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Regulation mechanism of EM parameters in natural ferrite and its application in microwave absorbing materials

Science China(Technological sciences) 2006年第1期49卷 38-49页

作者： ZHENG Yongchun1,2. WANG Shijie2. FENG Junming2. LI Chunlai1, OUYANG Ziyuan1,2. LIU Jianzhong1 & LI Xiaobiao2.1. National Astronomical Observatories, chinese Academy of sciences, {2. 100012. China 2. State Key Laboratory of Environmental Geochemistry, {3. of Geochemistry, chinese Academy of sciences, Guiyang 550002. China 1. National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China 2. State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

Electromagnetic (EM) parameters (ε ′, ε ″, μ ′, μ″ ) of several M2.Fe2.4 and Fe2.3.type natural ferrites with different {3. occurrences are measured in this pa-per. The measurement results show that EM parameters of a magmatic-occurring natural ferrite is very different from other types occurring from sedimentary-metamorphic iron deposit, hydrothermal vein iron deposit, outer contact of magmatic iron deposit. It has potential to be used as magnetic absorbent in microwave absorbing materials. After min-eral separation and concentration, this magmatic-occurring natural ferrite was processed into type A ferrite absorbent. Type A natural ferrite absorbent is a kind of magnetic material with low dielectric constants, high magnetic conductivity and high EM loss. Its EM pa-rameters are ε ′ = 58.60, ε ″ = 10.0, μ ′ = 1.2.1.5, μ ″ = 1.0-1.2. respectively. In order to illuminate the regulation mechanism of EM parameters, we studied the chemical and mineral composition of type A ferrite absorbent. There is high concentration of natural impurities, which regulate the EM parameters of type A ferrite greatly. For comparison, the other types of natural ferrite, single-phase magnetite and two-phase iron minerals (ilmen-ite and magnetite), have few impurity. Thus regulation mechanism of EM parameters was absent in these ferrites. As a result, the regulation of EM parameters is advantageous to develop type A natural ferrite as excellent absorbent, lowers the reflectivity coefficients and enhances the absorbing efficiency of MAM made from it. Furthermore, the impurities in type A natural ferrite and its effects on EM parameters are very difficult to simulate in the synthesize ferrite. The carbonyl-iron powder is another kind of absorbent that is used ex-tensively in MAM. To compare the absorbing properties of these two absorbent, type A natural ferrite and carbonyl-iron powder were mixed with rubber and processed into mi-crowave absorbing sheets with the same procedures and tec

关键词： natural impure ferrite, complex permittivity, complex permeability, microwave absorbing materials.

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Changchengite—A New Iridium Bismuthide-Sulphide from the Yanshan Mountains

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Acta Geologica Sinica(English Edition) 1997年第4期71卷 486-490,514页

作者： Yu Zuxianginstitute of geology, chinese Academy of {2. {3., 2. Baiwanzhuang, beijing 10003. institute of geology Chinese Academy of Geological Sciences 26 Baiwanzhuang Beijing 100037 [?]Yu Zuxiang Born in 193. graduated from the Specialty of Mineralogy and Petrology Department of Geology Beijing College of Geology in 1953 now research professor at the institute of geology Chinese Academy of Geological Sciences. He has long engaged in the study of mineralogy geochemistry and mineral deposits related to ultrabasic rocks. He is a member of the Committee on New Minerals and Minerals Names of GSC.

Changchengite occurs in chromite orebodies in dunite and in platinum placer deposits in chromite orebodies nearby. The mineral occurs as massive aggregates or veinlets on margins of iridisite (IrS2. and replaces it. Opaque. Lustre metallic. Colour steel-black. Streak black. Hm = 3.7. VHN2.= 165 kg/ mm2. Isotropic. Cleavage none. Density 11.96 g/ cm3. Seven electron microprobe analyses give the following mean chemical results (wt. %): S 7.2. Cu 0.3. Te 0.4, Ir 41.2. Pt 2.8 and Bi 47.3.with total 99.1. The simplified formula is IrBiS. The strongest X-ray powder diffraction lines (hkl, d, I) are 2.0, 2.75 (70); 2.1, 2.51 (60); 3.1, 1.860 (100); 440. 1.090 (50) and 600, 1.02. (50). The X-ray powder diffraction pattern is similar to that of mayingite. After the diffraction data are indexed the mineral is determined to be cubic. The space group is P2.3.with a = 0.6164(4) nm, V = 0.2.42.nm3.and Z = 4.

