| 1. |
- Chai, Yifan, et al.
(författare)
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Study on strength and reduction characteristics of iron ore powder-green carbon composite briquettes
- 2024
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 377
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Tidskriftsartikel (refereegranskat)abstract
- The metallurgical industry is a key sector for carbon emissions, and in recent years, there has been widespread attention on the use of biomass resources as a green, renewable, and carbon–neutral energy source material for low carbon ironmaking processes. The waste wood after hydrothermal-pyrolysis carbonization has the characteristics of low content of harmful elements and high content of fixed carbon. In this study, the waste wood after hydrothermal-pyrolysis two-step carbonization treatment was used as a reducing agent for the reduction of iron ore to prepare iron ore powder- green carbon composite briquettes (ICCB) with two carbon–oxygen ratios. The study investigated the effects of reduction behavior and reaction temperature on the reduction performance of the ICCB. The results indicate that with the increase in reaction temperature, the volume of the ICCB gradually contracts, leading to a reduction in mass. The shrinkage rate of the ICCB during self-reduction at 1200℃ is significantly higher than during co-reduction, and the shrinkage effect of the C/O 0.5 ICCB is more pronounced than that of the C/O 0.8 ICCB. Due to the excessive carbon content in the C/O 0.8 ICCB, the carbon cannot be fully consumed during the reaction process, resulting in consistently low compressive strength of the ICCB, with a compressive strength of 12 N after reduction at 1200℃. In contrast, the iron phase in the C/O 0.5 ICCB gradually recrystallizes during the reduction process, ultimately yielding plastic iron briquettes with compressive strengths exceeding 3000 N after different reaction behaviors at 1200℃. In summary, reducing the carbon-to-oxygen ratio and increasing the reaction temperature contribute to the volume contraction and enhanced compressive strength of the ICCB during the reduction process.
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| 2. |
- Chen, Zhiwen, et al.
(författare)
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Interface engineering of NiS@MoS2 core-shell microspheres as an efficient catalyst for hydrogen evolution reaction in both acidic and alkaline medium
- 2021
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Ingår i: Journal of Alloys and Compounds. - : ELSEVIER SCIENCE SA. - 0925-8388 .- 1873-4669. ; 853
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical splitting of water is one of the most reliable and effective ways for the sustainable production of pure hydrogen on a large scale, while the core of this technology lies in the development of highly active non-noble-metal-based electrocatalysts to lower the large dynamic overpotentials of electrode materials. Here, an interface engineering strategy is demonstrated to construct an efficient and stable catalyst based on NiS@MoS2 core-shell hierarchical microspheres for the hydrogen evolution reactions (HER). The ultrathin MoS2 nanosheets in-situ grow on the surface of NiS hierarchical micro-sized spheres constructed by porous nanoplates, endowing the composites with rich interfaces, well-exposed electroactive edges, high structural porosity and fast transport channels. These advantages are favorable for the improvement of catalytic sites and the transport of catalysis-relevant species. More importantly, the intimate contact between MoS2 nanosheets and NiS nanoplates synergistically favors the chemical sorption of hydrogen intermediates, thereby reducing the reaction barrier and accelerating the HER catalytic process. As a result, the optimized NiS@MoS2 catalyst manifests impressive HER activity and durability, with a low overpotential of 208 mV in 0.5 M H2SO4 and 146 mV in 1.0 M KOH at 10 mA cm(-2), respectively. This work not only provides an effective way to construct core-shell hierarchical microspheres but also a multiscale strategy to regulate the electronic structure of heterostructured materials for energy-related applications. (C) 2020 Elsevier B.V. All rights reserved.
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| 3. |
- Huang, Shoushuang, et al.
(författare)
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An advanced electrocatalyst for efficient synthesis of ammonia based on chemically coupled NiS@MoS2 heterostructured nanospheres
- 2021
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Ingår i: Sustainable Energy & Fuels. - : Royal Society of Chemistry. - 2398-4902. ; 5:10, s. 2640-2648
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Tidskriftsartikel (refereegranskat)abstract
- The electrochemical reduction of nitrogen, as a sustainable alternative to the known Haber-Bosch process, possesses promising application prospects in the development of renewable energy storage systems. However, the yield of NH3 and Faraday efficiency are usually very low owing to the loss of active electrocatalysts and competitive hydrogen evolution reactions. Herein, uniform NiS@MoS2 core-shell microspheres are controllably prepared as a potential catalyst for an ambient electrocatalytic N-2 reduction reaction. The NiS@MoS2 microspheres possess highly active intrinsic, sufficient accessible active sites, high structural porosity, and convenient transport channels, consequently boosting the transmission of electrons and mass. Additionally, the interfacial interaction between NiS and MoS2 facilitates electron transfer, which further improves the catalytic activity by optimizing the free energies of reaction intermediates. As a result, the titled NiS@MoS2 shows excellent electrochemical activity and selectivity, capable of achieving a relatively high NH3 yield of 9.66 mu g h(-1) mg(cat)(-1) at -0.3 V (vs. the reversible hydrogen electrode, RHE) and a high FE of 14.8% at -0.1 V vs. RHE in 0.1 M Na2SO4. The work demonstrated here may open a new avenue for the rational design and synthesis of catalysts for the electrochemical synthesis of ammonia.
