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A small-scale experimental study of CO_(2) enhanced injectivity methods of the high-rank coal

Petroleum Science 2021年第5期18卷 1427-1440页

作者： qing-he niu Li-Wen Cao Shu-Xun Sang Wei Wang Wei Yuan Jiang-Fang Chang Xiao-Jun Jia Wei-Min Zheng Zeng-Xue Zhang State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang050043China hebei Technology and Innovation Center on Safe and Efficient Mining of Metal Mines Shijiazhuang050043China School of Resource and Earth Science China University of Mining and TechnologyXuzhou221008China Jiangsu Key Laboratory of Coal-based Greenhouse Gas Control and Utilization China University of Mining and TechnologyXuzhou221008China hebei Academy of Emergency Management Shijiazhuang050081China hebei Iron and Steel Group Mining Co. LtdTangshan063000China Minmetals Mining Holding Co. LtdHefei241000China

The attenuation of CO_(2)injectivity has become the biggest technical barrier for the application of CO_(2)enhanced coalbed methane recovery(CO_(2)-ECBM).Commonly,the intermittent CO_(2)injection,N2 displacing CO_(2)and pre-fracturing are the potential CO_(2)enhanced injectivity methods for coal reservoirs,but their mechanism and effectiveness remain to be *** paper thus conducted small-scale experiments to simulate the working process of these engineering measures by an independently developed experimental *** show that the CO_(2)injectivity of coal is remarkably improved by the intermittent injection mode since the CO_(2)injection time is increased by folds and the loss of reservoir pressure can be complemented in *** N_(2)displacing CO_(2)method promotes the desorption of CO_(2)and reduces the swelling strain,with the result that the permeability of coal is improved by 74.82%and 64.95%compared with the methods of the primary subcritical CO_(2)(Sub CO_(2))and supercritical CO_(2)(Sc CO_(2))***,the permeability reduces again with the secondary CO_(2)*** permeability of the coal sample after pre-fracturing is averagely improved by 1-2 orders of magnitude,the irreversible permeability loss rate,average stress sensitivity coefficient and the permeability loss rate due to adsorption are averagely reduced by 95.885%,61.538%and 96.297%,*** indicates that the permeability of coal after pre-fracturing is no longer sensitive to both the effective stress and Sc CO_(2)adsorption,the injectivity is thus improved and *** CO_(2)enhanced injectivity effects of the intermittent CO_(2)injection,the N_(2)displacing CO_(2)and the pre-fracturing are various,which thus can be selected individually or jointly to improve the CO_(2)injectivity according to the reservoir physical properties and geological *** research deepens the understanding of the functional mechanism of CO_(2)enhanced injectivity method

关键词： Supercritical CO_(2) Permeability Intermittent injection N_(2)displacing CO_(2) Pre-fracturing

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Morphologic changes of simple star dunes during the growth process in Dunhuang,China

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Journal of Mountain Science 2022年第4期19卷 1095-1106页

作者： AN Zhi-shan ZHANG Ke-cun TAN Li-hai niu qing-he LIU Ben-li niu Bai-cheng Dunhuang Gobi and Desert Research Station Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Key Laboratory of Desert and Desertification Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

Star dune is one typical kind of aeolian geomorphology in global sand *** has attracted scholars in various research fields for years because of its unique morphologic features like Egyptian *** landform pattern of star dune is mainly dominated by factors such as regional wind regime,sand availability,and local *** dunes grow vertically as they accumulate sand brought in from different directions;however,little is known regarding morphologic changes during this *** stability of star dunes based on quantitative data is another unsolved question due to the limitation in measuring equipment or other *** whether the star dune can grow into star sand hills is another scientific problem which needs to be *** this paper,the heightening development process and morphological changes of star dunes were monitored in Mingsha Mountain of Dunhuang with the 3D laser *** show that the star dunes in Mingsha Mountain were formed by a group of relatively steady winds,which were northwest,northeast and south *** the increase of the height of the star dunes,the morphological parameters of the dune,such as the volume and bottom area,did not show regular *** surface erosion of both Dune 1 and Dune 2 during the observation period was closely related to the regional wind *** the growth of the star dunes,the overall trend of the dunes was relatively steady and the dune shape maintained its stability although the aspect and slope of the sand dunes changed,indicating that the stability of star dune was not complete and was ***,the variation range of the dune slope was proportional to the volume change of the dune.

