Controlling vertical phase separation of the active layer to enable efficient exciton dissociation and charge carrier transport is crucial to boost power conversion efficiencies (PCEs) of pseudoplanar heterojunction (...
详细信息
Controlling vertical phase separation of the active layer to enable efficient exciton dissociation and charge carrier transport is crucial to boost power conversion efficiencies (PCEs) of pseudoplanar heterojunction (PPHJ) organic solar cells (OSCs). However, how to optimize the vertical phase separation of PPHJ OSCs via molecule design is rarely reported yet. Herein, ternary polymerization strategy is employed to develop a series of polymer donors, DL1-DL4, and regulate their solubility, molecular aggregation, molecular orientation, and miscibility, thus efficiently manipulating vertical phase separation in PPHJ OSCs. Among them, DL1 not only has enhanced solubility, inhibited molecular aggregation and partial edge-on orientation to facilitate acceptor molecules, Y6, to permeate into polymer layer and increase donor/acceptor interfaces, but also sustains high crystallinity and appropriate miscibility with Y6 to acquire ordered molecular packing, thus achieving optimized vertical phase separation to well juggle exciton dissociation and charge transport in PPHJ devices. Therefore, DL1/Y6 based PPHJ OSCs gain the best exciton dissociation probability, highest charge carrier mobilities and weakest charge recombination, and thus afford an impressive PCE of 19.10%, which is the record value for terpolymer donors. It demonstrates that ternary polymerization is an efficient method to optimize vertical phase separation in PPHJ OSCs for high PCEs. Ternary polymerization strategy is employed to manipulate the vertical phase separation in pseudoplanar heterojunction (PPHJ) organic solar cells (OSCs). The terpolymer DL1, with enhanced solubility, partial edge-on orientation, and high crystallinity, endows DL1/Y6 PPHJ blend film with the optimized vertical phase separation. Therefore, DL1/Y6 based PPHJ OSCs afford an impressive PCE of 19.10%, which is the record for terpolymer ***
Solution processible organic solar cells (OSCs) have attracted much attention as one of the most promising candidates for sustainable energy techniques over the past two decades. So far, the power conversion efficienc...
详细信息
Solution processible organic solar cells (OSCs) have attracted much attention as one of the most promising candidates for sustainable energy techniques over the past two decades. So far, the power conversion efficiency (PCE) of OSCs has reached over 18% and increasingly closed the gap with inorganic and hybrid solar cells, which exceeds the requirement in efficiency towards commercial application. Low cost is generally labeled as one of the potential advantages of OSCs, compared with other photovoltaic technologies. However, currently most of the high-performance materials need tedious synthetic steps and/or suffer from relatively high cost. In addition, halogenated solvents which are highly toxic and expensive are widely used during processing;besides, they are not environmentally friendly, which would bring about extra expense for management and disposal. Thus, the development of low-cost high-performance materials, and cheap and "green" processing for OSCs is the imperative and urgent issue to be solved towards industrial-scale production. In this review, we summarize the recent advances in low-cost materials and eco-friendly processing for OSCs from the aspects of the synthetic method, photoactive materials, interfacial materials and processing solution. We hope that this review affords an overview and deep understanding of low-cost materials and processing solutions for OSCs. Finally, we will provide our perspectives on possible directions and challenges to further reduce the material cost of OSCs.
Background: Pulsed ultrasound (US) is widely used both as a diagnostic imaging tool and a therapeutic approach. However, many of the mechanisms underlying the therapeutic effects of non-thermal US remain unclear, espe...
详细信息
Background: Pulsed ultrasound (US) is widely used both as a diagnostic imaging tool and a therapeutic approach. However, many of the mechanisms underlying the therapeutic effects of non-thermal US remain unclear, especially in skeletal muscles, which play a crucial role in the body's metabolism. The aim of this study was to investigate the effects of US on myotubes. Methods: In this study, C2C12 myoblasts were utilized. After differentiating into myotubes, the cells were exposed to US irradiation at an intensity of 3.0 W/cm2, with a 20 % duty cycle, an acoustic frequency of 1 MHz, and a pulse repetition frequency of 100 Hz for 5 min. The cells were then collected and analyzed for genomic and metabolomic alterations, as well as mitochondrial function. Results: Cell viability remained unaffected after US irradiation. The mitogen-activated protein kinase (MAPK) signaling pathway was the most activated, while the expression of various RNAs was significantly altered. Purine metabolism was highly activated, with an increase in the abundance of metabolites associated with this pathway. Furthermore, mitochondrial respiration in the myotubes increased following US irradiation. Conclusion: This study investigated the impact of US irradiation on myotubes using genomic analysis, metabolomic analysis, and mitochondrial function. US irradiation activated the MAPK signaling pathway, which in turn enhanced purine metabolism and improved mitochondrial respiration.
