Fe3O4-CDs confined within a ZIF crystal matrix prevent the aggregation of metal nanoparticles and facilitate the fabrication of Fe3C/Fe-CNT catalysts by one-step pyrolysis at 900 °C in the absence of a H2 atmosphere.

Maximizing the utilization efficiency of monatomic Fe sites in Fe-N-C catalysts poses a significant challenge for their commercial applications. Herein, a structural and electronic dual-modulation is achieved on a Fe-N-C catalyst to substantially enhance its catalytic performance. We develop a facile multi-component ice-templating co-assembly (MIC) strategy to construct two-dimensional (2D) arrays of monatomic Fe-anchored hollow carbon nanoboxes (Fe-HCBA) via a novel dual-outward interfacial contraction hollowing mechanism. The pore engineering not only enlarges the physical surface area and pore volume but also doubles the electrochemically active specific surface area. Additionally, the unique 2D carbon array structure reduces interfacial resistance and promotes electron/mass transfer. Consequently, the Fe-HCBA catalysts exhibit superior oxygen reduction performance with a six-fold enhancement in both mass activity (1.84 A cm-2) and turnover frequency (0.048 e- site-1 s-1), compared to microporous Fe-N-C catalysts. Moreover, the incorporation of phosphorus further enhances the total electrocatalytic performance by three times by regulating the electron structure of Fe-N4 sites. Benefitting from these outstanding characteristics, the optimal 2D P/Fe-HCBA catalyst exhibits great applicability in rechargeable liquid- and solid-state zinc-air batteries with peak power densities of 186 and 44.5 mW cm-2, respectively. A structural and electronic dual-modulation is achieved on 2D arrays of hollow carbon nanoboxes, exhibiting exceptional performance in rechargeable zinc-air batteries.

为满足当前经济发展对专业人才的要求,创新应用型人才的培养是高等学校教学工作的重点,"分析方法选择及方案设计"课程是江苏理工学院应用化学专业开设的专业核心课,作者从教学目标的定位、教学内容的选择、教学方法的创新、考核方式的优化等几个方面对课程进行了教学探索,希望能够为学生综合实践能力的提高、教学质量的提升、相关课程的教学和改革提供思路与借鉴.

科技创新是驱动社会发展、增强综合国力的永恒动力。培养并造就具有强大科技创新能力的人才队伍是新时代下高等学校面临的重大又颇具挑战性的任务。因此，如何提高大学生的科技创新能力十分重要。在教育教学活动中基于“翻转课堂教学—实验室（或研究室）开放——学生课题立项—学科（或专业）竞赛—毕业设计（论文）”五位一体的集成模式下培养大学生的科技创新能力，以期激发学生的创新思维，提升人才培养质量，为相关教学改革提供思路与借鉴。

A new azobenzene-based symmetric amphiphile was synthesized and characterized using 1H NMR spectroscopy. Its self-assembly behavior as well as photo-responsive behavior in its solution and gel states were investigated. Such a compound can self-assemble into fiber mesophases in water solvent. After irradiation of the gels with UV light, the trans isomer of the compound rapidly photoisomerized to the cis isomer, which resulted in a rapid destruction of the gel. High temperature also caused a rapid drop in viscosity. To verify the antimicrobial activity of the hydrogel, live and death assays of human fibroblasts L929 properties were used for in vitro cell viability studies. The compound was converted to the terminal tertiary amine in a quaternary ammonium salt molecule by using hydrochloric acid. This azobenzene quaternary ammonium salt has a relatively better antimicrobial effect biocidal activity that was demonstrated when challenged against Escherichia coli on in vitro conditions.

分析化学是高校重要的专业基础课之一.本文以江苏理工学院环境科学专业为例,针对分析化学课程教学现状,从优化教学内容、多种教学方法并举、开展线上线下混合式教学以及优化考核方式等方面,探讨了分析化学课程教学改革措施,以期达到激发学生学习兴趣,提高教学质量,增强学生综合能力的目的.

在"线上+线下"混合式教学模式下,根据线上与线下两种教学模式的特点,本文探讨了线性代数教学过程的课前、课中与课后三个阶段的教学方式与教学内容的设计安排.

A new amphiphilic surfactant (C4-Azo-C5-HDA) was formed by liquid crystals (LCs) based on azobenzene, whose structures were characterized by 1H-NMR spectroscopy. The reversible hydrogelation upon changes in temperature and light exposure was also studied. Under the irradiation of UV light, the trans-isomer of C4-Azo-C5-HDA rapidly photoisomerized to the cis-isomer, resulting in rapid disruption of the gel. The thermotropic liquid crystal behavior of the gelator was investigated via Differential Scanning Calorimetry (DSC) and Polarizing Optical Microscopy (POM). The biocompatibility experiment of multi-stimulus response of the liquid crystal provides a potential driving force for the development of biomaterials.

