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41.
先进天基太阳天文台(Advanced Space-based Solar Observatory, ASO-S)卫星是我国首颗太阳观测卫星, 主要观测太阳耀斑和日冕物质抛射以及产生它们的磁场结构. ASO-S卫星的科学应用系统是科学卫星工程的6大系统之一, 它连接科学用户和卫星数据, 为将卫星的科学数据转化为科学成果提供保障. 科学应用系统的数据库是连接软件与海量数据的枢纽, 为科学数据生产和用户服务及运行提供数据层的支撑. 介绍了科学应用系统的数据库架构设计、数据库的选择以及数据库性能优化和表样例. 这里的数据库包括观测计划、工程参数、运维日志、科学数据、定标数据和特征事件识别等数据库. 这些数据库的建设将为ASO-S卫星工程科学应用系统的顺利运行提供数据支撑, 也可以为未来其他科学卫星类似数据库的搭建提供参考和借鉴. 相似文献
42.
射电望远镜具有极高的系统灵敏度,且系统内、系统间及台址内电子设备众多,电磁环境复杂,科学合理地评估台址内电子设备辐射发射对射电天文观测的影响,对系统电磁兼容性设计、无线电管理、屏蔽改造等有重要的指导意义。浅析了射电望远镜系统灵敏度及射电天文领域仪器设备辐射发射相关评估标准;基于射电望远镜系统灵敏度及观测需求,计算了南山25 m射电望远镜馈源口面干扰电平限值,并给出了天线旁瓣增益的计算方法;提出一种基于干扰电平限值、旁瓣增益、干扰测量、路径衰减的电子设备电磁辐射评估方法,并针对南山25 m射电望远镜天线驱动电磁辐射进行了评估,给出了屏蔽需求。 相似文献
43.
Study on the isotherms of the interaction between suspended particles and Cu (II) in the Huanghe River 总被引:4,自引:0,他引:4
The isotherms of the interaction between the suspended particles and Cu2+, and the effects of lysine and asparaginic acid on the isotherms in the Huanghe (Yellow) River were studied by applying the
theory and method of interfacial stepwise ion/coordination particle exchange. We obtained a new stepped river isotherm, formed
by two curves joined together with a “plateau” in the middle. The adsorption equilibrium constantsK
1 andK
2 were calculated by using the isothermal equation of surface stepwise ion exchange. Amino acid in small amount promotes exchange
adsorption of the suspended particles with Cu2+. The degree of promotive action relates to the isoelectric point of amino acid. The promotive effect of lysine is bigger
than that of asparaginic acid.
Project 29361001 supported by NSFC. 相似文献
44.
Ying Pan Jun-xi Wu Li-ming Luo Yan-li Tu Cheng-qun Yu Xian-zhou Zhang Yan-jun Miao Yan Zhao Jun-ling Yang 《山地科学学报》2017,14(8):1604-1614
Ecosystem multifunctionality(EMF), the simultaneous provision of multiple ecosystem functions, is often affected by biodiversity and environmental factors. We know little about how the interactions between biodiversity and environmental factors affect EMF. In this case study, a structural equation model was used to clarify climatic and geographic pathways that affect EMF by varying biodiversity in the Tibetan alpine grasslands. In addition to services related to carbon, nitrogen, and water cycling, forage supply, which is related to plantproductivity and palatability, was included in the EMF index. The results showed that 72% of the variation in EMF could be explained by biodiversity and other environmental factors. The ratio of palatable richness to all species richness explained 8.3% of the EMF variation. We found that air temperature, elevation, and latitude all affected EMF, but in different ways. Air temperature and elevation impacted the aboveground parts of the ecosystem, which included plant height, aboveground biomass, richness of palatable species, and ratio of palatable richness to all species richness. Latitude affected EMF by varying both aboveground and belowground parts of the ecosystem, which included palatable speciesrichness and belowground biomass. Our results indicated that there are still uncertainties in the biodiversity–EMF relationships related to the variable components of EMF, and climatic and geographic factors. Clarification of pathways that affect EMF using structural equation modeling techniques could elucidate the mechanisms by which environmental changes affect EMF. 相似文献
45.
