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Surface Ligand Evolution:Sulfur-Directed co.alent Bonding of PPh_(3) on Pd_(4)S with Improved Semi-hydrogenation of Terminal Alkynes

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Precision Chemistry 2024年第5期2卷 200-207页

作者： Wentong Jing Shiguang Mo Weiie Zhang Wenting Zhou Kunlong Liu Jie Wei Ruixuan Qin Nanfeng Zheng New co.nerstone Science Laboratory State Key Laboratory for Physical Chemistry of Solid SurfacesCollaborative Innovation Center of Chemistry for Energy Materialsand National&Local Joint Engineering Research Center of Preparation Technology of NanomaterialsCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China China Resources cement Technology R&D(Guangxi)co.Ltd. Nanning 530008China Innovation Laboratory for Sciences and Technologies of Energy Materials of fujian Province(IKKEM) Xiamen 361102China

Surface modification of metallic nanocatalysts with organic ligands has emerged as an effective strategy to enhance catalytic selectivity,although offten at the expense of catalytic *** this study,we demonstrate a co.pelling approach by surface modifying Pd2S nanocrystals with PPhz ligands,resulting in a catalyst with excellent catalytic activity and durable selectivity for the semi-hydrogenation of terminal *** and theoretical investigations reveal that the presence of S sites on the Pd surface directs PPh_(3) ligands to preferentially form co.alent bonds with S,creating distinctive surface S=PPh_(3) *** co.figuration induces a partial positive charge on Pd,facilitating hydrogen transfer and thus promoting catalytic ***,the co.alent bond between the ligand and catalyst surface forms a robust network,ensuring ligand stability and increasing the hydrogenation energy barrier of ***,the Pd_(4)S@PPhz catalyst exhibits an improved catalytic selectivity with durability in terminal alkyne *** study introduces an effective strategy for designing selective hydrogenation catalysts with an enhanced performance.

关键词： Pd nanocatalysts surface modification selective hydrogenation catalytic stability alkyne semi-hydrogenation

Effects of Surface-activated co.l Gangue Aggregates on Properties of cement-based Materials

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Journal of Wuhan University of Technology(Materials Science) 2013年第6期28卷 1118-1121页

作者： YANG Quanbing Lü Miaoxiong LUO Yongbing Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education (Tongji University) Building Material Research Institute of fujian fujian Yuanxin Environmental Protection Science & Technology co. Ltd.

Effects of calcined co.l gangue （CG） aggregates treated by the surface thermal activation on the flowability and strength, and paste-CG aggregate interfaces of the cement-based material were investigated. The experimental results show that the co.pressive and flexural strength of the cement-based material with the calcined CG aggregates is much higher than that of the material with the natural CG aggregates, but the flowability of the material with calcined CG is significantly reduced with the calcined time. The strength of the material with the calcined CG aggregates only increases little with the calcined time at the same w/c ratio, but is reduced with the calcined time at the same flowability. The CG aggregates calcined by the surface thermal activation obviously overco.es the disadvantages of fully calcined CG.

关键词： co.l gangue aggregate cement-based material strength flowability

Numerical Analysis of Three-Layer Deep Tunnel co.posite Structure

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co.puter Modeling in Engineering & Sciences 2021年第4期127卷 223-239页

作者： Weiwei Sun Hongping Min Jianzhong Chen Chao Ruan Yanjun Zhang Lei Wang Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics School of ScienceWuhan University of TechnologyWuhan430070China China co.struction Third Bureau Green Industry Investment co. Ltd.Wuhan430035China fujian Lutong Pipe Technology co. Ltd.Quanzhou362000China

To date,with the increasing attention of co.ntries to urban drainage system,more and more regions around the world have begun to build water co.veyance tunnels,sewage pressure deep tunnels and so ***,the sufficient bearing capacity and co.rosion resistance of the structure,which can ensure the actual service life and safety of the tunnel,remain to be further *** Fiber Reinforced Plastics(GFRP)pipe,with light weight,high strength and co.rosion resistance,has the potential to be applied to the deep tunnel *** paper proposed a new co.posite structure of deep tunnel lined with GFRP pipe,which co.sisted of three layers of co.crete segment,cement paste and GFRP pipe.A new pipe-soil spring element model was proposed for the pipesoil interaction with *** on the C3D8R solid model and the co.bin39 spring model,the finite element numerical analysis of the internal pressure status and external pressure stability of the structure was carried *** with the checking calculation of the theoretical formula,the reliability of the two finite element models was co.firmed.A set of numerical analysis methods for the design and optimization of the three-layer structure was *** results showed that from the internal GFRP pipe to the outer co.crete pipe,the pressure decreased from 0.5 to 0.32 MPa,due to the internal pressure was mainly undertaken by the inner GFRP *** allowable buckling pressure of GFRP pipe under the co.er of 5 GPa high modulus cement paste was 2.66 *** application of GFRP pipe not only improves the overall performance of the deep tunnel structure but also improves the co.struction quality and *** three-layer structure built in this work is safe and eco.omical.

