Addition reactions of nitrones on the reconstructed C(100)-2 x 1 surfaces

In this paper, the reactions of nitrone, N-methyl nitrone, N-phenyl nitrone and their hydroxylamine tautomers (vinyl-hydroxylamine, N-methyl-vinyl-hydroxylamine and N-phenyl-vinyl-hydroxylamine) on the reconstructed C(100)-2 x 1 surface have been investigated using hybrid density functional theory (B3LYP), Moller-Plesset second-order perturbation (MP2) and multi-configuration complete-active-space self-consistent-field (CASSCF) methods. The calculations showed that all the nitrones can react with the surface "dimer" via facile 1.3-dipolar cycloaddition with small activation barriers (less than 12.0 kJ/mol at B3LYP/6-31g(d) level). The [2+2] cycloaddition of hydroxylamine tautomers on the C(100) surface follows a diradical mechanism. Hydroxylamine tautomers first form diradical intermediates with the reconstructed C(I 00)-2 x I surface by overcoming a large activation barrier of 50-60 kJ/mol (B3LYP), then generate [2+2] cycloaddition products via diradical transition states with negligible activation barriers. The surface reactions result in hydroxyl or amino-terminated diamond surfaces, which offers new opportunity for further modifications. (C) 2007 Elsevier B.V. All rights reserved.

Addition reaction of nitrones on the reconstructed Si(100)-2 x 1 surface

The reaction of nitrone, N-methyl nitrone, and their hydroxylamine tautomers (vinyl-hydroxylamine and N-methyl vinyl-hydroxylamine) on the reconstructed Si(100)-2 x 1 surface has been investigated by means of hybrid density functional theory (B3LYP) and Moller-Plesset second-order perturbation (MP2) methods. The calculations predicted that both of the nitrones should react with the surface dimer via facile concerted 1,3-dipolar cycloaddition leading to 5-member-ring compounds. The reaction of hydroxylamine tautomers on the Si(100) surface follows pi-complex (intermediate) mechanism. For the reaction of N-methyl vinyl-hydroxylamine, the pi-complex intermediate undergoes [2+2] cycloaddition leading to a 4-member-ring compound. But in the reaction of vinyl-hydroxylamine, the intermediate undergoes H-migration reaction ("ene" reaction) resulting in the oxime-terminated Si surface. All the surface reactions result in the hydroxyl-terminated silicon surfaces, which are very useful for the further modification of the semiconductor.

