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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.

A model for the optical flares from the Galactic transient SWIFT J195509+261406

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Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 91-93页

作者： XU Ming & HUANG YongFeng Department of Astronomy,nanjing university,nanjing 210093,china Department of Astronomy Nanjing University Nanjing China

The Galactic hard X-ray transient SWIFT J195509+261406 was first observed as gamma-ray burst GRB *** 3 days after the burst,more than forty optical flares had been ***,we propose that this peculiar event should be associated with a white *** hard X-ray burst itself may be triggered by a collision between two planets orbiting the white *** cracked fragments produced in the collision then fell onto the surface of the white dwarf over several days,giving birth to the observed optical flares via cyclotron *** model can satisfactorily explain the basic features of the observations.

关键词： gamma-ray bursts white dwarfs cyclotron radiation

On the variational principle for the topological pressure for certain non-compact sets

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Science china Mathematics 2010年第4期53卷 1117-1128页

作者： PEI Yu 1 & CHEN ErCai 1,2,1 Department of Mathematics,nanjing Normal university,nanjing 210097,china 2 Center for Nonlinear Science,nanjing university,nanjing 210093,china Department of Mathematics Nanjing Normal University Nanjing China Center for Nonlinear Science Nanjing University Nanjing China

Let (X,d,T) be a dynamical system,where (X,d) is a compact metric space and T:X → X is a continuous *** assume that the dynamical system satisfies g-almost product property and the uniform separation *** compute the topological pressure of saturated sets under these two *** the uniform separation property does not hold,we compute the topological pressure of the set of generic *** give an application of these results to multifractal analysis and finally get a conditional variational principle.

关键词： uniform separation property g-almost product property topological pressure of non-compact sets variational principle BS-dinmension

Comparing logic coverage criteria on test case prioritization

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Science china(Information Sciences) 2012年第12期55卷 2826-2840页

作者： FANG ChunRong 1,2,CHEN ZhenYu 1,2 & XU BaoWen 1 1 State Key Laboratory for Novel Software Technology,nanjing university,nanjing 210093,china 2 Software Institute,nanjing university,nanjing 210093,china State Key Laboratory for Novel Software Technology Nanjing University Nanjing China Software Institute Nanjing University Nanjing China

Logic coverage criteria have been widely used in the testing of safety-critical *** the past few years,fault-based logic coverage criteria have been studied intensively both in theory and in ***,there is a lack of authentic evidence of the comparison of fault-based logic coverage criteria with other logic coverage criteria,such as branch coverage and modified condition/decision coverage(MC/DC).In this paper,we present a comprehensive empirical study that compares these logic coverage criteria on test case prioritization,which is currently a hot topic in software *** useful conclusions are drawn from our research:(1) Fine-grained coverage criteria are always more effective and efficient.(2) The effectiveness of fault-based logic coverage criteria is not significantly different from that of MC/DC in terms of statistics,but the former is more stable.(3) A random strategy is more effective than branch coverage if a certain number of test cases are redundant.

关键词： fault detection capability logic coverage fault-based testing test case prioritization

Lipschitz classes on local fields

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Science china Mathematics 2007年第7期50卷 1005-1014页

作者： Wei-yi SU~(1+) Guo-xiang CHEN~2 1 Department of Mathematics,nanjing university,nanjing 210093,china 2 Department of Mathematics,nanjing Audit university,nanjing 211815,china Department of Mathematics Nanjing University Nanjing China Department of Mathematics Nanjing Audit University Nanjing China

The Lipschitz class Lipαon a local field K is defined in this note,and the equivalent relationship between the Lipschitz class Lipαand the Holder type space C~α(K)is ***,those important characteristics on the Euclidean space R^n and the local field K are compared,so that one may interpret the essential differences between the analyses on R^n and ***,the Cantor type fractal functionθ(x)is showed in the Lipschitz class Lip(m,K),m＜(ln 2/ln 3).

关键词： local field Holder type space Lipschitz class Cantor type fractal function 11F85 46F05 43A25 28A80 28A78

The early high-energy afterglow emission from short GRBs

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Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 157-160页

作者： HE HaoNing & WANG XiangYu Department of Astronomy,nanjing university,nanjing 210093,china Department of Astronomy Nanjing University Nanjing China

We calculate the high energy afterglow emission from short Gamma-Ray Bursts(SGRBs) in the external shock *** are two possible components contributing to the high energy afterglow:electron synchrotron emission and synchrotron self-Compton(SSC) *** find that for typical parameter values of SGRBs,the early high-energy afterglow emission in 10 MeV-10 GeV is dominated by synchrotron *** a burst occurring at redshift z = 0.1,the high-energy emission can be detectable by Fermi LAT if the blast wave has energy E ≥ 1051 ergs and the fraction of electron energy εe≥ *** provides a possible explanation for the high energy tail of SGRB 081024B.

