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11篇 您的检索式:作者名="Dameng Li"
    题名 作者 年代 出处 被引量
1Advanced characterization of pores and fractures in coals by nuclear magnetic resonance and X-ray computed tomography显示文摘This paper demonstrates capabilities of low-field nuclear magnetic resonance (NMR) and microfocus X-ray computed tomography (μCT) in advanced, nondestructive, and quantitative characterization of pore types, producible porosity, pore structure, and spatial disposition of pore-fractures in coals. Results show that the NMR transverse relaxation time (T2) at 0.5–2.5, 20–50, and >100 ms correspond to pores of <0.1 μm, >0.1 μm, and fractures, respectively. A much higher T2 spectrum peak reflects a much better development of pores (or fractures) corresponding to the T2, and vice versa. Three basic components in coals, i.e., the pores (or fractures), coal matrix, and minerals have their distinctive range of CT numbers. Among these, the CT number of pores is commonly less than 600 HU. The producible porosity, which is a determination of permeability, can be calculated by T2 cutoff value (T2C) of coal NMR. The coal pore structure can be efficiently estimated by the newly proposed 'T2C based model'. Finally, μCT scan was proven capable of modeling and spatial visualization of pores and fractures.YAO YanBin, LIU DaMeng, CAI YiDong & LI JunQian School of Energy Resources, China University of Geosciences, Beijing 100083, China 2010Science China Earth Sciences2010,53,6:61
2Microvesicle-delivery miR-150 promotes tumorigenesis by up-regulating VEGF,and the neutralization of miR-150 attenuate tumor development显示文摘Tumor-associated macrophages(TAMs)mostly exhibit M2-like(alternatively activated)properties and play posi-tive roles in angiogenesis and tumorigenesis.Vascular en-dothelial growth factor(VEGF)is a key angiogenic factor.During tumor development,TAMs secrete VEGF and other factors to promote angiogenesis;thus,anti-treatment against TAMs and VEGF can repress cancer development,which has been demonstrated in clinical trials and on an experimental level.In the present work,we show that miR-150 is an oncomir because of its promotional effect on VEGF.MiR-150 targets TAMs to up-regulate their secre-tion of VEGF in vitro.With the utilization of cell-derived vesicles,named microvesicles(MVs),we transferred an-tisense RNA targeted to miR-150 into mice and found that the neutralization of miR-150 down-regulates miR-150 and VEGF levels in vivo and attenuates angiogenesis.There-fore,we proposed the therapeutic potential of neutralizing miR-150 to treat cancer and demonstrated a novel,natu-ral,microvesicle-based method for the transfer of nucleic acids.Yuchen Liu Luming Zhao Dameng Li Yuan Yin Chen-Yu Zhang Jing Li Yujing Zhang 2013Protein & Cell2013,4,12:18
3Small non-coding RNAs transfer through mammalian placenta and directly regulate fetal gene expression显示文摘Jing Li Yujing Zhang Dameng Li Yuchen Liu Danping Chu Xiaohong Jiang Dongxia Hou Ke Zen Chen-Yu zhang 2015Protein & Cell2015,6,6:9
4Pore structure of selected Chinese coals with heating and pressurization treatments显示文摘Pore structure of Chinese coals with heating and pressurization treatments was studied using small angle X-ray scattering(SAXS),N2adsorption/desorption isotherms and scanning electron microscope(SEM).SAXS was performed for some samples after heat treatment at seven elevated temperatures from 25 to 250°C at 0 MPa and for other samples with hydrostatic pressure treatment at 0,5,10,15 and 20 MPa at the room temperature.The results show that N2adsorption isotherm together with SAXS could be a comprehensive method to evaluate the pore shape and the pore size distribution:the pore shapes are generally spherical for low rank coal and they are mainly ellipsoidal for high rank coal.All these measurements were then interpreted using the fractal theory to reveal relationship between surface fractals and coal rank,and the evolution of surface fractals under heating and pressurization treatments.The results show that surface fractal dimension(Ds)changes with different treating temperature and pressure and maximum vitrinite reflectance(Ro,m).Especially in the bituminous stage,Ds shows an increasing trend with Ro,m under varied temperatures.Moreover,Ds shows an increasing trend with increasing temperature before 200°C,and a decreasing trend after 200°C.Furthermore,the results show that Ds has a more complex relationship with Ro,m under varied treating temperature than that under varied treating pressure.CAI YiDong LIU DaMeng PAN ZheJun YAO YanBin LI JunQian QIU YongKai 2014Science China Earth Sciences2014,57,7:5
5Pore structure and its impact on CH 4 adsorption capacity and flow capability of bituminous and subbituminous coals from Northeast China显示文摘Yidong Cai Dameng Liu Zhejun Pan Yanbin Yao Junqian Li Yongkai Qiu 2013Fuel2013,,:2
6Geological controls on prediction of coalbed methane of No. 3 coal seam in Southern Qinshui Basin, North China显示文摘Yidong Cai Dameng Liu Yanbin Yao Junqian Li Yongkai Qiu 2011International Journal of Coal Geology2011,,2:1
7Petrophysics characteristics of coalbed methane reservoir: a comprehensive review显示文摘Petrophysics of coals directly affects the development of coalbed methane(CBM).Based on the analysis of the representative academic works at home and abroad,the recent progress on petrophysics characteristics was reviewed from the aspects of the scale-span porefracture structure,permeability,reservoir heterogeneity,and its controlling factors.The results showed that the characterization of pore-fracture has gone through three stages:qualitative and semiquantitative evaluation of porefracture by various techniques,quantitatively refined characterization of pore-fracture by integrating multiple methods including nuclear magnetic resonance analysis,liquid nitrogen,and mercury intrusion,and advanced quantitative characterization methods of pore-fracture by high-precision experimental instruments(focused-ion beam-scanning electron microscopy,small-angle neutron scattering and computed tomography scanner)and testing methods(m-CT scanning and X-ray diffraction).The effects of acoustic field can promote the diffusion of CBM and generally increase the permeability of coal reservoirs by more than 10%.For the controlling factors of reservoir petrophysics,tectonic stress is the most crucial factor in determining permeability,while the heterogeneity of CBM reservoirs increases with the enhancement of the tectonic deformation and stress field.The study on lithology heterogeneity of deep and high-dip coal measures,the spatial storage-seepage characteristics with deep CBM reservoirs,and the optimizing production between coal measures should be the leading research directions.Qifeng JIA Dameng LIU Yidong CAI Xianglong FANG Lijing LI 2021Frontiers of Earth Science2021,15,2:1
