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Variations and trends of trans-boundary runoff in the longitudinal range-gorge region

Journal of Mountain Science 2017年第2期14卷 316-324页

作者： YU Yan-ling PAN Feng LIU Xin-you chen Wen-hua HE Da-ming Water Conservancy College Yunnan Agricultural UniversityKunming 650201China Key Laboratory of International River and Transboundary Eco-security Yunnan UniversityKunming 650091China Electric power engineering college Kunming University of Science and TechnologyKunming 650093China State Key Laboratory of hydrology water resources and hydraulic engineering Hohai UniversityNanjing 210098China Hydrology and water resources Bureau Yunnan ProvinceKunming 650106China Baoshan College Baoshan 678000China

The mountainous hydrological process usually shows high variation to climate change and human action. In the Longitudinal Range-Gorge Region（LRGR）, Southwestern China and Southeast Asian, the transboundary runoff variations are much more sensitive and complex under the interaction of climate change, ＂corridor-barrier＂ functions in LRGR,and dams building. In this paper, based on the long hydrological records（1956-2013） from three mainstream hydrological stations in Nu River,Lancang River, and Red River, the region runoff variations were analyzed. The results show out： i） the regional runoff changes were strongly influenced by the ＂Corridor-Barrier＂ functions in LRGR from west to east, the variability extent of annual runoff increased, but tended to decrease after 2009 and the reduced extents also increased; ii） the annual runoff change in the three rivers had high concentration degrees; iii） there were periodicities of 33 years of runoff change in Nu River and Lancang River, and 30 years in Red River, and the lower flow period would continue for 8-9 years in Nu River and Lancang River but only for 4 years in Red River; iv） since 2010, as the two mega dams of Xiaowan and Nuozhadu built in Lancang River mainstream, their variations of annual runoff were quite different. The research results could offer a scientific base for sustainable utilization,conservation, and management of the regional water resources

关键词： Runoff variations Climate change "Corridor-barrier" functions Longitudinal rangegorge region Transboundary rivers

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A new fluorescence probing strategy for the detection of parathion-methyl based on N-doped carbon dots and methyl parathion hydrolase

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Chinese Chemical Letters 2017年第8期28卷 1675-1680页

作者： Wei Song Hai-Juan Zhang Ying-hua Liu Cui-ling Ren Hong-Li chen College of Chemistry and Chemical Engineering Lanzhou UniversityLanzhou 730000China Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province Lanzhou 730000China Lanzhou Institute of Chemical Physics Chinese Academy of SciencesLanzhou 730000China

A new facile fluorescence probing strategy, which was based on N-doped carbon dots（NCDs） and methyl parathion hydrolase（MPH）, was developed for the determination of parathion-methyl（PM）. The fluorescence intensity of NCDs-MPH system was proportional to PM concentration in the range of 2.38–73.78 mmol/L, with a detection limit of 0.338 mmol/L. Moreover, the present simple and facile method could be used to determine methyl parathion in environmental and agricultural samples ***, the detection mechanism of this system is inner filter effect and molecular interactions between NCDs and p-nitrophenol, which is the hydrolysis product of PM catalyzed by methyl parathion hydrolase.

关键词： N-doped carbon dots Parathion-methyl Methyl parathion hydrolase Inner filter effect Fluorescence

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Determination of Enantiomeric Purity of ν-Pyrrolidinyl Phenylpropanol by Capillary Electrophoresis Using β-Cyclodextrin Polymer as Chiral Selector

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Chinese Chemical Letters 2001年第4期12卷 357-358页

作者： Tong WU Xin ZHOU Jia hua chen Jun ling GU Ruo Nong FU College of Chemical Engineering and Material Science Beijing Institute of Technology Beijing 100081 Bioorgnic Molecule Engineering Education Department Opening Laboratory Peiking University Beijing 100871

Enantiomer of n-pyrrolidinyl phenylpropanol was studied by capillary electrophoresis using b-cyclodextrin polymer as chiral selector. We determined the enantiomeric excess value of n-pyrrolidinyl phenylpropanol with R... 详细信息

关键词： Capillary electrophoresis n-pyrrolidinyl phenylpropanol enantiomeric excess value enantioseparation b-cyclodextrin polymer.

