Optical properties of NdxGd1−xAl3(BO3)4 crystal

The optical properties of Nd x Gd 1-x Al\-3(BO\-3)\-4 (NGAB) crystal are reported. The refractive index of it were mesured by V_prism method. The absorption spectra and the flourescence specra of NGAB were also obtained. The optical parameters of NGAB were calculated following J_O theory, the three optical parameters are Ω 2 =1 805×10 -20 , Ω 4=1 85×10 -20 , Ω 6=3 793×10 -20 (RMS=1 4×10 -7 ) and β c( 4F 3/2 → 4I 11/2 ) is about 0 53.     

Structural dependences of the η~6 complexes of 3-amino-9-ethylcarbazole with chromium tricarbonyl fragment on third-order optical nonlinearities

Degenerate four-wave mixing measurements, using the 35 ps pulses at 532 nm, have been employed to investigate the third-order nonlinear optical parameters of two chromium tricarbonyl complexes η6-bonded to 3-amino-9-ethylcarbazole at either the NH2-substituted aryl ring (1) or the unsubstituted ring (2) and their precursor 3-amino-9-ethylcarbazole (AECz). The second-order hyperpolarizability γ of the compounds 1 and 2 were found to be 42.9×10-31 and 35.9×10-31 esu, respectively, approximately one order of magnitude greater than AECz. The relation between the molecular structure and second-order hyperpolarizability of the compounds 1 and 2 was explored in detail based on the three-level model and the density functional theory (DFT) calculation. The theoretical results indicate that the spatial distri-bution of electron density has the profound role in the third-order nonlinear optical properties.     

Theoretical study on photophysical property of C_(60)M(CO)_5 (M=Cr,Mo and W)

Configurations of three η2 models of transition-metal 60 fullerene derivatives C60M(CO)5(M=Cr,Mo and W) have been optimized at B3LYP/LanL2DZ level.On the basis of the optimized geometrical structures,their electronic spectra and the frequency dependence of third-order nonlinear optical polarizabilities γ in different optical processes of third-harmonic generation(THG),electric-field-induced sec-ond-harmonic generation(EFISHG) and degenerate four-wave mixing(DFWM) are calculated by using TDB3LYP model based on LanL2DZ level coupled with the SOS(sum-over-state) method.The obtained results show that their electronic spectra have a red shift compared with that of 60 fullerene and dif-ferent transition-metal functional groups added to C60 cage may result in different spectrum properties.For the three studied species,(η2-C60)Mo(CO)5 has the largest third-order nonlinear optical polarizability.     

Nonlinear optical properties of Eu<Subscript>2</Subscript>O<Subscript>3</Subscript> doped 5ZnO-20Nb<Subscript>2</Subscript>O<Subscript>5</Subscript>-75TeO<Subscript>2</Subscript> glasses

The third-order optical nonlinearities, including third-order nonlinear susceptibility X^(3), nonlinear refractive index (n2) and temporal response, were measured with forward DFWM using Nd:YAG mode-locked pulse laser. The results show that Eu203 doped 5ZnO-20Nb2O5-75TeO2 glasses have large n2 and ultra-fast temporal response. Raman spectra show that Eu2O3 dopant induces the changes in the local structure of glasses. The higher the dopant concentration, the larger the nonlinear refractive n2 and the faster the temporal response. The enhancement on the third-order optical nonlinearities can be attributed to the deformation of the electronic clouds in [TeO4] enhanced by Eu2O3 dopant.     

Linear and third-order nonlinear optical properties for the heptamethine cyanine chromophore H-aggregates thin film

The thin film of a heptamethine cyanine chromophore HC was prepared by spin-coating technique. Its surface morphology and linear optical property were characterized by atomic force microscopy (AFM) and UV-visible absorption spectroscopy. The results show that HC molecules are arranged in a well-ordered H-aggregate type. The third-order nonlinear optical properties of the spin-coating film were also measured by degenerate four-wave mixing (DFWM) measurement. Enhanced third-order nonlinear susceptibility can be attributed to molecular aggregation effects, and the corresponding mechanism was dealt with by collective electronic oscillator (CEO) approach.     

Quantum Size-Dependent Third-Order Nonlinear Optical Susceptibility in Semiconductor Quantum Dots

The density matrix approach has been employed to investigate the optical nonlinear polarization in a single semiconductor quantum dot(QD). Electron states are considered to be confined within a quantum dot with infinite potential barriers. It is shown, by numerical calculation, that the third-order nonlinear optical susceptibilities for a typical Si quantum dot is dependent on the quantum size of the quantum dot and the frequency of incident light.     

