Organic light-emitting diodes (OLEDs) have attracted significant attention because of their promise for application in full-colour flat-panel displays and solid-state lighting sources. The ratio of singlet excitons to triplet excitons is 1:3 under electrical excitation. The internal quantum efficiency (IQE) of conventional fluorescent OLEDs is limited to 25% because only singlet excitons are available for light emission. Thermally activated delayed fluorescence (TADF) is a promising way to obtain a high nearly 100% IQE by converting triplet excitons up to the singlet state level by the reverse intersystem crossing (RISC). The key to design TADF materials is to combine a small energy gap (ΔE_ST) between the lowest singlet excited states (S₁) and lowest triplet excited states (T₁) with high photoluminescence quantum efficiency simultaneously. This review summarizes the recent progress in TADF materials, focusing on the design strategies and device performance.

Boron-Dipyrromethene (BODIPY) dyes have been widely applied due to their outstanding optical and electronic properties. The research on BODIPY-based conjugated polymers has attracted considerable attention in recent years. In comparison with their monomers, BODIPY-based conjugated polymers display lower band gap, red-shifted absorption maximum, and higher charge carrier mobilities. Accordingly, BODIPY-based conjugated polymers have prospect applications in organic semiconducting materials and organic solar cells. In this paper, the preparation, structure-property relationships, and applications of BODIPY-based conjugated polymers were reviewed. Furthermore, the rational design strategies as well as the future development of BODIPY-based conjugated polymers were discussed.

Selective hydrogenation is an effective method to remove trace acetylene in ethylene derived from the steam cracking. It is very significant to develop the high efficient catalyst for the selective hydrogenation of acetylene. Here, the types of the catalysts (such as mono-noble and non-noble metals as well as bimetallic-/multi-metals) and their performance are introduced. The influences of support, promoter and preparation method on the catalyst structure and reactivity are analyzed. Particularly, the geometric and the electronic effects on the catalyst performance are elaborated.

The synthetic fibers characterized in this paper are polypropylene fiber, polyhexamethylene sebacamide fiber and polyethylene terephthalate fiber. Inverse gas chromatography was used with n-alkane and distilled water as probe molecules. The surface wettability of different fibers was determined by measuring the dispersive component of surface free energy and the net retention volume of water molecule. The factors of influence on the surface wettability were also discussed. The results show that the chemical structure unit of the synthetic fiber is the decisive factor for the surface wettability. The polypropylene fiber with nonpolar groups has good lipophilicity, while polyhexamethylene sebacamide fiber with polar groups has good hydrophilicity. The yarn structure affects the expansion level when fiber is heated, which has a great effect on temperature dependence of the dispersive component of surface free energy.

The extraction of active ingredients from discard tobacco leaves was investigated by solvent extraction. The effect of extraction time, extraction temperature and liquid-solid ratio was studied using the Response Surface Method (RSM) with the Box-Behnken Design (BBD) method. The optimized extraction temperature was 42.54 ℃, extraction time was 6 hours and liquid-solid ratio was 12.31 mL/g. The extraction yield of essential oil was achieved as high as 7.94% under above conditions and nicotine accounted for 32.25%, pinane for 23.14% and vitamin E for 14.11% of the oleoresin.

Nanometer alumina was prepared by using aluminum-air battery discharge product. The experiment was carried out to study the temperature and the amount of acid for the discharge product reaction, and the influence of reactant titration speed on the precursor and the influence of calcination conditions on the nanometer alumina dispersion. The results show that the discharge product can be completely dissolved when m(sulfuric acid):m(discharge)=5:2 and the reaction temperature is at 100 ℃, the pure ammonium aluminum carbonate precursor can be achieved when the titration speed of aluminum sulfate is less than 16 mL/min, when the precursor is heated at the low temperature of 300 ℃ first, and then calcinated at the high temperature of 1 200 ℃, the monodispersed α-Al₂O₃ can be around 50 nm.

Lithium-air batteries with the highest specific energy has become a hot research topic in the field of chemical power source. Among the components of lithium-air batteries, design and preparation of air electrode is a key factor for improving the performance of lithium-air batteries. A new catalyst of LaNiO₃ with high catalytic activity is prepared by a simple synthetic method. The experimental results show that the lithium-air battery with LaNiO₃ catalyst has a good charge-discharge performance, which discharge capacity is 1 109 mAh·g^-1 and discharge voltage platform is 2.59 V. The impact of two kinds of carbon materials (Super P and GNS) as the catalyst carrier on the charge-discharge performance of lithium air battery is studied in detail. It can be found that the porous structure of electrode is more advantageous to the improvement of performance of lithium-air battery. Furthermore, the necessity of controlling water content in the electrolyte(1 mol·L^-1 LiTFSI/TEGDME)is also discussed. A good cyclic performance of lithium air batteries with LaNiO₃/Super P air electrode can be obtained in an electrolyte (water content < 1×10^-5). The capacity retention of lithium air batteries after the fifth cycle is 96.21%. There is no obvious change for the voltage platform.

Two two-dimensional organic-inorganic cupric bromide perovskites (p-F-C₆H₅C₂H₄-NH₃)₂-CuBr₄(P1)and (CH₃(CH₂)₃NH₃)₂-CuBr₄(P2)were prepared and applied to solid solar cells as novel hole transport materials (HTMs). The P1 and P2 films were characterized by UV/Vis、XRD and SEM. The photocurrent measurement and electrochemical impedance spectroscopy (EIS) were performed for devices based on P1 or P2. The effect of the additions of Li-TFSI and TBP to P1 and P2 was also researched. The results show that the additions of Li-TFSI and TBP can improve the hole conductivities of P1 and P2 and their charge transfer abilities. The P1 and P2 based devices with additives of Li-TFSI and TBP achieve 0.50% and 0.56% of PCE, respectively.

