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81.
Michael John Klink Neelan Laloo Anny Leudjo Taka Vusumzi Emmanuel Pakade Mzimkhulu Ephraim Monapathi Johannes Sekomeng Modise 《Molecules (Basel, Switzerland)》2022,27(11)
The disinfection of wastewater using nanoparticles (NPs) has become a focal area of research in water treatment. In this study, zinc oxide (ZnO) NPs were synthesized using the microwave heating crystallization technique and characterized using transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Qualitative well diffusion and quantitative minimum inhibitory concentration (MIC) tests were conducted to determine the antimicrobial activity of ZnO NPs against selected waterborne pathogenic microbes. FTIR spectral studies confirmed that the binding of urea with Zn occurs through Zn–O stretching. XRD confirmed the crystallized identity in a hexagonal ZnO wurtzite-type structure. The formation of zones of inhibition and low MIC values in the antimicrobial analysis were indicative of the effective antimicrobial activity of zinc oxide nanoparticles against the test microorganisms. The application of metallic nanoparticles in water treatment could curb the spread of waterborne microbial diseases. 相似文献
82.
Asami Yoshii Yuzuka Onaka Koki Ikemoto Tomoo Izumi Sota Sato Hiroshi Kita Hideo Taka Hiroyuki Isobe 《化学:亚洲杂志》2020,15(14):2181-2186
Oligo‐meta‐phenylenes have been designed and synthesized as multipotent base materials of single‐layer organic light‐emitting devices. Simple molecular structures of oligo‐meta‐phenylenes composed of linear phenylene arrays benefited from the wealth of modern reactions available for biaryl couplings and were concisely synthesized in a series. Structure‐performance relationship studies with the first seven congeners revealed key features important for the multipotent materials in single‐layer devices. As a result, highly efficient phosphorescent electroluminescence was made possible in a highly simplified device architecture comprising one‐region, single‐layer configurations. Detailed investigations with hole‐only devices disclosed that the hole mobility was effectively retarded by potent materials, which should facilitate hole/electron recombination for electroluminescence. 相似文献
83.
84.
85.
Setsuo Kashino Jun‐ichiro Taka Takeo Fukunaga Hiroyuki Ishida 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):549-552
A centrosymmetric and short O—H?O hydrogen bond was found in isomorphic crystals of potassium hydrogen trans‐glutaconate monohydrate (potassium hydrogen trans‐pent‐2‐ene‐1,5‐dioate, K+·C5H5O4?·H2O), (I), and rubidium hydrogen trans‐glutaconate monohydrate (rubidium hydrogen trans‐pent‐2‐ene‐1,5‐dioate, Rb+·C5H5O4?·H2O), (II). The O?O distance at room temperature is 2.444 (3) Å in (I), and 2.417 (4) Å in (II). The O?O distance for (I) showed no significant decrease at low temperatures. 相似文献
86.
87.
Summary
Conditions are given for the nonlinear differential equation (1)L
n
y+f(t, y, ..., ...,y
(n–1)=0to have solutions which exist on a given interval [t0, )and behave in some sense like specified solutions of the linear equation (2)L
n
z=0as t.The global nature of these results is unusual as compared to most theorems of this kind, which guarantee the existence of solutions of (1)only for sufficiently large t. The main theorem requires no assumptions regarding oscillation or nonoscillation of solutions of (2).A second theorem is specifically applicable to the situation where (2)is disconjugate on [t
0, ),and a corollary of the latter applies to the case where Lz=z
n. 相似文献
88.
Dong‐Feng Li Taka‐aki Okamura Wei‐Yin Sun Norikazu Ueyama Wen‐Xia Tang 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(5):m280-m282
The asymmetric unit of the three‐dimensional CuII–WIV polymeric assembly {[Cu(en)2][Cu(en)][W(CN)8]·4H2O}n (en is ethylenediamine, C2H8N2) or {[Cu2W(CN)8(C2H8N2)3]·4H2O}n, which can be named as polymeric bis(ethylenediamine)copper(II) (ethylenediamine)copper(II) octacyanotungstate(IV) tetrahydrate or penta‐μ‐cyano‐tricyanotris(ethylenediamine)dicopper(II)tungsten(IV) tetrahydrate, consists of two half [Cu(en)2]2+ cations (Cu2+ on inversion centres), a [Cu(en)]2+ cation and a [W(CN)8]4? ion, together with four water molecules. The latter CuII site is coordinated by five N atoms from an en ligand and by three cyanides in a distorted square‐pyramidal geometry. The CuII atoms of the two [Cu(en)2]2+ cations reside in an elongated octahedral coordination environment, and one of them is localized at a centre of inversion. The W atom is coordinated by eight cyano groups in an irregular square antiprism. Five of these act as bridging units connecting the W and the three Cu atoms, to form an infinite three‐dimensional porous network containing a zigzag ladder structure. 相似文献
89.
90.
Lipkowitz KB D'Hue CA Sakamoto T Stack JN 《Journal of the American Chemical Society》2002,124(47):14255-14267
A hypothesis concerning asymmetric induction by chiral catalysts is posited, tested, and found to be valid. The hypothesis states that chiral catalysts that are efficient at inducing asymmetry will have their region of maximum stereoinduction spatially congruent with the site of chemistry but inefficient catalysts will not. A simple mapping strategy (stereocartography) is used to assess where the region of maximum stereoinduction is located around a given catalyst. The protocol compares interaction energies between mirror image probes at each point in space around the catalyst being considered. The probes are models of the actual transition states of the reaction being catalyzed by a particular catalyst. The hypothesis was tested on three Diels-Alder reactions. Seventeen of the eighteen catalysts conform to the hypothesis. The idea of using this as a catalyst design tool is presented. 相似文献