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| 4. |
- Huang, Shoushuang, et al.
(författare)
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Construction of Fe-doped NiS-NiS2 Heterostructured Microspheres Via Etching Prussian Blue Analogues for Efficient Water-Urea Splitting
- 2022
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Ingår i: Small. - : Wiley-V C H Verlag GMBH. - 1613-6810 .- 1613-6829. ; 18:14
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Tidskriftsartikel (refereegranskat)abstract
- Developing efficient and robust non-precious-metal-based catalysts to accelerate electrocatalytic reaction kinetics is crucial for electrochemical water-urea splitting. Herein, Fe-doped NiS-NiS2 heterostructured microspheres, an electrocatalyst, are synthesized via etching Prussian blue analogues following a controlled annealing treatment. The resulting microspheres are constructed by mesoporous nanoplates, granting the virtues of large surface areas, high structural void porosity, and accessible inner surface. These advantages not only provide more redox reaction centers but also strengthen structural robustness and effectively facilitate the mass diffusion and charge transport. Density functional theory simulations validate that the Fe-doping improves the conductivity of nickel sulfides, whereas the NiS-NiS2 heterojunctions induce interface charge rearrangement for optimizing the adsorption free energy of intermediates, resulting in a low overpotential and high electrocatalytic activity. Specifically, an ultralow overpotential of 270 mV at 50 mA cm(-2) for the oxygen evolution reaction (OER) is achieved. After adding 0.33 M urea into 1 M KOH, Fe-doped NiS-NiS2 obtains a strikingly reduced urea oxidation reaction potential of 1.36 V to reach 50 mA cm(-2), around 140 mV less than OER. This work provides insights into the synergistic modulation of electrocatalytic activity of non-noble catalysts for applications in energy conversion systems.
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| 5. |
- Le, Thanh-Tung, et al.
(författare)
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Phosphorus-doped Fe7S8@C nanowires for efficient electrochemical hydrogen and oxygen evolutions: Controlled synthesis and electronic modulation on active sites
- 2021
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Ingår i: Journal of Materials Science & Technology. - : JOURNAL MATER SCI TECHNOL. - 1005-0302. ; 74, s. 168-175
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Tidskriftsartikel (refereegranskat)abstract
- Developing low-cost, efficient, and stable non-precious-metal electrocatalysts with controlled crystal structure, morphology and compositions are highly desirable for hydrogen and oxygen evolution reactions. Herein, a series of phosphorus-doped Fe7S8 nanowires integrated within carbon (P-Fe7S8@C) are rationally synthesized via a one-step phosphorization of one-dimensional (1D) Fe-based organic-inorganic nanowires. The as-obtained P-Fe7S8@C catalysts with modified electronic configurations present typical porous structure, providing plentiful active sites for rapid reaction kinetics. Density functional calculations demonstrate that the doping Fe7S8 with P can effectively enhance the electron density of Fe7S8 around the Fermi level and weaken the Fe-H bonding, leading to the decrease of adsorption free energy barrier on active sites. As a result, the optimal catalyst of P-Fe7S8-600@C exhibits a relatively low overpotential of 136 mV for hydrogen evolution reaction (HER) to reach the current density of 10 mA/cm(2), and a significantly low overpotential of 210 mV for oxygen evolution reaction (OER) at 20 mA/cm(2) in alkaline media. The work presented here may pave the way to design and synthesis of other prominent Fe-based catalysts for water splitting via electronic regulation. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.
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| 6. |
- Sun, Shao, et al.
(författare)
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Evolution of future precipitation extremes: Viewpoint of climate change classification
- 2022
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Ingår i: International Journal of Climatology. - : Wiley. - 0899-8418 .- 1097-0088. ; 42:2, s. 1220-1230
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is often described as the average changes in temperature and precipitation; however, it is the change in climate extremes determines the levels of socioeconomic impacts related to climate change. It is generally believed that global warming drives increase in frequency, intensity and duration of precipitation extremes, but these changes vary regionally. Focusing on the relationships between evolution of extreme events and long-term climate change, here we propose a novel classification scheme based on Kӧppen's system and changes in mean and variability of precipitation, divide the global climate into 20 different changing types and reveal the regional evolution of precipitation extremes. We find that precipitation extremes ascend significantly in wetting regions, especially in tropical and temperate zones, independent with changed variability. As for drying regions, the evolution of extremes is related to precipitation variability. An increase of extremes can still be detected in fluctuant-drying areas, while a slight decrease can be seen in stabilized-drying areas. It is surprising to find increase in both wetness and dryness extremes which implies higher intensity of meteorological hazards in densely populated areas. Based on the current and projected growth of population exposure to precipitation extremes, we identify some hotspots with high potential risk in the future.
