| 1. |
- Wang, Dong, et al.
(författare)
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Optimized fire resistance of alkali-activated high-performance concrete by steel fiber
- 2024
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Ingår i: Journal of thermal analysis and calorimetry (Print). - : Springer Nature. - 1388-6150 .- 1588-2926.
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Tidskriftsartikel (refereegranskat)abstract
- The behavior of alkali-activated ultra-high-performance concrete (A-UHPC) at elevated temperatures is unknown. This study addresses this gap by investigating the behavior of A-UHPC under varying temperatures with steel fiber additions (1%, 2%, and 3%), and considering target temperatures (20 °C, 200 °C, 400 °C, 600 °C, and 800 °C) as design variables. As the results, A-UHPC with steel fibers showed improved fire resistance, suffering less compressive strength loss at 800 °C than fiber-free A-UHPC. High temperatures initially optimized A-UHPC’s microstructure at 200 °C but later caused damage through microstructure propagation. Steel fibers enhanced A-UHPC’s ductility, resulting in ductile failure even at 800 °C. A-UHPC exhibited a unique mechanical degradation pattern under elevated temperatures, distinct from ordinary cement-based concrete. Empirical models accurately predicted its behavior, offering valuable insights for engineers dealing with heavy loads and high temperatures.
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| 2. |
- Deng, Junjie, et al.
(författare)
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A method for assessing the coastline recession due to the sea level rise by assuming stationary wind-wave climate
- 2015
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Ingår i: Oceanological and Hydrobiological Studies. - : Uniwersytet Gdanski. - 1730-413X .- 1897-3191. ; 44:3, s. 362-380
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Tidskriftsartikel (refereegranskat)abstract
- The method introduced in this study for future projection of coastline changes hits the vital need of communicating the potential climate change impact on the coast in the 21th century. A quantitative method called the Dynamic Equilibrium Shore Model (DESM) has been developed to hindcast historical sediment mass budgets and to reconstruct a paleo Digital Elevation Model (DEM). The forward mode of the DESM model relies on paleo-scenarios reconstructed by the DESM model assuming stationary wind-wave climate. A linear relationship between the sea level, coastline changes and sediment budget is formulated and proven by the least square regression method. In addition to its forward prediction of coastline changes, this linear relationship can also estimate the sediment budget by using the information on the coastline and relative sea level changes. Wind climate change is examined based on regional climate model data. Our projections for the end of the 21st century suggest that the wind and wave climates in the southern Baltic Sea may not change compared to present conditions and that the investigated coastline along the Pomeranian Bay may retreat from 10 to 100 m depending on the location and on the sea level rise which was assumed to be in the range of 0.12 to 0.24 m.
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| 3. |
- Wang, Bohan, et al.
(författare)
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Low-temperature and flexible strategy to in-situ fabricate ZrSiO4-based ceramic composites via doping and tuning solid-state reaction
- 2023
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Ingår i: JOURNAL OF ADVANCED CERAMICS. - : Tsinghua University Press. - 2226-4108 .- 2227-8508. ; 12:6, s. 1238-1257
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Tidskriftsartikel (refereegranskat)abstract
- Synthetic zircon (ZrSiO4) ceramics are typically fabricated at elevated temperatures (over 1500 degrees C), which would lead to high manufacturing cost. Meanwhile, reports about preparing ZrSiO4-based ceramic composites via controlling the solid-state reaction between zirconia (ZrO2) and silica (SiO2) are limited. In this work, we proposed a low-temperature strategy to flexibly design and fabricate ZrSiO4-based ceramic composites via doping and tuning the solid-state reaction. Two ceramic composites and ZrSiO4 ceramics were in-situ prepared by reactive fast hot pressing (FHP) at approximately 1250 degrees C based on the proposed strategy, i.e., a ZrSiO4-SiO2 dual-phase composite with bicontinuous interpenetrating and hierarchical microstructures, a ZrSiO4-ZrO2 dual-phase composite with a microstructure of ZrO2 submicron- and nano-particles embedded in a micron ZrSiO4 matrix, and ZrSiO4 ceramics with a small amount of residual ZrO2 nanoparticles. The results showed that the phase compositions, microstructure configurations, mechanical properties, and wear resistance of the materials can be flexibly regulated by the proposed strategy. Hence, ZrSiO4-based ceramic composites with different properties can be easily fabricated based on different application scenarios. These findings would offer useful guidance for researchers to flexibly fabricate ZrSiO4-based ceramic composites at low temperatures and tailor their microstructures and properties through doping and tuning the solid-state reaction.
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| 4. |
- Xu, Dongqing, et al.
(författare)
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The RING-Finger E3 Ubiquitin Ligase COP1 SUPPRESSOR1 Negatively Regulates COP1 Abundance in Maintaining COP1 Homeostasis in Dark-Grown Arabidopsis Seedlings
- 2014
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Ingår i: The Plant Cell. - : Oxford University Press (OUP). - 1040-4651 .- 1532-298X. ; 26:5, s. 1981-1991
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Tidskriftsartikel (refereegranskat)abstract
- CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1) functions as an E3 ubiquitin ligase in both plants and animals. In dark-grown Arabidopsis thaliana seedlings, COP1 targets photomorphogenesis-promoting factors for degradation to repress photomorphogenesis. Little is known, however, about how COP1 itself is regulated. Here, we identify COP1 SUPPRESSOR1 (CSU1), a RING-finger E3 ubiquitin ligase, as a regulator of COP1. Genetic evidence demonstrates that csu1 mutations suppress cop1-6 phenotypes completely in the dark. Furthermore, CSU1 colocalizes with COP1 in nuclear speckles and negatively regulates COP1 protein accumulation in darkness. CSU1 can ubiquitinate COP1 in vitro and is essential for COP1 ubiquitination in vivo. Therefore, we conclude that CSU1 plays a major role in maintaining COP1 homeostasis by targeting COP1 for ubiquitination and degradation in dark-grown seedlings.
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