气候变化和人类活动对中国地表水文过程影响定量研究

利用中国372个水文站月径流数据（1960-2000年）及41个水文站年径流数据（2001-2014年）,采用基于Budyko假设的水热耦合平衡方程,构建气候变化和人类活动对径流变化影响定量评估模型,在Penman-Monteith潜在蒸发分析基础上,进一步分析气象因子对径流变化的弹性系数,量化气候变化和人类活动对径流变化的影响。结果表明：① 中国北方地区流域径流变化对各气象因子弹性系数明显大于中国南方地区。就全国而言,径流变化对各因子的弹性系数为：降水>土地利用/土地覆盖变化（LUCC）>相对湿度>太阳辐射>最高气温>风速>最低气温;② 1980-2000年,气候变化总体上有利于增加中国年径流量,而降水对年径流量增加的贡献最为显著;③ 1980-2000年,中国南方流域中,气候变化对年径流变化的影响以增加作用为主,而北方流域,以减少年径流作用为主。对中国大多数流域径流变化而言,人类活动的影响主要以减少年径流量为主。2001-2014年,气候变化以减少径流量为主,人类活动对径流变化的影响程度明显增强,气候变化与人类活动对径流变化的贡献率分别为53.5%、46.5%。该研究对气候变化与人类活动影响下,中国水资源规划管理、防灾减灾及保障水资源安全具有重要理论与现实意义。     

DEM空间插值方法对土壤侵蚀模拟的影响研究——以USPED分析干热河谷典型冲沟为例

为探索不同空间插值方法得到的DEM如何影响土壤侵蚀模拟效果,本文选择金沙江干热河谷区典型冲沟为研究对象,利用野外测量高程数据,采用反距离加权(IDW)、析取克里格(DK)、局部多项式(LPI)和张力样条函数(ST)4种方法构建高精度DEM。基于USPED模型模拟冲沟的土壤侵蚀,对比不同空间插值方法的精度、土壤侵蚀的空间分布,采用相对差系数对比不同插值在土壤侵蚀研究中的相似性。结果表明：DEM空间插值的精度排序为ST相似文献   

Dehydration experiments on natural omphacites: qualitative and quantitative characterization by various spectroscopic methods

A series of natural omphacites from a wide range of P, T occurrences were investigated by electron microprobe (EMP), infrared (IR)-, Mössbauer (MS)- and optical spectroscopy in the UV/VIS spectral range (UV/VIS), secondary ion mass spectrometry (SIMS) and single crystal structure refinement by X-ray diffraction (XRD) to study the influence of hydrogen loss on valence state and site occupancies of iron. In accordance with literature data we found Fe²⁺ at M1 as well as at M2, and in a first approach assigned Fe³⁺ to M1, as indicated by MS and XRD results. Hydrogen content of three of our omphacite samples were measured by SIMS. In combination with IR spectroscopy we determined an absorption coefficient: ε _i,tot = 65,000 ± 3,000 lmol_H2O ^?1 cm^?2. Using this new ε _i,tot value, we obtained water concentrations ranging from 60 to 700 ppm H₂O (by weight). Hydrogen loss was simulated by stepwise heating the most water rich samples in air up to 800°C. After heat treatment the samples were analyzed again by IR, MS, UV/VIS, and XRD. Depending on the type of the OH defect, the grade of dehydration with increasing temperature is significantly different. In samples relatively poor in Fe³⁺ (<0.1 Fe³⁺ pfu), hydrogen associated with vacancies at M2 (OH bands around 3,450 cm^?1) starts to leave the structure at about 550°C and is completely gone at 780°C. Hydrogen associated with Al³⁺ at the tetrahedral site (OH bands around 3,525 cm^?1, Koch-Müller et al., Am Mineral, 89:921–931, 2004) remains completely unaffected by heat treatment up to 700°C. But all hydrogen vanished at about 775°C. However, this is different for a more Fe³⁺-rich sample (0.2 Fe³⁺ pfu). Its IR spectrum is characterized by a very intense OH band at 3,515 cm^?1 plus shoulder at 3,450 cm^?1. We assign this intense high-energy band to vibrations of an OH dipole associated with Fe³⁺ at M1 and a vacancy either at M1 or M2. OH release during heating is positively correlated with decrease in Fe²⁺ and combined with increase in Fe³⁺. That dehydration is correlated with oxidation of Fe²⁺ is indirectly confirmed by annealing of one sample in a gas mixing furnace at 700°C under reducing conditions keeping almost constant OH^? content and giving no indication of Fe²⁺-oxidation. Obtained data indicate that in samples with a relatively high concentration of Fe²⁺ at M2 and low-water concentrations, i.e., at a ratio of Fe^{2+ M2}/H > 10 dehydration occurs by iron oxidation of Fe²⁺ exclusively at the M2 site following the reaction: \( {\left[ {{\text{Fe}}^{{{\text{2 + [ M2]}}}}{\text{OH}}^{ - } } \right]} = {\left[ {{\text{Fe}}^{{{\text{3 + [ M2]}}}} {\text{O}}^{{{\text{2}} - }} } \right]} + {\text{1/2}}\;{\text{H}}_{{\text{2}}} \uparrow . \) In samples having relatively low concentration of Fe²⁺ at M2 but high-water concentrations, i.e., ratio of Fe^{2+ M2}/H < 5.0 dehydration occurs through oxidation of Fe²⁺ at M1.     

