16 research outputs found

    Thickness-Independent Capacitive Performance of Holey Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> Film Prepared through a Mild Oxidation Strategy

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    The Ti3C2Tx film with metallic conductivity and high pseudo-capacitance holds profound promise in flexible high-rate supercapacitors. However, the restacking of Ti3C2Tx sheets hinders ion access to thick film electrodes. Herein, a mild yet green route has been developed to partially oxidize Ti3C2Tx to TiO2/Ti3C2Tx by introducing O2 molecules during refluxing the Ti3C2Tx suspension. The subsequent etching away of these TiO2 nanoparticles by HF leaves behind numerous in-plane nanopores on the Ti3C2Tx sheets. Electrochemical impedance spectroscopy shows that longer oxidation time of 40 min yields holey Ti3C2Tx (H-Ti3C2Tx) with a much shorter relax time constant of 0.85 s at electrode thickness of 25 ”m, which is 89 times smaller than that of the pristineTi3C2Tx film (75.58 s). Meanwhile, H-Ti3C2Tx film with 25 min oxidation exhibits less-dependent capacitive performance in film thickness range of 10–84 ”m (1.63–6.41 mg cm−2) and maintains around 60% capacitance as the current density increases from 1 to 50 A g−1. The findings clearly demonstrate that in-plane nanopores not only provide more electrochemically active sites, but also offer numerous pathways for rapid ion impregnation across the thick Ti3C2Tx film. The method reported herein would pave way for fabricating porous MXene materials toward high-rate flexible supercapacitor applications.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

    Methodological Framework for Modelling and Empirical Approaches (Deliverable D1.1 in the H2020 MSCA ITN project SHAPE-IT)

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    The progress in technology development over the past decades, both with respect to software and hardware, offers the vision of automated vehicles as means of achieving zero fatalities in traffic. However, the promises of this new technology – an increase in road safety, traffic efficiency, and user comfort – can only be realized if this technology is smoothly introduced into the existing traffic system with all its complexities, constraints, and requirements. SHAPE- IT will contribute to this major undertaking by addressing research questions relevant for the development and introduction of automated vehicles in urban traffic scenarios. Previous research has pointed out several research areas that need more attention for a successful implementation and deployment of human-centred vehicle automation in urban environments.In SHAPE-IT, for example, a better understanding of human behaviour and the underlying psychological mechanisms will lead to improved models of human behaviour that can help to predict the effects of automated systems on human behaviour already during system development. Such models can also be integrated into the algorithms of automated vehicles, enabling them to better understand the human interaction partners’ behaviours.Further, the development of vehicle automation is much about technology (software and hardware), but the users will be humans and they will interact with humans both inside and outside of the vehicle. To be successful in the development of automated vehicles functionalities, research must be performed on a variety of aspects. Actually, a highly interdisciplinary team of researchers, bringing together expertise and background from various scientific fields related to traffic safety, human factors, human-machine interaction design and evaluation, automation, computational modelling, and artificial intelligence, is likely needed to consider the human-technology aspects of vehicle automation.Accordingly, SHAPE-IT has recruited fifteen PhD candidates (Early Stage Researchers – ESRs), that work together to facilitate this integration of automated vehicles into complex urban traffic by performing research to support the development of transparent, cooperative, accepted, trustworthy, and safe automated vehicles. With their (and their supervisors’) different scientific background, the candidates bring different theoretical concepts and methodological approaches to the project. This interdisciplinarity of the project team offers the unique possibility for each PhD candidate to address research questions from a broad perspective – including theories and methodological approaches of other interrelated disciplines. This is the main reason why SHAPE-IT has been funded by the European Commission’s Marie SkƂodowska-Curie Innovative Training Network (ITN) program that is aimed to train early state researchers in multidisciplinary aspects of research including transferable skills. With the unique scope of SHAPE-IT, including the human-vehicle perspective, considering different road-users (inside and outside of the vehicle), addressing for example trust, transparency, and safety, and including a wide range of methodological approaches, the project members can substantially contribute to the development and deployment of safe and appreciated vehicle automation in the cities of the future.To achieve the goal of interdisciplinary research, it is necessary to provide the individual PhD candidate with a starting point, especially on the different and diverse methodological approaches of the different disciplines. The empirical, user-centred approach for the development and evaluation of innovative automated vehicle concepts is central to SHAPE- IT. This deliverable (D1.1 “Methodological Framework for Modelling and Empirical Approaches”) provides this starting point. That is, this document provides a broad overview of approaches and methodologies used and developed by the SHAPE-IT ESRs during their research. The SHAPE-IT PhD candidates, as well as other researchers and developers outside of SHAPE-IT, can use this document when searching for appropriate methodological approaches, or simply get a brief overview of research methodologies often employed in automated vehicle research.The first chapter of the deliverable shortly describes the major methodological approaches to collect data relevant for investigating road user behaviour. Each subchapter describes one approach, ranging from naturalistic driving studies to controlled experiments in driving simulators, with the goal to provide the unfamiliar reader with a broad overview of the approach, including its scope, the type of data collected, and its limitations. Each subchapter ends with recommendations for further reading – literature that provide much more detail and examples.The second chapter explains four different highly relevant tools for data collection, such as interviews, questionnaires, physiological measures, and as other current tools (the Wizard of Oz paradigm and Augmented and Virtual Reality). As in the first chapter this chapter provides the reader with information about advantages and disadvantages of the different tools and with proposed further readings.The third chapter deals with computational models of human/agent interaction and presents in four subchapters different modelling approaches, ranging from models based on psychological mechanisms, rule-based and artificial intelligence models to simulation models of traffic interaction.The fourth chapter is devoted to Requirements Engineering and the challenge of communicating knowledge (e.g., human factors) to developers of automated vehicles. When forming the SHAPE-IT proposal it was identified that there is a lack of communication of human factors knowledge about the highly technical development of automated vehicles. This is why it is highly important that the SHAPE-IT ESRs get training in requirement engineering. Regardless of the ESRs working in academia or industry after their studies it is important to learn how to communicate and disseminate the findings to engineers.The deliverable ends with the chapter “Method Champions”. Here the expertise and association of the different PhD candidates with the different topics are made explicit to facilitate and encourage networking between PhDs with special expertise and those seeking support, especially with regards to methodological questions.Transport and Plannin

