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Acoustic multipath structure in direct zone of deep water and bearing estimation of tow ship noise of towed line array

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Chinese Physics B 2022年第5期31卷 429-437页

作者： Zhi-Bin Han Zhao-Hui Peng Jun Song Lei Meng Xiu-Ting Yang Bing Su Unit 92578 of PLA China State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China

In the towed line array sonar system,the tow ship noise is the main factor that affects the sonar *** noise cancelling methods assume that the noise is towards the endfire direction of the *** acoustic experiment employing a towed line array is conducted in the western Pacific Ocean,and a strange bearing-splitting phenomenon of the tow ship noise is observed in the *** tow ship noise is split into multiple noise signals whose bearings are distributed between 10°and 90°deviating from the endfire *** multiple interferences increase the difficulty in recognizing the target for the sonar operator and noise ***,making the mechanism clear and putting forward the tow ship noise splitting bearing estimation method are *** this paper,the acoustic multi-path structure of the tow ship in deep water is *** it is pointed out that the bearing-splitting phenomenon is caused by the main lobe of direct rays and bottom-reflected rays,as well as several side lobes of direct ***,the indistinguishability between the elevation angle and the bearing angle due to the axial symmetry of a strict horizontal line array causes the bearing to deviate from the endfire *** on the theory above,a method of estimating bearing of the tow ship noise in deep water is *** theoretical analysis results accord with the experimental results,which helps to identify the target and provide correct initial bearing guidance for noise cancelation methods.

关键词： deep water direct zone towed line array the tow ship noise

Bearing splitting and near-surface source ranging in the direct zone of deep water

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Chinese Physics B 2016年第12期25卷 77-84页

作者：吴俊楠周士弘彭朝晖张岩张仁和 State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of Sciences College of Physics University of Chinese Academy of Sciences

Sound multipath propagation is very important for target localization and identification in different acoustical zones of deep water. In order to distinguish the multipath characteristics in deep water, the Northwest Pacific Acoustic Experiment was conducted in 2015. A low-frequency horizontal line array towed at the depth of around 150 m on a receiving ship was used to receive the noise radiated by the source ship. During this experiment, a beating-splitting phenomenon in the direct zone was observed through conventional beamforming of the horizontal line array within the frequency band 160 Hz- 360 Hz. In this paper, this phenomenon is explained based on ray theory. In principle, the received signal in the direct zone of deep water arrives from two general paths including a direct one and bottom bounced one, which vary considerably in arrival angles. The split bearings correspond to the contributions of these two paths. The beating-splitting phenomenon is demonstrated by numerical simulations of the bearing-time records and experimental results, and they are well consistent with each other. Then a near-surface source ranging approach based on the arrival angles of direct path and bottom bounced path in the direct zone is presented as an application of bearing splitting and is verified by experimental results. Finally, the applicability of the proposed ranging approach for an underwater source within several hundred meters in depth in the direct zone is also analyzed and demonstrated by simulations.

关键词： direct zone deep water bearing splitting near-surface source ranging

Sound propagation from the shelfbreak to deep water

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Science China(Physics,Mechanics & Astronomy) 2014年第6期57卷 1031-1037页

作者： QIN JiXing ZHANG RenHe LUO WenYu PENG ZhaoHui LIU JianJun WANG DeJun State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of Sciences Graduate University of Chinese Academy of Sciences

Motivated by a phenomenon in an experiment conducted in the Northwestern Pacific indicating that the energy of the received signal around the sound channel axis is much greater than that at shallower depths,we study sound propagation from the transitional area(shelfbreak)to deep *** simulations with different source depths are first performed,from which we reach the following *** the source is located near the sea surface,sound will be strongly attenuated by bottom losses in a range-independent oceanic environment,whereas it can propagate to a very long range because of the continental *** the source is mounted on the bottom in shallow water,acoustic energy will be trapped near the sound channel axis,and it converges more evidently than the case where the source is located near the sea ***,numerical simulations with different source ranges are *** comparing the relative energy level in the vertical direction between the numerical simulations and the experimental data,the range of the air-gun source can be approximated.

