Formation of a silicato complex of zinc in aqueous solution and its accelerating effect on the formation of silica scales in cooling water systems

This study elucidates the effect of zinc (Zn), which is an anticorrosive water additive, on the formation of silica scales from cooling water. In these experiments, the silica scales were analyzed by EPMA, and the results indicate that Zn is sorbed into the silica scales during formation. Measurements of the solubility of Zn(OH)(2) at various concentrations of silicic acid demonstrate that Zn is present as a silicato complex of Zn (SCZ) in cooling water. From adsorption experiments of the SCZ on silica and alumina, which are major components of the silica scales, it can be concluded that the SCZ accelerates the formation of silica scales from cooling water.     

Scaling laws for gas-solid riser flow through two-fluid model simulation

Scale up of gas-solid circulating fluidized bed (CFB) risers poses many challenges to researchers.In this paper,CFD investigation of hydrodynamic scaling laws for gas-solid riser flow was attempted on the basis of two-fluid model simulations,in particular,the recently developed empirical scaling law of Qi,Zhu,and Huang (2008).A 3D computational model with periodic boundaries was used to perform numerical experiments and to study the effect of various system and operating parameters in hydrodynamic scaling o...     

Small molecular logic systems can draw the outlines of objects via edge visualization

The recently-discovered ability of small logical molecules to recognize edges is exploited to achieve outline drawing from binary templates. Outlines of arbitrary curvature, several colours and thicknesses down to 1 mm are drawn in around 30 min or less by employing a common laboratory two-colour ultraviolet lamp. The outlines and the light dose-driven XOR logic with fluorescence output or ‘off–on–off’ action which is observed in the irradiated regions are modelled by combining foundational principles of photochemistry, acid–base neutralization and diffusion.     

Reactive Polymer as Artificial Solid Electrolyte Interface for Stable Lithium Metal Batteries

Lithium (Li) metal anodes have the highest theoretical capacity and lowest electrochemical potential making them ideal for Li metal batteries (LMBs). However, Li dendrite formation on the anode impedes the proper discharge capacity and practical cycle life of LMBs, particularly in carbonate electrolytes. Herein, we developed a reactive alternative polymer named P(St-MaI) containing carboxylic acid and cyclic ether moieties which would in situ form artificial polymeric solid electrolyte interface (SEI) with Li. This SEI can accommodate volume changes and maintain good interfacial contact. The presence of carboxylic acid and cyclic ether pendant groups greatly contribute to the induction of uniform Li ion deposition. In addition, the presence of benzyl rings makes the polymer have a certain mechanical strength and plays a key role in inhibiting the growth of Li dendrites. As a result, the symmetric Li||Li cell with P(St-MaI)@Li layer can stably cycle for over 900 h under 1 mA cm⁻² without polarization voltage increasing, while their Li||LiFePO₄ full batteries maintain high capacity retention of 96 % after 930 cycles at 1C in carbonate electrolytes. The innovative strategy of artificial SEI is broadly applicable in designing new materials to inhibit Li dendrite growth on Li metal anodes.     

Rapid amplitude-modulation of a diarylethene photoswitch: en route to contrast-enhanced fluorescence imaging

A water soluble diarylethene (DAE) derivative that displays exceptionally intense fluorescence from the colorless open form has been synthesized and characterized using UV/vis spectroscopy and fluorescence microscopy. We show that the bright emission from the open form can be rapidly switched using amplitude modulated red light, that is, by light at wavelengths longer than those absorbed by the fluorescent species. This is highly appealing in any context where undesired background fluorescence disturbs the measurement, e.g., the autofluorescence commonly observed in fluorescence microscopy. We show that this scheme is conveniently applicable using lock-in detection, and that robust amplitude modulation of the probe fluorescence is indeed possible also in cell studies using fluorescence microscopy.

A water soluble diarylethene derivative displaying exceptionally bright fluorescence in the open isomeric form has been used for emission amplitude-modulation. We apply this scheme in fluorescence microscopy, aiming to suppress undesired background.     

Suppression of electron correlations in the superconducting alloys of Rh17−xIrxS15

We have studied the effect of Iridium doping (Rh_17?xIr_xS₁₅) in the rhodium sites of the strongly correlated superconductor Rh₁₇S₁₅. Even at low levels of doping (x = 1 and 2) we see a drastic change in the superconducting properties as compared to those of the undoped system. We deduce that there is a reduction in the density of states at the Fermi level from reduced Pauli susceptibility and Sommerfeld coefficient in the doped samples. Moreover, the second magnetization peak in the isothermal magnetization scan (‘fishtail’) which was very prominent in the magnetization data of the undoped crystal is suppressed in the doped samples. The temperature dependence of resistivity of the doped crystals show a remarkably different behavior from that of the undoped crystal with the appearance of a minima at lower temperatures, the position of which is fairly constant at different fields. Our data supports the notion that Iridium, which is a bigger atom than rhodium expands the lattice thereby, reduces the electron correlations that existed due to the interaction between closer lying rhodium atoms in the undoped system.     

Identification of chemical ingredients of peanut stems and leaves extracts using UPLC‐QTOF‐MS coupled with novel informatics UNIFI platform

Peanut stems and leaves have been used traditionally as both herbal medicines and special food in Asia. In this study, the main functional compounds of peanut stems and leaves extracts were identified using UPLC separation coupled to high resolution mass spectrometry (QTOF‐MS), and a traditional medicine library. Three different extraction solvents (ethyl acetate, petroleum ether and n‐butanol) were evaluated to prepare the extracts of peanut stems and leaves. A total of 283 chemical compounds were identified in peanut stems and leaves extracts, of which 207 compounds are tentatively new identifications in Genus Arachis. The integration of data acquisition and processing with the traditional medicine library provides a simple, efficient process to effectively facilitate the identification of chemical ingredients in complex natural product extracts. The integrated workflow for separation, detection and identification of functional compounds in natural products using UPLC/QTOF‐MS greatly improves productivity for development of traditional herbal medicines. Copyright © 2016 John Wiley & Sons, Ltd.     

Formation of molecular glasses and the aggregation in solutions for lanthanum(III), calcium(II), and yttrium(III) complexes of octanoyl-DL-alaninate

Octanoylalaninato-metal (metal = calcium(II), yttrium(III), lanthanum(III), and zinc(II)) complexes were prepared and the first three metal complexes were found to readily form transparent and stable molecular glasses from methanol and chloroform solutions. The process of glass formation from solution was studied in detail. The effect of the central metal ions on the formation of glassy states was remarkable: the lanthanum and calcium complexes assumed glassy or crystalline states depending on the isolation method and the yttrium complex had a large tendency to assume an amorphous state, whereas the zinc complex did not assume a pure and stable glassy-state. The glass transition temperatures were 50 degrees C for the yttrium complex and 70-75 degrees C for the lanthanum and calcium complexes when these complexes are monohydrates prepared by a solvent-cast method, whereas they increase by 10-30 degrees for the hemihydrates which were obtained by an annealing treatment at 110 degrees C. The coordinated water was eliminated from the solid above the glass transition temperature. The glassy state was regarded as a result of the self-aggregation of the metal complex in solution by an entanglement of the methylene chains with one another. SAXS showed the presence of two disordered bilayer structures with 2.2 nm and 4.5 nm periods in the glassy states. The structures of the molecular assemblies in the solid states and solutions were compared by SAXS and NMR studies. EXAFS studies confirmed the coordination numbers of oxygen atoms around the yttrium and lanthanum atoms in the glassy states for the yttrium and lanthanum complexes to be about 7.