钙钛矿型LaCoO3的光催化活性

对钙钛矿型ＡＢＯ３复合氧化物的物理化学性质已有许多研究,但对其光催化活性很少报道．我们曾报道ＳｒＴｉＯ３［１］、ＰｂＴｉＯ３［２］等的制备及其对水溶性染料的光催化降解．本文报道ＬａＣｏＯ３的制备及其光催化活性．ＬａＣｏＯ３用柠檬酸络合法制取,所用试剂...     

钡对氧化铝的高温热稳定作用

在汽车正常工作状况下汽车催化剂所处的氛围常高达１０００℃ ,这就要求催化剂有较高的热稳定性．催化剂的热稳定性除了依赖于活性组分的耐热性能外 ,还取决于涂层（γ Ａｌ２Ｏ３）的热稳定性 ,因此提高γ Ａｌ２Ｏ３ 涂层的高温耐热性非常重要．研究表明 ,Ａｌ２Ｏ３ 前驱体的结构、颗粒度及制备方法可以影响γ Ａｌ２Ｏ３ 涂层的比表面积和热稳定性 ［１ -３］,而在涂层中引入某些添加剂 ,如稀土氧化物Ｌａ２Ｏ３、碱土氧化物ＢａＯ、ＳｒＯ等对提高Ａｌ２Ｏ３ 的热稳定性更有效［４ -７］．其中 ,Ｌａ２Ｏ３ 除了抑制Ａｌ２Ｏ３ 的表相…     

（C_5H_7S_2）_3〔Bi_2Cl_9〕的合成和晶体结构

标题化合物由ＢｉＣｌ３和乙酰丙酮在ＨＣＩ（气）／Ｃ２Ｈ５ＯＨ溶剂中通入Ｈ２Ｓ气体反应而得。晶体属四方晶系，Ｍｒ＝１１３０．７６，空间群Ｐ４１２１２。晶胞参数ａ＝ｂ＝８．８６７（２），ｃ＝４１．５１１（４）Ａ；Ｖ＝３２６４（１）Ａ３，Ｚ＝４，Ｄｃ＝２．３０ｇｃｍ（－３），μ（ＭｏＫα）＝１１８．６０７ｃｍ（－１），Ｆ（０００）＝２１０４．晶体结构由重原子法求得。最终偏离因子Ｒ＝０．０７２。晶体由分立的（Ｃ５Ｈ７Ｓ２）＋阳离子和［Ｂｉ２Ｃｌ９］３－阴离子组成。每个Ｂｉ原子和６个Ｃｌ原子形成畸变的八面体配位。２个［ＢｉＣｌ６］八面体共面构成具有２次轴对称的［Ｂｉ２Ｃｌ９］（３－）配阴离子。还讨论了阳离子种类对Ｂｉ配阴离子结构类型的影响。     

异丙醇铝改进的原子转移自由基聚合催化体系

以α 溴代异丁酸乙酯［２ （ＥｉＢ） Ｂｒ］ 为引发剂,溴化亚铜（ＣｕＢｒ）／ 联二吡啶（ｂｐｙ）／ 异丙醇铝［Ａｌ（ＯｉＰｒ）３］ 为复合催化剂,在环己酮溶液中进行了甲基丙烯酸正丁酯（ＢＭＡ） 的原子转移自由基聚合（ＡＴＲＰ） ．研究了异丙醇铝对聚合速率及产物分子量分布的影响．异丙醇铝可与引发剂和聚合物中的羰基配位,使相邻的Ｃ—Ｂｒ 键活化,ＡＴＲＰ 反应可以在较低温度下进行．适量溴化铜的加入,可调节ＡＴＲＰ 活性,可得到分子量可控且分子量分布窄的ＰＢＭＡ（ ＭＷＤ＝ １－３ ～１－５） ．     