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Demystifying the catalysis in lithium–sulfur batteries:Characterizationmethods and techniques

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SusMat 2021年第1期1卷 51-65页

作者： Chuannan Geng Wuxing hua DaweiWang Guowei ling chen Zhang Quan-Hong Yang Nanoyang Group State Key Laboratory of Chemical EngineeringSchool of Chemical Engineering and TechnologyTianjin University and Collaborative Innovation Center of Chemical Science and EngineeringTianjinChina School of Chemical Engineering The University of New SouthWalesSydneyAustralia UNSW Digital Grid Futures Institute The University of New South WalesSydneyAustralia School of Marine Science and Technology Tianjin UniversityTianjinChina Joint School of National University of Singapore Tianjin UniversityInternational Campus of Tianjin UniversityFuzhouChina

Lithium–sulfur(Li-S)batteries are promising next-generation energy storage systems with ultrahigh energy ***,the intrinsic sluggish“solid–liquid–solid”reaction between S8 and Li2S causes unavoidable shuttling of polysulfides,severely limiting the practical energy density and cycling ***,the catalysis process has been introduced for the sulfur redox reaction to accelerate the conversion of polysulfides,providing a positive remedy for the polysulfides ***,in-depth understanding of the catalyst evaluation criteria and catalytic mechanism still lies in the“black box”,and precise characterization technique is the key to unlock this *** this review,we provide a comprehensive overview of characterization techniques on the catalyst in Li-S batteries from two aspects of catalytic performance and catalytic mechanism,highlighting their significance and calling for more efforts to develop precise and fast techniques for Li-S ***,we envision the future development of characterization for better understanding the catalysis toward practical Li-S battery.

关键词： catalysis catalyst characterization lithium-sulfur batteries polysulfides shuttling

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Structure identification of 4-amino-2-(arylamino)thiazole-5-carboxylic esters

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Chinese Chemical Letters 2016年第2期27卷 302-304页

作者： Hai-Long Zhao hua-Long chen Jie Zhou Bai-ling Xu Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation Institute of Materia Medica Chinese Academy of Medical Sciences & Peking Union Medical College

In our previous work,we found a new method by chance for the synthesis of thiazole derivatives with diversified substitutes on 2-and 5-positions of the thiazole scaffold which was published in Chinese Chemical Letters[2014,Vol.25 p.411].The structures were identified by ~1H NMR,^（13）C NMR and HRMS as 2-alkoxy-4-amino-Narylthiazole-5-carboxamides.

关键词： In ppm Structure identification of 4-amino-2 arylamino)thiazole-5-carboxylic esters HRMS

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Sparse and Low-Rank Covariance Matrix Estimation

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Journal of the Operations Research Society of China 2015年第2期3卷 231-250页

作者： Sheng-Long Zhou Nai-hua Xiu Zi-Yan Luo ling-chen Kong Department of Applied Mathematics Beijing Jiaotong UniversityBeijing 100044China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong UniversityBeijing 100044China

This paper aims at achieving a simultaneously sparse and low-rank estimator from the semidefinite population covariance *** first benefit from a convex optimization which develops l1-norm penalty to encourage the sparsity and nuclear norm to favor the low-rank *** the proposed estimator,we then prove that with high probability,the Frobenius norm of the estimation rate can be of order O(√((slgg p)/n))under a mild case,where s and p denote the number of nonzero entries and the dimension of the population covariance,respectively and n notes the sample ***,an efficient alternating direction method of multipliers with global convergence is proposed to tackle this problem,and merits of the approach are also illustrated by practicing numerical simulations.

