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Active oxygen center in oxidative coupling of methane on La_(2)O_(3) catalyst

Journal of energy Chemistry 2021年第9期30卷 649-659页

作者： Xiaohong Zhou Yaoqi Pang Zebang Liu evgeny I.Vovk Alexander Pvan Bavel Shenggang Li Yong yang School of Physical Science and Technology Shanghai Tech UniversityShanghai 201210China Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shell Technology Centre Amsterdam P.O.Box 380001030 BN AmsterdamNetherlands CAS Key Laboratory of Low-Carbon Conversion Science and engineering Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201210China

La_(2)O_(3) catalyzed oxidative coupling of methane(OCM) is a promising process that converts methane directly to valuable C_(2)(ethylene and ethane) products. Our online MS transient study results indicate that pristine surface without carbonate species demonstrates a higher selectivity to C_(2) products, and a lower light-off temperature as well. Further study is focused on carbonate-free La_(2)O_(3) catalyst surface for identification of active oxygen species associated with such products behavior. XPS reveals unique oxygen species with O 1 s binding energy of 531.5 e V correlated with OCM catalytic activity and carbonates removal. However, indicated thermal stability of this species is much higher than the surface peroxide or superoxide structures proposed by earlier computation models. Motivated by experimental results,DFT calculations reveal a new more stable peroxide structure, formed at the subsurface hexacoordinate lattice oxygen sites, with energy 2.18 e V lower than the previous models. The new model of subsurface peroxide provides a perspective for understanding of methyl radicals formation and C_(2) products selectivity in OCM over La_(2)O_(3) catalyst.

关键词： In-situ XPS Online MS DFT Oxidative coupling of methane High C_(2)selectivity Active oxygen center La_(2)O_(3)catalyst

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In silico design of anti-tumor mini-protein targeting MDM2

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Chinese Chemical Letters 2023年第5期34卷 256-258页

作者： Jinghui Zhang Huixin Xu Baishi Wang Xuekai Zhang Lei Fu Yannan Li Guanzhao Wu Zitong Zhao Lu Liu Ting yang Zheyu Zhang Jinbo yang Tao Jiang Peiju Qiu Rilei Yu Key Laboratory of Marine Drugs Chinese Ministry of EducationSchool of Medicine and PharmacyOcean University of ChinaQingdao 266003China Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology Qingdao 266237China Innovation Center for Marine Drug Screening&evaluation Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao 266003China Department of Biological engineering College of Chemical and Biological EngineeringShandong University of Science and TechnologyQingdao 266590China

We designed a disulfide-crosslinked mini-protein with a two-helical topology consisting of L-and Damino acids,which was exceptionally stable in ***,we further used it as a scaffold to design mini-proteins targeting p53 positive tumor *** on bifunctional grafting,key residues from the transactivation domain of p53 and a designed unnatural amino acid were grafted into the helix constituted by L-amino acids to confer the mini-protein with MDM2 inhibitory ***,ten Arg residues were introduced to improve its membrane penetrating *** the mini-proteins,UPROL-10e showed nano-molar binding affinity on MDM2 and cellular toxicity on p53 expressing HCT116cells.

关键词： Protein design Antitumor agents In silico design Constrained peptide epitope grafting

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Three new species of Anthomedusae(Hydrozoa:Hydroidomedusa) from the Guangdong coastal water, China

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Acta Oceanologica Sinica 2020年第4期39卷 84-88页

作者： Caixue Zhang Jiaqi Huang Shengli Sun Sheng Ke Guohuan yang Zhiguang Song Yaoqian Liu College of Chemistry and environmental Sciences Guangdong Ocean UniversityZhanjiang 524088China College of Ocean and earth Sciences Xiamen UniversityXiamen 361005China

The samples of Anthomedusae were collected from the Guangdong coastal water,*** new species of Anthomedusae,*** condensum Huang,Zhang et Sun,***.,Hydractinia leizhouensis Huang,Zhang et yang,***.,and Cladosarsia simpl... 详细信息

关键词： Anthomedusae Australomedusidae Hydractiniidae Corynidae new species China

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土地退化和荒漠化防治领域国际标准化现状与思考

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中国水土保持科学 2020年第6期18卷 147-152页

作者：崔向慧却晓娥杨柳中国林业科学研究院荒漠化研究所北京100091 全国防沙治沙标准化技术委员会北京100091

土地退化和荒漠化是影响人类生存和发展的全球重大生态问题,研究制订相关国际标准并加以推广应用,有助于全球、国家和区域层面土地退化和荒漠化防治工作的有序高效开展。首先概述目前全球土地退化和荒漠化现状及发展趋势,然后综述土地... 详细信息

