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Electric-stimulus rate encoding algorithm of Mandarin tonal information in cochlear implant

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Progress in Natural Science:Materials International 2006年第12期16卷 1315-1321页

作者： GUAN Tian~1. GONG Qin~1.and YE Datian~2**(1. Department of Biomedical Engineering, Tsinghua university, {1. 1.0084, china 2. Research Center of Biomedical Engineering, graduate School at Shenzhen, Tsinghua university, Shenzhen 51.055, china) [a]Department of Biomedical Engineering Tsinghua University Beijing China [b]Research Center of Biomedical Engineering Graduate School at Shenzhen Tsinghua University Shenzhen China

The modern multi-channel cochlear implants usually extract and encode the temporal envelope cues. This kind of algorithms can hardly satisfy the users who speak tonal languages, such as Mandarin. Many studies have tried to enhance the recognition ability of Mandarin through encoding tonal information and made suggestions to frequency-modulate the fixed pulse-rate carrier with the extracted tonal information based on the rate-pitch theory in electric hearing. However, how to encode and deliver the tonal information such as F_0by changing electric-stimulus rate has not got further study in clinical electric-stimulus mode. The present paper focuses on this matter by piecewise calculating the appreciable electric-stimulus rates. Then an electric-stimulus encoding algorithm of Mandarin tone is brought forward and testified through acoustic simulations. Such conclusion can be drawn that this algorithm of electric-stimulus rate could convey tonal information well and help to enhance the Mandarin speech recognition ability.

关键词： cochlear implant tone fundamental frequency electric-stimulus rate.

Mineralogy and crystal structure determination of Mg-fillowite

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Science china Earth Sciences 2005年第5期48卷 635-646页

作者： MA Zhesheng 1., SHI Nicheng 1.& YE Danian 2 1. china {1. of Geosciences, beijing 1.0083, china 2. Institute of Geology, Chinese Academy of Sciences, beijing 1.0029, china 1. china {1. of Geosciences 100083 Beijing China 2. Institute of Geology Chinese Academy of Sciences 100029 Beijing China

Accurate crystal structure determination of complex phosphate Mg-fillowite ? Na2Ca(Mn4Mg2Fe)7[PO4]6 has been finished. Mg-fillowite occurs in muscovite-pegmatite in the Altay area, Xinjiang, china. It is of the trigonal lattice, with space group R-3, unit cell a=1.51.3(3) nm, c=4.31.1.2) nm, V=8.5736 nm3, Z = 1.. The R-factor of the determination accuracy is R (I > 2σ ( I )) = 0.0776. The cationic polyhedra consist of two kinds of structural units: compound col- umn and screw column. In three-dimensional space, they are linked with each other through corner sharing or edge sharing to build the entire structure. There are 45 atoms in an asymmetric unit and 720 atoms in a unit cell. In terms of types and connection manners of the coordination polyhedra, the degree of complicity is rarely seen in all mineral crystal structures. Study of such a structure is significant for the classification of phosphate and the building rule of coordination polyhedra in a complex crystal structure.

关键词： Mg-fillowite, complex phosphate, crystal structure, coordination polyhedron.

Calculating soil moisture by remote sensing and analyzing hydrologic cycle process in the Yellow River basin

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Science china(Technological Sciences) 2004年第z1期47卷 1-13页

作者： YANG Shengtian1.& LIU Changming1. 2 1. School of Environmental Sciences, beijing Normal {1., beijing 1.0875, china 2. Institute of Geographic Science and Natural Resources Research, beijing 1.01.1. china beijing Normal Univ Sch Environm Sci Beijing 100875 Peoples R China Inst Geog Sci & Nat Resources Beijing 100101 Peoples R China

Based on the AVHRR pathfinder remote sensing data, soil moisture, precipitation and evaporation during the period of 1.82—1.98, soil moisture of all layers of soil-profile (0—1.m) in the Yellow River basin over the 1. years are calculated by the remote sensing model of calculating soil water. The Yellow River basin is divided into seven subcatchments as control sections at the location of six hydrologic stations (Lanzhou, Toudaoguai, Longmen, Sanmenxia, Huayuankou and Lijin). After calculating soil moisture and obtaining runoff data and precipitation data, the dynamical features of hydrological cycle in the Yellow River basin are analyzed for the period from 1.82 to 1.88 using water balance method. The conclusions are as follows: It is feasible to calculate the soil water on the macro-scale, in the soil profile with temporal continuity by means of remote sensing and survey in land. Some values of the key water cycle factors in the Yellow River are obtained, which include the annual precipitation of 4000 km3, the evapotranspiration of 3000-3500 km3, and the soil moisture transformation of ?500- 500 km3. Consequently, we analyzed the process of the water cycle in the Yellow River over the 1. years, and the results show that the segment upstream of Lanzhou city is a relatively humid region, and the area of internal waters and the reaches of Shanshan is the most desiccated region. Therefore, the runoff in the depth process is intensive and the runoff-generating process is weak in more arid regions.

