| 1. |
- Zhang, Zhao Yang, et al.
(författare)
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Photochemical Phase Transitions Enable Coharvesting of Photon Energy and Ambient Heat for Energetic Molecular Solar Thermal Batteries That Upgrade Thermal Energy
- 2020
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 142:28, s. 12256-12264
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Tidskriftsartikel (refereegranskat)abstract
- Discovering physicochemical principles for simultaneous harvesting of multiform energy from the environment will advance current sustainable energy technologies. Here we explore photochemical phase transitions - a photochemistry-thermophysics coupled regime - for coharvesting of solar and thermal energy. In particular, we show that photon energy and ambient heat can be stored together and released on demand as high-temperature heat, enabled by room-temperature photochemical crystal↔liquid transitions of engineered molecular photoswitches. Integrating the two forms of energy in single-component molecular materials is capable of providing energy capacity beyond that of traditional solar or thermal energy storage systems based solely on molecular photoisomerization or phase change, respectively. Significantly, the ambient heat that is harvested during photochemical melting into liquid of the low-melting-point, metastable isomer can be released as high-temperature heat by recrystallization of the high-melting-point, parent isomer. This reveals that photon energy drives the upgrading of thermal energy in such a hybrid energy system. Rationally designed small-molecule azo switches achieve high gravimetric energy densities of 0.3-0.4 MJ/kg with long-term storage stability. Rechargeable solar thermal battery devices are fabricated, which upon light triggering provide gravimetric power density of about 2.7 kW/kg and temperature increases of >20 °C in ambient environment. We further show their use as deicing coatings. Our work demonstrates a new concept of energy utilization - combining solar energy and low-grade heat into higher-grade heat - which unlocks the possibility of developing sustainable energy systems powered by a combination of natural sunlight and ambient heat.
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| 2. |
- Peng, Jianhui, et al.
(författare)
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Achieving ultra-high electromagnetic wave absorption by anchoring Co0.33Ni0.33Mn0.33Fe2O4 nanoparticles on graphene sheets using microwave-assisted polyol method
- 2018
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Ingår i: Ceramics International. - : ELSEVIER SCI LTD. - 0272-8842 .- 1873-3956. ; 44:17, s. 21015-21026
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Tidskriftsartikel (refereegranskat)abstract
- The Co0.33Ni0.33Mn0.33Fe2O4/graphene nanocomposite for electromagnetic wave absorption was successfully synthesized from metal chlorides solutions and graphite powder by a simple and rapid microwave-assisted polyol method via anchoring the Co0.33Ni0.33Mn0.33Fe2O4 nanoparticles on the layered graphene sheets. The Fe3+, Co2+, Ni2+ and Mn2+ ions in the solutions were attracted by graphene oxide obtained from graphite and converted to the precursors Fe(OH)(3), Co(OH)(2), Ni(OH)(2), and Mn(OH)(2) under slightly alkaline conditions. After the transformations of the precursors to Co-Ni-Mn ferrites and conversion of graphene oxide to graphene under microwave irradiation at 170 degrees C in just 25 min, the Co0.33Ni0.33Mn0.33Fe2O4/graphene nanocomposite was prepared. The composition and structure of the nanocomposite were characterized by X-ray diffraction (XRD), inductive coupled plasma emission spectroscopy (ICP), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (RS), transmission electron microscopy (TEM), etc. It was found that with the filling ratio of only 20 wt% and the thickness of 2.3 mm, the nanocomposite showed an ultra-wide effective absorption bandwidth (less than -10 dB) of 8.48 GHz (from 9.52 to 18.00 GHz) with the minimum reflection loss of - 24.29 dB. Compared to pure graphene sheets, Co0.33Ni0.33Mn0.33Fe2O4 nano particles and the counterparts reported in literature, the nanocomposite exhibited much better electromagnetic wave absorption, mainly attributed to strong wave attenuation, as a result of synergistic effects of dielectric loss, conductive loss and magnetic loss, and to good impedance matching. In view of its thin thickness, light weight and outstanding electromagnetic wave absorption property, the nanocomposite could be used as a very promising electromagnetic wave absorber.
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| 3. |
- Peng, Chen, et al.
(författare)
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Industrial Internet of Things enabled supply-side energy modelling for refined energy management in aluminium extrusions manufacturing
- 2021
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Ingår i: Journal of Cleaner Production. - : Elsevier Science Ltd. - 0959-6526 .- 1879-1786. ; 301
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Tidskriftsartikel (refereegranskat)abstract
- To improve industrial sustainability performance in manufacturing, energy management and optimi-sation are key levers. This is particularly true for aluminium extrusions manufacturing dan energy -intensive production system with considerable environmental impacts. Many energy management and optimisation approaches have been studied to relieve such negative impact. However, the effectiveness of these approaches is compromised without the support of refined supply-side energy consumption information. Industrial internet of things provides opportunities to acquire refined energy consumption information in its data-rich environment but also poses a range of difficulties in implementation. The existing sensors cannot directly obtain the energy consumption at the granularity of a specific job. To acquire that refined energy consumption information, a supply-side energy modelling method based on existing industrial internet of things devices for energy-intensive production systems is proposed in this paper. First, the job-specified production event concept is proposed, and the layout of the data acqui-sition network is designed to obtain the event elements. Second, the mathematical models are developed to calculate the energy consumption of the production event in three process modes. Third, the energy consumption information of multiple manufacturing element dimensions can be derived from the mathematical models, and therefore, the energy consumption information on multiple dimensions is easily scaled. Finally, a case of refined energy cost accounting is studied to demonstrate the feasibility of the proposed models. ? 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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| 4. |
- Qin, Tao, et al.
