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The impact of the climate drying during the Holocene within the Nile River Valley System (NRVS) has been the focus of recent debate in the archaeological community. It is argued that the increased contribution of aeolian material from the neighboring Sahara Desert during the last ~7,000 years has changed the isotope compositions of bioavailable Sr relative to the geological background and thus hinders provenance investigations of human remains within the NRVS. This study reports new trace element and strontium (Sr), neodymium (Nd), and lead (Pb) isotope compositions for a combined total of 125 samples consisting of human tooth enamel and various faunal samples from different time periods, and present-day botanical samples from 11 archaeological sites along the NRVS. The new isotope data combined with published data do not support a time-dependent increase in a Saharan aeolian bioavailable Sr component during the Holocene within the NRVS; in general, Sr isotope compositions for human enamel samples match those of their corresponding faunal matrices, and these define a similar range of isotope compositions over the various time periods. The Nd and Pb isotope compositions for human tooth enamel reported here also support the limited contribution of Saharan aeolian dust within the NVRS. [ABSTRACT FROM AUTHOR]

The denitrification activity of catalyst can be improved by adding additives. In this paper, the Nd, Nb co-doped V-Mo/Ti De-NOx catalyst was prepared by impregnation method. The physical and chemical properties of the catalyst were analyzed by XRD, N8 -adsorption and desorption, H8 -TPR, XPS, NH3 -TPD. The results showed that the peak temperature of H 2 reduction of the catalyst modified by Nd and Nb moved to the direction of low temperature, indicating that the addition of Nd and Nb can adjust the dispersion degree of the active components of the catalyst to a certain extent. V-Mo-Nd-Nb/Ti catalyst has the higher Oa content, which is beneficial to its denitrification performance. The overall denitrification activity of Nd and Nb co-doped catalyst is better than that of V-Mo/Ti catalyst. The denitrification efficiency of the catalyst can reach 71. 8% at 210 oC,and the formation of N2O can also be reduced. Moreover, the catalyst also has excellent resistance to SO2 and H2O. After 28 h reaction, the denitration efficiency of the catalyst can still reach about 93 %. [ABSTRACT FROM AUTHOR]

The present work, we prepared a novel catalyst by linking Nd complex on Fe 3 O 4 nanoparticles as green catalyst and characterized by FT-IR, SEM, EDX, ICP-OES, XRD and TGA methods. Then, catalytic activity of this catalyst was tested in the oxidation reactions and synthesis of tetrazoles. Easy preparation and easy separation, chemical and hydrothermal stability, the use of inexpensive materials, high reusable are outstanding properties of this protocol. Magnetic nanoparticle functionalized with neodymium complex as catalyst and characterized by SEM, XRD, FT-IR, TGA, EDX and ICP techniques. Then, catalytic activity of prepared catalyst was examined in the synthesis of tetrezoles and oxidation reactions in which observed short reaction time and high yield in these reactions. [ABSTRACT FROM AUTHOR]

Application of ultrasound and microwave assisted technology on the dissolution of neodymium (Nd) from waste magnet using organic reagent (s) was investigated. Amongst all the organic solvents, acetic acid appears to be effective while yielding higher Nd leaching efficiency. The characteristics pattern of XRD and SEM-EDAX study ascertained the magnet waste phase as Nd-Fe-B. Factors influencing the leaching of Nd such as time (0-5 h), [CH 3 COOH] (0.1–0.5 M), ultrasound power (0 W–120 W), pulp density(S/L) (1–5%) and microwave power (450-900 W) have been studied. Quantitative (~99.99%) Nd recovery was achieved under optimum ultrasound assisted leaching condition; time: 120 min, ultrasound power: 90 W, [CH 3 COOH]: 0.4 M and particle size range: 75–106 μm. Almost all Nd dissolution was attained at the suitable MW power of 900 W leading to reduce leaching time by 120 min than the regular mechanical stirring leaching (65.03% Nd resulted in 240 min). The enhancement of Nd leaching was mainly due to unique cavitation action of ultrasoundation and high heating energy produced from microwave to break the solid matrix of waste magnet, leading to diffuse the Nd metal ion into lixivaint phase as ascertained from SEM results of the magnet waste sample before and after ultrasound wave / microwave treatment. Unlabelled Image • Ultrasonic/microwave-assisted leaching study for recovery of Nd from magnet waste. • Leaching study of Nd was carried out by adopting various organic green solvents. • Sonication/microwave found be key on yielding high Nd leaching than regular process. • Nd leaching maximized by dil.CH 3 COOH at mild ultrasonic power (90 W) with 900watt MW. • Proposed process is an environmental-friendly, low cost and highly efficient approach. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new electrolyte Bet-EG-Nd 2 O 3 was developed to electrodeposition of Nd metal near room temperature. • Electrodeposition of neodymium metal be achieved in Bet-EG using Nd 2 O 3 as precursor. • The existence form of Nd 2 O 3 in Bet-EG DES is complex ion [Nd 2 (bet) 8 (H 2 O) 4 ]6+. • Temperature plays a central role in controlling Nd(III) diffusion rate and morphology of Nd depositd. The electrodeposition of neodymium was investigated in betaine-ethylene glycol (Bet-EG) deep eutectic solvent (DES) containing neodymium oxide (Nd 2 O 3) at different temperatures ranging from 353 K to 373 K. The electrochemical behavior of Nd 2 O 3 dissolved in Bet-EG DES was researched by cyclic voltammetry, potentiodynamic polarization and chronoamperometry methods. Cyclic voltammograms (CVs) manifest that Nd(III) reduction in Bet-EG is an irreversible process with diffusion-controlled, and the reduction overpotential of Nd(III) decreases with the increase of the temperature. The temperature has an impact on the diffusion coefficient of Nd(III) species, obeying the Arrhenius equation. The activation energy is estimated to be 36.78 kJ mol−1. The cathodic polarization analysis shows that the rise of temperature promotes the reduction of Nd(III). The UV–Vis and ESI-MS analyses show that [Nd 2 (bet) 8 (H 2 O) 4 ]6+ complex anions are formed as Nd 2 O 3 is dissolved in Bet-EG DES. Electrodeposited neodymium with various morphologies were characterized and analyzed by EDX, XPS, XRD and SEM. It is found that the electrodeposition temperature has a great effect on the morphology of Nd electrodeposits. Depending on the deposition temperature, metallic Nd with submicron particles or porous structures were obtained. [ABSTRACT FROM AUTHOR]

