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A new 28-Ni-added poly(polyoxometalate)with B atoms:synthesis,structure and catalysis for Knoevenagel condensation

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Science China Chemistry 2023年第5期66卷 1394-1399页

作者： Chen lian Hai-lou li Guo-Yu Yang Key Laboratory of Cluster Science of Ministry of Educaiton School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing102488China

The synergistic effect of trivacant B-α-Ge W_(9)O_(34)fragments as structure-directing agents and inorganic B-O segments as intramolecular decoration afforded an unprecedented 28-Ni-added huge cluster K_(2)Na_(14)H_(10)[{Ni_(6)(OH)_(3)(H_(2)O)_(6)(Ge W_(9)O_(34))}{Ni_(8)-(μ_(6)-O)(OH)_(3)(H_(2)O)(BO(OH)_(2))(B_(2)O_(3)(OH)_(2))(Ge W_(9)O_(34))_(2)}]_(2)·46H_(2)O(1)under hydrothermal *** polyoxoanion of 1contains two half-units,[{Ni_(6)(OH)_(3)(H_(2)O)_(6)(Ge W_(9)O_(34))}{Ni_(8)(μ_(6)-O)(OH)_(3)(H_(2)O)(BO(OH)_(2))(B_(2)O_(3)(OH)_(2))(Ge W_(9)O_(34))_(2)}]^(13-),which joined together via Ni-O=W *** most fascinating feature is that each half-unit can be regarded as the fusion of an Ni_(6)(OH)_(3)(H_(2)O)_(6)(B-α-Ge W_(9)O_(34))({Ni_6Ge W_(9)})and a previously unobserved sandwiched Ni_(8)(μ_(6)-O)(OH)_(3)(H_(2)O)(BO(OH)_(2))(B_(2)O_(3)-(OH)_(2))(B-α-Ge W_(9)O_(34))_(2)({(Ni_(8)BB_(2))@(Ge W_(9))_(2)}),in which the{Ni_(8)BB_(2)}cluster contains a lindqvist-type{Ni_(6)}core capped by two Ni O_(6)octahedra and further decorated by a BO(OH)_(2)({B})group and a binuclear B_(2)O_(3)(OH)_(2)({B_(2)})***,1 as a heterogeneous catalyst,has good catalytic activity for Knoevenagel condensation under mild reaction conditions.

关键词： polyoxometalate hydrothermal synthesis high-nuclearity TMAPs knoevenagel condensation

A ring-shaped 12-Ti-substituted poly(polyoxometalate):synthesis,structure,and catalytic properties

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Science China Chemistry 2022年第5期65卷 892-897页

作者： Hai-lou li Chen lian Guo-Yu Yang Key Laboratory of Cluster Science(Ministry of Education) School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 102488China

A new ring-shaped 12-Ti-substituted poly(polyoxometalate)(poly(POM)),K_(10)H_(15)[{K_(2)Na(H_(2)O)_(3)}@{(Ti_(2)O)_(2)(Ti_(4)O_(4))_(2)(A-α-1,3,5-GeW_(9)O_(36))_(2)(A-α-2,3,4-GeW_(9)O_(36))_(2)}]·45H_(2)O(1),has been made under hydrothermal conditions,showing the highest number of Ti centers in Keggin-type poly(POM)family to *** obvious feature is that two types of novel chiral trivacant[GeW_(9)O_(36)]^(14-)(A-α-1,3,5-GeW_(9)O_(36)and A-α-2,3,4-GeW_(9)O_(36))segments have been first discovered in POM chemistry,and four[GeW_(9)O_(36)]^(14-)segments are alternately connected by two Ti_(2)O and two Ti_(4)O_(4)cores to form a ring-shaped poly(POM),in which two types of linking modes,Ti_(2)O and Ti_(4)O_(4)bridging cores,are observed for the first time in *** transformation of achiral precursors into chiral POM segments is of great significance for the POM synthetic ***,1 as a heterogeneous catalyst can effectively catalyze the oxidation of various thioethers and mustard gas simulant 2-chloroethyl ethyl sulfide(CEES).

