诸暨洞室工程稳定性评价     

郭家良  张雷 《上海国土资源》1991,(1):47-58

本文主要根据杭铁诸暨387洞室工程所取得的地质资料及室内岩石物理力学试验指标为依据,对该工程的围岩进行分类、並对围岩进行有限元方法的分析,及对围岩局部块体利用赤平极射投影方法进行稳定性验算,对该工程主体洞室的稳定性作出评价。  相似文献   

罗锅沟大爆破技术          下载免费PDF全文

朱铎 《探矿工程》1994,(4):43-45

以罗锅沟大爆破为例，介绍了洞室大爆破的施工组织，并着重问述了在进行技术设计时，应注意以下几点：（１）药室的布置及爆破参数的确定；（２）起爆网路的设计；（３）施工设计；（４）安全校核及安全措施。  相似文献   

华南叠加-重熔型花岗岩的成生机制     

Feng Zhiwen Xia Weihua Zhang Jintong Chen Ziying 《地球科学》1986,(1)

南岭成矿带是太平洋及印度洋板块对中国大陆板块联合作用的结果。囊括大量稀有-有色金属矿床的中心弧形构造-岩浆岩系正是这个“钳式”应力场作用的集中体现,“深部叠加-重熔”——以板块持续运动和相对高速率运动产生并贮集能量为前提,以俯冲板块不断带入新的挥发物质为条件,随着动力热和挥发组分的不断回流—汇集—贮集而使仰冲板块深部预热的原地或途中固化-半固化的先期熔融的岩浆岩发生了二次甚至多次的熔融作用。  相似文献   

箱法在草地温室气体通量野外实验观测中的应用研究   总被引：31，自引：0，他引：31  

杜睿  王庚辰  吕达仁  孔琴心  刘广仁  万小伟  张斌  王艳芬  季保明 《大气科学》2001,25(1):61-70

利用静态箱法采样,配以气相色谱仪法分析对草地N2O、CH4和CO2温室气体通量进行了较系统的现场测量,同时对箱体内外温度进行同步观测。在对野外原位观测实验数据进行定量分析的基础上,论证了静态箱法对草原土壤-植被系统的N2O、CH4和CO2通量测量的适用性和科学性,讨论了实验结果的可靠性。  相似文献   

Geochemical modeling of magma mixing and magma reservoir volumes during early episodes of Kīlauea Volcano’s Pu‘u ‘Ō‘ō eruption     

Patrick J. Shamberger  Michael O. Garcia 《Bulletin of Volcanology》2007,69(4):345-352

Geochemical modeling of magma mixing allows for evaluation of volumes of magma storage reservoirs and magma plumbing configurations. A new analytical expression is derived for a simple two-component box-mixing model describing the proportions of mixing components in erupted lavas as a function of time. Four versions of this model are applied to a mixing trend spanning episodes 3–31 of Kilauea Volcano’s Puu Oo eruption, each testing different constraints on magma reservoir input and output fluxes. Unknown parameters (e.g., magma reservoir influx rate, initial reservoir volume) are optimized for each model using a non-linear least squares technique to fit model trends to geochemical time-series data. The modeled mixing trend closely reproduces the observed compositional trend. The two models that match measured lava effusion rates have constant magma input and output fluxes and suggest a large pre-mixing magma reservoir (46±2 and 49±1 million m³), with little or no volume change over time. This volume is much larger than a previous estimate for the shallow, dike-shaped magma reservoir under the Puu Oo vent, which grew from ∼3 to ∼10–12 million m³. These volumetric differences are interpreted as indicating that mixing occurred first in a larger, deeper reservoir before the magma was injected into the overlying smaller reservoir. Electronic Supplementary Material Supplementary material is available at and is accessible for authorized users.  相似文献   

Magmatic structures in the Krkonoše–Jizera Plutonic Complex,Bohemian Massif: evidence for localized multiphase flow and small-scale thermal–mechanical instabilities in a granitic magma chamber     

Jiří Žák  Josef Klomínský 《Journal of Volcanology and Geothermal Research》2007

The present paper examines magmatic structures in the Jizera and Liberec granites of the Krkonoše–Jizera Plutonic Complex, Bohemian Massif. The magmatic structures are here interpreted to preserve direct field evidence for highly localized magma flow and other processes in crystal-rich mushes, and to capture the evolution of physical processes in an ancient granitic magma chamber. We propose that after chamber-wide mixing and hybridization, as suggested by recent petrological studies, laminar magma flow became highly localized to weaker channel-like domains within the higher-strength crystal framework. Mafic schlieren formed at flow rims, and their formation presumably involved gravitational settling and velocity gradient flow sorting coupled with interstitial melt escape. Local thermal or compositional convection may have resulted in the formation of vertical schlieren tubes and ladder dikes whereas subhorizontal tubes or channels formed during flow driven by lateral gradients in magma pressure. After the cessation or deceleration of channel flow, gravity-driven processes (settling of crystals and enclaves, gravitational differentiation, development of downward dripping instabilities), accompanied by compaction, filter pressing and melt segregation, dominated in the crystal mush within the flow channels. Subsequently, magmatic folds developed in schlieren layers and the magma chamber recorded complex, late magmatic strains at high magma crystallinities. Late-stage magma pulsing into localized submagmatic cracks represents the latest events of magmatic history of the chamber prior to its final crystallization. We emphasize that the most favorable environments for the formation and preservation of magmatic structures, such as those hosted in the Jizera and Liberec granites, are slowly cooling crystal-rich mushes. Therefore, where preserved in plutons, these structures may lend strong support for a “mush model” of magmatic systems.  相似文献   

