Preparation of NiO nanoparticles from Ni（OH）2-NiCO3-4H2O precursor by mechanical activation

A mechanical activation process was introduced as a facile method for producing nickel oxide nanopowders. The precursor compound Ni（OH）2-NiCO3-4H2O was synthesized by chemical precipitation. The precursor was milled with NaCl diluent. A high-energy ball milling process led to decomposition of the precursor and subsequent dispersal in NaCl media. Nickel oxide nanocrystalline powders were produced by subsequent heat treatment and water washing. Milling rotation speed, milling time, ball-to-powder ratio （BPR）, and nickel chlo-ride-to-precursor ratio were introduced as influential parameters on the wavelength of maximum absorption （λmax）. The effects of these pa-rameters were investigated by the Taguchi method. The optimum conditions for this study were a milling rotation speed of 150 r/min, a mill-ing time of 20 h, a BPR of 15/1, and a NaCl-to-powder weight ratio （NPR） of 6/1. In these conditions,λmax was predicted to be 292 nm. The structural properties of the samples were determined by field emission scanning electron microscopy, X-ray diffraction, and energy dispersive spectrometry.     

Surface modification of Ti-49.8at%Ni alloy by Ti ion implantation: phase transformation,corrosion, and cell behavior

The Ti-49.8at%Ni alloy was modified by Ti ion implantation to improve its corrosion resistance and biocompatibility. The chemical composition and morphologies of the Ti Ni alloy surface were determined using atomic force microscopy(AFM), auger electron spectroscopy(AES), and X-ray photoelectron spectroscopy(XPS). The results revealed that Ti ion implantation caused the reduction of Ni concentration and the formation of a Ti O2 nano-film on the Ti Ni alloy. The phase transformation temperatures of the Ti–Ti Ni alloy remained almost invariable after Ti ion implantation. Electrochemical tests indicated that the corrosion resistance of Ti Ni increased after Ti ion implantation. Moreover, the Ni ion release rate in 0.9% Na Cl solution for the Ti Ni alloy remarkably decreased due to the barrier effect of the Ti O2 nano-film. The cell proliferation behavior on Ti-implanted Ti Ni was better than that on the untreated Ti Ni after cell culture for 1 d and 3 d.     

Revisiting Al-Ni-Zr bulk metallic glasses using the ＇cluster-resonance＇ model

Six series of alloys,namely,Ni3Zr6Alx,Ni3Zr7Alx,Ni4Zr9Alx,Ni3Zr8Alx,Ni3Zr9Alx and Ni3Zr10Alx (x=1,1.5,2,3) were designed in this work and the bulk metallic glass (BMG) formation of these compositions was investigated by copper mold suction casting. A centimeter-scale BMG sample was obtained for the Ni4Zr9Al2 (Al13.3Ni26.7Zr60 in atomic percent) composition. The thermal glass parameters for this BMG were determined to be ΔTx = 68 K,Trg = 0.579,and γm = 0.689. Using the ’cluster-resonance’ model for glass formation an optimal BMG composition was determined using the cluster formula [Ni3Zr9](Al2Ni1).     

Extraction of Aluminum and Iron from Boiler Slag by Sulfuric Acid

This paper presents a new method of recycling aluminum and iron in boiler slag derived from plants that use coal as fuel. The new method integrates efficient extraction and reuse of the leached pellets together. An elemental analysis of aqueous solutions leached by sulfuric acid was determined by EDTA-Naz-ZnCl2 titration method. The components and microstructures of the samples were examined by means of XRF, XRD and SEM. An aluminum extraction efficiency of 86.50% was achieved when the sintered pellets were leached using 4 mol · L^- 1 H2SO4 at solid/ liquid [m（g）/V（mL）] ratio of 1 ： 5 at 80 ℃ for 24 h. An iron extraction efficiency of 94.60% was achieved in the same conditions for the maximum extraction efficiency of Al. The extraction efficiencies of Al and Fe increased with an increase in temperature, leaching time and acidity. The concentration of alumina and iron hydroxide in the final product was determined to be 99.12% and 92.20% respectively. This product of alumina would be used directly for the production of metallic aluminum.     

