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1.
Origin of ore-forming fluid in the Piaotang tungsten deposit in Jiangxi Province: Evidence from helium and argon isotopes 总被引:5,自引:0,他引:5
The Piaotang tungsten deposit in Jiangxi Province is one of the most important tungsten deposits in the South China Tungsten Metallogenic Province.In this study,we selected wolframite and chalcopyrite from the main mineralizing stage of the Piaotang tungsten deposit,and analyzed the helium and argon isotopic compositions in fluid inclusions of these minerals.The results show a 3He/4He ratio of 0.17 to 0.86 R/Ra,which fall within the range between continental crust(0.01―0.05 R/Ra) and air-saturated water(1 R... 相似文献
2.
Isotopic geochemical characteristics of helium in garnet and omphacite of eclogite in the Dabie Mountains are discussed. Concentrations
of3He and4He in garnet and omphacite are 3.9 × 10−14–24.0 × 10−14 and 0.48 × 10−7–9.42 × 10−7cm13.g−1, respectively. Values of3He/4He have a range of (1.19–4.63) × 10−7. Helium In the eclogite is derived from both mantle and crust. Isotopic geochemical data of helium indicate that eclogite
in the Dabie Mountains might be formed in depleted mantle and the age of the cologite would be Indo-China epoch. 相似文献
3.
The helium and argon isotopic compositions of the ore-forming fluids from the molybdenum deposits such as Jinduicheng, Donggou, Shijiawan, and Sandaozhuang, which are located in the East Qinling molybdenum belt in south margin of North China Block (SMCNB), are reported in this paper. The origin and the evolution of the ore-forming fluids and their coupled-relationships with the intra-continental collision and orogenic process of Qinling Orogen in Mesozoic-Cenozoic have been discussed. The 3He/4He and 40Ar/36Ar values (3He/4He=1.38-3.64 Ra, and 40Ar/36Ar=295.68-346.39, respectively) of the fluid inclusions in pyrite from the molybdenum deposits in East Qinling suggest that, the ore-forming fluid system is mixed by two end members. One is the high temperature deep-derived fluid congenetic with the porphyries generated by crust-mantle mixing, and the other is the low-temperature meteoric water which is rich in crustal radiogenic He with the component of atmospheric Ar. From the Pb isotopic composition, and ore-bearing potential of the porphyry and the regional stratum, we can conclude that the ore-forming materials of the deposits in the East Qinling molybdenum belt are derived from the deep source by the mixing of lower crust and upper mantle. Therefore, the formation of the molybdenum deposits in SMNCB can be related to the crust-mantle interaction, which is accompanied by the intra-continental orogenic and extension process in the post-collision period of Qinling Orogen. The granitic porphyries which are related to Mo mineralization are not simple crust-remelting type granites or S type granites, but belong to syntexis-type or mantle-derived granites, hence their formation has a profound and regional geodynamic background. 相似文献
4.
New helium isotopic data of ores and rocks from the Altay orogenic zone, Xinjiang, China are reported, which show that the
pegmatites from No. 3 vein in the Keketuohai area have high3He/4He ratios up to 1.795 × 10−6 and 2.54 × 10−6. Such a result suggests that the metallogenic process of rare metal deposits in the Altay orogenic zone might be related
to mantle degassing. 相似文献
5.
Helium isotopic composition of inclusion fluid in pyrites from Machangqing copper deposit, China, has been measured. The measurements,
with3He/4He ratios ranging from 0.46–2.08 Ra, indicate that the helium in ore-forming fluid is a mixture of crust and mantle, and are
consistent with the fact that the parental magma responsible for the formation of ore-forming fluid of the deposit is of crust-mantle
provenance. 相似文献
6.
