Characterization of Dry‐Spun Acrylic Fiber Wastewater by Particle Size Distribution,Biodegradability, and Chemical Composition          下载免费PDF全文

Qinghong Wang  Guangxu Yan  Bin Cai  Chunmao Chen  Shaohui Guo 《洁净——土壤、空气、水》2014,42(10):1393-1401

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Geophysical signatures of uranium mineralization and its subsurface validation at Beldih,Purulia District,West Bengal,India: a case study          下载免费PDF全文

Animesh Mandal  W.K. Mohanty  S.P. Sharma  Arkoprovo Biswas  Joydip Sen  A. K. Bhatt 《Geophysical Prospecting》2015,63(3):713-726

The Beldih open cast mine of the South Purulia Shear Zone in Eastern India is well known for apatite deposits associated with Nb–rare‐earth‐element–uranium mineralization within steeply dipping, altered ferruginous kaolinite and quartz–magnetite–apatite rocks with E–W strikes at the contact of altered mafic–ultramafic and granite/quartzite rocks. A detailed geophysical study using gravity, magnetic, and gradient resistivity profiling surveys has been carried out over ～1 km² area surrounding the Beldih mine to investigate further the dip, depth, lateral extension, and associated geophysical signatures of the uranium mineralization in the environs of South Purulia Shear Zone. The high‐to‐low transition zone on the northern part and high‐to‐low anomaly patches on the southeastern and southwestern parts of the Bouguer, reduced‐to‐pole magnetic, and trend‐surface‐separated residual gravity–magnetic anomaly maps indicate the possibility of highly altered zone(s) on the northern, southeastern, and southwestern parts of the Beldih mine. The gradient resistivity survey on either side of the mine has also revealed the correlation of low‐resistivity anomalies with low‐gravity and moderately high magnetic anomalies. In particular, the anomalies and modeled subsurface features along profile P6 perfectly match with subsurface geology and uranium mineralization at depth. Two‐dimensional and three‐dimensional residual gravity models along P6 depict the presence of highly altered vertical sheet of low‐density material up to a depth of ～200 m. The drilling results along the same profile confirm the continuation of uranium mineralization zone for the low‐density material. This not only validates the findings of the gravity model but also establishes the geophysical signatures for uranium mineralization as low‐gravity, moderate‐to‐high magnetic, and low‐resistivity values in this region. This study enhances the scope of further integrated geophysical investigations along the South Purulia Shear Zone to delineate suitable target areas for uranium exploration.  相似文献   

THE USE OF SHEAR GRADIENT VORTICITY IN TROPICAL CYCLONE HEAVY PRECIPITATION PREDICTION: A HIGH-RESOLUTION NUMERICAL CASE STUDY     

汤杰  袁慧玲  王元  费建芳 《热带气象学报(英文版)》2012,18(4):403-411

This study introduces a new dynamical quantity, shear gradient vorticity (SGV), which is defined as vertical wind shear multiplying the horizontal component of vorticity gradient, aiming to diagnose heavy precipitation induced by some strong convective weather systems. The vorticity gradient component can be used to study the collision or merging process between different vortexes or the deformation of a vortex with a sharp vorticity gradient. Vertical wind shear, another contributed component of SGV, always represents the environmental dynamical factor in meteorology. By the combined effect of the two components, overall, SGV can represent the interaction between the environmental wind shear and the evolution of vortexes with a large vorticity gradient. Other traditional vorticity-like dynamical quantities (such as helicity) have the limitation in the diagnosis of the convection, since they do not consider the vorticity gradient. From this perspective, SGV has the potential to diagnose some strong convective weather processes, such as Extratropical Transition (ET) of tropical cyclones and the evolution of multicell storms. The forecast performance of SGV for the numerical ET case of Typhoon Toraji (0108) has been evaluated. Compared with helicity, SGV has shown a greater advantage to forecast the distribution of heavy precipitation more accurately, especially in the frontal zone.  相似文献   