关键词： polyoxometalate hydrothermal synthesis Ti-oxo cluster chiral catalytic oxidation

Microstructure and magnetic properties of(SmCo+FeCo)/NdFeB multicomponent nanocomposite magnets fabricated by HPTC with change in heating temperature and composition

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Journal of Rare Earths 2020年第7期38卷 742-748,I0003页

作者： Guangwei Huang li lou Wenpeng Song Ming li Fuchen Hou Xiaohong li State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China College of Materials Science and Engineering Hebei University of EngineeringHandan 056038China

We report the fabrication of bulk anisotropic(SmCo+FeCo)/NdFeB multicomponent nanocomposite magnets using high-pressure thermal compression(HPTC).The correlations among microstructure,magnetic properties,heating temperature and composition of the HPTC nanocomposite magnets were *** HPTC magnet made under variable temperatures(VT),with 19 wt% of FeCo phase,exhibits a maximum energy product of 32 MGOe,which is much higher than that(14 MGOe) for the HPTC magnet made under a constant temperature(CT).When the FeCo content increases to^23 wt%,the HPTC magnet made under VT still remains a high energy product of about 25 *** increasing NdFeB content,the(SmCo+FeCo)/NdFeB multicomponent nanocomposite magnets exhibit an enhanced magnetic anisotropy and *** work is beneficial to fabricating high-performance and low-cost permanent magnets for practical applications.

关键词： Nanocomposite magnets Bulk nanostructures Anisotropy Texture Rare earths

Effect of Casting Modulus on Microstructure and Segregation in K441 Superalloy Casting

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Journal of Materials Science & Technology 2011年第9期27卷 831-840页

作者： Weiguo Jiang Jiasheng Dong li Wang Langhong lou Institute of Metal Research Chinese Academy of Sciences Shenyang-110016 China

Four castings with different modulus have been designed to simulate different thickness sections of a turbine blade during casting process. The microstructure has been observed by optical microscopy （OM） and scanning electron microscopy （SEM）. The micro-segregation was tested by energy dispersive spectroscopy （EDS） and the macro-segregation was analyzed by using Metalscan 2500 spectrometers. The experimental results show that the microstructure of casting is affected by modulus apparently. The smaller the modulus, the finer the microstructure. The average grain size of castings with modulus of 0.29, 1.57, 3.10 and 5.0 mm is 0.3, 1.5, 2.7 and 4.3 mm, and the volume fraction of eutectic is 0, 0.1%, 0.2% and 1.0%, respectively. The micro/macro segregation is affected by the modulus apparently. The smaller the modulus, the lower the segregation level. When the modulus of casting increases, the content of AI increases, while the content of W, Cr and Mo decreases both in inner grain and near grain boundary. The content of AI and Mo in inner grain is higher than that near grain boundary, while the content of Cr and W in inner grain is lower than that near grain boundary.

关键词： Superalloy Turbine blade Casting modulus Microstructure Segregation

A new 4-Ti-added polyoxometalate

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Tungsten 2024年第2期6卷 465-471页

作者： Hai-lou li Chen lian Guo-Yu Yang MOE Key Laboratory of Cluster Science School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 102488China

A new inorganic–organic hybrid 4-Ti-added polyoxometalate:[H_(2)N(CH_(3))_(2)]_(2)Na_(3)H_(5)[{Ti(C_(2)O_(4))(H_(2)O)}_(2){Ti(C_(2)O_(4))}_(2)(B-β-SbW_(9)O_(33))_(2)]·22H_(2)O(1)has been successfully made and further characterized by infrared spectroscopy,thermogravimetric analysis,powder X-ray diff raction and single-crystal X-ray diff *** polyoxoanion of 1 exhibits a Krebs-type structure that is constructed from two[B-β-SbW_(9)O_(33)]^(9)−fragments fused together by a belt of four additional Ti atoms decorated by oxalate ***,1 as a heterogeneous catalyst exhibits high activity for Knoevenagel condensation under mild reaction conditions.

关键词： Polyoxometalate Ti-added POM Krebs-type structure Knoevenagel condensation

Metalorganic Chemical Vapor Deposition of GaAs on Si Substrate Prepared by Room Temperature Chemical Cleaning Treatment

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Chinese Physics Letters 1997年第9期14卷 690-693页

作者： YIN Min lou li-ren FU Zhu-xi Structure Research Laboratory University of Science and Technology of China and Chinese Academy of SciencesHefei 230026 Department of Physics University of Science and Technology of ChinaHefei 230026

A new method for metalorganic chemical vapor deposition(MOCVD)of GaAs on Si substrates is *** of the usual high temperature surface cleaning treatment for Si substrate,the new method uses room temperature HF vapor polishing in the preparation chamber in the MOCVD system as the first step of the *** crystal GaAs layers with mirror-like surfaces were obtained.

