Effect of samarium on the N_(2) selectivity of Sm_(x)Mn_(0.3-x)Ti catalysts during selective catalytic reduction of NO_(x) with NH_(3)

This work aims to study the improvement effect of Sm on Mn-based catalysts for selective catalytic reduction (SCR) of NO with NH3.A series of Sm_(x)Mn_(0.3-x)-xTi catalysts (x=0,0.1,0.15,0.2,and 0.3) were prepared by co-precipitation.Activity tests indicated that the Sm_(0.15)Mn_(0.15)Ti catalyst showed superior performances,with a NO conversion of 100%and N_(2)selectivity above 87%at 180–300℃.The characterizations showed that Sm doping suppressed the crystallization of TiO_(2)and Mn2O3phases and increased the specific surface area and acidity.In particular,the surface area increased from 152.2 m^(2)·g^(-1)for Mn0.3Ti to 241.7 m^(2)·g^(-1)for Sm_(0.15)Mn_(0.15)Ti.These effects contributed to the high catalytic activity.The X-ray photoelectron spectroscopy (XPS) results indicated that the relative atomic ratios of Sm^(3+)/Sm and Oβ/O of Sm_(0.15)Mn_(0.15)Ti were 76.77at%and 44.11at%,respectively.The presence of Sm contributed to an increase in surface-absorbed oxygen (Oβ) and a decrease in Mn^(4+)surface concentration,which improved the catalytic activity.In the results of hydrogen temperature-programmed reduction(H_(2)-TPR),the presence of Sm induced a higher reduction temperature and lower H_(2)consumption (0.3 mmol·g^(-1)) for the Sm_(0.15)Mn_(0.15)Ti catalyst compared to the Mn0.3Ti catalyst.The decrease in Mn^(4+)weakened the redox property of the catalysts and increased the N_(2)selectivity by suppressing N_(2)O formation from NH3oxidation and the nonselective catalytic reduction reaction.The in situ diffuse reflectance infrared Fourier transform spectra (DRIFTs) revealed that NH3-SCR of NO over the Sm_(0.15)Mn_(0.15)Ti catalyst mainly followed the Eley–Rideal mechanism.Sm doping increased surface-absorbed oxygen and weakened the redox property to improve the NO conversion and N_(2)selectivity of the Sm_(0.15)Mn_(0.15)Ti catalyst.

Effects of samarium addition on microstructure and mechanical properties of as-cast Al-Si-Cu alloy

The effects of rare earth samarium （Sm） additions on the microstructure and mechanical properties of as-cast Al-Si-Cu alloy were investigated by optical microscopy and scanning electron microscopy （SEM）. The results show that Sm can effectively refine the a（Al） dendrite and the eutectic silicon. In addition, the shape of iron-rich phases changes from the Chinese script-like to slender-like ones and the volume fraction of iron-rich phases is decreased by the addition of Sm. Two kinds of Sm-rich interrnetallics are found： AlSiSm and AlSiCuSm. The plate-like AlSiCuSm phase always associates with the needle-like AISiSm phase. The mechanical properties are improved by the addition of Sm, and the good ultimate tensile strength （220 MPa） and elongation （3. 1%） are obtained from the Al-Si-Cu-1.0Sin alloy.

Luminescent Properties of Samarium Ion in Calcium Molybdate

Trivalent samarium ion (Sm^(3+)) activated calcium molybdate (CaMoO_4) phosphor was prepared by solid-state reaction in air. The XRD pattern of the powder CaMoO_4∶Sm shows that the CaMoO_4∶Sm single phase is developed fully through our preparation procedure. The excitation spectrum of CaMoO_4∶Sm is composed of a broad absorption of host and some sharp lines of the f-f transition absorption of Sm^(3+). Illustrated in photoluminescence spectrum, CaMoO_4 doped with Sm^(3+) displays orange red emission that is ascribed to the inner 4f^5 electron transitions ~6H_(7/2)(orange)and ~6H_(9/2)(red)of Sm^(3+). Different from the sites of Sm^(3+) in CdWO_4, the Sm^(3+) ions substitute for the Ca^(2+) and form only one type emission center in the CaMoO_4 crystal lattice.

