二碘化铕的相变结构及荧光性质

本文用ＤＴＡ、Ｘ－ｒａｙ粉末衍射和荧光光度计等方法研究了ＥｕＩ２的相变和结构及荧光性质，用退火和淬火的方法得到了ＥｕＩ２的三种不同结构，并在荧光光谱上有不同的反映，首次发现ＥｕＩ２的低温变体，ＥｕＩ２－Ⅲ，正交晶系，空间群为ｐｎｍａ，ａ＝１．２２８７ｎｍ，ｂ＝０．４８８７ｎｍ，ｃ＝０．８３８４ｎｍ，Ｚ＝４。     

石墨炉原子吸收光谱法测定虾粉中镉含量的不确定度评定

对石墨炉原子吸收光谱法测定虾粉中镉含量进行了不确定度评价。分析了整个测试过程中不确定度的来源,并对各不确定度分量进行了计算,当虾粉中镉的含量为0．389mg／kg时,扩展不确定度为0．008mg／kg（k=2）。     

固体粒子对板式膜吸收过程的传质强化

分别采用纯CO2-去离子水和不同浓度的NaOH溶液为实验体系,在板式膜器中研究了第三相固体粒子对膜吸收过程传质效果的影响．分别考察了在不同粒子种类、搅拌转速、传质体系、化学反应强度、膜孔隙率等因素下固体粒子对传质强化的影响．结果表明,随着粒子固含率的增大,传质系数和增强因子均有所提高,当粒子固含率增大到一定范围后,传质系数和增强因子的变化趋于平缓．在固含率一定的条件下,不同种类的固体粒子对膜吸收过程的强化效果随着固体粒子密度的增加而减小．传质系数随着搅拌转速的增大而增大,但高搅拌转速下固体粒子的强化作用减弱．膜吸收过程的传质系数和增强因子随着化学反应强度的增强而增加．随着粒子固含率的增大,不同膜孔隙率对传质效果的差异减小,且孔隙率越小,固体粒子对膜吸收传质过程的强化效果越好．其中,对于纯CO2-去离子水体系,当孔隙率为20％,粒子固含率为1．5gL^（-1）时,固体粒子的加入可使传质系数提高1．45倍,增强因子可达2．45．     

C−H?Pd interactions and cyano-bridged heteronuclear polymeric complexes

Three new heterometallic complexes, [Cu(N-Meim)₄Pd(μ-CN)₂(CN)₂]_n (1), [Zn(N-Meim)₃Pd(μ-CN)₂(CN)₂]_n (2) and [Cd(N-Meim)₂Pd(μ-CN)₄]_n (3), have been isolated from the reactions of M[Pd(CN)₄] (M = Cu(II), Zn(II) or Cd(II)) and N-Meim (N-methylimidazole) with in different molar ratios. All complexes have been characterized by X-ray analyses, vibrational (FT-IR and Raman) spectra, thermal and elemental analyses. The crystallographic analysis reveals that the crystal structures of 1 and 2 are 1D coordination polymer, while 3 presents a 2D network. In the Cu(II) and Zn(II) complexes, two cyanide groups of [Pd(CN)₄]²⁻ coordinated to the adjacent M(II) ions and distorted octahedral and square pyramidal geometries of complexes are completed by four and three nitrogen atoms of N-Meim ligands, respectively. The Cd(II) ion is six-coordinate, completed with the two nitrogen atoms of N-Meim ligands in the axial positions and the four nitrogen atoms from bridging cyano groups in the equatorial plane. The most striking features of complexes 1-3 are the presence of obvious C-H?Pd hydrogen-bonding interactions between the Pd(II) and hydrogen atoms of N-Meim ligand. This weak hydrogen bonding plays a crucial role in the architecture of the network polymers. The adjacent chains are held together by C-H?Pd, C-H?π or π?π interactions, forming three-dimensional network.     

Laser-induced fluorescence and infrared spectroscopic studies on the specific solvation of tris(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)europium(III) in an ionic liquid

