Une technique prometteuse pour la réalisation de dispositifs laser solides émettant dans l'ultraviolet consiste à disposer en cascade plusieurs cristaux non linéaires générant des sommes de fréquence à partir d'une émission laser fondamentale située dans le proche infra-rouge.Cependant, à ce jour, peu de cristaux non linéaires offrent la possibilité de générer de manière efficace des longueurs d'onde voisines ou inférieures à 250 nm.Dans ce but, les plus gros efforts de recherche actuels s'orientent vers des cristaux contenant des groupements borate.Après une description des principaux cristaux non linéaires proposés pour ce type d'application, nous présenterons les études que nous menons sur des matériaux de type fluoroborate, dérivés des oxoborates de terre rare et de calcium TrCa 4 O(BO 3 ) 3 (Tr = terre rare), et sur des matériaux de structure huntite TrMe 3 (BO 3 ) 4 (Me = Al, Ga, Sc).
Micro–nano symbiotic superamphiphobic surfaces can prevent liquids from adhering to metal surfaces and, as a result, improve their corrosion resistance, self-cleaning performance, pollution resistance, and ice resistance. However, the fabrication of stable and controllable micro–nano symbiotic superamphiphobic structures on metal surfaces commonly used in industry remains a significant challenge. In this study, a laser-electrochemical hybrid subtractive–additive manufacturing method was proposed and developed for preparing copper superamphiphobic surfaces. Both experimental and fluid simulation studies were carried out. Utilizing this novel hybrid method, the controllable preparation of superamphiphobic micro–nano symbiotic structures was realized. The experimental results showed that the prepared surfaces had excellent superamphiphobic properties following subsequent modification with low surface energy substances. The contact angles of water droplets and oil droplets on the surface following electrodeposition treatment reached values of 161 ± 4° and 151 ± 4°, respectively, which showed that the prepared surface possessed perfect superamphiphobicity. Both the fabrication method and the test results provided useful insights for the preparation of stable and controllable superamphiphobic structures on metal surfaces in the future.
Introduction Solar photovoltaic (PV) power generation, a crucial part of global renewable energy, has been advancing swiftly. However, effective promotion of PV generation relies not only on enhancing generation efficiency but also on thorough evaluations of construction suitability. This study addresses this gap by developing a comprehensive evaluation framework for assessing the suitability of photovoltaic power station locations in China. Methods This research developed a subjective-objective evaluation framework that integrates the Analytic Hierarchy Process (AHP) and the Criteria Importance Through Intercriteria Correlation (CRITIC) method. This framework allows for a comprehensive analysis of photovoltaic power station location suitability. Long-term meteorological data and remote sensing products were used to calculate solar radiation and photovoltaic potential data, which were then applied to evaluate the suitability of photovoltaic generation across China. Results The study revealed that from 2000 to 2020, China's average annual solar radiation was 5,896.437 MJ·m −2 , and the total photovoltaic generation amounted to 1.10726 × 10 15 KWh. By 2020, the average score for photovoltaic construction suitability in China was 0.1058, with suitable areas comprising 51.1% of the national territory. High-suitability regions were primarily concentrated in Northwest China, including Xinjiang and Gansu, where suitability scores exceeded 7.5 and annual generation surpassed 213 KWh. In contrast, southeastern coastal and southern provinces such as Jiangsu, Zhejiang, and Fujian exhibited lower suitability scores (<3.5) and annual average generation of less than 19.2262 KWh, primarily due to limited land availability and reduced solar radiation. Discussion The findings emphasize the critical need to prioritize photovoltaic development in Northwest China, where favorable conditions offer considerable potential for large-scale photovoltaic generation. These regions possess rich solar resources and extensive land suitability, making them optimal for photovoltaic power station construction. In contrast, southeastern coastal areas and southern provinces are less suitable for photovoltaic development due to constraints in land availability and solar radiation levels. This study provides valuable insights for strategic photovoltaic development planning in China.
Superhydrophobic surface with anisotropic wetting and no low‐surface‐energy modification is investigated in which laser ablation, ultrasonic cleaning with degreasing solution, and electrodeposition are used sequentially. The macrogrooves are prepared by laser, and the micro–nanoscale structures on macrogrooves are prepared by electrodeposition, which is important to study the effect of hierarchical structures on anisotropic wetting. Herein, the surface morphology and surface crystal structure are discussed with respect to the laser‐ablated surface and the subsequent degreasing solution super‐cleaning/electrodeposited surfaces. At the same time, stainless steel surfaces with grooves of different periodic intervals (30–150 μm) and depths (10–40 μm) are systematically fabricated by laser only. When the periodic interval is smaller (<=50 μm), the static anisotropy is not obvious (5°–7°). However, the smaller the groove periodic interval and the greater the depth (<=30 μm), the more obvious the sliding anisotropy. Finally, dense and uniform micro–nanostructures on laser‐ablated grooves are prepared by electrodeposition. The micro–nanohierarchical structures prepared by electrodeposition not only can make the droplets have superhydrophobic properties but also enhance the water drop's anisotropic sliding ability.
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