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1.
通过对 1 0 1 0~ 1 0 4 0℃氧化气氛下烧成的高白钛乳浊釉的试验 ,探讨了化学成分、晶粒大小对钛釉的影响 ,遴选出屑石型高白乳浊釉的最佳配方。  相似文献   

2.
The Qitianling calc-alkaline granite in Hunan Province (South China) has attracted much attention since the discovery of the Furong super-large tin deposit. The present study provides new mineralogical data to address their implications for exploration of tin deposits. In the Taoxiwo granite in the southeastern part of the Qitianling granite body, Sn-rich titanite was identified as an important type of Sn-bearing mineral. The titanite commonly occurs with biotite as euhedral crystals, exhibiting typical envelope-like shape and sector-zoning texture. These indicate that the titanite most likely crystallized in the magmatic stage. Electron-microprobe analyses show that the titanite is enriched in tin up to 1.12 wt% SnO2, with an average of 0.43 wt%. With the crystallization of the granite, primary minerals undertook hydrothermal alteration by magma-derived fluids. Subsequently, in the hydrothermal stage, the primary Sn-bearing titanite was altered (at least partially), but still preserved its typical envelope-shaped outline. Micro-scale cassiterite is a representative product of such alteration; other secondary minerals include fluorite, ilmenite, Sn-bearing rutile and quartz. Therefore, the titanite, commonly present in the calcalkaline granites, can be treated as an important Sn-carrying mineral in the Qitianling granite, reflecting the primary magmatic environment with tin enrichment. The hydrothermal alteration of the primary titanite and subsequent crystallization of cassiterite recorded a process of leaching and accumulation of tin in magmatic-hydrothermal evolution of the Sn-bearing granite. Thus, this titanite has important implications for tin exploration. Supported by National Natural Science Foundation of China (Grant Nos. 40730423 and 40221301) and Project of China Geological Survey (Grant No. 1212010632100)  相似文献   

3.
Using newly determined Sm isotopic abundances for correcting the isobaric interference of 144Sm on 144Nd and the established mass bias relationship between Sm and Nd, a series of in situ Nd isotopic measurements were conducted for relatively high Nd concentrations of natural geological materials, including apatite, titanite, monazite and perovskite on a Neptune multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS), coupled to a 193 nm ArF excimer laser ablation system. The results show that Ce has no significant influence on the precision and accuracy of Nd isotopic analyses for LREE-enriched geological minerals and that our approach is efficient in obtaining reliable 143Nd/144Nd and 147Sm/144Nd ratios for those materials with Sm/Nd<1 (147Sm/144Nd<0.6). When combined with trace element and U-Pb isotope data, the in situ Nd isotopic data can provide important information on geological processes.  相似文献   

4.
报导了前驱体溶液的pH值对Bi-Ti溶液的水解特性的影响,并探讨了乙醇胺的催化作用机理。研究表明,乙醇胺可调节溶液的pH值,其机理是与HAc反应,并与Bi+离子生成稳定的络合物.前驱体溶液的pH值是决定溶胶、凝胶质量的主要因素.pH值较小时,溶液容易产生沉淀;pH值较大时,溶液中有大量的浑浊物;只有pH值在2.5~4之间的溶液才能形成均匀稳定的溶胶和凝胶  相似文献   

5.
Using newly determined Sm isotopic abundances for correcting the isobaric interference of ^144Sm on ^144Nd and the established mass bias relationship between Sm and Nd, a series of in situ Nd isotopic measurements were conducted for relatively high Nd concentrations of natural geological materials, including apatite, titanite, monazite and perovskite on a Neptune multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS), coupled to a 193 nm ArF excimer laser ablation system. The results show that Ce has no significant influence on the precision and accuracy of Nd isotopic analyses for LREE-enriched geological minerals and that our approach is efficient in obtaining reliable ^143Nd/^144Nd and ^147Sm/^144Nd ratios for those materials with Sm/Nd〈1(^147Sm/^144Nd〈0.6). When combined with trace element and U-Pb isotope data, the in situ Nd isotopic data can provide important information on geological processes.  相似文献   

6.
通过对花岗岩类中的铁、钛等副矿物特征及其与花岗岩成岩物质来源和形成条件等关系的研究,提出铁、钛副矿物是复成因多世代的,它们形成于一定的物理化学条件下,具有重要的成因意义。其中磁铁矿和榍石代表偏高的氧逸度和富钙的介质,钛铁矿代表偏低的氧逸度和贫钙的介质。钛铁矿能在氧速度变化幅度较大的范围内形成和稳定。  相似文献   

7.
针对多层压电降压变压器制作过程中改性钛酸铅(PT)瓷料轧膜成型问题,从理论上分析聚乙烯醇(PVA)溶液对碱性瓷料成型的失效问题,实验中采用水洗陈腐的方法改变钙改性PT碱性瓷料pH值,再利用聚乙烯醇(PVA)粘接剂进行轧制,实验结果表明轧膜成型效果好,烧成的陶瓷压电性能优良,克服了碱性电子瓷料不能采用PVA成型的困难,该方法对于其它碱性瓷料成型也具有一定的借鉴意义.  相似文献   

8.
引进了(K,L)-内射性和(K,L)-伪内射性,这里K和L分别是模范畴上短正合列类的子类和模范畴态射类的子类。然后对这样定义的广义内射性进行了不依赖于预根理论的讨论,并对伪内射性与伪投射性之间的关系作了讨论。  相似文献   

