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Tuning the Electrically Conductive Network of Grafted Nanoparticles in Polymer Nanocomposites by the Shear Field

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Chinese Journal of Polymer Science 2020年第12期38卷 1426-1434页

作者： Yan-Long Luo xiao hui duan Bin Li Xin-Ling Chen Yang Yang Gao Li-Qun Zhang Cllege of Science Nanjing Forestry UniversityNanjing 210037 China KeyLaboratoryof Bejing Ciy on Preparation and Pocessing of Novel Polmer Materials Bejing University ofChemical TechnologyBejing 100029China State Key Laboratory of Organic-lnorganic Composites Bejing Universityof Chemical Technology Bejing 10029China School of Chemical Engneering and Technology.Sun Yat sen University Zhuhai 519082 China

Contolling the formation of the conductive network in the polymer nanocomposites(PNCs)is very meaningful to enhance their electrical *** this work,we investigated the effect of grafted nanoparticles(NPs)on the conductive probability of PNCs in the quiescent state as well as under the shear field via a coarse grained molecular dynamics *** is found that the smallest percolation threshold is realized at the moderate grafting density,the moderate length of grafted chains or the moderate interaction between grafted chains and free *** to it,the dispersion state of NPs varies from the contact aggregation to the uniform *** analyzing the connection mode among NPs,the probabilty of NPs which connect three other ones reaches the maximum value at their moderate dispersion state which is responsible for the optimal conductive *** addition,the main cluster size is characterized to better understand the conductive network which is consistent with the percolation *** is interesting to find that the percolation threshold is smaller under the shear field than under the quiescent *** shear field induces more NPs which connect three other *** benefits the formation of the new conductive ***,the anisotropy of the conductive probability is reduced with increasing the grafting *** summary,this work provides a clear picture on how the conductive network of grafted NPs evolves under the shear field.

关键词： Conductive network Grafted nanoparticles Molecular dynamics simulation

The effects of pre-equilibrium emission and secondary decay on the determination of freeze-out volume at intermediate energies

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Chinese Physics C 2021年第5期45卷 173-178页

作者： hui-xiao duan Dong-Hai Zhang Fan Zhang Hai-Shun Wu Key Laboratory of Magnetic Molecules and Magnetic Information Materials Ministry of Education School of Chemistry and Material ScienceShanxi Normal UniversityLinfen 041004China Institute of Modern Physics Shanxi Normal UniversityLinfen 041004China Department of Electronic Information and Physics.Changzhi University Changzhi 046011China

The effects of pre-equilibrium emission and secondary decay on the determination of the freeze-out volume are investigated using the isospin-dependent quantum molecular dynamics model accompanied by the statistical decay model ***-mass projectiles and large-mass targets with central collisions are studied at intermediate *** is revealed that the proton yields of pre-equilibrium emission are smaller than those of secondary ***,the determination of the freeze-out volume from the proton yields is more easily affected by pre-equilibrium ***,the percentage of proton yields in the freezeout stage is found to be approxim-ately 50%.

关键词： freeze-out volume nuclear temperature quadrupole momentum

Crystalline-amorphous M@MN_x(M=Co,Fe,Ni)encapsulated in nitrogen-doped carbon for enhanced efficient and durable hydrogen evolution reaction

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Rare Metals 2024年第4期43卷 1547-1556页

作者： Yang Yang xiao-Chuan duan Shao-hui Guo Xian-Ming Zhang College of Materials Science and Engineering College of ChemistryKey Laboratory of Interface Science and Engineering in Advanced MaterialsTaiyuan University of TechnologyYuci030600China