ABSTRACTThe design and synthesis of a new azobenzene‐based methacrylate monomer (Azo‐IEM) was demonstrated, and its polymerization behavior during reversible addition‐fragmentation chain transfer (RAFT) polymerization was investigated. Well‐defined homopolymer and amphiphilic block copolymer containing Azo‐IEM monomeric units were successfully prepared as evidenced by NMR and GPC analysis. Moreover, the photo‐triggered reversible isomerization of polymer products in selected solvents was investigated. Finally, TEM analysis showed that there were significant differences in the nanoparticle morphologies when the block copolymer samples were irradiated with different wavelengths of light (i.e., UV and visible). The size and shapes of the p(HEMA‐b‐Azo‐IEM) polymer capable of transitions upon changes in Vis/UV light exposure which prepared from MeOH/CHCl3 mixture solvent. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47870.

With houttuynia cordata as carbon source, photoluminescent carbon quantum dots (CDs) were obtained via a one-step hydrothermal procedure. The absorption band of metronidazole (MNZ, maximum absorption wavelength at 319 nm) can well overlap with the excitation bands of CDs (maximum excitation wavelength at 320 nm). A fluorescent approach has been developed for detection of MNZ based on the inner filter effect (IFE), in which as-prepared CDs act as an IFE fluorophore and the MNZ as an IFE absorber. We have investigated the mechanism of quenching the fluorescence of CDs and found that the IFE leads to an exponential decay in fluorescence intensity of CDs with increasing concentration of MNZ, but showed a good linear relationship (R 2 = 0.9930) between ln(F 0/F) with the concentration of MNZ in the range of 3.3 × 10-6 to 2.4 × 10-4 mol L-1. Due to the absence of surface modification of the CDs or establishing any covalent linking between the absorber (MNZ) and the fluorophore (CDs), the developed method is simple, rapid, low-cost and less time-consuming. Meanwhile, it possesses a higher sensitivity, wider linear range, and satisfactory selectivity and has potential application for detection of MNZ in pharmaceutical preparations.

A series of new thermotropic liquid crystals (LCs) containing azobenzene units was synthesized. The structures of the compounds were characterized by means of NMR and FTIR spectroscopy. Their mesomorphic behaviors were investigated via differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Based on the POM and DSC measurements, the optical properties of the Razo-ester were tested using UV-vis spectroscopy. The azobenzene side chain displayed a strong ability to influence the formation of thermotropic LCs.

仪器分析实验是应用化学系专业以及其它相关专业的一门重要专业课程,学好实验过程中用到的各类分析仪器能够给同学们在将来的科研和工作中带来较大帮助,而对相关仪器的维护,能够使同学更加深入地了解仪器的原理与构造组成,使用技巧以及检测应用,本论文从教学内容选择、教学方法以及考核手段三个方面对分析仪器的维护课程进行教学探索,以期为相关实践课程提供借鉴.

《仪器分析》是面向环境类研究生开设的一门重要的专业学位课程,本文基于学院环境工程领域专业研究生的特点,从大纲的修订、教学内容和教学方法以及考核体系等进行了改革与实践,取得了较好的教学效果.

The method of continuous determination of gold,silver and palladium in copper anode low grade copper slag was established and compared with the fire test method. First,the copper anode low grade copper slag was digested with nitric acid+EDTA+tartaric acid to obtain a digestion solution containing silver,palladium and a small amount of gold. The effects of nitric acid,EDTA and tartaric acid dosage on digestion were investigated. The results showed that the digestion was the best when the dosage of nitric acid,EDTA and tartaric acid were 30mL,3mL and 1.5g,respectively. Then,the residue was subjected to secondary digestion with aqua regia to obtain a digestion solution containing gold and a small amount of silver and palladium. The effects of aqua regia dosage on digestion were investigated. The results showed that the amount of aqua regia required to complete the digestion was 15mL. Finally,the contents of gold, silver and palladium in digestion solution were determined by flame atomic absorption spectrometer. The relative standard deviations of Au,Ag and Pd in the copper anode low grade copper slag were less than 1% (n=10),and the recoveries were between 95.57% and 98.70% by this method. The experimental results are accurate,reliable and reproducible,which is consistent with the results of fire test method.

Polyether-modified polysiloxane graft poly(2-vinylpyridine) (PMP-g-P2VP) copolymer, which was confirmed by NMR spectra and GPC, was synthesized for separation of dsDNA by capillary electrophoresis. EOF measurement results showed that the synthesized copolymer-coated capillaries in this report could suppress EOF effectively compared to the bare fused-silica capillaries. The effectiveness of PMP-g-P2VP polymer as a media for DNA analysis was discussed. Significant improvement in resolution of dsDNA analysis was demonstrated compared to the conventional polymer matrix. Results showed that 100-bp DNA ladder samples achieved separation in a 30 cm effective capillary length at 2.0% concentration by using this copolymer. Finally, the relationships between morphologies of copolymer in glass surface and the separation efficiencies were studied by scanning electron microscope (SEM). (c) 2016 Wiley Periodicals, Inc.

