西藏甲玛矿床南坑高分异Ⅰ型花岗斑岩及黑云母矿物学特征     

陈国良  张忠坤  孙渺  林彬  赫健  唐攀  格桑顿珠  苏贵喆  任绍渊  胡海涛 《矿物岩石地球化学通报》2021,40(2):411-424

高硅花岗岩对于理解浅部岩浆房的行为具有重要意义。本文对西藏甲玛矿区南坑矿段的花岗斑岩开展了岩相学、岩石地球化学及黑云母矿物学研究。结果显示,该花岗斑岩具有高SiO2(73.39%~77.99%)、高K2O(4.34%~6.45%)和低P2O5(0.03%~0.06%)特征,铝饱和指数为0.97~0.98,富集Rb、Th、U和Pb,明显亏损Ba、Nb、Ta、Sr、P、Ti和Eu等,属准铝质高分异I型花岗岩类;其中的黑云母具有高Al2O3(9.87%~10.92%)、高MgO(13.38%~14.64%)、高F(0.56%~1.11%)和高Cl(0.07%~0.12%)特征,Mg#为0.61~0.63,属镁质黑云母,黑云母源区为壳幔混合源。研究认为,该区花岗斑岩可能为甲玛矿区浅部埃达克质二长花岗斑岩的岩浆经矿物结晶分异演化出高硅残余熔体,并以岩脉形式上侵就位,而残留在岩浆房的物质结晶形成似斑状二长花岗岩,二者构成互补的关系,即主体为似斑状二长花岗岩,补体为高分异花岗斑岩。  相似文献   

Effect of freeze–thaw cycles on strength and ductility and microstructure of cement-treated silt with polypropylene fiber     

Kou  Hai-lei  Liu  Jia-hui  Guo  Wei  Hua  Su-dong  Pan  Yu-tao 《Acta Geotechnica》2021,16(11):3555-3572

Acta Geotechnica - In this paper, the strength, ductility and microstructure behavior of cement-treated silt with polypropylene fiber was studied by a host of experimental studies. The influence of...  相似文献   

山东省广饶县地下水位多年动态及其地质环境效应分析     

刘帅  刘志涛  段晓飞  冯颖  蒋书杰  黄松 《中国地质调查》2021,8(3):49-57

山东省广饶县地下淡水资源丰富,是本区工农业生产和生活用水的重要水源,长期大量开采地下水引发了地下水降落漏斗、咸水入侵、地面沉降等地质环境问题。通过对广饶县地下水多年监测资料的整理和分析,揭示了本区地下水水位的变化规律,预测了地下水水位的变化趋势。分析表明: 在现状开采条件下,浅层地下水降落漏斗已基本稳定,无加重趋势。考虑地面沉降和咸水入侵的发展趋势,提出深层地下水的约束埋深不应大于80 m,甄庙地区咸水入侵临界水位为10 m,这为当地地下水的合理开采与环境地质问题的防治提供了依据。  相似文献   

两次强降水过程雨滴谱特征及差异     

李侠丽  潘先洁  童应祥  倪婷  黄国贵  李景安  陶杰  姚祎  凌新锋 《气象科技》2019,47(2):322-328

利用寿县观测站内的Parsivel激光雨滴谱仪结合观测站雨量数据及雷达基数据,分析了发生在2015年6月26—30日梅雨期间和2015年8月7—10日超强台风"苏迪罗"影响期间2次强降水过程的雨滴谱结构特征及其差异,拟合了雨强与雷达反射率因子之间的关系。结果表明:雨强的大小直接影响雨滴谱的特征参量,且随着雨强增大而增大;梅雨锋暴雨中1.0mm直径≤1.5mm的粒子所占比例最多,雨强贡献率最大;台风雨中0.75mm直径≤1.0mm的粒子所占比例最多,但1.0mm直径≤1.25mm的粒子对雨强的贡献最大,说明较大粒子对强降水的贡献较大。  相似文献   

