Concentrations of B,Sm, Gd and H in 24 Reference Materials*     

Denis M. SHAW  Patti L.C. SMITH 《Geostandards and Geoanalytical Research》1991,15(1):59-66

Analysis of 24 reference materials for B, Sm, Gd, H, has been carried out over several years, using prompt gamma neutron activation analysis. The results are compared with values obtained by other workers, in order to better calibrate these standards. In most cases our results of repeated analysis of RMs show agreement with results from other laboratories, using various methods. A djustments to working values are proposed in some cases.  相似文献   

The Petrology of an Adamellite-Porphyrite from the New England Bathylith (New South Wales)     

WILKINSON  J. F. G.; VERNON  R. H.; SHAW  S. E. 《Journal of Petrology》1964,5(3):461-488

The paper presents an account of the occurrence, petrography,mineralogy, and geochemistry of several intrusions of adamellite-porphyrite,an early member of the New England Bathylith (N.S.W.). The rockis composed of phenocrysts of quartz, andesine, hornblende,biotite, augite (and minor orthopyroxene) which are set in afine-grained quartzofeldspathic groundmass. Compositions ofsilicate phenocrysts (which reveal widespread evidence of cataclasis)accord with coexisting phases of an assemblage appropriate tointermediate rocks. Xenolith mineralogy is similar to equivalentminerals occurring as phenocrysts. The recalculated bulk compositionof a rock represented by the modal andesine, hornblende, biotite,augite, and magnetite of the adamellite-porphyrite is similarto the composition of a biotite–diorite; the compositionof the quartzo-feldspathic groundmass plots in the low-meltingregion of the NaAISi₃O₈-KAISi₃O₈-SiO₂-H₂O system. Evidence ispresented to indicate a hybrid origin for the adamellite-porphyritewhereby disrupted biotite-diorite was invaded and mixed withlow-melting silicic alkalic liquid.  相似文献   

Understanding the textures and origin of shock melt pockets in Martian meteorites from petrographic studies,comparisons with terrestrial mantle xenoliths,and experimental studies     

Erin L. WALTON  Cliff S. J. SHAW 《Meteoritics & planetary science》2009,44(1):55-76

Abstract— We present a textural comparison of localized shock melt pockets in Martian meteorites and glass pockets in terrestrial, mantle‐derived peridotites. Specific textures such as the development of sieve texture on spinel and pyroxene, and melt migration and reaction with the host rock are identical between these two apparently disparate sample sets. Based on petrographic and compositional observations it is concluded that void collapse/variable shock impedance is able to account for the occurrence of pre‐terrestrial sulfate‐bearing secondary minerals in the melts, high gas emplacement efficiencies, and S, Al, Ca, and Na enrichments and Fe and Mg depletion of shock melt compositions compared to the host rock; previously used as arguments against such a formation mechanism. Recent experimental studies of xenoliths are also reviewed to show how these data further our understanding of texture development and can be used to shed light on the petrogenesis of shock melts in Martian meteorites.  相似文献   

The Geochemistry of Scapolite Part II. Trace Elements, Petrology, and General Geochemistry     

SHAW  DENIS M. 《Journal of Petrology》1960,1(3):261-285

Fifty scapolites have been analysed spectrographically for numerouselements. Average concentrations (p.p.m.) were as follows: B25, Be 9-3, Ga 33, Ti 82, Li 56, Cu 4-4, Zr 59, Mn 57, Sr 1,800,Pb 45, Ba 120, Rb 20. The following were seldom or never detected:Cr, Ni, Co, Mo, Sn, V, Sc, Ag, Y, La. The major elements Ca,Na, K were also determined. The distribution of the trace elementscan be explained by isomorphous substitution, but no detailedcorrelation of trace elements with each other or with majorelements was found. Refractive indices were determined and the relation betweenaverage index and per cent Me was examined: correlation waspoor, which may in part be attributed to analytical error. Examination of scapolite parageneses shows that scapolite characteristicallyoccurs in the upper amphibolite facies or the pyroxene hornfelsfacies: it is not restricted to these and may occur in any faciesfrom zeolitic to granulitic and in any hornfels facies. Theelements generally concentrated in scapolite include Ca, Na,C, Cl, S, H, B, Be, Li, Sr, Pb. The presence of C, Cl, S, Htestify to genesis in the presence of high partial pressureof CO₂, Cl₂, SO₃, H₂O (or related compounds), that is in pneumatolytic,pegmatitic, or hydrothermal environments. The concentrationof B, Be, Li can also be attributed to these conditions. The source of the elements concentrated in scapolite must inpart be common rocks. In a limited contact zone, the nearbymagma supplied some elements, but where regional scapolitizationhas taken place the presence of magma is less clear. Many commonrocks or rock series contain all the necessary constituents,but some particular conjunction of conditions is necessary forscapolite to form, or it would be more common.  相似文献   

