Siamese network based the tracker is a hot topic in the field of visual object tracking. However, Siamese trackers still have a robustness gap compared with state‐of‐the‐art algorithms. Therefore, ...focusing on the issue, this letter adds Frequency Channel Attention (FCA) and adaptive template feature map to the framework of Siamese neural network. FCA can enhance feature representation of effective channels and improve feature discrimination by modeling the correlation between each channel of the image. In this algorithm, by theoretical analysis and experimental validation, restriction is broken through a simple yet effective FCA network sampling strategy and a Siamese‐FCA tracker with significant performance gain is successfully trained. Meanwhile, in order to better adjust the proportion between target and background, the tracker selects suitable size of the target feature map. Moreover, extensive ablation studies are conducted to demonstrate the effectiveness of the proposed tracker. Fairly, the experimental results of five test benchmarks, including OTB2013, OTB2015, VOT2016, VOT2018 and UAV123 datasets, shows that the proposed algorithm performs outstanding. In particular, the issue of similarity and small target tracking failure is overcome. The average running frame rate reaches 86 frames per second, which can meet the real‐time requirements.
Spinal cord injury (SCI) can cause paralysis and serious chronic morbidity, and there is no effective treatment. Based on our previous experimental results of spinal cord fusion (SCF) in mice, rats, ...beagles, and monkeys, we developed a surgical protocol of SCF for paraplegic human patients. We designed a novel surgical procedure of SCF, called sural nerve transplantation (SNT), for human patients with lower thoracic SCI and distal cord dysfunction.
We conducted a clinical trial (ChiCTR2000030788) and performed SNT in 12 fully paraplegic patients due to SCI between T1 and T12. We assessed pre- and postoperative central nerve pain, motor function, sensory function, and autonomic nerve function. Conduction of action potentials across the sural nerve transplant was evaluated. Neural continuity was also examined by diffusion tensor imaging (DTI).
Among the 12 paraplegic patients enrolled in this clinical trial, seven patients demonstrated improved autonomic nerve functions. Seven patients had clinically significant relief of their symptoms of cord central pain. One patient, however, developed postoperative cord central pain (VAS: 4). Five patients had varying degrees of recovered sensory and/or motor functions below the single neurologic level 1 month after surgery. One patient showed recovery of electrophysiologic, motor-evoked potentials 6 months after the operation. At 6 months after surgery, DTI indicated fusion and nerve connections of white cord and sural nerves in seven patients.
SNT was able to fuse the axonal stumps of white cord and sural nerve and at least partially improve the cord central pain in most patients. Although SNT did not restore the spinal cord continuity in white matter in some patients, SNT could restore spinal cord continuity in the cortico-trunco-reticulo-propriospinal pathway, thereby restoring in part some motor and sensory functions. SNT may therefore be a safe, feasible, and effective method to treat paraplegic patients with SCI. Future clinical trials should be performed to optimize the type/technique of nerve transplantation, reduce surgical damage, and minimize postoperative scar formation and adhesion, to avoid postoperative cord central pain.
http://www.chictr.org.cn/showproj.aspx?proj=50526, identifier ChiCTR2000030788.
To date, the fabrication of advanced anode materials that can accommodate both Na+ and K+ storage is still very challenging. Herein, we developed a facile solvothermal and subsequent annealing ...process to synthesize SnS2/RGO composite, in which SnS2 nanosheets are bonded on RGO, and investigated their potential as anodes for Na+ and K+ storage. When used as an anode in SIBs, the as-prepared SnS2/RGO displays preeminent performance (581 mAh g−1 at 0.5 A g−1 after 80 cycles), which is a significant improvement compared with pure SnS2. More encouragingly, SnS2/RGO also exhibits good cycling stability (130 mAh g−1 at 0.3 A g−1 after 300 cycles) and excellent rate capability (520.8 mAh g−1 at 0.05 A g−1 and 281.4 mAh g−1 at 0.5 A g−1) when used as anode for PIBs. The well-engineered structure not only guarantees the fast electrode reaction kinetics, but also ensures superior pseudocapacitance contribution during repeated cycles, which has been proved by kinetic analysis.