Preliminary study on electrochemical reduction of carbon dioxide on nickel and platinum electrodes

The electrochemical reduction of carbon dioxide was investigated on nickel and platinum electrodes in 0.5 mol dm^-3 KHCO3 solutions. The main products were formic acid and carbon monoxide during the electroreduction of CO2, and the Faradaic efficiency for this process depended on the characteristics of the electrode. At ambient temperature and pressure, the Faradaic efficiency was measured to be 8.6% and 2.5 % respectively for the production of formic acid and CO with Pt electrode at - 1.3V vs Ag/AgCl （saturated KCl）. At this same potential, the Faradaic efficiency was measured to be 8.9% and 1.7% respectively with Ni electrode. Tafel plots showed that the electrochemical reduction of CO2 was not limited by the mass transfer process in the range of -0.8 to - 1.2V vs Ag/AgCl （saturated KCl）.     

The uptake of ethyl iodide on black carbon surface

The importance of the iodine chemistry in the atmosphere has been demonstrated by recent obserations. The uptake of ethyl iodine on black carbon surface was inestigated at 298 K for the first time. Degussa FW2 （an amorphous black carbon comprising medium oxides） was used as black carbon sample. Black carbon surface was found to be deactiated in reaction with C2H51, and the uptake coefficient （r） was dependent on the time of exposure. The alue of （2.3±0.9）×10^-2 was determined for the initial uptake coefficient （No）. The result suggests that the heterogeneous loss of C2H51 on carbonaceous aerosols may be important under the atmospheric conditions.     

New crystal structure of molecular complex 1-piperidine carboxylate-piperidinium-H<Subscript>2</Subscript>O studied by X-ray single crystal diffraction

Piperidine absorbs CO2 and H2O in air to form a molecular complex： piperidium-l-piperidinecarboxylate-H2O. The structure of the complex was characterized by X-ray single crystal diffraction. The crystal structure was determined to be triclinic, space group P1^-with a=0.648 6（8） nm, b=0.809 200） nm, c= 1.357 1（16） nm, a=96.96706）°, β =102.506（15）°,γ=104.202 05）°, Z=2. The complex is stabilized via five hydrogen bonds between the three components, N-O electrostatic interaction and O-O interaction （electron transfer） betweenl-piperidinecarboxylate and H2O. Due to electron transference of carbamate ion, the oxygen atom in water molecule is strongly negatively charged and the O-H bond is considerably shorter than that of the free molecule of water. The formation of the molecular complex is a reversible process and will decompose upon heating. The mechanism of formation and stabilization is further investigated herein.     

Spectrofluorimetric determination of artemisinin with pyronine B as the substrate for horseradish peroxidase

Enzyme-catalytic fluorescence determination of artemisinin （qinghaosu, QHS） was developed using pyronine B （PB） as substrate of horseradish peroxidase （HRP）. The interaction between HRP and QHS was an enzyme-substrate model. The catalytic characteristic of HRP in the oxidation reaction, in which the fluorescence of PB was decreased in the presence of QHS, was studied. The steady-state catalytic rate depended upon enzyme and substrate concentrations, and the Michaelis-Menten parameters Km, Vmax and Kcat were 8.4×10^-5mol·L^-1, 7.4×10^-6mol·L^-1s^-1 and 50.23s^-1. The catalytic activity of enzyme was inhibited in the presence of deactivated agents and at high temperature, respectively. Under optimum conditions, linear relationship between fluorescence intensity change （F0-F） of pyronine B and concen- tration of QHS was in the range of 1.41×10^-7-1.27×10^-6mol·L^-1. The detection limit （3σ） was determined to be 2.7×10^-8mol·L^-1. The proposed method was applied to the concentration determination of QHS in the media of plasma or urine samples.     

