Study on Electrochemical Copolymerization of Aniline and 3-Methylthiophene in HMIMBF4 Ionic Liquid and Its Properties

Electrochemical polymerization of aniline and 3-methylthiophene has been accomplished in 1-methylimidazium tetrafluoroborate （HMIMBF4） ionic liquid. Homopolymer and copolymers of aniline and 3-methylthiophene were obtained successfully. The copolymer was studied by cyclic voltammetry and electrochemical impedance spectroscopy. The formation of copolymer has been confirmed by FT-IR and UV spectra. The atomic force microscope （AFM） was used for microstructural analysis. Both the homopolymer and the copolymer had the catalytic activity for the hydroquinone.     

无烟煤掺混白酒酒糟制备生物质水煤浆

利用白酒酒糟与贵州无烟煤按不同比例掺混制备生物质水煤浆(BCWS),考查了酒糟掺混量、添加剂种类及含量对水煤浆成浆性能的影响。结果表明,在萘磺酸系添加剂(MF、NNO)和木质素磺酸钙(LS)三种添加剂中,MF的分散效果要优于其他两种,且添加量为0.5%时最佳;表观黏度为1 000 m Pa·s时,无烟煤单独制浆最大成浆浓度为70%,而掺混3%(干基)酒糟的BCWS定黏浓度为65.8%,浆体稳定性在3d以上;BCWS属于宾汉塑性流体,酒糟含有大量的亲水性含氧官能团,以及其管束和脉络结构,会引起BCWS表观黏度的升高,有利于提高BCWS的稳定性。     

不同P负载量对Co-Mo/γ-Al_2O_3煤焦油加氢脱硫性能影响的研究

以分步浸渍法在固定MoO_3、CoO含量(质量分数)为13.50%、2.11%的条件下,通过改变磷酸浓度,制备了不同P负载量的Co-Mo/γ-Al_2O_3催化剂。考察了不同的P负载量催化剂对内蒙古赤峰中温煤焦油加氢脱硫性能的影响。并以NH3程序升温脱附(NH_3-TPD)、X射线衍射(XRD)、X射线光电子能谱(XPS)等手段对催化剂的结构性质进行了表征。结果表明,适宜的P负载量可减弱活性组分与载体间的相互作用,利于活性组分均匀分散在载体表面,改善了催化剂的还原、硫化性能和酸性分布,从而提高了催化剂的加氢脱硫活性。当磷酸质量分数为4%时,催化剂表现出最佳的加氢脱硫性能,硫脱除率达到96.98%。不同P负载量Co-Mo/γ-Al_2O_3催化剂加氢脱硫活性对应的磷酸浓度顺序为:4%2%6%1%08%。     

Specific Proteins in the Indirect Somatic Embryogenesis of Freesia Refracta

IntroductionHaberlandt[1]proposed the conception of plantso-matic embryo in 1902, which states that plant cellsexhibit totipotency; each cell could divide ceaselesslyand eventually develops into a mature plantlet. Allthese provide a theoretical evidence for somatic embryo-genesis. The related researches reveal thatplantembry-ogenesis occurs as a result of the selective expression ofsets of genes that allowthe synthesis of special proteinsin a temporal and spatial sequential manner under themut…     

Rapid and effective sample cleanup based on graphene oxide-encapsulated core–shell magnetic microspheres for determination of fifteen trace environmental phenols in seafood by liquid chromatography–tandem mass spectrometry

In this study, graphene oxide-encapsulated core–shell magnetic microspheres (GOE-CS-MM) were fabricated by a self-assemble approach between positive charged poly(diallyldimethylammonium) chloride (PDDA)-modified Fe₃O₄@SiO₂ and negative charged GO sheets via electrostatic interaction. The as-prepared GOE-CS-MM was carefully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer analysis (VSM), and X-ray photoelectron spectroscopy (XPS), and was used as a cleanup adsorbent in magnetic solid-phase extraction (MSPE) for determination of 15 trace-level environmental phenols in seafood coupled to liquid chromatography–tandem mass spectrometry (LC–MS/MS). The obtained results showed that the GOE-CS-MM exhibited excellent cleanup efficiency and could availably reduce the matrix effect. The cleanup mechanisms were investigated and referred to π–π stacking interaction and hydrogen bond between GOE-CS-MM and impurities in the extracts. Moreover, the extraction and cleanup conditions of GOE-CS-MM toward phenols were optimized in detail. Under the optimized conditions, the limits of detection (LODs) were found to be 0.003–0.06 μg kg⁻¹, and satisfactory recovery values of 84.8–103.1% were obtained for the tested seafood samples. It was confirmed that the developed method is simple, fast, sensitive, and accurate for the determination of 15 trace environmental phenols in seafood samples.     

A 13C NMR study of the molecular dynamics and phase transition of confined benzene inside titanate nanotubes

This work investigated the nanoconfinement effect on the molecular dynamics and phase transition of confined benzene inside titanate nanotubes with a uniform inner diameter of approximately 5.3 nm. For 13C-enriched organics, the 13C nuclear spin-spin relaxation was demonstrated as a sensitive tool to differentiate molecular translational motion and reorientation and, thus, was shown to be advantageous over the commonly employed 1H and 2H NMR for studying complex phase diagram, specifically, for separating the phase behavior of translational motion and the phase behavior of molecular reorientation. In such an approach, the melting of translational motion of confined benzene was explicitly observed to take place in a broad temperature range below the bulk melting temperature. The abrupt change of the 13C nuclear spin-spin relaxation time of the confined liquid benzene at about 260 K suggested that nanoconfinement induced two topologically distinct liquid phases.     

多层波纹钢板式干摩擦减振器实验研究

多层波纹钢板式干摩擦减振器具有结构简单、加工工艺好、减振效果显著等特点 ,具有广阔的应用前景 ,与传统的减振材料及结构相比 ,波纹钢板减振器具有耐高低温、耐腐蚀、承载能力更大、寿命更长以及可靠性更高等优点。本文研究了多层波纹钢板式干摩擦减振器制备工艺方法、动静态实验方法以及动静态特性 ,并研究了影响波纹钢板隔振性能的主要影响因素。实验结果表明 ,多层波纹钢板式干摩擦减振器具有良好的迟滞阻尼性能 ,减振器的刚度和能耗系数都随变形量的变化而呈非线性变化 :减振器的性能决定于钢板厚度、波纹高度、相对自由间隙和钢板层数等参数。对于不同参数的减振器 ,频响曲线的共振频率范围变化不大。该种减振器可以在较宽的频率范围工作。研究结果为多层波纹钢板减振器的进一步应用研究奠定了基础