Interaction of methanesulfonic acid with actinide ions. The new complexes HImid[Np(C2O4)(CH3SO3)3(H2O)2], [NpO2(Terpy)(CH3SO3)(H2O)]·2H2O, and [UO2(CH3SO3)2(H2O)]

Complexation of methanesulfonic acid with Np(IV), Np(V), and U(VI) ions in aqueous solutions was studied. New crystalline compounds HImid[Np(C₂O₄)(CH₃SO₃)₃(H₂O)₂] (I), [NpO₂(Terpy)(CH₃SO₃)·(H₂O)]·2H₂O (II), and [UO₂(CH₃SO₃)₂(H₂O)] (III) were isolated. The absorption spectra of all the compounds in the IR, visible, and UV ranges were examined. The relationship between the composition, crystal structure, and IR and electronic absorption spectra of the complexes is discussed. Original Russian Text ? G.B. Andreev, N.A. Budantseva, I.G. Tananaev, B.F. Myasoedov, 2009, published in Radiokhimiya, 2009, vol. 51, no. 3, pp. 197–201.     

Crystal structure of uranyl μ3-oxoacetate [(UO2)3(μ3-O)2(OOCCH3)2(H2O)2]

The crystal structure of [(UO₂)₃(₃-O)₂(OOCCH₃)₂(H₂O)₂] consists of uranium coordination polyhedra (CPs) combined via common equatorial edges into ribbons, with ₃-O atoms being common for three CPs. The structure was compared with that of known complexes with ₃-oxo atoms.Translated from Radiokhimiya, Vol. 46, No. 5, 2004, pp. 396–400.Original Russian Text Copyright © 2004 by Charushnikova, Krot, Starikova.     

FeVO4/Cu3(BTC)2(H2O)3异质结制备及光催化性能

以Cu片和1, 3, 5-苯三甲酸为原料,电化学法制备经典Cu-MOF材料Cu₃(BTC)₂(H₂O)₃,即HKUST-1,作为基底金属有机框架材料(MOFs),采用室温沉积法制备FeVO₄/HKUST-1异质结复合材料,通过XRD、SEM、BET、UV-Vis DRS等对其晶体结构、形貌、比表面积、光吸收性能等进行了表征。结果表明:FeVO₄与HKUST-1复合形成异质结后,有利于光生电子-空穴的产生和转移,对目标染料污染物罗丹明B(RhB)的降解性能显著增强。可见光照射120 min后,异质结体系中RhB的降解率可达93%,而单一FeVO₄或HKUST-1体系中仅为12%和5%。此外,对材料的组成比例进行了优化,当FeVO₄与HKUST-1摩尔比为1∶1时,制备的FeVO₄/HKUST-1复合材料具有最佳的光催化性能。进一步,考察了其循环使用的稳定性,循环5次后对RhB的降解效率仍保持在90%以上,稳定性良好。      

多孔材料[ZnNa（H3btc）（H2O）2]·（H2O）2的合成、晶体结构及吸附性能研究

合成了一种多孔金属有机骨架材料[ZnNa(H3btc)(H2O)2].(H2O)2,分析晶体结构,并采用体积法气体吸附实验,考察了该配合物的吸附气体性能。实验测试结果表是:该配合物为双核,中心Zn2+与三羧基和二个水构成双四面体配位模式),中心Na+与四羧基和二个水构成正八面体配位模式;该配合物对CO2饱和吸附量较大,在p=20bar,t=20℃条件下达到14.25mmol/g,且随着温度升高,可缩短饱和吸附时间,但吸附性能有所下降。     

Crystal and molecular structure of a crystal solvate of cesium tris(pivaloyltrifluoroacetonato)dioxouranate, Cs[UO2(ButCOCHCOCF3)3]·1.5C6H6·H2O

