The vibration behavior of the ground and houses caused by monorail traffic is discussed in this paper. The environmental ground vibration problem discussed herein occurs in a residential area near a monorail used for ...The vibration behavior of the ground and houses caused by monorail traffic is discussed in this paper. The environmental ground vibration problem discussed herein occurs in a residential area near a monorail used for public transportation, Vibrations were measured on the ground at the side of monorail piers lacing the residential area and within the affected houses. Results indicate that the vibration level in the house was 60 dB or more, a level high enough to warrant complaints, Peculiar geological and geographical features are thought to contribute to the amplification of low frequency （-10 Hz） ground vibrations to irritable levels in these homes even though a distance of≥30 m separates the residential area and the monorail.展开更多
Multimodal cancer synergistic therapy exhibited remarkable advantages over monotherapy in producing an improved therapeutic efficacy. In this work, Janus-type γ-Fe2 O3/SiO2 nanoparticles(JFSNs) are conjugated with gl...Multimodal cancer synergistic therapy exhibited remarkable advantages over monotherapy in producing an improved therapeutic efficacy. In this work, Janus-type γ-Fe2 O3/SiO2 nanoparticles(JFSNs) are conjugated with glucose oxidase(GOx) for synergistic cancer starvation/chemodynamic therapy. The γ-Fe2O3 hemisphere of JFSNs can perform photoacoustic/T2 magnetic resonance dual-modal imaging of tumors.GOx on the surface of JFSNs catalyzes the decomposition of glucose and produces H2O2 for cancer starvation therapy. Subsequently, the γ-Fe2O3 hemisphere catalyzes the disproportionation of H2O2 to generate highly reactive hydroxyl radicals in an acidic tumor microenvironment. The close distance between GOx and JFSNs ensures adequate contact between the γ-Fe2O3 hemisphere and its substrate H2O2, thus enhancing the catalytic efficiency. This synergy of glucose depletion, biotoxic H2O2 and hydroxyl radicals significantly suppresses 4 T1 mammary tumor growth with minimal adverse effects.展开更多
We investigate the effect of alpha stable noise on stochastic resonance in a single-threshold sensor system by analytic deduction and stochastic simulation. It is shown that stochastic resonance occurs in the threshol...We investigate the effect of alpha stable noise on stochastic resonance in a single-threshold sensor system by analytic deduction and stochastic simulation. It is shown that stochastic resonance occurs in the threshold system in alpha stable noise environment, but the resonant effect becomes weakened as the alpha stable index decreases or the skewness parameter of alpha stable distribution increases. In particular, for Cauchy noise a nonlinear relation among the optimal noise deviation parameter, the signal amplitude and the threshold is analytically obtained and illustrated by using the extreme value condition for the output signal-to-noise ratio. The results presented in this communication should have application in signal detection and image restoration in the non-Gaussian noisy environment.展开更多
Thermal and acoustic environments pose severe challenges to find optimal design that exhibits ideal acoustic characteristics the structural design of hypersonic vehicles. One of them is to in a frequency band, which i...Thermal and acoustic environments pose severe challenges to find optimal design that exhibits ideal acoustic characteristics the structural design of hypersonic vehicles. One of them is to in a frequency band, which is discussed in this paper through topology optimization aiming at resonance sound radiation in thermal environments. The sound radiation at resonance fre- quencies is the main component of response, minimization on which is likely to provide a satisfactory design. A bi-material plate subjected to uniform temperature rise and excited by harmonic loading is studied here. Thermal stress is first evaluated and considered as prestress in the following dynamic analysis; radiated sound power is then calculated through Rayleigh inte- gral. Sensitivity analysis is carried out through adjoint method considering the complicated relationship between stress-induced geometric stiffness and design variables. As the resonance frequency is constantly changing during the optimization, its sensi- tivity should be considered. It is also noticed that mode switching may occur, so mode tracking technique is employed in this work. Some numerical examples are finally discussed.展开更多
文摘The vibration behavior of the ground and houses caused by monorail traffic is discussed in this paper. The environmental ground vibration problem discussed herein occurs in a residential area near a monorail used for public transportation, Vibrations were measured on the ground at the side of monorail piers lacing the residential area and within the affected houses. Results indicate that the vibration level in the house was 60 dB or more, a level high enough to warrant complaints, Peculiar geological and geographical features are thought to contribute to the amplification of low frequency （-10 Hz） ground vibrations to irritable levels in these homes even though a distance of≥30 m separates the residential area and the monorail.