    Joint energy consumption optimization method for wing-diesel engine-powered hybrid ships towards a more energy-efficient shipping

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    Wing-diesel engine-powered hybrid ships can effectively reduce fuel consumption and CO2 emissions by using wind energy as the auxiliary driving power. The energy optimization management of the hybrid system can further improve the ship's energy efficiency. To achieve this purpose, it is significant to establish an effective energy consumption model for the energy optimization management of the hybrid system. Therefore, an energy consumption model is established based on the energy conversion analysis of the hybrid power system in this paper. This model can effectively describe the energy consumption of the hybrid ship under different navigational environmental conditions. Then, a joint optimization method of the wing attack angle and of the sailing speed for the hybrid ship is proposed by adopting a swarm intelligence optimization algorithm, in order to reduce energy consumption and CO2 emissions of the hybrid ship under different navigational environmental conditions. Finally, the energy consumption optimization potentials by adopting the hybrid power system and the proposed joint optimization method are analyzed. The results show that the energy consumption and CO2 emissions along a typical route can be reduced by about 4.5%. This study provides an important basis for future practical operations of wing-diesel engine-powered hybrid ships.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

    The Involvement of Occipital and Inferior Frontal Cortex in the Phonological Learning of Chinese Characters

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    Neural changes related to the learning of the pronunciation of Chinese characters in English speakers were examined using fMRI. We examined the item-specific learning effects for trained characters and the generalization of phonetic knowledge to novel transfer characters that shared a phonetic radical (part of a character that gives a clue to the whole character's pronunciation) with trained characters. Behavioral results showed that shared phonetic information improved performance for transfer characters. Neuroimaging results for trained characters over learning found increased activation in the right lingual gyrus, and greater activation enhancement in the left inferior frontal gyrus (Brodmann's area 44) was correlated with higher accuracy improvement. Moreover, greater activation for transfer characters in these two regions at the late stage of training was correlated with better knowledge of the phonetic radical in a delayed recall test. The current study suggests that the right lingual gyrus and the left inferior frontal gyrus are crucial for the learning of Chinese characters and the generalization of that knowledge to novel characters. Left inferior frontal gyrus is likely involved in phonological segmentation, whereas right lingual gyrus may subserve processing visual-orthographic information

