Extraction studies of cobalt (Ⅱ) and nickel (Ⅱ) from chloride solution using PC88A

Solvent extraction study of cobalt and nickel were carried out from a chloride solution with a high ratio of Co to Ni using the sodium salt of PC88A as extractant diluted in kerosene. The solution was generated in batches by leaching a tungsten super alloy scraps. The results show that extraction rate of metal ions increases with increase of aqueous phase pH value. The pH0.5 value difference of 1.40 with PC88A indicates the possible separation of cobalt and nickel. Increase of the concentration of the solvent can enhance the percentage extraction of both metal ions. Improvement of temperature is beneficial to extraction separation of cobalt and nickel. Extraction and stripping processes were also studied in a cross-current solvent extraction unit and the results were also given.

Effects of Cerium Doping at Ti Sites and Europium Doping at Ba Sites on Dielectric Properties of BaTiO_3 Ceramics

Two special rare earth elements cerium and europium were chosen to conduct chemical modification of the BaTiO3 structure. The cold-pressing ceramic processing technique was used to prepare barium titanate ceramics doped with Ce at Ti sites and with Eu at Ba sites on the base of formulas Ba （ Ti1 -x Cex ） O3 （x = 0. 05, 0. 10 ） （CBT） and （ Ba1-y Euy ） Ti1-x/8O3 （ y = 0. 05, 0. 10） （EBT）. Associated with structures and microstructures, the effects of cerium and europium doping on dielectric properties of BaTiO3 ceramics were discussed. The CBT ceramics exhibit a pseudocubic perovskite structure, while the EBT ceramics exhibit a tetragonal perovskite structure with the exception of the existence of a small percentage of the Eu2Ti2O7 phase. The Curie peak of BaTiO3 shifts towards room temperature at rates of 3 ℃/mol Ce atoms and 10 ℃/mol Eu atoms（ Eu≤5% ）, respectively. Compared with the CBT ceramics, the EBT ceramics show significant advantages, such as a narrow fine grain size distribution（ 1 μm）, a lower porosity and a higher density（5.85 g/cm^3）, more stable dielectric-temperature dependence（ ε′= 1600-1800 at t 〈 50℃ ） and a lower dissipation factor（ 〈 0. 05 ）. The stability of dielectric constant with frequency in BaTiO3 can extend to 107 Hz due to Ce and Eu doping.

Na_xCoO_2热电性质的第一性原理研究(英文)

热电材料能够进行热能与电能的直接转化,对其进行理论研究对实际应用具有指导意义.NaxCoO2是一种新型的热电功能材料,近年来逐渐成为研究的热点.本文在基于密度泛函理论的第一性原理电子结构研究的基础上,利用恒定弛豫时间近似条件下的线性波尔兹曼方程研究了这种材料体系的热电性质,得出了其热电功率在确定温度下作为Na原子含量的函数.

Enzymatic treatment of estrogens and estrogen glucuronide

Natural and synthetic estrogens from sewage treatment systems are suspected to influence the reproductive health of the animals in the rivers. In this article, we investigated the enzymatic treatment of three estrogens （estrone, 17β-estradiol, and 17α-ethynyletstradiol） by a fungal laccase which oxidize phenolic compounds with dissolved oxygen. The elimination of the estrogenic activities by enzymatic oxidation was demonstrated by medaka vitellogenin assay. In addition, we developed an enzymatic treatment system comprised of β-D-glucuronidase and the laccase for 17β-estradiol 3-（β-D-glucuronide） degradation. The two enzymes eliminated 17β-estradiol 3-（β- D-glucuronide） and the intermediate, 17β-estradiol, efficiently.

Density Measurement of Liquid Ni-Ta Alloys by a Modified Sessile Drop Method

The density of liquid Ni-Ta alloys was measured by using a modified sessile drop method. It is found that the density of the liquid Ni-Ta alloys decreases with the increasing temperature, but increases with the increase of tantalum concentration in the alloys. The molar volume of liquid Ni-Ta binary alloys increases with the increase of temperature and tantalum concentration.

Measurement and analyses of molten Ni-Co alloy density

With the advent of powerful mathematical modeling techniques for material phenomena,there is renewed interest in reliable data for the density of the Ni-based superalloys.Up to now,there has been few report on the density of molten Ni-Co alloy.In order to obtain more accurate density data for molten Ni-Co alloy,the density of molten Ni-Co alloy was measured with a modified sessile drop method,and the accommodation of different atoms in molten Ni-Co alloy was analyzed.The density of alloy is found to decrease with increasing temperature and Co concentration in the alloy.The molar volume of molten Ni-Co alloy increases with increasing Co concentration.The molar volume of Ni-Co alloy determined shows a positive deviation from the linear molar volume,and the deviation of molar volume from ideal mixing increases with increasing Co concentration over the experimental concentration range.