东天山红山高硫型浅成低温铜-金矿床氧化带的形成机理和硫酸盐矿物的系列发现及意义

Located in the Paleozoic uplift along the southern margin of Tu-Ha basin in eastern Xinjiang, the newly discovered Hongshan Cu-Au deposit occurs in the superimposed Mesozoic volcanic basin upon the north section of later Paleozoic Dananhu-Tousuquan accretionary arc. Kalatage Cu-Au orebelt is controlled by NWW-trend faults, and includes Hongshan and Meiling Cu-Au deposits. The host rocks of Hongshan ore district are mainly rhyolitic-dacitic ignimbrites, whereas Cu-Au mineralization is closely related to quartz porphyry, rhyolitic porphyry and granitic porphyry. Mineralization styles are dominantly veinlet-disseminated and veinlet, occasionally stockwork. The mineral association is chalcopyrite, pyrite, bornite, chalcocite and sphalerite. The hydrothermal alteration consists of silicfication, sericitization, alunitization, pyrophylitization, illitization, hydromuscovitization, and chloritization. Hongshan Cu-Au deposit, on the edge of the desert, is one of the driest areas in eastrn Tianshan. Moreover， the highest temperature has been up to 60℃, and the average rainfall receives only 34.1mm/y. The light rainfall and rapid evaporation in the vicinity of this deposit have allowed the formation of a great variety of water-soluble sulfates. Oxidization zone of this deposit lies on the upper part of primary sulfide orebodies appearing with a depth of 50-60m, which is dominant in sulfate minerals. 1. Based on the field observation, the volcanic and sub-volcanic rock composition, hydrothermal alteration, ore structure and mineralization characteristics, this paper proposed that the Hongshan Cu-Au deposit belongs to a transitional type from high-sulfide epithermal to porphyry Cu-Au deposit, which corresponds with the typical HS-epithermal deposit such as Zijinshan Au-Cu deposit in Fujian Province, SE-China. 2. The Hongshan copper-gold deposit was controlled by the tectonic, stratum, magma activity and volcanic apparatus, whereas Au mineralization is closely related to quartz porphyry, rhyolitic porphyry and fine grained pyritization in hydrothermal activity, and Cu mineralization is closely related to quartz porphyry and hydrothermal explosive breccia. 3. Oxidation zone of Hongshan Cu-Au deposit lies on the upper part of primary sulfide orebodies deposit. 23 sulfate minerals were identified in this work. The results of samples XRD and chemical analysis were furthermore confirmed through thermal, infrared spectrum and mössbauer spectrum analysis. Among those, nine minerals as Ferricopiapite, Cuprocopiapite, Rhomboclase, Parabutlerite, Krausite, Yavapaiite, Metasideronatrite Kroehnkite and Paracoquimbite were founded in China for the first time. And Paracoquimbite was secondly reported in the world (first case reported at 1938 in Chile). 4. EPMA analysis shows that Al impurity in crystal lattice is important to polytype formation of paracoquimbite and coquimbite besides stack fault. 5. Compared with Meiling Cu-Au deposit in the same Kalatage ore belt from the characteristics of δ34S of barite, lithofacies, hydrothermal alteration and homogeneous temperature, Hongshan Cu-Au deposit belongs to the same metallogenic system of HS-epithermal type as Meiling Cu-Au deposit. But Hongshan Cu-Au deposit has less extensive alteration and shallower denudation. 6. Sulfur isotope analyses show that δ34S values of pyrites vary in the range of +1.86‰~+5.69‰, with an average of 3.70‰, mostly in the range of +1.86‰~+3.20‰, and δ34Scp<δ34Spy. Therefore ore-forming fluid of porphyry comes from mantle and was contaminated by the earth’s crust. Sulfur isotope has reached balance in ore-forming process. 7. Sulfur isotope analyses show that δ34S values of sulfates vary in the range of +2.15‰~+6.73‰, with an average of +3.74‰, mostly equals as δ34S values of primary sulfides in Hongshan Cu-Au deposit. So supergene sulfates inherit sulfur of primary sulfide. δ34S values are mostly same in different sulfates. As well as pyrite and chalcopyrite, volcanic hot spring and associated native sulfur underground also provide water medium and sulfur during the formation process of sulfate. 8. According to the EPMA of sample chalcopyrite and pyrite in Hongshan Cu-Au, the value of Cu/Ni is 0.98-34.72, mostly close to the value of 5, which shows that Hongshan deposit is a typical volcanogenic magmaic hypothermal deposit. Au and Ag, Zn, Te and Bi are positive correlation, Cu and Hg, Se, Sb are positive correlation, indicates Au and Cu don’t locate in the factor of mineralization of same mineralization groups. The reasons of gold concentration in the oxidation zone are: 1). Change of redox potential (Eh) makes gold to deposit from the liquid of mineralization zone; 2). PH is one of the most factors of gold’s deposition; 3). Soluble complex and colloid of gold can be adsorbed easily. 9. The biotite and hornblende K-Ar isotopic ages from the wall rock－quartz diorite, biotite granite and monzonite granite are 231.99±3.45Ma, 237.97±2.36Ma and 296.53±6.69Ma respectively. The ore-bearing rhyolitic breccia lava contains breccia of the biotite granite which indicates the volcanism and related Cu-Au mineralization occurred later than the granite, possibly in Mesozoic. K-Ar ages of granitoids in Sanya, Baishiquan and Hongliugou area and Molybdenite Re-Os age of Baishan Mo deposit all are in Triassic. Besides late Paleozoic magmatism, igneous magmatic event of Mesozoic was widespread in eastern Tianshan. 10. The K-Ar age dating indicates that the K-Ar age of Voltaite occurred below surface 1m is 56.02±3.98Ma, K-Ar age of Ferricopiapite occurred below surface 1.5m is 8.62±1.12Ma, K-Ar age of Yavapaiite occurred below surface 14 m is 4.07±0.39Ma, and K-Ar age of Voltaite occurred below surface 10 m is 14.73±1.73Ma. So the age interval of oxidation zone of Hongshan copper-golden bed is between 60 -3.38Ma. Oxidization occurred at Caenozoic era (from 65Ma), which can be identified through comparing with different deposits oxidation zone in other countries. The coupling between global tectonic event and climatic change event which occur from Caenozoic era has some effect on epigeosphere system, which can act on the surface of bed oxidation zone similarly. It induces that the age mentioned above coincide with collision of India-Asia and multistage uplifting of Qinhai-Tibet Plateau happened subsequently. Bed oxidation zone is the effect and record of collision and uplifting of Tibet Plateau. The strong chemical weathering of surface accumulation to which was leaded by PETM event occurred Paleocene and Eocene is the reason of Voltaite sharply rises. On the contrary, Ferricopiapite formed due to the global cold weather. The predecessor did much research through biota, isotopes, susceptibility, but this paper try to use different sulfate mineral instead of climatic change. So the research of sulfate minerals not only indicates a great deal of oxidized zone feature, but also the intergrowth of sulfate minerals may be used to trace paleoenviroment and paleoclimate of oxidation zone. 11. Analysis of the information of alteration and mineralization features of four bore cores, induced activity polarization well logging and Eh-4 geophysical section, deep mineralization anomaly objects of Hongshan ore districts shows low resistance, middle and high polarization, measurements of Eh-4 consecutive conductance section show the existing of concealed porphyry ore body deeper than 450m, on the top of and around rock body there are low resistance body ranged from 100-300Ω•m, this area may be the ore-bearing part. In a word, Hongshan Cu-Au deposit deposit is a combine of upper HS-style epithermal Au deposit and deeper porphyry mineralization system. It has great potential to find large HS-style epithermal-porphyry Au-Cu deposits. This paper consists of seven chapters and twenty seven sections. The geological character of deposit is basic condition in this work. Constitute of oxidation zone, research of sulfate mineral, relation between oxidation and primary zone, K-Ar ages of potassic sulfate are key parts of thesis. Genesis of ore deposit is the further expansion of this research. Analysis of ore-controlling factors is the penetration above basic. Analysis of potential is application of exploration.

