56 research outputs found

    Research on Fault Diagnosis Method Based on Rule Base Neural Network

    Get PDF
    The relationship between fault phenomenon and fault cause is always nonlinear, which influences the accuracy of fault location. And neural network is effective in dealing with nonlinear problem. In order to improve the efficiency of uncertain fault diagnosis based on neural network, a neural network fault diagnosis method based on rule base is put forward. At first, the structure of BP neural network is built and the learning rule is given. Then, the rule base is built by fuzzy theory. An improved fuzzy neural construction model is designed, in which the calculated methods of node function and membership function are also given. Simulation results confirm the effectiveness of this method

    High efficiency perovskite solar cells: from complex nanostructure to planar heterojunction

    Get PDF
    Air Force Office of Scientific Research [FA9550-13-1-0101]Perovskite solar cells have garnered great attention in recent years as promising high performance next-generation solar cells with long-term stability at low cost. Since the seminal work of Miyasaka and others in 2009, the power conversion efficiency (PCE) of perovskite-based dye-sensitized solar cells (DSSCs) has rapidly increased from 3.8% to 15% over the past four years, exceeding the highest efficiency of conventional organic dye-sensitized DSSCs. Recently, the perovskite has been demonstrated to act successfully as an active layer in simple planar-heterojunction solar cells with no need of complex nanostructured DSSC architectures, leading to an attractively high PCE of 15.4% at a competitive low manufacturing cost. In this Feature Article, we aim to review the recent impressive development in perovskite solar cells, and discuss the prognosis for future progress in exploiting perovskite materials for high efficiency solar cells

    Influence of microstructure of carbon fibre reinforced polymer on the metal in contact

    Get PDF
    Abstract(#br)The influence of the microstructure of carbon fibre reinforced polymers (CFRPs) with epoxy matrix (E-CFRP) and nylon matrix (T-CFRP) on the galvanic behaviour of DP590 steel, 6022-aluminium alloy, 1040-steel and AZ31-magnesium alloy was investigated in the GMW14872 solution. The E-CFRP/metal couples were initially more galvanic corrosion resistant, but their galvanic corrosion gradually became more severe than the T-CFRP/metal couples. The effective micro-defects in the surface polymer layer of the CFRP samples critically determined the galvanic corrosion. A detailed surface layer model was proposed, the electrochemical processes through the surface polymer layers during galvanic corrosion were discussed. A better understanding on the microstructure of CFRP determined by composites manufacture process can be obtained

    Facile and effective synthesis of hierarchical TiO2 spheres for efficient dye-sensitized solar cells

    Get PDF
    National Natural Science Foundation of China [51072170, 21021002]; National Basic Research Program of China [2012CB932900]Three-dimensional (3D) crystalline anatase TiO2 hierarchical spheres were successfully derived from Ti foils via a fast, template-free, low-temperature hydrothermal route followed by a calcination post-treatment. These dandelion-like TiO2 spheres are composed of numerous ultrathin nanoribbons, which were subsequently split into fragile nanoflakes as a result of the decomposition of Ti-complex intermediates to TiO2 and H2O at high temperature. The dye-sensitized solar cells (DSSCs) employing such hierarchically structured TiO2 spheres as the photoanodes exhibited a light-to-electricity conversion efficiency of 8.50%, yielding a 28% enhancement in comparison with that (6.64%) of P25-based DSSCs, which mainly benefited from the enhanced capacity of dye loading in combination with effective light scattering and trapping from hierarchical architecture

    Garden-like perovskite superstructures with enhanced photocatalytic activity

    Get PDF
    Chinese Scholarship Council; National Natural Science Foundation of China [51072170, 21021002]; National Basic Research Program of China [2012CB932900]; Minjiang Scholar Program and Georgia Institute of TechnologyBy subjecting amorphous flower-like TiO2 to a facile hydrothermal synthesis in the presence of Sr2+, garden-like perovskite SrTiO3 superstructures were achieved. The amorphous TiO2 was preformed using ZnO flowers as templates. Different three-dimensional SrTiO3 architectures were coexisted in the garden, including SrTiO3 flowers composed of several hollow sword-shaped petals, many sheet-shaped petals or numerous flake-shaped petals, and SrTiO3 grass consisting of a number of long blades. These SrTiO3 superstructures were simultaneously grown on fluorine-doped tin oxide (FTO) substrates. On the basis of a comprehensive study on the effects of growth time, temperature, initial concentrations of precursor, and pH, the formation of these various hierarchical architectures was attributed primarily to the dissolution of amorphous TiO2 and precipitation of perovskite crystals, followed by the Ostwald ripening process of perovskite nanocrystals and self-organization of perovskite building blocks. Interestingly, this approach can be readily extended to create other perovskite structures, including dendritic BaTiO3 and nest-like CaTiO3, as well as PbTiO3 transformed from plate-like pyrochlore Pb2Ti2O6 after post-thermal treatment. Garden-like SrTiO3 superstructures showed a superior photocatalytic performance when compared to other as-prepared semiconductors and perovskite materials (i.e., ZnO, TiO2, BaTiO3, CaTiO3 and PbTiO3), probably due to their intrinsic photocatalytic activity and special garden-like features with a coexistence of various structures that significantly facilitated the adsorption and diffusion of methyl blue (MB) molecules and oxygen species in the photochemical reaction of MB degradation

