检索结果-南通市图书馆

Ultraefficient thermoacoustic conversion through a split ring resonator

Advanced Photonics 2020年第3期2卷 69-77页

作者： Lu Lan Yueming Li Tiffany Yang-Tran Ying Jiang Yingchun Cao Ji-Xin Cheng Boston University Department of Biomedical EngineeringBostonMassachusettsUnited States Boston University Department of Mechanical EngineeringBostonMassachusettsUnited States Boston University Department of Electrical and Computer EngineeringBostonMassachusettsUnited States Boston University Photonics Center BostonMassachusettsUnited States

Microwaves,which have a∼10-cm wavelength,can penetrate deeper into tissue than photons,heralding exciting deep tissue applications such as modulation or imaging via the thermoacoustic effect.thermoacoustic conversion efficiency is however very low,even with an exogenous contrast agent.We break this low-conversion limit,using a split ring resonator to effectively collect and confine the microwaves into a submillimeter hot spot for ultrasound emission and achieve a conversion efficiency over 2000 times higher than other reported thermoacoustic contrast agents.Importantly,the frequency of emitted ultrasound can be precisely tuned and multiplexed by modulation of the microwave pulses.Such performance is inaccessible by a piezoelectric-based transducer or a photoacoustic emitter and,therefore,split ring resonators open up new opportunities to study the frequency response of cells in ultrasonic biomodulation.For applications in deep tissue localization,a split ring resonator can be used as a wireless,battery-free ultrasound beacon placed under a breast phantom.

关键词： thermoacoustic effect metamaterial photoacoustic effect split ring resonator ultrasound

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Analysis of influencing factors of excitation parameters for magnetoacoustic tomography with current injection

引用

Chinese Physics B 2023年第5期32卷 496-503页

作者：李粟刘国强郭亮张文伟卢朝森夏慧 College of Information and Control Engineering China University of PetroleumQingdao 266580China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China College of Electrical and Automation Engineering Shandong University of Science and TechnologyQingdao 266510China

Magneto-acoustic tomography with current injection(MAT-CI) is a type of hybrid imaging;under the excitation of the static magnetic field, the thermoacoustic effect and the Lorentz force effect will exist at the same time. Therefore,the detected signal is a mixed signal generated by the simultaneous action of the two effects, but the influence of excitation parameters on the two effects is different. In this paper, for objects with different conductivity, the proportion of thermoacoustic signal(TA) and magneto-acoustic signal(MA) in the mixed signal is quantitatively analyzed in terms of three aspects: the magnetic induction intensity, pulse excitation and injection current polarity. Experimental and simulation analyses show that the intensity ratio of MA to TA is not affected when the conductivity varies from 0.1 S/m to 1.5 S/m and other conditions remain unchanged. When the amplitude of the pulse excitation and the strength of the magnetic induction are different, the growth rates of MA and TA are different, which has a significant impact on the proportion of the two signals in the mixed signal. At the same time, due to the Lorentz force effect, MA is affected by the polarity of the injected current and the direction of the static magnetic field. The combination of the static magnetic field and the injected current can not only distinguish the two signals in the mixed signal, but also effectively enhance the intensity of the mixed signal and improve the quality of the reconstructed image.

关键词： magneto-acoustic tomography with current injection(MAT-CI) thermoacoustic effect Lorentz force effect acoustic source

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：