YAlO 3 (YAP) single crystals doped with Lu and Nd were grown by the Floating Zone (FZ) method to evaluate their scintillation properties particularly emissions in the near-infrared (NIR) range. The Nd concentration was fixed to 0 or 1 mol% while the Lu concentration was varied from 0 to 30%. When X-ray was irradiated, the scintillation of Nd-doped samples was observed predominantly at 1064 nm due to 4 F 3/2  →  4 I 11/2 transition of Nd 3+ . In contrast, a weak emission around 700 nm appeared in the samples doped with only Lu, and the emission origin was attributed to defect centers. In the Nd 3+ -doped samples, the decay time was 94–157 μs due to the 4f-4f transitions of Nd 3+ whereas the Lu-doped samples showed signal with the decay time of 1.45–1.54 ms. The emission origin of the latter signal was attributed to the perovskite lattice defect. [ABSTRACT FROM AUTHOR]

A novel, fast and reliable sample preparation procedure for the simultaneous separation of Sr, Pb, and Nd has been developed for subsequent isotope ratio analysis of sediment digests. The method applying a fully automated, low-pressure chromatographic system separates all three analytes in a single-stage extraction step using self-packed columns filled with DGA Resin. The fully automated set-up allows the unattended processing of three isotopic systems from one sediment digest every 2 h, offering high sample throughput of up to 12 samples per day and reducing substantially laboratory manpower as compared to conventional manual methods. The developed separation method was validated using the marine sediment GBW-07313 as matrix-matched certified reference material and combines quantitative recoveries (>90% for Sr, >93% for Pb, and >91% for Nd) with low procedural blank levels following the sample separation (0.07 μg L Sr, 0.03 μg L Pb, and 0.57 μg L Nd). The average δ values for Sr, Pb, and Nd of the separated reference standards were within the certified ranges ( δ (Sr/Sr) of −0.05(28) ‰, δ(Pb/Pb) of −0.21(14) ‰, and δ(Nd/Nd) of 0.00(7) ‰). The DGA Resin proved to be reusable for the separation of >10 sediment digests with no significant carry-over or memory effects, as well as no significant on-column fractionation of Sr, Pb, and Nd isotope ratios. Additional spike experiments of NIST SRM 987 with Pb, NIST SRM 981 with Sr, and JNdi-1 with Ce revealed no significant impact on the measured isotopic ratios, caused by potential small analyte peak overlaps during the separation of Sr and Pb, as well as Ce and Nd. [ABSTRACT FROM AUTHOR]

The effects of pressure on the Nd 3+ -doped MgO:LiNbO 3 single crystal have been studied by luminescence spectroscopy at low temperature and high pressures from ambient conditions up to 33 GPa. Specifically, the pressure-induced evolution of the emission spectra, corresponding to the 4 F 3/2 → 4 I 9/2 , 4 I 11/2 transitions, and the excitation spectra, corresponding to the 4 I 9/2 → 4 F 5/2 + 2 H 9/2 , and 4 I 9/2 → 4 F 7/2 + 4 S 3/2 transitions, show a gradual red-shift that follows a linear pressure dependence and a decrease in the intensity of the spectra with increasing pressure. The initial effect of increasing pressure on the MgO:LiNbO 3 crystal is the modification of the relative amount of the several centers in the sample. At pressures around 20 GPa the characteristic multicenter Nd 3+ structure eventually disappears indicating that all the centers have very similar environments near this pressure. At higher pressures, observed changes seem to have a different origin. The evolution of Nd 3+ luminescence is studied in the frame of crystal-field theory in order to evaluate its capability of monitoring the pressure-induced structural changes. Crystal-field analysis, under approximated C 3v symmetry, shows a smooth increase of the overall crystal-field strength on the luminescent ion, which can be related to the volume reduction as pressure increases. Crystal-field parameters also show a general monotonic behavior with pressure that indicates a structural modification of the local structure that, maintaining the trigonal symmetry around the impurity ion, evolves towards a lower axial character. No evidences of a phase transition have been observed in the studied pressure range. [ABSTRACT FROM AUTHOR]