关键词： sound propagation transitional area deep water parabolic equation

The bimodality of the Luzon Strait deep water

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Acta Oceanologica Sinica 2014年第5期33卷 17-27页

作者： WU Qingsong ZHAO Jianru ZHANG Junbiao SHI Weiyong LIU Chunqiu Key Laboratory of Engineering Oceanography the Second Institute of Oceanography State Oceanic Administration Key Laboratory of Submarine Geosciences the Second Institute of Oceanography State Oceanic Administration State Reasearch Centre for Island Exploitation and Management the Second Institute of Oceanography State Oceanic Administration

Combined conductivity-temperature-depth （CTD） casts and Argo profiles, 3 086 historical hydrocasts were used to quantify the water column characteristics in the northern South China Sea （SCS） and its adjacent waters. Based on a two-dimensional ＂gravest empirical mode＂（GEM）, a gravitational potential （4, a vertically integrated variable） was used as proxy for the vertical temperature profiles TG（P, φ）. φ integrated from 8 MPa to the surface shows a close relationship with the temperature, except in the deep layer greater than 15 MPa, which was caused by the bimodal deep water in the region. The GEM temperature profiles successfully revealed the bimodality of the Luzon Strait deep water, that disparate hydrophic vertical profiles can produce distinct specific volume anomaly （δ） in the SCS and the western Philippine Sea （WPS）, but failed in the Luzon Strait, where different temperature profiles may produce a same 6. A significant temperature divergence between the SCS water and the WPS water confirmed that the bimodal structure is strong. The deepwater bifurcation starts at about 15 MPa, and gets stronger with increasing depth. As the only deep channel connecting the bimodal-structure waters, water column characteristics in the Luzon Strait is in between, but much closer to the SCS water because of its better connectivity with the SCS. A bimodal temperature structure below 15 MPa reveals that there was a persistent baroclinic pressure gradient driving flow through the Luzon Strait. A volume flux predicted through the Bashi Channel with the hydraulic theory yields a value of 5.62×10^6 m^3/s using all available profiles upstream and downstream of the overflow region, and 4.03×10^6 and 2.70×10^6 m^3/s by exclusively using the profiles collected during spring and summer, respectively. No volume flux was calculated during autumn and winter because profiles are only available for the upstream of the Bashi Channel during the corresponding period.

关键词： Luzon Strait historical hydrocasts gravest empirical mode deep water bimodality volume flux

Feasibility Study on Common Methods for Wave Force Estimation of deep water Combined Breakwaters

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Journal of Ocean University of China 2015年第4期14卷 629-635页

作者： YU Dingyong TANG Peng SONG Qingguo College of Engineering Ocean University of China

China's newly enacted Breakwater Design Specifications(JTS154-2011) explicitly state that breakwaters with water depths greater than 20 m are categorized as deep-water breakwaters, and emphasize that design principles, methods and construction requirements are different from those of common shallow water breakwaters. However, the specifications do not make any mention of how to choose wave force calculation methods of deep-water breakwaters. To study the feasibility of different formulae for wave force estimation of deep water combined breakwaters, the wave force calculated by the Sainflou's, Goda's, modified Goda's and specifications' methods are compared for various water depths and wave heights in this paper. The calculated results are also compared with experimental data. The total horizontal forcing and the pattern of pressure distributions are presented. Comparisons show that the wave pressure distributions by the four methods are similar, but the total horizontal forces are different. The results obtained by the Goda's method and the specified formulae are much closer to the experimental data. As for the wave force estimation for the deepwater mixed embankment foundation bed parapet, the Goda's formula is applied in the case with a water depth of less than 42 m. The Specifications method is suitable for standing waves. In the wave force estimates of breastworks, Sainflou's and the modified Gaoda's formulae are no longer applicable for the foundation bed of mixed embankment.

关键词： combined breakwater breast wave force deep water feasibility

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deep water英译汉翻译实践报告

Deep Water英译汉翻译实践报告

作者：孙淑君宁波大学

学位级别：硕士

本翻译实践报告以美国作家Katherine Nichols的叙事性非虚构类青少年文学作品deep water(《深水》)的第二章至第六章作为翻译材料,针对文本中出现的专有名词、个性化语言以及修辞格进行翻译研究,并以美国翻译理论家劳伦斯·韦努蒂提出... 详细信息

本翻译实践报告以美国作家Katherine Nichols的叙事性非虚构类青少年文学作品deep water(《深水》)的第二章至第六章作为翻译材料,针对文本中出现的专有名词、个性化语言以及修辞格进行翻译研究,并以美国翻译理论家劳伦斯·韦努蒂提出的归化和异化翻译为理论指导,提出相应的翻译策略与技巧。通过本次翻译实践,研究发现:针对不同的专有名词,包括地名、人名和电影名,需要分别采取归化和异化策略下意译、音译加注等相应的翻译技巧;人物语言的翻译需要考虑人物性格以及文化元素,运用省译、增译、直译加注翻译等方法;同一种修辞格的翻译可以合理采用归化或异化进行汉译,呈现出不同的翻译效果。本翻译实践报告分为四部分:第一章介绍翻译项目背景、翻译过程及其翻译目的和意义;第二章分析翻译文本的语言特征与翻译难点;第三章就文本语言特征提出具体的归化和异化翻译技巧;第四章是对本次翻译实践的总结以及译者的感悟。本次报告也为归化与异化指导下的叙事性非虚构类青少年文学作品的翻译,提供了可行性建议。