Evidence for inertial droplet clustering in weakly turbulent clouds     

KATRIN LEHMANN  HOLGER SIEBERT  MANFRED WENDISCH  RAYMOND A. SHAW 《Tellus. Series B, Chemical and physical meteorology》2007,59(1):57-65

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Integrated water resource management and institutional integration: realising the potential of spatial planning in England   总被引：1，自引：0，他引：1  

SUE KIDD  DAVE SHAW 《The Geographical journal》2007,173(4):312-329

This paper explores the various dimensions of integration that need consideration in developing appropriate institutional arrangements for integrated water resource management (IWRM), drawing upon both IWRM and spatial planning sources. As a result, a framework of integration in IWRM is set out. This is then used to consider the strengths and weaknesses of the new spatial planning system in England, and its potential to contribute to IWRM activities that are being developed, partly in response to the European Union Water Framework Directive. From this analysis it is argued that, taken overall, spatial planning is well placed to meet these challenges and it could in fact play a much more central role than is currently envisaged. An alternative model for IWRM in England is set out which sees the new river basin management plans as integral, rather than parallel, to the spatial planning system.  相似文献   

The problem of recognizing melt-out till     

SYLVI HALDORSEN  JOHN SHAW 《Boreas: An International Journal of Quaternary Research》1982,11(3):261-277

Deposition of till by melt-out was described as early as a hundred years ago, and today the criteria which provide evidence to support an interpretation of melt-out till are available. The most important criteria are (P₁) the presence of unlithified, sorted and stratified sediments within or interstratified with the till(s). (P₂) the presence of a statistically preferred orientation of stone axes closely related to ice-flow condition, and (P₃) a configuration of till with a recognizable textural or lithological property closely related to the configruation of englacial debris with regard to P₁. Based on P₁ and P₂ and on regional aspects, tills composing ridges transverse to the dircetion of ice flow are interpreted as mult-out till and flow till. The interpretation of till genesis must be based on the balnce of probability, as absolute proof is unrealistic in most cases.  相似文献   

面向活动地点推荐的个人时空可达性方法   总被引：2，自引：1，他引：1  

陈洁  陆锋  翟瀚  萧世伦 《地理学报》2015,70(6)

如何在时空制约条件下合理安排个人活动与出行是现代社会中人们日常工作和生活的迫切需求。个人时空可达性研究以个人时空行为视角聚焦个人在时空条件下开展各种活动的自由度,长期以来一直受到人文地理学、社会学和交通工程学等领域的广泛关注。本文基于时间地理学理论,提出一种个人时空可达性方法,顾及活动地点开放时间、最短活动时长及个人活动偏好,实现个人时空可达性分析与评价。然后,利用城市餐饮类服务设施空间位置、营业时间、公众评级等多维时空属性信息及城市路网数据检验方法有效性。本文提出的个人时空可达性方法可为空间规划、时空行为研究提供方法支撑,同时,面向个性化活动地点推荐,可为个人智慧出行提供策略与指导,并且在公众位置信息服务及位置社交网络内容服务等方面具有良好的应用前景。  相似文献   

Three-dimensional P and S wave velocity structures of the Sichuan basin and Longmen Shan: Implications for Seismic Hazard     

WANG Maomao  Judith HUBBARD  Andreas PLESCH  John H. SHAW  JIA Dong  LI Yiquan 《《地质学报》英文版》2013,87(Z1):399-400

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砂土围压下的废轮胎拉拔试验评估     

张达德  张家豪 《岩土力学》2011,32(3):733-737

由于轮胎具有高强度与耐久特性,将废旧轮胎作为加筋土壤结构物的加筋材料,应是21世纪处理废轮胎的一个方向。由于轮胎为一立体结构材料,其所造成的边界影响将不同于普遍使用的平面式土工织布与土工格栅,藉由柔性前壁可有效改善砂土挤压所造成的前壁效应。以完整和一侧被切割轮胎进行试验,在前壁与侧壁效应良好的控制下,经切割的废轮胎能与砂土紧密夯实并增加受正向应力面积,其拉出阻抗优于完整轮胎。当轮胎减少一侧的胎唇钢丝,切割轮胎发生的变形量大于完整轮胎的变形量。以不同的连接材料评估两个轮胎的加筋成效,其结果显示轮胎与轮胎间的拉伸变形将影响其拉拔阻抗,需藉由低延伸性材料与刚性夹片限制轮胎的变形。因此,采用废旧轮胎进行加筋填筑时,需注意轮胎产生的沉陷变形量,此工法可用于边坡或路堤的加筋工程。  相似文献