点删除下的图的$A_\alpha$特征值的交错性

设$G$为具有顶点集$V$, 边集$E$的简单图, 本文给出了图$G$与其子图$G-U$的$A_\alpha$特征值的交错不等式, 其中$U\subset V$. 作为应用, 我们利用该交错不等式导出了一些关于图的独立数, 点覆盖数, 哈密尔顿性及支撑数的$A_\alpha$ 谱条件.     

点星网与度量空间的映像

拓扑空间X的覆盖列{P_i}_(i∈N)被称为空间X的点星网,若x∈X,则{st(x,P_i)}_(i∈N)是x在X中的网.本文刻画具有cs有限cs覆盖列的点星网的空间,并将其表示为度量空间在确定映射下的像.在假设集族性质β满足适当的条件下,证明对拓扑空间X下述条件相互等价:(1) X具有β且cs覆盖列的点星网.(2)X具有β且sn覆盖列的点星网.(3)X是Cauchy sn对称空间且具有σ-β的cs网.(4) X是Cauchy sn对称空间且具有σ-β的sn网.(5) X是度量空间的序列覆盖、π且σ-β映像.(6) X是度量空间的1序列覆盖、紧且σ-β映像.这些工作以局部有限集族与点有限集族为特例,拓展了从基到cs网的研究,丰富了映射与空间的相互分类思想.     

脂质体封端CsPbX3(X=Cl,Br,I)纳米晶体的制备及在发光二极管中的应用

以脂质体充当表面封端配体修饰合成后的CsPbX₃纳米晶体.封端CsPbX₃纳米晶能保持原始形状和粒径大小,相对量子产率提升至（100±3）%,发射光谱在411~626 nm范围内可调.将其存储于空气（温度25℃,相对湿度50%）中150 d仍保持立方晶型.以DOPC-CsPbBr₃为颜色转换器可制造显色指数高达91.2的白色发光二极管,应用前景广阔.     

Facile Synthesis and Properties of UiO-66 Electrode Material for Supercapacitors

A block-like metal-organic framework UiO-66 was prepared by in-situ growth one-pot hydrothermal process. The as-synthesized material was characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The electrochemical properties used as a supercapacitor electrode material were evaluated by cyclic voltammetry(CV), galvanostatic charge-discharge measurement(GCD) and electrochemical impedance spectroscopy(EIS) in 2 M KOH solution, exhibiting a high specific capacitance(311 F·g~(-1) at 1 A·g~(-1)), suggesting its promising potential as a supercapacitor electrode material.     

Co_3O_4/reduced Graphene Oxide Composite as An Enhanced Material for Electrochemical Detection of Paracetamol in Human Serum

In this paper, we present a novel, reliable and sensitive electrochemical sensor for the determination of paracetamol based on hollow carbon Co_3O_4 nanosheets/reduced graphene oxide composite(Co_3O_4/r-GO). The Co_3O_4/r-GO was prepared via a rapid one-step microwave solvothermal process. Some series of techniques that included scanning electron microscopy, X-ray diffraction and Raman were carried out to characterize the morphology and structure of as-prepared materials. Most importantly, the developed electrochemical sensor exhibited a wide linear range of 0.05 to 900.0 μM and a low detection limit of 14.0 nM(S/N = 3) by using differential pulse voltammetry. Furthermore, the selectivity, repeatability, stability and practical applicability were further studied with satisfactory results.     

氮、铁共掺杂碳纳米粒子的制备及在过氧化氢和葡萄糖检测中的应用

以L-酒石酸和一水柠檬酸为混合碳源,以乙二胺为氮源和聚合试剂,并添加六水三氯化铁,通过一锅溶剂热法合成了氮、铁共掺杂碳纳米粒子(N/Fe-CNPs),采用制备的N/Fe-CNPs模拟过氧化物酶催化过氧化氢(H₂O₂)氧化3,3',5,5'-四甲基 产生可溶性的蓝色产物,联合葡萄糖氧化酶建立了测定H₂O₂和葡萄糖含量的新方法。 结果显示:H₂O₂及葡萄糖的浓度与反应体系的吸光度呈良好的线性关系,H₂O₂的线性范围为0.2~20 μmol/L,葡萄糖的线性范围为0.1~1.0及1.0~80 μmol/L,最低检出限分别可达42.5和76.1 nmol/L。     

丝素蛋白/TiO2复合催化剂的制备及其可见光催化性能

通过溶胶-凝胶法制备了不同掺杂量的丝素蛋白/TiO2复合纳米材料,并研究了其可见光催化活性.用粒度分析、X射线衍射(XRD)、紫外-可见漫反射光谱(UV-Vis-DRS)、平带电位、Zeta-电位、元素分析等方法表征了所制备的催化剂样品.结果显示,在可见光照射下,反应2 h时,丝素蛋白/TiO2-400℃的Cr(VI)光催化还原效率达36%,甲酸降解效率达3.4%;相对纯TiO2,丝素蛋白/TiO2的可见光吸收能力均有提高,以丝素蛋白/TiO2-400℃的增幅最大;相对纯TiO2,丝素蛋白/TiO2的平带电位均有不同程度负移,这意味着光生电子有了更强的还原能力;TiO2-400℃、素蛋白/TiO2-300℃、丝素蛋白/TiO2-400℃、丝素蛋白/TiO2-500℃的Zeta-电位值分别为29、31、36、33 mV,说明丝素蛋白/TiO2-400℃在水中形成的溶胶系统分散程度最高.     

Theoretical IR,Raman and NMR spectra of 1,2- and 1,3-dimethylenecyclobutane

Equilibrium geometries, rotational constants, harmonic vibrational frequencies, infrared intensities, Raman activities, and ¹H and ¹³C NMR spectra were calculated for 1,2-dimethylenecyclobutane and its less stable isomer 1,3-dimethylenecyclobutane by using MP2, DFT (B3PW91), and RHF theoretical methods involving the 6-311++G⁷ basis set.The properties calculated theoretically have been compared with the experimental values. The internal coordinates defined for both isomers were used in the potential energy distribution (PED) analysis. The theoretical vibrational and NMR spectra form the basis to differentiate particular compounds in reaction mixture.