PREDICTION OF DAMAGE IN R/C SHEAR PANELS SUBJECTED TO REVERSED CYCLIC LOADING

In this paper, the damage prediction of shear-dominated reinforced concrete (RC) elements subjected to reversed cyclic shear is presented using an existing damage model. The damage model is primarily based on the monotonic energy dissipating capacity of structural elements before and after the application of reversed cyclic loading. Therefore, it could be universally applicable to different types of structural members, includeing shear-dominated RC members. The applicability of the damage model to shear-dominated RC members is assessed using the results from reversed cyclic shear load tests conducted earlier on eleven RC panels. First, the monotonic energy dissipating capacities of the panels before and after the application of reversed cyclic loading are estimated and employed in the damage model. Next, a detailed comparison between the analytically predicted damage and the observed damage from the experimental tests of the panels is performed throughout the loading history. Subsequently, the effects of two important parameters, the orientation and the percentage of reinforcement, on the damage of such shear-dominated panels are studied. The research results demonstrated that the analytically predicted damage is in reasonably good agreement with the observed damage throughout the entire loading history. Furthermore, the orientation and percentage of reinforcement is found to have considerable effect on the extent of damage.     

洞庭湖湿地景观特征与农业产业化模式研究

洞庭湖湿地是我国最大的淡水湖泊湿地景观生态系统之一,湿地农业资源丰富,农业开发历史悠久,生产化水平较高,是我国重要的农业商品基地。由于过去长期受传统耕作方式的影响,农业产业化程度较低,农业经济发展缓慢;本文根据洞庭湖湿地景观特征,对洞庭湖湿地农业资源和湿地农业开发现状进行了评价和分析,指出了湿地农业开发中存在的问题,提出了洞庭湖湿地农业产业化开发利用模式,以实现洞庭湖湿地农业经济的飞速发展。     

TOWARDS UNIFICATION OF THE SOCIO‐ECOLOGICAL SCIENCES: THE VALUE OF COUPLED MODELS

The major environmental problems of the twenty‐first century, including climate change, water scarcity, pollution and resource exhaustion, represent a new category of crisis and highlight the desperate need for an integrated science of socio‐ecological phenomena. To help establish the foundations of such a science, we explore three traditions of mathematical theory: the Lotka–Volterra interactions of ecological theory, niche construction models of population genetics, and theory from the gene–culture coevolution tradition. We review the theoretical tools of each of these traditions in explaining cultural articulation with the environment. Although the theoretical core of the science we propose does not exist, cultural evolutionary theory supplies useful tools to analyse endogenous culture, cultural dynamics, and deeply rooted behavioural links to the environment. We also present a coupled model for demonstration, and suggest that coupled socio‐ecological models can provide a formal theory to help address the emergent socio‐ecological problems of the future.     

Equation and Adequation: The World Traced by the Phillips Curve

This paper considers the power of abstract formalization in capitalism, via an account of the politics and geography of an equation. The equation in question lies behind the Phillips curve, which describes the relation between price inflation and unemployment or output. I examine the evolution of the equation and its relation to macroeconomics' renewed emphasis, since the late 1960s, on long‐run monetary neutrality. Considering the Phillips curve and its theoretical and technical armature as social practice, I discuss some of the political and distributional questions that arise from the mode of spatial and temporal abstraction particular to modern macroeconomic analysis and policy‐making. The paper has three parts: a brief history of the Phillips curve, an examination of its modern equation‐form, and an analysis of its part in the dialectical process of “real abstraction”, through which logical space and time prioritize and produce both the spatial “macro” and the temporal “long‐run”.     

Rotational behavior of degraded traditional mortise-tenon joints: experimental tests and hysteretic model

This article presents the results of an experimental study on the rotational behavior of degraded Chinese traditional mortise-tenon joints with different degradation types and different degradation degrees. Six joint specimens degraded through artificially simulated method, were tested by reversed cyclic loading, from which the moment-rotation curves were obtained. The results indicated that the rotational behavior of these joints is semi-rigid, the hysteretic curve shapes of degraded joints are same to that of joint without degradation. The maximum moment, yield moment, and initial rotational stiffness of degraded joints decreases as the degraded degree increases, whose empirical degradation relationships were obtained based on the test data. A hysteretic model for degraded traditional mortise tenon joints was proposed. Experimental results were used to validate the proposed hysteretic model. Good agreement between predictions and tests was observed.     

