2-substituted-1-amino-o-carboranes 2-R-1-NH_(2)-o-C_(2)B_(10)H_(10)(R=CH_(3),1a;R=Ph,1b)were synthesized and the reactions of these compounds with the yttrium dialkyl complex[Y(L)(CH_(2)SiMe3)_(2)](L=[2-(2,5-Me_(2)C_(...2-substituted-1-amino-o-carboranes 2-R-1-NH_(2)-o-C_(2)B_(10)H_(10)(R=CH_(3),1a;R=Ph,1b)were synthesized and the reactions of these compounds with the yttrium dialkyl complex[Y(L)(CH_(2)SiMe3)_(2)](L=[2-(2,5-Me_(2)C_(4)H_(2)N)C_(6)H4NC(Ph)=NDipp]-,Dipp=2,6-iPr_(2)C_(6)H_(3))were investigated.The 1H NMR spectroscopy indicate that the reaction of ytrrium dialkyl complex with one equivalent of 2-R-1-NH_(2)-o-C_(2)B_(10)H_(10) produce the mixture of ytrrium alkyl-amido complex[Y(L)(2-R-1-NH-o-C_(2)B_(10)H_(10))(CH_(2)SiMe3)](R=CH_(3),2a;R=Ph,2b)and bis(amido)complex[Y(L)(2-R-1-NH-o-C_(2)B_(10)H_(10))_(2)](R=CH_(3),3a;R=Ph,3b).The yttrium bridging imido complex[Y(L)(2-CH_(3)-1-N-o-C_(2)B_(10)H_(10))]_(2)(4a)was obtained by heating the mixture at 55℃for 12 h.Complex 3a was isolated and characterized by treating the yttrium dialkyl complex with two equivalents of 1a.The structures of complexes 3a and 4a were verified by single-crystal Xray diffraction.CCDC:2424136,3a;2424137,4a.展开更多
The recovery of rare earths from industrial rare earth leaching solution is typically achieved through the ammonium carbonate precipitation method,which presents challenges in terms of prolonged production cycle and a...The recovery of rare earths from industrial rare earth leaching solution is typically achieved through the ammonium carbonate precipitation method,which presents challenges in terms of prolonged production cycle and ammonia nitrogen pollution.The present study explored the synthesis of crystalline yttrium carbonate in a sodium carbonate system,employing a conventional mother liquor derived from yttrium chloride.The growth of yttrium carbonate was explored through the lens of density functional theory(DFT)calculations,unveiling a novel perspective on its formation mechanism.The synthesized yttrium carbonate demonstrates enhanced crystallinity,with a D50value of 19.75μm achieved under reaction conditions comprising a temperature of 60℃,stirring rate of 200 r/min,feeding rate of 4 mL/min,and aging time of 30 h.The molar ratio for precipitation is set at 1.6:1.The morphology of yttrium carbonate undergoes a transition from needle-like structures to sheet-like formations,ultimately culminating in the formation of spherical aggregates.The variation in surface energy among distinct crystal planes and CO_(3)^(2-)configurations within crystal cells accounts for this phenomenon.The DFT calculations unveil a progression of growth and trans formation in yttrium carbonate,commencing from a one-dimensional configuration and culminating in a multidimensional morphology.展开更多
0.05 wt.%Y was incorporated into IN718 alloy powders,and specimens were fabricated using selective laser melting(SLM)technology.High-temperature tensile tests were then performed at 650℃on both the as-built and heat-...0.05 wt.%Y was incorporated into IN718 alloy powders,and specimens were fabricated using selective laser melting(SLM)technology.High-temperature tensile tests were then performed at 650℃on both the as-built and heat-treated specimens.The results revealed that both the as-built and heat-treated 0.05Y-IN718 specimens exhibit a slight increase in tensile strength compared to 0Y-IN718 specimen,attributed to the formation of Y-O and Y-Al-O nano-oxides.Notably,the ductility of 0.05Y-IN718 alloy was largely improved in as-built state,but only marginally improved in heat-treated state.Previous research suggests that the improved ductility can be ascribed to Y effect on grain boundary purification and alterations in the morphology of carbides andδphase.However,an in-depth analysis was conducted based on the scanning/transmission electron microscope and density functional theory results and demonstrated that it is Y segregation in the Laves/γmatrix interface that actually plays the vital role for enhancing interfacial bonding.Hence,the extremely fast cooling rate during SLM processing facilitates mass accumulation of Y in the interdendritic region or cellular wall,achieving a large improvement in the ductility.展开更多
In order to enhance the service life of refractories for melting and casting of titanium alloy,preparation of yttrium oxide coatings on the refractories surface is an effective solution.The improvement of thermal shoc...In order to enhance the service life of refractories for melting and casting of titanium alloy,preparation of yttrium oxide coatings on the refractories surface is an effective solution.The improvement of thermal shock stability of the coating is beneficial to its spalling resistance during the high-temperature service,and the available slurry with good performance is the prerequisite.The effects of the varieties and contents of dispersant(sodium tripolyphosphate,sodium hexametaphosphate,sodium pyrophosphate,citric acid and polycarboxylate ammonium salt)and binder(aluminum dihydrogen phosphate,zirconium acetate and yttria sol)on the stability,rheological and thixotropic properties of yttrium oxide waterbased slurry were investigated,and the effects of slurry composition design on the thermal shock resistance of the coating were focused.The results showed that the introduction of polycarboxylate ammonium salt as dispersant significantly improved the stability of the slurry,and the varieties of the binders had significant effects on the dispersibility of the slurry.When aluminum dihydrogen phosphate and polycarboxylate ammonium salt were used as binder and dispersant,respectively,the slurry had better stability,suitable rheological and thixotropic properties.By using aluminum dihydrogen phosphate as binder,the coating had good thermal shock resistance and no obvious cracks were observed for the coating after thermal shock,which was attributed to the yttrium aluminate binding phase generated in the coating.An effective method was provided for preparing yttrium oxide coatings with enhanced thermal shock resistance applied in the process of titanium alloy melting and casting.展开更多