黄铁矿热转变过程的岩石磁学研究

Pyrite is the most stable iron-sulfide in reduced environment, and plays an important role in geochemical iron-sulfur cycling of sediments. Thus, the presence of pyrite in sediments and rocks is an important indicator of sedimentary environments. Previous studies on the thermal products of pyrite showed that all of the products (e.g., pyrrhotite, magnetite, hematite) have strong capability of carrying remanence. To deepen our understanding of the environmental and paleomagnetic significances of pyrite, the mineral transformation processes of pyrite upon heating were systematically investigated in this study using intergrated rock magnetic experiments (in both argon and air atmospheres) and X-ray diffraction analysis. The room temperature susceptibility of the paramagnetic pyrite is about 2.68×10-5 SI. In argon atmosphere (reducing environment), pyrite was transformed into monoclinic stable single domain (SD) pyrrhotite above 440 C. The corresponding coercive force and remanence coercivity are about 20 mT and 30 mT, respectively. In contrast, in air atmosphere (oxidation environment), the intermediate thermal products of pyrite are magnetite and pyrrhotite, which were quickly further oxidated to SD hematite, which has coercivity of about 1400 mT. In addition, the hematite particles gradually grow from SD to PSD grain size region by multiple heating runs. The transformation processes of pyrite in oxidation atomosphere can be interpreted by three possible pathways: (1) pyrite→magnetite→hematite; (2) pyrite→pyrrhotite→magnetite→hematite; and (3) pyrite→pyrrhotite→hematite. Low-temperature magnetic experiments show no transitions for pyrite. Despite that low-temperature magnetic method is not suitable for identification of pyrite, it is clear in this study that the high-temperature thermomagnetic measurements (e.g.,  -T and J-T curves) are very sensitive to the presence of pyrite in sediments and rocks. Nevertheless, for the thermal treatment products, low-temperature magnetic measurements showed the 34 K transition of pyrrhotite and the 250 K Morine transition of hematite. Iron-sulfide has also been found on Martian meteorolites by other workers. Therefore, systematic study of rock magnetism of pyrite (and other iron-sulfides) and their products will have great significances for both paleomagnetism and planetary magnetism.

