TODGA树脂小柱分离-多接收电感耦合等离子体质谱（MC-ICP-MS）法测定岩石样品中Nd同位素比值

通过改进岩石样品分析物Nd的化学分离,实现Nd同位素比值的准确分析,为研究青藏高原岩石成因,揭示物质来源提供技术支持。采用TODGA萃淋树脂分离基体及其与Nd相邻的稀土元素,多接收电感耦合等离子体质谱（MC-ICP-MS）法测定Nd同位素比值,建立了简捷实用的地质样品Nd同位素分析方法。样品HF-HNO3分解, HNO3(3 mol/L )- H3BO3(0.12 mol/L)提取,上柱后,先用6 mL HCl(2.8 mol/L)淋洗干扰轻稀土,再用6 mL HCl(2.2 mol/L)淋洗分析物Nd,Nd淋洗液由MC-ICP-MS测定其同位素比值。分析国际岩石标准物质BCR-2、BHVO-2和AGV-2,所得143Nd/144Nd同位素比值（平均值 ± 2σ）分别为0.512638 ± 0.0000007、0.512990 ± 0.0000012和0.512792 ± 0.000016,这些同位素数据在误差范围内,与推荐值和文献值完全一致。方法适合各种类型地质样品,为西藏不同地区不同岩石提供了可靠的Nd同位素分析数据。     

稀土配合物Et~2NC~6H~4CH=CHC~5H~4NC~1~6H~3~3Ln(TTA)~4(Ln=La,Nd,Dy,Yb)的合成、表征与成膜性能

合成了四(α-噻吩甲酰三氟丙酮)合稀土(La,Nd,Dy,Yb)酸(E)-N-十六烷基-4-[2-(4-二乙氨基苯基)乙烯基]吡啶四个新的稀土配合物.用元素分析、紫外可见光谱、红外光谱、小角X射线衍射、差热-热重分析和摩尔电导对配合物进行了表征.研究了它们的表面压-面积(π一A)等温线行为,研究结果表明它们具有良好的成膜(Langmuir)性能,La,Nd,Dy和Yb配合物零压分子平均截面积A_(π-0)分别为1.94,1.93,1.73和1.85nm~2/分子.     

稀土配合物Et~2NC~6H~4CH=CHC~5H~4NC~1~6H~3~3Ln(TTA)~4(Ln=La,Nd,Dy,Yb)的合成、表征与成膜性能

合成了四(α-噻吩甲酰三氟丙酮)合稀土(La,Nd,Dy,Yb)酸(E)-N-十六烷基-4-[2-(4-二乙氨基苯基)乙烯基]吡啶四个新的稀土配合物。用元素分析、紫外可见光谱、红外光谱、小角X射线衍射、差热-热重分析和摩尔电导对配合物进行了表征。研究了它们的表面压-面积(π-A)等温线行为。研究结果表明它们具有良好的成膜(Langmuir)性能, La, Nd, Dy和Yb配合物零压分子平均截面积A~π~→~0分别为1.94,1.93,1,73和1.85nm^2/分子。     

配合物[Li(DME)~3] [(t-BuCp)~2Nd(NPh~2)~2]·1/2 DME的合成及晶体结构

本文合成了配合物[ Li(DME)~3] [(t-BuCp)~2Nd(NP-h~2)~2]·1/2 DME 并测定了其晶体结构. 晶体结构利用Patterson 和Fourier 技术得到, 并经最小二乘法修正.转入各向异性温度因子后, 按理论模型投入所有氢原子坐标, 最后一致性因子R=0.042, Rw=0.040.     

