Fuzzy Linear Programming Approach for Solving Fuzzy Transportation Problems with Transshipment

To find the fuzzy optimal solution of fuzzy transportation problems it is assumed that the direct route between a source and a destination is a minimum-cost route. However, in actual application, the minimum-cost route is not known a priori. In fact, the minimum-cost route from one source to another destination may well pass through another source first. In this paper, a new method is proposed to find the fuzzy optimal solution of fuzzy transportation problems with the following transshipment: (1) From a source to any another source, (2) from a destination to another destination, and (3) from a destination to any source. In the proposed method all the parameters are represented by trapezoidal fuzzy numbers. To illustrate the proposed method a fuzzy transportation problem with transshipment is solved. The proposed method is easy to understand and to apply for finding the fuzzy optimal solution of fuzzy transportation problems with transshipment occurring in real life situations.     

New Polymer‐Supported Mono‐ and Bis‐Cinchona Alkaloid Derivatives: Synthesis and Use in Asymmetric Organocatalyzed Reactions

The straightforward synthesis of polystyrene‐supported Chinchona alkaloids and their application in the asymmetric dimerization of ketenes is reported. Six different immobilized derivatives, consisting of three dimeric and two monomeric 9‐O ethers, were prepared by “click” anchoring of soluble alkaloid precursors on to azidomethyl resins. The resulting insoluble polymer‐bound (IPB) organocatalysts were employed for promoting the dimerization of in‐situ generated ketenes. After opening of the ketene dimer intermediates with N,O‐dimethylhydroxylamine, valuable Weinreb amides were eventually obtained in good yield (up to 81 %) and excellent enantiomeric purity (up to 96 % ee). All of the IPB catalysts could be recycled effectively without significant loss of activity and enantioselectivity. The extension to other asymmetric transformations (meso‐anhydride desymmetrization and α‐amination of 2‐oxindoles) is also briefly discussed.     

Ring closing and opening reactions leading to aza-polycyclic aromatic compounds

A series of functionalized aza-polycyclic aromatic compounds were prepared by a superacid-promoted ring closing and opening reaction cascade. A reaction mechanism is proposed, which involves reactive dicationic intermediates. A key step in the conversions involves ipso protonation of an aryl group and elimination of an alkyl phenyl group.     

An Efficient Inclusion Complex Based Fluorescent Sensor for Mercury (II) and its Application in Live-Cell Imaging

Journal of Fluorescence - The formation of an inclusion complex between hydroxypropyl-β-cyclodextrin (H-CD) and 4-acetylphenyl-4-(((6-chlorobenzo[d]thiazol-2-yl)-imino)-methyl)-benzoate (L)...     

石墨烯氢氧化钴复合催化剂的一步合成及其对酸性橙的催化降解(英文)

用一步合成自组装法制备出了氢氧化钴与还原氧化石墨烯(Co(OH)2/rGO)的复合催化剂,并将其用于水中染料的催化降解实验.通过X射线衍射(XRD),激光拉曼(Raman)光谱,透射电镜(TEM),X射线能量色散谱(EDS)以及X射线光电子能谱(XPS)等一系列分析手段对催化剂的结构形貌进行了详细的表征,表征结果证实氢氧化钴很好地附着在还原石墨烯的表面.最后初步考察了催化剂催化单过硫酸钾(PMS)降解酸性橙(AO7)的性能.结果表明,催化剂显示出了高效的催化性能,酸性橙的色度可在12 min内完全去除,总有机碳(TOC)实验也表明染料降解的同时也可获得较高的矿化度.循环稳定性实验表明在进行到第三次实验时,催化剂仍能保持高的催化活性,将酸性橙在16 min内降解完毕.     

Low temperature deposition of SrS:Cu,F ACTFEL device by electron beam evaporation

Photoluminescence (PL) and electroluminescence (EL) of SrS:Cu,F alternating current thin film electroluminescent (ACTFEL) device prepared by electron beam/thermal multi-source evaporation are presented. The active layer was grown at 380 °C and neither post-deposition annealing nor sulphur co-evaporation was performed. Two bands at 380 and 435 nm were present in the PL spectrum, which are suggested to be due to donor acceptor recombination. EL spectrum consisted of an additional band at 535 nm, which is attributed to Cu⁺ intracenter emission. The device exhibited yellowish white EL emission with chromaticity coordinates x=0.25, y=0.27 and low threshold voltage.     

Green Emitting Cerium Doped CaS Whiskers Grown by Solid State Diffusion Method

Undoped and cerium doped Calcium sulfide (CaS) phosphors were synthesized using solid state diffusion method. The X-ray diffraction pattern revealed that both undoped and doped CaS crystallites have cubic structure with average crystallite size varying from 20 to 30 nm. Scanning electron micrographs indicated that Ce doped CaS phosphors were composed of whiskers with different dimensions and orientations. The optical properties of undoped and Ce doped particles were characterized using Photoluminescence (PL) and UV-Vis absorption spectroscopy. The PL emission spectrum of cerium doped CaS phosphors for an excitation wavelength 465 nm showed a main peak at 500 nm and a shoulder peak at 556 nm due to 5d?→?4f transition in Ce³⁺ ions. The variation of PL intensity with cerium concentration was investigated and the maximum PL intensity was obtained for a doping concentration of 3 wt.%. The optical band gap of the samples was estimated from the diffuse reflectance spectrum and was found to increase with increase in cerium concentration. The enhanced optical properties of these phosphors can be exploited in various optoelectronic devices including displays and bioimaging techniques.