A_2BO_4型催化活性材料结构与性能的研究Ⅰ．［La_（k－x）Sr_x□_（1－k）］_2Cu_（1－y）□_yO_（4－δ）体系

以硝酸盐为原料，用柠檬酸络合法按［Ｌａ１－ｋＳｒｘ□ｋ－ｘ］２ＣｕＯ４（Ｘ＝０、０．０５、０．１、０．１５、０．２，ｋ＝０．０２５）的配比制备了５个样品．应用多晶Ｘ射线衍射法研究了此Ｌａ－Ｓｒ－Ｃｕ－Ｏ系列Ａ２ＢＯ４型复合氧化物的非完整结构．结构研究表明，此系列结构空位型非完整的存在，使结构中Ｂ位的铜离子变价为Ｃｕ２＋和Ｃｕ３＋．但是，随着Ａ位Ｓｒ加入量的增加，Ａ位空位的减少，结构中Ｂ位Ｃｕ３＋量随之减少，Ｃｕ２＋量随之增加，样品对于ＣＯ氧化的催化性能缓慢下降，而ＮＯ还原的催化能力增强．高价态的Ｃｕ３＋的存在是实现对ＣＯ催化氧化的条件；而Ｃｕ２＋给电子能力促进了Ｎｏ－的生成，是ＮＯ催化还原的活性来源．从此系列样品的催化性能和精细结构的研究可得出，适当地调节Ａ２ＢＯ４型结构中Ａ位和Ｂ位的空位及Ｓｒ２＋的掺入量，使Ｂ位Ｃｕ２＋和Ｃｕ３＋保持适当的比例，可获得ＣＯ催化氧化和ＮＯｘ催化还原同时具有较高活性的催化活性材料．     

3-甲基-3-氧杂丁环甲醇的阳离子型开环聚合

三元和四元环醚具有较大的环张力而易于聚合．Ｖａｎｄｅｎｂｅｒｇ等［１］曾经以（ｉ－Ｂｕ３）Ａｌ／Ｈ２Ｏ为引发剂,使３－甲基－３－（三甲基硅氧甲基）氧杂丁环进行开环聚合反应,合成的聚合物水解后得到线形的聚甲基羟甲基醚．本文以ＢＦ３·ＯＥｔ２为引发剂,对３－甲基－３－氧杂丁环甲醇进行直接引发,实现了开环聚合反应,得到基本线形或轻度支化的聚醚多元醇．１　实验部分１．１　聚合物的合成　聚合装置同文献［１］．所用试剂按文献［１］方法处理．向烧瓶中加入２０ｍＬ的二氯乙烷和０．１ｍｏｌ３－甲基－３－氧杂丁环甲…     

Synthesis, Crystal Structure and Magnetic Property of Disodium Biscarbonato cobaltate(Ⅱ) Tetrahydrate, Na_2Co(CO_3)_2·4H_2O

ＩｎｔｒｏｄｕｃｔｉｏｎＡｓｅａｒｌｙａｓ１８５１,Ｄｅｖｉｌｌｅ［１］ｆｉｒｓｔｉｄｅｎｔｉｆｉｅｄｓｅｖｅｒａｌｄｏｕｂｌｅｃａｒｂｏｎａｔｅｓｏｆｔｈｅｆｏｒｍｕｌＡ２ＣＯ３·ＭＣＯ３·４Ｈ２Ｏ（Ａ＝Ｎａ,ＫａｎｄＭ＝Ｍｇ,Ｎｉ,Ｃｏ）ａｎｄｒｅｐｏｒｔｅｄｔｈｅｐｏｔａｓｓｉｕｍｃｏｍ－ｐｏｕｎｄｓｗｉｔｈａｎｏｒｔｈｏｒｈｏｍｂｉｃｓｙｓｔｅｍ［１］．Ｓｉｎｃｅｅａｃｈｏｆｔｈｅｔｈｒｅｅｃａｒｂｏｎａｔｅｏｘｙｇｅｎｓｉｓａｂｌｅｔｏｐａｒｔｉｃｉｐａｔｅｉｎｃｏｏｒｄｉｎａｔｉｏｎ…     

有机锗倍半氧化物的快原子轰击质谱分析

在不同的水解条件下，合成羧乙基锗倍半氧化物（Ｇｅ－１３２）和乙氧羰基乙基锗倍半氧化物。采用快原子轰击质谱（ＦＡＢＭＳ）技术分别对３种化合物进行分析，证明有机锗化合物是以聚合物的形式存在，分子结构通式为｛［ＧｅＣＨ２ＣＨ２ＣＯＯＨ］２Ｏ３｝ｎ，聚合系数ｎ分别为１、２和３。     

