GIS-based method of delimitating trade area for retail chains

Delimitating trade area with accuracy is a major concern for retail and service companies who want to adapt their marketing strategy to be competitive in today's highly competitive chain industry. A collection of methods have been proposed to delimitating trade area, but either some are too simple or the necessary data are not available. In this article, a geographic information system-based method for precisely delimitating trade area is proposed. It is based on the fact that the social and economic activities are actualized along the street networks. The trade area can be delineated in terms of time distance with high precision taking the practical traffic situations into account. In addition, centered on this method of delimitating trade area, a wide array of functions can be extended to support both operational day-to-day and long-term strategic decision making for retailers.     

Post-earthquake changes and prediction of debris flow scales in Subao River Valley,Beichuan County,Sichuan Province,China

Subao River lies along the Beichuan–Yingxiu fault in Beichuan County, which has been heavily impacted by the Wenchuan earthquake on 12 May 2008 and has become sources of many geo-hazards. On 24 September 2008, a rainstorm triggered a large debris flow in the catchment, causing several deaths and significant damages. A case study on changes of the debris flow was conducted in the river. The peak discharges were calculated in the Guanmenzi, Huangnidi, and Daanshan gullies. Results indicated that the peak discharges corresponded to various return periods in different gullies: 200 years in Daanshan, 100 years in Huangnidi, and 50 years in Guanmenzi. However, the triggering precipitation in these three gullies was only of a 20-year return period. The debris flows had undergone significant changes. Analysis indicated that the changes should be ascribed to the flow characteristics, initiation conditions, and the channel blockage impacted by the rapid accumulation of loose material. Channel blockage was the principal factor increasing the scale of the debris flow. The values on the blocking coefficient were presented based on density, height, and other characteristics of dams. Finally, all of the peak debris flow discharges of the Subao River Valley for a 20-year return period were calculated using the recommended blocking coefficient values.     

The occurrence and distribution of phenylphenanthrenes,phenylanthracenes and binaphthyls in Palaeozoic to Cenozoic shales from China

The distributions of phenylphenanthrenes, phenylanthracenes and binaphthyls in sediment extracts have been investigated in a set of lacustrine shales from the Eocene Shahejie Formation (well SG 1) in the western Depression of Liaohe Basin, East China. All isomers of these phenyl substituted polycyclic aromatic hydrocarbons (PAHs) have been identified in the m/z 254 mass chromatograms by comparison of the mass spectra and standard retention indices with those published elsewhere. The 2,2′-binaphtyl/1,2′-binaphthyl ratio values show a linear increase with increasing maturity, and have a good correlation with T_max (°C). Therefore, they can be used as an effective maturity indictor for source rocks in this study. In the main phase of the oil generation window, the 3-phenylphenanthrene and 2-phenylphenanthrene prevail over other isomers, and some thermodynamically unstable isomers including all phenylanthracenes, 4-phenylphenanthrene and 1,1′-binaphthyl are present at very low concentrations or below the detection limit in the m/z 254 mass chromatograms. The absolute concentrations of individual phenylphenanthrene and binaphthyl isomers were obtained by comparison of the peak areas with that of internal standard phenanthrene-d10. All isomers are present at low concentrations at low maturity stages and then show an abrupt increase at a depth of ≈3100 m, corresponding to the onset of the intensive C₁₅₊ hydrocarbon generation. The Phenylphenanthrene Ratio (2- + 3-PhP)/[(2- + 3-PhP) + (4- + 1- + 9-PhP)] shows a reverse change with increasing maturity at the low maturity stage. It displays a drastic increase at a depth of ≈3100 m and then remains at a nearly constant value. This study can expand the understanding of the formation and distribution of phenyl substituted PAHs in sedimentary organic matter deposited in various environments.     

