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2-Connected Factor-critical Graphs G with Exactly ｜E(G)｜＋ 1 Maximum Matchings

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Acta Mathematicae Applicatae Sinica 2017年第4期33卷 1001-1014页

作者： ming-hua li Yan liU School of Mathematical Sciences South China Normal University Guangzhou 510631 China

A connected graph G is said to be a factor-critical graph if G - v has a perfect matching for every vertex v of G. In this paper, the 2-connected factor-critical graph G which has exactly ｜E（G）｜＋ 1 maximum matchi... 详细信息

关键词： maximum matching factor-critical graph 2-connected graph

Effect of the microstructure of Al 7050-T7451 on anodic oxide formation in sulfuric acid

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International Journal of Minerals,Metallurgy and Materials 2009年第4期16卷 432-438页

作者： Jian-hua liu ming li Song-mei li Min huang School of Materials Science and Engineering Beihang University Beijing 100083 China

The effect of the microstructure of an Al 7050-T7451 substrate on the anodic oxide formation in sulfuric acid was studied in this article. The microstructure of the substrate was assessed by optical microscope （OM） and transmission electron microscope （TEM）. The surface and cross-section morphologies of the oxide films were examined by scanning electron microscope （SEM）. The chemical composition of intermetallic particles in the alloys and films was investigated using energy dispersive spectroscope （EDS）. The roles of intermetallic phases and grain or subgrain boundaries on the oxide film formation were researched using the potentiodynamic and potentiostatic polarization technique in sulfuric acid solution. The results show that the transition of coarse intermetallic particles or grain （subgrain） boundaries at the surface of Al alloys can be characterized by potentiodynamic polarization curves. The surface and cross-section micrographs of the anodic layer seem to preserve the microstructure of the substrate. Large cavities in the anodic films are caused by the preferential dissolution of coarse AItCuMg particles and the entrance of Cu-rich remnants into the electrolyte during anodizing. The Al7Cu2Fe particles tend to be occluded in the oxide layer or lose from the oxide surface because of peripheral trenching. Small pores in the films are induced by the dissolution of precipitates in grain or subgrain boundaries. The film surface of recrystallized grain bodies is smooth and homogeneous.

关键词： aluminum alloys anodic oxide intermetallic particles grain boundaries

Buried interface management via bifunctional NH_(4)BF_(4)towards efficient CsPbI_(2)Br solar cells with a V_(oc)over 1.4 V

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Journal of Energy Chemistry 2024年第2期89卷 364-370,I0009页

作者： Fazheng Qiu ming-hua li Jinpeng Wu Jin-Song Hu School of Materials Science and Engineering NingboTech UniversityNingbo 315100ZhejiangChina Beijing National Laboratory for Molecular Sciences(BNLMS) Institute of ChemistryChinese Academy of SciencesBeijing 100190China College of Chemical Engineering Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China

CsPbI_(2)Br perovskite solar cells(PSCs)have drawn tremendous attention due to their suitable bandgap,excellent photothermal stability,and great potential as an ideal candidate for top cells in tandem solar ***,the abundant defects at the buried interface and perovskite layer induce severe charge recombination,resulting in the open-circuit voltage(V_(oc))output and stability much lower than ***,a novel buried interface management strategy is developed to regulate interfacial carrier dynamics and CsPbI_(2)Br defects by introducing ammonium tetrafluoroborate(NH_(4)BF_(4)),thereby resulting in both high CsPbI_(2)Br crystallization and minimized interfacial energy ***,NH_(4)^(+)ions could preferentially heal hydroxyl groups on the SnO_(2)surface and balance energy level alignment between SnO_(2)and CsPbI_(2)Br,enhancing charge transport efficiency,while BF_(4)^(-)anions as a quasi-halogen regulate crystal growth of CsPbI_(2)Br,thus reducing perovskite ***,it is proved that eliminating hydroxyl groups at the buried interface enhances the iodide migration activation energy of CsPbI_(2)Br for strengthening the phase *** a result,the optimized CsPbI_(2)Br PSCs realize a remarkable efficiency of 17.09%and an ultrahigh V_(oc)output of 1.43 V,which is one of the highest values for CsPbI_(2)Br PSCs.

