遥感影像低秩信息的矩阵填充复原方法

提出一种基于矩阵填充的遥感低秩信息复原方法,通过"确定性采样"与"热启动技术",利用奇异值阈值迭代收缩算子进行了椒盐噪声去除与去厚云修复试验.试验表明,本文方法对于因污染或遮挡等原因造成的信息缺损问题的复原效果占优,其在信息复原的同时能较好地保留细节纹理信息并保持图像结构的连贯性.此法可用于遥感影像椒盐类孤立的点状噪声去除与厚云修复复原中,尤其是当影像矩阵具备区域结构内容相似性及纹理规则等低秩特征时,这种复原效果更佳.     

基于潮流能直驱式海水淡化系统的建模与仿真

提出使用捕能系统捕获潮流能带动低压海水泵把低压海水转换为高压海水进行海水淡化,并对海水淡化过程中的浓海水进行能量回收。潮流能海水淡化关键在于提高效率和进入海水淡化系统时的海水压力的稳定。潮流能海水淡化系统采用直驱方式和能量回收系统提高了潮流能转换效率,而且系统中的高、低压蓄能器对海水淡化过程中海水压力起着稳定的作用。基于线性流体力学理论,推导出潮流能直驱式海水淡化系统的数学模型,模型考虑了水液压系统内部件的滑动摩擦力和泄露量。并对数学模型在系统压力、产水量和产水比能耗等方面进行仿真。仿真结果达到系统压力稳定、产水比能耗低。     

基于大数据的武汉市疫后人口恢复研究

利用手机信令和百度位置服务大数据,以2019年为基准,从居住与就业人口、对外城际联系和内部人口流动3个方面分析了2020年武汉市疫后人口恢复情况.研究结果表明,截至2020年12月,武汉市居住、就业人口分别恢复至基准时段的97％和92％,但内部区域差异明显,与经济发展水平密切相关;截至2020年9月,城市内部人口流动已...     

射气-闪烁法测定地下热水的镭-226和氡-222浓度

地下热水中放射性浓度较高的226 Ra和222 Rn对于研究地下热水的形成和循环具有重要的意义。阐明了实验室测定地下热水226 Ra和222 Rn放射性浓度的射气-闪烁法的仪器组成、测试原理、测试步骤、水样前处理和结果换算,讨论了在测试过程中各仪器和试验方法所需参数的选取及确定的具体操作。结果表明:在本试验中,所用放射性测试仪器FD-125型氡钍分析仪的最佳阈电压为2V,对应的最佳工作高压为450 V;所采用的3个闪烁室的校正因子分别为0.005 428、0.005 567和0.005 060;进行前处理提取水样226 Ra时,pH值应控制在2.5~3.0之间,可确保方法回收率最大。     

基于嫦娥一号卫星数据的柏拉图(Plato)月坑地质研究

通过CCD图像对Plato坑周围区域的线性地貌进行解译和构造方位统计,发现2组明显的线性构造优选方向,一组为NNE—SSW向,一组NWW—SEE向。分析后认为,这是在早期区域应力场作用下形成的,之后受到雨海事件和Plato事件的影响发生再活动,但是区域总体构造格架基本保持不变。使用IIM光谱研究发现,溅射物造成了Plato坑西部和东部在光谱上的差异。坑底玄武岩相对月海玄武岩基性物质含量要低,结合DEM分析认为坑底玄武岩并非从单点溢出。通过对Plato坑壁因垮塌而出露基岩的光谱研究和对本区域平底型月坑宽深比的统计,认为本区域属于高地与月海过渡的地区,在物质成分上受到雨海堆积物的影响而含有较多的低反射率基性物质。最后尝试性地对该地区的地质演化过程进行了推演,得出对本地区地质演化的粗略认识。     

上海民防工程建设与地下空间开发利用

基于上海城市灾害特点与发展趋势的初步分析,提出充分利用地下空间资源、加强民防工程建设的建议,以有助于进一步提高上海防灾抗灾减灾综合能力。结合上海特殊的地质条件,分析了地下空间民防工程建设中的主要问题及其防治对策,以期提高城市土地综合利用效率,并有效保障城市安全与可持续发展。     

