EVALUATION OF CAPACITY SPECTRUM METHOD FOR ESTIMATING THE PEAK INELASTIC RESPONSES

The accuracy of the capacity spectrum method (CSM) depends on the precise estimation of equivalent period and damping ratio as well as the modification of the demand spectrum. In this paper, the CSM provided in ATC-40 for estimating the peak inelastic responses is evaluated. First, the effect of equivalent period and damping ratio estimation on the accuracy of the CSM is assessed. Analyses results indicate that the difference between estimation methods is large when the structural nonlinearity is large, but becomes negligible as the hardening ratio increases. Next, the reduction factors provided in ATC-40 and Eurocode are evaluated. It is found that the acceleration responses obtained using the factor of Eurocode is closer to the actual ones than those obtained using the factors of ATC-40. Finally, the demand spectrum is constructed using the peak absolute acceleration and pseudo-acceleration. The results obtained using the peak absolute acceleration is found to be generally larger than those obtained using the pseudo-ones. Since the original CSM generally underestimates the response, the use of peak absolute acceleration in the construction of demand spectrum produces the response relatively closer to the exact one. However, the use of peak absolute acceleration overestimates the response more when the original CSM overestimates the response.     

Multi-sectoral Cluster Modelling: The Evaluation of Scottish Enterprise Cluster Policy

This article describes the ex post cluster evaluation framework being developed by Scottish Enterprise. It focuses primarily on the macro level evaluation and, in particular, on the use of multi-sectoral modelling techniques to identify the effects of cluster policy on key indicators such as gross domestic product (GDP), unemployment and competitiveness. The Scottish Input-Output (I-O) table is a key element in this approach. The strengths and weaknesses of I-O data, both as a basis for this analysis and as a means of identifying important intra-cluster linkages are explored. Further, the article describes methods for visual representation of the linkages identified using such a method.     

抗战胜利后国民政府的棉纱布抛售政策研究

本文主要探讨抗战胜利后在纺织事业管理委员会(代表国民政府)之管制下,中国纺织建设公司(代表国营纱厂)和上海及苏浙皖区棉纺织工业组成的第六区机器棉纺织工业同业公会(代表民营纱厂)实行棉纱布抛售政策的过程,进而探析纺织资本家对该政策的态度及其与政府的关系.     

云南剑川海门口遗址饱水古木降解的微观构造分析

文中采用扫描电镜(SEM)和透射电镜(TEM)对海门口遗址饱水古木进行降解机理分析。结果表明:古木细胞次生壁收缩严重并与胞间层分离;胞间层保存较完好,呈连续网状。说明古木纤维素和半纤维素降解相对严重,木质素降解相对较轻。古木主要是受细菌降解,通过SEM和TEM均可见明显的细菌腐朽特征。细菌首先侵入细胞腔,再通过S3层侵入细胞壁内部。细胞壁内由于降解而产生的空隙在几十到几百纳米之间。饱水古木也受到了一定程度的真菌降解,但这类真菌主要降解古木内淀粉等物质,对细胞壁物质降解能力差,主要是使古木变色。     

Spatial Analysis of Snow-and Rain-Generated Highflows In Southern Ontario

Highflows (including floods) in southern Ontario are often thought to be generated primarily by spring snow-melt. This paper shows that, on the contrary, a significant proportion of highflows results from rain and rain-on-snow. Highflows are divided and analysed according to the generating process. Five parameters are estimated and used to characterize both snowmelt- and rainfall-generated highflows: mean number of events per year; mean date of highflows; standard deviation of date of highflows; mean specific excess discharge; and mean duration of event. The spatial variability of these parameters was described by a first-order trend surface, and the results are discussed in the context of practical applications .
On a sou vent pensé que les fortes crues des eaux (y-compris les mondatrous) dans le sud de I'Ontario provenaient principalement de la fonte des neiges prin-tannière. Or, cet article démontre qu'une proportion importante de ces crues sont le résultat des précipitations et de l'action de la pluie sur la neige. Cinq paramètres ont été mis au point et servent a décrire la fonte des neiges ainsi que les precipitations qui engendrent ces crues: une moyenne du nombre de crues par année; une moyenne des fortes crues; écart type des dates de ses fortes crues; une moyenne du débit excessif; et la durée moyenne de la crue. La variabilité spatiale de ces paramètres a été mesurée par surface ajustée de premier ordre et les résultats obtenus sont examinés dans un contexte d'applications pratiques .     

Local Knowledge and Economic Realities Affecting Soil Erosion in the Rach Rat Catchment,Vietnam

Several parts of Binh Phuóc Province, southern Vietnam, suffer from degraded soils and vegetation as a result of both natural erosion of weak mud rocks and sandstones and intensive human activity, especially through land clearing for agriculture on unstable slopes, deforestation, and abandonment of poor farmland. The underlying cause of this land degradation has been the farming habits of migrants of varying ethnic groups who have settled in the area since 1980. The indigenous farming knowledge of these people and the role of that knowledge in soil erosion were examined by a series of household surveys. They enabled farming practices to be related to ground cover established from a 2002 Landsat 7 ETM (Enhanced Thematic Mapper), and erosion data from a series of erosion bridge measurements. A GIS (Geographical Information System) approach was piloted as a means of identifying areas vulnerable to erosion. This could then be combined with the understanding of farming practices to reveal the relative roles of farmer behaviour, crop cover, and slope and soil characteristics in the erosion process. Land use, local people's knowledge and economic realities are the main factors, as well as natural conditions, that drive this land degradation.