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1.
Yin-Feng Wang Meng Li Jin-Ming Teng He-Ye Zhou Chuan-Feng Chen 《Advanced functional materials》2021,31(49):2106418
Recently, circularly polarized organic light-emitting diodes (CP-OLEDs) fabricated with thermally activated delayed fluorescence (TADF) emitters are developed rapidly. However, most devices are fabricated by vacuum deposition technology, and developing efficient solution-processed CP-OLEDs, especially nondoped devices, is still a challenge. Herein, a pair of triptycene-based enantiomers, (S,S)-/(R,R)-TpAc-TRZ, are synthesized. The novel chiral triptycene scaffold of enantiomers avoids their intermolecular π–π stacking, which is conducive to their aggregation-induced emission characteristics and high photoluminescence quantum yield of 85% in the solid state. Moreover, the triptycene-based enantiomers exhibit efficient TADF activities with a small singlet-triplet energy gap (ΔEST) of 0.03 eV and delayed fluorescence lifetime of 1.1 µs, as well as intense circularly polarized luminescence with dissymmetry factors (|gPL|) of about 1.9 × 10−3. The solution-processed nondoped CP-OLEDs based on (S,S)-/(R,R)-TpAc-TRZ not only display obvious circularly polarized electroluminescence signals with gEL values of +1.5 × 10−3 and −2.0 × 10−3, respectively, but also achieve high efficiencies with external quantum, current, and power efficiency up to 25.5%, 88.6 cd A−1, and 95.9 lm W−1, respectively. 相似文献
2.
针对检重秤测量过程中受振动干扰影响严重的问题,提出一种基于外部输入非线性自回归模型(NARX)的动态神经网络系统辨识的抗振新方法。通过加速度传感器的冗余分布,对检重秤系统的振动特性进行估计,结合空载传送情况下称重传感器由振动干扰产生的误差,利用动态神经网络对振动干扰信号进行自动辨识,建立振动信号分析模型,用以匹配消除动态检重信号中的振动扰动。在共振状态下,与滑窗滤波、自适应陷波等传统抗振方法进行的仿真与测试实验对比,证明基于多加速度传感器的动态称重抗振性能更优,最终实现运行速度达2 m/s,最大秤量200.0 g,满足国家标准《GB/T 27739-2011自动分检衡器》XIII级要求的检重秤搭建。 相似文献
3.
盐渍土在我国的分布区域非常广泛,尤其是在沿海地区,盐渍土由于自身的盐胀性和腐蚀性会对公路路基造成很大的破坏。因此,公路盐渍土路基的防腐蚀处理和病害防治对保证公路工程的建设质量具有重要意义。基于此,本文对公路盐渍土路基的病害成因进行了简要的分析,并提出了相应的防治策略。 相似文献
4.
Jiajia Yan Teng Zhang Haizheng Tao Hongbing Zhan Yuanzheng Yue 《Journal of the American Ceramic Society》2021,104(6):2560-2570
We study the structure, crystallization, and performances of the sealing glasses with the composition (mol.%) of 12Al2O3·8B2O3·40SiO2·40RO (R = Mg, Ca, Sr) for solid oxide fuel cells (SOFCs) before and after isothermal treatment at 700°C, which is within the operation temperature range (600-800°C) of SOFCs. The crystallization behavior has been investigated by differential scanning calorimetry and X-ray diffraction under both dynamic and isothermal conditions. The structural evolution is probed using the Raman and nuclear magnetic resonance spectroscopies. The performances of the sealing glasses are characterized in terms of the coefficient of thermal expansion, the crystallization-induced stress at glass–steel interface. We find that strong crystallization occurs at the operation temperature (700°C) far below the crystallization onset temperature measured by DSC. The structure origin of this anomalous crystallization is discussed in terms of structural heterogeneity of the three studied glasses. We determine the residual stress at the interface between the Ca-containing glass and the steel after isothermal treatment at 700°C for 48 h, but this stress does not lead to falling off the glass layer from the steel. This indicates that this glass is a good candidate to be applied in SOFCs. 相似文献
5.