Metal‐organic frameworks (MOFs), owing the merits of ordered and tailored channel structures in the burgeoning crystalline porous materials, have demonstrated significant promise in construction of ...high‐performance separation membranes. However, precisely because this crystal structure with strong molecular interaction in their lattice provides robust structural integrity and resistance to chemical and thermal degradation, crystalline MOFs typically exhibit insolubility, infusibility, stiffness and brittleness, and therefore their membrane‐processing properties are far inferior to the flexible amorphous polymers and hinder their subsequent storage, transportation, and utilization. Hence, focusing on film‐formation and crystallization is the foundation for exploring the fabrication and application of MOF membranes. In this review, the film‐forming properties of crystalline MOFs are fundamentally analyzed from their inherent characteristics and compared with those of amorphous polymers, influencing factors of polycrystalline MOF membrane formation are summarized, the trade‐off relationship between crystallization and membrane formation is discussed, and the strategy solving the film formation of crystalline MOFs in recent years are systematically reviewed, in anticipation of realizing the goal of preparing crystalline membranes with optimized processability and excellent performance.
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•SMAE was synthesized, and was used as a co-curing agent with DDM to cure EP.•At a 5 % dosage, the LOI value reached 39.7 %, successfully passing UL 94 V-0.•SMAE primarily exerted a ...blowing-out effect in EP.•The impact strength of 5 %SMAE/EP increased to 14.15 kJ/m2 by 25 % relatively to the pure EP.
In this study, a novel phosphorus-containing flame retardant, SMAE, was prepared through a nucleophilic addition of N,N'-bis(salicylidene)ethylenediamine (SAED) and phenyl hypophosphite. SMAE can dissolve well in epoxy resin and provides molecular-level flame retardancy. By using SMAE as a co-curing agent and DDM to cure epoxy resin, EP/SMAE composites with excellent flame retardancy and good mechanical properties were obtained. As the dosage gradually increases, the limited oxygen index (LOI) values continue to rise. At a 5 % dosage, the Limiting Oxygen Index (LOI) value can reach 39.7 % and meet the UL 94 V-0 standard. It is observed that SMAE mainly exerts a blowing-out effect in EP. In addition, the use of SMAE as a co-curing agent can improve the impact strength of EP. The impact strength of 5 % SMAE/EP can reach 14.15 kJ/m2, which is 25 % higher than that of pure EP.
Tracker based on the Siamese network is an important research direction of target tracking. However, Siamese trackers have the problem of insufficient characteristic expression ability extensively. ...To improve the situation, we introduced the effective attention module multi-frequency attention, which considers the attention mechanism from the frequency domain perspective and effectively raises the efficiency of feature representation of the tracker. Meanwhile, densely connected neural networks are applied to the tracker, which integrates the surface orientation information and deep-seated semantic features about the object, which will contribute to enhancing the localization and expression ability of the tracker. The proposed method achieves excellent results on Siamese network tracking. In order to prove the effectiveness of our strategy, we conducted experiments on benchmarks, including OTB100, OTB2013, VOT2016, and VOT2018, and the obtained results indicate that strategy we proposed achieves high accuracy and efficiency and still keeps outstanding with the effect of occlusion and illumination. Experiments show that the proposed method fulfills real-time tracking.
Although current Siamese-based trackers have achieved impressive performance in visual object tracking by balancing accuracy and speed, their sensitivity to adversarial perturbation makes them face ...many risks in practical applications ( e.g., automatic drive). In this paper, we first propose a general attack method against Siamese-based trackers, and then carefully design an online augmentation strategy based on adversarial examples to improve the tracking accuracy. To ensure both attack and augmentation trackers simultaneously, two opposing losses are proposed to push and pull the gap between the template patch and search regions. Specifically, most Siamese-based trackers employ the cross-correlation module to associate features of two branches. The similarity between the template patch and the search region will be reflected on the cross-correlation map, which is the focus of our method. SiamCAR is the main research object of this paper; the tracking accuracy after deception and enhancement is reduced by 64.62% and improved by 0.88%, respectively. We also transfer our attack method to SiamRPN++, SiamBAN, SiamGAT, and TrDiMP. Extensive experiments on the popular benchmark datasets indicate the effectiveness and universality of our method.
