RS-485总线在远程自动抄表系统中的应用

介绍利用RS-485总线实现智能化社区远程自动抄表系统的结构和硬件电路设计方法。系统以RS-485总线构成的通信网络为基础,以集中控制器为核心,控制抄读一栋楼内的各个住户的用电量,每栋楼集中抄读到的电量数据通过电话线远程传输到社区管理中心,实现对社区各住户远程自动抄表功能。该系统结构灵活实用,易扩展,很容易应用到社区“三表”的自动抄表系统中。     

基于隐函数曲面的三维断层网络建模与不确定性分析

针对地质环境中不同断层构造出现交叉、削截等现象而构成的复杂断层网络,本文基于隐函数曲面重建提出了一种三维断层网络隐式建模方法。该方法首先以径向基隐函数曲面重建理论为基础,基于地质剖面图中断层轮廓线数据以及断层产状信息隐式构建三维断层面模型;然后使用二叉树结构描述不同断层间的空间拓扑关系构建断层网络模型;最后,考虑断层建模中产状信息估计的不确定性,定义了断层面法向量概率分布模型,采用信息熵指标定量评价断层模型质量。以贵州水银洞金矿床为实例矿床,选定包含多条断层的区域作为试验区,采用该方法构建了实例三维断层网络模型,结果表明,基于隐函数曲面的三维断层网络建模方法能快速构建区域内多条断层的三维断层网络模型和拓扑结构,有助于复杂断层网络快速建模和三维形态分析,为断层构造定量研究提供基础。     

CAN总线与LPT通信接口设计的与实现

现场总线是用于自动化系统最底层的现场设备或仪表互联的通信网络。CAN是现场总线中的一种,具有较高的性价比和较强的实时处理能力。微机LPT并行口具有增强工作方式(EPP),可以进行双向快速数据传输。用CAN控制器SJA1000设计实现计算机并口LPT与CAN总线通信,介绍了并行口EPP方式的信号定义,寄存器工作时序及利用EPP模式进行数据快速双向传输的方法。给出了通信接口电路的设计方法和CAN总线与并行口EPP模式的通信程序,并对通信程序进行了的调试与验证。     

浅覆盖区第四系三维地质结构模型快速构建--以运漕幅为例

在浅覆盖区地质调查中,钻探和物探等方法常用于揭示地质体三维空间分布。本文借用三维可视化方法,以运漕幅作为研究区域,利用钻孔资料和人工解译的地质图快速构建第四系三维地质结构模型,以展现研究区第四系宏观地层格架。文中详细介绍了模型构建的数据源及流程。最后,结合虚拟勘探线剖面成果模型,探索以立体形象的方式显示区域地层分布。所构建的第四系模型可称之为三维地质图,其价值即体现在形象的展现地质体空间分布。     

嵌入式Linux技术在遥测数字地震电源站中的应用

高精度遥测数字地震仪作为新一代地震勘探仪器,对我国油气资源的地震勘探开发起着极其重要的作用。嵌入式Linux技术是一种基于嵌入式微处理器的高性能、低功耗的嵌入式系统解决方案,为研制新型遥测数字地震电源站提供了一条新途径。介绍了应用PPC405高性能嵌入式微处理器及FPGA芯片构建的双层堆叠式电源站硬件系统,并在该硬件构架上完成了U Boot、嵌入式Linux内核、JFFS2文件系统的移植及电源站相关驱动程序和应用程序的开发,实现了遥测数字地震电源站的数据传输和网络交互功能。     

用电子版传统地质报告构建煤炭勘探区三维地质模型方法与软件研究

本文探讨将电子版的传统地质报告转化为三维地质模型的技术方法。首先分析了传统地质报告中可用于三维地质建模的主要数据源,认为煤层底板等高线图和勘探线剖面图是两种主要的数据源;然后分析了由电子版的传统地质报告构建三维地质模型的技术关键是由煤层底板等高线构建煤层底板曲面的不规则三角网、断层曲面的三角网和将二维剖面转化为三维剖面。讨论了三维建模前的数据预处理:将打断的等高线接起来;仔细处理等高线与断面交线相遇时的"未及"与"过伸";为等高线赋高程;用等高线为断面交线赋高程。提出了半自动分区构建被断层切断的煤层底板曲面的方法。给出了断层曲面的两种构建方法:相邻煤层底板等高线图的断面交线相连;相邻剖面图上断面交线相连。讨论了煤、岩层体的构建方法中煤层顶板曲面和侧环面的构建。指出了今后煤田勘探队在编制地质报告的图件中应该注意的几个问题。     

