A rope-shaped solar filament and a IIIb flare

On September 14–18, 2000, a medium-small solar active region was observed at Ganyu Station of Purple Mountain Observatory. Its spots were not large, but it had a peculiar active filament. On Sep.16, a flare of importance III_b with rather intense geophysical effects was produced. Our computation of the magnetic structure of the active region reveals that the rope-shaped filament was concerned with a low magnetic arc close to magnetic neutral line. An intense shear of magnetic field occurred near magnetic rope. The QSL analysis shows that a 3-D magnetic reconnection might appear in the vicinity of filament, and this can be used to interpret the formation of a large flare.     

甲醛还原Pt/TiO2催化剂用于温和条件下高效催化氧化甲醛（英文）

通过浸渍法(IM)和沉积-沉淀(DP)法制备了一系列Pt/TiO2P25)催化剂,并分别用甲醛溶液和氢气还原处理催化剂.利用原位红外监测催化剂表面吸附物种在反应过程中的变化,探究了催化剂制备和还原条件及Pt负载量对催化剂结构和催化氧化甲醛活性的影响.结果显示,用DP法制备并用甲醛还原的Pt/P25催化剂中Pt颗粒分散均匀,并具有合适的粒径和高浓度的表面活性氧,显示出良好的甲醛氧化活性.在空速30 000 ml/(g·h)、反应温度30°C和甲醛初始浓度50 mg/m的条件下,0.4%Pt/P25(DP-HCHO)上的甲醛转化率达到98%,并能稳定运行100 h以上.相比之下,Pt/P25(DP-H2)由于表面活性氧较少,不利于甲酸盐氧化,活性较低.Pt/P25(IM-H2)虽然具有高浓度的表面活性氧,却同时具有最大的Pt颗粒粒径,在甲醛转化为甲酸盐和甲酸盐氧化两步反应中的活性均较差,因而甲醛氧化活性最差.     

青藏高原祖尔肯乌拉山地区火山岩Ar-Ar年代学初步研究

对祖尔肯乌拉山地区 4个火山岩样品进行了Ar -Ar年龄测定 ,其坪年龄分别为 (40 91± 1 18)Ma、(41 0 7± 0 80 )Ma、(42 0 0± 1 31)Ma、(39 0 0± 2 0 6 )Ma。它们代表了这些火山岩的形成时代 ,表明本区在古近纪始新世中期发生过大规模的火山活动     

葛洲坝至胭脂坝长江干流段江豚活动规律

长江江豚是我国一级保护野生动物,也是长江生态系统的指示性物种,其种群数量恢复情况及活动规律一直备受关注。本文选择长江宜昌段江豚活动频繁的葛洲坝下游至胭脂坝江段为研究区域,于2021年6月-2022年5月采用定点目测、水上流动监测与无人机监测相结合的方法分区监测长江江豚的游泳行为,分析长江江豚的活动规律,构建了长江江豚出水头次的零膨胀泊松回归模型,识别影响长江江豚出水头次的关键因素,建立长江江豚出水头次与各因素间的相关关系。结果表明:(1)葛洲坝至胭脂坝长江干流段监测到最大江豚出水头次为19头次,长江江豚集群规模以2~3头最为常见,占比达58.1%;长江江豚主要表现出4种行为特征,各行为占比从大到小依次为:玩耍＞休息＞摄食＞抚幼。(2)长江江豚在葛洲坝下游近坝区(A区,葛洲坝至至喜长江大桥)出水头次最多,且在秋冬季节累计出水头次多于春夏季节,冬季累计出水头次最高,达252头次。(3)长江江豚出水头次与电站下泄流量呈显著负相关;浊度增大,长江江豚出水的概率减小。本文研究结果对长江江豚生态保护策略及长江十年禁渔效果评估具有重要参考价值。     

Experimental research on the effect of slope morphology on bank collapse in mountain reservoir

Farmers along the Amazon River each year face multiple natural hazards that threaten crop production and limit the potential for agricultural development of the expansive floodplain and active channel. In this paper we report the findings of a study of natural hazard-related risk associated with rice production on silt bars in the active channel of the Amazon River near Iquitos, Peru. Data were gathered in four rice producing communities in 2014 using household surveys (n = 83 households), focus group discussions, surveying of land elevations along the Amazon River, and interpretation of remote sensing imagery. The probability, extent, and severity of rice crop shortfalls were estimated for recent production years and the economic losses to farming households were also assessed. Our findings point to a very high risk of crop shortfalls due to natural hazards, suggesting that a good year brings rice farmers bounty and a bad year, near penury. River stage reversals (repiquetes) and edaphic conditions were found to be more problematic than the often cited hazard of high and/or early floods. Also surprisingly, farmers’ perceptions of hazards and risk diverged markedly from actual shortfalls experienced during the production years studied. Our results provide the first quantitative estimates of risk due to the multiple natural hazards along the Amazon River and point to the need to assist lowland farmers with risk mitigation so as to unlock the considerable potential of Amazon floodlands for agricultural production.     

面向道路网络地图示意化的线形简化方法

针对当前示意网络地图线形状简化方法中存在需要人工干预或地图认知度低的问题,本文提出自动化程度高并能保证良好地图认知的线形状简化方法.该方法通过合理设定线形状简化中所需的阈值以避免人工干预,提高了线形状简化过程的自动化程度,并通过在简化过程中应用平滑算法,以减少示意结果中线对象在方向上的转折数,从而提高了简化度和清晰度.试验表明该方法不仅可以生成清晰的示意结果,并且能够保证良好的地图认知度.     

建筑群负荷引起的大地水准面起伏及对高程的影响

The paper studies the ground vertical deformation and the geoid undulation caused by loading of neighboring buildings, based on the loading tides theory. The influence on elevation is also considered. The results show that the ground vertical deformation and the geoid undulation both reach millimeter magnitude. Therefore, it is obvious that the building loading significantly affects the precise engineering surveying, and it must be seriously considered in application.      

实时精密单点定位中的数据预处理研究

提出了适用于实时环境的一套数据预处理方案,包括钟跳修复、联合使用Geometry-Free和Melbourne-Wübbena组合进行周跳探测。通过丰富的实验算例,说明了对观测值进行钟跳修复的必要性;证明了联合使用GF与MW组合能够准确有效地探测出实际数据中存在的以及手工模拟加入的周跳。     

北斗GEO卫星轨道算法研究

通过实际采集的北斗广播星历数据分析了GEO广播星历的相关轨道根数特性,北斗GEO卫星广播星历拟合坐标旋转法,给出了适用于北斗GEO卫星的轨道计算方法,通过理论分析和试验验证了北斗GEO法的可用性与正确性。     

面向电网巡检的多旋翼无人机航测系统关键技术研究及应用

针对无人机电力巡检所面临的定位精度低、近距离巡检操控难度大、自动化程度低、人为操控事故风险高等问题,本文提出了利用多旋翼无人机RTK差分定位技术、复杂塔型飞行规则机器学习算法等无人机航测系统技术,研发面向电网巡检的无人机智能操作系统及控制终端,提升电网线路日常管理和应急指挥的规范性、便利性和经济性,为电网管理部门提供一种低成本、易操作、高效率、机动灵活的新型巡检模式。