荧光标记-高效液相色谱测定多肽（PC2～PC6）的研究

基于多肽(Polypeptides PC2~PC6)中富有巯基(-SH)官能团,其与单溴二胺(Monobromobimanes mBBr)能够发生缩合反应,生成具有荧光信号的多肽衍生物;通过优化色谱分离条件,建立了高效液相色谱(荧光检测器)测定多肽的方法;试验中利用质谱鉴定了PCs与mBBr缩合反应的比例关系。结果显示,通过比较PCs标记前后化合物的质谱图,PCs与mBBr反应比例关系为1∶1,稳定性好;高效液相色谱-荧光法测定多肽化合物,五种化合物间分离度较好,出峰时间集中在16.6~22.0min间;PC2,PC3,PC4,PC5和PC6线性相关性系数>0.999 1,方法定量限分别为0.3,0.05,0.3,0.5和0.8 mg·L-1,回收率范围为83.0%~102.0%;重线性较好,RSD<2.0%,该方法实现了多肽类化合物快速、准确定量分析。     

Hexacyanoferrate‐based ionic liquids as Fenton‐like catalysts for deep oxidative desulfurization of fuels

Two hexacyanoferrate‐based ionic liquids, [C₄Py]₃Fe(CN)₆ and [C₁₆Py]₃Fe(CN)₆, were synthesized and characterized using Fourier transform infrared and mass spectroscopies and CHN analysis. They were employed as Fenton‐like catalysts in extraction and catalytic oxidative desulfurization of model oil with dibenzothiophene (DBT), benzothiophene (BT), 4,6‐dimethyldibenzothiophene (4,6‐DMDBT), 4‐methyldibenzothiophene (4‐MDBT) and 3‐methylbenzothiophene (3‐MBT) as substrates. Various polar solvents, such as ionic liquids, water and organic solvents, were applied to choose a suitable extractant. The results showed the removal of DBT reached 97.1% with [C₄Py]₃Fe(CN)₆ as a catalyst and 1‐n‐octyl‐3‐methylimidazolium hexafluorophosphate ([C₈mim]PF₆) as an extractant under optimal conditions. The activity of sulfur removal followed the order DBT > 3‐MBT > BT > 4‐MDBT >4,6‐DMDBT. The effect of water content on sulfur removal was investigated by adding various concentrations of H₂O₂. It was found that excess water had a positive effect on sulfur removal but the catalysts were less sensitive than [FeCl₄^?]‐based catalysts to water. The mechanism was studied using electron spin‐resonance spectroscopy and gas chromatography–mass spectrometry. O₂^?? may be the active oxygen species in the catalytic oxidative desulfurization process and the oxidation products of various sulfur compounds were the corresponding sulfoxides and sulfones. Copyright © 2016 John Wiley & Sons, Ltd.     

One-step preparation of branched PEG functionalized AIE-active luminescent polymeric nanoprobes

The synthesis of amphiphilic aggregation-induced emission(AIE) dyes based organic nanoparticles has recently attracted increasing attention in the biomedical fields. These AIE dyes based nanoparticles could effectively overcome the aggregation caused quenching effect of conventional organic dyes, making them promising candidates for fabrication of ultrabright organic luminescent nanomaterials. In this work, AIE-active luminescent polymeric nanoparticles(4-NH_2-PEG-TPE-E LPNs) were facilely fabricated through Michael addition reaction between tetraphenylethene acrylate(TPE-E) and 4-arm-poly(ethylene glycol)-amine(4-NH_2-PEG) in rather mild ambient. The 4-NH_2-PEG can not only endow these AIE-active LPNs good water dispersibility, but also provide functional groups for further conjugation reaction. The size, morphology and luminescent properties of 4-NH_2-PEG-TPE-E LPNs were characterized by a series of techniques in detail. Results suggested that these AIE-active LPNs showed spherical morphology with diameter about 100–200 nm. The obtained 4-NH_2-PEG-TPE-E LPNs display high water dispersibility and strong fluorescence intensity because of their self assembly and AIE properties of TPE-E.Biological evaluation results demonstrated that 4-NH_2-PEG-TPE-E LPNs showed negative toxicity toward cancer cells and good fluorescent imaging performance. All of these features make 4-NH_2-PEG-TPE-E LPNs promising candidates for biological imaging and therapeutic applications.     

Synthesis,structure and catalytic polymerization activity of half‐sandwich cyclometallated iridium complexes

A series of mononuclear half‐sandwich cyclometallated iridium complexes with Schiff base ligands were synthesized in good yields. Five air‐stable C,N‐chelate mode complexes were obtained smoothly through metal‐mediated C─H bond activation. Treatments of dimeric metal complexes [Cp*IrCl₂]₂ with ligands L1–L5 afforded the corresponding C,N‐chelate mononuclear half‐sandwich iridium(III) complexes 1 – 5 . These iridium complexes exhibit high catalytic activity for norbornene polymerization. Both steric and electronic effects of the substituted groups have influences on the behaviors of the polymerization process. All complexes were characterized using infrared and NMR spectroscopies and elemental analysis. Molecular structures of complexes 1 , 2 and 5 were further confirmed using single‐crystal X‐ray analysis.     

Effects of pattern dependence on high-power polarization-division-multiplexing applications

High-power polarization-division-multiplexing (PDM) systems or functional modules, such as self-phase-modulation (SPM)-based all-optical regenerators, cross-phase-modulation (XPM)-based wavelength convertors or format convertors, all-optical logical gate, and so on, may suffer from the effects of pattern dependence. Such effects are experimentally investigated using relative time delay variation between bit sequences with orthogonal polarization states in a 2 × 10.65 Gb/s high-power on-off keying (OOK) PDM system. Eye-diagram-based signal-to-noise ratio (SNR) and bandwidth of broadened spectrum are measured and compared. An eye-diagram-based SNR fluctuation of up to 4 dB may occur as the delay changes.     

About Thinning Invariant Partition Structures

Bernoulli-p thinning has been well-studied for point processes. Here we consider three other cases: (1) sequences (X ₁,X ₂,??); (2) gaps of such sequences (X _n+1?X ₁) _n???; (3) partition structures. For the first case we characterize the distributions which are simultaneously invariant under Bernoulli-p thinning for all p??(0,1]. Based on this, we make conjectures for the latter two cases, and provide a potential approach for proof. We explain the relation to spin glasses, which is complementary to important previous work of Aizenman and Ruzmaikina, Arguin, and Shkolnikov.     

Classification of extensions of torus algebra II

We use extension theory and algebraic methods to give a complete characterization of extensions of torus algebra by stable Cuntz algebras,and prove certain classification theorems of these extension algebras.