89 research outputs found

    El proyecto arquitectónico en el paisaje del patrimonio moderno de Valladolid. El colegio internado de la Sagrada Familia.

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    El Colegio Internado Sagrada Familia está situado a apenas tres kilómetros al sur de la ciudad de Valladolid, en un área en que la casualidad hizo que en relativamente poca distancia se situasen tres edificios de uso escolar pioneros de la modernidad en Valladolid. Acompañando al que aquí le comentamos, se encuentran el Colegio Apostólico de los Padres Dominicos (Fisac, 1957) y el Colegio de San Agustín (Cecilio Sánchez Robles Tarín, 1961). La implantación del Colegio Internado Sagrada Familia se produce en un lugar llano ocupado por los últimos pinos del pinar de Antequera, incorporando al diseño de sus espacios libres la Acequia de Valladolid. Los árboles de ribera junto al canal y los grandes pinos en toda la parcela, con sus tallos largos y esbeltos, se convierten en un potente elemento proyectual del que los arquitectos se sirven con gran inteligencia para crear visiones equilibradas en el edificio. El edificio escolar pretende mimetizarse con el entorno, pasar desapercibido e integrarse a través de una cuidada elección de sus materiales. De hecho, en el colegio cuentan como anécdota que los arquitectos vinieron de Madrid con una maqueta y viendo el solar la giraron y colocaron de tal forma que respetase el mayor número posible de árboles existentes.Máster en Investigación e Innovación en Arquitectura. Intervención en el Patrimonio, Rehabilitación y Regeneració

    Source-Aware Spatial-Spectral-Integrated Double U-Net for Image Fusion

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    In image fusion tasks, pictures from different sources possess distinctive properties, therefore treating them equally will lead to inadequate feature extracting. Besides, multi-scaled networks capture information more sufficiently than single-scaled models in pixel-wised problems. In light of these factors, we propose a source-aware spatial-spectral-integrated double U-shaped network called (SU)2\rm{(SU)^2}Net. The network is mainly composed of a spatial U-net and a spectral U-net, which learn spatial details and spectral characteristics discriminately and hierarchically. In contrast with most previous works that simply apply concatenation to integrate spatial and spectral information, a novel structure named the spatial-spectral block (called S2\rm{S^2}Block) is specially designed to merge feature maps from different sources effectively. Experiment results show that our method outperforms the representative state-of-the-art (SOTA) approaches in both quantitative and qualitative evaluations for a variety of image fusion missions, including remote sensing pansharpening and hyperspectral image super-resolution (HISR)

    Modeling Paragraph-Level Vision-Language Semantic Alignment for Multi-Modal Summarization

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    Most current multi-modal summarization methods follow a cascaded manner, where an off-the-shelf object detector is first used to extract visual features, then these features are fused with language representations to generate the summary with an encoder-decoder model. The cascaded way cannot capture the semantic alignments between images and paragraphs, which are crucial to a precise summary. In this paper, we propose ViL-Sum to jointly model paragraph-level \textbf{Vi}sion-\textbf{L}anguage Semantic Alignment and Multi-Modal \textbf{Sum}marization. The core of ViL-Sum is a joint multi-modal encoder with two well-designed tasks, image reordering and image selection. The joint multi-modal encoder captures the interactions between modalities, where the reordering task guides the model to learn paragraph-level semantic alignment and the selection task guides the model to selected summary-related images in the final summary. Experimental results show that our proposed ViL-Sum significantly outperforms current state-of-the-art methods. In further analysis, we find that two well-designed tasks and joint multi-modal encoder can effectively guide the model to learn reasonable paragraphs-images and summary-images relations

    Ultrafast Charge Transfer in Atomically Thin MoS2/WS2 Heterostructures

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    Van der Waals heterostructures have recently emerged as a new class of materials, where quantum coupling between stacked atomically thin two-dimensional (2D) layers, including graphene, hexagonal-boron nitride, and transition metal dichalcogenides (MX2), give rise to fascinating new phenomena. MX2 heterostructures are particularly exciting for novel optoelectronic and photovoltaic applications, because 2D MX2 monolayers can have an optical bandgap in the near-infrared to visible spectral range and exhibit extremely strong light-matter interactions. Theory predicts that many stacked MX2 heterostructures form type-II semiconductor heterojunctions that facilitate efficient electron-hole separation for light detection and harvesting. Here we report the first experimental observation of ultrafast charge transfer in photo-excited MoS2/WS2 heterostructures using both photoluminescence mapping and femtosecond (fs) pump-probe spectroscopy. We show that hole transfer from the MoS2 layer to the WS2 layer takes place within 50 fs after optical excitation, a remarkable rate for van der Waals coupled 2D layers. Such ultrafast charge transfer in van der Waals heterostructures can enable novel 2D devices for optoelectronics and light harvesting