安宁河断裂带测区古构造残余应力随深度分布          下载免费PDF全文

安欧  高国宝 《地震工程学报》1996,18(4):54-58

以岩体正交异性弹性理论为基础，用Ｘ射线法，在安宁河断裂带测区，选取了９个钻孔的岩芯，测量了岩体中宏观残余应力场的水平和铅直三维主应力及最大剪和随深度的分布。分析了其沿深度的分布规律，求得了其铅直梯度值。  相似文献   

Application of AMD to the Determination of Crop Protection Agents in Drinking Water. Part IV: Fundamentals of a Confirmatory Test     

K. Burger  H. Jork  J. Khler 《洁净——土壤、空气、水》1996,24(1):6-15

A method is described for the determination of fifteen active ingredients of plant protecting products in ground-, raw, and drinking water. After extraction and enrichment of the pesticides from the water sample with solid-phase extraction, the extract is fractionated on silica-coated TLC plates, first in a so-called screening gradient by AMD (automated multiple development). The detection of the pesticides is performed by UV multidetection. Positive results from the first separation are confirmed by a second separation on silica in an AMD gradient of distinctly different selectivity, compared to the first separation. Following this strategy, it is possible to distinguish nearly all nonvolatile, from water extractable, active ingredients of plant protecting products in the market. UV spectra are taken for further confirmation of positive results. In most cases, this is possible even at the limit of determination. All chromatograms and spectra shown are raw data, resulting from the confirmatory test DIN 38407 part 11, in the laboratory of one participant*). The method is standardized in the meantime as DIN V 38407-11.  相似文献   

陆面上总体输送系数的特征   总被引：7，自引：4，他引：7  

苗曼倩  钱峻屏 《气象学报》1996,54(1):95-101

利用气象铁塔的风、温梯度资料，对陆面上近地层湍流拖曳系数ＣＤ和总体输送系数ＣＨ（或ＣＥ）的大小和日变化规律进行研究。发现陆面上较粗糙的地表，ＣＤ和ＣＨ可以比海面上大一个量级左右。而且存在着明显的日变化。它们对地表面动力粗糙度变化的反应较敏感。本工作为气候及大气环流模式研究中陆面参数化过程提供了重要依据。  相似文献   

山门银矿床物化探勘查效果及标志   总被引：1，自引：0，他引：1  

杨贵林  刘志和 《吉林地质》1992,11(1):81-87

本文着重阐述了山门银矿床地球物理、地球化学特征及物化探勘查效果。建立了山门锻矿床平面的物化探找矿标志和卧龙、龙王剖面的物化探找矿标志。总结了物化探方法与地质互相配合综合找矿的有效性。  相似文献   

碎裂蚀变岩金矿带上的地球物理场特征分析及应用     

姜义生 《铀矿地质》1992,(4)

本文介绍了在山东招远北截金矿上进行的磁(△T)及甚低频(VLF)电磁场测量,分析了碎裂蚀变岩金矿带上磁场强度降低和甚低频电磁场强度增大的特征,并以此特征为判据,对金矿外围未知地段的构造作了推断解释,提出了可供钻探验证的有利部位。  相似文献   

共轭梯度法在新井参数设计中的应用     

宋梅  张石峰 《新疆地质》2004,22(3):311-314

通常情况下,含水层的参数可分别借助于Dupuit和Theis井流公式,在局部地段利用稳定流和非稳定流抽水试验获得.在新井设计阶段,一般是依据现有参照井数据进行线性或非线性插值计算,但插值受插值表的约束,效率不高.本次研究采用2次优化方法,用网格法确定所求参数最优估计值作为下一步的叠代初值.用共轭梯度法逐步逼近所求参数的精确解,高效地利用参照井的基本数据得到了精度较高的新井参数,为准确地设计新井提供可靠的依据,实地应用效果良好.  相似文献   

Understanding the structural setting in the Southern Apennines (Italy): insight from Gravity Gradient Tensor     

Maurizio Fedi  Luigi Ferranti  Giovanni Florio  Italiano Giori  Francesco Italiano 《Tectonophysics》2005,397(1-2):21

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