Developing earth-abundant electrocatalysts for hydrogen evolution reaction(HER)is important for the sustainable energy ***,efficient and stable heterocatalysts consisting of crystalline-amorphous M@MN_(x)(M=Co,Fe,Ni)encapsulated in N-doped carbon layers supported with N-doped graphene sheets(denoted as M@MN_(x)@NC-NG)are synthesized by facile hydrothermal reaction and nitridation *** the nitriding process,metal ions in M(tzbc)_2(H_(2)O)_4(tzbc=4-(1H-1,2,4-triazol-1-yl)benzoic acid)complexes are reduced to crystalline M cores,accompanied by the formation of amorphous MN_(x)shells;the tzbc ligands are insitu carbonized to form outermost N-doped carbon(NC)layers that connect with inner MN_(x)via M-N-C motifs inherited from the complex precursors and inhibit the transition of MN_(x)from amorphous to crystalline *** Co@CoN_(x)@NC-NG catalyst exhibits excellent HER activity with small overpotentials of 45 and 64 mV at a cathode current density of 10 mA·cm^(-2)and low Tafel slopes of 40 and 85 mV·dec^(-1)in 0.5 mol·L^(-1)H_(2)SO_4 and1.0 mol·L^(-1)KOH electrolytes,*** Co@CoN_(x)@NC-NG retains 97%of the initial overpotential after 100,000 s in both acidic and alkaline *** outstanding HER performance originates from the crystalline-amorphous Co@CoN_(x)that redistributes electrons around the heterointerfaces,facilitating the conversion process of H^(+)/H_(2)O to hydrogen and thereby promoting HER *** outermost NC layers serve as the armor of Co@CoN_(x),and graphene nanosheets act as carriers of egg-like Co@CoN_(x)@NC and conduction paths for electron shuttles,ensuring stable and continuous electrocatalytic hydrogen production.

关键词： Hydrogen evolution reaction Electrocatalysts Iron group metals Heterojunction Crystalline-amorphous structure

First Principles Study of AI-Li Intermetallic Compounds

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Chinese Journal of Chemical Physics 2012年第6期25卷 659-665,I0003页

作者： Hai-li Yu xiao-hui duan Yong-jun Ma Min Zeng State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials :SouthwestUniversity of Science and Technology Mianyang 621010 China

The structural properties, heats of formation, elastic properties, and electronic structures of four compositions of binary A1-Li intermetallics, A13Li, A1Li, A12Li3, and A14Li9, are ana- lyzed in detail by using density functional theory. The calculated formation heats indicate a strong chemical interaction between A1 and Li for all the A1-Li intermetallics. In partic- ular, in the Li-rich A1-Li compounds, the thermodynamic stability of intermetallics linearly decreases with increasing concentration ***. According to the computational single crystal elastic constants, all the four A1-Li intermetallic compounds considered here are mechani- cally stable. The polycrystalline elastic modulus and Poisson＇s ratio have been deduced by using Voigt, Reuss, and Hill approximations, and the calculated ratios of bulk modulus to shear modulus indicate that the four compositions of binary A1-Li intermetallics are brittle materials. With the increase of Li concentration, the bulk modulus of A1-Li intermetallics decreases in a linear manner.

关键词： First principles A1-Li intermetallic compound Mechanical property Forma-tion heat Elastic properties

Accurate Distinction of Weak and Strong AC Grids for Emerging Hierarchical-Infeed LCC-UHVDC Systems

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 772-777页

作者： Hao xiao Xianzhong duan Yi Zhang Department of Electrical and Computer Engineering University of ManitobaWinnipeg R3T 2N2ManitobaCanada State Key Laboratory of Advanced Electromagnetic Engineering and Technology Hubei Electric Power Security and High Efficiency Key LaboratorySchool of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430074HubeiChina RTDS Technologies Inc. Winnipeg R3T 2E1ManitobaCanada

Distinction of weak and strong AC grids for emerging hierarchical-infeed LCC-UHVDC systems is important for planning and operation departments. However, accuracy of earlier distinction methods is limited as they were developed by empirical reasoning without rigorous theoretical analysis. Hence in this letter, hierarchical-infeed interactive effective short-circuit ratio (HIESCR) index is first used for strength evaluation of HIDC systems with complex inter-inverter interactions considered. Boundary HIESCR (BHIESCR) is also introduced in the proposed distinction method of weak and strong AC grids. That is, weak (or strong) AC grids are, respectively, identified when HIESCR is less (or greater) than BHIESCR. Second, it is shown BHIESCR remains almost unchanged as 3.0 versus various system parameters and rated operation variables based on rigorous theoretical analysis. This salient feature makes the proposed method more accurate than earlier methods. Finally, the proposed method is validated by simulations based on the PSCAD/EMTDC program.