Effects of Samarium on Liver and Kidney of Rats

Spraque-Dawley(SD)big rats with weaning weight of (195±15) g were randomly divided into 4 groups with 8 males and 8 females each group. One group drank de-ionized water served as control and also used for analysis with the background. The other three groups were cultured for five months by drinking de-ionized water with 3.0, 4.5 and 6.0 mg·L-1 Sm (NO3)3, respectively. Compared with the rats in control, it is found that the organs of the treated rats are apparently pathologically changed, such as liver swell, lung intumescence, peritoneum conglutination and hardness. Especially, in the high Sm group, the pathological percentage in liver and lung is up to 30% . The pathological changes in liver and lung show that rare earth Sm does hazard biological effects to animals. With increasing Sm concentration, the weight rate of organ/body has a tendency of increasing; the activity of superoxide dismutase (SOD) in liver and kidney decreases, but the maglonydiadehyde (MDA) concentration increases, indicating the abilities of anti-oxidation and the lipid per-oxi-dation inhibition degenerate, which leads to hard pathological changes in organs. Moreover, the relative weight rate of organ/body, the activity of SOD and the MDA concentration are remarkably lager in liver than in kidney and other organs, suggesting that the biological effect of Sm on liver is the greatest and Sm has a high affinity for liver.

Tribological performance of nanometer samarium borate

Nanometer crystal samarium borate with a particle size of 20～40?nm was prepared using replacing solvent drying technique. The wear resistance and load carrying capacity of 500SN base oil could be improved and the friction coefficient could be decreased by the addition of nanometer samarium borate. But the dosage of samarium borate nanoparticles had to be controlled at a relatively low level, a higher concentration of nanoparticles was not of beneficial to the tribological performance of the oil. The optimal dosage of nanometer samarium borate is 1.0%. Tribochemical reactions took place in the tribological process, which resulted in the formation of deposition products including diboron trioxide and disamarium trioxide. Fe 2B and FeB were also found on the wear scar. The improvement of tribological properties of the oil comes from the formation of deposition layer and permeating layer. [

Effect of rare earth samarium addition on the kinetics of precipitation in Al-Cu-Mn casting alloy

The mechanical properties of Al-Cu-Mn casting alloy mainly depend on the morphology, distribution, size, and number ofθ′（Al2Cu） precipitates. In this study, we have analyzed the effect of rare earth samarium （Sm） addition on the kinetics of precipitation in the Al-Cu-Mn casting alloy by using differential scanning calorimetry （DSC） and high-resolution transmission electron microscopy. Thermal ef-fect peaks that are attributed to the formation and the dissolution of Guinier-Preston （GP） zone andθ′phase were identified from the DSC curves. The activation energy ofθ′formation was calculated by using both the Kissinger method and the analytical model, and the corre-sponding results were compared. Results suggest that the activation energy ofθ′formation in Al-Cu-Mn alloy is dramatically higher than that in Al-Cu-Mn-Sm alloy. Accordingly, it is concluded that the addition of rare earth Sm decreases the activation energy ofθ′formation and promotes the formation ofθ′precipitates.

Polymerization of Acrylonitrile Initiated by Di（2，6－di－tert－butyl－4－methylphenoxo） Samarium Complex

The polymerization of acrylonitrile initiated by organolanthanide complexes alone is studied for the first time. The effect of polymerization conditions on catalytic activity of the title complex and molecular weight of the polymers produced have been studied.

Laser stealth absorbent of samarium oxysulfide prepared by flux method

A novel 1064 tun laser stealth absorbent of SmzO2S was prepared by flux method. The effects of different calcining temperatures and fluxes on the reflective property of Sm2O2S were investigated. The phase composition, morphology, and reflectivity of the powders were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and ultraviolet-visible spectrophotometer （UVPC）. The results showed that pure phase of Sm202S could be obtained with Na2CO3 as flux above 950~C, and the reflectivity decreased with the calcination temperature increasing. Compared with other samarium compounds, the reflectivity at 1064 nm of Sm2O2S was the lowest. Different fluxes had great impact on the phase composition, particle morphology, and reflectivity of the products. In short, Sm2O2S was suitable as a kind of absorbent against 1064 nm laser.