关键词： changchengite new mineral new iridium bismuthide-sulphide Yanshan Mountains chromite ore body platinum placer deposit

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Science China Earth sciences 2004年第10期47卷 896-911页

作者： ZHANG Changhou1,2. WU Ganguo1,2. WANG Genhou2. ZHANG Weijie2.& SONG Honglin2.1. Key Laboratory of Lithospheric Tectonics and Lithoprobing Technology, China University of Geosciences, Ministry of Education of China, beijing 100083. China 2. School of Earth sciences and Mineral Resources, China University of Geosciences, beijing 100083. China 1. Key Laboratory of Lithospheric Tectonics and Lithoprobing Technology China University of Geosciences Ministry of Education of China 100083 Beijing China 2. School of Earth sciences and Mineral Resources China University of Geosciences 100083 Beijing China

The northwest trending tectonic belt in the middle part of the Mesozoic intraplate Yanshan Orogenic Belt, northeast Hebei Province, is composed of thrusts, extensional faults, strike-slip faults and syntectonic sedimentations as well. The northeastward basement-involved major thrusting deformation occurred between 174Ma and 168MaBP and was followed by an intrusion of the granitic plutonic rocks. As a part of the post-thrusting extensional deformations a northwest extending volcano-sedimentation system of Late Jurassic and Early Cretaceous formed in the southwest side of the belt. These volcano-sedimentary sequences are divided into Tuchengzi Formation, Zhangjiakou Formation, Yixian Formation and Jiufotang Formation re- spectively. They are characterized by southeastward migration as a result of the increasing down-dip slip displacement along the major extensional fault toward the southeast of the belt. The provenance area of the Jiufotang Formation north to it experienced southwestward thrusting during and after its later sedimentation. The thrusting in this stage resulted in the formation of an asymmetric footwall syncline with vergence to SW in the Jiufotang Formation in the NE side of the basin. Finally a dextral strike-slip deformation occurred along the NW tectonic belt. The striking tectono-geomorphological features and present seismic activities along this belt indicate that it has been being active since Cenozoic era and is still in the active state at present. This northwest extending tectonic belt was following the same direction and location as the existing fault systems within the basement as revealed by former geological and geophysical studies. So it is reasonable to infer the Mesozoic deformation along this belt to be a result of reactivation of the basement structures in a favorable tectonic stress field. The reactivation of basement struc- tures might be taken as one of the mechanisms of intraplate deformation and orogeny.

关键词： Yanshan Orogenic Belt, northwest extending tectonic complex, thrust system, geochronology.

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Sorption behavior of U(VI), ^(2.4)U(VI) and ^(2.8)U(VI) onto fracture-filling clays in Beishan granite, Gansu: Application to selecting the site of high-level radwaste repository in China

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Science China Earth sciences 2005年第10期48卷 1649-1655页

作者： MIN Maozhong1,2. LUO Xingzhang3. WANG Ju4, JIN Yuanxin4 & WANG Rucheng1 1. Department of Earth sciences, State Key Laboratory of Mineral Deposit Research, Nanjing University, Nanjing 2.0093. China 2. center of Materials Analysis, Nanjing University, Nanjing 2.0093. China 3. Department of Environmental Science and Engineering, Nanjing University, Nanjing 2.0093. China 4. {2. {3. institute, Nuclear Industry, {2. 10002., China Department of Earth sciences State Key Laboratory of Mineral Deposit Research Nanjing University Nanjing China center of Materials Analysis Nanjing University Nanjing China Department of Environmental Science and Engineering Nanjing University Nanjing China beijing geology {2. Nuclear Industry beijing China

The first results of sorption experiments of U(VI), 2.4U(VI) and 2.8U(VI) onto original (unpurified) fracture-filling clays from No.1 monzonitic granite intrusion, Beishan area, Gansu Province, China are reported. The monzonitic granite intrusion is a potential location for a high-level radwaste (HLW) repository in China. The present experimental results show that the maximum U(VI) sorption reached 92. at near-neutral pH and the distribution coefficient (Kd) was 12.6 mL/g. A high sorption capacity of the fracture-filling clays in host rock on radioactive ele-ments is necessary for HLW deep geological disposal repository. No preferential sorption of 2.4U onto the clays was found. Finally, the sorption of U(VI) onto the clays was also modeled using a surface complexation model.

关键词： HLW geological disposal repository, granite, uranium, radionuclide, clay, sorption.

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Petrology of the Non-mafic UHP Metamorphic Rocks from a Drillhole in the Southern Sulu Orogenic Belt,Eastern-Central China

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Acta Geologica Sinica(English Edition) 2003年第2期77卷 173-186页

作者： ZHANG Zeming, XU Zhiqin and XU Huifeninstitute of geology, chinese Academy of {2. {3., 2. Baiwanzhuang Rd., beijing 10003. E-mail: zzm@***. institute of geology Chinese Academy of Geological Sciences 26 Baiwanzhuang Rd. Beijing 100037

