白云凹陷第三系储层中铁白云石的成因机理及与CO2活动的关系     

庞江  罗静兰  马永坤  蔡国富  雷川  李弛  李晓艳  张月霞 《地质学报》2019,93(3):724-737

白云凹陷第三系储层中发育大量的铁白云石,受研究区热流背景的影响,铁白云石主要见于高地温梯度地区埋深1000～3000m、地层温度60～130℃的浅—中部地层中及CO_2热流体活动区域。铁白云石的δ~(13)C值(-2.83‰～-1.83‰)具有无机成因的特征,与研究区气藏中幔源岩浆成因CO_2的δ~(13)C值较为一致,铁白云石的δ~(18)O值(-9.45‰～-5.37‰)和~(87)Sr/~(86)Sr值(0.7101～0.7161)也反映了其沉淀受到深部热流体活动的影响。以两口典型CO_2气井为例,储层中流体包裹体均一温度及蒙脱石向伊利石的演化特征证明储层经历了热流体侵入;CO_2热流体活动区域不仅是铁白云石集中分布地带,并出现片钠铝石+铁白云石+菱铁矿等示踪CO_2运移、聚集的自生矿物组合。地层中铁白云石、高岭石含量与气藏中CO_2的含量呈正相关关系,绿泥石含量与CO_2、铁白云石含量呈反消长关系。高地温梯度地区丰富的CO_2热流体活动是该地区储层中铁白云石沉淀与含量高的重要原因,无机岩浆成因CO_2是铁白云石沉淀的主要碳源,CO_2热流体充注造成绿泥石等黏土矿物异常转化,为铁白云石沉淀提供了所需的Fe~(2+)、Mg~(2+)离子。  相似文献   

Study on wetting deformation characteristics of coarse granular materials and its simulation in core-wall rockfill dams     

Xiongxiong Zhou  Shichun Chi  Maohua Wang  Yufeng Jia 《国际地质力学数值与分析法杂志》2020,44(6):851-873

The wetting deformation of coarse granular materials is often considered to be an important cause of the core wall rockfill dam cracks during impounding. By analyzing existing research results, this paper proposes a hyperbolic relationship between the wetting axial strain and wetting stress level and puts forwards a warped surface relationship among spherical stress, shear stress, and the ratio of wetting volumetric strain to wetting axial strain. To illustrate its practicability, the wetting strain model's parameter determination process is introduced and the rockfill materials wetting parameters are determined using the triaxial wetting test data. Moreover, the collapse settlement of Guanyinyan rockfill dam during first impounding is numerically simulated using the proposed method to calculate rockfill wetting deformation and verified by field measurements and monitoring data. The results show that the calculative method of wetting deformation proposed in this paper is reasonable and practical; the wetting deformation of upstream rockfill materials would cause an adverse deformation trend, which may lead to crack occurrence at the upstream slope and dam crest; and the Guanyinyan rockfill dam cracks on the top of junction mainly caused by the wetting deformation of upstream rockfill.  相似文献   

Performance of the CMA-GD Model in Predicting Wind Speed at Wind Farms in Hubei, China     

许沛华  成驰  王文  陈正洪  钟水新  张艳霞 《热带气象学报(英文版)》2023,29(4):473-481

This study assesses the predictive capabilities of the CMA-GD model for wind speed prediction in two wind farms located in Hubei Province, China. The observed wind speeds at the height of 70m in wind turbines of two wind farms in Suizhou serve as the actual observation data for comparison and testing. At the same time, the wind speed predicted by the EC model is also included for comparative analysis. The results indicate that the CMA-GD model performs better than the EC model in Wind Farm A. Th...  相似文献   

创新资源协同空间联系与区域经济增长——基于中国省域数据的实证分析   总被引：2，自引：1，他引：1  

吕海萍  池仁勇  化祥雨 《地理科学》2017,37(11):1649-1658

以中国31个省域为空间样本,运用趋势面、引力模型和探索性空间数据分析法研究中国创新资源协同空间联系的动态变化特征,通过构建创新资源协同势能与区域经济增长空间面板计量模型,实证探讨创新资源协同空间联系与区域经济增长关系。研究结果表明：2003~2014年中国各省域创新资源协同状况整体呈现“东南高,西北低”的空间分布特征;创新资源协同空间联系呈现显著的区域不平衡性,空间网络结构分布格局变化显著：从简单雏形逐渐发育为“鸡爪型”、多核心复杂化的“网络型”空间结构;创新资源协同势能呈现显著的空间正相关,主要向东部沿海地区集聚;实证结果显示中国区域经济增长存在显著的空间溢出效应,创新资源协同空间联系对区域经济增长表现出显著的促进效应,可以通过直接效应、间接效应和总效应空间溢出促进区域经济增长。  相似文献   

