10 research outputs found

    學前兒童友伴關係的相關因素研究

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    [[abstract]]本研究之目的係探討學前兒童之年齡、性別、家庭社經水準、父母教養行為及個人氣 質等變項與他們之友伴關係的相關性。 受試對象為160名四歲至六歲的學前兒童。利用「父母教養行為問卷」、「兒童氣 質量表」、「照片式社會計量法」,以皮爾遜積差相關分析、淨相關分析、多元逐步 迴歸分析及三因子變異數分析等統計方法來進行研究。 本研究的主要發現為:(1)年齡與社會偏好度有顯著正相關。(2)男生的社會影 響力較高,而女生的社會偏好度則較高。(3)家庭社經水準與幼兒友伴關係無顯著 相關。(4)父母的愛護教養行為與社會偏好度有顯著正相關。(5)幼兒氣質性中 的活動量、適應度、趨避性及反應閾皆與社會影響力有顯著正相關,同時活動量、反 應閾與社會偏好度則皆有顯著負相關,而趨避性則與社會偏好度則為顯著正相關。( 6)能顯著預測社會影響力之變項依序為:趨避性、活動量、性別、精神獎勵、寬鬆 ;能顯著預測社會偏好度之變項則依序為反應閾、年齡、趨避性、活動量、適應度、 性別。(7)男生分裂及打鬥等行為的被提名次數方面要顯著的多於女生。(8)不 同友伴地位的幼兒在合作、分裂、打鬥及領導者等行為的被提名次數方面有顯著的差 異。

    Characterization of one-part alkali-activated slag with rice straw ash

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    In this paper, fresh (setting and rheology) and hardened properties (strength and shrinkage) of one-part alkali-activated slag (AAS) with and without rice straw ash (RSA) are comprehensively investigated. The reaction kinetics and microstructure of the mixtures are characterized by a series of experimental techniques. The results reveal that RSA plays dual roles in AAS, as a precursor (though not fully reactive) and an internal curing agent. The reactive K and Si in RSA participate in the formation of C-(A)-S-H gel and the alkaline groups dissolved from the ash facilitate the hydrolysis of slag. Besides, the porous RSA absorbs liquid in the first day and releases it afterwards, thus providing internal curing to the matrix. The consistency index of the paste becomes higher with the incorporation of RSA. Both autogenous and drying shrinkage of AAS, which are considered as two problematic issues for this material, are mitigated by RSA.Materials and Environmen

    Recycling of ferronickel slag tailing in cementitious materials: Activation and performance

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    As an industrial by-product containing pozzolanic components, recycled ferronickel slag (FNS) has the potential to be supplementary cementitious materials (SCMs) to reduce the massive carbon footprint of the cement industry, however, the main limitation of ferronickel slag as SCMs is the low hydration rate at an early age. In this study, the pozzolanic activity property results indicate that if the proportion is more than 10 %, FSN can hardly participate in the cement hydration reaction during the early stage, even the mechanical strength of FNS-mortar decreases obviously with the higher proportion of ferronickel slag. Therefore, mechanical grinding and steam curing at an early age are applied to promote the reaction activity of the recycled ferronickel slag tailing in this study. Compared with standard curing, the compressive strength of hardened FNS-cement paste with steam curing at 60 °C or 80 °C increased by 8.2 % or 33.8 %, and the connected porosity decreased by 18.9 % or 17.3 %. And MgO in the ferronickel slag exists as Mg2SiO4 in raw materials and enters the C-S-H gel with the formation of M-S-H gel during the secondary hydration stage. This study provides a theoretical basis for solid waste-based concrete and promotes the recycling, conservation, and resources of solid waste in building materials.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.Materials and Environmen

    A comprehensive review on the prediction of ship energy consumption and pollution gas emissions