    Selection and characterization of single-chain recombinant antibodies against spring viraemia of carp virus from mouse phage display library

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    Antibody-displaying phage library was selected after three rounds of panning against spring viraemia of carp virus (SVCV) by phage display technology. Eight positive clones which could produce soluble single-chain fragment variable (scFv) antibody induced by isopropyl-beta-D-thiogalactopyranoside (IPTG) were obtained. Dot blot results showed that the eight scFv antibodies could recognize SVCV. The soluble scFv antibodies showed a molecular weight 29 kD by Western blot. All scFv antibodies could recognize SVCV proteins specifically without cross-reaction with other virus proteins by ELISA. Indirect immunofluorescence results showed that all of these scFv antibodies reacted positively with virus in the SVCV-infected cells. These scFv antibodies will be useful tools to establish immunological detection methods for SVCV. (C) 2013 Elsevier B.V. All rights reserved.Antibody-displaying phage library was selected after three rounds of panning against spring viraemia of carp virus (SVCV) by phage display technology. Eight positive clones which could produce soluble single-chain fragment variable (scFv) antibody induced by isopropyl-beta-D-thiogalactopyranoside (IPTG) were obtained. Dot blot results showed that the eight scFv antibodies could recognize SVCV. The soluble scFv antibodies showed a molecular weight 29 kD by Western blot. All scFv antibodies could recognize SVCV proteins specifically without cross-reaction with other virus proteins by ELISA. Indirect immunofluorescence results showed that all of these scFv antibodies reacted positively with virus in the SVCV-infected cells. These scFv antibodies will be useful tools to establish immunological detection methods for SVCV. (C) 2013 Elsevier B.V. All rights reserved

    Greenhouse gas emissions from different land-use areas in the Littoral Zone of the Three Gorges Reservoir, China

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    A series of ecological projects, including forest and dike-pond projects, were constructed in the littoral zone of the Three Gorges Reservoir (TGR) to maintain the ecological safety of this area. Previous ecological designs mainly focused on the functions of ecological engineering for environmental purification, economic value and increased biodiversity. However, the variations in land-use may alter the emissions of greenhouse gases (GHGs), which were ignored in our previous design. In this paper, the carbon sequestration benefits of ecological engineering were evaluated after dynamically monitoring the GHG emissions from different land-use sites during the growing (April-September) and submerged (October-March) seasons. The results showed that CH4 fluxes in the dike-ponds (3.76 CH4-mg m(-2) h(-1)) and rice paddies (6.09 +/- 1.60 mg-CH4 m(-2) h(-1)) were significantly higher than those in the natural littoral zone (0.77 +/- 0.27 mg-CH4 m(-2) mg-CH(4)m(-2) h(-1)) and forest project (0.57 +/- 0.31 mg-CH4 m(-2) h(-1)) during the growing season. There were no significant differences in the CO2 fluxes from different land-use sites. The emission of N2O from different land-use sites was low and ranged from -0.02 to 0.07 mg-N2O m(-2) h(-1). The growing season contributed to more than 76% of the cumulative annual GHG emissions. Direct GHG emissions and the carbon sequestration ability of species determined the net carbon sinks in the littoral zone. Net carbon sinks in the forest projects with different understory plant communities showed a small variation, with a range of -2.58 to 3.40 t-CO2 ha(-1) year(-1), but the design of the dike-pond projects should favor species that are positive net carbon sinks, e.g., Sagittaria (19.76 t-CO2 ha(-1) y(-1)) and Canna generalis (16.79 t-CO2 ha(-1) y(-1)), rather than those that are negative net carbon sinks, e.g., Trapa natans (-11.79 t-CO2 ha(-1) y(-1)). (C) 2017 Elsevier B.V. All rights reserved

    Spectral Characteristics of Biological Soil Crusts under the Different Types in the Water-Wind Erosion Crisscross Region on the Loess Plateau