Soil erosion has become a major global environmental problem and is particularly acute on the Loess Plateau (LP), China. It is therefore highly important to control this process in order to improve ecosystems, protect ecological security, and maintain the harmonious relationship between humans and nature. We compared the effects of rainfall and land use (LU) patterns on soil erosion in different LP watersheds in this study in order to augment and improve soil erosion models. As most research on this theme has so far been focused on individual study areas, limited analyses of rainfall and LU patterns on soil erosion within different- scale watersheds has so far been performed, a discrepancy which might influence the simulation accuracies of soil erosion models. We therefore developed rainfall and LU pattern indices in this study using the soil erosion evaluation index as a reference and applied them to predict the extent of this process in different-scale watersheds, an approach which is likely to play a crucial role in enabling the comprehensive management of this phenomenon as well as the optimized design of LU patterns. The areas considered in this study included the Qingjian, Fenchuan, Yanhe, and Dali river watersheds. Results showed that the rainfall erosivity factor (R) tended to increase in these areas from 2006 to 2012, while the vegetation cover and management factor (C) tended to decrease. Results showed that as watershed area increased, the effect of rainfall pattern on soil erosion gradually decreased while patterns in LU trended in the opposite direction, as the relative proportion of woodland decreased and the different forms of steep slope vegetation cover became more homogenous. As watershed area increased, loose soil and craggy terrain properties led to additional gravitational erosion and enhanced the effects of both soil and topography. 相似文献
46.
47.
贵州与印度的夏季风的异同分析 总被引:3,自引:0,他引:3
季风作了气象科学的一个重要课题,许多人都作了大量研究,中国和印度均处于季风区,印度季风和中国季风的研究已作了大量研究,揭露了不少事实,但中国季风的研究多指我国的东部,而贵州位于我国西南部,地处东亚季风和印度季风之间的过渡区,因此,对贵州省的论及较少,从气候的角度出发,把贵州和印度的季风的某些特征量,如降雨、风、环流等进行对比分析,在一定程度上反映了贵州和印度夏季风的主要异同。 相似文献
48.
正1 Introduction The conflict between resources and the environment has been increasingly outstanding as the population,economy and society around the globe have developed rapidly since the 21st century.An important challenge that the human 相似文献
49.
在柱坐标下将黑子周围的环形区域(黑子除外)内的振荡分解为朝向黑子传播的(入射的)波和离开黑子传播的(出射的)波。对无黑子的环形区域内的振荡也进行了同样的分解。将黑子周围的入射波看成是被黑子磁流管磁化了的介质(介质内的磁场基本是水平的)中的波。而无黑子区的入射波看成是非磁化介质中的波。比较这两种波在固定波数下功率随频率的分布发现,在磁化介质中不同径向除n的声波(p模)频率系统降低,同时功率也降低,降低的功率最高达非磁化介质中波的功率的30%。而比较在固定频率下功率随波数的分布发现,磁场中f模及n=1,2,3的p模的脊向高波数方向位移,功率的降低受频率调制,即声波在某些有限的频带中被吸收。这些观测表明,在磁场中p模与磁声重力波(MAG)产生了模式混合或耦合。模式混合的存在支持了模式转换作为p模式被黑子吸收的机制的解释。此外,本文还分析了转换的MAG波进入黑子磁流管(其中的磁场基本上是垂直的)后进一步被吸收,吸收的功率最高达MAG波的20%。在磁流管内没有进一步观测到模式的转换 相似文献
50.
在分析观测数据解码以及观测数据质量指标的基础上编制软件,对采集到的原始GPS观测数据进行解码与多路径效应、周跳等质量指标的分析计算,并对质量指标进行直观、实时的图形显示。介绍所写软件在工程实践中的应用,并与TEQC软件进行比较,证明了软件的正确性和可靠性。 相似文献