首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 343 毫秒
1.
采用Netzsch STA409PC同步热分析仪研究了苏州高岭石(KW125)在30℃~1 200℃间的热分解过程。采用"Netzsch Thermokinetics software"软件对其脱羟基机理进行了非等温动力学研究。基于等转化法评价了反应活化能及反应进程的依存关系。基于多元非线性拟合确定了最可能反应机理及动力学参数。研究结果表明:苏州高岭石在30℃~1200℃温度范围的热分解为脱羟基与相转变等两个阶段。其脱羟基(30℃~800℃)过程中活化能呈现三个变化:197.68 kJ/mol±12.95 kJ/mol→181.04kJ/mol±18.98kJ/mol→269.7kJ/mol±14.64kJ/mol。脱羟基反应遵循三步连续反应模型t:f,f;(D3-Fn-Fn),一个三维扩散(D3)反应,然后是两个n序列(Fn)反应。第一步,f(α)=3(1-α)^2/3/(2(1-(1-α)^1/3),E1=185.27 kJ/mol,logA=10.83s^-1;第二步,f(α)=(1-α)^n,n=1.75,E2=187.81 kJ/mol,logA=10.32s^-1;第三步,f(α)=(1-α)^n,n=4.4,E3=262.70 kJ/mol,logA=13.26s^-1。  相似文献   

2.
堇青石低热膨胀机理研究   总被引:3,自引:0,他引:3       下载免费PDF全文
张振禹  耿建刚 《地质科学》1997,32(3):308-312
本文根据垄青石晶体结构特点和有关热力学资料,建立了堇青石热膨胀系数的理论计算模式:半定量计算方法,α=αMgO × 1/3 × 2/3;定量计算方法,α=ΔS/ΔT/2/(a × b).分别计算了堇青石、印度石的线热膨胀系数,半定量计算结果:α=3.31 × 10-6-1(堇青石、印度石);定量计算结果,a=1.54 × 10-6℃-1(堇青石),α=0.85 × 10-6℃-1(印度石),与实验测定结果(堇青石:α=2.3 × 10-6℃-1,印度石:α=1.0 × 10-6-1)吻合。  相似文献   

3.
于靖  张华 《水科学进展》2015,26(5):714-721
为研究城市小型河流中污染物的物理迁移过程规律,分析基流条件下流动水体与暂态存储区之间的滞留交互作用,采用溴化锂(LiBr)作为保守性示踪剂进行野外现场示踪试验,结合一维溶质运移存储模型(One-dimensional Transport with Inflow and Storage model, OTIS)定量解析潜流交换特性,估算纵向弥散系数(D)、潜流交换面积(As)、主河道断面面积(A)和潜流交换系数(α).模型度量指标DaI值和均方根误差值结果表征参数模拟结果可靠性高,拟合效果理想.由泵入点O至下游1 300 m设置的A、B、C、D 4处监测点的模拟结果表明,水文参数DAsAα均随水文条件而变,OB河段(0~600 m)潜流交换能力较弱,主要以对流弥散过程为主;BD河段(600~1 300 m)具有较强的暂态存储能力,对溶质的滞留时间长;BC(600~1 000 m)和CD(1 000~1 300 m)河段交换系数分别为(3.42×10-6±0.65×10-6)s-1和(2.87×10-6±0.81×10-6 )s-1;河段BC存在2.2×10-5m3/(s·m)的侧向补给流量.4个河段对比发现,城市河流渠道化、河床沉积物贫瘠等特征导致潜流交换能力弱化.  相似文献   

