叠前深度偏移技术在城市活动断层探测中的优势

本文介绍了Kirchhoff积分法叠前深度偏移和波动方程叠前深度偏移两种偏移方法,并通过对Marmousi数据模型和实际数据资料处理,对比叠前深度偏移成像与叠后时间偏移成像和常规叠加剖面的应用效果。实际结果表明：对于速度横向变化剧烈的复杂地质体,叠前深度偏移成像精度更高,适合于城市活动断层的高精度探测。     

大型节事活动对旅游目的地形象影响的实证研究

以北京奥运会后旅京欧美游客为例,选取142份样本,利用Spss16.0,对研究模型及假设进行证明。结果表明,北京奥运会的成功举办对旅游目的地形象改善有显著影响;通过对旅游目的地形象具体项目进行分析,可知北京奥运会的成功举办对旅游目的地形象中的"国内交通便利"、"干净环境"、"节日庆典活动独特"、"接近性好"等项目影响最大,其后顺序为"适合休息的舒适氛围"、"住宿设施合适"、"安全"等。最后对作为旅游目的地的北京城市营销提出建议,并指出了今后的研究思路和方向。     

丹寨各乡镇洪涝灾害及降水的时空变化特征

利用2014—2020年丹寨地区6个乡镇洪涝灾情统计数据和21个区域气象自动站逐日降水资料,采用统计分析方法,分析洪涝灾害及降水的时空分布。结果表明：2014—2020年丹寨境内共出现24次洪涝灾害,2015年6月8日洪涝灾害最重,2020年洪涝灾害最多;从月分布来看,最多最重主要在6月,最少为4月,后半夜（00—03时）是洪涝多发时段;暴雨日数与洪涝灾害时空分布基本相似。受地形作用的影响,洪涝灾害具有季节性、局地性强,成灾率较高,日变化明显等特征;扬武镇、排调镇、雅灰乡出现暴雨和洪涝灾害相对较多,兴仁镇、南皋乡相对较少;中部以南的龙泉镇、排调镇、雅灰乡、扬武镇的洪涝灾害主要因夜间和持续性强降雨导致,而北部的南皋乡、兴仁镇的洪涝灾害主要因夜间强降雨导致。     

Treatment of Cr(VI) contaminated water with Pannonibacter phragmitetus BB

Pannonibacter phragmitetus BB was utilized to treat hexavalent chromium [Cr(VI)] contaminated water. Cr(VI) concentration of the contaminated water (pH 10.85) was 534 mg/L. With the inoculum size ranging from 1 to 20 %, P. phragmitetus BB completely reduced Cr(VI) within 27 h when the initial medium concentration exceeded 20 g/L. The lag time of bio-reduction by Cr(VI)-induced cells was 24 h, which was longer than the non-Cr(VI)-induced cells. Under the agitation condition, an obvious bio-reduction lag phase existed and Cr(VI) was completely reduced within 24 h. However, the lag phase was not observed under the static condition, Cr(VI) was reduced continuously after inoculation and Cr(VI) was completely reduced after 27 h incubation. The main chromium components after Cr(VI) reduction were Cr(OH)₃, Cr₂O₃ and CrCl₃. The results of this study are fundamentally significant to the application of P. phragmitetus BB in the treatment of Cr(VI) contaminated water.     

黄河流域非物质文化遗产的空间分异格局及其影响机制

以黄河流域9省区441个县域单元为研究区域,采用最邻近点指数、核密度估计、全局莫兰指数等方法分析黄河流域560项国家级非物质文化遗产的空间分布格局,并利用地理探测器的分异和交互作用探测影响因素与因子间的耦合互馈关系。结果表明：（1）黄河流域非遗空间分布地区差异显著。在区域分布上,中游非遗最多,下游非遗最少;在省域分布上,山西非遗最多,四川非遗最少;在县域分布上,菏泽市牡丹区非遗最多。（2）黄河流域非遗的最邻近指数为0.78,且置信度为99%,在空间分布上呈明显的集聚分布特征。（3）核密度呈集聚分布态势,形成“多核四带”的空间分布格局。（4）经济社会文化因素比自然因素的影响更显著,其中文化因素的博物馆和全国重点文物保护单位因子对非遗的空间分布影响最强,经济因素的人口、地区生产总值和城镇化水平因子较强,社会因素的交通和民族因子较弱,自然地理因素的地形地貌、气温、降水量因子的影响力整体最弱,因子间交互作用探测对非遗空间分布的影响解释力更强。     