槲皮素修饰碳糊电极吸附溶出伏安法测定血清中的铅

建立了用槲皮素修饰碳糊电极吸附溶出伏安法测定血清中的铅的方法.在浓度为0.10mol·/L的甲酸钠-盐酸缓冲溶液(pH=4.3)中,于-0.10V(vs.SCE)搅拌富集,再在-0.70V静止还原40s后,阳极化扫描.于-0.42V左右获得一灵敏的铅阳极溶出峰.在最佳条件下,富集不同的时间,其二阶导数峰电流与铅离子在1.0×10-8-8.0×10-7mol·/L和2.0×10-9-6.0×10-8mol·/L两个范围内呈线性关系,检出限为6.0×10-8mol·/L,同时对电极反应机理进行了讨论.     

Combustion characteristics of unburned pulverized coal and its reaction kinetics with CO2

The combustion characteristics of two kinds of unburned pulverized coal (UPC) made from bituminous coal and anthracite were investigated by thermogravimetric analysis under air. The reaction kinetics mechanisms between UPC and CO₂ in an isothermal experiment in the temperature range 1000-1100℃ were investigated. The combustion performance of unburned pulverized coal made from bituminous coal (BUPC) was better than that of unburned pulverized coal made from anthracite (AUPC). The combustion characteristic indexes (S) of BUPC and AUPC are 0.47×10-6 and 0.34×10-6%2·min-2·℃-3, respectively, and the combustion reaction apparent activation energies are 91.94 and 102.63 kJ·mol-1, respectively. The reaction mechanism of BUPC with CO₂ is random nucleation and growth, and the apparent activation energy is 96.24 kJ·mol-1. By contrast, the reaction mechanism of AUPC with CO₂ follows the shrinkage spherical function model and the apparent activation energy is 133.55 kJ·mol-1.     

I-V andC-V properties of TiO2 thin film by pulsed-laser reactive deposition

TiO-2 thin films have bee deposited on p-Si(111) substrates by pulsed-laser ablation of metallic Ti target in the O-3 ambient. The current-voltage and capacitance-voltage of the Al/TiO-2/Si capacitors are measured. The results show that the dielectric constant of thin film after being annealed at 700℃ is found to be 46, and the border trap density and the interface state density at the TiO-2/p-Si interface are 1.8×10 12 cm -2 and 2×10 12 eV -1·cm -2, respectively. The conduction mechanisms of as-deposited films are also discussed.     

Graphite-polypyrrole coated 316L stainless steel as bipolar plates for proton exchange membrane fuel cells

316L stainless steel (SS 316L) is quite attractive as bipolar plates in proton exchange membrane fuel cells (PEMFC). In this study, graphite-polypyrrole was coated on SS 316L by the method of cyclic voltammetry. The surface morphology and chemical composition of the graphite-polypyrrole composite coating were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). A simulated working environment of PEMFC was applied for testing the corrosion properties of graphite-polypyrrole coated SS 316L. The current densities in the simulated PEMFC anode and cathode conditions are around 3×10-9 and 9×10-5 A·cm-2, respectively. In addition, the interfacial contact resistance (ICR) was also investigated. The ICR value of graphite-polypyrrole coated SS 316L is much lower than that of bare SS 316L. Therefore, graphite-polypyrrole coated SS 316L indicates a great potential for the application in PEMFC.     

Structural dependences of the <Emphasis Type="Italic">η</Emphasis><Superscript>6</Superscript> complexes of 3-amino-9-ethylcarbazole with chromium tricarbonyl fragment on third-order optical nonlinearities

Degenerate four-wave mixing measurements, using the 35 ps pulses at 532 nm, have been employed to investigate the third-order nonlinear optical parameters of two chromium tricarbonyl complexes η6-bonded to 3-amino-9-ethylcarbazole at either the NH2-substituted aryl ring （1） or the unsubstituted ring （2） and their precursor 3-amino-9-ethylcarbazole （AECz）. The second-order hyperpolarizability y of the compounds 1 and 2 were found to be 42.9×10^-31 and 35.9×10^-31 esu, respectively, approximately one order of magnitude greater than AECz. The relation between the molecular structure and second-order hyperpolarizability of the compounds I and 2 was explored in detail based on the three-level model and the density functional theory （DFT） calculation. The theoretical results indicate that the spatial distribution of electron density has the profound role in the third-order nonlinear optical properties.     

