The Panzhihua intrusion in southwest China is part of the Emeishan large igneous province and host of a large Fe-Ti-V ore deposit.In previous interpretations it was considered to be a layered,differentiated sill with ...The Panzhihua intrusion in southwest China is part of the Emeishan large igneous province and host of a large Fe-Ti-V ore deposit.In previous interpretations it was considered to be a layered,differentiated sill with the ore deposits at its base.New structural and petrological data suggest instead that the intrusion has an open S-shape,with two near-concordant segments joined by a discordant dyke-like segment. During emplacement of the main intrusion,multiple generations of mafic dykes invaded carbonate wall rocks,producing a large contact aureole.In the central segment,magmatic layering is oriented oblique to the walls of the intrusion.This layering cannot have formed by crystal settling or in-situ growth on the floor of the intrusion;instead we propose that it resulted from inward solidification of multiple,individually operating,convection cells.Ore formation was triggered by interaction of magma with carbonate wall rocks.展开更多
By means of techniques such as inductively coupled plasma-mass spectrometry （ICP-MS） and X-ray fluorescence spectrometry （XRF）,REE geochemical characteristics and depositional environment of the black shales in Ba...By means of techniques such as inductively coupled plasma-mass spectrometry （ICP-MS） and X-ray fluorescence spectrometry （XRF）,REE geochemical characteristics and depositional environment of the black shales in Baiguoyuan Ag-V deposit,Xingshan,Hubei Province,were studied in this work. The black shales in a typical TC5 profile of Doushantuo Formation of upper Sinian period were obviously enriched in REE,especially in LREE. The REE patterns of the investigated samples normalized by Post Archean Australian Shale （PAAS） showed a flat or slight rightward inclination. The characteristic elements,their ratio and correlation diagrams showed that it should be hot-water deposit and the black shale in the study area was of a sedimentary origin. Redox sensitive metal elements pattern,trace elements index measurement in anoxic environment,Ce anomaly and δEu negative anomaly showed that the deposit environment of the black shales was a reducing and anoxic one and a slight change of the sea level could be identified. The samples relatively focused on the superimposed area of sedimentary rock and basalt in the diagram of La/Yb-ΣREE and La/Yb-Ce/La. So there might be accession of hot-water sedimentation during the period of the formation of the black rock series,mostly in normal terrigenous sedimentation with the participation of deep hot-water deposit.展开更多
We present a study of the fabrication of monolayer MoS_2 on n-Si(111) substrates by modified thermal evaporation deposition and the optoelectrical properties of the resulting film. The as-grown MoS_2 ultrathin film is...We present a study of the fabrication of monolayer MoS_2 on n-Si(111) substrates by modified thermal evaporation deposition and the optoelectrical properties of the resulting film. The as-grown MoS_2 ultrathin film is about 10 nm thick, or about a few atomic layers of MoS_2. The film has a large optical absorption range of 300-700 nm and strong luminescence emission at 682 nm. The optical absorption range covered almost the entire ultraviolet to visible light range, which is very useful for making high-efficiency solar cells. Moreover, the MoS_2/Si heterojunction exhibited good rectification characteristics and excellent photovoltaic effects. The power conversion efficiency of the heterojunction device is about 1.79% under white light illumination of 10 m W/cm^2. The results show that the monolayer MoS_2 film will find many applications in high-efficiency optoelectronic devices.展开更多
GaN rods were deposited by chemical vapor deposition (CVD) onto sapphire (0 0 0 1) and amorphous quartz. The reactive Ga species in vapor the phase was formed with NH4Cl and gallium. The unidirectional growth was cata...GaN rods were deposited by chemical vapor deposition (CVD) onto sapphire (0 0 0 1) and amorphous quartz. The reactive Ga species in vapor the phase was formed with NH4Cl and gallium. The unidirectional growth was catalyzed with gold nanoparticles formed onto the substrate prior to the CVD reaction in order to induce a vapor-liquid-solid (VLS) mechanism. However, this method of synthesis seems to be influenced by other growth mechanisms which formed additional depositions of GaN with different morphology than the rods catalyzed by gold nanoparticles. The moieties of GaN that grew in the absence of gold formed branches in the rods or increased the lateral growth of rods resulting in larger diameters than the size of the gold particle that guided the growth.展开更多
