Three Isomeric Chiral Metal-organic Frameworks Determined by Different Halogen Ions

Three isomeric metal-organic frameworks,[Cd2（X）（btc）（DMA）3]n（X = Cl（1）,Br（2）,I（3）,H3btc =1,3,5-benzenetricarboxylic acid and DMA = N,Nˊ-dimethylacetamide）,have been synthesized and characterized by elemental analysis,infrared spectra（IR）,thermogravimetric（TG） analyses and single-crystal X-ray diffraction.Single-crystal X-ray analysis reveals that compounds 1–3 crystallize in the orthorhombic P212121 space group,and feature a three-dimensional（3D） extended framework containing dinuclear [Cd2（COO）3] units as the secondary building units（SBUs）.Topological analysis reveals that compounds 1–3 can be simplified into a 3-connected srs topological network.     

Block Copolymer Supported Gold Nanoparticles Assemblies with Exposed Gold Surface

Polymer-involved nanoparticles or nanoparticle assemblies are now facing a crossroad, where the exposure of nanoparticle and multiple nanoparticles cannot be obtained at the same time. Therefore, a new series of nanoparticle clusters is synthesized, where multiple gold nanoparticles assemble with amphiphilic block copolymers supporting inside. The exposure of gold nanoparticles of the structure is confirmed and increases the reduction rate of 4-nitrophenol by 60%. The assemblies can also be used as surface enhanced Raman scattering(SERS) probes with an enhancement factor(EF) as high as 3×10³.     

泡沫铝负载钌基催化剂应用于N2O的低温催化分解研究

将导热性能良好的泡沫铝作为载体,羰基钌为前驱体制备了一系列不同形态的钌基催化剂应用于N2O的低温催化分解研究.采用XRD、XPS、SEM、TEM、BET、H2-TPR等方法对催化剂进行了表征,于石英管固定床反应器上对催化剂性能进行了评价.重点考察了泡沫铝作为催化剂载体的可行性、载体的处理方法对催化剂活性的影响以及RuO2、Ru、Ru3(CO)12所表现出的活性差异.结果表明:泡沫铝作为催化剂载体,能够促进N2O的催化分解;泡沫铝经H2O2处理有利于提高其对活性中心的附着力,提高催化活性;N2O浓度为1%,Ru负载量为0.3%,活性中心分别为Ru3(CO)12、Ru、RuO2时,N2O完全转化温度依次为285、380和415℃;活性较高的Ru3(CO)12/泡沫铝催化剂在长时间作用后活性组分转变为RuO2.     

褐煤中有机氮的赋存形态分布和分子结构特征

利用X射线光电子能谱(XPS)分析了先锋褐煤(XL)、小龙潭褐煤(XLT)和胜利褐煤(SL)及其萃取残渣表面有机氮的形态分布。结果表明,三种萃取残渣表面五种有机氮的含量分布各异,但均以吡咯型氮为主。考察了在300℃下Na OH催化的褐煤萃取残渣的超临界甲醇解反应,XL、XLT和SL萃取残渣超临界甲醇解所得石油醚可溶物的收率分别为46.0%、43.8%和47.6%(质量分数)。用傅里叶变换离子回旋共振质谱(FTICR/M S)分析石油醚可溶物中的含氮化合物(NCCs)。结果表明,NCCs主要包括N_1、N_1O_1-N_1O_5、N_2、N_2O_1-N_2O_4、N_3O_2和N_5O_2-N_5O_4类化合物。根据不饱和度和碳原子数的分布推测了NCCs的分子结构特征,表明绝大部分NCCs含羟基和羧基等含氧官能团,氮原子主要以吡咯、吡啶和氨基的形式存在于芳环结构中,以1-3个芳环的结构为主。褐煤中的-C-O-桥键的断裂是生成NCCs的一个重要路径。     

Comparison of Two Rhodamine-Polyamine Polystyrene Solid-phase Fluorescence Sensors for Hg(II) Detection Based on Theoretical Calculation

Two novel rhodamine-based polystyrene solid-phase fluorescence sensors PS-PA-I and PS-PA-II with different lengths of polyamines were synthesized for Hg(II) determination. The detection mechanism involving the Hg(II) chelation-induced spirocycle open of rhodamine was proposed with the aid of theoretical calculation. The stronger N-Hg bond and the longer polyamine chain in PS-PA-II led to a better selectivity, much higher and more quickly fluorescence response to Hg(II).     

Revisiting Chiral Extrapolation by Studying a Lattice Quark Propagator

The quark propagator in the Landau gauge is studied on the lattice, including the quenched and the unquenched results. No obvious unquenched effects are found by comparing the quenched quark propagator with the dynamical one. For the quenched and unquenched configurations, the results with different quark masses have been computed. For the quark mass function, a nonlinear chiral extrapolating behavior is found in the infrared region for both the quenched and dynamical results.     

Unquenched Effects and Quark Mass Dependence of Lattice Gluon Propagator in Infrared Region

In this paper, the gluon propagator in Landau gauge has been studied on a lattice, including the quenched and the unquenched one. The small geometry size of lattice we use is 16^3 × 32, and the big one is 20^3 × 64. For the quenched approximation, we fit the numerical results and give a little different fitting values. We also obtain unquenched effects by comparing the gluon propagator resulting from the quenched and unquenched configurations, for both the two-flavor and three-flavor cases. For the unquenched configurations, an obvious quark mass dependence has not been found in the small quark mass case, but is found in the three-flavor case when the quark mass is big.     

区域经济发展的属性模式识别模型

本将属性模式识别系统应用于区域经济发展优先级别的评价中。在建立评价指标体系的基础上。根据各指标的权重，提出确定区域经济发展中心的属性测度模型。并以黄河流域的12个大城市为样本，给出了一种比较科学的、切实可行的区域经济发展优先级别的评价方法。     

非水体系中哌啶在银电极表面的表面增强喇曼散射

本文测定了哌啶在甲醇溶液中吸附在银电极表面的表面增强喇曼散射(SERS)光谱,及其随电位的变化,同时还测定了电极经不同氧化-还原循环(ORC)预处理时的SERS谱,对所得结果进行了分析比较,并进一步研究了非水体系和水体系SERS谱之间的关系.实验结果表明:哌啶在甲醇体系中比在水体系中SERS谱的增强因子要小,并且它们的SERS谱线随电位的变化也有一定的差别.     

肌红蛋白在氧化镍纳米粒子中的固定及新型生物传感器的制备

研究了在氧化镍纳米粒子改性石墨电极(GE)上肌红蛋白(Mb)的直接电化学行为, 并制备了新型H2O2 传感器.在0.1 mol/L 磷酸盐缓冲溶液(PBS, pH 7.0)中, 肌红蛋白有稳定而明确的氧化还原峰,电子转移速率常数为6.48/s;式量电位为-0.34 V(vs·SCE), 表面覆盖量8.06×10-10 mol/cm2.二甲亚砜(DMSO)的存在对加速肌红蛋白分子与电极之间的电子传递起了重要作用.光谱分析表明: 固定在Mb/NiO/DMSO膜中肌红蛋白能保持其生物活性,对H2O2有电催化活性,电催化响应与H2O2浓度呈线性关系,线性范围为0.8～24 μmol/L;检出限为0.039 μmol/L. 对H2O2的表观米氏常数为0.21 mmol/L, 灵敏度为417 mA cm2 L/mol, 呈现出高亲和性.