Chitin powder and chitin-aerogel were prepared from shrimp wastes and used to uptake Y^(3+)from aqueous solutions and concentrate this rare earth element from phosphogypsum(PG).Chitin aerogel displays a specific surfa...Chitin powder and chitin-aerogel were prepared from shrimp wastes and used to uptake Y^(3+)from aqueous solutions and concentrate this rare earth element from phosphogypsum(PG).Chitin aerogel displays a specific surface area of 945 m^(2)/g,while chitin powder is 3.6 m^(2)/g,which largely influences its adsorption ability.Regarding the adsorption in synthetic solutions,the effect of pH on Y^(3+)removal is strong for chitin powder adsorbent.In contrast,no big pH influence was detected for chitin aerogel.Electrostatic interactions and chelation can highlight the proposed mechanism of Y^(3+)on chitin adsorbents for the powder and aerogel.Furthermore,in addition to these interactions,pore filling/pore diffusion is the main mechanism of Y^(3+)removal in the chitin aerogel.Chitin aerogel is efficient in concentrating 8 times the Y^(3+)from PG,a very complex matrix.The complex chitin aerogel-Y^(3+)can be a secondary source of rare earth elements for other applications.展开更多
Y_(3)Fe_(5)O_(12)(YIG)crystals are highly desirable for the fabrication of mid-infrared isolators with the rapid growth of optical communications,although it is rather challenging to grow large size and high-quality s...Y_(3)Fe_(5)O_(12)(YIG)crystals are highly desirable for the fabrication of mid-infrared isolators with the rapid growth of optical communications,although it is rather challenging to grow large size and high-quality single crystals.Dy^(3+)doping is expected to improve the optical and magneto-optical prope rties.However,high quality Dy:YIG crystals and the adjustment of Dy^(3+)on the structure and optical behavior of YIG crystal remain unclear,impeding its practical applications.Herein,a series of Y_(3-x)Dy_(x)Fe_(5)O_(12)(x=0,0.5,1.0,1.5,3)solid solution crystals was grown by the flux-Bridgman method and single crystals up to 25 mm were obtained.With the introduction of Dy^(3+),lattice parameters are gradually enlarged from 1.2379 nm(YIG)to 1.2420 nm(DyIG).Typical Dy^(3+)absorption peaks are observed around 1070,1265 and 1670 nm.The refractive index decreases from 2.37(500 nm)to 2.10(2500 nm)for YIG crystal,and it reduces from 2.47(500 nm)to 2.16(2500 nm)for DyIG crystal.The optical bandgaps remain almost unchanged for Dy:YIG crystals.The optical dispersion of the refractive indices was finely fitted by the Wemple and DiDomenico(WDD)and the Sellmeier models,respectively.With the increase of Dy^(3+)content,the saturation magnetization(Ms)decreases significantly from 23.62 emu/g(YIG)to 5.33 emu/g(DyIG).Small coercive field is persisted for this system,endowing small external magnetic field.These results provide valuable references for the manipulation of rare earths on the properties of magnetooptical crystals,which is beneficial to the design of high-performance garnet crystals for the application of optical switching and non-reciprocal related devices.展开更多
In order to reduce or eliminate the adverse effects of calcium impurity,the interaction of Ca and rare earth Y co-doping on the preparation of WC-Co cemented carbides was investigated.X-ray diffraction,scanning electr...In order to reduce or eliminate the adverse effects of calcium impurity,the interaction of Ca and rare earth Y co-doping on the preparation of WC-Co cemented carbides was investigated.X-ray diffraction,scanning electron microscopy and transmission electron microscopy were employed to analyze the phase compositions,particle sizes and morphologies of them,respectively.The results show that the second type of"yttrium barrier effect"is observed and the adverse influence of Ca-rich phase on tungsten powder can be eliminated by it.The flexural strength and fracture toughness of YG6-0.01%Ca+0.09%Y alloy are 2199.5 MPa and 11.49 MPa·m^(1/2),showing improvement of 6.5% and 2.7% compared to YG6 alloy,respectively.The evolutions of Ca-rich phase and Y-rich phase at the every alloy preparation stage of WO_(3),W,WC and cemented carbides are obtained.Furthermore,the strengthening mechanism of WC-Co cemented carbide with co-addition of Ca and Y is proposed.展开更多
The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(D2EHPA) as extracting agent.The extracting agents were supported on a macro porous polymeric resi...The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(D2EHPA) as extracting agent.The extracting agents were supported on a macro porous polymeric resin XAD-7(solid phase).Yttrium ions extraction and discharge tests were performed,firstly from a synthetic aqueous solution of 100 mg/L Y(liquid phase) at 25℃ with stirring.The effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid(S/L)ratio on the yttrium recovery were studied.The most favorable conditions for yttrium ions extraction are;20 vol% D_(2)EHPA functionalized resin,pH=1.5 and an S/L ratio of 10 mg/mL The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/L [H_(2)SO_(4)] as stripping solution.Up to 80% yttrium is extracted,while 75% yttrium is recovered in the striping solution.In all experiments,the reaction equilibrium is reached after 20 min,and the kinetics for the extraction stage was determined as a second-order model.Also,experiments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is 1.5.Cyclic tests of extraction and discharge for yttrium ions show that the functionalized resin can work at least five cycles without decreasing its efficiency.Finally,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H_(2)SO_(4),demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.展开更多
