对台风麦莎(2005)的熵流特征初步分析

根据热力学第二定律推导出熵平衡方程,并在数值模拟输出结果的基础上利用熵平衡方程中的熵流项来分析2005年台风"麦莎"发生、发展和消亡各阶段的熵流特征.(1) 从对流层的低层到对流层的高层,台风中心附近的熵流分布会逐渐由负熵流占优势互补趋向于以正熵流为主;(2) 对流层中层500 hPa的负熵流分布显示出,随着台风的强度加强(减弱),台风中心附近的负熵流强度也会随之加强(减弱);(3) 台风中心附近的负熵流分布和强度特征对于台风强度和未来移动路径有一定的指示意义.     

0.6～2.0GPa压力下部分熔融角闪辉长岩的纵波波速

利用超声波透射-反射法,测量了0.6～2.0 GPa、最高1 085℃条件下角闪辉长岩的纵波波速(vp),详细统计了部分熔融阶段实验产物组分的体积百分含量,利用矿物含量和弹性参数,计算了角闪辉长岩的纵波波速.实验测量和理论计算显示了较一致的vp-t关系,即高压下角闪辉长岩的vp随温度升高先缓慢降低,在温度约800～900℃后转而大幅下降.实验产物显示,样品在温度达812℃(0.6 GPa)、865℃(1.0 GPa)和919℃(2.0 GPa)后发生矿物脱水和部分熔融,熔体含量随温度升高显著增加.熔体是导致高温阶段岩石vp快速降低的主要原因.在初熔阶段vp随熔体增加而降低尤为显著,可能是初熔时矿物脱水生成的自由水及含水量高的熔体,以微细熔体薄膜浸润矿物边界或裂隙所导致.     

Seismic performance of a 3D full‐scale high‐ductile steel–concrete composite moment‐resisting frame—Part II: Test results and analytical validation

This paper presents the results of a multi‐level pseudo‐dynamic seismic test program that was performed to assess the performance of a full‐scale three‐bay, two‐storey steel–concrete composite moment‐resisting frame built with partially encased composite columns and partial‐strength beam‐to‐column joints. The system was designed to develop a ductile response in the joint components of beam‐to‐column joints including flexural yielding of beam end plates and shear yielding of the column web panel zone. The ground motion producing the damageability limit state interstorey drift caused minor damage while the ultimate limit state ground motion level entailed column web panel yielding, connection yielding and plastic hinging at the column base connections. The earthquake level chosen to approach the collapse limit state induced more damage and was accompanied by further column web panel yielding, connection yielding and inelastic phenomena at column base connections without local buckling. During the final quasi‐static cyclic test with stepwise increasing displacement–amplitudes up to an interstorey drift angle of 4.6%, the behaviour was ductile although cracking of beam‐to‐end‐plate welds was observed. Correlations with numerical simulations taking into account the inelastic cyclic response of beam‐to‐column and column base joints are also presented in the paper together. Inelastic static pushover and time history analysis procedures are used to estimate the structural behaviour and overstrength factors of the structural system under study. Copyright © 2008 John Wiley & Sons, Ltd.     

Rainfall network design using kriging and entropy

The spatial distribution of rainfall is related to meteorological and topographical factors. An understanding of the weather and topography is required to select the locations of the rain gauge stations in the catchment to obtain the optimum information. In theory, a well‐designed rainfall network can accurately represent and provide the needed information of rainfall in the catchment. However, the available rainfall data are rarely adequate in the mountainous area of Taiwan. In order to provide enough rainfall data to assure the success of water projects, the rainfall network based on the existing rain gauge stations has to be redesigned. A method composed of kriging and entropy that can determine the optimum number and spatial distribution of rain gauge stations in catchments is proposed. Kriging as an interpolator, which performs linear averaging to reconstruct the rainfall over the catchment on the basis of the observed rainfall, is used to compute the spatial variations of rainfall. Thus, the rainfall data at the locations of the candidate rain gauge stations can be reconstructed. The information entropy reveals the rainfall information of the each rain gauge station in the catchment. By calculating the joint entropy and the transmitted information, the candidate rain gauge stations are prioritized. In addition, the saturation of rainfall information can be used to add or remove the rain gauge stations. Thus, the optimum spatial distribution and the minimum number of rain gauge stations in the network can be determined. The catchment of the Shimen Reservoir in Taiwan is used to illustrate the method. The result shows that only seven rain gauge stations are needed to provide the necessary information. Copyright © 2007 John Wiley & Sons, Ltd.     

