Stable SiOC/Sn Nanocomposite Anodes for Lithium‐Ion Batteries with Outstanding Cycling Stability

Silicon oxycarbide/tin nanocomposites (SiOC/Sn) are prepared by chemical modification of polysilsesquioxane Wacker‐Belsil PMS MK (SiOC_MK) and polysiloxane Polyramic RD‐684a (SiOC_RD) with tin(II)acetate and subsequent pyrolysis at 1000 °C. The obtained samples consist of an amorphous SiOC matrix and in‐situ formed metallic Sn precipitates. Galvanostatic cycling of both composites demonstrate a first cycle reversible capacity of 566 mAhg^?1 for SiOC_MK/Sn and 651 mAhg^?1 for SiOC_RD/Sn. The superior cycling stability and rate capability of SiOC_RD/Sn as compared to SiOC_MK/Sn is attributed to the soft, carbon‐rich SiOC matrix derived from the RD‐684a polymer, which accommodates the Sn‐related volume changes during Li‐uptake and release. The poor cycling stability found for SiOC_MK/Sn relates to mechanical failure of the rather stiff and fragile, carbon‐poor matrix produced from PMS MK. Incremental capacity measurements outline different final Li–Sn alloy stages, depending on the matrix. For SiOC_RD/Sn, alloying up to Li₇Sn₂ is registered, whereas for SiOC_MK/Sn Li₂₂Sn₅ stoichiometry is reached. The suppression of Li₂₂Sn₅ phase in SiOC_RD/Sn is rationalized by an expansion restriction of the matrix and thus prevention of a higher Li content in the alloy. For SiOC_MK/Sn on the contrary, the matrix severely ruptures, providing an unlimited free volume for expansion and thus formation of Li₂₂Sn₅ phase.     

The star function for meromorphic functions of several complex variables

We define an analogue of the Baernstein star function for a meromorphic function f in several complex variables. This function is subharmonic on the upper half-plane and encodes some of the main functionals attached to f. We then characterize meromorphic functions admitting a harmonic star function.     

Generalized Alexandroff Duplicates and CD 0(K) spaces

We define and investigateCD _Σ,Γ(K, E)-type spaces, which generalizeCD ₀-type Banach lattices introduced in [1]. We state that the space CD _Σ,Γ(K, E) can be represented as the space of E-valued continuous functions on the generalized Alexandroff Duplicate of K. As a corollary we obtain the main result of [6, 8].     

Non-Stationary Ordering Policies for Multi-Item Inventory Systems Subject to a Single Resource Constraint

This paper studies the multi-item inventory problem with a single constraint. Two well-known approaches to this problem are the Lagrangian method and the fixed-cycle approach. Both of these methods generate stationary ordering policies. A competing approach is presented here that generates non-stationary ordering policies, with order quantities that vary over time. These non-stationary policies are, in all cases, preferred to those generated by the Lagrangian approach, and in some cases preferred to those generated by the fixed-cycle approach. Computational results comparing the three methods are also given.     

Bimetallic complexes of Schiff base bis-[4-hydroxycuomarin-3-yl]-1N,5N-thiocarbohydrazone as a potentially dibasic pentadentate ligand. Synthesis, spectral, and antimicrobial properties

The Schiff base bis-[4-hydroxycuomarin-3-yl]-¹N,⁵N-thiocarbohydrazone, H²L, was prepared by the reaction of 4-hydroxycoumarine-3-carbaldehyde with thiocabohydrazide in 2:1 molar ratio. The ligand and its binuclear complexes with Cu(II), Ni(II), Zn(II), Co(II), Mn(II), Fe(III) and Cr(III) ions were characterized via elemental analysis, ¹H NMR, mass spectrometry, infrared, and electronic spectra, as well as room temperature magnetic susceptibilities. Furthermore, the thermal stabilities of two representative complexes were also investigated. The Schiff base and its metal complexes were screened for their antifungal and antibacterial activities against different species of pathogenic fungi and bacteria and their biopotency have been discussed.     

Interfacial Behavior of Cysteine between Mild Steel and Sulfuric Acid as Corrosion Inhibitor

Interfacial behavior of cysteine (Cys) between mild steel and sulfuric acid solution as a corrosion inhibitor has been studied with electrochemical AC (alternating current) and DC (direct current) techniques at (25.0±0.1) °C. The AC impedance results were evaluated using equivalent circuits in which a constant phase element (CPE) has been replaced with double layer capacitance (C_dl) to represent the frequency distribution of experimental data. Changes in impedance parameters (charge transfer resistance and double layer capacitance) indicated that cysteine molecules acted by accumulating at the metal/solution interface. The fractional coverage of the metal surface () was determined using AC impedance results and it was found that the adsorption of cysteine on the mild steel surface followed a Langmuir isotherm model with a standard free energy of adsorption (ΔG⁰_ads) of −35.1 kJ·mol⁻¹.To clarify the type of interaction between mild steel surface and cysteine molecules with a molecular orbital approach, electronic properties, such as, the highest occupied molecular orbital (HOMO) energy, the lowest unoccupied molecular orbital (LUMO) energy, and the frontier molecular orbital coefficients have been calculated. Energy gaps for the interaction of mild steel surface and cysteine molecules (E_{LUMO Fe}−E_{HOMO Cys} and E_{LUMO Cys}−E_{HOMO Fe}) were used to determine whether cysteine molecules acted as electron donors or electron acceptors when they interacted with the mild steel surface. The local reactivity was evaluated through the condensed Fukui indices. Theoretical calculations were carried out using the density functional theory (DFT) at B3LYP level with the 6-311++G(d,p) basis set for all atoms by Gaussian 03W program.     

