An Aligned and Laminated Nanostructured Carbon Hybrid Cathode for High‐Performance Lithium–Sulfur Batteries

An aligned and laminated sulfur‐absorbed mesoporous carbon/carbon nanotube (CNT) hybrid cathode has been developed for lithium–sulfur batteries with high performance. The mesoporous carbon acts as sulfur host and suppresses the diffusion of polysulfide, while the CNT network anchors the sulfur‐absorbed mesoporous carbon particles, providing pathways for rapid electron transport, alleviating polysulfide migration and enabling a high flexibility. The resulting lithium–sulfur battery delivers a high capacity of 1226 mAh g⁻¹ and achieves a capacity retention of 75 % after 100 cycles at 0.1 C. Moreover, a high capacity of nearly 900 mAh g⁻¹ is obtained for 20 mg cm⁻², which is the highest sulfur load to the best of our knowledge. More importantly, the aligned and laminated hybrid cathode endows the battery with high flexibility and its electrochemical performances are well maintained under bending and after being folded for 500 times.     

Die Wiederentdeckung der Wöhlk‐Probe

Woehlk's test is a detection reaction for lactose and maltose from 1904. It was first used clinically for the analysis of sugars in urine. In science education the test can show in a simple way the lactose content of dairy products. This is interesting because many people react intolerant to lactose. The exact reaction mechanism of Woehlk reaction (similarly: Umikoff reaction, Woehlk‐Malfatti‐proof, Fearon's test) is still unknown despite many efforts.     

Transparent,Ultrahigh‐Gas‐Barrier Films with a Brick–Mortar–Sand Structure

Transparent and flexible gas‐barrier materials have shown broad applications in electronics, food, and pharmaceutical preservation. Herein, we report ultrahigh‐gas‐barrier films with a brick–mortar–sand structure fabricated by layer‐by‐layer (LBL) assembly of XAl‐layered double hydroxide (LDH, X=Mg, Ni, Zn, Co) nanoplatelets and polyacrylic acid (PAA) followed by CO₂ infilling, denoted as (XAl‐LDH/PAA)_n‐CO₂. The near‐perfectly parallel orientation of the LDH “brick” creates a long diffusion length to hinder the transmission of gas molecules in the PAA “mortar”. Most significantly, both the experimental studies and theoretical simulations reveal that the chemically adsorbed CO₂ acts like “sand” to fill the free volume at the organic–inorganic interface, which further depresses the diffusion of permeating gas. The strategy presented here provides a new insight into the perception of barrier mechanism, and the (XAl‐LDH/PAA)_n‐CO₂ film is among the best gas barrier films ever reported.     

Exact S‐wave solution of the trigonometric pöschl‐teller potential

The trigonometric Pöschl‐Teller (PT) potential describes the diatomic molecular vibration. By using the Nikiforov‐Uvarov method, we have obtained the exact analytical s‐wave solutions of the radial Schrödinger equation (SE) for the trigonometric PT potential. The energy eigenvalues and corresponding eigenfunctions are calculated in closed forms. Some numerical results are presented too. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012     

An alternative to the “Star Path” enhancement of the ADMA linear scaling method for protein modeling

With the aim of improving the performance of macromolecular quantum chemistry conformation analysis and reaction path following methods, the Adjustable Density Matrix Assembler (ADMA) method has already been combined with some faster although less accurate density matrix extrapolation methods, such as the Löwdin‐Inverse‐Löwdin (LIL) extrapolation along a potential energy surface, and a strategically arranged back‐and‐forth switching between these methods has been proven to be advantageous. Here, an alternative approach is proposed and investigated, based on several actual test calculations, where the “inexpensive” LIL density matrix extrapolation steps are replaced by only somewhat more expensive, but still ADMA‐based calculations, where in the “rough‐search stage,” only interactions of shorter distances within the macromolecule are considered. It is shown that this approach is viable, as an alternative to the “Star Path” method including both ADMA and LIL steps. © 2017 Wiley Periodicals, Inc.