sub-harmonic contrast imaging promises to improve ultrasound imaging quality by taking advantage of increased contrast to tissue signal.The aim of this study is to examine the hysteretic nonlinearity of sub-harmonic component emitted from microbubbles.Two kinds of microbubble solutions,i.e.Sonovue■and a self-developed contrast agent,are utilized in the study.The hysteretic curves for increasing and decreasing acoustic pressure are theoretically predicted by the Marmottant model and confirmed by measurements.The results reveal that for both microbubble solutions,the development of the rising ramp undergoes three stages,i.e.occurrence,growth and saturation;while hysteresis effect appears in the descending ramp.Sono Vue■microbubbles exhibit better sub-harmonic performance over the self-developed UCAs microbubbles due to the difference of elastic properties of the shell.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10904067 and 10774074, and the Specialized Research Fund for the Doctoral Programme of Higher Education of China under Grant No 20090091120050.
文摘The influence of the nonlinearity of electrodynamic loudspeakers on the performance of thermoacoustic refrigerators with the loudspeakers as acoustic sources is studied by nonlinear equivalent circuit models of electrodynamic loudspeakers driven by current and voltage. The simulated results demonstrate that there are different nonlinear effects between current-drive and voltage-drive refrigerators, and the differences are mainly induced by the motional electromotive force caused by the coil moving in the magnetic field. With voltage driving, the influence of the nonlinearity of the loudspeaker on the diaphragm displacement and acoustic output power is much smaller than that with current driving. Therefore, considering the nonlinearity of the loudspeakers, a proper driving method must be chosen according to the practical applications although little difference is found with the linear models.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10874088, 10874087 and 10574071, and the Key Project of the Ministry of Education of China under Grant No 107051.
文摘We present a systematic study on the extraordinary resonant scattering in imperfect acoustic cloak by means of acoustic scattering theory. Analysis results demonstrate that the resonances are inevitable due to the perturbation to the ideal clo^k, and specific resonance modes are excited by specific order waves. The strength of resonance is determined by the magnitude of perturbation and each order wave＇s sensitivity to the perturbation. Further studies reveal the unique scattering characters of different resonance modes.
文摘We found an error in our previous report [Chin. Phys. Lett. 26（2009）077809] concerning the JCPDS data which was used to compare with our data. It should read as JCPDS No 21-1272 （α = 3.7850A, c = 9.5140A, c/α = 2.5140, and V = 136.30A^3）,
基金Supported by the National Natural Science Foundation of China under Grant Nos 10204014 and 10474044.
文摘A confocally and coaxially arranged pair of focused transmitter and receiver represents one of the best geometries for medical ultrasonic imaging and non-invasive detection. We develop a simple theoretical model for describing the nonlinear propagation of a confocal ultrasonic beam in biological tissues. On the basis of the parabolic approximation and quasi-linear approximation, the nonlinear Khokhlov-Zabolotskaya-Kuznetsov （KZK） equation is solved by using the angular spectrum approach. Gaussian superposition technique is applied to simplify the solution, and an analytical solution for the second harmonics in the confocal ultrasonic beam is presented. Measurements are performed to examine the validity of the theoretical model. This model provides a preliminary model for acoustic nonlinear microscopy.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10874088 and 10874087, the Key Project of the Ministry of Education of China under Grant No 107051, the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No 200802840032, and State Key Laboratory of Electrical Insulation and Power Equipment, Xi＇an Jiaotong University （EIPE09202）.
文摘The Ag-doping effects on Ti02 nanoparticles are investigated by means of x-ray diffraction （XRD） and Raman scattering spectroscopy. XRD and Raman results indicate that Ag-doping stabilizes the rutile phase in TiO2. We find an Ag-doping induced lattice expansion in both anatase and rutile phases. The Ag-doping has different influences on the lattice distortion for anatase and rutile phases, that is, the e/a-value for the anatase phase decreases with 0.5% Ag-doping and then increases with 1~ Ag-doping while that for the rutile phase shows a gradual increase with increasing Ag-doping. We have ascribed the different variations of lattice distortion due to Ag-doping to the change of interracial interaction between the anatase and rutile phases induced by different Ag concentrations.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.10074033 and 10274032)the N ational Natural Science Foundation of Jiangsu Province(BK2004081)SRF for ROCS.SEM.and TWAS(No.03-390).
