Effect of operating conditions on the removal of Pb2+ by microporous titanosilicate ETS-10 in a fixed-bed column

The breakthrough behavior of Pb2+ in an ETS-10 fixed bed was experimentally examined at various operating conditions. Results showed that the adsorption amount of Pb2+ ions per unit mass of ETS-10 particles in a column is about 1.68 mmol/g under the experimental conditions. This amount was not markedly affected by the operating conditions because of the rapid adsorption rate of Pb2+ ions on ETS-10. In the presence of competitive metal ions, the amount of Pb2+ adsorbed on ETS-10 was slightly reduced. An overshoot of the effluent concentrations of competitive metal ions Cu2+ and Cd2+ was observed in the adsorption systems of binary and ternary solutions. This is ascribed to the replacement of pre-adsorbed Cu2+ and Cd2+ ions by Pb2+ ions. The ETS-10 column broken up by Pb2+ ions can be regenerated by using an EDTA-Na2 solution and the regenerated column can be reused.     

Single-wall carbon nanotube-containing cathode interfacial materials for high performance organic solar cells

Water/alcohol soluble cathode interfacial materials(CIMs)are playing important roles in optoelectronic devices such as organic light emitting diodes,perovskite solar cells and organic solar cells(OSCs).Herein,n-doped solution-processable single-wall carbon nanotubes(SWCNTs)-containing CIMs for OSCs are developed by dispersing SWCNTs to the typical CIMs perylene diimide(PDI)derivatives PDIN and PDINO.The Raman and X-ray photoelectron spectroscopy(XPS)measurement results illustrate the ndoped behavior of SWCNTs by PDIN/PDINO in the blend CIMs.The blended and n-doped SWCNTs can tune the work function and enhance the conductivity of the PDI-derivative/SWCNT(PDI-CNT)composite CIMs,and the composite CIMs can regulate and down-shift the work function of cathode,reduce the charge recombination,improve the charge extraction rate and enhance photovoltaic performance of the OSCs.High power conversion efficiency(PCE)of 17.1%and 17.7%are obtained for the OSCs based on PM6:Y6 and ternary PM6:Y6:PC₇₁ BM respectively with the PDI-CNTcomposites CIMs.These results indicate that the ndoped SWCNT-containing composites,like other n-doped nanomaterials such as zero dimensional fullerenes and two dimensional graphenes,are excellent CIMs for OSCs and could find potential applications in other optoelectronic devices.     

Microwave-Assisted Enzymatic Extraction of Flavonoids from Armeniaca mume Sieb. Blossom and Their Immunomodulating Effect in Mice with DSS-Induced Colitis

Armeniaca mume Sieb. blossom is among the traditional Chinese edible flowers, and it is widely used in the food and pharmaceutical industries. Flavonoids are among the most abundant bioactive compounds in A. mume Sieb. blossom. However, the research on the extraction of flavonoids from A. mume Sieb. blossom and their immunomodulating function is insufficient. In this study, we developed a microwave-assisted enzymatic extraction of flavonoids from A. mume Sieb. blossom (FAMB) and explored their immunomodulating effect on mice with dextran sulfate sodium salt-induced colitis. The results showed that the optimum parameters for microwave-assisted enzymatic extraction of FAMB were as follows: cellulase: 2.0%; microwave power: 200 W; microwave action time: 5 min; and enzymatic hydrolysis time: 50 min. FAMB significantly promoted the lymphocyte proliferation and natural killer (NK) cell killing activity in colitis mice, and increased the concentrations of TNF-α, IFN-γ, and IL-2 in serum. FAMB also significantly reduced the apoptosis of spleen lymphocytes in these mice. These results demonstrated that the microwave-assisted enzymatic method could significantly improve the yield and efficacy extraction of FAMB. FAMB showed a good immunomodulation effect on colitis mice.     

