还原温度对双介孔钴基催化剂费-托合成性能的影响

通过等体积浸渍法制备了双介孔钴基催化剂,采用XRD、BET、SEM、H₂-TPR等手段考察了催化剂的性质,并研究了还原温度对催化剂结构及费托合成催化性能的影响。结果表明,随着还原温度的提高,催化剂活性位增加,活性增加,但增加到一定程度后活性降低,而甲烷选择性随着还原温度的提高逐渐增加,这是反应过程中催化剂表面存在的钴氧化物,使得水煤气反应变得活跃,烃产物移向低碳烃。     

2,6,6-三甲基-双环[3,1,1]庚基-3-(4-芳基-2-噻唑)腙类化合物的合成及其抑菌和抗肿瘤活性研究

以α-蒎烯为起始原料,经加成、氧化、缩合制得中间体,继而与α-溴代芳基乙酮在常温下反应合成12个新型2,6,6-三甲基-双环[3,1,1]庚基-3-(4-芳基-2-噻唑)腙类化合物,产率达52.4%~88.9%.其结构经1H NMR,13C NMR,IR,LC/MS和元素分析进行了确证.初步生物活性测试结果表明:部分目标化合物具有较好的抑菌活性和一定的抗肿瘤活性.     

Synthesis and antibacterial properties of new phenothiazinyl- and phenyl-nitrones

The synthesis of new phenothiazinyl- and phenyl-nitrones under classical versus microwave heating conditions is described. Better yields were obtained under microwave irradiation in the condensation reactions of phenothiazyl-carbaldehyde with hydroxylamine derivatives. The structures of the new phenothiazinyl-nitrones were assigned on the basis of MS, FT–IR and NMR spectra. The new nitrones and some known phenyl-nitrones were screened for their antibacterial and antifungal activity against several Candida species, Gram negative bacteria, such as E. coli, Citrobacter spp, Morganella spp, Pseudomonas aeruginosa, Klebsiella pneumoniae (± ESBL), Proteus spp, Acinetobacter spp and the Gram positive bacterium Staphylococcus aureus, with moderate results.     

Benign synthesis of N-(8-quinolyl)pyridine-2-carboxamide) ligand (Hbpq), and its Ni (II) and Cu (II) complexes. A fluorescent probe for direct detection of nitric oxide in acetonitrile solution based on Hbpq copper(II) acetate interaction

The ligand Hbpq = N-(8-quinolyl)pyridine-2-carboxamide) has been prepared using tetrabutylammonium bromide (TBAB) as an environmentally friendly reaction medium. Four new complexes of this ligand, [M(bpq)X] (M = Cu(II), X = SCN̄ (1), N₃̄ (2); M = Ni(II), X = SCN̄ (3), N₃̄ (4)), have also been synthesized and fully characterized. The crystal and molecular structures of [Cu(bpq)(NCS)]_n (1) have been determined by X-ray crystallography. Copper(II) ion adopts a distorted square pyramidal (4 + 1) coordination in this complex. Hbpq ligand shows a strong emission at 500 nm in acetonitrile solution. The emission is quenched in the presence of copper(II) acetate, apparently because of the formation of [Cu(L)(OAc)(H₂O)] complex. Introduction of nitric oxide (NO) into the acetonitrile solution at room temperature induces an increase in the fluorescence intensity, presumably due to the reduction of Cu(II) to Cu(I). This process is reversible and can form a basis for direct detection of NO.     

煤炭间接液化:从基础到工业化

中国需要自主发展煤炭间接液化工业化技术,以缓解油品供应的紧张局面,保障经济的可持续发展.近年来中国成功地进行了煤炭间接液化示范厂的运行,掌握了成熟可靠的费托合成催化剂技术和大型合成反应器技术,正在设计和建设百万吨级合成油商业厂.本文简要介绍了国内外煤炭间接液化技术发展状态,评述了我国煤炭间接液化技术在费托合成反应机理、催化剂研制、反应动力学、反应器设计、系统工艺集成、油品加工等方面从基础到工程技术的研究进展,分析了我国建设百万吨级煤炭间接液化商业厂需要解决的关键基础和工程技术问题,并对我国未来煤制油产业化发展的前景以及所面临的挑战与对策进行了展望.     

Synthesis,Crystal Packing,and Ambipolar Carrier Transport Property of Twisted Dibenzo[g,p]chrysenes

A versatile method for the synthesis of dibenzo[g,p]chrysene (DBC) derivatives based on regio‐ and stereoselective stannyllithiation to diarylacetylenes is described. This method affords a variety of DBCs possessing both electron‐donating and electron‐withdrawing functional groups. These twisted molecules take brickwork packing structures in single crystals. Thus, ambipolar carrier transport properties with mobility values of up to 10^?3 cm² V^?1 s^?1 in the amorphous state were achieved. Functional groups on DBC frameworks are considered to increase carrier mobility through the enhancement of intermolecular interactions in the brickwork packing structures.     