4.
曾庆理  刘庆生  邱宁 《地球科学》2009,34(6):993-1000
中国大陆科学钻探(CCSD) 主孔中318~380m (A)、420~470m (B) 和530~600m (C) 深度分布三段高铁钛榴辉岩, 它们具有高全铁(FeOT) (平均15.36%、14.09%和20.83%)、高TiO2 (平均3.89%、3.28%和4.10%) 和低SiO2 (平均44.64%、48.64%和41.10%) 含量分布特征.岩石磁性测量结果表明, A段样品为低磁化率(平均3.61×10-7m3·kg-1)、低天然剩余磁化强度(平均0.12×10-3Am2·kg-1) 和低Q值(平均8.03);B段样品为高磁化率(平均12.55×10-7m3·kg-1) 和中等天然剩余磁化强度(平均1.47×10-3Am2·kg-1) 及Q值(平均26.42);C段样品磁化率介于A、B段之间(平均9.73×10-7m3·kg-1), 而天然剩余磁化强度(平均10.05×10-3Am2·kg-1) 和Q值(平均138.571) 最大.岩石磁学和岩相学研究表明, A、B两段样品代表了新鲜或轻度退变质榴辉岩的磁性特征, 但就研究的代表性样品的磁性岩石学特征而言, B段样品显示的退变质程度稍高于A段; C段榴辉岩样品密度最大, 主要为新鲜榴辉岩, 氧逸度明显高于A、B两段样品, 且存在大量出溶过程形成的以薄层结构为标志特征的赤铁矿-钛铁矿固溶体, 可能是样品高天然剩磁的主要原因.   相似文献   

5.
在由-αA l2O3和T iO2合成-βA 12T iO5时,文献报道有待定归属相(称作x相)先于-βA 12T iO5出现在煅烧后的混合物内,该x相表现出中间产物相特征,据说它在混合物内的含量随煅烧温度升高而增大,1 400℃时出现-βA 12T iO5,且x相与未转化反应物均转变成-βA 12T iO5。研究煅烧共凝胶法前驱体制备-βA 12T iO5的固相反应以及-βA 12T iO5的热分解过程,以了解该待定归属相的生成、演变规律。同文献报道的x相相比该相的初始生成温度、转化为-βA 12T iO5的温度均有明显降低,1 150℃煅烧共凝胶法前驱体所获产物的XRD图谱(18°≤2θ≤58°)内出现3个归属该x相的衍射峰,它们的峰中心分别位于2θ=41.2,°44.0,°24.9°(按相对峰强大小排列)。M gO掺杂使该x相与少量-βA 12T iO5相共同出现于1 150℃及1 200℃煅烧物内。1 250℃煅烧使该相失稳,转变为-βA 12T iO5,同时使未转化的金红石、-αA l2O3完成固相反应。对比表明x相的转变温度具有阈值特征,前驱体的微细化使之大大降低。本研究首次发现,伴随-βA 12T iO5在1 100℃下的热分解,该待定归属相重新出现,说明该相随热过程条件改变具有生成-消亡-重新生成的可逆性。它的消亡及重新生成体现出同-βA 12T iO5此消彼长的相关性。它应该是除-βA 12T iO5、A 12T i7O15以外的第三种铝、钛复合氧化物。  相似文献   

6.
滤水管长度计算公式: L=Q·α/d·(2·7)式中 L—过滤器长度,m; Q—单井出水量,m~3/h; d—滤水管缠丝外径,mm; α—经验系数(见表2—2)。算例:某井建在粗砂砾石含水层中,渗透系数K>70m/d,设计井管直径450mm,滤  相似文献   

7.
为查明郴州市地下热水资源的特征及储量,本文选取许家洞地区两个典型地热田,通过地热地质调查、水质测试等方法调查了研究区的地质条件、地热流体场特征、地下热水水化学类型。基于上述研究开展了许家洞地区地热资源储量的分析评价。研究结果表明:(1)区内地下热水受断裂构造控制,是入渗地下水沿着断裂构造在深部循环过程中吸收隐伏岩体中的热能形成的;(2)地下热水水化学类型主要为HCO3-Ca型、HCO3-Ca·Na型或HCO3·SO4-Ca·Mg型,为低温、无色透明的弱碱性水;(3)热水的主要补给来源为大气降水,水分入渗后主要沿区内发育的北东向断裂构造(F24、F7、F25、F8)运移到一定深度,地下水逐渐增温变成地下热水,在断裂交汇处沿着不均匀发育的岩溶裂隙系统向上运移,以温泉形式出露于地表;(4)研究区地下热水每年可提供热能约3.23×108MJ,每年可节约标准煤资源约1.18×104  相似文献   