The Drillhole ZK703.with a depth of 558 m is located in the Donghai area of the southern Sulu ultrahigh-pressure (UHP) metamorphic belt, eastern China, and penetrates typical UHP eclogites and various non-mafic rocks, including peridotite, gneiss, schist and quartzite. Their protoliths include ultramafic, mafic, intermediate, intermediate-acidic, acidic igneous rocks and sediments. These rocks are intimately interlayered, which are meters to millimeters thick with sharp and nontectonic contacts, suggesting in-situ metamorphism under UHP eclogite facies conditions. The following petrologic features indicate that the non-mafic rocks have experienced early-stage UHP metamorphism together with the eclogites: (1) phengite relics in gneisses and schists contain a high content of Si, up to 3.52.p.f.u. (per formula unit), while amphibolite-facies phengites have considerably low Si content (3.2. p.f.u.); (2. jadeite relics are found in quartzite and jadeitite; (3. various types of symplectitic coronas and pseud

关键词： UHP metamorphism non-mafic rock drillhole Dabie-Sulu orogenic belt eastern-central China

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shrimp dating of the Bangong Lake SSZ-type ophiolite: Constraints on the closure time of ocean in the Bangong Lake-Nujiang River,northwestern Tibet

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chinese Science Bulletin 2007年第7期52卷 936-941页

作者： SHI RenDeng1,2.1 School of Earth and Space sciences, University of Science and Technology of China, Hefei 2.002., China 2.institute of geology, {2. Academy of {3. sciences, beijing 10003., China (email: shird@***) School of Earth and Space sciences University of Science and Technology ofChina Hefei 230026 China

The Bangong Lake ophiolite is located in the westernmost part of the Bangong Lake-Nujiang River suture zone. It is a tectonic mélange consisting of numerous individual blocks of peridotite, pillowed and massive lavas and mafic dykes with SSZ-type ophiolitic geochemical affinity formed at the end of a Wilson circle. The shrimp U-Pb ages of the co-magmatic zircon domains from one gabbroic dyke (Sample 01Y-155) range from 162.5±8.6 Ma to 177.1±1.4 Ma with an average of 167.0±1.4 Ma (n = 12. MSWD = 1.2., suggesting that the subduction of the Bangong Lake Neo-Tethyan Ocean started before the Middle Jurassic. It is inferred that the tectonic transform from spreading to subduction of the Neo-Tethyan Ocean began before the Middle Jurassic in the Bangong Lake area.

关键词：西藏班公湖怒江缝合带古海洋闭合时期 SSZ型蛇绿岩 shrimp 测年

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An Experimental Study on Three Quaternary Phases in the Fe-Sn-Sb-S System: Pb-Free Franckeite, Pb-Free Cylindrite and (Fe, Sb)-Ottemannite s.s.

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Acta Geologica Sinica(English Edition) 1988年第4期1卷 393-405页

作者： Li Jiuling Huang Jiashan Zhou Kezi Zhang Guilan institute of Mineral Deposits, chinese Academy of {2. {3., beijing institute of Mineral Deposits Chinese Academy of Geological Sciences Beijing

Experimental studies on the two solid solutions franckeite s.s. and cylindrite s.s. yielded among others thePb-free endmembers of franckeite and cylindrite respectively. In these endmembers the lead content of the twomineral phases are completely substituted by bivalent tin. A third phase, ottemannite s.s. with （Fe. Sb）-bearingcompositions, was further identified in the Pb-free 4-component system Fe-Sn-Sb-S. Pb-free franckeite andcylindrite could only be synthesized as homogeneous phases at high temperatures. The ottemannite s.s. was ob-tained at 600℃ but an extensive existing range was also confirmed at temperatures below 500℃. The phase relations were discussed in the pseudoternary subsystem SnS-SnS2.FeSb2.4. The following se-quence of Pb-free phases and phase assemblages were observed under increasing Sn4+content at 600℃:herzenhergite （SnS）+franckeite, franckeite, franckeite+cylindrite, cylindrite, cylindrite+（Fe, Sb）-ottemannite.（Fe, Sb）-ottemannite. （Fe. Sb）-ottemannite+berndtite （SnS2.. The assemblage cylindrite+berndtite was identi-fied in synthetic systems involving Pb. The phase Fe. Sb-ottemannite s.s. appears to be stable only under Pb-de-ficient and high sulfur fugacity conditions.

