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1Ridge subduction and porphyry copper-gold mineralization:An overview显示文摘Many large porphyry Cu-Au deposits are connected to adakitic rocks known to be closely associated with ridge subduction. For example, there are several subducting ridges along the east Pacific margin, e.g., in Chile, Peru, and South America, most of which are associated with large porphyry Cu-Au deposits. In contrast, there are much fewer ridge subductions on the west Pacific margin and porphyry Cu-Au deposits are much less there, both in terms of tonnage and the number of deposits. Given that Cu and Au are moderately incompatible elements, oceanic crust has much higher Cu-Au concentrations than the mantle and the continental crust, and thus slab melts with their diagnostic adakitic chemistry have systematically higher Cu and Au, which is favorable for mineralization. Considering the geotherm of subducting slabs in the Phanerozoic, ridge subduction is the most favorable tectonic setting for this. Therefore, slab melting is the likely link in the spatial association between ridge subduction and Cu-Au deposits. Geochemical signatures of slab melting and hence maybe ridge subduction in less eroded regions in eastern China, the central Asian orogenic belt etc. may indicate important exploration targets for large porphyry Cu-Au deposits.SUN WeiDong LING MingXing YANG XiaoYong FAN WeiMing DING Xing LIANG HuaYing 2010Science China Earth Sciences2010,53,4:97
2Hydrothermal ore deposits in collisional orogens显示文摘Hydrothermal ore deposits at convergent plate boundaries represent extraordinary metal enrichment in the continental crust. They are generally associated with felsic magmatism in extensional settings at high thermal gradients. Although their formation is common during accretionary orogeny, more and more ore deposits have been discovered recently in the collisional orogens of China. Because collisional orogeny was operated in a compressional regime at low thermal gradients, it is not favorable for mobilization of ore-forming elements and thus for the production of hydrothermal ore deposits. Nevertheless, continental collision is generally preceded by oceanic subduction, which enables the preliminary enrichment of ore-forming elements in the mantle wedge due to chemical metasomatism by subducting slab-derived fluids. This gave rise to metal pre-enriched domains in the overriding lithosphere, which may be reactivated by extensional tectonism for hydrothermal mineralization either immediately during accretionary orogeny or at a later time during and after collisional orogeny. It is these tectonic processes that have resulted in the progressive enrichment of ore-forming elements through the geochemical differentiation of the subducting oceanic crust, the metasomatic mantle domains and the mafic juvenile crust, respectively, at different depths. Finally, the reactivation of metal pre-enriched domains by continental rifting in the orogenic lithosphere is the key to the metallogenesis of collisional orogens.Yongfei Zheng Jingwen Mao Yanjing Chen Weidong Sun Pei Ni Xiaoyong Yang 2019Science Bulletin2019,64,3:26
3Deep carbon cycles constrained by a large-scale mantle Mg isotope anomaly in eastern China显示文摘Although deep carbon recycling plays an important role in the atmospheric CO_2 budget and climate changes through geological time,the precise mechanisms remain poorly understood.Since recycled sedimentary carbonate through plate subduction is the main light-δ^(26)Mg reservoir within deep-Earth,Mg isotope variation in mantle-derived melts provides a novel perspective when investigating deep carbon cycling.Here,we show that the Late Cretaceous and Cenozoic continental basalts from 13 regions covering the whole of eastern China have low δ^(26)Mg isotopic compositions,while the Early Cretaceous basalts from the same area and the island arc basalts from circum-Paciic subduction zones have mantle-like or heavy Mg isotopic characteristics.hus,a large-scale mantle low δ^(26)Mg anomaly in eastern China has been delineated,suggesting the contribution of sedimentary carbonates recycled into the upper mantle,but limited into the lower mantle.his large-scale spatial and temporal variation of Mg isotopes in the mantle places severe constraints on deep carbon recycling via oceanic subduction.Shu-Guang Li Wei Yang Shah Ke Xunan Meng Hengci Tian Lijuan Xu Yongsheng He Jian Huang Xuan-Ce Wang Qunke Xia Weidong Sun Xiaoyong Yang Zhong-Yuan Ren Haiquan Wei Yongsheng Liu Fancong Meng Jun Yan 2017National Science Review2017,4,1:23
