27.3-day and Average 13.6-day Periodic Oscillations in the Earth’s Rotation Rate and Atmospheric Pressure Fields Due to Celestial Gravitation Forcing

Variation in length of day of the Earth (LOD, equivalent to the Earth’s rotation rate) versus change in atmospheric geopotential height fields and astronomical parameters were analyzed for the years 1962-2006. This revealed that there is a 27.3-day and an average 13.6-day periodic oscillation in LOD and atmospheric pressure fields following lunar revolution around the Earth. Accompanying the alternating change in celestial gravitation forcing on the Earth and its atmosphere, the Earth’s LOD changes from minimum to maximum, then to minimum, and the atmospheric geopotential height fields in the tropics oscillate from low to high, then to low. The 27.3-day and average 13.6-day periodic atmospheric oscillation in the tropics is proposed to be a type of strong atmospheric tide, excited by celestial gravitation forcing. A formula for a Tidal Index was derived to estimate the strength of the celestial gravitation forcing, and a high degree of correlation was found between the Tidal Index determined by astronomical parameters, LOD, and atmospheric geopotential height. The reason for the atmospheric tide is periodic departure of the lunar orbit from the celestial equator during lunar revolution around the Earth. The alternating asymmetric change in celestial gravitation forcing on the Earth and its atmosphere produces a "modulation" to the change in the Earth’s LOD and atmospheric pressure fields.     

老挝巴勉岩金矿钻探施工实践

境外钻探施工不但有施工技术方面的难题,更重要的是会遇到境外的施工环境、语言等诸多让人担忧让人却步的从未接触过的问题。介绍了在老挝巴勉岩金矿进行钻探施工遇到的各种难题及解决办法。     

螺旋钻进模拟月壤过程的热场分析

介绍了一种新型的月壤钻具,为了了解新型螺旋钻具在钻进模拟月壤过程中的热场分布,优化了钻进过程参数,通过理论计算建立了钻进过程热场分布模型,并通过实验进行了验证,同时进行了热电偶测温实验.测温结果显示,所建立的模型较好地符合钻进过程的温度分布;在相同的条件下,钻进过程的温度随着转速的降低而升高.计算分析和实验结果表明:月...     

月球重力场研究的论述

月球重力场探测是了解月球内部结构构造最有效的手段之一,也是未来登陆点选择的重要依据.在众多方法中,卫星重力探测是进行全月球覆盖以及获得月球深部信息的重要方法.本文叙述了当前月球重力探测历史和重力模型发展过程,并对这些模型进行比较分析.在了解前沿研究方法的基础上讨论了月球重力位场解算的基本原理、高精度月球重力场获得的方法...     

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.     

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。     

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.     

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...     

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。