The leaching of neodymium (Nd) and praseodymium from scrap permanent magnet bearing 64.37% Fe, 30.57% Nd and 0.42% Pr and 0.71% B was carried out using HCl solution. X-ray fluorescence (XRF) and X-ray diffraction (XRD) analyses study ensured the elements of the above metals as Nd-Fe-B in the solid phase . The leaching parameters – HCl concentration, time, temperature, particle size, pulp density (S/L) – were investigated to obtain the suitable leaching condition for the effective dissolution of both Nd and Pr. At the conditions of 0.2 M HCl, temperature 90°C, leaching time 240 min, particle size 76–105 µm, agitation speed 800 rpm and pulp density (PD) 1%, the leaching efficiencies of Nd and Fe were 99.99% and 61.36%, respectively. The optimum leaching condition was established by minimizing iron co-extraction vis-à-vis the quantitative recovery of Nd and Pr. The iron content of the leach liquor was removed by the precipitation method using lime (Ca(OH)2) at pH 4.0. After the removal of iron, the solvent extraction (SX) parameters were optimized and the McCabe–Thiele diagram for extraction and stripping was developed. The McCabe–Thiele plot for extraction with 0.8 M NaD2EHPA (30% neutralized) and stripping with 8% H2SO4showed two stages at A:O = 2:1 and O: A = 4:1, respectively, for the quantitative recovery of Nd and Pr. The final strip solution bearing 72 g/L Nd and 1.088 g/L Pr was crystallized to produce (Nd)2(SO4)3and (Pr)2(SO4)3, respectively. [ABSTRACT FROM PUBLISHER]

Rate of evaporation of Sm and Nd from their mixture was studied based on their ion intensities using thermal ionization mass spectrometry. Because of the comparatively larger evaporation rate of Sm, it was found possible to get the isotopic composition of Nd (fission product monitor) free from isobaric interference of Sm isotopes. The decrease in ion intensity of Sm was studied as a function of time and filament temperature. Based on this study, an easy and time effective method for the determination of burn-up of spent nuclear fuel was examined and the results are compared with that obtained by the conventional method. Typical burn-up value obtained for a pressurized heavy water reactor fuel dissolver solution using the direct method by preferential evaporation of Sm is: 0.84 at.%, whereas the one obtained by the use of conventional method is 0.82 at.%. In both the cases, Nd was employed as the fission product monitor. [ABSTRACT FROM AUTHOR]

This work mainly investigated the effect of Nd substitution on the microstructure, mechanical properties and damping capacity of Mg–Zn–Y–Zr alloy. Obtained results indicate that the phase constituent of the Mg–Zn–Y–Zr alloy and the chemical composition of W-phase vary with the partial substitution of Nd for Y. After solution treatment at 480 °C for 8 h, the secondary phases dissolve into the matrix and ZnZr particles precipitate at grain interiors. During subsequent aging treatment, higher density of β 1 ′ and β 2 ′ phases, Mg 12 Nd phase, long period stacking ordered (LPSO) and stacking fault (SF) structures precipitate in Mg–Zn–Y–Zr alloy with Nd substitution. The precipitation strengthening further help the ultimate tensile strength and yield strength of the alloy with Nd substitution reach up to 268 MPa and 164 MPa, respectively. The damping capacities of the investigated alloys decrease dramatically after heat treatment. The decline in damping of solution-treated alloys can be ascribed to the increasing number of solute atoms and ZnZr particles. Due to the stacking fault probability, LPSO and SF structures induced by the Nd substitution are believed to be the new damping source to contribute to the damping capacity of Mg–Zn–Y–Zr alloy besides dislocations. [ABSTRACT FROM AUTHOR]

Neodymium (Nd) ion implantation was conducted on the Mg-Gd-Zn-Zr alloy to improve its corrosion resistance in simulated body fluids for biomedical applications. X-ray photoelectron spectroscopy reveals that a hybrid structure layer composed of Nd2O3, Gd2O3 and metallic Nd was formed in the implanted layer after Nd ion implantation. The electrochemical test and hydrogen evolution test demonstrate that the enhanced corrosion resistance of the implanted alloy was achieved under a proper dose. Nevertheless, the corrosion characteristics of the alloys obtained by the two test methods showed a different trend, and the hydrogen evolution test provided a greater reliability of evaluated result. It was found that the corrosion rate decreased first with increasing dose and then increased rapidly and even higher than that of the bare alloy. [ABSTRACT FROM AUTHOR]

The authors demonstrate a mode‐locked Nd:fibre laser working at 910 nm incorporating a phase biased non‐linear loop mirror. The broadest spectral width of the pulse is 11.9 nm and the output power is 20 mW with 450 mW pump power. The dechirped pulse width is 206 fs. To the best of authors' knowledge, this is the first demonstration of a 900 nm femtosecond neodymium fibre laser based on a non‐linear loop mirror. [ABSTRACT FROM AUTHOR]

Optical characteristics of a new laser crystal Nd:YbVO4 were studied. The optical parameters of a-cut and c-cut Nd:YbVO4 crystals were calculated by the Judd-Ofelt theory. The absorption cross-section of a-cut Nd:YbVO4 crystal was 5.34x10-20 cm² at 808 nm, while it was 4.20x10-18 cm² of c-cut Nd:YbVO4 crystal. The properties of energy transfer between Nd and Yb ions in Nd:YbVO4 crystal were discussed. In the fluorescence spectra, a peak at 472 nm appeared, which resulted from the coupling interaction between two Yb ions. [ABSTRACT FROM AUTHOR]

