Centrifuge model test on dynamic behavior of group-pile foundation With inclined piles and its numerical simulation

In this paper, dynamic behavior of a grouppile foundation with inclined piles in loose sand has been investigated with centrifuge model tests. The test results are also simulated with elastoplastic dynamic finite element method, in which, not only sectional force of piles, stress of ground, but also deformation of piles are calculated using a three-dimensional elastoplastic dynamic finite element analysis (Code name: DGPILE-3D). The numerical analyses are conducted with a full system in which a superstructure, a pile foundation and surrounding ground are considered together so that interaction between pile foundation and soils can be properly simulated because the nonlinearities of both the pile and the ground are described with suitable constitutive models. Different types of piles, vertical pile or inclined pile, are considered in order to verify the different characteristics of a group pile foundation with inclined piles. The validity of the calculation is verified by the model tests.     

视角系数能否预测景观认知——以东京 文化遗产庭园为例

文化遗产景观正在面临城市化的挑战。为了解游客对城市背景下文化遗产庭园的认知,探索景观形态和游客认知之间的关系,对东京都内6个文化遗产庭园进行了游客认知的调查,并利用球面相机拍摄的全景图计算观测点各景观要素的视角系数。结果发现,天空、庭园、背景建筑的视角系数均与文化遗产庭园的安静感、尺度感、质感、构成感及开阔感显著相关,其中庭园的视角系数是对认知项目最有效的预测因子,并且其预测性不会因为游客国籍或性别的改变而有很大的变化。此外,园外现代建筑的视角系数与庭园的自然感、人工感及历史感均无明显关系。发现将景观认知研究拓展到文化遗产景观的空间形态领域,为文化遗产景观的评价提供了潜在的环境指标,亦是景观评价公众参与的一次实践经验。     

Lead solubility in FeO x -CaO-SiO2 slags at iron saturation

Experiments have been carried out to determine the equilibria between FeO _x -CaO-SiO₂ slag and lead metal in iron crucibles at temperatures ranging from 1473 to 1573 K. It has been found that the highest lead solubilities are observed in the silica-saturated iron silicate slags, while the lowest solubilities are observed in the CaO-saturated calcium ferrite slags. The activity coefficient of PbO varies from 0.15 to 3, depending on the slag composition. Changes in temperature do not have a significant impact on the activity coefficient. The activity of FeO and pct Fe³⁺/pct Fe²⁺ ratios have been determined as a function of slag composition. These new experimental data have been incorporated into an optimized thermodynamic slag model using the computer package FACT.     

关于三峡库区周边坡体岩石特性的考察

岩石强度的载荷速率相关性与岩石的时间相关性特性及粘弹性性质密切相关,而且强度的栽荷速率相关性越大,越容易发生蠕变破坏。对于坡体来说,如果构成坡体的岩石的时间相关性很显著．那么即使在比较低的应力下仅施加一点载荷,也容易发生变形。针对三峡库区周边滑坡多发,采集了组成滑坡坡体的4类主要岩石-泥岩、灰岩、泥质砂岩及砂岩。通过室内岩石力学强度试验,获得了不同岩石的强度特性曲线及表示载荷速率相关性的参数n。利用一个试件通过载荷速率交替变换获得了不同应变速率下的应力-应变曲线,从而根据强度的变化率不仅获得了峰值强度的载荷速率相关性,而且还求得了残余强度的载荷速率相关性。在单轴压缩试验中,残余强度的n值与峰值强度的n值有较大的差异,但在三轴压缩试验中两者的差异却不太明显。而且在气干状态下,不管是峰值强度还是残余强度的n值均随着围压的增加而增加。     

Electrochemical supercapacitor behavior of nanoparticulate rutile-type Ru1−xVxO2

Rutile-type Ru_1−xV_xO₂ nanoparticles possessing high surface area were prepared by a polymerizable-complex method and its electrochemical supercapacitor behavior was studied. X-ray diffractometry, energy-dispersive X-ray analysis, and N₂ adsorption/desorption measurements were used to characterize the structure of the products. The electrochemical supercapacitor behavior of thick and thin films was studied by cyclic voltammetry in various acidic, neutral, and alkaline electrolytes. Ru_1−xV_xO₂ exhibited extremely enhanced supercapacitive properties compared to pure RuO₂. The highest surface redox activity was achieved with an acidic electrolyte. Ru_1−xV_xO₂ showed negligible surface redox activity in neutral electrolytes.     

