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WAVE CURRENT FORCE COEFFICIENTS ON INCLINED CYLINDER AND A NEW ESTIMATION METHOD

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China Ocean Engineering 1990年第3期5卷 283-296页

作者： Teng Bin and Li Yucheng Research Assistant, dalian university of technology, dalian Professor, dalian university of technology, dalian dalian Univ of technology

Based on the review of present force coefficients estimation methods, a new method in the frequency domain, revised cross-spectrum estimation method, is presented in this paper. Some experiments on the wave-current force on inclined cylinders are also described and the wave current force coefficients are estimated by the revised cross-spectrum estimation method. From the results, it is found that the wave and current directions have some regular effect on the coefficients. According to the results, some empirical formulas are obtained for converting the wave-current force coefficients on inclined cylinders into a unified coefficient. Comparisons show that the unified coefficients are in good agreement with other results.

关键词： WAVE CURRENT FORCE COEFFICIENTS ON INCLINED CYLINDER AND A NEW ESTIMATION METHOD Mean

ARNOLDI TYPE ALGORITHMS FOR LARGE UNSYMMETRICMULTIPLE EIGENVALUE PROBLEMS

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Journal of Computational Mathematics 1999年第3期17卷 257-274页

作者： Zhong-xiao Jia(Department of Applied Mathematics, dalian university of technology, dalian 116024, China) 大连理工大学应用数学系辽宁大连

As is well known, solving matrix multiple eigenvalue problems is a very difficult topic. In this paper, Arnoldi type algorithms are proposed for large unsymmetric multiple eigenvalue problems when the matrix A involved is diagonalizable. The theoretical background is established, in which lower and upper error bounds for eigenvectors are new for both Arnoldi's method and a general perturbation problem, and furthermore these bounds are shown to be optimal and they generalize a classical perturbation bound due to W. Kahan in 1967 for A symmetric. The algorithms can adaptively determine the multiplicity of an eigenvalue and a basis of the associated eigenspace. Numerical experiments show reliability of the algorithms.

关键词： Arnoldi's process large unsymmetric matrix multiple eigenvalue diagonalizable error bounds

BIVARIATE FRACTAL INTERPOLATION FUNCTIONS ON RECTANGULAR DOMAINS

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Journal of Computational Mathematics 2002年第4期20卷 349-362页

作者： Xiao-yuan Qian (Department of Applied Mathematics, dalian university of technology, dalian 116024, China) Department of Applied Mathematics Dalian University of Technology Dalian 116024

Non-tensor product bivariate fractal interpolation functions defined on gridded rectangular domains are constructed. Linear spaces consisting of these functions are introduced. The relevant Lagrange interpolation problem is discussed. A negative result about the existence of affine fractal interpolation functions defined on such domains is obtained.

关键词： fractal bivariate functions interpolation

Electrochemical behaviour of commercially pure titanium and Co-Cr alloy in Ringer's solution

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Rare Metals 2002年第4期21卷 266-270页

作者： LIANG Chenghao and MOU ThanqiSchool of Chemical Engineering, dalian university of technology, dalian 116012, China School of Chemical Engineering Dalian University of Technology Dalian 116012

The electrochemical behaviors of commercially pure titanium (CP Ti) and Co-Cralloy in Ringer's solution have been investigated. The results indicate that the electric potentialof passive region for CP Ti is up to 3000 mV, and its passive current density is 3.078 μA/cm^*** excellent corrosion resistance of CP Ti can be attributed to the formation of TiO_2 oxide *** passive region of Co-Cr alloy is 770 mV, which is narrower than that of CP Ti. However, nohysteresis loops are found in the reverse scanning curves of Cu-Cr alloy. A complex oxide film ofCo_3O_4, Co_2O_3, and Cr_2O_3 formed on the surface provides Co-Cr alloy with a stableelectrochemistry property. The corrosion rates of the crevice samples increase with the pH value ofmedium decreasing. The electron probe microanalyzer (EPMA) analysis indicates that Ti in CP Ti andCo, Cr in Co-Cr alloy dissolve in crevice area due to the Sealed-Cell effect.