Knowledge of aerosol chemistry in densely populated regions is critical for effective reduction of air pollution, while such studies have not been conducted in Changzhou, an important manufacturing base and populated city in the Yangtze River Delta (YRD), China. This work, for the first time, performed a thorough chemical characterization on the fine particulate matter (PM2.5) samples, collected during July 2015 to April 2016 across four seasons in this city. A suite of analytical techniques was employed to measure the organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), water-soluble inorganic ions (WSIIs), trace elements, and polycyclic aromatic hydrocarbons (PAHs) in PM2.5; in particular, an Aerodyne soot particle aerosol mass spectrometer (SP-AMS) was deployed to probe the chemical properties of water-soluble organic aerosol (WSOA). The average PM2.5 concentration was found to be 108.3 µg m−3, and all identified species were able to reconstruct ∼ 80 % of the PM2.5 mass. The WSIIs occupied about half of the PM2.5 mass (∼ 52.1 %), with SO42−, NO3−, and NH4+ as the major ions. On average, nitrate concentrations dominated over sulfate (mass ratio of 1.21), indicating that traffic emissions were more important than stationary sources. OC and EC correlated well with each other and the highest OC ∕ EC ratio (5.16) occurred in winter, suggesting complex OC sources likely including both secondary and primary ones. Concentrations of eight trace elements (Mn, Zn, Al, B, Cr, Cu, Fe, Pb) can contribute up to ∼ 5.0 % of PM2.5 during winter. PAH concentrations were also high in winter (140.25 ng m−3), which were predominated by median/high molecular weight PAHs with five and six rings. The organic matter including both water-soluble and water-insoluble species occupied ∼ 21.5 % of the PM2.5 mass. SP-AMS determined that the WSOA had average atomic oxygen-to-carbon (O ∕ C), hydrogen-to-carbon (H ∕ C), nitrogen-to-carbon (N ∕ C), and organic matter-to-organic carbon (OM ∕ OC) ratios of 0.54, 1.69, 0.11, and 1.99, respectively. Source apportionment of WSOA further identified two secondary OA (SOA) factors (a less oxidized and a more oxidized oxygenated OA) and two primary OA (POA) factors (a nitrogen-enriched hydrocarbon-like traffic OA and a local primary OA likely including species from cooking, coal combustion, etc.). On average, the POA contribution outweighed SOA (55 % vs. 45 %), indicating the important role of local anthropogenic emissions in the aerosol pollution in Changzhou. Our measurement also shows the abundance of organic nitrogen species in WSOA, and the source analyses suggest these species are likely associated with traffic emissions, which warrants more investigations on PM samples from other locations.

高等数学是一门重要的公共基础课.其教学质量直接影响到学生后续专业课程的学习和能力的提高.探讨了高等数学这门课程在教学内容中存在的不足及教学内容改革面临的困难,并提出了关于高等数学教学内容改革的五点优化设想:加大教材改革力度、课堂教学与网络教学相结合、充分利用学生手中的电子资源、考核模式与内容多样化和充分调动教师的积极性.

A new supramolecular gelator was formed by combining a polyetheramine surfactant, an azobenzene liner, and a silane group. This amphiphilic surfactant was evaluated in a DMSO/H2O mixing solvent to test the gelation ability by inversion of the vials. The azobenzene-based gelator was found to rapidly and reversibly transform from gel to solution upon changes in temperature and light. Upon heating, it caused disruption of the p-p bonding, which was confirmed by 1H NMR at different temperatures. Height of the foam columns and the surface tension of solution can be photocontrolled stability, which showed a novel smart surfactant was formed.

基于大学数学课程的性质和大学生的认知结构特点,对课堂教学导入的重要性与作用进行了探讨.介绍了大学数学课堂教学的几个导入技巧与教学实例.

A series of cellulose-based "hydrogels were produced by crosslinking of hydroxypropylcellulose (HPC) and carboxymethylcellulose sodium salt (CMCNa) with citric acid (CA) and the gelation ability of the prepared crosslinked polymers was investigated in detail. It was found that the swelling ratio of the prepared hydrogels was closely related with their preparation conditions, such as reaction time and temperature. The gelators and resulting hydrogels were characterized by scanning electron microscopy (SEM), differential scanning calorimeter (DSC), and Fourier transform infrared spectroscopy (FTIR), respectively. The biocompatibility of the hydrogels was verified by in vitro cell viability studies on fibroblasts L929. The results showed that these crosslinked hydrogels can be used for potential biomaterial applications.