Engineering high‐performance and low‐cost bifunctional catalysts for H_(2)(hydrogen evolution reaction[HER])and O_(2)(oxygen evolution reaction[OER])evolution under industrial electrocatalytic conditions remains cha...Engineering high‐performance and low‐cost bifunctional catalysts for H_(2)(hydrogen evolution reaction[HER])and O_(2)(oxygen evolution reaction[OER])evolution under industrial electrocatalytic conditions remains challenging.Here,for the first time,we use the stronger electronegativity of a rare‐Earth yttrium ion(Y^(3+))to induce in situ NiCo‐layered double‐hydroxide nanosheets from NiCo foam(NCF)treated by a dielectric barrier discharge plasma NCF(PNCF),and then obtain nitrogen‐doped YNiCo phosphide(N‐YNiCoP/PNCF)after the phosphating process using radiofrequency plasma in nitrogen.The obtained NYNiCoP/PNCF has a large specific surface area,rich heterointerfaces,and an optimized electronic structure,inducing high electrocatalytic activity in HER(331mV vs.2000mA cm^(−2))and OER(464mV vs.2000mA cm^(−2))reactions in 1MKOH electrolyte.X‐ray absorption spectroscopy and density functional theory quantum chemistry calculations reveal that the coordination number of CoNi decreased with the incorporation of Y atoms,which induce much shorter bonds of Ni and Co ions and promote long‐term stability of N‐YNiCoP in HER and OER under the simulated industrial conditions.Meanwhile,the CoN‐YP_(5) heterointerface formed by plasma N‐doping is the active center for overall water splitting.This work expands the applications of rare‐Earth elements in engineering bifunctional electrocatalysts and provides a new avenue for designing highperformance transition‐metal‐based catalysts in the renewable energy field.展开更多
Short Retraction NoticeThe paper does not meet the standards of "Journal of Applied Mathematics and Physics". This article has been retracted to straighten the academic record. In making this decision the Ed...Short Retraction NoticeThe paper does not meet the standards of "Journal of Applied Mathematics and Physics". This article has been retracted to straighten the academic record. In making this decision the Editorial Board follows COPE's Retraction Guidelines. The aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused.Editor guiding this retraction: Prof. Wen-Xiu Ma (EiC of JAMP)The full retraction notice in PDF is preceding the original paper, which is marked "RETRACTED".展开更多
[Objective] The effects of yttrium nitrate （YNO3） on biomass and antioxi- dant systems of paddy rice （Yttrium （Y）; Oxidative stress; Dismutases （SOD）; Per- oxidases （POD）, Catalases （CAT）, Paddy rice （Trit...[Objective] The effects of yttrium nitrate （YNO3） on biomass and antioxi- dant systems of paddy rice （Yttrium （Y）; Oxidative stress; Dismutases （SOD）; Per- oxidases （POD）, Catalases （CAT）, Paddy rice （Triticum aestivum）） together with the occurrences of Y in soils were investigated to assess its ecotoxicological effects on plant. [Method]Y solutions with various concentrations were sprinkled on soil sam- ples, which were well mixed and then put into culture dishes to culture paddy rice seeds for further evaluation. [Result] The results indicated that 25-100 mg/kg Y treatments significantly increased the biomass （total weight, root weight, shoot weight and leaf weight）, chlorophyll （CHL） content and protein content of paddy rice, whereas 200-800 mg/kg Y treatments had a converse effect. Similarly, biomarker for the antioxidant systems including superoxide dismutases （SOD）, peroxidases （POD） and catalases （CAT） all exhibited similar trends in both shoots and roots of paddy rice. At the same time, the malonaldehyde （MDA） content increased at from 25 to 100 mg/kg and decreased with concentrations of Y from 100 to 800 mg/kg in both shoots and roots of paddy rice. This indicated that Y could stimulate the growth of plant at low concentration, but inhibit the growth at relatively high concen- tration. [Conclusion] The levels of Y were 641＋49, 328_＋16 and 473_＋40 mg/kg in soils collected from mining area, farmland and navel orange orchard respectively. The levels of Y in the investigated area were higher than the benefit level （100 mg/kg）, which could cause low biomass as well as low activity of SOD, POD and CAT in paddy rice. Therefore, a more careful use of Y is necessary in crop management.展开更多
The yttrium as a sintering aid was introduced into polycarbosilane（PCS） to prepare yttrium-containing PCS（PYCS）.Two types of yttrium-containing SiC fibres,the SiC（OY） fibres and the SiC（Y） fibres,were fabricat...The yttrium as a sintering aid was introduced into polycarbosilane（PCS） to prepare yttrium-containing PCS（PYCS）.Two types of yttrium-containing SiC fibres,the SiC（OY） fibres and the SiC（Y） fibres,were fabricated with PYCS.The structural evolution and the associated properties on changing from SiC（OY） to SiC（Y） fibres during the sintering process were studied.The chemical composition of the SiC（OY） fibres is SiC1.53O0.22Y0.005 with an amorphous structure.The composition of SiC（Y） fibres is SiC1.23O0.05Y0.005.The fibres are composed of a large number of β-SiC crystallites with a size of 50 nm and a small amount of α-SiC crystalline.The tensile strength and fracture toughness of the SiC（OY） fibres are 2.25 GPa and 2.37 MPa·m1/2,respectively,and 1.61 GPa,1.91 MPa·m1/2,respectively for SiC（Y） fibres.The SiC（Y） fibres have a higher thermal stability than the SiC（OY） fibres.展开更多
This study aimed to investigate the toxicity of rare earth ion yttrium under the stress of leaching agent ammonium sulfate （NH4）2SO4. [Method] By using earthworms as indicator organisms of environmental pol ution, a...This study aimed to investigate the toxicity of rare earth ion yttrium under the stress of leaching agent ammonium sulfate （NH4）2SO4. [Method] By using earthworms as indicator organisms of environmental pol ution, acute toxic ef-fects of rare earth yttrium on earthworms under the stress of ammonium sulfate were investigated with filter paper contact method. [Result] Under single stress of rare earth yttrium, the semi-lethal concentration after 48 and 24 h was LC50=213.41 mg/L and LC50=322.63 mg/L, respectively. ② Under single stress of ammonium sul-fate, the semi-lethal concentration after 48 h and 24 h was LC50=13.89 g/L and LC50=15.05 g/L, respectively. ③ In combined treatment of low concentration （10 g/L） of ammonium sulfate and different doses of rare earth yttrium, the semi-lethal con-centration after 48 and 24 h was LC50=198.65 g/L and LC50=399.85 g/L, respective-ly; in combined treatment of middle concentration （14 g/L） of ammonium sulfate and different doses of rare earth yttrium, the semi-lethal concentration after 48 and 24 h was LC50=167.3 mg/L and LC50=256.73 mg/L, respectively; in combined treatment of high concentration （20 g/L） of ammonium sulfate and different doses of rare earth yttrium, the semi-lethal concentration after 48 h and 24 h was LC50=31.03 mg/L and LC50=127.65 mg/L, respectively. [Conclusion] Low concentration of ammonium sulfate could reduce the toxicity of rare earth yttrium to earthworms and produce certain antagonism against rare earth yttrium; middle concentration ammonium sulfate in-creased the toxicity of rare earth yttrium to earthworms and produced relatively sig-nificant synergistic effects; high concentration ammonium sulfate significantly in-creased the toxicity of rare earth yttrium to earthworms. Compared with ammonium sulfate, dead earthworms exposed to rare earth yttrium were more easily fractured, and living earthworms showed insensitive response to acupuncture.展开更多