8Evaluation and modeling of gas permeability changes in anthracite coals显示文摘Li Junqian Liu Dameng Yao Yanbin 2013Fuel2013,111,:1
9Layer-dependent signatures for exciton dynamics in monolayer and multilayer WSe2 revealed by fluorescence lifetime imaging measurement显示文摘Two-dimensional(2D)transition-metal dichalcogenide(TMD)materials have aroused noticeable interest due to their distinguished electronic and optical properties.However,little is known about their complex exciton properties together with the exciton dynamics process which have been expected to influence the performance of optoelectronic devices.The process of fluorescence can well reveal the process of exciton transition after excitation.In this work,the room-temperature layer-dependent exciton dynamics properties in layered WSe2 are investigated by the fluorescence lifetime imaging microscopy(FLIM)for the first time.This paper focuses on two mainly kinds of excitons including the direct transition neutral excitons and trions.Compared with the lifetime of neutral excitons(<0.3 ns within four-layer),trions possess a longer lifetime(~6.6 ns within four-layer)which increases with the number of layers.We attribute the longer-lived lifetime to the increasing number of trions as well as the varieties of trion configurations in thicker WSe2.Besides,the whole average lifetime increases over 10%when WSe2 flakes added up from monolayer to four-layer.This paper provides a novel tuneable layer-dependent method to control the exciton dynamics process and finds a relatively longer transition lifetime of trions at room temperature,enabling to investigate in the charge transport in TMD-based optoelectronics devices in the future.Yuanshuang Liu Huanglong Li Cuicui Qiu Xiangmin Hu Dameng Liu 2020Nano Research2020,13,3:0
10Visualization of MF/Diesel RCCI Combustion Process and Soot Emission显示文摘Based on the optical engine,the ignition characteristics,combustion process and soot emission characteristics of diesel under different 2-Methylfuran(MF) atmospheres were investigated by high-speed photography and in-cylinder combustion analysis technology.The results show that at the same main injection timing,the ignition time of reactivity controlled compression ignition(RCCI) combustion mode is earlier than pure diesel combustion,and the ignition point is concentrated near the nozzle.Diesel acts as a spark plug to ignite the mixture,but the flame develops slowly in the early stages and the pressure in the cylinder rises slowly.Compared with pure diesel,RCCI combustion model has smaller peak values of in-cylinder pressure and heat release rate,shorter ignition delay period,earlier combustion phase and shorter combustion duration.At main spray time at 6℃A BTDC and 12℃A BTDC,with the increase of MF premixing ratio from 0 to 0.75,the peak cylinder pressure decreased by 19.6% and 26% respectively.In addition,with the increase of the MF heat value ratio,the area of KL factor> 1.5 in the combustion chamber decreased and the space integral natural luminescence(SINL) peak value decreased by 48.37%,and the soot formation rate and yield decreased significantly.However,when the MF heat value ratio was too large(75% of the total calorific value),the ignition delay period increased,and misfire occurred at the main injection timing of 0℃A BTDC.The RCCI mode of MF/diesel dual fuel has better stability,and better control effect can be obtained at different main inj ection timing.HUANG Chen NI Xiao GE Dameng LI Song ZHANG Wanzhi LIU Jinping ZHANG Tingting 2024Journal of Thermal Science2024,33,2:0
11P-wave and S-wave response of coal rock containing gas-water with different saturation: an experimental perspective显示文摘The acoustic response of gas and/or water saturated coal rock is fundamental for establishing the correspondence between the physical properties of the coal reservoir and the characteristics of the well-logging response,which is the technology essential for the geophysical exploration of coalbed methane(CBM).This acoustic response depends on water(Sw)and gas(Sg)saturation among other factors.In this study,we performed acoustic tests on dry and different gas-water saturated coal samples with different degrees of metamorphism and deformation,collected from several coal mining areas in China.These tests enabled us to analyze the influence of coal type and gas-water saturation on the acoustic response of CBM formations.Our results show that the acoustic velocity of P-wave and S-wave(Vp and Vs,respectively),and the relative anisotropy of and Vs,increased with increasing vitrinite reflectance,density,Vp and Sw.WithSw increasing from 0 to 100%,the growth rate of the acoustic velocity decreased with increasing vitrinite reflectance.The Vp/Vs ratio of tectonic coal was generally higher than that of primary coal.The growth rate of the relative anisotropy in tectonic coal was markedly higher than that in primary coal.Dameng LIU Lijing LI Zheng ZHAO Wei CHEN Yidong CAI Yongkai QIU Yingfang ZHOU 2023Frontiers of Earth Science2023,17,1:0
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