Dye‐Incorporated Polynaphthalenediimide Acceptor for Additive‐Free High‐Performance All‐Polymer Solar Cells

All‐polymer solar cells (all‐PSCs) can offer unique advantages for applications in flexible devices, and naphthalene diimide (NDI)‐based polymer acceptors are the widely used polymer acceptors. However, their power conversion efficiency (PCE) still lags behind that of state‐of‐the‐art polymer solar cells, due to low light absorption, suboptimal energy levels and the strong aggregation of the NDI‐based polymer acceptor. Herein, a rhodanine‐based dye molecule was introduced into the NDI‐based polymer acceptor by simple random copolymerization and showed an improved light absorption coefficient, an up‐shifted lowest unoccupied molecular orbital level and reduced crystallization. Consequently, additive‐free all‐PSCs demonstrated a high PCE of 8.13 %, which is one of the highest performance characteristics reported for all‐PSCs to date. These results indicate that incorporating a dye into the n‐type polymer gives insight into the precise design of high‐performance polymer acceptors for all‐PSCs.     

微波辅助萃取-气相色谱-负化学电离/电子轰击电离-飞行时间质谱法测定烟草中农药残留

建立了微波辅助萃取结合气相色谱-飞行时间质谱(GC-TOF MS)技术在负化学电离(NCI)源和电子轰击电离(EI)源两种模式下测定烟草中24种农药残留的分析方法。烟叶样品于100℃下用二氯甲烷-正己烷(3:1, v/v)混合溶剂微波萃取10 min,萃取液经弗罗里硅土固相萃取柱净化后进行检测分析。在NCI源和EI源质谱模式下,24种农药的线性关系均良好(r²>0.99),相对标准偏差分别小于8.6%和9.1%,定量限分别为0.3~6.9 μg/kg和10.2~44.9 μg/kg,加标回收率分别为75.2%~94.8%和75.0%~95.1%。比较两种离子源模式下的色谱图和质谱图,NCI源模式较EI源模式的选择性好、灵敏度高、基质干扰小、图谱简单易于解析,检出限低一个数量级以上,在分析低含量、复杂基质的样品时更具优势。     

Solid-liquid Equilibria in the Quaternary System Na＋, K＋//Br-, B4O72--H2O at 298 K

According to the compositions of the underground gasfield brines in the west of Sichuan Basin, the solu- bilities and densities of the solid-liquid equilibria in the quaternary system Na＋, K＋//Br-, B4O72--H2O at 298 K were determined by the method of isothermal solution saturation. From the experimental data, the phase diagram, water content diagram and density-composition diagram were obtained. This quaternary system is of simple eutectic type, without double salt and solid solution. There are two invariant points, five univariant curves, four fields of crystalli- zation in the system. The equilibrium solid phases are Na2BaO7·10H20, K2B4O7·4H2O, NaBr·2H2O and KBr. Na2B4O7·10H2O has a larger crystallization field, and NaBr·2H2O has a smaller crystallization field. It is also found that bromide has the salting-out effect on borate in the quaternary system Na＋, K＋//Br-, B4O72--H2Oat 298 K.     

光化学反应在分析化学中应用的研究——利用铜(Ⅱ)的阻化作用测定微量铜

在酸性介质中,碘离子在紫外光照射下产生的碘分子,与体系内预先加入的一定量的Na₂S₂O₃作用,当Na₂S₂O₃作用完后,再产生的碘分子将使淀粉指示剂显色。蓝色出现的时间与Na₂S₂O₃的含量有关。某些金属离子对此反应会起加速作用,且反应速度的改变与金属离子浓度呈良好的线性关系。我们在研究应用上述体系测定环境样品中微量铬(Ⅵ)时发现,铜(Ⅱ)对此反应有明显的阻化作用。本文研究了利用铜(Ⅱ)的光阻化作用测定铜的可能性和确定光照时间与铜(Ⅱ)浓度的定量关系。     

A Dynamic Model and Parameter Identification of High Viscosity Magnetorheological Fluid-Based Energy Absorber with Radial Flow Mode