HU WenXuan SONG YuCai CHEN XiaoMing TAO MingXin ZHANG LiuPing 《科学通报(英文版)》2007,52(3):380-387
This study presents noble gaseous data of the corundum megacrysts from the Cenozoic basalts in Changle, Shandong Province, eastern China. It is known that no noble gaseous data of corundum megacryst have been documented before. The 3He/4He ratios (1.13-7.37 Ra) of the corundums from Changle vary from atmosphere to MORB values; the 20Ne/22Ne (9.67-10.75) and 21Ne/22Ne (0.0280-0.0372) data define two linear trends on Ne three-isotope diagram, respectively, along the MFL and the correlation line between atmosphere and MORB; the 38Ar/36Ar (0.177-0.194) ratios, the 40Ar/36Ar (280.9 -404.2) ratios and the 128-136Xe/132Xe ration with obvious 129Xe excess are generally higher than at-mospheric component, but the 40Ar/36Ar ratios are much closer to atomospheric ratio. The isotopic compositions of noble gases (particularly for He and Ar) of the corundums are similar to those of py-roxene, anorthoclase megacrysts, and mantle-derived xenoliths from this area, and those of man-tle-derived xenoliths from several areas in eastern China. Therefore, the noble gases trapped in the corundums probably are from mantle source, representing a ‘mixed fluid' produced by the interaction between the lithospheric mantle and fluids releasing from the convective plate. Both the noble gas isotopic compositions and the oxygen isotopic compositions of the solid corundums are not the characteristics of crustal source. These suggest that the corundums crystallized from mantle-derived magmas with minimal crustal contamination. 相似文献
7.
A novel spectrofluorimetric method for the determination of L-ascorbic acid is proposed. It is based on the inhibition of
L-ascorbic acid on the formation of 2,3-diaminophenazine, which is an oxidation product ofo-phenylenediamine catalyzed by laccase. The fluorescence (at λcx/λcm=464 nm /530 nnm) was enhanced strongly in the presence of organic media. The mechanism ofo-phenylenediamine oxidation reaction catalyzed by laccase in the presence of L-ascorbic acid is discussed. L-ascorbic acid
is determined in the ethanol, 1,4-dioxane and acetone over the linear range of 4.0×10−7≈1.2×10−4 mol/L, 4.0×10−7≈8.0×10−5 mol/L and 4.0×10−7≈1.0×10−4 mol/L with a detection limit of 1.20×10−5 mol/L, 1.19×10−5 mol/L and 1.24×10−8 mol/L, respectively. The method has been successfully applied to the simple and rapid determination of L-ascorbic acid in
pharmaceuticals and milk powder.
Supported by National Natural Science Foundation of China and the Special Funds of State Education Committe for Doctorate
Research
Huang Zuyun: born in Aug. 1963. Ph.D 相似文献
8.
A series of experimental methods including 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test, alkaline
phosphatase (ALP) activity measurement, mineralized function, Oil Red O stain and measurement were employed to assess the
effect of Dy3+ on the osteogenic and adipogenic differentiation of mouse primary bone marrow stromal cells (BMSCs) and the adipogenic trans-differentiation
of mouse primary osteoblasts (OBs). The results showed that Dy3+ had no effect on BMSC proliferation at concentrations of 1×10−8 and 1×10−5 mol/L, but inhibited BMSC proliferation at other concentrations. Dy3+ had no effect on OB proliferation at concentrations of 1×10−10 and 1×10−9 mol/L, but inhibited OB proliferation at other concentrations. Dy3+ had no effect on the osteogenic differentiation of BMSCs at concentrations of 1×10−9 and 1×10−7 mol/L, and promoted osteogenic differentiation of BMSCs at other concentrations at the 7th day. The osteogenic differentiation
of BMSCs was inhibited by Dy3+ at concentration of 1×10−5 mol/L at the 14th day, but promoted osteogenic differentiation of BMSCs at concentrations of 1×10−9, 1×10−8, 1×10−7 and 1×10−6 mol/L with the maximal effect at concentration of 10−6 mol/L. Dy3+ promoted mineralized function of BMSCs at any concentration. Dy3+ had no effect on adipogenic differentiation of BMSCs at concentration of 1×10−7 mol/L, but inhibited adipogenic differentiation of BMSCs at other concentrations. Dy3+ inhibited adipocytic trans-differentiation of OBs at any concentration, suggesting that Dy3+ had protective effect on bone and the protective effect on bone may be mediated by modulating differentiation of BMSCs away
from the adipocyte and inhibiting adipocytic trans-differentiation of OBs which may promote differentiation and mineralization
of OBs. These results may be valuable for better understanding the mechanism of the effect of Dy3+ on pathogenesis of osteoporosis.