青海共和盆地结构构造与能源资源潜力

共和盆地处于西秦岭、南祁连、东昆仑造山带结合部,其中发现了高温干热岩及多套烃源岩,但地热藏和油气藏的成因、资源潜力与分布规律尚不清楚,难以对其开展准确评价和有效勘探开发。本文在系统研究共和盆地及周缘地层发育、沉积充填、构造变形与盆地深部结构的基础上,深入探讨了盆地演化的动力学机制,分析了盆地地热藏和油气藏的成藏主控因素,预测了有利分布区带和勘探方向。多期活动的哇洪山—温泉、多禾茂、瓦里贡、塘格木右行走滑逆冲断裂与青海南山左行走滑逆冲断裂异向、同向相交(切),叠加地幔上涌作用,导致在中新生代共和盆地长期处于走滑-伸展的独特环境,并控制了盆地7个隆起、断陷构造单元的展布及属性。它经历了6期演化阶段：早中三叠世处于昆北弧前盆地及陆缘火山弧带,共和盆地基底主要岩石发育;晚三叠世阿尼玛卿洋闭合并发生碰撞造山,共和盆地褶皱基底形成;晚三叠纪末期发生碰撞后伸展,发育初始小型陆内裂谷盆地;在侏罗纪—白垩纪区域性伸展环境下形成局部断陷盆地;古近纪晚期—中新世发育拉分-断陷盆地;中新世末至今发育陆内前陆盆地。形成了3个大构造-沉积层序和8个亚层序,发育了深海陆棚相-碳酸盐岩台地相-火成岩相以及多旋回的冲积...     

Ambient Noise Tomography of Jinan: The Migration of Groundwater and the Formation of Geothermal Water

Jinan is an important city in eastern China, with rich groundwater in the region. There are four famous springs in the urban area and an abundance of geothermal water in the northern part, which makes the migration of groundwater in this area a very important issue. To study the shallow shear wave velocity structure and groundwater migration in Jinan, we utilized almost a month of continuous waveform data from 175 short period seismometers deployed by the Chinese Academy of Geological Sciences, in order to calculate the cross-correlation function. We picked 7749 group dispersion curves and 6117 phase dispersion curves with a period range of 0.2–2 s. Through inversion, we obtained the fine three-dimensional shear wave velocity and azimuthal anisotropy structure (0–2.4 km). Combining the results with local geological and hydrological data, the following conclusions were reached. (1) There are widespread high velocity anomalies in the region between the Qianfoshan and Wenhuaqiao faults, as well as to the east of the Wenhuaqiao Fault, which may be related to the intrusive gabbro known as the Jinan Intrusive Rock. (2) The two distinct high velocity anomalies in our model (referred to as west and east Jinan Intrusive Rock in this paper) may indicate that the Jinan Intrusive Rock was broken through crustal movement. (3) There is an obvious low velocity layer under the intrusive rock, which could be the channel of groundwater migration. The precipitation in the southern mountain region seeps down into the ground, then is blocked by the Jinan Intrusive Rock and can only progress downwards to a deeper part, where the groundwater is heated by the geothermal gradient. The heated water finally arrives at the northern part and forms geothermal water. (4) The depth of the low velocity layer beneath the Jinan Intrusive Rock varies laterally, which may indicate that the depth of the groundwater migration is different beneath the west and east Jinan Intrusive Rock. (5) There is strong azimuthal anisotropy in southern Jinan, with nearly E-W fast orientation, which may be related to the tilt limestone layering structure.     

