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Synergistic effect of microwave irradiation and CaF2 on vanadium leaching

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International Journal of Minerals,Metallurgy and Materials 2017年第2期24卷 156-163页

作者： jing-peng Wang Yi-min Zhang jing Huang Tao Liu School of Resource and Environmental Engineering Wuhan University of Science and Technology Wuhan 430081 China Hubei Provincial Engineering Technology Research Center of High Efficient Cleaning Utilization for Shale Vanadium Resource Wuhan 430081 China Hubei Provincial Collaborative Innovation Center for High Efficient Utilization of Vanadium Resource Wuhan 430081 China

The effect and mechanism of microwave irradiation on vanadium leaching were studied via a comparison between microwave heating and conventional heating. The results show a synergistic effect of microwave irradiation and calcium fluoride （CaF2） on the vana- dium leaching efficiency. It is confirmed that the vanadium leaching process can be improved by microwave irradiation when CaF2 is present. The leaching rate of vanadium under microwave irradiation is increased by 8%-15% when 5wt% CaF2 is added; by contrast, in the absence of CaF2, the leaching rate is almost unaffected compared to that by conventional heating. Morphological analysis reveals that the particles are gradually eroded by acid under microwave irradiation, whereas some of the fine particles in samples subjected to conventional heating are tightly covered by a flocculent silicate product. Moreover, a large amount of A1 and V and a small amount of Si are dissolved from samples under microwave heating, as revealed by the elemental analysis of leachates. Fourier transform infrared spectroscopic analysis also indicates a higher mass transfer coefficient in the diffusion layer of the raw material by microwave irradiation. When CaF2 is present, the reaction energy barrier is lowered and the leaching process is controlled by the tightly covered product layer, resulting in a prominent effect of mi- crowave irradiation.

关键词： vanadium extraction leaching microwave irradiation calcium fluoride synergistic effects

Energy and Charge Transfer from Guest to Host in Doped Organic Electroluminescent Devices

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Chinese Physics Letters 2002年第9期19卷 1356-1358页

作者： Li Hong-Jian, peng jing-Cui Department of Applied Physics Hu"nan University College of Physics Science and Technology Central South University

The luminescence properties of doped organic electroluminescent devices are explained by means of a Hamiltonian model. The results show that there is a corresponding relation between the amount of transferred charge and the change of the energy originating from charge transfer, and the relation can be influenced by dopant concentration. As the amount of transferred charge increases, the total energy decreases and the luminescence intensity increases. Therefore, we deduce that the energy transfer from guest to host may be derived from the charge transfer. For a given organic electroluminescent device, the maximum value of the conductivity can be observed in a specific dopant concentration. The calculated results show that the greater the transferred charges, the higher the conductivities in doped organic electroluminescent devices. The results agree basically with experimental results.

关键词： Charge transfer

Spatial Variation in CO_(2) Concentration Improves the Simulated Surface Air Temperature Increase in the Northern Hemisphere

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Advances in Atmospheric Sciences 2024年第8期41卷 1614-1628,1676-1685页

作者： jing peng Li DAN Xiba TANG CAS Key Laboratory of Regional Climate-Environment for Temperate East Asia Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Laboratory of Cloud-Precipitation Physics and Severe Storms(LACS) Institute of Atmospheric PhysicsBeijing 100029China

The increasing concentration of atmospheric CO_(2) since the Industrial Revolution has affected surface air ***,the impact of the spatial distribution of atmospheric CO_(2) concentration on surface air temperature biases remains highly *** incorporating the spatial distribution of satellite-derived atmospheric CO_(2) concentration in the Beijing Normal University Earth System Model,this study investigated the increase in surface air temperature since the Industrial Revolution in the Northern Hemisphere(NH) under historical conditions from *** comparison with the increase in surface temperature simulated using a uniform distribution of CO_(2),simulation with a nonuniform distribution of CO_(2)produced better agreement with the Climatic Research Unit(CRU) data in the NH under the historical condition relative to the baseline over the period *** June-July-August(JJA) surface air temperature increased by 1.28℃ ±0.29℃ in simulations with a uniform distribution of CO_(2),by 1.00℃±0.24℃ in simulations with a non-uniform distribution of CO_(2),and by 0.24℃ in the CRU *** decrease in downward shortwave radiation in the non-uniform CO_(2) simulation was primarily attributable to reduced warming in Eurasia,combined with feedbacks resulting from increased leaf area index(LAI) and latent heat *** effects were more pronounced in the non-uniform CO_(2)simulation compared to the uniform CO_(2) *** indicate that consideration of the spatial distribution of CO_(2)concentration can reduce the overestimated increase in surface air temperature simulated by Earth system models.

