威海地区榴辉岩及其变质作用

威海地区榴辉岩位于秦岭大别苏北胶南巨型榴辉岩带的北东段。榴辉岩体大小悬殊,呈透镜状、不规则状、脉状及似层状等赋存在早元古代荆山岩群变质层状岩系、尖晶石橄榄透闪片岩及晚元古代片麻状花岗闪长岩、片麻状二长花岗岩中,并与围岩一起经受了后期的构造变形改造。榴辉岩退变分带的核部为榴辉岩,次外边为榴闪岩,最外边为斜长角闪岩或石榴斜长角闪岩。三个变质作用阶段的特征是：前榴辉相阶段为中压相系绿帘角闪岩相;榴辉岩相阶段为高压相系;榴辉岩退变质阶段相当于中压相系的角闪麻粒岩相—角闪岩相。变质作用ＰＴｔ轨迹呈顺时针方向。榴辉岩形成于９００Ｍａ左右。     

基于常规炮检距地震数据预测黄陵矿区煤层气富集区

常规AVO技术预测煤层气,一般需要炮检距大于1.5倍煤层埋深。通过对黄陵矿区常规地震数据进行AVO异常分析,发现黄陵矿区具备明显煤层气AVO异常,而且在最大偏移距为煤层埋度1.11倍、入折射平均角为29°左右时,该区二号煤层顶板反射界面反射系数对入折射平均角的梯度达到最大值(0.1680)。由此认为叠前地震资料的最大偏移距只要接近、等于或略大于目的层深度,就足以反映振幅随偏移距的变化特征,即足以满足该区煤层气AVO反演对地震资料偏移距的要求。通过对常规地震资料的精细处理,对该区煤层富集区进行预测。黄陵矿区AVO异常解释主要基于垂直反演剖面和顺层反演切片,以此圈出约1.6km2、呈近南北向条带状分布的煤层气(瓦斯)富集区。截至2013年底,在生产巷道掘进过程中,已发现14处瓦斯涌出点与预测结果一致。     

Geochemistry of a continental saline aquifer for CO2 sequestration: The Guantao formation in the Bohai Bay Basin,North China

The Neogene Guantao formation in the Beitang sag in the Bohai Bay Basin (BBB) of North China, a Mesozoic–Cenozoic sedimentary basin of continental origin, has been chosen as a candidate for a pilot field test of CO₂ sequestration. Hydrogeological and geochemical investigations have been carried out to assess its suitability, taking advantage of many existing geothermal wells drilled to 2000 m or greater depths. Water samples from 25 wells and drill cores of three sections of the Guantao formation were collected for measurements of mineralogy, water chemistry and isotopes (δ¹⁸O, δD, δ¹³C, ¹⁴C). Formation temperature estimated by chemical geothermometry is in the range of 60–80 °C. Geochemical modeling of water–rock–CO₂ interaction predicts a strong geochemical response to CO₂ injection. Besides the elevated porosity (33.6–38.7%) and high permeability (1150–1980 mD) of the Ng-III formation and a favorable reservoir–caprock combination, it is also found that the formation contains carbonates that will react with CO₂ after injection. The low salinity (TDS < 1.6 g/L) offers high CO₂ solubility. The ¹⁴C age of the formation water indicates a quasi-closed saline aquifer system over large time scales, the lateral sealing mechanism for CO₂ sequestration requires further investigation. The CO₂ storage capacity of the Guantao formation within the Beitang sag is estimated to be 17.03 Mt, assuming pure solubility trapping.     

