推进可再生能源在建筑中的规范化应用

建设部总工程师王铁宏日前在由国家发改委、建设部和山东省人民政府联合举办的“2007济南太阳能利用大会”上表示，要大力推进可再生能源在建筑中的规范化应用。这是我国政府举办的第一次太阳能利用会议，目的在于加强太阳能热利用技术的交流，促进太阳能热利用的国际合作，推进我国太阳能热利用的发展。     

厄尔尼诺现象已形成并将持续

2006年12月1日，世界气象组织（WMO）确认，一个中等强度的厄尔尼诺现象已在太平洋上形成，并将至少持续到2007年第一季度。     

土石混合料剪切面分形特征试验研究

土石混合料因具有良好的工程特性而被广泛应用于道路、堤坝等工程，填筑体受力后往往沿薄弱面发生剪切破￡混合料的抗剪强度成为稳定和变形分析的重要力学指标。由于土石混合料物质组成的复杂性、结构分布的不规律性及采柠困难性，且受检测仪器的限制，确定其强度指标较为困难。应用改进的直剪试验仪进行了不同类别、不同最大粒径土石福料的室内大型直剪试验，在获得强度指标同时，再现剪切面的实际情况，量测剪切面的起伏特征。根据分形几何学原理，切面具有良好的分形特征，应用三角形棱柱表面积覆盖法编程计算了剪切面的分形维数。初步建立了剪切面分形维数与福料杭萌强度之间的关系，用来快速预测土石混合料的强度指标。     

修正的莫尔-库仑理论的解析和验证

根据主应力可分解为静水应力和偏应力,以及它们在应力莫尔圆和变形方面的相关性,推导出修正的莫尔-库仑理论的数学表达式。从理论上解决了库仑理论和莫尔理论存在的许多缺陷,特别是中间主应力对材料抗剪强度的影响。它的四参数准则的计算结果与一些混凝土的试验数据相当吻合。     

三峡引水工程秦巴段输水隧洞稳定性分析

三峡引水工程秦巴段隧洞总长占线路总长的80%。为了分析隧洞施工及运营中可能发生的工程地质问题,在地质调查、地应力测量和岩石力学参数测试的基础上,利用Ansys有限元软件对引水工程北部不同深度、不同截面形态的隧洞围岩的应力重分布情况进行了模拟计算,得到了圆形隧洞、城门形隧洞和马蹄形隧洞围岩的应力分布结果。利用Hoek-Brown强度准则,得到了隧洞围岩的强度/应力比值,进而对不同深度、不同截面形态的隧洞围岩的稳定性进行了分析。初步认为:隧洞埋深小于1000m时,应优先考虑圆形隧洞和马蹄形隧洞;埋深大于1000m时,应优先考虑城门形隧洞。这项研究成果为引水工程深埋隧洞的设计提供了参考依据。     

0707号强热带风暴“帕布”强度变化探讨

从环境风引导气流垂直切变、倾斜结构来探讨0707号强热带风暴“帕布”的高层对流云团7次生消的变化特征,同时,也探讨双台风对“帕布”强度的影响。     

马来西亚用于可持续发展的能源:能源政策和替代能源

能源通常被称为经济发展的催化剂,在全球范围内,人均能源消费通常被用作衡量一个特定国家经济发展水平的"晴雨表"。马来西亚政府认识到能源是社会和经济发展中至关重要的组成部分,一直在不断地评述自己的能源政策以保证长期可靠的和安全的能源供应,着力保证可耗竭的和可再生的两种能源资源的可持续性。本文的目的是介绍政府为保证能源供应的长期可靠性和安全性所采用的各种能源政策,还讨论不可再生和可再生能源资源在目前的五种燃料多样化战略能源结构中的作用。除此之外,本文还介绍了马来西亚的替代能源和实施的能源效率项目。     

浅谈我国海外能源(主指石油)投资与地缘政治风险

要保持我国经济的快速持续增长,确保能源安全供应是必不可少的。本文简要介绍了目前世界能源地缘政治的新格局,从我国海外能源投资的风险与挑战、海外工作人员的人身安全挑战、石油海上运输安全挑战及恐怖活动与海盗袭击4个方面进行了分析,并提出了几点肤浅认识。     

Study of Aerodynamic Parameters on Different Underling Surfaces

Aerodynamic parameters including the zero-plane displacement (d), roughness length (20), and friction velocity (u*) on the different underlying surfaces of heavy-grazing site, medium-grazing site, light-grazing site, no-grazing site, dune, inter-dune, grassland, rice paddy site, wheat site, soybean site, and maize site have been computed based on the Monin-Obukhov similarity theory by utilizing the micrometeorologically observed data of dune and vegetation in the semi-arid area at Naiman, Inner Mongolia of China, conducted jointly by the Institute of Desert Research, Chinese Academy of Sciences and the National Institute of Agro-Environmental Sciences of Japan in 1990-1994. And their relationships between wind speed and Richardson number are analyzed. The aerodynamic characteristics of different man-made disturbed grassland ecosystems are also compared. Result shows that the vegetation coverage and the above-ground biomass decrease with the increase in man-made stress of the grassland. The roughness length for different underlying surfaces is closely related to vegetation height, above-ground biomass, and ground surface undulation, and Richardson number Ri is also its influencing factor. The friction velocity varies largely on different underlying surfaces, and it is positively proportional to wind speed and roughness length. The aerodynamic parameters of various times on the same underlying surface are different, too. Above results indicate that grassland and vegetation are of significance in preventing desertification, especially in the arid and semi-arid land ecosystems. And the results of this paper are also important for constructing the land surface physical process as well as regional climate model.     

Comparison of Three Tropical Cyclone Intensity Datasets

Analyzed in this paper are the 16-yr (1988-2003) tropical cyclone (TC) intensity data from three major forecast centers of the western North Pacific, i.e., China Meteorological Administration (CMA), Regional Specialized Meteorological Center Tokyo (RSMC Tokyo), and Joint Typhoon Warning Center (JTWC) of the United States. Results show that there are significant discrepancies (at 1% significance level) in the intensity of TCs among the three centers, with a maximum difference for the same TC over 30 m s-1. The flight reconnaissance over TC can minish the discrepancy to some extent. A climatic and persistent prediction model is set up to study the impact of initial data from different forecast centers on the prediction of TC intensity. It is obtained that the root mean square error (RMSE) of a 4-yr independent test is the largest using data from JTWC, while the smallest using data from RSMC Tokyo. Average absolute deviation in 24-h intensity prediction is 2.5 m s-1 between CMA and RSMC Tokyo data, and 4.0 m s-1 between CMA and JTWC data, with a maximum deviation reaching 21 m s-1. Such a problem in the initial value increases the difficulty in intensity prediction of TCs over the western North Pacific.