    Preimage Attacks on 4-round Keccak by Solving Multivariate Quadratic Systems

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    In this paper, we present preimage attacks on 4-round Keccak-224/256 as well as 4-round Keccak[r=640,c=160,l=80r = 640,c = 160,l = 80] in the preimage challenges. We revisit the Crossbred algorithm for solving the Boolean multivariate quadratic (MQ) system, propose a new view for the case D=2D = 2 and elaborate the computational complexity. The result shows that the Crossbred algorithm outperforms brute force theoretically and practically with feasible memory costs. In our attacks, we construct Boolean MQ systems in order to make full use of variables. With the help of solving MQ systems, we successfully improve preimage attacks on Keccak-224/256 reduced to 4 rounds. Moreover, we implement the preimage attack on 4-round Keccak[r=640,c=160,l=80r = 640,c = 160,l = 80], an instance in the Keccak preimage challenges, and find 78-bit matched \textit{near preimages}. Due to the fundamental rule of solving MQ systems, the complexity elaboration of Crossbred algorithm is of independent interest

    Perylene Diimide as a Precise Graphene-like Superoxide Dismutase Mimetic

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    Here we show that the active portion of a graphitic nanoparticle can be mimicked by a perylene diimide (PDI) to explain the otherwise elusive biological and electrocatalytic activity of the nanoparticle construct. Development of molecular analogues that mimic the antioxidant properties of oxidized graphenes, in this case the poly(ethylene glycolated) hydrophilic carbon clusters (PEG–HCCs), will afford important insights into the highly efficient activity of PEG–HCCs and their graphitic analogues. PEGylated perylene diimides (PEGn–PDI) serve as well-defined molecular analogues of PEG–HCCs and oxidized graphenes in general, and their antioxidant and superoxide dismutase-like (SOD-like) properties were studied. PEGn–PDIs have two reversible reduction peaks, which are more positive than the oxidation peak of superoxide (O2•–). This is similar to the reduction peak of the HCCs. Thus, as with PEG–HCCs, PEGn–PDIs are also strong single-electron oxidants of O2•–. Furthermore, reduced PEGn–PDI, PEGn–PDI•–, in the presence of protons, was shown to reduce O2•– to H2O2 to complete the catalytic cycle in this SOD analogue. The kinetics of the conversion of O2•– to O2 and H2O2 by PEG8–PDI was measured using freeze-trap EPR experiments to provide a turnover number of 133 s–1; the similarity in kinetics further supports that PEG8–PDI is a true SOD mimetic. Finally, PDIs can be used as catalysts in the electrochemical oxygen reduction reaction in water, which proceeds by a two-electron process with the production of H2O2, mimicking graphene oxide nanoparticles that are otherwise difficult to study spectroscopically

    Gate-dependent Pseudospin Mixing in Graphene/Boron Nitride Moire Superlattices

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    Electrons in graphene are described by relativistic Dirac-Weyl spinors with a two-component pseudospin1-12. The unique pseudospin structure of Dirac electrons leads to emerging phenomena such as the massless Dirac cone2, anomalous quantum Hall effect2, 3, and Klein tunneling4, 5 in graphene. The capability to manipulate electron pseudospin is highly desirable for novel graphene electronics, and it requires precise control to differentiate the two graphene sub-lattices at atomic level. Graphene/boron nitride (graphene/BN) Moire superlattice, where a fast sub-lattice oscillation due to B-N atoms is superimposed on the slow Moire period, provides an attractive approach to engineer the electron pseudospin in graphene13-18. This unusual Moire superlattice leads to a spinor potential with unusual hybridization of electron pseudospins, which can be probed directly through infrared spectroscopy because optical transitions are very sensitive to excited state wavefunctions. Here, we perform micro-infrared spectroscopy on graphene/BN heterostructure and demonstrate that the Moire superlattice potential is dominated by a pseudospin-mixing component analogous to a spatially varying pseudomagnetic field. In addition, we show that the spinor potential depends sensitively on the gate-induced carrier concentration in graphene, indicating a strong renormalization of the spinor potential from electron-electron interactions. Our study offers deeper understanding of graphene pseudospin structure under spinor Moire potential, as well as exciting opportunities to control pseudospin in two-dimensional heterostructures for novel electronic and photonic nanodevices

    20(S)-Protopanaxadiol Inhibits Titanium Particle-Induced Inflammatory Osteolysis and RANKL-Mediated Osteoclastogenesis via MAPK and NF-κB Signaling Pathways

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    Osteolysis is a principal reason for arthroplasty failure like aseptic loosening induced by Titanium (Ti) particle. It is a challenge for orthopedic surgeons. Recent researches show that 20(S)-protopanaxadiol can inhibit inflammatory cytokine release in vitro. This study aims to assess the effect of 20(S)-protopanaxadiol on Ti particle-induced osteolysis and RANKL-mediated osteoclastogenesis. Micro-CT and histological analysis in vivo indicated the inhibitory effects of 20(S)-protopanaxadiol on osteoclastogenesis and the excretion of inflammatory cytokines. Next, we demonstrated that 20(S)-protopanaxadiol inhibited osteoclast differentiation, bone resorption area, and F-actin ring formation in a dose-dependent manner. Moreover, mechanistic studies suggested that the suppression of MAPK and NF-κB signaling pathways were found to mediate the inhibitory effects of 20(S)-protopanaxadiol. In conclusion, 20(S)-protopanaxadiol may suppress osteoclastogenesis in a dose- dependent manner and it could be a potential treatment of Ti particle-induced osteolysis
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