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| 1 | Spatial and temporal trends of climate change in Xinjiang, China显示文摘在 65 个气象学的车站的从 1961 ~ 2005 的系列数据集被用来揭示气候的空间、时间的趋势的温度和降水时间在 Xinjiang 变化,中国。年度、季节的吝啬的空气温度和全部的降水用 Mann-Kendall (MK ) 测试被分析,反的距离加权(IDW ) 插值,和 R/S 方法。结果显示那:(1 ) 在过去的 45 年里增加的温度和降水,而是温度的增加比降水的更明显;(2 ) 为温度增加,更高纬度并且更高举起更快增加,不过,纬度在增加以后有更大的影响。北 Xinjiang 显示出比南部的 Xinjiang 的更快的温暖,特别在夏天;(3 )降水的增加在南部的 Xinjiang 主要在冬季发生在北 Xinjiang 并且在夏天。Ili,在 Xinjiang 有大多数降水,显示出降水的弱增加;(4 ) 尽管温度和降水一般来说增加了,增加在 Xinjiang 内是不同的;(5 ) 林中小丘索引(H) 分析显示那个气候变化将继续当前的趋势。 | LI Qihu CHEN Yaning SHEN Yanjun LI Xingong XU Jianhua | 2011 | Journal of Geographical Sciences2011，21，6： | 41 |
| 2 | Theoretical analysis and experimental results of interference striation pattern of underwater target radiated noise in shallow water waveguide显示文摘在浅水里不变的波导是一个吸引人的话题在最近散发的噪音的直接波浪的三 decades.The 干扰现象在水下从海表面和海底部的目标和思考波浪能被看作浅水 waveguide.The 干扰有条纹或刻痕之状态的一个典型盒子直接波浪和它的思考的模式有效并且为更好理解浅水波导 invariant.The 的本质的全面数字干扰 pheno | LI Qihu WANG Lei WEI Chonghua LI Yi MA Xuejie YU Haichun | 2011 | Chinese Journal of Acoustics2011，30，1： | 13 |
| 3 | A new method of passive ranging for underwater target:distance information extraction based on wave guide invariant显示文摘The study of wave guide invariant in underwater acoustics is one of attracted topics in recent 30 years.The interferences of direct wave and reflect wave from sea surface and sea bottom of underwater target radiated noise inherent the information of target distance.Extraction of these distance information will provide a possible new way in passive ranging for underwater target.The theoretical analysis and the results of at sea experiments show that the LOFAR(Low Frequency Analysis Record) figure inherently contains the range and moving information of passive acoustic sources,even in the situation that the receiver is only one single hydrophone.The theoretical analysis of extraction of target distance information by using wave guide invariant is presented in this paper.It is shown that,based on the interference striation pattern of target,the hydrophone array system is possible to extract the distance information with quite high array gain.Although the mathematical constrain conditions in forming interference striation pattern are different for individual array element,but it is proved that the differences of time delays between array elements can be used in compensation of beamforming.The theoretical analysis,system simulation and some results of at sea experiment show a new way in passive ranging and target recognition. | LI Qihu | 2015 | Chinese Journal of Acoustics2015，34，2： | 9 |
| 4 | Acoustic vector sensor signal processing显示文摘声学的向量传感器同时, colocately 并且直接在声学的地里在单个点象压力一样测量粒子速度的直角的部件以便是可能的改进性能传统在水下声学的测量设备或察觉系统并且为解决扩大新想法实际在水下的声学的设计问题。尽管出现在的声学的向量传感器历史在水下声学的区域不长,但是与巨大、潜在的军人一起要求声学的向量传感器在最后一十年有强壮的发展趋势,它正在演变为中的一一个重要在水下声学的技术。在这个背景下面,我们试着在声学的向量传感器信号处理上在学习考察最近的进步,例如信号察觉, DOA 评价, beamforming 等等。 | SUN Guiqing LI Qihu ZHANG Bin | 2006 | Chinese Journal of Acoustics2006，25，1： | 7 |
| 5 | Towed line array sonar platform noise suppression based on spatial matrix filtering technology显示文摘The spatial matrix filter was designed and used for solving the problem to detect a weak target who was influenced by the strong nearby platform noise interference of the towed Une array sonar.The MFP technology and the DOA estimation technology were combined together by using the sound propagation characteristics of both target and interference.The spatial matrix filter with platform noise zero response constraint was designed by the near-field platform noise normal modes copy vectors and the far-field plane wave bearing vectors together.The optimal solution of the optimization problem for designing the spatial matrix filter was deduced directly,and it was simplified by the generalized singular value decomposition.The total response error to the plane wave bearing vectors and the total response to the platform noise copy vectors were given.The phenomena that strong interferences existed in the bearing course and blind areas existed after filtering were analyzed by the correlation between the platform noise copy vectors and the plane wave bearing vectors.It could be found from simulations that it has less blind area and higher detection ability by using the spatial matrix filtering technology. | HAN Dong LI Jian KANG Chunyu HUANG Haining LI Qihu | 2013 | Chinese Journal of Acoustics2013，32，4： | 5 |
