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A self-steering close-talking microphone array

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Progress in Natural Science:Materials International 2005年第11期15卷 1044-1049页

作者： PENG Ke, YANG Xinfeng and XU Boling (state key laboratory of Modern Acoustics, Institute of Acoustics, nanjing university, nanjing 210093, china) state key laboratory of Modern Acoustics Institute of Acoustics Nanjing University Nanjing 210093 China

For communication in extremely noisy environments, close-talking microphone arrays are useful. Differential microphone array systems possessing excellent nearfield directivity and strong farfield-noise reduction capability are very suitable for close-talking situations. In order to improve the focusing effect at the desired bearing in the nearfield, we propose a novel self-steering system of close-talking arrays with the first-order differential sub-arrays in this paper. Calculations of directivity patterns and directivity factors show that when a kind of optimized beamforming technique is adopted even small arrays with a focusing configuration will exhibit a satisfactory nearfield directivity which is electronically steerable within a specific range. The superiority of the proposed array system is verified by experiments with real acoustic data.

关键词： close-talking array differential array self-steering directivity factor.

Study on lithogeochemistry of Middle Jurassic basalts from southern china represented by the Fankeng basalts from Yongding of Fujian Province

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Science china Earth Sciences 2006年第10期49卷 1020-1031页

作者： ZHOU Jincheng1,2, JIANG Shaoyong1,2, WANG Xiaolei1,2, YANG Jinghong 1,2 & ZHANG Mengqun 3 1. state key laboratory of Mineral Deposit Research, nanjing university, nanjing 210093, china 2. Department of Earth Sciences, nanjing university, nanjing 210093, china 3. Modern Analysis Center, nanjing university, nanjing 210093, china 1. state key laboratory of Mineral Deposit Research Nanjing University Nanjing 210093 China 2. Department of Earth Sciences Nanjing University Nanjing 210093 China 3. Modern Analysis Center Nanjing University Nanjing 210093 China

There exists an E-W trending Middle Jurassic volcanic zone in southern china. The Fankeng basalts in the Yongding basin of Fujian Province are considered to be a typical example. The Fankeng basalts have TiO2 contents in the range of 1.92%-3.21%. They are classified as high-Ti basalts. They also have higher total Fe (averaging FeO* = 11.09%). The Middle Jurassic Fankeng basalts from southwestern Fujian have obvious distinctive lithogeochemical features from early Cre- taceous basalts from southeastern coast of china. They have higher HFSE, such as Th, Nb, Ta, Zr and Ti. Their element ratios related with HFSE, such as Zr/Ba, La/Nb, La/Ta ,Zr/Y, Ti/Y, Ba/Nb, K/Ti and Rb/Zr are similar to those of OIB. The most samples have ε Nd(T) of-0.70-0.24, which are near chondrite. Some samples have higher ε Nd(T) of ***, these basaltic magmas might be derived from depleted asthenospheric mantle. The lithogeochemical characteristics of the Fankeng basalts may be caused by interaction between asthenosphere and lithosphere at the time. The (Early-) Middle Jurassic basalts and gabbros from southeastern Hunan, southern Jiangxi and northern Guangdong provinces show similar geochemical features to those of the Fankeng basalts from the Yongding of Fujian. Occurrence of these OIB-type basalts in the area may be regarded as the petrological mark of upwelling of asthenosphere at the time. Upwelling of asthenosphere has led to tectonic extension and the formation of rifted basin in the area.

关键词： interaction between asthenosphere and lithosphere, lithogeochemistry, basalts, Middle Jurassic, southern china.

Recent progress of solar physics research in china

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Research in Astronomy and Astrophysics 2011年第12期11卷 1377-1402页

作者： Cheng Fang 1 School of Astronomy and Space Science,nanjing university,nanjing 210093,china 2 key laboratory of Modern Astronomy and Astrophysics(nanjing university),Ministry of Education,china School of Astronomy and Space Science Nanjing University Nanjing 210093 China key laboratory of Modern Astronomy and Astrophysics (nanjing university) Ministry of Education China

Owing to the largely improved facilities and working conditions, solar physics research in china has recently shown marked development. This paper reports on the recent progress of solar physics research in china's Mainland, mainly focusing on several hot issues, including instrumentations, magnetic field observations and research, solar flares, filaments and their eruptions, coronal mass ejections and related processes, as well as active regions and the corona, small-scale phenomena, solar activity and its predictions. A vision of the future is also described.