经济地理学新的思维范畴   总被引：8，自引：0，他引：8  

姚士谋  管驰明  范宇 《地球科学进展》2001,16(4):473-477

全球经济一体化与信息时代的到来，给经济地理学带来了新的变化，加之实践的检验，经济地理学由过去那些“区位论”，“生产布局”相应地发展到空间理论和信息理论，重在分析机制因素，时空的变化也更加深刻了，本学科比较综合，具有广阔的区域空间，复杂的内涵 ，其学科的创新在于在时空耦合度上使经济和社会同人口，资源，生态环境之间保持和谐，高效优化有序的发展，逐步建立具有我国特色的资源节约型的社会经济消费体系。着重分析了经济地理学新的思维范畴与研究趋势，强调用科学方法来检验以前的结论，用统计方法（层面分析）来解释数量关系，用GIS的分析法来印证空间布局的合理性。  相似文献   

地震灾害死亡人口快速评估方法对比研究   总被引：1，自引：0，他引：1  

王曦  周洪建  张弛 《地理科学》2018,38(2):314-320

中国是世界上地震活动最为频繁的国家之一,属于地震多发区。在收集分析国内外关于地震灾害死亡人口评估模型的基础上,选取10种模型以2000年以来中国典型地震灾害为案例验证其适用性。结果表明：① 对于5.7级（含）以下地震,10种模型的评估结果基本都在合理范围内,可采用各评估结果的区间值来支撑应急决策;5.7~6.6级（含）地震,10种评估方法得到的结果表现出不同程度的偏差,可采用多数评估结果指向的死亡人口数量级来支撑应急决策;6.6级以上地震,则只能采用有特定适用范围的基于结构易损性的评估结果来支撑应急决策,且也存在较大的不确定性。② 从地震灾害人员伤亡动态评估方法、地震—地质灾害死亡人口快速评估方法和快速评估软件系统方面进行了相关讨论。此研究可为地震灾害死亡人口快速评估模型的改进与发展提供借鉴。  相似文献   

Village-level multidimensional poverty measurement in China: Where and how   总被引：2，自引：2，他引：0  

Yanhui Wang  Yefeng Chen  Yao Chi  Wenji Zhao  Zhuowei Hu  Fuzhou Duan 《地理学报(英文版)》2018,28(10):1444-1466

Village is an important implementation unit of national poverty alleviation and development strategies of rural China, and identifying the poverty degree, poverty type and poverty contributing factors of each poverty-stricken village is the precondition and guarantee of taking targeted measures in poverty alleviation strategies of China. To respond it, we construct a village-level multidimensional poverty measuring model, and use indicator contribution degree indices and linear regression method to explore poverty factors, while adopting Least Square Error (LSE) model and spatial econometric analysis model to identify the villages’ poverty types and poverty difference. The case study shows that: (1) Spatially, there is obvious territoriality in the distribution of poverty-stricken villages, and the poverty-stricken villages are concentrated in contiguous poverty-stricken areas. The areas with the highest VPI, in a descending order, are Gansu, Yunnan, Guizhou, Guangxi, Hunan, Qinghai, Sichuan, and Xinjiang. (2) The main factors contributing to the poverty of poverty-stricken villages in rural China include road construction, terrain type, frequency of natural disasters, per capita net income, labor force ratio, and cultural quality of labor force. The main causes of poverty include underdeveloped road construction conditions, frequent natural disasters, low level of income, and labor conditions. (3) Chinese poverty-stricken villages include six main subtypes, and most poverty-stricken villages are affected by multiple poverty-forming factors, reflected by a relatively high proportion of the three-factor dominant type, four-factor coordinative type, and five-factor combinative type. (4) There exist significant poverty differences in terms of geographical location and policy support, and the governments still need to carry out targeted poverty alleviation measures according to local conditions. The research can not only draw a macro overall poverty-reduction outline of impoverished villages in China, but also depict the specific poverty characteristics of each village, helping the government departments of poverty alleviation at all levels to mobilize all kinds of anti-poverty resources.  相似文献   

Comparison of a Manual and an Automated Tracking Method for Tibetan Plateau Vortices     

Julia CURIO  Yongren CHEN  Reinhard SCHIEMANN  ANDrew G.TURNER  Kai Chi WONG  Kevin HODGES  Yueqing LI 《大气科学进展》2018,35(8):965-980