Ll_0 FePt thin films with 001crystalline growth fabricated by ZnO addition and rapid thermal annealing

FePt films with a high degree of order S of the L10 structure （S 〉 0.90） and well defined [001] crystalline growth perpendicular to the film plane are fabricated on thermally oxidized Si substrates by the addition of ZnO and a successive rapid thermal annealing （RTA） process. The optimum condition to prepare high-ordering L10 FePtZnO films is 20 vol% ZnO addition and 450 ℃ annealing. The effect of the ZnO additive on the ordering process of the L10 FePtZnO films is discussed. In the annealing process, Zn atoms move to the film surface and evaporate. The motion of the Zn atoms accelerates the intergrain exchange and decreases the ordering temperature.

Density of liquid NiCoAlCr quartemary alloys measured by modified sessile drop method

The densities of liquid NiCoAlCr quaternary alloys with a fixed molar ratio of Ni to Co to Al (x(Ni):x(Co):x(Al)≈73:12.15) which is close to the average value of the commercial Ni-based superalloys TMS75, INCO713, CM247LC and CMSX-4, and the mass fraction of chromium changes from 0 to 9% were measured by a modified sessile drop method. It is found that with increasing temperature and chromium concentration in the alloys, the densities of the liquid NiCoAlCr quaternary alloys decrease, whereas the molar volume of the liquid NiCoAlCr quaternary alloys increases. And the liquid densities of NiCoAlCr quaternary alloys calculated from the partial molar volumes of nickel, cobalt, aluminum and chromium in the corresponding Ni-bases binary alloys are in good agreement with the experimental ones, i.e. within the error tolerance range the densities of the liquid Ni-based multi-component alloys can be predicted from the partial volumes of elements in Ni-based binary alloys in liquid state. The molar volume of liquid NiCoAlCr binary alloy shows a negative deviation from the ideal linear mixing and the deviation changes small with the increase of chromium concentration at the same temperature.

Multilayer polarization elements and their applications to polarimetric studies in vacuum ultraviolet and soft X-ray regions

Multilayer polarization elements and their applications to polarimetric studies in 20～400 eV region are mainly reviewed. General principle of selecting material combinations to get high linear polarizance multilayers of reflection type is given with practical examples,with periodic or non-periodic layer structures depending on the usage. Transmission type is introduced as linear polarizer and phase shifter. Their applications include polarization diagnosis of laboratory optical systems and synchrotron radiation beamlines of linear and circular polarization,magnetic rotation experiments such as Faraday rotation and magnetic Kerr rotation on magnetic films and multilayers,and ellipsometry to measure optical constants of thin films precisely. Polarization analysis of soft X-ray fluorescence using multilayer-coated grating is also mentioned. Finally this review is summarized with outlook of further developments.

自组织生长CdSe-ZnSe量子点的光致发光

利用不同温度下的光致发光和时间分辨光谱研究了生长在GaAs( 1 1 0 )衬底上的CdSe ZnSe自组织量子点的发光特性 ,发现浸润层量子阱的激子发光淬灭比量子点的淬灭过程快得多 ,量子点的激子辐射复合寿命远大于浸润层量子阱的激子复合寿命 .根据不同尺寸的量子点复合寿命的差异 。

A comparison of the pre-calling period between Japanese and southeastern Asian populations of Spodoptera litura

The pre-calling behavior of female adults of the common cutworm, Spodoptera litura （Lepidoptera： Noctuidae） collected in southern Japan and southeastern Asian countries was investigated. Most females started calling on days 1-4 after adult emergence. In three populations obtained in Saga prefecture in Kyushu mainland, Japan, two different patterns of pre-calling period （PCP） were observed： one was the above-mentioned pattern shown by most individuals, and the other was a pattern in which females sexually matured within several hours after emergence. Diel periodicity was shown in the time of calling activity, and its pattern varied among the populations. Pre-calling period was stable over successive generations in the laboratory.

Efficiency and Output Power Evaluation of a Wavelength Converter Based on FWM in a Single Mode Fiber

A frequency domain analysis is presented to determine the performance characteristics of a tunable all-optical wavelength converter using four-wave mixing (FWM) in a single mode fiber (SMF) around the zero dispersion wavelength using two pump lasers. The output converted signal power as well as efficiency evaluated at a bit rate of 10 Gb/s show that the signal power is substantially higher at lower values of wavelength separation.

Three-Dimensional Lattice Boltzmann Simulation of Two-Phase Flow Containing a Deformable Body with a Viscoelastic Membrane

The lattice Boltzmann method(LBM)with an elastic model is applied to the simulation of two-phase flows containing a deformable body with a viscoelastic membrane.The numerical method is based on the LBM for incompressible two-phase fluid flows with the same density.The body has an internal fluid covered by a viscoelastic membrane of a finite thickness.An elastic model is introduced to the LBM in order to determine the elastic forces acting on the viscoelastic membrane of the body.In the present method,we take account of changes in surface area of the membrane and in total volume of the body as well as shear deformation of the membrane.By using this method,we calculate two problems,the behavior of an initially spherical body under shear flow and the motion of a body with initially spherical or biconcave discoidal shape in square pipe flow.Calculated deformations of the body(the Taylor shape parameter)for various shear rates are in good agreement with other numerical results.Moreover,tank-treading motion,which is a characteristic motion of viscoelastic bodies in shear flows,is simulated by the present method.