Synthesis, characterization, and biological activities of Pt（Ⅱ） and Pd（Ⅱ）complexes with 2′,3′,4′,5,7-pentahydroxy flavone

Pt(Ⅱ) and Pd(Ⅱ) complexes with 2′,3′,4′,5.7-pentahydroxy-flavone were synthesized and characterized by ele-mental analysis, molar conductance, IR, ′HNMR, TG-DTA, UV-Vis spectroscopic techniques, and fluorescence analysis.The scavenging effect on the superoxide radical (O2) and the inhibitory effect on lipid peroxides were also investigated. Both the ligand and the complexes exhibit scavenging effect on superoxide radicals, and the effect of the complexes is greater than that of the ligand. The Pt(Ⅱ) complex exhibits the strongest scavenging efficiency. Both Pt(Ⅱ) and Pd(Ⅱ) com-plexes have the inhibitory effect on lipid peroxides, and the effect of the complexes is greater than that of the ligand, but the Pt(Ⅱ) complex has a high effect of promoting lipid peroxides.     

Fluorescence and cofluorescence enhancement of Tb（Ⅲ） complexes with pyromellitic acid by M （M = Gd, La, Ca, and Sr ions）

Fluorescence and cofluorescence properties of Tb(Ⅲ) solid complexes were studied using pyromellific acid (PMA) as ligand and fluorescence inert ions as doping elements. The cofluorescence enhancement, a result of ligand sensi-tized fluorescence, was observed in Th(Ⅲ) solid complexes doped with fluorescent inert ions La(Ⅲ), Gd(Ⅲ), Ca(Ⅲ), and Sr(Ⅲ). The effect of the type and content of doping elements on fluorescence enhancement was studied, and optimum con-ditions were determined. The results show that Gd (La, Ca, Sr) has clear cofluorescence effect in solid complex Tb-M-PMA system, and in present work, rare earth complex fluorescent powder that emits bright green fluorescence at ultraviolet exci-tation was obtained, which had potential application as fluorescent anti-counterfeit ink,     

Synthesis and Structure of Tetrapyridine Diperrhenate Zinc(Ⅱ) Complex py_4Zn(OReO_3)_2

Although a considerable nUmber of perrhenates of alkaline, alkaline-earth and transitionmetals have been Prepared and some of theirstrUctlires were determined [1,2], only a few ofthe complexes in which ReO. acts as the anionor ligand were synthesized and the crystal smicfores were described. For example, the comPlexes L.Cu(ReO.), (L=NH,, py) prepared by reaction of Cu(ReO.), with ammonia or pyridinewere reported [3], but no crystal struCtUre wasdetermined. The s~e of Ni(tmp),' ReO. was…     

Adsorption behavior of Pd(Ⅱ) from aqueous solutions by D201 resin

The adsorption and desorption behaviors of Pd(Ⅱ) on D201 resin were investigated. The effects of parameters including HCl concentrations, initial metal ion concentrations, contact time, and temperature on the adsorption of Pd(Ⅱ) were studied by batch method. The HCl concentration for studying the effects was set from 0.01 to 2 mol·L-1 and the optimal adsorption condition is in 0.01 mol·L-1 HCl solution. The adsorption isotherm of Pd(Ⅱ) on D201 resin was determined and the equilibrium data fitted the Langmui...     

Synthesis and luminescence properties of rare earth ternary complexes consisting of Tb（Ⅲ）, β-diketones and 1,10-phenanthroline （phen）

In order to study the luminescent properties of ternary rare earth complexes with β-diketone ligand, three new β-diketone ligands, 1-phenyl-3-(p-phenylethynylphenyl)-1,3-propanedione(HPPP), 1-(2-thienyl)-3-(p-phenylethynylphenyl)-1,3-propanedione (HTPP) and 1-(2-furyl)-3-(p-phenylethynylphenyl)-1,3-propanedione (HFPP), were synthesized by Sonogashira coupling reaction and Claisen condensa- tion. Three new ternary rare earth complexes, TbL3phen (L = PPP, TPP, or FPP), were synthesized by the reaction of rare earth chloride TbCl3,1,10-phenanthroline (phen) with HPPP, HTPP, or HFPP respectively, in alcohol solution. The compositions were characterized by means of elemental analysis, chemical analysis, and IR spectra. Luminescent properties of the three new complexes have been studied. The results show that the ternary Tb(III) complexes only emit the weak fluorescence of the Tb(III) ion, which reveals the triplet state energy of the ligands does not match well with the excited state vibrating energy of Tb3 ion.     