4Cropland redistribution to marginal lands undermines environmental sustainability显示文摘Cropland redistribution to marginal land has been reported worldwide;however,the resulting impacts on environmental sustainability have not been investigated sufficiently.Here we investigated the environmental impacts of cropland redistribution in China.As a result of urbanization-induced loss of high-quality croplands in south China(~8.5 t ha^(-1)),croplands expanded to marginal lands in northeast(~4.5 t ha^(-1)) and northwest China(~2.9 t ha^(-1)) during 1990-2015 to pursue food security.However,the reclamation in these low-yield and ecologically vulnerable zones considerably undermined local environmental sustainability,for example increasing wind erosion(+3.47%),irrigation water consumption(+34.42%),fertilizer use(+20.02%) and decreasing natural habitats(-3.11%).Forecasts show that further reclamation in marginal lands per current policies would exacerbate environmental costs by 2050.The future cropland security risk will be remarkably intensified because of the conflict between food production and environmental sustainability.Our research suggests that globally emerging reclamation of marginal lands should be restricted and crop yield boost should be encouraged for both food security and environmental benefits.Wenhui Kuang Jiyuan Liu Hanqin Tian Hao Shi Jinwei Dong Changqing Song Xiaoyong Li Guoming Du Yali Hou Dengsheng Lu Wenfeng Chi Tao Pan Shuwen Zhang Rafiq Hamdi Zherui Yin Huimin Yan Changzhen Yan Shixin Wu Rendong Li Jiuchun Yang Yinyin Dou Wenbin Wu Liqiao Liang Bao Xiang Shiqi Yang 2022National Science Review2022,9,1:13
5Effects of elevated CO_2 concentration and nitrogen supply on biomass and active carbon of freshwater marsh after two growing seasons in Sanjiang Plain, Northeast China显示文摘An experiments were carried out with treatments differing in nitrogen supply (0, 5 and 15 g N/m2) and CO2 levels (350 and 700 μmol/mol) using OTC (open top chamber) equipment to investigate the biomass of Calamagrostis angustifolia and soil active carbon contents after two years. The results showed that elevated CO2 concentration increased the biomass of C. angustifolia and the magnitude of response varied with each growth period. Elevated CO2 concentration has increased aboveground biomass by 16.7% and 17.6% during the jointing and heading periods and only 3.5% and 9.4% during dough and maturity periods. The increases in belowground biomass due to CO2 elevation was 26.5%, 34.0% and 28.7% during the heading, dough and maturity periods, respectively. The responses of biomass to enhanced CO2 concentrations are differed in N levels. Both the increase of aboveground biomass and belowground biomass were greater under high level of N supply (15 g N/m2). Elevated CO2 concentration also increased the allocation of biomass and carbon in root. Under elevated CO2 concentration, the average values of active carbon tended to increase. The increases of soil active soil contents followed the sequence of microbial biomass carbon (10.6%) > dissolved organic carbon (7.5%) > labile oxidable carbon (6.6%) > carbohydrate carbon (4.1%). Stepwise regressions indicated there were significant correlations between the soil active carbon contents and plant biomass. Particularly, microbial biomass carbon, labile oxidable carbon and carbohydrate carbon were found to be correlated with belowground biomass, while dissolved organic carbon has correlation with aboveground biomass. Therefore, increased biomass was regarded as the main driving force for the increase in soil active organic carbon under elevated CO2 concentration.ZHAO Guangying LIU Jingshuang WANG Yang DOU Jingxin DONG Xiaoyong 2009Journal of Environmental Sciences2009,21,10:13
