26 research outputs found

    Experimental Assessment on the Hysteretic Behavior of a Full-Scale Traditional Chinese Timber Structure Using a Synchronous Loading Technique

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    In traditional Chinese timber structures, few tie beams were used between columns, and the column base was placed directly on a stone base. In order to study the hysteretic behavior of such structures, a full-scale model was established. The model size was determined according to the requirements of an eighth grade material system specified in the architectural treatise Ying-zao-fa-shi written during the Song Dynasty. In light of the vertical lift and drop of the test model during horizontal reciprocating motions, the horizontal low-cycle reciprocating loading experiments were conducted using a synchronous loading technique. By analyzing the load-displacement hysteresis curves, envelope curves, deformation capacity, energy dissipation, and change in stiffness under different vertical loads, it is found that the timber frame exhibits obvious signs of self-restoring and favorable plastic deformation capacity. As the horizontal displacement increases, the equivalent viscous damping coefficient generally declines first and then increases. At the same time, the stiffness degrades rapidly first and then decreases slowly. Increasing vertical loading will improve the deformation, energy-dissipation capacity, and stiffness of the timber frame

    Deep Learning for Feynman's Path Integral in Strong-Field Time-Dependent Dynamics

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    Feynman's path integral approach is to sum over all possible spatio-temporal paths to reproduce the quantum wave function and the corresponding time evolution, which has enormous potential to reveal quantum processes in classical view. However, the complete characterization of quantum wave function with infinite paths is a formidable challenge, which greatly limits the application potential, especially in the strong-field physics and attosecond science. Instead of brute-force tracking every path one by one, here we propose deep-learning-performed strong-field Feynman's formulation with pre-classification scheme which can predict directly the final results only with data of initial conditions, so as to attack unsurmountable tasks by existing strong-field methods and explore new physics. Our results build up a bridge between deep learning and strong-field physics through the Feynman's path integral, which would boost applications of deep learning to study the ultrafast time-dependent dynamics in strong-field physics and attosecond science, and shed a new light on the quantum-classical correspondence

    Three new constructions of asymptotically optimal periodic quasi-complementary sequence sets with small alphabet sizes

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    Quasi-complementary sequence sets (QCSSs) play an important role in multi-carrier code-division multiple-access (MC-CDMA) systems. They can support more users than perfect complementary sequence sets in MC-CDMA systems. It is desirable to design QCSSs with good parameters that are a trade-off of large set size, small periodic maximum magnitude correlation and small alphabet size. The main results are to construct new infinite families of QCSSs that all have small alphabet size and asymptotically optimal periodic maximum magnitude correlation. In this paper, we propose three new constructions of QCSSs using additive characters over finite fields. Notably, these QCSSs have new parameters and small alphabet sizes. Using the properties of characters and character sums, we determine their maximum periodic correlation magnitudes and prove that these QCSSs are asymptotically optimal with respect to the lower bound.Nanyang Technological UniversityAccepted versionThe work of Gaojun Luo was supported by NTU Research under Grant 04INS000047C230GRT01. The work of Xiwang Cao was supported by the National Natural Science Foundation of China under Grant 11771007 and Grant 61572027. The work of Minjia Shi was supported in part by the National Natural Science Foundation of China under Grant 12071001and Grant 61672036, in part by the Excellent Youth Foundation of Natural Science Foundation of Anhui Province under Grant 1808085J20, and in part by the Academic Fund for Outstanding Talents in Universities under Grant gxbjZD03. The work of Tor Helleseth was supported by the Research Council of Norway under Grant 247742//O70 and Grant 311646/O70

    The thermal analysis of the heat dissipation system of the charging module integrated with ultra-thin heat pipes

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    Electric vehicles (EV) played an important role fighting greenhouse gas emissions that contributed to global warming. The construction of the charging pile, which was called as the ''gas station'' of EV, developed rapidly. The charging speed of the charging piles was shorted rapidly, which was a challenge for the heat dissipation system of the charging pile. In order to reduce the operation temperature of the charging pile, this paper proposed a fin and ultra-thin heat pipes (UTHPs) hybrid heat dissipation system for the direct-current (DC) charging pile. The L-shaped ultra-thin flattened heat pipe with ultra-high thermal conductivity was adopted to reduce the spreading thermal resistance. ICEPAK software was used to simulate the temperature and flow profiles of the new design. And various factors that affected the heat dissipation performance of the system were explored. Simulation results showed that the system had excellent heat dissipation capacity and achieved good temperature uniformity. Rather than solely relied on the fans, this new design efficiently dissipated heat with a lower fan load and less energy consumption