关键词： the Yellow River, soil moisture, remote sensing, hydrologic cycle.

ORDER RESULTS FOR ALGEBRAICALLY STABLEMONO-IMPLICIT RUNGE-KUTTA METHODS

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Journal of Computational Mathematics 1999年第6期17卷 639-644页

作者： Ai-guo Xiao(1. Department of Mathematics, Xiangtan university, Xiangtan 41.1.5,{1.2. ICMSEC, Chinese Academy of Sciences, beijing 1.080,{1.) Xiangtan Univ Dept Math Poona 411005 Maharashtra India Chinese Acad Sci ICMSEC Beijing 100080 Peoples R China

It is well known that mono-implicit Runge-Kutta methods have been applied in the efficient numerical solution of initial or boundary value problems of ordinary differential equations. Burrage (1.94) has shown that the order of an s-stage monoimplicit Runge-Kutta method is at most s+1.and the stage order is at most 3. In this paper, it is shown that the order of an s-stage mono-implicit Runge-Kutta method being algebraically stable is at most min((s) over tilde, 4), and the stage order together with the optimal B-convergence order is at most min(s, 2), where [GRAPHICS]

关键词： ordinary differential equations mono-implicit Runge-Kutta methods order algebraical stability

Explicit analytical solutions of the anisotropic Brinkman model for the natural convection in porous media(Ⅱ)

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Science china(Physics,Mechanics & Astronomy) 2005年第4期48卷 422-430页

作者： CAI Ruixian1. GOU Chenhua1. 2 & ZHANG Na1.1. Institute of Engineering Thermophysics, Chinese Academy of Sciences, beijing 1.0080,{1. 2. graduate School, Chinese Academy of Sciences, beijing 1.0080,{1. 1. Institute of Engineering Thermophysics Chinese Academy of Sciences 100080 Beijing China 2. graduate School Chinese Academy of Sciences 10080 Beijing China

Some algebraically explicit analytical solutions are derived for the anisotropic Brinkman model―an improved Darcy model―describing the natural convection in porous media. Besides their important theoretical meaning (for example, in analyzing the non-Darcy and anisotropic effects on the convection), such analytical solutions can be the benchmark solutions that can promote the development of computational heat and mass transfer. Some solutions considering the anisotropic effect of permeability have been given previously by the authors, and this paper gives solutions including the anisotropic effect of thermal conductivity and the effect of heat sources.

关键词： explicit analytical solution, porous medium, natural convection, Brinkman model, anisotropic.

A new orthogonality relationship for orthotropic thin plate theory and its variational principle

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Science china(Physics,Mechanics & Astronomy) 2005年第3期48卷 371-380页

作者： LUO Jianhui 1., LONG Yuqiu 2 & LIU Guangdong 1.1. College of Civil Engineering, Hunan university, Changsha 41.082,{1. 2. Department of Civil Engineering, Tsinghua university, beijing 1.0084,{1. 1. College of Civil Engineering Hunan University 410082 Changsha China 2. Department of Civil Engineering Tsinghua University 100084 Beijing China

The thought how dual vectors are constructed in a new orthogonality relationship for theory of elasticity is generalized into orthotropic thin plate bending problems by using the analogy theory between plane elasticity problems and plate bending problems. Dual differential equations are directly obtained by using a mixed variables method. A dual differential matrix to be derived possesses a peculiarity of which principal diagonal sub-matrixes are zero matrixes. Two independently and symmetrically orthogonality sub-relationships are discovered. By using the integral form for elastic bending theory of orthotropic thin plate the orthogonality relationship is demonstrated. By selecting felicitous dual vectors a new orthogonality relationship for theory of elasticity can be generalized into elastic bending theory of orthotropic thin plate. By using the integral form a variational principle which is relative to differential form and a whole function expression are proposed.

关键词： theory of elasticity, thin plate theory, dual vectors, orthogonality relationship, orthotropic, variational principle.

