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Nano Research 2024年第1期17卷 297-306页

作者： Jing Xie Zhenjiang Lu Yue Feng Jianguo Huang Jindou Hu Aize Hao Yali Cao State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources College of ChemistryXinjiang UniversityUrumqi 830046China

Defect modulation currently plays a decisive role in addressing the poor photoabsorption,sluggish electron hole separation,and high CO_(2)activation barrier in photocatalytic CO_(2)***,hunting for a straightforward strategy to balance the concentration of oxygen vacancy and metal cation defect in one photocatalyst is still a great ***,a bismuth vacancies BiOBr nanosheets(BiOBr-1)on the exposed[001]facets were constructed via an acetic acid molecule modification strategy,which can repair oxygen defect by bismuth vacancy in low-temperature solid-state chemical *** from the formed bismuth defects that can not only broaden light absorption and elevate charge separation efficiency,but also enhance adsorption and activation of CO_(2)molecules,the evolution rates of photocatalytic CO_(2)conversion into CO(71.23μmol·g^(-1)·h^(-1))and CH4(8.90μmol·g^(-1)·h^(-1))attained by BiOBr-1 are superior 7.1 and 11 times to that of plate-like *** photocatalytic mechanisms including adsorption concentration and activation process of CO_(2)are further revealed by the in situ diffuse reflectance infrared flourier transform spectra(DRIFTS).This finding of the existence of distinct defects in ultrathin nanosheets undoubtedly leads to new possibilities for photocatalyst design using two-dimensional materials with high solar-driven photocatalytic activity.

关键词： solid-state synthesis BiOBr metal vacancies photocatalysis carbon dioxide reduction

Cobalt-doped TiO_(2)@C hierarchical nanocomposites derived from Ti_(3)C_(2) MXene as cathodes for hybrid magnesium-lithium batteries

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Nano Research 2024年第1期17卷 253-261页

作者： Xiaohui Li Yakun Tang Lang Liu Yue Zhang Yang Gao Mao Qian Wenjie Ma State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources College of ChemistryXinjiang UniversityUrumqi 830017China

TiO_(2)has been explored in hybrid magnesium-lithium batteries(HMLBs)due to the advantages of low self-discharge and small volume expansion during ion ***,how to improve the inherently low ionic and electrical conductivity of TiO_(2)is the problem that needs to be *** this work,a smart strategy is adopted to prepare cobalt-doped TiO_(2)@C(Co^(4+)-TiO_(2)@C)hierarchical nanocomposite derived from Co(II)(OH)n@*** with TiO_(2)@C(without cobalt doping),Co^(4+)-TiO_(2)@C shows the highest specific capacity(154.7 mAh·g^(-1)at 0.1 A·g^(-1)after 200 cycles)and extraordinary rate performance in *** excellent electrochemical performance of Co4+-TiO_(2)@C is ascribed to the synergistic effect of the hierarchical structure and *** experimental results and density functional theory(DFT)calculation reveal that the cobalt-doping has effectively improved the electronic conductivity and reduced the Li+migration *** work provides a new insight to design TiO_(2)-based cathode materials with high-performance in HMLBs.

关键词： Ti_(3)C_(2)MXene TiO_(2) hybrid magnesium-lithium batteries hierarchical structure cobalt-doping

Triangle-free Graphs with Three Positive Eigenvalues

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Algebra Colloquium 2024年第3期31卷 525-540页

作者： Fang Duan School of Mathematical Sciences Xinjiang Normal UniversityUrumqi 830017China

A graph G is called triangle-free if G does not contain any triangle as its induced *** G_(n)be the set of triangle-free graphs of order n each of which has three positive *** this paper,we find 20 specific graphs in G_(n),each of which has nullity no more than 2,and we show that in terms of three graph transformations all the other graphs of G_(n)can be constructed from these 20 specific ***,we completely characterize the triangle-free graphs with exactly three positive eigenvalues.

关键词： positive(negative)inertia index nullity triangle-free graph

Molecular Dynamics-Based Simulation of Polyethylene Pipe Degradation in High Temperature and High Pressure Conditions

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Fluid Dynamics & Materials Processing 2024年第9期20卷 2139-2161页

作者： Guowei Feng Qing Li Yang Wang Nan Lin Sixi Zha Hang Dong Ping Chen Minjun Zheng School of Mechanical Engineering Xinjiang UniversityUrumqi830046China xinjiang Yian Special Inspection Engineering Company Limited Urumqi830063China xinjiang Uygur Autonomous Region Inspection Institute of Special Equipment Urumqi830000China Pressure Pipe Department China Special Equipment Inspection and Research InstituteBeijing100013China Tarim Oilfield Branch Company Korla841000China Yimai Cai Oil and Gas Management Area Tarim Oilfield Branch OfficeKorla841000China