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| 7. |
- Wang, Peijun, et al.
(författare)
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A Web-based cost-effective training tool with possible application to brain injury rehabilitation
- 2004
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Ingår i: Computer Methods and Programs in Biomedicine. - : Elsevier BV. - 0169-2607. ; 74:3, s. 235-243
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Tidskriftsartikel (refereegranskat)abstract
- Virtual reality (VR) has provoked enormous interest in the medical community. In particular, VIR offers therapists new approaches for improving rehabilitation effects. However, most of these VR assistant toots are not very portable, extensible or economical. Due to the vast amount of 3D data, they are not suitable for Internet transfer. Furthermore, in order to run these VR systems smoothly, special hardware devices are needed. As a result, existing VIR assistant toots tend to be available in hospitals but not in patients' homes. To overcome these disadvantages, as a case study, this paper proposes a Web-based Virtual Ticket Machine, called WBVTM, using VRML [VRML Consortium, The Virtual Reality Modeling Language: International Standard ISO/IEC DIS 14772-1, 1997, available at http://www.vrml.org/Specifications/VRML97], Java and EAI (External Authoring Interface) [Silicon Graphics, Inc., The External Authoring Interface (EAI), available at http://cosmosoftware.com/developer/eai.htmt], to help people with acquired brain injury (ABI) to relearn basic living skills at home at a low cost. As these technologies are open standard and feature usability on the Internet, WBVTM achieves the goals of portability, easy accessibility and cost-effectiveness. (C) 2003 Elsevier Ireland Ltd. All rights reserved.
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| 8. |
- Wang, Peijun, et al.
(författare)
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A web-based interactive virtual environment for mobile phone customization
- 2005
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Ingår i: Journal of Computing and Information Science in Engineering. - : ASME International. - 1530-9827 .- 1944-7078. ; 5:1, s. 67-70
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Tidskriftsartikel (refereegranskat)abstract
- With globalization, more and more companies are becoming multisited. Efficient and timely collaboration and communication among the development team members become critical for product success. This paper proposes a web-based virtual environment for mobile phone customization, named VMPDS (Virtual Mobile Phone Design Space). The features of this system include the combination of web technology and VR (Virtual Reality) technology, the ability to deal with and extend the product model database, adequate interaction for three-dimensional product model customization, and usefulness for the examination and evaluation of product concept design. The system is implemented by using standard open technologies to assure accessibility and platform independence.
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| 9. |
- Wang, Peijun, et al.
(författare)
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Development of a web-based customer-oriented interactive virtual environment for mobile phone design
- 2003
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Ingår i: Proceedings of the 23rd Computers and Information in Engineering Conference - DETC/CIE'03. - 0791836991 - 0791836983 ; 1, s. 1183-1191
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Konferensbidrag (refereegranskat)abstract
- During recent years, mobile phone companies have experienced market-related difficulties that result in increasing competition globally. In an attempt to maintain or increase their market share, enterprises reorganize their resources and employ new technologies to sharpen their competitive edges. Moreover, with the globalization, more and more companies become multi-sited. Efficient and timely collaboration and communication among the Development team members become critical for product success. This paper proposes a web-based interactive virtual environment for mobile phone design, named VMPDS (Virtual Mobile Phone Design Space). The features of the system include the combination of web technology and VR (Virtual Reality) technology, the ability to deal with and extend the product model database, adequate interaction for 3-D product model modification and customization, and usefulness for the examination and evaluation of product concept design. The system is implemented by using standard open technologies such as VRML (Virtual Reality Modeling Language), Java, SAI (Script Authoring Interface) and EAI (External Authoring Interface) to assure accessibility and platformindependence.
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| 10. |
- Wang, Peijun, et al.
(författare)
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Web-based Interactive VR-CAD System for Conceptual design and Analysis
- 2007
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Ingår i: Journal of Southwest Jiaotong University. ; 15:4, s. 294-300
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Tidskriftsartikel (refereegranskat)abstract
- To overcome the bottleneck of the one-way translation from VR (virtual reality) to CAD in VR-based CAD system, this paper proposes a Web-based VR-CAD system WVCD (Web-based virtual conceptual designer) to support both customers’ and design team members' involvement in the conceptual design and analysis activity over the Internet. It provides users with both parametric and freehand methods to create and edit 3D conceptual models with different levels of complexity in a VR environment intuitively without the need of switching between the VR environment and CAD tools. As a simple and low-cost VR-CAD system, WVCD can help to popularize and improve the Web-based collaborative conceptual design.