关键词： Pb-Free Franckeite An Experimental Study on Three Quaternary Phases in the Fe-Sn-Sb-S System Ottemannite s.s Fe Sb Sn

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The tectonic setting and geochemical characteristics of metamorphic basement in the southwest of the Yangtze Plate

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chinese Science Bulletin 1999年第S2期44卷 266-268页

作者： ZHANG Hongxiang~1, LIU Congqiang~2. HUANG Zhilong~2.and XU Zhifang~1 1. institute of Geophysics, {3. Academy of {2., {3. 100101, China 2. institute of Geochemistry, {3. Academy of {2., Guiyang 550002. China institute of Geophysics Chinese Academy of Sciences Beijing 100101 China institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China

THE Dahongshan Group (in short DG) and its basement Dibadu Formation (in short DF) in the southeastof the Yangtze Plate are one of the oldest geological units in the Yangtze Plate. It is established in thisnote by means of geochemistry that the system of trench-arc-basin was formed by the subducting at thesouthwestern boundary of the Yangtze Plate in Lower Proterozoic Subera. And the existence of enrichedmantle EMI is argued by the way of trace elements geochemistry. 1 Regional geological setting There is a unit of the typical two-layer structure platform in the southwest of the Yangtze Plate. Themetamorphic basement of this platform is made up of Suberathem Dahongshan Group and SuberathemKunyang Group. Above them, there have covered expansive continental deposits from Mesozoic. The primary rocks of DG are composed of deposited limestone, sandstone and basalts. The basalts represent

关键词： Dahongshan Group(DG) Dibadu Formation(DF) tectonic geochemistry.

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Mechanism for calcite dissolution and its contribution to development of reservoir porosity and permeability in the Kela 2.gas field,Tarim Basin,China

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Science China Earth sciences 2008年第4期51卷 567-578页

作者： YU BingSong1,3. DONG HailLiang2.3.& RUAN Zhuang1,3.1 State Key Laboratory of geological Processes and Mineral Resources, China University of Geosciences, {2. 100083. China 2.Department of {3., Miami University,Oxford, OH 45056, USA 3.Geomicrobiology Laboratory, China University of Geosciences, {2., 100083. China State Key Laboratory of geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China Department of geology Miami University Oxford OH 45056 USA Geomicrobiology Laboratory China University of Geoscien

This study is undertaken to understand how calcite precipitation and dissolution contributes to depth-related changes in porosity and permeability of gas-bearing sandstone reservoirs in the Kela 2.gas field of the Tarim Basin, Northwestern China. Sandstone samples and pore water samples are col-lected from well KL2.1 in the Tarim Basin. Vertical profiles of porosity, permeability, pore water chem-istry, and the relative volume abundance of calcite/dolomite are constructed from 3.00 to 4000 m below the ground surface within major oil and gas reservoir rocks. Porosity and permeability values are in-versely correlated with the calcite abundance, indicating that calcite dissolution and precipitation may be controlling porosity and permeability of the reservoir rocks. Pore water chemistry exhibits a sys-tematic variation from the Na2.O4 type at the shallow depth (3.00-3.3. m), to the NaHCO3.type at the intermediate depth (3.3.―3.95 m),and to the CaCl2.type at the greater depth (3.2.―3.3. m). The geochemical factors that control the calcite solubility include pH, temperature, pressure, Ca2. concen-tration, the total inorganic carbon concentration (ΣCO2., and the type of pore water. Thermodynamic phase equilibrium and mass conservation laws are applied to calculate the calcite saturation state as a function of a few key parameters. The model calculation illustrates that the calcite solubility is strongly dependent on the chemical composition of pore water, mainly the concentration difference between the total dissolved inorganic carbon and dissolved calcium concentration (i.e., [ΣCO2. -[Ca2.]). In the Na2.O4 water at the shallow depth, this index is close to 0, pore water is near the calcite solubility. Calcite does not dissolve or precipitate in significant quantities. In the NaHCO3.water at the intermedi-ate depth, this index is greater than 0, and pore water is supersaturated with respect to calcite. Massive calcite precipitation was observed at this depth interval and

关键词： calcite dissolution porosity thermodynamic Tarim Basin

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REE Geochemistry and Mineralization Characteristics of the Zudong and Gnanxi Granites, Jiangxi Province

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Acta Geologica Sinica(English Edition) 1989年第2期63卷 139-157页

作者： Huang Dianhao, Wu Chengyu institute of Mineral Deposits, chinese Academy of {2. {3., beijing and Han Jiuzhu Southern Jiangxi {2. Survey Party, Jiangxi Bureau of geology and Mineral Resources, Ganzhou Zhang Zhong min institute of Mineral Deposits Chinese Academy of Geological Sciences Beijing China

The Zudong and Guanxi granites are original rocks of the ion adsorption-type HREE and LREE deposits in weathering crust of granites. The ΣREE value and LREE/HREE ratio of the Zudong granite are 2.4 ppm and 0.81-0.2. respectively, and the average Y/ΣREE ratio is 3..8-54.5%. This is mainly due to magmatic crystallization and evolution and deuteric metasomatism (albitization, muscovitization and fluorite-doveritization). These alterations resulted in endogenic mineralizations of yttrium-group REE fluorine carbonates, silicates and arsenates. The Guanxi granite is characterized by LREE enrichment (the average LREE/HREE ratio is 2.43..

关键词： REE Geochemistry and Mineralization Characteristics of the Zudong and Gnanxi Granites Jiangxi Province

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