Supported by the Foundation for Key Program of Ministry of Education of China (Grant No. 208018) 相似文献
9.
The electroanalytical method of ferriheme was studied by linear sweep voltammetry in medium of 0.05 mol/L Tris+0.05 mol/L
NH3−NH4Cl buffer at hang mercury drop electrodes (HMDE). Heme exhibits two pair reversible redox peaks and one irreversible peak.
The cathodic peak potentials are−;0.236 V, −0.422 V and −1.408 V respectively. The first and the third peaks can be used for
directly quantitative determination of heme concentrations. The peak currents are good linear relationship with heme concentration
in ranges of 3×10−6–6×10−5 mol/L and 3×10−7–1.5×10−5 mol/L respectively.
Supported by the National Natural Science Foundation of China
Lju Huihong: born in 1965, Lecturer. Visiting scholar from Xiangyang Teacher’s College, Hubei, 441053 相似文献
10.
TiO-2 thin films have bee deposited on p-Si(111) substrates by pulsed-laser ablation of metallic Ti target in the O-3 ambient. The current-voltage and capacitance-voltage of the Al/TiO-2/Si capacitors are measured. The results show that the dielectric constant of thin film after being annealed at 700℃ is found to be 46, and the border trap density and the interface state density at the TiO-2/p-Si interface are 1.8×10 12 cm -2 and 2×10 12 eV -1·cm -2, respectively. The conduction mechanisms of as-deposited films are also discussed. 相似文献
11.
GENG HaoRan SUN ChunJing WANG Rui QI XiaoGang ZHANG Ning 《科学通报(英文版)》2007,52(15):2031-2034
The densities of Sb and Bi melts were investigated by an improved Archimedean method. The results show that the density of the Sb melt decreases linearly with increasing temperature,but the density of the Bi melt firstly increases and then decreases as the temperature increases. There is a maximum density value of 10.002 g/cm3 at 310 ℃ ,about 39℃ above the melting point. The temperature depend-ence of the Sb melt is well fitted with the expression ρ =6.8590-5.8105×10-4T,and that of the Bi melt is fitted with ρ =10.3312-1.18×10-3T. The results were discussed from a microstructure viewpoint. 相似文献
12.
ZHOU Lei TIAN Jiwei ZHANG Xiaoqian 《科学通报(英文版)》2005,50(24):2885-2890
The turbulent dissipation along with temperature and salinity was measured on board R/V Dong Fang Hong 2 over the shelf break of the East China Sea from March 7 to 9, 2004. Applying the Turner angle, it is found that the 'diffusive' double diffusion, salt-fingering, and stable stratification coexist in the upper water column of about 50 m. Below that depth, there exists weak salt-fingering. The turbulent dissipation rates are enhanced along the ray paths of M2 internal tides emanating from the shelf break with values ranging from 1.0×10^-9 W·kg^-1 to 1.2×10^-6 W·kg^-1. The corresponding diapycnal mixing rates are from 1×10^-6 m^2· s^-1 to 1×10^-2 m^2· s^-1. The spatially averaged mixing rate over the whole observation section is 2.3×10^-3 m^2· s^-1, which is much larger than 1×10^-5 m^2·s^-1 of the background diapycnal mixing rate in the open ocean. 相似文献
13.
Determination of isocarbophos by cathodically sweeping oscilliopolarography is described. In a 1.0×10−5 mol/L sodium dodecylbenzene sulfonate (SDS)+0.1 mol/L HAC-NaAC (pH=4.0) buffer medium, isocarbophos and its alkaline hydrolysate
exhibited sensitive second derivative wave at −0.50 V and −0.48 V respectively. The peak current was linearly proportional
to the concentration of isocarbophos in the range of 5.40×10−6−1.05×10−4 mol/L by detecting isocarbophos directly. The detection limit was 3.60×10−6 mol/L with the relative standard derivation (RSD) of 7.3%. By employing an alkaline hydrolysis, the peak current was linearly
proportional to the concentration of isocarbophos in the range from 7.70×10−7 mol/L to 1.24×10−4 mol/L, and the detection limit was 5.80×10−7 mol/L with RSD of 3.1%. The hydrolysis procedure and the electrode reaction were studied by voltammetry.