新型六核钼原子簇化合物{[Mo3（μ3—S）（μ—S2）2（dtp）3]—（μ3—S）（η…

［Ｍｏ３（μ３－Ｏ）（μ－Ｓ）３（μ－ＯＡｃ（ｄｔｐ）３（ｐｙ）］和［Ｍｏ３（μ－Ｓ）３（μ－ＯＡｃ（ｄｔｐ）３－（ｐｙ）］（ｄｔｐ＝Ｓ２Ｐ（ＯＣ２Ｈ５）２＾－）族合物分别与金属化合物ＢｉＩ３和ＳｂＢｒ３进行原子簇反应均能获得意外产物｛［Ｍｏ３（μ３－Ｓ）（μ－Ｓ２）２（ｄｔｐ）３］（μ３－Ｓ）（η＾３－Ｓ２）［Ｍｏ２（μ３－Ｓ）（μ－Ｓ）３（μ－ＯＡｃ）（ｄｔｐ）２］｝六核钼簇。其结构实际上是由     

MoO3在Al2O3薄膜表面扩散的研究

氧化物和盐类在高比表面载体上的单层分散现象已被大量实验所证实［１］．ＭｏＯ_３在γ－Ａｌ_２Ｏ_３等高比表面载体上的分散已经研究很多,近来的研究证实ＭｏＯ３等在α－Ａｌ２Ｏ３等小比表面载体上也能自发单层分散［２］,但是分散的过程仍然缺乏直接的观察研究．本工作通过多种表面分析方法首次研究了ＭｏＯ３在平整无定形的Ａｌ２Ｏ３薄膜上的扩散过程以及影响因素．发现除温度升高外、水汽的存在对该扩散过程也有促进作用．１实验部分１．１样品的制备采用ＳＳ－３２００真空磁控溅射镀膜机,通入Ａｒ－Ｏ２作为反应气,直流磁控…     

Anodic Synthesis and Characterization of Na-Pb-O, Na-Pb-Bi-O Crystals

Crystals of Na-Pb-O and Na-Pb-Bi-O were electrosynthesized on the anode from molten salts. The resulting crystals have a hexagonal structure, in which the base ions (Pb and Bi) are in high oxidation states. By using KOH/NaOH (atomic ratio K:Na=I:I) mixture as a flux,incorporation of K ions into the lattice is inhibited while incorporation of Bi ions is enhanced. The magnetic measurement shows that the Na-Pb-Bi-O crystals are dominated by diamagnetism.     

Ba-K-Bi-O和Ba-K-Pb-O氧化物的碘量滴定

本文提出了碘量法滴定Ba－K－Bi-O和Ba－K－Pb－O氧化物中Ba和Pb的名义价态，然后据此计算这些氧化物中K和Ba含量的方法。该法适用于正常条件下合成的具有ABO3型钙钛矿结构的Ba－K－Bi-O和Ba－K－Pb－O晶体。用本法的滴定结果表明，Tc为31K的Ba－K－Bi-O超导体的K含量为0．4，当K含量减少时，Tc随之下降。     

Structure and thermoelectric properties of the new quaternary bismuth selenides A(1-x)M(4-x)Bi(11+x)Se21 (A = K and Rb and Cs; M = Sn and Pb)--members of the grand homologous series Km(M6Se8)m(M(5+n)Se(9+n))

Several members of the new family A(1-x)M(4-x)Bi(11+x)Se21 (A = K, Rb, Cs; M = Sn, Pb) were prepared by direct combination of A2Se, Bi2Se3, Sn (or Pb), and Se at 800 degrees C. The single-crystal structures of K(0.54)Sn(3.54)Bi(11.46)Se21, K(1.46)Pb(3.08)Bi(11.46)Se21, Rb(0.69)Pb(3.69)Bi(11.31)Se21, and Cs(0.65)Pb(3.65)Bi(11.35)Se21 were determined. The compounds A(1-x)M(4-x)Bi(11+x) Se21 crystallize in a new structure type with the monoclinic space group C2/m, in which building units of the Bi2Te3 and NaCl structure type join to give rise to a novel kind of three-dimensional anionic framework with alkali-ion-filled tunnels. The building units are assembled from distorted, edge-sharing (Bi,Sn)Se6 octahedra. Bi and Sn/Pb atoms are disordered over the metal sites of the chalcogenide network, while the alkali site is not fully occupied. A grand homologous series Km(M6Se8)m(M(5+n)Se(9+n)) has been identified of which the compounds A(1-x)M(4-x)Bi(11+x)Se21 are members. We discuss here the crystal structure, charge-transport properties, and very low thermal conductivity of A(1-x)M(4-x)Bi(11+x)Se21.     