Separation of Samarium(Ⅲ)and Gadolinium(Ⅲ)by A Push-pull Liquid Membrane System

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Thermochemical Study on Coordination Complex of Samarium with Salicylic Acid and 8-Hydroxyquinoline

The coordination complex Sm（C7H5O2）2·（C9H6NO）, synthesized from the reaction of samarium chloride sixhydrate with salicylic acid and 8-hydroxyquinoline, was characterized with IR, elemental analysis, molar conductance, and thermogravimatric analysis. The standard molar enthalpies of solution of [ SmCl3·6H2O （s） ], [ 2C7H6O3 （s） ], [ C9H7NO （ s ） ] and [ Sm （C7H5O3） 2·（ C9H6NO ） （ s ） ] in the calorimetric solvent were determined with the solution-reaction isoperibol calorimeter at 298.15 K to be △sHm^- [ SmCl3·6H2O （s）, 298.15 K ] = - 103.98 ± 0.04 kJ·mol^-1, △sHm^- [2 C7H6O3 （s）, 298.15 K] = 16.35±0.14 kJ·mol^-1,△sHm^-[C9H7NO （s）, 298.15 K] = -6.11±0.08 kJ·mol^-1 and △sHm^-[Sm（C7H5O3）2·（C9H6NO） （s）, 298.15 K] = - 130.08 ± 0.04 kJ·mol^-1, respectively. The enthalpy was determined to be △rHm^- = 89.59 ±0.18 kJ·mol^-1 for the reaction SmCl3·6H2O（s） ＋ 2C7H6O3（s） ＋ C9H7NO（s） = Sm （C7H5O3） 2·（C9H6NO） （ s ） ＋ 3HCl （g） ＋ 6H2O （ l ）. According to the above results and the data given in literature and through Hess＇ law, the standard molar enthalpy of formation of Sin（ C7H5O3 ）2·（C9H7NO）（s） was estimated to be △rHm^- [ Sm （C7H5O3）2·（C9H6NO） （s）, 298.15 K] = - 2055.9 ± 3.03 kJ·mol^-1.

Influence of samarium content on microstructure and mechanical properties of recycled die-cast YL112 aluminum alloys

The influence of Sm （Samarium） content on microstructure and mechanical properties of recycled die-cast YLl12 aluminum alloys was investigated. The results show that many small Sm-rich particles form in the recycled die-cast YLl12 alloys with Sm addition. At the same time, the secondary dendrite arm spacing in the YLl12 alloys modified with Sm is smaller than that of the unmodified alloy. The eutectic Si of recycled die- cast YL112-xSm alloys transforms from coarse acicular morphology to fine fibres. Mechanical properties of the investigated recycled die-cast YLl12 aluminum alloys are enhanced with Sm addition, and a maximal ultimate tensile strength value （276 MPa） and elongation （3.76%） are achieved at a Sm content of 0.6wt.%. Due to the modification of eutectic Si by Sm, numerous tearing ridges and tiny dimples on the fractures of tensile samples are observed.

Facile Synthesis of Amidines via Intermolecular Reductive Coupling of Nitriles with Azobenzene Promoted by Samarium Diiodide

The intermolecular reductive coupling of nitrites with azobenzene induced by SmI2 was studied. Amidine derivatives were prepared in good yields under neutral and mild conditions.

Reductive cyclodimerization of arylmethylidenemalononitriles promoted by samarium and catalytic amount of iodine： facile synthesis of cyclopentene derivatives

Samarium and a catalytic amount of iodine were used to obtain functionalized cyclopentenes by reductive dimerization followed by intramolecular cyclization of 1， 1-dicyanoalkenes under mild conditions.

Simultaneous Determination of Samarium and Gadolinium by a Automated Stopped-flow Analyzer

The present paper contains the reaction mechanism of the rare earth complex with 2-(2-arsenophenylazo)-7-(2, 6-dichloro-4-fluoro-phenylazo)- 1, 8-dihydroxynaphthalene-3, 6-disulfonic acid (DCF-arsenazo) studied preliminarily with a fully automated stopped-flow analyzer. A method with a high sensitivity and selectivity is proposed for the simultaneous determination of samarium and gadolinium based on the differential kinetic reaction of the rare earth complex with DCF-arsenazo. Sm and Gd in their concentrated oxides were determined with the relative errors less than 6%.