关键词： Covariance matrix Sparse and low-rank estimator Estimation rate Alternating direction method of multipliers

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Covalent hadronic molecules induced by shared light quarks

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Communications in Theoretical Physics 2022年第12期74卷 62-86页

作者： hua-Xing chen School of Physics Southeast UniversityNanjing 210094China

After examining Feynman diagrams corresponding to the ■, ■, ■, and ■ hadronic molecular states, we propose a possible binding mechanism induced by shared light quarks. This mechanism is similar to the covalent bond in chemical molecules induced by shared electrons. We use the method of QCD sum rules to calculate its corresponding light-quark-exchange diagrams, and the obtained results indicate a model-independent hypothesis: the light-quark-exchange interaction is attractive when the shared light quarks are totally antisymmetric so they obey the Pauli principle. We build a toy model with four parameters to formulize this picture and estimate binding energies of some possibly-existing covalent hadronic molecules. A unique feature of this picture is that the binding energies of the(I)JP=(0)1+■ hadronic molecules are much larger than those of the (I)JP=(0)1+■ ones, while the(I)JP=(1/2)1/2+■ hadronic molecules have similar binding energies.

关键词： hadronic molecule covalent bond QCD sum rules

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PRELIMINARY APPLICATION OF WHOLE BODY DIFFUSION WEIGHTED IMAGING IN SCREENING METASTASIS

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Chinese Medical Sciences Journal 2008年第3期23卷 178-182页

作者： Yong-jing Guan hua-wei ling Ke-min chen Department of Radiology Ruijin Hospital School of Medicine Shanghai Jiaotong University Shanghai 200025

Objective To investigate the feasibility of whole body diffusion weighted imaging (WB-DWI) in screening metastasis. Methods WB-DWI was performed in 24 patients diagnosed with various types of primary tumors. The three-dimensional maximum intensity projection reconstruction and black-and-white flip technique were used to observe metastatic lesions, and the results were compared with those of bone scintigraphy. Results By WB-DWI scanning sequence at b = 800 s/mm2, all the bone lesions found by bone scintigraphy in the cohort were well identified, and other lesions of soft tissue and organs were also well demonstrated. Its screening capability was equivalent with bone scintigraphy in screening metastases in bones (P = 0.062). Conclusion WB-DWI was practicable with the parameter settings attempted in metastases screening.

关键词： magnetic resonance imaging whole body diffusion weighted imaging apparent diffusion coefficient metastasis

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Role of iron ore in enhancing gasification of iron coke:Structural evolution,influence mechanism and kinetic analysis

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 58-69页

作者： Jie Wang Wei Wang Xuheng chen Junfang Bao Qiuyue Hao Heng Zheng Runsheng Xu School of Chemistry and Materials Science Hubei Engineering UniversityXiaogan 432000China Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Institue of Ironmaking Technology Baosteel Central Research InstituteShanghai 201999China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The utilization of iron coke provides a green pathway for low-carbon *** uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification,the effect of iron ore on the microstructure of iron coke was ***,a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric *** findings indicate that compared to coke,iron coke exhibits an augmentation in micropores and specific surface area,and the micropores further extend and *** provides more adsorption sites for CO_(2) molecules during the gasification process,resulting in a reduction in the initial gasification temperature of iron *** the heating rate in non-isothermal gasification can enhance the reactivity of iron *** metallic iron reduced from iron ore is embedded in the carbon matrix,reducing the orderliness of the carbon structure,which is primarily responsible for the heightened reactivity of the carbon *** kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore ***,as the proportion of iron ore increases,the activation energy for the carbon gasification gradually decreases,from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15wt%.

关键词： low-carbon ironmaking iron coke gasification structural evolution kinetic model

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Decay properties of the X(3872)through the Fierz rearrangement

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Communications in Theoretical Physics 2022年第2期74卷 60-77页

作者： hua-Xing chen School of Physics Southeast UniversityNanjing 210094China

We systematically construct all the tetraquark currents of J^(PC)=1^(++) with the quark configurations[cq][cq],[cq][qc],and[cc][qq](q=u/d).Their relations are derived using the Fierz rearrangement of the Dirac and color indices,through which we study decay properties of the X(3872)under both the compact tetraquark and hadronic molecule *** conduct a search for the X(3872)→χ_(c0)π,η_(c)ππ,and χ_(c1)ππ decay processes in particle experiments.

关键词： exotic hadron tetraquark state hadronic molecule Fierz rearrangement QCD sum rules

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