LQC—Ⅱ型三维电阻率采集系统的设计研究

本文设计一种三维并行直流电法勘探系统：LQC—Ⅱ型三维电阻率采集系统,由主机、电测子站和多模式智能电极三部分组成。主机控制电测子站完成16通道、24位数据电性数据的并行采集与传输,每个电测子站控制与之相连的16个电板的同步与状态转换。以1台主机控制16个电测子站和256个智能电极对水池低阻体模型进行电极扫描式测量,获取32640个数据的测量为例,整个测量时间约30分钟。     

现场总线CAN通信中多线程的应用

现场总线是用于自动化系统最底层的现场设备或仪表互联的通信网络。CAN是现场总线中的一种，具有较高的性能价格比和较强的实时处理能力。文章以采用CAN总线的通讯网络结构的校园消费系统为例，介绍在CAN总线通信中如何采用基于多线程的通信程序实现实时的接收、处理和发送数据的功能，对多个线程之问的协作关系进行了分析，以及对采用信号量实现线程的互斥和同步问题进行了详细的论述，最后给出了利用Delphi编写的线程的框架。     

基于MATLAB的BP神经网络在砂土液化评价中的应用

本文运用MATLAB的神经网络工具箱(NNT)建立砂土液化BP网络预测模型,并以南京地铁1#线玄武门站—南京站区间隧道砂土液化评价为例,阐述了基于MATLAB的BP网络应用于砂土液化分析的可行性和应用价值。     

钻井局域网实时监控设备研发

为实现钻井指挥部对各钻井站点钻采工艺的远程监控,在前期钻井工艺参数自动实时监测的单机研发基础上,本文应用TIA portal软件进行主站从站组网监控研究,实验设备用Siemens1200PLC做主控机,用Siemens200PLC做从站控制机监控钻采现场工艺参数,通过主控机与各从站点组态,实现主控机对从站主从控制。装机后在钻采现场进行了无线网传输实验,实验结果表明:应用互联网通信技术解决无线网断点续传问题,能够实现了钻采实时监控数据短距离传输。     

基于MPI环境的并行程序设计

MPI(Message Passing Interface)是消息传递并行程序设计的标准之一,概述了MPI的概念和组成,着重介绍了支持并行程序设计的消息传递接口(MPI)以及在MPI环境下的并行程序设计方法,并给出一个MPI并行程序设计实例,说明了MPI的程序设计流程和主从并行计算流程,由此提出了一个Master/Slave结构的设计模式。     

VSAT应急通讯系统在西北艰险地区地质调查中的应用

基于VSAT小站的应急通讯系统针对野外地质调查工作特点,遵循任务牵引、技术先进、机动灵活、平战结合原则进行系统设计与架构,可实现网络数据交换与传输、视讯会商、语音通话及传真等功能。在西北艰险地区开展了基于地质调查工作的系统测试与应用,实现了野外现场视频、语音信号与西安中心固定站的实时传输,同时实现了与北京地质力学研究所卫星便携站和视频会议终端双向视频的实时传输互联。      

Peridotitic diamonds from the Slave and the Kaapvaal cratons—similarities and differences based on a preliminary data set

A comparison of the diamond productions from Panda (Ekati Mine) and Snap Lake with those from southern Africa shows significant differences: diamonds from the Slave typically are un-resorbed octahedrals or macles, often with opaque coats, and yellow colours are very rare. Diamonds from the Kaapvaal are dominated by resorbed, dodecahedral shapes, coats are absent and yellow colours are common. The first two features suggest exposure to oxidizing fluids/melts during mantle storage and/or transport to the Earth's surface, for the Kaapvaal diamond population.

Comparing peridotitic inclusions in diamonds from the central and southern Slave (Panda, DO27 and Snap Lake kimberlites) and the Kaapvaal indicates that the diamondiferous mantle lithosphere beneath the Slave is chemically less depleted. Most notable are the almost complete absence of garnet inclusions derived from low-Ca harzburgites and a generally lower Mg-number of Slave inclusions.

