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Modeling the Underwater Acoustic Field Excited by an Airborne Rapidly Moving Source Using Wavenumber Integration

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西北工业大学学报 2007年第6期25卷 855-859页

作者： Zhang Yipeng ma yuanliang Institute of Acoustic Engineering Northwestern Polytechnical University Xi＇an 710072 China

It is complicated to model the acoustic field in stratified ocean for airborne aircraft,due to high speed of the source and air-to-water sound *** our knowledge,there are very few papers in the open literature dealing with this complicated problem;but,in our opinion,they all require great amount of *** now propose a different method that requires much less *** improve the wavenumber integration method to model the received temporal signal for a moving source in stratified ocean and sum up in a concise form the core of our paper as follows:(A) Eq.(11) can be calculated by means of fast Chirp Z transform and the signals at all N time points are generated simultaneously;(B) direct numerical evaluation of the wavenumber integral in Eq.(4) produces large numerical errors;so it is necessary to shift the integration slightly below the real axis;(C) we compare the computation cost of direct calculation method with that of our fast calculation method;from the results presented in table 1,we can see that the fast calculation method consumes much less computation time,particularly for long duration signals;(D) for an airborne rapidly moving source,we compute the Doppler-shifted signals in shallow water and analyze their short-time Fourier transform;from Fig.1b,we can see that the received signals have multiple frequency components for a tonal source due to source motion and that each component corresponds to an arrival path.

关键词：水下声学空气-水声传播快速移动资源波数整合

Optimal design and verification of temporal and spatial filters using second-order cone programming approach

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Science in China(Series F) 2006年第2期49卷 235-253页

作者： YAN Shefeng ma yuanliang Institute of Acoustic Engineering Northwestern Polytechnical University Xi'an 710072 China

Temporal filters and spatial filters are widely used in many areas of signal processing. A number of optimal design criteria to these problems are available in the literature. Various computational techniques are also presented to optimize these criteria chosen. There are many drawbacks in these methods. In this paper, we introduce a unified framework for optimal design of temporal and spatial filters. Most of the optimal design problems of FIR filters and beamformers are included in the framework. It is shown that all the design problems can be reformulated as convex optimization form as the second-order cone programming （SOCP） and solved efficiently via the well-established interior point methods. The main advantage of our SOCP approach as compared with earlier approaches is that it can include most of the existing methods as its special cases, which leads to more flexible designs. Furthermore, the SOCP approach can optimize multiple required performance measures, which is the drawback of earlier approaches. The SOCP approach is also developed to optimally design temporal and spatial two-dimensional filter and spatial matrix filter. Numerical results demonstrate the effectiveness of the proposed approach.

关键词： filter design beamformer design spatial filter design second-order cone programming.

Calculation of baffle effect and mutual interaction between elements for an underwater acoustic conformal array with application to the optimization of projecting beampattern

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Chinese Science Bulletin 2007年第18期52卷 2584-2591页

作者： HE ZhengYao ma yuanliang Acoustic Engineering Institute Northwestern Polytechnical University Xi'an 710072 China

The boundary element theory together with the optimization method is used to calculate the driving voltage weighting vector of a conformal array of underwater acoustic projecting transducers to obtain a low-sidelobe beampattern. At first, the relationship between the acoustic radiated field and the vibra- tion velocity of the array is formulated from the boundary element equation when the boundary im- pedance of the array baffle is specified. Then, the mutual impedance matrix of the array is calculated, and the relationship between the driving voltage and the vibration velocity of the transducers is pre- sented based on the equivalent circuit principle. At last, the driving voltage weighting vector of the array is calculated through an optimization method to obtain a low-sidelobe projecting beampattern. Computer simulation is conducted for a 14-element conformal array. An experiment has been carried out to measure the radiation directivity of the array in an anechoic water tank. The calculated and the experimental results show that the proposed method accounts for the acoustic effect of the baffle and the mutual interactions among transducers successfully and obtain a low-sidelobe projecting beam- pattern, and at the same time provide the largest amplitude of pressure in the axial direction when the maximum amplitude of the driving voltage weighting vectors keeps unchanged.