土地退化和荒漠化是影响人类生存和发展的全球重大生态问题,研究制订相关国际标准并加以推广应用,有助于全球、国家和区域层面土地退化和荒漠化防治工作的有序高效开展。首先概述目前全球土地退化和荒漠化现状及发展趋势,然后综述土地退化和荒漠化防治领域国际标准化现状和国际标准化组织在该领域的工作进程,从实现全球“土地退化零增长”目标、履行国际公约等方面分析开展该领域国际标准工作的必要性,最后基于国际需求和中国的优势,提出我国完善标准体系、培养标准人才、服务“一带一路”倡议、提出国际标准提案以及提升国际影响力等推进国际标准化工作的举措,以及申请依托中国设立秘书处,成立国际标准化组织土地退化和荒漠化防治技术委员会(LDC-TC)的设想和工作方案,包括技术委员会的业务范围、工作机制和内容以及总体目标等。

关键词：土地退化和荒漠化标准化现状国际标准化组织

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Natural regeneration responses to thinning and burning treatments in ponderosa pine forests and implications for restoration

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Journal of Forestry Research 2022年第3期33卷 741-753页

作者： Tzeidle N.Wasserman Amy e.M.Waltz John Paul Roccaforte Judith D.Springer Joseph e.Crouse ecological Restoration Institute Northern Arizona UniversityP.O.Box 15017FlagstaffAZ86011-5017USA

Understanding naturally occurring pine regeneration dynamics in response to thinning and burning treatments is necessary not only to measure the longevity of the restoration or fuels treatment,but also to assess how well regeneration meets forest sustainability guidelines and whether natural regeneration is sufficient for maintaining a sustainable forest structure and composition.A synthesis review was carried out on the effects of mechanical thinning and prescribed burn treatments on natural pine regeneration response in frequent-fire ponderosa pine forests across the western United *** focus was on site-specific variability in pine regeneration dynamics,temporal trends in regeneration presence and abundance,and response to treatment as described in the current literature using 29 studies that met our evidence-based review *** showed that the effects of thinning and burning treatments on regeneration depended on time since *** thinning,prescribed burning,and thinning plus burn treatments all increased seedling density,but there was high variability among sites and *** were mixed results in the short-term(ears)with both increasing and decreasing regeneration,and a general increase in regeneration 11−20 years *** long-term studies(>20 years)concluded that stands can return to pre-treatment densities in terms of total trees per hectare and forest floor duff levels when there are no maintenance treatments *** studies showed the average ponderosa pine seedling presence,survival and growth found in today’s forests to be at a high density;this combined with missed fire cycles could contribute to future fire risk and reduce the efficacy of maintaining fuel reduction goals.

关键词： Regeneration Ponderosa pine Frequent-fire Treatments Thinning Burning

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Upward Molten Flow for Optimization of Fluid Flow in Continuous Casting Tundish

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Journal of Iron and Steel Research International 2010年第11期17卷 29-33页

作者： A R Alaei H edris e Shirani Department of Materials engineering Isfahan University of Technology Department of Mechanical engineering Isfahan University of Technology

Fluid flow pattern and buoyancy force support the motion of nonmetallic inclusions toward thetundish slag. Upward molten flow was investigated. To understand the fundamentals of the process, physical modelling was carried out with the utilization of a 1 ： 4 scale model. Numerical modelling was carried out in line with the physicai modelling to examine details of the flow pattern and rotational effect caused by the upward flow with the Commercial CFD （Computational Fluid Dynamics） package environment, FLUeNT. The two-equation κ-ε model was used to simulate the turbulence. Multiphase fluid flow was numerically simulated by using the Volume of Fluid （VoF） method. The simulation can predict free surface waves and other phenomena, which can be used to optimize these important metallurgical operations.

关键词： upward flow continuous casting tundish numerical model water model

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Different Routes to the Pore engineering of Spherical MCM-41

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Journal of Wuhan University of Technology(Materials Science) 2003年第2期18卷 1-5页

作者：刘世权 e F Vansant University of Antwerp (Belgium)

Different routes,including the replacements of the template,addition of pore expander and hydrothermal post-synthesis treatment have been used for the pore engineering of spherical MCM-41.A comparison among the pore engineering effects of these methods has been *** results show that the hydrothermal post-synthesis treatment affords the synthesized material with a larger pore size and narrow pore size distribution without changing the spherical *** far as the pore-size expansion is concerned,the addition of DMTA is the most effective one,but this might be limited by the spherical *** the replacement of C 16TMABr with the Gemini surfactant GeM 16-8-16 with an addition of DMTA gives rise to the largest pore volume and surface area.

