2,199 research outputs found
Incorporation of adaptive compression into a GPU parallel computing framework for analyzing large-scale vessel trajectories
No full textAutomatic Identification System (AIS) offers a wealth of vessel navigation data, which underpins research in maritime data mining, situational awareness, and knowledge discovery within the realm of intelligent transportation systems. The flourishing marine industry has prompted AIS satellites and base stations to generate massive amounts of vessel trajectory data, escalating both data storage and calculation costs. The conventional Douglas-Peucker (DP) algorithm used for trajectory compression sets a uniform threshold, which hampers effective compression. Additionally, compressing and accelerating the computation of large datasets poses a significant challenge in real-world applications. To address these limitations, this paper aims to develop a new Graphics Processing Unit (GPU) parallel computing and compression framework that enables the acceleration of the optimal threshold calculation for each trajectory automatically in maritime big data mining. It achieves this by incorporating a new Adaptive DP with Speed and Course (ADPSC) algorithm, which utilizes the dynamic navigation characteristics of different vessels. It can effectively solve the associated computational time cost concern when using the ADPSC algorithm to compress vast trajectory datasets in the real world. Additionally, this paper proposes a novel evaluation metric for assessing compression efficacy based on the Dynamic Time Warping (DTW) method. Comprehensive experiments encompass vessel trajectory datasets from three representative research areas: Tianjin Port, Chengshan Jiao Promontory, and Caofeidian Port. The experimental results demonstrate that 1) the newly developed ADPSC method outperforms in terms of compression, and 2) the designed GPU parallel computing framework can significantly shorten the compression time for extensive datasets. The GPU-accelerated compression methodology not only minimizes storage and transmission costs for data from both manned and unmanned vessels but also enhances data processing speed, supporting real-time decision-making. From a theoretical perspective, it provides the key to the puzzle of realizing the real-time anti-collision of manned and unmanned ships, particularly in complex waters. It hence makes significant contributions to maritime safety in the autonomous shipping era
Two-stage correction prediction of wind power based on numerical weather prediction wind speed superposition correction and improved clustering
No full textThe unavoidable wind power prediction error poses a challenge for wind power to participate in day-ahead scheduling plan. This paper proposes a two-stage correction method considering NWP wind speed and power correction. Firstly, this paper fully considers the historical similarity of NWP wind speed, and adopts the improved clustering distance for segment matching and wind speed correction based on the extracted most relevant trend component, which enhances the utilization of NWP information and avoids the randomness and uncertainty of the intelligent correction method, and gram angular field (GAF) and stacked autoencoder (SAE) are used for feature extraction and conditional variational autoencoder (CVA) is used to generate specific samples to ensure the adequacy of the clustering process. Secondly, considering the historical similarity of error of predicted power, the power is further corrected based on the proposed weighted double-constraint to realize the secondary calibration. The Proposed method is applied to several wind farms in China to verify its effectiveness. The results show that the proposed method reduces the NRMSE by 3.82 % and NMAE by 3.40 % compared with direct prediction in the wind farms in western Inner Mongolia, which is important for promoting wind power consumption and maintaining the safe and stable operation of the power system
Elevated temperature and CO2 strongly affect the growth strategies of soil bacteria
