KBi4F13:一个具有高激光损伤阈值的中红外非线性光学材料

通过KF和Bi₂O₃在HF的水溶液中的水热反应合成了化合物KBi₄F₁₃,首次用X-射线单晶衍射技术鉴定了它的晶体结构。对它进行了XRD、ATR-FTIR、UV-Vis-NIR、TG、SHG测试。测试结果表明该化合物具有能够相位匹配的二阶非线性光学性能,其粉末倍频效应强度约为KDP的一半;粉末激光损伤阈值为120 MW·cm^-2,远远高于同等条件下测试的商品化红外非线性光学材料AgGaS₂的粉末激光损伤阈值(5 MW·cm^-2);粉末的红外吸收边可达20 μm;热分解温度为220℃。以上结果表明该物是有潜在应用价值的具有高激光损伤阈值的中红外非线性光学晶体材料。     

KBi4F13:一个具有高激光损伤阈值的中红外非线性光学材料

通过KF和Bi₂O₃在HF的水溶液中的水热反应合成了化合物KBi₄F₁₃,首次用X-射线单晶衍射技术鉴定了它的晶体结构。对它进行了XRD、ATR-FTIR、UV-Vis-NIR、TG、SHG测试。测试结果表明该化合物具有能够相位匹配的二阶非线性光学性能,其粉末倍频效应强度约为KDP的一半;粉末激光损伤阈值为120MW·cm^-2,远远高于同等条件下测试的商品化红外非线性光学材料AgGaS₂的粉末激光损伤阈值(5MW·cm^-2);粉末的红外吸收边可达20μm;热分解温度为220℃。以上结果表明该物是有潜在应用价值的具有高激光损伤阈值的中红外非线性光学晶体材料。     

Zn掺杂Co9S8纳米材料的制备及其在超级电容器和电催化析氢中的应用

采用原位溶剂热生长法设计合成了锌掺杂Co₉S₈纳米颗粒。各种表征技术和性能测试结果表明：锌掺杂Co₉S₈纳米颗粒的孔尺寸为18 nm,比表面积为23 m²·g^-1;同时微量的锌掺杂显著增强了Co₉S₈的电催化析氢（HER）活性及电容器性能。在HER性能测试中,当电流密度为10 mA·cm^-2时电位为-361 mV,电流密度最高可达38.26 mA·cm^-2,且具有优异的循环稳定性。同时在电容器性能测试中具有较高的比电容,当电流密度为1 A·g^-1时,质量比电容和面积比电容分别为235.48 F·g^-1和812.4 mF·cm^-2。     

(Pr0.9La0.1)2(Ni0.74Cu0.21Ga0.05) O4+δ纳米纤维阴极的制备及电化学性质

采用静电纺丝法制备了（Pr_0.9La_0.1）₂（Ni_0.74Cu_0.21Ga_0.05）O_4+δ（PLNCG）氧化物纳米纤维。利用热重-差热分析（TG-DTA）、X射线衍射（XRD）、傅里叶变换红外光谱（FT-IR）和扫描电子显微镜（SEM）对材料的物相及微观形貌进行分析。研究表明950℃煅烧5 h得到平均直径420 nm、形貌均一的PLNCG氧化物纤维;1 000℃烧结2 h得到紧密附着在Ce_0.9Gd_0.1O_2-δ（CGO）电解质上的网状结构纤维阴极。电化学阻抗谱（EIS）测试结果表明纳米纤维阴极具有比粉体阴极更优越的性能。700℃的极化电阻（R_P）为0.134 Ω·cm²,比同组分的粉末阴极减少32%（R_P=0.197 Ω·cm²）。以纤维阴极构筑的电解质支撑单电池Ni-CGO/CGO/PLNCG在700℃的最大输出功率密度为231 mW·cm^-2。氧分压测试结果表明阴极反应的速率控制步骤为电荷转移过程。     

