23 research outputs found

    Approaching Disorder-Tolerant Semiconducting Polymers

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    Doping has been widely used to control the charge carrier concentration in organic semiconductors. However, in conjugated polymers, n-doping is often limited by the tradeoff between doping efficiency and charge carrier mobilities, since dopants often randomly distribute within polymers, leading to significant structural and energetic disorder. Here, we screen a large number of polymer building block combinations and explore the possibility of designing n-type conjugated polymers with good tolerance to dopant-induced disorder. We show that a carefully designed conjugated polymer with a single dominant planar backbone conformation, high torsional barrier at each dihedral angle, and zigzag backbone curvature is highly dopable and can tolerate dopant-induced disorder. With these features, the designed diketopyrrolopyrrole (DPP)-based polymer can be efficiently n-doped and exhibit high n-type electrical conductivities over 120 S cm−1, much higher than the reference polymers with similar chemical structures. This work provides a polymer design concept for highly dopable and highly conductive polymeric semiconductors

    Universal Adhesives- Different Curing Methods and Applications

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    The adhesive is a kind of material with good adhesion properties which could join objects by adhesion of surfaces via forces of adhesion and cohesion. There are many kinds of adhesives. This paper mainly classifies them by curing method, from UV curing and heat curing to moisture curing and microwave curing, and describes the corresponding mechanisms. Furthermore, it covers the advantages and disadvantages, application ranges, and related chemical compounds of different curing ways for adhesives. This can broaden our understandings of different ways of adhesive curing. Besides, it could also help us choose the most appropriate curing method according to different requirements in daily life

    Ballistic cluster–cluster aggregation model optimization

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    In this paper, an optimized model based on the ballistic cluster–cluster aggregation model is proposed to study the optical properties of aggregated particle structures. The critical improvement of the optimized model is the ability to arbitrarily select the original number of particles in the simulation and set different sizes of particles, whereas the original model is limited to 2n particles. Herein, the discrete dipole approximation method was used to calculate the optical extinction properties of the aggregation structure. First, the effect of porosity, which is a significant parameter, is explored, and acceptable error values are calculated. Second, simulations are performed using the optimized model for conditions applicable to the original model (N = 2n), and the difference between the two model calculations is assessed. Finally, the extinction performance of the aggregate with an arbitrary number of particles (N ≠ 2n) simulated by the optimized model is calculated and compared with the results obtained by the interpolation method. The numerical results verify the generalizability and accuracy of the optimized model

    Influence of Recycled Fine Aggregate Content on Properties of Soft Soil Solidified by Industrial Waste Residue

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    The influence of recycled fine aggregate content on the properties of soft soil solidified by industrial waste residue was systematically studied. First, the addition of recycled fine aggregate may provide skeleton support, which was conducive to improving the solidification properties. Comparing the addition of recycled fine aggregate content and a composite solidification agent separately, the compressive strength increased 48.01 times and 1.32 times, respectively. Second, the composition and quantity of the hydration products were analyzed by X-ray diffraction (XRD) and thermal gravity analysis (TG/DTG). In addition to silicon dioxide and aluminum oxide, a number of new minerals, including hydrated calcium silicate, calcium hydroxide and ettringite, were produced under different recycled fine aggregate contents. The diffraction peak of hydrated calcium hydroxide was weak, which indicated that the crystallinity and relative content was low. The main reason for this was that it was consumed as the activator of the secondary hydration reaction of blast furnace slag. With the increase in recycled fine aggregate content, the total weight loss (hydration products, crystal water, impurities) increased significantly, at rates of 6.9%, 7.0%, 7.2%, 8.8% and 9.7%. The addition of recycled fine aggregate does not change the composition and quantity of the hydration products, and the increased weight loss in this part might be caused by the cement paste attached to the surface of the recycled fine aggregate. Finally, their microstructure was analyzed by scanning electron microscopy (SEM). Larger and more pores appeared in the solidification system with the increase in recycled fine aggregate, and a large amount of ettringite was prepared. An excess in recycled fine aggregate caused more pores, and the negative impact of too many pores exceeded the lifting effect of the aggregate, resulting in the decline of its mechanical properties. Therefore, there was a suitable range for the use of recycled fine aggregate, which was not more than 40%. In conclusion, recycled fine aggregate not only acts as a skeleton to improve solidification strength, but could also realize the comprehensive utilization of waste, which provided a new scheme for solid waste utilization and soft soil solidification

    Combined Amperometry and Electrochemical Cytometry Reveal Differential Effects of Cocaine and Methyphenidate on Exocytosis and the Fraction of Chemical Release

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    Amperometry with nanotip electrodes has been applied to show cocaine and methylphenidate not only trigger declines in vesicle content and exocytotic catecholamine release in a model cell line but also differentially change the fraction of transmitter released from each individual vesicle. In addition, cocaine accelerates exocytotic release dynamics while they remain unchanged after methylphenidate treatment. The parameters from pre-spike feet for the two drugs are also in opposition, suggesting this aspect of release is affected differentially. As cocaine and methylphenidate are psychostimulants with similar pharmacologic action but have opposite effects on cognition, these results might provide a missing link between the regulation of exocytosis and vesicles and the effect of this regulation on cognition, learning, and memory. A speculative chemical mechanism of the effect of these drugs on vesicle content and exocytosis is presented

