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Reservoirs are artificial ecosystems that modify the hydrological and environmental components nearby. The long-term monitoring of fish assemblages in reservoirs may provide key information to understand how these artificial ecosystems allow fish population fluctuations and identify proper conservation strategies. A sentinel-site approach method assessed changes in fish assemblages in the Feitsui Reservoir (1024 ha) over 14 years, including the periods 2006–2008, 2010–2011, 2016, 2018, and 2020. Fish assemblages, sampled using gill nets, were composed of 38 species (12 families and 8 orders) with Cyprinidae as the dominant family; the fish fauna were dominated by species of the family Cyprinidae (71%) and Cichlidae (20.3%). Principal component analysis and nonmetric multidimensional scaling categorized the assemblages into two groups (cold and warm seasons), and we identified three parameters that were significantly correlated with the season (p < 0.05): SD (R = −0.04), Chl-a (R = 0.01), and algal count (R = 0.19); the algal count was higher in the warm season than in the cold season. The fish assemblage in the cold and warm seasons contained no exclusive taxa, contributing to the dissimilarity between the groups. The fish assemblage for the years before and after 2010 indicated partial overlap between the two groups; S. macrops contributed greatly to the separation of the two periods (>10% each; SIMPER) and O. mossambicus was dominant in assemblage structures after 2010. Our findings show the importance of long-term fish monitoring for the investigation of the effects of nonnative fish species on native fish species composition.

Kinetic instabilities arising from anisotropic electron velocity distributions are ubiquitous in ionospheric, cosmic, and terrestrial plasmas, yet there are only a handful of experiments that purport to validate their theory. It is known that optical field ionization of atoms using ultrashort laser pulses can generate plasmas with known anisotropic electron velocity distributions. Here, we show that following the ionization but before collisions thermalize the electrons, the plasma undergoes two-stream, filamentation, and Weibel instabilities that isotropize the electron distributions. The polarization-dependent frequency and growth rates of these kinetic instabilities, measured using Thomson scattering of a probe laser, agree well with the kinetic theory and simulations. Thus, we have demonstrated an easily deployable laboratory platform for studying kinetic instabilities in plasmas.

Abstract: TiO2 nanoparticle-coated nickel wires were produced by electrical heating in various nanofluid concentrations ranging from 0.01 to 1wt.% with various processing heat fluxes from 0 to 1000kW/m2. The experimental results demonstrated up to 82.7% enhancement on critical heat flux (CHF) in condition of coated nickel wire (processed in 1wt.% with 1000kW/m2) boiling in pure water. The contact angle measurement revealed that the hydrophilic porous coating formed by vigorous vaporization of TiO2 nanofluid in nucleate boiling regime enormously modified the wettability of heating surface consequently improving the CHF. Besides, it is evident that the coverage of nanoparticle deposition tended to become more complete as concentration and processing heat flux increased based on SEM and EDS analysis. The nanoparticles dispersed in base fluid exhibited little effect on CHF enhancement and could even hinder the percentage of CHF augmentation from boosting, which demonstrated that one could enhance CHF by using only small amount of nanoparticles just adequate to form surface coatings instead of preparing working fluid with great bulk. However, according to the boiling curves in all cases of coated nickel wires, it is supposed that the nucleate boiling heat transfer coefficient deteriorates as a result of thermal resistance resulted from the occurrence of nanoparticle deposition. In summary, the coated porous structure of nanoparticles leads to enhance CHF and to decrease boiling heat transfer coefficient. [Copyright &y& Elsevier]

We present detailed studies on exciton-photon coupling and polariton emission based on a poly(1,4-phenylenevinylene) copolymer, Super Yellow (SY), in a series of optical microcavities and optoelectronic devices, including light-emitting diode (LED) and light-emitting transistor (LET). We show that sufficiently thick SY microcavities can generate ultrastrong coupling with Rabi splitting energies exceeding 1 eV and exhibit spectrally narrow, nearly angle-independent photoluminescence following lower polariton (LP) mode dispersion. When the microcavity is designed with matched LP low-energy state and exciton emission peak for radiative pumping, the conversion efficiency from exciton to polariton emission can reach up to 80%. By introducing appropriate injection layers in a SY microcavity and optimizing the cavity design, we further demonstrate a high-performance ultrastrongly coupled SY LED with weakly dispersive electroluminescence along LP mode and a maximum external quantum efficiency (EQE) of 2.8%. Finally, we realize an ultrastrongly coupled LET based on vertical integration of a high-mobility ZnO transistor and a SY LED in a microcavity, which enables a large switching ratio, uniform emission in the ZnO pattern, and LP mode emission with a maximum EQE of 2.4%. This vertical LET addresses the difficulties of achieving high emission performance and precisely defining the emission area in typical planar LETs, and opens up the possibility of applying various strongly coupled emitters for advanced polariton devices and high-resolution applications.