The Fermi-Walker Derivative on the Spherical Indicatrix of a Space Curve

In this paper Fermi-Walker derivative and Fermi-Walker parallelism and non-rotating frame concepts are given along the spherical indicatrix of a curve in E ³. First, we consider a curve in Euclid space and investigate the Fermi-Walker derivative along the tangent. The concepts which Fermi-Walker derivative are analyzed along its tangent. Then, the Fermi-Walker derivative and its theorems are analyzed along the principal normal indicatrix and the binormal indicatrix of any curve in E ³.     

(1)H NMR and viscometric studies on cationic gemini surfactants in presence of aromatic acids and salts

In this paper, we are reporting the influence of addition of aromatic acids (anthranilic and benzoic acid) and their sodium salts on the micellar morphological changes in three cationic gemini surfactant solutions, viz. 5 mM tetramethylene-1,4-bis(N-hexadecyl-N,N-dimethylammonium bromide), 10 mM pentamethylene-1,5-bis(N-hexadecyl-N,N-dimethylammonium bromide), and 10 mM hexamethylene-1,6-bis(N,-hexadecyl-N,N-dimethylammonium bromide). The solubilization site of the counterions (obtained from the additives) near the micellar surface are inferred by 1H NMR. The behavior is explained in the light of binding of counterions to the micelle as well as the nature of the functional group attached to the additive.     

Remarkable synergistic effect in cobalt-iron nitride/alloy nanosheets for robust electrochemical water splitting

Design and synthesis of noble-metal-free bifunctional catalysts for efficient and robust electrochemical water splitting are of significant importance in developing clean and renewable energy sources for sustainable energy consumption.Herein,a simple three-step strategy is reported to construct cobalt-iron nitride/alloy nanosheets on nickel foam(CoFe-NA/NF)as a bifunctional catalyst for both hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).The electrocatalyst with optimized composition(CoFe-NA2/NF)can achieve ultralow overpotentials of 73 mV and 250 mV for HER and OER,respectively,at a current density of 10 mA cm^-2 in 1 M KOH.Notably,the electrolyzer based on this electrocatalyst is able to boost the overall water splitting with a cell voltage of 1.564 V to deliver 10 mA cm^-2 for at least 50 h without obvious performance decay.Furthermore,our experiment and theoretical calculation demonstrate that the combination of cobalt-iron nitride and alloy can have low hydrogen adsorption energy and facilitate water dissociation during HER.In addition,the surface reconstruction introduces metal oxyhydroxides to optimize the OER process.Our work may pave a new pathway to design bifunctional catalysts for overall water splitting.     

The reaction of 2‐amino‐3‐cyano‐4,5,6,7‐tetrahydrobenzo[b]‐thiophene with diethyl malonate: synthesis of coumarin,pyridine, and thiazole derivatives

The reaction of 2‐amino‐3‐cyano‐4,5,6,7‐tetrahydrobenzo[b]thiophene ( 1 ) with diethyl malonate ( 2 ) gave two products: 3 and 4 . The reactivity of 3 toward a variety of chemical reagents was studied to give azoles, azines, and their fused derivatives. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:168–175, 2001     

Synthesis of sterically encumbered porphyrins as catalysts for shape‐selective oxidations

A general method is described for the synthesis of sterically encumbered porphyrins whose shielding superstructure can take on the enzymatic role of substrate discrimination. This method is based on an improved synthesis of pyrroles substituted with a 2,6‐dibromophenyl group, followed by a Suzuki cross‐coupling to replace the Br with aryl groups. Porphyrins assembled from such pyrrole units have a barrel shape with the metal center completely fenced by four β‐substituted terphenyl shielding wings. The Fe and Mn porphyrins prove to be excellent catalysts for regioselective epoxidation of alkenes.     

Energy Levels and Transition Rates for Ti XIV

Physics of Particles and Nuclei Letters - Energy levels, wavelengths, oscillator strengths, transition probabilities, line strengths, and lifetimes are calculated for transitions in Ti XIV. The...     

Di­aqua­bis­(pyridine‐2‐carbox­amide‐κ2N1,O2)­nickel(II) disaccharinate tetrahydrate

In the crystal structure of the title compound, [Ni(C₆H₆N₂O)₂(H₂O)₂](C₇H₄NO₃S)₂·4H₂O or [Ni(pia)₂(H₂O)₂](sac)₂·4H₂O (pia is picolin­amide or pyridine‐2‐carbox­amide, and sac is the saccharinate anion), the Ni²⁺ cation, located on a centre of symmetry, is coordinated by two symmetry‐related aqua ligands together with a pair of symmetry‐related bidentate pia mol­ecules and exhibits a distorted octahedral environment. The unique unligated sac anion in the asymmetric unit resides on a general position and has a single negative charge. The coordinated water mol­ecules link the sac ions to the metal complex via O—H⋯O hydrogen bonds. In addition, the sac ions are linked to the metal complex via intermolecular π–π interactions between the benzene ring of the sac ion and the pyridine ring of a pia ligand. Each uncoordinated water mol­ecule is hydrogen bonded to sac moieties through O—H⋯O and O—H⋯N hydrogen bonds.     

Phase equilibria in the Al-Cu-Fe system at a temperature of 853 K in the aluminum enriched region

The phase equilibria in the Al-Cu-Fe system at 853 K in the aluminum enriched region are studied using the methods of scanning and transmission electron microscopy, X-ray phase analysis, and electron probe microanalysis. An isothermal cross section of the system is constructed. Crystal lattice parameters of the phases based on binary and ternary compounds are determined. Approximant phases are not found to form in the quasicrystalline i-phase region.     

Differentiation of herbs linked to "Chinese herb nephropathy" from the liquid chromatographic determination of aristolochic acids

A HPLC method was developed and applied to analyze aristolochic acids (AA-I and AA-II) in Chinese medicinal herbs. The herb samples were extracted by using ultrasonication with the extraction efficiency of better than 82%. Extracts were then filtered and injected onto a C18 column eluting under a gradient program using methanol and water-containing 0.5% acetic acid. The method with the detection limits of 1.33 ng for AA-I and 7.29 ng for AA-II per injection was successfully applied for the analysis of traditional Chinese medicine (TCM) and related products and differentiation of Chinese medicinal herbs that have previously been misused and caused toxicological effects. The developed protocol provided an example that analysis of selected component markers could serve for health security and quality control of TCM consumption.     

QCM-DNA biosensor based on plasma modified PT/TiO2 nanocomposites

A quartz crystal microbalance DNA biosensor based on plasma prepared polythiophene /titanium dioxide (PT/TiO₂) nanocomposite was developed for the detection of genetically modified organisms (GMOs). DNA hybridization was studied by quartz crystal microbalance (QCM) and cyclic voltammetry (CV) measurements. Single stranded DNA probes were immobilized on the PT/TiO₂ coated quartz crystal electrode and the hybridization between the immobilized probe and the target complementary sequence in solution was monitored. The developed QCM-DNA biosensor represented promising results for a real-time, label-free, direct detection of DNA samples for the screening of genetically modified organisms.