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    Ship energy consumption and emission prediction are critical for ship energy efficiency management and pollution gas emission control, both of which are major concerns for the shipping industry and hence continue to attract global attention and research interest. This article examined the energy efficiency data sources, big data analysis for energy efficiency, and analyzed the ship energy consumption and emission prediction models. The ship energy consumption and pollution gas emission prediction models are comprehensively summarized based on the modeling method and principles. The theoretical analysis and artificial intelligence-based ship energy consumption model, as well as the top-down and bottom-up ship emission prediction models, are thoroughly examined in terms of influencing factors, model accuracy, data sources, and practical applications. On this basis, the challenges of ship energy consumption and emission prediction are discussed, and future research suggestions are proposed, providing a foundation for the development of ship energy consumption and emission prediction technologies. The analysis results show that the principles, parameters of concern, and data quality all have a significant impact on the performance of the prediction models. Consequently, the prediction model's accuracy can be improved by combining intelligent algorithms and machine learning. In the future, high precision, self-adapting, ship fuel consumption and emission prediction models based on artificial intelligence technology should be further studied, in order to improve their prediction performance, and thus providing solid foundations for the optimization management and control of the ship energy consumption and emissions.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.Transport Engineering and Logistic

    On the magnetic nanoparticle injection strategy for hyperthermia treatment

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    We developed a dedicated computational framework by coupling the lattice-Boltzmann-method (LBM) modeling and the particle-swarm-optimization (PSO) algorithm to search optimal strategies of magnetic nanoparticle (MNP) injection for hyperthermia-based cancer treatment. Two simplified tumor models were considered: a circular model representing geometrically regular tumors and an elliptic model representing geometrically irregular tumors, both sharing the same area. The temperature distribution in the tumor and its surrounding healthy tissue was predicted by solving the Pennes’ bio-heat transfer equation (PBHTE). Both single- and multi-site injection strategies were explored. The results suggest that the multi-site injection strategies generally work well, while the single-site injection strategy fails even on the simplest circular tumor model. The more the injection sites, the better the performance. In particular, when the number of injection sites reaches eight, all temperature requirements can be nearly 100% satisfied in both tumor models. Whether or not including the minimum dose requirement in the objective function only affects the optimization results by less than 2%. The thermal dose was also assessed by considering both temperature and heat exposure time. It was found that the optimal multi-site injection strategies perform reasonably well for both tumor models. Although the setting is only two dimensional and the optimization is on very simplified tumor models, the framework adopted in this present study works well and can provide useful insights into magnetic hyperthermia treatment.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.ChemE/Transport Phenomen

    Probing Cation Displacements in Antiferroelectrics: A Joint NMR and TEM Approach

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    High-resolution scanning transmission electron microscopy (STEM) enjoys great advantages for atomic-resolution visualization of the atomic structure, while failing to disclose structural information along the atomic columns. On the other hand, solid-state nuclear magnetic resonance (NMR) spectroscopy is highly sensitive to the three-dimensional, local structure around atoms in the bulk sample but typically cannot provide an intuitive visualization of the structure. Thus, the combination of atomic-resolution (S)TEM and solid-state NMR spectroscopy has the potential to establish an in-depth, multidimensional structural understanding. Here, we explore this novel strategy to probe the structure of antiferroelectric perovskite oxides PbZrO3 and (Pb,La)(Zr,Sn,Ti)O3. We combine complementary information regarding the in-plane displacement vector mapping from STEM with the analysis of local PbO12 environments from 207Pb NMR spectroscopy to provide unprecedented insight into Pb displacements. For PbZrO3, an ordered 4-fold in-plane displacement modulation is clearly revealed via STEM imaging; meanwhile, the out-of-plane information is provided by two discrete 207Pb NMR signals attributed to two crystallographic Pb sites in the 2D-PASS NMR spectrum. In the chemically modified (Pb,La)(Zr,Sn,Ti)O3 system, disorder of the structure manifests in not only an inhomogeneous displacement modulation but also a broad distribution of 207Pb chemical shifts, related to significant disorder of displacement magnitudes and a favoring of larger displacements. We show that the displacement distribution depends on whether both in-plane and out-of-plane displacements or only out-of-plane displacements are considered. Our findings demonstrate the advantages in the structural analysis using combined TEM and NMR approaches, hence laying the foundation work for controlling and optimizing functional properties.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.RST/Storage of Electrochemical Energ