The excellent suspension stability of the high-viscosity linear polysiloxane magnetorheological fluid (HVLP MRF) makes it a great controlled medium for magnetorheological energy absorbers (MREAs). In our previous work, the Herschel–Bulkley flow model (HB model) was used to describe the shear-thinning rheological behavior and establish the dynamic model of an HVLP MRF-based MREA with radial flow mode. However, as the established model was implicit, the MREA response time increased and the buffer effect was degraded. To improve the time response characteristics, an explicit dynamic model based on the HB model incorporating minor losses (called the E-HBM model) is proposed in this study. The model parameters were identified based on the HBM model. To verify the E-HBM model, five evaluation parameters for the energy absorption performance of the MREA, that is, peak force, mean force, crush force efficiency, specific energy absorption, and stroke efficiency, were introduced to compare the theoretical results with the experimental results obtained using a high-speed drop tower facility with a mass of 600 kg. Then, the relative error of the crush force efficiency, specific energy absorption, and stroke efficiency was quantitatively and comprehensively analyzed considering the E-HBM model and experimental results. The results indicate that the proposed E-HBM model agrees with the impact behavior of the radial flow mode MREA.     

阔叶箬竹叶和箬竹叶中挥发油的提取及成分分析

采用水蒸气蒸馏法分别提取阔叶箬竹叶和箬竹叶中的挥发油,用乙醚作溶剂进行多次萃取,利用气相色谱-质谱(GC-MS)联用分析二者的化学成分并进行比较。从阔叶箬竹叶提取的挥发油中共鉴定出37种化合物,主要成分为叶醇、1-己醇、苯甲醇、己醛、2-乙基呋喃、β-紫罗兰酮等。从箬竹叶提取的挥发油中共鉴定出49种化合物,主要成分为叶醇、苯甲醇、β-紫罗兰酮、2-己烯醛、苯乙醇、2-甲氧基-4-乙烯基苯酚、2-乙基呋喃等。两种箬叶挥发油中相对含量最高的成分都为叶醇,都含有酮、醛、醇、酚、酯类化合物,且酮、醛、醇的含量明显高于其他成分。     

Improving Soluble Expression of Tyrosine Decarboxylase from Lactobacillus brevis for Tyramine Synthesis with High Total Turnover Number

Applied Biochemistry and Biotechnology - The soluble expression of tyrosine decarboxylase (TDC) in heterologous host is often challenging. Here, acidic condition was found to be favorable for...     

Mesoscale Simulation of Bacterial Chromosome and Cytoplasmic Nanoparticles in Confinement

In this study we investigated, using a simple polymer model of bacterial chromosome, the subdiffusive behaviors of both cytoplasmic particles and various loci in different cell wall confinements. Non-Gaussian subdiffusion of cytoplasmic particles as well as loci were obtained in our Langevin dynamic simulations, which agrees with fluorescence microscope observations. The effects of cytoplasmic particle size, locus position, confinement geometry, and density on motions of particles and loci were examined systematically. It is demonstrated that the cytoplasmic subdiffusion can largely be attributed to the mechanical properties of bacterial chromosomes rather than the viscoelasticity of cytoplasm. Due to the randomly positioned bacterial chromosome segments, the surrounding environment for both particle and loci is heterogeneous. Therefore, the exponent characterizing the subdiffusion of cytoplasmic particle/loci as well as Laplace displacement distributions of particle/loci can be reproduced by this simple model. Nevertheless, this bacterial chromosome model cannot explain the different responses of cytoplasmic particles and loci to external compression exerted on the bacterial cell wall, which suggests that the nonequilibrium activity, e.g., metabolic reactions, play an important role in cytoplasmic subdiffusion.     

Syntheses,crystal structures,spectroscopic and magnetic properties of two trinuclear iron complexes with carboxylate and oximate mixed-bridge ligands

Transition Metal Chemistry - Two trinuclear oxo-centered iron(III) complexes [Fe3(μ3-O)Salox(L1)5(MeOH)2] (1) and [Fe3(μ3-O)Salox(L1)5(EtOH)2]·2EtOH·2H2O (2)...     

Time-delayed feedback control of improved friction-induced model: application to moving belt of particle supply device

Nonlinear Dynamics - In this paper, based on the original friction-induced oscillation, we propose a new friction-induced mathematical model associated with moving belt of particle supply device....