For the accurate prediction of equilibrium distribution ratios of rare earth metals during solvent extraction under non-ideal conditions, the extraction equilibria of yttrium （Ⅲ） and europium （Ⅲ） from the hydroc...For the accurate prediction of equilibrium distribution ratios of rare earth metals during solvent extraction under non-ideal conditions, the extraction equilibria of yttrium （Ⅲ） and europium （Ⅲ） from the hydrochloric acid solutions with P507 in Shellsol D70 were studied. A chemically-based model was established and the extraction equilibrium constants were determined by the nonlinear least squares method. The proposed model involves the cation exchange reaction and the solvation extraction in the low and high acidity regions, respectively. In the model, the nonideality of the aqueous phase and was corrected by considering the complexation of the metals with Cl- and by replacing with its effective concentration, respectively. This model was verified by fair agreement between the calculated metal distribution ratios and those experimentally obtained in the single metal systems. The feed concentrations for the systems are in wide ranges of the metal （up to 0.1 mol/L）, hydrochloric acid （0.07-3.00 mol/L） and the extractant （0.25-1.00 mol/L）. The model enables the engineering prediction of the equilibrium distribution ratios with good accuracy in a binary metal system.展开更多
Y2O3 nanomaterials have been widely used in transparent ceramics and luminescent devices. Recently there are many studies focusing on controlling the size and morphology of Y2O3 in order to obtain better materials per...Y2O3 nanomaterials have been widely used in transparent ceramics and luminescent devices. Recently there are many studies focusing on controlling the size and morphology of Y2O3 in order to obtain better materials performance. In present study, yttrium oxyhydroxide precursor was synthesized via a facile solvothermal process through the dissolution-re-crystallization mechanism of Y2O3 raw powders in the ethylenediamine solvent, then nanosized yttrium oxide crystal was prepared from the precursor through post heat treatment process. The effects of solvothermal treatment temperature, holding time, solvent kinds and post heat treatment parameters on crystalline structure, grain shape and size of nanocrystal were investigated by XRD, TEM and TGA-DTA measurements. TEM images reveal that the morphology of product after post heat treatment at 460℃for 12 h is rice-like nanocrystal. XRD shows that this product is pure cubic Y2O3 cphase. Present study reveals that high purity Y2O3 with rice-like morphology can be easily prepared with average size around 30 nm under suitable post heat treatment parameters. In addition, the effects of solvents such as water and ethanol etc. on the crystal structure and morphology were also investigated. It is suggested that dissolution-recrystallization process may be the main mechanism for the formation of nano-sized YOOH precursors under solvothermal reaction condition, and the ethylenediamine solvent is likely to play an important role in controlling the transformation process of yttria precursors to the Y2O3 nanocrystal.展开更多
A novel yttrium citrate-templated conversion method for morphology controlled synthesis of Y2O3 microspheres, microflowers and microsheets was reported for the first time. The precursors with controllable morphologies...A novel yttrium citrate-templated conversion method for morphology controlled synthesis of Y2O3 microspheres, microflowers and microsheets was reported for the first time. The precursors with controllable morphologies were synthesized with a homogenous precipitation method in aqueous solution without any surfactant. Y2O3 samples with well-preserved morphological architectures were obtained by a subse-quent thermal transformation strategy. The chemical formula of the precursor was identified and a two-stage growth mechanism was proposed. The effects of the aging time, reaction temperature, reactant concentration and molar ratio of yttrium nitrate to sodium citrate were discussed. The photoluminescence properties of the Y2O3：Eu3＋ microspheres, microflowers and microsheets prepared were also studied.展开更多
In this work,we present a new and fast method to obtain the single phase YFeO(YIG,cubic) and YFeO(YIP, orthorhombic) nanocrystals based on hydrothermal technique. The influence of initial Y/Fe mole ratio and calcinati...In this work,we present a new and fast method to obtain the single phase YFeO(YIG,cubic) and YFeO(YIP, orthorhombic) nanocrystals based on hydrothermal technique. The influence of initial Y/Fe mole ratio and calcination temperature on the nature, purity, phase structure, and morphology of the product was investigated by X-ray diffraction(XRD), Fourier-transform infrared(FT-IR) spectroscopy,energy-dispersive(EDX) X-ray spectroscopy, and field emission scanning electron microscopy(FESEM).The results show that the transformation of the as-synthesized YIG from amorphous to orthorhombic and finally to cubic phase occurs with the increase of annealing temperature. On this basis, the pure cubic phase YIG can be obtained by calcination(at 1100℃) of the precursor which is prepared using the hydrothermal treatment of mole ratio of Y:Fe = 1:1.5 exposure to an ammonia atmosphere. Also, the initial Y/Fe mole ratio of 1:1 and calcination temperature of 1000 ℃ are the optimal conditions to form single-phase nanocrystalline YIP. Further, vibrating sample magnetometry(VSM) measurements illustrate the average magnetic saturation, coercivity and remanence of 2.73 and 15.00 emu/g, 42.74 and40.02 Oe, and 1.65 and 4.30 emu/g for YIP and YIG nanocrystals, revealing their soft ferromagnetic character.展开更多
Polystyrene doped with yttrium ethoxide was prepared. The coordination between yttrium atom and benzene ring in the polystyrene doped with yttrium ethoxide was confirmed by means of IR, XPS.