基金This work was supported by the National Key Research and Development Program of China(2018YFA0704003)the Basic Research Program of Shenzhen(JCYJ20180305163452667,JCYJ20180507182413022,and JCYJ20170412111100742)+3 种基金the National Natural Science Foundation of China(81903564,31771036,51703132,and 21874119)the Guangdong Provincial Natural Science Foundation of Major Basic Research and Cultivation Project(2018B030308003)the Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Institutions of China(161032)We thank Instrumental Analysis Center of Shenzhen University(Lihu Campus).
文摘Multimodal cancer synergistic therapy exhibited remarkable advantages over monotherapy in producing an improved therapeutic efficacy. In this work, Janus-type γ-Fe2 O3/SiO2 nanoparticles(JFSNs) are conjugated with glucose oxidase(GOx) for synergistic cancer starvation/chemodynamic therapy. The γ-Fe2O3 hemisphere of JFSNs can perform photoacoustic/T2 magnetic resonance dual-modal imaging of tumors.GOx on the surface of JFSNs catalyzes the decomposition of glucose and produces H2O2 for cancer starvation therapy. Subsequently, the γ-Fe2O3 hemisphere catalyzes the disproportionation of H2O2 to generate highly reactive hydroxyl radicals in an acidic tumor microenvironment. The close distance between GOx and JFSNs ensures adequate contact between the γ-Fe2O3 hemisphere and its substrate H2O2, thus enhancing the catalytic efficiency. This synergy of glucose depletion, biotoxic H2O2 and hydroxyl radicals significantly suppresses 4 T1 mammary tumor growth with minimal adverse effects.
基金Supported by National Natural Science Foundation of China under Grant Nos.11072182 and 11272241
文摘We investigate the effect of alpha stable noise on stochastic resonance in a single-threshold sensor system by analytic deduction and stochastic simulation. It is shown that stochastic resonance occurs in the threshold system in alpha stable noise environment, but the resonant effect becomes weakened as the alpha stable index decreases or the skewness parameter of alpha stable distribution increases. In particular, for Cauchy noise a nonlinear relation among the optimal noise deviation parameter, the signal amplitude and the threshold is analytically obtained and illustrated by using the extreme value condition for the output signal-to-noise ratio. The results presented in this communication should have application in signal detection and image restoration in the non-Gaussian noisy environment.
基金supported by the National Natural Science Foundation of China(Grant Nos.11321062,91016008 and 91216107)
文摘Thermal and acoustic environments pose severe challenges to find optimal design that exhibits ideal acoustic characteristics the structural design of hypersonic vehicles. One of them is to in a frequency band, which is discussed in this paper through topology optimization aiming at resonance sound radiation in thermal environments. The sound radiation at resonance fre- quencies is the main component of response, minimization on which is likely to provide a satisfactory design. A bi-material plate subjected to uniform temperature rise and excited by harmonic loading is studied here. Thermal stress is first evaluated and considered as prestress in the following dynamic analysis; radiated sound power is then calculated through Rayleigh inte- gral. Sensitivity analysis is carried out through adjoint method considering the complicated relationship between stress-induced geometric stiffness and design variables. As the resonance frequency is constantly changing during the optimization, its sensi- tivity should be considered. It is also noticed that mode switching may occur, so mode tracking technique is employed in this work. Some numerical examples are finally discussed.