Long-term changes in the production by estuarine macrobenthos affected by multiple stressors

The macrobenthic production of an estuarine system was evaluated over a 14-year study period in a seagrass bed and in a sandflat. Over this period, the estuary suffered severe eutrophication and extreme weather events with important impacts on the community, impairing system functioning and ultimately the goods and services provided by the estuary (decline in the seagrass bed, decreased community production and/or a boost in the production by opportunist species, such as Hydrobia ulvae). Following the anthropogenic impacts, management measures were introduced which allowed a gradual recovery of the seagrass bed and a new macrobenthic community structure manifested by production increases of slow-growing species, such as Scrobicularia plana and Hediste diversicolor. There was a gradual re-orientation of energy into population biomass instead of population density but this was not translated into higher community production, mainly due to the decreased production of opportunist species (H. ulvae and several polychaetes). Several weather extreme events occurred during this post-mitigation phase - floods, heatwaves and droughts, all of which had negative impacts on macrobenthic dynamics and production. The heatwaves led to the greatest decreases in macrobenthic production, mainly due to S. plana perhaps associated with its physiological intolerance of higher temperatures. The prolonged drought that followed the heatwaves maintained low levels of production by S. plana and H. ulvae. With climate change, the frequency and intensity of extreme weather events are likely to increase worldwide so that the recovery of impacted/disturbed systems from impacts such as eutrophication may be seriously affected by these additional stressors, compromising attempts to improve the ecological quality of estuarine ecosystems.     

Research on the inversion of elemental abundances from Chang’E-2 X-ray spectrometry data

The elemental abundances of lunar surface are the important clues to study the formation and evolution history of the Moon. In 2010, China＇s Chang＇E-2 （CE-2） lunar orbiter carried a set of X-ray spectrometer （XRS） to investigate the elemental abundances of the lunar surface. During CE-2＇s life span around the Moon, the XRS ex- perienced several events of solar flare. The X-ray solar monitor onboard recorded the spectra of solar X-rays at the same time. In this paper, we introduced the XRS instrument and data product. We analyzed the characteristics of the XRS data. Using the data obtained during an M solar flare event which had occurred on Feb. 16, 201 l, we derived the elemental abundances ofMg, A1, Si, Ca and Fe of the lunar surface in the Oceanus Procellarum. Finally, we dis- cussed the factors that influence the accuracy of the inversion.     

月表高程分布特征及其分级标准初探

月球是地球的唯一天然卫星,也是现阶段深空探测的主要天体。月表形貌研究有助于了解月球的状态、结构和组成,能够为探究月球起源和演化等科学问题提供直接、可靠的证据。与地貌分类相比,月貌研究起步较晚,发展较为缓慢。尽管月貌研究已取得了一定进展,但月球形貌分类过程中仍旧缺乏对于形貌指标,如高程等的应用,对于形貌特征的描述仍存在部分缺失。本文通过分析月球表面高程的整体特征以及月海、撞击坑、南极艾肯盆地等典型地质构造单元的高程特征,认为-2500 m等高线能够较好的区分月海内部区域;-1500 m等高线能够较好的区分月海区域与月陆区域;1000 m等高线与南极艾肯盆地边界拟合程度较好;3000 m等高线能够较好地突出月陆地区撞击坑的边界。在此基础上,提出以-2500 m、-1500 m、1000 m、3000 m 4个高程值作为月球形貌分类体系中的高程分类标准,将月球表面划分为极低海拔、低海拔、中海拔、高海拔和极高海拔5个形貌类型。     

数值模拟技术在聚合物驱油过程中跟踪调整应用

利用Eclipse数值模拟软件研究大庆油田北一区断西主力油层沉积特征、开发状况、剩余油分布规律,并对该区块在注入超高分子量聚合物过程中改注抗盐聚合物的特征变化进行借助计算机数值模拟技术进行研究,提前掌握区块运行规律,结合区块生产状况,提出相应的措施调整方案,进一步提高聚合物驱油开发效果。