Geothermobarometric calculations suggest that Slave diamonds originally formed at very similar thermal conditions as observed beneath the Kaapvaal (geothermal gradients corresponding to 40–42 mW/m² surface heat flow), but the diamond source regions subsequently cooled by about 100–150 °C to fall on a 37–38 mW/m² (surface heat flow) conductive geotherm, as is evidenced from touching (re-equilibrated) inclusions in diamonds, and from xenocrysts and xenoliths. In the Kaapvaal, a similar thermal evolution has previously been recognized for diamonds from the De Beers Pool kimberlites. In part very low aggregation levels of nitrogen impurities in Slave diamonds imply that cooling occurred soon after diamond formation. This may relate elevated temperatures during diamond formation to short-lived magmatic perturbations.

Generally high Cr-contents of pyrope garnets (inside and outside of diamonds) indicate that the mantle lithosphere beneath the Slave originally formed as a residue of melt extraction at relatively low pressures (within the stability field of spinelperidotites), possibly during the extraction of oceanic crust. After emplacement of this depleted, oceanic mantle lithosphere into the Slave lithosphere during a subduction event, secondary metasomatic enrichment occurred leading to strong re-enrichment of the deeper (>140 km) lithosphere. Because of the extent of this event and the occurrence of lower mantle diamonds, this may be related to an upwelling plume, but it may equally just reflect a long term evolution with lower mantle diamonds being transported upwards in the course of “normal” mantle convection.     

基于VSAT小站的应急保障系统在东昆仑地区的示范应用

论述了VSAT系统的组成结构、系统在东昆仑地区试验的内容以及试验中所取得的经验和遇到的问题,其中试验内容主要包含了VSAT便携站卫星电话试验,音视频传输试验,单兵、便携站、固定站点对点测试及联机测试等。基于VSAT小站的应急保障系统在东昆仑试验区可实现的主要功能包括野外现场与指挥中心间的VOIP语音、计算机数据及图像视频的通信;各地质工作节点间的视讯会议或视频会商;野外临时作业现场之间的语音视频通信与数据支持等,为应急保障系统的进一步研建工作提供了科学依据。      

槽波地震勘探仪器的发展现状

高性能槽波地震勘探仪器的研制能够有力推进槽波地震勘探方法在煤矿地质构造勘察等领域的有效应用。通过分析槽波地震勘探实例,对比国内外多款新型槽波地震仪采集站,结果表明:无线遥测式地震仪是槽波地震勘探仪器的主要发展方向;新型采集站都使用有Δ-Σ技术的24位AD转换器,前置增益都是多倍率。地震仪器采集站的性能满足槽波地震勘探需要,但是地震检波器的性能制约了槽波地震仪整机性能的提高。分析6种不同类型地震检波器的原理和性能,目前地震检波器主要是围绕提高灵敏度,拓宽频率响应范围和增强抗干扰能力3个方面进行研究。其中高性能压电式地震检波器在槽波地震勘探中有较好应用前景,进一步介绍了一种压电地震检波器芯体及测试结果。      

Mantle Xenoliths from the Southeastern Slave Craton: Evidence for Chemical Zonation in a Thick, Cold Lithosphere

We present the first data on the petrology of the mantle lithosphereof the Southeastern (SE) Slave craton, Canada. These are basedon petrographic, mineralogical and geochemical studies of mantlexenoliths in Pipe 5034 of the Cambrian Gahcho Kué kimberlitecluster. Major types of mantle xenoliths include altered eclogite,coarse garnet or spinel peridotite, and deformed garnet peridotite.The peridotites belong to the low-temperature suite and formedat T=600–1300°C and P= 25–80 kbar in a thick(at least 220–250 km), cool lithosphere. The SE Slavemantle is cooler than the mantle of other Archaean cratons andthat below other terranes of the Slave craton. The thick lithosphereand the relatively cool thermal regime provide favourable conditionsfor formation and preservation of diamonds beneath the SE Slaveterrane. Similar to average Archaean mantle worldwide, the SESlave peridotite is depleted in magmaphile major elements andcontains olivine with forsterite content of 91–93·5.With respect to olivine composition and mode, all terranes ofthe Slave mantle show broadly similar compositions and are relativelyorthopyroxene-poor compared with those of the Kaapvaal and Siberiancratons. The SE Slave spinel peridotite is poorer in Al, Caand Fe, and richer in Mg than deeper garnet peridotite. Thegreater chemical depletion of the shallow upper mantle is typicalof all terranes of the Slave craton and may be common for thesubcontinental lithospheric peridotitic mantle in general. Peridotiticxenoliths of the SE Slave craton were impregnated by kimberliticfluids that caused late-stage recrystallization of primary clinopyroxene,spinel, olivine and spinel-facies orthopyroxene, and formationof interstitial clinopyroxene. This kimberlite-related recrystallizationdepleted primary pyroxenes and spinel in Al. The kimberliticfluid was oxidizing, Ti-, Fe- and K-rich, and Na-poor, and introducedserpentine, chlorite, phlogopite and spinel into peridotitesat P < 35 kbar. KEY WORDS: kimberlite xenolith; lithosphere; mantle terrane; chemical zoning; thermobarometry; Slave craton     