| 6 | Multipath structure of the typical under-ice sound channel in the Arctic:theory and experiment显示文摘Considering the typical acoustic environment of the Arctic, this paper proposes a method based on OASES-Bellhop coupled model to rapidly analyze the multipath structure of the under-ice sound channel. Firstly the proposed model refers to ice plate as stratified elastic media with some roughness. Secondly,it uses the perturbation method and Kirchhoff approximation theory to solve the scattering loss due to the sea ice inhomogeneity. Finally, the model predicts the multipath structure of the under-ice channel through Ray theory. The results of the numerical simulation and experiment indicate that the typical Arctic sound channel presents multipath structures due to the sea ice and seabed in the range of 6 km, respectively.The sea ice reflection paths are stable,with a short multipath spread within 14 ms. The seabed reflection paths have relatively weak strength. The proposed OASES-Bellhop coupled model successfully predicts the amplitude and delay of the multipath structure with small error,which indicates the proposed model is able to analyze and predict the multipath structure of the observed acoustic environment in experiment. | LIU Chonglei HUANG Haining YIN Li LIU Na WEI Chonghua LI Qihu | 2019 | Chinese Journal of Acoustics2019，38，1： | 3 |
| 7 | The interference characteristics of platform and towed body noise in shallow water for active/passive towed array sonar显示文摘拖引的站台噪音的干扰特征源于推进器并且拖引身体因为活跃 / 被动的拖引的数组被分析。在浅水环境,反映的直接波浪和底部 / 海表面飘动,这被显示出将严重影响声纳系统的性能。为以各种各样的参数计算干扰的到达( DOA )的方向的公式例如数组深度,一些拖引电缆线,是干扰噪音的 derived.The 效果因为声纳系统的察觉性能是系统模拟的 described.The 结果为减少这些种干扰的效果提供方法。 | LI Qihu LI Shuqiu SUN Changyu YU Huabing | 2007 | Chinese Journal of Acoustics2007，26，3： | 3 |
| 8 | Iterative inverse beamforming algorithm and its application in multiple targets detection of passive sonar显示文摘With the increasing of detection ability of passive sonar,the weak signal detection problem in multiple interferences becomes more and more important.In the time/bearing record(TBR) display of sonar detection,when there exist traces of multiple interferences,the identification of weak signal is difficult or impossible.The adaptive noise cancellation technique provides the theoretical basis for suppressing strong interferences.But the solution for finding the steady-state optimum filter matrix is quite difficult due to the real time calculation of inverse matrix of input data correlation matrix.The iterative inverse beamforming(IBF) algorithm for solving the optimum filter vector,which is expressed by inverse matrix of the ocean environment data,is derived in this paper,by which,the optimum filter can be eventually expressed as a sum of series simple matrices of constructed from sensor data.Based on the algorithm proposed in this paper,some examples of at sea experiment are provided.The strong interferences are cancelled and the weak signal is emerged,even it didn't appear in the conventional beamforming(CBF) processing. | LI Qihu WEI Chonghua XUE Shanhua | 2017 | Chinese Journal of Acoustics2017，36，2： | 2 |
| 9 | Research on beamforming method for dual-line array with space mismatch between the two line arrays显示文摘当在双线的数组的二个线数组之间的空格是延期和的 mismatched.The 择向性功能,延期减去 beamforming 被推出,延期和和延期减去 beamforming 的港口/右舷辨别也在理想的地位下面两个都被学习时,双线的数组的港口/右舷辨别的性能将严重被降级并且在双线的数组的二个线数组之间的空格在下面被错配的地位。分析结果证明延期减去 beamforming 有港口 / 右舷辨别的更好的性能。最后,海试用结果表明理论结果。 | WANG Huakui LI Qihu HUANG Haining YE Qinghua LI Shuqiu ZHANG Chunhua | 2008 | Chinese Journal of Acoustics2008，27，1： | 2 |