Yttrium isopropoxide was prepared directly by the reaction between yttrium and isopropyl alcohol using mercuric chloride and iodine as catalyst. Yield is above 83% . This method possesses the merits of easy operationa...Yttrium isopropoxide was prepared directly by the reaction between yttrium and isopropyl alcohol using mercuric chloride and iodine as catalyst. Yield is above 83% . This method possesses the merits of easy operational approach, high product purity, high reaction rate and high production rate. Compared with the previous reported results , the period needed was shortened by 19 h and the yieid increased by 8% . The period needed for preparation is about 5 hows. These results are better than the present report . The dehydrolysis method of isopropyl alcohol and the composition of catalyst were presented.展开更多
文摘2-substituted-1-amino-o-carboranes 2-R-1-NH_(2)-o-C_(2)B_(10)H_(10)(R=CH_(3),1a;R=Ph,1b)were synthesized and the reactions of these compounds with the yttrium dialkyl complex[Y(L)(CH_(2)SiMe3)_(2)](L=[2-(2,5-Me_(2)C_(4)H_(2)N)C_(6)H4NC(Ph)=NDipp]-,Dipp=2,6-iPr_(2)C_(6)H_(3))were investigated.The 1H NMR spectroscopy indicate that the reaction of ytrrium dialkyl complex with one equivalent of 2-R-1-NH_(2)-o-C_(2)B_(10)H_(10) produce the mixture of ytrrium alkyl-amido complex[Y(L)(2-R-1-NH-o-C_(2)B_(10)H_(10))(CH_(2)SiMe3)](R=CH_(3),2a;R=Ph,2b)and bis(amido)complex[Y(L)(2-R-1-NH-o-C_(2)B_(10)H_(10))_(2)](R=CH_(3),3a;R=Ph,3b).The yttrium bridging imido complex[Y(L)(2-CH_(3)-1-N-o-C_(2)B_(10)H_(10))]_(2)(4a)was obtained by heating the mixture at 55℃for 12 h.Complex 3a was isolated and characterized by treating the yttrium dialkyl complex with two equivalents of 1a.The structures of complexes 3a and 4a were verified by single-crystal Xray diffraction.CCDC:2424136,3a;2424137,4a.
基金Project supported by the National Natural Science Foundation of China(52174250,92062110)the Youth Jinggang Scholars Program in Jiangxi Province(QNJG2020048)。
文摘The recovery of rare earths from industrial rare earth leaching solution is typically achieved through the ammonium carbonate precipitation method,which presents challenges in terms of prolonged production cycle and ammonia nitrogen pollution.The present study explored the synthesis of crystalline yttrium carbonate in a sodium carbonate system,employing a conventional mother liquor derived from yttrium chloride.The growth of yttrium carbonate was explored through the lens of density functional theory(DFT)calculations,unveiling a novel perspective on its formation mechanism.The synthesized yttrium carbonate demonstrates enhanced crystallinity,with a D50value of 19.75μm achieved under reaction conditions comprising a temperature of 60℃,stirring rate of 200 r/min,feeding rate of 4 mL/min,and aging time of 30 h.The molar ratio for precipitation is set at 1.6:1.The morphology of yttrium carbonate undergoes a transition from needle-like structures to sheet-like formations,ultimately culminating in the formation of spherical aggregates.The variation in surface energy among distinct crystal planes and CO_(3)^(2-)configurations within crystal cells accounts for this phenomenon.The DFT calculations unveil a progression of growth and trans formation in yttrium carbonate,commencing from a one-dimensional configuration and culminating in a multidimensional morphology.
基金support of the National Natural Science Foundation of China(No.52101068)China Postdoctoral Science Foundation(No.2022T150342)+2 种基金Postdoctoral International Exchange Program(No.YJ20210129)support of Shuimu Tsinghua program(No.2020SM100)supported by the Advanced Computing Center of Yunnan University.
文摘0.05 wt.%Y was incorporated into IN718 alloy powders,and specimens were fabricated using selective laser melting(SLM)technology.High-temperature tensile tests were then performed at 650℃on both the as-built and heat-treated specimens.The results revealed that both the as-built and heat-treated 0.05Y-IN718 specimens exhibit a slight increase in tensile strength compared to 0Y-IN718 specimen,attributed to the formation of Y-O and Y-Al-O nano-oxides.Notably,the ductility of 0.05Y-IN718 alloy was largely improved in as-built state,but only marginally improved in heat-treated state.Previous research suggests that the improved ductility can be ascribed to Y effect on grain boundary purification and alterations in the morphology of carbides andδphase.However,an in-depth analysis was conducted based on the scanning/transmission electron microscope and density functional theory results and demonstrated that it is Y segregation in the Laves/γmatrix interface that actually plays the vital role for enhancing interfacial bonding.Hence,the extremely fast cooling rate during SLM processing facilitates mass accumulation of Y in the interdendritic region or cellular wall,achieving a large improvement in the ductility.
基金financially supported by the National Natural Science Foundation of China(No.U21A2057).
文摘In order to enhance the service life of refractories for melting and casting of titanium alloy,preparation of yttrium oxide coatings on the refractories surface is an effective solution.The improvement of thermal shock stability of the coating is beneficial to its spalling resistance during the high-temperature service,and the available slurry with good performance is the prerequisite.The effects of the varieties and contents of dispersant(sodium tripolyphosphate,sodium hexametaphosphate,sodium pyrophosphate,citric acid and polycarboxylate ammonium salt)and binder(aluminum dihydrogen phosphate,zirconium acetate and yttria sol)on the stability,rheological and thixotropic properties of yttrium oxide waterbased slurry were investigated,and the effects of slurry composition design on the thermal shock resistance of the coating were focused.The results showed that the introduction of polycarboxylate ammonium salt as dispersant significantly improved the stability of the slurry,and the varieties of the binders had significant effects on the dispersibility of the slurry.When aluminum dihydrogen phosphate and polycarboxylate ammonium salt were used as binder and dispersant,respectively,the slurry had better stability,suitable rheological and thixotropic properties.By using aluminum dihydrogen phosphate as binder,the coating had good thermal shock resistance and no obvious cracks were observed for the coating after thermal shock,which was attributed to the yttrium aluminate binding phase generated in the coating.An effective method was provided for preparing yttrium oxide coatings with enhanced thermal shock resistance applied in the process of titanium alloy melting and casting.