High-density polyethylene(HDPE)pipes have gradually become the first choice for gas networks because of their excellent *** the use of pipes increases,there will unavoidably be a significant amount of waste generated when the pipes cease their operation life,which,if improperly handled,might result in major environmental contamination *** this study,the thermal degradation of polyethylene materials is simulated for different pressures(10,50,100,and 150 MPa)and temperatures(2300,2500,2700,and 2900 K)in the framework of Reactive Force Field(ReaxFF)molecular dynamics *** main gas products,density,energy,and the mean square displacement with temperature and pressure are also *** findings indicate that raising the temperature leads to an increase in the production of gas products,while changing the pressure has an impact on the direction in which the products are generated;the faster the temperature drops,the less dense the air;both temperature and pressure increase impact the system’s energy conversion or distribution mechanism,changing the system’s potential energy as well as its total energy;the rate at which molecules diffuse increases with temperature,and decreases with *** results of this investigation provide a theoretical basis for the development of the pyrolytic treatment of polyethylene waste materials.

关键词： ReaxFF MD high-density polyethylene degradation temperature pressure

Room-temperature ferromagnetism and half-metallicity in monolayer orthorhombic CrS_(2)

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Frontiers of physics 2024年第4期19卷 137-146页

作者：雷博程李奥林周文哲王云鹏熊威陈羽欧阳方平 School of Physics Science and Technology and Xinjiang Key Laboratory of Solid-State Physics and DevicesXinjiang UniversityUrumqi 830046China School of Physics and Hunan Key Laboratory for Super-Microstructure and Ultrafast Processand Hunan Key Laboratory of Nanophotonics and DevicesCentral South UniversityChangsha 410083China School of Physics Science and Technology and Xinjiang Laboratory of Phase Transitions and Microstructures in Condensed Matter PhysicsYili Normal UniversityYining 835000China Powder Metallurgy Research Institute and State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China

Two-dimensional materials with high-temperature ferromagnetism and half-metallicity have the latest applications in spintronic *** on first-principles calculations,we have investigated a novel two-dimensional CrS_(2) phase with an orthorhombic *** results suggest that it is stable in dynamics,thermodynamics,and *** ground state of monolayer orthorhombic CrS_(2) is both ferromagnetic and half-metallic,with a high Curie temperature of 895 K and a large spin-flipping gap on values of 0.804 *** room-temperature ferromagnetism and halfmetallicity can maintain stability against a strong biaxial strain ranging from–5%to 5%.Meanwhile,increasing strain can significantly maintain the out-of-plane magnetic anisotropy.A density of states analysis,together with the orbital-resolved magnetic anisotropy energy,has revealed that the strain-enhanced MAE is highly related to the 3d-orbital splitting of Cr *** results suggest the monolayer orthorhombic CrS_(2) is an ideal candidate for future spintronics.

关键词： orthorhombic CrS_(2) Curie temperature magnetic anisotropy energy biaxial strain first-principles calculations

Embedding Generalized Petersen Graph in Books

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Chinese Annals of Mathematics,Series B 2016年第3期37卷 385-394页

作者： Bin ZHAO Wei XIONG Yingzhi TIAN Jixiang MENG College of Mathematics and System Science Xinjiang University

A book embedding of a graph G consists of placing the vertices of G on a spine and assigning edges of the graph to pages so that edges in the same page do not cross each other. The page number is a measure of the quality of a book embedding which is the minimum number of pages in which the graph G can be embedded. In this paper, the authors discuss the embedding of the generalized Petersen graph and determine that the page number of the generalized Petersen graph is three in some situations, which is best possible.

关键词： Book embedding Page number Generalized Petersen graph

Small glitches: the role of strange nuggets?

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Research in Astronomy and Astrophysics 2016年第3期16卷 91-98页

作者： Xiao-Yu Lai Ren-Xin Xu School of Physics Xinjiang University xinjiang Astronomical Observatory Chinese Academy of Sciences School of Physics Peking University Kavli Institute for Astronomy and Astrophysics Peking University