In the separation of rare earth elements by solvent extraction with organophosphorus extractants, bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272) leads to lower extraction percentage but higher separation factor. In order to increase the extraction of Pr and Nd by Cyanex 272, its mixtures with amine extractants, such as tri-octyl/decyl amine (Alamine 336), trioctylamine (TOA) and tri-2-ethylhexyl amine (TEHA) have been employed from chloride solution. Among the studied extractant mixtures, the combination of Cyanex 272 and Alamine 336 showed that the best extraction ability and the maximum synergistic enhancement factors were 14.2 for Pr and 12.2 for Nd at Cyanex 272 mole fraction of 0.5. The role of Alamine 336 in this mixture was to extract hydrogen ions released from Cyanex 272. The overall solvent extraction reaction was identified by applying a slope analysis method to the experimental data. Moreover, it was found that the concentration ratio of Alamine 336 to chloride ion affected the enhancement in the extraction of the two metals. The quantitative stripping of both Pr and Nd was possible from the loaded mixture by using HCl or H 2 SO 4 solution. [ABSTRACT FROM AUTHOR]

In this study, the bioaccumulation and toxicity of neodymium (Nd) in planarian Dugesia japonica were investigated. The results showed that with the increasing dietary Nd supplementation, the concentration of Nd in the planarian showed a significant linear increase and the balance of mineral elements was broken with the decrease of Ca, Fe and Mo, and the increase of K and Mg. The content of soluble proteins and the activities of superoxide dismutase (SOD) and catalase (CAT) decreased with the increase of Nd concentration, while the content of H2O2 rose gradually. The mortality was directly proportional to the Nd concentration. The results indicated that planarian is a very sensitive aquatic animal to Nd contamination and can be an indicator organism for Nd pollution. [ABSTRACT FROM AUTHOR]

Highlights: [•] First study on competition behaviour of metal uptake in cementitious systems. [•] Nd environment remains unchanged in the presence and absence of Zn. [•] The Nd environment consists of ∼7–8 O at 2.42Å, ∼7–8 Si at 3.7Å and ∼5–6 Ca at 3.8Å. [•] Zn data exhibit distinct differences in the presence and absence of coabsorbing Nd. [ABSTRACT FROM AUTHOR]

Neodymium and praseodymium ions, singly and in combination, have been doped into a poly(vinyl alcohol)-borax matrix. X-ray diffraction shows structural correlations from 2 to 6 Å and 15 Å, while small angle neutron scattering indicates that the rare-earth ions do not affect the nanoscale structures of the gels. Differential scanning calorimetry shows the glass transition temperature to increase with concentration of Pr in the gel. Excitation in the ultraviolet region leads to luminescent emission in the visible region. Simultaneous absorption in the visible region then leads to luminescent emission in the near infra-red region. The spectral qualities of the emission bands can be varied by choosing appropriate relative ratios of rare-earth species. [ABSTRACT FROM AUTHOR]

Effects of Nd additions (0-4 wt-%) on microstructures and properties of Mg-Al-Ca alloy at room temperature and 150uC have been investigated. The results showed that Mg-6Al-2Ca alloy consisted of α-Mg matrix, Mg17Al12, Mg-Ca and Al-Ca phases. The amount of Al-Nd phase increases with the increasing of Nd content while that of Mg17Al12 decreases. On the other hand, Nd refines the microstructure of as cast and extruded alloys. The ultimate strength and yield strength of experimental alloys are improved with the addition of Nd, and the largest values are 319 and 210 MPa respectively at room temperature. When the temperature was elevated to 150°C, with the increasing of Nd, ultimate strength and yield strength of experimental alloys are first increased and subsequently decreased. Mg-6Al-2Ca-xNd alloy has the best ultimate strength and yield strength at 150°C, which reaches 265 and 179 MPa respectively when the content of Nd reached 3%. [ABSTRACT FROM AUTHOR]

Abstract: Isotopic characterization of aerosol mineral particles (atmospheric dust) of varying sizes is essential in classifying source areas, and for determining the source of dust deposited over oceans and icesheets. However, the effect of atmospheric transport on radiogenic isotopic compositions is not well constrained, making provenance interpretation difficult. In order to investigate the isotopic variability of 176Hf/177Hf, 87Sr/86Sr and 143Nd/144Nd we analyzed eight airborne dust samples in two size fractions collected along a cross-Atlantic transect through a dust storm originating in the Sahara in late 2002. Past measurements of 176Hf/177Hf, 87Sr/86Sr and 143Nd/144Nd of dust have focused primarily on coarse sized particles (<30μm), whereas far field deposition is primarily finer particles (<2μm). Strontium or neodymium isotopic sorting based on distance is not evident in our dataset; however, the combined isotopic ratios of the dust collected suggest a Saharan origin. Hafnium isotopic compositions show an east to west trend towards more radiogenic compositions across the Atlantic, suggesting grain and mineral sorting during dust transport along the ~4000km transect. Transport models with variable dust particle diameter and wind speed demonstrate the preferential depletion of the high-density mineral zircon during transport of dust from the source area. The transport model combined with a simple two component mixing model show that the Hf isotopic composition changes can be explained by the loss of the mineral zircon during transport. Modeling of this “zircon effect” with distance from the dust source in the Hf isotopic composition of marine, terrestrial and glacial dust deposits may reveal additional information concerning dust transport and sources in the geologic past. [Copyright &y& Elsevier]

