Synthesis and selective recognition toward zinc ion of chiral poly(imine‐triazole)

A novel AB type of clickable monomer, (S)‐2‐[(2‐azido‐1‐phenylethylimino)methyl]‐5‐propargyloxyphenol (AMPP) was designed and polymerized to yield a class of main‐chain chiral poly(imine‐triazole)s through the metal‐free click reaction. With the thermally induced polymerization, the desired polytriazoles can be easily prepared in high yields by a stepwise heating‐up process and have the number‐average molecular masses ranging from 5.1 × 10³ to 58.1 × 10³ (polydispersity indices = 1.38?1.68). The polymers were characterized by Fourier Transform Infrared spectroscopy (FTIR), ¹H Nuclear Magnetic Resonance (NMR), and gel permeation chromatography, and their optical properties were studied by fluorescence and circular dichroism (CD) spectroscopies. As a chemosensor, these polymers exhibited a selective “turn‐on” fluorescence enhancement response toward Zn²⁺ ion over other cations such as Na⁺, K⁺, Mg²⁺, Ca²⁺, Ag⁺, Pb²⁺, Cd²⁺, Hg²⁺, Mn²⁺, and Ni²⁺ in dimethyl sulfoxide. However, the Zn²⁺‐induced fluorescence signal was subject to serious interference by Al³⁺, Cu²⁺, Cr³⁺, and Fe³⁺ ions. Interestingly, the chiral polymer showed distinctive changes in the CD spectra on complexation with Zn²⁺, which allowed for the discrimination of this ion in the presence of other species tested including those interfering ions observed in the fluorescent detection. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2248–2257     

PtM/MxBy (M=Ni,Co, Fe) Heterostructured Nanobundles as Advanced Electrocatalyst for Hydrogen Evolution Reaction

Optimizing the electronic and synergistic effect of hybrid electrocatalysts based on Pt and Pt-based nanocatalysts is of tremendous importance towards a superior hydrogen evolution performance under both acidic and alkaline conditions. However, developing an ideal Pt-based hydrogen evolution reaction (HER) electrocatalyst with moderated electronic structure as well as strong synergistic effect is still a challenge. Herein, we fabricated boron (B)-doped PtNi nanobundles by a two-step method using NaBH₄ as the boron source to obtain PtNi/Ni₄B₃ heterostructures with well-defined nanointerfaces between PtNi and Ni₄B₃, achieving an enhanced catalytic HER performance. Especially, the PtNi/Ni₄B₃ nanobundles (PtNi/Ni₄B₃ NBs) can deliver a current density of 10 mA cm⁻² at the overpotential of 14.6 and 26.5 mV under alkaline and acidic media, respectively, as well as outstanding electrochemical stability over 40 h at the current density of 10 mA cm⁻². Remarkably, this approach is also universal for the syntheses of PtCo/Co₃B and PtFe/Fe₄₉B with outstanding electrocatalytic HER performance.     

Parameter optimization and performance study of Ni–P coatings prepared by pulse-assisted jet electrochemical deposition

Journal of Solid State Electrochemistry - Jet electrochemical deposition is a relatively new technology for selective electrochemical deposition. Its advantages include high deposition accuracy and...     

Graphdiyne:from Preparation to Biomedical Applications

Graphdiyne(GDY)is a kind of two-dimensional carbon nanomaterial with specific configurations of sp and sp2 carbon atoms.The key progress in the preparation and application of GDY is bringing carbon materials to a brand-new level.Here,the various properties and structures of GDY are introduced,including the existing strategies for the preparation and modification of GDY.In particular,GDY has gradually emerged in the field of life sciences with its unique properties and performance,therefore,the development of biomedical applications of GDY is further summarized.Finally,the challenges of GDY toward future biomedical applications are discussed.     

Effect of temperature on the morphologies and electrochemical properties of polyaniline-gold fibrillar nanocomposites

The polyaniline-gold (PANI-AuNPs) fibrillar nanocomposites were prepared via a simple one-pot synthesis route in ethylene glycol (EG) medium. The morphology of PANI-AuNPs was characterized by transmission electron microscopy (TEM), and their electrochemical properties were studied by CV, TAF and EIS measurement using an electrochemical workstation. The results show that the morphology of nanocomposites can be controlled by changing the temperature. The diameter of PANI-AuNPs composite nanofiber reduce from about 80 to 30 nm, and the size of AuNP also reduce from about 20 to 4 nm, with the rise of synthesized temperature. When the synthesized temperature is 10°C, the distribution of AuNPs is the best, and the amount of AuNPs dispersed in PANI is the most, as well as the electrochemical performance of PANI-AuNPs is the most excellent.     

磁场对微乳液法合成聚苯胺结构及其电化学行为的影响

在不同磁场强度下,采用微乳液聚合法合成导电聚苯胺(PANI),以碳纸负载PANI为工作电极,通过循环伏安测试方法,探讨了磁场、氧化剂浓度和聚合时间对微乳液聚合法合成PANI电化学性能的影响;并通过X射线衍射(XRD)、四探针电导率测试和傅立叶红外光谱(FTIR)对产物结构和性能的表征分析,印证了循环伏安分析结果的可靠性.实验结果表明,与无磁条件下制备的PANI相比,磁场条件下制备的PANI具有较高的导电性和规整度;FTIR谱图分析表明,由于磁场的取向作用使分子间相互作用力降低,分子链离域程度增大,使磁场条件下合成PANI的主要特征峰有向低频方向移动的趋势,但分子的基本结构单元没有发生变化.研究结果显示,利用负载PANI的碳纸为工作电极,能够对微乳液法合成PANI的电化学行为进行有效的实时表征.     

An efficient method for solving the mixed direct-inverse problem of the transonic rotational flow in plane casades

The method in [1] has been extended to the case of rotational flow in this paper. A new method for dealing with the shock wave is presented. This method has the advantages of both the shock-fitting and the shock capturing methods. The direct problem and the mixed direct-inverse problem of the rotational flow in a transonic plane cascade at both design and off design conditions are solved, and the results show that the present method has rapid convergence rate and high accuracy even for the flow with moderately strong shocks. The calculations have been carried out on the DPS-8 computer, and for the direct problem, only 50–80 iterations are needed, and 50–80 seconds of CPU time are required.     

Lattice-Boltzmann Models for heat transfer

A multispeed heat transfer lattice Boltzmann model is presented. The model possesses the perfect gas state equation with arbitrary special heat ratio. The macroscopic conservation equations are derived by the Chapman-Enskog method. The one dimensional simulation for the sinusoidal energy distributions are compared with the theoretical results, showing good agreement. The theoretical conductivity in the energy equation is in accordance with the simulations.     

Near field acoustic solution of a rotating point source in frequency domain

I.IntroductionAerodyntalcnoiseofturbomaChinrynotoalythectstheenvironmentbutalsosometimesresultsinstructuredamage.Aeroacoustics,asaintewhsciPlineofacousticsandaerodynamics,isattractingmorandmoreatteDtionandresearch.TherearetwoimportalltcontentsonthenoiseproducingmechAnsmsinaeroacousticproblem.OneisaboutthesourcesofnoiseinturbomachinryGenetallytherearethreetyPesofsources:thickness,forceandturbulencestress,correspondingrespectivelyTomonopole,dipoleandquadruplesourcesThelatertwokindsofsourcesh…     

三维粘流—无粘干扰流动方程组部分正则性问题

本文讨论了三维粘流一无粘干扰流动方程组部分正则性问题，引入了新的三维粘流－无粘干扰流动假设，并得到了相应的结论。