关键词： Star dune 3D laser scanner Dunhuang Morphologic change

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Growth,nutritional quality,and energy use efficiency in two lettuce cultivars as influenced by white plus red versus red plus blue LEDs

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International Journal of Agricultural and Biological Engineering 2020年第2期13卷 33-40页

作者： Zhengnan Yan Dongxian he Genhua niu qing Zhou Yinghua Qu Key Laboratory of Agricultural Engineering in Structure and Environment of Ministry of Agriculture and Rural Affairs China Agricultural UniversityBeijing 100083China Texas A&M AgriLife Research Center at Dallas Texas A&M University SystemDallasTX 75252USA

Red plus blue light-emitting diodes(LEDs)are commonly applied in plant factories with artificial lighting due to photosynthetic pigments,which absorb strongly in red and blue light regions of the ***,plants grown under natural environment are used to utilizing broad-wide spectrum by long-term *** order to examine the effects of addition light added in red plus blue LEDs or white LEDs,green and purple leaf lettuces(Lactuca sativa *** and Ziya)were hydroponically cultivated for 20 days under white LEDs,white plus red LEDs,red plus blue LEDs,and red plus blue LEDs supplemented with ultraviolet,green or far-red light,*** results indicated that the addition of far-red light in red plus blue LEDs increased leaf fresh and dry weights of green leaf lettuce by 28%and 34%,*** of ultraviolet light did not induce any differences in growth and energy use efficiency in both lettuce cultivars,while supplementing green light with red plus blue LEDs reduced the vitamin C content of green leaf lettuce by 44%and anthocyanin content of purple leaf lettuce by 30%compared with red plus blue LEDs,*** absorbencies of purple leaf lettuce grown under red plus blue LEDs supplemented with green light were lower in green light region compared with those grown under red plus blue LEDs,which was associated with anthocyanin *** plus red LEDs significantly increased leaf fresh and dry weights of purple leaf lettuce by 25%,and no significant differences were observed in vitamin C and nitrate contents compared with white *** weight,light and electrical energy use efficiencies of hydroponic green and purple leaf lettuces grown under white plus red LEDs were higher or no significant differences compared with those grown under red plus blue *** conclusion,white plus red LEDs were suggested to substitute for red plus blue LEDs in hydroponic lettuce(*** and Ziya)production in plant factories with artif

关键词： plant factory hydroponic lettuce light-emitting diodes(LED) light energy use efficiency artificial lighting absorption spectrum anthocyanin content photosynthetic pigments

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Robust fault detection and optimization for a network of unmanned vehicles with imperfect communication channels

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Chinese Journal of Aeronautics 2014年第1期27卷 65-75页

作者： niu Erzhuo Wang qing Dong Chaoyang School of Automation Science and Electrical Engineering Beihang University School of Aeronautical Science and Engineering Beihang University

The observer-based robust fault detection and optimization for a network of unmanned vehicles with imperfect communication channels and norm bounded modeling uncertainties are addressed. The network of unmanned vehicles is modeled as a discrete-time uncertain Markovian jump system. Based on the model, a residual generator is constructed and the sufficient condition for the existence of the desired fault detection filter is derived in terms of linear matrix inequality. Furthermore, a time domain optimization approach is proposed to improve the performance of the fault detection system. The problem of detecting small faults can be formulated as an optimization problem and its solution is given. For preventing false alarms, a new adaptive threshold function is established. The combined fault detection and optimization algorithm and the adaptive threshold are then applied to a network of highly maneuverable technology vehicles to illustrate the effective- ness of the orooosed aooroach.