关键词： Inorganic perovskite Buried interface Defect Stability Open-circuit voltage loss

Instability of solution-processed perovskite films:origin and mitigation strategies

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Materials Futures 2023年第1期2卷 26-59页

作者： Shuo Wang ming-hua li Yan Jiang Jin-Song Hu Beijing National Laboratory for Molecular Sciences(BNLMS) Institute of ChemistryChinese Academy of SciencesBeijing 100190People’s Republic of China School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081People’s Republic of China University of Chinese Academy of Sciences Beijing 100049People’s Republic of China

Perovskite solar cells(PSCs)are promising next-generation photovoltaics due to their unique optoelectronic properties and rapid rise in power conversion ***,the instability of perovskite materials and devices is a serious obstacle hindering technology *** quality of perovskite films,which is an important prerequisite for long-term stable PSCs,is determined by the quality of the precursor solution and the post-deposition treatment performed after perovskite ***,we review the origin of instability of solution-processed PSCs from the perspectives of the precursor solutions and the perovskite *** addition,we summarize the recent strategies for improving the stability of the perovskite ***,we pinpoint possible approaches to further advance their long-term stability.

关键词： stability perovskite solar cells precursor solution perovskite films degradation

Design of dual-functional protic porous ionic liquids for boosting selective extractive desulfurization

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Petroleum Science 2024年第4期21卷 2817-2829页

作者： Jin-Rui Zhang Jie Yin Jing He Hong-Shun Ran Wei Jiang Hong-Ping li Wen-Shuai Zhu hua-ming li ming Zhang School of the Environment and Safety Engineering&Institute for Energy Research Jiangsu UniversityZhenjiang212013JiangsuChina School of Chemistry and Chemical Engineering Jiangsu UniversityZhenjiang212013JiangsuChina

Porous ionic liquids have demonstrated excellent performance in the field of separation,attributed to their high specific surface area and efficient mass ***,task-specific protic porous ionic liquids(PPILs)were prepared by employing a novel one-step coupling neutralization reaction strategy for extractive *** single-extraction efficiency of PPILs reached 75.0%for ***,adding aromatic hydrocarbon interferents resulted in a slight decrease in the extraction efficiency of PPILs(from 45.2%to 37.3%,37.9%,and 33.5%),indicating the excellent extraction selectivity of *** experimental measurements and density functional theory calculations reveal that the surface channels of porous structures can selectively capture dibenzothiophene by the stronger electrophilicity(Eint(HS surface channel/DBT)=-39.8 kcal mol^(-1)),and the multiple extraction sites of ion pairs can effectively enrich and transport dibenzothiophene from the oil phase into PPILs throughπ...π,C-H...πand hydrogen bonds ***,this straightforward synthetic strategy can be employed in preparing porous liquids,offering new possibilities for synthesizing PPILs with tailored functionalities.

关键词： Protic porous ionic liquids Extractive desulfurization Selectivity Density functional theory

Enhancement of post-annealing stability in Co/Ni multilayers with perpendicular magnetic anisotropy by Au insertion layers

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Rare Metals 2016年第10期35卷 779-783页

作者： Yi Cao ming-hua li Kang Yang Xi Chen Guang Yang Qian-Qian liu Guang-hua Yu School of Materials Science and Engineering University of Science and Technology Beijing

Enhancement of post-annealing stability in Co/ Ni multilayers with perpendicular magnetic anisotropy （PMA） was obtained by inserting Au layers into Ni/Co interfaces. After annealing at 350 ℃, the effective mag- netic anisotropy density （Kef0 for Ta（3）/Pt（2）/[Co（0.3）/ Ni（0.6）/Au（0.3）]× 3/Co（0.3）/Pt（1）/Ta（3）（in nm） keeps at 0.48 × 105 J·m^-3. Scanning transmission electron micro- scopy-high-angle annular dark field （STEM-HAADF） analysis shows that the diffusion between Ni and Co layers is obstructed by the Au insertion layers among them, which is responsible for the post-annealing stability enhancement of the multilayers. Multilayers with Pt insertion layers were also investigated as reference samples in this work. Com- pared with Pt-layer-inserted Co/Ni multilayers, the Au insertion layers are found to bring seldom interfacial PMA to the multilayers, making it competitive in being employed to enhance the post-annealing stability of PMA Co/Ni multilayers which are used for magnetic random access memory devices （MRAM）.

关键词： Co/Ni multilayers Perpendicular magnetic anisotropy Post-annealing stability Au insertion layers

Tunable perpendicular anisotropic magnetoresistance in CoO/Co/Pt heterostructures

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Rare Metals 2023年第2期42卷 579-584页

作者： Qian-Qian liu Guang Yang Jing-Yan Zhang Guo-Nan Feng Chun Feng Qian Zhan ming-hua li Guang-hua Yu Department of Materials Physics and Chemistry University of Science and Technology BeijingBeijing100083China