基于熵值法的淮海经济区城市中心性评价

根据城市中心性的内涵,从生产中心性、商贸中心性、信息中心性、交通中心性和科教中心性5方面构建城市中心性的综合评价指标体系,并运用熵值法实证分析了淮海经济区主要城市的中心性.淮海经济区城市的中心性主要表现为生产、信息和科教方面的中心性,且区域差异较小,该区主要城市的中心性均不太显著,其中徐州的城市中心性相对较强.     

属性识别模型在艾比湖水质评价中的应用

根据新疆博尔塔拉蒙古自治州环境监测站对艾比湖5个代表性的监测断面最近5年的水质实测资料,结合熵权法和国家地表水环境质量标准系统地建立了属性识别模型,运用属性计算和属性得分详细评价了艾比湖的水质.模型评价结果表明:艾比湖的水质污染主要为氨氮、磷、砷的污染.就空间而言,湖心2水质较好,没有出现V类水质,其次为喇叭口,博乐河口与精河河口水质较差;就时间而言,2003年各监测断面水质均属I类,之后逐渐恶化,到2008年半数以上的监测断面属于V类水质,且与改进密切值法的评价结果比较,结果较吻合.采用属性识别模型评价湖泊水质,概念清晰,计算简单,评价结果客观、合理,可以反映出艾比湖水质的现状,是湖泊水质评价中简便实用的评价方法之一.     

Input data selection for solar radiation estimation

Model input data selection is a complicated process, especially for non‐linear dynamic systems. The questions on which inputs should be used and how long the training data should be for model development have been hard to solve in practice. Despite the importance of this subject, there have been insufficient reports in the published literature about inter‐comparison between different model input data selection techniques. In this study, several methods (i.e. the Gamma test, entropy theory, AIC (Akaike's information criterion)/BIC (Bayesian information criterion) have been explored with the aid of non‐linear models of LLR (local linear regression) and ANN (artificial neural networks). The methodology is tested in estimation of solar radiation in the Brue Catchment of England. It has been found that the conventional model selection tools such as AIC/BIC failed to demonstrate their functionality. Although the entropy theory is quite powerful and efficient to compute, it failed to pick up the best input combinations. On the other hand, it is very encouraging to find that the new Gamma test was able to choose the best input selection. However, it is surprising to note that the Gamma test significantly underestimated the required training data while the entropy theory did a better job in this aspect. This is the first study to compare the performance of those techniques for model input selections and still there are many unsolved puzzles. Copyright © 2009 John Wiley & Sons, Ltd.     

Genesis of high-magnesium andesites and associated basalts from Saga–Futagoyama, northwest Kyushu, southwest Japan

High-magnesium andesites associated with basalts erupted after the opening of the Sea of Japan are present at Saga–Futagoyama in northwest Kyushu, southwest Japan. High Mg/(Mg + Fe) [=0.84] of orthopyroxene phenocrysts and bulk rock Mg–Fe–Ni compositions suggest that these high-magnesium andesites were originally primitive melts insignificantly modified in crustal magma chambers. K_D^Ca–Na [= (Ca/Na)_pl/(Ca/Na)_{bulk rock}] ranges from 1.21 to 0.97 and suggests that the high-magnesium andesite magmas would originally have contained H₂O less than 1.8 wt.%. Nb/La does not show a negative correlation with respect to SiO₂. These lines of evidence indicate that hydrous components derived from the subducting slab would not have played a significant role in the genesis of the high-magnesium andesite magmas. Instead, the normative olivine − quartz − [CaTs + Jd] compositions and a negative correlation between Sr/Nd and SiO₂ indicate that the basalt-high-magnesium andesite association would have been formed by multi-stage partial melting of relatively anhydrous source at pressure ranging from 1.5 to 0.5 GPa.