New copper(II) complexes including pyridine-2,5-dicarboxylic acid: synthesis,spectroscopic, thermal properties,crystal structure and how these complexes interact with purified PON 1 enzyme

We report the synthesis of two square-pyramidal copper(II) complexes, [Cu(2,5-pydc)(2-aepy)(H₂O)]·H₂O, 1, and [Cu(2,5-pydc)(2-ampy)(H₂O)]·H₂O, 2 (2-aepy = 2-(aminoethyl)pyridine, 2-ampy = 2-(aminomethyl)pyridine, 2,5-pydc = pyridine-2,5-dicarboxylic acid or isocinchomeronic acid). The synthesized complexes have been characterized by X-ray diffraction, FT-IR, elemental, and thermal analysis techniques. The crystal structure of 1 was established by X-ray analysis. Powder X-ray diffraction analysis showed that the complexes are pure. The inhibition of human serum paraoxonase 1 (PON 1, EC 3.1.8.1) enzyme with these complexes were investigated. We used diethyl 4-nitrophenyl phosphate as a substrate to measure the paraoxonase activity of PON 1 enzyme spectrophotometrically. Complexes 1 and 2 decreased the in vitro PON 1 activity with different inhibition mechanisms. Complexes 1 and 2 inhibited paraoxonase activity of this enzyme as competitively and noncompetitively, respectively.     

New metal complexes with diclofenac containing 2-pyridineethanol or 2-pyridinepropanol: synthesis,structural, spectroscopic,thermal properties,catechol oxidase and carbonic anhydrase activities

Four new neutral diclofenac-based complexes, [Co(dicl)2(2-pyet)2] 1, [Ni(dicl)2(2-pyet)2] 2, [Cu2(dicl)2(2-pyet)2] 3, and [Cu2(dicl)2(2-pypr)2] 4 have been synthesized and characterized by elemental analysis, FT-IR, thermal analysis. Complexes 1, 3, and 4 have also been characterized by X-ray single-crystal structural analysis. The compounds of Co(II) and Ni(II) have octahedral geometry with two diclofenac and two 2-pyridineethanol ligands in the coordination sphere. The compounds of Cu(II) have square-pyramidal geometry and Cu(II) ions are linked via oxygens to the bridging 2-pyridineethanol or 2-pyridinepropanol ligands. The Δν values acquired by FT-IR are in agreement with the single XRD data. Studies on the thermal properties are reported and the complexes are stable to 196, 216, 215, and 201 °C in air, respectively. Two dinuclear Cu(II) complexes have demonstrated catalytic activity on oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone showing saturation kinetics at high substrate concentrations. The diclofenac complexes are investigated as inhibitors of the human cytosolic isoforms hCA I and II. The complexes are good as hCA I inhibitors (Kis of 1.52–55.06 μM) but only moderately efficient as hCA II inhibitors (Kis of 0.23–5.61 μM).     

Cell‐Derived Vesicles for Single‐Molecule Imaging of Membrane Proteins

A new approach is presented for the application of single‐molecule imaging to membrane receptors through the use of vesicles derived from cells expressing fluorescently labeled receptors. During the isolation of vesicles, receptors remain embedded in the membrane of the resultant vesicles, thus allowing these vesicles to serve as nanocontainers for single‐molecule measurements. Cell‐derived vesicles maintain the structural integrity of transmembrane receptors by keeping them in their physiological membrane. It was demonstrated that receptors isolated in these vesicles can be studied with solution‐based fluorescence correlation spectroscopy (FCS) and can be isolated on a solid substrate for single‐molecule studies. This technique was applied to determine the stoichiometry of α3β4 nicotinic receptors. The method provides the capability to extend single‐molecule studies to previously inaccessible classes of receptors.     

Record 12.34% stabilized conversion efficiency in a large area thin‐film silicon tandem (MICROMORPH™) module

Mass‐adoption of thin‐film silicon (TF‐Si) photovoltaic modules as a renewable energy source can be viable if the cost of electricity production from the module is competitive with conventional energy solutions. Increased module performance (electrical power generated) is an approach to reduce this cost. Progress towards higher conversion efficiencies for ‘champion’ large area modules paves the way for mass‐production module performance to follow. At TEL Solar AG, Trübbach, Switzerland, significant progress in the absolute stabilized module conversion efficiency has been achieved through optimized solar cell design that integrates high‐quality amorphous and microcrystalline TF‐Si‐deposited materials with efficient light management and transparent conductive oxide layers in a tandem MICROMORPH™ module. This letter reports a world record large area (1.43 m²) stabilized module conversion efficiency of 12.34% certified by the European Solar Test Installation; an increase of more than 1.4% absolute compared with the previous record for a TF‐Si triple junction large area module. This breakthrough result generates more than 13.2% stabilized efficiency from each equivalent 1 cm² of the active area of the full module. Copyright © 2015 John Wiley & Sons, Ltd.