Geochemistry and Petrogenesis of Late Cretaceous–Paleocene Granites from the Tengchong Block, Western Yunnan: Implications for Angle-switching of Subducting Slab

The Cenozoic geological hallmark of Western Yunnan is the characteristic voluminous Late Cretaceous-Eocene granites; however, their geological background and petrogenesis have not been well constrained and elucidated. In this study, we present new zircon U-Pb dating, along with geochemical and Sr-Nd-Hf isotopic data for granites from the Tengchong–Lianghe granitoid belt (as abbreviated to Tengliang belt) and West Yingjiang batholiths from the Tengchong block. The mineralogical and geochemical features of the Tengliang granites and the West Yingjiang batholiths are ascribed to aluminous S-type granites and weak peraluminous I-type, respectively. Zircon U-Pb analyses yielded consistent ages ranging from 67.5 Ma, 68.4 Ma and 66.2 Ma from the Tengliang granitoid belt and 50.4 Ma to 60.8 Ma for three samples from the west Yingjiang batholiths. The Tengliang granites were emplaced during the Late Cretaceous (68?66 Ma) and demonstrate negative εHf(t) values (?24 to ?4) and initial?87Sr/86Sr ratios of 0.7101–0.7139 and significant negative εNd(t) values from ?8.91 to ?13.2, indicating a Proterozoic sedimentary source or enriched components. The hornblende-bearing I-type granites from West Yingjiang are characterized by lower initial?87Sr/86Sr ratios of 0.7076–0.7106, compared to Tengliang granite and negative whole-rock εNd(t) values from ?4.0 to ?11.9. The early Eocene west Yingjiang gneissic granites show wide ranges of εHf(t) values from +7.4 to ?8.5 and T2DM of 1.30–0.65 Ga, indicating partial melting of ancient crust with contributions of depleted mantle materials. In combination with the regional background and previous studies, we propose that such a spatio-temporal distribution of the Tengchong granitoid belt might be related to the rollback or angle-switching of the Neo-Tethyan subducting slab. This study sheds new light on the evolutionary history of the Tengchong block.     

1979-2014年东北地区雪深时空变化与大气环流的关系

基于被动微波遥感反演的雪深数据集（1979-2014年）,利用Mann-Kendall检验、R/S分析、相关分析和小波分析等方法研究了东北地区雪深时空变化特征及其与大气环流的关系。结果表明：1979-2014年,东北地区年均雪深总体呈减小趋势,减小速率为-0.084 cm·（10a）^-1。其中,春季雪深减小速率最大,为-0.19 cm·（10a）^-1（P<0.05）,其次是冬季[-0.17 cm·（10a）^-1],而秋季雪深减小速率最小,仅为-0.05 cm·（10a）^-1。空间上,平原区（东北平原和三江平原）与少部分高原区（呼伦贝尔高原西南部）年均雪深呈增大趋势,山地（大、小兴安岭和长白山）与高原大部（内蒙古高原）雪深呈减小趋势,而且雪深增大区域的面积和变化速率均小于雪深减小的地区。东北地区年均雪深变化的Hurst指数为0.85,表明雪深未来减小的持续性很强;同时雪深变化具有22 a的主周期。春秋季雪深变化与东亚槽强度及北半球极涡面积呈显著负相关性,而冬季雪深与北半球副高强度关系密切。     

嫩江地区中晚加里东期区域变质岩系构造背景

按板块构造划分,嫩江地区位于兴蒙造山带东段兴安地块与松嫩地块交会部位,区内多期次的构造叠加作用强烈,是研究兴蒙造山带构造演化的关键地区之一。从研究区中晚加里东期区域变质岩系的区域地质背景着手,结合现有的区域地层和构造资料,对区内中晚加里东期区域变质岩系岩石学及地球化学特征、变质变形特征进行分析,通过野外地质产状和岩石共生组合的分析、变质作用及变质相的划分、构造环境判别等方法对区内中晚加里东期所经历的构造背景问题进行研究,认为研究区经历了弧后拉张→岛弧火山喷发沉积→弧后边缘海盆地伸展→弧后边缘盆地沉积的大地构造背景。区内中晚加里东期区域变质岩系的研究,对于重建嫩江地区加里东期构造背景具有重要意义。