Scanning tunnelling microscopy study of a columnar metallomesogen: bis(β-diketonato)palladium(II) complexes on graphite

Scanning tunnelling microscopy is used to analyse the structure of the columnar metallomesogen bis[1-(3',4',5'-trioctyloxyphenyl)-3-(4'-octyloxphenyl)prop [Pd(II)BPOC8], on the basal plane of highly oriented pyrolytic graphite. It is observed with near molecular level resolution that adsorbed molecules form a regular two-dimensional (2D) arrangement on the surface. The intermolecular spacing in the 2D crystallization is significantly shorter than in the intercolumnar mesophase, indicating that the alkyl chains of adjacent molecules interdigitate. Change in the carbon length of alkyl side chain groups results in a change in molecular periodicity in the 2D crystal. Models for the unit cell are proposed based on computer simulation.     

Global stability of a three-dimensional bio-reactor with inhibition responses

A three-dimensional bio-reactor model of exploitative competition of two predator organisms with inhibition responses for the same renewable organism with reproductive properties is considered. By constructing a modified Lyapunov function and using LaSalle’s invariant principle, it is shown that the lower “break-even” concentration predator organism survives in the competition.      

Na3AlF6-Al2O3熔盐体系中ZnFe2O4基阳极的电化学行为

研究了ＺｎＦｅ２Ｏ４基阳极在Ｎａ３ＡｌＦ６－Ａｌ２Ｏ３熔盐体系中的电化学稳定性，讨论了电极的析氧历程并得到了析氧过电位与阳极表观电流密度之间的Ｔａｆｅｌ关系式，η＝０．１２＋０．０５２ｌｏｇｉ（ｉ＝０．０１５－０．４４Ａ／ｃｍ＾２）用三角波电位扫描法测定了电极析氧过程的伏安曲线。     

Fabrication of silicon oxycarbide fibers from alkoxide solutions along the sol–gel process

Spinnable solutions are obtained in the sol–gel system of tetraethoxide (TEOS, Si(OC₂H₅)₄) and vinyltrimethoxysilane (VTMS, CH₂=CHSi(OCH₃)₃) under aqueous condition (water) with acid catalysts (HNO₃ and HCl). Polysiloxane (PSO) fibers are drawn from the solution and characterized by spectroscopic and structural analyses. ²⁹Si-nuclear magnetic resonance NMR) spectral analysis of the PSO fiber indicates the incorporation of atomic carbon in the silica network. ¹³C-NMR analysis shows the existence of considerable amount of hydroxyl groups in the PSO fiber. The spinnablity of the solution is studied by varying the mole ratios of the alkoxides, solvents and catalysts as well as precursor chemistries. The amount of water and catalysts are found to be important for the attaining of a spinnable state in the solution. SiOC fibers are obtained after pyrolysis of the PSO fibers with a high ceramic yield (88 wt%). The high ceramic yield attributes to the incorporation of vinyl-groups in the gel fiber that enhances crosslinking during pyrolysis. The SiOC fiber has a tensile strength of 776 MPa and electrical conductivity of 3.6 × 10⁻⁴ S/m.     

Global robust exponential stability analysis for stochastic interval neural networks with time-varying delays

In this paper, the global exponential stability is investigated for a class of stochastic interval neural networks with time-varying delays. The parameter uncertainties are assumed to be bounded in given compact sets. Based on Lyapunov stable theory and stochastic analysis approaches, the delay-dependent criteria are derived to ensure the global, robust, exponential stability of the addressed system in the mean square. The criteria can be checked easily by the LMI control toolbox in Matlab. A numerical example is given to illustrate the effectiveness and improvement over some existing results.     

A Silicon Nanowire‐Based Electrochemical Sensor with High Sensitivity and Electrocatalytic Activity

A new kind of silicon nanowire (SiNWs)‐based nanoelectrode assembly, a gold‐nanoparticle‐decorated silicon nanowire array (AuNPs@SiNWsAr), is employed for the construction of high‐performance electrochemical sensors. Significantly, the electrochemical nanosensors are capable of sensitive detection of various electroactive molecules (e.g., dopamine (DA), ascorbic acid (AA), hydrogen peroxide (H₂O₂), and glucose). Further, DA molecules loaded on the surface of AuNPs@SiNWsAr preserve stable high electroactivity overnight without special protection, while free DA molecules may lose their biological activity due to severe oxidization in ambient environment. These findings may offer new opportunities for the design of high‐performance electrochemical nanosensors with high sensitivity and robust stability.     

Enrichment of the spindle fiber attachments from mouse liver cell nuclei

Spindle fiber attachments (SFAs) were enriched in a fraction of nuclei isolated from mouse livers. The enrichment method combines sonication, treatment with 2 mol/L NaCl and high speed centrifugation. SFA was enriched 27-fold on the average (n = 4) when measured by radioimmunoassay. The basic method offers opportunities for further increases of yield and for the enrichment of SFA of other vertebrates.