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Tunable strain effect on the charge/orbital ordering state in electron-doped La0.9Hf0.1MnO3 films

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Science China(Physics,Mechanics & Astronomy) 2013年第3期56卷 535-539页

作者： WANG Lin GUO ErJia WU ZhenPing gao ju Department of Physics The University of Hong Kong Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of Sciences Institute for Metallic Materials IFW DresdenHelmholtzs traβe 20Dresden 01069Germany

The impact of the lattice strain on the charge/orbital ordering state was studied by using a heterostructure composed with electron-doped La 0.9 Hf 0.1 MnO 3(LHMO) and ferro-and piezoelectric 0.67Pb(Mg1/3Nb2/3)*** ferroelectric poling induces a significant reduction in the biaxial tensile strain in the LHMO film,leading to a decrease in the film resistance over the whole temperature range and an increase in the insulator to metal transition temperature T *** resistance of LHMO film exhibits different responses to the external electric fields and lattice deformation,which is attributed to the coactions of converse piezoelectric effect and ferroelectric polarity *** modification of charge/orbital ordering phase by the electric fields and ferroelectric polarization suggests that the unstable states in the manganites are sensitive to strain effects.

关键词： electron-doped manganite strain effects

Understanding of mineral change mechanisms in coal mine groundwater reservoir and their influences on effluent water quality:a experimental study

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International Journal of Coal Science & Technology 2021年第1期8卷 154-167页

作者： Kai Zhang Huifang Li Jiaming Han Binbin Jiang ju gao School of Chemical and Environmental Engineering China University of Mining and TechnologyBeijingBeijing100083China State Key Laboratory of Water Resource Protection and Utilization in Coal Mining Beijing102211China

This paper presents results of an experimental study to characterize the law of mineral change of fallen rock in coal mine groundwater reservoir ant its influence on water *** minerals of the underground reservoir of Daliuta Coal Mine is taken as the research *** experiments were designed and conducted to simulate water–rock action in the *** mineral composition was analyzed by X-ray diffractometer(XRD),the surface morphology of the mineral was analyzed by scanning electron microscope(SEM),and the specific surface area,total pore volume and average pore diameter of the mineral were measured by fast specific surface/pore analyzer(BET).The experimental results show that the sandstone and mudstone in the groundwater reservoir of Daliuta Coal Mine account for 70%and 30%,*** pore diameter is 15.62–17.55 nm,and pore volume is 0.035 cc/*** pore structure is a key factor in the occurrence of water–rock *** to the water–rock simulation experiment,the quartz content before the water–rock action is about 34.28%,the albite is about 21.84%,the feldspar is about 17.48%,and the kaolinite is about 8.00%.After the water–rock action,they are 36.14%,17.78%,11.62%,and 16.75%,*** content of albite and orthoclase is reduced while the content of kaolinite is increased,that is,the Na+content becomes higher,and the Ca2+and Mg2+contents become *** research builds a good theoretical foundation for revealing the role of water and rock in underground coal reservoirs.

关键词： Coal mine underground reservoir Fallen rock Water-rock interaction Rock composition

Synthesis,structure,and luminescence properties of melilite Dy^(3+):Lu_(x)CaLa_(0.98-x)Ga_(3)O_(7) phosphors for use in yellow light-emitting devices

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Journal of Rare Earths 2024年第8期42卷 1489-1495,I0003页

作者： Yunyun Liu Chuanxin Huang Meng Wang Xihu Wang Yan Wang ju gao School of Opto-Electronic Engineering Zaozhuang UniversityZaozhuang277160China Key Laboratory of Functional Materials and Devices for Informatics of Anhui Educational Institutions Department of PhysicsFuyang Normal UniversityFuyang236037China Key Laboratory of Optoelectronic Materials Chemistry and Physics Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou350002.China