Peridotitic mantle xenoliths from kimberlites on the Ekati Diamond Mine property, N.W.T., Canada: major element compositions and implications for the lithosphere beneath the central Slave craton

The composition, structure and thermal state of the lithosphere beneath the Slave craton have been studied by analysing over 300 peridotitic mantle xenoliths or multiphase xenocrysts entrained within kimberlites in the Lac de Gras area. These xenoliths are derived from seven kimberlites located on the Ekati Diamond Mine™ property and define a detailed stratigraphic profile through the central Slave lithosphere from less than 120 km down to 200 km. Two dominant peridotite types are present, namely garnet-bearing harzburgite and lherzolite with rare occurrences of chromite-facies peridotite, websterite and wehrlite. The pressures and temperatures (P–T's) defined by the entire data-set range from 28 to 62 kbar and 650 to 1250 °C, respectively, and approximately intersect the diamond stability field at 900 °C and 42 kbar. There is no apparent change in the geotherm with depth that is discernable beyond the resolution of the various thermobarometers. The peridotites can be divided into two compositional zones—a shallow layer dominated by garnet harzburgite that straddles the diamond–graphite boundary and a deeper layer that is strongly dominated by garnet lherzolite. Compositionally, the harzburgites (and to a lesser extent, the shallow lherzolites) are ultra-depleted relative to the more fertile deeper layer, irrespective of whether they reside within the graphite or diamond stability field. This ultra-depleted layer beneath Ekati continues to 150 km.     

Petrological constraints on seismic properties of the Slave upper mantle (Northern Canada)

Modes and compositions of minerals in Slave mantle xenoliths, together with their pressures and temperatures of equilibrium were used to derive model depth profiles of P- and S-wave velocities (Vp, Vs) for composites equivalent to peridotite, pyroxenite and eclogite. The rocks were modeled as isotropic aggregates with uniform distribution of crystal orientations, based on single-crystal elastic moduli and volume fractions of constituent minerals. Calculated seismic wave velocities are adjusted for in situ pressure and temperature conditions using (1) experimental P- and T- derivatives for bulk rocks' Vp and Vs, and (2) calculated P- and T- derivatives for bulk rocks' elastic moduli and densities. The peridotite seismic profiles match well with the globally averaged IASP91 model and with seismic tomography results for the Slave mantle. In peridotite, an observed increase of seismic wave velocities with depth is controlled by lower degrees of chemical depletion in the deeper upper mantle. In eclogite, seismic velocities increase more rapidly with depth than in peridotite. This follows from contrasting first-order pressure derivatives of bulk isotropic moduli for eclogite and peridotite, and from the lower compressibility of eclogite at high pressures. Our calculations suggest that depletion in cratonic mantle has a distinct seismic signature compared to non-cratonic mantle. Depleted mantle on cratons should have slower Vp, faster Vs and should show lower Poisson's ratios due to an orthopyroxene enrichment. For the modelled Slave craton xenoliths, the predicted effect on seismic wave velocities would be up to 0.05 km/s.     

