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The vibrational and electronic spectra as well as the magnetic properties of the ion [Co(NH3)4]2+are given and discussed. [Co(NH3)4](ReO4)2 crystallizes cubically and is isostructural with the compounds [Zn(NH3)4](ReO4)2, [Zn(NH3)4](MnO4)2, [Cd(NH3)4](ReO4)2, [Cd(NH3)4](MnO4)2, [Zn(NH3)4]- (OsO3N)2 and [Cd(NH3)4](OsO3N)2. 相似文献
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In our study, the single‐use & eco‐friendly electrochemical sensor platform based on herbal silver nanoparticles (AgNPs) was developed for detection of mercury (II) ion (Hg2+). For this purpose, the surface of pencil graphite electrode (PGE) was modified with AgNPs and folic acid (FA), respectively. The concentrations of AgNPs and FA were firstly optimized by differential pulse voltammetry (DPV) to obtain an effective surface modification of PGE. Each step at the surface modification process was characterized by using cyclic voltammetry (CV) and electrochemical impedence spectroscopy (EIS). The limit of detection (LOD) for Hg2+ was estimated and found to be 8.43 μM by CV technique. The sensor presented an excellent selectivity for Hg2+ against to other heavy metal ions such as Ca2+, Cd2+, Cr3+, Cu2+, Mg2+, Ni2+, Pb2+, Zn2+, Co2+ and Mn2+. Moreover, a rapid, selective and sensitive detection of Hg2+ was successfully performed in the samples of tap water within 1 min. 相似文献
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E. T. Stepkowska J. M. J. M. Bijen J. L. Perez-Rodriguez A. Justo P. J. Sanchez-Soto M. A. Aviles 《Journal of Thermal Analysis and Calorimetry》1994,42(1):41-65
A simple water sorption/retention (WS/WR) test, followed by stepwise static heating, was applied to the study of cement quality and the reactivity of its grain surface.
The physically bound water and hence the specific surface both in the unhydrated and in the hydrated state were estimated
as a function of the hydration time. Rehydration after heating at 220°C and contact with air was different inWS from that inWR samples, which indicates a difference in microstructure. XRD proved the formation of portlandite during the sorption test
and eventual heating at 200°C, and its transformation into carbonates on contact with air, especially on heating at 400°C.
The contents of these compounds were estimated from the mass difference between 400 and 800°C, which was compatible with the
mass change between 220 and 400°C and this indicates surface reactivity. The test may serve for the routine study of cement.
Dedicated to Professor Lisa Heller-Kallai on the occasion of her 65th birthday 相似文献
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