关键词： spatial variations of CO_(2) surface air temperature Earth system model land surface albedo leaf area index

Efficient Visible Electroluminescence from Porous Silicon Diodes Passivated by Carbon Films

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Chinese Physics Letters 2002年第7期19卷 1013-1015页

作者： Li Hong-Jian, peng jing-Cui Department of Applied Physics Hu"nan University

By using n-butylamine as a carbon resource, carbon film is deposited on the p-n porous silicon (PS) surface with a radio-frequency glow discharge plasma system. Raman spectra and infrared reflection (IR) spectra of the carbon films indicate that there are amine-group and hydrogen atoms therein. The IR spectra of the passivated PS samples exhibit that the PS surfaces are mainly covered with Si-C, Si-N and Si-O bonds. Electroluminescence (EL) spectra show that the EL intensity of the passivated PS diodes increases greatly and the blueshift of the EL peak occurs compared with the diodes without treatment. Both of these are stable while the passivated diodes are exposed to the air indoors. The I-V characteristics reveal that the passivated diodes have a smaller series resistance and a lower onset voltage. The influence of the carbon film passivation on EL properties of PS has also been discussed. The results have proven that carbon film passivation is a good way to enhance the PS luminescent intensity and stability

关键词： Passivation

Diversity and Characterization of Potential H_2-Dependent Fe(Ⅲ)-Reducing Bacteria in Paddy Soils

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Pedosphere 2012年第5期22卷 673-680页

作者： LI Hui-Juan peng jing-jing LI Hong-Bo Key Lab of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021(China) Graduate University of Chinese Academy of Sciences Beijing 100059(China)

Microbial ferric iron reduction, with organic carbon or hydrogen as the electron donor, is one of the most important biogeochemical processes in anoxic paddy soils; however, the diversity and community structure of hydrogen-dependent dissimilatory iron-reducers remain unknown. Potential H2-dependent Fe（III）-reducing bacteria in paddy soils were explored using enrichment cultures with ferrihydrite or goethite as the electron acceptor and hydrogen as the electron donor. Terminal restriction fragment length polymorphism （T-RFLP） analysis and cloning/sequencing were conducted to reveal bacterial community structure. Results showed that Geobacter and Clost^dium were the dominant bacteria in the enrichment cultures. Fe（III） oxide mineral phases showed a strong effect on the community structure; Geobaeter and Clostridium were dominant in the ferrihydrite treatment, while Glostridium spp. were dominant in the goethite treatment. These suggested that H2-dependent Fe（lII）-redueing bacteria might be widely distributed in paddy soils and that besides Geobacter, Clostmdium spp. might also be an important group of H2-dependent Fe（III）-reducing microorganisms.

关键词： bacterial community structure Clostridium enrichment culture Geobaeter , terminal restriction fragment length poly-morphism

Phosphorus Limitation on Carbon Sequestration in China under RCP8.5

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Advances in Atmospheric Sciences 2023年第7期40卷 1187-1198页

