宝格德乌拉隐伏多金属矿勘探中综合找矿模式的研究

研究区属得尔布干成矿带,是区域地质、地球物理和地球化学所确定的银铅锌等多金属矿的在成矿有利远景区。由于第四系覆盖严重,对地质、化探找矿带来较多不利影响,笔者以宝格德乌拉地区隐伏多金属矿勘探为例,沿综合物探方法研究与应用这一主线,并结合地质、化探阶段性成果,摸索出一套在该区行之有效的热液型隐伏多金属矿的综合找矿模式,用以指导该区深入开展找矿工作,并归纳总结出了其地质-地球物理-地球化学模型,为相近成矿条件地区的找矿工作提供借鉴。     

石屏-建水断裂水平错断河流的几何特征与断层活动性研究

通过对石屏-建水断裂带西北段断层错断8条河流的几何形态研究,发现河流水平位错量(△h)与断层线以上河长(L)、汇水面积(A)及断裂带宽度(W)之间存在正相关的线性关系,表明研究区内的断层活动在时间和空间上都没有较大的变化.同时通过对这几条河流的纵剖面进行分析,认为研究区内断层活动的水平分量远远大于垂直分量,水平运动将河道拉长,形成“水坝”效应,使上游河道发生堆积,下游河道发生侵蚀.     

基于无人机倾斜摄影的像控点布设对空三精度的影响

倾斜摄影测量是新型测绘的数据采集方法之一,它能够获取常规航空摄影无法得到的地物立面纹理信息和几何信息,但是在像控点布设和空中三角测量(简称"空三")方面还没有制定相应的技术规范,不利于这一新技术的推广应用.本文以大疆210无人机搭载五拼倾斜相机进行倾斜摄影测量工程为例,设计了4种像控点布设方案,分别进行空三加密处理,同时取部分像控地标作为检查点,分析了不同像控点布设方案对空三精度的影响,提出了在周边均匀与区域内部适当布设控制点的"倾斜摄影区域布控法".结果表明:优化的控制点布设方案,能够减少控制点数量,平面和高程精度达到1:500测图精度标准,并消除三维实景模型的系统误差.     

Radiation belt electron acceleration induced by gyroresonant interaction with magnetosonic waves

Using Cluster 4 satellite data, we examine activities of fast magnetosonic (MS) waves in the outer radiation belt near the location L=4.2 on 28 May 2005. We adopt a Gaussian distribution to fit the observed power spectral density of MS waves and find the fitting wave strength to be 245 pT. We then calculate the bounce-averaged diffusion coefficients and show that these diffusion coefficients are pronounced within a region of pitch angles about 25°–70°. By solving a 2D Fokker-Planck diffusion equation, we simulate the dynamic evolution of the electron phase space density (PSD), and demonstrate that significant increases in electron PSDs at energies of MeVs occur mainly within the aforementioned pitch-angle range over a time scale of several hours. The current results suggest that the interaction between MS waves and electrons could be an important mechanism of electron acceleration in the radiation belt.     

利用MERRA-2地表温压资料进行中国区域GNSS水汽反演的精度分析北大核心CSCD

为分析美国宇航局发布的最新MERRA-2再分析资料地表温压产品在中国区域进行GNSS水汽反演的精度,联合中国区域609个地面气象站实测温度和气压数据、48个GNSS站及并址探空站资料,评估MERRA-2温压产品及其在GNSS PWV反演中的精度。结果表明:1)MERRA-2气压和温度年均bias分别为-0.01 hPa和0.38 K,年均RMSE分别为1.08 hPa和2.66 K,MERRA-2再分析资料温压产品在中国区域具有较高的精度;2)MERRA-2再分析资料温压产品在中国大部分地区呈现负偏差,精度从高到低依次为南方地区、北方地区、西北地区和青藏高原地区;3)将MERRA-2温压产品的PWV反演结果与并址探空站实测PWV进行对比可知,MERRA-2再分析资料温压产品反演的GNSS PWV平均RMSE为2.16 mm,能较好地反映PWV的日变化。因此,MERRA-2地表温压产品在中国区域的气象研究及GNSS水汽监测中具有重要意义。     

动、定砂床底部剪切力对比试验研究

在河口海岸工程中,常常会面临岸滩冲蚀、岸线演变、航道淤积、建筑物底部淘刷等涉及泥沙起动和输运的问题,而水流对底床的剪切力是研究泥沙起动与输运的重要参数。本文利用自行设计的底床剪切力测量装置,在不同流速的水流中,分别在固定砂床(定床)和可移动砂床(动床)上进行了底部剪切力的直接测量;同时,根据试验中声学多普勒流速仪(ADV)测得的流速信息,采用湍流动能法对底床剪切力进行了估算。结果显示:当比例系数取值0.19时,估算出的底床剪切力与测量值吻合较好。对测量结果进行分析后发现,流速较小、砂粒未起动时,动、定砂床上的底部剪切力大致相同;在有砂粒起动的情况下,动床上的底部剪切力比定床上的大,相对差值最大约20%。因此当涉及底床剪切力的问题时,需要先确认床面形式,然后再进行分析研究。     

双基准站RTK测量代替等级控制测量的方法

提出了RTK测量的改进措施,基于双基准站RTK测量误差分析,推导了其测量限差,探讨了RTK测量代替等级控制测量的问题,并以试验数据进行了验证。     

Ecophysiological responses to drought stress in Populus euphratica

Ecophysiological responses to drought stress of Populus euphratica in Alashan Desert Eco-hydrology Experimental Research Station were investigated. Results show that under mild and moderate drought stress, stomatal length, aperture,area and density is likely to decrease in the early days, but afterwards this is likely to recovery with treatment over the passage of treatment time. Under severe drought stress, these properties appear to decline continuously. However, after45 days of drought-stress treatment, the decline is not as noticeable as before, indicating that Populus euphratica could possibly reduce water evaporation by shutting down the stoma, leading to an improvement in its water use efficiency with better survival under drought stress conditions. The leaf area first decreases, and then increases under mild and moderate drought stress conditions, with the average values under different degree of stress found to be approximately 129.52,120.08, 116.63 and 107.28 cm2, respectively. Under moderate stress conditions, the leaf water potential appears to show a continuous decline where the average values under different degree of stress are found to be-1.27,-1.85,-4.29 and-4.80 MPa, respectively. In terms of proline content, the results demonstrate that this factor appears to increase significantly under moderate and severe drought stress conditions. Especially under severe drought stress condition, the content is found to be more than 700 μg/g. Ranging over average values of 14.64 and 15.90 nmol/g under moderate and severe drought stress, respectively, Malondialdehyde content is found to increase quite rapidly under moderate and severe drought stress conditions at first, which then appears to decrease gradually with the treatment over time.     

环境信息学在循环经济系统中的应用

本文分析循环经济模式的物质循环和信息流的特点,尤其是循环经济活动对环境的作用以及在信息流方面的表现,讨论正在发展中的环境信息学理论与方法及其发展趋势,在此基础上,具体分析面向循环经济系统的环境信息学的特点,可能发挥的作用以及环境信息学在循环经济模式下如何开展研究和需要重点关注的问题。