关键词： Fault detection andoptimization Imperfect communicationchannel Network Uncertainty Unmanned vehicle

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Spatial confinement of copper single atoms into covalent triazinebased frameworks for highly efficient and selective photocatalytic CO_(2)reduction

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Nano Research 2022年第9期15卷 8001-8009页

作者： Guocheng Huang qing niu Yuxin he Jinjin Tian Mingbin Gao Chaoyang Li Ning An Jinhong Bi Jiangwei Zhang Department of Environmental Science and Engineering Fuzhou UniversityFuzhou 350108China Advanced Chemical Engineering and Energy Materials Research Center China University of Petroleum(East China)Qingdao 266580China State Key Laboratory of Photocatalysis on Energy and Environment Fuzhou UniversityFuzhou 350108China National Engineering Laboratory for Methanol to Olefins Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Anhui Chuangpu Instrument Technology Co. LTD.Hefei 230088China

Converting CO_(2)into carbonaceous fuels via photocatalysis represents an appealing strategy to simultaneously alleviate the energy crisis and associated environmental problems,yet designing with high photoreduction activity catalysts remains a compelling ***,combining the merits of highly porous structure and maximum atomic efficiency,we rationally constructed covalent triazine-based frameworks(CTFs)anchoring copper single atoms(Cu-SA/CTF)photocatalysts for efficient CO_(2)*** Cu single atoms were visualized by high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)images and coordination structure of Cu-N-C2 sites was revealed by extended X-ray absorption fine structure(EXAFS)*** as-prepared Cu-SA/CTF photocatalysts exhibited superior photocatalytic CO_(2)conversion to CH4 performance associated with a high selectivity of 98.31%.Significantly,the introduction of Cu single atoms endowed the CuSA/CTF catalysts with increased CO_(2)adsorption capacity,strengthened visible light responsive ability,and improved the photogenerated carriers separation efficiency,thus enhancing the photocatalytic *** work provides useful guidelines for designing robust visible light responsive photoreduction CO_(2)catalysts on the atomic scale.

关键词： covalent triazine-based frameworks Cu single atoms photocatalytic CO_(2)reduction visible light selectivity

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Fine mapping and characterization of the awn inhibitor B1 locus in common wheat(Triticum aestivum L.)

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The Crop Journal 2020年第4期8卷 613-622页

作者： Jianqing niu Shusong Zheng Xiaoli Shi Yaoqi Si Shuiquan Tian Yilin he Hong-qing Ling State Key Laboratory of Plant Cell and Chromosome Engineering Institute of Genetics and Developmental BiologyThe Innovative Academy of Seed DesignChinese Academy of SciencesBeijing 100101China College of Life Sciences University of Chinese Academy of SciencesBeijing 100049China

Awns play an important role in seed dispersal and photosynthesis of *** major awn inhibitors(Hd,B1,and B2)are reported in ***,the molecular mechanism underlying awnlessness remained unknown until *** this study,we identified two F8 recombinant inbred lines(RILs)that were segregating for awn *** order to identify the causal gene for awn length in the heterozygous inbred families(HIFs),SNPs were called from RNA sequencing(RNA-Seq)data for HIF-derived progenies with long and short *** between long and short awn plants were evenly distributed on chromosomes(chr)other than chromosome 5 *** on chr 5 A were clustered in a region distal 688 Mb on the long arm,where inhibitor B1 was *** suggested that B1 was the causal segregating *** precisely mapped B1 to^1 Mb region using two HIF-derived *** that the lines segregated for long,intermediate and short awn phenotypes we speculated that B1 should have a dosage effect on awn *** differentially expressed genes(DEGs)located in the candidate region were regarded as candidate genes for B1,because the molecular expression pattern was consistent with the *** with long and short awns showed no difference on grain yield and other agronomic traits.

关键词： dosage mapping evenly

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Internal Conversion Process of Chlorophyll a in Solvents in Femtosecond Pump-Probe Laser Fields

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Chinese Journal of Chemical Physics 2008年第3期21卷 211-216页

作者： Kai niu Li-qing Dong Shu-lin Cong Department of Physics Dalian University of Technology Dalian 116024 China

The internal conversion （IC） processes of chlorophyll a （chl-a） in solvents are studied based on the reduced density matrix theory. The IC times can be obtained by simulating the experimental fluorescence depletion spectra （FDS）. The calculated IC times of chl-a in ethyl acetate, tetrahydrofuran and dimethyl formamide are 141, 147, and 241 fs, respectively. The oscillation feature of the FDS results from the forward and backward transfer of the population between coupled electronic states. The effects of diabatic coupling between two electronic states on the IC time and the FDS are described. The influence of molecule-reservoir coupling on the IC time is also investigated.