The crystal and molecular structure of cesium tris(pivaloyltrifluoroacetonato)uranylate prepared in the form of a crystal solvate Cs[UO₂(Bu ^t COCHCOCF₃)₃]·1.5C₆H₆·H₂O was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic system, a = 26.9099(9), b = 13.1549(4), c = 24.4586(8) ?, β = 90.418(2)°, V = 8658.0(5) ?³ (at 100 K), Z = 8, space group C2/c. Of the three β-diketonate ligands, two are coordinated to the uranyl ion in the bidentate fashion, and the third ligand, in the monodentate fashion, so that the equatorial coordination number of the uranyl ion is 5. The crystal structure is built of sandwich-type dimers in which two cesium cations are arranged between two tris(pivaloyltrifluoroacetonato)uranylate anions. The coordination sphere of the cesium cation is built of oxygen atoms of the β-diketone and uranyl groups, fluorine atom of the CF₃ group, and π-coordinated benzene molecule. In addition, 0.5 benzene molecule and one water molecule (per formula unit) occupy structural voids.     

Thermodynamic properties of (TeO2)0.95 ? n ? z(ZnO)z(Na2O)n(Bi2O3)0.05 glasses

The heat capacity (C _p ⁰) of the tellurite glasses

Al(H2PO2)3/聚氨酯弹性体复合材料的制备及阻燃性能

采用熔融共混技术,将Al（H₂PO₂）₃引入聚氨酯热塑性弹性体,制备了一系列次磷酸铝/聚氨酯弹性体复合材料（Al（H₂PO₂）₃/TPU）。采用极限氧指数（LOI）、垂直燃烧（UL-94）、锥形量热测试、TG和SEM研究了Al（H₂PO₂）₃对Al（H₂PO₂）₃/TPU复合材料阻燃性能及热稳定性的影响,采用力学测试研究Al（H₂PO₂）₃对其力学性能的影响。阻燃测试表明,Al（H₂PO₂）₃可以有效提高Al（H₂PO₂）₃/TPU复合材料的阻燃性能。当Al（H₂PO₂）₃添加量为20wt%时,Al（H₂PO₂）₃/TPU复合材料UL-94级别达到V-0级,LOI达到30.5vol%。热重测试表明,Al（H₂PO₂）₃的加入会导致复合材料热分解温度降低,但其残炭率有明显升高。锥形量热测试表明,Al（H₂PO₂）₃的加入有效降低复合材料热释放速率峰值（pHRR）和总热释放（THR）,并明显提高其火灾安全性能,其中20wt% Al（H₂PO₂）₃/TPU的pHRR和THR相对纯TPU分别下降65.7%和20.2%。SEM表明,Al（H₂PO₂）₃/TPU复合材料炭渣致密性有明显提高。在此基础上,采用TGA-FTIR联用分析Al（H₂PO₂）₃/TPU复合材料阻燃机制,研究发现,Al（H₂PO₂）₃在燃烧过程中可以有效促进TPU裂解产物成炭,降低可燃性气体生成量,从而提高复合材料阻燃性能。     

Room temperature metathetic synthesis and characterization of α-hopeite, Zn3(PO4)2·4H2O

The synthesis of crystalline zinc phosphates (α-hopeite phase) through the metathetic pathway has been investigated. The reaction has been carried out by room-temperature grinding. High lattice energy of the by-product NaCl has driven the reaction in the forward direction, and as a result, stable phosphate phases have been synthesized. Reaction of a different phosphorus source (like Na₃PO₄, Na₂HPO₄, NaH₂PO₄, and K₂HPO₄) with ZnCl₂ has been attempted. The structural, vibrational, thermal, optical, and chemical properties of synthesized powders are determined by powder X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and diffused reflectance spectra (DR) in the UV-vis range. The direct band gap of the title compound was determined to be 3.6 ± 0.2 eV.     