基金Project supported by Brazilian National Council for Scientific and Technological Development/CNPq(405982/2022-4,303992/2021-2)Coordination for the Improvement of Higher Education Personnel/CAPES(CAPESPRINT Program)。
文摘Chitin powder and chitin-aerogel were prepared from shrimp wastes and used to uptake Y^(3+)from aqueous solutions and concentrate this rare earth element from phosphogypsum(PG).Chitin aerogel displays a specific surface area of 945 m^(2)/g,while chitin powder is 3.6 m^(2)/g,which largely influences its adsorption ability.Regarding the adsorption in synthetic solutions,the effect of pH on Y^(3+)removal is strong for chitin powder adsorbent.In contrast,no big pH influence was detected for chitin aerogel.Electrostatic interactions and chelation can highlight the proposed mechanism of Y^(3+)on chitin adsorbents for the powder and aerogel.Furthermore,in addition to these interactions,pore filling/pore diffusion is the main mechanism of Y^(3+)removal in the chitin aerogel.Chitin aerogel is efficient in concentrating 8 times the Y^(3+)from PG,a very complex matrix.The complex chitin aerogel-Y^(3+)can be a secondary source of rare earth elements for other applications.
基金Project supported by Joint Fund NSAF of National Natural Science Foundation of ChinaChina Academy ofEngineering Physics(U2130124)+1 种基金Shanghai Municipal Commission of Economy and Informatization,China(GYQJ-2020-1-19)theNational Natural Science Foundation of China(52172121)。
文摘Y_(3)Fe_(5)O_(12)(YIG)crystals are highly desirable for the fabrication of mid-infrared isolators with the rapid growth of optical communications,although it is rather challenging to grow large size and high-quality single crystals.Dy^(3+)doping is expected to improve the optical and magneto-optical prope rties.However,high quality Dy:YIG crystals and the adjustment of Dy^(3+)on the structure and optical behavior of YIG crystal remain unclear,impeding its practical applications.Herein,a series of Y_(3-x)Dy_(x)Fe_(5)O_(12)(x=0,0.5,1.0,1.5,3)solid solution crystals was grown by the flux-Bridgman method and single crystals up to 25 mm were obtained.With the introduction of Dy^(3+),lattice parameters are gradually enlarged from 1.2379 nm(YIG)to 1.2420 nm(DyIG).Typical Dy^(3+)absorption peaks are observed around 1070,1265 and 1670 nm.The refractive index decreases from 2.37(500 nm)to 2.10(2500 nm)for YIG crystal,and it reduces from 2.47(500 nm)to 2.16(2500 nm)for DyIG crystal.The optical bandgaps remain almost unchanged for Dy:YIG crystals.The optical dispersion of the refractive indices was finely fitted by the Wemple and DiDomenico(WDD)and the Sellmeier models,respectively.With the increase of Dy^(3+)content,the saturation magnetization(Ms)decreases significantly from 23.62 emu/g(YIG)to 5.33 emu/g(DyIG).Small coercive field is persisted for this system,endowing small external magnetic field.These results provide valuable references for the manipulation of rare earths on the properties of magnetooptical crystals,which is beneficial to the design of high-performance garnet crystals for the application of optical switching and non-reciprocal related devices.
基金Project supported by the National Natural Science Foundation of China(51564036,52164043)the Natural Science Foundation of Jiangxi Province(2002BAB204013)the Key Research and Development Program of Science and Technology Deprtment of Jiangxi Province(20192BBE50034)。
文摘In order to reduce or eliminate the adverse effects of calcium impurity,the interaction of Ca and rare earth Y co-doping on the preparation of WC-Co cemented carbides was investigated.X-ray diffraction,scanning electron microscopy and transmission electron microscopy were employed to analyze the phase compositions,particle sizes and morphologies of them,respectively.The results show that the second type of"yttrium barrier effect"is observed and the adverse influence of Ca-rich phase on tungsten powder can be eliminated by it.The flexural strength and fracture toughness of YG6-0.01%Ca+0.09%Y alloy are 2199.5 MPa and 11.49 MPa·m^(1/2),showing improvement of 6.5% and 2.7% compared to YG6 alloy,respectively.The evolutions of Ca-rich phase and Y-rich phase at the every alloy preparation stage of WO_(3),W,WC and cemented carbides are obtained.Furthermore,the strengthening mechanism of WC-Co cemented carbide with co-addition of Ca and Y is proposed.
基金Project supported by Secretariat of Research and Postgraduate Studies National Polytechnic Institute (20221369 and 20231939)Consejo Nacional de Ciencia y Tecnologia CONACyT。
文摘The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(D2EHPA) as extracting agent.The extracting agents were supported on a macro porous polymeric resin XAD-7(solid phase).Yttrium ions extraction and discharge tests were performed,firstly from a synthetic aqueous solution of 100 mg/L Y(liquid phase) at 25℃ with stirring.The effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid(S/L)ratio on the yttrium recovery were studied.The most favorable conditions for yttrium ions extraction are;20 vol% D_(2)EHPA functionalized resin,pH=1.5 and an S/L ratio of 10 mg/mL The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/L [H_(2)SO_(4)] as stripping solution.Up to 80% yttrium is extracted,while 75% yttrium is recovered in the striping solution.In all experiments,the reaction equilibrium is reached after 20 min,and the kinetics for the extraction stage was determined as a second-order model.Also,experiments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is 1.5.Cyclic tests of extraction and discharge for yttrium ions show that the functionalized resin can work at least five cycles without decreasing its efficiency.Finally,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H_(2)SO_(4),demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.
