基于WebGIS的地震复发周期与危险性分析     

刘云华  单新建  李卫东  马照松  张国宏 《地震》2010,30(4):58-64

根据地震复发周期模型, 利用现有的地质构造等资料把南北地震带划分为若干相对独立的活动构造区, 对能量积累阶段及地震危险性的预测建立相应的数学模型, 并构建基于WebGIS的网络计算平台, 由客户端任意在研究区选择构造分区, 并输入所选构造分区相应的计算参数, 提交到集群服务器计算模型进行计算, 对所选构造分区的地震危险性阶段及潜在震级进行预测并把结果以WebGIS方式返回给客户端。 实现了利用远程计算技术与并行算法对活动断裂能量积累与释放过程的模拟计算, 其结果可以为判定地震中短期预测的地点和震级提供依据。  相似文献   

中国化石能源使用可持续性评估——基于1990～2006年数据   总被引：2，自引：0，他引：2  

赵震宇  宋冬林 《地理科学》2010,(1)

进入1990年代,中国经济走上了前所未有的快速增长轨道,而化石能源作为推动经济增长的最主要动力源泉却同时也是造成环境恶化的双刃剑。采用加拿大生态经济学家Ree和Wackernagel共同发展的生态足迹模型,对1990～2006中国化石能源使用的生态足迹和生态承载力进行了计算,得到了该时期中国化石能源使用已处于生态赤字状态的评估结果。而化石能源使用过程中单位能源的CO2排量没有得到显著改善和森林覆盖率没有明显的增长是造成该时期中国化石能源使用处于生态赤字状态的主要原因。  相似文献   

A painting type of flexible piezoelectric device for ocean energy harvesting     

《Applied Ocean Research》2017

Energy harvesting using piezoelectric materials can be realised by periodic external force. Piezoelectric material directly converts strain energy into electric power to capture a wasted ambient kinetic energy. This recovered energy can be used for operating wireless sensors, such as those found in environmental monitoring, mechanical sensing and structural diagnostic. In our previous work, a flexible piezoelectric device, FPED, was proposed and developed as an energy harvester for generating electric power from flow-induced vibration in ocean and wind environments. In this study a FPED with a painted piezoelectric layer, highly durable in order to withstand extreme bending and weathering caused by waves and currents, is proposed and developed by spray coating for use as an ocean energy harvester. A numerical method is developed to predict electro-fluid–structure interactions and to evaluate electrical performance and mechanical behaviours of the painted FPED. Additionally, validation of the numerical model is provided through several experimental tests. This study also investigates the relationship between the stiffness of the painted FPED and the vibrated frequency, as well as determining their influence on the electrical performance. Finally, the outcomes from a field test, conducted in real ocean space, is presented to provide information on electrical performance, mechanical behaviours and durability of painted FPEDs. The paper shows that a painted FPED is a useful and robust energy harvester for generating electric power from harsh environments.  相似文献   

Harnessing the wind: A case study of applying Flettner rotor technology to achieve fuel and cost savings for Fiji's domestic shipping industry     

《Marine Policy》2017

For over 5000 years, humans have successfully harnessed the power of wind to transport people and goods across the world's oceans. This research expands on previous studies of the unique Flettner rotor propulsion system and the demonstrable success in reducing fuel consumption and carbon dioxide (CO₂) emissions. Recent examples such as Enercon's E-ship 1 have proven seaworthy and economically viable along major shipping routes. The remote Pacific island countries (PICS), however, have the unique characteristics of retaining a remarkable seafaring heritage while remaining on the periphery of global commerce. With data obtained from a field study of Fiji's domestic shipping, this research analyzes the potential for implementing Flettner rotor systems to achieve more economically viable alternatives to the current situation. The findings show that with an incremental approach and the addition of a government fuel savings incentive, the Government Shipping Franchise Scheme (GSFS) subsidies could be significantly lowered for Fiji's ten uneconomical shipping routes. Four scenarios of 5%, 10%, 15%, and 25% fuel savings contrast the baseline data on one extreme with a zero-emissions scenario on the other. The most likely fuel savings scenario of between 10% and 15% results in a 20-year government savings of between 348,042 and 522,063 U.S. dollars and a 20-year cumulative reduction in CO₂ emissions of between 2931 and 4396 t. The paper concludes that Flettner rotors show promising results in reducing fuel consumption and CO₂ emissions and recommends future studies in collaboration with the Fiji government to develop practical strategies of implementation.  相似文献   

An energy-based interpretation of sand liquefaction due to vertical ground motion     

