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5-羟甲基糠醛在CuPd(111)上的加氢反应机理研究

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原子与分子物理学报 2025年第4期42卷 53-57页

作者：张兴云周广丽石云山东临沂大学化学化工学院临沂276000

采用密度泛函理论,利用包含零点能校正的PBE-D3方法研究了5-羟甲基糠醛在双金属催化剂CuPd(111)上表面的加氢还原反应,考虑了两种反应路径,第一种反应路径是侧链上的醛基氧首先发生加氢反应生成F-CHOH中间体,然后F-CHOH中间体继续加氢生... 详细信息

采用密度泛函理论,利用包含零点能校正的PBE-D3方法研究了5-羟甲基糠醛在双金属催化剂CuPd(111)上表面的加氢还原反应,考虑了两种反应路径,第一种反应路径是侧链上的醛基氧首先发生加氢反应生成F-CHOH中间体,然后F-CHOH中间体继续加氢生成2,5-二羟甲基呋喃;第二种反应路径是侧链上的醛基碳先加氢原还原生成F-CH_(2)O中间体,生成的F-CH_(2)O进一步加氢还原生成2,5-二羟甲基呋喃.计算了两种竞争反应路径的活化能垒和反应热,结果表明,5-羟甲基糠醛在CuPd(111)面加氢还原生成2,5-二羟甲基呋喃的最佳反应路径为:F-CHO→F-CHOH→F-CH_(2)OH.

关键词： 5-羟甲基糠醛活化能垒反应热

Design of Ti_(2)AlC/YSZ TBCs for more efficient in resisting CMAS attack

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Journal of Advanced Ceramics 2023年第9期12卷 1712-1730页

作者： Lei Guo Yanyan li guang li School of Materials Science and Engineering Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Advanced Joining Technology Key Lab of Advanced Ceramics and Machining TechnologyMinistry of EducationTianjin 300072China Shanghai Institute of Space Power-Sources Shanghai 200240China

Ti_(2)AlC has been demonstrated as the promising protective layer material for thermal barrier coatings(TBCs)against calcium-magnesium-alumina-silicate(CMAS)*** this study,the reliability of Ti_(2)AlC coatings against the CMAS corrosion was explored,and new Ti_(2)AlC/YSZ TBCs more efficiently resistant to CMAS were *** fabricated Ti_(2)AlC coatings inevitably contain some impurity phases(TiC and Al2Ti3),the contents of which were minimized by optimizing the spraying *** tests revealed that Ti_(2)AlC/YSZ TBCs yielded higher resistance to the CMAS attack than YSZ TBCs,but with long-term exposure to CMAS,the Ti_(2)AlC protective coating exhibited microstructure degradation due to the presence of the impurity phases,which caused the formation of a layer mixed with Al_(2)O_(3)and TiO_(2)rather than a continuous compact Al_(2)O_(3)layer on the ***-oxidation schemes were designed in air or with a controlled oxygen partial pressure,which revealed that the pre-oxidation at an oxygen partial pressure of~630 Pa could promote a continuous Al_(2)O_(3)layer formed on the Ti_(2)AlC protective coating ***,a vacuum heat treatment at 867℃for 10 h before pre-oxidation was beneficial for the formation of the compact Al_(2)O_(3)*** the above scheme design,new Ti_(2)AlC/YSZ TBCs were obtained,which had reduced impurity phase contents and a pre-oxide layer with an ideal structure on the *** TBCs exhibit higher microstructure stability exposed to CMAS and more efficient CMAS resistance.

关键词： thermal barrier coatings(TBCs) calcium-magnesium-alumina-silicate(CMAS) Ti_(2)AlC/YSZ pre-oxidation design corrosion resistance mechanisms

A Note on the Perturbations of Compact Quantum Metric Spaces

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Acta Mathematica Sinica,English Series 2016年第10期32卷 1214-1220页

作者： li guang WANG School of Mathematical Sciences Qufu Normal University

In this short note, we consider the perturbation of compact quantum metric spaces. We first show that for two compact quantum metric spaces （A, P） and （B, Q） for which A and B are subspaces of an order-unit space t and P and Q are lip-norms on A and B respectively, the quantum Gromov-Hausdorff distance between （A, P） and （B, Q） is small under certain conditions. Then some other perturbation results on compact quantum metric spaces derived from spectral triples are also given.

关键词： Compact quantum metric space quantum Gromov-Hausdorff distance C*-algebra lip-norm spectral triple

Semistability of Frobenius Direct Image of Representations of Cotangent Bundles

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Acta Mathematica Sinica,English Series 2018年第11期34卷 1677-1691页

作者： ling guang li School of Mathematical Sciences Tongji University

Let k be an algebraically closed field of characteristic p 〉 0, X a smooth projective variety over k with a fixed ample divisor H, FX：X → X the absolute Frobenius morphism on X. Let E be a rational GLn（k）-bundle on X, and ρ：GLn（k） → GLm（k） a rational GLn（k）-representation of degree at most d such that ρ maps the radical R（GLn（k）） of GLn（k） into the radical R（GLm（k）） of GLm（k）. We show that if FXN＊（E） is semistable for some integer N ≥ max0 〈 r 〈 m （rm） · logp（dr）, then the induced rational GLm（k）-bundle E（GLm（k）） is semistable. As an application, if dim X=n, we get a sufficient condition for the semistability of Frobenius direct image FX＊（ρ＊（ΩX1））, where ρ＊（ΩX1） is the vector bundle obtained from ΩX1 via the rational representation ρ.

