化学探头法与荧光光谱法测定水中溶解氧量

探讨了化学探头法和荧光光谱法测定水中溶解氧的关系。分别用F检验和t检验对两组数据进行了比较,结果表明两组数据的精密度和系统误差都没有显著差异,两种方法测定溶解氧的相对标准偏差(RSD,n=9)分别为0.35%,0.33%。进而又探讨了溶解氧与NaCl含量、温度之间的关系,结果表明溶解氧含量随NaCl含量的增加、温度的升高而逐渐降低。     

Disjoint hypercyclic powers of weighted translations on groups

Let G be a locally compact group and let 1 ≤ p < 1. Recently, Chen et al. characterized hypercyclic, supercyclic and chaotic weighted translations on locally compact groups and their homogeneous spaces. There has been an increasing interest in studying the disjoint hypercyclicity acting on various spaces of holomorphic functions. In this note, we will study disjoint hypercyclic and disjoint supercyclic powers of weighted translation operators on the Lebesgue space L ^p(G) in terms of the weights. Sufficient and necessary conditions for disjoint hypercyclic and disjoint supercyclic powers of weighted translations generated by aperiodic elements on groups will be given.     

光触发自修复聚合物研究进展

近几年,由于光触发自修复聚合物具有可控快速等优势,其在自修复聚合物领域中占据了重要的地位。光触发自修复聚合物实现自修复的方法主要分为3类,分别是基于光交联反应的自修复、基于光触发交换反应的自修复和基于光热效应的自修复。本文主要从光触发自修复聚合物的修复机制以及修复过程中涉及的化学本质两个方面,重点阐述了上述3类光触发自修复方法的最新研究进展,强调3种光触发自修复之间的联系和共同点。同时,对光触发自修复聚合物未来的发展前景进行了展望。     

沉淀分离-电感耦合等离子体原子发射光谱(ICP-AES)法测定银铜合金中的磷

建立了沉淀分离银、铜,电感耦合等离子体原子发射光谱(ICP-AES)法测定银铜合金中微量磷的分析方法。重点研究了氯化银沉淀分离银和硫化铜沉淀分离铜的条件,以及ICP-AES法测定磷的工作条件和谱线选择。结果表明,沉淀分离后[Ag~+]0.1mg/L,[Cu~(2+)]1mg/L,Cu的干扰可以忽略;仪器功率1.3kW时,分析线P 213.617nm时,方法的检出限0.076mg/L;测定银铜合金中0.00092%~0.0032%的磷含量,相对标准偏差5.3%~1.7%(n=7),样品加标回收率94.4%~103%,方法简便、快速,已应用于实际生产中。     

Porous nitrogen-doped graphene for high energy density supercapacitors in an ionic liquid electrolyte

Porous nitrogen-doped graphene (PNG) has been prepared via simple thermal treatment of graphene oxide and urea, and the morphology and structure of the PNG have been characterized by using a range of electron microscopy, X-ray photoelectron spectroscopy, and other techniques. The electrochemical performances of the PNG have been investigated in an ionic liquid electrolyte by cyclic voltammetry and galvanostatic charge-discharge via both three-electrode and two-electrode configurations. The PNG electrode delivers a specific capacitance of 310 F g^?1 at 1 A g^?1 with good cycling stability over 4000 cycles. The high electrochemical performance is ascribed to the porous structure and nitrogen-doping in the PNG. The porous structure enables high specific surface area and rapid ion mobility, contributing to double layer capacitance, while the N-doping enhances electrochemical activity and electric conductivity, contributing to pseudocapacitance. Meanwhile, the ionic liquid electrolyte enables a very wide working voltage of 3 V, leading to a high energy density up to 163.8 W h kg^?1. The fabricated supercapacitor can light up a LED for a long while with low self-discharge, showing good potential for practical application.     

TiO2/BiVO4, a Heterojuncted Microfiber with Enhanced Photocatalytic Performance for Methylene Blue under Visible Light Irradiation

Novel TiO₂/BiVO₄ microfiber heterojunctions were constructed using cotton as biomorphic templates. The as-synthesized samples were characterized by scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectra and photocatalytic experiment. The morphology of the as-synthesized TiO₂/BiVO₄ composites was consisted of a large quantity of microfiber structures with diameter from 2.5 μm to 5 μm, and the surface of samples became more coarse and compact with the increase of weight ratio of TiO₂. The TiO₂/BiVO₄ samples with proper content (10.00wt%) showed the highest pho-tocatalytic degradation activity for methylene blue (MB) degradation among all the samples under visible light, and 88.58%MB could be degraded within 150 min. The enhancement of photocatalytic activity was mainly attributed to the formation of n-n heterojunction at the contact interface of TiO₂ and BiVO₄, which not only narrowed the band gap of BiVO₄ for extending the absorption range of visible light, but also promoted the transfer of charge carriers across interface. A possible photodegradation mechanism of MB in the presence of TiO₂/BiVO₄ microfibrous photocatalyst was proposed.     

经典N=2李共形超代数的导子和第二上同调群

研究了经典N=2李共形超代数的导子和第二上同调群的结构,并应用第二上同调群的结果确定了该李共形超代数的泛中心扩张.     

解析Sobolev型空间上的算子与算子代数

介绍Hardy-Sobolev空间和Fock空间及其算子与算子代数研究方面所做的工作,包括对这两类空间上几类特殊算子有界性、紧性、Fredholm性、指标理论、谱和本性谱、范数和本性范数、Schatten-p类的讨论,以及由它们所生成的C~*-代数的研究.     

一类特殊的Koszul Calabi-Yau DG代数

假设一个连通上链DG代数A的基分次代数A~#或者同调分次代数H(A)是由一次元素x,y生成的代数kx,y/(xy+yx).本文证明A是Koszul Calabi-Yau DG代数.     

李color三系的Frattini子系的性质

给出了李color三系的Frattini子系的定义,得到了李color三系的Frattini子系的一些性质·特别的,证明了李color三系T有分解T=T_1⊕T_2⊕…⊕T_m,则φ(T)有分解φ(T)=φ(T_1)⊕φ(T_2)⊕…⊕φ(T_m).