Dy^(3+) and Lu^(3+) co-doped CaLaGa_(3)O_(7) phosphors were prepared via high-temperature solid-phase *** electronic structures of LuxCaLa_(0.98-x)Ga_(3)O_(7) were investigated by the first-principles *** influence of Lu^(3+) on yellow light emission was studied using X-ray diffraction(XRD)and photoluminescence(PL) *** XRD results indicate that compared to Dy^(3+):CaLaGa_(3)O_(7),the cell parameters of Dy^(3+):LuCaLaGa_(3)O_(7) tend to decrease,which is due to the smaller radius of Lu^(3+).When pumped by blue GaN laser diode(LD),the emission peaks of phosphors with different Lu^(3+)doping concentrations in the visible region are similar,with the strongest peak at 574 nm in the yellow light region,which is sensitive to human *** optimal doping concentration of Lu^(3+) is confirmed to be1 at%,when all emission spectra and measured fluorescence lifetimes are taken into ***,the optimal phosphor composition Dy^(3+):Lu_(x)CaLa_(0.98-x)Ga_(3)O_(7)(x=0.01) has an internal quantum efficiency(IQE) of 46.94% and an external quantum efficiency(EQE) of 15.19%.Most notably,the prepared phosphor demonstrates excellent thermal stability and a high activation energy(0.203 eV).In addition,the International Illumination Commission color coordinates of the Dy^(3+):LuxCaLa_(0.98-x)Ga_(3)O_(7) phosphors are in the yellow light *** above analysis indicates that the Dy^(3+):LuxCaLa_(0.98-x)Ga_(3)O_(7)(x=0.001)phosphor has promising application prospects in yellow light-emitting devices.

关键词： Dy^(3+):Lu_(x)CaLa_(0.98-x)Ga_(3)O_(7)phosphors Yellow emission Structure characteristics Luminescent properties Rare earths

Study on the adsorptive catalytic voltammetry of aloe-emodin at a carbon paste electrode

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Science China Chemistry 2005年第5期48卷 442-448页

作者： LI ju'nan gao Peng LI Xiangling YAN Zhihong MAO Xun College of Chemistry Xiangtan University Xiangtan 411105 China College of Chemistry Xiangtan University Xiangtan 411105 China College of Chemistry Xiangtan University Xiangtan 411105 China College of Chemistry Xiangtan University Xiangtan 411105 China College of Chemistry Xiangtan University Xiangtan 411105 China

A new catalytic voltammetric method for the determination of anthraqunone medi-cines at a carbon paste electrode (CPE) was described for the first time. The mechanism of the catalytic reaction was investigated by using linear sweep voltammetry, cyclic voltammetry, con-stant potential electrolysis and so on. The experiment results indicate that aloe-emodin was effi-ciently accumulated at a CPE by adsorption. In the following potential scan, aloe-emodin was reduced to homologous anthrahydroquinone compound, then the compound was immediately oxidized to aloe-emodin by the dissolved oxygen, and the aloe-emodin was again reduced at the CPE. As a result, a cyclic catalytic reaction was established. But a reversible redox reaction of aloe-emodin can only be observed at a mercury electrode, no catalytic reaction occurs there. A sensitive catalytic voltammetric peak of aloe-emodin was obtained at about ?0.60 V (vs. SCE) in 0.56 mol/L NH3-NH4Cl buffer (pH 8.9). The proposed method was applied to the determination of aloe-emodin in the Radix Rhei with satisfactory results. The determination results were in good agreement with reference values obtained by the HPLC. The adsorptive catalytic voltammetry for the determination of organic compound at CPE, chemically modified electrode and other solid electrodes could be significant in the studies on pharmacology, pharmacodynamics, toxicity of medicine, clinical medicine and biochemistry.

关键词： aloe-emodin, adsorptive catalytic voltammetry, carbon paste electrode.

