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Statistical Distributions of Wavelengths

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China Ocean Engineering 1997年第3期12卷 315-324页

作者： Yu, dy Xu, DL Ocean Univ Qingdao Coll Engn Qingdao 266003 Peoples R China Ocean Univ Qingdao Phys Oceanog Lab Qingdao 266003 Peoples R China

The statistical distribution of wavelength is directly derived from a two-dimensional and spatially homogeneous Gaussian wave field. The present result differs from both the result of Rayleigh distribution and Sun's result (1988b) which is transformed through the period distribution derived from a two-dimensional and stationary Gaussian wave field. A laboratory experiment shows that the present result is more consistent with the observations in the wave tank than the others.

关键词： statistical distribution wavelength laboratory experiment

Impact Buckling and Post-Buckling of Elasto-Viscoplastic Cylindrical Shell Under Torsion

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China Ocean Engineering 1997年第1期12卷 43-52页

作者： Wang, dy Chen, TY Department of Naval Architecture and Ocean Engineering Shanghai Jiaotong University Shanghai 200030 China

The dynamic torsional buckling and post-buckling of elasto-plastic circular cylindrical shell is studied. By the usage of the Bodner-Partom constitutive relation, the present visco-plastic problem is treated as an orthotropic elastic problem. Based on the nonlinear large deflection shell therory, the governing dynamic buckling equation is solved by the Runge-Kutta method, and the critical buckling stress is determined by the B-R criterion. The present paper is mainly focused on the imperfection sensitivity, the strain rate sensitivity, and the dynamic post-buckling characters for the shell loaded dynamically with a constant shear strain rate. Numerical results show that the critical shear stress and imperfection sensitivity will increase with the increase of strain rate. It is found that the elastic buckling stress is more sensitive to imperfection than the visco-plastic buckling. The present research also reveals some dynamic post-buckling characters for the cylindrical shell, and it is shown that the shell will vibrate with the amplitude proportional to the strain rate in elastic buckling but improportional to the strain rate in visco-plastic buckling. An interesting phenomenon is found that when the strain rate is sufficiently high, there is no dynamic visco-plastic buckling occurrence and the shell produces a harmonic oscillation with a very small amplitude.

关键词： viscoplasticity cylindrical shell torsion buckling impact

A Whitecap Coverage Model Based on the Surface Slope For Criterion of Wave Breaking

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China Ocean Engineering 1998年第1期13卷 73-85页

作者： Xu, DL Yu, dy Lu, HM Ocean Univ Qindao Phys Oceanog Lab Qingdao 266003 Peoples R China Ocean Univ Qindao Sch Engn Qingdao 266003 Peoples R China

Using the limit surface slope as a criterion of wave breaking, a simple model for estimating the spatial fraction of breaking surface of sea at an instant, which is regarded as the whitecap coverge in this paper, is analytically derived from the probability density of surface slope based on Gaussian statistics. The resulting fraction is found depending on the fourth moment of wave spectum, m(4), as well as the critical threshold of surface slope. By expressing the fourth moment in terms of the Neumann spectrum, a formula linking the fraction and wind speed for fully developed sea states is obtianed. Another formula relating the fraction to both wind speed and fetch (or duration) is achieved by expressing m, in terms of the Krylov spectrum and applying the empirical relationships used in the SMB ocean wave predicting technique. A comparison between these results and the field data of whitecap coverage collected by Monahan and O'Muircheartuigh shows an encouraging agreement.

关键词： whitecap coverage criterion of wave breaking wind speed wind fetch wind duration fully developed sea state fetch-limited sea state

Spectral Characteristics of Wind-Waves in Laboratory

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China Ocean Engineering 1998年第2期13卷 183-190页

作者： Lu, HM Xu, DL Yu, dy Ocean Univ Qingdao Phys Oceanog Lab Qingdao 266003 Peoples R China Ocean Univ Qingdao Coll Engn Qingdao 266003 Peoples R China

Spectral characteristics of wind-generated waves in labortaory are presented on the basis of a systematic measurement in a large-scale wind-wave channel and compared with those in the field. A marked characteristics of the measured spetra is the existence of secondary spectrum-peak. The dependence of spectral peak-frequency, peak-value and zeroth-order moment on wind speed and fetch are presented and found roughly similar to those in the field represented by the JONSWAP spectrum, regardless of the differences in coefficient. The spectral slope beta at high-frequencies are found somewhat greater than those of field wind-waves in both cases of deep and shallow waters. Except for the low-frequency part, the spectral forms measured in different wind conditions are similar and fit for the JONSWAP spectrum with gamma = 6 and beta = 5.5. Some relevant problems are discussed.