Tibetan Plateau vortices(TPVs) are mesoscale cyclones originating over the Tibetan Plateau(TP) during the extended summer season(April–September).Most TPVs stay on the TP,but a small number can move off the TP to the east.TPVs are known to be one of the main precipitation-bearing systems on the TP and moving-off TPVs have been associated with heavy precipitation and flooding downstream of the TP(e.g.,in Sichuan province or over the Yangtze River Valley).Identifying and tracking TPVs is difficult because of their comparatively small horizontal extent(400–800 km) and the limited availability of soundings over the TP,which in turn constitutes a challenge for short-term predictions of TPV-related impacts and for the climatological study of TPVs.In this study,(i) manual tracking(MT) results using radiosonde data from a network over and downstream of the TP are compared with(ii) results obtained by an automated tracking(AT) algorithm applied to ERA-Interim data.Ten MT-TPV cases are selected based on method(i) and matched to and compared with the corresponding AT-TPVs identified with method(ii).Conversely,ten AT-TPVs are selected and compared with the corresponding MT-TPVs.In general,the comparison shows good results in cases where the underlying data are in good agreement,but considerable differences are also seen in some cases and explained in terms of differences in the tracking methods,data availability/coverage and disagreement between sounding and ERA-Interim data.Recommendations are given for future efforts in TPV detection and tracking,including in an operational weather forecasting context.  相似文献   

Acidity of Aerosols during Winter Heavy Haze Events in Beijing and Gucheng,China     

Xiyuan?Chi  Pengzhen?He  Zhuang?Jiang  Xiawei?Yu  Fange?Yue  Longquan?Wang  Bokun?Li  Hui?Kang  Cheng?Liu  Zhouqing?XieEmail author 《Acta Meteorologica Sinica》2018,32(1):14-25

We investigated the acidity and concentrations of water-soluble ions in PM_2.5 aerosol samples collected from an urban site in Beijing and a rural site in Gucheng, Hebei Province from November 2016 to January 2017 to gain an insight into the formation of secondary inorganic species. The average SO₄^2–, NO₃^–, and NH₄⁺ concentrations were 8.3, 12.5, and 14.1 μg m^–3, respectively, at the urban site and 14.0, 14.2, and 24.2 μg m^–3, respectively, at the rural site. The nitrogen and sulfur oxidation ratios in urban Beijing were correlated with relative humidity (with correlation coefficient r = 0.79 and 0.67, respectively) and the aerosol loadings. Based on a parameterization model, we found that the rate constant of the heterogeneous reactions for SO₂ on polluted days was about 10 times higher than that on clear days, suggesting that the heterogeneous reactions in the aerosol water played an essential role in haze events. The ISORROPIA II model was used to predict the aerosol pH, which had a mean (range) of 5.0 (4.9–5.2) and 5.3 (4.6–6.3) at the urban and rural site, respectively. Under the conditions with this predicted pH value, oxidation by dissolved NO₂ and the hydrolysis of N₂O₅ may be the major heterogeneous reactions forming SO₄^2– and NO₃^– in haze. We also analyzed the sensitivity of the aerosol pH to changes in the concentrations of SO₄^2–, NO₃^–, and NH₄⁺ under haze conditions. The aerosol pH was more sensitive to the SO₄^2– and NH₄⁺ concentrations with opposing trends, than to the NO₃^– concentrations. The sensitivity of the pH was relatively weak overall, which was attributed to the buffering effect of NH₃ partitioning.  相似文献   

地形对台风“海燕”暴雨增幅作用的观测与模拟     

郑艳  杨仁勇  程守长  蔡亲波  任福民 《气象科技》2018,46(6):1147-1153

1330号台风"海燕"过程影响海南岛的强降水落区和强降水极值点(毛感乡)均位于南部地区,利用海南省区域加密自动站、三亚多普勒雷达以及0.25°×0.25°ERA-interim再分析资料对强降水成因进行观测分析,应用WRF Ver3.1.1模式对"海燕"进行模拟试验。结果表明:(1)"海燕"从海南岛南部近海北上阶段,其外围的偏东风或偏南风与五指山、吊罗山形成向南开口的"厂"字形地形正交,加密自动站和多普勒雷达在五指山区及"厂"字形地形南侧均探测到多个β中尺度风向辐合切变线或气旋性辐合涡旋,毛感乡附近存在明显的风向辐合,地面辐合中心与小时雨量大值区基本吻合。(2)"厂"字形地形迎风坡的强迫抬升导致气流垂直速度增大,毛感乡附近存在的水平的β中尺度辐合切变和垂直的β中尺度环流,有利于边界层辐合和中高层辐散增强,降水显著增幅。(3)数值模拟的强降水落区和降水极值点与实况基本一致,极值雨量较实况偏小;地形对山区及山脉迎风(背风)坡的雨量增(减)幅作用明显;有地形时,在五指山区及"厂"字形地形南侧容易产生β中尺度风向辐合区。  相似文献