Institutional Repository of GuangZhou Institute of Energy Conversion, CAS
Not a member yet
23976 research outputs found
Sort by
Enhancing solar energy utilization: A red-emitting Sr<sub>2</sub>In<sub>0.5</sub>Sb<sub>0.5</sub>O<sub>4:</sub>Mn<SUP>4+</SUP> phosphor with both UV and green excitation for plant growth
No full textRed light in sunlight promotes plant growth and development, while UV and green light are poorly absorbed by plants. Converting UV and green light into red light can enhance solar energy utilization and improve photosynthetic efficiency, significantly shortening the plant growth cycle. Herein, we report a novel red-emitting Sr2In0.5Sb0.5O4:Mn4+ phosphor that can be effectively excited by both UV and green light. According to Dexter's theory, Mn4+ is calculated to be in a weak crystal field. When excited at 330 or 520 nm, the characteristic photoluminescence (PL) peak appears at similar to 695 nm, which is attributed T-4(2g) -> (4)A(2g) transition of Mn4+. The optimal doping concentration of Mn4+ is 0.003, and the concentration quenching mechanism was determined to be a dipole-dipole interaction. Additionally, a red LED device was fabricated by encapsulating Sr2In0.5Sb0.497O4:0.003Mn(4+) phosphor with a 365 nm UV chip, exhibiting bright red light when driven by 150 mA current. The corresponding electroluminescence (EL) spectrum matches well with the absorption spectra of phytochromes P-R and P-FR, indicating that Sr2In0.5Sb0.5O4:Mn4+ phosphor has promising applications in plant growth
Thermal analysis with high accuracy of multi-beam mask fabrication
No full textFor a 7 nm technology node and beyond, multi-beam mask fabrication based on charged particles has attracted attention widely and shows great advantages in terms of throughput. However, the heating effect during mask writing is a serious problem and makes deformation error. To address this issue, an accurate analysis of heating with multi-beam writing is necessary. In this study, the thermal effects of electron beams on a mask during writing time (exposure time and nonexposure time) were simulated with a finite element numerical method. The variation in the temperature field with two writing paths (S-shaped and E-shaped) was analyzed. A comparative analysis of the mask's deformation under different writing paths was conducted. Numerical research shows that the thermal analysis method in this study provides a guide for optimizing the process parameters of mask fabrication
Heat extraction performance of the super-long gravity heat pipe applied to geothermal reservoirs of multi-aquifers
No full textThe super -long gravity heat pipe (SLGHP) is a novel down -hole heat exchanger (DHE), which is in fastdeveloping and extremely suitable for deep -earth geothermal energy exploitation. The SLGHP itself has very high heat transfer coefficient, making the poor heat transfer capability of the surrounding geothermal formulations become the bottleneck constraining the overall performance of the SLGHP geothermal system. Inspired by the enhancing effect of the flowing groundwater in the aquifers on the thermal performance of the traditional DHE system, the present work proposes a heat transfer enhancement strategy based on arousing inter -layer crossflow in wellbore-connected multi -aquifers for the SLGHP geothermal system. A detailed numerical study is conducted to examine the effects of key parameters like the permeability and thickness of aquifers, the distance and pressure difference between aquifers. It is found that: i) a larger aquifer permeability leads to larger heat extraction rate of the SLGHP, but the heat extraction rate increment decreases due to the marginal effect when the aquifer permeability is larger than 10-12 m2; ii) a larger pressure difference improves the heat extraction of the SLGHP, the groundwater flow pattern from the deep to the shallow aquifers rather than the reversed pattern is found to be more beneficial due to the geothermal gradient; iii) the distance between aquifers shows a composite impact on the heat extraction performance of the SLGHP. A larger distance not only enlarges the heat transfer area between the SLGHP and the groundwater, but also creates an impeding effect on the heat uptake of SLGHP from the geothermal formation owing to the presentence of temperature -lowered groundwater in the flow path ending -part in the wellbore. In addition, the aquifer's thickness is found to have great impacts on the SLGHP heat extraction rate, and the "cask" effect may be encountered when the thickness difference between the connected aquifers is considerably large
Top-down fabrication of active interface between TiO2 and Pt nanoclusters. Part 2: Catalytic performance and reaction mechanism in CO oxidation
No full textIn this work, following Part 1 that has found a redispersion process from Pt nanoparticles (NPs, about 3.4 nm) to nanoclusters (NCs, about 1 nm) on TiO 2 and elucidated its mechanism, we carefully investigated the catalytic performance of the obtained Pt NC catalyst in CO oxidation as well as the corresponding reaction mechanism. The Pt NC catalyst excels than its parent catalyst in terms of both intrinsic and apparent activity. Detailed studies by combining kinetic measurements, isotopic labeling reaction experiments, and low-temperature operando FT-IR unambiguously demonstrated that the Pt NCs deposited on TiO 2 can form unique interfacial sites that enable to active O 2 at very low temperature, thus the CO adsorbed on TiO 2 can diffuses to, and reacts with, the activated oxygen, rendering a high activity at low temperatures. This work is contributory in understanding the origin of the high activity of the supported metal cluster catalysts. (c) 2024, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved
Top-down fabrication of active interface between TiO2 and Pt nanoclusters. Part 2: Catalytic performance and reaction mechanism in CO oxidation
No full textIn this work, following Part 1 that has found a redispersion process from Pt nanoparticles (NPs, about 3.4 nm) to nanoclusters (NCs, about 1 nm) on TiO 2 and elucidated its mechanism, we carefully investigated the catalytic performance of the obtained Pt NC catalyst in CO oxidation as well as the corresponding reaction mechanism. The Pt NC catalyst excels than its parent catalyst in terms of both intrinsic and apparent activity. Detailed studies by combining kinetic measurements, isotopic labeling reaction experiments, and low-temperature operando FT-IR unambiguously demonstrated that the Pt NCs deposited on TiO 2 can form unique interfacial sites that enable to active O 2 at very low temperature, thus the CO adsorbed on TiO 2 can diffuses to, and reacts with, the activated oxygen, rendering a high activity at low temperatures. This work is contributory in understanding the origin of the high activity of the supported metal cluster catalysts. (c) 2024, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved
Access Repository Dashboard
Do you manage Institutional Repository of GuangZhou Institute of Energy Conversion, CAS? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!