关键词： Semistability principal bundle Probenius morphism cotangent bundle

On Maximal Abelian Self-adjoint Subalgebras of Factors of Type II_1

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Acta Mathematica Sinica,English Series 2005年第3期21卷 569-576页

作者： li guang WANG Institute of Mathematics Chinese Academy of Sciences Beijing 100080 P. R. China Department of Mathematics Qufu Normal University Qufu 273165 P. R. China

In this note, we show that if N is a proper subfactor of a factor M of type Ⅱ1 with finite Jones index, then there is a maximal abelian self-adjoint subalgebra （masa） A of N that is not a masa in ,M. Popa showed that there is a proper subfactor R0 of the hyperfinite type Ⅱ1 factor R such that each masa in R0 is also a masa in R. We shall give a detailed proof of Popa＇s result.

关键词： Maximal abelian self-adjoint subalgebra Index Von Neumann algebra Factor,Conditional expectation

Nuclear Parton Distribution

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Chinese Physics Letters 1996年第7期13卷 508-511页

作者： XUE Da-li li guang-lie Institute of High Energy Physics Chinese Academy of SciencesBeijing 100039 CCAST(World Laboratory) Beijing 1000803 Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100080

The quark and gluon distributions in nuclei are investigated by a parton model,where the common partons of several nucleons and the non-nucleonic components are *** comparisons of this model with the data for F_(2)^(A... 详细信息

关键词： quark nucleon

Effects of surface roughness on CMAS corrosion behavior for thermal barrier coating applications

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Journal of Advanced Ceramics 2021年第3期10卷 472-481页

作者： Lei GUO guang li Zhilin GAN School of Materials Science and Engineering Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Advanced Joining Technology Key Lab of Advanced Ceramics and Machining Technology of Ministry of EducationTianjin 300072China

Calcium-magnesium-alumina-silicate (CMAS) corrosion is an important cause for thermal barrier coating (TBC) failure,which has attracted increased *** this study,some thermal barrier coating (TBC) materials including YSZ (yttria partially stabilized zirconia),GdPO_(4),and LaPO_(4) were prepared into bulks,and the effects of their surface roughness on wettability and spreading characteristics of molten CMAS were ***-fabricated and polished bulks with different surface roughness were exposed to CMAS corrosion at 1250 ℃ for 1 and 4 h,following by macro and micro *** revealed that compared with the as-fabricated bulks,molten CMAS on the polished samples had lower wettability and a smaller spreading area,mainly attributable to the reduced capillary force to drive the melt ***,GdPO_(4) and LaPO_(4) bulks exhibited lower CMAS wettability than YSZ *** is thus considered that reducing the surface roughness is beneficial to CMAS corrosion resistance of TBCs.

关键词： thermal barrier coating(TBC) calcium-magnesium-alumina-silicate(CMAS) surface roughness wetting spreading

Magnesium isotope geochemistry of the carbonate-silicate system in subduction zones

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National Science Review 2022年第6期9卷 23-33页

作者： Shui-Jiong Wang Shu-guang li State Key Laboratory of Geological Processes and Mineral Resources and Institute of Earth SciencesChina University of Geosciences (Beijing) CAS Key Laboratory of Crust-Mantle Materials and Environments School of Earth and Space SciencesUniversity of Science and Technology of China

The lighter magnesium(Mg) isotopic signatures observed in intraplate basalts are commonly thought to result from deep carbonate recycling, provided that the sharp difference in Mg isotopic composition between surface carbonates and the normal mantle is preserved during plate subduction. However, deep subduction of carbonates and silicates could potentially fractionate Mg isotopes and change their chemical compositions. Subducting silicate rocks that experience metamorphic dehydration lose a small amount of Mg, and preserve the original Mg isotopic signature of their protoliths. When the dehydrated fluids dissolve carbonate minerals, they may evolve into lighter Mg isotopic compositions. The solubility of carbonate minerals in fluids decreases in the order of calcite, aragonite, dolomite, magnesite and siderite, leading to selective and partial dissolution of carbonate minerals along the subduction path. At the island arc depth(70–120 km), the metamorphic fluid dissolves mainly Mg-poor calcites, and thus the fluid has difficulty modifying the Mg isotopic system of the mantle wedge and associated arc basalts. At the greater depth of the back arc system or continental margin(>150 km), the supercritical fluid can dissolve Mg-rich carbonate minerals, and its interaction with the mantle wedge could significantly imprint the light Mg isotopic signature onto the mantle rocks and derivatives. Meanwhile, the carbonate and silicate remaining within the subducting slab could experience elemental and isotopic exchange, during which the silicate can obtain a light Mg isotopic signature and high CaO/Al2O3, whereas the carbonates, particularly the Ca-rich limestone, shift Mg isotopes and Mg O contents towards higher values. If this isotopic and elemental exchange event occurs widely during crustal subduction, subducted Ca-rich carbonates can partially transform into being Mg-rich, and a portion of recycled silicates(e.g. carbonated eclogites) can have light Mg isotopic composition

关键词： magnesium isotope fractionation deep carbon cycle subduction carbonate

Correction of the Directional Correlation of Oriented Nuclei for Detector Efficiency

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Chinese Physics Letters 1999年第11期16卷 796-797页

作者： li guang-sheng China Institute of Atomic Energy Beijing 102413

Correction of the directional correlation of oriented nuclei for detector efficiency has been investigated by using in-beam γ-ray spectroscopic method. The result indicates that this correction is quite necessary for the low-energy γ-rays. On the basis of the corrected directional correlation of oriented nuclei ratios the spin assignment of the new rotational band for 170Hf was yielded.

关键词： method. directional correction