Foundation item: Supported by the Foundation of Chinese-France Cooperation Program on Advanced Research
Biography: ZHANG Wu-ming (1929-), female, Professor. 相似文献
14.
通过对滇西富碱斑岩型多金属矿区稀有气体同位素组成的研究表明,黄铁矿和石英脉等流体包裹体中3He/4He值主要为0.160 8~3.470 0 Ra,远高于地壳特征值,而整体略低于地幔特征值;20Ne/22Ne和21Ne/22Ne平均值分别为11.271和0.032 2,接近地幔同位素组成;40Ar/36Ar和38Ar/36Ar平均值分别为395.51和0.197 6,均高于大气比值,而低于MORB比值;128~136Xe/130Xe值与大气相比均表现出过剩的特征。综合研究表明,滇西多金属矿区包裹体中稀有气体同位素组成在显示含矿流体的幔源特征的同时,又表现出强烈的地壳特征;成矿流体主要源于深部地幔,在参与交代蚀变过程中,其性质由熔浆向热液过渡,同时引发壳幔物质叠加混染,正是这种流体作用构成了滇西新生代富碱斑岩多金属成矿的内在统一制约因素。 相似文献
15.
Preparation and properties of C/C-SiC brake composites fabricated by warm compacted-<Emphasis Type="Italic">in situ</Emphasis> reaction 下载免费PDF全文
Carbon fibre reinforced carbon and silicon carbide dual matrix composites (C/C-SiC) were fabricated by the warm compacted-in situ reaction. The microstructure, mechanical properties, tribological properties, and wear mechanism of C/C-SiC composites at
different brake speeds were investigated. The results indicate that the composites are composed of 58wt% C, 37wt% SiC, and
5wt% Si. The density and open porosity are 2.0 g·cm−3 and 10%, respectively. The C/C-SiC brake composites exhibit good mechanical properties. The flexural strength can reach up
to 160 MPa, and the impact strength can reach 2.5 kJ·m−2. The C/C-SiC brake composites show excellent tribological performances. The friction coefficient is between 0.57 and 0.67
at the brake speeds from 8 to 24 m·s−1. The brake is stable, and the wear rate is less than 2.02×10−6 cm3·J−1. These results show that the C/C-SiC brake composites are the promising candidates for advanced brake and clutch systems. 相似文献
16.
Zhenrong Sun Shenyi Wang Yanping Huang Jiyun Lin Liangen Ding Zugeng Wang 《科学通报(英文版)》1998,43(5):399-402
The nonlinear refractive indexesn
2 for the ethanol solutions of 1, 10-phenanthroline (2.0 × 10−3 mol · L−1), [bis(l, 10-phenanthroline) lanthanum (III)] nitrate (1.0 × 10−3 mol · L−1), and [nitrato-fluoracil-bis (1, 10-phenanthroline) lanthanum (III) ] nitrate (1.0 × 10−3 mol · L−1) are first measured, the third-order nonlinear optical susceptibilities χ(3) and 〈γ〉 are calculated, and the mechanisms of the third-order optical nonlinearities enhanced by lanthanum (III) are discussed
preliminarily. 相似文献
17.