关键词： gamma-ray burst radiation mechanism blast wave

MI-QSAR models for prediction of corneal permeability of organic com-pounds

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Acta Pharmacologica Sinica 2006年第2期27卷 193-204页

作者： Cheng CHEN Jie YANG~2 State Key Laboratory of Pharmaceutical Biotechnology,College of Life Science,nanjing university,nanjing 210093,china State Key Laboratory of Pharmaceutical Biotechnology College of Life Science Nanjing University Nanjing China

Aim:To derive a theoretical model for the prediction of corneal permeability ofmiscellaneous organic compounds in drug ***:A training set of 28structurally diverse compounds was used to build up the membrane-interactionquantitative structure-activity relationship(MI-QSAR)*** intramolecular solute descriptors were computed using molecular mechanics,molecular dynamics simulations and quantum *** QSAR models wereoptimized using multidimensional linear regression fitting and a stepwise method.A test set of 8 compounds was evaluated using the models as part of a ***:Significant MI-QSAR models(R=0.976,S-0.1301,F=70.957)ofcorneal permeability of organic compounds were *** permeabil-ity was found to depend upon the sum of net atomic charges of hydrogen atomsattached to the heteroatoms(N,O),the sum of the absolute values of the netatomic charges of oxygen and nitrogen atoms,the principal moment of inertia(X),the Connolly accessible area and the conformational flexibility of the solute-mem-brane ***:The MI-QSAR models indicated that the cornealpermeability of organic molecules was not only influenced by the organic solutesthemselves,but also related to the properties of the solute-membrane complex,that is,the interactions of the molecule with the phospholipid-rich regions ofcellular membranes.

关键词： cornea permeability quantitative structureactivity relationship theoretical models

An MSX infrared analysis of the superbubble around the giant HII region NGC3603

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Science china(Physics,Mechanics & Astronomy) 2010年第S1期53卷 271-273页

作者： WANG Jia & CHEN Yang Department of Astronomy,nanjing university,nanjing 210093,china Department of Astronomy Nanjing University Nanjing China

Using the MSX mid-infrared observations,we reveal a 100pc-scale superbubble surrounding the giant HII region *** suggest that the diffuse surrounding infrared emission in bands A,C,and D is dominated by that of PAH and the emission in band E is dominated by that of dust *** fitted dust temperature is consistent with heating by the central cluster's UV *** derived gas-to-dust mass ratio for the bubble shell is of order 102.

关键词： superbubble HII region cluster PAH dust

A STUDY ON THE RELATION BETWEEN THE VARIATION OF THE PRECIPITATION IN EASTERN JIANGHUAI WATERSHED AND SEDIMENT TRANSPORT IN CHIHE RIVER VALLEY

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Chinese Geographical Science 2002年第1期12卷 44-49页

作者： ZHANG Jian chun, PENG Pu zhuo(Department of Urban and Resources Sciences,nanjing university,nanjing 210093,P.R.china ) Department of Urban and Resources Sciences Nanjing University Nanjing P. R. China

Rainfall resource is very important to the development of society and economy,especially to eastern Jianghuai watershed which is now facing serious challenge of water shortage. Based on the observational records covering the period from 1957 to 1999,the characteristics of precipitation changing over eastern JiangHuai watershed and its connection to sediment discharge in Chihe River valley were studied using tendency analysis and correlation analysis .Results show that the rainfall in this area had a declining tendency in Spring at a rate of -21.2mm/10a, annual and Summer precipitation was increasing at the rate of 10.6mm/10a and 14.8mm/10a. The gray correlation analysis shows that sediment discharge correlates most closely with runoffs and the frequency of the rainstorm with a daily precipitation of 50-100mm, on the second place,with the rainfall and the frequency of the rainstorm of a daily precipitation no less than 100mm;and thirdly with the number of rainy days. In addition, the paper suggests the major countermeasures and methods for controlling of soil and water losses in this area.

关键词： eastern Jianghuai watershed Chihe River rainfall sediment discharge correlation grade