8.
李想  徐倩  徐开喜  吴国学 《世界地质》2016,35(1):123-132
采用地质、物探、化探找矿方法,对漠河元宝山金矿进行综合研究。结果表明,目前已发现矿体4条,矿化体3条,Au平均品位2.15×10~(-6);赋矿地层为侏罗系中统漠河组;控矿构造为NEE向漠河推覆构造。磁场强度ΔT值一般在-30~20 nT,ΔΤ最大值为133.1 n T;视极化率最大值为23.58%,平均值为10.58%;视电阻率一般在500Ω·m以下,最高为1 200Ω·m,显示物探异常具低阻、高极化特征。漠河组地层金元素丰度值为8.06×10~(-9),标准离差为0.25,变化系数为0.912。黄铁矿δ~(34)S值为3.3×10~(-3)~5.3×10~(-3),极差为2.5×10~(-3),平均值为4.5×10~(-3),具有岩浆硫特点;石英中流体包裹体的δ18O值为5.2×10~(-3)~9.6×10~(-3),δD值为-125×10~(-3)~-112×10~(-3),δ18O和δD变化范围较大,反映在成矿过程中有大气降水加入。根据地质和物化探异常特征等综合信息,认为矿区西部小金沟(HS-8水系组合异常)有良好的找矿前景。  相似文献   

9.
利用高温粉末X射线衍射研究了高纯地质成因文石从室温到1 073 K的相变过程以及文石和方解石的热膨胀性质,并分析了地质成因与生物成因文石的差异和影响因素。结果表明:斜方晶系的文石在693~733 K转变为三方晶系的方解石,相变临界温度为723 K,摩尔体积增加5.97%;文石在300~663 K的体积热膨胀系数α(V)(10-5/K)随绝对温度T(K)的变化规律为:α(V)=3.59(79)+7.17(170)×10-3T,文石的热膨胀具有强烈的各向异性[轴向热膨胀系数α(c)α(b)α(a)];方解石在733~973 K的热膨胀系数α(10-5/K)为:α(V)=3.78(25),α(a)=-0.27(2),α(c)=4.31(29),a轴具有负热膨胀。生物成因的文石相变温度比合成和地质成因文石低60~140 K,粉末状文石相变温度低于单晶和未被破坏的整块文石;粉末状的生物成因文石和方解石与非生物成因的文石和方解石的热膨胀系数接近,然而整块的生物成因的文石有更小的热膨胀系数。  相似文献   

10.
根据位场理论,将观测曲面上测得的△T(或Za)视为位函数,代入偶层位公式的极限形式,求解出对应于△T(或Za)的等效偶层的磁化强度J(α,β,γ)。将J(α,β,γ,)代入偶层场强分量表达式 (α)/(α)n(1/r)dS 只要给定了方向u,就可得到△T沿该方向的一阶导数。将J(α,β,γ)代入(α)T/(α)x,(α)T/(α)y,(α)T/(α)z的积分表达式就能得到△T的二阶导数。因为使用的是二重积分形式的导数的精确表达式,它克服了空间域差商求导的致命弱点。特别是该方法能将起伏地形曲面上的场值向上延拓(包括曲化平)和求一阶(或二阶)导数两个转换过程集中在一个积分表达式中,一次计算完毕。  相似文献   

11.
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.  相似文献   

12.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.  相似文献   

13.
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).  相似文献   

14.
HYDROGEOLOGY     
正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level  相似文献   

15.
正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),  相似文献   

16.
17.
正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-  相似文献   

18.
正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-  相似文献   

19.
正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)  相似文献   

20.
GEOCHEMISTRY     
正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号