| 71. |
- Zhang, Yong, 1982, et al.
(författare)
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Properties of Undoped Few-Layer Graphene-Based Transparent Heaters
- 2020
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Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- In many applications like sensors, displays, and defoggers, there is a need for transparent and efficient heater elements produced at low cost. For this reason, we evaluated the performance of graphene-based heaters with from one to five layers of graphene on flexible and transparent polyethylene terephthalate (PET) substrates in terms of their electrothermal properties like heating/cooling rates and steady-state temperatures as a function of the input power density. We found that the heating/cooling rates followed an exponential time dependence with a time constant of just below 6 s for monolayer heaters. From the relationship between the steady-state temperatures and the input power density, a convective heat-transfer coefficient of 60 W·m−2·°C−1 was found, indicating a performance much better than that of many other types of heaters like metal thin-film-based heaters and carbon nanotube-based heaters.
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| 72. |
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| 73. |
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| 74. |
- Zhang, Yong, 1982, et al.
(författare)
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Transparent heaters based on CVD grown few-layer graphene
- 2022
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Ingår i: Journal of Materials Science: Materials in Electronics. - : Springer Science and Business Media LLC. - 1573-482X .- 0957-4522. ; 33:7, s. 3586-3594
-
Tidskriftsartikel (refereegranskat)abstract
- The outstanding thermal and optical properties of graphene make it tremendously interesting as heating elements. In this work, we demonstrate few-layer graphene as heating elements on glass substrate by chemical vapor deposition (CVD) method combined with a layer-by-layer transfer process. The electrothermal performance was studied in terms of applied voltage, heating/cooling rate and input power density. The results show that a three-layer graphene film heater can reach an equilibrium temperature up to 102 °C and a maximum heating rate of 1.8 °C/s when 60 V voltage was applied. Simulations were further performed to rationalize the experimental results, in which the effect of heat transfer coefficient, electric conductivity, and the effective stress distribution was discussed. It was found that the adhesion between graphene and substrate is very important for the heat performance, especially at high temperatures. Our results indicate that graphene-based films are promising candidate materials for the next generation of transparent heating elements.
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| 75. |
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| 76. |
- Zhang, Zhfei, et al.
(författare)
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Characterization of CNT Enhanced Conductive Adhesives in Terms of Thermal Conductivity
- 2012
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Ingår i: ECS Transactions. - : The Electrochemical Society. - 1938-5862 .- 1938-6737. - 9781607683186 ; 44:1, s. 1011-1017
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Konferensbidrag (refereegranskat)abstract
- CNTs have excellent thermal, electrical and mechanical properties. They can be used in various ways. One researched field of application is CNT-polymer composites which combine common technologies with advanced materials. This paper will focus on the thermal property of CNT-Ag-filled adhesives and compares the new materials with conventional, electrical Ag-filled conductive adhesives. Several analytical methods, FTIR, Raman analysis, SEM and TEM have been carried out to examine the different surface conditions after physicval and chemical modification of CNTs. The thermal conductivities of composites containing different types of CNTs were investigated. The incorporation of CNTs into polymers resulted in enhancement of the thermal conductivity compared to Ag-filler. The increase of thermal conductivity with addition of CNT filler is obvious, especially for the purified CNT. The value of thermal conductivity is about two times higher than the Ag-filled conductive adhesive. However, improvement on thermal conductivity of the surface modified CNT-filled conductive adhesives is not so obvious. Since the thermal conduction in CNT is by phonon transfer, the nanometric size and the huge interface lead to strong phonon-scattering at the interface. Thus, a relatively low interfacial area, weak interfacial adhesion promotes the conduction of phonons and minimizes coupling losses. According to this, the non-treated MWCNTs seem to have the highest potential to improve the thermal conductivity of epoxies.
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| 77. |
- Zhao, Changhong, 1982, et al.
(författare)
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Synthesis of graphene quantum dots and their applications in drug delivery
- 2020
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Ingår i: Journal of Nanobiotechnology. - : Springer Science and Business Media LLC. - 1477-3155. ; 18:1
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Forskningsöversikt (refereegranskat)abstract
- This review focuses on the recent advances in the synthesis of graphene quantum dots (GQDs) and their applications in drug delivery. To give a brief understanding about the preparation of GQDs, recent advances in methods of GQDs synthesis are first presented. Afterwards, various drug delivery-release modes of GQDs-based drug delivery systems such as EPR-pH delivery-release mode, ligand-pH delivery-release mode, EPR-Photothermal delivery-Release mode, and Core/Shell-photothermal/magnetic thermal delivery-release mode are reviewed. Finally, the current challenges and the prospective application of GQDs in drug delivery are discussed.[Figure not available: see fulltext.]
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| 78. |
- Zhou, Hua, et al.
(författare)
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Design for Embedded Chinese Display Smart Card
- 2006
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Ingår i: 2006 Conference on High Density Microsystem Design and Packaging and Component Failure Analysis, HDP'06; Shanghai; China; 27 June 2006 through 28 June 2006. - 9781424404889 ; , s. 152-156
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Konferensbidrag (refereegranskat)abstract
- The storage and display of Chinese character data and the battery life are two bottle-necks of a Chinese display smart card which is one kind of super smart cards. This paper presented a new idea to realize the Chinese display which was a practice of embedded font solution. A dieform regular MCU, a smart card MCU and a graphical LCD controller(LCD driver) provided the main functions of the system to show Chinese characters on a graphical LCD panel, to receive operations from users and to run monitor program or, moreover, COS (Card Operating System). 2-Wire serial interface (TWI) was selected to be the communication protocol between the main MCU and the LCD controller in order to reduce the connection numbers and to enhance reliability. To minimize power consumption is one main design target for extending battery life. Besides selecting components with low power consumption, a power control scheme was designed to meet this requirement. A functional demonstrator was assembled in order to check the system desigh and to do the debug work.
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| 79. |
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| 80. |
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