    Enhanced corrosion protection by Al surface immobilization of in-situ grown layered double hydroxide films co-intercalated with inhibitors and low surface energy species

    Get PDF
    Abstract(#br)In this work, a novel in-situ grown layered double hydroxide (LDH) film co-intercalated with inhibitors (vanadates) and low surface energy substance (laurates) was immobilized on Al substrates. A long-term monitoring of electrochemical impedance spectra (EIS) of the various samples in 3.5 wt.% NaCl solution demonstrated the synergetic protection of the intercalated two functional species. Meanwhile, the X-ray diffraction (XRD) result of the samples after immersion in NaCl solution for a long time presented the anion-exchange process between vanadates/laurates and chlorides. The synergetic effect of the two species loaded film significantly contributed to the enhanced long-term corrosion protection of aluminum

    Active corrosion protection by a smart coating based on a MgAl-layered double hydroxide on a cerium-modified plasma electrolytic oxidation coating on Mg alloy AZ31

    Get PDF
    A composite coating was produced via (i) plasma electrolytic oxidation (PEO) with Ce salt sealing, on which layered double hydroxides (LDHs) were deposited via a hydrothermal treatment, and (ii) then modified by phytic acid (PA) via an ion-exchange reaction. The final coating (characterized using XRD, XPS, FT-IR, SEM, EDS and GDOES) consisted of LDHs/Mg(OH)/CeO/Ce(OH) with a non-uniform Ce distribution. The corrosion protection and self-healing ability were investigated using polarization curves, EIS, immersion tests and SVET. The composite coating modified with PA showed the most superior corrosion protection and self-healing ability, attributed to the synergistic effect between Ce species and phosphate

    ChatRadio-Valuer: A Chat Large Language Model for Generalizable Radiology Report Generation Based on Multi-institution and Multi-system Data

    Full text link
    Radiology report generation, as a key step in medical image analysis, is critical to the quantitative analysis of clinically informed decision-making levels. However, complex and diverse radiology reports with cross-source heterogeneity pose a huge generalizability challenge to the current methods under massive data volume, mainly because the style and normativity of radiology reports are obviously distinctive among institutions, body regions inspected and radiologists. Recently, the advent of large language models (LLM) offers great potential for recognizing signs of health conditions. To resolve the above problem, we collaborate with the Second Xiangya Hospital in China and propose ChatRadio-Valuer based on the LLM, a tailored model for automatic radiology report generation that learns generalizable representations and provides a basis pattern for model adaptation in sophisticated analysts' cases. Specifically, ChatRadio-Valuer is trained based on the radiology reports from a single institution by means of supervised fine-tuning, and then adapted to disease diagnosis tasks for human multi-system evaluation (i.e., chest, abdomen, muscle-skeleton, head, and maxillofacial &\& neck) from six different institutions in clinical-level events. The clinical dataset utilized in this study encompasses a remarkable total of \textbf{332,673} observations. From the comprehensive results on engineering indicators, clinical efficacy and deployment cost metrics, it can be shown that ChatRadio-Valuer consistently outperforms state-of-the-art models, especially ChatGPT (GPT-3.5-Turbo) and GPT-4 et al., in terms of the diseases diagnosis from radiology reports. ChatRadio-Valuer provides an effective avenue to boost model generalization performance and alleviate the annotation workload of experts to enable the promotion of clinical AI applications in radiology reports

    Rare and low-frequency coding variants alter human adult height

    Get PDF
    Height is a highly heritable, classic polygenic trait with ~700 common associated variants identified so far through genome - wide association studies . Here , we report 83 height - associated coding variants with lower minor allele frequenc ies ( range of 0.1 - 4.8% ) and effects of up to 2 16 cm /allele ( e.g. in IHH , STC2 , AR and CRISPLD2 ) , >10 times the average effect of common variants . In functional follow - up studies, rare height - increasing alleles of STC2 (+1 - 2 cm/allele) compromise d proteolytic inhibition of PAPP - A and increased cleavage of IGFBP - 4 in vitro , resulting in higher bioavailability of insulin - like growth factors . The se 83 height - associated variants overlap genes mutated in monogenic growth disorders and highlight new biological candidates ( e.g. ADAMTS3, IL11RA, NOX4 ) and pathways ( e.g . proteoglycan/ glycosaminoglycan synthesis ) involved in growth . Our results demonstrate that sufficiently large sample sizes can uncover rare and low - frequency variants of moderate to large effect associated with polygenic human phenotypes , and that these variants implicate relevant genes and pathways
    corecore