长白山天池火山区电性结构和岩浆系统   总被引：36，自引：3，他引：36       下载免费PDF全文

汤吉  邓前辉  赵国泽  李文军  宣飞  晋光文  白登海  詹艳  梁竞阁  蒲兴华  王继军  李国深  洪飞  马明志  陈风学 《地震地质》2001,23(2):191-200

在长白山火山区及其附近 ,沿 5条伞状测线和 1条北西向测线进行了 6 1个大地电磁测深点的观测。用Robust等方法对观测资料进行了处理 ;应用阻抗张量分解方法消除了局部不均匀体的影响 ;计算了反映地下横向不均匀性的地磁感应矢量。利用RRI二维自动反演等技术对资料进行了解释。结果表明 :在近地表存在低阻体 ,并分别与长白山天池水体、聚龙泉温泉、锦江温泉及长白山山门附近的地下水相对应。在长白山天池及其以北和以东地区 ,约 12km深处存在电阻率很低的地质体 ,电阻率为 10到几十Ω·m ,可能是地壳岩浆囊。在测区范围内 ,地壳电性结构在南北方向存在着明显的横向变化 ,而东西方向相对均匀 ,变化比较平缓  相似文献   

长白山火山喷发物的堆积类型及火山活动机理     

张成梁  张普林 《吉林地质》1992,11(2):37-46

本文对长白山火山地质发展过程中的两大喷发期和七个喷发阶段作了系统阐述,详细划分、描述了喷发物堆积类型及特征,论述了火山活动机理及演化历程。首次指出长白山火山基浪堆积,对新发现的侵入相和次火山岩相岩百与喷出相岩石做了对比,指出同源于一个碱性岩浆房。  相似文献   

Chemical Mechanism Development: Laboratory Studies and Model Applications     

Harald Geiger  Ian Barnes  Karl H. Becker  Birger Bohn  Theo Brauers  Birgit Donner  Hans-Peter Dorn  Manfred Elend  Carlos M. Freitas Dinis  Dirk Grossmann  Heinz Hass  Holger Hein  Axel Hoffmann  Lars Hoppe  Frank Hülsemann  Dieter Kley  Björn Klotz  Hans G. Libuda  Tobias Maurer  Djuro Mihelcic  Geert K. Moortgat  Romeo Olariu  Peter Neeb  Dirk Poppe  Lars Ruppert  Claudia G. Sauer  Oleg Shestakov  Holger Somnitz  William R. Stockwell  Lars P. Thüner  Andreas Wahner  Peter Wiesen  Friedhelm Zabel  Reinhard Zellner  Cornelius Zetzsch 《Journal of Atmospheric Chemistry》2002,42(1):323-357

Within the German Tropospheric Research Programme (TFS) numerous kinetic and mechanistic studies on the tropospheric reaction/degradation of the following reactants were carried out: oxygenated VOC, aromatic VOC, biogenic VOC, short-lived intermediates, such as alkoxy and alkylperoxy radicals.At the conception of the projects these selected groups were classes of VOC or intermediates for which the atmospheric oxidation mechanisms were either poorly characterised or totally unknown. The motivation for these studies was the attainment of significant improvements in our understanding of the atmospheric chemical oxidation processes of these compounds, particularly with respect to their involvement in photooxidant formation in the troposphere. In the present paper the types of experimental investigations performed and the results obtained within the various projects are briefly summarised. The major achievements are highlighted and discussed in terms of their contribution to improving our understanding of the chemical processes controlling photosmog formation in the troposphere.  相似文献   

Product study of the reaction of OH radicals with isoprene in the atmosphere simulation chamber SAPHIR     

M. Karl  H.-P. Dorn  F. Holland  R. Koppmann  D. Poppe  L. Rupp  A. Schaub  A. Wahner 《Journal of Atmospheric Chemistry》2006,55(2):167-187

Atmospheric oxidation of isoprene and its oxidation products methacrolein (MACR) and methyl vinyl ketone (MVK) have an important impact on the photochemical activity in the boundary layer, in particular in forested areas. The oxidation of isoprene by OH radicals was investigated in chamber experiments conducted under tropospheric conditions in the atmosphere simulation chamber SAPHIR at the Research Center Jülich. The aim was to determine the product yield of MVK and MACR in the OH-induced isoprene oxidation and the rate constant of their reaction with OH under real atmospheric conditions. The recently published updated degradation scheme for isoprene from Geiger et al. (2003) was used to determine rate constants and product yields. The fractional yields in the isoprene peroxy radical reaction with NO were found to be 0.41±0.03 for MVK and 0.27±0.03 for MACR. The rate coefficient for MACR with OH was found to be in very good agreement with the recommended value of IUPAC Atkinson (Atkinson et al., 2005). while the rate coefficient for MVK with OH was 27% lower.  相似文献