Thermodynamics analysis of indium iodide polycrystal synthesis

According to the thermodynamics analysis, the molar enthalpy change, the molar entropy increase, the Gibbs free energy change and the balance constant of indium iodide polycrystal synthesis reaction were calculated in order to evaluate the feasibility of reaction temperature on 653 K. After the temperature 653 K was applied in the synthesis experiment, indium iodide polycrystal was successfully obtained by the two‐zone vapor transporting method. The result of X‐ray diffraction analysis indicates the temperature 653K can be used for indium iodide polycrystal synthesis.     

Purification and Characterization of Hyaluronate Lyase from <Emphasis Type="Italic">Arthrobacter globiformis</Emphasis> A152

A hyaluronate lyase was obtained by cultivating Arthrobacter globiformis strain A152. The enzyme was purified to homogeneity from the supernatant by ammonium sulfate fractionation, Q Sepharose Fast Flow, and Sephadex G-100 chromatography. The purification resulted in a 32.78-fold increase in hyaluronate lyase activity with specific activity of 297.2 U/mg. The molecular weight of the enzyme determined by SDS-PAGE was approximately 73.7 kDa. Using hyaluronic acid (HA) as a substrate, the maximal reaction rate (V_max) and the Michaelis–Menten constant (K_m) of hyaluronate lyase were found to be 4.76 μmol/min/ml and 0.11 mg/ml, respectively. The optimum pH and temperature values for hyaluronate lyase activity were pH 6.0 and 42 °C, respectively. This enzyme was stable at pH 4–10, 5–7, and 5–7 at 4, 37, and 42 °C, respectively. Investigation about temperature effects on hyaluronate lyase displayed that it was stable at 30–37 °C and also showed high activity at 37 °C. The enzymatic activity was enhanced by Ca²⁺ and was strongly inhibited by Cu²⁺ and SDS. These properties suggested that the hyaluronate lyase in this study could bring promising prospects in medical and industry applications.     

A new phosphine oxide host based on ortho-disubstituted dibenzofuran for efficient electrophosphorescence: towards high triplet state excited levels and excellent thermal, morphological and efficiency stability

An efficient host for blue and green electrophosphorescence, 4,6‐bis(diphenylphosphoryl)dibenzofuran ( o‐ DBFDPO ), with the structure of a short‐axis‐substituted dibenzofuran was designed and synthesised. It appears that the greater density of the diphenylphosphine oxide (DPPO) moieties in the short‐axis substitution configuration effectively restrains the intermolecular interactions, because only very weak π–π stacking interactions could be observed, with a centroid‐to‐centroid distance of 3.960 Å. The improved thermal stability of o‐ DBFDPO was corroborated by its very high glass transition temperature (T_g) of 191 °C, which is the result of the symmetric disubstitution structure. Photophysical investigation showed o‐ DBFDPO to be superior to the monosubstituted derivative, with a longer lifetime (1.95 ns) and a higher photoluminescent quantum efficiency (61 %). The lower first singlet state excited level (3.63 eV) of o‐ DBFDPO demonstrates the stronger polarisation effect attributable to the greater number of DPPO moieties. Simultaneously, an extremely high first triplet state excited level (T₁) of 3.16 eV is observed, demonstrating the tiny influence of short‐axis substitution on T₁. The improved carrier injection ability, which contributed to low driving voltages of blue‐ and green‐emitting phosphorescent organic light‐emitting diodes (PHOLEDs), was further confirmed by Gaussian calculation. Furthermore, the better thermal and morphological properties of o ‐DBFDPO and the matched frontier molecular orbital (FMO) levels in the devices significantly reduced efficiency roll‐offs. Efficient blue and green electrophosphorescence based on the o ‐DBFDPO host was demonstrated.     

一类单圈T函数的判定

多项式函数作为一类密码学中常用的T-函数,其可逆性、周期性一直是相关研究中的重要问题.借助于2-adic整数的乘法公式,给出了T-函数p(x)=a0⊕a1x⊕…⊕adxd(mod2n)是单圈函数的充要条件.     

Absorption enhancement of ultrathin crystalline silicon solar cells with frequency upconversion nanosphere arrays

A design of ultrathin crystalline silicon solar cells patterned with α-NaEr_(0.2)Y_(0.8)F_4 upconversion nanosphere(NSs) arrays on the surface was proposed. The light trapping performance ofα-NaEr_(0.2)Y_(0.8)F_4 NSs with different ratios of sphere diameter to sphere pitch was systematically studied by COMSOL Multiphysics. The influence of different NS diameters and ratio to the average optical absorption of ultrathin crystalline silicon solar cell was calculated, as well as the short circuit current densities. The results show that the average optical absorption of solar cells with 2.33 μm silicon covered by α-NaEr_(0.2)Y_(0.8)F_4 NSs of 100 nm in diameter and 5.2 in ratio has improved by 8.5% compared to planar silicon solar cells with the same thickness of silicon. The light trapping performance of different thicknesses of silicon solar cells with the optimized configuration of NSs was also discussed. The results indicate that our structure enhances the light absorption. The presented model will be the basis for further simulations concerning frequency upconversion of α-NaEr_(0.2)Y_(0.8)F_4 materials.     

A novel immunoassay based on the dissociation of immunocomplex and fluorescence quenching by gold nanoparticles

This study reports a novel, simple and sensitive immunoassay using fluorescence quenching caused by gold nanoparticles coated with antibody. The method is based on a non-competitive heterogeneous immunoassay of human IgG conducted by the typical procedure of sandwich immunocomplex formation. Goat anti-human IgG was first adsorbed on polystyrene microwells, and human IgG analyte was captured by the primary antibody and then sandwiched by antibody labeled with gold nanoparticles. The sandwich-type immunocomplex was subsequently dissociated by the mixed solution of sodium hydroxide and trisodium citrate, the solution obtained, which contains gold nanoparticles coated with antibody, was used to quench fluorescence. The fluorescence intensity of fluorescein at 517 nm was inversely proportional to the logarithm of the concentration of human IgG in the dynamic range of 10-5000 ng mL⁻¹ with a detection limit of 4.7 ng mL⁻¹. The electrochemical experiments and the UV-vis measurements were applied to demonstrate whether the immunoglod was dissociated completely and whether the gold nanoparticles aggregated after being dissociated, respectively. The proposed system can be extended to detect target molecules such as other kinds of antigen and DNA strands, and has broad potential applications in disease diagnosis.     

ZrO2晶相对ZnO/ZrO2+SAPO-34双功能催化剂上合成气制烯烃反应的影响

烯烃是重要的化工原料,目前主要通过石油催化裂化得到.随着石油资源的消耗以及人们对烯烃需求的日益增长,开发非石油路线制取烯烃势在必行.合成气可以从煤、天然气和生物质等获得,由合成气作为重要的C1平台分子一步制取烯烃(STO)的过程受到了广泛关注.将合成气制甲醇/二甲醚的金属催化剂与甲醇制烯烃的分子筛催化剂耦合得到的混合双...