H2掺混比例对NH3自燃温度影响的数值模拟

氨-氢融合是提高NH₃活化氛围解决车用氨燃料着火难、可燃域窄和燃烧速度慢的有效途径。为了揭示掺氢比例对氨自着火温度的影响规律及作用机制，采用Chenkin化学动力学软件计算了氨氢混合物(H₂/NH₃=0～100%)在初始压力1～50 bar，当量比0.5、1和2时的自燃温度。结果发现：当掺氢比例低于30%时，可明显降低氨氢混合物的自燃温度。初始压力升高，对氨氢混合物着火起促进作用，但随着氢气掺混比例增加这种促进作用被不断弱化。当氨气比例较高时，链分支反应：NH₂+NO=NNH+OH是主要促进着火的反应，但随着氢气比例升高被第三体链分支反应：H₂O₂(+M)=OH+OH(M)替代。     

A facile chemical route to α-Zn3(PO4)2·4H2O hierarchical sphere structures assembled by nanosheets

Novel α-Zn₃(PO₄)₂·4H₂O hierarchical sphere structures have been synthesized by a simple chemical method through the reaction between zinc acetate and orthophosphoric acid by using cetyltrimethylammonium bromide (CTAB) as capping reagent at room temperature. The structures and morphologies of the as-obtained products were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The influences of the synthetic parameters on the morphologies of the final products were investigated. The experimental results clearly show that both the concentration of CTAB aqueous solution and the concentration of initial reagents play important roles in the formation of the α-Zn₃(PO₄)₂·4H₂O hierarchical sphere structure. Detailed proofs indicated that the process of crystal growth was dominated by a self-assembly growth mechanism.     

含钛磷酸盐玻璃NaTi2(PO4)3-0.9Ca3(PO4)2的析晶行为

利用差热分析、X射线衍射仪、液氮吸附BET孔经测试仪对组成为NaTi2(PO4)3-0.9 Ca3(PO4)2的含钛磷酸盐玻璃的析晶行为进行了研究.通过对该玻璃相继进行成核、析晶和酸浸泡处理制备了NaTi2(PO4)3骨架多孔微晶玻璃.证明该玻璃在646℃8h成核处理过程中产生了旋节分解特征的成分偏聚,形成了富TiO2玻璃相和富CaO玻璃相交错生长的连通结构,成核处理后的玻璃在738℃析晶过程中依次在富钛相和富钙相中析出NaTi2(PO4)3和β-Ca3(PO4)2.成核过程对析晶的促进作用是通过促进NaTi2(PO4)3的析出而实现的.     

硼酸钾钙(K2O·CaO·4B2O3·12H2O)的结晶动力学

以硼酸、氢氧化钾和二水氯化钙为原料,以水为溶媒,采用易于工业化、无污染的水溶液法制备形貌规整、尺寸均匀的硼酸钾钙(K_2O·CaO·4B_2O_3·12H_2O)晶体。在20℃下,对K_2O·CaO·4B_2O_3·12H_2O晶体进行结晶过程研究,得到K_2O·CaO·4B_2O_3·12H_2O的动力学方程和相关的反应速率方程。     

NH3/CO2制冷系统的研究

介绍了CO₂作为冷媒的主要特点及其制冷系统形式,论述了NH₃/CO₂制冷技术的研究内容和试验结论,提出了NH₃/CO₂制冷系统的最佳适用范围。通过大量的系统试验数据和分析表明,NH₃/CO₂制冷系统有着极高的运行效率和安全、环保效应。CO₂因其环保和节能的特点在不久的将来将成为最有前景的制冷剂之一。     

NH3/CO2制冷系统应用分析

本文对NH₃/CO₂制冷系统应用进行了简要分析,从安全和节能等多个方面论述了NH₃/CO₂制冷系统的优势,并介绍了NH₃/CO₂制冷系统在相关项目应用的情况。     

Microwave-assisted preparation of Ca6Si6O17(OH)2 and β-CaSiO3 nanobelts

Xonotlite (Ca₆Si₆O₁₇(OH)₂) nanobelts were synthesized by a microwave-assisted hydrothermal method at 180 °C for 90 min independent of the feeding molar ratio of Ca(NO₃)₂·4H₂O to Na₂SiO₃·9H₂O in the range of 0.8-3.0. Crystalline wollastonite (β-CaSiO₃) nanobelts were obtained by microwave thermal transformation of Ca₆Si₆O₁₇(OH)₂ nanobelts at 800 °C for 2 h. Ca₆Si₆O₁₇(OH)₂ nanobelts were used as both the precursor and the template for the preparation of β-CaSiO₃ nanobelts. The morphology and size of Ca₆Si₆O₁₇(OH)₂ nanobelts could be well preserved during the microwave thermal transformation process. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and selected area electron diffraction (SAED).     