Indium sulfide has been proved to be a high-capacity anode material for sodium-ion batteries, but severe volume changes and low electrical conductivity limit its practical electrochemical ...performance. Based on this, graphene (RGO)-loaded In2S3 nanosheets array composites (In2S3/RGO) are synthesized by a simple reflux method to enhance charge transfer and ion diffusion kinetics as well as the structural stability of electrodes. By optimizing the amount of RGO, In2S3/RGO exhibits a high specific capacity of 450 mAh g−1 at 2 A g−1 after 500 cycles with a capacity fading of 0.04% per cycle (from 2nd to 500th) and remarkable rate performance of 460 mAh g−1 at 12 A g−1. The XRD and HRTEM analysis indicates that In2S3/RGO is based on a conversion mechanism for energy storage. Furthermore, the In2S3/RGO//Na3V2(PO4)3 full cell is successfully fabricated. The simple and efficient synthesis method and the excellent sodium storage properties offer great prospects for the practical application of In2S3/RGO.
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•In situ growth of In2S3 nanosheet arrays on RGO was achieved by a simple reflux method.•The In2S3/RGO composite exhibits ultratable cycling performance and ultrahigh rate capability.•The redox reactions are dominated by pseudocapacitive behavior.•Revealed the energy storage mechanism of In2S3/RGO by ex-situ XRD patterns and HRTEM images.
To investigate the synergistic flame retardant effect of various elements, three flame retardants (SMAE, SDPS, SDPB) with similar chemical structure and containing different flame retardant elements ...were designed, synthesized, and applied to TPU. The test results showed that SMAE had a phosphorus-nitrogen synergistic effect and primarily exerted its flame retardant effect in the gaseous phase. The limiting oxygen index value of the TPU/4SMAE reached 32 % and passed UL 94 V-0 rating test. SDPB was obtained by introducing the boron, which further enhanced the flame retardant effect in the gaseous phase. The thermogravimetric combined with Fourier transform infrared spectroscopy results showed that TPU/4SDPB had the lowest intensity of gaseous phase products. With only 2 wt% SDPB, TPU can pass UL 94 V-0 test. Therefore, it also demonstrated that there was a good synergy between boron and phosphorus and nitrogen. SDPS was obtained by introducing the silicon, which can exert the flame retardant effect in the condensed phase. Scanning electron microscopy results showed that char layer of TPU/SDPS was the densest and silicon was retained as Si-O and Si-C in the char layer. However, the gaseous phase flame retardant effect of SDPS was restrained, and TPU/4SDPS only passes the V-2 rating. Hence, this work provided the direction of Schiff base derivatives flame retardants structure design in TPU.
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•Three Schiff base derivatives (SMAE, SDPS, SDPB) were designed and synthesized.•4 wt% SMAE or SDPB endows TPU with LOI values over 30 %, passing UL 94 V-0 rating.•SDPS containing P, N and Si elements has the best barrier and protective effect.•2 wt% SDPB containing P, N and B elements can make TPU pass UL 94 V-0 test.•TPU/SDPB had the lowest intensity of gas phase products.
Optical loss is one of the main factors that restrict the power conversion efficiency (PCE) of perovskite solar cells (PSCs). Anti-reflective coating and light-trapping structure is one of the ...effective methods to enhance light capture and thus improve PCE. Through the finite-difference time-domain (FDTD) method, polydimethylsiloxane (PDMS) anti-reflection coatings with different light-trapping structures were introduced in the air–glass interface of planar heterojunction-based PSCs. Calculating the optical absorption, the inverted-pyramid structure had the best anti-reflection performance. On this basis, in order to further improve photon absorption of perovskite layers, an optical coupling structure with double-decker inverted pyramids are designed by inserting an inverted pyramid structure between perovskite layer and TiO2. According to the cross-sectional |E|2 distribution of the EM wave inside the device, three different marshalling patterns of the optical coupling structure are proposed and studied to select the best one for PSCs. This kind of marshalling pattern can highly enhance light harvesting of perovskite solar cells, thus increasing the generation rate of charge carrier in perovskite layers and improving the PCE.
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