Six kinds of ionic liquids (ILs) with anion of BF₄^- and cation of 1-alkyl-3-methylimidazole were applied to extract bitumen from oil sands as additive agent combined with toluene or acetone/heptane composite solvent. The effect of the carbon chain length of the 1-position imidazole ring on the extraction of bitumen and solid entrainment was investigated. The results demonstrate that the extraction ratios are reduced with the increase of the length of 1-position carbon chain of cation in both acetone/heptane and toluene systems. The extraction ratio is reduced from 9.29% to 8.55% in acetone/heptane composite solvent system, and reduced from 10.05% to 9.45% in toluene system. But, in both systems, the extraction ratio assisted with ionic liquids of which 1-positon carbon chain is n-butyl was higher than that of which 1-position carbon chain is n-propyl. In addition, the FTIR spectrum results indicate that assisted with the 6 kinds of ILs, much less clay fines in the recovered bitumen are found than that using toluene extraction alone.

Vacuum transfers lines are pipelines connecting vacuum furnaces and distillation columns and are most important pipelines in petrochemical plants. A well-designed transfer line can help not only to increase the evaporation rate, but also to improve the product's quality and lower the energy consumption. In the present work, the DPM model was used to simulate the two-phase flow in transfer lines. The calculation result shows that the type of transition sections significantly affects the pressure and temperature drop within the pipeline. Multi-stage tube diameter expansions of transfer lines will reduce the fluctuation of the flow field. The usage of trousers-shaped three-way tubes will reduce the maximum velocity within pipelines. Most evaporated residual oil is the lighter component and the heavier residual oil evaporates slightly. Collisions between droplets and walls are most likely at the bends of transfer lines.

For the first time, the structure of doped ceria-carbonate composite electrolytes in solid oxide fuel cells is modeled by a two phase random lattice, which is then converted into a random resistor network to calculate the ionic conductivity of the composite electrolytes. The dependence of O^2- and H⁺ conductivities on the volume fraction of carbonate, the grain size of doped ceria and temperature is simulated. The simulation results are compared with the experimentally obtained conductivities of samarium doped ceria-carbonate composite electrolytes. The simulation and experimental results are found to be in good agreement.

Three protein ligands, antibody binding domain Z (SpA_Z), its four repeats of SpA_4z (which currently used in some commercially available protein A adsorbents) and alkaline resistant mutant SpA_4m were coupled onto Sepharose CL-6B to prepare affinity adsorbents: SpAZ-Sepharose, SpA_4Z-Sepharose and SpA_4m-Sepharose. Adsorption equilibria of antibody on SpAZ-Sepharose and SpA_4Z-Sepharose indicates that antibody has much high affinity to both beads, and the affinity increased significantly with an increment of domain Z in the ligands. Furthermore, calorimetric measurement of antibody and affinity beads was carried out in an isothermal titration calorimeter to analyze the thermal behavior of antibody adsorption. The results indicate that the immobilization of the ligand lead to a decrease of the affinity, and it is driven by enthalpy. The research provided an insight into the interaction mechanism between protein A ligand and antibody. NaOH is the most commonly used chromatographic clean-in-place (CIP) reagent. Mutant SpA_4m was constructed to improve the SpA alkaline tolerance towards CIP treatment. The results of differential scanning calorimetry show that SpA_4m has higher T_m value than SpA_4z nd SpA_Z, indicating the novel mutant is more stable. The chromatographic results also reveal that SpA_4m has greater tolerance to alkaline condition. Therefore, the research provides insight into the interaction mechanism between SpA ligand and antibody and tolerance of the ligand to alkaline condition.

7-Dehydrocholesterol is an important intermediate in synthesizing vitamin D₃, while the chemical synthesis and the biological transformation techniques could not satisfy the requirement of industrial production so far. The emerge of synthetic biology has provided another choice for the heterologous synthesis of secondary metabolites. Saccharomyces cerevisiae and Yarrowia lipolytica are model organisms in industry. The ergosterol biosynthesis may suppress the 7-dehydrocholesterol production in S.cerevisiae. The combined strategy of knocking out erg5, a non-essential gene for ergosterol synthesis, and introducing human dhcr24 gene encoding C24 reductase resulted in 2.62 mg·L^-1 7-dehydrocholesterol production in shake flask culture. The ergosterol did not show any influence on the synthesis of 7-dehydrosterol in Y.lipolytica. After integrating the human dhcr24 gene into rDNA site of the genome, the highest production of 7-dehydrosterol in Y.lipolytica was 27.91 mg·L^-1. The results in this study provide a reference of the discovery of suitable chassis for the biosynthesis of sterol metabolites.

It is fundamental to study the principles on how to adjust the polymorphic crystals of organic compounds in the fields of pharmaceutics, fuels and pesticides. Theophylline is a kind of methyl purine analogues, and has polymorphic crystals including the form I, II, III, IV and M. Taking into account the structural similarity between adenosine and theophylline, we studied the effect of oligonucleotides containing adenosines on the solution crystallization process of theophylline. The results indicate that adopting the oligonucleotide of d(A₁₀) or d(A₂₀) as the additive the crystallization process of theophylline ethanol-water solution is greatly affected to facilitate the formation of M form. Molecular modeling calculations disclose that there are strong interactions between the nucleotide segment containing adenosines and crystallographic important faces of theophylline, which in turn facilitates the growth of M form of theophylline during the crystallization.