The influence of chloride concentration on the salt spray corrosion behaviour of new AZ91D and AM50 alloys containing rare earth (RE) elements was evaluated. The corrosion rate of both materials increased with increasing chloride concentration, particularly for NaCl concentrations above 2 wt-%. The addition of Nd or Gd reduced the amount of β-Mg17Al12 phase and resulted in the formation of RE containing intermetallics that were less noble than the Al-Mn inclusions but more noble than the β-Mg17Al12 phase. The latter modifications decreased the corrosion rate of the AM50 alloy by up to 90% but did not give a clear benefit to the corrosion resistance of the AZ91D alloy. [ABSTRACT FROM AUTHOR]

Abstract: Laser glass gain medium that can convert low cost 808nm diode laser into 2.7μm has attracted considerable interest due to its potential application for medical surgery fiber laser system. In this study, enhanced 2.7μm emission has been achieved in Er3+:germanate glass by co-doping with Nd3+ ions under the excitation of an 808nm diode laser. In the co-doped sample, the experimental results show that the harmful visible emissions via up-conversion were effectively restricted. The reduction of 1.5μm emission was also detected in the co-doped sample, which indicates significant de-excitation of 4I13/2 Er3+ ion through energy transfer and non-radiative decay in Nd3+ ions. In conclusion, the 2.7μm emission enhancement achieved was due to the increased optical absorption of 808nm, efficient energy transfer (ET) with efficiency of 81.73% between Er3+ and Nd3+ ions, and shortening the lifetime of the lower lasing level 4I13/2 Er3+ in the co-doped sample. Therefore, Er3+/Nd3+ co-doped germanate glass could be used to fabricate fiber optical gain media for 2.7μm laser generation. [Copyright &y& Elsevier]

Abstract: The rare earth (RE) added Ti–Si alloys are potential candidates for lightweight structural materials, especially in high-temperature fields, but up to now related fundamental information is still rare. In this work, samples of Ti–8Si–5Nd, Ti–13Si–5Nd, and Ti–20Si–5Nd are designed to investigate the effect of RE element Nd on the microstructural evolution and compressive properties of the Ti–Si alloys. Experimental results indicate that all the samples are composed of α-Ti, β-Ti, Nd and Ti5Si3 phases according to the XRD patterns. The Ti–8Si–5Nd alloy shows a typical hypoeutectic structure with primarily precipitated bulky Ti5Si3 and Nd. Ti–13Si–5Nd alloy has lamellar eutectic structure and the Ti–20Si–5Nd alloy exhibits a coarsened homogeneous primary Nd, Ti5Si3 precipitation and microcrystalline eutectic structure. The added Nd and primarily-precipitated Nd5Si3 particles work as inoculants and refine the grain size of Ti5Si3, because of their similar hexagonal structure, atomic bond and atomic distribution of the outer crystal surface. The refined grain size and homogeneous distribution of Ti5Si3 phases in the Nd added Ti–Si alloys (especially the hypoeutectic alloy) are effective to improve the mechanical properties. The Ti–8Si–5Nd alloy exhibits the best plasticity (14.545%) and compressive strength (1191MPa) among the three samples and shows good potential for structural materials. [Copyright &y& Elsevier]

Abstract: Separation possibilities of Pr and Nd from chloride solution containing La at initial aqueous phase pH of 4.94 have been investigated by using solvent extraction technique. Cyanex 272 and its mixture with solvating, cationic and anionic extractants like TBP, TOPO, DOS, Cyanex 301, Versatic-10, Alamine 308, and Alamine 336 have been employed as extractant systems for the separation of LREEs. Under comparable conditions, saponified Cyanex 272 showed some better separation capability than unsaponified Cyanex 272 towards Pr and Nd over La. Among the studied extractant mixtures, the combination of saponified Cyanex 272 and TBP led to complete separation of Pr and Nd over La. Based on this assumption, McCabe–Thiele diagram was constructed by using mixture of 1M saponified Cyanex 272 and 0.5M TBP for the extraction of Pr and Nd and its batch simulation of three stages counter current extraction studies indicated that the extraction of Pr, Nd and La was 80%, 90% and 2%, respectively. The quantitative stripping of both Pr and Nd metals were achieved from loaded organic phase by contact with 1M HCl solution. A solvent extraction process was proposed to separate Pr and Nd over La. [Copyright &y& Elsevier]

The effects of micro-alloying with small amounts of Sc and Nd elements on the microstructure and mechanical properties of Al-Mg-Mn alloy were systematically investigated. The results show that the grains of Al-Mg-Mn alloy can be refined by the addition of minor Sc and Nd. Adding 0.2 wt.% Sc or 0.2 wt.% Nd element to Al-Mg-Mn alloy can improve the strength and recrystallization temperature. Especially, after a combined addition of 0.1 wt.% Sc and 0.1 wt.% Nd, owing to the AlMgNd phase formed in the alloy, which pinned at the grain boundary can hinder the migration of the grain boundary during annealing process, the recrystallization temperature of the Al-Mg-Mn alloy is increased by 100 °C, and the increments of tensile strength and yield strength are 65 and 55 MPa, respectively. [ABSTRACT FROM AUTHOR]