Electrochemical behavior of Cu(II) reduced in CH3OH and DMSO

The cyclic voltammetry and the potential-time curve after galvanostatic electrolysis were used to study the electrode processes of Cu(n) in CH3OH solution and DMSO solution. The electroreduction of Cu(Ⅱ) to Cu on a Pt electrode proceeds in two steps: Cu(Ⅱ) + e = Cu(Ⅰ); Cu(I) + e = Cu. The reduction potential of Cu(n) in DMSO solution is more negative than that in CH3OH solution, and the diffusion coefficient of Cu(Ⅱ) ion in DMSO solution is larger than that in CH3OH solution because the polarity of DMSO is larger than that of CH3OH observably and has a stronger solvating power.     

Distribution of Phosphorus and Its Effects on Precipitation Behaviors and Tensile Properties of IN718C Cast Superalloy

The effect of phosphorus on the precipitations of γ",γ' and δ phases and associated tensile properties in IN718C alloy are investigated in this study.It is revealed that P atoms are dissolved in the grain interior to a relatively high degree and hence influence the precipitation behaviors in the grain interior and improve the tensile strength of IN718C alloy.γ" and γ' phases did not precipitate in the alloy without P addition during air cooling,while γ" and γ' phases precipitated in the grain interior during air cooling in the alloys with P addition,and the amounts of γ" and γ' phases increased with increasing P content.Therefore,the Vickers micro-hardness in the as-cast state increased gradually with increasing P content.In double-aging state,the sizes of γ" and γ' phases in the alloys with P addition were larger than that in the alloy without P addition,while the sizes were invariable when the P content(wt%)was higher than 0.015.Therefore,the micro-hardness and tensile strength of IN718C alloy treated by double aging increased first and then kept invariable with increasing P content.The precipitations of δ phases both in the grain interior and on grain boundaries were inhibited by P markedly.The inhibitory effect of P on δ phase enhanced gradually with increasing content of P,but the plasticity increased first and then decreased.What is more,the crack tended to propagate into the matrix around the particles(Laves phases and NbC carbides)in the alloys without P addition at the beginning of the tensile fracture,while it tended to propagate along the interfaces between the matrix and those particles in the alloys with P addition,which resulted from the synthetical effect of P on γ" γ' and δ phases.     

Preparation and characterization of bis(dimolybdo-nonatungstogermanate)lanthanates of potassium

The heteropoly complexes K12[Ln(GeW9Mo2O39)2] · nH2O (Ln = La, Ce, Pr, Nd, and Sm) were prepared for the first time and characterized by chemical analysis, infrared (IR) spectrum, ultraviolet (UV) spectrum, X-ray powder diffraction, and thermal analysis. IR, UV spectra, and X-ray powder diffraction studies show that the structure of the heteropoly complexes is a square antiprism consisting of eight oxygen atoms of two GeW9Mo2O398-, heteropolyanions and a lanthanide ion. The thermostability of heteropoly complexes is lower than that of saturated Keggin structure dodecatungstogermanate.     