| 10 | Programmable multi-channel white noise generator显示文摘The pseudo-random number is widely applied in digital signalprocessing.The white noise number is the basis of generating random numbers ofdesired probability distributions.The design philosophy of a programmabledigital multi-channel white noise generator is proposed in this paper.In stead ofthe conventional shift register,by using high speed static RAM and digital signalprocessing chip,the multi-channel independent white noise is generated.It satis-fies the requirement in the fields of radar,sonar and communication.The analysisof design principle,block diagram and the results of system simulation is illus-trated. | LI Qihu, LIU Jinbo, YIN Li, ZHAO Guoying, LIU Wei CHENG Yufeng JIANG Hong(Institute of Acoustics. Academia Sinica Beijing 100080) | 1992 | Chinese Journal of Acoustics1992，11，3： | 2 |
| 11 | The optimum linear data fusion for dependent observations显示文摘Data fusion is one of the attractive topic in sonar signal processing. Decision level data fusion of multi-sensor (multi-array) system is described in this paper. Follow the discussion in Ref. [1], the optimum linear data fusion algorithm for N dependent observations is derived. It is proved that the estimation error of data fusion is not greater than that of individual components. The expression of estimation error and weight coefficients are presented. The results of numerical calculation and some examples are illustrated. The effect of dependence of observation data for the final estimation error is presented. | LI Qihu (Institute of Acoustics, Academia Sinica Beijing 100080) | 2001 | Chinese Journal of Acoustics2001，20，2： | 2 |
| 12 | Influence of different parameters on numerical simulation of vertical-axis marine current turbine based on OpenFOAM显示文摘Using the PimpleDyMFoam solver in open-source computing software OpenFOAM,based on the SST k-ωturbulence model and PIMPLE algorithm,a numerical simulation method of vertical-axis marine current turbines(VMCTs)is proposed,and the calculated results are compared with the experimental results.The results show that the numerical simulation method is feasible.Compared with other commercial softwares,this method has the advantages of higher solution efficiency and greater flexibility.According to the needs of users,the solver can be built on the basis of original code,and the corresponding discrete method can be optimized.This method can achieve optimization algorithms,save time and cost,etc.Secondly,the effects of different parameters(mesh density,time step,the selection of sidewall boundary conditions and inlet turbulence intensity)on numerical simulation of the VMCT are studied in detail.The findings summarize an effective CFD simulation strategy based on OpenFOAM and provide a valuable reference for future CFD simulations of VMCTs. | JI Renwei SHENG Qihu SUN Ke LI Yan ZHANG Yuquan ZHANG Liang | 2020 | 排灌机械工程学报2020，38，4： | 2 |
| 13 | Synthesis and proper- ties of X - type alkyl sulfonate gemini surfaetants derived fi'om cyanuric chloride显示文摘 | LI PENGFEI CHEN QIHU ZHAO JIALE | 2012 | Journal of Surfaetants and Detergents2012，4，45： | 1 |
| 14 | Application of adaptive filter in time delay estimation——generalized quadratic interpolation method显示文摘The time delay estimation(TDE)of two different received sig-nals from the same source has attracted many interests of researchers inthe field of signal processing.A method described for precisely estimatingtime delay in this paper is based on the assumption that little prioriknowledge on statistical characteristics is available for the received signals.The variance of the estimate is derived.The basic architecture of thismethod is to use the adaptive noise canceller,in the steady state,andto interpolate the weight coefficients by using a generalized quadratic inter-polation matrix.The formula of the time delay estimation is presented.The method proposed by F.A.Reed is a special case of this method.The hardware implementation is much easier than that of theconventional time delay estimation method.The results of the systemsimulation and the experimental results at sea show a good agreementwith the theoretical analysis. | WANG Jinlin and LI Qihu(Institute of Acoustics , Academia Sinica , Beijing 100080) | 1992 | Chinese Journal of Acoustics1992，11，1： | 1 |