《Computers and Geotechnics》2017

In several recent earthquakes, high vertical ground accelerations accompanied by liquefaction were observed. Downhole records have also shown that large vertical accelerations do not necessarily originate from the source, but rather get amplified towards the ground surface. Given the advantages of energy-based interpretation of liquefaction triggering due to S-waves, this approach is used together with finite element analyses to investigate vertical motion amplification and ensuing liquefaction. The results show the importance of the post-resonance response cycles, while hysteretic damping based on total stresses, accounting for the water in the pores, is shown to be very low, explaining the observed amplification.  相似文献   

Seasonal variations in internal wave energy in a Scottish sea loch     

F. Cottier  M. Inall  C. Griffiths 《Ocean Dynamics》2004,54(3-4):340-347

Near-continuous observations of an internal wave field were made over a period of 13 months at a location in Inchmarnock Water at the northern end of the Clyde Sea. This paper sets out to determine the seasonal form of the energy density of the internal wave field at this location based on the hypothesis that it varies smoothly throughout the year, being greater in summer than in winter. The mooring was maintained between June 1999 and July 2000 in 150-m water with seven deployments. Estimates of kinetic and potential energy density were derived from Acoustic Doppler Current Profiler (ADCP) and vertical temperature profiles respectively. Both were shown to vary on time scales less than 1 month with median values of mean kinetic energy (KE) density0.5 J m^–3 and for mean potential energy (PE) density0.01 J m^–3. The energy of the internal wave field was found to be continuous and without a clear seasonal form. Further, it was also always non-zero with intermittent peaks of much higher energy. In the late autumn the system experienced complete vertical overturning driven by local convective processes destroying the thermocline and causing a reduction in the overall KE density.Responsible Editor: Jens KappeubergOrginally presented as a poster at PECS 2002, Hamburg Germany  相似文献   

Water use by intensively cultivated willow using estimated stomatal parameter values     

Harald Grip  Sven Halldin  Anders Lindroth 《水文研究》1989,3(1):51-63

Large land areas in Sweden are planned to be planted with high producing, short rotation forest stands of willow in the beginning of the 1990s. Since willow is a highly hydrophilic species, this new land use may have strong implications on water resources. To assess these implications, evaporation of Salix viminalis and Salix viminalis x caprea stands in lysimeters was analysed with the simple, yet physically realistic KAUSHA model. Parameter values for the Lohammar equation were deduced (b = 100 m³ kg^?1, k_max = 0.01 m s^?1), believed to be applicable to other sites. Simulated evaporation during the 1980 growth season for a normal stand with a production of 12 tonnes of dry matter per hectare per season was 526 mm, of which 375 mm was transpiration, 56 mm interception evaporation, and 95 mm soil evaporation. For an optimally irrigated 20-tonnes stand, the total evaporation was 584 mm, of which 430 mm was transpiration. As a comparison, Penman open water evaporation was 430 mm. To avoid soil water stress in the 20-tonnes stand, 140 mm was needed as irrigation, equivalent to 25 per cent of the mean annual precipitation. Since intensively cultivated willow plantations seemed to be using much water, it was concluded that introduction of this agri-forestry practice must be carefully planned to make use of this property, e.g. in biological filters or in reclaiming water-logged land.  相似文献   

天津市夜间城市热岛的数值模拟   总被引：7，自引：0，他引：7  

边海  铁学熙 《地理学报》1988,(2)

本文基于Myrap等人的工作,提出了一个能量平衡模式,并用实测的天津市夜间近地面温度场对模式进行了验证.应用这个模式,可给出天津市近地面热岛的适当预报,同时,可对天津市夜间城市热岛中各能量通量的空间变化进行讨论.  相似文献   

空气节能器研制与应用     

唐文模  洪祥炎  张家良  杨迪寰 《广东海洋大学学报》1990,(1)

本文针对渔船使用增压柴油机中存在的极待解决的问题,提出了增设空冷节能器的必要性,并设计研制出了空冷节能器。试验结果表明,该空冷节能器节油率达8%,总排温降低70～100℃,增加功率20%,压力损失△P_K<160mmH_2O。  相似文献   

Energy conversion evolution at lunar polar sites     

James D. Burke 《Journal of Earth System Science》2005,114(6):633-635

Lunar polar environments have many advantages from the standpoint of energy supply to robotic and human surface bases. Sunlight is nearly continuous and always horizontal at peaks of perpetual light, while waste heat rejection is aided by the existence of cold, permanently shadowed regions nearby. In this paper a possible evolution of lunar polar energy systems will be described, beginning with small robotic photovoltaic landers and continuing into the development of increasingly powerful and diverse energy installations to provide not only electric power but also piped-in sunlight, air conditioning and high-temperature process heat.  相似文献