酯交换法合成碳酸甲乙酯催化剂的研究进展

碳酸甲乙酯（EMC）是一种环境友好型的不对称碳酸酯，因其独特的结构性质被广泛用作溶剂或有机合成中间体，特别是随着锂离子电池的迅猛发展，其作为电池电解液主要成分市场需求量急增。文中简单介绍了光气法、氧化羰化法和酯交换法合成碳酸甲乙酯的研究进展。重点针对最具发展前景的酯交换法合成EMC工艺路线中所用催化剂进行了综述；讨论和分析了该路线所用催化剂的类型、结构、性质及性能，并对当前研究中存在的问题进行了归纳和分析总结。最后本文分析并展望了酯交换法合成EMC催化剂的研究方向及新型合成工艺发展趋势，提出研发经济、高效、稳定且制备工艺简单的非均相催化剂，并与反应精馏技术耦合是今后的主要发展趋势，期望为EMC的高效合成提供参考和借鉴。     

Novel inorganic precursors [Co4.32Zn1.68(HCO2)18(C2H8N)6]/SiO2 and Co4.32Zn1.68(HCO2)18(C2H8N)6]/Al2O3 for Fischer–Tropsch synthesis

The silica- and alumina-supported Co–Zn catalysts were synthesized by thermal decomposition of new inorganic precursors [Co_4.32Zn_1.68(HCO₂)₁₈(C₂H₈N)₆]/SiO₂ or Al₂O₃. A novel coordination polymer formulated as [Co_4.32Zn_1.68(HCO₂)₁₈(C₂H₈N)₆] (1) was prepared using the solvothermal technique and characterized by elemental analysis, FT-infrared spectroscopy. Thermal stability of the complex 1 was investigated by thermogravimetric analysis and differential scanning calorimetry, and its structure was determined by single-crystal X-ray diffraction. Characterization of catalysts was carried out using powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and BET specific surface area. The catalysts were evaluated for Fischer–Tropsch synthesis (FTS) in the temperature range 200–300 °C. The results revealed that the synthesized catalysts have higher selectivity to the desired products at 260 °C. The performance of the catalysts was compared to those of catalysts constructed via impregnation method and the fabricated catalysts show higher activity and selectivity than the reference catalysts.     

铜吡啶配合物催化合成1-甲氧基-2,2,6,6-四甲基哌啶-4-醇

目前1-烷氧基-2,2,6,6-四甲基哌啶基化合物的合成主要是以醛酮法为主。醇法合成虽然醇价格便宜，但合成效率很低。为解决这一问题，本文对醇法合成工艺进行了深入探讨，并以乙醇和4-羟基-2,2,6,6-四甲基哌啶氮氧自由基（ZJ-701）为原料，30%过氧化氢为氧化剂，氯化铜和吡啶配合物为催化剂，通过氧化和自由基偶合合成了1-甲氧基-2,2,6,6-四甲基哌啶-4-醇，通过红外光谱、核磁共振谱和质谱表征了其结构。通过实验进一步优化了反应时间、温度等一系列合成条件。研究结果表明：当反应时间为12h，反应温度为78℃，n(ZJ-701)∶n(乙醇)∶n(H₂O₂)∶n(CuCl₂)∶n(吡啶)=1∶39.25∶17.01∶0.034∶0.36时，产品产率最高，为60.6%，质量分数为98.8%，熔点为87～90℃。该方法具有原料乙醇便宜易得、反应条件温和、产品提纯容易等优点。     

[学科发展]机构学中机构重构的理论难点与研究进展——变胞机构演变内涵、分岔机理、设计综合及其应用

生产力发展与工程技术革新要求机构具备可自重组与可重构及“一机多用”的功能，以满足复杂工况需求。可重构机构具有可变活动度和可变构态，可以满足多任务、多工况与多功能的要求，然而，决定其设计方法的演变内涵与分岔机理的研究目前仍不为学者们充分了解。从变胞机构的演变与分岔机理的角度，以旋量理论、李群与李代数及微分流形为主要工具，揭示了机构演变内涵及运动与约束空间的内在关联关系；探究了机构演变中的分岔机理与可控奇异位形，回顾了变胞机构与折纸及折展机构的历史渊源，综述了变胞机构的构型设计、性能综合与新型设计理念及其创新应用。     

Synthesis of ZnS nanoparticles of required size by precipitation in aerosol microdroplets

Zinc sulphide (ZnS) nanoparticles were prepared by an aerosol method from zinc acetate and sodium sulphide (Na₂S) aqueous solutions. Aqueous solution of zinc acetate was dispersed into the form of microdroplets, which were introduced by airflow to vigorously stirred aqueous solution of Na₂S, which was in excess. Microdroplets served as microreactors, so the reaction took place only in limited volume. Particle size distribution was studied by transmission electron microscopy and by dynamic light scattering measurements. In this work, the equation that allows us to predict the final size distribution of ZnS nanoparticles using exact concentration of zinc acetate was derived and ZnS nanoparticles with predicted mean particle diameter around 50 and 70?nm were successfully synthetised.     

A Strategy for Discovering Heterochiral Bioactive Peptides by Using the OB2nP Library and SPOTs Method

d -Amino acid containing peptides are promising as drug lead compounds because of their expected higher stability in vivo. A heterochiral random peptide library called the one-bead–2ⁿ-peptide (OB2ⁿP) library, which can display 2ⁿ peptide diastereomers per bead, has been developed. Through screening of the OB2ⁿP library and subsequent binding assay among the peptide diastereomers synthesized in parallel by means of the SPOTs method, new heterochiral mimotopes for the anti-β-endorphin monoclonal antibody have been obtained. One mimotope was a new ligand for the μ-opioid receptor. The screening strategy enabled d -amino acid containing drug leads to be obtained efficiently by expanding searchable chemical space without increasing the experimental scale.     

Microstructured Fischer‐Tropsch Reactor Scale‐up and Opportunities for Decentralized Application

Current projects focusing on the energy transition in traffic will rely on a high‐level technology mix for their commissioning. One of those technologies is the Fischer‐Tropsch synthesis (FTS) that converts synthesis gas into hydrocarbons of different chain lengths. A microstructured packed‐bed reactor for low‐temperature FTS is tested towards its versatility for biomass‐based syngas with a high inert gas dilution. Investigations include overall productivity, conversion, and product selectivity. A 60‐times larger pilot‐scale reactor is further tested. Evaporation cooling is introduced which allows to increase the available energy extraction from the system. From that scale on, an autothermal operation at elevated conversion levels is applicable.     

Observations of Membrane Domain Reorganization in Mechanically Compressed Artificial Cells

Giant unilamellar vesicles (GUVs) are considered to be the gold standard for assembling artificial cells from the bottom up. In this study, we investigated the behavior of such biomimetic vesicles as they were subjected to mechanical compression. A microfluidic device is presented that comprises a trap to capture GUVs and a microstamp that is deflected downwards to mechanically compress the trapped vesicle. After characterization of the device, we show that single-phase GUVs can be controllably compressed to a high degree of deformation (D=0.40) depending on the pressure applied to the microstamp. A permeation assay was implemented to show that vesicle bursting is prevented by water efflux. Next, we mechanically compressed GUVs with co-existing liquid-ordered and liquid-disordered membrane phases. Upon compression, we observed that the normally stable lipid domains reorganized themselves across the surface and fused into larger domains. This phenomenon, observed here in a model membrane system, not only gives us insights into how the multicomponent membranes of artificial cells behave, but might also have interesting consequences for the role of lipid rafts in biological cells that are subjected to compressive forces in a natural environment.