"uuid","repository link","title","author","contributor","publication year","abstract","subject topic","language","publication type","publisher","isbn","issn","patent","patent status","bibliographic note","access restriction","embargo date","faculty","department","research group","programme","project","coordinates"
"uuid:858534fe-7e68-49a3-8d67-a47a955ec82d","http://resolver.tudelft.nl/uuid:858534fe-7e68-49a3-8d67-a47a955ec82d","Luminescence of Ce3+ at two different sites in ?-Sr2P2O7 under vacuum ultraviolet-UV and x-ray excitation","Hou, D.; Han, B.; Chen, W.; Liang, H.; Su, Q.; Dorenbos, P.; Huang, Y.; Gao, Z.; Tao, Y.","","2010","A series of Ce3+ doped ?-Sr2?2xCexNaxP2O7 phosphor compounds has been prepared using a high-temperature solid-state reaction technique. The luminescence properties under vacuum ultraviolet-UV and x-ray excitation were studied. Luminescence spectra reveal three UV-emitting peaks at about 310, 330, and 350 nm from which we conclude that Ce3+ occupies two distinct sites in ?-Sr2P2O7. The influences of the doping concentration, the temperature, and the excitation wavelength on the luminescence of Ce3+ at the Ce(I) and Ce(II) sites together with the decay characteristics are discussed. The light yield under x-ray excitation is found to be around 10?000 photons/MeV.","cerium; cerium compounds; doping profiles; luminescence; phosphors; sodium compounds; strontium compounds; ultraviolet radiation effects; X-ray effects","en","journal article","American Institute of Physics","","","","","","","","Applied Sciences","RRR/Radiation, Radionuclides and Reactors","","","",""
"uuid:3e3d348c-fdc2-4646-8a59-954ad70f7dea","http://resolver.tudelft.nl/uuid:3e3d348c-fdc2-4646-8a59-954ad70f7dea","Groundwater–surface water interactions, vegetation dependencies and implications for water resources management in the semi-arid Hailiutu River catchment, China – a synthesis","Zhou, Y.; Wenninger, J.; Yang, Z.; Yin, L.; Huang, J.; Hou, L.; Wang, X.; Zhang, D.; Uhlenbrook, S.","","2013","During the last decades, large-scale land use changes took place in the Hailiutu River catchment, a semi-arid area in northwest China. These changes had significant impacts on the water resources in the area. Insights into groundwater and surface water interactions and vegetation-water dependencies help to understand these impacts and formulate sustainable water resources management policies. In this study, groundwater and surface water interactions were identified using the baseflow index at the catchment scale, and hydraulic and water temperature methods as well as event hydrograph separation techniques at the sub-catchment scale. The results show that almost 90% of the river discharge consists of groundwater. Vegetation dependencies on groundwater were analysed from the relationship between the Normalized Difference Vegetation Index (NDVI) and groundwater depth at the catchment scale and along an ecohydrogeological cross-section, and by measuring the sap flow of different plants, soil water contents and groundwater levels at different research sites. The results show that all vegetation types, i.e. trees (willow (Salix matsudana) and poplar (Populus simonii), bushes (salix – Salix psammophila), and agricultural crops (maize – Zea mays)), depend largely on groundwater as the source for transpiration. The comparative analysis indicates that maize crops use the largest amount of water, followed by poplar trees, salix bushes, and willow trees. For sustainable water use with the objective of satisfying the water demand for socio-economical development and to prevent desertification and ecological impacts on streams, more water-use-efficient crops such as sorghum, barley or millet should be promoted to reduce the consumptive water use. Willow trees should be used as wind-breaks in croplands and along roads, and drought-resistant and less water-use intensive plants (for instance native bushes) should be used to vegetate sand dunes.","","en","journal article","European Geosciences Union (EGU)","","","","","","","","Civil Engineering and Geosciences","Water Management","","","",""
"uuid:97bf6b5c-caf9-4864-9053-15c4e2a694e8","http://resolver.tudelft.nl/uuid:97bf6b5c-caf9-4864-9053-15c4e2a694e8","Impacts of 5d electron binding energy and electron-phonon coupling on luminescence of Ce 3+ in Li 6 Y(BO 3 ) 3","Ou, Yiyi (Sun Yat-sen University); Zhou, Weijie (Sun Yat-sen University); Hou, Dejian (Hanshan Normal University, Chaozhou); Brik, Mikhail G. (Chongqing University of Posts and Telecommunications; University of Tartu; Jan Długosz University); Dorenbos, P. (TU Delft RST/Luminescence Materials); Huang, Yan (Institute of High Energy Physics Chinese Academy of Science); Liang, Hongbin (Sun Yat-sen University)","","2019","In this work, the crystal structure and electronic structure as well as the synchrotron radiation vacuum ultraviolet-ultraviolet-visible (VUV-UV-vis) luminescence properties of Li 6 Y(BO 3 ) 3 (LYBO):Ce 3+ phosphors were investigated in detail. The Rietveld refinement and DFT calculation reveal the P2 1 /c monoclinic crystal phase and the direct band gap of the LYBO compound, respectively. Only one kind of Ce 3+ 4f-5d transition is resolved in terms of the low temperature VUV-UV excitation, UV-vis emission spectra and luminescence decay curves. Furthermore, by constructing the vacuum referred binding energy (VRBE) scheme and applying the frequency-degenerate vibrational model, the impacts of 5d electron binding energy and electron-phonon coupling on luminescence of Ce 3+ in LYBO are analysed. The results show that the Ce 3+ emission in LYBO possesses a moderate intrinsic thermal stability. With the increase in concentration, the thermal stability of the emission gets worse due to the possible thermally-activated concentration quenching. In addition, the simulation of Ce 3+ emission profile at low temperature reveals that the 4f-5d electronic transitions of Ce 3+ ions can be treated to couple with one frequency-degenerate vibrational mode having the effective phonon energy of ∼257 cm −1 with the corresponding Huang-Rhys parameter of ∼6, which indicates a strong electron-phonon interaction of Ce 3+ luminescence in the Li 6 Y(BO 3 ) 3 host. Finally, the X-ray excited luminescence spectrum of the LYBO:5%Ce 3+ phosphor is measured to check the potential scintillator applications.","","en","journal article","","","","","","","","","","","RST/Luminescence Materials","","",""