基金National Natural Science Foundation of China,Grant/Award Number:52177162the Natural Science Foundation of Zhejiang Province,Grant/Award Numbers:LZ22E070003,LQ22E020006+1 种基金the Funding Project for Academic/Technical Leaders of Jiangxi Province,Grant/Award Number:20225BCJ22003the Natural Science Foundation of Jiangxi Province,Grant/Award Number:20212ACB211001。
文摘Engineering high‐performance and low‐cost bifunctional catalysts for H_(2)(hydrogen evolution reaction[HER])and O_(2)(oxygen evolution reaction[OER])evolution under industrial electrocatalytic conditions remains challenging.Here,for the first time,we use the stronger electronegativity of a rare‐Earth yttrium ion(Y^(3+))to induce in situ NiCo‐layered double‐hydroxide nanosheets from NiCo foam(NCF)treated by a dielectric barrier discharge plasma NCF(PNCF),and then obtain nitrogen‐doped YNiCo phosphide(N‐YNiCoP/PNCF)after the phosphating process using radiofrequency plasma in nitrogen.The obtained NYNiCoP/PNCF has a large specific surface area,rich heterointerfaces,and an optimized electronic structure,inducing high electrocatalytic activity in HER(331mV vs.2000mA cm^(−2))and OER(464mV vs.2000mA cm^(−2))reactions in 1MKOH electrolyte.X‐ray absorption spectroscopy and density functional theory quantum chemistry calculations reveal that the coordination number of CoNi decreased with the incorporation of Y atoms,which induce much shorter bonds of Ni and Co ions and promote long‐term stability of N‐YNiCoP in HER and OER under the simulated industrial conditions.Meanwhile,the CoN‐YP_(5) heterointerface formed by plasma N‐doping is the active center for overall water splitting.This work expands the applications of rare‐Earth elements in engineering bifunctional electrocatalysts and provides a new avenue for designing highperformance transition‐metal‐based catalysts in the renewable energy field.
文摘Short Retraction NoticeThe paper does not meet the standards of "Journal of Applied Mathematics and Physics". This article has been retracted to straighten the academic record. In making this decision the Editorial Board follows COPE's Retraction Guidelines. The aim is to promote the circulation of scientific research by offering an ideal research publication platform with due consideration of internationally accepted standards on publication ethics. The Editorial Board would like to extend its sincere apologies for any inconvenience this retraction may have caused.Editor guiding this retraction: Prof. Wen-Xiu Ma (EiC of JAMP)The full retraction notice in PDF is preceding the original paper, which is marked "RETRACTED".
基金Supported by the National Natural Science Foundation of China(21067003,51364015)the National High-Tech Research and Development Program of China(2012BAC11B07)the Jiangxi Natural Science Foundation(20114BAB203024)~~
文摘[Objective] The effects of yttrium nitrate （YNO3） on biomass and antioxi- dant systems of paddy rice （Yttrium （Y）; Oxidative stress; Dismutases （SOD）; Per- oxidases （POD）, Catalases （CAT）, Paddy rice （Triticum aestivum）） together with the occurrences of Y in soils were investigated to assess its ecotoxicological effects on plant. [Method]Y solutions with various concentrations were sprinkled on soil sam- ples, which were well mixed and then put into culture dishes to culture paddy rice seeds for further evaluation. [Result] The results indicated that 25-100 mg/kg Y treatments significantly increased the biomass （total weight, root weight, shoot weight and leaf weight）, chlorophyll （CHL） content and protein content of paddy rice, whereas 200-800 mg/kg Y treatments had a converse effect. Similarly, biomarker for the antioxidant systems including superoxide dismutases （SOD）, peroxidases （POD） and catalases （CAT） all exhibited similar trends in both shoots and roots of paddy rice. At the same time, the malonaldehyde （MDA） content increased at from 25 to 100 mg/kg and decreased with concentrations of Y from 100 to 800 mg/kg in both shoots and roots of paddy rice. This indicated that Y could stimulate the growth of plant at low concentration, but inhibit the growth at relatively high concen- tration. [Conclusion] The levels of Y were 641＋49, 328_＋16 and 473_＋40 mg/kg in soils collected from mining area, farmland and navel orange orchard respectively. The levels of Y in the investigated area were higher than the benefit level （100 mg/kg）, which could cause low biomass as well as low activity of SOD, POD and CAT in paddy rice. Therefore, a more careful use of Y is necessary in crop management.
基金Projects (51175444,50532010) supported by the National Natural Science Foundation of ChinaProject (2011121002) supported by the Fundamental Research Funds for the Central Universities, ChinaProject (2009J1009) supported by Scientific and Technological Innovation Platform of Fujian Province,China
文摘The yttrium as a sintering aid was introduced into polycarbosilane（PCS） to prepare yttrium-containing PCS（PYCS）.Two types of yttrium-containing SiC fibres,the SiC（OY） fibres and the SiC（Y） fibres,were fabricated with PYCS.The structural evolution and the associated properties on changing from SiC（OY） to SiC（Y） fibres during the sintering process were studied.The chemical composition of the SiC（OY） fibres is SiC1.53O0.22Y0.005 with an amorphous structure.The composition of SiC（Y） fibres is SiC1.23O0.05Y0.005.The fibres are composed of a large number of β-SiC crystallites with a size of 50 nm and a small amount of α-SiC crystalline.The tensile strength and fracture toughness of the SiC（OY） fibres are 2.25 GPa and 2.37 MPa·m1/2,respectively,and 1.61 GPa,1.91 MPa·m1/2,respectively for SiC（Y） fibres.The SiC（Y） fibres have a higher thermal stability than the SiC（OY） fibres.
基金Supported by National Natural Science Foundation of China(Grant No.21067003,51364015)National High-Tech Research and Development Program of China(GrantNo.2012BAC11B07)+1 种基金Natural Science Foundation of Jiangxi Province(Grant No.20114BAB203024)Science and Technology Project of the Education Department ofJiangxi Province~~
文摘This study aimed to investigate the toxicity of rare earth ion yttrium under the stress of leaching agent ammonium sulfate （NH4）2SO4. [Method] By using earthworms as indicator organisms of environmental pol ution, acute toxic ef-fects of rare earth yttrium on earthworms under the stress of ammonium sulfate were investigated with filter paper contact method. [Result] Under single stress of rare earth yttrium, the semi-lethal concentration after 48 and 24 h was LC50=213.41 mg/L and LC50=322.63 mg/L, respectively. ② Under single stress of ammonium sul-fate, the semi-lethal concentration after 48 h and 24 h was LC50=13.89 g/L and LC50=15.05 g/L, respectively. ③ In combined treatment of low concentration （10 g/L） of ammonium sulfate and different doses of rare earth yttrium, the semi-lethal con-centration after 48 and 24 h was LC50=198.65 g/L and LC50=399.85 g/L, respective-ly; in combined treatment of middle concentration （14 g/L） of ammonium sulfate and different doses of rare earth yttrium, the semi-lethal concentration after 48 and 24 h was LC50=167.3 mg/L and LC50=256.73 mg/L, respectively; in combined treatment of high concentration （20 g/L） of ammonium sulfate and different doses of rare earth yttrium, the semi-lethal concentration after 48 h and 24 h was LC50=31.03 mg/L and LC50=127.65 mg/L, respectively. [Conclusion] Low concentration of ammonium sulfate could reduce the toxicity of rare earth yttrium to earthworms and produce certain antagonism against rare earth yttrium; middle concentration ammonium sulfate in-creased the toxicity of rare earth yttrium to earthworms and produced relatively sig-nificant synergistic effects; high concentration ammonium sulfate significantly in-creased the toxicity of rare earth yttrium to earthworms. Compared with ammonium sulfate, dead earthworms exposed to rare earth yttrium were more easily fractured, and living earthworms showed insensitive response to acupuncture.