(författare)
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Efficient Synthesis of Angular Selective Surfaces Based on Accurate Equivalent Circuit Analysis
- 2023
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480. ; 71:6, s. 2625-2638
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Tidskriftsartikel (refereegranskat)abstract
- A new efficient synthesis method of angular selective surfaces (ASSs) based on the accurate equivalent circuit model is proposed. The angular dispersion of different components under oblique incidence is modeled by virtual lumped elements in the angular domain. The processes of obtaining the equivalent circuit for substrates, electrically small grids and patch arrays are presented in detail. The synthesized circuits are simple and accurate. Full-wave simulations are carried out to obtain the angular dispersion of different structures, and the calculated results are in good agreement with those of the equivalent circuit. A third-order ASS with bandpass response and a second-order ASS with a tunable bandwidth are given as design examples. The implemented second-order ASS shows the 0.33 to 0.52 tunable bandwidth in the angular domain. The transmission loss is better than 1.2 dB when the incidence angle is 65°-77°. The simulation results and calculated results are in good agreement with the measured results.
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| 5. |
- Wang, Shuping, 1987, et al.
(författare)
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Influence of drying conditions on the contact-hardening behaviours of calcium silicate hydrate powder
- 2017
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Ingår i: Construction and Building Materials. - : Elsevier BV. - 0950-0618. ; 136, s. 465-473
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Tidskriftsartikel (refereegranskat)abstract
- Contact-hardening is a new type of binding property for amorphous calcium silicate hydrate (C-S-H) withwhich a hardened specimen can be prepared in a few minutes by compressing C-S-H powders directly.However, the relation between contact-hardening behaviours and the drying conditions of powders isstill poorly understood. In this study, the influence of air-drying and oven-drying on the physical propertiesand microstructure of hydrothermally synthesised C-S-H powders were investigated. The results provide further insight into the contact-hardening behaviours of these powders by measuring the bulk density, mechanical strength and water-resistant properties of the compacts. Factors affecting particleparticle contact and hardening of C-S-H powders are discussed in parallel with the mechanical properties and microstructure of the compacts. The result highlights that the moisture content, which is highly related to the drying conditions, is essential to contact hardening of C-S-H.
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| 6. |
- Kang, Kai, et al.
(författare)
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Auction-based cloud service allocation and sharing for logistics product service system
- 2021
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Ingår i: Journal of Cleaner Production. - : Elsevier Ltd. - 0959-6526 .- 1879-1786. ; 278
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Tidskriftsartikel (refereegranskat)abstract
- Sustainability is increasingly viewed as a desired goal of social development. The logistics industry without exception is aware of the importance of sustainable development. To achieve this goal, the logistics industry is leveraging cutting-edge technologies, such as product service systems (PSS) and cloud manufacturing (CMfg), to design logistics product service systems (LPSS). In LPSS, public logistics resources are allocated to customers and private logistics resources are shared between customers. However, logistics resource allocation and sharing services have been impeded by a lack of efficient methods. In this context, this paper proposes an auction-based cloud service allocation and sharing method for LPSS. Firstly, LPSS is defined and elaborated based on the adoption of PSS in the logistics industry. Secondly, multi-unit Vickery (MV) auctions and one-sided Vickrey-Clarke-Groves (O-VCG) combinatorial auctions are proposed to address logistics resource allocation and sharing problems respectively in LPSS. Two auctions are introduced specifically, and their relevant properties are investigated, including incentive compatibility, allocative efficiency, budget balance, and individual rationality. Thirdly, computational studies are conducted to examine the performance of two auctions. The results reveal that MV auctions can efficiently allocate public logistics resources through ensuring the utility of logistics service providers under dynamic supply and demand. Additionally, O-VCG auctions can effectively integrate and share idle private logistics resources, which promotes sustainability in the logistics industry. Through integrating MV auctions with O-VCG auctions, the utility of logistics service providers can be increased.
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| 7. |
- Li, Qi, 1990, et al.
