Unifying Charge Generation,Recombination, and Extraction in Low‐Offset Non‐Fullerene Acceptor Organic Solar Cells

Even though significant breakthroughs with over 18% power conversion efficiencies (PCEs) in polymer:non‐fullerene acceptor (NFA) bulk heterojunction organic solar cells (OSCs) have been achieved, not many studies have focused on acquiring a comprehensive understanding of the underlying mechanisms governing these systems. This is because it can be challenging to delineate device photophysics in polymer:NFA blends comprehensively, and even more complicated to trace the origins of the differences in device photophysics to the subtle differences in energetics and morphology. Here, a systematic study of a series of polymer:NFA blends is conducted to unify and correlate the cumulative effects of i) voltage losses, ii) charge generation efficiencies, iii) non‐geminate recombination and extraction dynamics, and iv) nuanced morphological differences with device performances. Most importantly, a deconvolution of the major loss processes in polymer:NFA blends and their connections to the complex BHJ morphology and energetics are established. An extension to advanced morphological techniques, such as solid‐state NMR (for atomic level insights on the local ordering and donor:acceptor π? π interactions) and resonant soft X‐ray scattering (for donor and acceptor interfacial area and domain spacings), provide detailed insights on how efficient charge generation, transport, and extraction processes can outweigh increased voltage losses to yield high PCEs.     

Superior Oxygen Reduction Reaction on Phosphorus‐Doped Carbon Dot/Graphene Aerogel for All‐Solid‐State Flexible Al–Air Batteries

Carbon dots have been recognized as one of the most promising candidates for the oxygen reduction reaction (ORR) in alkaline media. However, the desired ORR performance in metal–air batteries is often limited by the moderate electrocatalytic activity and the lack of a method to realize good dispersion. To address these issues, herein a biomass‐deriving method is reported to achieve the in situ phosphorus doping (P‐doping) of carbon dots and their simultaneous decoration onto graphene matrix. The resultant product, namely P‐doped carbon dot/graphene (P‐CD/G) nanocomposites, can reach an ultrahigh P‐doping level for carbon nanomaterials. The P‐CD/G nanocomposites are found to exhibit excellent ORR activity, which is highly comparable to the commercial Pt/C catalysts. When used as the cathode materials for a primary liquid Al–air battery, the device shows an impressive power density of 157.3 mW cm^?2 (comparing to 151.5 mW cm^?2 of a similar Pt/C battery). Finally, an all‐solid‐state flexible Al–air battery is designed and fabricated based on our new nanocomposites. The device exhibits a stable discharge voltage of ≈1.2 V upon different bending states. This study introduces a unique biomass‐derived material system to replace the noble metal catalysts for future portable and wearable electronic devices.     

Nonwoven rGO Fiber‐Aramid Separator for High‐Speed Charging and Discharging of Li Metal Anode

Li metal, which has a high theoretical specific capacity and low redox potential, is considered to the most promising anode material for next‐generation Li ion‐based batteries. However, it also exhibits a disadvantageous solid electrolyte interphase (SEI) layer problem that needs to be resolved. Herein, an advanced separator composed of reduced graphene oxide fiber attached to aramid paper (rGOF‐A) is introduced. When rGOF‐A is applied, F^? anions, generated from the decomposition of the LiPF₆ electrolyte during the SEI layer formation process form semi‐ionic C? F bonds along the surface of rGOF. As Li⁺ ions are plated, the “F‐doped” rGO surface induces the formation of LiF, which is known as a component of a chemically stable SEI, therefore it helps the Li metal anode to operate stably at a high current of 20 mA cm^?2 with a high capacity of 20 mAh cm^?2. The proposed rGOF‐A separator successfully achieves a stable SEI layer that could resolve the interfacial issues of the Li metal anode.     

Boosting Superior Lithium Storage Performance of Alloy‐Based Anode Materials via Ultraconformal Sb Coating–Derived Favorable Solid‐Electrolyte Interphase

Alloy materials such as Si and Ge are attractive as high‐capacity anodes for rechargeable batteries, but such anodes undergo severe capacity degradation during discharge–charge processes. Compared to the over‐emphasized efforts on the electrode structure design to mitigate the volume changes, understanding and engineering of the solid‐electrolyte interphase (SEI) are significantly lacking. This work demonstrates that modifying the surface of alloy‐based anode materials by building an ultraconformal layer of Sb can significantly enhance their structural and interfacial stability during cycling. Combined experimental and theoretical studies consistently reveal that the ultraconformal Sb layer is dynamically converted to Li₃Sb during cycling, which can selectively adsorb and catalytically decompose electrolyte additives to form a robust, thin, and dense LiF‐dominated SEI, and simultaneously restrain the decomposition of electrolyte solvents. Hence, the Sb‐coated porous Ge electrode delivers much higher initial Coulombic efficiency of 85% and higher reversible capacity of 1046 mAh g^?1 after 200 cycles at 500 mA g^?1, compared to only 72% and 170 mAh g^?1 for bare porous Ge. The present finding has indicated that tailoring surface structures of electrode materials is an appealing approach to construct a robust SEI and achieve long‐term cycling stability for alloy‐based anode materials.     