Synthesis and emission analysis of novel rare earth complex Eu（TTA）3（2NH2-Phen）

The rare earth ternary complex of Eu 3+ with thenoyltrifluoroacetone,and 4,7-2NH2 phenanthroline was synthesized and well characterized by UV,fluorescent,IR spectrometry and X-ray diffractometry(XRD)as well as elemental analysis.The results show that the complex of Eu(III)emits strong red luminescence when excited by UV light,and Eu(TTA)3(2NH2-Phen)has the higher sensitized luminescent efficiency and longer lifetime than Eu(TTA)3(Phen).In device of ITO/PVK/Eu(TTA)3(2NH2-Phen)/Al,the spectra of Eu(TTA)3(2NH2-Phen)with different ratios for spin-cast film were monitored.The main emitting peak at 614 nm can be attributed to the transition of 5 D0→ 7 F2 of Eu 3+ and this process results in the enhancement of red emission from electroluminescence device.The effect and mechanism of the ligands on the luminescence properties of europium complex were discussed.The results show that the luminescence intensity of the title complexes greatly increases in comparison with that of their corresponding complexes,revealing that the second ligands form very good synergistic effect with the first ligands.The title complexes possess excellent thermal stability properties,and are hopefully developed into fine PL and EL red materials.     

Effect of synergistic action of ultrasonic vibration and solidification pressure on tensile properties of vacuum counter-pressure casting aluminum alloy

The effect of synergistic action of ultrasonic vibration and solidification pressure on tensile properties of vacuum counter-pressure casting ZL114 A alloys was studied systemically through testing and analyzing the tensile strength and elongation subjected to different ultrasonic powers and solidification pressures. The results indicate that the synergistic action of ultrasonic vibration and solidification pressure can result in the refinement of grains and improvement of tensile properties. Both the highest tensile strength and elongation of aluminum alloy were obtained under synergistic action of 600 W ultrasonic power and 350 kPa solidification pressure. Moreover, the tensile fracture morphology shows obvious ductile fracture characteristics. When the solidification pressure is lower than 300 kPa, the effect of ultrasonic power on tensile strength and elongation is more obvious, but when the solidification pressure is higher than 300 kPa, the effect of solidification pressure on tensile strength and elongation is greater. Meanwhile, the size and morphology of the eutectic silicon were improved significantly by the ultrasonic vibration and pressurized solidification. The strip and massive eutectic silicon phase are completely converted into small short rod-like and evenly distributed Si phases at the grain boundary of primary α-Al.     

Synthesis and fluorescent properties in complexes of Eu(Ⅲ), Tb(Ⅲ), and Sm(Ⅲ) with β-diketone and 2,2'-bipyridine

Three new rare earth ternary complexes,RE(PB)3bpy (RE-Sm3+,Eu3+,and Tb3+),were synthesized by the reaction of 1-(p-phenylethynyl-phenyl)-1,3-butanedione (HPB) and 2,2'-bipyridine (bpy) with rare earth chloride REC13,respectively,in alcohol solution.The compositions were characterized by means of infrared (IR) spectra,chemical analysis,elemental analysis,and thermodynamic analysis.Luminescent properties of the three complexes were studied.At room temperature,under UV light excitation,the Sm3+,Eu3+,and Tb3+ complexes exhibit characteristic emission of the central ions.The fluorescence spectra show that the fluorescence emission intensity of Eu3+ complex is the strongest.The narrow strongest emission band of Eu3+ complex is considered to be a valuable material with bright red fluorescence.     

Crystal structure and electrochemical behaviors of Pt/mischmetal film electrodes

The Ml(La-rich mischmetal0films with a thin Pt layer on the substrate of chemically coarse ITO glass or silicon slices were prepared by magnetic sputtering tchnique.The crystal structure and surface morphology of the films were investigated by X-ray diffraction(XRD)analysis and atomic force microscopy(AFM),respectively, The electrochemical hydridation/dehydridation behaviors of the films in KOH solution were studied by using cyclic voltammagraph and electrochemical impedance spectrum(EIS)as well.The AFM results show that the Pt cover layer on the M1 films is of island structure with a grain of 150-200nm in size.The presence of a thin Pt layer can provide sufficient high electrocatalytic activity for the electrochemical charge-transfer reaction.The electrochemical reduction and oxidation reaction occur on the Pt layer,and the diffusion of H into the Ml film is the rate-controlled step.The Pt coatings also act as protective layers,preventing oxidation and/or poisoning of the underlying Ml films in air.     