Theoretical study on photophysical property of C60M（CO）5 （M=Cr,Mo and W）

Configurations of three η2 models of transition-metal [60]fullerene derivatives C60M（CO）5（M=Cr, Mo and W） have been optimized at B3LYP/LanL2DZ level. On the basis of the optimized geometrical structures, their electronic spectra and the frequency dependence of third-order nonlinear optical polarizabilities γ in different optical processes of third-harmonic generation （THG）, electric-field-induced second-harmonic generation （EFISHG） and degenerate four-wave mixing （DFWM） are calculated by using TDB3LYP model based on LanL2DZ level coupled with the SOS （sum-over-state） method. The obtained results show that their electronic spectra have a red shift compared with that of [60]fullerene and different transition-metal functional groups added to C60 cage may result in different spectrum properties. For the three studied species, （η^2-C60）Mo（CO）5 has the largest third-order nonlinear optical polarizability.     

High-energy ion treatments of amorphous As40Se60 thin films for optical applic ations

The treatment of 100 MeV Ag swift-heavy ion(SHI) irradiation with five different fluences(3 1010, 1 1011, 3 1011, 1 1012, and3 1012ions/cm2) was used to design optical and structural properties of amorphous(a-) As40Se60 chalcogenide thin films. Swanepoel method was applied on transmission measurements to determine the changes in optical bandgap, Tauc parameter and linear optical parameters, i.e., linear optical absorption, extinction coefficient and linear refractive index. Dispersion of the material was determined by Wemple–DiDomenico relation.Changes in nonlinear optical parameters of third-order optical susceptibility and nonlinear refractive index were determined using semi-empirical relations. Changes in surface morphology of the films were investigated using SEM observation, which indicated that fluence 3 1012ions/cm2was upper threshold limit for these films for ion treatment. It is observed that optical bandgap reduces from 1.76 eV to 1.64 eV, and nonlinear refractive index increases from 1.31 10 10[esu] to 1.74 10 10[esu]. Linear refractive index initially increases from 2.80 to 3.52(for fluence3 1010ions/cm2) and then keeps decreasing. The observed changes in optical properties upon irradiation were explained in terms of structural rearrangements by Raman measurement. The study was compiled with the previous literature to propose SHI as an effective optical engineering technique to achieve desired changes according to the need of optical/photonic applications.     

Nonlinear optical properties and optical limiting response of a metal cluster [PPh4][ Cp＊ MoS3（CuBr）3]

Nonlinear optical properties of a metal cluster [PPh4][Cp*MoS3(CuBr)3] have been studied, with the third-order susceptibility χ^[3]) for this cluster determined by degenerate four-wave mixing (DFWM) experiment, the optical limiting (OL) effect observed by transmission technique,and the nonlinear absorption measured by using Z-scan technique.     

Improving the sulfidation-flotation of fine cuprite by hydrophobic flocculation pretreatment

Hydrophobic flocculation pretreatment was performed to assess its effect on the recovery of fine cuprite in sulfidation-flotation. The results of the micro-flotation experiment showed that cuprite recovery is related to the particle size, and that an excessive content of fine particles (<18 μm) impacted the recovery of coarse particles. When hydrophobic flocculation pretreatment was used, the recovery of fine cuprite in sulfidation-flotation increased from 60.3% to 86.3% under optimum conditions (pH 9.5; sodium oleate concentration, 2×10-4 mol·L-1; stirring time, 6 min; stirring speed, 1600 r·min-1). The laser particle size analysis and optical microscopy results indicate that hydrophobic flocculation pretreatment effectively reduces the content of fine cuprite, and augments the apparent particle size in the pulp. We performed the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory and extended DLVO theory calculations to further support the interpretation of the results.     

