We made aggregates of cholesteric liquid crystalline Cylinders with Double-Twist orientational structure (DTC) and investigated their rigid-body rotation under a temperature gradient, focusing on how the rotational speed should depend on the cylinder size. The experimental results showed that the angular velocity of the DTC aggregates linearly increased with the height of the cylinders and was inversely proportional to the base area. With a phenomenological equation, we analyzed the torque caused by the heat flux and its balance with the viscous friction, and found that the simple analysis well explained the size-dependence of the rotation of the DTC aggregates. The coupling constant between the heat flux and the torque to drive the rigid-body rotation was in the same order of magnitude as that for the director rotation.
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http://dx.doi.org/10.1140/epje/i2019-11867-x | DOI Listing |
ACS Nano
January 2025
Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, P. R. China.
Along with the development of miniaturization, integration, and high power of electronic chips in the 5G and artificial intelligence era and their urgent need for technologies enabled to solve high heat flux dissipation in limited space, investigating bioinspired extreme superwettability surfaces with high-efficiency condensation heat transfer (CHT) performance has attracted great interest in academic and industrial communities. Compared with filmwise condensation of flat hydrophilic surfaces featured with continuous liquid films, dropwise condensation of flat hydrophobic surfaces is a more efficient type of energy transport way. However, discrete condensate drops can only shed off the hydrophobic flat surfaces under gravity until their sizes reach the capillary length of liquid, e.
View Article and Find Full Text PDFPlants (Basel)
January 2025
Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.
Alpine meadows are vital ecosystems on the Qinghai-Tibet Plateau, significantly contributing to water conservation and climate regulation. This study examines the energy flux patterns and their driving factors in the alpine meadows of the Qilian Mountains, focusing on how the meteorological variables of net radiation (), air temperature, vapor pressure deficit (), wind speed (), and soil water content () influence sensible heat flux () and latent heat flux (). Using the Bowen ratio energy balance method, we monitored energy changes during the growing and non-growing seasons from 2022 to 2023.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Faculty of Safety Engineering and Civil Protection, Fire University, 52/54 Slowackiego Street, 01-629 Warsaw, Poland.
The main purpose of this article was to determine the smoke-generating and thermal properties of selected types of natural leather. Differences in the amount of smoke generated from the type of finish used in the technological processing of leather were observed. Research has shown that the burnt nubuck (367) sample with exposure at the heat flux intensity of 25 kW/m without the presence of a pilot burner flame achieved the highest value of the specific optical density D.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia.
We have proposed and developed a method for measuring the thermal conductivity of highly efficient thermal conductors. The measurement method was tested on pure metals with high thermal conductivity coefficients: aluminum (99.999 wt.
View Article and Find Full Text PDFSci Total Environ
January 2025
School of Resource and Environmental Science, Wuhan University, Wuhan 430079, China.
Forest age structures have been substantially affected by natural disturbances and anthropogenic activities worldwide. Their changes can significantly influence local and nonlocal climate through both the biogeochemical and biophysical processes. However, numerous studies have focused on the biogeochemical effect of forest age changes whereas the biophysical effect has received far less attention.
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