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The Fine Characterization and Potential Photocatalytic Effect of Semiconducting Metal Minerals in Danxia Landforms
摘要： The Danxia landform is representative of the Cretaceous continental red sediment. The careful identi?cation and potential environmental effects of minerals in Danxia red beds have yet to be clearly reported. In this work, reddish sandstone samples were collected from Lang Mountain Danxia landform in Xinning, Hunan province, China, and their mineral phases, element distribution, microstructure, and the spatial relationship of different minerals were investigated using polarizing optical microscope, environmental scanning electron microscopy, energy-dispersive X-ray analysis, electron probe microanalysis, micro-Raman spectra, micro- X-ray diffraction, X-ray ?uorescence spectroscopy, and high-resolution transmission electron microscopy. The results revealed that iron oxide (mainly hematite) and titanium oxide (mainly anatase) were the dominant minerals in Danxia red layers. Microcrystalline hematite was suggested as being the coloring mineral. Anatase, reported here for the ?rst time in Danxia red beds, constituted the content of titanium in the red layer (0.17–0.57%) and was present in a signi?cantly higher amount than the adjacent limestone formation (0.13%). Over 95% of Fe/Ti oxides served as a cementation agent along the framework of coarse-grain minerals (quartz and feldspar). The hematite and anatase were visible-light-responsive semiconductors, with a band gap of 2.01 eV and 3.05 eV, respectively. Photoelectrochemical experiments were performed on synthetic hematite, anatase, and their coupled material. The inactive hematite displayed an enhanced 23-fold photocurrent at 0.8 V (vs. Ag/AgCl) when coupled with anatase. Furthermore, in a photodegradation experiment using methyl orange dye under simulated sunlight, the coupled material showed decolorizing ef?ciency 2.4 times that of hematite. The anatase, therefore, prominently improved the photocatalytic activities of hematite. It is proposed that these semiconducting minerals in red beds produce oxygen reactive species and have signi?cant environmental effects, which is of great importance.
关键词： photocatalysis,anatase,hematite,environmental effect,Danxia landform
更新于2025-09-23 15:22:29
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Effect of number of collectors (N) on the environment due to single slope solar desalination unit coupled with N identical evacuated tubular collectors
摘要： This research paper talks about the investigation of the effect of number of collectors on the environment due to single slope solar desalination unit (SSSDU) coupled with N identical evacuated tubular collectors (N-ETC). The analysis is observed for typical days of May and December for the atmospheric situation of New Delhi with the help of analytical program fed in MATLAB. The average daily energy output has been estimated followed by the evaluation of amount of carbon mitigated and enviroeconomic parameter for various values of N at selected value of flow of fluid mass per unit time. The input data required for the numerical computations have been taken from IMD, Pune, India. It has been observed that the value of environmental cost or enviroeconomic parameter increases with the raise in the value of N at selected value of fluid flow mass/unit time.
关键词： Number of collectors,Environmental effect,evacuated tubular collector (ETC),single slope solar still (SSSS)
更新于2025-09-23 15:21:01
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Energy conversion from environmental fluctuations to coherent fields by Cooper-pair box quantum meta-materials
摘要： Electromagnetic waves propagating in open Cooper-Pair Boxes (CPBs) system is studied by using Maxwell-Bloch equations and Lindblad master equation. The results demonstrate an ensemble of CPBs as highly non-linear meta-material for electromagnetic waves. Incorporating the CPBs in a ring resonator or a Fabry-Perot cavity, one finds that: (1) With weak environmental couplings and CPBs in superconducting phase dominant regime, the non-linearity is enhanced and the system exhibits regular optical hysteresis. (2) With finite environmental couplings and CPBs in charge dominant regime, the Josephson effect and environmental effect can constructively interplay to produce a gain. In the later case, the electromagnetic field would be amplified by the CPB medium, indicating energy conversion from the environment to coherent fields mediated by CPBs.
关键词： environmental effect,Maxwell-Bloch equations,optical hysteresis,Josephson effect,electromagnetic waves,Lindblad master equation,quantum meta-materials,Cooper-Pair Boxes
更新于2025-09-09 09:28:46