含油岩石弹性特征及其与油气的关系

本文用准噶尔盆地东部油区58口井共2257块油气储层岩芯标本,在常温常压和模拟地下温度压力下对V_P/V_S及衰减系数进行了精确测量,结合密度、孔隙度及岩石学研究获得个同岩性地层含油、水、气不同流体的V_P/V_S比、泊松比及不同深度的速度校正曲线;用回归分析获得V_P-V_S,密度-速度,密度-孔隙度的相关关系式;用数学统计获得稠油地区岩芯砂岩的速度特征值;用AVO技术进行模型计算和实例验证.为油气碳氢检测,测井速度标定,声阻抗及演,模型正演等提供了有价值的数据.     

荒漠河岸胡杨(Populus euphratica)树干液流的时滞效应

以2012年4—9月树干液流速率与环境因子的实测数据,分析了荒漠河岸胡杨(Populus euphratica)树干液流的时滞效应。结果表明:不同月份胡杨树干液流速率对不同环境因子的时滞不同;4—9月,胡杨树干液流速率峰值时间比太阳辐射峰值时间晚约1h,比空气温度峰值时间早约1h,比水汽压差峰值时间早约2h,比空气相对湿度谷值时间早约2h;对影响胡杨树干液流速率的环境因子进行了主成分分析,发现胡杨树干液流速率与1h以前的第1主成分、第2主成分相关性最高,相关系数分别为0.864、0.875;对错位前后胡杨树干液流速率与环境因子进行多元线性回归分析发现,在胡杨树干液流的数值模拟中,考虑液流相对于环境因子的时滞效应可以提高模型的拟合精度。     

青海表土花粉分布规律及其与植被的关系

对青海地区63个样点进行植被调查及表土样点分析结果显示:青海地区山地针叶林、针阔混交林、高山灌丛-灌丛草甸、温带草原、灌木-半灌木荒漠及高寒荒漠植被区均有相对独特的花粉组合特征。乔木类中桦呈超代表性,云杉、柏、杨属呈低代表性;灌木、草本中白刺、沙拐枣、柽柳呈低代表性,蒿、藜、麻黄呈超代表性,蔷薇科金露梅、银露梅在自身为优势种的落叶灌丛群落中呈低代表性,在针阔叶林、灌丛草甸过渡带中呈适中代表性。禾本科、莎草科、菊科、豆科、十字花科呈低代表性。A/C值在不同生态环境下的变化幅度较大,但数据组显示A/C值中位数值由半干旱向干旱植被区逐次降低,如草甸和草原为4.14,高山灌丛为2.93,荒漠草原为1.22,荒漠灌丛为0.13,荒漠戈壁为0.05。可见,A/C值能很好地反映环境干湿程度,是环境干旱程度的良好指标。     

长三角房价收入比时空演变格局及收敛性研究

房价收入比是衡量房地产健康状况和探测居民住房支付能力的重要指标。以2008—2018年长三角307个区县为研究单元,运用数值-位序法则和趋势面分析对房价收入比的总体分布特征进行探究,利用LISA时间路径分析房价收入比的时空动态性特征,并检验区域房价收入比的收敛性。结果表明： ① 长三角房价收入比总体上呈上升趋势,空间上表现为东高西低、南高北低的格局,上海、浙江、江苏和安徽依次降低。② 上海和浙江南部房价收入比的空间结构更具动态性,而江苏和安徽更加稳定;长三角房价收入比的空间演化整体上具有较强的空间锁定效应和空间整合性。③ 长三角区县房价收入比整体上不存在σ收敛,但各时间段上均存在显著的绝对β收敛,且各省份内部也均存在着俱乐部收敛现象。城市群房价收入比的变动对居民的流动有着重要的指示作用,并具有扩散效应和虹吸效应。加强城市群房地产市场一体化建设,是促进城市群区域一体化发展的有效途径。     

Comparison of conceptual landscape metrics to define hillslope-scale sediment delivery ratio