    Effect of coordination number of particle contact force on rutting resistance of asphalt mixture

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    Optimizing asphalt mix design at the indoor stage is of significant importance for enhancing the rutting resistance of asphalt mixture, which is affected by its structural characteristics. In this work, the coordination number of particle contact force (CNpcf) was proposed as an indicator to represent contact characteristics of skeleton structure aggregates in asphalt mixture. Nine asphalt mixtures with different gradations were designed, and the relationship of CNpcf with the number of aggregate contact zones (CZ) was established by combining rutting tests and digital image processing technique (DIP). The Mann-Whitney U test was implemented to analyze the distribution properties of inter-particle contacts before and after the rutting test. In addition, the resistance to the further expansion of rutting was analyzed. The results revealed a significant positive correlation (PCCs = 0.843, R2 = 0.711) between CNpcf and CZ. The content of coarse aggregates in the dominant structure did not exhibit monotonic related to anti-rutting performance of the asphalt mixture. Therefore, an optimum aggregate content of 57% was utilized. The Mann-Whitney U test revealed that the mesoscale skeleton structure of the asphalt mixes before and after rutting exhibited excellent stability. This study further indicated the applicability of combining CNpcf to adjust the mix design to enhance the rutting resistance of asphalt mixture and to prevent rutting expansion in flexible pavement.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Pavement Engineerin

    Nano-layer based 1T-rich MoS2/g-C3N4 co-catalyst system for enhanced photocatalytic and photoelectrochemical activity

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    Photocatalytic disinfection based on semiconductors has been expected to tackle bio-contaminated water issue by leveraging reactive oxygen species (ROS) as “green” bactericide. However, semiconductor along usually inactivates bacteria tardily due to the fierce competition between high recombination rate of photo-excited charge carriers and the capture of them on surface to catalyse reactions. In this study, we in situ hybridized a cost-effective co-catalyst (MoS2) on an earth-abundant semiconductor (g-C3N4 in nanosheets) based on similar nano-layered configuration. The spontaneously synthesized MoS2 nano-layers (5–8 layers) was dominant in 1 T-phase which was found serviceable for efficient charge separation possibly by extracting electrons from g-C3N4 nanosheets through the fully contacted interface and accelerated charge transfer in highly conductive metallic MoS2, meanwhile affording additional active sites both at edges and on basal plans relative to edge-active 2H MoS2. The optimized 1 T-rich MoS2/g-C3N4 nanocomposite impressively enlarged the photocurrent density by a factor of 5.5 compared to bare g-C3N4 and promoted the formation of H2O2 as the main ROS, thus leading to a better photocatalytic water disinfection performance than those of single component catalysts, 2H-rich counterpart and physical MoS2/g-C3N4 mixture. This strategy would potentially enlighten the construction of other effective co-catalysts as alternatives to the expensive noble metals in catalysing photo-activated reactions.</p

    Image_2_A cuproptosis-related lncRNA signature predicts the prognosis and immune cell status in head and neck squamous cell carcinoma.jpeg

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    IntroductionThe incidence of head and neck squamous cell carcinoma (HNSCC), one of the most prevalent tumors, is increasing rapidly worldwide. Cuproptosis, as a new copper-dependent cell death form, was proposed recently. However, the prognosis value and immune effects of cuproptosis-related lncRNAs (CRLs) have not yet been elucidated in HNSCC.MethodsIn the current study, the expression pattern, differential profile, clinical correlation, DNA methylation, functional enrichment, univariate prognosis factor, and the immune effects of CRLs were analyzed. A four-CRL signature was constructed using the least absolute shrinkage and selection operator (LASSO) algorithm.ResultsResults showed that 20 CRLs had significant effects on the stage progression of HNSCC. Sixteen CRLs were tightly correlated with the overall survival (OS) of HNSCC patients. Particularly, lnc-FGF3-4 as a single risk factor was upregulated in HNSCC tissues and negatively impacted the prognosis of HNSCC. DNA methylation probes of cg02278768 (MIR9-3HG), cg07312099 (ASAH1-AS1), and cg16867777 (TIAM1-AS1) were also correlated with the prognosis of HNSCC. The four-CRL signature that included MAP4K3-DT, lnc-TCEA3-1, MIR9-3HG, and CDKN2A-DT had a significantly negative effect on the activation of T cells follicular helper and OS probability of HNSCC. Functional analysis revealed that cell cycle, DNA replication, and p53 signal pathways were enriched.DiscussionA novel CRL-related signature has the potential of prognosis prediction in HNSCC. Targeting CRLs may be a promising therapeutic strategy for HNSCC.</p
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