东北冷涡的结构及其演变特征的个例综合分析

利用NCEP再分析资料、FY-2C、CloudSat云探测卫星和实况观测等资料对2009年6月27—30日出现的东北冷涡的热力动力结构、三维流场和云系演变特征进行了分析,并初步探讨了冷涡的发生、发展机理。结果表明:该冷涡冷心结构最初始于高层,随后逐渐向下伸展。成熟阶段的冷涡,对流层整层为冷心结构,冷中心位于对流层中高层,其上即平流层低层为暖心结构,中心东西两侧上升气流随高度向外倾斜,经向风趋于对称。发展初期温度槽落后于高度槽,且轴线向西倾斜,斜压性特征明显;至成熟阶段,温度中心与高度中心趋于重合,轴线近于竖直,显示出正压的特征;到减弱阶段,由于低层偏北风减弱明显,轴线又略向西倾斜。冷涡云带的产生与低层辐合带密切相关。CloudSat云探测卫星资料分析结果表明,冷涡环流内多中小尺度对流云团发展,且分布极不均匀。此次个例的研究结果揭示出冷涡的形成和发展跟对流层中上层切断低压的生成发展与对应的地面低压逐步耦合的动力学过程紧密相关,其中,冷暖气流呈旋转式下沉和上升,在冷涡中心形成偶极;对流层高层的干冷空气总是沿着等熵面从高层穿越等压面向下侵入到冷涡中心附近,干侵入使冷涡加强发展并维持其冷心结构。干侵入机制实际就是高位涡的侵入和下传,对预报冷涡的发展演变具有重要指示意义。     

冬季高海拔复杂地形下GRAPES Meso要素预报的检验评估

利用GRAPES(Globe/Regional Assimilation and Prediction System)对2010年温哥华奥运会6个场馆气温、相对湿度、风及降水量的预报结果,采用预报准确率、平均误差、平均绝对误差、Alpha Index、TS和ETS评分等统计量对其进行了较详细的评估。结果表明:GRAPESMeso预报相对湿度的准确率最高,且随预报时效的增加,其变化趋于稳定。起初模式对相对湿度的预报偏干,之后逐渐变为预报偏湿;气温预报偏低;风速预报偏大。逐日各要素预报检验结果表明,气温的变化幅度最小;各级降水检验发现,晴雨预报的TS评分最高,且随降水增大,ETS评分逐渐接近TS。与其他模式预报结果对比发现,GRAPES-Meso对复杂地形下要素预报还存在一定的不足。本研究还发现,模式存在一定的系统误差,若能有效订正其误差,将有助于改进模式预报。     

松辽盆地北部葡萄花油层隐蔽油气藏分布规律

松辽盆地北部姚家组一段中的古土壤层可作为层序地层划分的依据.在姚家组一段中识别出3个不整合面,由盆地边缘向中心分别以河流侵蚀面-古土壤层-强烈生物作用面为标志,其下部为进积型的低位体系域三角洲砂质沉积,中部为退积型的水侵体系域三角洲砂质沉积,顶部为以泥质岩为主的加积型高水位体系域平原淤积相沉积,构成了完整的储盖组合.本文建屯了受平缓坡折控制平坦古地貌背景下的大型陆相坳陷盆地层序地层学模式,认为坡折带控制岩性油藏分布,坡折带以下广泛分布的三角洲砂体成为大面积岩性油藏储集体.坡折带附近的近源区发育多层位三角洲砂岩复合体,形成了多层、厚层岩性油藏,远离坡折带的远源区分布着大面积的三角洲外前缘砂体,可形成砂岩透镜体岩性油藏和上倾尖灭岩性油藏.     

欧洲地区不同温室气体背景下土地利用/覆盖变化的气候效应

通过温室气体排放和土地利用/覆盖变化,人类活动对气候变化产生显著影响。为了探究在不同温室气体浓度（Greenhouse gas concentration,GHG）背景下,相同的土地利用/覆盖变化（Land Use and Land Cover Change,LULCC）对于欧洲区域气候的影响差异,采用CESM（Community Earth System Model）耦合模式进行了模拟研究。研究发现,在1850年温室气体浓度背景下,土地利用/覆盖变化导致欧洲中东部地区降水显著增加,而在2000年温室气体浓度背景下,土地利用/覆盖变化导致欧洲中东部地区降水减少。温室气体增加后,LULCC导致该地区对流层低层大气环流由辐合变为辐散,气温以及大气水汽含量降低,这些变化能较大程度的改变LULCC对区域降水的净影响力。     

Physiological Effect onHylocereus undulatusandHylocereus undatus under Simulated Karst Soil Water Deficiency

