The study of lithium fast ion conductors of Li3xLa0.67−xScyTi1−2yNbyO3 system

Perovskite-type lithium fast ion conductors of Li_3xLa_0.67−xSc_yTi_1−2yNb_yO₃ system were prepared by solid state reaction. X-Ray powder diffraction shows that perovskite solid solution form in the ranges of x=0.10, y≤0.10. AC impedance measurements indicate that the bulk conductivities and the total conductivities are of the order of 10⁻⁴ S·cm⁻¹ and 10⁻⁵ S·cm⁻¹ at 25 °C respectively. The compositions have low bulk activation energies of about 17 kJ/mol in the temperature ranges of 298 – 523 K and total activation energies of about 37 kJ/mol in the temperature ranges of 298 – 523 K.     

Continuous preparation of decorated nano zinc oxide organic sols with intense luminescence

A sort of decorated nano ZnO organic sols have been successively prepared by pulsed laser ablation at the interface of ZnO target and a flowing liquid containing polymers. It is found that the decorated nano ZnO ethanol sols, the decorated nano ZnO-PS (polystyrene) cyclohexane sols and the decorated nano ZnO-PMMA (polymethyl methacrylate) ethyl butyrate sols all have strong fluorescence emission at 329 nm and 411 nm, 308 nm and 317 nm, and at 330 nm and 400 nm, respectively. The results show the decorating for nano ZnO will intensely affect their luminescence, and the wavelength and intensity of luminescence can be adjusted or controlled by the different decoration.     

STUDIES ON cis-trans-ISOMERIZATION AND REACTION KINETICS OF A μ, η~2-VINYL LIGAND IN A TRIOSMIUM CLUSTER

The dihydride cluster H_2O_(s_3)(CO)_(10) reacts with ethyne to give a cis-adduct [O_(s_3)H(μ,η~2-CH=CH_2)(CO)_(10)]. The high deuterated cluster D_2O_(s_3)(CO)_(10), the reaction of D_2O_(s_3)(CO)_(10)with ethyne C_2H_2 to form the vinyl product cluster [O_(s_3)D(μ, η~2-CH=CHD)(CO)_(10)], and thereaction of H_2O_(s_3)(CO)_(10) with the deuterated ethyne C_2D_2 to form [O_(s_3)H(μ,η~2-CD=CDH)(CO)_(10)] have been reported primarily in this paper. The two cis-adducts undergo cis-trans-isomerization of μ,η~2-vinyl ligands under a small amount of the nucleophile pyridine. Usingthe combination of deuteration and dynamic ~1H,~2H NMR spectra, we report the experimen-tal evidence determined by the dynamic ~1H, ~2H NMR spectra, mechanism, and kinetic dataof the isomerization.     

Simultaneous two color image capture for sub-diffraction localization fluorescence microscopy

A sub-diffraction limit fluorescence localization microscope was constructed using a standard cooled 1.4 mega-pixel fluorescence charge-coupled device (CCD) camera to simultaneously resolve closely adjacent paired quantum dots on a flat surface with emissions of 540 and 630 nm. The images of the overlapping Airy discs were analyzed to determine the center of the point spread function after noise reduction using Fourier transformation analysis. The Cartesian coordinates of the centers of the point spread functions were compared in serial images. Histograms constructed from serial images fit well to Gaussian functions for resolving two quantum dots separated by as little as 10 nm in the x–y coordinates. Statistical analysis of multiple pairs validated discrimination of inter-fluorophore distances that vary by 10 nm. The method is simple and developed for x–y resolution of dilute fluorophores on a flat surface, not serial z sectioning.     

液相色谱-离子阱质谱法测定香菇中的核苷酸

采用液相色谱-电喷雾串联质谱法检测香菇中核苷酸。流动相为甲醇和0.1%甲酸溶液,采用梯度洗脱程序,色谱柱为Zorbax XDB-C18（150×2.0mmid,5μm）,流速为0.2mL·min-1。以准分子离子和二级碎片离子对样品中4种核苷酸进行定性和定量,方法的检测限分别为0.500、0.050、0.020、0.010μg/g,相关系数分别为0.9952、0.9967、0.9935、0.9987,相对标准偏差范围为3.25%—9.45%,样品的回收率为78.2%—115.3%。该法快速、灵敏度高、重现性好。     

Graphitization of activated carbon under high pressures and high temperatures

Activated carbon was treated at 5.0 GPa up to 1600 ^°C and the structural evolution in the graphitization process was investigated. The graphitization temperature is reduced to 1200 ^°C at 5 GPa, as reflected by x-ray diffraction patterns. Honeycomb-like structures come into being in the high-pressure sintering temperature range of 1000–1100 ^°C and slice-like structures appear after graphitization. Raman frequency and half width drop drastically near the graphitization temperature, and the appearance of D and D′ lines indicates there are still some disorder structures in the graphitized activated carbon.     

Enhanced electrochemical properties of LiMnPO4/C via doping with Cu

Li_0.98Cu_0.01MnPO₄/C composite cathode materials for lithium ion battery are synthesized by sol-gel method followed by heat treatment in the air. Field-emission scanning electron microscopy measurements show that both firing temperature and carbon content affect the morphology of the end products. X-ray powder diffraction analysis indicates that the samples are olivine-structured. The galvanostatic charge?Cdischarge results show that the optimal firing temperature registers 500°C and that the electrochemical performances of Li_0.98Cu_0.01MnPO₄/C are improved by elevating its carbon amount. The cyclic ability and rate performances of LiMnPO₄ are greatly improved by doping Cu.     

Diode-pumped Q-switched and mode-locked Nd:Gd0.3Lu0.33Y0.37VO4 laser with EO modulator and single-walled carbon nanotube

By using both the single-walled carbon nanotube saturable absorber (SWCNT-SA) and the electro-optic (EO) modulator, the stably doubly Q-switched and mode-locked (QML) operation of Nd:Gd_0.3Lu_0.33Y_0.37VO₄ laser has been demonstrated. The QML laser characteristics such as the pulse width, single-pulse energy, etc., have been measured for different modulation frequencies of the EO modulator (f_e) and reflectivity (R) of output coupler. In comparison with the solely passively QML laser with SWCNT-SA, the experimental results show that the doubly QML laser can generate more stable and shorter pulses with higher pulse energy. At 9.24 W pump power, f_e=1 kHz and R=93.5%, the doubly QML laser has compressed the Q-switched envelope pulse width 88% and improved the mode-locked pulsed energy 55 times.     

Simultaneous chromatic dispersion monitoring,extinction ratio enhancement and wavelength conversion using four-wave mixing

This paper presents a multi-functional all-optical device performs simultaneous chromatic dispersion (CD) monitoring, extinction ratio (ER) improvement and tunable wavelength conversion using four-wave mixing (FWM) in a single piece of highly nonlinear optical fiber (HNLF). The multi-functional ability arises from the nonlinear power transfer function (PTF) between the input signal and the output idler wave, which not only maps the CD information of the signal onto the average power of idler wave, but also transfers the data information to the idler wave with ER enhancement, making the device compact and cost effective. Furthermore within the wavelength tuning range the monitoring sensitivity and output ER can be much higher compared to all optical monitors and regenerators proposed before. Numerical simulations are then used to demonstrate the efficiency of this method.