6Geological and Geochemical Constraints on the Newly Discovered Yangchongli Gold Deposit in Tongling Region, Lower Yangtze Metallogenic Belt显示文摘The newly discovered Yangchongli gold deposit is a unique independent gold deposit in the Tongling ore-cluster region controlled by the tectonic alteration firstly discovered in the Lower Yangtze Metallogenic Belt(LYMB). The host magmatic rocks mainly consist of monzodiorite and K-feldspar granite. The LA-ICP-MS U-Pb zircons dating yielded weighted mean ^(206)Pb/^(238)U ages of 140.7 ± 1.8 Ma and 126.4 ± 1.2 Ma for the monzodiorite and K-feldspar granite, respectively. Monzodiorites are enriched in Sr, Ba, Rb, and depleted in Y, Yb with high Sr/Y and La/Yb ratios, similar to the geochemical features of adakite, considered as products of differentiation of mafic magmas originating from lithospheric mantle melt/fluids caused by metasomatism during paleo-Pacific Plate subduction in the Mesozic. In contrast, the compositions of K-feldspar granites are A-type granites, indicating an extensional tectonic background. Gold ores hosted in the fracture zone occurred as quartz vein within cataclastic rock. Sulfur and lead isotopes from pyrites show crust-mantle mixing characteristics. Metal components from strata also took part in the gold mineralization, and resulted from two episodes of magmatism that were probably related to tectonic transition from a compressive to an extensional setting between 140–126 Ma, which led to the Mesozoic large-scale polymetallic mineralization events in eastern China.DUAN Liu'an GU Huangling YANG Xiaoyong 2017Acta Geologica Sinica(English Edition)2017,91,6:11
7Development of a model to simulate soil heavy metals lateral migration quantity based on SWAT in Huanjiang watershed,China显示文摘Lateral transportation of soil heavy metals in rainfall events could significantly increase the scope of pollution. Therefore, it is necessary to develop a model with high accuracy to simulate the migration quantity of heavy metals. A model for heavy metal migration simulation was developed based on the SWAT(Soil and Water Assessment Tool) model. This model took into consideration the influence of soil p H value, soil particle size, runoff volume, sediment amount,concentration of water-soluble heavy metals dissolved in runoff and insoluble absorbed to the soil particles. This model was reasonable in Huanjiang watershed, Guangxi Zhuang Autonomous Region, south China, covering an area of 273 km^2. The optimal drainage area threshold was determined by analyzing the effects of watershed subdivision on the simulation results to ensure the simulation accuracy. The main conclusions of this paper were:(1) watershed subdivision could affect simulation migration quantity of heavy metals;(2) the quantity of heavy metals transported by sediment accounted for 97%–99% of the total migration quantity in the study watershed. Therefore, sediment played the most important role in heavy metal migration;(3) the optimal drainage area threshold percentage to ensure high simulation accuracy was determined to be 2.01% of the total watershed;(4) with the optimal threshold percentage, this model could simulate the migration quantity of As, Pb and Cd accurately at the total watershed and subwatershed level. The results of this paper were useful for identifying the key regions with heavy metal migration.Pengwei Qiao Mei Lei Sucai Yang Jun Yang Xiaoyong Zhou Nan Dong Guanghui Guo 2019Journal of Environmental Sciences2019,31,3:11
8Geochemical characteristics of the Xuanwei Formation in West Guizhou:Significance of sedimentary environment and mineralization显示文摘The Upper Permian Xuanwei Formation widely occurs in western Guizhou,unconformably overlying the Emeishan basalts,and mainly consists of black shales.It is~170 m thick at Cuyudong Village,Weining County,West Guizhou,China,where the samples of black shale and sandy shale were collected and analyzed.The shales mainly contain SiO2,18.9%?44.1%,Al2O3,14.8%?52.8%,Fe2O3,1.0%?41.2%,LOI,3.2%?21.1%,TiO2,1.0%-6.7%,and MgO,0.2%?2.5%.The contents of all other major elements are lower than 1.0%.It is shown that the black shales have higher contents of Fe2O3 and LOI than normal shales.The siderites occurred in the black shales with higher contents of Fe2O3,which may be attributed to hydrothermal