The aim of this study was to evaluate four metrics to define the spatially variable (regionalised) hillslope sediment delivery ratio (HSDR). A catchment model that accounted for gully and streambank erosion and floodplain deposition was used to isolate the effects of hillslope gross erosion and hillslope delivery from other landscape processes. The analysis was carried out at the subcatchment (~ 40 km²) and the cell scale (400 m²) in the Avon-Richardson catchment (3300 km²), south-east Australia. The four landscape metrics selected for the study were based on sediment travel time, sediment transport capacity, flux connectivity, and residence time. Model configurations with spatially-constant or regionalised HSDR were calibrated against sediment yield measured at five gauging stations. The impact of using regionalised HSDR was evaluated in terms of improved model performance against measured sediment yields in a nested monitoring network, the complexity and data requirements of the metric, and the resulting spatial relationship between hillslope erosion and landscape factors in the catchment and along hillslope transects. The introduction of a regionalised HSDR generally improved model predictions of specific sediment yields at the subcatchment scale, increasing model efficiency from 0.48 to > 0.6 in the best cases. However, the introduction of regionalised HSDR metrics at the cell scale did not improve model performance. The flux connectivity was the most promising metric because it showed the largest improvement in predicting specific sediment yields, was easy to implement, was scale-independent and its formulation was consistent with sedimentological connectivity concepts. These properties make the flux connectivity metric preferable for applications to catchments where climatic conditions can be considered homogeneous, i.e. in small-medium sized basins (up to approximately 3000 km² for Australian conditions, with the Avon-Richardson catchment being at the upper boundary). The residence time metric improved model assessment of sediment yields and enabled accounting for climatic variability on sediment delivery, but at the cost of greater complexity and data requirements; this metric might be more suitable for application in catchments with important climatic gradients, i.e. large basins and at the regional scale. The application of a regionalised HSDR metric did not increase data or computational requirements substantially, and is recommended to improve assessment of hillslope erosion in empirical, semi-lumped erosion modelling applications. However, more research is needed to assess the quality of spatial patterns of erosion depicted by the different landscape metrics.     

A sedimentary record of the rise and fall of the metal industry in Bergslagen,south central Sweden

Detailed stratigraphic analyses of sediments deposited in Lake Botjärnen, a small boreal forest lake in the shield terrain of central Sweden, clearly reflect progressively increasing human impact on terrestrial and aquatic ecosystems following settlement and establishment of an iron industry in the 17th century. Rising frequencies of pollen and spores from light-demanding plants provide evidence of extensive forest clearance for charcoal and timber production, which peaked in the early 20th century. An associated increase in catchment erosion is reflected by changing carbon and nitrogen elemental content and carbon–isotope composition of sediment organic matter and by increased magnetic susceptibility of the sediments. Records of air-borne pollutants (lead, zinc and sulphur) can be correlated to the development of local and regional mining and metal industry as inferred from historical accounts. Rapid recession of the iron industry led to re-forestation and recovery of the aquatic nutrient status to pre-industrial conditions over the past 100 years. The chronology of the sediment succession, which is based on ²¹⁰Pb and ¹³⁷Cs radionuclide data in combination with radiocarbon dating, is confirmed by historical lead pollution trends established for the region.     

基于线粒体Cytb基因的10种石珊瑚的系统发育关系

通过PCR扩增直接测序得到10种徐闻石珊瑚线粒体Cyt b基因部分序列,分析其碱基组成和变异频率,并采用Neighbor-Joining和Maximum Parsimony法构建系统发育树。结果显示:序列中A+T比例为61.0%,G+C比例为39.0%,前者明显高于后者,碱基替换主要发生在密码子第3位;滨珊瑚科分类与传统分类存在一定差异,揭示传统形态学分类可能受珊瑚骨骼生长可塑性限制,造成分类不准确;刺柄珊瑚属与蜂巢珊瑚科各属亲缘关系较近。     

A 16 ka climate record deduced from δ^13C and C/N ratio in Qinghai Lake sediments, northeastern Tibetan Plateau

1 INTRODUCTION δ13C in organic matters from lacustrine sedi- ments varies with several factors including aquatic plants, vegetation type in the catchment, atmos- pheric CO2 concentration, climate (temperature and precipitation), and properties of water, …