金沙江流域泥石流的组合赋权法危险度评价   总被引：7，自引：0，他引：7  

张晨  王清  陈剑平  谷复光  张文 《岩土力学》2011,32(3):831-836

针对目前地质灾害危险性评价中对指标权重确定方法的缺陷,使用改进的层次分析法和熵值法确定金沙江流域泥石流的各影响因素权重。在此基础上,提出一种新的组合赋权规则,使两类权重间的差异程度和分配系数间的差异程度相一致,从而排除人为因素及数据奇异点的影响,得到相对客观准确的结果。以金沙江的典型泥石流作为计算实例,对现场数据进行了提取之后,使用上述方法计算出影响因子的权重,将权重代入经典的危险性分析模型进行评估。计算结果与当地泥石流的实际情况和发展趋势相符合,从而证明了该方法的合理性。  相似文献   

南海表层沉积物中细粒组分的稀土元素地球化学特征     

刘建国  陈忠  颜文  陈木宏  殷学博 《地球科学》2010,35(4):563-571

对南海表层沉积物中的细粒组分进行电感耦合等离子体质谱法测试, 探讨南海稀土元素分布特征及其影响因素.结果表明, 南海表层沉积物中稀土元素分布主要与陆源物质输入、生物活动和火山物质补给密切相关.南海细粒组分的配分模式与中国黄土的接近, 与周边的珠江、湄公河等河流输入物质也有相似性, 而与南海碱性玄武岩存在显著差异, 表明南海沉积物主要来自于周边大陆.稀土元素趋势分析表明, 珠江口往外至海南岛南部海域中沉积物朝东南方向向陆坡输送; 台西南至珠江口往外海域沉积物大多向南输运; 吕宋岛西部海域包括黄岩岛附近海域的火山物质主要向西北方向输送, 向西可达113°E、向北可至20°N附近; 南海南部沉积物整体上向南沙海槽西北部附近海域输送.   相似文献   

地质构造复杂程度定量化评价——以涡北煤矿为例   总被引：1，自引：0，他引：1  

舒建生  贾建称  王跃忠  宫文 《煤田地质与勘探》2010,38(6):22-26

针对涡北煤矿地质构造严重影响煤矿生产问题,通过分析矿井断层发育特征和展布规律,综合断层发育特征、沉积介质和经济技术3方面的因素,建立了矿井构造评价指标模型;采用灰色关联分析方法和等性块段综合指数评价方法,对矿井构造复杂程度作出了定量化综合评价和分类。结果表明,所得评价结果可靠,与矿井揭露基本符合,可为矿井生产提供指导性参考依据。   相似文献   

仰坡坡度对隧道洞口段动力响应的影响分析          下载免费PDF全文

王丽丽  吴志坚  梁庆国  孙文  王会娟 《地震工程学报》2016,38(4):519-524

采用动力有限元数值模拟的方法,设置四种不同仰坡坡度的模型,沿隧道轴向方向输入地震波,探究隧道洞口段及仰坡在不同仰坡坡度影响下的动力响应,并通过对无隧道通过的纯边坡模型与相同条件下有隧道通过的边坡模型的动力响应进行对比分析,研究隧道的存在对坡面动力响应的影响。研究结果表明:(1)由于临空面的存在,隧道洞口段的位移与加速度具有明显的放大效应。不同坡度模型的位移峰值皆位于y=0m断面的拱顶处,在距洞口y=40m后的各控制点位移差值迅速减小。(2)随着仰坡坡度的增加,同一断面处隧道的位移值随之增加,洞口段的截面变形也随之增大。(3)当坡度α≥60°时,坡面位移随着坡面高程的增加而增大;当坡度α60°时,坡面位移随着坡面高程的增加先增大后减小,在0.4~0.6倍坡高处达到最大,即随着坡度的增加,坡面的位移峰值也就越靠近坡顶。(4)隧道的存在对于坡面的稳定性有重要影响,这种影响在洞口附近尤为明显。  相似文献   

肾上皮样血管平滑肌脂肪瘤影像表现及病理对照          下载免费PDF全文

张福康  梁文  陈菲菲  全显跃  刘真喜 《CT理论与应用研究》2016,25(1):119-128

目的:探讨肾上皮样血管平滑肌脂肪瘤(EAML)的影像学特征及病理学特点,提高对该疾病的认识。材料和方法:回顾性分析2008年1月至2014年4月间本院7例经手术病理证实为肾脏EAML的影像学表现及病理特点。结果:7个病例8个病灶,其中5个病灶部分突出肾轮廓外,2个病灶突入肾窦,1个病灶同时突出肾轮廓外及肾窦;CT平扫3例呈稍高密度,2例呈等密度,1例MRI呈稍长T1短T2;增强扫描2例病灶呈“快进快出”,2例呈“快进慢出”;5例见“皮质掀起征”,5例见“黑星征”,其中4例同时出现“皮质掀起征”及“黑星征”;2例病理有恶性表现。组织学表现:肿瘤主要由上皮样细胞、平滑肌、厚壁血管及脂肪组成。免疫组化:常表达肿瘤细胞S-100、瘤细胞Vim、HMB-45、HHF-35及CD34。结论:肾上皮样血管平滑肌脂肪瘤的影像学表现多样化,影像学表现难与其他疾病相鉴别,当肿瘤部分突出肾轮廓外或向肾窦内生长,CT平扫密度呈稍高或等密度应考虑有EAML可能。   相似文献   