activities on seafloor.All analyzed shale samples have extremely high Ga,47.8×10-6-109.9×10-6(70.5×10-6 on average),higher than the industrial mining standard of Ga Resource Industry Standard.The total contents of rare-earth elements(REE) of 9 black shale samples vary from 213×10-6 to 1460×10-6,suggesting that these black shales are enriched in REE.The shale-normalized REE patterns display both positive and negative Ce anomalies(Ce/Ce* from 0.5 to 1.7),revealing that the Xuanwei shales were precipitated under oxic and anoxic conditions.The Rb-Sr chronological diagram of 6 shale samples in the Xuanwei Formation shows an age of 255±12 Ma.Strontium isotopic ratios(87Sr/86Sr)t0 range from 0.70635 to 0.70711,suggesting that these Xuanwei black shales might be derived from chemical weathering of the Emeishan basalts.ZHANG Zhengwei YANG Xiaoyong LI Shuang ZHANG Zhongshan 2010Chinese Journal Of Geochemistry2010,29,4:9
9Synergistic effects of elevated homocysteine level and abnormal blood lipids on the onset of stroke显示文摘Hyperhomocysteinemia and abnormal blood lipids are independent risk factors for stroke.However,whether both factors exert a synergistic effect in the onset of stroke remains unclear.The present study is a retrospective analysis of 2 089 cases of stroke and 2 089 control cases of simple intervertebral disk protrusion using a paired multivariate logistic regression method.Adjusting for known confounding variables including the patients’age,gender,smoking status,alcohol consumption status,patient and family medical history,and clinical biochemical indices,elevated homocysteine level was related to the onset of stroke.Patients with elevated homocysteine levels and abnormal blood lipids showed a 40.9%increase in the risk for stroke compared to patients with normal homocysteine levels and blood lipids(odds ratio 1.409;95%confidence interval1.127–1.761).These results indicate that elevated homocysteine and abnormal blood lipids exert synergistic effects in the onset of stroke.Patients with elevated homocysteine levels and abnormal blood lipids are predisposed to stroke.Lu Hao Liming Chen Xiaoyong Sai Zhefeng Liu Guang Yang Rongzeng Yan Lili Wang Caiyun Fu Xuan Xu Zhenzhen Cheng Qiang Wu Shuzhang Li 2013Neural Regeneration Research2013,8,31:9
10Seasonal Changes in Phytoplankton Biomass and Dominant Species in the Changjiang River Estuary and Adjacent Seas:General Trends Based on Field Survey Data 1959-2009显示文摘The characteristics of seasonal variation in phytoplankton biomass and dominant species in the Changjiang River Estuary and adjacent seas were discussed based on field investigation data from 1959 to 2009. The field data from 1981 to 2004 showed that the Chlorophyll-a concentration in surface seawater was between 0.4 and 8.5 μg dm-3. The seasonal changes generally presented a bimodal trend, with the biomass peaks occurring in May and August, and Chlorophyll-a concentration was the lowest in winter. Seasonal biomass changes were mainly controlled by temperature and nutrient levels. From the end of autumn to the next early spring, phytoplankton biomass was mainly influenced by temperature, and in other seasons, nutrient level(including the nutrient supply from the terrestrial runoffs) was the major influence factor. Field investigation data from 1959 to 2009 demonstrated that diatoms were the main phytoplankton in this area, and Skeletonema costatum, Pseudo-nitzschia pungens, Coscinodiscus oculus-iridis, Thalassinoema nitzschioides, Paralia sulcata, Chaetoceros lorenzianus, Chaetoceros curvisetus, and Prorocentrum donghaiense Lu were common dominant species. The seasonal variations in major dominant phytoplankton species presented the following trends: 1) Skeletonema(mainly S. costatum) was dominant throughout the year; and 2) seasonal succession trends were Coscinodiscus(spring) →Chaetoceros(summer and autumn) → Coscinodiscus(winter). The annual dominance of S. costatum was attributed to its environmental eurytopicity and long standing time in surface waters. The seasonal succession of Coscinodiscus and Chaetoceros was associated with the seasonal variation in water stability and nutrient level in this area. On the other hand, long-term field data also indicated obvious interannual variation of phytoplankton biomass and community structure in the Changjiang River Estuary and adjacent seas: average annual phytoplankton biomass and dinoflagellate proportion both presented increased trends during the 1950 s-2000 s.YANG Shu HAN Xiurong ZHANG Chuansong SUN Baiye WANG Xiulin SHI Xiaoyong 2014Journal of Ocean University of China2014,13,6:7