Structure and properties of single crystalline CaMg2Bi2, EuMg2Bi2, and YbMg2Bi2

Single crystals of CaMg(2)Bi(2), EuMg(2)Bi(2), and YbMg(2)Bi(2) were obtained from a Mg-Bi flux cooled to 650 °C. These materials crystallize in the CaAl(2)Si(2) structure-type (P ?3m1, No. 164), and crystal structures are reported from refinements of single crystal and powder X-ray diffraction data. EuMg(2)Bi(2) displays an antiferromagnetic transition near 7 K, which is observed via electrical resistivity, magnetization, and specific heat capacity measurements. Magnetization measurements on YbMg(2)Bi(2) reveal a weak diamagnetic moment consistent with divalent Yb. Despite charge-balanced empirical formulas, all three compounds are p-type conductors with Hall carrier concentrations of 2.0(3) × 10(19) cm(-3) for CaMg(2)Bi(2), 1.7(1) × 10(19) cm(-3) for EuMg(2)Bi(2), and 4.6(7) × 10(19) cm(-3) for YbMg(2)Bi(2), which are independent of temperature to 5 K. The electrical resistivity decreases with decreasing temperature and the resistivity ratios ρ(300 K)/ρ(10 K) ≤ 1.6 in all cases, indicating significant defect scattering.     

硝酸钾电解质溶液水化结构的分子动力学模拟

Molecular dynamics simulations were carried out to study the structure of ion clusters and hydration properties of KNO3 solution. The water molecule was treated as a simple-point-charge (SPC) model, and a four-site model for the nitrate ion was adopted. Both the Coulomb and Lennard-Jones interactions between all the charged sites were considered, and the long-range Coulomb electrostatic interaction was treated using Ewald summation techniques. The configuration of ionic pairs, the radial distribution function of the solution, and the effect of solution concentration on ionic hydration were studied in detail. It was found that there are ionic association phenomena in KNO3 solution and that the dimeric, triplet, solvent-separated ion pairs, and other complex clusters can be observed at high ionic concentration condition. As the concentration of solution decreases, the ionic hydration number increases, 5-7 for cation K+ and 3.5-4.7 for anion NO3-, which is in good agreement with former Monte Carlo and time-of-flight neutron diffraction results.     

Diffusive flux of nanoparticles through chemically modified alumina membranes

Surface chemistry plays an important role in determining flux through porous media such as in the environment. In this paper diffusive flux of nanoparticles through alkylsilane modified porous alumina is measured as a model for understanding transport in porous media of differing surface chemistries. Experiments are performed as a function of particle size, pore diameter, attached hydrocarbon chain length and chain terminus, and solvent. Particle fluxes are monitored by the change in absorbance of the solution in the receiving side of a diffusion cell. In general, flux increases when the membranes are modified with alkylsilanes compared to untreated membranes, which is attributed to the hydrophobic nature of the porous membranes and differences in wettability. We find that flux decreases, in both hexane and aqueous solutions, when the hydrocarbon chain lining the interior pore wall increases in length. The rate and selectivity of transport across these membranes is related to the partition coefficient (K(p)) and the diffusion coefficient (D) of the permeating species. By conducting experiments as a function of initial particle concentration, we find that K(p)D increases with increasing particle size, is greater in alkylsilane-modified pores, and larger in hexane solution than water. The impact of the alkylsilane terminus (-CH(3), -Br, -NH(2), -COOH) on permeation in water is also examined. In water, the highest K(p)D is observed when the membranes are modified with carboxylic acid terminated silanes and lowest with amine terminated silanes as a result of electrostatic effects during translocation.     

