室内空间用户行为的智能手机识别

针对地磁匹配中经常会出现相似点,造成定位偏差较大的问题,该文提出利用智能手机识别用户室内行为方式的方法,为地磁匹配算法提供筛选条件。开发了智能手机传感器数据采集工具,获取用户在室内环境下的行为数据。原始数据首先利用一阶低通滤波和平滑滤波算法进行去噪处理,再经过数据分割和特征提取后,应用于行为识别过程。行为识别模型的建立主要使用两种方法,K最近邻算法和隐式马尔可夫模型,并研究了两种方法的不足以及改进途径。通过针对识别准确度的对比实验,在输入最合适的数据的条件下,隐式马尔可夫模型的准确度略优于K最近邻算法。两种方法的识别准确率均在95%以上,能够有效地提高地磁定位精度。利用室内用户行为数据辅助地磁室内定位,很好地改善了地磁数据单一、定位精度较低的问题。     

The fluid geochemistry of Icelandic high temperature geothermal areas

Icelandic high temperature geothermal systems are considered to number thirty three, thereof three are submarine and seven subglacial. All are briefly described but the chemistry of fluids from twenty four of them is considered. The fluid in the three submarine areas and those four on land that are closest to the sea are relatively saline but to a differing extent mixed with groundwater. The rest contain dilute fluids. The fluids of the central highland systems are mostly locally derived but may in some instances be quite old whereas those in the northerly Krafla area which is inland and the Öxarfjörður area which is close to the sea appear to be a mixture of local and central highland water, but those in the inland Hengill, Geysir, Námafjall and Theistareykir areas appear to have travelled relatively long distances from the central highlands. The gas observed is magmatic except in the northerly Öxarfjördur area close to the sea where it is apparently derived from organic sediments.     

华北太行岩墙群斜锆石生长世代和U-Pb年龄及其对岩浆演化的启示

斜锆石U-Pb定年是基性岩墙时代确定的有效方法。前人对太行岩墙群高分异组岩墙(Ti O2通常1%,Mg O一般6%)进行了较多的定年,但缺少对低分异组岩墙(Ti O2约为1%,Mg O6%)的高精度测年。两者年龄是否一致是讨论两组岩墙是否来源于同一岩浆的基本前提。本研究对华北太行岩墙群丰镇地区低、高分异组代表性岩墙进行了斜锆石离子探针207Pb/206Pb定年。结果表明,低分异组车道沟岩墙207Pb/206Pb平均年龄为1768±4Ma(n=9,MSWD=2.1);而高分异组酸刺湾岩墙斜锆石207Pb/206Pb年龄可以分为两组,加权平均值分别为1780±3Ma(n=8,MSWD=0.65)和1760±3Ma(n=5,MSWD=1.7)。斜锆石成分分析表明,酸刺湾岩墙两组年龄对应的矿物成分存在差异,如晚期斜锆石比早期更富Ti,Zr/Hf比值变化范围相对较小。据此认为,酸刺湾岩墙两组斜锆石可能结晶于岩浆不同阶段:早期(~1780Ma)的斜锆石可能结晶于成分更加原始的岩浆,很可能形成于岩浆房中;晚期(~1760Ma)的斜锆石可能结晶于成分更加演化的岩浆,可能是岩浆通道(岩墙)或岩浆房中。Zr/Hf值与单点年龄的负相关趋势可能记录了单斜辉石的结晶过程。已有的太行岩墙群U-Pb年代学结果集中于1785~1760Ma。我们的研究认为,太行岩墙群岩浆房存在了约20Myr,即岩浆房形成于~1785Ma,岩墙就位于1785~1760Ma。     