11A Geochemical Study of an REE-rich Carbonatite Dyke at Bayan Obo,Inner Mongolia,Northern China显示文摘An REE-rich carbonatite dyke was found in Dulahala, close to the Bayan Obo superlarge REE-Nb-Fe mineral deposit in Inner Mongolia, northern China. The REE content in the dyke varies greatly, from 1% up to 20% (wt), which might constitute rich REE ores. Light REEs in the carbonatite are enriched and highly fractionated relative to heavy REEs and there is no Eu anomaly. The REE and trace element distribution patterns of the carbonatite are identical to those of fine-grained dolomite marble which is the host rock of the Bayan Obo REE-Nb-Fe superlarge mineral deposit. This indicates a petrogenetic linkage between the REE-rich carbonatite and the mineralizations in this region.YANG Xueming ZHENG Yongfei YANG Xiaoyong ZHANG Peishan M.J.LE BAS 2000Acta Geologica Sinica(English Edition)2000,74,3:7
12Mineralization,Geochemistry and Zircon U-Pb Ages of the Paodaoling Porphyry Gold Deposit in the Guichi Region,Lower Yangtze Metallogenic Belt,Eastern China显示文摘The newly discovered Paodaoling porphyry Au deposit from the Guichi region, Lower Yangtze River Metallogenic Belt(LYRB), contains >35 tons of Au at an average grade of ~1.7 g/t. It is a porphyry ‘Au-only' deposit, as revealed by current exploration in the depths, mostly above-400 m, which is quite uncommon among coeval porphyry mineralization along the LYRB. Additionally, there are also Cu-Au bearing porphyries and barren alkaline granitoids in the Paodaoling district. Zircon LA-ICP-MS U-Pb dating of the Cu-Au-bearing porphyries yield an age of 141–140 Ma, falling within the main magmatic stage of the LYRB, whereas the barren granites give an age of 125–120 Ma, coeval with the regional Atype granites. The Cu-Au-bearing porphyries are LILE-, LREE-enriched and HFSE-depleted, typical of arc magmatic affinities. The barren granites are HFSE-enriched, with lower LREE/HREE ratios and pronounced negative Eu anomalies. The Cu-Au-bearing porphyries in the Paodaoling district have high oxygen fugacities and high water content. Pyrite sulfur isotopes of the Paodaoling gold deposit indicate a magmatic-sedimentary mixed source for the ore-forming fluids. Based on the alteration and poly-metal zonation of the deepest exploration drill hole from the Paodaoling Au deposit, we propose that Cu ore bodies could lie at depth beneath the current Au ore bodies. The magmatism and associated Cu-Au mineralization of the Paodaoling district are likely to have formed in a subduction setting, during slab rollback of the paleo-Pacific plate.DUAN Liu'an YANG Xiaoyong DENG Jianghong WANG Fangyue LEE Insung 2018Acta Geologica Sinica(English Edition)2018,92,2:6
13^(40)Ar/^(39)Ar Dating of the Shaxi Porphyry Cu-Au Deposit in the Southern Tan-Lu Fault Zone, Anhui Province显示文摘从在 Yangtze metallogenic 带的更低的部分的 Shaxi 斑岩的斜长石和黑云母的四件样品好久被分析有 ^(40 ) 的决心 Ar/^(39 ) Armethod。结果根据在 isochron 和高原年龄之间的协议与信心的高水平产出 126 妈的可再现的年龄到 135 妈。四 Ar-Ar 年龄在分析错误以内是相对一致的。这些年龄与也一致,但是比精确的更多,以前的 K-Ar 和 Rb-Sr 年龄并且因此沿着中间在斑岩形成和联系 Cu-Au 矿化作用的时间提供更好的限制降低 Yangtze metallogenic 带的部分。126 ~ 135 妈的年龄被解释代表 Shaxi 斑岩的恼人的时间,以便 Cu-Au 矿化作用以后应该由于 post-magmatic 发生了热水的事件。YANG Xiaoyong ZHENG Yongfei XIAO Yilin DU Jianguo SUN Weidong 2007Acta Geologica Sinica(English Edition)2007,81,3:6