BiVO4的添加对Nd0.2Ce0.8O1.9电解质微观结构和性能的影响

采用溶胶凝胶法制备BiVO₄（BV）和Nd_0.2Ce_0.8O_1.9（NDC）粉末,研究BV的加入对NDC电解质结构、形貌及电性能的影响。实验结果表明,NDC-5BV电解质的微观结构更致密,700℃时总电导率（σ_t）提高至3.35×10^-2 S·cm^-1,极化电阻（R_p）降低34%以上。单电池在700℃时的最大功率密度（MPD）为514 mW·cm^-2,开路电压（OCV）在70 h内可以保持良好的长期稳定性。     

ZnIn2S4/Au纳米片阵列的制备及其可见光响应光电化学固氮特性

采用简单的水热法合成出单晶ZnIn₂S₄纳米片阵列以实现可见光响应光电化学固氮。并采用光沉积法将超细Au纳米颗粒（5 nm）沉积于ZnIn₂S₄纳米片的棱角位置处,实现了可见光俘获和载流子分离能力的同时增强。当负载合适含量的Au纳米颗粒,ZnIn₂S₄纳米片阵列的光电固氮活性由1.092 μg·cm^-2·h^-1提升至2.262 μg·cm^-2·h^-1。我们还提出一个简单模型用以阐明其性能增强机制,这也被光致发光（PL）谱和光电化学（PEC）性能结果所证实。     

(Pr0.9La0.1)2(Ni0.74Cu0.21Ga0.05)O4+δ-Ce0.9Gd0.1O2-δ复合阴极的制备及电化学性质

采用EDTA-柠檬酸盐法制备了（Pr_0.9La_0.1）₂（Ni_0.74Cu_0.21Ga_0.05）O_4+δ（PLNCG）,并与Ce_0.9Gd_0.1O_2-δ（CGO）形成复合阴极PLNCG-CGO。XRD和SEM分析结果表明PLNCG与CGO在1 000℃具有较好的化学相容性。电化学阻抗测试结果表明PLNCG-30% CGO复合阴极在700℃的极化电阻为0.092 Ω·cm²;过电位为39.3 mV时,电流密度达到113.3 mA·cm^-2。氧分压分析表明电极反应的速率控制步骤为电荷转移过程。阳极支撑单电池（Ni-CGO/CGO/PLNCG-30% CGO）在700℃的最大输出功率密度达到569 mW·cm^-2,开路电压（OCV）为0.76 V。综上结果预示PLNCG-30% CGO复合阴极是一种有发展前景的电极材料。     

疏水性对溶胶-凝胶SiO2薄膜抗真空污染及抗激光损伤能力的影响

以正硅酸乙酯作为前驱体, 利用碱催化方式制备了SiO₂溶胶, 通过在溶胶中添加含疏水基团(-CH₃)的六甲基二硅氮烷(HMDS)对溶胶进行改性, 使用添加不同物质的量比HMDS改性后的溶胶用提拉法在K9基片上镀膜, 获得了具有疏水性能的SiO₂薄膜。采用自制接触角测量仪、紫外-可见-近红外分光光度计研究了薄膜的水接触角和透过率。测试了薄膜的激光损伤阈值, 并观察了激光辐照后薄膜的损伤形貌。通过真空污染实验对薄膜的抗污染能力及抗激光损伤能力进行了研究。实验结果表明:经疏水改性的溶胶所镀制的薄膜激光损伤阈值由未改性样品的24.3 J·cm^-2增加到37 J·cm^-2(1 064 nm, 10 ns), 且抗真空污染能力大大加强:在真空环境下保存168 h后, 未改性样品的峰值透过率下降了2%, 而疏水改性后的样品峰值透过率仅下降了0.25%, 并保持了较高的激光损伤阈值(30.8 J·cm^-2)。     