The extraction constant and the two-phase stability constant (K_D,Mβ₃) of tris(2-thenoyltrifluoroacetonato)europium(III) between 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C₄mim][Tf₂N]) as an ionic liquid and an aqueous phase were determined by considering the extraction equilibria including anionic tetrakis(2-thenoyltrifluoroacetonato)europate(III). Specific solute-solvent interactions between the neutral Eu(III) chelate and [C₄mim][Tf₂N] molecules were revealed from the relationships between the distribution constant of the enol form of 2-thenoyltrifluoroacetone (Htta) as a proton chelate and the distribution constant (K_D,M) of the neutral Eu(III) chelate because the [C₄mim][Tf₂N] system gave the high K_D,Mβ₃ value compared with those in conventional molecular solvents such as benzene and 1,2-dichloroethane. The coordination environment of Eu³⁺ in the neutral Eu(III) chelate in [C₄mim][Tf₂N] was investigated by time-resolved laser-induced fluorescence spectroscopy and infrared absorption spectroscopy. Both methods consistently indicated that not only the Eu(III) chelate extracted but also Eu(tta)₃(H₂O)₃ synthesized as a solid crystal were almost completely dehydrated in [C₄mim][Tf₂N] saturated with water. Consequently, the higher K_D,M or extractability of the neutral Eu(III) chelate in the [C₄mim][Tf₂N] system can be ascribed to the dehydration of the Eu(III) chelate, which is caused by the specific solvation with [C₄mim][Tf₂N] molecules.     

Tuning the physicochemical properties of diverse phenolic ionic liquids for equimolar CO2 capture by the substituent on the anion

Phenolic ionic liquids for the efficient and reversible capture of CO(2) were designed and prepared from phosphonium hydroxide and substituted phenols. The electron-withdrawing or electron-donating ability, position, and number of the substituents on the anion of these ionic liquids were correlated with the physicochemical properties of the ionic liquids. The results show that the stability, viscosity, and CO(2)-capturing ability of these ionic liquids were significantly affected by the substituents. Furthermore, the relationship between the decomposition temperature, the CO(2)-absorption capacity, and the basicity of these ionic liquids was quantitatively correlated and further rationalized by theoretical calculation. Indeed, these ionic liquids showed good stability, high absorption capacity, and low absorption enthalpy for CO(2) capture. This method, which tunes the physicochemical properties by making use of substituent effects in the anion of the ionic liquid, is important for the design of highly efficient and reversible methods for CO(2)-capture. This CO(2) capture process using diverse phenolic ionic liquids is a promising potential method for CO(2) absorption with both high absorption capacity and good reversibility.     

Time-Resolved Photoluminescence Spectra of Porous Si

Ｔｉｍｅ－ＲｅｓｏｌｖｅｄＰｈｏｔｏｌｕｍｉｎｅｓｃｅｎｃｅＳｐｅｃｔｒａｏｆＰｏｒｏｕｓＳｉＦＥＩＨａｏ－ｓｈｅｎｇ，ＨＡＮＬｉ，ＣＨＥＹａｎ－ｌｏｎｇ，ＮＩＥＲｕｉ－ｊｕａｎａｎｄＬＩＴｉｅ－ｊｉｎ（ＤｅｐａｒｒｍｅｎｔｏｆＰｈｙｓｉｃｓａｎｄＤ...     

An Explanation on the Electron Ionization Mass Spectra of Crown Ethers by MNDO Computational Method

ＡｎＥｘｐｌａｎａｔｉｏｎｏｎｔｈｅＥｌｅｃｔｒｏｎＩｏｎｉｚａｔｉｏｎＭａｓｓＳｐｅｃｔｒａｏｆＣｒｏｗｎＥｔｈｅｒｓｂｙＭＮＤＯＣｏｍｐｕｔａｔｉｏｎａｌＭｅｔｈｏｄＹＵＡＮＨｕ－ｓｈａｎ，ＴＡＮＧＭｉｎｇ－ｓｈｅｎｇａｎｄＷＵＹａｎｇ－ｊｉｅ（...     

铁酸镁超微粒子的制备及结构特征

采用两种方法制得了尖晶石结构纯相MgFe2O4样品．Moessbauer分析发现，一种样品表现出了完全的超顺磁性，另一种表现出了部分超顺磁性．这揭示出了样品具有很小的粒子尺度．首次在实验上发现了MgFe2O4IR-V2谱带的劈裂现象，报导了拉曼光谱，通过ESR分析，进一步揭示了两样品的结构特征，并讨论了性质之间的相关性。     

蒙旦树脂化学组成的研究

采用阴离子交换色谱和硅胶－氧化铝柱色谱对云南寻甸蒙旦树脂（ＸＤＳＺ）、潦浒蒙旦树脂（ＬＨＳＺ）、昭通蒙旦树脂（ＺＴＳＺ）和吉林舒兰蒙旦树脂（ＳＬＳＺ）进行了族组分的分离。树脂游离酸，树脂结合酸，树脂烃和树脂醇在各树脂中的百分含量分别为ＸＤＳＺ１１．８６，８．７６，１２．３０，４５．９９；ＬＨＳＺ１５．８９，１３．９１，４．９０，４５．９９；ＳＬＳＺ２５．４６，８．０７，１７．４０，３６．２２；ＺＴ