Transarterial radioembolization using radionuclide-labeled microspheres has shown efficacy in the treatment of hepatocellular carcinoma (HCC). In this study, a novel formulation of Polyvinyl alcohol-collagen microsphe...
详细信息
Transarterial radioembolization using radionuclide-labeled microspheres has shown efficacy in the treatment of hepatocellular carcinoma (HCC). In this study, a novel formulation of Polyvinyl alcohol-collagen microspheres (PCMs) with an optimal settling rate is developed. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses confirm that the PCMs have uniform morphology with diameters ranging from 20 to 30 mu m. These microspheres are successfully labeled with I-131, exhibiting good in vitro stability. Subsequently, I-131-labeled PCMs are administered via the hepatic artery into rats with orthotopic HCC, leading to a significant increase in median overall survival (p < 0.05). Single photon emission computed tomography (SPECT/CT) imaging and immunohistochemical assessments demonstrate precise biodistribution and stable retention of I-131-PCMs in the liver for up to 14 days. Magnetic resonance imaging (MRI) further reveals the inhibition of tumor growth following I-131-PCM treatment. In summary, the I-131-PCMs display high radiolabeling efficiency, stability, and a promising radioembolization effect in the orthotopic HCC rodent model, highlighting their potential for use in interventional cancer therapy.
The limited exciton diffusion length (LD) of organic semiconductors constraints exciton dissociation in pseudo-planar heterojunction (PPHJ) organic solar cells (OSCs), which is deemed the bottleneck hampering the furt...
详细信息
The limited exciton diffusion length (LD) of organic semiconductors constraints exciton dissociation in pseudo-planar heterojunction (PPHJ) organic solar cells (OSCs), which is deemed the bottleneck hampering the further improvement in their power conversion efficiencies (PCEs). Herein, a solid-additive strategy was proposed to efficiently prolong the LD in PPHJ OSCs by developing a volatile solid additive, SA-5F, and blending it in non-fullerene acceptors. The addition of SA-5F endowed a Y6+ film with improved crystallinity and more compact molecular stacking, resulting in a higher photoluminescence quantum yield, larger overlap between its absorption and emission spectra, and shorter intermolecular distance compared with a pristine Y6 film. Thus, the Y6+ film achieved a higher exciton diffusion coefficient of 1.36 x 10-3 cm2 s-1 and, thus, similar to 24% improvement in the LD to 10.27 nm. The prolonged LD enabled D18/Y6+-based PPHJ devices to realize more efficient exciton dissociation and weaker charge recombination compared with their D18/Y6 counterparts. Therefore, D18/Y6+-based PPHJ OSCs afforded an impressive PCE of 19.11%, which is among the highest values reported to date. Moreover, this strategy exhibits excellent universality in improving the photovoltaic performance of different systems. Thus, it was demonstrated that introducing a solid additive is an efficient and universal strategy to prolong the LD in PPHJ OSCs and consequently boost their PCEs. A solid additive, SA-5F, is employed to promote molecular stacking, which leads to higher crystallinity, boosting the exciton diffusion coefficient and then exciton diffusion length. Thus, D18/Y6+-based PPHJ OSCs afford an impressive PCE of 19.11%.
Incorrect species delimitation will lead to inappropriate conservation decisions, especially for threatened species. The takin (Budorcas taxicolor) is a large artiodactyl endemic to the Himalayan-Hengduan-Qinling Moun...
详细信息
Incorrect species delimitation will lead to inappropriate conservation decisions, especially for threatened species. The takin (Budorcas taxicolor) is a large artiodactyl endemic to the Himalayan-Hengduan-Qinling Mountains and is well known for its threatened status and peculiar appearance. However, the speciation, intraspecies taxonomy, evolutionary history, and adaptive evolution of this species still remain unclear, which greatly hampers its scientific conservation. Here, we de novo assembled a high-quality chromosome-level genome of takin and resequenced the genomes of 75 wild takins. Phylogenomics revealed that takin was positioned at the root of Caprinae. Population genomics based on the autosome, X chromosome, and Y chromosome SNPs and mitochondrial genomes consistently revealed the existence of two phylogenetic species and recent speciation in takins: the Himalayan takin (B. taxicolor) and the Chinese takin (B. tibetana), with the support of morphological evidence. Two genetically divergent subspecies were identified in both takin species, rejecting three previously proposed taxonomical viewpoints. Furthermore, their distribution boundaries were determined, suggesting that large rivers play important roles in shaping the genetic partition. Compared with the other subspecies, the Qinling subspecies presented the lowest genomic diversity, higher linkage disequilibrium, inbreeding, and genetic load, thus is in urgent need of genetic management and protection. Moreover, coat color gene (PMEL) variation may be responsible for the adaptive coat color difference between the two species following Gloger's rule. Our findings provide novel insights into the recent speciation, local adaptation, scientific conservation of takins, and biogeography of the Himalaya-Hengduan biodiversity hotspot.