EFFECTS OF HEAT TREATMENT AND ENVIRONMENT ON CRACK PROPAGATION RATE IN STEEL GC-4 UNDER CORROSION FATIGUE AND STRESS CORROSION

Comparative investigations were carried out of the effect of heat treatment regimes Jor steelGC-4(40CrMnSiMoVA)on its crack propagating rates,from corrosion fatigue,(da/dN)_(CF),or stress corrosion cracking,(da/dt)_(SCC),in media with various constituentsand pH values.Both(da/dN)_(CF) and(da/dt)_(SCC) accelerate with the increase of yield stressof the steel,yet the former is far less than the later.In comparison with media,the(da/dt)_(SCC) in distilled water is slightly greater than that in 3.5% NaCl solution,and the(da/dN)_(CF) in distilled water is far less than that in 3.5% NaCl solution.With the pH valueincreasing in 3.5% NaCl solution,the(da/dN)_(CF) lowers down and the(da/dt)_(SCC) speedsup.An explanation was also proposed with concept of the cyclic hardening and softening atcrack tip,as well as the crack closure and occluded cell effect.     

Microstructures and mechanical properties of Al-Cu-Mn alloy with La and Sm addition

The effect of single addition of La or Sm on the microstructures and mechanical properties of an Al-Cu-Mn alloy were investigated by microstructure characterization and tensile test.The results show that addition of La or Sm into the Al-Cu-Mn alloy can remarkably increase the density of θ' phase and refine the microstructure,and thus,improves the mechanical properties at room temperature.La addition results in a more considerable increase in the density and refinement of θ' phase than Sm addition.La addition has a more significant contribution on the mechanical properties of the Al-Cu-Mn alloy than Sm addition.in addition,a new phase of Al6Cu6La is formed in the Al-Cu-Mn alloy with La addition.     

Co-colouration Effects in the Systems of Metal(Ⅱ)-Rare Earth(Ⅲ)-Xanthene Dye and Their Influences on Photometric Determination of Metal Ions

After comparing the influences of each rare earth(Ⅲ),11 species of metal(Ⅱ)and 8 species of acidictriphenylmethane dye on the formation of coloured coordination compound in the system of Metal(Ⅱ)-RE(Ⅲ)-Dye,it was proven that the co-colouration effect can be caused only by the xanthene dyes(XD)con-taining substituting hydroxy.group on the ortho-position of etheric oxygen group.Besides,the radius of met-al(Ⅱ)must not be smaller than a definite limit;otherwise,no co-colouration appears.Furthermore,the acid-ity of medium is another important factor to affect co-colouration,Bromopyrogallol red causesco-colouration of Pb(Ⅱ)-RE(Ⅲ)only,owing to its higher chromophoric acidity;while alizarin violet causesco-colouration of M(Ⅱ)-RE(Ⅲ)(M=Pb,Ca,Sr and Ba),due to its lower chromophoric acidity.The condi-tions causing co-colouration,the regularities of co-colouration and the influences of co-colouration inphotometric determination of metals were discussed.     

Syntheses, characteristics and fluorescence properties of complexes of terbium with benzoic acid and its derivatives

The binary complexes of terbium with benzoic acid and its derivatives (phthalic acid, iso-phthalic acid, oaminobenzoic acid, salicylic acid, sulfosalicylic acid) were synthesized and their compositions were identified by elemental analyses. UV, IR of the complexes were investigated. The UV spectra indicate that the complexes‘ ultraviolet absorption is mainly the ligands‘ absorption, but the location of peak drifts. The IR spectra show that the IR spectra of complexes are different from those of free ligands, and the band at 400 - 500 cm^-1 , due to the stretching vibration of Tb--O, is absent for free ligands. The fluorescence properties were investigated by using luminescence spectroscope, the results show that all the six complexes of terbium exhibit excellent luminescence, due to the transition from the lowest excited state ^5D4 to ^7F ground state manifold, the complexes of terbium with sulfosalicylic acid have the strongest fluorescence intensity, and is stronger than o-aminobenzoic acid-terbium, whose fluorescence intensity is regarded as the strongest one in the literature, and even stronger than some phosphor of terbium.     