A Novel Flexible Electrochemical Ascorbic Acid Sensor Constructed by Ferrocene Methanol doped Multi-walled Carbon Nanotube Yarn

An ascorbic acid (AA) electrochemical sensor was fabricated by ferrocene methanol (Fc−OH) modified multi-walled carbon nanotube yarn (CNTY). The prepared sensor (Fc−OH/CNTY) exhibited outstanding flexibility, highly stretchability, excellent bendability and obviously electrocatalytic activity for oxidation of ascorbic acid. The morphology of Fc−OH/CNTY was evaluated by scanning electron microscope. The electrochemical behaviour of Fc−OH/CNTY sensor was studied by cyclic voltammetry and amperometry measurements. Moreover, the influence of Fc−OH concentration, applied potential and electrolyte solution pH were also investigated to obtain the best sensor performance. The prepared sensor exhibited a wide linear range from 3 μM to 3.0 mM toward AA, and a detection limit of 1.32 μM (S/N=3). It also possessed a good lifetime and a fast response speed (2.83 s). In addition, the Fc−OH/CNTY sensor remained 90 % and 60 % of its initial activity after 100 and 500 times bending, respectively, which indicated a potential application on flexible, implantable and/or wearable electrochemical sensors.     

Ni(OH)2量子点助催化剂修饰α-Fe2O3光阳极增强光电分解水性能

氢气具有无毒、能量密度高以及燃烧过程零污染等优点,被誉为是未来代替化石能源的优质新型能源载体.探索高效的、可持续的制氢技术对氢气能源发展至关重要.其中,光电化学水分解电池以太阳能作为驱动力将水分解成氢气和氧气,是解决能源和环境危机的理想途径之一.α-Fe2O3是一种窄带隙(～2.1 eV)半导体,可以吸收约40％的太阳光,同时具有天然丰度高、成本低等优点,是目前备受关注的光阳极材料.然而,由于α-Fe2O3空穴扩散距离短和表面产氧动力学慢等缺点,导致α-Fe2O3的光电分解水效率仍然较低.针对上述问题,目前主要通过掺杂、构建异质结和负载助催化剂等手段来改善其性能.其中,负载助催化剂可以有效降低水氧化活化能和促进表面电荷分离,是改善光阳极性能的有效手段.本文采用离子吸附和螯合剂调控水解两步法,将Ni(OH)2量子点(Ni(OH)2 QDs)原位生长于α-Fe2O3表面,成功构建了Ni(OH)2 QDs/α-Fe2O3复合光阳极.透射电子显微镜结果表明,Ni(OH)2以直径为3–5 nm的量子点附着于α-Fe2O3纳米棒表面,并形成独特且牢固的异质结结构.光电水氧化性能表明,所制备的Ni(OH)2 QDs/α-Fe2O3光电阳极表现出良好的光电性能,其光电流达到了1.93 mA·cm?2(1.23 V vs.RHE),是单纯α-Fe2O3的3.5倍,且Ni(OH)2 QDs助催化剂使α-Fe2O3的起始电位降低了～100 mV.2 h稳定性测试结果表明,Ni(OH)2 QDs助催化剂在提升α-Fe2O3光电水氧化性能的同时,自身能够保持良好的稳定性,这在Ni(OH)2作为光电水氧化助催化剂的研究中较为少见.通过电化学活性面积、开路电压、电化学阻抗谱、注入效率和强度调制光电流谱等表征了Ni(OH)2 QDs对α-Fe2O3光阳极和电解液界面电荷传输的影响.结果表明,Ni(OH)2 QDs不仅能充分暴露水氧化活性位点,促进载流子在界面快速迁移,而且能有效钝化α-Fe2O3表面态,从而降低光生电子-空穴表面复合几率.本文可为多功能和高效量子点助催化剂/半导体光阳极的构建及在光电分解水制氢方面的应用提供一定借鉴.     