Effect of oat hay provision method on growth performance,rumen fermentation and blood metabolites of dairy calves during preweaning and postweaning periods

The comparison of the effects of all forage offering methods would be particularly useful information in modeling growth performance and rumen fermentation of dairy calves. Therefore, this study attempted to evaluate the effects of methods of oat hay provision on growth performance, rumen fermentation and biochemical blood indices of dairy calves during preweaning and postweaning periods. At birth, 40 female Polish Holstein-Friesian calves (3 days of age; 39.6 ± 0.39 kg BW) were randomly assigned to four treatment groups differing in the access to chopped oat hay: CON (control, starter without oat hay), OH (starter feed containing 10% DM basis oat hay), OH-FC (starter feed containing 10% DM basis oat hay and oat hay fed as free-choice provision in different buckets) and FC (starter feed and oat hay fed as free-choice provision in different buckets). The calves were weaned on day 56, and then the study continued until day 84. Intakes of starter feed and oat hay were recorded daily, whereas BW and hip height (HH) on day 3 and then every 14 days. Samples of blood were collected on the initiation of experiment and then every 14 days, and rumen contents on day 28, 56 and 84. No treatment effects were found for starter, starch, CP, total DM intake, average daily gain, feeding efficiency, change in HH, ruminal fluid pH, concentrations of ruminal propionate and NH₃-N, concentrations of urea nitrogen and non-esterified fatty acids in the blood. There were differences between treatments in terms of ruminal total volatile fatty acids and molar concentrations of acetate, butyrate and acetate to propionate ratio; highest in OH and OH-FC groups, especially during the postweaning period. On the other hand, lower concentrations of iso-valerate were found in OH and OH-FC groups on day 56 and 84. The concentrations of IGF-I throughout the experiment and β-hydroxybutyrate during the postweaning period in the blood were influenced by treatment, with the greatest values observed in OH and OH-FC calves. Results of this study indicate that starter feed containing chopped oat hay improves rumen fermentation parameters, which might allow successful transition from preruminant to mature ruminant state. Also, providing chopped oat hay with pelleted starter feed seems to be a better method than free-choice supplementation.     

Photoluminescence and piezoelectric behaviour of Y2Zr2O7 pyrochlore‐based multifunctional materials and the influence of Eu3+ and Sm3+

Y₂Zr₂O₇‐doped with Eu³⁺ and Sm³⁺ phosphors were prepared for the first time as multifunctional smart materials using a solid‐state reaction method at 1400^oC. Thermal behaviour, crystal structure, surface morphology, and elemental analysis were characterized using thermogravimetric (TG) and differential thermal (DTA) analyses, X‐ray diffraction (XRD) and scanning electron microscope equipped with energy‐dispersive X‐ray spectroscopy (SEM‐EDX). Experimental results revealed that both phosphors have a pyrochlore structure with a cubic crystal system. Photoluminescence properties were also measured and red emission was observed from Y_1.90Eu_0.10Zr₂O₇ and Y_1.90Sm_0.10Zr₂O₇ phosphors. Dielectric constant, loss tangent, piezoelectric charge constant, and Curie temperature of all the samples were determined using an LCR‐meter, d₃₃‐meter, and TG/DTA. Eu doping in Y₂Zr₂O₇ resulted in a high dielectric constant (9.61) and low loss tangent (1.67%) values, whereas high piezoelectric charge constant (0.68 pC/N) and high Curie temperature (820°C) could be obtained using Sm‐doped Y₂Zr₂O₇.     

棘孢木霉挥发性次级代谢产物检测及抑菌活性分析

木霉是一类具有重要生防价值的丝状真菌。文中首先对分离自浙江省绍兴市和广东省佛山市共12株棘孢木霉Trichoderma asperellum进行平板拮抗评价,然后采用顶空固相微萃取气质联用法(HS-SPME-GC-MS)检测拮抗性较好的两株菌的挥发性次级代谢产物。结果表明,棘孢木霉ZJSX5003和GDFS1009菌丝生长迅速,对尖孢镰孢菌Fusariumoxysporum抑制率分别达73%和74%。挥发性次级代谢产物主要是醇类和酮类,其中包含异丁醇、异戊醇、3-甲基-3-丁烯-1-醇、3-羟基-2-丁酮、2,3-丁二醇和6-正戊基-2H-吡喃-2-酮(6-PAP)。进一步通过体外抑菌试验,证实6-PAP具有较好的抑制尖孢镰孢菌的效果,为开发以木霉菌代谢产物如6-PAP为主要成分的生防制剂提供指导。     

软枣猕猴桃控制授粉对果实和种子的影响

为了研究软枣猕猴桃授粉规律,以11年生软枣猕猴桃紫果3号为试验材料,设置剪留花柱数量为0、2、5、8、11、14、17和23(全留对照组)共8个处理。人工授粉,收获后调查测定其单果重、坐果率、果型指数、果实可溶性固形物含量和果实内含种子数量。结果表明:随着授粉柱头数的增加,单果重等主要指标相应增加;当授粉柱头数增至为8时,其果型指数和果实可溶性固形物含量与对照全留柱头23相比差异不明显;当授粉柱头数增至为11时,其单果重、坐果率和果实内含种子数量与对照全留柱头23相比差异不明显。据此软枣猕猴桃充分授粉的数量级指标为11,当授粉柱头数小于11时,产量降低、品质下降;当授粉柱头大于11时,浪费花粉。生产上可利用猕猴桃精准充分授粉技术,节约使用花粉或减少果园雄株数量,以提高生产效率。