班公湖带多不杂超大型富金斑岩铜矿床的成岩成矿年代学、岩石学及高氧化岩浆¬流体-成矿作用

Duobuza copper deposit, newly discovered typical gold-rich porphyry copper deposit with superlarge potential, is located in the Tiegelong Mesozoic tectonic -magmatic arc of the southern edge of Qiangtang block and the northern margin of Bangonghu-Nujiang suture. Quartz diorite porphyrite and grandiorite porphyry, occurred in stock, are the main ore-bearing porphyries. As the emplacement of porphyry stock, a wide range of hydrothermal alteration has developed. Within the framework of the ore district, abundant hydrothermal magnetite developed, and the relationship between precipitation of copper and gold and hydrothermal magnetite seems much close. Correspondingly, a series of veinlets and network veinlets occurred in all alteration zones. Therefore, systematic research on such a superlarge high-grade Duobuza gold-rich porphyry copper deposit can fully revealed the metallogenic characteristics of gold-rich porphyry copper deposits in this region, establish metallogenetic model and prospecting criteria, and has important practical significance on the promotion of regional exploration. In addition, this research on it can enrich metallogenic theory of strong oxidation magma-fluid to gold-rich porphyry copper deposit, and will be helpful to understand the metallogenic characteristics in early of subduction of Gangdese arc stages and its entire evolution history of the Qinghai-Tibet Plateau, the temporal and spatial distribution of ore deposits and their geodynamics settings. Northern ore body of Duobuza copper deposit have been controlled with width (north-south) about 100 ~ 400 m, length (east-west) about 1400 m, dip of 200 °, angle of dip 65 °~ 80 °. And controlled resource amount is of 2.7 million tons Cu with grade 0.94% and 13 tons Au with 0.21g/tAu. Overall features of ore body are large scale, higher grade copper, gold-rich. Ore occurred in the body of granodiotite porphyry and quartz diorite porphyrite and its contact zone with wall rock. Through the detailed mapping and field work studies, some typies of alteration are identificated as follows: albitization, biotititation, sericitization, silication, epidotization, chloritization, carbonatization, illitization, kaolinization and so on. The range of alteration is more than 10km2. Wall alteration zone can be divided into potassic alteration, moderate argillization alteration, argillization, illite-hydromuscovite or propylitization from ore-bearing porphyry center outwards, but phyllic alteration has not well developed and only sericite-quartz veins occurred in local area. Moreover, micro-fracture is development in ore district , and correspondingly a series of veinlets are development as follows: biotite vein (EB type), K-feldspar-biotite-chalcopyrite-quartz vein, magnetite-antinolite-K-feldspar vein, quartz-chalcopyrite-magnetite veins (A-type), quartz-magnetite-biotite-K-feldspar vein, chalcopyrite veinlets in potassic alteration zone; (2) chalcopyrite occurring in the center vein–quartz vein (B type), chalcopyrite veinlets, chalcopyrite-gypsum vein in intermediate argillization alteration; (3) chalcopyrite- pyrite-quartz vein, pyrite-quartz vein, chalcopyrite-gypsum veins, quartz-gypsum- molybdenite-chalcopyrite vein in argillization alteration; (4) gypsum veins, quartz-(molybdenite)-chalcopyrite vein, quartz-pyrite vein, gypsum- chalcopyrite vein, potassium feldspar veinlets, Carbonate veins, quartz-magnetite veins in the wall rock. In short, various veins are very abundant within the framework of the ore district. The results of electronic probe microscopy analysis (EMPA) indicate that Albite (Ab 91.5~99.7%) occurred along the rim of plagioclase phenocryst and fracture, and respresents the earliest stages of alteration. K-feldspar (Or 75.1~96.9%) altered plagioclase phenocryst and matrix or formed secondary potassium feldspar veinlets. Secondary biotite occurred mainly in phenocryst, matrix and veinlets, belong to magnesium-rich biotite formed under the conditions of high-oxidation magma- hydrothermal. Chloritization developed in all alteration zones and alterd iron- magnesium minerals such as biotite and hornblende and then formed chlorite veinlets. As the temperature rises, Si in the tetrahedral site of chlorite decreased, and chlorite component evolved from diabantite to ripiolite. The consistent 280℃~360℃ of formation temperature hinted that chlorite formed on the same temperature range in all alteration zones. However, formation temperature range of chlorite from the gypsum-carbonate-chlorite vein was 190℃~220℃, and it may be the product of the latest stage of hydrothermal activity. The closely relationship between biotite and rutile indicate that most of rutiles are precipitated in the process of biotite alteration and recrystallization. In addition, the V2O3 concentration of rutile from ore body in Duobuza gold-rich porphyry copper deposit is >0.4％, indicate that V concentration in rutile has important significance on marking main ore body of porphyry copper deposit. Apatites from Duobuza deposit all are F-rich. And apatite in the wall rock contained low MnO content and relatively high FeO content, which may due to the basaltic composition of the wall rocks. The MnO in apatite from altered porphyry show a strong positive correlation with FeO. In addition, Cl/F ratio of apatite from wall rock was highest, followed by the potassic alteration zone and potassic alteration zone overprinted by moderate argillization alteration was the lowest. SO2 in Apatite are in the scope of 0 to 0.66%, biotite in the apatite has the highest SO2, followed by the potassic alteration zone, potassic alteration zone overprinted by moderate argillization alteration, and the lowest in the surrounding rocks, which may be caused by the decrease of oxygen fugacity of hydrothermal fluid and S exhaust by sulfide precipitation in potassic alteration. Magnetite in the wall rock have higher Cr2O3 and lower Al2O3 features compared with altered porphyry, this may be due to basalt wall rock generally has high Cr content. And magnetites have higher TiO2 content in potassic alteration than moderate argillization alteration overprinted by potassic alteration, argillization and wall rock, suggested that its formation temperature in potassic alteration was the highest among them. The ore minerals mainly are chalcopyrite and bornite, and Au contents of chalcopyrite, bornite, and pyrite are similar with chalcopyrite slightly higher. The Eu* negative anomaly of disseminated chalcopyrite was relatively lower than chalcopyrite in veinlets. Within a drill hole, the Eu* negative anomaly of disseminated chalcopyrite was gradually larger from bottom to top. Magnetite has the same distribution model, with obvious negative Eu* abnormal, and ΣREE in great changes. The gypsum has the highest ΣREE content and the obvious negative anomaly, and biotite obviously has the Eu* abnormal. Based on the petrographic and geochemical characteristics, five series of magmatic rocks can be broadly classified; they are volcanic rocks of the normal island arc, high-Nb basaltic rocks, adakites, altered porphyry and diorite. The Sr, Nd, Hf isotopes and geochemistry of various series of magmatic rock show that they may be the result of mixing between basic magma and various degrees of acid magma coming from lower crust melted by high temperature basic underplating from partial melting of the subduction sediment melt metasomatic mantle wedge. Furthermore S isotope and Pb isotope of the sulfide, ore-bearing porphyries and volcanic rocks indicated ore-forming source is the mantle wedge metasomatied by subduction sediment melt. Oxygen fugacity of magma estimated by Fe2O3/FeO of whole rock and zircon Ce4+/Ce3+ indicated that the oxidation of basalt-andesitic rocks is higher than ore-forming porphyry, and might imply high-oxidation characteristics of underplated basic magma. Its high oxidative mechanism is likely mantle sources metasomatied by subduction sediment magma, including water and Fe3+. And such high oxidation of basaltic magma is conducive to the mantle of sulfides in the effective access to melt. And the An component of dark part within plagioclase phenocryst zoning belong to bytownite (An 74%), and its may be a result of magma composition changes refreshment by basaltic magma injection. SHRIMP zircon U-Pb and LA-ICP-MS zircon U-Pb geochronology study showed that the intrusions and volcanic rocks from Duobuza porphyry copper deposit belong to early Cretaceous magma series (126~105Ma). The magma evolution series are as follows: the earliest diorite and diorite porphyrite → ore-bearing porphyry and barren grandiorite porphyry →basaltic andesite → diorite porphyrite → andesite → basaltic andesite, and magma component shows a evolution trend from intermediate to intermediate-acid to basic. Based on the field evidences, the formation age of high-Nb basalt may be the latest. The Ar-Ar geochronology of altered secondary biotite, K-feldspar and sericite shows that the main mineralization lasting a interval of about 4 Ma, the duration limit of whole magma-hydrothermal evolution of about 6 Ma, and possibly such a long duration limit may result in the formation of Duobuza super-large copper deposit. Moreover, tectonic diagram and trace element geochemistry of volcanic rocks and diorite from Duobuza porphyry copper deposit confirm that it formed in a continental margin arc environment. Zircon U-Pb age of volcanic rocks and porphyry fall in the range of 105~121Ma, and Duobuza porphyry copper deposit locating in the north of the Bangonghu- Nujiang suture zone, suggested that Neo-Tethys ocean still subducted northward at least early Cretaceous, and its closure time should be later than 105 Ma. Three major inclusion types and ten subtypes are distinguished from quartz phenocrysts and various quartz veins. Vapor generally coexisting with brine inclusions, suggest that fluid boiling may be the main ore-forming mechanism. Raman spectrums of fluid inclusions display that the content of vapor and liquid inclusion mainly contain water, and vapor occasionally contain a little CO2. In addition, the component of liquid inclusions mainly include Cl-, SO42-, Na+, K+, a small amount of Ca2+, F-; and Cl- and Na+ show good correlation. Vapor mainly contains water, a small amount of CO2, CH4 and C2H6 and so on. The daughter minerals identified by Laman spectroscopy and SEM include gypsum, chalcopyrite, halite, sylvite, rutile, potassium feldspar, Fe-Mn-chloride and other minerals, and ore-forming fluid belong to a complex hydrothermal system containing H2O-NaCl-KClFeCl2CaCl2. H and O isotopic analysis of quartz phenocryst, vein quartz, magnetite, chlorite and gypsum from all alteration zones show that the ore-forming fluid of Duobuza gold-rich porphyry copper deposit consisted mainly of magmatic water, without addition of meteric water. Duobuza gold-rich porphyry copper deposit formed by the primary magmatic fluid (600-950C), which has high oxidation, ultra-high salinity and metallogenic element-rich, exsolution direct from the magma, and it is representative of the typical orthomagmatic end member of the porphyry continuum. Moreover, the fluid evolution model of Duobuza gold-rich porphyry copper deposit has been established. Furthermore, two key factors for formation of large Au-rich porphyry copper deposit have been summed up, which are ore-forming fluids earlier separated from magma and high oxidation magma-mineralization fluid system.

