Adsorption of U(VI) ions from low concentration uranium solution by thermally activated sodium feldspar

The thermally activated sodium feldspar (TASF), a novel material, was prepared by calcinating the micron sodium feldspar (SF) at 450 °C for 45 min. The TASF and the SF were characterized using X-ray diffraction and mercury injection porosimetry, and the TASF was found to have larger specific surface area and larger porosity than SF. The effects of the initial pH, temperature, contact time and initial U(VI) ions concentration on the adsorption of U(VI) ions from the low concentration uranium solution by TASF were investigated. The maximum adsorption efficiency of TASF for 0.5 mg/L uranium solution amounted to 95.49 % when the initial pH was 5.0, the temperature, 318 K, and and the contact time, 600 min. The relationship between the adsorption capacity q _e and equilibrium concentration C _e can well be described by Freundlich equation. Adsorption isotherm and the analysis by FT-IR coupled with SEM revealed that U(VI) ions were adsorbed onto the surface of TASF in multimolecular or cluster states, and that the intraparticle diffusion occurred in spontaneous process. The basic thermodynamic parameters including free energy change, entropy change and enthalpy change were calculated to comprehend the intrinsic features and spontaneous nature of the adsorption process. The FT-IR spectroscopic characterization for the TASF indicated that many groups were involved in the adsorption process of U(VI) ions, and the –OH group played a more important role. The experimental results suggested that TASF had great adsorption efficiency and strong potentiality of enrichment and recovery for the low concentration U(VI).     

基于多重氢键组装的双杯冠合成及对铯离子的络合

合成了一种基于多重氧键组装形成的新型双杯冠化合物,利用核磁共振氢谱(1H NMR)和碳谱(13C NMR)以及高分辨质谱(ESI-HRMS)对组装前体分子结构进行了表征.通过一维和二维核磁共振氢谱(2D NOESY)研究了该双杯冠的的自组装结构,并采用核磁共振和紫外-可见光谱的方法测定了其对铯离子的络合.实验表明,通过氢键组装形成的双杯冠化合物,由于阻止了单杯冠分子内组装而限制了冠醚环构象改变,其萃取率由单杯冠的82％提高到96％.     

Synthesis of gold nanoplates by aspartate reduction of gold chloride

Single crystal nanoplates with thickness less than 30 nm, characterized by hexagonal and truncated triangular shapes bounded mainly by [111] facets, were obtained in large quantities by aspartate reduction of gold chloride.     

Glycerol-Assisted Hydrophobic Interaction Chromatography Improving Refolding of Recombinant Human Granulocyte Colony-Stimulating Factor

Efficient refolding of recombinant proteins in the forms of inclusion bodies at higher concentration remains challenging. Here, we report a strategy of a dual-gradient hydrophobic interaction chromatography (HIC) mode to refold recombinant human granulocyte colony-stimulating factor from its inclusion bodies at high protein concentration. The strategy was taken to meet the demand of dynamic refolding proceeding by gradually decrease the denaturant (guanidine-HCl) concentration and gradually increase the hydrophilicity of media (column of Poros PE 20) with glycerol as additive to provide a mild refolding surroundings. Compared with dilution method, this dual-gradient HIC process gave about 8.5-fold of increase in specific activity and 30% increase in soluble protein recovery. Furthermore, much higher protein concentration could be obtained at the same time.     

α带小波紧框架的显式构造方法

文中研究了对应于α-带尺度函数的小波紧框架,这个小波紧框架是由V₁中的n个函数ψ¹,ψ²,...,ψⁿ构成. 首先给出了这n个函数构成小波紧框架的充分条件, 并借助尺度函数给出了构造小波紧框架的显式公式. 如果尺度函数的符号是有理函数,则可以构造出符号为有理函数的小波紧框架. 其次给出类似于正交小波的小波紧框架的分解与重构算法,并构造了小波紧框架的数值算例.     

Design of compactly supported trivariate orthogonal wavelets

In this paper, a method is developed for constructing compactly supported trivariate orthogonal wavelets from univariate orthogonal wavelets, essential idea of the approach is permutation of conjugate quadrature filter. Nonseparable and separable wavelets can be achieved from univariate orthogonal wavelets. Two examples are given to demonstrate this method.     

Fabrication and optical property of silicon oxide layer coated semiconductor gallium nitride nanowires

Quasi one-dimensional GaN-SiO(2) nanostructures, with a silicon oxide layer coated on semiconductor GaN nanowires, were successfully synthesized through as-synthesized SiO(2) nanoparticles-assisted reaction. The experimental results indicate that the nanostructure consists of single-crystalline wurtzite GaN nanowire core, an amorphous SiO(2) outer shell separated in the radial direction. These quasi one-dimensional nanowires have the diameters of a few tens of nanometers and lengths up to several hundreds of micrometers. The photoluminescence spectrum of the GaN-SiO(2) nanostructures consists of one broad blue-light emission peak at 480 nm and another weak UV emission peak at 345 nm. The novel method, which may results in high yield and high reproducibility, is demonstrated to be a unique technique for producing nanostructures with controlled morphology.     

Highly-efficient photosensitizer based on AIEgen-decorated porphyrin for protein photocleaving

An AIEgen decorated porphyrin (TPETPyP) with ¹O₂ quantun yield as high as 0.85 in PBS was facilely prepared through a simple one-step reaction for efficient photocleavage of proteins in PDT.     

具有低SO_2氧化活性的Pt/Zr_xTi_(1-x)O_2柴油车氧化催化剂的制备及性能

采用共沉淀法制备了一系列ZrxTi1-xO2(x=0.0,0.1,0.5,0.9,1.0)复合氧化物,并以此为载体,用等孔体积浸渍H2PtCl6制得Pt/ZrxTi1-xO2柴油车氧化催化剂.运用N2吸附-脱附,X射线多晶粉末衍射,X射线光电子能谱,H2程序升温还原和NH3程序升温脱附等手段对催化剂进行了表征.结果表明,在系列催化剂样品中,Zr0.1Ti0.9O2复合氧化物主要以锐钛矿形式存在,具有较好的织构性能,样品的比表面积达94m2/g,孔体积为0.33cm3/g.相应地,Pt/Zr0.1Ti0.9O2催化剂表现出优异的催化氧化性能,HC和CO的起燃温度(T50)分别为185和174oC,完全转化温度(T90)分别为197和201oC;且具有较低的SO2氧化活性,350oC时SO2仅转化25.5%.