Structural and optical properties of Zn1−xNixTe thin films prepared by electron beam evaporation technique

Zn1-xNixTe thin films with different composition(x=0.0, 0.05, 0.10, 0.15 and 0.20) were deposited on glass substrate by electron beam evaporation technique followed by its characterization using advanced structural and optical analysis techniques. Structural properties of the prepared thin films were studied by X-ray diffraction(XRD). The XRD patterns revealed that the binary compounds transformed into a ternary compound with cubic structure having preferred orientation along the c-direction with(111) planes. Composition analysis of the films was determined by energy dispersive analysis of X-rays(EDAX) and found to be in agreement with the precursor composition. Optical properties such as extinction coefficient(k) and band gap energy of these films were examined by using a spectroscopic ellipsometer. It was found that the extinction coefficient(k) increased with the addition of Ni content in the alloy. In comparison, the band gap energy was also determined by using transmission spectra and found to be agreed with that of the ellipsometric results. These analyses confirm that the band gap energy decreases with the increase of Ni content in the alloy.     

添加钇不锈钢热处理过程中其氧化物夹杂物的温度依赖性演化

The evolution of oxide inclusions during isothermal heating of 18Cr–8Ni stainless steel with yttrium addition at temperatures of 1273 to 1573 K was investigated systematically. Homogeneous spherical Al–Y–Si(–Mn–Cr) oxide inclusions were observed in as-cast steel. After heating, most of the homogeneous inclusions were transformed into heterogeneous inclusions with Y-rich and Al-rich parts, even though some homogeneous oxide particles were still observed at 1273 and 1573 K. With the increase in heating temperature, more large-sized inclusions were formed. The shape of the inclusions also changed from spherical to irregular. The maximum transformation temperature of inclusions was determined to be 1373 K. The evolution mechanism of inclusions during heating was proposed to be the combined effect of the (i) internal transformation of inclusions due to the crystallization of glassy oxide and (ii) interfacial reaction between inclusions and steel matrix. Meanwhile, the internal transformation of inclusions was considered to be the main factor at heating temperatures less than 1473 K.     

Electrocatalytic oxidation of H<Subscript>2</Subscript>O<Subscript>2</Subscript> at a carbon paste electrode modified with a nickel (II)-5, 11, 17, 23-tetra-tert-butyl-25, 27-bis(Diethylcarbamoylmethoxy) calix[4] arene complex and its application

Electrochemical behavior of a carbon paste electrode (CPE) modified with nickel(II)-5, 11, 17, 23-tetra-tert-butyl-25, 27-bis(diethylcarbamoylmethoxy) calix[4]arene (Ni (II)-L) complex and its electrocatalytic activity towards the oxidation of hydrogen peroxide were investigated by cyclic voltammetric technique in a 5.0×10⁻² mol/L NaClO₄+1.0×10⁻³ mol/L NaOH solution. It was found that Ni(II)-L acts as an effective catalyst for the oxidation of hydrogen peroxide. The modified electrode exhibited a linear response over a hydrogen peroxide concentrations in the range of 2.0×10⁻⁵−1.0×10⁻⁴ mol/L with a detection limit as low as 1.0×10⁻⁶ mol/L. The relative standard deviation was 3.5% for 5 successive determinations of H₂O₂ at 1.0×10⁻⁵ mol/L. The modified electrode was used successfully in rainwater analysis. Foundation item: Supported by the Natural Science Foundation of Hubei Province (98J040). Biography: Li Chun ya(1972-), Ph. D. candidate, research direction: electroanalysis and electrosynthesis.     

The giant magnetocaloric effect in Gd<Subscript>5</Subscript>Si<Subscript>2</Subscript>Ge<Subscript>2</Subscript> with low purity gadolinium

The giant magnetocaloric effect Gd5Si2Ge2 alloy was prepared with 99wt% low purity commercial Gd. Powder XRD and magnetic measurements showed that the Gd5Si2Ge2 alloy annealed at 1200℃ for 1h had a significant magnetic- crystallographic first order phase transition at about 270 K. The maximal magnetic entropy change is 17.55 J· kg^-1· K^-1 under a magnetic field change of 0-5 T. The distinct increase of magnetic entropy change belongs to the first-order phase transition from the orthorhombic Gd5Si4-type to the monoclinic Gd5Si2Ge2-type after high temperature heat-treatment.     