内蒙古龙头山Ag-Pb-Zn多金属矿床成矿模式及找矿模型

The recent years research indicated that middle-south section of Da Hinggan Mountains metallogenic belt has two periods(Hercynian and Yanshanian) characteristics of metallogenesis, as well as the most of ore deposits in the area closely relate to Permian strata. Longtoushan ore deposit discovered in 2004 is an Ag-Pb-Zn polymetallic ore deposit born in Permian and located in the east hillside of the metallogenic belt, which has considerable resources potentials. It has important research value for its good metallogenic location and blank research history. Base on the detail field geology studies, the geology characteristics of "two stages and three kinds of metallogensis" has established. According to further work through geochemistry research including trace element, REE, S, Pb and Sr isotope, as well as petrography, microtemperature measurement, Laser Raman analysis and thermodynamics calculation of fluid inclusion, origin and characteristic of the ore-forming material and fluid has been discussed. And a new technology of single pellet Rb-Sr isochrones has been tried for dating its born time. Bae on above work, study of ore deposit comparison has been carried out, and metallogesis controlling factor and geological prospecting symbol have been summarized. Finally, metallogenic model and prospecting model have been established. According to above, the next step work direction has been proposed. Main achievement of the paper are listed as follow: 1.Longtoushan ore deposit has experienced two metallogenic periods including hot-water sedimentation period and hydrothermal reformation period. There are three kinds of metallizing phase: bedded(or near-bedded) phase, vein-shaped phase and pipe-shaped phase. The mian metallogenic period is hot-water sedimentation period. 2.Ore deposit geochemistry research indicated that the metal sulfides have charcateristic of hot-water sedimentation metallogensis, but generally suffered later hydrothermal transformation. The barite mineral isotope content is homogenous, showing the seabed hot-water sedimentation origin characteristic. Wall rock, such as tuff is one of metallogenic material origins. Both of Pb model age and Rb-Sr isochrone research older age value than that of strata, possibly for been influenced by hydrothermal transformation, and interfusion of ancient basis material. 3.There are two kinds of main metallogenic fluid inclusion in barite of the Longtoushan ore deposit, which are rich gas phase( C type) and liquid phase (D type). Their size is 2～7um, and principal components is H2O. Both kinds of fluid inclusion have freezing point temperature -7.1～-2.4℃ and -5.5～-0.3℃, salinity 4.0～10.6wt% and 0.5～8.5wt%, homogeneous temperature 176.8～361.6℃ and 101.4～279.9℃, which peak value around 270℃ and 170℃, respectively. Density of the ore-forming fluid is 0.73～0.97g/cm3, and metallogenic pressure is 62.3×105～377.9×105Pa. Above characteristic of the fluid inclusion are well geared to that of ore deposit originated in seabed hot-water sedimentation. 4.Through the comparison research, that Longtoushan ore deposit has main characteristic of hot-water sedimentation ore deposit has been indicated. Ore-forming control factor and prospecting symbol of it has been summarized, as well as metallogenic model and prospecting model. Next step work direction about prospecting has also been proposed finally.

