Phase transition induced by lithium insertion in αI- and αII-VOPO4

Lithium insertion in α_I-VOPO₄ and α_II-VOPO₄, either by chemical or electrochemical route, leads to the same new compound: α_I-LiVOPO₄ (space group P4/nmm). The structure, resolved by neutron and synchrotron diffraction, is made up of planes of corner-connected PO₄ and VO₅ polyhedra, whereas lithium atoms are located between the layers. The reversal of the short vanadyl bond that corresponds to the insertion-induced α_II-α_I transition finds an explanation in terms of lattice energy. It favors the migration of lithium ions in the (0 0 1) interlayer planes, a key parameter for the electrochemical performance as electrode material in Li-ion batteries.     

α-钨钒硅酸钾(α-K3H2SiW11VO40·6H2O)的晶体结构

α-K₃H₂SiW₁₁VO₄₀·6H₂O属六方晶系,空间群为P6₂,晶胞参数:a=b=19.084Å,c=12.489Å,V=3939.17ų,Z=3;D₀=3.86gcm^-3,D_m=3.81gcm^-3。晶体内含有分立的α-SiW₁₁VO₄₀^5-阴离子,其形状、大小类同于α-SiW₁₂O₄₀^4-,仅是一个W原子为V原子所取代。一个V原子与十一个W原子呈无序分市,共占据十二个原子位置。三个K原子和六个结晶水的位置已经确定。     

Refinement of α-CsB9O14 crystal structure

The structure of α-CsB₉O₁₄ was re-examined because the first determination corresponded to a poor reliability factor (12.9%). Single crystals were obtained by heating, melting and slow cooling a stoichiometric mixture (1:4) of β-Cs[B₅O₆(OH)₄]·2H₂O and H₃BO₃. This compound crystallizes in the non-centrosymmetric orthorhombic space group P222₁ (and not P4₁22) with the following parameters: a=8.732(2)Å, b=8.767(3)Å, c=15.736(4)Å, V=1204.6(6)ų, Z=4; after taking into consideration twinning, the structure was refined from 3188 reflections until R₁=0.0304. It consists of two infinite, interleaved three-dimensional boron-oxygen frameworks of the Fundamental Building Blocks formed by two B₃O₆ and one B₃O₇ groups; its shorthand notation is 9:∞³[(3:2Δ+T)+2(3:3Δ)] (Δ, triangle BO₃ and T, tetrahedron BO₄). Knowledge of the correct space group and the structure of α-CsB₉O₁₄ may help in the study of its physical properties, especially the non-linear optical ones.     

Ba0.95Ce0.8Ho0.2O3-α的离子导电性

用高温固相反应法制备了Ba_0.95Ce_0.8Ho_0.2O_3-α，X–射线衍射表明，该材料为单相钙钛矿型斜方晶结构。以该材料为固体电解质，多孔性铂为电极，用气体浓差电池方法和交流阻抗谱方法分别测定了材料在600 ~ 1000℃温度范围，潮湿氢气、干燥和潮湿的空气中的离子迁移数和电导率，研究了该材料的离子导电性，并与BaCe_0.8Ho_0.2O_3-α作了比较。结果表明，在600 ~ 700 ℃、潮湿氢气中，Ba_0.95Ce_0.8Ho_0.2O_3-α是纯的质子导体，质子迁移数为1；在800 ~ 1000 ℃，是质子和电子的混合导体，质子迁移数为0.97 ~ 0.93。而BaCe_0.8Ho_0.2O_3-α在潮湿氢气中几乎是纯的质子导体，在600 ~ 900 ℃，质子迁移数为1；在1000 ℃，质子迁移数为为0.99。在600 ~ 1000℃温度范围内、干燥的空气中，它们都是氧离子和电子空穴的混合导体，氧离子迁移数分别为0.24 ~ 0.33和0.17 ~ 0.30；在潮湿的空气中，它们都是质子、氧离子和电子空穴的混合导体，质子迁移数分别为0.11 ~ 0.00 和0.09 ~ 0.01，氧离子迁移数分别为0.41 ~ 0.33和0.27 ~ 0.30。在潮湿的氢气和空气中，在600 ~ 800 ℃温度范围内，Ba_0.95Ce_0.8Ho_0.2O_3-α的质子电导率高于BaCe_0.8Ho_0.2O_3-α，但在800 ~ 1000 ℃温度范围内，Ba_0.95Ce_0.8Ho_0.2O_3-α的质子电导率则低于BaCe_0.8Ho_0.2O_3-α。在600 ~ 1000 ℃温度范围内、潮湿和干燥的空气中，氧离子电导率总是高于BaCe_0.8Ho_0.2O_3-α。     