关键词：变换器共形天线阵边界元理论最优化法

Statistics of underwater ambient noise at high sea states arisen from typhoon out zones in the Philippine Sea and South China Sea

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Acta Oceanologica Sinica 2022年第7期41卷 153-165页

作者： Qiulong Yang Kunde Yang Shunli Duan yuanliang ma School of marine Science and Technology Northwestern Polytechnical UniversityXi’an710072China Key Laboratory of Ocean Acoustics and Sensing Ministry of Industry and Information TechnologyXi’an710072China Key Laboratory of marine Environmental Information Technology Ministry of Natural ResourcesTianjin300171China

Oceanic noise is the background interference in sonar performance prediction and evaluation at high sea *** of underwater ambient noise during Typhoons Soulik and Nida were analyzed on the basis of experimental measurements conducted in a deep area of the Philippine Sea and the South China *** linear regression,frequency correlation matrix(FCM),Burr distribution and Gumbel distribution were described for the analysis of correlation with environmental parameters including wind speed(WS),significant wave height(SWH),and the inter-frequency relationship and probability density function of noise levels(NLs).When the typhoons were quite close to the receivers,the increment of NLs exceeded 10 *** ambient noise was completely dominated by wind agitation,NLs were proportional to the cubic and quintic functions of WS and SWH,*** fitted results between NLs and oceanic parameters were different for“before typhoon”and“after typhoon”.The fitted slopes of linear regression showed a linear relationship with the logarithm of *** average observed typhoon-generated NLs were 5 dB lower than the Wenz curve at the same wind force due to the insufficiently developed sea state or the delay between NLs and *** cross-correlation coefficient of FCM,which can be utilized in the identification of noise sources in different bands,exceeded 0.8 at frequencies higher than 250 ***,standard deviation increased with *** kurtosis was equal to 3 at>400 Hz *** characteristics of NLs showed good agreement with the results of FCM.

关键词： statistics underwater acoustics cruise-measured ambient noise typhoon Philippine Sea South China Sea deep ocean

6G:Ubiquitously Extending to the Vast Underwater World of the Oceans

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Engineering 2022年第1期8卷 12-17页

作者： yuanliang ma Qunfei Zhang Honglei Wang School of marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072China

*** There is a significant gap between atmospheric space and undersea space for wireless radio *** interface between air and seawater is a barrier to prevent radio wave transmission across the *** is because seawater is an electrically conducting medium,and radio waves suffer significant absorptive attenuation *** a result,there is no internet,reliable mobile communication,high-quality video,and long-distance duplex wireless communication in the underwater world of *** is pitiful since the oceans share 71%of the surface of our planet and are of great importance to our economy,ecology,and living environment.

关键词： communication wireless planet

matched-field localization using a virtual time-reversal processing method in shallow water

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Chinese Science Bulletin 2011年第8期56卷 743-748页

作者： ZHANG TongWei YANG KunDe ma yuanliang College of marine Northwestern Polytechnical University Xi'an 710072 China

Time-reversal processing(TRP) is an implementation of matched-field processing(MFP) where the ocean itself is used to construct the replica *** paper introduces virtual time-reversal processing(VTRP) that is implemented electronically at a receiver array and simulates the kind of processing that would be done by an actual TRP during the reciprocal propagation *** is a forward propagation process,while VTRP is a back-propagation process,which exploits the properties of reciprocity and superposition and is realized by weighting the replica surface with the complex conjugate of the data received on the corresponding element,followed by summation of the processed received *** number of parabolic equation computational grids of VTRP is much smaller than that of MFP in a range-dependent *** a result,the localization surface of VTRP can be formed faster than its MFP counterpart in a range-dependent *** performance of VTRP for source localization is validated through numerical simulations and data from the Mediterranean Sea.

关键词：匹配场处理时间反转定位方法虚拟多功能一体机浅水传播过程定位表面

A study of the mixed layer of the South China Sea based on the multiple linear regression

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Acta Oceanologica Sinica 2012年第6期31卷 19-31页

作者： DUAN Rui YANG Kunde ma yuanliang HU Tao College of marine Northwestern Polytechnical UniversityXi'an 710072China Key Laboratory of Underwater Acoustic Environment Institute of AcousticsChinese Academy of SciencesBeijing 100190China

