Fabric and crystal characteristics of Bohai and Arctic sea ice

1　ＩｎｔｒｏｄｕｃｔｉｏｎＢｏｈａｉｏｎｅ ｙｅａｒｉｃｅａｎｄＡｎｔａｒｃｔｉｃｏｎｅｈａｖｅｔｈｅｓｉｍｉｌａｒｓｕｒｆａｃｅ ｆｅａｔｕｒｅｓａｎｄｃｏｒｒｅ ｓｐｏｎｄｉｎｇｆａｂｒｉｃａｎｄｃｒｙｓｔａｌｃｈａｒａｃｔｅｒｉｓｔｉｃｓ (Ａｌｌｉｓｏｎ 1 997;Ｌｉｅｔａｌ.1 997;Ｑｉｎ 1 991 ) .ＤｕｒｉｎｇｔｈｅＣｈｉｎａＦｉｒｓｔＡｒｃｔｉｃＥｘｐｅｄｉｔｉｏｎ ,ｔｈｅｒｅｓｕｌｔｓｉｎｔｈｅｓｔｕｄｙｏｆｏｎｅ ｙｅａｒｉｃｅｆｒｏｍＢｏｈａｉａｎｄＡｎｔａｒｃｔｉｃｗｅｒｅｕｓｅｄｆｏ…     

非饱和土中溶质迁移参数反演的HISR方法

以非饱和土中溶质迁移参数反演问题为背景, 依据正则化方法的思路, 以Itakura Saito距离作为同伦函数中的平凡问题, 将同伦方法引入非线性参数反演问题的求解, 进而提出一种求解非线性参数反演问题的大范围收敛(HomotoyItakura SaitoRegularization, HISR) 方法.为保证迭代稳定性, 并同时削弱观测噪声的影响, 同伦参数的修正采用了连续化修正方法.本文将HISR方法应用于求解带有平衡及非平衡吸附效应的一维非饱和土中溶质迁移参数反演问题, 计算结果表明HISR方法具有大范围收敛性及计算稳健性, 同时有较强的抵抗观测噪声的能力.      

In the Mountain''''s Shadow: Japan''''s Silk Reelers Blazed an Asian Path of Economic Development

1 Introduction: A Dissonant Fragment On entering Chichibu, many visitors feel as if they were passing through a time warp into another country or a bygone era as the train leaves behind Tokyo抯crowded suburbs and winds through steep slopes forested with oaks, beeches and cedars. The Oku Chichibu highlands, however, are a mere 70 kilometers northwest of Tokyo, or about 50 minutes by rail, less than the average two-hour of daily commute of 搒alarymen?within metropolitan area. The sense of s…     

地震对框架结构累积损伤影响分析

将框架结构等效为剪切型模型,采用三线型刚度退化模型,考虑累积损伤效应对结构刚度产生的影响进行时程分析,并利用改进的Park-Ang损伤模型计算得到结构的损伤情况.表明;结构的第一层损伤最为严重;地震序列不同,引起结构的损伤值也不相同;考虑损伤累积效应对结构的弹塑性地震反应有着显著的影响,建议在结构设计的第二个阶段,考虑材料的累积损伤和地震能量吸收与耗散,这样更能够体现结构的最不利反应状态,有利于制定合理的结构抗震措施.     

压电智能传感结构在土木工程中的研究和应用

压电智能结构是目前智能结构的研究热点之一,用途广阔,并取得了丰富的研究成果：文章综述了压电智能结构中的传感器／驱动器及其系统和基于压电传感器的常用监测方法以及在土木工程中的研究和应用等,并对压电智能传感结构工程实用化的前景提出看法。     

Numerical Simulation of Wave Forces on Seabed Pipelines

A three-step finite element method(FEM)together with Large Eddy Simulation(LES)is ap-plied to incompressible turbulent flow around seabed pipelines at relatively high Reynolds numbers.Bothtwo-dimensional and three-dimensional numerical simulation is carried out to determine thethree-dimensional effect.The results of numerical simulation agree quite well with the wave forces actingon pipeline models measured in physical model test.     

碟形网箱水动力特性的研究

根据物模实验得到碟形网箱在不同海况条件下的受力并给出了其估算方法和公式及其相关系数的取值,同时总结了碟形网箱的运动特性。     

New Material of Sinosauropteryx (Theropoda:Compsognathidae) from Western Liaoning,China

An incomplete specimen of Sinosauropteryx prima collected from the Early Cretaceous Yixian Formation of the Dawangzhangzi area in Lingyuan, western Liaoning is depicted. It represents the first systematically described material of this feathered compsognathid outside the Sihetun area in Beipiao. This specimen shows some diagnostic features of Sinosauropteryx prima, such as the very short forelimb in relation to hindlimb with the length ratio of humerus plus radius to femur plus tibia just around 30%, and the long and massive first manual ungual subequal in length to radius. The presence of Sinosauropteryx prima only at Sihetun and Dawangzhangzi supports the suggestion that the fossil-bearing beds in the Sihetun and Dawangzhangzi areas are equivalent to each other within the Yixian Formation.     

An Introduction to 2-CCD Digital Particle Image Velocimetry System and Its Application in Ocean Engineering

The basic principle of particle image velocinmetry(PIV)is described.When a PIV image is an-alyzed by the method of auto-correlation,there is a direction ambiguity of 180~0 in velocity measurement.The problem can be solved by using"Image Shifting Technique",but this makes devices much complicat-ed and difficult to control.A new arrangement of 2-CCD(Charge Coupled Device)fully digitized PIV sys-tem,which can also solve the problem successfully,is introduced in the paper.As an example of applica-tion of the system,an experimental result of flow field around a horizontal cylinder in wave is presented.     

Numerical Simulation of Freak Waves Based on the Four-Order Nonlinear Schrdinger Equation

A numerical wave model based on the modified four-order nonlinear Schrdinger (NLS) equation in deep water is developed to simulate freak waves. A standard split-step, pseudo-spectral method is used to solve NLS equation. The validation of the model is firstly verified, and then the simulation of freak waves is performed by changing sideband conditions. Results show that freak waves entirely consistent with the definition in the evolution of wave trains are obtained. The possible occurrence mechanism of freak waves is discussed and the relevant characteristics are also analyzed.