Structure and Magnetic Properties of Nd(Fe,Mo) 12 N x Prepared by Mechanically Alloying

Ｂｅｃａｕｓｅｏｆｆｉｎｅｇｒａｉｎｓ,ｔｈｅｍａｇｎｅｔｓｐｒｅｐａｒｅｄｂｙｔｈｅｍｅｃｈａｎｉｃａｌａｌｏｙｉｎｇ（ＭＡ）ｔｅｃｈｎｉｑｕｅｈａｖｅｈｉｇｈｅｒｃｏｅｒｃｉｖｉｔｙｃｏｍｐａｒｅｄｗｉｔｈｔｈｏｓｅｐｒｅｐａｒｅｄｂｙｔｒａ...     

Antibacterial Characteristics of ZnO-CeO2 Nano-Powder Prepared by Laser Vapor Condensation

Microbialpollutionandcontaminationbymicroor ganismshaveproducedvarioustroublesinindustryandothervitalfields ,suchasdegradationandinfec tion .Thenewpasteurizationandantibacterialtech niqueshavebeendemandedandstudied[1] .Inrecentyears ,therareearthmetaloxid…     

Structural and Electrochemical Characteristics of Mg0.94 La0.06 Ni AlloyPrepared by Ball Milling

The amorphous Mg0.94Lao.o6Ni alloy was synthesized by ball milling for different time at 400 r min^-1. Electrochemical performances of the alloy electrodes were investigated and the results show that the specimens would reach their maximum electrochemical discharge capacities at the first charge/discharge cycle. The cyclic tests and X-ray diffraction(XRD) results show that discharge capacities would decrease rapidly due to the crystallization of the amorphous and the oxidization of magnesium on the particle surface during the electrochemical charge/discharge cycling. In addition, the DTA and SEM results reveal that the thermal stabilities will be improved and the size of the alloy will be decreased with the ball-milling time. The amorphous Mgo.96Lao.04Ni alloy prepared by ball milling for 40 h at 400 r min^-1 shows the bestelectrochemical properties.     

La2O3-promoted Ni/H-ZSM-5 catalyzed aqueous-phase guaiacol hydrodeoxygenation to cyclohexanol

Hydrodeoxygenation(HDO) of renewable lignin-derived biomass in aqueous-phase to produce high value-added products is of great significance.However,developing new catalysts with high activity and excellent stability in an aqueous phase faces considerable challenges.Rare earth doping can effectively regulate the water exchange rate constant(WERC) value of the catalyst and play an important role in promoting the hydrolysis of ether bonds.Therefore,in this paper the bimetallic supported catalyst Ni-...     

Facile synthesis of Ag/La2O2CO3 hierarchical micro/nanostructures for antibacterial activity and phosphate removal

In this study, hierarchical Ag/La₂O₂CO₃ micro/nanostructures (MNSs) were synthesized by in situ loading Ag nanoparticles (NPs) on the surface of the La₂O₂CO₃ MNSs. The prepared La₂O₂CO₃ MNSs present flower-like shape and can be tuned by the molar ratio of La (NO₃)₃ and CO(NH₂)₂. In the molar ratio of 1:2 to 1:55, the La₂O₂CO₃ MNSs mainly consist of polyhedral rods, irregular rods and irregular spindles and their size is about 10, 8 and 7 μm, respectively. After loading Ag NPs, the spindle-like Ag/La₂O₂CO₃ MNSs were used for phosphate removal and antibacterial activity. At the initial phosphate concentration of 20 mg/L, the removal rate is 59.6%. The Ag/La₂O₂CO₃ MNSs have significant antibacterial activity and their MIC values for S. aureus and E. coli are 31.3 and 15.6 μg/mL, respectively. The results indicate that Ag/La₂O₂CO₃ MNSs may have good application prospects in open water to inhibit bacterial growth.     

Synthesis and Luminescence Properties of Ternary Europium Complexes inTitania Matrix in the Presence of Dimethylformamide by a Sol-Gel Process

Thesol-gelmethodoffersanewapproachtothesynthesisofglasses,ceramics,fibersand.compositesrelatedtotheopticalproperties['j.Sincesomelanthanideionspossessgoodlumi-nescencecharacteristicsbasedontheelectronictransiti0nsamongthe4fenergylevels,aseriesofrareearthcompoundshavebeenstudiedforprac-ticalapplicationsasphosphors.SomestudiesonluminescencebehaviorofEuCl3andEu(NO3)3.alt.[z's]adsorbedonporousglasses,dopedintosol-gelderivedhostsandusedasaprobetostudytheenvironmentofEu3 duringthedifferentstages0f…     