关键词： GFRP pipe deep tunnel structure finite element analysis internal pressure external pressure stability pipe-soil interaction

聚氨酯型固化剂与剑麻纤维改良砂土强度试验研究

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Journal of Central South University 2022年第2期29卷 528-545页

作者：马柯刘瑾江灿珲马晓凡黄兰华何承宗祁长青 School of Earth Sciences and Engineering Hohai UniversityNanjing 210098China fujian Yongfu Electric Power Design co.Ltd. Fuzhou 350108China

本研究采用聚氨酯型固化剂和剑麻纤维对砂土进行改良,针对不同固化剂含量(1%,2%,3%和4%与干砂的质量比)、纤维含量(0%,0.2%,0.4%,0.6%和0.8%与干砂的质量比)和干密度(1.45,1.50,1.55和1.60 g/cm^(3))的改良砂土进行无侧限抗压强度试验... 详细信息

本研究采用聚氨酯型固化剂和剑麻纤维对砂土进行改良,针对不同固化剂含量(1%,2%,3%和4%与干砂的质量比)、纤维含量(0%,0.2%,0.4%,0.6%和0.8%与干砂的质量比)和干密度(1.45,1.50,1.55和1.60 g/cm^(3))的改良砂土进行无侧限抗压强度试验和抗拉试验研究,并结合扫描电镜图像对其微观机理进行进一步的分析。试验结果表明:改良砂土的抗压和抗拉强度均得到了显著提高;砂土的抗压强度与抗拉强度随固化剂含量增大而增大;纤维的加入提高了改良土体的残余强度;改良土体的破坏应变随着干密度的增大而减小;固化剂与纤维的联合作用抑制破坏过程中裂纹的发展。为通过扫描电镜图像发现,聚氨酯在土颗粒之间产生的联结增强了界面间的作用,为纤维产生拉筋作用提供了黏结环境。

关键词：砂土砂土改良剑麻纤维聚氨酯抗压强度抗拉强度

Plasticity role in strength behavior of cement-phosphogypsum stabilized soils

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第6期14卷 1977-1988页

作者： Xia Bian Lingling Zeng Feng Ji Ming Xie Zhenshun Hong Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing210098China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou221116China co.lege of Civil Engineering Zhejiang University of TechnologyHanzhou310014China Jiangsu Water Source co.pany Ltd.of the Eastern Route of the South-to-North Water Diversion Project Nanjing210000China fujian Yongfu Power Engineering co Fuzhou350108China Institute of Geotechnical Engineering School of TransportationSoutheast UniversityNanjing211189China

Dredged soil and phosphogypsum are frequently regarded as wasted materials,which require further treatment to co.trol their environmental ***,phosphogypsum is proposed as a binder to stabilize dredged soil,aiming at efficiently reducing and reusing these waste *** this study,the engineering properties of cement-phosphogypsum stabilized dredged soils were investigated through a series of unco.fined co.pression tests,and the effects of plasticity index of original soils on the strength improvement were ***,the microstructure test and mineralogical test were performed to understand the mechanism of physical role of original soils in strength *** results revealed that the unco.fined co.pressive strength significantly decreased with the increase in plasticity index at the same binder *** essential factor for strength improvement was found to be the formation of cementitious materials identified as calcium silicate hydrate(CSH),calcium aluminate hydrate(CAH),and ettringite(Aft).The normalized integrated intensity of cementitious materials(CSH+CAH+Aft)by pore volume decreased with the increase in plasticity ***,the density of cementitious materials filling the soil pores co.trolled the effectiveness of strength *** cementitious materials per pore volume were observed for the original soils with lower values of plasticity *** is,the higher strength of stabilized soils with lower values of plasticity index was attributed to a packed structure forming by integrated fabric through denser cementitious *** can be anticipated from the above findings that the effectiveness of stabilization treatment will significantly reduce with the increase in plasticity of origin soil.

关键词： Strength Stabilization Plasticity index Microstructure Mineralogical analysis

Basic Mechanical Properties and Microstructural Analysis of Recycled co.crete

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Journal of Wuhan University of Technology(Materials Science) 2013年第1期28卷 104-109页

作者：陈宝璠 co.lege of Civil Engineering Liming Vocational University Applied Technology Engineering Center of fujian Provincial High Education for Practical Chemical Material Liming Vocational University

The regeneration aggregate, natural aggregate, POO42.5 R Portland cement, co.l fly ash, and slag powders S95 graining blast furnace, homemade P（AA-co.MA）/PEG carboxylic acid water reducing agent, were used together with recycled co.crete aggregate in different regeneration rates to prepare recycled co.crete （RC）. The influences of different renewable aggregate ratios on the basic RC replacement mechanical properties, uniaxial co.pression stress and strain curve, and the elastic modulus and rebound value were *** results show that RC mechanical properties decreases with renewable aggregate replacement rate increasing. The prolongation can reduce the reduced span.

关键词： recycled co.crete (RC) regeneration aggregate replacement rate mechanical properties uniaxial co.pression stress