基金Project(P02426)supported by the Japan Society for the Promotion of Science for Postdoctoral Fellowships for Foreign Researchers
文摘For the accurate prediction of equilibrium distribution ratios of rare earth metals during solvent extraction under non-ideal conditions, the extraction equilibria of yttrium （Ⅲ） and europium （Ⅲ） from the hydrochloric acid solutions with P507 in Shellsol D70 were studied. A chemically-based model was established and the extraction equilibrium constants were determined by the nonlinear least squares method. The proposed model involves the cation exchange reaction and the solvation extraction in the low and high acidity regions, respectively. In the model, the nonideality of the aqueous phase and was corrected by considering the complexation of the metals with Cl- and by replacing with its effective concentration, respectively. This model was verified by fair agreement between the calculated metal distribution ratios and those experimentally obtained in the single metal systems. The feed concentrations for the systems are in wide ranges of the metal （up to 0.1 mol/L）, hydrochloric acid （0.07-3.00 mol/L） and the extractant （0.25-1.00 mol/L）. The model enables the engineering prediction of the equilibrium distribution ratios with good accuracy in a binary metal system.
基金Project supported by SRF for ROCS, SEM (2003-14) and Science and Technology Department of Zhejiang Province (2003C11027)
文摘Y2O3 nanomaterials have been widely used in transparent ceramics and luminescent devices. Recently there are many studies focusing on controlling the size and morphology of Y2O3 in order to obtain better materials performance. In present study, yttrium oxyhydroxide precursor was synthesized via a facile solvothermal process through the dissolution-re-crystallization mechanism of Y2O3 raw powders in the ethylenediamine solvent, then nanosized yttrium oxide crystal was prepared from the precursor through post heat treatment process. The effects of solvothermal treatment temperature, holding time, solvent kinds and post heat treatment parameters on crystalline structure, grain shape and size of nanocrystal were investigated by XRD, TEM and TGA-DTA measurements. TEM images reveal that the morphology of product after post heat treatment at 460℃for 12 h is rice-like nanocrystal. XRD shows that this product is pure cubic Y2O3 cphase. Present study reveals that high purity Y2O3 with rice-like morphology can be easily prepared with average size around 30 nm under suitable post heat treatment parameters. In addition, the effects of solvents such as water and ethanol etc. on the crystal structure and morphology were also investigated. It is suggested that dissolution-recrystallization process may be the main mechanism for the formation of nano-sized YOOH precursors under solvothermal reaction condition, and the ethylenediamine solvent is likely to play an important role in controlling the transformation process of yttria precursors to the Y2O3 nanocrystal.
基金Project supported by the National Natural Science Foundation of China (50990304)State "973" Project (2007CB936704)
文摘A novel yttrium citrate-templated conversion method for morphology controlled synthesis of Y2O3 microspheres, microflowers and microsheets was reported for the first time. The precursors with controllable morphologies were synthesized with a homogenous precipitation method in aqueous solution without any surfactant. Y2O3 samples with well-preserved morphological architectures were obtained by a subse-quent thermal transformation strategy. The chemical formula of the precursor was identified and a two-stage growth mechanism was proposed. The effects of the aging time, reaction temperature, reactant concentration and molar ratio of yttrium nitrate to sodium citrate were discussed. The photoluminescence properties of the Y2O3：Eu3＋ microspheres, microflowers and microsheets prepared were also studied.
基金financial support of this work from University of Kashan by Grant No. 363030/12
文摘In this work,we present a new and fast method to obtain the single phase YFeO(YIG,cubic) and YFeO(YIP, orthorhombic) nanocrystals based on hydrothermal technique. The influence of initial Y/Fe mole ratio and calcination temperature on the nature, purity, phase structure, and morphology of the product was investigated by X-ray diffraction(XRD), Fourier-transform infrared(FT-IR) spectroscopy,energy-dispersive(EDX) X-ray spectroscopy, and field emission scanning electron microscopy(FESEM).The results show that the transformation of the as-synthesized YIG from amorphous to orthorhombic and finally to cubic phase occurs with the increase of annealing temperature. On this basis, the pure cubic phase YIG can be obtained by calcination(at 1100℃) of the precursor which is prepared using the hydrothermal treatment of mole ratio of Y:Fe = 1:1.5 exposure to an ammonia atmosphere. Also, the initial Y/Fe mole ratio of 1:1 and calcination temperature of 1000 ℃ are the optimal conditions to form single-phase nanocrystalline YIP. Further, vibrating sample magnetometry(VSM) measurements illustrate the average magnetic saturation, coercivity and remanence of 2.73 and 15.00 emu/g, 42.74 and40.02 Oe, and 1.65 and 4.30 emu/g for YIP and YIG nanocrystals, revealing their soft ferromagnetic character.
文摘Polystyrene doped with yttrium ethoxide was prepared. The coordination between yttrium atom and benzene ring in the polystyrene doped with yttrium ethoxide was confirmed by means of IR, XPS.
基金This work was funded by National '863' Foundation (863-715-020-01-01)
文摘Yttrium isopropoxide was prepared directly by the reaction between yttrium and isopropyl alcohol using mercuric chloride and iodine as catalyst. Yield is above 83% . This method possesses the merits of easy operational approach, high product purity, high reaction rate and high production rate. Compared with the previous reported results , the period needed was shortened by 19 h and the yieid increased by 8% . The period needed for preparation is about 5 hows. These results are better than the present report . The dehydrolysis method of isopropyl alcohol and the composition of catalyst were presented.