Geochemistry of the Archean Kam Group, Yellowknife Greenstone Belt, Slave Province, Canada

The geochemistry and isotope systematics of Archean greenstone belts provide important constraints on the origin of the volcanic rocks and tectonic models for the evolution of Archean cratons. The Kam Group is a approximately 10-km-thick pile of submarine, tholeiitic mafic, and subordinate felsic volcanic rocks erupted between 2712 and 2701 Ma that forms the bulk of the Yellowknife greenstone belt in the dominantly granite-metasedimentary Slave Province. Mafic rocks range from Normal-mid-ocean range basalt-like basalts to slightly light-rare-earth-element-enriched (LREE-enriched) but Nb-depleted basaltic andesites and andesites, whereas dacitic to rhyodacitic felsic rocks are strongly LREE-enriched and highly depleted in Nb. The varepsilonTNd range from +5 to -3 in the mafic to intermediate rocks and from 0 to -5.5 in the felsic rocks. The varepsilonTNd decreases with increasing La/Sm, SiO2 and decreasing Nb/La, suggesting that as the mafic magmas evolved they were contaminated by older basement rocks. Gneissic granitoids >2.9 Ga in age, found at the base of the Kam Group, have varepsilonTNd between -6 and -9 and are excellent candidates for the contaminant. The geochemical and isotopic data, combined with the submarine eruptive setting and field evidence for existing continental basement, support a continental margin rift model for the Kam Group. Similar geochemical-isotopic studies are required on other Slave greenstone belts in order to test evolutionary models for the Slave Province.     

The electrical structure of the Slave craton

The Slave craton in northwestern Canada, a relatively small Archean craton (600×400 km), is ideal as a natural laboratory for investigating the formation and evolution of Mesoarchean and Neoarchean sub-continental lithospheric mantle (SCLM). Excellent outcrop and the discovery of economic diamondiferous kimberlite pipes in the centre of the craton during the early 1990s have led to an unparalleled amount of geoscientific information becoming available.

Over the last 5 years deep-probing electromagnetic surveys were conducted on the Slave, using the natural-source magnetotelluric (MT) technique, as part of a variety of programs to study the craton and determine its regional-scale electrical structure. Two of the four types of surveys involved novel MT data acquisition; one through frozen lakes along ice roads during winter, and the second using ocean-bottom MT instrumentation deployed from float planes.

The primary initial objective of the MT surveys was to determine the geometry of the topography of the lithosphere–asthenosphere boundary (LAB) across the Slave craton. However, the MT responses revealed, completely serendipitously, a remarkable anomaly in electrical conductivity in the SCLM of the central Slave craton. This Central Slave Mantle Conductor (CSMC) anomaly is modelled as a localized region of low resistivity (10–15 Ω m) beginning at depths of 80–120 km and striking NE–SW. Where precisely located, it is spatially coincident with the Eocene-aged kimberlite field in the central part of the craton (the so-called “Corridor of Hope”), and also with a geochemically defined ultra-depleted harzburgitic layer interpreted as oceanic or arc-related lithosphere emplaced during early tectonism. The CSMC lies wholly within the NE–SW striking central zone defined by Grütter et al. [Grütter, H.S., Apter, D.B., Kong, J., 1999. Crust–mantle coupling; evidence from mantle-derived xenocrystic garnets. Contributed paper at: The 7th International Kimberlite Conference Proceeding, J.B. Dawson Volume, 1, 307–313] on the basis of garnet geochemistry (G10 vs. G9) populations.

Deep-probing MT data from the lake bottom instruments infer that the conductor has a total depth-integrated conductivity (conductance) of the order of 2000 Siemens, which, given an internal resistivity of 10–15 Ω m, implies a thickness of 20–30 km. Below the CSMC the electrical resistivity of the lithosphere increases by a factor of 3–5 to values of around 50 Ω m. This change occurs at depths consistent with the graphite–diamond transition, which is taken as consistent with a carbon interpretation for the CSMC.

Preliminary three-dimensional MT modelling supports the NE–SW striking geometry for the conductor, and also suggests a NW dip. This geometry is taken as implying that the tectonic processes that emplaced this geophysical–geochemical body are likely related to the subduction of a craton of unknown provenance from the SE (present-day coordinates) during 2630–2620 Ma. It suggests that the lithospheric stacking model of Helmstaedt and Schulze [Helmstaedt, H.H., Schulze, D.J., 1989. Southern African kimberlites and their mantle sample: implications for Archean tectonics and lithosphere evolution. In Ross, J. (Ed.), Kimberlites and Related Rocks, Vol. 1: Their Composition, Occurrence, Origin, and Emplacement. Geological Society of Australia Special Publication, vol. 14, 358–368] is likely correct for the formation of the Slave's current SCLM.