摘要：Research of the acoustic local effect of metamaterial is widely used in the fields of environmental science,military industry and *** this paper,the metamaterial is designed by annular columnar *** acoustic local effect in slender columnar structure with two layers of rings in air is *** prove that when the plane acoustic wave is incident into the model,complex interference and diffraction *** at different frequencies,multipolar acoustic local effect existes and cycle distribution phenomenon is *** is noteworthy that this phenomenon has very weak relatedness with the materials and acoustic parameters of the *** research of this metamaterial design in this paper has definite reference significance in the acoustic communication and amplification of the acoustic signal detection.

摘要：The acoustic focusing effect of metamaterial has a wide range of applications in medicine,acoustic imaging,signal detection,*** paper presents an acoustic metamaterial applied to the acoustic focusing *** formation of acousticmetamaterial is designed into a cylindrical structure with three layers of ludox,cork and fluid rubber,which can produce a focusingphenomenon when acoustic waves propagate in *** these strange phenomena,a scientific description is given *** can also be concluded that when the frequency of the incident acoustic wave increases?the number of peripheral bandsoutside the focusing poles will increase ***,there are numerous groups of multipolar focusing phenomena inhigh *** design of this acoustic metamaterial is successful through theorietical and experimental verification,therefore,it can be applied to acoustic communication and test.

摘要：The signal processing technology based on material with negative refractive index provides researchers with the latest ideas. As a new nondestructive bio-photonic technology, photoacoustic tomography is a kind of imaging method based on the differences of optical absorption within the biological organization However, photoacoustic tomography by the scanning sensor or by the sensors array at present has its inherent disadvantages that may lead to poor real-time performance and high cost in the imaging process. The characteristics of acoustic lens with negative refractive index such as focusing, filtering and directional control on acoustic wave, are very suitable for solving the problem in photoacoustic tomography. With an analysis on the nega-tive quality response of acoustic lens and the advantages of negative refractive imaging, we proposed an approach using the lens to change the current photoacoustic imaging methods. The experiment showed that the imaging effectiveness of photoacoustic tomography by the designed lens is very impressive that the pressure distribution of the absorber is basically consistent with the image of the absorber. In addition, the result of 0. 6 times wavelength in the experimental image is demonstrated on sub-wave-length photoacoustic imaging through the lens designed in this work.

摘要：目前,超声技术被广泛使用,超声频段内期望信号的质量成为关键因素.利用平面波展开法设计一种局域共振型声子晶体结构的带阻滤波器,对10 MHz以内的超声频段进行仿真分析.得出频率在4.5 MHz以下和7.25-10MHz为通带,该频段内亦可实现信号增强;4.5 - 7.25 MHz为禁带,具有较好的滤波作用.所设计的声子晶体结构体积较小,可适用于小尺寸的超声探头前端,实现原始的非电量信号直接滤波.

摘要：以CO_2声光调制器为基础,设计频率为40MHz的声光调制器匹配的驱动源电路。通过正弦波振荡器皮尔斯电路产生幅度、频率稳定且可调的正弦信号,运用高频三极管2SC2786作为缓冲电路,选取SCM-1芯片设计混频电路提取中频信号,最后采用MHW6222功放芯片对中频信号进行高频低噪声功率放大。实验的结果表明,CO_2声光调制器驱动源完全满足声光调制器的正常工作要求。

摘要：动态Web网页的开发方法有多种,其中JSP与Servlet的结合为Web动态网页的实现带来良好应用前景,在易用性、效率、安全性和可移植性方面都有很好表现。在Web环境下,当有大量的用户访问数据库时,会对系统的效率带来很大的影响。为此,分析了几种数据库连接管理方法的优缺点,并讨论了采用连接池模式的设计方法和需要注意的问题。

摘要：在分析比较各种开关的基础上,选择霍尔传感器开关设计了一套全自动照明控制系统。该系统通过房门的打开和闭合控制照明灯的亮灭,门每开一次,照明灯自动点亮或熄灭,门关闭则对照明灯不起作用。电路中用霍尔传感器将房门的开关动作信号转变为电信号,用CD4017计数/脉冲分配器接收该电信号,并将该电信号转变为控制信号来触发双向可控硅导通,进而控制房间照明灯的开关。设计了实际电路并进行了仿真实验。结果表明,该系统基本实现了对照明灯的控制功能,有比较明显的节能作用,制作简便,成本低廉,可广泛应用于公共场所洗手间的照明控制。

摘要：声子晶体的滤波特性引起了科技工作者的广泛关注.在二维三组元局域共振声子晶体中,通过引入两种不同填充率的共振单元分别位于规则的六角形的角顶和中心构成的缺陷态波导结构,以此为基础构建声子晶体相应的实验模型,然后基于Comsol仿真平台,模拟特定频率的声波激励声子晶体过程,计算声子晶体幅频响应函数。仿真结果表明,声子晶体可以方便设计出新型的高效、声滤波器。

摘要：光声成像是一种新近迅速发展起来、基于生物组织内部光学吸收差异、以超声作媒介的无损生物光子成像方法。在分析当前光声成像系统中传统声学透镜的倏逝波衰减导致包含图像细节的高频信息丢失的基础上,提出使用负折射透镜,让倏逝波参与成像,突破传统声学透镜的衍射极限,从而大幅提高成像分辨率。同时依据光声效应产生的超声波具有波的特性,在研究中还发展、完善了声学信息系统的相关理论以及三维声成像技术。通过实验对比得到了超越普通声学透镜的生物组织的光声成像效果。

摘要：声表面波( SAW)滤波器在现代生产生活与军事中有着广泛的应用。SAW 滤波器制造成本比较高,成本与性能的性价比比较低。为了推动 SAW 滤波器的应用发展,需要进一步提升其性能。利用声学超材料结构设计新型 SAW 滤波器基片,可以有效提高 SAW 滤波器的滤波性能,并有效改善现有滤波器在带宽控制方面的问题。利用声学超材料设计了一种新的SAW 滤波器基片。这种基片相较于现有产品,不仅成本比较低廉,在信号处理等性能方面也有比较大的优化。研究结果对SAW 滤波器的应用和声表面波滤波性能的优化有着重要的意义,有很好的现实价值。