关键词： Hierarchical-Infeedinteractive effective short-circuit ratio hierarchical-infeed LCC-UHVDC systems inter-inverter interactions strong AC grids weak AC grids

High-throughput screening of single-atom catalysts confined in monolayer black phosphorus for efficient nitrogen reduction reaction

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Nano Research 2024年第4期17卷 2360-2367页

作者： xiao-Yan Li Manyi duan Pengfei Ou Department of Electrical and Computer Engineering University of TorontoTorontoOntario M5S 1A4Canada School of Physics and Electronic Engineering Sichuan Normal UniversityChengdu 610101China Department of Chemistry Northwestern UniversityEvanstonIL 60208USA

The discovery of metal-nitrogen centers as the active sites for electrolysis has aroused significant interest in utilizing single-atom catalysts for nitrogen reduction reaction(NRR).Properly designed nanostructured catalysts that strongly interact with nitrogen molecules(N_(2))can promote adsorption and activation,thereby resulting in efficient catalysts with high stability,activity,and *** this study,using density functional theory calculations,we selected monolayer black phosphorus(BP)as the substrate and screened a series of single-atom transition metals confined in tri-coordinated and tetra-coordinated active centers(without and with N dopants)to electro-catalyze *** a result,we have identified two promising candidates(Hf_(1)-N_(1)P_(2)-1 and Tc_(1)-N_(4)),which exhibit not only low overpotentials of 0.56 and 0.49 V but also high thermodynamic and electrochemical stability,as well as good selectivity towards NRR over the competing hydrogen evolution *** also demonstrate the ability of Hf_(1)-N_(1)P_(2)-1 and Tc_(1)-N_(4) to activate and hydrogenate N_(2) by donating electrons and regulating charge *** study not only predicts new BP-based promising catalysts but also provides guidance for the rational design of high-performance NRR electrocatalysts under ambient conditions.

关键词： N_(2) electroreduction reaction single-atom catalysts black phosphorus density functional theory high-throughput calculations

Joint Sample Position Based Noise Filtering and Mean Shift Clustering for Imbalanced Classification Learning

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Tsinghua Science and Technology 2024年第1期29卷 216-231页

作者： Lilong duan Wei Xue Jun Huang xiao Zheng School of Computer Science and Technology Anhui University of TechnologyMaanshan 243032China Institute of Artificial Intelligence Hefei Comprehensive National Science CenterHefei 230088China

The problem of imbalanced data classification learning has received much *** classification algorithms are susceptible to data skew to favor majority samples and ignore minority *** weighted minority oversampling technique(MWMOTE)is an effective approach to solve this problem,however,it may suffer from the shortcomings of inadequate noise filtering and synthesizing the same samples as the original minority *** this end,we propose an improved MWMOTE method named joint sample position based noise filtering and mean shift clustering(SPMSC)to solve these ***,in order to effectively eliminate the effect of noisy samples,SPMsC uses a new noise filtering mechanism to determine whether a minority sample is noisy or not based on its position and distribution relative to the majority *** that MWMOTE may generate duplicate samples,we then employ the mean shift algorithm to cluster minority samples to reduce synthetic replicate ***,data cleaning is performed on the processed data to further eliminate class *** on extensive benchmark datasets demonstrate the effectiveness of SPMsC compared with other sampling methods.