Holocene Palaeoclimates of Africa

Examination of climatic inferences based on palynological, geomorphic, sedimentological, and other proxy data reveals a coherent picture of a generally wet early Holocene and drier conditions, with a time-transgressive clinal change commencing ca, 4500 B.P. The large-scale climatic periods in Africa during the Late Quaternary were interrupted by abrupt oscillations and rapid transitions. The magnitude and direction of climatic changes show distinct regional variation. However, in the monsoon-domain areas, abrupt drought events occurred conspicuously at ca. 12,000–11,500, 8500, 7500, 4500, 4000–3700, and 2000 uncalibrated radiocarbon years B.P. Further investigations are required to gain a more precise chronology of these events, which appear to have been crucial for some of the most salient developments in Africa's prehistory.     

Bridging the cultures: architecture,models and computers in 1960s Cambridge

ABSTRACT

In the 1960s a unique research centre was founded in the Department of Architecture at the University of Cambridge. Before that date research in architecture was fragmentary and consisted largely of individual studies of topics in architectural history. Under the direction of Sir Leslie Martin, who had been appointed Professor of Architecture in 1956, a group of young architecture graduates embarked on a programme of research in the newly established centre for Land Use and Built Form Studies. Informed by the interest in the idea of the ‘model’ that was prevalent across the disciplines in Cambridge at this time and by using the power of the University Mathematical Laboratory’s ‘Titan’ mainframe computer, the group developed conceptual and mathematical models that operated across the range of architectural scales from building to city. This paper describes that work and sets it in the context of Leslie Martin’s role in reshaping architectural education in Britain.     

Dome Strengthening By Encircling Ties: A Monitored Experiment

This study describes a new strategy of conservation of historical monuments based on the combined use of monitoring analysis and empiric reappraisal. Over time, the mechanical behavior of domes—their lack of stability due to the horizontal thrusts generated by their self-weight—has been analyzed by architects and engineers, starting from the observation of damage. This process, which was mathematically demonstrated for the first time by the famous Viviani’s analysis of Santa Maria del Fiore in Florence, has provided over the centuries a number of enhancements in dome structural conception, thus leading to the final solution, referred to as encircling tie rod intervention. Based on these premises, the experimental case of Santa Maria del Quartiere dome in Parma, Italy, is discussed herein. Indeed, it has been considered a good opportunity to present the method used in its strengthening-intervention assessment, further validated by the monitoring system installed. In this monitored in-scale experiment, the empiric classical solution to the primeval dome’s thrust finds its confirmation and offers further possibilities of recalibration during time, thus indicating structural monitoring that may be described as a possible and desirable “alternative to intervention”, in step with “minimum intervention” and “reversibility” principles.     

榆阳区明长城典型遗址的雨蚀破坏模式分析

现有的夯土遗址雨蚀病害分类方式关注的是多次降雨后遗址破坏的静态结果,以识别病害、辨明病因为主要目的。为进一步研究水土作用方式在夯土雨蚀病害发育过程中的作用,明确雨蚀病害的动态发育过程,在现场调查的基础上对榆阳区明代夯土长城的雨蚀病害进行分类、统计、分析,综合考虑侵蚀模式、雨蚀动态响应过程和劣化程度三个方面提出雨蚀破坏模式,分别为干湿破坏、冲刷破坏和降雨导致的重力侵蚀三种,三种破坏模式的提出为研究夯土遗址雨蚀和降雨间的响应关系提供新思路。     

《毛诗》经学化的过程及其特点与得失

本文主要论述三个问题：一、西汉前期,有经学的指导思想,但没有《诗经》经学的范本。即《子夏序》是不存在的,并从六个方面加以证明。二、《毛诗》经学化的过程。三、《毛诗》经学化的模式及其特点与得失。