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| 11. |
- Wei, Ting, et al.
(författare)
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Developed and developing world responsibilities for historical climate change and CO2 mitigation
- 2012
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 109:32, s. 12911-12915
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Tidskriftsartikel (refereegranskat)abstract
- At the United Nations Framework Convention on Climate Change Conference in Cancun, in November 2010, the Heads of State reached an agreement on the aim of limiting the global temperature rise to 2 degrees C relative to preindustrial levels. They recognized that long-term future warming is primarily constrained by cumulative anthropogenic greenhouse gas emissions, that deep cuts in global emissions are required, and that action based on equity must be taken to meet this objective. However, negotiations on emission reduction among countries are increasingly fraught with difficulty, partly because of arguments about the responsibility for the ongoing temperature rise. Simulations with two earth-system models (NCAR/CESM and BNU-ESM) demonstrate that developed countries had contributed about 60-80%, developing countries about 20-40%, to the global temperature rise, upper ocean warming, and sea-ice reduction by 2005. Enacting pledges made at Cancun with continuation to 2100 leads to a reduction in global temperature rise relative to business as usual with a 1/3-2/3 (CESM 33-67%, BNU-ESM 35-65%) contribution from developed and developing countries, respectively. To prevent a temperature rise by 2 degrees C or more in 2100, it is necessary to fill the gap with more ambitious mitigation efforts.
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| 12. |
- Ye, Tao, et al.
(författare)
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Reducing livestock snow disaster risk in the Qinghai–Tibetan Plateau due to warming and socioeconomic development
- 2022
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 813
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Tidskriftsartikel (refereegranskat)abstract
- Global warming can have positive or negative impacts on society depending on sectors and changes in climate impact drivers, resulting in opportunities or risks. The same holds true for social-economic changes. However, past research has mostly focused on assessing risks, leaving potential opportunities under-addressed. Here, we simulated the impact of climate change and socioeconomic development on livestock snow disasters over the Qinghai–Tibetan Plateau during 1986–2100, by integrating the drivers of climate and socioeconomic changes via an event-based disaster risk assessment model. Model results show climate change and socioeconomic development contributes about equally to reducing livestock loss in snow disasters by 4% yr−1 up to 2100 under representative concentration pathway 8.5 and shared-socioeconomic pathway 5. The marginal benefit from climate change was projected to be a 43.2% reduction in annual average loss per degree kelvin warming, and that from socioeconomic development was a 12.4% reduction per 100% increase in gross domestic production. In a 2 °C warmer world, the annual average loss could be 91% smaller compared with the baseline period (1986–2005). Limiting global warming to 1.5 °C instead of 2 °C would reduce the benefit by 5%, requiring a 135% increase in the marginal benefits of prevention capacity to offset the reduction.
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| 13. |
- Zhang, Jie, et al.
(författare)
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Nested hollow architectures of nitrogen-doped carbon-decorated Fe, Co, Ni-based phosphides for boosting water and urea electrolysis
- 2022
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Ingår i: Nano Reseach. - : Tsinghua University Press. - 1998-0124 .- 1998-0000. ; 15, s. 1916-1925
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Tidskriftsartikel (refereegranskat)abstract
- Tailoring the nanostructure/morphology and chemical composition is important to regulate the electronic configuration of electrocatalysts and thus enhance their performance for water and urea electrolysis. Herein, the nitrogen-doped carbon-decorated tricomponent metal phosphides of FeP4 nanotube@Ni-Co-P nanocage (NC-FNCP) with unique nested hollow architectures are fabricated by a self-sacrifice template strategy. Benefiting from the multi-component synergy, the modification of nitrogen-doped carbon, and the modulation of nested porous hollow morphology, NC-FNCP facilitates rapid electron/mass transport in water and urea electrolysis. NC-FNCP-based anode shows low potentials of 248 mV and 1.37 V (vs. reversible hydrogen electrode) to attain 10 mA/cm(2) for oxygen evolution reaction (OER) and urea oxidation reaction (UOR), respectively. In addition, the overall urea electrolysis drives 10 mA/cm(2) at a comparatively low voltage of 1.52 V (vs. RHE) that is 110 mV lower than that of overall water electrolysis, as well as exhibits excellent stability over 20 h. This work strategizes a multi-shell-structured electrocatalyst with multi-compositions and explores its applications in a sustainable combination of hydrogen production and sewage remediation.
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