关键词： MOCVD polishing mirror

A giant Ce-containing poly(tungstobismuthate): Synthesis, structure and catalytic performance for the decontamination of a sulfur mustard simulant

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Chinese Chemical Letters 2024年第10期35卷 465-468页

作者： Chen lian Si-Han Zhao Hai-lou li Xinhua Cao College of Chemistry and Chemical Engineering Xinyang Normal UniversityXinyang 464000China MOE Key Laboratory of Cluster Science School of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 102488China

A novel Ce-containing poly(tungstobismuthate)Cs18Na8H_(2)0[Ce3(H_(2)O)10W8Bi4O_(2)8(B-α-Bi W9O_(3)3)4]2·64H_(2)O(1)has been synthesized by a facile one-pot self-assembly reaction *** structural characterization is realized by virtue of single-crystal X-ray diffraction,infrared spectroscopy,powder X-ray diffraction and thermogravimetric *** polyoxoanion of 1 is an octameric architecture consisting of two tetrameric entities[Ce3(H_(2)O)10W8Bi4O_(2)8(B-α-Bi W9O_(3)3)4]23-linked by two Ce–O–W bonds,and adjacent polyoxoanions are further combined together by means of Ce3+linkers,resulting in an infinite 1D chain *** 1 is the currently largest tungstobismuthate,and also represents the first example of lanthanide-encapsulated tungstobismuthate exhibiting an extended ***,compound 1 as a heterogeneous catalyst,exhibits high activity for the oxidative decontamination of a sulfur mustard simulant,2-chloroethyl ethyl sulfide(CEES)into 2-chloroethyl ethyl sulfoxide(CEESO).

关键词： Polyoxometalates Tungstobismuthate Cluster Lanthanide Oxidation

Reaction site and mechanism in the UV or visible light induced TiO2 photodegradation of Orange G

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Journal of Environmental Sciences 2006年第1期18卷 180-183页

作者： YANG Shi-ying lou li-ping WU Xiao-na CHEN Ying-xu Department of Environmental Engineering Zhejiang University Hangzhou 310029 China College of Environmental Science and Engineering Ocean University of China Qingdao 266003 China

For TiO2 heterogeneous reaction, the reaction site and the detailed mechanism are interesting and controversy topics. In this paper, effects of surface fluorination of TiO2 on the photocatalytic degradation of an azo dye, Orange G（OG） under UV or visible light irradiation were investigated, and the possible reaction site and mechanism were elucidated. The adsorption of OG on TiO2 was nearly inhibited by fluoride but its UV light induced photodegradation rate was greatly increased by a factor of about 2.7, which was due to the more generated free hydroxyl radicals. It supported the views that fluoride could desorb the oxidant species from surface and that the reaction sites could move to the bulk solution. In TiO2/Vis system, the observed inhibition effects of fluorination could be interpreted by the competitive adsorption, which provided additional evidences that the visible light sensitized photodegradation of dye pollutants on the catalyst surface.

关键词： photocatalytic degradation mechanism adsorption fluorination dye pollutants

Involvement of chloride anion in photocatalytic process

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Journal of Environmental Sciences 2005年第5期17卷 761-765页

作者： YANG Shi-ying CHEN Ying-xu lou li-ping WU Xiao-na Department of Environmental Engineering Zhejiang University Hangzhou 310029 China College of Environmental Sciences anti Engineering Ocean University of China Qingdao 266003 China

The effect of Cl^- on photocatalytic degradation（PCD） of pollutants is an important factor since it is ubiquitous in nature. In general, Cl^- showed an inhibition on photodegradation due to its scavenging HO- radicals. In this paper, experiments were carried out to examine the effects of CI on the PCD of Methylene Blue （MB） and Orange II （OII） in aqueous TiO2 suspensions under UV light illumination. It was found that low concentration of Cl^- （〈 0.01 mol/L） showed little influence on both dyes, however, high concentration of Cl^- （〉 0.10 mol/L） had a very different influence on the decolorization of dyes： a significant inhibition for MB but a great promotion for Oll. In the presence of 0.50 mol/L Cl^- , the rate decreased by 70% for MB while increased 7.5-fold for Oll. Furthermore, two bands in the ultraviolet region of Oll were rapidly broken down. The proposed mechanism was discussed in detail.

关键词： photocatalytic degradation TiO2 dye pollutants chloride ion mechanism