内蒙古二连浩特北部阿仁绍布地区晚石炭世花岗岩Sr-Yb分类及其成因

对分布在内蒙古二连浩特北部阿仁绍布地区的晚石炭世花岗岩类,依据Sr、Yb含量,划分为低Sr高Yb型、极低Sr高Yb型和低Sr低Yb型花岗岩3种类型。低Sr高Yb型花岗岩类相对低Si、富Al,Na2O〉K2O,稀土元素分馏中等,有或无负Eu异常,Sr含量低,平均为183×10-6,Ba含量较高,平均585×10-6,Y含量高,平均30.06×10-6,Rb/Sr比值较低,平均0.97;极低Sr高Yb型花岗岩富Si、REE,低Al、Sr、Ba,高的Rb/Sr比值（平均为7.47）,具明显的负Eu异常等;低Sr低Yb型花岗岩富Si,贫Al、Ca、Mg,重稀土元素（Y、Yb）含量低,Y含量在（7.26～10.6）×10-6之间,平均9.76×10-6,Yb含量在（1.04～1.89）×10-6之间,平均1.44×10-6,δEu=0.64～0.94,具弱负Eu异常,微量元素Ba含量高,Rb/Sr比值低。3种类型的花岗岩类过铝指数（A/CNK）多小于1.0,说明它们均源自变质火成岩的部分熔融。由于源区的深度不同（pT条件不同）和残留的主要矿物相不同,它们的岩石地球化学特征存在差异。极低Sr高Yb型花岗岩形成深度最浅（中上地壳）,熔融残留相以斜长石为主;低Sr高Yb型花岗岩类形成于中下地壳,熔融残留相为斜长石和辉石;低Sr低Yb型花岗岩形成深度最深,推测可能形成于加厚下地壳（〉40km）底部,熔融残留相为石榴子石、斜长石和角闪石。     

石油测井820系列绘图仪常见故障及排除方法

820及820G型热敏绘图仪是数控测井系统中比较常用的一种现场绘图设备。本文根据多年的使用及维修经验,总结了电-驱-板-头4步维修法,对一些常见的故障的判断和维修提供了方法和思路。     

页岩气、深盆气成藏模式质疑

页岩不生气,和致密砂岩一样只能作为储层。阿巴拉契亚盆地盆地志留系和泥盆系致密砂岩气显示完全的碳同位素反序(δ13C1>δ13C2>δ13C3),它的幔源特征证明了紧邻致密砂岩层之下的页岩层中的天然气同样来源于地幔。所谓"吸附式成藏模式"、"活塞式成藏模式"与有机成因一样,非但毫无根据的,并且实践上将油气勘探开发引向歧途。     

下庄矿田鲁溪地区铀矿找矿前景分析

通过对下庄矿田鲁溪地区笋洞岩体花岗岩特征,U含量、Th/U比值等特点进行研究,推测鲁溪地区具备较好的铀成矿物质来源。对铀成矿紧密相关的控矿构造和基性岩脉的展布特征、分布规模,揭露情况,以及与成矿紧密的绢云母化、绿泥石化、碳酸盐化等围岩蚀变进行了研究,预测鲁溪地区具有较大的铀成矿潜力。并根据成矿条件,把铀矿化类型确定为硅化带型和"交点"型。     

Signal-purity-spectrum-based colored deconvolution

Signal to noise ratio (SNR) and resolution are two important but contradictory characteristics used to evaluate the quality of seismic data. For relatively preserving SNR while enhancing resolution, the signal purity spectrum is introduced, estimated, and used to define the desired output amplitude spectrum after deconvolution. Since a real reflectivity series is blue rather than white, the effects of white reflectivity hypothesis on wavelets are experimentally analyzed and color compensation is applied after spectrum whitening. Experiments on real seismic data indicate that the cascade of the two processing stages can improve the ability of seismic data to delineate the geological details.     

Distribution of ice thickness and subglacial topography of the “Chinese Wall” around Kunlun Station,East Antarctica

As fundamental parameters of the Antarctic Ice Sheet, ice thickness and subglacial topography are critical factors for studying the basal conditions and mass balance in Antarctica. During CHINARE 24 (the 24th Chinese National Antarctic Research Expedition, 2007/08), the research team used a deep ice-penetrating radar system to measure the ice thickness and subglacial topography of the “Chinese Wall” around Kunlun Station, East Antarctica. Preliminary results show that the ice thickness varies mostly from 1600 m to 2800 m along the “Chinese Wall”, with the thickest ice being 3444 m, and the thinnest ice 1255 m. The average bedrock elevation is 1722 m, while the minimum is just 604 m. Compared with the northern side of the ice divide, the ice thickness is a little greater and the subglacial topography lower on the southern side, which is also characterized by four deep valleys. We found no basal freeze-on ice in the Gamburtsev Subglacial Mountains area, subglacial lakes, or water bodies along the “Chinese Wall”. Ice thickness and subglacial topography data extracted from the Bedmap 2 database along the “Chinese Wall” are consistent with our results, but their resolution and accuracy are very limited in areas where the bedrock fluctuates intensely. The distribution of ice thickness and subglacial topography detected by ice-penetrating radar clarifies the features of the ice sheet in this “inaccessible” region. These results will help to advance the study of ice sheet dynamics and the determination of future locations of the GSM’s geological and deep ice core drilling sites in the Dome A region.