SrCe0.9Yb0.1O3-α陶瓷的导电性

以高温固相反应法合成了质子导电性氧化物陶瓷SrCe0.9Yb0.1O3-α.粉末XRD结果表明,该陶瓷样品为单一斜方相钙钛矿型结构.以陶瓷样品为固体电解质、多孔性铂为电极,采用交流阻抗谱技术和气体浓差电池方法分别测定了样品在600～1000 ℃下、干燥空气及湿润氢气中的电导率及离子迁移数,研究了样品的离子导电特性.结果表明,在600～1000 ℃下干燥空气中,陶瓷样品的最大电导率为0.026 S·cm-1,氧离子迁移数为0.03～0.2,是一个氧离子与空穴的混合导体;在湿润氢气中,陶瓷样品的最大电导率为0.015 S·cm-1. 600～800 ℃时,陶瓷样品的质子迁移数为1,是一个纯的质子导体,而在900～1000 ℃时,陶瓷样品的质子迁移数为0.91～0.97,是一个质子与电子的混合导体,质子电导占主导.     

Hydrodeoxygenation of Anisole over Ni/α-Al2O3 Catalyst

Ni-based catalysts supported on di erent supports (α-Al₂O₃,γ-Al₂O₃, SiO2, TiO₂, and ZrO₂) were prepared by impregnation. Effects of supports on catalytic performance were tested using hydrodeoxygenation reaction (HDO) of anisole as model reaction. Ni/α-Al₂O₃ was found to be the highest active catalyst for HDO of anisole. Under the optimal conditions, the anisole conversion is 93.25% and the hydrocarbon yield is 90.47%. Catalyst characteriza-tion using H₂-TPD method demonstrates that Ni/α-Al₂O₃ catalyst possesses more amount of active metal Ni than those of other investigated catalysts, which can enhance the cat-alytic activity for hydrogenation. Furthermore, it is found that the Ni/α-Al₂O₃ catalyst has excellent repeatability, and the carbon deposited on the surface of catalyst is negligible.     

Ba0.9Sr0.1Ce0.9Nd0.1O3-α陶瓷的离子导电性

用高温固相反应法制备了质子导电性陶瓷Ba0.9Sr0.1Ce0.9Nd0.1O3-α。用粉末X-射线衍射(XRD)和扫描电子显微镜(SEM)对该陶瓷材料进行了表征;用交流阻抗谱技术和气体浓差电池方法研究了材料在500~900℃温度范围内、不同气体气氛中的离子导电性,并与BaCe0.9Nd0.1O3-α和Ba0.9Ca0.1Ce0.9Nd0.1O3-α材料的导电性进行了比较。结果表明,该陶瓷材料为单一钙钛矿型BaCeO3斜方晶结构,具有良好的致密性,在高温下、CO2或水蒸气气氛中具有较高的稳定性。在湿润氢气气氛中、500~800℃温度范围内,材料的质子迁移数为1,是一个纯的质子导体;在900℃下,质子迁移数为0.964,是一个质子与电子的混合导体,质子迁移数高于BaCe0.9Nd0.1O3-α(在700~900℃温度范围内,质子迁移数为0.95)。在湿润空气气氛中,材料的质子迁移数为0.019~0.032,氧离子迁移数为0.093~0.209,是一个质子、氧离子和电子空穴的混合导体,总电导率高于Ba0.9Ca0.1Ce0.9Nd0.1O3-α。在氢-空气燃料电池条件下,材料的离子迁移数为0.957~0.903,是一个质子、氧离子和电子的混合导体,离子电导率高于Ba0.9Ca0.1Ce0.9Nd0.1O3-α。     

