Structural Characterization,Vibrational Studies and Electrical Properties of 2-Amino-3-benzyloxy Pyridinium Perchlorate

A title organic-inorganic hybrid material 2-amino-3-benzyloxy pyridinium perchlorate was synthesized by slow evaporation at room temperature using 2-amino-3-benzyloxypyridine as the structure-directing agent. The structure of the title compound was determined by means of single-crystal X-ray diffraction at 293 K. The results show that this compound crystallizes in the centrosymetric monoclinic system with a space group of P2₁/n and lattice parameters of a=0.7025(5) nm, b=1.2635(5) nm, c=1.5766(5) nm, Z=4 and V=1.3905(2) nm³. The crystal structure has been determined and refined to R₁=0.0367 and wR₂=0.1022 using 2326 independent reflections and can be described as a succession of organic and inorganic layers parallel to the bc plane. In this arrangement, hydrogen bonds and van der Waals interactions between different species play an important role in the two-dimensional(2D) network cohesion. This compound was also characterized by means of infrared spectroscopy, Raman spectroscopy and thermogravimetric analysis-differential thermal analysis(TG-DTA). Moreover, protonic conduction of this compound determined by an impedance analyzer has been studied in the temperature range of 303-373 K.     

非线性边界条件下二阶奇异差分方程的正解

本文我们考虑如下二阶奇异差分边值问题\begin{equation*}\begin{cases}-\Delta^{2} u(t-1)=\lambda g(t)f(u) ,\ t\in [1,T]_\mathbb{Z},\\u(0)=0,\\ \Delta u(T)+c(u(T+1))u(T+1)=0,\end{cases}\end{equation*}正解的存在性. 其中, $\lambda>0$, $f:(0,\infty)\rightarrow \mathbb{R}$ 是连续的,且允许在~$0$ 处奇异.通过引入一个新的全连续算子, 我们建立正解的存在性.     

铂沉积对Ga2O3-SiO2纳米粒子光催化性能的提高（英文）

Ga2O3‐SiO2 nanoparticles were prepared by a sol‐gel method and Pt was then immobilized on their surface via photo‐assisted deposition (PAD). The produced samples were characterized using X‐ray diffraction (XRD), ultraviolet and visible spectroscopy, photoluminescence emission spectroscopy, and surface area measurements. The catalytic performances of the Ga2O3‐SiO2 and Pt/ Ga2O3‐SiO2 samples were evaluated for the degradation of cyanide using visible light. XRD and EDX results showed that the Pt was well dispersed within the Ga2O3‐SiO2 phase and was detected on the surface of the catalyst, which confirmed the successful loading of Pt ions by the PAD method. BET results revealed that the surface area of Ga2O3‐SiO2 was higher than that of Pt/Ga2O3‐SiO2 . 0.3 wt% Pt/Ga2O3‐SiO2 exhibited the highest photocatalytic activity for degradation of cyanide under visible light. The catalyst could be reused with no loss in activity for the first 10 cycles.     

易测量非球面定义及应用

本文提出了一种新型、易于用传统光学干涉仪测量的非球面。该非球面的检测主要基于Zemax光学程序软件设计的多重配置特性。第一配置为易于测量非球面,第二配置为采用平行平面玻璃板或单透镜作为零位校正器,用于检测第一配置的非球面。本文通过一些实例,说明了易测量非球面检测技术的应用和优势,证实了与圆锥或普通非球面相比,易测量非球面更易于操作与检测,同时有利于减小光学像差。     

浸渍硅胶薄层色谱板分离钴和镍及数字图像分析法定量(英文)

Thin layer chromatography(TLC) of cobalt and nickel has been performed on silica gel layers induced with alkali mediated cellulose extract.A novel combination of 10% aqueous solutions of Tween-20 and potassium thiocyanate in 1∶1(v/v) was identified as the best mobile phase for the selective separation of Co2+from Ni2+on the impregnated Silica Gel G layers.The chromatographic characteristics of the cations were studied and the limits of detection as well as the limits of quantification for Co2+and Ni2+were determined.The quantitative estimation of the cations was achieved from the digital image analysis of respective chromatograms.The proposed quantitative method was successfully applied with 0-0.50% error for the determination of Co2+from Ni2+in spiked samples of bauxite,soil and rock containing common cations such as Al3+,Fe2+,Ti4+,Zn2+,Mn2+,Cu2+,Cr6+,Mg2+,etc.under the optimized chromatographic conditions.     

Energy distribution of cosmic rays in the Earth’s atmosphere and avionic area using Monte Carlo codes

Cosmic rays cause significant damage to the electronic equipments of the aircrafts. In this paper, we have investigated the accumulation of the deposited energy of cosmic rays on the Earth’s atmosphere, especially in the aircraft area. In fact, if a high-energy neutron or proton interacts with a nanodevice having only a few atoms, this neutron or proton particle can change the nature of this device and destroy it. Our simulation based on Monte Carlo using Geant4 code shows that the deposited energy of neutron particles ranging between 200 MeV and 5 GeV are strongly concentrated in the region between 10 and 15 km from the sea level which is exactly the avionic area. However, the Bragg peak energy of proton particle is slightly localized above the avionic area.     

Unleashing a Microcomputer in the Laboratory, Part II Second in a series of three articles

This is the second article in a series discussing the use of the microcomputer in the laboratory. Part I examined the features of the PET* microcomputer which make it a useful partner in the laboratory. It showed how the microcomputer can be used to control four types of devices: (1) the devices which only require control signals, (2) the devices which talk only, (3) the devices which listen only, and (4) the devices which both talk and listen.     

Synthesis,characterization and evaluation of antidengue activity of enantiomeric Schiff bases derived from S-substituted dithiocarbazate

A series of Schiff bases have been successfully synthesized through the acid-catalyzed condensation of S-substituted dithiocarbazates and three enantiomerically pure monoterpenes, (1 R )-(+)-camphor, (1 S )-(-)-camphor, (1 R )-(-)-camphorquinone, (1 S )-(+)-camphorquinone, ( R )-(-)-carvone and ( S )-(+)-carvone. Spectroscopic results revealed that the Schiff bases containing camphor or carvone likely adopted an E -configuration along the characteristic imine bond while those containing camphorquinone assumed a Z -configuration. The antidengue potential of these compounds was evaluated based on DENV 2 caused cytopathic effect (CPE) reduction-based in vitro evaluation. The compounds were validated through secondary foci forming unit reduction assay (FFURA). Compounds were also tested for their cytotoxicity against Vero cells. The compounds showed variable degrees of antiviral activity with the camphor compounds displaying the highest antidengue potential. The enantiomers of the compounds behaved almost similarly during the antiviral evaluation.