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Science China Chemistry 2025年

作者： Shiguo Fu Xiaofeng Zhang Kaixuan Wang Linfeng Chen Fan Xia Yong cui Yan Liu School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative Molecules and State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University Faculty of Materials Science and Chemistry China University of Geosciences

Enantioselective separations of racemates using porous materials are highly attractive and significant in both fundamental research and technological applications. However, achieving controlled chiral pore surfaces to create the necessary driving force for enantiomer discrimination poses a fundamental challenge. Herein, we demonstrate that chiral covalent organic frameworks(COFs) possess the essential characteristics for effective enantioseparations through synthetic control over pore surfaces. We synthesized three 3D chiral COFs (CCOFs) featuring abundant chiral recognition sites on the pore walls via the condensation of enantiopure dialdehyde of 2,2′-dihydroxy-1,1′-binaphthyl and tetraamine. All CCOFs with high stability exhibit an 11-fold interpenetrated framework with tubular open channels, decorated with dihydroxyl or diethoxyl groups. The CCOFs with dihydroxyl groups serve as solid adsorbents for the adsorptive separation and solid-phase extraction of various chiral 1-phenylethanol-derived enantiomers, particularly racemic drugs, achieving up to 98%enantiomeric excess. In contrast, the CCOF with diethoxy groups is unable to resolve the racemates. These CCOF materials can be recycled and reused without any apparent loss of performance. Density functional theory (DFT) calculations reveal that the enantiospecific recognition arises from the well-organized chiral inner sphere and multiple chiral host-guest interactions.

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Heterogeneity of mature oligodendrocytes in the central nervous system

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Neural Regeneration Research 2025年第5期20卷 1336-1349页

作者： Chao Weng Adam M.R.Groh Moein Yaqubi Qiao-Ling cui Jo Anne Stratton G.R.Wayne Moore Jack P.Antel Neuroimmunology Unit Montreal Neurological Institute-HospitalDepartment of Neurology and NeurosurgeryMcGill UniversityMontrealQCCanada Department of Neurology Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina

Mature oligodendrocytes form myelin sheaths that are crucial for the insulation of axons and efficient signal transmission in the central nervous *** evidence has challenged the classical view of the functionally static mature oligodendrocyte and revealed a gamut of dynamic functions such as the ability to modulate neuronal circuitry and provide metabolic support to *** the recognition of potential heterogeneity in mature oligodendrocyte function,a comprehensive summary of mature oligodendrocyte diversity is *** delve into early 20th-century studies by Robertson and Río-Hortega that laid the foundation for the modern identification of regional and morphological heterogeneity in mature ***,recent morphologic and functional studies call into question the long-assumed homogeneity of mature oligodendrocyte function through the identification of distinct subtypes with varying myelination ***,modern molecular investigations,employing techniques such as single cell/nucleus RNA sequencing,consistently unveil at least six mature oligodendrocyte subpopulations in the human central nervous system that are highly transcriptomically diverse and vary with central nervous system *** and disease related mature oligodendrocyte variation denotes the impact of pathological conditions such as multiple sclerosis,Alzheimer's disease,and psychiatric ***,caution is warranted when subclassifying mature oligodendrocytes because of the simplification needed to make conclusions about cell identity from temporally confined *** studies leveraging advanced techniques like spatial transcriptomics and single-cell proteomics promise a more nuanced understanding of mature oligodendrocyte *** research avenues that precisely evaluate mature oligodendrocyte heterogeneity with care to understand the mitigating influence of species,sex,central nervous system region,age,and disease,

关键词： aging central nervous system diseases electron microscopy heterogeneity immunohistochemistry myelin sheath natural history neuroglia oligodendroglia single-cell gene expression analysis

Perovskite LiBaH3 for photo-assisted dinitrogen fixation

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Science China Chemistry 2025年

作者： Kaixun cui Yeqin Guan Yongli Cai Runze Wang Qianru Wang Wenbo Gao Jianping Guo Ping Chen Department of Chemical Physics University of Science and Technology of China Dalian Institute of Chemical Physics Chinese Academy of Sciences Center of Materials and Optoelectronics Engineering University of Chinese Academy of Sciences

Establishing supply chains for future ammonia energy systems requires the development of efficient materials and processes for ammonia production under mild conditions. Recent researches disclose unique functionalities of binary alkali and alkaline earth metal hydrides in mediating ammonia synthesis. Thanks to the rich compositional and structural properties of the metalhydrogen system, we herein report that LiBaH3, as a narrow band gap perovskite hydride, exhibits a strong response to visible light illumination. Specifically, hydridic hydrogen undergoes reductive elimination of producing H2and creates an electron-rich surface. Such an environment favors dinitrogen fixation to form N–H bonds. Based on this chemical property, a chemical looping ammonia synthesis process mediated by LiBaH3and driven by both photo and thermal energies was proposed and *** work demonstrates that hydride perovskites are promising candidates for mediating photo-assisted nitrogen fixation reactions.