Ba0.9La0.1Ce0.9Nd0.1O3-α陶瓷的离子导电性

用高温固相反应法制备了Ba0.9La0.1Ce0.9Nd0.1O3-α质子导电性陶瓷,粉末X-射线衍射(XRD)分析表明,该陶瓷为单一钙钛矿型斜方晶结构。在500~900℃温度范围内,分别用气体浓差电池方法和交流阻抗谱技术研究了材料在不同气体气氛中的离子导电性,并与Ba0.9Ca0.1Ce0.9Nd0.1O3-α材料的离子导电性进行了比较。结果表明,在500~900℃温度范围内、湿润氢气中,Ba0.9La0.1Ce0.9Nd0.1O3-α材料的质子迁移数为1,是一个纯的质子导体。在干燥空气中,该材料是一个氧离子和电子空穴的混合导体,氧离子迁移数为0.295~0.081,氧离子电导率高于Ba0.9Ca0.1Ce0.9Nd0.1O3-α。在湿润空气中,该材料是一个质子、氧离子和电子空穴的混合导体,质子迁移数为0.151~0.009,氧离子迁移数为0.300~0.107,质子电导率低于Ba0.9Ca0.1Ce0.9Nd0.1O3-α材料。在氢-空气燃料电池条件下,Ba0.9La0.1Ce0.9Nd0.1O3-α材料是一个质子、氧离子和电子的混合导体,离子迁移数为0.964~0.853,离子电导率与Ba0.9Ca0.1Ce0.9Nd0.1O3-α材料相近。     

等离子体辅助法合成α-Si3N4/SiO2纳米梳

晶体的α-Si3N4内核和非晶的SiO2外壳组成的纳米梳通过简单的直流电弧方法合成。通过X射线衍射(XRD)、扫描电子显微术(SEM)、透射电子显微术(TEM)、傅里叶红外光谱(FTIR)等对纳米梳进行表征。纳米梳的光致发光谱展现了两个强的发光峰,分别在450和511 nm。α-Si3N4/SiO2核壳结构纳米梳生长机制为等离子体辅助气-固生长机制。     

等离子体辅助法合成α-Si3N4/SiO2纳米梳

晶体的α-Si₃N₄内核和非晶的SiO₂外壳组成的纳米梳通过简单的直流电弧方法合成。通过X射线衍射（XRD）、扫描电子显微术（SEM）、透射电子显微术（TEM）、傅里叶红外光谱（FTIR）等对纳米梳进行表征。纳米梳的光致发光谱展现了两个强的发光峰,分别在450和511nm。α-Si₃N₄/SiO₂核壳结构纳米梳生长机制为等离子体辅助气-固生长机制。     

SrCe0.95Er0.05O3-α固体电解质的导电性

SrCe_0.95Er_0.05O_3-α ceramic of a single orthorhombic phase of perovskite-type SrCeO₃ was prepared by high-temperature solid state reaction. Using the ceramic as solid electrolyte and porous platinum as electrodes, the measurements of conductivities and ionic transport numbers on SrCe_0.95Er_0.05O_3-α ceramic were performed by using electrochemical methods in the temperature range of 600～1 000 ℃ in wet hydrogen, dry air and wet air, respectively. The results indicate that the sample is a pure protonic conductor with a maximal conductivity of 0.01 S·cm^-1 in wet hydrogen, a mixed conductor of oxide-ion and hole in dry air, and a mixed conductor of proton, oxide-ion and hole in wet air.     