关键词： wind-wave channel spectral characteristics JONSWAP spectrum

dynamic Buckling of Laminated Composite Bars Subjected to Axial Impact

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China Ocean Engineering 1998年第2期13卷 127-134页

作者： Wang, dy Chen, TY Xin, GN Shanghai Jiao Tong Univ Sch Naval Architecture & Ocean Engn Shanghai 200030 Peoples R China

The impact buckling of a laminated composite bar is investigated in case of one of its ends moving due to axial impact compression. The governing equations considering the first- order shear deformation effect are derived by the Hamilton principle and solved by the finite difference method. The critical axial shortness is determined by the B - R cirterion. The given example is used to highlight the influences of initial imperfection, impact velocity, stress wave and coupled stiffness. It is found that the unsymmetrically laminated bar has a quite different dynamic buckling behaviour from that of the symmetrically laminated bar.

关键词： impact buckling laminated bar stress wave coupled stiffness axial impact

SERS and RAIR for Molecular Structure of Phenylazonaphthalene-terminated Self-Assembled Monolayer

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Chinese Chemical Letters 2001年第11期12卷 1027-1028页

作者： Zhang, DH Zhang, JM Shen, dy Chinese Acad Sci Inst Chem Ctr Mol Sci State Key Lab Polymer Phys & Chem Beijing 100080 Peoples R China

The SAMs of 10-[4-(4-phenylazo)naphth-1-oxyl]-1-decanethioI (Compound 1) on gold were prepared. Their molecular structures were determined by surface enhanced Raman spectroscopy (SERS) and reflection absorption infrar... 详细信息

关键词： self-assembled SERS RAIR

Analysis of dynamic Structure-Fluid Interaction response of a Floating Laminated Composite Plate

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China Ocean Engineering 1997年第4期12卷 363-372页

作者： Tang, WY Wang, dy Chen, TY Shanghai Jiao Tong Univ Dept Naval Architecture & Marine Engn Shanghai 200030 Peoples R China

In consideration of the effects of transverse shear deformation and structure-fluid interaction, the analytical expression of fluid force between a floating laminated composite plate and liquid surface is obtained. By expanding the displacements into Fourier series, the structure-fluid coupling dynamic response is solved. The effects of lamination angle, layer number, depth of fluid region and loading forms on dynamic response are investigated.

关键词： composite structure laminated plate structure-fluid interaction dynamic response

EFFECT OF ELECTROLESS PLATING COBALT UPON CHARACTERISTICS OF NICKEL HYDROXIDE ELECTRODEFORreCHARGEABLEALKALINEBATTERIES

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中国有色金属学会会刊：英文版 1998年第4期8卷 135-141页

作者： Wang, XY Zhang, YS Yan, J Yuan, HT Song, dy Nankai Univ Inst New Energy Mat Chem Tianjin 300071 Peoples R China

ＩＮＴＲＯＤＵＣＴＩＯＮＮｉｃｋｅｌｈｙｄｒｏｘｉｄｅｅｌｅｃｔｒｏｄｅｓｈａｖｅｂｅｅｎｗｉｄｅｌｙｕｓｅｄａｓｐｏｓｉｔｉｖｅｅｌｅｃｔｒｏｄｅｉｎＮｉＣｄ，ＮｉＨ２ａｎｄＮｉＭＨｓｅｃｏｎｄａｒｙｂａｔ... 详细信息

ＩＮＴＲＯＤＵＣＴＩＯＮＮｉｃｋｅｌｈｙｄｒｏｘｉｄｅｅｌｅｃｔｒｏｄｅｓｈａｖｅｂｅｅｎｗｉｄｅｌｙｕｓｅｄａｓｐｏｓｉｔｉｖｅｅｌｅｃｔｒｏｄｅｉｎＮｉＣｄ，ＮｉＨ２ａｎｄＮｉＭＨｓｅｃｏｎｄａｒｙｂａｔｅｒｉｅｓ．Ｉｍｐｒｏｖｅｍｅｎｔ...

关键词： nickel hydroxide electrode electroless plating cobalt electrode performance electrochemical impedance conductivity

ENSO events and interannual variations of winter sea-ice in the Greenland, the Kara and the Barents Seas

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Chinese Science Bulletin 1997年第16期42卷 1382-1385页

作者： Wu, BY Gao, dy Huang, RH Chinese Acad Sci Inst Atmospher Phys Beijing 100029 Peoples R China

A number of researches show that ENSO is a phenomenon related not only to interannual variations in the tropical atmosphere and ocean, but also to climatic anomalies in the high latitudes. On the one hand, ENSO results in a teleconnection in the middle-high latitudes; on the other hand, the atmospheric circulation anomalies in the middle-high latitudes play an impor-

关键词： interannual variations sea-ice ENSO variation velocity.