(författare)
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Compact and low loss electrochemical capacitors using a graphite / carbon nanotube hybrid material for miniaturized systems
- 2019
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 412, s. 374-383
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Tidskriftsartikel (refereegranskat)abstract
- With the establishment of the internet of things (IoT) and the rapid development of advanced microsystems, there is a growing demand to develop electrochemical capacitors (ECs) to replace bulky electrolytic capacitors on circuit boards for AC line filtering, and as a storage unit in energy autonomous systems. For this purpose, ECs must be capable of handling sufficiently high signal frequencies, display minimum energy loss through self-discharge and leakage current as well as maintaining an adequate capacitance. Here, we demonstrate ECs based on mechanically flexible, covalently bonded graphite/vertically aligned carbon nanotubes (graphite/VACNTs) hybrid materials. The ECs employing a KOH electrolyte exhibit a phase angle of −84.8°, an areal capacitance of 1.38 mF cm−2 and a volumetric capacitance (device level) of 345 mF cm−3 at 120 Hz, which is among the highest values for carbon based high frequency ECs. Additionally, the performance as a storage EC for miniaturized systems is evaluated. We demonstrate capacitive charging/discharging at μA current with a gel electrolyte, and sub-μA leakage current reached within 50 s, and 100 nA level equilibrium leakage within 100 s at 2.0 V floating with an ionic liquid electrolyte.
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| 8. |
- Peng, Wenhong, et al.
(författare)
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Over 18% ternary polymer solar cells enabled by a terpolymer as the third component
- 2022
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Ingår i: Nano Energy. - : Elsevier BV. - 2211-2855. ; 92
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Tidskriftsartikel (refereegranskat)abstract
- “Ternary blending” and “random terpolymerization” strategies have both proven effective for enhancing the performance of organic solar cells (OSCs). However, reports on the combination of the two strategies remain rare. Here, a terpolymer PM6-Si30 was constructed by inserting chlorine and alkylsilyl-substituted benzodithiophene (BDT) unit (0.3 equivalent) into the state-of-the-art polymer PM6. The terpolymer exhibitsadeep highest-occupied-molecular-orbital energy and good miscibility with both PM6 and BTP-eC9 (C9) and enables its use as a third component into PM6:PM6-Si30:C9 bulk-heterojunction for OSCs. The resulting cells exhibit maximum power conversion efficiency (PCE) of 18.27%, which is higher than that obtained for the optimized control binary PM6:C9-based OSC (17.38%). The enhanced performance of the PM6:PM6-Si30:C9 cells is attributed to improved charge transport, favorable molecular arrangement, reduced energy loss and suppressed bimolecular recombination. The work demonstrates the potential of random terpolymer as a third component in OSCs and highlights a new strategy for the construction of a ternary system with improved photovoltaic performance.
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| 9. |
- Wei, Xiuyu, 1979, et al.
(författare)
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XPS and AES surface analysis of WC-Co-(Cr) cemented carbide after immersion in neutral solution
- 2020
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Ingår i: Surface and Interface Analysis. - : Wiley. - 1096-9918 .- 0142-2421. ; 52:12, s. 845-849
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Tidskriftsartikel (refereegranskat)abstract
- The binder phase Co in WC-Co cemented carbide is dissolved easily in corrosive media (even in neutral solution), which has limited its application in a wider range. In this paper, the influence of Cr on corrosion resistance of WC-Co immersed in neutral solution was studied, with a focus on the surface chemistry of the corrosion product. The results show that in neutral solution, the corrosion is mainly caused by the selective dissolution of Co and the dominant surface corrosion product after immersion is Co (OH)(2). The corrosion resistance of WC-Co cemented carbide can be improved by the addition of Cr. This can be explained by the formation of more protective chromium containing oxide on the binder phase of WC-Co-Cr alloy, leading to reduced corrosion rate.
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| 10. |
- Yang, Minmin, et al.
(författare)
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Advances in understanding of health-promoting benefits of medicine and food homology using analysis of gut microbiota and metabolomics
- 2020
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Ingår i: Food Frontiers. - : Wiley. - 2643-8429. ; 1:4, s. 398-419
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Forskningsöversikt (refereegranskat)abstract
- The health-promoting benefits of medicine and food homology (MFH) are known for thousands of years in China. However, active compounds and biological mechanisms are unclear, greatly limiting clinical practice of MFH. The advent of gut microbiota analysis and metabolomics emerge as key tools to discover functional compounds, therapeutic targets, and mechanisms of benefits of MFH. Such studies hold great promise to promote and optimize functional efficacy and development of MFH-based products, for example, foods for daily dietary supplements or for special medical purposes. In this review, we summarized pharmacological effects of 109 species of MFH approved by the Health and Fitness Commission in 2015. Recent studies applying genome sequencing of gut microbiota and metabolomics to explain the activity of MFH in prevention and management of health consequences were extensively reviewed. We discussed the potentiality in future to decipher functional activities of MFH by applying metabolomics-based polypharmacokinetic strategy and multiomics technologies. The needs for personalized MFH recommendations and comprehensive databases have also been highlighted. This review emphasizes current achievements and challenges of the analysis of gut microbiota and metabolomics as a new avenue to understand MFH.
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