(Ce0.9Nd0.1)1-xMoxO2-δ(0.00≤x≤0.10)的合成、表征与电性能

采用溶胶-凝胶法合成(Ce0.9Nd0.1)1-xMoxO2-δ(x=0.00、0.02、0.05、0.10)氧化物,通过X射线衍射(XRD)、场发射扫描电镜(FESEM)等手段对氧化物进行结构表征,交流阻抗谱测试电性能.结果表明:所有样品均为单一萤石立方结构;少量MoO3的加入提高了材料的致密性,降低了材料的总电阻、晶界电阻和晶界电阻在总电阻中所占比例,提高了材料的电导率.1200 ℃烧结样品24 h,测试温度700℃时,(Ce0.9Nd0.1)1-xMoxO2-δ(x=O.00)总电导率和晶界电导率分别为0.05和O.19 S·m-1,掺Mo材料(Ce0.9Nd0.1)1-xMoxO2(x=0.02)的总电导率和晶界电导率分别为2.42和3.96 S·m-1.     

钕修饰载体的PtRu/Nd/C薄膜结构及电催化性能

采用离子束多靶溅射沉积技术(IBS),在Nd修饰的碳载体上制备了PtRu/Nd/C纳米合金薄膜作为直接甲醇燃料电池(DMFC)阳极催化剂,并对PtRu/Nd/C薄膜催化剂进行了不同条件的氧化处理.应用XRD,XPS,AFM等分析手段研究了薄膜表面的成分、化学状态、结构及表面形貌,并用循环伏安法(CV)测试了薄膜催化剂对甲醇的催化氧化性能.结果表明,由于溅射产生的Pt+,Ru+和稀土Nd膜层之间的相互作用,使PtRu/Nd薄膜的表面形貌发生粗化并抑制了PtRu薄膜表层的择优生长,增大了PtRu/Nd/C薄膜催化剂的电化学比表面积,催化活性明显提高;经氧化处理后,PtRu/Nd/C催化剂表面RuO2物种数量增加,进一步提高了催化剂对甲醇的催化性能,特别是PtRu/Nd/C薄膜催化剂经40min的氧化处理后,出现异常的电流峰.     

(C5H5)2NdCl·2LiCl 与正丁基锂的反应: [Li(DME)3][(C5H5)3Nd(μ-H)Nd(C5H5)3]的合成及其晶体结构

研究了(C5H5)2NdCl·2LiCl与正丁基锂在THF溶液中的反应, 并从该反应液中分离到了钕的氢化物[Li(DME)3][(C5H5)3Nd(μ-H)Nd(C5H5)3] 1. 化合物1经X射线单晶结构测定表明属单斜晶系, 空间群P21/c, 晶胞参数为a=0.9670(2) nm, b=2.1001(5) nm, c=2.1279(7) nm, β=90.89(2)°, Z=4, V=4.321 (2) nm3, Mr=957.36, Dc=1.47 g·cm-3, F(000)=1936, R=0.094, wR=0.100. 1的晶胞中包含两个独立的晶体分子, 每一分子由阴阳离子对[Li(DME)3]+和[(C5H5)3Nd(μ-H)Nd(C5H5)3]-组成. 钕原子与3个η5-C5H5基团配位, 且两个(C5H5)3Nd经氢桥键相连构成阴离子. Nd1-H和Nd2-H键长均为0.218(1) nm.     

红酒中的~(87)Sr/~(86)Sr同位素比测定

研究了多接收电感耦合等离子体质谱(MC-ICP-MS)测定红酒样品中87Sr/86Sr同位素比的分析方法,并用建立的分离测定方法参加了欧洲参考物质与测量研究所(IRMM)组织的CCQM-P105国际比对,即红酒中87Sr/86Sr同位素比的分析比对.红酒样品经微波消解后,采用Dowex 50W×8树脂分离纯化锶,用MC-ICP-MS精确测定锶组分中的87Sr/86Sr同位素比,同时对测量结果的不确定度进行了分析和评定.     