Abstract: The microstructures, mechanical and corrosion properties of three extruded Mg–2Zn–0.46Y–xNd alloys (x =0.0, 0.5, 1.0wt%) were studied by optical microscopy, scanning electronic microscopy (SEM), electrochemical measurements and tensile tests. Microstructural observations indicated that Nd led to the uniformity and the variation of morphology of major second phase; tensile tests showed that Nd can improve the ductility at moderate amount (0.5wt%) and will be detrimental up to 1.0%; Mg–2Zn–0.46Y–0.5Nd alloy exhibited excellent mechanical properties (σ b , 269.0MPa, σ 0.2, 165.6MPa and elongation, 24%); electrochemical tests revealed that Nd can enhance the corrosion resistance and Mg–2Zn–0.46Y–1.0Nd alloy had lowest corrosion current density, which was reasoned that the line-shape and rodlike NdZn2 phase might serve as corrosion barriers and the dissolved Nd can raise the electrode potential of the matrix. [Copyright &y& Elsevier]

Abstract: The Sr and Nd isotopic composition of dust extracted from recent snow layers at the top of Berkner Island ice sheet (located within the Filchner–Ronne Ice Shelf at the southern end of the Weddell Sea) enables us, for the first time, to document dust provenance in Antarctica outside the East Antarctic Plateau (EAP) where all previous studies based on isotopic fingerprinting were carried out. Berkner dust displays an overall crust-like isotopic signature, characterized by more radiogenic 87Sr/86Sr and much less radiogenic 143Nd/144Nd compared to dust deposited on the EAP during glacial periods. Differences with EAP interglacial dust are not as marked but still significant, indicating that present-day Berkner dust provenance is distinct, at least to some extent, from that of the dust reaching the EAP. The fourteen snow-pit sub-seasonal samples that were obtained span a two-year period (2002–2003) and their dust Sr and Nd isotopic composition reveals that multiple sources are at play over a yearly time period. Southern South America, Patagonia in particular, likely accounts for part of the observed spring/summer dust deposition maxima, when isotopic composition is shifted towards “younger” isotopic signatures. In the spring, possible additional inputs from Australian sources would also be supported by the data. Most of the year, however, the measured isotopic signatures would be best explained by a sustained background supply from putative local sources in East Antarctica, which carry old-crust-like isotopic fingerprints. Whether the restricted East Antarctic ice-free areas produce sufficient eolian material has yet to be substantiated however. The fact that large (>5μm) particles represent a significant fraction of the samples throughout the entire time-series supports scenarios that involve contributions from proximal sources, either in Patagonia and/or Antarctica (possibly including snow-free areas in the Antarctic Peninsula and other areas as well). This also indicates that additional dust transport, which does not reach the EAP, must occur at low-tropospheric levels to this coastal sector of Antarctica. [Copyright &y& Elsevier]

Abstract: A new method for the radiogenic isotope (U–Th–Pa–Ra, Sr, Nd, Hf) analysis of the soluble and insoluble components found within ice cores is presented. Melting experiments with rock standards in the presence of EDTA indicate that carbonates, as well as silicates, can be buffered sufficiently to preclude dissolution. The use of EDTA allows adsorbing species, such as Th and Hf, to remain in solution during melting thus fully separating the dust (insoluble) and sea salt (soluble) components of the ice after filtration. A new elemental separation scheme for low sample masses, less than 5 mg solid material, utilizes 4 primary ion exchange columns and two “clean-up” columns to fully isolate U, Th, Pa, Ra, Sr, Nd, and Hf while maintaining high yields. Elution schemes measured for USGS rock standards and a Chinese loess are presented to provide a comparison for variable matrix compositions. Mass spectrometer techniques were modified to measure small aliquots of the standards, equivalent to the amounts found in ice core samples, 10 ng and less. A MC-ICPMS was employed for the measurement of U, Th, Pa, Ra, and Hf; results of the experiments show that with ion yields up to 1%, rock standards have errors for 234U/238U of 1%, 230Th/232Th of 1.5%, [228Ra] of 9%, and 176Hf/177Hf of 100 ppm. MC-TIMS measurements of Sr and Nd show similar errors for small sample sizes: 87Sr/86Sr of 50 ppm and 143Nd/144Nd of 80 ppm. This new analytical method increases the number of possible tracers measured from a single sample, reducing separation times and sample consumption, as well as providing the addition of a radiometric clock, U-series, to the traditional suite of isotopic tracers, Sr, Nd, and Hf. [Copyright &y& Elsevier]

Abstract: The present article deals with the use of Si nanoclusters as efficient sensitizers towards Er3+ or Nd3+ ions. For this purpose, reactive magnetron co-sputtering process has been used for the fabrication of the doped layers. Depending on the deposition parameters, the photoluminescent properties of the rare earth have been analyzed. Thus, the effect of the hydrogen rate as a possible way to optimize the coupling rate between Er3+ and Si nanoclusters has been evidenced. On the other part, we have shown that above a critical Nd concentration within the silicon rich silicon oxide layer (SRSO), a concentration quenching occurs and the photoluminescence of the Nd3+ ions decreases dramatically. Two decay times have been determined linked to the surrounding of the Nd3+ ions. [Copyright &y& Elsevier]