尼泊尔Ms8.1级地震中国西藏地区地震震害特征分析     

高锦瑞  尼玛  文升梁  张建龙 《中国地震研究》2016,30(2):271-280

2015年4月25日尼泊尔发生Ms8.1级地震,对我国西藏地区造成较大人员伤亡与房屋破坏,道路、通讯等生命线工程及水利等基础设施损坏严重。本文介绍了本次地震的基本情况,并在现场地震烈度调查和地震损失评估的基础上,对灾区震害情况进行了分析,给出了灾区房屋类别与破坏情况以及生命线系统与各行业的受损情况。通过分析此次地震的灾害特点,指出了灾区在抗震设防中存在的问题,最后提出应加大地震地质灾害的防治力度,科学编制恢复重建规划,加强防震减灾宣传,提高农牧民抗震设防意识,加强农牧区房屋建筑的指导和监管,减少地震人员伤亡和损失,促进西藏地区经济的和谐发展。  相似文献   

用浅层地震剖面研究大城东断裂的活动性   总被引：1，自引：0，他引：1  

温超  周月玲  彭远黔  孟立朋  冉志杰  王燕 《中国地震》2016,32(4):695-701

地震方法是针对厚覆盖区断裂的一种不可替代的探测技术,在大城东断裂上采用浅层地震探测方法,获得了2条高质量叠加时间剖面图以及深度剖面图,这些图像清晰地显示了大城东断裂的浅部构造特征以及活动特征。本次探测工作中,在大城东断裂的东侧发现了1条倾角较陡的断裂,表明大城东断裂是由2条断裂组成的断裂带。  相似文献   

Seismic dynamic monitoring in CO<Subscript>2</Subscript> flooding based on characterization of frequency-dependent velocity factor     

Jun-Hua Zhang  Jun Li  Wen Xiao  Ming-You Tan  Yun-Ying Zhang  Shi-Ling Cui  Zhi-Peng Qu 《应用地球物理》2016,13(2):307-314

The phase velocity of seismic waves varies with the propagation frequency, and thus frequency-dependent phenomena appear when CO₂ gas is injected into a reservoir. By dynamically considering these phenomena with reservoir conditions it is thus feasible to extract the frequency-dependent velocity factor with the aim of monitoring changes in the reservoir both before and after CO₂ injection. In the paper, we derive a quantitative expression for the frequency-dependent factor based on the Robinson seismic convolution model. In addition, an inversion equation with a frequency-dependent velocity factor is constructed, and a procedure is implemented using the following four processing steps: decomposition of the spectrum by generalized S transform, wavelet extraction of cross-well seismic traces, spectrum equalization processing, and an extraction method for frequency-dependent velocity factor based on the damped least-square algorithm. An attenuation layered model is then established based on changes in the Q value of the viscoelastic medium, and spectra of migration profiles from forward modeling are obtained and analyzed. Frequency-dependent factors are extracted and compared, and the effectiveness of the method is then verified using a synthetic data. The frequency-dependent velocity factor is finally applied to target processing and oil displacement monitoring based on real seismic data obtained before and after CO₂ injection in the G89 well block within Shengli oilfield. Profiles and slices of the frequency-dependent factor determine its ability to indicate differences in CO₂ flooding, and the predicting results are highly consistent with those of practical investigations within the well block.  相似文献   

The thermal history and uplift process of the Ouxidaban pluton in the South Tianshan orogen: Evidence from Ar-Ar and (U-Th)/He     

Bin Zhang  Wen Chen  JingBo Sun  Shun Yu  JiYuan Yin  Jie Li  Yan Zhang  XinYu Liu  Li Yang  Xia Yuan 《中国科学:地球科学(英文版)》2016,59(2):349-361

The uplift and exhumation process in the Tianshan orogen since the late Paleozoic were likely related to the preservation of ore deposits. This study involved reconstructing the whole tectonic thermal history of the Ouxidaban pluton in central South Tianshan Mountains based on hornblende/plagioclase Ar-Ar and zircon/apatite(U-Th)/He methods. The thermal history and uplift process of central South Tianshan Mountains since the late Paleozoic were analyzed according to the results of previous works and cooling/exhumation rate features. The hornblende yields a plateau age of 382.6±3.6 Ma, and the plagioclase yields a weighted mean age of 265.8±4.9 Ma. The Ouxidaban pluton yields weighted mean zircon(U-Th)/He age of 185.8±4.3 Ma and apatite(U-Th)/He age of 31.1±2.9 Ma, respectively. Five stages of tectonic thermal history of South Tianshan Mountains since the late Paleozoic could be discriminated by the cooling curve and modeling simulation:(1) from the latest Silurian to Late Devonian, the average cooling rate of the Ouxidaban pluton was 7.84°C/Ma;(2) from the Late Devonian to the latest Middle Permian, the average cooling rate was about 2.07°C/Ma;(3) from the latest Middle Permian to the middle Eocene, the cooling rate decreased to about 0.68°C/Ma, suggesting that the tectonic activity was gentle at this time;(4) a sudden increase of the cooling rate(5.00°C/Ma) and the exhumation rate(0.17 mm/a), and crustal exhumation of ~1.83 km indicated that the Ouxidaban pluton would suffer a rapid uplift event during the Eocene(~46?35 Ma);(5) since the middle Eocene, the rapid uplift was sustained, and the average cooling rate since then has been 1.14°C/Ma with an exhumation rate of about 0.04 mm/a and an exhumation thickness of 1.33 km. The strong uplift since the Cenozoic would be related to a far-field effect from the Indian and Eurasian plates' collision. However, it was hysteretic that the remote effect was observed in the Tianshan orogenic belt.  相似文献   

Industrial Wastewater COD Degradation Technology – Taiwan Solar Cell Plant          下载免费PDF全文

Kun‐Cheng Lai  Jet‐Chau Wen  Wei‐Ting Chen  Chiou‐Mei Chen  Shao‐Yang Huang  Shu‐Min Shen  Chi‐Min Shu 《洁净——土壤、空气、水》2016,44(4):333-338

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