关键词： ringer's solution biomedical material electrochemical behaviors

Phase Separation and Theta-compositions of PPES/NMP/non-solvent Systems

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Journal of Materials Science & technology 2005年第3期21卷 430-432页

作者： Yi SU and Xigao JIAN Department of Polymer Science, dalian university of technology, dalian 116012, China Department of Polymer Science Dalian University of Technology Dalian 116012 China

Poly (phthalazinone ether sulfone) (PPES) with 1:1 and 1:3 ratios of bisphenol A (BPA) unit to phthalazinone unit were selected as samples. Polymer precipitation curves for the ternary systems PPES (1:1)/NMP/ non-solvent and PPES (1:3)/NMP/non-solvent were determined by a titration method. Comparison between two sets of data is made. Non-solvents used were H2O, ethyl ether (EE), diethylene glycol (DEGC), ethyleneglycol methylether (EGME) and butanone (BO). NMP/non-solvent theta-compositions for PPES (1:1) and PPES (1:3) were also estimated. It was found that the volume ratio of non-solvent to NMP at the property mutation or worsening of PPES membrane is close to the theta-composition.

关键词： Polymer precipitation curve Poly (phthalazinone ether sulfone) Theta-composition

Changes of microbial community structures and functional genes during biodegradation of phenolic compounds under high salt condition

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Journal of Environmental Sciences 2009年第6期21卷 821-826页

作者： WANG Ping,QU Yuanyuan,ZHOU Jiti School of Environmental and Biological Science and technology,dalian university of technology,dalian 116024,China. School of Environmental and Biological Science and technology Dalian University of Technology Dalian 116024 China

The changes of microbial community structures and functional genes during the biodegradation of single phenol and phenol plus p-cresol under high salt condition were *** was found that the phenol-fed system（PFS） exhibited stronger degrading abilities and more stable biomass than that of the phenol plus p-cresol-fed system（PCFS）.The microbial community structures were revealed by a modern DNA fingerprint technique,ribosomal intergenic spacer analysis（RISA）.The results indicated that the microbial community of PFS changed obviously when gradually increased phenol concentration,while PCFS showed a little change.16S rRNA sequence analysis of the major bands showed that Alcanivorax *** was predominant species during phenolic compounds ***,amplified functional DNA restriction analysis（AFDRA） on phenol hydroxylase genes showed that the fingerprints were substantially different in the two systems,and the fingerprints were not the same during the different operational periods.

关键词： phenolic compounds high salt phenol hydroxylase ribosomal intergenic spacer analysis amplified functional DNArestriction analysis

EFFECT OF GRAVITY FIELD ON SOLIDIFICATION BEHAVIOR OF STEEL INGOT

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Acta Metallurgica Sinica(English Letters) 1995年第2期8卷 110-114页

作者： CHEN Weide ZHENG Xianshu JIN Junze(dalian university of technology,dalian,China dalian Univ of technology Dalian China

By means of numerical simulation. the in fluence of gravity on fluid flow,patterns has been *** result shows that with the increase of inclined angle,the velocity of fluid flow decreases and the isotherms become flatt... 详细信息

关键词： gravity field fluid flow.solidification behavior channel segregation

EFFECT OF AUSTENITIC DENDRITES ON MECHANICAL PROPERTIES OF DUCTILE IRON

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Acta Metallurgica Sinica(English Letters) 1992年第11期5卷 375-377页

作者： ZHOU Jiyang XIE Zuhua ZHONG Fenqi dalian university of technology,dalian,China dalian Univ of technology Dalian China

Impact toughness of ductile nodular cast iron loaded perpendicular to the austenitic dendrites is found to be 43% higher than that parallel to *** tensile strength and elongation of the former are 23% and 30% lower th... 详细信息

关键词： ductile iron austenitic dendrite mechanical property

RANDOM　CHARACTERISTICS　OF　FLOW　FLUCTUATING　PRESSURE　AND　DYNAMIC　RESPONSE　ON　THE　SHAFT　SPILLWAY

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Journal of Hydrodynamics 1995年第2期7卷 28-34页

作者： Cui Li(dalian university of technology, dalian 116023, P. R. China) dalian Univ of technology Dalian China

The flow down a shaft spillway, connected with tunnel, results in nonsymmetric vortex around the axis of the shaft. The greater the nonsymmetry, the greater the pressure fluctuation and random vibration of *** paper deals with an attempt to determine the fluctuating pressure characteristics in the shaft. Stochastic theory and random time series are employed to analyse the sample function x(t) , its x(t) and x(t), and their correlations:The moments of the spectra are obtained:The fluctuating pressure characteristics are related to the non-symmetric inlet vortex. The relation between the point pressure spectra and fluctuating pressures on the shaft wall are indicated and *** paper gas further into the simulated test on the framed over-flow tower and puts forward an effective proposed way. Besides the calculation in frequency domain, computation in time domain is also ueed to analyse the same structure. The vibration source and the method to remove it are found out.

关键词： shaft spillway dynamic response random characteristics