Molten solvent extraction behavior of trivalent La, Sm, Dy, and Yb with tri-n-butyl phosphate into molten paraffin wax at 60℃

The extraction behavior of La3 , Sm3 , Dy3 , and Yb3 in sodium acetate-acetic acid medium was studied with tri-n-butyl phosphate (TBP) at 60 ~C using paraffin wax as a diluent. The extraction percentage is greater than 85% in the pH range of 6 to 8. The result of slope analysis method indicates that the compositions of the extracted species are different between the light and heavy rare earths. The formula of the extracted species is found to be La(TBP)(OH)(Ac)2 for La3 and Yb(TBP)(OH)3 for Yb3 . The effects of extracting time, the concentration of TBP in the organic phase and salts on the extraction efficiency were also discussed.     

Preparation and properties of Cu matrix composite reinforced by carbon nanotubes

Cu matrix composites reinforced by carbon nanotubes(CNTs) were prepared. The effect of carbon nanotubes on mechanical and tribological properties of the Cu matrix composites were investigated. The chemical method for coating CNTs was reported. The morphology of the fracture surfaces and worn surface were examined by SEM.The results show that Cu/coated-CNTs composites have higher hardness, much better wear resistance and antifriction properties than those of the reference Cu alloy (Cu-10Sn) and Cu/uncoated-CNTs composite sintered under the same conditions. The optimal mechanical properties of the composites occurred at 2. 25%(mass fraction) of CNTs. The excellent wear resistance and anti-friction properties are attributed to the fiber strengthening effect of CNTs and the effect of the spherical wear debris containing carbon nanotubes on the tribo-surface.     

Adsorption of Au(Ⅲ) by amino-modified monodispersed PGMA microspheres and deposition of gold nanoparticles

Monodispersed poly(glycidyl methacrylate)(PGMA) microspheres with various amounts of amino groups(PGMA-NH_2) were used to adsorb Au(Ⅲ) from simulated wastewaters. Gold nanoparticle-coated PGMA functional microspheres can be directly obtained via the adsorption process. The adsorption kinetics follows pseudo-second model, and 10 min is enough for reaching at equilibrium. The adsorption isotherm follows Langmuir model, and the adsorption amounts for Au(Ⅲ) are 8.25 and 21.75 mol·kg^-1 at 298 and 328 K, respectively. The relative separation coefficients between Au(Ⅲ), Pt(Ⅵ), Pd(Ⅱ)and Co(Ⅱ), Cu(Ⅱ); Ni(Ⅱ), Fe(Ⅲ) are all higher than 100 when 1 < pH < 3. Furthermore, the characterization analysis of X-ray diffraction(XRD), thermogravimetrydifferential scanning calorimetry(TG-DSC), scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS), transmission electron microscopy(TEM) and Fourier transform infrared spectroscopy(FTIR) confirms that AuCl_4^-has been reduced to Au^0 nanoparticles and deposited onto the surface of PGMA-NH_2. The current work shows a good prospect for PGMA-NH_2 to be a valid adsorbent for the recovery of gold and the possible fabrication of gold nanoparticles by reduction-deposition process without any reductant.     

An impedance response model for inhibitory effect of antibiotics on bacterial growth in biometallurgy

An impedance response model reflecting the inhibitory effect of antibiotics on bacterial growth in biomet-allurgy was established. Three inhibition parameters, i.e. the maximum amount inhibitory constant of the bacterial growth(K1), the maximum specific growth inhibitory constant(K2) and the lag time inhibitory constant(K3), were included in the model. The influence of these parameters on the response curve was discussed in detail. By fitting experimental data towards the proposed model, three growth parameters (A,μm and λ) in the presence of antibiotics were gained and compared. The results show that the growth ability of bacteria is decreased due to the influence of antibiotics. The experimental and fitted curves have goodness-of-fit in the range of 0. 987-1. 008. Moreover, the kinetic growth parameters obtained from this model are closed to those from the Logistics popular growth model.These results show that the proposed model is validity to reflect the inhibitory effect of antibiotics on bacteria.