Elasticity of CaTiO3–CaSiO3 perovskites

Polycrystalline specimens in the CaTiO₃–CaSiO₃ perovskite system have been hot-pressed in a 2000-ton uniaxial split-sphere apparatus (USSA-2000) at pressures up to 15 GPa and temperature of 1550°C, for the compositions CaTiO₃, Ca(Ti_0.75Si_0.25)O₃, Ca(Ti_0.5Si_0.5)O₃. For the specimens with the bulk densities within 1% of the X-ray density, compressional and shear wave velocity measurements have been conducted using ultrasonic interferometry. The measured adiabatic bulk moduli (K _s ) for the CaTiO₃ and Ca(Ti_0.5Si_0.5)O₃ perovskites are 175(1) and 188(1) GPa and shear moduli (G) of 106(1) and 109(1) GPa. In situ X-ray diffraction studies at high pressure and temperature resulted in isothermal values for K ₀ of 170(5) and 185(5) GPa, respectively. For the unquenchable CaSiO₃ perovskite, elasticity theory and systematics were used to predict K ₀=212(7) GPa and G ₀=112(5) GPa; this shear modulus is 37% less than that for (Mg,Fe)SiO₃ perovskite, suggesting that CaSiO₃ perovskite cannot be ignored in modeling the composition of the Earth’s lower mantle. Received: 27 June 1997 / Revised, accepted: 25 November 1997     

3 质子磁力仪

3.1 质子磁力仪原理3.1.1 核子的旋进原子和分子的磁矩是由原子核的磁矩,电子的自旋磁矩和轨道磁矩三部分合成的。通常电子的磁矩是以玻尔磁子μ_B 为单位,核子磁矩以核磁子μ_N为单位,而μ_N=1/1836.2μ_B可见,与电子的磁矩相比,核子的磁矩是很微弱的。这里所说的磁矩是磁偶极矩的简称,严格地说,粒子或原子核的磁矩是磁量子数最大时磁矩矢量在磁场方向分量的期望值。在质子磁力仪中,使用的工作物质有水、酒精、煤油、苯、庚烷、丙酮等富含氢的液体,在组成这些物质的分子里,电子的轨道磁矩和自旋磁矩各自成对地抵消了,如果我们不考虑原子核的磁矩,则这类物质是逆磁性的。另外,组成分子的原子如氧、碳的原子核内,质     

矿物3CaO·3Al_2O_3·BaSO_4形成过程研究

ｅｏｒｅａｎｕ等［１］研究ＣａＯＡｌ２Ｏ３Ｍｘ（ＳＯ４）Ｙ［Ｍ＝Ｍｇ２＋、Ｓｒ２＋、Ｂａ２＋、Ｚｎ２＋、Ｆｅ２＋、Ｆｅ３＋、Ａｌ３］系统中,形成类似于矿物３ＣａＯ·３Ａｌ２Ｏ３·ＣａＳＯ４（硫铝酸钙）的可能性时,报道合成了新矿物３ＣａＯ·３Ａｌ２Ｏ３·ＢａＳＯ４（简写为３ＣＡ·ＢａＳＯ４）;部分学者［２,３］研究过它的胶凝性能等。在有关文献中,研究者制备研究用纯矿物的煅烧条件、获得样品的矿相组成不尽相同。如文献［１］在温度１４００℃保温２４０ｍｉｎ,制备的样品包括铝酸钙（ＣａＯ·Ａｌ２Ｏ３…     

Electron paramagnetic resonance of Sc3+-stabilized CO 3 3− molecule-ion in natural calcite

Electron paramagnetic resonance (EPR) spectra of CO ₃ ^3– molecule-ions stabilized by Sc³⁺ in natural calcite were identified and studied at X-band frequencies and room temperature. The principal values of the g-tensor (g _xx= 1.9997, g _yy = 2.0030, g _zz = 1.9972) and the direction cosines of the g and A tensors for CO ₃ ^3– -Sc³⁺ center were found to be close to that for the well-known CO ₃ ^3– -Y³⁺ center. A quantitative comparison of different impurity contents in calcite samples and analysis of the intensities of forbidden transitions were used to identify Sc³⁺. An estimation of the unpaired electron spin density on the nuclei of paramagnetic centers confirms that both centers, CO ₃ ^3– -Sc³⁺ and CO ₃ ^3– -Y³⁺, have the same nature.     