关键词：归化异化非虚构 deep water 翻译实践报告

Spatial correlation of the high intensity zone in deep-water acoustic field

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Chinese Physics B 2016年第12期25卷 69-76页

作者：李鋆李整林任云 State Key Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100190 China Haikou Laboratory of Acoustics Institute of Acoustics Chinese Academy of Sciences Haikou 570105 China

The spatial correlations of acoustic field have important implications for underwater target detection and other ap- plications in deep water. In this paper, the spatial correlations of the high intensity zone in the deep-water acoustic field are investigated by using the experimental data obtained in the South China Sea. The experimental results show that the structures of the spatial correlation coefficient at different ranges and depths are similar to the transmission loss structure in deep water. The main reason for this phenomenon is analyzed by combining the normal mode theory with the ray theory. It is shown that the received signals in the high intensity zone mainly include one or two main pulses which are contributed by the interference of a group of waterbome modes with similar phases. The horizontal-longitudinal correlations at the same receiver depth but in different high intensity zones are analyzed. At some positions, more pulses are received in the arrival structure of the signal due to bottom reflection and the horizontal-longitudinal correlation coefficient decreases accordingly. The multi-path arrival structure of receiving signal becomes more complex with increasing receiver depth.

关键词： spatial correlations deep water high intensity zone normal mode

INHIBITION OF ALLELOPATHIC RICE COMBINED WITH HERBICIDE AND deep water ON WEEDS IN PADDY FIELD

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INHIBITION OF ALLELOPATHIC RICE COMBINED WITH HERBICIDE AND ...

Seismic geomorphology and main controls of deep-water gravity flow sedimentary process on the slope of the northern South China Sea

中国第三届植物化感作用学术研讨会、第八届全国杂草科学大会、联合国粮农组织——中国“水稻化感作用论坛”

作者： Jing-lun WU,Gui LI,Yi-zhuan WANG,Li-ping LIU Institute of Plant Protection,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China

Field experiments were conducted to examine the effects of herbicide on the interference of allelopathic rice in weeds under different water depth on soil *** results showed that allelopathic rice could inhibit the germination and growth of bamyardgrass[Echinochloa crusgalli(L.) Beauv]effectively,and bensulfuron methyl[30g(a.i)/ha]applied 6 days later after

关键词： Rice(Oryza sativ.L) allelopathy herbicide deep water weed

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Science China Earth Sciences 2012年第10期55卷 747-757页

作者： LI Lei WANG YingMin XU Qiang ZHAO JingZhou LI Dong School of Petroleum Resources Xi'an Shiyou UniversityXi'an 710065China College of Geosciences China University of PetroleumBeijing 102249China CNOOC Research Institute Beijing 100027China

The Quaternary continental slope of the Baiyun Sag in northern South China Sea is characterized by a complex topography and abundant gravity flow ***-resolution 3-D seismic data in this area allow for a detailed study of the seismic geomorphology and deep-water gravity flow depositional *** Quaternary continental slope in the northern South China Sea is an above-graded *** intraslope basin lies within the above-grade continental ***,erosion,and deposition processes tend to develop a gentle topography and consequently a graded *** upper continental slope,which is above the slope equilibrium profile,is dominated by erosion and ***,slumps and erosional channels are developed within this continental *** intraslope basin is located below the slope equilibrium profile and is potential accommodation space where sediments transported by gravity flows could be deposited,forming lobe *** the influence of gravity flow supply,gravity flow duration,continental slope topography,equilibrium profile,and accommodation,a slump-erosional channel-lobe depositional system is developed in the Quaternary continental slope in the Baiyun *** deep-water gravity flow depositional process and the distribution of gravity flow sediments are greatly influenced by the continental slope topography,while the continental slope topography at the same time is reshaped by deep-water gravity flow depositional process and its *** study of the interplay between the continental slope and gravity flow is helpful in predicting the distribution of the deep-water gravity flow sediments and the variation of sediment quality.

关键词： seismic geomorphology deep water gravity flow sedimentary process South China Sea

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