考虑内定向误差的外方位元素精度分析

在对数据质量的要求越来越严格的今天,我们对数据质量的评价也必须越来越系统、可靠。本文就是在系统分析的基础上推导出了求解外方位元素的误差传递模型,并从中分析了内定向误差对外方位元素精度的影响,从而改进和完善了外方位元素精度的评定方法,使得外方位元素精度的评定具有更高的精确性和可靠性。     

A comparison of TRMM to other basin-scale estimates of rainfall during the 1999 Hurricane Floyd flood

The volumetric rainfall attributed to Hurricane Floyd in 1999 was computed for the bulk of the Tar, Neuse, and Cape Fear River Basins in eastern North Carolina, USA from the Tropical Rainfall Measuring Mission (TRMM) Multi-Satellite Precipitation Analysis (TMPA) research product, and compared with volumes computed using kriged gauge data and one centrally located radar. TMPA showed similar features in the band of heaviest rainfall with kriged and radar data, but was higher in the basin-scale integrations. Furthermore, Floyd’s direct runoff volumes were computed and divided by the volumetric rainfall estimates to give runoff coefficients for the three basins. The TMPA, having the larger storm totals, would suggest greater infiltration during Floyd than the gauge and radar estimates would. Finally, we discuss a concept for adjusting the United States Department of Agriculture Natural Resources Conservation Service rainfall-runoff model when predicting discharge values from real-time TMPA in ungauged river basins.

菲律宾棉兰老岛2019年4次MW>6.0地震断层运动模型及库仑应力传输研究

基于雷达干涉测量技术,利用ALOS-2、Sentinel-1卫星升降轨雷达影像,获得2019-10~12发生在菲律宾棉兰老岛的4次M_W>6.0地震的同震形变场,并以此形变结果为约束,反演得到4次地震的断层运动模型。综合分析发现,此次地震序列由3条断裂的破裂引起,其中2019-10-16和2019-10-31的2次地震为同一发震断裂,2019-10-31地震断层破裂区域位于2019-10-16地震断层破裂的东北延伸段,最大滑动量约为1.1 m,约为2019-10-16地震最大滑动量的2倍。2019-10-29地震由一条独立断层破裂引起,断层最大滑动量约为2.0 m。2019-12-15地震由一条东北向倾斜断层破裂引起,断层最大滑动量约为3.0 m。此外,2019-10-16地震引起2019-10-29地震显著滑动区明显的正向库仑应力传输;而2019-10-29地震显著增加了2019-10-31地震震源区域的库仑应力;前3次地震对2019-12-15地震孕震断层的库仑应力传输总和为负值,说明静态库仑应力传输可能不是此次地震触发的主要诱因。     

Effect of Temperature on the Acoustic Reflection Characteristics of Seafloor Surface Sediments

Because the sound speeds of seawater and seafloor sediment both increase with temperature,the influence of tempera-ture on the bottom reflection characteristics of seafloor sediments needs to be investigated.Based on the calculation of the temperature-controlled experimental measurement data of typical seafloor surface sediment samples,the temperature-dependent acoustic characteristics,including acoustic impedance,acoustic impedance ratio between surface sediment and seawater,and reflection coefficient,were analyzed.The effective density fluid model was used to analyze and explain the reflection coefficient variation of surface sediments with temperature and predict the dispersion characteristics.Results show that the acoustic impedance of the seabed sediment increases with temperature,whereas the acoustic impedance ratio and acoustic reflection coefficient slightly decrease.The acoustic impedance,acoustic impedance ratio,and acoustic reflection coefficient of sandy,silty,and clayey sediments vary similarly with tem-perature variation.Moreover,the influence of temperature on these acoustic characteristics is independent of detection frequencies.     

The evolutionary status of HD 104237, ε Cha and HD 100546

Using the new data from Hipparcos and the TD-1 UV data, we fix the positions of three objects, HD 104237, HD 100546 and ε Cha in the HR diagram and discuss their theoretical evolutionary status.     

宽甸岩金预测区指示元素的优选

本文介绍了在宽甸无已知金矿床地区岩金预测工作中优选指示元素的思路。依据金矿地球化学理论,参考成矿带内已知金矿地球化学资料初选指示元素作为化学分析项目。化学分析结果出来后,编制地球化学图件时,考虑到减轻图幅负担和编图工作量,突出有用找矿信息,我们利用元素的变异性和致矿系数筛选出具有明显变异性和较高致矿性的元素,在此基础上利用元素间统计相关性和空间相关性,保留与成矿元素Au有明显相关性的元素,作为优选出的指示元素。