[Li3DME][(η~5-C_5H_5)_3Nd(μ-H)Nd(η~5-C_5H_5)_3]的合成及其分子结构

标题配合物是以THF作溶剂,通过(C_5H_5)_2NdCl·ZLiCl和甲基萘钠的还原反应合成的。其晶体属单斜晶系,P 2/c空间群,晶胞参数α=9.235(2)A,b=11.695(2)A,c=20.810(3)A,β=92.88(1)°,Z=2。研究结果表明,标题配合物由相互不相联的〔Li3DME〕~ 和〔(η~5-C_5H_5)_3Nd(μ-H)Nd(η~5-C_5H_5)_3〕~-离子对组成。阳离子中,Li原子与由3个DME提供的6个O原子配位,形成八面体构型,Li—O平均键长为2.116A;阴离子中,2个Nd原子不直接键合,系通过桥H联接,Nd—H=2.19A。此外,每个Nd原子各有3个C_5H_5~-与之配位,Nd—C平均键长为2.812A。     

热电离质谱法测定次纳克级钕同位素比值

采用热电离质谱法测定次纳克级钕同位素的比值。应用金属铼带对0.1~0.5ng Nd同位素标准样品进行测定,在不添加任何发射剂或者电离增强剂的条件下,采用特定的聚焦程序,获得了0.4~1V的142 Nd+稳定离子流,持续时间可达30min以上。电流范围在1 700~2 000mA之间时,质量分馏效应缓慢变低稳定。应用此方法对42个0.1~0.5ng La Jolla国际标准样品和18个0.1~0.5ng LRIG-Nd室内参考标准样品进行测定,143 Nd/144 Nd比值分别为0.511 852±0.000 002(2SE)和0.512 201±0.000 003(2SE),与其他报道参考值相符。     

Precise thermal ionization mass spectrometric measurements of 142Nd/144Nd and 143Nd/144Nd isotopic ratios of Nd separated from geological standards by chromatographic methods

A chromatographic separation technique for ¹⁴²Nd/¹⁴⁴Nd and ¹⁴³Nd/¹⁴⁴Nd isotope ratio measurements is established and applied to the analyses of geological standards of basaltic compositions (BCR-2, BIR-1) using Isoprobe-T TIMS. The instrument was tested for reliability and reproducibility to measure Nd isotope composition using the synthetic standard JNdi-1. The techniques were also applied to a carbonatite lava sample, OL-6, Oldoinyo Lengai, to check the validity of method for carbonatite matrix. The isotope ratios of ¹⁴³Nd/¹⁴⁴Nd for synthetic Nd standard JNdi-1, geological standards BCR-2, BIR-1, and carbonatite lava sample OL-6 obtained by these methods are in good agreement with previously published data. The ¹⁴³Nd/¹⁴⁴Nd values for JNdi-1 and BCR-2 have an external precision of ±13 ppm and ±15 ppm (2σ), respectively. The JNdi-1 and BCR-2 data for ¹⁴²Nd/¹⁴⁴Nd has an external precision of ±12 ppm and ±8 ppm (2σ), respectively. The ¹⁴²Nd/¹⁴⁴Nd composition of the two geological standards BCR-2 and BIR-1 are indistinguishable from synthetic mono-element standard JNdi-1, and they all fall within the 12 ppm (2σ) envelope of external precision. The external reproducibility is sufficient to distinguish and resolve 20 ppm anomalies in ¹⁴²Nd/¹⁴⁴Nd values.     

High-Precision Measurements of the 143Nd/144Nd Isotope Ratio in Certified Reference Materials without Nd and Sm Separation by Multiple Collector Inductively Coupled Plasma Mass Spectrometry

We present a precise and accurate method for the determination of ¹⁴³Nd/¹⁴⁴Nd isotope ratio without Nd and Sm separation by multiple collector inductively coupled plasma mass spectrometry. We corrected instrumental mass discrimination by applying the natural constant ¹⁴⁶Nd/¹⁴⁴Nd ratio as an internal standard after isobaric interference correction of ¹⁴⁴Sm on ¹⁴⁴Nd using interference-free ¹⁴⁷Sm/¹⁴⁹Sm ratio for Sm mass fractionation. The present method was validated by duplicate analyses of several certified reference materials after dissolution and cation-exchange resin purification. The precision (2σ) of the ¹⁴³Nd/¹⁴⁴Nd ratio is less than 10 ppm (internal) and 20 ppm (external), respectively.     

