新冠疫情防控前后湖北恩施地震台背景噪声变化分析

利用2018年1月至2020年3月恩施地震台站观测的垂直分量连续波形数据,通过计算噪声功率谱密度和概率密度函数,统计其不同频段功率谱密度分布情况,对比分析疫情前后恩施地区噪声水平变化特征.同时,将2018年、2019年和2020年垂直向地震噪声的加速度幅值进行对比,发现春节前几日的加速度幅值变化曲线高度一致,表明这三年...     

上海创意产业发展策略研究

全球产业结构变迁的趋势下,产业结构创新是经济发展的迫切需要。上海产业结构处在重要转型期,创意产业发展对产业结构调整、增强城市国际竞争力和经济抗风险能力具有重要作用。在国内外创意产业发展背景下,从人文地理学视角,对上海75个创意产业集聚区部分创意产业开发商、管理人员、专家进行深度访谈和问卷调查,问卷内容包括3个方面:(1)上海发展创意产业的前瞻性;(2)发展创意产业的空间格局;(3)发展创意产业的环境配套。问卷调查结果显示上海创意产业具有很强优势,在重要产业发展方面应采取不同措施,空间布局和环境配套需要完善。旨在探讨产业结构调整形势下,上海创意产业发展应采取的主要策略,为上海创意产业的发展提供重要的理论依据,同时为其他地区发展创意产业提供借鉴。     

Hourly Variation of Surface Urban Heat Island over the Yangtze River Delta Urban Agglomeration

Great progress has been made on the remote investigation of Surface Urban Heat Island (SUHI) across multiple time scales. However, limited by the remote sensing models and resolution tradeoff of satellite-derived Land Surface Temperatures (LSTs), currently the hourly regimes of SUHI over typical urban agglomerations in typical seasons remain unclear. Using MODIS imageries as the main data source as well as by incorporating a diurnal temperature cycle model (i.e., INA08), this study, to our knowledge, firstly examined the hourly variations of the spatial pattern and intensity of the SUHIs for the Yangtze River Delta urban agglomeration in both the summer and winter. The results demonstrated that, in the summer, a general trend of ‘heat island’ was observed for every city during a diurnal cycle. ‘Cold spots’ also occur within most of the cities from around 08:00 to 21:00, mostly as a result of the cooling effect of urban vegetation or water body under strong solar insolation. However, these ‘cold spots’ disappear after 21:00. For this season, the hourly variations of the SUHI intensity are similar to those of the LSTs: They both rise rapidly in the morning, reach the maxima at around 12:00 to 14:00, then gradually decrease and continue until the sunrise of the next day. In the winter, surface urban cool islands (SUCIs) were observed for most of the cities, but these SUCIs mostly disappear during the afternoon to the early evening (around 14:00~17: 00), and then all the cities bounce back to exhibit heat islands. Within this season, the hourly variations of the SUHI intensity differ from those of the LST. There also exist large differences of the hourly variations of SUHI intensity between using the rural area and forest as the non-urban background for estimation of the intensity, with the former reaching its maximum (around 18:00) significantly later than the latter reaching its maximum (around 13:30).     

宁夏区域震源参数特征研究

利用宁夏区域数字地震台网记录的发生于宁夏区域2008～2014年210个ML2.0～4.9地震波资料,采用Brune模式,将台站获取的速度记录进行几何扩散校正、介质衰减校正及仪器校正,对速度谱在频率域积分得到震源位移谱,使用遗传算法计算拐角频率及零频极限,进而计算震源半径、地震矩等小震震源参数,并系统分析各参数特征及其相互关系。结果显示,地震矩范围为1011～1015 N·m,震源破裂半径为60～766 m,拐角频率为1.6～22.2 Hz,地震应力降范围为0.01～7.63 MPa,视应力范围为0.01～3.11 MPa,地震矩、拐角频率、矩震级及里氏震级等震源参数之间表现出一定的对数线性或半对数线性关系。     

从“数字地球”看测绘工程专业的教育改革

在构建“数字地球”过程中 ,测绘学科和测绘行业将会发挥非常重要的作用。同时也对承担测绘人才教育的高等院校提出了新的挑战和要求。承担测绘高级专门人才培养的高校测绘工程专业也应适应这种趋势 ,对测绘专业教育进行深入、细致的改革 ,改变传统的人才培养模式 ,培养更多能促进社会进步、发展测绘事业的专门人才 ,为“数字地球”、“数字中国”的建设做出贡献。     

人卫观测中拖长星像的中心定位

提出应用于人造卫星观测中确定拖长星像中心的平均几何中心法 ,介绍了该方法的基本原理与实现步骤。将中值滤波应用于CCD数据的预处理并收到较好的效果。利用实际观测资料初步验证了平均几何中心法 ,结果表明 ,与通常采用的重心法相比 ,此方法对人卫观测中的拖长星像进行中心定位的精度较高。     

多传感器系统电路规范化设计探讨

系多传感器系统规范化研究之一，重点讨论电路设计的主要问题和相应的规范。     

Multi-objective Emergency Scheduling for Geological Disasters

Natural Hazards - Because of the specific time and distance constraints, emergency management departments usually build multiple depots (resource centers) to serve the widely dispersed customers...     

Chemistry and source identification of wet precipitation in a rural watershed of subtropical China

South China is one of the regions severely suffering from acid rain in the world.However,few systematic studies of rural precipitation chemistry have been performed in comparison with the extensive studies on their urban counterparts of this region.In order to characterize the current acid rain status and identify its possible sources in the rural area of South China,we analyzed precipitation collected event by event from a rural forested watershed in southern Anhui Province between March 2007 and February 2010.The results showed that the concentrations of major ions within precipitation in the studied rural area were significantly lower than those reported for the urban areas of the same latitude in China.Nevertheless,the precipitation acidity(with an average pH value of 4.49) and the frequency of acid rain(95%) were considerably high.The relatively high ratio of(SO42+ NO 3)/(Ca2+ +NH4+) was the main cause of acid rain in this rural area,as SO 2 and NO x were the main precursors of acid rain,while Ca2+ and NH4+acted as the dominant neutralizers to the acidity.Source identification indicated that Ca2+ and Mg2+ mainly were derived from alkaline dust,SO42,NO 3 and NH4+originated mainly from anthropogenic sources such as industrial and agricultural activities,most Na +,Cl,K + and some of Mg2+ were derived from the sea.The results suggested that the major ions within precipitation in the rural area of South China were related to the meso-scale and long-range transport of particles and aerosols in the air.