Mesolamellar phases containing [Fe(CN)6]3? anion

The mesostructured lamellar phases with the general formula [C _n H_2n+1N(CH₃)₃]₃[Fe(CN)₆] (n = 14, 16, 18) were prepared by ion-exchange/precipitation reaction of alkyltrimethylammonium surfactants and K₃[Fe(CN)₆] complex in aqueous medium. The phases were characterized using powder X-ray diffraction, high-resolution transmission electron microscopy, IR spectroscopy, thermogravimetric, and differential scanning calorimetry means. The results obtained all support a proposed model of crystal structure for these materials, in which the layers are constructed by monolayer of the discrete complex molecules, and the surfactants tails of opposite head groups deeply penetrate and arrange with a tilt angle of 63°.     

[Ru(bpy)2L](PF6)2 /Pt/TiO2光催化剂的合成及其可见光驱动分解水产氢性能研究

合成了一个新的光敏配合物[Ru(bpy)2L](PF6)2(RHIPB,L=2-羟-4-(1-氢咪唑并[4,5-f]1,10-邻菲罗啉)基苯甲酸),通过IR、MS、UV-Vis、SEM、XRD、CV等手段对目标化合物的结构和性质进行了表征。以RHIPB为光敏剂,制备了光催化剂6%RHIPB/0.5%Pt/TiO2(质量分数)(Ⅰ),系统考察并优化了目标光化剂的光催化分解水产氢性能。实验结果表明:在100mL含50mg复合光催化剂6%RHIPB/0.5%Pt/TiO2的水中,当牺牲剂TEOA浓度为5%(体积比),pH=5时,在可见光照射下,催化剂可持续产氢3h,平均产氢速率2578μmol·h-1·g-1。机理研究表明激发态的光敏剂分子RHIPB*可以将电子注入TiO2的导带,从而激发催化反应。     

稀土铽配合物Tb（4-ClBA）3·2H2O变温荧光性能研究

利用高温附件和荧光光谱研究了稀土铽配合物Tb(4-ClBA)3.2H2O的变温荧光性能。温度变化范围是50～300℃。结果表明,该配合物随着温度的升高荧光发射强度总体趋势逐渐下降,随着温度下降,荧光强度逐渐增加。该配合物经过6次升温-降温循环测定,其荧光发射强度总体上依然保持稳定的下降-增加趋势。对比其它类型稀土配合物,Tb(4-ClBA)3.2H2O具有热稳定性良好,可在50～300℃循环使用的特点。这为高灵敏度荧光-温度传感器的应用提供了新型的材料。     

稀土永磁材料Sm3(Fe,Ti,Co)29Nx

研究了Sm3(Fe,Ti,Co)29母合金的制备工艺,并对合金元素的选择及添加量进行了探讨.试验研究发现Ti元素可有效抑制α-Fe的生成并起到稳定Sm-Fe 329相的作用;熔炼时至少熔炼四遍可得到组织均匀的铸态试样;合理设计加料顺序可以减小Sm的挥发量,多加入20%～30%的Sm可有效的补偿Sm的挥发.成功的制备了Sm3(Fe,Ti,Co)29 329相母合金.     

Reducing ultra-low thermal expansion of β-Zr2O(PO4)2 by substitutions?

The ultra-low thermal expansion of β-Zr₂O(PO₄)₂ could still be reduced by chemical modifications, according to previous works on uranium and thorium IV homologues that evidenced a contracting effect of big cations. However, the present study shows that the only isovalent cations likely to substitute for Zr^IV or P^V are either harmful, or unstable, chemically or thermally. Furthermore, aliovalent modifications seem to be forbidden by the crystal structure of the material, leaving probably very few perspectives of improvement. Vanadium however improves significantly the crystallinity of the material and lowers the α-β transition temperature.