    Modeling Fluency and Faithfulness for Diverse Neural Machine Translation

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    Neural machine translation models usually adopt the teacher forcing strategy for training which requires the predicted sequence matches ground truth word by word and forces the probability of each prediction to approach a 0-1 distribution. However, the strategy casts all the portion of the distribution to the ground truth word and ignores other words in the target vocabulary even when the ground truth word cannot dominate the distribution. To address the problem of teacher forcing, we propose a method to introduce an evaluation module to guide the distribution of the prediction. The evaluation module accesses each prediction from the perspectives of fluency and faithfulness to encourage the model to generate the word which has a fluent connection with its past and future translation and meanwhile tends to form a translation equivalent in meaning to the source. The experiments on multiple translation tasks show that our method can achieve significant improvements over strong baselines

    Colloidal Synthesis and Optical Properties of Cs<sub>2</sub>CuCl<sub>4</sub> Nanocrystals

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    Lead-free copper halide perovskite nanocrystals (NCs) are emerging materials with excellent photoelectric properties. Herein, we present a colloidal synthesis route for orthorhombic Cs2CuCl4 NCs with a well-defined cubic shape and an average diameter of 24 ± 2.1 nm. The Cs2CuCl4 NCs exhibited bright, deep blue photoluminescence, which was attributed to the Cu(II) defects. In addition, passivating the Cs2CuCl4 NCs by Ag+ could effectively improve the photoluminescence quantum yield (PLQY) and environmental stability

    Effect of different application duration of a venous foot pump on prevention of venous thromboembolism after hip and knee arthroplasty: a multicenter prospective clinical trial

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    Abstract Objective To investigate the optimal duration of applying a venous foot pump (VFP) in the prevention of venous thromboembolism (VTE) following hip and knee arthroplasty. Methods A total of 230 patients undergoing hip and knee arthroplasty between March 2021 and March 2022 in orthopaedic departments of four major teaching hospitals were prospectively enrolled. Patients were randomly divided into five groups based on the duration of the VFP application. Postoperative deep vein thromboses (DVT), including proximal, distal, and intermuscular DVT, were recorded for analysis. Postoperative blood coagulation examinations, such as D-dimer and active partial thromboplastin time (APTT), pain outcome, and degree of comfort were also collected. Results Two of the 230 patients withdrew due to early discharge from the hospital, and 228 patients were included in the final analysis. The mean age was 60.38 ± 13.33 years. The baseline characteristics were comparable among the five groups. Compared with the other groups, patients treated with 6-hour VFP had the lowest incidence of DVT (8.7%, 4/46), followed by those treated with 1-hour VFP (15.2%, 7/46), 12-hour VFP (15.6%, 7/45), 18-hour VFP(17.8%, 8/45) and 20-hour VFP(21.7%, 10/46), but with no significant difference (P = 0.539). Regarding postoperative blood coagulation examinations, patients treated with 6-hour VFP had the lowest D-dimer (P = 0.658) and the highest APTT (P = 0.262) compared with the other four groups. 6-hour VFP also had the lowest pain score (P = 0.206) and the highest comfort score (P = 0.288) compared with the other four groups. Conclusions Six hours may be the optimal duration of applying VFP for the prevention of VTE in patients undergoing hip and knee arthroplasty in terms of VTE incidence, postoperative blood coagulation examinations, pain outcomes, and comfort scores

    Morphology and Phylogeny of Two Novel Ciliates, Arcanisutura chongmingensis n. gen., n. sp and Naxella paralucida n. sp from Shanghai, China

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    The morphologies of two novel ciliates, Arcanisutura chongmingensis n. gen., n. sp. and Naxella paralucida n. sp., collected from Shanghai, China, have been investigated using live observation and silver staining methods. Arcanisutura n. gen. can be easily distinguished from related genera by its inconspicuous, oblique anterior suture. Arcanisutura chongmingensis n. sp. is mainly recognized by its elongated body with a tail-like posterior end, 25-33 somatic kineties, and 4-11 excretory pores. Naxella paralucida n. sp. can be distinguished from its congeners based on its two short nassulid organelles, fusiform trichocysts, 37-49 somatic kineties, and 16 nematodesmal rods. The small-subunit (SSU) rRNA gene sequences of these two species are presented, revealing the phylogenetic positions of Arcanisutura and Naxella. Phylogenetic analyses show that Arcanisutura forms a sister clade to other synhymeniid genera, namely, Chilodontopsis, Orthodonella, and Zosterodasys; Naxella is most closely related to Nassula spp. and is located within the monophyletic clade of the family Nassulidae

    Supplementary_Material – Supplemental material for Kinesio taping is superior to other taping methods in ankle functional performance improvement: a systematic review and meta-analysis

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    <p>Supplemental material, Supplementary_Material for Kinesio taping is superior to other taping methods in ankle functional performance improvement: a systematic review and meta-analysis by Yun Wang, Yu Gu, Jiancong Chen, Wenhao Luo, Wanying He, Zhongyu Han and Jing Tian in Clinical Rehabilitation</p
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