微波辐射下KF/nano-γ-Al2O3催化合成二硫代氨基甲酸酯类化合物

本文报道以缺电子烯烃、胺类和二硫化碳为原料,以PEG-400为溶剂,在固体碱KF/nano-γ-Al_2O_3催化下,经微波辅助的Michael加成反应高效地合成二硫代氨基甲酸酯类化合物,收率为76.5%～91.6%。对催化剂、溶剂、微波功率、反应时间等影响因素进行了考察,确定了优化的反应条件。该方法具有反应时间短、收率高和环境友好等特点。另外,本文还报道了苯甲醛、酮类、胺类与二硫化碳四组分在PEG-400溶液中,在固体碱KF/nano-γ-Al_2O_3催化下,经微波辐射"一锅法"合成二硫代氨基甲酸酯类化合物的反应,收率为73.4%～82.8%。     

Highly stretchable conductors comprising composites of silver nanowires and silver flakes

Journal of Nanoparticle Research - In this work, a process of thermal decomposition of metal carbonyls in oxygen-enriched supercritical carbon dioxide was studied. Manganese, iron, cobalt, and...     

4s和4p半核态引入价态(导致杂化指数降低)可以减弱Mon (n=2∽18)团簇的二聚体现象的第一性原理研究

钼团簇因具有独特的结构、电子和物理化学性质,被期待在未来的纳米科技中扮演重要角色,但是它们的基态结构至今还存在争议. 本研究采用粒子群优化(CALYPSO)方法对Mo_n (n=2∽18)团簇的晶体结构进行全局域能量最小化搜索,并结合第一性原理方法进一步优化. 计算表明：当4s和4p半核态不作为价态时,Mo_n (n=2∽18)团簇有明显的二聚体趋势,原子数为偶数的团簇往往是“幻数”团簇,具有较高的稳定性;但是,将4s和4p电子作为价电子后,平均杂化指数H_sp、H_sd和H_pd显著降低,二聚体趋势急剧减弱. 本文报道了Mo_n(n=11,14,15)团簇的新基态结构,证明了半核态对于Mo_n团簇是十分重要的.     

A Rolling Bearing Fault Classification Scheme Based on k-Optimized Adaptive Local Iterative Filtering and Improved Multiscale Permutation Entropy

The health condition of the rolling bearing seriously affects the operation of the whole mechanical system. When the rolling bearing parts fail, the time series collected in the field generally shows strong nonlinearity and non-stationarity. To obtain the faulty characteristics of mechanical equipment accurately, a rolling bearing fault detection technique based on k-optimized adaptive local iterative filtering (ALIF), improved multiscale permutation entropy (improved MPE), and BP neural network was proposed. In the ALIF algorithm, a k-optimized ALIF method based on permutation entropy (PE) is presented to select the number of ALIF decomposition layers adaptively. The completely average coarse-graining method was proposed to excavate more hidden information. The performance analysis of the simulation signal shows that the improved MPE can more accurately dig out the depth information of the time series, and the entropy value obtained is more consistent and stable. In the research application, rolling bearing time series are decomposed by k-optimized ALIF to obtain a certain number of intrinsic mode functions (IMFs). Then the improved MPE value of effective IMF is calculated and input into backpropagation (BP) neural network as the feature vector for automatic fault identification. The comparative analysis of simulation signals shows that this method can extract fault information effectively. At the same time, the experimental part shows that this scheme not only effectively extracts the fault features, but also realizes the classification and identification of different fault modes and faults of different degrees, which has a certain application prospect in the research and application direction of rolling bearing fault identification.     

Synthesis of narrowly distributed polystyrene-encapsulated silica nanoparticles via emulsion polymerization

Polystyrene (PS)-encapsulated silica nanoparticles were successfully synthesized by conventional emulsion polymerization for solving the aggregation matter of nanoscaled silica. The grafting coupling agents and PS on the silica surface were detected by Fourier Transform Infrared (FTIR) spectroscopy. The influence of silica and monomer to water ratios and initiator concentration on particle size distribution of the nanocomposite latex was investigated. The particle size distribution firstly narrowed and then broadened with the increase of silica and monomer to water ratios and initiator concentration. The narrow distribution could be controlled in an appropriate silica and monomer to water ratio and an initiator concentration of 1/15 and 2 wt%, respectively. From the evaluation of transmission electron microscopy (TEM) micrographs and dynamic light scattering (DLS) measurement, it was proved that the nanocomposite latex did not have all sphere-like shape, but contained tiny amounts of irregular bodies. The formation mechanism of PS-encapsulated silica nanoparticles was also discussed.