14Metallogenic geochemistry of Sb-mineralization in southern margin of North China platform显示文摘1 Geological setting THE Sb mineralization zone in the south margin of North China platform is located in the transitional edgeof North China plate and Yangtze plate, belonging to Qinling fold system, whose tectonic line is inNWW-SEE direction regionally. Because of the huge compression caused by the collision of the twoplates, the rocks undergone strong deformation and metamorphism have very complicated structures. Theregional deep fault-Shuanghuaishu fault-controls Sb-mineralization zone belt, and all the Sb-oredeposits or mineralized spots appear alone at the very southern margin of the fault. The lithostragraphirunits in the mineralized zone are relatively simple, mainly composed of Jiebei Group (Pt2J2) of QinglingFormation (with middle-high metamorphsim) and the upper Triassic system (with little metamorphism).YANG Xiaoyong~1, YANG Xueming~1, ZHANG Jianjun~2, CAO Gaoshe~2 and ZHANG Zhengwei~2 1. Department of Earth and Space Sciences, University of Science and Technlogy of China, Hefei 230026, China 2. Institute of Geology, Henan Bureau of Geology and Mineral Resources, Zhengzhou 450053, China 1999Chinese Science Bulletin1999,44,S2:6
15High performance integrated photonic circuit based on inverse design method显示文摘The basic indexes of all-optical integrated photonic circuits include high-density integration,ultrafast response and ultralow energy consumption.Traditional methods mainly adopt conventional micro/nano-structures.The overall size of the circuit is large,usually reaches hundreds of microns.Besides,it is difficult to balance the ultrafast response and ultra-low energy consumption problem,and the crosstalk between two traditional devices is difficult to overcome.Here,we propose and experimentally demonstrate an approach based on inverse design method to realize a high-density,ultrafast and ultra-low energy consumption integrated photonic circuit with two all-optical switches controlling the input states of an all-optical XOR logic gate.The feature size of the whole circuit is only 2.5μm×7μm,and that of a single device is 2μm×2μm.The distance between two adjacent devices is as small as 1.5μm,within wavelength magnitude scale.Theoretical response time of the circuit is 150 fs,and the threshold energy is within 10 fJ/bit.We have also considered the crosstalk problem.The circuit also realizes a function of identifying two-digit logic signal results.Our work provides a new idea for the design of ultrafast,ultra-low energy consumption all-optical devices and the implementation of high-density photonic integrated circuits.Huixin Qi Zhuochen Du Xiaoyong Hu Jiayu Yang Saisai Chu Qihuang Gong 2022Opto-Electronic Advances2022,5,10:5
16Groundwater Systems and Resources in the Ordos Basin,China显示文摘Ordos 盆是在西北的中国的大规模沉积的盆。到顶的从底部的 hydrostratigraphic 单位是 pre 寒武纪的变形岩石,更低的古生代的碳酸盐岩石,上面对中生代碎屑状的岩石和新生代存款古生代。全部的厚度直到 6000 m。三个地下水系统在 Ordos 盆是在场的,基于地质的设置,即石灰岩地区常见的地形地下水系统,白垩纪碎屑状的地下水系统和第四级的地下水系统。这份报纸系统地描述每个系统的地下水流动模式和对地下水资源的全面评价。HOU Guangcai LIANG Yongping SU Xiaosi ZHAO Zhenghong TAO Zhengping YIN Lihe YANG Yuncheng WANG Xiaoyong 2008Acta Geologica Sinica(English Edition)2008,82,5:5
17Graphite dust deposition in the HTR-10 steam generator显示文摘Graphite dust has an important effect on the safe operation of a high-temperature gas-cooled reactor(HTR).The present study analyzes temperature and flow field distributions in the HTR-10 steam generator.The temperature and flow field distributions are then used to study thermophoretic deposition and turbulent deposition.The results show that as the dust diameter increases,the thermophoretic deposition decreases,while the turbulent deposition first decreases and then increases.The thermophoretic deposition is higher at higher reactor powers,with turbulent deposition growing more rapidly at higher reactor power.For small particles,the thermophoretic deposition effect is greater than the turbulent deposition effect,while for large particles,the turbulent deposition effect is dominant.Wei Peng Yanan Zhen Xiaoyong Yang Suyuan Yu 2013Particuology2013,11,5:5
18Preparation of silver tin oxide powders by hydrothermal reduction and crystallization显示文摘Silver tin oxide composite powders were synthesized by the hydrothermal method with a silver ammine solution and a Na2SnO3 solution as raw materials. H2C2O4 was used as the co-precipitator of silver ions and tin ions. The co-precipitation conditions were investigated. The results show that the co-precipitate of Ag2C2O4 and Sn(OH)4 is available when the pH value of the solution is 4.27-8.36. Using the obtained precipitate as precursor,the reduction of Ag+ and the crystallization of tin oxide were carried out simultaneously by the hydrothermal method and silver tin oxide composite powders were obtained. The composite powders were characterized by X-ray diffraction (XRD) analysis,scanning electron microscope (SEM),and energy spectrum analysis. The results show that the silver tin oxide composite powders are small with a diameter of about 2 μm and with homogeneous distribution of tin.DU Zuojuan YANG Tianzu GU Yingying QIU Xiaoyong DOU Aichun 2007Rare Metals2007,26,5:4