Multiple linear regression （MLR） method was applied to quantify the effects of the net heat flux （NHF）, the net freshwater flux （NFF） and the wind stress on the mixed layer depth （MLD） of the South China Sea （SCS） based on the simple ocean data assimilation （SODA） dataset. The spatio-temporal distributions of the MLD, the buoyancy flux （combining the NHF and the NFF） and the wind stress of the SCS were presented. Then using an oceanic vertical mixing model, the MLD after a certain time under the same initial conditions but various pairs of boundary conditions （the three factors） was simulated. Applying the MLR method to the results, regression equations which modeling the relationship between the simulated MLD and the three factors were calculated. The equations indicate that when the NHF was negative, it was the primary driver of the mixed layer deepening; and when the NHF was positive, the wind stress played a more important role than that of the NHF while the NFF had the least effect. When the NHF was positive, the relative quantitative effects of the wind stress, the NHF, and the NFF were about i0, 6 and 2. The above conclusions were applied to explaining the spatio-temporal distributions of the MLD in the SCS and thus proved to be valid.

关键词： mixed layer multiple linear regression South China Sea vertical mixing model

SiO_(2)/g-C_(3)N_(4)复合材料的3D打印制备及对染料废水的处理性能

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工业水处理 2024年第3期44卷 64-73页

作者：赵文璞赵晓东季惠明马元良马生花沈铸睿天津大学材料科学与工程学院先进陶瓷与加工技术教育部重点实验室天津300350 青海民族大学物理与电子信息工程学院青海西宁810007 南开大学材料科学与工程学院天津300350

使用直写型3D打印的方式制备了高比表面积与多孔结构的SiO_(2)/g-C_(3)N_(4)复合气凝胶材料,并对材料的微观形貌、多孔结构进行了表征,测试了其对于模拟溶液中高浓度罗丹明B(RhB)的吸附及催化降解性能。研究结果表明,3D打印SiO_(2)块体... 详细信息

使用直写型3D打印的方式制备了高比表面积与多孔结构的SiO_(2)/g-C_(3)N_(4)复合气凝胶材料,并对材料的微观形貌、多孔结构进行了表征,测试了其对于模拟溶液中高浓度罗丹明B(RhB)的吸附及催化降解性能。研究结果表明,3D打印SiO_(2)块体气凝胶比表面积达482.1 m^(2)/g,具备孔隙体积为1.195 cm^(3)/g的纳米多孔结构,对RhB具有好的吸附性能。经g-C_(3)N_(4)修饰所得的SiO_(2)/g-C_(3)N_(4)复合气凝胶材料孔结构与比表面积变化不大,除仍保持较高的吸附性能外,在紫外光照下对RhB(100 mg/L)的去除率可达99%以上。经5次循环测试后SiO_(2)/g-C_(3)N_(4)复合气凝胶对RhB的去除率仍达92.98%,相比之下3D打印SiO_(2)气凝胶仅为55.75%。机理分析表明,复合材料中的g-C_(3)N_(4)可吸收光能并生成光生电子空穴对,其与H_(2)O和O_(2)作用产生氧化活性物质超氧自由基,最终均参与光催化氧化还原反应中对RhB大分子的催化氧化降解。3D打印结构具有的高比表面积实现了催化剂与RhB大分子较大的反应接触面积,提高了复合材料的光催化降解效率及循环稳定性。

关键词： 3D打印 SiO_(2)/g-C_(3)N_(4)复合气凝胶吸附降解

Forward acoustic scattering by moving objects:Theory and experiment

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Chinese Science Bulletin 2012年第4期57卷 313-319页

作者： LEI Bo YANG KunDe ma yuanliang WANG Lu Institute of Acoustic Engineering Northwestern Polytechnical UniversityXi'an 710072China

The normal mode model for scattering in shallow water is employed to investigate the forward scattering with a target crossing the source-receiver axial line. An experiment was conducted in a littoral environment to analyze forward scattering by a slowly moving object. The theoretical and experimental results show that the sound field aberration takes minimum values if the object is located mid-point along the source-receiver line, whereas it attains its maximum if the object is close to the source or receiver. The total field is either enhanced or suppressed if the object crosses different Fresnel zones. In addition, the duration of shad- ow-induced aberration is dependent on the width of the first Fresnel zone, which is longest at the mid-point of the source-receiver line.

关键词：声散射实验物体移动菲涅尔区前向散射散射模型持续时间