CuO-SiO2和Cu2O-SiO2薄膜的制备及其光学性能

以CuSO₄·5H₂O和正硅酸乙酯为前驱体,配制了稳定透明的Cu²⁺-SiO₂复合溶胶电解液。采用电化学-溶胶凝胶方法,在恒电位-0.9 V下得到Cu-SiO₂复合膜,该复合薄膜分别在250和450℃的热处理后得到Cu₂O-SiO₂和CuO-SiO₂复合薄膜。采用XRD、SEM/EDX和台阶仪表征了复合薄膜的组成、形貌和厚度;采用紫外-可见光谱和Z扫描技术研究了复合薄膜的线性和三阶非线性光学性能。结果表明Cu₂O-SiO₂和CuO-SiO₂复合薄膜中的Cu含量、Cu的形态（如Cu₂O、CuO）及Cu₂O或CuO颗粒大小影响薄膜的光学带隙和三阶非线性光学性能,2种薄膜的光学带隙分别是2.67和2.54 eV,三阶非线性极化率χ^（3）分别为2.31×10^-6和1.36×10^-6 esu。     

Tm3+/Er3+/Ho3+共掺SiO2-Bi2O3-AlF3-BaF2玻璃发光性能

采用高温熔融法制备了Tm³⁺/Er³⁺/Ho³⁺共掺的铋硅酸盐50SiO₂-40Bi₂O₃-5AlF₃-5BaF₂玻璃。研究了在808 nm激光器（Laser Diode）激发下Tm³⁺/Er³⁺/Ho³⁺共掺的铋硅酸盐在2 060 nm处的发光性能,同时测试及分析了该铋硅酸盐玻璃的差热特性、吸收光谱及荧光光谱。根据吸收光谱以及Judd-Oflet理论,计算了Ho³⁺的Judd-Oflet强度参数Ω_t（t=2,4,6）以及Tm³⁺/Er³⁺/Ho³⁺相应的吸收截面。铋硅酸盐玻璃中,Tm₂O₃、Er₂O₃和Ho2O3掺杂浓度分别为0.75%、1.0%和0.5%时,2 060 nm处Ho³⁺∶⁵I₇→⁵I₈发射峰强度达到最大。对Tm³⁺/Er³⁺/Ho³⁺ 3种离子的光谱性质和离子间可能存在的能量传递也做了分析。Ho³⁺在1 953 nm处的最大吸收截面σ_abs为9.08×10^-21 cm²,在2 060 nm处的最大发射截面σem为11.68×10^-21 cm²,辐射寿命τ_mea为2.75 ms,具有良好的增益效应σ_emτ（3.212×10^-20 cm^-2·ms）。     

Phase relations in the K2W2O7-K2WO4-KPO3-Bi2O3 system and structure of K6.5Bi2.5W4P6O34

The phase relations in the cross-section of the K₂W₂O₇-K₂WO₄-KPO₃ containing 15 mol% Bi₂O₃ were undertaken using flux method. Crystallization fields of K_6.5Bi_2.5W₄P₆O₃₄, K₂Bi(PO₄)(WO₄), Bi₂WO₆, KBi(WO₄)₂ and their cocrystallization areas were identified. Novel phase K_6.5Bi_2.5W₄P₆O₃₄ was characterized by single-crystal X-ray diffraction: sp. gr. P−1, a=9.4170(5), b=9.7166(4), c=17.6050(7) Å, α=90.052(5)°, β=103.880(5)° and γ=90.125(5)°. It has a layered structure, which contains {K₇Bi₅W₈P₁₂O₆₈}_∞ layers stacked parallel to ab plane and sheets composed by potassium atoms separating these layers. Sandwich-like {K₇Bi₅W₈P₁₂O₆₈}_∞ layers are assembled from [W₂P₂O₁₃]_∞ and [BiPO₄]_∞ building units, and are penetrated by tunnels with K/Bi atoms inside. FTIR-spectra of K₂Bi(PO₄)(WO₄) and K_6.5Bi_2.5W₄P₆O₃₄ were discussed on the basis of factor group theory.     