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    The study on spectral characteristics of biological soil crust in the water-wind erosion crisscross region in the Loess Plateau has important scientific value for the identification of biological soil crust based on remote sensing technology at regional scale, also provides important technical support for estimating the effect of biological soil crust on regional soil erosion control. The spectra of higher vegetation as well as the biological soil crust of algae with different coverage and different types of mosses were measured and quantified by Surface Species Spectrometry. The results are as follows, the algal bio-soil crust has similar spectral characteristics with soil in the water-wind erosion crisscross region in the Loess Plateau, and there is no obvious "peak valley" characteristic in the spectral curve. The reflectivity was reduced by the increasing coverage of the biological soil crust. Compared with the bare area, the spectral reflectance normalized mean of algae biological soil crust deceased 8. 64%, 15. 80% and 23. 09% respectively in the coverage of 10% to 20%, 30% to 40% and 50% to 60% in the visible area. The absorption characteristic at 680 nm (Chlorophyll) became increasingly obvious and the absorption valley at 2 200 nm (secondary mineral) became smaller as the coverage of algae biological soil crust increased. The spectral curve of moss biological soil crust showed the reflection peak of the green band, the absorption valley of the red light band and the high reflection of the near infrared band, which is similar with the vegetation. In the range of 760 similar to 930 nm, the slope of moss biological soil crust was 2. 5 to 4. 5 timed higher than that of vegetation. The study can provide some theoretical basis and technical support for the identification of biological soil crust

    Effects of canopy gaps on N2O fluxes in a tropical montane rainforest in Hainan of China

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    Background and aims: Tropical montane rainforests play an important role in increasing atmospheric N2O concentration. Although accurate estimations of N2O fluxes in tropical montane rainforests are critical for predicting global climate change, there are still considerable uncertainties about the spatial and temporal variability of the emissions. This study aims to investigate the effects of canopy gap caused by typhoons on N2O emissions, a key factor for understanding the spatial heterogeneity and supporting environmental regulations. Methods: N2O fluxes were measured monthly using static chambers both inside and outside two large canopy gaps in the tropical montane rainforest of the Jianfengling National Natural Reserve on Hainan Island, south of China, from August 2012 to July 2013. Results: Mean annual N2O emissions were 2.19 +/- 0.43 kg N2O-N ha(-1) yr(-1) inside canopy gaps, and 1.19 +/- 0.29 kg N2O-N ha(-1) yr(-1) outside canopy gaps, revealing substantial differences in N2O emissions resulting from forest structure. Moreover, N2O emission rates within canopy gaps during the wet season (2.89 kg N2O-N ha(-1) yr(-1)) were significantly higher than those during the dry season (1.34 kg N2O-N ha(-1) yr(-1)), suggesting strong regulation of soil moisture and precipitation in controlling soil N dynamics. However, there were significant nonlinear relationships between N2O fluxes and water filled pore space, and soil temperature within canopy gaps, but no significant relationships were found under the closed canopy. Conclusions: Contribution of canopy gaps should be considered to avoid underestimation of N2O emission rates from disturbed forests. Interestingly, emissions from gaps are more strongly coupled with climate drivers (moisture and temperature), with important implications for climate change projections. Therefore, the further research is needed to study the biogeochemical processes and mechanisms behind such phenomenon. (C) 2017 Elsevier B.V. All rights reserved

    The on-orbit calibration of DArk Matter Particle Explorer

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    The DArk Matter Particle Explorer (DAMPE), a satellite-based cosmic ray and gamma-ray detector, was launched on December 17, 2015, and began its on-orbit operation on December 24, 2015. In this work we document the on-orbit calibration procedures used by DAMPE and report the calibration results of the Plastic Scintillator strip Detector (PSD), the Silicon-Tungsten tracKer-converter (STK), the BGO imaging calorimeter (BGO), and the Neutron Detector (NUD). The results are obtained using Galactic cosmic rays, bright known GeV gamma-ray sources, and charge injection into the front-end electronics of each sub-detector. The determination of the boundary of the South Atlantic Anomaly (SAA), the measurement of the live time, and the alignments of the detectors are also introduced. The calibration results demonstrate the stability of the detectors in almost two years of the on-orbit operation
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