Mechanism of RE on the Electrochemical Properties of Multicomponent Hydrogen Storage Alloys of RENi~5 Type

ＭｅｃｈａｎｉｓｍｏｆＲＥｏｎｔｈｅＥｌｅｃｔｒｏｃｈｅｍｉｃａｌＰｒｏｐｅｒｔｉｅｓｏｆＭｕｌｔｉｃｏｍｐｏｎｅｎｔＨｙｄｒｏｇｅｎＳｔｏｒａｇｅＡｌｏｙｓｏｆＲＥＮｉ５ＴｙｐｅＪｉａｎｇＪｉａｎｊｕｎ（江建军）（ＨｕａｚｈｏｎｇＵｎｉｖｅｒｓｉ...     

Effect of Preparation Methods on Hydriding Properties of La1.5Mg17 Ni0.5 Composite Materials

La1.5Mg17Ni0.5 hydrogen storage materials were prepared by hydriding combustion synthesis (HCS) and mechanical alloying (MA) method respectively. The experimental results show that the hydrogen absorption properties of La1.5Mg17Nio.5 prepared by MA are better than that by HCS. La1.5Mg17Nio.5 prepared by MA can absorb 6.73 mass% hydrogen at 523 K within 1 min, and 4.92 mass% hydrogen at 423 K. The improvement of hydriding properties of La1.5Mg17Ni0.5alloy prepared by MA can be ascribed to the formation of nano-crystalline and defects during the mechanical alloying.     

Effects of La-Rich Rare Earth Alloys on Structure and Mechanical Properties of ZL101A Alloy

ＥｆｅｃｔｓｏｆＬａＲｉｃｈＲａｒｅＥａｒｔｈＡｌｏｙｓｏｎＳｔｒｕｃｔｕｒｅａｎｄＭｅｃｈａｎｉｃａｌＰｒｏｐｅｒｔｉｅｓｏｆＺＬ１０１ＡＡｌｏｙＬｉＨｕａｊｉ（李华基），ＴａｎＨｕｉｘｉｎ（谭会辛），ＺｈｕＺｈｅｎｃｈａｏ（祝阵超）（Ｃｈｏｎｇ...     

Initial Activation of Hydrogen-Storage Alloy Electrode by Chemical Modification

Ｔｈｅｍｉｓｃｈｍｅｔａｌ（Ｍｍ）ｈｙｄｒｏｇｅｎｓｔｏｒａｇｅａｌｏｙｓｈａｖｅｓｏｆａｒｂｅｅｎｓｕｃｃｅｓｆｕｌｙｄｅｖｅｌｏｐｅｄａｓａｈｉｇｈｃａｐａｃｉｔｙｎｅｇａｔｉｖｅｅｌｅｃｔｒｏｄｅｍａｔｅｒｉａｌｆｏｒｓｅｃｏｎｄａｒｙｂ...     

Effect of La3+ on seed germination and seedling growth of Salvia miltiorrhiza

The purpose of this study is to determine the effect of La³⁺ solution on seed germination and seedling growth of Salvia miltiorrhiza. Different concentrations of La³⁺ were used on seed by soaking treated to determine which concentration is the most suitable for the growth of S. miltiorrhiza. Results show that the low concentration of La³⁺ displays the promotion effect on S. miltiorrhiza seed germination rate and germination potential, and the promotion effect reaches the highest level when the concentration of La³⁺ solution is 30 mg/L, the germination index and vigor index are the highest in 20 mg/L, and it can also increase the contents of soluble sugar, soluble protein and chlorophyll. Meanwhile, the activity of antioxidant enzyme system (CAT and SOD) are improved, thus the photosynthesis and resistance of plant are enhanced. On the contrary, when the La³⁺ concentration is high, La³⁺ can inhibit plant growth. Thus La³⁺ displays the "homesis effect" on S. miltiorrhiza growth.     

Holmium-doped Porous Silicon Prepared by a New Electrochemical Approach and Its Photoluminescence

Ｐｏｒｏｕｓｓｉｌｉｃｏｎ（ＰＳ）ｗａｓｆｏｕｎｄｔｏｅｍｉｔｖｉｓｉｂｌｅｌｕｍｉｎｅｓｃｅｎｃｅａｔｒｏｏｍｔｅｍｐｅｒａｔｕｒｅｂｙＣａｎｈａｍｉｎ１９９０［１］．Ｔｈｉｓｐｈｅｎｏｍｅｎｏｎｉｍｐｌｉｅｄａｐｏｔｅｎｔｉａｌａｐｐｌｉｃａｔｉ...     