Conditions for ponderomotive resonances in the Kapitza-Dirac effect

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Frontiers of physics 2015年第5期10卷 75-81页

作者： Chao Yu Jingtao Zhang Zhenrong Sun ju gao Dong-Sheng Guo State Key Laboratory of Precision Spectroscopy Department of Physics East China Normal University Shanghai 200062 China Department of Physics Shanghai Normal University Shanghai 200234 China Suzhou Jingpin Advanced Materials Co. Ltd. Jiangsu FOHO Science Park Fenhu Town Suzhou 215211 China School of Physics Peking University Beijing 100871 China

By applying a nonperturbative quantum electrodynamic theory, we study ponderomotive resonances when an electron beam is scattered by a standing photon wave. Our study shows that the pondero- motive parameter Up, the ponderomotive energy per laser-photon energy, for each of the two traveling laser modes possesses a minimum valuehω/（mec2）. Ponderomotive resonances occur only when the ratio of the laser photon energy to the electron rest-mass energy is a fraction, where the denomina- tor is twice the square of a positive integer and the numerator is the total ponderomotive number, which is also a positive integer.

关键词： Kapitza-Dirac effect strong laser physics nonperturbative quantum electrodynamics

The preparation of grid-textured V2O5 films and their potential applications in gas sensing

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Science China(Technological Sciences) 2020年第3期63卷 467-471页

作者： CHENG Rong HUANG WeiYi LIU XiangBo LING Francis Chi Chung gao ju NI Hao Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Department of Physics The University of Hong KongHong KongChina College of Science China University of Petroleum(Huadong)Qingdao 266580China

Novel nano-structured films of V2O5 are prepared by pulsed laser deposition method. Nanoscaled V2O5 ridges lie on SrTiO3 substrate and construct into grid-textured structures. Structural properties of the films have been analyzed by scanning electron microscope, X-ray diffraction and transmission electron microscope. The films have enlarged surface-to-volume ratio due to the ridge-channel structure which makes them applicable to gas sensing. Therefore, gas sensors based on the V2O5 films have been assembled which present reliable sensing properties to gaseous acetone, and ethanol at room temperature. The physical-chemical reactions between adsorbed O2^– and testing gases are the possible reason for this property.

关键词： V2O5 thin film gas sensing

Effects of long-term green manure application on the content and structure of dissolved organic matter in red paddy soil

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Journal of Integrative Agriculture 2018年第8期17卷 1852-1860页

作者： gao Song-juan gao ju-sheng CAO Wei-dong ZOU Chun-qin HUANG Jing BAI Jinshun DOU Fu-gen College of Resources and Environmental Sciences Center for ResourcesEnvironment and Food Security/Key Laboratory of Plant-Soil InteractionsMinistry of EducationChina Agricultural UniversityBeijing100193P.R.China Key Laboratory of Plant Nutrition and Fertilizer Ministry of Agriculture/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081P.R.China Red Soil Experimental Station in Hengyang Chinese Academy of Agricultural SciencesQiyang 426182P.R.China Soil and Fertilizer Institute Qinghai Academy of Agriculture and Forestry SciencesQinghai UniversityXining 810016P.R.China Texas A&M Agri Life Research Center at Beaumont Texas77713USA

Dissolved organic matter(DOM) plays important roles in soil biogeochemistry activity and nutrients transportation in soils, but studies regarding the long-term effects of green manures on the content and structure of DOM in red paddy soil have not been reported yet. A long-term green manure experiment established in 1982 was utilized to test the DOM contents in different treatments, and the spectral characteristics of DOM were investigated by using ultraviolet-visible(UV-Vis) spectrometry and Fourier transform infrared(FTIR) spectrometry. The experiment included four cropping systems: ricerice-milk vetch(RRV), rice-rice-rape(RRP), rice-rice-ryegrass(RRG) and rice-rice-winter fallow(RRF), among them, milk vetch, rape, and ryegrass are popular winter green manure species in southern China. The results showed that the content of dissolved organic carbon(DOC), which is widely used to estimate the concentration of DOM, was significantly promoted after the incorporation of green manures compared with the other sampling stages. The contents of aromatic groups and the degree of humification of DOM increased in RRV and RRP, suggesting more complex compositions of the soil DOM after long-term application of milk vetch and rape. The contents of phenol, alcohol and carboxylic acid group at the mature stage of early rice were significantly higher than those at the stage of after green manures turned over, especially for the RRV treatment. The absorption ratio of FTIR indicated that winter plantation of rape increased the aromatic-C/aliphatic-C ratio, and ryegrass increased the aromatic-C/carboxyl-C ratio. In conclusion, long-term planting of milk vetch and rape as green manures increased the degree of aromaticity, humification and average molecular weight of DOM, and made the DOM more stable in red paddy soil.

