地声学：一门研究海底的重要学科

地声学是一门研究海底沉积物声学特性的学科，也是一门用声学方法研究海底沉积物地学特性的学科，地声学的发展和水声学、海洋学、地质学、地球物理学及地理学等多个学科有密切的关系，对于海洋工程建设，海底资源开发及港口、航道和海防等各项海洋事业的发展重要的实用意义，文章简单介绍了国内外在地声学方面的一些工作情况，说明了地声学研究所涉及的一些主要问题，并对我国今后开展研究的方向以及应当采取的措施提出一些建议和设  

Geoacoustic Inversion Based on a Vector Hydrophone Array

We propose a geoacoustic inversion scheme employing a vector hydrophone array based on the fact that vector hydrophone can provide more acoustic field information than traditional pressure hydrophones. Firstly, the transmission loss of particle velocities is discussed. Secondly, the sediment sound speed is acquired by a matchedfield processing （MFP） procedure, which is the optimization in combination of the pressure field and vertical particle velocity field. Finally, the bottom attenuation is estimated from the transmission loss difference between the vertical particle velocity and the pressure. The inversion method based on the vector hydrophone array mainly has two advantages： One is that the MFP method based on vector field can decrease the uncertain estimation of the sediment sound speed. The other is that the objective function based on the transmission loss difference has good sensitivity to the sediment attenuation and the inverted sediment attenuation is independent of source level. The validity of the inverted parameters is examined by comparison of the numerical results with the experimental data.  

Geodesic Acoustic Mode in Toroidally Axisymmetric Plasmas with Non-Circular Cross Sections

The geodesic acoustic mode in general toroidally axisymmetric plasmas such as Tokamak and spherical torus is studied in detail. The mode structure is found and the dispersion equation is derived and solved for arbitrary toroidally axi-symmetric plasmas. Besides the finite aspect ratio, effects of elongation and triangularity on this mode are clarified.  

“中国东西部地区声学学术交流会”将于7月在丽江市召开

为促进中国西部地区声学科技事业的发展,及该地区与全国各地声学科技工作者之间的交流与沟通,浙江省声学学会、陕西省声学学会、西安声学学会、重庆市电子学会及四川省声学学会经协商,联合发起定于2003年7月中旬在云南丽江市召开“2003’中国东西部地区声学学术交流会”会议由中国电子科技集团公司26所,中国声学学会超声电子学分会及四川省声学学会共同承办。会议诚望和欢迎东西部地区和全国各地从事声学科技工作的广大科技专家、学者及管理人员,为开发西部多做贡献,积极投稿,并踊跃参加交流。  

评介《神秘的声音世界》

关定华教授编写的科普书《神秘的声音世界》已于2001年4月由济南山东教育出版社出版、山东省新华书店发行。本书是周光召院士主编的《21世纪学科发展丛书》中的声学篇。丛书的宗旨是“促进学科发展、推动科技进步和普及科学知识、提高全民科技文化素质”,而科学普及以“青少年群体”为重要对  

第四届海峡两岸声学技术交流研讨会在杭州成功召开

2008年起两岸三地即沪港台声学会之间在上海声学会名誉理事章奎生教授的倡议联络下,经沪港台三地声学会的共同商议确定了开展学术交流研讨会的机制。2008年6月中旬、2009年11月下旬和2010年7月下旬先后在香港理工大学、台北科技大学和上海现代设计集团章奎生声学设计研究所召开了前3届两岸三地声学技  

Geoacoustic inversion based on reflection model of effective density fluid approximation

In order to obtain the physical and geoacoustic properties of marine sediments,an inverse method using reflection loss of different grazing angles is presented.The reflection loss is calculated according to the reflection model of effective density fluid approximation.A two-step hybrid optimization algorithm combining differential evolution and particle swarm optimization along with Bayesian inversion is employed in estimation of porosity,mean grain size,mass density and bulk modulus of grains.Based on the above physical parameters,geoacoustic parameters,including sound speed and attenuation,are further calculated.According to the numerical simulations,we can draw a conclusion that all the parameters can be well estimated with the exception of bulk modulus of grains.In particular,this indirect inverse method for bottom geoacoustic parameters performs high accuracy and strong robustness.The relative errors are 0.092%and 17%,respectively.Finally,measured reflection loss data of sandy sediments at the bottom of a water tank is analyzed,and the estimation value,uncertainty and correlation of each parameter are presented.The availability of this inverse method is verified through comparison between inverse results and part of measured parameters.  

Low-Frequency Hydroacoustic Experiments on the Shelf Using the Data of Geoacoustic Sediment Model

Acoustic and seismoacoustic methods have become the most perspective and intensely developed meth- ods in the research of dynamic processes and inho- mogeneities in shallow water. Seismoacoustic moni- toring allows one to draw conclusions about the pres- ence of different inhomogeneities in the water environ- ment and to identify various dynamic processes in the oceanic shelf zone. Studies of the propagation of hy- droacoustic signals of different frequencies and config- urations are widely discussed in scientific publications in Russia, China and the United States Solutions to inversion problems in acoustics, the con- struction of geoacoustic models and research of low- frequency acoustic signals with respect to the absorb- ing bottom are without any doubt at the forefront of underwater acoustics.  

纪念马大猷院士声学贡献专题研讨在国际声学大会成功举行

2013年6月4日在加拿大的蒙特利尔,田静研究员和向宁教授在第21届国际声学大会(ICA2013Montreal)上成功组织了"纪念马大猷院士声学贡献专题研讨",来自世界各地声学巨匠和青年才俊纷纷投稿,回顾了先生在声学领域的主要贡献,并深情地缅怀了与先生一起时的点点滴滴。2013年6月2—7日,每三年一度的国际声学大会在加拿大蒙特利尔举行。这是声学界的一次盛会,也是声学家们的节日。与以往不同的是,在这届大会上,中国声学学会理事长田静研究员和美国伦斯勒理工  

田静主编当选为国际声学委员会副主席

2013年6月5日,在加拿大蒙特利尔举行的第21届国际声学委员会会员代表大会上,《声学学报》(中、英文版)主编、中国声学学会理事长、田静研究员当选为第22届国际声学委员会(2013—2016)副主席。国际声学委员会成立于1951年,隶属于国际纯物理与应用物理联盟(IUPAP)和国际应用与理论力学联盟,是国际科学委员会合作伙伴。其宗旨在于促进国际间声学领域的研究、开发、教育与标准化等方面的