文摘Subharmonics or ultraharmonics provides better contrast-to-tissue ratio (CTR) than the fundamental or the second harmonics, having prospective application in medical diagnosis. In this paper, subharmonic and ultra-harmonic emissions are theoretically studied through nonlinear oscillation of encapsulated bubbles. The optimized frequencies for emissions of the subharmonics and ultra-harmonics are discussed. In addition, sound pressure de-pendences of the subharmonics and ultraharmonics are studied in theory as well as in measurement. Results reveal that the developments of both subharmonics and ultrahar-monics have the same trend, i.e. occurrence, growth and saturation, but the generation of ultraharmonic is a little earlier than that of subharmonic.
基金supported by the National Basic Research Program 973(2011CB707900)National Natural Science Foundation of China(81127901,81227004,11174141,11274170 and 11161120324)+2 种基金the Natural Science Foundation of Jiangsu Province of China(BK2011543 and BE2011110)the National High Technology Research and Development Program 863(2012AA022700)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The nonlinearity has significant effect on the ultrasonic therapy using phased ar- rays. A numerical approach is developed to calculate the nonlinear sound field generated from a phased array based on the Gaussian superposition technique. The parameters of the phased array elements are first estimated from the focal parameters using the inverse matrix algorithm; Then the elements are expressed as a set of Gaussian functions; Finally, the nonlinear sound field can be calculated using the Gaussian superposition technique. In the numerical simulation, a 64~ 1 phased array is used as the transmitter. In the linear case, the difference between the results of the Gaussian superposition technique and the Fresnel integral is less than 0.5%, which verifies the feasibility of the approach. In the nonlinear case, the nonlinear fields of single-focus modes and double-focus modes are calculated. The results reveal that the nonlinear effects can improve the focusing performance, and the nonlinear effects are related with the source pressures and the excitation frequencies.
基金supported by the National Natural Science Foundation of China(11074126,10674069)NSFC-KOSEF
文摘A laser ultrasonics method is used to surface wave traveling on the surface of materials characterize the propagation properties of with sub-surface defect in 2D. Linear and nonlinear propagation properties of ultrasonics caused by the defects have been detected in experiment. A theoretical model is proposed and used to study the linear and nonlinear properties of ultrasonics caused by the defect. The numerical results indicate that the nonlinear ultrasonic wave will be excited when a finite amplitude ultrasonics propagates on the surface of materials with sub-surface defect. The theoretical analysis confirms that the nonlinear wave is caused by the ＂clapping＂ of the interface of defect instead of the mode conversions of ultrasonics.
基金supported by the National Natural Science Foundation of China(10874087,1087408)
文摘Under combined irradiation of laser and ultrasound, cavitary bubbles are generated on the surface of gold nanoparticle. The laser-induced thermal effect, ultrasonic cavitation el- fect and the synergistic effect of laser and ultrasound are studied by means of the investigation of the dynamical process for the vibration of the cavitation bubble, with different external con- ditions such as laser power, ultrasound intensity, etc. It is found that dynamical process of the cavitation bubble can be modified by the irradiation of laser or ultrasound. The enhancement of laser power can increase the critical radius of the cavitation bubble, while that of ultrasound may intensify the vibration. Cavitation bubble may become more stable due to the synergistic effect of laser and ultrasound. It is also found that variation of the coupling between laser and ultrasound can affect synergistic effect.
基金the National Natural Science Foundation of China(10574071)
文摘Iodine release in potassium iodide solution has been investigated under the irradiations of ultrasound and visible light respectively and simultaneously. We have observed that the amount of iodine liberated under the combined irradiation of ultrasound and visible light is larger than the sum of that under the respective irradiations of ultrasound and visible light, indicating a synergistic effect of ultrasound and visible light irradiations. Based on the investigation of the reaction kinetics of iodine liberated, we have ascribed the synergistic effect to the perfect stirring of the photochemical reactor induced by the applying simultaneous ultrasound. The ideal stirring can result in the homogenization of the primary light effect in the whole reaction medium, which induces the acceleration of the photochemical reaction. On behavior of our knowledge, there are few reports on the investigations of utilizing the combination of ultrasonic energy and light energy to accelerate the reaction yield and rate as well as the kinetics of the reaction.
基金This work was supported partly by the special Funds for Major State Based Research Projects and the Trans-Century Training Programme Foundation for the Talents by the State Education Commission
文摘The interactions between solitary waves and impurities have been studied experimentally in a 1D nonlinear coupled pendulum chain under vertical excitation. The mass and the coupling are unique, except a single pendulum with length impurity in the chain. The experiment reveals: the long impurity repels breather and attracts kink while the short one attracts breather and repels kink under higher frequency driving, and the long impurity attracts breather and repels kink while the short one repels breather and attracts kink under the lower frequency driving. These results prove the current theoretical prediction based on continuum-limit approximation.