High-pressure anisotropic distortion of Pb3Bi2S6: a pressure-induced, reversible phase transition with migration of chemical bonds

The compound Pb 3Bi 2S 6 is investigated by X-ray diffraction on single crystals in a diamond-anvil cell between 0.0001 and 10.5 GPa. It undergoes a first-order phase transition at hydrostatic pressure between 3.7 and 4.9 GPa. The space group symmetry changes from Bbmm to Pbnm, and the unit-cell volume decreases by 4%. The transition is strongly anisotropic, with a contraction along one of the crystal axes by 16% and expansion along another one by 14%. This is a piezoplastic phase transition, a displacive pressure-induced phase transition with systematic shearing of atomic planes and a migration of chemical bonds in the structure. In the case of Pb 3Bi 2S 6 the transition is achieved by the change of the archetypal architecture of the structure-building modules from a PbS-like to a SnS-like arrangement and a loss of mirror planes on the contact surfaces of modules. The phase transition is reversible with a preservation of the single crystal, which is a result of the stereochemical influence and migration of the s (2) lone electron pairs of Pb (II) and Bi (III).     

SEPARATING SCN^- FROM DESULPHURIZATION WASTE SOLUTION OF COCKING PLANT BY D241 RESIN

SCN- from desulphurization waste solution of cocking plant was separated by D241 anion exchange resin. When SCN- concentration of the waste liquid is 0.116mg/ml, its dynamic exchange capability is 93.61 mg/g resin. The condition of use KOH as eluted solution to elute SCN- is KOH concentration 0.5mol/L, flow velocity 60 ml/h, with 60ml eluted solution can completely elute SCN- which exchanged from waste solution. Vaporized the eluted solution, obtain the KSCN crystal in which the concentration of SCN- is 53.34%, converts to KSCN is 89.2%. SCN- crystal was separate out from Na2S2O3/KOH mixed solution. The relationship between the proportion of Na2S2O3/KOH,free liquids in crystal and the saturation solution volume when crystal appear、 the content of KSCN in crystal: the ratio of K2S2O3/KSCN show direct ratio with the saturation solution volume when the crystal birth, r2=0.9964; when the ratio of K2S2O3/KSCN is between 0.15 and 0.25, the content of SCN in the crystals grow with K2S2O3 content increases, the content of free liquids in crystal also along with it increase; When the ratio of Na2S2O3/KOH is 0.15, the content of SCN- is 54.56%;convert to KSCN is 76.2%. When the ratio of K2S2O3/KSCN is 0.25, the content of SCN- is 65.28%;convert to KSCN is 91.2%. When the ratio of K2S2O3/KSCN exceeds 0.25, the content of SCN- in the crystals and the content of free liquids in crystal reduce when the ratio of K2S2O3/KSCN increase.     

Fluorescence Spectra of Model Compounds for Light-emitting Alternating Copolymers in Heterogeneous Environments

Cao1 et al. reported that certain surfactant-like additives dissolved or dispersed in the EL polymer significantly improved electron injection from relatively high work function metals such as Al. The open question is what effect of surfactant on the photophysical properties is. Up to now, no report concerning this aspect has been documented. In our previous work2, a type of novel high-efficiency light-emitting nitrogen-containing poly (phenylene vinylene) (PPV)-related copolymers was synthe…     

Bismuth Detection in Alkaline Electrolyte via Anodic Stripping Voltammetry for Battery Separator Evaluation

Anodic stripping voltammetry (ASV) has been widely used for the detection of several heavy metal ions in neutral and acidic solution, in many cases employing electrodes and/or solutions incorporating Bi. In this work we demonstrate that Bi(OH)₄⁻ ion concentration can be measured in highly alkaline 8.5 M KOH solution using ASV. The addition of Pb in similar concentrations to the Bi(OH)₄⁻ being measured is shown to improve both the sensitivity and precision of the method. When the Pb additive is employed, a formal limit of detection of 8.5 ppb is achieved, compared to 17.3 ppb when the Pb additive is not used. Due to the use of Bi additives in alkaline battery chemistries, it follows that separators which limit Bi(OH)₄⁻ diffusion into the bulk electrolyte and away from the electrodes are of interest. For this purpose, we utilize ASV to determine Bi(OH)₄⁻ diffusion rates through Celgard 3501, cellophane 350P00, and Nafion 211. Bi(OH)₄⁻ crossover rates, as determined by ASV, are shown to be repeatable and consistent with expectations from the known separator structure.