ICP-AES法测定稀土镁合金(ZM6)中钕、锌、锆、铁、硅元素

介绍了用ICP-AES法分析稀土镁合金(ZM6)中钕、锆等五元素．通过对分析务件的选择，排除了基体镁和共存元素的干扰，确定了分析方法，用该方法分析五元素快捷、简便、准确度扣精密度较好。     

High-spin electronic states of lanthanide-arene complexes: Nd(benzene) and Nd(naphthalene)

Neodymium (Nd) complexes of benzene and naphthalene were synthesized in a laser-ablation supersonic molecular beam source. High-resolution electron spectra of these complexes were obtained using pulsed-field ionization zero electron kinetic energy (ZEKE) spectroscopy. Second-order M?ller-Plesset perturbation calculations were employed to aid spectral and electronic-state assignments. The adiabatic ionization energies were measured to be 38 081 (5) cm(-1) for Nd(benzene) and 37 815 (5) cm(-1) for Nd(naphthalene). For the Nd(benzene) complex, the observed frequencies of 831 and 286 cm(-1) were assigned to C-H out-of-plane bending and Nd(+)-C(6)H(6) stretching modes in the (6)A(1) ion state and 256 cm(-1) to the Nd-C(6)H(6) stretching mode in the (7)A(1) neutral state. To confirm these assignments, the ZEKE spectrum of the deuterated species was recorded, and the corresponding vibrational frequencies were measured to be 710 and 277 cm(-1) in the ion state and 236 cm(-1) in the neutral state. For the Nd(naphthalene) complex, the observed vibrational modes were C(10)H(8) bending (394 cm(-1)), Nd(+)-C(10)H(8) stretching (286 and 271 cm(-1)), Nd(+)-C(10)H(8) bending (80 cm(-1)), and C(10)H(8) twisting (105 cm(-1)) in the (6)A(') ion state and metal-ligand bending (60 cm(-1)) and ligand twisting (55 cm(-1)) in the (7)A(') neutral state. The formation of the ground state of the Nd(benzene) complex requires 4f → 5d and 6s → 5d electron excitation of the Nd atom, whereas the formation of the ground state of Nd(naphthalene) involves the 6s → 5d electron promotion.     

Rapid and precise determination of Sr and Nd isotopic ratios in geological samples from the same filament loading by thermal ionization mass spectrometry employing a single-step separation scheme

Thermal ionization mass spectrometry (TIMS) offers the excellent precision and accuracy of the Sr and Nd isotopic ratio analysis for geological samples, but this method is labour intensive, expensive and time-consuming. In this study, a new analytical protocol by TIMS is presented that aims at improving analytical efficiency and cutting down experimental cost. Using the single-step cation exchange resin technique, mixed Sr and rare earth elements (REEs) fractions were separated from matrix and evaporated to dryness. Afterwards, mixed Sr + REEs fractions were dissolved and loaded onto the same Re filament using 1 μL of 2 M HCl. Then, Sr and Nd were sequentially measured without venting using TIMS. In contrast to conventional TIMS methods, the merits of this analytical protocol are its cost- and time-saving adaptations. The applicability of our method is evaluated by replicated measurements of ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd for nine international silicate rock reference materials, spanning a wide range of bulk compositions. The typical internal precision in this study is ca. 0.001% (RSE) for ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd; the analytical results obtained for these standard rocks show a good agreement with reported values, indicating the effectiveness of the proposed method.     

