1,033 research outputs found

    The Wing Pavilion:A Participatory Action Approach to Bamboo Architectural Research in Chinese Universities

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    The application of bamboo construction techniques in Chinese architecture remains behind its potential. Chinese universities began conducting participatory action research on bamboo as a building material. Students from the Huazhong University of Science and Technology designed the wing pavilion: a temporary bamboo structure built in six days inside the Nan Sha Bird Eco-Park, Guangzhou. The process combined handcraft and digital techniques within five steps: pre-design, formulation, successive answers, project, and conclusion of the theory. Eight bamboo arches interconnected to create a six-meter span roof. Each arch was pre-fabricated with two layers of split bamboo and one slender bamboo culm as reinforcement. The cartesian plane technique was utilised to overcome the indeterminacy of bamboo. Details could be fuller, and the roof lacked enough strength. More important than a perfect result, the principles of bamboo architecture transferred to students, and a range of scales can replicate the methodology. The technical solution reflected a Western functionality with an Asian essence. Many of the now underprivileged people will benefit from it since bamboo is abundant in China. Keywords: Bamboo architecture, participatory action research, green building, architectural education. DOI: 10.7176/ISDE/10-5-03 Publication date:June 30th 201

    Numerical study on the coupled vibration characteristics of dual-rotors system with little rotation speed difference

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    In view of statically indeterminate structures of the decanter centrifuge, an iteration calculation model of nonlinear bearing stiffness is built innovatively. Based on gear meshing stiffness, material and lubricant film damping, coupled dual-rotors vibration model of screw-differential mechanism-bowl is constructed using solid elements. Applying ANSYS modal analysis, critical speeds along with vibration modes of dual-rotors and single-rotor are simulated, and the impacts of the differential mechanism and single-rotor modal on dual-rotors modal are obtained. Built on the harmonic response analysis, the results indicate that the system responses differently for the different rotors by manipulating the dynamic responses of the centrifuge under single rotor unbalance excitation. On the basis of transient structural analysis, beat vibration characteristics of dual-rotors system with little rotation speed difference are obtained, and a conclusion of the system responses separately for the unbalance mass of different rotors at a low rotating speed is acquired. The models and methods adopted in simulation are proved to be reasonable and feasible by experiment. The results have certain significance for the design and the dynamic balancing technique of the decanter centrifuge

    Learning to Ask for Data-Efficient Event Argument Extraction

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    Event argument extraction (EAE) is an important task for information extraction to discover specific argument roles. In this study, we cast EAE as a question-based cloze task and empirically analyze fixed discrete token template performance. As generating human-annotated question templates is often time-consuming and labor-intensive, we further propose a novel approach called "Learning to Ask," which can learn optimized question templates for EAE without human annotations. Experiments using the ACE-2005 dataset demonstrate that our method based on optimized questions achieves state-of-the-art performance in both the few-shot and supervised settings.Comment: work in progres

    Laminin-511 and integrin beta-1 in hair follicle development and basal cell carcinoma formation

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    <p>Abstract</p> <p>Background</p> <p>Initiation of the hair follicle placode and its subsequent growth, maturation and cycling in post-natal skin requires signaling interactions between epithelial cells and adjacent dermal cells and involves Shh signaling via the primary cilium. Previous reports have implicated laminins in hair follicle epithelial invagination.</p> <p>Results</p> <p>Here we use a human BCC model system and mouse mutants to re-evaluate the role of laminin-511 in epithelial invagination in the skin. Blocking laminin 511 and 332 in BCCs maintains primary cilia and Shh signalling, but prevents invagination. Similarly, in laminin-511 and dermal beta-1 integrin mutants, dermal papilla development and primary cilia formation are normal. Dermal beta-1 integrin mutants have normal hair follicle development.</p> <p>Conclusions</p> <p>Our data provides support for a primary role of laminin-511 promoting hair follicle epithelial downgrowth without affecting dermal primary cilia and Shh target gene induction.</p

    Enhancement of polar phases in PVDF by forming PVDF/SiC nanowire composite

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    Different contents of silicon carbide (SiC) nanowires were mixed with Poly(vinylidene fluoride) (PVDF) to facilitate the polar phase crystallization. It was shown that the annealing temperature and SiC content affected on the phase and crystalline structures of PVDF/SiC samples. Furthermore, the addition of SiC nanowire enhanced the transformation of non-polar Ξ± phase to polar phases and increased the relative fraction of Ξ² phase in PVDF. Due to the nucleating agent mechanism of SiC nanowires, the ion-dipole interaction between the negatively charged surface of SiC nanowires and the positive CH2 groups in PVDF facilitated the formation of polar phases in PVDF

    Major Population Expansion of East Asians Began before Neolithic Time: Evidence of mtDNA Genomes

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    It is a major question in archaeology and anthropology whether human populations started to grow primarily after the advent of agriculture, i.e., the Neolithic time, especially in East Asia, which was one of the centers of ancient agricultural civilization. To answer this question requires an accurate estimation of the time of lineage expansion as well as that of population expansion in a population sample without ascertainment bias. In this study, we analyzed all available mtDNA genomes of East Asians ascertained by random sampling, a total of 367 complete mtDNA sequences generated by the 1000 Genome Project, including 249 Chinese (CHB, CHD, and CHS) and 118 Japanese (JPT). We found that major mtDNA lineages underwent expansions, all of which, except for two JPT-specific lineages, including D4, D4b2b, D4a, D4j, D5a2a, A, N9a, F1a1'4, F2, B4, B4a, G2a1 and M7b1'2'4, occurred before 10 kya, i.e., before the Neolithic time (symbolized by Dadiwan Culture at 7.9 kya) in East Asia. Consistent to this observation, the further analysis showed that the population expansion in East Asia started at 13 kya and lasted until 4 kya. The results suggest that the population growth in East Asia constituted a need for the introduction of agriculture and might be one of the driving forces that led to the further development of agriculture

    Full velocities and propagation directions of coronal mass ejections inferred from simultaneous full-disk imaging and Sun-as-a-star spectroscopic observations

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    Coronal mass ejections (CMEs) are violent ejections of magnetized plasma from the Sun, which can trigger geomagnetic storms, endanger satellite operations and destroy electrical infrastructures on the Earth. After systematically searching Sun-as-a-star spectra observed by the Extreme-ultraviolet Variability Experiment (EVE) onboard the Solar Dynamics Observatory (SDO) from May 2010 to May 2022, we identified eight CMEs associated with flares and filament eruptions by analyzing the blue-wing asymmetry of the O III 52.58 nm line profiles. Combined with images simultaneously taken by the 30.4 nm channel of the Atmospheric Imaging Assembly onboard SDO, the full velocity and propagation direction for each of the eight CMEs are derived. We find a strong correlation between geomagnetic indices (Kp and Dst) and the angle between the CME propagation direction and the Sun-Earth line, suggesting that Sun-as-a-star spectroscopic observations at EUV wavelengths can potentially help to improve the prediction accuracy of the geoeffectiveness of CMEs. Moreover, an analysis of synthesized long-exposure Sun-as-a-star spectra implies that it is possible to detect CMEs from other stars through blue-wing asymmetries or blueshifts of spectral lines.Comment: Accepted by Ap
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