No full textAbstract The trait-based strategies of microorganisms appear to be phylogenetically conserved, but acclimation to climate change may complicate the scenario. To study the roles of phylogeny and environment on bacterial responses to sudden moisture increases, we determine bacterial population-specific growth rates by 18 O-DNA quantitative stable isotope probing ( 18 O-qSIP) in soils subjected to a free-air CO 2 enrichment (FACE) combined with warming. We find that three growth strategies of bacterial taxa – rapid, intermediate and slow responders, defined by the timing of the peak growth rates – are phylogenetically conserved, even at the sub-phylum level. For example, members of class Bacilli and Sphingobacteriia are mainly rapid responders. Climate regimes, however, modify the growth strategies of over 90% of species, partly confounding the initial phylogenetic pattern. The growth of rapid bacterial responders is more influenced by phylogeny, whereas the variance for slow responders is primarily explained by environmental conditions. Overall, these results highlight the role of phylogenetic and environmental constraints in understanding and predicting the growth strategies of soil microorganisms under global change scenarios
Wind farm cluster power prediction based on graph deviation attention network with learnable graph structure and dynamic error correction during load peak and valley periods
No full textThe power prediction accuracy of wind farm cluster (WFC) seriously affects its consumption and the safe and stable operation of power system. The fluctuation of power between wind farms (WFs) significantly affects the wind power ultra-short-term prediction (WPUP) accuracy of WFC. In this regard, this paper proposes a graph deviation attention network (GDAN) considering improved clustering distance and learnable graph structure (LGS) for predicting and correcting the wind power of WFC. And used a weighted distance function combining sequence convergence smoothing effect and correlation to dynamically divide the WFC, and to learn and construct the graph structure. Proposed the GDAN with LGS to mine the convergence correlation of WF sub-clusters and establish power prediction model. Considering the characteristics of load peak and valley periods (LPVP), introduced a power correction coefficient to reduce the error, and used the successive variational mode decomposition (SVMD) to extract its key components to achieve power prediction and correction. The proposed method is applied to the WFC in Western Inner Mongolia, China. Compared with the comparison model before correction, the RMSE, MAE and MAPE are reduced by 4.27 %, 3.55 % and 17.92 % respectively, and the R2 and Pr are increased by 11.87 % and 9.88 % respectively
PtRu nanoparticles embedded in nitrogen doped carbon with highly stable CO tolerance and durability
No full textAs is well known, the lower durability and sluggish methanol oxidation reaction (MOR) of PtRu alloy electrocatalyst blocks the commercialization of direct methanol fuel cells (DMFCs). Here, we design a new PtRu electrocatalyst, with highly stable CO tolerance and durability, in which the PtRu nanoparticles are embedded in nitrogen doped carbon layers derived from carbonization of poly(vinyl pyrrolidone). The newly fabricated electrocatalyst exhibits no loss in electrochemical surface area (ECSA) and MOR activity after potential cycling from 0.6-1.0 V versus reversible hydrogen electrode, while commercial CB/PtRu retains only 50% of its initial ECSA. Meanwhile, due to the same protective layers, the Ru dissolution is decelerated, resulting in stable CO tolerance. Methanol oxidation reaction (MOR) testing indicates that the activity of newly fabricated electrocatalyst is two times higher than that of commercial CB/PtRu, and the fuel cell performance of the embedded PtRu electrocatalyst was comparable to that of commercial CB/PtRu. The embedded PtRu electrocatalyst is applicable in real DMFC operation. This study offers important and useful information for the design and fabrication of durable and CO tolerant electrocatalysts
sj-pdf-1-ajs-10.1177_03635465231198501 – Supplemental material for Inhibition of IKKβ via a DNA-Based In Situ Delivery System Improves Achilles Tendinopathy Healing in a Rat Model
No full textSupplemental material, sj-pdf-1-ajs-10.1177_03635465231198501 for Inhibition of IKKβ via a DNA-Based In Situ Delivery System Improves Achilles Tendinopathy Healing in a Rat Model by Zilu Ge, Mingyu Yang, Danfeng Wei, Dong Wang, Renliang Zhao, Xiangtian Deng, Yunfeng Tang, Qian Fang, Zhencheng Xiong, Chengshi Wang, Guanglin Wang, Wei Li and Kanglai Tang in The American Journal of Sports Medicine</p
Author response image 1.
