Synthesis and x‐ray crystal structures of hypervalent hexacoordinate antimony compounds without halogen ligands

Hypervalent hexacoordinate antimony‐ate complex { 2‐Et₄N : Rf₃Sb⁻Et₄N⁺ (Rf: o‐C₆H₄C(CF₃)₂O‐)} was synthesized by the reaction of Rf₂SbCl with lithium 1,1,1,3,3,3‐hexafluoro‐2‐(2‐lithiophenyl)‐2‐propoxide followed by countercation exchange. Reaction of 2‐Et₄N with triethyloxonium tetrafluoroborate gave the O‐ethylated adduct ( 3 ). X‐ray crystallographic analysis of 2‐Et₄N and 3 showed distorted octahedral structures of these compounds. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:33–37, 2001     

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.     

无损残余应力测量及其新技术

简述及比较了主要的残余应力无损测量技术，重点为磁力法，并介绍一台新的磁力仪MAPS，且对MAPS及传统磁力仪作了比较，同时以X射线及中子衍射得到的结果验证了MAPS的可靠性，也介绍了文献上较少见的火车钢轨残余应力分布图。     

A Novel Route to the Fused Maleic Anhydride Moiety of CP Molecules

A seven‐step cascade reaction —in which selective mesylation, epoxide formation, epoxide lysis, cyclization, reiterative oxidation, and nitrogen–oxygen exchange occur sequentially—facilitates the construction of the maleic anhydride moiety of CP molecules 1 and 2 (>93% yield per step). Unstable intermediates of this reaction sequence were detected, providing evidence for the proposed mechanism and resulting in the discovery of a new chemical entity.     

Strain relaxation of CdTe films growing on lattice-mismatched substrates

We have deposited CdTe films by laser-assisted epitaxy approach and investigated the influence of substrate and film thickness on the film properties. Grown on Si(001), GaAs(001), and quartz substrates; the CdTe films exhibit preferential orientation along the cubic CdTe(111) direction. When the films are thin (<500 nm), a blueshift of the band gap and splitting of valence bands were observed. These results are attributed to the existence of residual strains induced by mismatch of the film lattice constant with that of the substrate, and by their difference in thermal expansion coefficients. The bulk band-gap energy of 1.5 eV was achieved on the surface of thick CdTe films grown on Si(001) substrate, indicating that strain was almost completely relaxed in this case. Our results demonstrate that by a proper selection of substrate and film thickness it is possible to grow film semiconductors with band gap approaching those of bulk crystals.     

Biofuel cell controlled by enzyme logic network — Approaching physiologically regulated devices

A “smart” biofuel cell switchable ON and OFF upon application of several chemical signals processed by an enzyme logic network was designed. The biocomputing system performing logic operations on the input signals was composed of four enzymes: alcohol dehydrogenase (ADH), amyloglucosidase (AGS), invertase (INV) and glucose dehydrogenase (GDH). These enzymes were activated by different combinations of chemical input signals: NADH, acetaldehyde, maltose and sucrose. The sequence of biochemical reactions catalyzed by the enzymes models a logic network composed of concatenated AND/OR gates. Upon application of specific “successful” patterns of the chemical input signals, the cascade of biochemical reactions resulted in the formation of gluconic acid, thus producing acidic pH in the solution. This resulted in the activation of a pH-sensitive redox-polymer-modified cathode in the biofuel cell, thus, switching ON the entire cell and dramatically increasing its power output. Application of another chemical signal (urea in the presence of urease) resulted in the return to the initial neutral pH value, when the O₂-reducing cathode and the entire cell are in the mute state. The reversible activation–inactivation of the biofuel cell was controlled by the enzymatic reactions logically processing a number of chemical input signals applied in different combinations. The studied biofuel cell exemplifies a new kind of bioelectronic device where the bioelectronic function is controlled by a biocomputing system. Such devices will provide a new dimension in bioelectronics and biocomputing benefiting from the integration of both concepts.