    Numerical study on unstable surfaces of oblique detonations

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    In this study, the onset of cellular structure on oblique detonation surfaces is investigated numerically using a one-step irreversible Arrhenius reaction kinetic model. Two types of oblique detonations are observed from the simulations. One is weakly unstable characterized by the existence of a planar surface, and the other is strongly unstable characterized by the immediate formation of the cellular structure. It is found that a high degree of overdrive suppresses the formation of cellular structures as confirmed by the results of many previous studies. However, the present investigation demonstrates that cellular structures also appear with degree of overdrive of 2.06 and 2.37, values much higher than similar to 1.8 suggested previously in the literature for the critical value defining the instability boundary of oblique detonations. This contradiction could be explained by the use of differently shaped walls, a straight wall used in this study and a custom-designed curved wedge system so as to induce straight oblique detonations in previous studies. Another possible reason could be due to the low and possibly insufficient resolution used in previously published studies. Hence, simulations with different grid sizes are also performed to examine the effect of resolution on the numerical solutions. Using the present results, analysis also shows that although the characteristic lengths of unstable surfaces are different when the incident Mach number changes, these length scales are proportional to tangential velocities. Hence, the interior time determined by the overdrive degree is identified, and its limitation as the instability parameter is discussed.In this study, the onset of cellular structure on oblique detonation surfaces is investigated numerically using a one-step irreversible Arrhenius reaction kinetic model. Two types of oblique detonations are observed from the simulations. One is weakly unstable characterized by the existence of a planar surface, and the other is strongly unstable characterized by the immediate formation of the cellular structure. It is found that a high degree of overdrive suppresses the formation of cellular structures as confirmed by the results of many previous studies. However, the present investigation demonstrates that cellular structures also appear with degree of overdrive of 2.06 and 2.37, values much higher than similar to 1.8 suggested previously in the literature for the critical value defining the instability boundary of oblique detonations. This contradiction could be explained by the use of differently shaped walls, a straight wall used in this study and a custom-designed curved wedge system so as to induce straight oblique detonations in previous studies. Another possible reason could be due to the low and possibly insufficient resolution used in previously published studies. Hence, simulations with different grid sizes are also performed to examine the effect of resolution on the numerical solutions. Using the present results, analysis also shows that although the characteristic lengths of unstable surfaces are different when the incident Mach number changes, these length scales are proportional to tangential velocities. Hence, the interior time determined by the overdrive degree is identified, and its limitation as the instability parameter is discussed

    Spatial-temporal vegetation succession in Yao'an County, Yunnan Province, Southwest China during 1976-2014: A case survey based on RS technology for mountains eco-engineering

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    The remote sense (RS) technology was adopted to explore the vegetation succession from 1976 to 2014 in Yao'an County, Yunnan Province, Southwest China. The results showed: (i) the changes in the distribution range of major vegetation types in the study area. In the 6 statistic years after 1976, in the study area, the distribution range of the secondary vegetation shrank greatly in 4 different subareas (northeast, southeast, northwest and northwest subarea), at 4 different altitudes (1500-1800 m, 1800-2100 m, 2100-2400m and 2400-2700m), on 4 different gradients (0-8 degrees, 8-15 degrees, 15-25 degrees, 25-35 degrees) and on 4 different aspects but the flat land (sunny slope, semi-sunny slope, semi-shadowy slope, and shadowy slope); by contrast, in the study area, the distribution range of artificial vegetation expanded greatly in all the subareas, at 2 different altitudes (1800-2100 m and 2100-2400 m), on 3 different gradients (0-8 degrees, 8-15 degrees, 15-25 degrees), and on the 4 different aspects but the flat land. (ii) The increase and decrease in distribution area of major vegetation types in the study area. During the research period, the total area of major vegetation fluctuated between 1471.92 and 1196.94 km(2), averaging 1255.52 km(2) annually, with the fluctuation rate between -4.67% and 17.24%. In the second statistic year (1989), the total area of major vegetation decreased sharply, and then remained relatively stable afterward. During the research period, the distribution area of the secondary vegetation decreased sharply in the 6 statistic years after 1976, in contrast to the sharp increase in the distribution area of artificial vegetation in such 6 years. During the research period, the total area of major vegetation decreased by 258.73 km(2) in total, among which the total area of the secondary vegetation decreased by 342.52 km(2) in contrast to the increase in artificial vegetation by 83.78 km(2) in total. Thus, it indicated that the secondary vegetation in the study area had been damaged seriously, and the construction of artificial vegetation lagged behind, so there was a potential danger in ecological safety, which should be concerned and precautioned. (C) 2014 Elsevier B.V. All rights reserved.The remote sense (RS) technology was adopted to explore the vegetation succession from 1976 to 2014 in Yao'an County, Yunnan Province, Southwest China. The results showed: (i) the changes in the distribution range of major vegetation types in the study area. In the 6 statistic years after 1976, in the study area, the distribution range of the secondary vegetation shrank greatly in 4 different subareas (northeast, southeast, northwest and northwest subarea), at 4 different altitudes (1500-1800 m, 1800-2100 m, 2100-2400m and 2400-2700m), on 4 different gradients (0-8 degrees, 8-15 degrees, 15-25 degrees, 25-35 degrees) and on 4 different aspects but the flat land (sunny slope, semi-sunny slope, semi-shadowy slope, and shadowy slope); by contrast, in the study area, the distribution range of artificial vegetation expanded greatly in all the subareas, at 2 different altitudes (1800-2100 m and 2100-2400 m), on 3 different gradients (0-8 degrees, 8-15 degrees, 15-25 degrees), and on the 4 different aspects but the flat land. (ii) The increase and decrease in distribution area of major vegetation types in the study area. During the research period, the total area of major vegetation fluctuated between 1471.92 and 1196.94 km(2), averaging 1255.52 km(2) annually, with the fluctuation rate between -4.67% and 17.24%. In the second statistic year (1989), the total area of major vegetation decreased sharply, and then remained relatively stable afterward. During the research period, the distribution area of the secondary vegetation decreased sharply in the 6 statistic years after 1976, in contrast to the sharp increase in the distribution area of artificial vegetation in such 6 years. During the research period, the total area of major vegetation decreased by 258.73 km(2) in total, among which the total area of the secondary vegetation decreased by 342.52 km(2) in contrast to the increase in artificial vegetation by 83.78 km(2) in total. Thus, it indicated that the secondary vegetation in the study area had been damaged seriously, and the construction of artificial vegetation lagged behind, so there was a potential danger in ecological safety, which should be concerned and precautioned. (C) 2014 Elsevier B.V. All rights reserved