| 15 | Numerical simulation of blade-wake interaction of vertical axis idal turbine显示文摘 | LI Zhichuan SHENG Qihu ZHANG Liang | 2012 | Advanced Materials Research2012，346，： | 1 |
| 16 | A simplified ZOOM FFT algorithm in digital sonar显示文摘DEMON and LOFAR have been proved the powerful means in underwater acoustic signal processing, especially in weak signal detection and target noise classification. Sometimes one need to know the fine structure of frequency spectrum of received signal. It is necessary to take a very long data to get high frequency resolution. This is not always possible due to the hardware and software limitation. Zoom FFT is one of the trade-off consideration for solving high frequency resolution problem, if we are only focus on some special frequency bins. Previous discussions mainly bifurcate into two different representations, the Complex Modulation and Cascade FFT. The former one traditionally needs some kind of special treatments, such as the complex modulation, Lowpass filtering, down-sampling. While the latter achieves the same result by two cascade FFT, with necessary modifications in phase and amplitude, thus is feasible for real-time implementation. Based on some theoretical analysis, a relationship between the complex moduIation and cascade FFT has been described in this paper. In addition, the selection of parameters such as windows function, sample rate, overlap factor have been discussed. Finally, the algorithm is presented and some simulation results are | LI Qihu LI Weichang ZHAO Wenli(Institute of Acoustics, Academia Sinica Beijing 100080) | 1999 | Chinese Journal of Acoustics1999，18，2： | 1 |
| 17 | Precise bearing and automatic target tracking in digital sonar显示文摘Precise bearing and Automatic Target Thacking (ATT) for moving vessels is an important thesis in passsive sonar design. Thaditionally in the analogue sonar, DOA (Direction Of Arrival) of the target is determined by the single beam steerillg directioll, which rotate some kind of compensator to steer the target. The compensator is typically made of many electronic and mechanical components. The bearing accuracy substantially depellds on the accuracy of tapped delay line and many mechanical factors. With the application of digital technique in sonar, the precise bearing and ATT technique have attracted much interests for sonar designer. For a digital sonar the multi-beam system has discrete beam direction, which distributed in space, each beam has its fixed steering direction. It is important to use them to estimate precisely DOA of target and then to track the target automatically when the target is moving. An algorithm, which can precisely estimate the value of DOA of the target, is derived in this paper. The relationship among bearing accuracy and the array aperture, signal frequency band is expressed. The expression of time-delay estimation and bearing accuracy is presented. DOA of the target can be precisely calculated by the parabolic interpolation in the neighbourhood of the main lobe of the directivity function. It is easy to implement ATT technique in real time by DSP chips. The results of system simulation show that the algorithm derived in this paper has very good performance in target tracking. | LI Qihu YIN Li ZHAO Guoying and ZHANG Cheng (Institute of Acoustics, Academia Sinica, Beijing 100080) | 1996 | Chinese Journal of Acoustics1996，15，1： | 1 |
| 18 | A passive synthetic aperture phase correction algorithm for the asymmetric twin-line array sonar显示文摘一个被动的合成的孔基于为解决港口右舷辨别问题在的阶段修正算法不结盟拖引的成双线的数组声纳,被描述。这个方法通过使用估计的阶段修正进成双线的数组的一个数组创造一个虚拟数组。因为合成虚拟数组在成双线的数组与另外的数组被排列,区别的正确港口右舷结果能被数组基于新合成成双线的数组处理获得。建议方法的效果被显示出由模仿并且在拖引的成双线的数组声纳的海试用结果。与低额外的计算负担,建议方法是容易的适用于实践。 | LI Yu ZHANG Yangfan HUANG Haining LI Shuqiu LI Qihu ZHANG Chunhua | 2007 | Chinese Journal of Acoustics2007，26，4： | 1 |