A new method for multi-exponential inversion of NMR relaxation measurements

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Science china(Physics,Mechanics & Astronomy) 2004年第3期47卷 265-276页

作者： WANG Zhongdong1. 2, XIAO Lizhi1.& LIU Tangyan1.1. Petroleum university, {1. 1.2249, china 2. Liaohe Petroleum Administration, Panjin 1.401., china 1. Petroleum university 102249 Beijing China 2. Liaohe Petroleum Administration 124011 Panjin China

A new method for multi-exponential inversion to NMR T1.and T2 relaxation time distributions is suggested and tested. Inversion results are compared with MAP-II which is based on SVD algorithm and widely accepted in the industry. Inversed NMR relaxation spectra that have different pre-assigned relaxation times from echo trains with different SNR confirm that the new method with 1. to 64 equally spaced time constants in logarithm scale will ensure the relaxation distribution. Testing results show that the new inversion algorithm is a valuable tool for rock core NMR experimental analysis and NMR logging data process and interpretation.

关键词： NMR, inversion, relaxation, core analysis, well logging.

Discovery of Paleogene marine stratum along the southern side of Yarlung-Zangbo suture zone and its implications in tectonics

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Science china Earth Sciences 2005年第5期48卷 647-661页

作者： LI Guobiao 1., WAN Xiaoqiao 1., LIU Wencan 1., LIANG Dingyi 1.& Hyesu Yun 2 1. china {1. of Geosciences, beijing 1.0083, china 2. Chungnam National {1., Daejon, 305-350, Korea 1. china {1. of Geosciences 100083 Beijing China 2. Chungnam National university 305-350 Daejon Korea

The Jiachala Formatiom is a new lithostratigraphic unit set up in this paper. This is the first report on the Paleogene marine sequences and microfaunas in Gyangze to the southern side of the Yarlung-Zangbo suture zone. On the basis of fossil abundance, species diversity, dominant species and first and last occurrences of key species, three dinoflagellate assemblages and three polynological assemblages were recognized in the Jiachala Formatiom. They are in ascending order as follows: Apectodinium quinquelatum-Apectodinium hyperacanthum, Cannin- gia chinensis-Palaeoperidinium pyrophorum and Cymatiosphaera reticulosa-Samlandia chla- mydophora dinoflagellate assemblages, and Arliaceoipollenites baculatus-Anacolosidites sub- trudens, Aglaoreidia cyclops-Pinuspollenites microinsigis, and Elaeangnacites asper-Ilexpol- lenites iliacus polynological Assemblages. According to the assemblages, the age of the Jiachala Formation is referred to Paleocene-early Eocene. The preliminary study on the Jiachala Forma- tion shows that this group of Paleogene deposits accumulated in an underfilled peripheral fore- land basin which was in response to the load of the crust thickening resulted from the Asia-India collision. The stratigraphic evidences provided by the evolution of foreland basin indicate that the India-Asia initional collision should occure near the Cretaceous/Paleogene boundary. The de- velopment and evolution of the southern Tibet foreland basin was under the control of the stress field from the subduct-collision between India and Asia and the structure pattern of the basement. The withering of Tethys Sea might occur after early Eocene in the Gyangze basin and should be after Priabonian of late Eocene in southern Tibet.

关键词： Paleogene marine strata, Jiachala Formation, microfossils, underfilled peripheral foreland basin, initional collision, Gyangze.

Empirical likelihood confidence regions of the parameters in a partially linear single-index model

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Science china Mathematics 2005年第10期48卷 1333-1348页

作者： XUE Liugen~1.& ZHU Lixing~2 1. College of Applied Sciences,beijing {1. of Technology,beijing 1.0022,china 2. Department of Mathematics,Hong Kong Baptist {1.,Hong Kong,china 1. College of Applied Sciences Beijing University of Technology 100022 Beijing China 2. Department of Mathematics Hong Kong Baptist University Hong Kong China

In this paper, a partially linear single-index model is investigated, and three empirical log-likelihood ratio statistics for the unknown parameters in the model are suggested. It is proved that the proposed statistics are asymptotically standard chi-square under some suitable conditions, and hence can be used to construct the confidence regions of the parameters. Our methods can also deal with the confidence region construction for the index in the pure single-index model. A simulation study indicates that, in terms of coverage probabilities and average areas of the confidence regions, the proposed methods perform better than the least-squares method.

关键词： partially linear single-index model, empirical likelihood, confidence region, chi-square distribution, coverage probability.