9.
证明了当2≤u≤7和u≥38时,存在区组大小为4和指数为2的不完全的完备Mendelsohn设计(4,2)-IPMD(v,u)的充要条件为v≥3u+1,其中(v,u)≠(20,6)。  相似文献   

10.
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12.
假定D是一个5-(v,k,2)设计,G是一个D的自同构群,并且G的基柱Soc(G)=PSL(2,2n).利用PSL(2,q)的子群作用于投影线上的轨道,证明了G不能旗传递的作用在非平凡的5-(v,k,2)设计上.这是旗传递t-设计的分类问题的一个结果.  相似文献   

13.
Microorganisms that inhabit sub-seafloor lavas are capable of etching volcanic glass and creating micron-sized tunnels and pits. Mineralization of these bioalteration traces ensures that these textures survive deformation and transformation of the host glass to metamorphic minerals. The fossil record of such bioalteration textures extends far beyond volcanic glass from in-situ oceanic crust to include meta-volcanic glass from ophiolites and Precambrian greenstone belts. Investigation of petrographic thin se...  相似文献   

14.
(La,Sr)(Co,Fe)O_3与(La,Sr)MnO_3阴极材料的表征与性能   总被引:1,自引:0,他引:1  
采用氨水沉淀法分别制备La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF)与La0.8Sr0.2MnO3-δ(LSM)两种阴极材料,并用X射线衍射(XRD)、场发射扫描电子显微镜(FESEM)和比表面积(BET)对所制备材料的结构、晶粒大小、形貌及比表面积进行表征.结果表明,LSCF和LSM前驱体分别在900℃和1200℃煅烧5h后产物均形成单一正交的钙钛矿结构,但LSCF具有较小的粒径和较大的比表面积.电化学性能测试结果表明,LSCF阴极比LSM阴极的过电位低,且LSCF为阴极单电池的输出功率较高.  相似文献   

15.
The Busemann function plays a very important role in studying topology and geometry of a complete Riemannian manifold. In this paper, the Busemann functions on the real classical domain of the first type and the Cartan domain of the fourth type in the explicit formulas are obtained.  相似文献   

16.
In situ U-Pb dating of titanite by LA-ICPMS   总被引:4,自引:0,他引:4  
Titanite is an ideal mineral for U-Pb isotopic dating because of its relatively high U,Th and Pb contents.Here,we developed a technique for U-Pb dating of titanite using the 193 nm ArF laser-ablation system and Agilent 7500a Q-ICP-MS.Standards of titanite (BLR-1 and OLT-1) and zircon (91500 and GJ-1) were dated using single spot and line raster scan analytical methods.To check the matrix effect,titanite (BLR-1) and zircon (91500) standards were analyzed as the external standards.The weighted mean 206 Pb/238 U ages of OLT-1 titanite are 1015±5 Ma (2,n=24) and 1017±6 Ma (2,n=24) by single spot and line raster scan analyses,respectively,using BLR-1 titanite as the external standard.These ages are consistent with its reference age of about 1014 Ma.However,using 91500 zircon as the external standard,the weighted mean 206 Pb/238 U ages are 917±4 Ma (2,n=24) and 927±5 Ma (2,n=24) for BLR-1 titanite,and 891±4 Ma (2,n=24) and 901±5 Ma (2,n=24) for OLT-1 titanite by single spot and line raster scan analyses,respectively.It is evident that these ages are ~12% younger than their reference values.Our results reveal that significant matrix effect does exist between different kinds of minerals during LA-ICPMS U-Pb age determination,whereas it is insignificant between same minerals.Therefore,same mineral must be used as the external standard for fractionation corrections during in situ LA-ICPMS U-Pb age analysis.In addition,we determined U-Pb ages for titanites from the Early Cretaceous Fangshan pluton,which indicates a rapid cooling history of this pluton.  相似文献   

17.
设G是一个(mg+(m-1)r,mf-(m-1)r)—图,且g(x)≥r-1,给出了G是随机(m,r)—正交的(g,f)—可因子化图的一个充分条件.  相似文献   

18.
李爱芹  王海棠 《科学技术与工程》2007,7(20):5199-52035212
令N(Z)表示正整数(整数)集,N(Z)的非空有限子集S的和图G (S)是图(S,E),其中uv∈E当且仅当u v∈S;一个图G称为(整)和图,若它同构于某个SN(Z)的和图,(整)和数σ(G)(ζ(G))是使得G∪nK1是(整)和图的非负整数n的最小值。模和图是取SZm\{0}且所有算术运算均取模m(≥│S│ 1)的和图。一个图G的模和数ρ(G)是使得G∪ρK1是模和图的孤立点数ρ的最小值。对图Kr,s-E(rK2)(s>r≥4且s≥6)。研究了它的(模,整)和数,文中确定了图K4,5-E(4K2)的(模,整)和数。  相似文献   

19.
讨论了(1,β) 几何在AG(3,q)中的全嵌入。证明了当q>2时,一个(1,q) 几何能够全嵌入在AG(3,q)中当且仅当它是一个线性表示T*2 (H)。  相似文献   

20.
(mg+1,mf)-图的(g,f)-因子分解   总被引:1,自引:1,他引:0  
任意给定两个整数值函数,如果二部图是由这两个整数函数限制的二部图,那么对于该二部图的任意一个匹配,二部图存在一个由这两个整数函数限制的因子,而且该因子只包含匹配的任意给定的一条边,但不包含匹配的其它的边.  相似文献   

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