The Shangling vanadium deposit, which occurs in the Lower Devonian Tangding formation black rock series strata, has V2O5 reserves of more than 1.5 million tons and prospective reserves of more than 2 million tons. Pre...The Shangling vanadium deposit, which occurs in the Lower Devonian Tangding formation black rock series strata, has V2O5 reserves of more than 1.5 million tons and prospective reserves of more than 2 million tons. Preliminary studies on the occurrence state of vanadium(V) in this deposit have been conducted by artificial heavy minerals concentrates, leaching experiments, scanning and transmission electron microscopy and X-ray powder diffraction.These experiments have revealed no independent vanadium mineral occurrences in the Shangling vanadium deposit and the percentages of water-soluble vanadium, hydrochloric acid soluble vanadium and HF soluble vanadium were1.93 %, 21.42 % and 76.47 %, respectively. Based on our data and earlier research, we estimate that the valences state of V absorbed onto the surface of organic matter or clastic particles are +5 and +4, accounting for 10.00 % and13.35 % of the total amount of V, respectively and the valences state of V that exist in the octahedral crystal lattice of authigenic illite include +3 and +4, accounting for71.64 % and 4.83 % of the total amount of V, respectively.By calculating the correlation between the total organic carbon and V, we infer that after deposition and before entering the crystal lattice of illite, V occurs in the form of humate complex or is adsorbed by organic matter. About4.24 % of the Al is in the octahedral crystal lattice of illite,which was replaced by the vanadium under the metallogenic environments of Shanglin.展开更多
SiNx：H films with different N/Si ratios are synthesized by plasma-enhanced chemical vapor deposition （PECVD）. Composition and structure characteristics are detected by Fourier transform infrared spectroscopy （FTIR...SiNx：H films with different N/Si ratios are synthesized by plasma-enhanced chemical vapor deposition （PECVD）. Composition and structure characteristics are detected by Fourier transform infrared spectroscopy （FTIR） and X-ray photoelectron spectroscopy （XPS）. It indicates that Si-N bonds increase with increased NH3/SiH4 ratio. Electrical property investigations by I-V measurements show that the prepared films offer higher resistivity and less leakage current with increased N/Si ratio and exhibit entirely insulating properties when N/Si ratio reaches 0.9, which is ascribed to increased Si-N bonds achieved.展开更多
基金supported by a Famous overseas professor project MS2011ZGDZ[BJ]019 through China University of Geosciences (Beijing)and by the USA NSF "Continental Geodynamics" programGeologists from the Panzhihua mining company are thanked for their logistic support
文摘The Panzhihua intrusion in southwest China is part of the Emeishan large igneous province and host of a large Fe-Ti-V ore deposit.In previous interpretations it was considered to be a layered,differentiated sill with the ore deposits at its base.New structural and petrological data suggest instead that the intrusion has an open S-shape,with two near-concordant segments joined by a discordant dyke-like segment. During emplacement of the main intrusion,multiple generations of mafic dykes invaded carbonate wall rocks,producing a large contact aureole.In the central segment,magmatic layering is oriented oblique to the walls of the intrusion.This layering cannot have formed by crystal settling or in-situ growth on the floor of the intrusion;instead we propose that it resulted from inward solidification of multiple,individually operating,convection cells.Ore formation was triggered by interaction of magma with carbonate wall rocks.
基金Project supported by the Key Scientific and Technological Project of Hubei Province, China (2007AA301C51)
文摘By means of techniques such as inductively coupled plasma-mass spectrometry （ICP-MS） and X-ray fluorescence spectrometry （XRF）,REE geochemical characteristics and depositional environment of the black shales in Baiguoyuan Ag-V deposit,Xingshan,Hubei Province,were studied in this work. The black shales in a typical TC5 profile of Doushantuo Formation of upper Sinian period were obviously enriched in REE,especially in LREE. The REE patterns of the investigated samples normalized by Post Archean Australian Shale （PAAS） showed a flat or slight rightward inclination. The characteristic elements,their ratio and correlation diagrams showed that it should be hot-water deposit and the black shale in the study area was of a sedimentary origin. Redox sensitive metal elements pattern,trace elements index measurement in anoxic environment,Ce anomaly and δEu negative anomaly showed that the deposit environment of the black shales was a reducing and anoxic one and a slight change of the sea level could be identified. The samples relatively focused on the superimposed area of sedimentary rock and basalt in the diagram of La/Yb-ΣREE and La/Yb-Ce/La. So there might be accession of hot-water sedimentation during the period of the formation of the black rock series,mostly in normal terrigenous sedimentation with the participation of deep hot-water deposit.
