We studied the practicable alleviation of efficiency droop effect in GaN-based light emitting diodes (LEDs) with surface plasmon (SP) coupling. Our approach is based on a simple ABC model which is extended by a Purcell factor that relates the SP coupling rate to the radiative recombination rate based on Fermi's golden rule. Purcell factors as small as two are found to be sufficient to obtain a low efficiency droop of only 5.2% at a current density of 200 A/cm². It is shown that a high probability of photon extraction from the SP modes is required for enhanced light output power. SP coupling is more beneficial to improve LED performance within the “green-yellow gap” suffering from low luminescence efficiency (less than 20%).

Coreius guichenoti, once widely distributed in the upper reaches of the Jinsha River, has become a nationally protected species in China due to the profound impacts of cascade reservoirs. To assess the influence of substrate on the suitability of spawning habitat for C. guichenoti, this study develops a substrate-inclusive habitat model using fuzzy logic based on expert knowledge. Taking the Pingdi Town section of the lower Jinsha River—a historical spawning site for C. guichenoti—as a case study from March to July 2020, we simulated changes in the spawning habitat suitability index (HSI) and compared the results with those from traditional models that exclude substrate factors. The results showed that in the first and second halves of May, Weighted Usable Area (WUA) and Overall Suitability Index (OSI) increased by 42.31% and 38.73%, respectively, while MSP exhibited dramatic increases of 236.04% and 614.56%. These improvements were primarily observed along the riverbanks, where HSI increased by approximately 0.25. From a management perspective, the HSI results provide a scientific basis for optimizing ecological flow regulation. Incorporating substrate factors into spawning habitat models offers a more objective and comprehensive assessment of habitat quality. Habitat restoration measures, such as targeted substrate improvement in key riverbank areas, may further increase habitat suitability, providing additional opportunities for conservation planning in regulated rivers.

This paper investigates the influence of coarse particle size on pressure characteristics through horizontal pipe transportation experiments of coarse particles and sand-laden water. As particle size increases, the thin and long grain accumulation layer forming at the pipe bottom and particle clusters above the layer vanish, most grains roll and bounce more quickly, the instantaneous pressure fluctuation intensity increases exponentially, and the time-averaged pressure decreases linearly along the flow direction. The fluctuating pressure probability density tends to obey a Gaussian distribution, and the turbulence power below 16 Hz increases. After adding fine sand constituting sand-laden water flows, the instantaneous pressure fluctuation intensity, transportation energy loss speed and fluctuating pressure amplitudes increase. With increasing particle size, the fitted Gaussian distribution of the fluctuating pressure probability density changes from thin to short and wide, and the spectral power of the measured pressure fluctuations increases within the resolvable frequency range, especially in the range from 8 to 10 Hz.