Abstract: Hydrogenous ferromanganese crust deposits on seafloor and volcanic seamounts are archives of past isotopic compositions of the ocean. Isotopic compositions of long-life radiogenic isotopes that are dissolved in the ocean such as Nd and Pb, are mixtures of different erosion products (continents, volcanics arcs, ridges etc…) transported by oceanic currents or winds. Isotopic studies on Mn crusts are thus potential paleogeographic and paleoceanographic tracers. However, global paleogeography can drastically evolve over the period of growth of crust, as well as the latitude, longitude and water depth of the Mn crust. Thus each crust sampled a succession of geographic sites related to its spatial evolution through time. For this reason, valid information about the past ocean isotopic composition can only be extracted from Mn crust under the condition that the successive paleogeographic and paleodepth positions can be reconstructed for each Mn crust. We followed this approach for six hydrogenous Mn crusts from the Pacific Ocean that have recorded Pb and Nd isotopic signals for the past 80 Myr. The evolution of the isotopic data was considered within a proper geodynamical framework that takes into account the paleopositions of the Pacific plate and surrounding continents, of the hot spots and ridges as well as the paths of the six crusts. The differences and similarities between the Pb and Nd revealed by our analysis emphasize their complementarity as paleoceanographic tracers. The Nd isotopes are strongly influenced by the exchange between Indian and Pacific waters, specifically by the progressive closure of the Indonesian Gateway. The closed central Pacific characteristics are defined from the extrapolation of the isotopic trend. This highlights the important role played by erosion of volcanic arcs in the Nd isotopic value of seawater. Our approach also stresses the influence of local volcanic activity (ridges or active hot spot) for lead isotopes. [Copyright &y& Elsevier]

Nd3+-doped silicon-rich silicon oxide thin films have been fabricated by reactive magnetron co-sputtering of a pure silica target topped with Nd2O3 chips. The incorporation of silicon excess in the films has been controlled by the hydrogen partial pressure PH2 introduced in the plasma. Photoluminescence experiments have been made at room temperature using a non resonant excitation with Nd3+ ions. The influences of Nd3+ content and PH2 have been studied to improve the Nd3+ emission. Photoluminescence spectra reveal an enhancement of the Nd3+ emission at 0.9 µm and 1.1 µm when silicon nanoclusters and Nd3+ are embedded in a SiO2 matrix. [ABSTRACT FROM AUTHOR]

Abstract: Neodymium (Nd), as a member of rare earth elements, proved to enhance the photosynthesis rate and organic substance accumulation of spinach through the increase in carboxylation activity of Rubisco. Although the oxygenase activity of spinach Rubisco was slightly changed with the Nd3+ treatment, the specific factor of Rubisco was greatly increased. It was partially due to the promotion of Rubisco activase (R-A) activity but mainly to the formation of Rubisco–Rubisco activase super-complex, a heavier molecular mass protein (about 1200kD) comprising both Rubisco and Rubisco activase. This super-complex was found during the extraction procedure of Rubisco by the gel electrophoresis and Western-blot studies. The formation of Rubisco–R-A super-complex suggested that the secondary structure of the protein purified from the Nd3+-treated spinach was different from that of the control. Extended X-ray absorption fine structure study of the ‘Rubisco’ purified from the Nd3+-treated spinach revealed that Nd was bound with four oxygen atoms and two sulfur atoms of amino acid residues at the Nd–O and Nd–S bond lengths of 2.46 and 2.89Å, respectively. [Copyright &y& Elsevier]

Samples of the nominal composition (Y0.5Nd0.5-xHox) Ba2Cu3O7- d , 0 \le x \le 0.5, have been prepared using the conventional solid state reaction. The effect of holmium and neodymium substitution on electrical resistivity, transition temperature Tc, lattice parameters, size of crystallite and grain size has been investigated. X-ray diffraction, electron micro-probe scanning electron microscope and IR spectra, have been used in our investigation. The results show that the transition temperature Tc electron-hole jump rate and lattice parameters (a, b) have minimum values at x = 0.2, while c increases to maximum at x = 0.2. The size of crystallite, the electrical resistivity and grain size are also maximum at x = 0.2. The real composition, molecular state and electronic state of the prepared samples are discussed. [ABSTRACT FROM AUTHOR]

We report pure continuous-wave (CW) high-power (>100 mW) deep-ultraviolet (DUV) light sources emitting around 200-nm spectral region based on singly resonant sum-frequency mixing (SRSFM). Efficient DUV generation is made possible by use of a Brewster-cut CsLiB6O10 (CLBO) crystal near noncritically phase-matched (NCPM) condition for the SFM of 1-μm output of neodymium lasers. The CW radiation of fifth-harmonic wavelength of a neodymium laser at 213 nm was generated by the SFM of enhanced 1064-nm radiation with single-passing 266-nm radiation produced by external-resonant frequency doubling of a 532-nm green laser. With 1.8 W of 266-nm radiation incident upon a CLBO crystal, as much as 180 mW of CW 213-nm power has been produced. The sub-200-nm CW radiation with 140-mW power has also been achieved by SFM of 1064 nm with 244-nm radiation from a frequency-doubled Argon-ion laser in the CLBO crystal operated near the NCPM condition. [ABSTRACT FROM PUBLISHER]