关键词： Sun: general -- Sun: coronal mass ejections (CMEs) -- solar physics:recent progress

Crystal structure and single crystal EPR of (NH_4)_2(15-crown-5)_3[Cu(mnt)_2] and (NH_4)_2(benzo-15-crown-5)_4[Cu(mnt)_2]·0.5H_2O

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Science china Chemistry 2007年第5期50卷 607-613页

作者： SUI YunXia1, WEN LiLi2, ZHANG Huan3 & MENG QingJin2 1 Center of Modern Analysis, nanjing university, nanjing 210093, china 2 state key laboratory of Coordination Chemistry, Coordination Chemistry Institute, nanjing university, nanjing 210093, china 3 Jiangnan Institute of Computing technology, Wuxi 214083, china 1. Center of Modern Analysis Nanjing University Nanjing 210093 China 2. state key laboratory of Coordination Chemistry Coordination Chemistry Institute Nanjing University Nanjing 210093 China 3. Jiangnan Institute of Computing technology Wuxi 214083 China

The X-ray crystal structures of (NH4)2(15-crown-5)3[Cu(mnt)2] (1) and(NH4)2(benzo-15-crown-5)4-[Cu(mnt)2] ident to 0.5H2O (2) were *** single crystals arecomposed of distinct structures of ammonium-crown ether supramolecular cation and [Cu(mnt)2]^(2-)*** triple-decker dication in complex 1 and a sandwich dimmer in complex 2 wereobserved.X-Band EPR studies on the single crystals of both complex 1 and complex 2 have been carriedout at room temperature,which revealed that complex 2 showed a perfect hyperfine structure of Cuwhereas that of complex 1 could not be *** principal values and direction cosines of theprincipal axes of the g and A tensors were computed by a least-squares fitting *** spindensity of Cu(ll) was estimated according to the principal values of the A tensors and compared wellwith the results calculated based on DFT method.

关键词： supramolecular cation, H-bonding interaction, EPR, g and A tensors, DFT

Contourlet HMT model with directional feature

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Science china(Information Sciences) 2012年第7期55卷 1563-1578页

作者： WANG XiangHai 1,2,3 ,CHEN MingYing 1 ,SONG ChuanMing 1,2 ,XU MengChun 1 & FANG LingLing 3 1 College of Computer and Information technology,Liaoning Normal university,Dalian 116029,china 2 state key laboratory for novel software technology,nanjing university,nanjing 210093,china 3 Provincial key laboratory for Computer Information Processing technology,Soochow university,Suzhou 215006,china 1. College of Computer and Information technology Liaoning Normal University Dalian 116029 China2. State Key Laboratory for Novel Software Technology Nanjing University Nanjing 210093 China3. Provincial Key Laboratory for Computer Information Processing Technology Soochow University Suzhou 215006 China

According to Shanno's information theory,the directional feature of texture is defined as the value of directional variable when an image signal attains a singularity of random *** terms of this definition,we calculate the texture's directional features using Tamura's method and study the directional probability distribution of Contourlet *** we find that the directional features tend to be conveyed across parent and child *** on this conclusion,we establish a novel probability distribution model of hidden direction variables under the condition of hidden state variable's distribution,named Contourlet HMT model with directional *** structure and training method of the model are presented as ***,an unsupervised context-based image segmentation algorithm is proposed on the basis of the proposed *** effectiveness is verified via extensive experiments carried out on several synthesized images and remote sensing images.