Investigation of the cross-reaction mechanism of C<Subscript>6</Subscript>H<Subscript>5</Subscript>F-HNO<Subscript>2</Subscript> aqueous solution irradiated at 355 nm by transient absorbance spectrum technique

The transient absorption spectrum technique was employed to investigate the cross-reaction mechanism of C6H5F-HNO2 aqueous solution irradiated at 355 nm. The characteristic and the kinetic parameters of transient species were also detected. Hydroxyl radical derived from the photolysis of HNO2 was added to monofluorobenzene with a second-order rate constant of （5.83±0.17）×10^9 L·mol^-1·s^-1 to form an adduct, C6H5F…OH, which was able to react with HNO2 as the main reaction pathway with a rate constant of （8.3±0.1）×10^7 L·mol^-1·s^-1. The C6F6…OH adduct can also be decayed by elimination of H2O to yield monofluorophenyl radical C6H4F-. By GC-MS technique, the final products were identified to be monofluorophenol, nitro-monofluorobenzene, nitro-monofluorophenol and para-fluorobiphenyl.     

Kinetic studies of the decomposition reaction of adducts of dinuclear Fe(Ⅱ)/O2

Kinetic studies of the decomposition reaction of dinuclear Fe(Ⅱ) adducts [Fe₂(N-Et-HPTB){O₂P(OPh)₂}](Cl- O₄)₂ (1) and [Fe₂(N-Et-HPTB) {O₂P(Ph)₂}] (ClO₄)₂ (2) with O₂ have been carried out at low temperature using UV-vis spectra. The decomposition reaction of Fe(Ⅱ)/O₂ adducts was first-order in the experimental conditions, and the activation parameters were obtained. ?H^¹ = 85.62 kJ·mol^-1, ?S¹ = 19.43 J·mol^-1·K^-1 for compound (1) and ?H^¹ = 97.97 kJ·mol^-1, ?S^¹ = 55.68 J·mol^-1·K^-1 for compound (2). These results are similar to those of dioxygen adducts of other metals complexes and natural enzymes such as methane mono- oxygenase (MMOH).     

Electrochemical properties of LiNi<Subscript>0.5</Subscript>Mn<Subscript>1.3</Subscript>Ti<Subscript>0.2</Subscript>O<Subscript>4</Subscript>/Li<Subscript>4</Subscript>Ti<Subscript>5</Subscript>O<Subscript>12</Subscript> cells

Spinel compounds LiNi_0.5Mn_1.3Ti_0.2O₄ (LNMTO) and Li₄Ti₅O₁₂ (LTO) were synthesized by different methods. The particle sizes of LNMTO and LTO are 0.5–2 and 0.5–0.8 μm, respectively. The LNMTO/LTO cell exhibits better electrochemical properties at both a low current rate of 0.2C and a high current rate of 1C. When the specific capacity was determined based on the mass of the LNMTO cathode, the LNMTO/LTO cell delivered 137 mA·h·g⁻¹ at 0.2C and 118.2 mA·h·g⁻¹ at 1C, and the corresponding capacity retentions after 30 cycles are 88.5% and 92.4%, respectively.     