(3)PALEOZOOLOGY

20001609 Cao Changqun(Nanjing Instituteof Geology and Palaeontology,ChineseA-eodemy of Seienee、.Nan)川g,Jiangsu);Shang Qinghua The Study of Graptolite Re-f 1 eetance as the Indicator of Souree一RockMaturation in ordovieian and Silurian ofTarim Basin,ordos,Jiangsu Provinee(AeraPalaeolltologiea Siniea,ISSN 0001一6616,CN32一1188/Q,39(l),2000,P.151一156,3 illus.,2 tables,10 ref) Based on rhe graptolito refleetanee of Or-dovieian and 51]urian in Tar一rn Basi;z,Ordos,J iangsu Provin…     

超临界流体中MoO3与WO3溶解度实验探讨

超临界地质流体以其独特的性质对金属成矿元素具有超强的萃取、层析和搬运能力,在热液矿床成矿机制研究中对揭示成矿物质的源、流和汇起着特殊和重要作用。本文利用分析纯H2MoO4在高温下脱水制备了MoO3(白色斜方晶系),在冷封式高压釜中实验测定了417℃超临界条件下,MoO3在纯水中的溶解度分别为7.3(29MPa)、14.2(45MPa)、21.6(55MPa)、27.7(78MPa)、32.5(100MPa)、和34.2(150MPa)mmol/l,热液中钼的存在形式为H2MoO4。依据前人的实验方案,补充测定了WO3在4.0%NaCl水溶液中于450%条件下的溶解度,其值分别为27.51(50MPa)和30.52(100MPa)mmol/l。结合前人研究结果发现,MoO3、WO3的溶解度在临界区域内具有超临界现象,在超临界条件下其溶解度与石英的超临界溶解度行为基本相似,表现为溶解度随体系温度和压力的升高而增大,这对揭示岩浆热液型和石英脉型钨、钼矿床的形成机制具有重要指导作用。     

基于模型的3D3C采集设计与评价

对目前三维三分量(3D3C)地震勘探数据采集设计的方法进行了系统分析,利用聚焦射束分析技术(CFP),提出了基于模型的3D3C采集设计方法及其评价的参数。从模型出发的设计方法,能够使3D3C的采集结果更加真实可靠。      

(3)PALEOZOOLOGY

1 937/P,30(4),1 995.p.321一328,2 graphs1 rable,8 ref,with English absrraer)962149 Yong Ruidong(In、titute of Geolo-gy,Guizhou Bureau of Geology and MineralResourees);Yang Chengxi THE CAR-BONIFEROUS TRACEF()SSILS INGUIZll0U:DISCUSSION ON DISTRIBU-TION OF ZOOPHYCOS THROUGHOUTGEOLOGIC HISTORY(GZG,ISSN 1000一5943,CN52一1059/P,12(4),1995,l,.290一297,2 graphs,1 plat。,1 2 rof) l’raee fossils臼rc abundant in fhe Cdr-bonlferous strata,esPeelally in those …     

无机材料对PVA-H3BO3包埋固定化方法的改进

利用无机材料活性炭纤维、泥炭、蛭石、高岭土、珍珠岩、钙基膨润土、粉末活性炭和硅藻土对PVA-H3BO3固定化方法进行改进,包埋固定已筛选的阿特拉津降解菌,制成生物微球,在10℃条件下考察其对生物微球溶胀行为及生物微球去除阿特拉津效果的影响。结果表明,空白生物微球和高岭土改性生物微球对AT的去除符合零级动力学方程,其余10种生物微球对AT的去除符合一级动力学方程。活性炭改性生物微球对AT的去除半衰期最短,为2.61h;硝化泥炭改性生物微球对AT的去除半衰期最长,为39.93h。结合实验现象和扫描电镜分析结果显示,强碱泥炭、硅藻土、蛭石、130℃烘干泥炭、磺化泥炭、珍珠岩改性生物微球和未添加无机材料改性的生物微球未发生溶胀现象。     

昆明白泥井3号隧道围岩稳定性FLAC3D模拟

应用FLAC^3D数值模拟软件对昆明白泥井3号隧道围岩稳定性进行了分析和评价。结果表明隧道支护后围岩的最大变形出现在隧道右侧拱顶，为1．00cm；隧道支护后左侧拱和右侧拱脚处剪应变明显增大，为应力集中区；围岩可以通过自身应力、应变和能量的调整，使整个隧道围岩处于稳定状态；同时也表明FLAC^3D用于隧道围岩变形分析是可行的。