The changing vision of marine minerals

Non-fuel marine minerals are reviewed from the perspective of resources and their value as active analogs that can advance understanding of types of ancient ore deposits that formed in marine settings. The theory of plate tectonics is the largest influence in expanding our vision of marine minerals and in developing our understanding of geologic controls of mineralization in space and time. Prior to the advent of plate tectonics, we viewed the ocean basins as passive sinks that served as containers for particulate and dissolved material eroded from land. This view adequately explained marine placer deposits (heavy minerals and gems), aggregates (sand and gravel), and precipitates (phosphorites and manganese nodules). Although numerous sites of placer mineral deposits are known on continental shelves worldwide, current activity pertains to diamond mining off southwestern Africa, tin mining off southeastern Asia, and intermittent gold mining off northwestern North America, which are all surpassed economically by worldwide recovery of marine sand and gravel, in turn dwarfed by offshore oil and gas. With the advent of plate tectonics, plate boundaries in ocean basins are recognized as active sources of mineralization in the form of hydrothermal massive sulfide deposits and proximal lower-temperature deposits hosted in oceanic crust (mafic at ocean ridges and felsic at volcanic island arcs), and of magmatic Ni–Cu sulfide, chromite and PGE deposits inferred to be present in the oceanic upper mantle–lower crust based on their occurrence in ophiolites. Some 300 sites of hydrothermal active and relict mineralization, most of them minor, are known at this early stage of seafloor exploration on ocean ridges, in fore-arc volcanoes, at back-arc spreading axes, and in arc rifts; deposits formed at spreading axes and transported off-axis by spreading are present in oceanic lithosphere but are virtually unknown. The TAG (Trans-Atlantic Geotraverse) hydrothermal field in the axial valley of the Mid-Atlantic Ridge (latitude 26° N) is considered to exemplify a major Volcanogenic Massive Sulfide (VMS) deposit forming at a spreading axis. The most prospective of these occurrences lie within the 200 nautical mile (370 km)-wide Exclusive Economic Zone (EEZ) of the nations of the volcanic island arcs of the western Pacific where metal content of massive sulfides (Ag, Au, Ba, Cu, Pb, Sb, Zn) exceeds that at ocean ridges. Plate tectonics early provided a framework for mineralization on the scale of global plate boundaries and is providing guidance to gradually converge on sites of mineralization through regional scales of plate reorganization, with the potential to elucidate the occurrence of individual deposits (e.g., Eocene Carlin-type gold deposits). Investigation of the spectrum of marine minerals as active analogs of types of ancient mineral deposits is contributing to this convergence. Consideration of questions posed by Brian Skinner (1997) of what we do and do not know about ancient hydrothermal mineral deposits demonstrates the ongoing advances in understanding driven by investigation of marine minerals.     

Gem corundum deposits of Madagascar: A review

Madagascar is one of the most important gem-producing countries in the world, including ruby and sapphires. Gem corundum deposits formed at different stages in the geological evolution of the island and in contrasting environments. Four main settings are identified: (1) Gem corundum formed in the Precambrian basement within the Neoproterozoic terranes of southern Madagascar, and in the volcano-sedimentary series of Beforona, north of Antananarivo. In the south, high-temperature (700 to 800 °C) and low-pressure (4 to 5 kbar) granulites contain deposits formed during the Pan-African orogenesis between 565 and 490 Ma. They accompany mafic and ultramafic complexes (ruby deposits of the Vohibory group), skarns at the contact between Anosyan granites and the Proterozoic Tranomaro group (sapphire deposits of the Tranomaro–Andranondambo district), and shear-zone corridors cross-cutting feldspathic gneisses, cordieritites and clinopyroxenites in the Tranomaro, Vohimena and Androyan metamorphic series (biotite schist deposits of Sahambano and Zazafotsy, cordieritites of Iankaroka and Ambatomena). The circulation of fluids, especially along discontinuities, allowed in-situ alkaline metasomatism, forming corundum host rocks related to desilicified granites, biotitites, “sakenites” and “corundumites”. (2) Gem corundum also occurs in the Triassic detrital formations of the Isalo group, as giant palaeoplacers in the Ilakaka–Sakaraha area. Here, sapphires and rubies may come from the metamorphic granulitic terranes of southern Madagascar. (3) Gem corundum deposits occur within the Neogene-Quaternary alkali basalts from Ankaratra (Antsirabe–Antanifotsy area) and in the Ambohitra Province (Nosy Be, Ambato and Ambondromifehy districts). Primary deposits are rare, except at Soamiakatra where ruby in gabbroic and clinopyroxenite xenoliths within alkali-basalts probably derive from mantle garnet peridotites. The blue-green-yellow sapphires typical of basaltic fields are always recovered in palaeoplacer (in karst formed upon Jurassic limestones from the Montagne d'Ambre, Antsiranana Province) and alluvial and soil placers (Ankaratra volcanic massif). (4) Deposits occur within Quaternary eluvial, colluvial and alluvial concentrations, such as high-quality rubies from the Andilamena and Vatomandry deposits.     