关键词： directional feature Contourlet HMT Contourlet HMT with directional feature unsupervised texture segmentation

The Report of Virtual Exhibition software Development

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Wuhan university Journal of Natural Sciences 2001年第Z1期6卷 340-346页

作者： Yu Jian xin 1, Sun Yuan hao 1, Gong Zhen yu 2, Cao Jing 2 1. state key laboratory for novel software technology, nanjing university, nanjing 210093, china 2. Department of Computer Science and technology, nanjing university,nanjing 210093, china state key laboratory for novel software technology Nanjing University Nanjing 210093 China

The main structure and key techniques of our Virtual Exhibition software are summarized. It demonstrates the practice of software Engineering during the development of our project and discusses the use of UML in it.

关键词： software engineering software process software quality assurance software configuration management software configuration item UML virtual reality

Differential AR algorithm for packet delay prediction

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Progress in Natural Science:Materials International 2006年第4期16卷 437-440页

作者： JIAO Liangbao, ZHANG De and BI Houjie Institute of Acoustics, state key laboratory of Modern Acoustics, nanjing university, nanjing 210093, china Institute of Communication Technique, nanjing university, nanjing 210093, china [a]Institute of Acoustics State Key Laboratory of Modern Acoustics Nanjing University Nanjing China [b]Institute of Communication Technique Nanjing University Nanjing China

Different delay prediction algorithms have been applied in multimedia communication, among which linear prediction is attractive because of its low complexity. AR (auto regressive) algorithm is a traditional one with low computation cost, while NLMS (normalize least mean square) algorithm is more precise. In this paper, referring to ARIMA (auto regression integrated with moving averages) model, a differential AR algorithm (DIAR) is proposed based on the analyses of both AR and NLMS algorithms. The prediction precision of the new algorithm is about 5-10 db higher than that of the AR algorithm without increasing the computation complexity. Compared with NLMS algorithm, its precision slightly improves by 0.1 db on average, but the algorithm complexity reduces more than 90% . Our simulation and tests also demonstrate that this method improves the performance of the average end-to-end delay and packet loss ratio significantly.

关键词： AR algorithm NLMS algorithm differential AR algorithm ARIMA model.

IMPEDANCE CHARACTERISTICS OF POLYFURAN FILMS

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Chinese Journal of Polymer Science 2002年第5期20卷 419-423页

作者： Liang Li Xiao-bo Wan Gi Xue Department of Polymer the state key laboratory of Coordination Chemistry nanjing university nanjing 210093. china nanjing Univ Dept Polymer State Key Lab Coordinat Chem Nanjing 210093 Peoples R China

Electrochemical impedance spectroscopy (EIS) was first used for the characterization of polyfuran (PFu) films that had been formed electrochemically on an Au electrode. The polyfuran was measured in high oxidation state, intermediate oxidation state and reduction state, respectively. As the oxidation level is increased, the ionic conductivity of PFu/BF4- increases. And impedance studies on PFu show that the anion BF4- appears to be mobile with a high diffusion coefficient of approximately 10(-8) cm(2).s(-1).

关键词： polyfuran electrochemical impedance spectroscopy capacitance

Inclusion Behavior of Dimer β-CyclodextrinBridged with Aspartic Acid Derivative

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Chinese Chemical Letters 2001年第2期12卷 119-120页

作者： Le Xin SONG Coordination Chemistry Institute & state key laboratory of Coordination Chemistry, nanjing university, nanjing 210093 nanjing Univ Inst Coordinat Chem Nanjing 210093 Peoples R China nanjing Univ State Key Lab Coordinat Chem Nanjing 210093 Peoples R China

The (β-cyclodextrin (CD) dimer bridged with aspartic acid (ASP) derivative, FITC-ASP(NH-(-CD)2 (Host, FITC=fluorescein-4-isothiocyanate), was synthesized. Fluorescence polarization study showed that the novel host formed an inclusion compound, [FITC-ASP(NH-(-CD)2]ATA, for which Kd was determined to be 5.0×10-6 mol/L by Beacon 2000 Analyzer, when ATA (Guest) = Adm-Trp-Arg-Arg-NH2 (Adm = 1-adamantanecarboxylic acid, Trp = tryptophan, Arg = arginine), where Kd is the dissociation constant in aqueous solution at 298 K.

关键词： β-Cyclodextrin amino acid peptide inclusion compound fluorescence polarization.