Study of Adsorption Properties and Enriching RE on Clay Minerals by Ouantum Chemical Calculation

The order of adsorbability of three kinds of clay minerals and their selectivity of adsorption tocommon cations and RE ions have been studied by quantum chemical calculation.They are as follows:montmorilionite>halloysite>kaolinite,RE~(3+)>Al~(3+)>Ca~(2+)>Mg~(2+)>K~+>NH_4~+>Na~+,Sc~(3+)>La~(3+)>Ce~(3+)>Pr~(3+)>Nd~(3+)>Sm~(3+)>Eu~(3+)>Gd~(3+)>Tb~(3+)>Dy~(3+)>Ho~(3+)>Y~(3+)>Er~(3+)>Tm~(3+)>Yb~(3+)>Lu~(3+).Based onthese orders,the facts that RE is preferentially adsorbed in weathered residual type of clay mineral and lightRE and heavy RE are enriched at the upper layer and at the lower layer respectively in ore body have beenexplained.     

Effect of reduced graphene oxide-supported copper addition on electrochemical properties of La0.7Mg0.3Ni2.8Co0.5 electrodes

The reduced graphene oxide-supported copper(Cu@rGO) nanocomposite was introduced to improve the electrochemical properties of La_(0.7)Mg_(0.3)Ni_(2.8)Co_(0.5)alloy electrodes.Experimental results show that adding Cu@rGO nanocomposite with mass fractions of x wt%(x=0,3,6 and 9) to the alloy electrodes provides electrodes with maximum discharge capacities of 368.9 mAh/g(x=0),373.2 mAh/g(x=3),407.3 mAh/g(x=6) and 398.6 mAh/g(x=9),and high-rate dischargeabilities at a discharge current density of1200 mA/g of 40.5%(x=0),64.0%(x=3),82.0%(x=6) and 76.0%(x=9).The addition of Cu@rGO nanocomposite also provides alloy electrodes with hydrogen diffusion coefficients of 3.7×10~(-10) cm~2/s(x=0),4.1×10~(-10) cm~2/s(x=3),4.2×10~(-10) cm~2/s(x=6) and 4.0×10~(-10) cm~2/s(x=9).Clearly,the addition of 6 wt%Cu@rGO nanocomposite not only increases the electrochemical capacity of La_(0.7)Mg_(0.3)Ni_(2.8)Co_(0.5) alloy electrodes,but also improves their electrochemical kinetic properties.     

Magnetic Properties and Colossal Magnetoresistance of La0.7Sr0.3MnO3 Materials Doped with Fe

Ｔｈｅｄｉｓｃｏｖｅｒｙｏｆｔｈｅｃｏｌｏｓｓａｌｍａｇｎｅｔｏｒｅ ｓｉｓｔａｎｃｅｉｎｐｅｒｏｖｓｋｉｔｅｍａｎｇａｎｉｔｅｓｄｅｒｉｖｅｄｆｒｏｍＬａＭｎＯ3 ｈａｓａｒｏｕｓｅｄｍｕｃｈｉｎｔｅｒｅｓｔｏｗｉｎｇｔｏｉｔｓｐｏｔｅｎｔｉａｌａｐｐｌｉｃａｔｉｏｎａｎｄｔｈｅｏｒｅｔｉｃａｌｒｅｓｅａｒｃｈｖａｌｕｅｓ .Ｔｈｅｓｕｂｓｔｉｔｉｏｎｏｆｍｅｔａｌｅｌｅｍｅｎｔ,ｓｕｃｈａｓＣａ ,Ｓｒ,Ｂａ ,ｆｏｒＬａｉｎＬａＭｎＯ3 ,ｏｆｔｅｎｌｅａｄｓｔｏａｎｉｎｓｕｌａｔｏｒ ｍｅｔａｌｔｒａ…     

Promotional mechanism of activity of CeEuMnOx ternary oxide for low temperature SCR of NOx

Due to strong synergistic effect of the elements,a series of XEuMnO_x ternary oxides(X=Ce,Ni,Co,Sb,Sn,Mo) were synthesized by one-pot co-precipitation method,and composite components were identified and optimized to maintain high activity and superior SO₂ and H₂O endurance in selective catalytic reduction of NO_x with NH₃(NH₃-SCR).NO_x conversion of CeEuMnO_x ternary oxide catalysts attains more than 90% at 100-2...     