掺钕聚甲基丙烯酸甲酯的光学特性

Nd(DBM)3Phen-doped (DBM is dibenzoylmethane and Phen is phenanthroline) polymethyl methacrylate (PMMA) is prepared. Optical absorption, excitation and emission spectra were analyzed for Nd3+ in Nd(DBM)3Phen-doped PMMA. Using the Judd-Ofelt theory, the absorption spectrum was analyzed. The Judd-Ofelt(J-O) intensity parameters of Nd(DBM)3Phen-doped polymethyl methacrylate were calculated to be Ω2 = 20.97 × 10-20 cm2, Ω4 = 3.42 × 10-20 cm2, Ω6 = 2.90 × 10-20 cm2. The radiative lifetime (631 μs)of the excited 4F3/2 level is given. The stimulated emission cross-sections and the fluorescence branch ratios for the 4F3/2 →4 IJ/ transitions are also evaluated. Analysis reveals that Nd(DBM)3Phen-doped PMMA is promising for application in polymer optical fibers and planar waveguides.     

Absorption spectroscopic probe to investigate the interaction between Nd(III) and calf-thymus DNA

The interaction between Nd(III) and Calf Thymus DNA (CT-DNA) in physiological buffer (pH 7.4) has been studied using absorption spectroscopy involving 4f-4f transition spectra in different aquated organic solvents. Complexation with CT-DNA is indicated by the changes in absorption intensity following the subsequent changes in the oscillator strengths of different 4f-4f bands and Judd-Ofelt intensity (T(λ)) parameters. The other spectral parameters namely Slator-Condon (F(k)'s), nephelauxetic effect (β), bonding (b(1/2)) and percent covalency (δ) parameters are computed to correlate with the binding of Nd(III) with DNA. The absorption spectra of Nd(III) exhibited hyperchromism and red shift in the presence of DNA. The binding constant, K(b) has been determined by absorption measurement. The relative viscosity of DNA decreased with the addition of Nd(III). Thermodynamic parameters have been calculated according to relevant absorption data and Van't Hoff equation. The characterisation of bonding mode has been studied in detail. The results suggested that the major interaction mode between Nd(III) and DNA was external electrostatic binding.     

Synthesis, Crystal Structure and Optical Properties of a New Nd(Ⅲ) Nitronyl Nitroxide Complex [Nd(NIT2Py)2(NO3)3]

A new Nd(Ⅲ) nitronyl nitroxide complex [Nd(NIT2Py)2(NO3)3] (NIT2Py = 2-(2'-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) has been synthesized and structurally characterized by X-ray diffraction.It crystallizes in monoclinic, space group P21/n with a = 12.396(4), b =11.134(4), c = 23.360(7)(。A), β = 98.178(6)°, V= 3191.2(18)(。A)3, C24H32NgNdO13, Mr = 798.83, Dc =1.663 g/cm3, μ(MoKα) = 1.704 mm-1, F(000) = 1612, Z = 4, the final R = 0.0425 and wR = 0.0957for 6532 independentreflections with Rint = 0.0642 and 4552 observed reflections (I ＞ 2σ(I)).The complex exists as discrete mononuclear molecules and the neodymium(Ⅲ) ion is ten-coordinated with three bidentate nitrate anions and two radical ligands (NIT2Py) via bidentate chelating mode.The optical properties of the complex are discussed.     

Electrochemical study of the properties of Nd(III) and Nd(II) ions in molten LiCl-KCl-CsCl eutectic and individual CsCl

The electrochemical behavior of NdCl₃ solutions in eutectic LiCl-KCl-CsCl and individual CsCl melts was studied on an inert molybdenum electrode at temperatures in the range 573–943 K. Cyclic and differential pulse voltammetry and potentiometry at zero current and the electromotive forces method were used. The cathode reduction of Nd(III) ions to the metal was found to occur as a sequence of two stages. The formed Nd(II) ions were unstable above 798 K and underwent disproportionation 3Nd(II) ? 2Nd(III) + Nd_(m) in the salt melts. The conventional standard redox potential of the Nd(III)/Nd(II) pair in a eutectic LiCl-KCl-CsCl melt was measured over a wide temperature range. The main thermodynamic characteristics of the reaction NdCl_2(m) + 1/2Cl_2(g) ? NdCl_3(m) were determined.