新疆东天山葫芦铜镍硫化物矿床Re-Os同位素物质来源示踪研究

通过对葫芦铜镍硫化物矿石的Re-Os同位素物质来源示踪研究, 其¹⁸⁷Os/¹⁸⁸Os初始比值介于1.40~1.97,γOs值介于1110~1565,平均为1379, 表明在成矿过程及岩浆侵位期间有大量地壳物质加入到成矿系统中。     

配电网DG对反时限过电流保护的影响

针对分布式电源（DG）接入配电网后可能引起保护误动作的问题,分析了分布式电源接入配电网后对短路电流的影响,推导了各种情况下短路电流的计算公式,分析了反时限过电流保护误动作的可能性,对一个10 kV配电网的反时限过电流保护的启动电流和时间特性系数进行了整定计算,仿真分析了短路电流和动作时限的变化及反时限过电流保护误动的可能性.结果表明,仅当DG所在线路上DG上游发生故障时,处于故障点和DG之间的保护发生误动作的可能性较大.     

Contrasting magmatic structures between small plutons and batholiths emplaced at shallow crustal level (Sierras de Córdoba,Argentina)

Processes like injection, magma flow and differentiation and influence of the regional strain field are here described and contrasted to shed light on their role in the formation of small plutons and large batholiths their magmatic structures. The final geometric and compositional arrangement of magma bodies are a complex record of their construction and internal flow history. Magma injection, flow and differentiation, as well as regional stresses, all control the internal nature of magma bodies. Large magma bodies emplaced at shallow crustal levels result from the intrusion of multiple magma batches that interact in a variety of ways, depending on internal and external dynamics, and where the early magmatic, growth-related structures are commonly overprinted by subsequent history. In contrast, small plutons emplaced in the brittle-ductile transition more likely preserve growth-related structures, having a relatively simple cooling history and limited internal magma flow. Outcrop-scale magmatic structures in both cases record a rich set of complementary information that can help elucidate their evolution. Large and small granitic bodies of the Sierra Pampeanas preserve excellent exposures of magmatic structures that formed as magmas stepped through different rheological states during pluton growth and solidification. These structures reveal not only the flow pattern inside magma chambers, but also the rheological evolution of magmas in response to temperature evolution.     

《建筑工程抗震性态设计通则》与《规范》中地震作用的比较

《建筑工程抗震生态设计通则(试用)》是一部对我国抗震设计规范修订具有重大指导意义的试用标准。地震作用是抗震设计的首要问题,《通则》中地震作用计算方法与现行规范的差异引人关注。首先分析了《通则》和规范的场地设计谱,然后比较了二者地震作用计算方法,最后引入2个算例计算了水平地震作用的差别。对《通则》的应用,对修订和完善下一代规范有一定的参考作用。     

边坡渗流耦合变形分析方法的研究及其应用

边坡在渗流作用下应力场会发生变化,是渗流场耦合应力场的作用结果。给出了一种考虑饱和-非饱和流渗影响的边坡弹塑性有限元分析方法,采用了不同含水量对抗剪强度影响的模型,求解带有渗透力作用项的土体弹塑性平衡方程得到边坡的应力应变分布,并应用于某滑坡的实际降雨分析。该实例分析证实,由于渗流作用影响,边坡变形加大,最后形成潜在滑动面。利用渗流耦合变形的弹塑性有限元法分析大气降雨造成土体滑坡的变形和发展是可行的,其在实际工程中的应用是成功的。