    Cyanobacterial fossils from 252 Ma old microbialites and their environmental significance

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    The end-Permian mass extinction was followed by the formation of an enigmatic rock layer with a distinctive macroscopic spotted or dendroid fabric. This deposit has been interpreted as microbial reef rock, digitate dendrolite, digital thrombolite, dendritic thrombolite, or bacterial deposits. Agreement has been reached in considering them as microbialites, but not in their formation. This study has revealed that the spotted and dendroid microbialites were composed of numerous fossil casts formed by the planktic cyanobacterium, Microcystis, a coccoid genus that at the present-day commonly forms blooms in modern lakes, rivers, and reservoirs. The abundance of the fossils and the diagenesis they experienced has determined the macroscopic fabric: where they abundant, the rock appears as dendroid, otherwise, it appears as spotted. The ancient Microcystis bloom might produce toxin to kill other metazoans, and be responsible for the oceanic anoxia that has puzzled so many researchers for so many years.The end-Permian mass extinction was followed by the formation of an enigmatic rock layer with a distinctive macroscopic spotted or dendroid fabric. This deposit has been interpreted as microbial reef rock, digitate dendrolite, digital thrombolite, dendritic thrombolite, or bacterial deposits. Agreement has been reached in considering them as microbialites, but not in their formation. This study has revealed that the spotted and dendroid microbialites were composed of numerous fossil casts formed by the planktic cyanobacterium, Microcystis, a coccoid genus that at the present-day commonly forms blooms in modern lakes, rivers, and reservoirs. The abundance of the fossils and the diagenesis they experienced has determined the macroscopic fabric: where they abundant, the rock appears as dendroid, otherwise, it appears as spotted. The ancient Microcystis bloom might produce toxin to kill other metazoans, and be responsible for the oceanic anoxia that has puzzled so many researchers for so many years

    Emotional reactions to scandals: When does moral character make a difference?

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    A scandal can evoke public outrage when it is widely publicized and involves an individual who is perceived to have a high level of cultural representativeness. Two experiments showed that when the scandalous target's moral character was highlighted, emotional responses towards the target were least negative when the scandal was widely circulated and when the target was seen as a representative of his culture. These results suggest that when a cultural symbol is implicated in a widely-circulated scandal, the negative emotions directed towards the scandalous individual can be alleviated when the public remains confident in his or her commitment to morality
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