Sol-gel synthesis of K3InF6 and structural characterization of K2InC10O10H6F9, K3InC12O14H4F18 and K3InC12O12F18

K₃InF₆ is synthesized by a sol-gel route starting from indium and potassium acetates dissolved in isopropanol in the stoichiometry 1:3, with trifluoroacetic acid as fluorinating agent. The crystal structures of the organic precursors were solved by X-ray diffraction methods on single crystals. Three organic compounds were isolated and identified: K₂InC₁₀O₁₀H₆F₉, K₃InC₁₂O₁₄H₄F₁₈ and K₃InC₁₂O₁₂F₁₈. The first one, deficient in potassium in comparison with the initial stoichiometry, is unstable. In its crystal structure, acetate as well as trifluoroacetate anions are coordinated to the indium atom. The two other precursors are obtained, respectively, by quick and slow evaporation of the solution. They correspond to the final organic compounds, which give K₃InF₆ by decomposition at high temperature. The crystal structure of K₃InC₁₂O₁₄H₄F₁₈ is characterized by complex anions [In(CF₃COO)₄(OH_x)₂]^(5−2x)− and isolated [CF₃COOH_2−x]^(x−1)− molecules with x=2 or 1, surrounded by K⁺ cations. The crystal structure of K₃InC₁₂O₁₂F₁₈ is only constituted by complex anions [In(CF₃COO)₆]³⁻ and K⁺ cations. For all these compounds, potassium cations ensure only the electroneutrality of the structure. IR spectra of K₂InC₁₀O₁₀H₆F₉ and K₃InC₁₂O₁₂F₁₈ were also performed at room temperature on pulverized crystals.     

KCl-KBO2-K2CO3, K2MoO4-KBO2-K2CO3, and K2WO4-KBO2-K2CO3 ternary systems

phase diagrams of KCl-KBO₂-K₂CO₃, K₂MoO₄-KBO₂-K₂CO₃, and K₂WO₄-KBO₂-K₂CO₃ ternary systems were studied by a calculation-experimental method and differential thermal analysis (DTA). The coordinates of ternary eutectics were determined to be E ₁: 622°C, 8.5 mol % KBO₂, 56.5 mol % KCl, and 35 mol % K₂CO₃; E ₂: 710°C, 23 mol % KBO₂, 43 mol % K₂CO₃, and 34 mol % K₂MoO₄; E ₃: 710°C, 23 mol % KBO₂, 43 mol % K₂CO₃, and 34 mol % K₂WO₄. The specific heats of melting of the eutectics were determined.     

Li2SO4-Na2SO4-H2O和Li2SO4- K2SO4-H2O溶液的体积性质

本文用高精度数字式振荡管密度计测定了288K至318K温度范围内Li₂SO₄ + Na₂SO₄ + H₂O和 Li₂SO₄ + K₂SO₄ + H₂O三元体系的密度。混合溶液的离子强度范围从0.1到4.5 mol.kg_–1,混合溶液中Na₂SO₄和K₂SO₄的离子强度分数为0.2,0.4,0.6和0.8。用密度实验值拟合得到了不同温度下Pitzer离子相互作用模型混合参数θ_V和 ψ_V,模型的计算值与实验值的偏差在±0.002 g.cm_–3以内。用Pitzer模型计算了不同离子强度下三元体系的混合体积。     

Solubility in the Na2Cr2O7-(NH4)2Cr2O7-K2Cr2O7-H2O system

Solubility in the Na₂Cr₂O₇-(NH₄)₂Cr₂O₇-K₂Cr₂O₇-H₂O four-component water-salt system at 25, 50, and 75°C was studied for the first time. Phase field boundaries for individual salts and potassium and ammonium dichromate solid solutions, monovariant lines, and invariant points were determined. Experimental data were used to optimize the looped isohydric process of potassium dichromate preparation involving additional salts.     

