Nonlinear Dynamic Response of HDRB and Hybrid HDRB-Friction Sliders Base Isolation Systems

The isolation systems are usually made of rubber bearings that are sometimes coupled in hybrid combination with frictional devices; this is the case of an in-site experimental campaign, performed on a base isolated apartment building in Rapolla (south of Italy). Several dropout tests at initial displacements up to 17cm allowed to obtain in-site information on the true dynamic response of the isolation system (building and isolators). The tests carried out allow a comparison between the free vibration responses of a building, isolated by using a 28 HDRB isolation system only, or an HDRB-Friction Sliders Hybrid one. The paper highlights the main differences of the response in the superstructure (the structure over the isolation system) obtained by using only HDRB isolation system, or the Hybrid one (HDRB and Friction Sliders in parallel system). Analysis and comparisons of experimental data, show the influence of nonlinearities on structural higher modes amplification, especially observed by using the higher nonlinear Hybrid isolation system. Tests results confirm that, in the case of a regular superstructure, like the Rapolla building, the isolation system nonlinearities influence the structural response.     

Study on the characteristics of the marine boundary layer in the Equatorial Pacific

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台风区和外围暴雨区的旋转风、散度风动能收支

用完全的散度风(v_D)和旋转风(v_R)动能收支方程对8116台风和8407台风以及8116台风与其外围暴雨区的关系作了讨论。结果表明:台风区的有效位能通过散度风动能(K_D)转换为旋转风动能(K_R).台风向区域外部输出动能,在暴雨区上空通过涡度、散度场相互作用的转换机制由K_R向K_D转换,散度风加大触发对流发展产生暴雨,这可能是台风与其外围暴雨联系的一种能量过程。     

我国能源消费结构变化与气候特征

文章利用多项式法将气候耗能量从能源消费总量中分离出来，用统计分析的方法探讨了气候耗能量与气候因子之间的关系及其变化。研究表明：从20世纪50年代到80年代初期，旱涝灾害是影响我国气候耗能量的主要气候因子，它们之间存在显著的线性相关关系，随着经济的发展和人民生活水平的提高，旱涝灾害对气候耗能量的影响逐渐减弱，气温对气候耗能量的影响日趋显著，目前正处于过渡时期。     

海洋温差能发电技术的现状与前景

对海洋温差能发电技术的基本原理、类型、系统与装置、发展历史和现状作了全面的综述。介绍了国内外海洋温差发电技术的特点、难点和近期的研究热点,指出海洋温差发电技术必须与附属产品的开发利用相结合才能有竞争力,海洋温差发电技术要达到规模产业化还有相当长的路要走。     

香港自由港模式发展演化、动力机制及启示

文章在总结并回顾香港由转口贸易型自由港、加工贸易型自由港向综合型自由港和跨区域综合型自由港的演化历程的基础上,分析探讨了区位市场、运行机制、政策框架、要素投入等内部动因与国际经济环境、政治环境等外部动因的相互作用,共同推动其发展演化的动力机制。最后提出香港自由港发展演化对中国自由贸易区建立与发展的几点启示：1）依据其发展阶段与条件选择与之相适应的发展模式;2）选择区位条件有利的地区建设自由贸易区;3）自由贸易港或贸易区持续发展的必要条件是能保持相对稳定的政治环境和相对独立的行政单元;4）自由贸易港（区）功能和作用的充分发挥离不开自由的经济制度和仿真的国际化经营环境。     

Analysis and comparison of heat flux of landfast ice during 2016 in the Prydz Bay,Antarctica

Long term in situ atmospheric observation of the landfast ice nearby Zhongshan Station in the Prydz Bay was performed from April to November 2016. The in situ observation, including the conventional meteorological elements and turbulent flux, enabled this study to evaluate the sea ice surface energy budget process. Using in situ observations, three different reanalysis datasets from the European Centre for Medium-Range Weather Forecasts Interim Re-analysis(ERA-Interim), National Centers for Environmental Prediction Reanalysis2(NCEP R2), and Japanese 55-year Reanalysis(JRA55), and the Los Alamos sea ice model, CICE, output for surface fluxes were evaluated. The observed sensible heat flux(SH) and net longwave radiation showed seasonal variation with increasing temperature. Air temperature rose from the middle of October as the solar elevation angle increased.The ice surface lost more energy by outgoing longwave radiation as temperature increased, while the shortwave radiation showed obvious increases from the middle of October. The oceanic heat flux demonstrated seasonal variation and decreased with time, where the average values were 21 W/m~2 and 11 W/m~2, before and after August,respectively. The comparisons with in situ observations show that, SH and LE(latent heat flux) of JRA55 dataset had the smallest bias and mean absolute error(MAE), and those of NCEP R2 data show the largest differences.The ERA-Interim dataset had the highest spatial resolution, but performance was modest with bias and MAE between JRA55 and NCEP R2 compare with in situ observation. The CICE results(SH and LE) were consistent with the observed data but did not demonstrate the amplitude of inner seasonal variation. The comparison revealed better shortwave and longwave radiation stimulation based on the ERA-Interim forcing in CICE than the radiation of ERA-Interim. The average sea ice temperature decreased in June and July and increased after September,which was similar to the temperature measured by buoys, with a bias and MAE of 0.9°C and 1.0°C, respectively.     

包头地区风和风能资源

风能是地球表面空气流动所产生的动能,也是提供给人类的一种可利用的重要能源.文在第三次气候区划的基础上,对包头地区近40a(1971-2010)风及风能资源做了统计分析.结果表明,包头地区风能资源丰富,开发利用风能资源有着巨大的发展潜力.     

南极无冰区典型沉积环境石英砂表面结构特征及其在沉积环境识别中的应用

本文利用电镜扫描方法 (SEM)对比分析了南极乔治王岛无冰区海滩沉积、冰碛物以及阿德雷岛湖泊沉积等典型沉积环境中的石英砂表面结构特征 ,得出了乔治王岛各典型沉积环境中石英砂表面结构特征的颗粒频率曲线。结果表明 :不同沉积环境下的石英砂颗粒表面结构特征具有相似性 ,这主要和南极地区广泛发育的冰川作用有关 ,同时 ,它们也有各自典型的特征组合 ,这些典型特征组合的不同反映了石英砂后期的搬运历史和沉积环境的差异。本文还依据石英砂表面特征的颗粒出现频率 ,利用聚类分析方法对研究区内三级海岸阶地上的沉积物和一个未知成因的样品进行了沉积环境的判别分析 ,结果证明石英砂微形貌特征可以作为南极地区沉积环境识别的有效手段     

气旋爆发性发展过程的动力特征及能量学研究

本文对不同路径的爆发性气旋进行了动力特征及能量学研究。发现高空大值位涡空气的下伸是气旋爆发性发展的一个重要条件。初生气旋逐渐向强位涡区移近并形成上下位涡区相接的形势。使气旋迅速发展。高空急流与气旋发展有密切关系。发展中的气旋明显地向着急流左侧的辐散区移动。急流的突然加强及高空强风动量的不断下传，构成了下层的强风带及上下一致的急流结构。能量学研究指出在气旋发展前气旋内散度风动能向旋转风动能的转换突然增强。散度风动能在爆发气旋发展时有明显增长。