The Process of Acetonitrile Synthesis over γ-Al2O3 Promoted by Phosphoric Acid Catalysts

The influence of principal parameters (reaction temperature, ratio of acetic acid and ammonia, composition of reactionary mixture and promotion of catalysts) on the selectivity and yield of the desired product was studied in the reaction of catalytic acetonitrile synthesis by ammonolysis of acetic acid. The processing of γ-Al₂O₃ by phosphoric acid increases amount of the centers, on which carries out reaction of acetamide dehydration. The kinetic model of a limiting stage of reaction – the acetamide dehydration to acetonitrile was suggested. In the process of ammonolysis of acetic acid it was demonstrated that the use of catalysts promoted by phosphoric acid and ratio NH₃:CH₃COOH=(3-4):1 at temperatures of a reactor 360-390°С leads to the increase of acetonitrile productivity to 0.7-0.8 g/cm³·h and allows to minimize formation of by-products.     

Dual Sulfide–Disulfide Crosslinked Networks with Rapid and Room Temperature Self‐Healability

Polymer‐based crosslinked networks with intrinsic self‐repairing ability have emerged due to their built‐in ability to repair physical damages. Here, novel dual sulfide–disulfide crosslinked networks (s‐ssPxNs) are reported exhibiting rapid and room temperature self‐healability within seconds to minutes, with no extra healing agents and no change under any environmental conditions. The method to synthesize these self‐healable networks utilizes a combination of well‐known crosslinking chemistry: photoinduced thiol‐ene click‐type radical addition, generating lightly sulfide‐crosslinked polysulfide‐based networks with excess thiols, and their oxidation, creating dynamic disulfide crosslinkages to yield the dual s‐ssPxNs. The resulting s‐ssPxN networks show rapid self‐healing within 30 s to 30 min at room temperature, as well as self‐healing elasticity with reversible viscoelastic properties. These results, combined with tunable self‐healing kinetics, demonstrate the versatility of the method as a new means to synthesize smart multifunctional polymeric materials.

     

A novel 3D Tesla valve micromixer for efficient mixing and chitosan nanoparticle production

Current three-dimensional micromixers for continuous flow reactions and nanoparticle synthesis are complex in structure and difficult to fabricate. This paper investigates the design, fabrication, and characterization of a novel micromixer that uses a simple spatial Tesla valve design to achieve efficient mixing of multiple solutions. The flow characteristics and mixing efficiencies of our Tesla valve micromixer are investigated using a combination of numerical simulations and experiments. The results show that in a wide range of flow rates, viscoelastic solutions with different concentrations can be well mixed in our micromixer. Finally, experiments on the synthesis of chitosan nanoparticles are conducted to verify the practicability of our micromixer. Compared with nanoparticles prepared by conventional magnetic stirring, the size of nanoparticles prepared by micromixing is smaller and the distribution is more uniform. Therefore, our Tesla valve micromixer has significant advantages and implications for mixing chemical and biological reactions.     

Li2MnO3 content effects on thermal,structural, electrical and electrochemical properties of xLi2MnO3-(1-x)LiNi0.9Zn0.1O2 cathode materials

xLi₂MnO₃-(1-x)LiNi_0.9Zn_0.1O₂ (x = 0.1, 0.2 and 0.3) cathodes were prepared by two steps solid-state reaction method. Layered crystalline phases (space groups of C2/m for Li₂MnO₃ and R3m for LiNi_0.9Zn_0.1O₂) were detected in all cathodes. FTIR study also revealed the formation of the layered-type structures of all cathodes. The structural parameters were greatly influenced by the contents of Li₂MnO₃ in xLi₂MnO₃-(1-x)LiNi_0.9Zn_0.1O₂. The electrical conductivities were found in the range of 1.2 × 10^?6 to 2.7 × 10^?6 S/cm. The dielectric spectra revealed the interfacial polarization Maxwell–Wagner type dielectric dispersion existing in all samples. The cathodes delivered the discharge capacities of 149 (x = 0.1), 151 (x = 0.2) and 157 mAh/g (x = 0.3) with capacity retention between 94.6 and 96.8% when they were cycled from 3.0 to 4.5 V under 0.1C rate. The x = 0.3 cathode exhibited the highest cyclic performance (96.8%) after 10 cycles due to its lower cations disorder.