19Controlling synthesis and gas-sensing properties of ordered mesoporous In2O3-reduced graphene oxide(r GO) nanocomposite显示文摘Herein, we describe a strategy for fabricating ordered mesoporous In2O3-reduced graphene oxide(r GO)nanocomposite through ultrasonic mixing, where ordered mesoporous In2O3 nanoparticles are synthesized via the nanocasting route by using mesoporous silica as a hard template, which possess ordered mesostructure with a large surface area of 81 m2g-1, and r GO nanosheets are synthesized from graphite via graphene oxide(GO) as intermediate. After coupled with r GO, mesoporous In2O3 could maintain its ordered mesostructure. We subsequently investigate the gas-sensing properties of all the In2O3 specimens with or without r GO for different gases. The results exhibit the ordered mesoporous In2O3-r GO nanocomposite possesses significantly enhanced response to ethanol even at low concentration levels, superior over pure mesoporous In2O3 nanoparticles. Similar strategy could be extended to other ordered mesoporous metal oxide–r GO nanocomposite for improving the gas-sensing property.Ping Xue Xiaomei Yang Xiaoyong Lai Weitao Xia Peng Li Junzhuo Fang 2015Science Bulletin2015,60,15:4
20Genesis of tuff interval and its uranium enrichment in Upper Triassic of Ordos Basin, NW China显示文摘Recently measured high gamma ray values in the Yanchang Formation of the Upper Triassic in the Ordos Basin have added an interesting and controversial twist to the study of the formation’s uranium enrichment and genesis.High uranium and thorium contents in the tuffaceous layer cause high gamma ray values in the Yanchang Formation.Petrographic studies,major elements,rare earth elements(REEs),and trace elements have been systematically analyzed to determine the composition,geochemical environment,and diagenetic processes of the layer.The observed color of the tuffaceous layer in the study area varies from yellow to yellowish brown.The tuff consists of matrix supported with sub-rounded to sub-angular lithic fragments.These lithic fragments probably derived from pre-existing rocks and incorporated into the tuffaceous layer during volcanic eruption.Quartz,plagioclase,and biotite were observed in well to poorly sorted form,in addition to framboidal pyrite and organic laminae.Measured ratios of SiO_2/Al_2O_3 ranged from 3.277 to 6.105 with an average of 3.738.The ratio of TiO_2/Al_2O_3 varied from 0.037 to 0.201 with an average of 0.061,indicating that the sediments of the tuffaceous layer originated from an intermediate magma.REE distribution patterns show sharp negative Eu anomalies,indicating a reducing environment,which is suitable for uranium deposition.A reducing environment was confirmed by black shale in the base of the Yanchang Formation.Such black shale has high organic matter content that can take kerogene from mudstone and provide a reducing environment for uranium enrichment in the tuffaceous layer.Moreover,negative Eu anomalies and the REE patterns indicate a subduction-related volcanic arc environment as the magma source of the tuffaceous layers.High values of Rb,Ba,and Sr might be the result of fluid phase activities;low values of Hf and Eu indicate the involvement of crustal material during diagenesis of the tuff.Discrimination diagrams(Th/Yb vs Ta/Yb,Th/Hf vs Ta/Hf)suggest an active continental margin as the tectonic setting of source volcanoes.Plots of Nb versus Y,Rb versus Y+Nb,TiO_2 versus Zr,and Th/Yb versus Nb/Yb of the tuffaceous content point to calc-alkaline continental arc-related magmatism.We concluded that uranium enrichment in the tuffaceous layer was supported by oxidation–reduction.Shamim Akhtar Nosheen Sahir Xiaoyong Yang 2018Acta Geochimica2018,37,1:4
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