| 19 | Progresses and advances in Arctic underwater acoustics study显示文摘As a part of underwater acoustics, the study and development of Arctic Acoustics is later than underwater acoustics about several hundred years. After World War II, the study of Arctic Acoustics attracts many interests by some developed countries, especially U.S. and pre-Soviet Union. The research works obviously have some kinds of cold war brand. After the Cold War, with the gradual warming trend of Arctic area, the ocean & acoustic environment in Arctic and its adjacent area have been considerably concerned. The 8 countries of Arctic rim organized exclusive 'Arctic Council' in 1996. The white paper of 'China Arctic Policy'was published in January 26, 2018, the Chinese government declared that China is a close Arctic country, and is the responsible stakeholder of Arctic interests. The new advances in Arctic research works axe introduced in this paper, including the results of scientific survey and studies about Arctic underwater acoustics of Chinese researchers. It is showed that the Arctic underwater acoustical research area is not only parallely copy the topics what traditional underwater acoustics covered, e.g. environment noise,reverberation,and propagation, but also the topics which is specifically based on the Arctic environment. Some of these research fields cannot be included in the traditional shallow water, deep water acoustics, e.g. the ice-water interface feature, ice covered semi-acoustic channel effect, the communication and navigation of UUV in the condition of under ice, and the adaptation of sonar technique, equipment in the ice-covered environment, etc. | LI Qihu HUANG Haining YIN Li WEI Chonghua LI Yu XUE Shanhua LUAN Jingde | 2019 | Chinese Journal of Acoustics2019，38，1： | 1 |
| 20 | A beam interpolation algorithm in digital multi-beam sonar显示文摘Beamforming is one of the most important part of signal processing in sonar system.Traditionally, in the analogue system the bearing direction is steered by rotating some kind of time-delay compensator, which is usually made by machanic-clectronic components. But,there exists a fixed bias error in target tracking due to the application of discrete tapped delay line. With the development of digital sonar the multi-beamforming technique is extensively used in various sonar systems. In these systems each beam has a fixed bearing direction. The precise DOA (Direction Of Arrival) estimation of the target becomes more important in sonar design. General speaking, if the sampling frequency is high enough, it is possible to get arbitrary number of beams, which steer in any designated direction. But a hardware tradeoff must be taken account for a good designer. In order to obtain higher target spatial resolution and reduce the hardware cost, it is necessary to make some kind of interpolation algorithm in post beamforming. It is proved that in the most interested situation the behavior of directivity function in the neighborhood of main lobe depends on the sinc function and zero order Bessel function. The multi-beam data is actually the spatial sampling to these function. Based on the principle of parabolic interpolation, a simple but high accuracy beam interpolation technique is presented in this paper. The theoretical basis of three-point and five-point interpolation algorithm is described. As an example, the line array and circle array of hydrophones are illustrated to explain this algorithm. The results of system simulation show that the method proposed in this paper has good agreement with the theory. It can be used to improve the behavior of the directivity function and enhance the multi-target resolving ability of digital sonar system. It is also possible to use this technique to implement ATT (Automatic TargetTracking) in real time. | LI Qihu ZHANG Cunhua and LI Shuqiu(Institute of Acoustics, Academta Sinica, Beijing 100080) | 1995 | Chinese Journal of Acoustics1995，14，3： | 0 |
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