关键词： imbalanced data classification oversampling noise filtering clustering

GreenPhos,a universal method for in-depth measurement of plant phosphoproteomes with high quantitative reproducibility

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Molecular Plant 2024年第1期17卷 199-213页

作者： xiaoxiao duan Yuanya Zhang Xiahe Huang xiao Ma hui Gao Yan Wang Zhen xiao Chengcheng Huang Zhongshu Wang Bolong Li Wenqiang Yang Yingchun Wang State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental BiologyChinese Academy of SciencesBejing 100101China University of Chinese Academy of Sciences Bejing 100049China Key Laboratory of Photobiology Instute of BotanyChinese Academy of SciencesBejing 100093China

Protein phosphorylation regulates a variety of important cellular and physiological processes in ***-depth profiling of plant phosphoproteomes has been more technically challenging than that of animal *** is largely due to the need to improve protein extraction efficiency from plant cells,which have a dense cell wall,and to minimize sample loss resulting from the stringent sample clean-up steps required for the removal of a large amount of biomolecules interfering with phosphopeptide purification and mass spectrometry *** this end,we developed a method with a streamlined workflow for highly efficient purification of phosphopeptides from tissues of various green organisms including Arabidopsis,rice,tomato,and Chlamydomonas reinhardtii,enabling in-depth identification with high quantitative reproducibility of about 11000 phosphosites,the greatest depth achieved so far with single liquid chromatography-mass spectrometry(LC-MS)runs operated in a data-dependent acquisition(DDA)*** mainstay features of the method are the minimal sample loss achieved through elimination of sample clean-up before protease digestion and of desalting before phosphopeptide enrichment and hence the dramatic increases of time-and *** method,named GreenPhos,combined with single-shot LC-MS,enabled in-depth quantitative identification of Arabidopsis phosphoproteins,including differentially phosphorylated spliceosomal proteins,at multiple time points during salt stress and a number of kinase substrate *** is expected to serve as a universal method for purification of plant phosphopeptides,which,if samples are further fractionated and analyzed by multiple LC-MS runs,could enable measurement of plant phosphoproteomes with an unprecedented depth using a given mass spectrometry technology.

关键词： plant phosphoproteomics phosphopeptides LC–MS Arabidopsis salt stress

Clinical efficacy of femtosecond laser-assisted phacoemulsification in diabetic cataract patients

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World Journal of Clinical Cases 2024年第10期12卷 1733-1741页

作者： Yi-Fei Tang Zhi-hui duan Department of Glaucoma and Cataracts Han Yang Eyegood Ophthalmic HospitalWuhan 430056Hubei ProvinceChina

BACKGROUND Diabetic patients with cataracts encounter specific difficulties during cataract surgery due to alterations in microcirculation,blood supply,metabolism,and the *** phacoemulsification may not fully tackle these issues,especially in instances with substantial preoperative *** utilization of femtosecond laser-assisted phacoemulsification,in conjunction with Toric intraocular lens(IOL)implantation,offers a potentially more efficient *** research seeks to evaluate the efficacy and possible complications of this approach in diabetic cataract *** To investigate the clinical efficacy and complications of femtosecond laser-assisted phacoemulsification combined with Toric IOL implantation in diabetic cataract patients,comparing it with traditional phacoemulsification *** This retrospective study enrolled 120 patients with diabetes cataract from May 2019 to May *** patients were divided into two groups:the control group underwent traditional phacoemulsification and Toric IOL implantation,while the treatment group received Len Sx femtosecond laser-assisted *** measures included naked eye vision,astigmatism,high-level ocular phase difference detection,clinical efficacy,and *** There were no significant preoperative differences in astigmatism or naked eyesight between the two ***,postoperative improvements were observed in both groups,with the treatment group showing greater enhancements in naked eye vision and astigmatism six months after the ***-level corneal phase difference tests also indicated significant differences in favor of the treatment *** This study suggests that femtosecond laser-assisted phacoemulsification combined with Toric IOL implantation appears to be more effective in enhancing postoperative vision in diabetic cataract patients compared to traditional methods offering valuable insights for clinical practice.

关键词： Diabetic cataract Femtosecond laser-assisted phacoemulsification Toric intraocular lens implantation Naked vision