基金supported in parts by the National Natural Science Foundation of China (No. 60976071)the Scientific Project Program of Suzhou City (No. SYG201121)
文摘We present a study of the fabrication of monolayer MoS_2 on n-Si(111) substrates by modified thermal evaporation deposition and the optoelectrical properties of the resulting film. The as-grown MoS_2 ultrathin film is about 10 nm thick, or about a few atomic layers of MoS_2. The film has a large optical absorption range of 300-700 nm and strong luminescence emission at 682 nm. The optical absorption range covered almost the entire ultraviolet to visible light range, which is very useful for making high-efficiency solar cells. Moreover, the MoS_2/Si heterojunction exhibited good rectification characteristics and excellent photovoltaic effects. The power conversion efficiency of the heterojunction device is about 1.79% under white light illumination of 10 m W/cm^2. The results show that the monolayer MoS_2 film will find many applications in high-efficiency optoelectronic devices.
文摘GaN rods were deposited by chemical vapor deposition (CVD) onto sapphire (0 0 0 1) and amorphous quartz. The reactive Ga species in vapor the phase was formed with NH4Cl and gallium. The unidirectional growth was catalyzed with gold nanoparticles formed onto the substrate prior to the CVD reaction in order to induce a vapor-liquid-solid (VLS) mechanism. However, this method of synthesis seems to be influenced by other growth mechanisms which formed additional depositions of GaN with different morphology than the rods catalyzed by gold nanoparticles. The moieties of GaN that grew in the absence of gold formed branches in the rods or increased the lateral growth of rods resulting in larger diameters than the size of the gold particle that guided the growth.
基金the State Key Laboratory of Ore Deposit Geochemistry, Chinese Academy of Sciences, for supporting this projectfunded by the National Natural Science Foundation of China (Grant No. 41372105)the 12th Five-Year Plan Project of the State Key Laboratory of Ore Deposit Geochemistry, Chinese Academy of Sciences (SKLODGZY125-04)
文摘The Shangling vanadium deposit, which occurs in the Lower Devonian Tangding formation black rock series strata, has V2O5 reserves of more than 1.5 million tons and prospective reserves of more than 2 million tons. Preliminary studies on the occurrence state of vanadium(V) in this deposit have been conducted by artificial heavy minerals concentrates, leaching experiments, scanning and transmission electron microscopy and X-ray powder diffraction.These experiments have revealed no independent vanadium mineral occurrences in the Shangling vanadium deposit and the percentages of water-soluble vanadium, hydrochloric acid soluble vanadium and HF soluble vanadium were1.93 %, 21.42 % and 76.47 %, respectively. Based on our data and earlier research, we estimate that the valences state of V absorbed onto the surface of organic matter or clastic particles are +5 and +4, accounting for 10.00 % and13.35 % of the total amount of V, respectively and the valences state of V that exist in the octahedral crystal lattice of authigenic illite include +3 and +4, accounting for71.64 % and 4.83 % of the total amount of V, respectively.By calculating the correlation between the total organic carbon and V, we infer that after deposition and before entering the crystal lattice of illite, V occurs in the form of humate complex or is adsorbed by organic matter. About4.24 % of the Al is in the octahedral crystal lattice of illite,which was replaced by the vanadium under the metallogenic environments of Shanglin.
文摘SiNx：H films with different N/Si ratios are synthesized by plasma-enhanced chemical vapor deposition （PECVD）. Composition and structure characteristics are detected by Fourier transform infrared spectroscopy （FTIR） and X-ray photoelectron spectroscopy （XPS）. It indicates that Si-N bonds increase with increased NH3/SiH4 ratio. Electrical property investigations by I-V measurements show that the prepared films offer higher resistivity and less leakage current with increased N/Si ratio and exhibit entirely insulating properties when N/Si ratio reaches 0.9, which is ascribed to increased Si-N bonds achieved.