Transport properties of magnetron-sputtered CoO/Co/Pt heterostructures were investigated by physical property measurement *** types of magnetoresistance are observed in the heterostructures,including isotropic anisotropic magnetoresistance(AMR),AMR with geometric size effect,and interfacial effect.A reversal in sign of perpendicular AMR is found in the film CoO(3 nm)/Co(3 nm)/Pt(3 nm)compared to the film CoO(3 nm)/Co(3 nm)/CoO(3 nm),which is associated with ***,perpendicular AMR is tunable in the films CoO(3 nm)/Co(3 nm)/CoO(t)/Pt(3 nm)and CoO(3 nm)/Co(3 nm)/Pt(t)/CoO(3 nm)at will,with either positive or negative value,by varying the inserting layer *** electronic structure information of the samples was measured by X-ray photoelectron spectroscopy(XPS).The spin-related transport and XPS results manifest that magnetic proximity effect,surface scattering,together with oxygen migration contribute to the tunable function of Pt.

关键词： Perpendicular anisotropic magnetoresistance Magnetic proximity effect Surface scattering X-ray photoelectron spectroscopy

Synergistic catalysis of the N-hydroxyphthalimide on flower-like bimetallic metal-organic frameworks for boosting oxidative desulfurization

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Petroleum Science 2024年第1期21卷 674-682页

作者： Jing He Kun Zhu Wei Jiang Dong-Ao Zhu lin-hua Zhu Hai-Yan huang Wen-Shuai Zhu hua-ming li Institute for Energy Research Jiangsu UniversityZhenjiang212013JiangsuChina College of Chemistry and Chemical Engineering Hainan Normal UniversityKey Laboratory of Water Pollution Treatment and Resource Reuse of Hainan ProvinceHaikou571158HainanChina

Synergic catalytic effect between active sites and supports greatly determines the catalytic activity for the aerobic oxidative desulfurization of fuel *** this work,Ni-doped Co-based bimetallic metal-organic framework(CoNi-MOF)is fabricated to disperse N-hydroxyphthalimide(NHPI),in which the whole catalyst provides plentiful synergic catalytic effect to improve the performance of oxidative desulfurization(ODS).As a bimetallic MOF,the second metal Ni doping results in the flower-like morphology and the modification of electronic properties,which ensure the exposure of NHPI and strengthen the synergistic effect of the overall *** with the monometallic Co-MOF and naked NHPI,the NHPI@CoNi-MOF triggers the efficient activation of molecular oxygen and improves the ODS performance without an *** sulfur removal of dibenzothiophene-based model oil reaches 96.4%over the NHPI@CoNi-MOF catalyst in 8 h of ***,the catalytic product of this aerobic ODS reaction is sulfone,which is adsorbed on the catalyst surface due to the difference in *** work provides new insight and strategy for the design of a strong synergic catalytic effect between NHPI and bimetallic supports toward high-activity aerobic ODS materials.

关键词： Metal-organic frameworks Doped Bimetallic N-hydroxyphthalimide Aerobic processes Oxidative desulfurization

Insight into the oxidative desulfurization of high-sulfur petroleum coke under mild conditions:a journey of vanadium-substituted Dawson-type phosphotungstic acid

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Petroleum Science 2021年第3期18卷 983-993页

作者： Fu-Min li ming-Qing hua Yan-Chen Wei Ji-Xing liu Jia-Hong Gong Chao Wang Pei-Wen Wu Yan huang hua-ming li Wen-Shuai Zhu School of Chemistry and Chemical Engineering Jiangsu UniversityZhenjiang 212013China School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China School of the Environment and Safety Engineering Jiangsu UniversityZhenjiang 212013China

High-sulfur petroleum coke(HSPC),that is a by-product from slag oil in the coking process of refning,shows versatility values in practical applications and,however,concentrates the majority of organic ***,we design and construct a highly efective CTAB@HPA composites to be explored for the catalytic oxidative desulfurization of HSPC under mild conditions using hydrogen peroxide as the oxidant and 1-butyl-3-methylimidazole tetrafuoroborate ionic liquid as the *** results demonstrate that the sulfur content of HSPC could be strikingly reduced from 4.46 wt%to 2.48 wt%under 60℃ and atmospheric pressure,and that the organic sulfur in HSPC is mainly oxidized to sulfoxide,sulfone and sulfate,which latter can be directly separated from petroleum ***,the efect of reaction conditions on the desulfurization performance of HSPC as well as the catalytic oxidation reaction kinetic of HSPC desulfurization was systematically ***,a mechanism for the oxidative desulfurization of HSPC over CTAB@HPA catalysts was ***,this work provides new insight into how to construct active catalysts for the desulfurization of HSPC under mild conditions.

关键词： High-sulfur petroleum coke Dawson-type phosphotungstic acid Oxidative desulfurization Mild conditions Sulfate