"uuid:ba12e3b3-8f76-4569-802d-8ff76b32824f","http://resolver.tudelft.nl/uuid:ba12e3b3-8f76-4569-802d-8ff76b32824f","Microchannel Thermal Management System with Two-Phase Flow for Power Electronics over 500 W/cm2Heat Dissipation","Hou, F. (TU Delft Electronic Components, Technology and Materials; Chinese Academy of Sciences); Zhang, Hengyun (Shanghai University of Engineering Science); Huang, Dezhu (Shanghai University of Engineering Science); Fan, J. (TU Delft Electronic Components, Technology and Materials); Liu, Fengman (National Center for Advanced Packaging (NCAP China); Chinese Academy of Sciences); Lin, Tingyu (National Center for Advanced Packaging (NCAP China)); Cao, Liqiang (Chinese Academy of Sciences; National Center for Advanced Packaging (NCAP China)); Fan, Xuejun (Lamar University); Ferreira, Braham (University of Twente); Zhang, Kouchi (TU Delft Electronic Components, Technology and Materials)","","2020","In this article, a microchannel thermal management system (MTMS) with the two-phase flow using the refrigerant R1234yf with low global warming potential is presented. The thermal test vehicles (TTVs) were made of either single or multiple thermal test chips embedded in the substrates, which were then attached to the MTMS. The system included two identical aluminum microchannel heat sinks (MHSs) connected in series in the cooling loop, which also consisted of a gas flowmeter, a miniature compressor, a condenser, a throttling device, and accessory measurement components. The experimental results showed that the thermal management system could dissipate a heat flux of 526 W/cm2 while maintaining the junction temperature below 120 °C. For SiC mosfet with a higher junction temperature, e.g., 175 °C, the current system is expected to dissipate a heat flux as high as about 750 W/cm2. The effects of the rotational speed of the compressor, the opening of the throttling device, TTV layout on MHS, and a downstream heater on the cooling performance of the system were analyzed in detail. The study shows that the present thermal management with a two-phase flow system is a promising cooling technology for the high heat flux SiC devices.","Microchannel thermal management system (MTMS); power electronics; R1234yf; SiC MOSFET; two-phase flow","en","journal article","","","","","","Accepted Auhtor Manuscript","","","","","Electronic Components, Technology and Materials","","",""
"uuid:f74ff729-ee27-4f82-9b13-df259df17cb3","http://resolver.tudelft.nl/uuid:f74ff729-ee27-4f82-9b13-df259df17cb3","Condition assessment of underground corroded pipelines subject to hydrogen damage and combined internal pressure and axial compression","Qin, Guojin (Southwest Petroleum University; Shanghai Jiao Tong University); Zhang, Zhenwei (Southwest Petroleum University); Hou, Xiangqin (Southwest Petroleum University); Lu, Hongfang (Southeast University); Huang, Y. (TU Delft Safety and Security Science); Wang, Yihuan (Southwest Petroleum University; Shanghai Jiao Tong University)","","2023","In this work, a 3D finite element (FE) based model was developed to assess the condition of an underground hydrogen transmission pipeline containing a corrosion defect under combined internal pressure and soil movement-induced axial compression. The use of mechanical properties of X100 pipeline steel under different hydrogen charging time models the degree of hydrogen damage in pipelines. Parameter effects, i.e., axial compressive stress, hydrogen damage, defect geometries, and pipeline diameter-to-thickness ratio, were determined. The results demonstrated that the synergistic effect of axial compression, internal pressure, corrosion, and hydrogen damage can lead to a significant decrease in the failure pressure of pipelines. The failure pressure decreased with the wall thickness reduction and increased hydrogen damage, axial compressive stress, defect length, defect depth, and pipe diameter. The competitive effect was observed between the degree of metal loss and hydrogen damage in determining the burst capacity of pipelines. In situations where the pipeline integrity was severely compromised, the failure pressure exhibited minimal reduction despite the increasing severity of hydrogen damage. The stress distribution at the defect zone was influenced by axial compressive stress but remained unaffected by hydrogen damage under normal operating conditions (i.e., an internal pressure of 10 MPa). This work is expected to help operators understand the applicability of elder and in-service pipelines for hydrogen transmission.","Condition assessment; Corrosion; Finite element modeling; Hydrogen damage; Underground pipelines","en","journal article","","","","","","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.","","2024-03-09","","","Safety and Security Science","","",""