Get PDFNeurotransmitter is released at synapses by fusion of synaptic vesicles with the plasma membrane. To sustain synaptic transmission, compensatory retrieval of membranes and vesicular proteins is essential. We combined capacitance measurements and pH-imaging via pH-sensitive vesicular protein marker (anti-synaptotagmin2-cypHer5E), and compared the retrieval kinetics of membranes and vesicular proteins at the calyx of Held synapse. Membrane and Syt2 were retrieved with a similar time course when slow endocytosis was elicited. When fast endocytosis was elicited, Syt2 was still retrieved together with the membrane, but endocytosed organelle re-acidification was slowed down, which provides strong evidence for two distinct endocytotic pathways. Strikingly, CaM inhibitors or the inhibition of the Ca2+-calmodulin-Munc13-1 signaling pathway only impaired the uptake of Syt2 while leaving membrane retrieval intact, indicating different recycling mechanisms for membranes and vesicle proteins. Our data identify a novel mechanism of stimulus-and Ca2+-dependent regulation of coordinated endocytosis of synaptic membranes and vesicle proteins
C MXene Via Nb Alloying for Stable and High‐Efficient Supercapacitive Performances
No full textTi2C MXene with the lowest formula weight is expected to gain superior advantages in gravimetric capacitances over other heavier MXenes. Nevertheless, its poor chemical and electrochemical stability is the most fatal drawback and seriously hinders its practical applications. Herein, an alloy engineering strategy at the transition metal-sites of Ti2C MXene is proposed. Theoretical calculations reveal that the electronic redistribution of the solid-solution TiNbC MXene improves the electronic conductivity, induces the upward d-band center, tailors the surface functional groups, and increases the electron loss impedance, resulting in its excellent capacitive performance and high chemical stability. The as-prepared flexible TiNbC film delivers specific capacitance up to 381 F g(-1) at a scan rate of 2 mV s(-1) and excellent electrochemical stability without capacitance loss after 10000 charge/discharging cycles. This work provides a universal approach to develop high-performance and chemically stable MXene electrodes.This work was supported by the National Natural Science Foundation of China (grant nos. 52002296 and 51902232) and supported by Research Fund of Hubei Provincial Department of Education (grants nos. B2019006). The authors gratefully acknowledge the Analytical & Testing Center of Wuhan University of Science and Technology for the help on XPS analysis
Ti2TaC2: A novel out-of-plane ordered MXene towards flexible and cytocompatible supercapacitors
No full textExploring biocompatible and flexible supercapacitor electrode material is crucial for expanding the development of health monitoring bioelectronics. MXene films, due to their low cost, high conductivity, and excellent durability under different deformation conditions, are highly competitive in bioelectronic device applications compared with traditional carbon-based materials. Herein, a novel out-of-plane ordered double transition metal MXene (Ti2TaC2) is elaborately designed and originally synthesized, where Ti atoms preferentially reside in the outer transition metal layer and Ta atoms occupy in the middle layer. Theoretical calculations prove that the introduction of Ta species into Ti3C2 MXene enlarges the work function, raises the d-band center close to Fermi level and increases the density of states of d-orbital. Consequently, the Ti2TaC2 film delivers high specific capacitance of 313 F g(-1) at 2 mV s(-1) and excellent cycling stability without capacitance loss after 10,000 cycles at 10 A/g. Furthermore, the safety and cytotoxicity of Ti2TaC2 material are innovatively evaluated in vitro multiple cell lines (e.g., 293T, bEnd.3, PC-12, BV2 and HUVEC cells) and implanted into the subcutaneous tissue of mice, proving its good biosafety and cytocompatibility. The results suggest that flexible Ti2TaC2 MXene film may be a promising cytocompatible electrode material for long-term health monitoring bioelectronics.This work wassupported by the National Natural Science Foundation of China (grant numbers 22372127 and 52002296) and the 14th Five Year Plan “Hubei provincial advantaged characteristic disciplines (group) project of Wuhan University of Science and Technology” (grant number 2023A0202). The authors gratefully acknowledge the Analytical & Testing Center of Wuhan University of Science and Technology for the help on XPS analysis
Recent advances in multiple transition metal MXenes: Synthesis, properties, and applications in energy storage
No full textMXenes, a family of two-dimensional transition metal carbides, nitrides, and carbonitrides, are particularly favored in the energy storage field due to their exceptional electronical conductivity, diverse surface terminations, tunable compositions, excellent hydrophilicity, and ease of processing. As a new intriguing type of MXenes, multiple transition metal (MTM) MXenes comprising double transition metal, medium-entropy, and high-entropy MXene, have garnered significant attention since the first synthesis of Mo2TiC2Tx and Mo2Ti2C3Tx in 2015. This review comprehensively covers recent advancements in MTM MXenes and their composites, focusing on their categories, properties, synthesis and potential applications in energy storage. A detailed comparison of various MTM MXene synthesis methods is presented, highlighting their critical impacts on structure, surface functional groups and properties. Furthermore, the applications of MTM MXenes in supercapacitors, lithium-ion batteries, sodium-ion batteries, magnesium-ion batteries, zinc-ion batteries, and other rechargeable batteries system are thoroughly discussed. Finally, the challenges and future prospects of MTM MXenes are addressed to support their sustainable development in energy storage applications.This work was supported by the National Natural Science Foundation of China (grant numbers U23B2076 and 22372127), Natural Science Foundation of Hubei Province (grant number 2022CFA003), Youth Program of the Hubei Provincial Department of Education‘s Scientific Research Plan (Q20232707) and the 14th Five Year Plan “Hubei provincial advantaged characteristic disciplines (group) project of Wuhan University of Science and Technology” (grant number 2023A0202)
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