阿尔泰南缘侧向增生过程中的VMS矿床：地质、地球化学特征与成矿机制

The Chinese Altai is one of the most important volcanogenic massive sulfide (VMS) deposit districts in China. All orebodies were lenticular or bedded and stratabounded by a suite of early Devonian volcanic-sedimentary rocks. Hydrothermal feeder zones developed under some of the orebodies. All the ores are massive or laminated, and show typical characteristics of VMS deposit. Based on the mineralizing time and the metal assembles, we divide 3 metallogenic stages: 1, Fe orefroming stage associated with basaltic and sedimentary rocks during very early Devonian; 2, Cu-Pb-Zn oreforming stage associated with rhyolitic and sedimentary rocks during early Devonian; 3， Cu-Zn oreforming stage in the dacitic and basaltic rocks during mid. Devonian. The hosting rocks for all orebodies are different, but they show very similar geochemical and isotopic characteristics. All the felsic rocks show enriched lighted rare earth elements (REE) patterns (La/Yb>5), and with an obvious Eu negative anomalies (Eu/Eu*<0.6). In the meanwhile, all the mafic rocks show flat REE pattern and no Eu anomalies. The Ashele basalt show an apparent Ce negative anomalies (Ce/Ce* <0.76), All the volcanic roks in Chinese Altai show the decoupled property between the high field strength elements (HFSE) and large ion lithophile elements (LILE). The negative Nb, Ta characteristics with respect to adjacent elements indicate that subduction-modified source. The Nd(t) of the hosting rocks for all orebodies changed in a small range (-1.5~5), and the (87Sr/86Sr)i change in a big range. The initial Sr value of the hosting rocks in Mengku and Tiemuerte are obviously affected by the seawater (0.705~0.710), and initial Sr values of hosting rocks Ashele change in a small range (0.704~0.706). All Sr-Nd isotopes of ores have the same range with the hosting rocks, indicating that both the ores and volcanic rocks have the same island arc source. The mean sulfur isotopes of sulfides from Ashele and Mengku are 6.2‰ and 3.4‰, respectively, indicating a deep magmatic source. However, the sulfur isotopes of sulfides from Keketale, Tiemuerte and Keyinbulake changed in -15.8‰~9.9‰, -23.5‰~1.87‰, -8.3‰~1.6‰, respectively. And the big sulfur isotope range indicated that the sulfur of the ores was a combination biogenic and magmatic source. All volcanic rocks from the VMS deposits in the southern Chinese Altai show a typical subduction related environments. Based on the regional and locally geological evidence, here we propose that the southern Chinese Altai is an island arc system, and all VMS deposits formed during the lateral accretion process. No VMS deposit formed during the formation of the island arc during Silurian; Fe VMS deposit formed during the beginning of the opening of the backarc basin in very early Devonian; Cu-Pb-Zn VMS deposits formed during the mature stage of the backarc basin in early Devonian; at last the Cu-Zn VMS deposit formed during the rifted stage of the island arc itself.

13万年以来黄土高原东缘与捷克的风成沉积序列

The loess-paleosols in the Chinese loess plateau and Europe are the main eolian sediment sequences in mid-latitude area of north hemisphere. They record not only the paleoclimatic and paleoenvironmental processes since the last interglacial, but also the configuration of magnetic field during polarity transition. Comparisons of environmental magnetism, paleomagnetism and climate proxy analysis has been made for the loess/paleosol sequences in Datong and Czech Republic. The Datong loess/paleosol sequence is composed of the Holocene soil SO, the last glacial loess LI, the last interglacial soil SI and the upper penultimate loess L2. A basalt layer occurs in L2. The main magnetic minerals in LI and SI are magnetite, maghemite and ilmenite. The presence of local volcanic elastics in the loess and the characteristics of the magnetic minerals indicate that there are local materials in Datong loess, which differentiate the Datong loess from the central and eastern loess of the Chinese Loess Plateau. In addition, there are four polarity events in Datong loess, which are generally consistent with Gothenburg> Mono Lake, Laschamp and Blake events. Some signals of the East Asia monsoon were recorded in the Datong loess/paleosol sequences. Magnetic susceptibility, the content of >63um grains and the organic matter are used as climate proxies, which are similar to those of the typical eolian sediments in the loess plateau. In addition, it is possible that the Datong loess also recorded the Younger Dryas and the climatic fluctuations during the Holocene. The main magnetic minerals in the loess/paleosol at Znojmo section are magnetite, maghemite, hematite, pyrite, pyrrhotite and goethite. The morphology of these grains reveals that the iron sulfides originated from the eluvium loam above hypothetical ore deposits in the vicinity of the section or glaciofluvial sediments from nearby glacial margins. The pattern of the susceptibility variation at Dolni Vestonice section is coincident with that of the organic matter content. The grain size variation along the section recorded the climate instability since the last interglacial. The climate events in the Dolni Vestonice section may be correlated with the Heinrich events recorded in North Atlantic sediments, suggesting they controlled by the same marine-continent climate system.