Pulsar glitches, i.e. the sudden spin-ups of pulsars, have been detected for most known *** mechanism giving rise to this kind of phenomenon is uncertain, although a large data set has been *** the framework of the starquake model, based on Baym ＆ Pines, the glitch sizes（the relative increases of spin-frequencies during glitches） △Ω/Ω depend on the released energies during glitches, with less released energies corresponding to smaller glitch sizes. On the other hand, as one of the dark matter candidates,our Galaxy might be filled with so called strange nuggets（SNs） which are relics from the early *** this case collisions between pulsars and SNs are inevitable, and these collisions would lead to glitches when enough elastic energy has been accumulated during the spin-down process. The SN-triggered glitches could release less energy, because the accumulated elastic energy would be less than that in the scenario of glitches without SNs. Therefore, if a pulsar is hit frequently by SNs, it would tend to have more small glitches, whose values of ？？/？ are smaller than those in the standard starquake model（with larger amounts of released energy）. Based on the assumption that in our Galaxy the distribution of SNs is similar to that of dark matter, as well as on the glitch data in the ATNF Pulsar Catalogue and Jodrell Bank glitch table, we find that in our Galaxy the incidences of small glitches exhibit tendencies consistent with the collision rates between pulsars and SNs. Further testing of this scenario is expected by detecting more small glitches（e.g.,by the Square Kilometre Array）.

关键词： pulsars -- glitches -- quark-cluster stars -- strange nuggets

Performance evaluation for sustainability of wind energy project using improved multi-criteria decision-making method

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现代电力系统与清洁能源学报（英文） 2019年第5期7卷 1165-1176页

作者： Jiahui WU Haiyun WANG Weiqing WANG Qiang ZHANG College of Electrical Engineering Xinjiang UniversityUrumqi 830047China State Grid xinjiang Electric Power Research Institute Urumqi 830011China

Wind power can be an efficient way to alleviate energy shortage and environmental pollution,and to realize sustainable development in terms of energy *** sustainability assessment of a wind project among its alternatives is a complex task that cannot be solely simplified to environmental or economic *** requires the consideration of its technological and social aspects as well as other *** paper proposes a new method for selecting the most sustainable wind *** method is based on multi-criteria decision-making *** analytic hierarchy process and entropy weight method are combined to determine the weights of evaluation indexes,and an innovative index-weight optimization method based on the Lagrange conditional extremum *** fuzzy technique for order preference by similarity to the ideal solution is applied to rank wind project alternatives considering functionality and proportionality of the ***,the sensitive analysis is applied to verify the robustness of the proposed *** applicability of the method is demonstrated on a case study from China,where three main wind projects are analytically compared and *** results indicated that the sustainable level of calculated wind power can provide a reference point for the planning and operation of the wind *** results show that the proposed method is of both theoretical significance and practical application in engineering.

关键词： Analytic hierarchy process Comprehensive evaluation index Entropy method Fuzzy technique Order preference Wind power sustainability level

Aza-Michael addition reactions between nitroolefins and benzotriazole catalyzed by MCM-41 immobilized heteropoly acids in water

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Chinese Chemical Letters 2013年第1期24卷 28-30页

作者： Shao-Lei Xie Yong-Hai Hui Xiang-Ju Long Chang-Chun Wang Zheng-Feng Xie Key Laboratory of Oil & Gas Fine Chemicals Ministry of Education & Xinjiang Uyghur Autonomous RegionCollege of Chemistry and Chemical EngineeringXinjiang University

MCM-41 supported heteropoly acids （HPAs） catalysts were synthesized, characterized and their catalytic activity was evaluated in an aza-Michael addition reaction between nitroolefins and benzotriazole in water at room temperature. 50 wt% PW/MCM-41 showed the highest activity （up to 96% yield）. The catalyst was used in six consecutive experiments without obvious loss of activity, confirming the success of the anchoring process and the catalyst stability.

关键词： Aza-Michael additionMCM-41Heteropoly acidsHeterogenous catalysts

Directed Dominating Set Problem Studied by Cavity Method:Warning Propagation and Population Dynamics

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Communications in Theoretical Physics 2018年第12期69卷 785-794页

作者： Yusupjan Habibulla School of Physics and Technology Xinjiang University

The minimal dominating set for a digraph(directed graph) is a prototypical hard combinatorial optimization problem. In a previous paper, we studied this problem using the cavity method. Although we found a solution for a given graph that gives very good estimate of the minimal dominating size, we further developed the one step replica symmetry breaking theory to determine the ground state energy of the undirected minimal dominating set problem. The solution space for the undirected minimal dominating set problem exhibits both condensation transition and cluster transition on regular random graphs. We also developed the zero temperature survey propagation algorithm on undirected Erds-Rnyi graphs to find the ground state energy. In this paper we continue to develope the one step replica symmetry breaking theory to find the ground state energy for the directed minimal dominating set problem. We find the following.(i) The warning propagation equation can not converge when the connectivity is greater than the core percolation threshold value of 3.704. Positive edges have two types warning, but the negative edges have one.(ii) We determine the ground state energy and the transition point of the Erd?os-R′enyi random graph.(iii) The survey propagation decimation algorithm has good results comparable with the belief propagation decimation algorithm.

关键词： directed minimal dominating set replica symmetry breaking Erdos-Renyi graph warning propagation survey propagation decimation