He and Ar isotope geochemistry of pyroxene megacrysts and mantle xenoliths in Cenozoic basalt from the Changle–Linqu area in western Shandong 总被引:1,自引:0,他引:1
We performed a combined study of He–Ar isotopes and element geochemistry for pyroxene megacrysts and mantle xenoliths from Cenozoic basalt in the Changle–Linqu area in western Shandong.The results are used to trace the evolution of subcontinental lithospheric mantle after destruction of the North China Craton.The3He/4He ratios of pyroxene megacrysts,websterite,and dunites are 7.0–7.7 Ra,7.4 Ra,and 7.0–7.7 Ra,respectively.They are related to the origin of host basalts,and are slightly lower than that of mid-ocean ridge basalts(MORB).Their40Ar/36Ar ratios are much lower than that of MORB and close to that of air.The lherzolites and wehrlites represent the fragments of the newly accreted lithospheric mantle,and their REE and trace elements indicate that they experienced melt metasomatism and partial melting.The3He/4He ratios of their olivine are slightly lower than that of MORB,but3He/4He ratios of their clinopyroxene are low(2.3–7.1 Ra)and display an inverse correlation with(La/Yb)N.The40Ar/36Ar ratios of these clinopyroxene are much lower than that of MORB and close to the air ratio.Combining existing studies of petrology,Sr–Nd–Pb isotopes,O isotopes,trace elements,and Mg isotopes,we infer that the juvenile lithospheric mantle in the Changle–Linqu area was metasomatized by oceanic crust-derived melts,which transfer the supracrustal Ar isotope signatures to the mantle sources.The low4He abundance and low3He/4He ratios of clinopyroxene in the lherzolites and wehrlites are ascribed to metasomatism by crustal melts from the subducted Pacific plate. 相似文献
18.
Wu Feng-wu Ai Xin-ping Yan Chen-nong He Zhi-ke Meng Hui Zeng Yun-e 《武汉大学学报:自然科学英文版》2002,7(3):341-344
The light emission produced by thiourea in oxidation process by permanganate in acidic solution in the presence of Ru(phen)
2
3
+ is used to determine 1.0×10−5 −1.0×10−5 mol/L thiourea. The limit of detection is 9.8×10−9 mol/L and the relative standard deviation is 1.1% for a 1.0×10−5 mol/L thiourea solution (n=10). The method was applied satisfactorily to the determination of thiourea.
Foundation item, Support by Ministry of Education, Wuhan University and Alumni Association of it
Biography: Wu Feng-wu(1963-), Male, Ph. D, research direction: analytical chemistry. 相似文献
19.
A new chemiluminescence (CL) method for the determination of tetracycline and oxytetracycline is developed, based on the CL
reaction of tetracycline and oxytetracycline with Ru (bipy)3
2+ and Ce (IV). In sulfuric acid medium, the CL emission is generated upon continuous oxidtion of Ru(bipy)3
2+ by cerium (IV). The emission intensity is greatly enhanced when tetracycline and oxytetracycline are introduced into the
reaction system after acid degradation. Under the optimum conditions, the calibration curves are linear over the range of
8.0×10−8∼4.0×10−6 mol/L for tetracycline and of 2.0×10−7∼4.0×10−5 mol/L for oxytetracycline, with the detection limits are 4.2×10−8 mol/L for tetracycline and 1.5×10−7 mol/L for oxytetracycline, respectively. The proposed method was used for the determination of tetracycline and oxytetracycline
in pharmaceutical formulations with good results.
Foundation item: Supported by the National Natural Science Foundation of China and the Natural Science Foundation of Hubei
Province.
Biography: HAH He-you (1962), male, Associate profeddor, Ph.D graduate candidate. Present address, Department of Chemistry,
Huainan Teacher's College, Huainan. 相似文献
20.
Electrochemical behavior of a carbon paste electrode (CPE) modified with nickel(II)-5, 11, 17, 23-tetra-tert-butyl-25, 27-bis(diethylcarbamoylmethoxy)
calix[4]arene (Ni (II)-L) complex and its electrocatalytic activity towards the oxidation of hydrogen peroxide were investigated
by cyclic voltammetric technique in a 5.0×10−2 mol/L NaClO4+1.0×10−3 mol/L NaOH solution. It was found that Ni(II)-L acts as an effective catalyst for the oxidation of hydrogen peroxide. The
modified electrode exhibited a linear response over a hydrogen peroxide concentrations in the range of 2.0×10−5−1.0×10−4 mol/L with a detection limit as low as 1.0×10−6 mol/L. The relative standard deviation was 3.5% for 5 successive determinations of H2O2 at 1.0×10−5 mol/L. The modified electrode was used successfully in rainwater analysis.
Foundation item: Supported by the Natural Science Foundation of Hubei Province (98J040).
Biography: Li Chun ya(1972-), Ph. D. candidate, research direction: electroanalysis and electrosynthesis. 相似文献