The ternary strategy has been proved to be an efficient approach to improve the power conversion efficiency (PCE) of organic solar cells (OSCs). However, little attention has been paid to deriving ...the general design principle for selecting an appropriate third component. Herein, we proposed a facile strategy for third-component selection in non-fullerene acceptor-based ternary OSCs. By sharing the same central unit with the host acceptor and a single fluorinated end group, the designed non-fullerene acceptor can successfully function as the third component in ternary OSCs. Following this design principle, we synthesized the BTP-F acceptor, and then incorporated it into the PM6:BTP-eC9 blend. Encouragingly, the optimized ternary OSC exhibited a high PCE of 18.45%, which is among the highest efficiency values reported for OSCs so far. In addition, the PM6:BTP-eC9:BTP-F ternary OSC displayed superior stability compared to the host system. Systematic characterizations reveal that the introduction of BTP-F into the ternary blend increases the charge transport, improves the active-layer morphology and reduces non-radiative recombination, therefore leading to a simultaneously enhanced short-circuit current, fill factor and open-circuit voltage. Furthermore, the Y6-F and L8-BO-F acceptors have been also synthesized as the third components in ternary OSCs. Compared with the binary devices, the ternary devices all exhibited improved PCEs. These results confirm the general application of the strategy we proposed, which provides a new way to further improve the efficiency of ternary OSCs.
We synthesized three fluorinated non-fullerene acceptors, BTP-F, Y6-F and L8-BO-F, and further used them as the third components to fabricate ternary organic solar cells. The PM6:BTP-eC9:BTP-F ternary device yielded a high efficiency of 18.45%.
Abstract
Although the closed pore structure plays a key role in contributing low-voltage plateau capacity of hard carbon anode for sodium-ion batteries, the formation mechanism of closed pores is ...still under debate. Here, we employ waste wood-derived hard carbon as a template to systematically establish the formation mechanisms of closed pores and their effect on sodium storage performance. We find that the high crystallinity cellulose in nature wood decomposes to long-range carbon layers as the wall of closed pore, and the amorphous component can hinder the graphitization of carbon layer and induce the crispation of long-range carbon layers. The optimized sample demonstrates a high reversible capacity of 430 mAh g
−1
at 20 mA g
−1
(plateau capacity of 293 mAh g
−1
for the second cycle), as well as good rate and stable cycling performances (85.4% after 400 cycles at 500 mA g
−1
). Deep insights into the closed pore formation will greatly forward the rational design of hard carbon anode with high capacity.
A major issue in organic solar cells is the poor mobility and recombination of the photogenerated charge carriers. The active layer has to be kept thin to facilitate charge transport and minimize ...recombination losses. However, optical losses due to inefficient light absorption in the thin active layers can be considerable in organic solar cells. Therefore, light trapping schemes are critically important for efficient organic solar cells. Traditional light trapping schemes for thick solar cells need to be modified for organic thin film solar cells in which coherent optics and wave effects play a significant role. In this review, we discuss the light trapping schemes for organic thin film solar cells, which includes geometric engineering of the structure of the solar cell at the micro and nanoscale, plasmonic structures, and more.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Monthly runoff is divided into several subseries by variational mode decomposition.•Support vector machine models the input-output relationships of all the subseries.•Quantum-behaved particle swarm ...algorithm searches for suitable model parameters.•The hybrid method obtains satisfying results in the real-world simulations.
Accurate monthly runoff prediction plays an important role in the planning and management of water resources. However, owing to climate changes and human activities, natural runoff often contains a variety of frequency components, and existing monthly runoff estimation techniques may fail to capture potential change processes effectively. To overcome this problem, we have developed a hybrid model for monthly runoff prediction. First, observed runoff is decomposed into several subcomponents via variational mode decomposition. Second, support vector machine models based on quantum-behaved particle swarm optimization are adopted to identify the input-output relationships hidden in each subcomponent. Finally, the total output of all submodules is treated as the final forecasting result for the original runoff. Three quantitative indexes are considered to test the performance of the developed models. The monthly streamflow of two reservoirs in China’s Yangtze Valley is considered as the survey target. This area contains the world’s largest hydropower project (Three Gorges Reservoir) and the waterhead of the middle line of Asia's largest inter-basin water transfer project (Danjiangkou Reservoir). Test results indicate that the hybrid model provides better forecasting accuracy compared to several traditional methods (artificial neural networks and extreme learning machines), making it an effective tool for the scientific operation of hydropower reservoirs.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Alloying is an important approach to improving catalytic activities and realizing new functions of heterogeneous catalysts, which has extensively been employed in fabricating noble metal based ...bimetallic catalysts. However, it is technically unviable in the synthesis of alloyed transition metal compounds, which are emerging as important catalysts for water splitting, in a controllable manner using conventional wet chemical methods. Here we report nanoporous bimetallic (Co sub(1-x)Fe sub(x)) sub(2)P phosphides with controllable compositions and tuneable porosity, which are fabricated by the combination of metallurgical alloy design and electrochemical etching. By tailoring the Co/Fe ratios and nanoporosity, the bimetallic phosphides exhibit versatile catalytic activities towards HER and OER in acidic and basic electrolytes. As both the cathode and the anode of an electrolyser, nanoporous (Co sub(0.52)Fe sub(0.48)) sub(2)P shows an outstanding performance in water electrolysis, comparable to the commercial electrolyser with paired Pt/C and IrO sub(2) catalysts.