Synthesis of Aminomethyl Arylsulfides via Novel Synthetic Auxiliary Benzotriazole Promoted by Samarium Diiodide

Aminomethyl arylsulfides are synthesized through nucleophilic substitution of a benzotriazolate anion by thiolates promoted by samarium diiodide.

Reductive Cleavage of S-S Bond by Samarium Diiodide: Synthesis of β-Thioesters and β-Thionitriles

The reduction of disulfides by samarium diiodide led to sa arium thiolates (ArSSml2).This new thiolate anion species reacted smoothly with α, β -unsaturated esters (nitriles) to give 1,4-addition products β -thioesters and β -thionitriles in good yields under mild and neutralcondition.

Polymerization of Phenyl Isocyanate by Divalent Samarium Complex (ArO)_2Sm(THF)_4 (ArO=2,6-di-tert-butyl-4-methylphenoxo)

Phenyl isocyanate was for the first time successfully polymerized by divalent samarium complex (ArO)2Sm(THF)4. The monomer concentration and temperatur affected the polymerization greatly.

Study on the Process for Removal of Samarium from NdCl_3 Solution by Solvent Extraction with DEHPA

The process for removal of samarium from NdCl_3 solution containing a little samarium by solvent extrac-tion with unsaponated Di (2-ethyl hexyl) orthosphoric acid (DEHPA) at acidic range is reported. The in-dustrial experiments have been completed on a production line of 150 t Nd_2O_3 per annum in the Baotou ThirdRare Earth Factory. As a result of 9 step counter current extraction , Sm_2 O_3 content in Nd_2 O_3 drops down to0. 08 % from 0. 5% , the purity of neodymium oxide is over 99. 5% and the direct recovery of Nd_2O_3 is 92%～ 93% .

Structure and Luminescence of Carboxylic Acid Samarium and Europium Complexes

Two crystals, [Sm（Hcpna）（cpna）·3 H2O]n（1） and [Eu（Hcpna）（cpna）·2 H2O]n（2）,have been synthesized by solvothermal method based on Sm3+ and Eu3+ with multiple acid ligands5-（4-carboxyphenoxy）nicotinic acid（H2cpna）, and the new complexes have been characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy, thermogravimetric analysis and fluorescence analysis. Complex 1 exhibits a 1 D chain structure. It crystallizes in the triclinic system, space group P1 with a = 5.9738（11）, b = 12.528（2）, c = 18.021（4） ?, α = 93.156（3）o, β =98.067（3）o, γ = 92.692（3）o, V = 1331.3（4） ?3, Z = 2, S = 1.069, F（000） = 702, R = 0.0277 and wR =0.0688（I > 2σ（I））. Complex 2 shows a two-dimensional network structure, which crystallizes in monoclinic system, space group C2/c with a = 13.6733（19）, b = 18.422（3）, c = 10.4307（15） ?, β =93.881（2）o, V= 2621.4（7） ?3, Z = 4, S = 1.110, F（000） = 1372, R = 0.0302 and wR = 0.0811（I >2σ（I））. The solid-state fluorescent test results show tcomplex 1 has weaker fluorescence intensity than the ligand. However, complex 2 has excellent fluorescence properties, and can emit bright red light under the irradiation of ultraviolet lamp.

SORPTION BEHAVIOR AND MECHANISM OF SAMARIUM(III) ON AMINO METHYLENE PHOSPHONIC ACID RESIN

Sm(III) was quantitatively adsorbed by amino methylene phosphonic acid resin (APAR) in the medium of pH=5.0. The statically saturated sorption capacity is 251mg/g·resin. Sm(III) adsorbed on APAR can be reductively eluted by 2.0mol/L HCl. The sorption rate constant is k298= 1.35×10-5s-1. The sorption behavior of APAR for Sm(III) obeys the Freundlich isotherm. The enthalpy change △H of sorption is 24.9kJ/mol. The apparent activation energy is Ea=11.7kJ/mol. The sorption mechanism shows that the nitrogen and oxygen atoms of the functional group of APAR coordinated with Sm(III) to form coordination bond.