关键词： Fluorescence depletion spectrum Internal conversion Reduced density matrix

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Morphology, crystal structure and hydration of calcined and modified anhydrite

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International Journal of Minerals,Metallurgy and Materials 2014年第10期21卷 1028-1032页

作者： Xiao-qing niu Ji-chun Chen School of Urban Construction Huazhong University of Science and Technology Wuchang Branch

The effects of calcination and modification on the morphology （shapes and textures） and crystal structure of anhydrite powders were studied. The results show that, calcination at 100℃ causes anhydrite to disintegrate into smaller crystals, accompanied by a slight in- crease in d-spacing. Without calcination and modification, the solidification time and curing time of anhydrite are 15 and 77 h, respectively. After the treatment, however, the solidification time and curing time are shortened significantly to 9.5 and 14 rain, respectively. The com- pressive and flexural strengths of hydration products made from the treated anhydrite reach 10.2 and 2.0 MPa, respectively. The much shorter solidification and curing time make it possible to use anhydrite as a building and construction material.

关键词： anhydrite morphology crystal structure curing hydration calcination modification

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Systematics on production of superheavy nuclei Z=119-122 in fusion-evaporation reactions

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Nuclear Science and Techniques 2021年第10期32卷 59-71页

作者： Fei niu Peng-Hui Chen Zhao-qing Feng School of Physics and Optoelectronic Technology South China University of TechnologyGuangzhou 510640China College of Electrical Energy and Power Engineering Yangzhou UniversityYangzhou 225000China

The fusion dynamics of the formation of super-heavy nuclei were investigated thoroughly within the din-uclear system *** Monte Carlo approach was implemented in the nucleon transfer process to include all possible orientations,at which the dinuclear system is assumed to be formed at the touching configuration of dinuclear *** production cross sections of superheavy nuclei Cn,Fl,Lv,Ts,and Og were calculated and compared with the available data from *** evaporation residue excitation functions in the channels of pure neutrons and charged particles were systematically *** combinations of 44 Sc,48;50 Ti,49;51 V,52;54 Cr,58;62 Fe,and 62;64 Ni bombarding the actinide nuclides 238 U,244 Pu,248 Cm,247;249 Bk,249;251 Cf,252 Es,and 243 Am were calculated to produce the superheavy elements with Z¼119?*** obtained that the production cross sections sensitively depend on the neutron richness of the reaction *** structure of the evaporation residue excitation function is related to the neutron separation energy and fission barrier of the compound nucleus.

关键词： Dinuclear system model Fusion-evaporation reactions Superheavy nuclei Cross sections

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Nitric Oxide Regulates Dark-Induced Leaf Senescence Through EIN2 in Arabidopsis

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Journal of Integrative Plant Biology 2012年第8期54卷 516-525页

作者： Yun-Han niu Fang-qing Guo The National Key Laboratory of Plant Molecular Genetics and National Center for Plant Gene Research(Shanghai) Institute of Plant Physiology&EcologyShanghai Institutes for Biological Sciencesthe Chinese Academy of SciencesShanghai 200032China

The nitric oxide （NO）-deficient mutant nosllnoal exhibited an early leaf senescence phenotype. ETHY- LENE INSENSITIVE 2 （EIN2） was previously reported to function as a positive regulator of ethylene- induced senescence. The aim of this study was to address the question of how NO interacts with ethylene to regulate leaf senescence by characterizing the double mutant ein2-1 nosllnoal （Arabidopsis thaliana）. Double mutant analysis revealed that the nosllnoal-mediated, dark-induced early senescence phenotype was suppressed by mutations in EIN2, suggesting that EIN2 is involved in nitric oxide signaling in the regulation of leaf senescence. The results showed that chlorophyll degradation in the double mutant leaves was significantly delayed. In addition, nosllnoal-mediated impairment in photochemical efficiency and integrity of thylakoid membranes was reverted by EIN2 mutations. The rapid upregulation of the known senescence marker genes in the nosl/noal mutant was severely inhibited in the double mutant during leaf senescence. Interestingly, the response of dark-grown nosl/noal mutant seedlings to ethylene was similar to that of wild type seedlings. Taken together, our findings suggest that EIN2 is involved in the regulation of early leaf senescence caused by NO deficiency, but NO deficiency caused by NOSIlNOA1 mutations does not affect ethylene signaling.

关键词： Arabidopsis dark EIN2 leaf senescence nitric oxide.

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