安徽省华北型石炭—二叠纪地层多重划分与对比

安徽省华北型石炭—二叠纪地层的划分与对比一直存在着不同的观点。在《中国地层指南及中国地层指南说明书》（2001）思想框架下,采用多重地层分类原则,对区内岩石地层、生物地层、年代地层和层序地层进行划分对比研究。岩石地层可划分为本溪组、太原组、山西组、下石盒子组、上石盒子组和孙家沟组,其中山西组和上石盒子组为主要含煤地层;在生物地层方面,建立2个组合带和5个植物组合带;区内石炭纪地层仅发育上石炭统,二叠纪地层齐全;区内石炭二叠系含煤地层划分为6个三级层序。通过多重地层划分与对比,突出了不同地层单位的属性特征,优化了区域等时地层格架,有助于煤炭资源的预测与评价。     

2006年12月至2007年2月T213与ECMWF及日本模式中期预报性能检验

针对2006年12月至2007年1月T213模式96小时中期数值预报产品进行了天气学检验,并与ECMWF、日本模式96小时预报性能做了对比分析。结果表明,T213、ECMWF、日本模式对亚洲中高纬度地区大尺度环流形势演变和重大调整过程均有较好的预报能力,因此对重大灾害性天气的预报有较好的指示意义。三种模式相比,ECMWF模式对西风指数、850hPa温度、南支槽东移的预报较为准确。     

滇池固化淤泥重塑土的重塑时机及强度恢复特性试验

采用无侧限抗压强度试验和直剪试验,从单轴抗压强度、黏聚力、内摩擦角的角度探求了淤泥固化土重塑时导致的强度折减和重塑后土的强度恢复特性,并分析了重塑前养护龄期（T_前）、重塑后养护龄期（T_后）、水泥掺灰比（a_c）的影响。试验结果表明,重塑时机的选择对淤泥固化土的强度折减程度有显著的影响：T_前越长,破碎过程带来的强度折减越严重,且大致满足a_c越大、强度折减越严重的规律。从强度恢复特性来看：小水泥掺灰比的固化淤泥土经过T_后,其强度恢复较好;大掺灰比的重塑土其强度则较难恢复至固化土的水平,T_前越长,强度恢复越不利。从而得出了大掺灰比固化土宜早重塑,小掺灰比的重塑时间可适当延长的规律。     

Calcium Isotopic Fractionation and Compositions of Geochemical Reference Materials

High‐precision calcium isotopic compositions of a set of geological reference materials from the IAG (OU‐6), ANRT (UB‐N), MPI‐DING, USGS and GSJ, relative to NIST SRM 915a, are reported here. Measurements were performed by thermal ionisation mass spectrometry (Triton instrument) using a ⁴²Ca–⁴³Ca double spike. δ^44/40Ca values of selected reference materials, mainly felsic rocks, are reported for the first time. Felsic rock values of δ^44/40Ca ranged from 0.13‰ to 1.17‰, probably implying Ca isotopic fractionation could occur during magma evolution. δ^44/40Ca values of ultramafic rocks, ranging from 0.74‰ to 1.51‰, were positively correlated with MgO and negatively with CaO contents, possibly owing to Ca isotopic fractionation during partial melting. δ^44/40Ca of intermediate‐mafic rocks were around 0.78‰ and displayed limited variation, suggesting Ca isotopic fractionation is insignificant during magma evolution processes. As expected, δ^44/40Ca of sedimentary and metamorphic rocks varied widely due to complex geological processes.     

100hPa环流特征与2005年梅雨异常的关系

2005年7月5日入梅,7月14日出梅,入梅晚,梅雨期短,梅雨量少,致使我国主要雨带位置不是如常年一样维持在江淮流域,而是在江南地区南部和华南地区。使用NCEP再分析资料,分析了100hPa环流特征与梅雨异常的关系。结果表明,6月份江南地区南部和华南地区多雨时期,100hPa南亚高压中心基本停留在青藏高原南部地区上空,120°E上脊线位置大致在21～26°N之间摆动,较常年同期明显偏南。7月份,高压中心位置北抬,但不够稳定;120°E上脊线位置较6月份略偏北。6—7月期间,120°E上的100hPa南亚高压脊线位置比500hPa西北太平洋高压脊线位置基本偏北5个纬度左右,100hPa南亚高压东段脊线与500hPa副高脊线南北摆动趋势一致,100hPa南亚高压东段脊线北侧附近地区相应是暴雨区位置。     

Investigation of soil water hydrological process in the permafrost active layer using stable isotopes

Here, we studied the isotope characteristics and source contributions of soil water in the permafrost active layer by collecting soil samples in July 2018 in Yangtze River basin. Soil moisture and temperature showed decreasing trends from 0–80 cm, and an increasing trend from 80–100 cm. The value of δ¹⁸O and δD first increased and then decreased in the soil profile of 0–100 cm; however, d-excess increased from 0–100 cm. δ¹⁸O values became gradually positive from the southwest to northeast of the study area, while d-excess gradually increased from southeast to northwest. The evaporation water line (EL) was δD = 7.56 δ¹⁸O + 1.50 (R² = 0.90, p < 0.01, n = 96). Due to intense solar radiation and evaporation on the Tibetan Plateau, the elevation did not impact the surface soil. The altitude effect of the soil depths of 0–20 cm was not obvious, but the other soil layers had a significant altitude effect. Soil moisture and temperature were closely related to the stable isotopic composition of soil water. The contribution of precipitation to soil water on the sunny slope was 86%, while the contribution of the shady slope was 84%. However, the contribution of ground ice to soil water on sunny slope was 14% and the shady slope was 16%. The contribution of ground ice to soil water increased with increasing altitude on the sunny slope, but the contribution of ground ice to soil water had no obvious trend on the shady slope.     

Dirac quasinormal modes of the deformed Hořava-Lifshitz black hole spacetime

Using the third-order WKB approximation, we evaluate the quasinormal frequencies of massless Dirac field perturbation around a deformed black hole in the Hořava-Lifshitz gravity with coupling constant λ=1. Our result shows that the Hořava-Lifshitz parameter α plays an important role for the quasinormal frequencies and we discuss the variation of quasinormal frequencies with α. Moreover, we find that the massless Dirac field perturbations decay more slowly in the deformed Hořava-Lifshitz gravity.     

利用MAPGIS、GRAPHER软件绘制地形地质剖面图

利用地学中常用的Mapgis、Grapher等软件进行地形地质剖面图绘制,方便实用,提高绘制精度,并且其计算和操作过程非常直观。在地质工作中使用Grapher、Mapgis软件进行地质剖面绘制,可以方便进行地学分析,提高工作效率,取得良好的效果。     

铁矿石物相中磁性铁测试方法的改进

在传统的铁矿石物相分析中,磁性铁用盐酸溶解,有的样品溶解不完全,故而造成各单项加和低于全铁分析结果.笔者通过试验,发现用硫磷混酸或残渣碱熔能很好地分解磁性铁,使单项加和与全铁分析结果一致.