Abstract Modulating the arrangement of superstructures through noncovalent interactions has a significant impact on macroscopic shape and the expression of unique properties. Constructing ...π‐interaction‐driven hierarchical three‐dimensional (3D) superstructures poses challenges on account of limited directional control and weak intermolecular interactions. Here we report the construction of a 3D diamondoid superstructure, named π‐Diamond , employing a ditopic strained Z‐shaped building block comprising a porphyrin unit as bow‐limb double‐strapped with two m ‐xylylene units as bowstrings. This superstructure, reminiscent of diamond's tetrahedral carbon composition, is composed of double‐walled tetrahedron ( DWT ) driven solely by π‐interactions. Hetero‐π‐stacking interactions between porphyrin and m ‐xylylene panels drive the assembly of four building blocks predominantly into a DWT , which undergoes extension to create an adamantane unit and eventually a diamondoid superstructure wherein each porphyrin panel is shared by two neighboring tetrahedra through hetero‐π‐stacking. π‐Diamond exhibits a solid‐state fluorescent quantum yield 44 times higher than that of tetraphenylporphyrin along with excellent photocatalytic performance. The precise 3D directionality of π‐interactions, achieved through strained multipanel building blocks, revolutionizes the assembly of hierarchical 3D superstructures driven by π‐interactions.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Human immunodeficiency virus (HIV) infection is fast becoming widespread in the world with 37.7 million people living with HIV in 2020. Antiretroviral therapy involving chemical drugs has declined ...acquired immunodeficiency syndrome (AIDS)‐related mortality and improved the life quality of AIDS/HIV sufferers. However, the emergence of drug resistance and side effects are the main obstacles for the long‐term use of these chemicals as antiretroviral therapy. Recently, a lot of emphasis is being put on finding naturally occurring drug candidates that show activity against HIV and can be potentially used as antiretroviral therapy. In this study, different medicinal plants, Pistacia khinjuk, Teucrium stocksianum, Uncaria tomentosa, Pistacia integerrima, Trigonella gharuensis, and Artocarpus lakoocha, were explored for their anti‐HIV potential. Syncytium and p24 assays were performed to determine antiviral activity, while the MTT assay was used to determine cytotoxicity. Results showed that extracts from all six plants inhibited HIV replication in vitro. Also, extracts from Pistacia khinjuk, Teucrium stocksianum, Uncaria tomentosa, and Pistacia integerrima showed low cytotoxicity with a 50% cytotoxicity concentration value of >200 μM. Results of this study indicate that there is potential in these natural extracts to become candidate drugs to be used as complementary and alternative medicine for HIV infection.
Highlights
Important findings with reference to anti‐human immunodeficiency virus (HIV) activities and cytotoxicities of extracts from six different plants.
Extracts from all six plants inhibited HIV replication in vitro.
Pistacia khinjuk (concentration required for the effectiveness of 50% EC50 = 0.34 µM) and Teucrium stocksianum (EC50 = 0.57 µM) showed the highest anti‐HIV activities.
These natural extracts have the potential to become candidate drugs to be used as a complementary and alternative medicine for HIV.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The chemical structure of donors and acceptors limit the power conversion efficiencies achievable with active layers of binary donor-acceptor mixtures. Here, using quaternary blends, double cascading ...energy level alignment in bulk heterojunction organic photovoltaic active layers are realized, enabling efficient carrier splitting and transport. Numerous avenues to optimize light absorption, carrier transport, and charge-transfer state energy levels are opened by the chemical constitution of the components. Record-breaking PCEs of 18.07% are achieved where, by electronic structure and morphology optimization, simultaneous improvements of the open-circuit voltage, short-circuit current and fill factor occur. The donor and acceptor chemical structures afford control over electronic structure and charge-transfer state energy levels, enabling manipulation of hole-transfer rates, carrier transport, and non-radiative recombination losses.
Recent researches have provided strong circumstantial support to dendrites playing a key and possibly essential role in computations. In this paper, we propose an unsupervised learnable neuron model ...by including the nonlinear interactions between excitation and inhibition on dendrites. The model neuron self-adjusts its synaptic parameters, so that the synapse to dendrite, according to a generalized delta-rule-like algorithm. The model is used to simulate directionally selective cells by the unsupervised learning algorithm. In the simulations, we initialize the interaction and dendrite of the neuron randomly and use the generalized delta-rule-like unsupervised learning algorithm to learn the two-dimensional multi-directional selectivity problem without an external teacher’s signals. Simulation results show that the directionally selective cells can be formed by unsupervised learning, acquiring the required number of dendritic branches, and if needed, enhanced and if not, eliminated. Further, the results show whether a synapse exists; if it exists, where and what type (excitatory or inhibitory) of synapse it is. This leads us to believe that the proposed neuron model may be considerably more powerful on computations than the McCulloch–Pitts model because theoretically a single neuron or a single layer of such neurons is capable of solving any complex problem. These may also lead to a completely new technique for analyzing the mechanisms and principles of neurons, dendrites, and synapses.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Mammals have a dorsal cochlear nucleus (DCN), which is thought to be a cerebellum-like structure with similar features in terms of structure and microcircuitry to the cerebellum. Both the DCN and ...cerebellum perform their functions depending on synaptic and neuronal networks mediated by various glutamate receptors. Kainate receptors (KARs) are one class of the glutamate receptor family and are strongly expressed in the hippocampus, the cerebellum, and cerebellum-like structures. The cellular distribution and the potential role of KARs in the hippocampus have been extensively investigated. However, the cellular distribution and the potential role of KARs in cerebellum-like structures, including the DCN and cerebellum, are poorly understood. In this review, we summarize the similarity between the DCN and cerebellum at the levels of structure, circuitry, and cell type as well as the investigations referring to the expression patterns of KARs in the DCN and cerebellum according to previous studies. Recent studies on the role of KARs have shown that KARs mediate a bidirectional modulatory effect at parallel fiber (PF)-Purkinje cell (PC) synapses in the cerebellum, implying insights into their roles in cerebellum-like structures, including the DCN, that remain to be explored in the coming years.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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