关键词： spherical MCM-41 pore engineering pore expander post-synthesis treatment Gemini surfactant

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Different noncollinear magnetizations on two edges of zigzag graphene nanoribbons

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Chinese Physics B 2020年第12期29卷 424-428页

作者： yang Xiao Qiaoli Ye Jintao Liang Xiaohong Yan Ying Zhang College of Science Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Material Science and engineering Jiangsu UniversityZhenjiang 212013China

Based on density functional theory and non-equilibrium Green’s function method,we studied noncollinear magnetism and spin transport in a 180°domain wall made of zigzag graphene nanoribbon(ZGNR)with different noncollinear magnetic profiles on the top and bottom *** results show that a helical domain wall on the top(bottom)edge and an abrupt domain wall on the bottom(top)edge can survive in the *** indicates that such characteristic magnetization distribution can be obtained by some means,e.g.,the introduction of impurity on one *** to a wide ZGNR,a narrow ZGNR presents obvious coupling between the two edges which changes the magnetization and transmission *** for the above-mentioned distinct magnetic profile,the spin transport is blocked in the abrupt domain wall due to strong spin flip scattering while remains unaffected in the helical domain wall due to the spin mixing *** deduce a formula of the transmission for various magnetic profiles of the ZGNRs.A new result based on this formula is that the transmission at the Fermi level can be zero,one,and two by tuning the edge *** results provide insights into the noncollinear spin transport of the ZGNR-based devices.

关键词： graphene nanoribbon spintronic transport density functional theory nonequilibrium Green’s function

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efficient synthesis of fused pyrazoles via simple cyclization of o-alkynylchalcones with hydrazine

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Chinese Chemical Letters 2015年第5期26卷 623-626页

作者： Ying Li Chun-e.Dong Key Laboratory of Combinatorial Biosynthesis and Drug Discovery Wuhan UniversityMinistry of Education Wuhan University School of Pharmaceutical Sciences

The synthesis of pyrazole derivatives from o-alkynylchalcones and hydrazine via simple cyclization is described. This greener synthetic methodology provides a straightforward approach to the synthesis of a variety of ... 详细信息

关键词： Pyrazole o-Alkynylchalcones Hydrazine Cyclization

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Heterojunction architecture of Nb_(2)O_(5)/g-C_(3)N_(4)for enhancing photocatalytic activity to degrade organic pollutants and deactivate bacteria in water

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Chinese Chemical Letters 2022年第8期33卷 3792-3796页

作者： Xudong yang Jun Duan Xian Zhang Hongyu Zhang Xinlei Liu Yueqi Feng Maosheng Zheng The Key Laboratory of Resources and environmental System Optimization Ministry of EducationCollege of Environmental Science and EngineeringNorth China Electric Power UniversityBeijing 102206China The Key Laboratory of Water and Sediment Science Ministry of EducationCollege of Environment Science and EngineeringPeking UniversityBeijing 100871China

Water pollution has become a serious problem owing to the development of *** is a promising approach to remove various pollutants in water,such as organic pollutants and antibiotic resistance ***,the design of heterojunction between two semiconductors is an effective path to improve photocatalytic properties due to its potential in improving separation and transfer of photoinduced *** this study,Nb_(2)O_(5)/g-C_(3)N_(4)(NO/CN)composite materials were prepared through a one-step heating *** confirmed successful preparation of NO/CN heterojunction structure and better optical properties than pure g-C_(3)N_(4) and Nb_(2)O_(5).NO/CN composite materials showed excellent photocatalytic efficiency for escherichia coli(***)inactivation(95%)compared with the pure Nb_(2)O_(5)(10%) and g-C_(3)N_(4)(77%).Meanwhile,NO/CN exhibited better organic pollutants removal(Rh B for94%,methyl orange(MO)for 15%and methylene blue(MB)for 87%)under visible light,which is likely owing to the heterojunction structure between g-C_(3)N_(4) and Nb_(2)O_(5) that leads to the good separation of photogenerated electron-hole *** radical scavenging and electron spin resonance(eSR)experiments demonstrated that superoxide radicals(·O_(2)^(-)) and holes(h^(+)) were the dominant ***,the NO/CN was proposed to be a promising material for effective disinfection and removal of organic contaminants in water treatment.

关键词： Graphitic carbon nitride Niobium pentoxide Photocatalysis escherichia coli disinfection Dyes removal

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