Dragon fruit (Hylocereus undulates) was planted in a large area of karst region in recent years. To understand whether karst drought may impact on its physiological process is important and useful for planning and management of this fruit. In this study, we contrasted with a relative species Hylocereus undatus, and set up experiment to study physiological and biochemical trait and its response to different karst soil water level deficiency, so as to understand the mechanism of H. undulates and H. undatus in adaptation to karst drought condition. The results showed that, trends of physiological and biochemical response to drought was similar between two species. With the intensive of soil water deficiency, such toxin substance as malonaldehyde (MDA) increased, but meanwhile, two protective enzymes superoxide dismutase (SOD) and peroxidases (POD) and osmotic adjustment Proline (Pro) increase as well. Under relative water content (RWC) >50% condition, the enzyme can effectively protect the cells from toxin MDA injure, and Pro can also maintain the water needs through osmotic adjustment. However, under RWC < 40% condition, protective enzymes were not enough for cleaning MDA. Biomass was largest under RWC=70%–80%, with low root shoot ratio and high aboveground biomass. Biomass significantly decreased under RWC 30%–40%, which decline by 73.28% and 73.56% in H. undulates and H. undatus respectively. Therefore, RWC=70%–80% would be an optimal soil moisture while developing dragon fruit in karst, which is favor to fruit production. Under moderate drought e.g. RWC=50%–60%, plants may regulate by metabolic process and balance unfavorable substance, but it allocated much more biomass to root, reduced the aboveground biomass, which is not advance for fruit production.     

喀斯特湿地水葫芦(Eichhornia crassipes)生长及表型可塑性特征对不同富营养化水体的响应

选择桂林会仙喀斯特湿地,以不同富营养化水体中生长时期为6月(生长旺盛期)和8月(暴发高峰期)的水葫芦(Eichhornia crassipes)为研究对象,探讨不同富营养化条件下水葫芦的生长及表型可塑性响应特征,以揭示水葫芦对不同富营养化水体的生态适应机制.结果表明:水葫芦的株高、根长和叶绿素含量均随水体富营养化程度的增加而降低,叶柄数、叶柄宽、叶片数、叶长、叶宽、匍匐茎数和分株速率随着水体富营养化程度的增加而升高;各性状参数在暴发高峰期均略高于生长旺盛期;根生物量、茎生物量、叶生物量和总生物量均随水体富营养化程度的加深而增加,茎生物量高于根生物量和叶生物量;水葫芦生物量的分配以及性状间的权衡关系(根生物量比、茎生物量比、叶生物量比和茎叶比等)因生长时期的不同而呈现差异性,表现出较强的表型可塑性特征;水体总有机碳、总氮、总磷、硝态氮、氨氮和叶绿素a浓度分别与水葫芦的茎生物量、叶宽、匍匐茎数和分株速率间存在显著的正相关关系,与根长、株高、叶生物量比和茎叶比间存在显著的负相关关系;水葫芦的表型可塑性指数在0.009~0.792之间,叶重比的可塑性指数最大,根冠比最小,重度富营养化水体下的可塑性指数最大.在会仙喀斯特湿地不同富营养化水体环境中,水葫芦通过外部形态结构调节和生物量的配比关系,产生了有利于其入侵和存活的较强的表型可塑性,是其生存繁殖的重要响应机制之一.     

Relative impacts of increased greenhouse gas concentrations and land cover change on the surface climate in arid and semi-arid regions of China

Four dynamical downscaling simulations are performed with different combinations of land cover maps and greenhouse gas (GHG) levels using the Weather Research and Forecasting (WRF) model nested in the Community Earth System (CESM) model. A pseudo-global warming downscaling method is used to effectively separate the anthropogenic signals from the internal noises of climate models. Based on these simulations, we investigate the impacts of anthropogenic increase in GHG concentrations and land use and land cover change (LULCC) on mean climate and extreme events in the arid and semi-arid regions of China. The results suggest that increased GHG concentrations lead to significant increases in the surface air temperature at 2 m height (T2m) by 1–1.5 °C and greater increase in the warm day temperature (TX90p) than the cold day temperature (TX10p) in the arid and semi-arid regions. Moreover, precipitation increases by 30–50% in the arid region in cold season (November to March) due to the GHG-induced increase in moisture recycling rate and precipitation efficiency. LULCC leads to significant decreases in the T2m, TX90p, and TX10p by approximately 0.3 °C. The regional LULCC accounts for 66 and 68% decrease in T2m in warm and cold seasons, respectively. The rest changes in T2m results from the changes in lateral boundary condition induced by the global LULCC. In response to LULCC, both the warm and cold day temperatures show a significant decrease in cold seasons, which primarily results from the regional LULCC. LULCC-induced changes in precipitation are generally weak in the arid and semi-arid regions of China.