Reaction of a mixture of neodymium carbonate, HCl, oxamic acid and glutaric acid under hydrothermal conditions gives rise to a new mixed carboxylate of neodymium, [Nd4(H2O)2(OOC(CH2)3COO)4(C2O4)2], I. The structure, determined using single crystal X-ray diffraction, comprises a helical column formed by the grafting of the oxalate unit on to helical NdO9 chains, cross-linked by the glutarate anions. It is noteworthy that the pitch of the helix is equivalent to the length of the oxalate unit. Furthermore, I shows about 1.1 times the SHG activity of urea. [Copyright &y& Elsevier]

Fifty new Nd isotope analyses are presented from the North Bay area of the Grenville Province in Ontario. These data are used to map the extent of an allochthonous Grenvillian terrane which is an outlier of the Allochthonous Polycyclic Belt of the Grenville Province. Amphibolite facies orthogneisses from the allochthonous terrane have depleted mantle Nd model ages (T[subDM]) below 1.8 Ga, whereas the gneisses of the structurally underlying parautochthon, almost invariably have model ages above 1.8 Ga. The distribution of model ages is consistent with the distribution of distinct types of metabasic rock, used by other researchers as the criterion for recognizing rocks of the allochthonous and parautochthonous belts of the Grenville Province. The agreement between these different types of evidence demonstrates that Nd isotope mapping is a reliable and powerful tool for mapping terrane boundaries in high-grade metamorphic belts. [ABSTRACT FROM AUTHOR]

Oxygen pressure-temperature phase diagrams for Ln/sub 2/Ba/sub 4/Cu/sub 7/O/sub 15-/spl delta// (Ln-247) compounds (Ln=Er,Eu,Gd,Y and Yb) in the pressure range 2-32 bars of oxygen and temperature range 900-990/spl deg/C were studied. The required pressures for Ln-247 single phase synthesis are much lower than was previously found. In addition, phase-pure Ln-247 (Ln=Dy,Nd,Pr and Sm) samples were prepared at high oxygen pressure. The temperatures of the superconducting transition (T/sub c/) for fully oxygen loaded Ln-247 samples are in the range 63-94 K, except for Pr-247 which is not superconducting at temperatures above 4.2 K. These transition temperatures are, for the wider range of rare earth, considerably higher than previously reported. Evidence is presented for progressive underdoping of carriers with increasing rare earth ionic radius, suggesting that T/sub c/ has not been maximized. [ABSTRACT FROM PUBLISHER]

Neodymium-doped aluminum (Al-Nd) was used as a gate electrode and was anodized, forming a layer of Nd:Al2O3 as the dielectric for indium-zinc oxide (IZO) thin-film transistors (TFTs). The Nd:Al2O3 showed high capacitance (110 nF/cm2), high breakdown field (>;6 MV/cm), and low leakage current (<; 10-7 A/cm2 at 2.0 MV/cm) without hillocks when annealed at 300°C. The TFT showed a low operating voltage of 3 V, a low off current of ~10-13 A, a high mobility of 13.7 cm2 · V-1 · s-1, and excellent electrical stability because of the good interface coupling between Nd:Al2O3 and IZO, resulting from the low electronegativities of Al and Nd. [ABSTRACT FROM PUBLISHER]

Abstract: The oxygen relaxation in two cubic zirconias, Zr0.8R0.2O1.9 where R=Nd and Y, was compared with internal friction in the temperature range of 300–685K using forced torsion pendulum method. The internal friction of Zr0.8Nd0.2O1.9 was shown as a single peak at around 350–450K at frequencies of 0.32–9Hz. The activation enthalpy of relaxation in Zr0.8Nd0.2O1.9 was determined to be 1.12±0.1eV. The amplitude of the high-temperature peak in Y-doped zirconia was not observed for Zr0.8Nd0.2O1.9. The result suggests that the relatively lower mobility of oxygen is due to the doping of larger Nd cation to ZrO2 lattice. [Copyright &y& Elsevier]

The 773 K isothermal section of the title system is investigated by XRD, SEM, DSC, and EDS techniques. [ABSTRACT FROM AUTHOR]

Review: 24 refs. [ABSTRACT FROM AUTHOR]

Phase-pure monoclinic NdLuO3 is prepared by hydrothermal reaction of an alkaline (pH <13) solution of Nd(NO3)3 and Lu(NO3)3 (autoclave, 250 °C, 24 h) resulting in the nanocrystalline precursors LuO(OH) and Nd(OH)3 which are further calcined, compressed, and sintered in air (1600 °C, 8 h). [ABSTRACT FROM AUTHOR]

Galvanostatic electrolysis of Nd2O3-CuO pellets in molten LiF-CaF2 eutectics containing Li2O between 900 and 1040 °C leads to the formation of metallic neodymium in the form of liquid Cu-Nd alloys. [ABSTRACT FROM AUTHOR]

Nd8Co4-xAlxGe2C3 (x ≅ 0.65) is prepared by reaction of Ge and carbon in a Nd/Co eutectic flux (alumina crucible in evacuated silica tubes, 950 °C, 12 h). [ABSTRACT FROM AUTHOR]