Human gait analysis based on biological motion and evolutionary computing

Human motion has already deeply affected many aspects of psychological and social research. On the other hand, because of the huge challenges and new dimensions of its increasingly extreme applications, this field remains an inspiring area in which to explore rich possibilities in the fields of artificial intelligence and bio-informatics. In this research, we investigated a novel approach to identify individuals based on their gaits. Furthermore, we investigated a new avenue of the research toward the biometric identification of humans that involves the classification of human gait using the power of genetic programming (GP). Moreover, we also propose an approach that applies collaborative filter using multiple evolved classifiers to address the challenges of non-determinism and insufficient generality of GP.     

Competitive oxidation of formaldehyde and formate on amorphous copper-palladium-zirconium alloy electrodes in alkaline media

Raney-type Cu–Pd alloy electrodes were prepared from amorphous Cu–Pd–Zr ternary alloys by treatment with aq. HF, and competitive anodic oxidation reactions of HCHO and HCOO^– were studied on these electrodes in alkaline media. The initial HCHO oxidation product was HCOO^– even on Pd or Pd-rich alloy electrodes which should be more active to the HCOO^– oxidation than to HCHO. The product HCOO^– was oxidized only after a large decrease of the HCHO concentration in the electrolyte. The oxidation rate of HCOO^– was considerably lowered by the existence of even a small amount of HCHO, as well as by the introduction of CO. These results suggest that the HCHO electro-oxidation is accompanied by production of a surface contaminant such as adsorbed CO. The optimum nominal Pd atomic fraction in the Cu–Pd alloy electrodes suitable for the steady simultaneous oxidation of HCHO and HCOO^– in mixed solution was shown to be 0.25 and 0.4 in 1.0 M NaOH (M=moldm^–3) and 0.5 M K₂CO₃, respectively.     

基于最小二乘支持向量机预测器的传感器故障检测与数据恢复

本文介绍了最小二乘支持向量机（LS-SVM）回归的基本原理，提出了一种基于LS-SVM回归的时间序列预测器，并将其用于传感器的故障检测和数据恢复。论述了LS-SVM预测器的实现方法和步骤，并且将其应用于压力传感器的故障检测和数据恢复，同线性神经网络预测器、RBF神经网络预测器和BP神经网络预测器的比较结果表明，LS-SVM预测器具有更高的预测精度，更好的外推能力，计算效率最高，因此，LS-SVM预测器是传感器故障检测和短期数据恢复的一种有效方法。     

气干与湿润状态下多孔隙岩石的黏弹性特性与力学模型

为研究多孔隙岩石的变形特性,提出一个适用于多孔隙岩石的非线形流变模型（本构方程）.本模型是由弹簧与阻尼器串连组成,弹簧部分采用作者曾经提出的本构方程;代表黏性部分的阻尼器设定加载前黏度很小,随着荷载的增加而逐渐加大.在低应力水平下的蠕变试验中,由于弹性系数没有明显的下降,因而设定阻尼器的应变与蠕变应变相同.为验证模型的准确性,对泥质砂岩、大谷凝灰岩、田下凝灰岩与河津凝灰岩4类岩石分别进行理论计算与试验测试.对于各类岩石,计算得到的应力-应变曲线与实测曲线基本一致,而且用此流变模型,发现气干与湿润状态下杨氏模量具有明显的差异.研究结果表明,在这2种状态下,杨氏模量的差异是由于非弹性应变（即阻尼器的应变）不同而引起的.在湿润状态下,阻尼器的应变增加越大,杨氏模量则变得越小.即使在较低的应力条件下,阻尼器的应变比以往研究中所认为的应变要大很多.     

Normal spectral emittance of a nickel metal surface with rectangular microcavities

Spectral control of thermal radiation emitted from rectangular microcavities (0.5×0.5×0.5µm³) was investigated through emission experiments at high temperatures. The microcavities were fabricated on a mirror‐finished Ni metal surface. Through measurement of the normal spectral emittance, the maximum emittance was obtained around a wavelength of 0.87µm, which was very close to that (0.894µm) estimated from the cavity resonance theory. The emittance reached a maximum value of 0.95, and then decreased drastically with increasing wavelength, from the cut‐off wavelength. For a longer wavelength range from 1.7µm, it was equal to the emittance of the mirror‐finished surface. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20248