关键词： green manure red paddy soil dissolved organic matter ultraviolet-visible spectra Fourier transform infrared spectra

Effects of Magnesium Compound with Fertilizer on Daylily (Hemerocallis citrina Baroni) Growth and Soil Nutrients

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Agricultural Sciences in China 2006年第2期5卷 123-129页

作者： SUN Nan ZENG Xi-bai LI ju-mei gao ju-sheng WANG Bo-ren Soil ＆ Fertilizer Institute Chinese Academy of Agricultural Sciences Beijing 100081 P.R.China Institute of Agricultural Environment and Sustainable Development Chinese Academy of Agricultural Sciences/Key Laboratory of AgroEnvironment ＆ Climate Change Ministry of Agriculture Beijing 100081 P.R.China

Effects of two kinds of magnesium compound with fertilizer on Daylily （Hemerocallis citrina Baroni） growth, yield, and soil nutrients in red soil were studied. The results indicated that significant effects of magnesium applied to soils were observed in increasing Daylily （Hemerocallis citrina Baroni） yield, improving its growth, and strengthening its antivirus property as well as increasing the amount of exchangeable Mg, N, P, and K in red soil. In particular, the effects of magnesium compound fertilizer Ⅱ （MCF2） with higher Mg content were better than that of the others, which increased Daylily （Hemerocallis citrina Baroni） yield by 57.4, 32.8, and 14.5% compared to that of control treatment （CK）, chemical fertilizer with nitrogen, phosphorus, potassium treatment （CF）, and magnesium compound fertilizer Ⅰ treatment （MCF1） with lower Mg content. It increased soil Alkali N, available P, exchangeable K, and exchangeable Mg by 94.9, 46.5, 31.1, and 35.3%, respectively, compared with that of CK treatment. Therefore, the application of magnesium compound with fertilizer is an optimum method for improving red soil quality.

关键词： magnesium compound fertilizer Daylily (Hemerocallis citrina Baroni) growth soil nutrient

Historical trends in maize morphology from the 1950s to the 2010s in China

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Journal of Integrative Agriculture 2022年第8期21卷 2159-2167页

作者： MA Da-ling XIE Rui-zhi YU Xiao-fang LI Shao-kun gao ju-lin Agricultural College Inner Mongolia Agricultural UniversityHohhot 010019P.R.China Institute of Crop Sciences Chinese Academy of Agricultural Sciences/Key Laboratory of Crop Physiology and EcologyMinistry of Agriculture and Rural AffairsBeijing 100081P.R.China

The morphology of the plant and ear is a preliminary selection characteristic in breeding new varieties of *** new maize cultivars were developed from the 1950s through the 2010s in China,most had changes in both plant and ear morphological characteristics that contributed substantially to maize yield *** the seven decades,plant and ear height fluctuated with a small increase from the 1950s to 2000s,and then a decrease in the 2010s,while the ear ratio and internodes length below the ear decreased *** angles became significantly more upright,especially for the leaves above the ear,and the leaf area per plant improved *** orientation increased from the 1950s to the 2000s then decreased in the *** size and the anthesis-silking interval were both reduced *** diameter,kernel number,and kernel weight increased from the 1950 to the 2000s,then decreased in the 2010s under the same cultivation *** found that modern maize hybrids have a lower plant height,ear height and ear ratio which increased lodging resistance,a more erect leaf which increased high-density planting tolerance,and smaller ears and kernels which facilitated rapid dehydration during late grain *** morphological selection criteria,which are suitable for mechanized operations,are proposed as the focus for future maize breeding.

关键词： maize yield morphological characteristics breeding direction artificial selection improved maize cultivars mechanized farming