Effect of CO<Subscript>2</Subscript> concentrations on the activity of photosynthetic CO<Subscript>2</Subscript> fixation and extracelluar carbonic anhydrase in the marine diatom <Emphasis Type="Italic">Skeletonema costatum</Emphasis>

The growth and activity of photosynthetic CO2 uptake and extracellular carbonic anhydrase (CAext) of the marine diatom Skeletonema costatum were investigated while cultured at different levels of CO2 in order to see its physio-logical response to different CO2 concentrations under either a low (30 靘ol·m-2·s-1) or high (210 靘ol·m-2·s-1) irradiance. The changes in CO2 concentrations (4—31 靘ol/L) affected the growth and net photosynthesis to a greater extent under the low than under the high light re-gime. CAext was detected in the cells grown at 4 mol/L CO2 but not at 31 and 12 靘ol/L CO2, with its activity being about 2.5-fold higher at the high than at the low irradiance. Photo- synthetic CO2 affinity (1/ K1/2(CO2)) of the cells de-creased with increased CO2 concentrations in culture. The cells cultured under the high-light show significantly higher photosynthetic CO2 affinity than those grown at the low-light level. It is concluded that the regulations of CAext activity and photosynthetic CO2 affinity are dependent not only on CO2 concentration but also on light availability, and that the de-velopment of higher CAext activity and CO2 affinity under higher light level could sufficiently support the photosyn-thetic demand for CO2 even at low level of CO2.     

Compression behavior and equation of state of Ni77P23 amorphous alloy

The compression behavior of Ni77P23 amorphous alloy is investigated at room temperature in a diamond-anvil cell instrument using insitu high pressure energy dispersive X-ray diffraction with a syn- chrotron radiation source. The equation of state is determined by fitting the experimental data accord- ing to Birch-Murnaghan equation: -ΔV/V0=0.08606P-3.2×10-4P2 5.7×10-6P3. It is found that the structure of Ni77P23 amorphous alloy is stable under pressures up to 30.5 GPa.     

Synthesis,Structure and Antitumor Activities of [Ni（dien）2][Ni（CN）4] Complex

Ni(II)-dien complex was prepared and characterized by X-ray diffraction. The crystal belongs to triclinic system, space group P-1, with crystallographic parametersa=0.888 13(18) nm,b=0.890 10(18) nm,c=1. 591 8(3) nm, α=77.71(3)°, β=89.12(3)°, γ=61.24(3)°,Z=2. The two dien molecules coordinate to the central Ni atom, the six nitrogen atoms form a distorted octahedron. Preliminary pharmacological tests showed this complex had antitumor activity against HepG₂ and HL-60 cell linesin vitro. Foundation item, Supported by the National Natural Science Foundation of China (29972034) Biography: Li Tao (1976-), male, Ph. D candidate, research direction: ophthalmology and chemicalbiology.     

Analysis of the characteristics of the harmonics coefficient <Emphasis Type="Italic">J</Emphasis><Subscript>2</Subscript> of the Earth’s gravity field in different periods

The characteristics of the geopotential coefficient J2 in different periods are analyzed using satellite laser ranging data spanning the last 27 years.The satellites used in the analysis are Lageos1 and Lageos2.The variations in J2 are obtained by determining the dynamic orbit.The results show that there are strong seasonal and long-term variations.For different data spans,the seasonal variations agree well in terms of both amplitude and phase.Using all the data,the amplitude and phase of the annual term are 2.5 10-10 and 127°,respectively,while the amplitude and phase of the semiannual term are 0.94 10-10 and 213°,respectively.In the case of long-term variation,the secular variation in J2(J2) is-2.2 10-11 a-1 from 1984 to 2010.J2 differs for the different periods because of interannual variations,such as the "1998 anomaly".Another anomaly may have taken place during 2007-2010.Although the cause of the anomaly is unknown,it is an important observational constraint on the shape of the Earth.     

Surface tension and specific heat of liquid Ni<Subscript>70.2</Subscript>Si<Subscript>29.8</Subscript> alloy

The thermophysical properties of liquid alloys in me-tastable state are of importance for liquid-solid phase transformation under nonequilibrium conditions[1―10]. Sur-face tension and specific heat, two of the most important thermophysical properties, have significant influences on the process of crystal nucleation and growth. Furthermore, it is necessary to obtain these data so as to perform quan-titative research on rapid solidification[3―10]. The tradi-tional measurement methods, however,…