河北寿王坟铜矿成矿定年及同位素地球化学特征

Samples from carbonate wall-rocks, skarn, ore of skarn type, later calcite vein, and ore of porphyry type in Shouwangfen copper deposit district were collected. Systematic study was carried out on carbon, oxygen, rubidium, strontium and sulfur isotope compositions of carbonates and sulfides in these samples. The first Isochron dating by the Rb-Sr isotopes in chalcopyrite of ore sub-sample was done as well. The following conclusions were obtained. The age (113.6±4.3Ma), obtained by Rb-Sr isotope isochron dating of chalcopyrite and pyrite from sub-sample of skarn ores, probably represents the true mineralization age of skarn ores. That demonstrates the genetic relationship between granodiorite in Shouwangfen complex and skarn copper ores. On the other hand, the Rb-Sr isochron age (73±15Ma) of chalcopyrite from porphyry ores is a little incredible because of bad synthesizing evaluation. But combined with other age data of igneous rocks, it implies the possibility of hydrothermal mineralization in connection with magma activity during the fourth period of Yanshanian in Hebei Province, even in the whole northern edge of Huabei continental block. Together from structure analysis of sulfide sub-samples, from pretreating preccedure of Rb-Sr isotope isochron and its' valuating, we found out that Rb-Sr isotope isochron of sulfide sub-samples is influenced by the crystal structure of sulfides. That is, sulfide ores with very big crystals are not suitable for sub-sample isochron. Carbon, oxygen, sulfur and strontium compositions, of different minerals in these two kinds of ores, imply that the ore-forming hydrothermal fluids were probably derived from magma deep under the crust. The calcite ~(87)Sr/~(86)Sr ratios from the porphyry are consistent to the initial 87Sr/86Sr ratio of the Rb-Sr isochron of chalcopyrite and pyrite in the skarn ore, indicating that these two kinds of ores have the same source characteristic, although the porphyry deposit was formed probably 40 million years later than the skarn one according to our dating results. Skarn and skarn ores are usually considered as interaction product between carbonate wall-rocks and magmatic fluids, but the carbon of the sedimentary carbonate seems not involved in the skarn ores. Considering the connection of magmatic processes and hydrothermal ore formation in the Shouwangfen district, particularly, the spatial distribution of skarn-type and porphyry-type ores, it is possible that the Shouwangfen ore district corresponds to a hydrothermal ore-forming system, which was promoted by high-intruding magmatic rocks. Systematic stable isotopic research can help to reveal the upper part of this hydrothermal ore-forming system, which mainly related to heated and circulating meteoric water, and the lower part principally related to ascending magmatic fluids. Both skarn and porphyry ore-bodies are formed by up-intruding magmatic fluids (even more deep mantle-derived fluids).

贵州水银洞卡林型金矿床含金硫化物地球化学与金的赋存状态研究

　　以沉积岩为主要容矿岩石的卡林型金矿，是目前世界上储量最大的金矿类型之一，金“不可见”或其颗粒极细（纳米级）是该类型金矿最重要的特点之一。国内外大量研究已经证实，金主要赋存在含砷黄铁矿中，但金的赋存形式仍然是目前争论的焦点和研究的热点。贵州水银洞金矿床位于灰家堡背斜Au-Hg-Tl矿田的东段，是黔西南地区发现较晚、品位较富（6～18 g/t）的大型（55 t）隐伏卡林型金矿床，并已大规模开采利用，结束了我国卡林型金矿原生矿石不能开发利用的历史。 　　本次研究在系统显微岩相学研究的基础上，采用电子探针（EMPA）背散射电子图像（BSE）、波谱（WDS）和能谱（EDS）分析技术，对水银洞卡林型金矿床原生富矿石中不同类型含砷黄铁矿和毒砂的矿物学、地球化学以及金的赋存状态等进行了较系统的研究，取得的主要认识如下： 1. 水银洞金矿床原生矿石具有去碳酸盐化（Decarbonation）、硅化、硫化物化（Sulfidation）等典型卡林型金矿的热液蚀变特征。原生矿石中的主要载金矿物为含砷黄铁矿，其次为毒砂。 2. 根据含砷黄铁矿和毒砂的形态和结构特征，将含砷黄铁矿分为生物碎屑状含砷黄铁矿、细粒含砷黄铁矿、环带状含砷黄铁矿和细脉状含砷黄铁矿四种类型；毒砂分为板状毒砂和针状毒砂两种类型。毒砂晚于含砷黄铁矿的形成。 3. 电子探针分析表明，含砷黄铁矿中含有较高的Au，一般为300×10-6～3800×10-6，含有As 0.65～14.11 wt%、Sb 0.03～0.12 wt%、Co 0.03～0.08 wt%等元素。毒砂含Au较低，一般为300×10-6～1500 ×10-6。 4. 研究表明，含砷黄铁矿中的As与S含量具有明显的负相关关系，认为As替代S进入含砷黄铁矿和毒砂的结构；Au与As之间不是一种简单的线形正相关关系，而是分布在一个的楔形空间。结合前人的研究结果，认为含砷黄铁矿中的“不可见金”，可能主要以化学结合态金（Au1+）的形式进入含砷黄铁矿和毒砂结构。 5. 金的赋存状态研究表明，水银洞卡林型金矿床发现有两种金的赋存形式：（1）“不可见金”，主要赋存在黄铁矿的含砷环带之中；（2）次显微—显微自然金颗粒（0.1～6μm），主要见于含砷黄铁矿细脉或其集合体。这些自然金颗粒也有两种赋存形式：① 粗粒自然金颗粒（1～6μm），主要分布于早世代粗粒含砷黄铁矿颗粒的表面或晚世代细粒含砷黄铁矿颗粒的边缘，偶见于含Fe碳酸盐矿物的溶蚀空洞中，被解释为热液中的Au局部过饱和的产物；②细粒自然金颗粒（0.1～0.2μm），偶见于早世代粗粒含砷黄铁矿的含砷环带或其溶蚀空洞的边缘，被解释为黄铁矿含砷环带中的Au再溶解过饱和沉淀的产物。 6. 根据原生矿石显微岩相学结构、含砷黄铁矿矿物学与地球化学特征，探讨了含金—砷黄铁矿的形成过程，认为含砷黄铁矿中的Fe，可能主要来源于赋矿围岩中的含Fe碳酸盐矿物（方解石和白云石）溶解而释放的Fe，溶解Fe的硫化物化过程是水银洞卡林型金矿富集成矿的重要机制之一。 7. 结合野外地质观察，认为含Fe碳酸盐赋矿围岩是形成高品位、大型卡林型金矿床最有利的岩性，并提出了与去碳酸盐化有关的碳酸盐脉，是寻找深部隐伏卡林型金矿体的重要找矿标志之一。