The effect of pore water pressure on tunnel face stability          下载免费PDF全文

Qiujing Pan  Daniel Dias 《国际地质力学数值与分析法杂志》2016,40(15):2123-2136

The kinematic approach in combination with numerical simulation is used to examine the effect of pore water pressure on tunnel face stability. Pore water pressure distribution obtained by numerical calculations using FLAC^3D is used to interpolate the pore water pressure on a 3D rotational collapse mechanism. Comparisons are made to check the present approach against other solutions, showing that the present approach improves the existing upper bound solutions. Results obtained indicate that critical effective face pressure increases with water table elevation. Several normalized charts are also presented for quick evaluation of tunnel face stability. At the end of the paper, the influence of anisotropic permeability on tunnel face stability is also discussed, showing that the isotropic model leads to an overestimation of the necessary tunnel face pressure for anisotropic soils. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Role of buffer layer in electronic structures of iron phthalocyanine molecules on Au(111)     

孙家涛  潘理达  胡昊  杜世萱  高鸿钧 《海洋学报(英文版)》2010,29(9)

We investigate the electronic structures of one and two monolayer iron phthalocyanine (FePc) molecules on Au(111) surfaces. The first monolayer FePc is lying flat on the Au(111) substrate, and the second monolayer FePc is tilted at ～15° relative to the substrate plane along the nearest neighbour [101^-] direction with a lobe downward to the central hole of the unit cell in the first layer. The structural information obtained by first-principles calculations is in agreement with the experiment results. Furthermore, it is demonstrated that the electronic structures of FePc molecules in one-monolayer FePc/Au(111) system are perturbed significantly, while the electronic structures of FePc molecules in the second monolayer in two-monolayer FePc/Au(111) system remain almost unchanged due to the screening of the buffer layer on Au(111).  相似文献   

CP准晶结构模型的Hausdorff维数计算     

陈敬中  杜伯仁 《地球科学》1989,14(3):253-258

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新矿物—彭志忠石的发现及研究     

陈敬中  施倪存 《矿物学报》1989,9(1):20-24

彭志忠石产于湖南安化白钨矿区,是一种富含镁、锡、铝的复杂氧化物。矿物为浅黄褐色、浅黄色,少量无色,晶体呈六方板状。晶体化学式为:(Mg,Zn,Fe,Al)_4(Sn,Fe)_2(Al,□)_(10)O_(22)(OH)_2,空间群P_3ml,a=5.692(5)A,c=13.78(2)A,V=386.7A~3,Z=1。D=4.22(3)g/cm~3,H≥8,一轴正晶,ω=1.802(2),ε=1.814(2)。  相似文献   

A FUMIGATION DIFFUSION MODEL DURING THE MOUNTAIN-VALLEY WIND SHIFT PERIOD          下载免费PDF全文

Li Zongkai  Pan Yunxian  Zhou Chaofu  Jiang Weimei  Tang Shibao  Zhu Zengwang 《Acta Meteorologica Sinica》1988,2(2):196-204

The fumigation during the mountain-valley wind shift has been first identified as a special type of pol-lutant diffusion using the monitoring measurements of Dukou,Southwest Sichuan,China.Such a pheno-menon occurs frequently all year around but summer,particularly in winter months.A new model for thefumigation during the mountain-valley wind shift period is developed that allows satisfactory explanation ofthe fact.Analyses indicate that the model can more accurately predict not only the high concentration ofPollutants but the time and locality of the occurrence as well.The ground concentration of SO_2 during fumigation is several times up to over a decade higher thanthe daily mean for the whole region,one of the main contamination processes that affect the air quality ofthe city.The medel analyses provide a basis for more effective prediction of the quality and precautionstudy against the disaster.  相似文献   

原始黄铁矿莓体的发现与研究     

余江滨  潘侊 《矿物学报》1988,(4)

用扫描电子显微镜研究晋东南太原组下部黄铁矿矿石和煤岩中的黄铁矿,发现许多原始莓体保留着形成时的特征。这些特征反映出原始莓体大多数为硫磺细菌化石,少数由胶体形成。本文对莓体的成因、特征、形成环境等进行了论述。  相似文献