质子导体BaCe0.8Lu0.2O3-α的电性能

采用高温固相法制备了BaCe_0.8Lu_0.2O_3-α质子导体。运用X射线衍射仪（XRD）、扫描电镜（SEM）对该材料的物相结构、微观形貌进行了表征。在500~900℃温度范围内,应用交流阻抗谱和气体浓差电池方法研究了材料在不同气体气氛中的离子导电性和氢-空气燃料电池性能。结果表明,BaCe_0.8Lu_0.2O_3-α材料为单一斜方晶结构,具有良好的致密性。在500~900℃温度范围内,干燥或湿润的氮气、空气和氧气中,材料的电导率随着氧分压增大稍有增大。在湿润的氢气中,材料表现为纯的质子导电性。在以该材料为固体电解质的氢-空气燃料电池条件下,材料表现为质子、氧离子和电子的混合导电性,其中离子导电性始终占主导;氢-空气燃料电池在900℃下的最大输出功率密度为92.2mW·cm^-2,高于我们以前报道的BaCe_0.8RE_0.2O_3-α（RE=Pr,Eu,Ho,Er,等）材料。     

BaCe0.7Zr0.2La0.1O3-α陶瓷的制备和导电性

以高温固相反应法合成了BaCe_0.7Zr_0.2La_0.1O_3-α陶瓷。粉末XRD结果表明,该陶瓷材料为单一钙钛矿型BaCeO₃斜方晶结构。以陶瓷材料为固体电解质、多孔性铂为电极,采用交流阻抗谱技术和气体浓差电池方法分别测定了材料在500～900 ℃下,干燥空气、湿润空气和湿润氢气中的电导率以及离子迁移数,研究了材料的离子导电特性。结果表明,在500～900 ℃下干燥空气中,陶瓷材料的最大电导率为1.8 mS·cm^-1,氧离子迁移数为0.14～0.04,是一个氧离子与电子空穴的混合导体。在湿润空气中,陶瓷材料的最大电导率为2.0 mS·cm^-1,质子迁移数为0.48～0,氧离子迁移数为0.25～0.10,是质子、氧离子和电子空穴的混合导体。在湿润氢气中,陶瓷材料的最大电导率为3.6 mS·cm^-1。在500～700 ℃温度范围内,陶瓷材料的质子迁移数为1,是纯的质子导体;而在800～900 ℃温度范围内,陶瓷材料的质子迁移数为0.93～0.91,是质子与电子的混合导体,质子电导占主导。     

Ba0.95Ce0.90Y0.10O3-α固体电解质的质子导电性

本文通过高温固相反应合成了Ba_0.95Ce_0.90Y_0.10O_3-α固体电解质,测定了该固体电解质高温(600～1000℃)下的氢的电化学透过(氢气泵)速度。结果表明,该固体电解质在本实验条件下具有良好的质子导电性,其质子迁移数为0.8～1,在600～700℃的较低温度下,几乎显示纯粹的质子导电性。     

Synthesis of rac-2′-(trimethylsilyl)isovaline: A novel silicon-containing α,α-dialkylated α-amino acid

An efficient, convenient, and reliable multi-step synthesis of rac-2′-(trimethylsilyl)isovaline (rac-3) that uses inexpensive reagents in all steps has been developed, starting from diethyl malonate (overall yield 28%). Compound rac-3 is the first α-ethylated α,α-dialkylated silicon-containing α-amino acid.     