Optical nonlinearity and ultrafast dynamics of ion exchanged silver nanoparticles embedded in soda-lime silicate glass

Ag nanoparticles embedded in soda-lime silicate glass were fabricated by ion-exchange and subse-quently annealing method. Z-scan technique, femtosecond time-resolved optical Kerr effect （OKE） technique and femtosecond pump-probe experiment were used to investigate the effects of laser wavelength and laser pulse duration as well as annealing temperature on the third-order optical nonlinearity and ultrafast dynamics of the composites. It was found that the third-order susceptibility of Ag nanoparticles composite glass measured by 400 nm pulse source is larger than that measured by 800 nm pulse source due to an enhancement effect of local field near surface plasmon resonance of Ag nanoparticles in silicate glass. The third-order optical nonlinearity measured by ns laser source is about two orders of magnitude larger than that measured from fs pulse. The annealing temperature has an important effect on the third-order optical nonlinearity and ultrafast dynamics of the composites. Third-order nonlinear susceptibility up to 10^-l0 esu and fast relaxation process up to 0.2 ps have been obtained in Ag nanoparticles doped glass.     

茶碱PVC膜选择性电极的研究

In this Paper, PVC membrane Selective clectrodes are prepared for theophylline which are based on its ion-pair complexes with hexadecylt- rioctylammonium iodide (HTOA) , hexadecyltributyl-ammonium iodide (HTBA), hexadeeyltriophenylphosphonium iodide(HTPP), triphenyloctylphosphonium leoide(TPOP) and tri(p-tolyl) butylphosphonium iodide(TPTBP).The effects of the nature of associate counterions, the plastieizers and their concentrations in the membrane phase have been studied. The electrode based on theophylline-HTOA membrane has a sub-Nernstian response range from 2.0×10~2—6.3×10~(-5)mol/L,with an average slope of 48.0mV/pC. The limit of detection is 8.7×10~(-6)mol/L. The electrode responses were not affected by pH in the range 10-12. The potentiometric selectivity coefficients of various common inorganic and organic ions including those which are similar to theophylline in structure were determined. The Na_2CO_3-Na_2B_4O_7 buffer of pH 11 is selected as the background solution for potentiometric measurements. The electrode was used for determining the theophylline in pharmaceutical preparations with satisfactory results.     

多阶溶出伏安法直接测定健康人血清中半光氨酸的含量

以玻璃碳电极研究了在铁 (Ⅲ )存在下 ,微量半光氨酸的半微分溶出法行为 .发现在 pH =3.2缓冲溶液中半光氨酸浓度在 1.0× 10 -9～ 7.0× 10 -4 mol·L-1范围内与其溶出峰电流呈良好线性 ,富集 10min ,检测限为 5 .0× 10 -5mol·L-1,相对标准偏差为 2 .1% .     

钠抗镉对水生物毒性及吸收动力学的研究

测定Cd以及Cd在NaCl存在时对水蚯蚓（T.Tubifex）的毒性,并用~(109)Cd~(2+)标记测定水蚯蚓对Cd~(2+)吸收速度。实验发现随着Na~+变化Cd半致死量LC_(50)也发生变化,当Na~+浓度增加到8.0×10~(-2)mol·L~(-1)时,在48h时,毒性下降了21倍;在低于1.0×10~(-3)mol·L~(-1)NaCl时,水蚯蚓对Cd~(2+)吸收速度没有明显的变化,可当NaCl浓度大于1.0×10~(-2)mol·L(-1)时有明显下降（P<0.05）。用Lineweave-Burk法处理实验数据得到最大吸收速度V_max和米氏常数K_m,当Na~+提高时V_max基本保持为常数(5.5-7.5)×10~(-7)mol·g~(-1)·h~(-1),而K_m成倍增加,这表明Cd~（2+）和Na~+竞争相同的转移通道进入动物体内,从而导致影响Cd对水蚯蚓的毒性。     

Design and synthesis of a packaging polymer enhancing the sensitivity of fiber grating pressure sensor

A packaging polymer (PP-1) that can enhance the sensitivity of fiber Bragg grating(FBG) pressure sensor was designed and synthesized from hydroxyl terminated polypropylene oxide oligomers, toluene diisocyanate (TDI), 1,4-butandiol as chain extender, catalyzer, foam agent and foam stabilizer. The testing results show that the Young’s modulus, Poisson’ ratio of the packaging polymer are 9.0×10⁶ N?m^-2 and 0.49 respectively. The static pressure sensitivity of fiber optical Bragg gratings packaged by PP-1 was discussed. The theoretical pressure sensitivity of FBG packaged with the polymer cylinder is -1.73×10^-3 MPa^-1, which is 896 times of that of the bare FBG(-1.93×10^-6 MPa^-1). And its measured pressure sensitivity is -1.10 10^－3 MPa^-1, which is 558 times of that of the bare FBG.