Multiple functional and hard-to-quantify sensorial product attributes that can be satisfied by a large number of cosmetic ingredients are required in the design of cosmetics. To overcome this problem, a new optimization-based approach for expediting cosmetic formulation is presented. It exploits the use of a hierarchy of models in an iterative manner to refine the search for creating the highest-quality cosmetic product. First, a systematic procedure is proposed for optimization problem formulation, where the cosmetic formulation problem is defined, design variables are specified, and a set of models for sensorial perception and desired product properties are identified. Then, a solution strategy that involves iterative model adoption and two numerical techniques (i.e., generalized disjunctive programming reformulation and model substitution) is applied to improve the efficiency of solving the optimization problem and to find better solutions. The applicability of the proposed procedure and solution strategy is illustrated with a perfume formulation example. 相似文献
6.
Karolina Storesund Francine Amon Anne Steen‐Hansen Shayesteh Haghighatpanah Ida Larsson 《火与材料》2021,45(1):181-190
The aim of this exploratory study has been to investigate the fire properties and environmental aspects of different upholstery material combinations, mainly for domestic applications. An analysis of the sustainability and circularity of selected textiles, along with lifecycle assessment, is used to qualitatively evaluate materials from an environmental perspective. The cone calorimeter was the primary tool used to screen 20 different material combinations from a fire performance perspective. It was found that textile covers of conventional fibres such as wool, cotton and polyester, can be improved by blending them with fire resistant speciality fibres. A new three‐dimensional web structure has been examined as an alternative padding material, showing preliminary promising fire properties with regard to ignition time, heat release rates and smoke production. 相似文献
7.
Virginie Boy Wajdi Ben Khalifa Lucie Drvillon Yves Leme Thomas Lendormi Jean‐Louis Lanoisell 《加拿大化工杂志》2021,99(1):120-134
An original drying process combining air impingement and intermittent drying was studied on apple slices and mango cubes. The influence of four operating parameters (air velocity, drying/tempering periods, upper height, and air temperature) on the drying time and on the drying rate was evaluated. Continuous and intermittent drying were compared. The intermittency α = 1/7 (τon = 10 seconds and τoff = 60 seconds) gave the best results. A time savings of 54% for apple and 67% for mango was reached. In continuous drying, a time savings of 4620 seconds was observed by increasing the air velocity from 6 to 40 m s?1 for apple. Air temperatures of 328 K for apple and of 328 K or 338 K for mango were determined as optimum to prevent case‐hardening. Experimental results were fitted with the analytical solution of Fick's second law and the modified Page equation (average values R2 = 0.985 and 0.961, for apple and mango, respectively). For both products, the apparent moisture diffusivity Dapp, the drying constant k, the drying coefficient n, and the activation energy Ea, were identified. Activation energies calculated from the analytical solution were 30.3 and 36.8 kJ mol?1 and were 25.4 and 30.0 kJ mol?1 using the modified Page equation for apple and mango, respectively. Mango has an increased temperature sensitivity and thus will need less energy for drying than apple. 相似文献
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10.
针对3种不同粒径的高煤级煤开展了甲烷高压等温吸附测试,并对不同粒径煤样甲烷吸附前后的孔隙结构特征进行了对比研究。结果表明,不同粒径煤样的等温吸附曲线没有显著的差异,随着煤岩粒径的减小,煤岩的吸附速率和最大过剩吸附量呈逐渐增加的趋势。甲烷吸附前后,不同粒径煤样的孔隙结构发生了不同的变化。甲烷等温吸附前,随着煤岩粒径的减小,低温液氮吸附滞后环开度呈逐渐减小的趋势,等效吸附率曲率则先减小后增大;甲烷吸附后,DY-5煤样的低温液氮吸附滞后环开度减小,而DY-6煤样和DY-7煤样的低温液氮吸附滞后环开度有所增加,说明甲烷吸附对小粒径煤样中孔和大孔的影响较为显著。甲烷的吸附作用对各阶段孔隙均有影响。大粒径煤样在甲烷吸附作用影响下,孔隙连通性得以改善,而小粒径煤样在甲烷吸附作用后孔隙分布更加的集中。 相似文献