Oxidative carbonylation of aniline over a polymer-supported palladium-copper catalyst

The polymer-supported bimetallic catalyst FVP-PdCl2-2CuCl(2) (PVP, poly(N-vinyl-2-pyrrolidone), obtained in situ by the addition of CuCl2 to an alcoholic solution of PVP-PdCl2, exhibits high selectivity and activity for the oxidative carbonylation of aniline with carbon monoxide and oxygen to ethyl N-phenylcarbamate in the presence of a base (NaOAc) under atmospheric pressure. The strong synergic effect of Pd-Cu gives rise to a clear increase in the selectivity and activity. (C) 2000 Elsevier Science B.V. All rights reserved.

Thioreduction of cyclopentanone and hydrodesulfurization of dibenzothiophene over sulfided nickel or cobalt-promoted molybdenum on alumina catalysts

Two series of sulfided Ni or Co promoted Mo/alumina catalysts, having different Ni or Co loadings, were characterized by their activities for the transformation of cyclopentanone into cyclopentanethiol (flow reactor, 220 degrees C, atmospheric pressure) and for the hydrodesulfurization of dibenzothiophene (flow reactor, 340 degrees C, 3 MPa hydrogen pressure). The addition of the promoter increased significantly the activity of the Mo/alumina catalyst for both reactions, up to a maximum obtained with the catalysts having a (promoter)/(promoter+Mo) molar ratio equal to 0.3-0.4. This increase in activity was due in part to an increase in the hydrogenating properties of the Mo/alumina catalyst. However, an additional modification of the catalyst (basic and nucleophilic properties) must be considered to account for the spectacular effect of the promoter on the rate of the dibenzothiophene direct desulfurization reaction. (C) 1999 Elsevier Science B.V. All rights reserved.

Polymer-supported palladium-manganese bimetallic catalyst for the oxidative carbonylation of amines to carbamate esters

The polymer-supported bimetallic catalyst PVP-PdCl2-MnCl2 (PVP=poly(N-vinyl-2-pyrrolidone)) exhibits high activity and selectivity for the oxidative carbonylation of amines with carbon monoxide and oxygen to carbamate esters under atmospheric pressure in the presence of a base (NaOAc). This catalyst is prepared by the addition of MnCl2 to the alcoholic solution of PVP-PdCl2 in situ. A remarkable bimetallic synergic effect and the role of PVP in PVP-PdCl2-MXn (MXn=the second transition metal component such as NiCl2, CoCl2, MnCl2 and FeCl3) gives rise to an obvious increase in the conversion and selectivity for the reaction. Among the second metal components tested, Mn-Pd exerts the strongest synergic effect. (C) 1999 Elsevier Science B.V. All rights reserved.

Lipase-catalyzed regioselective acylation of diosgenyl saponins

Diosgenyl saponins were regio selectively acylated by Novozyme 435 with vinyl esters as acylating agents in THF to afford the corresponding mono- or diacyl diosgenyl saponins. (C) 2001 Elsevier Science Ltd. All rights reserved.

Development of a LCST membrane forming system for cellulose acetate ultrafiltration hollow fiber

A novel lower critical solution temperature (LCST) membrane forming system containing cellulose acetate (CA)/poly (vinyl pyrrolidone) (PVP 3 60K)/N-methyl-2-pyrrolidone (NMP)/1,2-propanediol with a weight ratio of 24.0:5.0:62.6:8.4 had been developed. CA hollow fiber ultrafiltration (UF) membranes were fabricated using the dry-wet spinning technique. The fibers were post-treated with a 200 mg/L hypochlorite solution over a period of 6 It at pH 7. The experimental results showed that water flux of a membrane decreased while retention increased with increasing CA concentration in a dope. It was concluded that the membrane pore size decreased with increasing CA concentration. The membrane fouling tendency for BSA was 3 times higher than that for PVP 24K. (C) 2004 Elsevier B.V. All rights reserved.