La0.8Sr0.2Ga0.8Mg0.2O3－α陶瓷的质子导电性能研究

采用溶胶-凝胶法合成了La_0.8Sr_0.2Ga_0.8Mg_0.2O_3－a陶瓷样品, 用XRD, DSC-TGA, SEM, 交流阻抗谱, 气体浓差电池及气体电化学透过等方法对样品的结构和性质进行了表征和测试. 首次对该样品的质子导电性能进行了研究. 该陶瓷样品具有良好的微观结构, 相对密度达95.1%; 氢浓差电池电动势的实测值与理论值吻合, 离子迁移数为1; 在干燥的氧气气氛中是一个纯的氧离子导体; 氢的电化学透过速率的实测值与理论值吻合, 证明该样品在氢气气氛中几乎是一个纯的质子导体, 质子电导率在1000 ℃时高达0.14 S•cm^－1.     

10 α -Hydroxy- β -isomorphine, a by-product of the synthesis of 10 α -hydroxymorphine

Abstract  

A new compound was isolated from the reaction mixture after O-demethylation of 6-O-acetyl-10α-acetoxycodeine with boron tribromide. The structure of this compound, 10α-hydroxy-β-isomorphine, was elucidated by spectral data, and its spatial arrangement was deduced from an NOE experiment. Capillary zone electrophoresis was used for separation of morphine and its 10-hydroxy analogues.     

Ba0.95Ce0.9Y0.1O3-α固体电解质的氧离子导电性

Ba_0.95Ce_0.9Y_0.1O_3-α solid electrolyte was prepared by high temperature solid state reaction. The electrochemical oxygen permeation (oxygen pumping) rates and oxide ion transport number in this electrolyte were detected in the temperature of 600～1000℃ . It was found that this electrolyte exhibited the oxide ion conduction with the oxide ion transport number of 0.3～0.5.     

Ba0.9La0.1Ce0.7Zr0.2Nd0.1O3-α陶瓷的化学稳定性和离子导电性

用高温固相反应法制备了Ba0.9La0.1Ce0.7Zr0.2Nd0.1O3-α陶瓷。粉末X-射线衍射(XRD)结果表明,该材料为单一钙钛矿型BaCeO3斜方晶结构,在高温下、CO2或水蒸气气氛中具有较高的稳定性。在500～900℃温度范围内,分别用交流阻抗谱技术和气体浓差电池方法研究了材料在不同气体气氛中的离子导电特性,并与Ba0.9Ca0.1Ce0.9Nd0.1O3-α材料的导电特性进行了比较。结果表明,在500～900℃温度范围内,干燥和湿润的氢气、氮气、空气和氧气气氛中,材料的电导率均随着温度升高和氧分压增加而增加,且材料在湿润气氛中的电导率稍高于相应的干燥气氛中的电导率(氢气气氛中则相反)。在湿润氢气中,材料的质子迁移数为1,是一个纯的质子导体;在干燥空气中,材料的氧离子迁移数为0.087～0.155,是一个氧离子与电子空穴的混合导体;在湿润空气中,材料的质子迁移数为0.001～0.004,氧离子迁移数为0.160～0.198,是一个质子、氧离子和电子空穴的混合导体。材料在干燥和湿润空气中的氧离子电导率均高于相同条件下Ba0.9Ca0.1Ce0.9Nd0.1O3-α材料的氧离子电导率。     

La0.8Sr0.2Ga0.8Mg0.2O3－α陶瓷的质子导电性能研究

采用溶胶-凝胶法合成了La_0.8Sr_0.2Ga_0.8Mg_0.2O_3－a陶瓷样品, 用XRD, DSC-TGA, SEM, 交流阻抗谱, 气体浓差电池及气体电化学透过等方法对样品的结构和性质进行了表征和测试. 首次对该样品的质子导电性能进行了研究. 该陶瓷样品具有良好的微观结构, 相对密度达95.1%; 氢浓差电池电动势的实测值与理论值吻合, 离子迁移数为1; 在干燥的氧气气氛中是一个纯的氧离子导体; 氢的电化学透过速率的实测值与理论值吻合, 证明该样品在氢气气氛中几乎是一个纯的质子导体, 质子电导率在1000 ℃时高达0.14 S•cm^－1.