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Hydrothermal Synthesis and Crystal Structure of a Novel Isophthalate-bridged Copper(II) Polymer with Two-dimensional Network Structure: [Cu_2(phen)(ipt)_2]_(2n)·nH_2O (ipt = isophthalate, phen = 1,10-phenanthroline)

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Chinese Journal of Structural Chemistry 2005年第12期24卷 1411-1415页

作者： cui Yun-Cheng LI Xiu-Mei LI Chuan-bi WANG Qing-Wei LIU Bo LI Guo-feng Jilin Normal University Siping Jilin 136000 China Department of Chemistry Tonghua Teachers college Tonghua Jilin 134002 China

A novel metal-organic coordination polymer [Cu2（phen）（ipt）2]2n-nH2O 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P21/c with a = 12.338（3）, b = 12.167（3）, c = 18.167（4）A, β= 111.686（14）°, V = 2534.1（10）A^3, C28H18Cu2N2O9, Mr = 653.52, Dc = 1.713 g/cm^3,μ（MoKα） = 1.740 mm^-1, F（000） = 1320, Z = 4, the final R = 0.0443 and wR = 0.0853 for 3543 observed reflections （1 〉 2σ（I））. It exhibits a novel two-dimensional network with tetra-Cu-ipt-as building units.

关键词： isophthalate coordination polymer hydrothermal synthesis crystal structure

RCV-based error density estimation in the ultrahigh dimensional additive model

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Science China Mathematics 2022年第5期65卷 1003-1028页

作者： feng Zou Hengjian cui School of Mathematical Sciences Capital Normal UniversityBeijing 100048China

In this paper,we mainly study how to estimate the error density in the ultrahigh dimensional sparse additive model,where the number of variables is larger than the sample ***,a smoothing method based on B-splines is applied to the estimation of regression ***,an improved two-stage refitted crossvalidation(RCV)procedure by random splitting technique is used to obtain the residuals of the model,and then the residual-based kernel method is applied to estimate the error density *** suitable sparse conditions,the large sample properties of the estimator,including the weak and strong consistency,as well as normality and the law of the iterated logarithm,are ***,the relationship between the sparsity and the convergence rate of the kernel density estimator is *** methodology is illustrated by simulations and a real data example,which suggests that the proposed method performs well.

关键词： ultrahigh dimensional additive model B-spline kernel density estimation refitted cross-validation method asymptotic property

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基于Fluent的复合沉淀池处理性能研究

河南城建学院学报 2020年第5期29卷 75-80页

作者：宿显瑞栗军生闫秋霞何路兴席航崔弼峰河南省第二建设集团有限公司河南郑州451464 河南碧之霄检测技术有限公司河南郑州450000 河南城建学院市政与环境工程学院河南平顶山467036

为进一步提高实验效率并提升复合沉淀池的处理效能,利用Solidworks软件对沉淀池进行二维建模,将建好的模型导入计算流体力学软件Fluent,并对不同工况下的沉淀池运行状况进行数值模拟。研究结果表明:当挡板深度为2 m时,复合沉淀池沉淀区... 详细信息

为进一步提高实验效率并提升复合沉淀池的处理效能,利用Solidworks软件对沉淀池进行二维建模,将建好的模型导入计算流体力学软件Fluent,并对不同工况下的沉淀池运行状况进行数值模拟。研究结果表明:当挡板深度为2 m时,复合沉淀池沉淀区域的流速最小,沉淀效能最好;基于Fluent软件的数值模拟模型可较好地完成沉淀池模拟实验。

关键词：计算流体力学复合沉淀池数值模拟 Fluent软件

Variation operators for singular integrals and their commutators on weighted Morrey spaces and Sobolev spaces

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Science China Mathematics 2022年第6期65卷 1267-1292页

作者： feng Liu Peng cui College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

In this paper,we investigate the boundedness and compactness for variation operators of CalderónZygmund singular integrals and their commutators on weighted Morrey spaces and Sobolev *** be precise,letρ>2 and K be a standard Calderón-Zygmund *** by V_(ρ)(T_(K))and V_(ρ)(T_(K,b)^(m))(m≥1)theρ-variation operators of Calderón-Zygmund singular integrals and their m-th iterated commutators,*** assuming that V_(ρ)(T_(K))satisfies an a priori estimate,i.e.,the map V_(ρ)(T_(K)):L^(p0)(R^(n))→L^(p0)(R^(n))is bounded for some p0∈(1,∞),the bounds for V_(ρ)(T_(K))and V_(ρ)(T_(K,b)^(m))on weighted Morrey spaces and Sobolev spaces are ***,the compactness properties of V_(ρ)(T_(K,b)^(m))on weighted Lebesgue and Morrey spaces are also *** applications,the corresponding results for the Hilbert transform,the Hermite Riesz transform,Riesz transforms and rough singular integrals as well as their commutators on the above function spaces are presented.