Currently,there is a lack of understanding regarding carbon(C)sequestration in China arising as a result of phosphorus(P)*** this study,a global land surface model(CABLE)was used to investigate the response of C uptake to P limitation after *** China,P limitation resulted in reduced net primary production(NPP),heterotrophic respiration,and net ecosystem production(NEP)in both the 2030s and the *** reductions in NEP in the period2061–70 varied from 0.32 Pg C yr^(-1)in China to 5.50 Pg C yr^(-1)at the global scale,translating to a decrease of 15.0%for China and 7.6%globally in the period 2061–70,relative to the changes including C and nitrogen *** ranges reflect variations in the magnitude of P limitation on C uptake(or storage)at the regional and global *** in China and at the global scale,these differences can be attributed to differences in soil nutrient controls on C uptake,or positive feedback between NPP and soil decomposition rates,or *** results highlight the strong ability of P limitation to influence the pattern,response,and magnitude of C uptake under future conditions(2030s–2060s),which may help to clarify the potential influence of P limitation when projecting C uptake in China.

关键词： phosphorus cycle carbon-nitrogen cycle carbon sink in China carbon storage in China net primary productivity climate change

Numerical and Experimental Investigation on Photothermal Performance of Polyimide/High-Electrical-Performance-Coating Composite Films Considering Surface Roughness

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Journal of Thermal Science 2022年第4期31卷 1206-1219页

作者： jing peng ZHOU Xiao XU Zhengyang XU Zhiguo School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 China Sunman(Zhenjiang)Co. LtdZhenjiang 212000China

Polyimide(PI)films are the common and important components on spacecraft for thermal *** parameter design accuracy has an important impact on the spacecraft thermal balance but there are few studies focusing on the effect of film surface *** the present study,photothermal properties of composite films made of PI films and germanium/indium tin oxide/aluminum coatings are obtained by UV-VIS-NIR *** film surface morphology of composite films is obtained by the atomic force *** present study creatively introduces surface roughness into modeling from the perspective of finite-difference time-domain(FDTD)*** FDTD method considering surface roughness is used to present a comprehensive investigation on the coating effect on the photothermal properties including transmittance and reflectance of composite *** on the random rough surface generated by root-mean-square(RMS)roughness and correlation length,the FDTD method is applied to characterize the electromagnetic field of composite *** has been found that the numerical accuracy is greatly improved and the numerical results agree well with the experimental data when surface roughness is *** results also show that coating material and thickness have remarkable impacts on photothermal properties of the composite films.

关键词： FDTD composite film surface roughness photothermal property coating material

Electronic properties and interfacial coupling in Pb islands on single-crystalline graphene

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Chinese Physics B 2022年第3期31卷 517-520页

作者： jing-peng Song Ang Li State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China University of Chinese Academy of Sciences Beijing 100049 China

Introducing metal thin films on two-dimensional(2D) material may present a system to possess exotic properties due to reduced dimensionality and interfacial effects. We deposit Pb islands on single-crystalline graphene on a Ge(110)substrate and studied the nano-and atomic-scale structures and low-energy electronic excitations with scanning tunneling microscopy/spectroscopy(STM/STS). Robust quantum well states(QWSs) are observed in Pb(111) islands and their oscillation with film thickness reveals the isolation of free electrons in Pb from the graphene substrate. The spectroscopic characteristics of QWSs are consistent with the band structure of a free-standing Pb(111) film. The weak interface coupling is further evidenced by the absence of superconductivity in graphene in close proximity to the superconducting Pb ***, the Pb(111) islands on graphene/Ge(110) are free-standing in nature, showing very weak electronic coupling to the substrate.

关键词： scanning tunneling microscopy graphene quantum well states superconducting proximity effect

Sub-additive Topological and Measure-theoretic Tail Pressures

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Acta Mathematica Sinica,English Series 2017年第12期33卷 1617-1631页

作者： jing Lan peng Yun Hua ZHOU College of Mathematics and Statistics Chongqing University Chongqing 401331 P. R. China

In this paper, we give some definitions of the topological tail pressures for sub-additive potentials and prove that they are equivalent if the potentials are continuous. Under some assumptions, we get a variational principle which exhibits the relationship between topological tail pressure and measure-theoretic tail entropy. Finally, we define a new measure-theoretic tail pressure for sub-additive potentials and some interesting properties of it are obtained.

关键词： Tail pressure variational principle sub-additive potential