新型Ni—Pd/碳化树脂催化剂的制备及在微量测定有机氧元素中的应用

本文报道一种新型Ni—Pd／碳化树脂催化剂的制备方法，用该法制备的催化剂具有高金属分散度和高机械强度，用于库仑法微量测定有机氧元素取得满意结果。文中对Ni和Pd颗粒在催化剂上表面形貌和分布、催化活性等作了初步探讨。     

Quantitative evaluation of protein recoveries in two-dimensional electrophoresis with immobilized pH gradients

In this study, metabolically radiolabeled Escherichia coli cell extracts were used to systematically evaluate protein recoveries at each step of two-dimensional (2-D) electrophoresis and using different sample application methods. Sample application using sample cups resulted in better protein recovery compared with sample loading by rehydration when the Multiphor system was used. At least 50% or more of an E. coli extract was lost when high protein amounts (500 microg) were loaded by rehydration using this system, which employs separate holders for rehydration and isoelectric focusing (IEF). In contrast, when the IPGphor system was used, rehydration sample loading consistently yielded the highest overall protein recoveries. These improved protein recoveries were due to integration of rehydration and electrophoretic separation in a single unit. Even at high protein loads (500 microg), less than 15-20% of the proteins were lost when proteins were loaded by rehydration using sample buffer containing 2% carrier ampholytes in the ceramic immobilized pH gradient (IPG) strip holders used for both rehydration and IEF. Regardless of the loading conditions used, carrier ampholytes in the sample buffer increased protein recoveries. Use of thiourea did not significantly affect protein recoveries but did improve protein resolution in 2-D gels as expected. In summary, these results show the best protein recoveries are obtained for all protein loads when samples are applied to IPG strips during rehydration using a single device for both rehydration and IEF. In contrast, the poorest recoveries are obtained when rehydration and IEF are performed in separate devices, and losses increase dramatically with increasing protein loads using this approach.     

A Novel Catalyst for Liquid Phase Hydrogenation of m-Dinitrobenzene to m-Phenylenediamine

A novel lanthana-promoted nickel catalyst supported on silica for the liquid phase hydrogenation of m-dinitrobenzene to m-phenylenediamine was prepared by an incipient wetness sequential impregnation method. It was found that Ni-La/SiO2 catalyst exhibited high activity and stability for m-dinitrobenzene hydrogenation. Over this catalyst, the conversion of m-dinitrobenzene and the yield of m-phenylenediamine were up to 97.1% and 93.5%, respectively,at 373 K and 2.6 MPa hydrogen pressure after reaction for 1 h.     

沙林酸印迹聚邻苯二胺纳米膜制备及结构表征

采用电化学聚合法合成了对有机磷毒剂沙林具有特异识别的聚邻苯二胺(PPD)分子印迹纳米膜(iPPD).利用石英晶体微天平(QCM)证实了印迹效应的存在，并用循环伏安法(CV)、AFM、XPS进行了系统的结构表征.结果表明，分子印迹膜的膜厚约20 nm，膜的表面呈“石林”状，疏松多孔，具有良好的吸附性能.分子印迹主要影响聚合物的三维排列，而聚合物的化学组成没有发生改变.该种分子印迹纳米膜在选择性检测军用毒剂沙林中具有良好的应用前景.     

Themed Issue on Graphdiyne

Graphdiyne(GDY)has characteristics of one-atom-thick two-dimensional layers comprising of sp and sp2 hybridized carbon atoms.The chemical and electronic structure gives GDY many unique and fascinating properties,such as rich chemical bonds,highly conjugated and super-large π structures,infinitely distributed pores and high inhomogeneity of charge distribution,etc.     

Aromatic amine‐terminated polysulfide oligomer: Synthesis and application in self‐healable polyurea

The dynamic chemistry of disulfide bonds has emerged as one of the most powerful tools used for the fabrication of organic compounds and self‐healing materials. In this article, a novel aromatic amine‐terminated polysulfide oligomer is first synthesized from thiol‐terminated polysulfide oligomer and bis(4‐aminophenyl) disulfide via disulfide metathesis mechanism. The resulting oligomer is confirmed by FTIR and ¹H NMR spectra and then successfully applied in constructing self‐healable polyurea material (A‐LP23‐I), which combines the advantages of higher strength of polyureas and excellent self‐healing ability of polysulfide‐based materials. After subjecting to a temperature of 75 °C for 48 h, both the tensile strength and ultimate elongation of A‐LP23‐I restore to more than 90% of the original values (3.32 MPa and 396%). This study demonstrates a novel strategy for synthesizing aromatic amine‐terminated oligomer. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1460–1466