Investigation of Structure and Hydriding Properties of La0.6 Nd0.4 Ni4.8 Mn0.2 Cux Alloys

The structure and hydriding performance of La0.6Nd0.4Ni4.8Mn0.2Cux (x = 0 ～ 0.4) alloys were investigated in order to develop suitable materials for metal hydride air conditioner. The effect of Cu addition on the crystal structure,equilibrium pressure, hydrogen capacity and hysteresis as well as hydrogen absorption/desorption kinetics were systematically studied by using the measurement of P-C isotherms, X-ray diffraction and scanning electron microscopy. As the amount of Cu increases, the plateau pressure increases and hydrogen absorption/desorption kinetics is improved, but the effective hydrogen storage capacity decreases. It is shown that variations in the basal plane parameter a can be used as an indication for the plateau pressure changes. With the increase of parameter a, the plateau pressure decreases. For La0.6 Nd0.4Ni4.8Mn0.2Cux(x = 0 ～ 0.4) alloys there is a relationship between the effective hydrogen storage capacities and the ratios of their unit cell parameters c and a. The effective hydrogen storage capacity decreases with increase of a/c.     

Study of Physicochemical Properties and Active Oxygen in Structures of Layered Mixed La_4BaCu_5-_xM_xO_(13 λ)(M=Mn,Co)

ＴｈｅｒｅｉｓｐｒｏｆｕｓｅｒｅｓｏｕｒｃｅｏｆｒａｒｅｅａｒｔｈｅｌｅｍｅｎｔｉｎＣｈｉｎａ,ｓｏｉｔｉｓｖｅｒｙｉｍｐｏｒｔａｎｔｔｏｓｔｕｄｙｔｈｅａｐｐｌｉｃａｔｉｏｎｏｆｔｈｅｒａｒｅｅａｒｔｈｃｏｍｐｏｕｎｄｓ［１］．Ｔｈｅｐｅｒｏｖｓ...     

Multiferroic properties of Bi5.75R0.25Fe1.4Ni0.6Ti3O18 (R = Eu,Sm, Nd,Bi and La) ceramics

An improved technique was used to prepare the ceramic samples of Bi_5.75R_0.25Fe_1.4Ni_0.6Ti₃O₁₈(BRFNT,R=Eu,Sm,Nd,Bi,and La).The five-layer Aurivillius phase of the samples was confirmed by X-ray diffraction(XRD)without detectable impurities.BRFNT samples exhibit the pseudo-tetragonal except the orthorhombic BSmFNT samples.The characteristic plate-like morphology was revealed by field emission transmission electron microscopy(FETEM)images.At ambient tempe rature,all the samples present both ferroelectric and magnetic properties and BEuFNT shows the best ferroelectric behavior with its remanent polarization as high as 14.9μC/cm²under 155 kV/cm,which is three times higher than that of Bi_5.75R_0.25Fe_1.4Ni_0.6Ti₃O₁₈.Moreover,the remanent magnetization of BEuFNT is increased up to 1.20 emu/g compared to that of Bi_5.75R_0.25Fe_1.4Ni_0.6Ti₃O₁₈which is only 0.53 emu/g.With increasing radius of the introduced A-site ions,the ferroelectric phase transition temperature(T_CE)is decreased while the magnetic phase transition temperature(T_CM)fluctuates.The decrease in both T_CEand T_CM corresponds to the upward shift of the related Raman modes and vice versa,indicating that the T_CEand the T_CM depend not only on the t factor,but also on the strength of the covalent bonds.     

Synthesis of La2MoO6@MWCNTs composite catalysts as Pt-free counter electrodes for dye-sensitized solar cell

Pt-free counter electrode(CE) composed of La2 MoO_6(La_2 O_3-MoO_3) was successfully synthesized by simple pyrolysis of lanthanum acetate(C_6 H_9 O_6 La·xH_2 O) and hexaammonium heptamolybdate tetrahydrate((NH4)6 Mo_7 O_(24)·4 H_2 O). Furthermore,three proportions composites catalysts of La2 MoO_6@MWCNTs based on La2 MoO_6 and multiwall carbon nanotubes(MWCNTs) were prepared and characterized as Ptfree catalyst for CE in dye-sensitized solar cells(DSSCs). The morphology and structure of La2 MoO_6@MWCNTs composites were determined by scanning electron microscopy, transmission electron microscope and X-ray diffraction. The electrochemical performance of La2 MoO_6@MWCNTs composite catalysts for CEs was determined by photocurrent-voltage measurements, cyclic voltammetry,electrochemical impedance spectroscopy, and Tafel polarization. The power conversion efficiencies of4.68%, 4.87% and 5.06% are obtained for La2 MoO_6:MWCNTs with the mass ratios of 5:1, 3:1 and 1:1 towards the reduction of I_3~-to I~-under the same conditions,respectively,which are superior to those of MWCNTs(3,94%) and La2 MoO_6(1.71%) electrodes. The experimental results reveal that the presence of MWCNTs results in an augmented active catalytic surface area and enhanced charge transfer from CE to the electrolyte.