关键词： variation operator Calderón-Zygmund singular integral commutator weighted Morrey space Sobolev space

Effects of Ti-and Nb-based transition element from single to multiple compound oxides and carbon-based composite additives on Mg-MgH2 hydrogen storage material

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Tungsten 2025年第1期7卷 32-49页

作者： Li-Rong Xiao Chen Chen Shuo Wang Zi-Yin Dai Hideo Kimura cui Ni Chuan-Xin Hou Xue-Qin Sun Si-Jie Guo Wei Du Xiu-Bo Xie School of Environmental and Material Engineering Yantai University Bosch HUAYU Steering Systems (Yantai) Co. Ltd.Ytp/MFE University of Tennessee Knoxville Shandong Key Laboratory of Eco-Environmental Science for the Yellow River Delta Shandong University of Aeronautics

MgH2is considered as a promising hydrogen storage material for its high hydrogen storage capacity,low cost and abundant resource ***,the low kinetics and high enthalpy formation of MgH2limit its wide *** the perspective of adding catalysts to enhance the hydrogen storage properties of Mg-MgH2,this article elaborated the main catalysts based on Ti and Nb transition elements,including single oxide catalysts,binary oxides catalysts（combined with Ni,Na,Sr,V,etc.）,multiple catalysts bound to carbon,and composite catalysts with Ti and Nb elements combined with MXene ***,the main pathways of various catalysts to reduce the reaction activity and broaden the hydrogen desorption channel were also *** Ti-based catalysts can enhance the reactive sites of the matrix by forming multivalent states,while Nb-based catalysts broaden the hydrogen reaction channels by forming tiny *** improving the size structure and enhancing the grain size stability,combined with carbon materials should be the future considerations.

关键词： Catalysts Mg-based hydrogen storage alloys Solid hydrogen storage Transition metal elements

Sulphate attack resistance of high-performance concrete under compressive loading

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第7期14卷 459-468页

作者： Hui XU Yu-xi ZHAO Lei cui bi XU Institute of Structural Engineering Zhejiang University School of Civil Engineering Newcastle University CCCC Tianjin Dredging Co. Ltd.

In this paper, an experimental study on the sulphate attack resistance of high-performance concrete (HPC) with two different water-to-binder ratios (w/b) under compressive loading is presented. The sulphate concentration, compressive strength, and the mass change in the HPC specimens were determined for immersion in a Na2SO4 solution over different durations under external compressive loading by self-regulating loading equipment. The effects of the compressive stress, the w/b ratio, and the Na2SO4 solution concentration on the HPC sulphate attack resistance under compressive loading were analysed. The results showed that the HPC sulphate attack resistance under compressive loading was closely related to the stress level, the w/b ratio, and the Na2SO4 solution concentration. Applying a 0.3 stress ratio for the compressive loading or reducing the w/b ratio clearly improved the HPC sulphate attack resistance, whereas applying a 0.6 stress ratio for the compressive loading or exposing the HPC to a more concentrated Na2SO4 solution accelerated the sulphate attack and HPC deterioration.

关键词： Sulphate attack resistance High-performance concrete (HPC) Compressive loading

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多量子阱红外探测器垂直光耦合研究

微细加工技术 2008年第3期 10-12,64页

作者：马楠邓军牟明威史衍丽崔碧峰张蕾沈光地北京工业大学光电子实验室北京100022 吉林大学长春130012 昆明物理所昆明650223

对多量子阱红外探测器制作中GaAs衬底减薄工艺程序进行了研究与讨论。通过将器件压焊封装进杜瓦瓶中,测量其室温和低温条件下I-V特性,以及在低温条件下的器件信噪比,并以傅里叶变换红外光谱仪对器件进行光谱测量,得到光电流谱,从而比较... 详细信息

对多量子阱红外探测器制作中GaAs衬底减薄工艺程序进行了研究与讨论。通过将器件压焊封装进杜瓦瓶中,测量其室温和低温条件下I-V特性,以及在低温条件下的器件信噪比,并以傅里叶变换红外光谱仪对器件进行光谱测量,得到光电流谱,从而比较了将器件衬底磨45°斜角的边耦合情况,以及直接将衬底减薄至(29±2)μm两种情况下器件的性能。并讨论了减薄材料在垂直入射情况下仍能引起器件光吸收的主要原因。结果表明,由于GaAs材料的各向异性,湿法腐蚀会使器件台面形成正梯形和倒梯形结构,其作用等同于器件磨至45°斜角,因此在垂直入射时器件也会有光电流产生。此外,在衬底进行减薄抛光后,衬底会有很小的起伏,这也可能引起光耦合,从而产生光电流。

关键词：多量子阱红外衬底减薄光耦合