NaBO2-NaCl-Na2CO3, NaBO2- Na2CO3-NaMoO4, NaBO2- Na2CO3-NaWO4, and NaBO2-NaCl-Na2WO4 ternary systems

The phase diagrams of the NaBO₂-NaCl-Na₂CO₃, NaBO₂-Na₂CO₃-Na₂MoO₄, NaBO₂- Na₂CO₃-Na₂WO₄, and NaBO₂-NaCl-Na₂WO₄ ternary systems were studied by a calculation-experimental method and differential thermal analysis. The coordinates of ternary eutectics were determined: E ₁: 612°C, 16 mol % NaBO₂, 42 mol % NaCl, and 42 mol % Na₂CO₃; E ₂: 568°C, 12 mol % NaBO₂, 28 mol % Na₂CO₃, and 60 mol % Na₂MoO₄; E ₃: 575°C, 12 mol % NaBO₂, 32 mol % Na₂CO₃, and 56 mol % Na₂WO₄; E ₄: 628°C, 8 mol % NaBO₂, 20 mol % NaCl, and 72 mol % Na₂WO₄; and E ₅: 655°C, 9 mol % NaBO₂, 53 mol % NaCl, and 38 mol % Na₂WO₄.     

Extension of the La7Mo7O30 structural type with La7Nb3W4O30 and La7Ta3W4O30 compounds

Two compounds of formula La₇A₃W₄O₃₀ (with A=Nb and Ta) were prepared by solid-state reaction at 1450 and 1490 °C. They crystallize in the rhombohedric space group R-3 (No. 148), with the hexagonal parameters: , and , . The structure of the materials was analyzed from X-ray, neutron and electronic diffraction. These oxides are isostructural of the reduced molybdenum compound La₇Mo₇O₃₀, which are formed of perovskite rod along [111]. An order between (Nb, Ta) and W is observed.     

Li2O-TiO2-SiO2-P2O5和Li2O-TiO2-Al2O3-P2O5体系锂离子固体电解质的制备及性能研究

一些具有NASICON型网格结构的固体电解质具有高的电导率和好的稳定性,NASICON的意思是Na Super Ionic Conductor[1]。当NaZr2(PO4)3中P5 被Si4 部分取代时便可以得到具有NASICON结构的Na1 xZr2SixP3-xO12体系,其具有高的钠离子电导率。然而有相同结构的Li1 xZr2SixP3-xO12体系的离子电导率却很低,这是因为Li 半径太小,而NASICON三维网格结构的离子通道太大,两者不匹配而使电导率下降[2]。但当LiZr2(PO4)3中Zr4 被离子半径小些的Ti4 取代,所得LiTi2(PO4)3的通道就与Li 半径相匹配,适合于锂离子的迁移,从而使其电导率…     

Structural chemistry of Sr3Cr2WO9, Ca3Cr2WO9, and Ba3Cr2WO9

We have studied the preparation and crystallographic structure of three perovskite-type compounds: Sr₃Cr₂WO₉, cubic, the lattice parameter of which is a = 7.812Å; Ca₃Cr₂WO₉, tetragonal, the lattice parameters of which are a = 5.408 Å and c = 7.635Å; and Ba₃Cr₂WO₉, hexagonal, the lattice parameters of which are a = 5.691 Å and c = 13.957Å. We have compared these three structures and shown the relationship between the dimensions of the alkaline-earth metal and the existence of the different structures.     

Preparation and structure of NaSr0.5Al2B2O7 and NaCa0.5Al2B2O7

Two compounds NaSr_0.5Al₂B₂O₇ and NaCa_0.5Al₂B₂O₇, have been found to crystallize into a new structure type by Rietveld refinement from X-ray powder diffraction data. Their structure belongs to hexagonal space group P6₃/m, with lattice parameters of , for NaSr_0.5Al₂B₂O₇ and , for NaCa_0.5Al₂B₂O₇, respectively. The structure is built up by [Al₂B₂O₇]²⁻ double layer and Na⁺/Ca²⁺ or Na⁺/Sr²⁺ ions alternatively stacking along the c-axis. The sites in the inter-double layer are fully occupied jointly by Na and Ca or Sr, but the intra-double layer sites are only half occupied solely by Na. A mechanism of the transition of the structure from CaAl₂B₂O₇ to present structure type by replacing only 1% Ca by Na (2%) as observed by Chang and Keszler (Mater. Res. Bull. 33 (1998) 299) is also proposed.