Ordinary piezoelectric force sensors are only capable of measuring dynamic forces but not static forces because of the charge leakage due to the finite resistance of piezoelectric materials and charge amplifiers. This...
详细信息
Ordinary piezoelectric force sensors are only capable of measuring dynamic forces but not static forces because of the charge leakage due to the finite resistance of piezoelectric materials and charge amplifiers. This paper presents a new strategy for in-process compensation of charge leakage for force measurement with wide spectrum from static to dynamic realized by piezoelectric force sensors. The compensation is in-process operated based on the concept of dynamic accumulation. In order to improve the measurement accuracy and long-term stability by the compensation, the zero offset generated by normalization, bias current and temperature drift are all theoretically analyzed and experimentally validated. Measurement experiments of four different types of force signals, which contain static, triangular, sinusoidal and random force signals acting on the piezoelectric force sensor, are conducted to validate the proposed strategy. In addition, the effect of different time constant of the piezoelectric sensor under different applied forces on the compensated results is analyzed. Performance tests containing accuracy, resolution, span and bandwidth have been conducted. It is validated that the proposed method has high sensitivity of sub-millinewton, long-term stability and wide spectrum from static signal to dynamic measurement capabilities, which would provide an effective and precise method for micro force measurement and control in ultra-precision machining, semiconductor industry and biomechanics fields.
Cutting force is a significant indicator for in-process monitoring of cutting status. Although dynamometers are widely used in cutting force measurement, they are not suitable for nano-cutting due to insufficient sens...
详细信息
Cutting force is a significant indicator for in-process monitoring of cutting status. Although dynamometers are widely used in cutting force measurement, they are not suitable for nano-cutting due to insufficient sensitivities and low integrating possibilities. This paper presents a smart tool holder composed by piezoelectric ceramics and a flexible hinge, which could be integrated with a fast tool servo (FTS), for three-axial cutting force measurements in micro/nano-cutting. An algorithm was developed for enabling its quasi-static force measurement. Experiments were performed to verify the capabilities of cutting force measurement, demonstrating a high measurement sensitivity for indicating the micro/nano-cutting status. (c) 2021 CIRP. Published by Elsevier Ltd. All rights reserved.
Sea turtles are marine flagship species and most of them are currently in a threatened state. Long-term surviving in the ocean has driven significant morphological and physiological changes for this group, which makes...
详细信息
Sea turtles are marine flagship species and most of them are currently in a threatened state. Long-term surviving in the ocean has driven significant morphological and physiological changes for this group, which makes them an ideal model for studying adaptive evolution of marine environments. Herein, we present a chromosome-scale genome of Lepidochelys olivacea with a genome size of 2.22 Gb and a contig N50 of 97.3 Mb. Comparative genomic analyses uncovered a suite of adaptive changes in genes related to olfaction, vision, virus defense, and longevity, which may help explain the genetic underpinnings of its marine environment adaptation. We also observed that the genome-wide heterozygosity of L. olivacea was low (6.45e-4), consistent with its prolonged population decline. Overall, our study provides valuable genetic resources for understanding evolutionary adaptations to aquatic environment and for the conservation of this threatened species.
The march toward marrying good business practice with sustainability in the global marketing contexts is articulated with the hope of decoupling consumption and affluence from environmental deterioration. However, the...
详细信息
The march toward marrying good business practice with sustainability in the global marketing contexts is articulated with the hope of decoupling consumption and affluence from environmental deterioration. However, the key question, whether and how chief executive officers' (CEO) psychological characteristics exert its influence on corporate marketing activities with relation to environmental conservation, is still unsolved. The current study aimed at examining how the personality traits of CEOs affect corporate green marketing program (GMP), with primary regard to CEO narcissism. On the basis of a moderated mediation analysis on a batch of survey data from a sample of manufacturing firms in China, the findings showed that narcissistic CEOs are often associated with the higher level of the corporate green marketing program. Besides, corporate environmental strategy (ES) plays a role of mediator in the relationship between CEO narcissism and the implementation of green marketing. Furthermore, regulatory pressure not only significantly drives corporate environmental strategy and green marketing program but also moderates the relationships among CEO narcissism, corporate environmental strategy, and green marketing program. This study shines light on the establishment of management mode, which could illuminate both business practitioners and policymakers on the governance of sustainability.
暂无评论