Recently, solar evaporators composed of photothermal materials and their carriers have been designed and produced to enhance the solar evaporation rates based on interfacial solar heating. However, maintaining the high evaporation rate while preventing salt accumulation remains a challenge. In this paper, a water transport channel was designed to move the brine outside the solar evaporator to the expandable polyethylene (EPE) foam around the evaporator, thereby preventing salt accumulation in the evaporator. The concentration of the treated seawater was not increased during continuous evaporation and therefore avoiding the treatment of the high-concentration brine. The salt-rejecting solar evaporator was composed of a top layer of photothermal materials for high solar absorption, a thermal barrier layer of EPE foam for floatation and heat insulation, and a rationally designed water transport channel of air-laid paper (ALP) for fast seawater delivery to the top layer and outside the evaporator. The water evaporation rate of the simulated seawater by the salt-rejecting evaporator under 1 kW·m–2 solar irradiance was significantly enhanced to 1.46 kg·m–2·h–1 (accompanied by a photothermal conversion efficiency of 91.7%), which was 3.74 times higher than evaporation rate of the simulated seawater alone. The salt-rejecting evaporator also displayed excellent stability and durability as the evaporation rate was unchanged after 16 cycles of use. Finally, the potential application of the salt-rejecting evaporator was demonstrated in a practical setting by packing 25 evaporators in an EPE foam plate.

Interfacial solar distillation (ISD) is an approach with low cost and low energy demand useful for seawater desalination and freshwater production. However, the commercial potential of ISD for applications such as polluted seawater desalination or industrial wastewater reuse may be hindered by low rejection of volatile and semivolatile contaminants. For the first time, the results of this study showed that the transport (from bulk water (B) to distilled water (D)) of volatile and semivolatile contaminants during the solar desalination process was highly correlated with compound volatility (R 2 = 0.858). The obtained relationship was verified to be capable of predicting the distillation concentration ratio (C D /C B,0 ) of different contaminants (K H = 6.29 × 10 −7 −2.94 × 10 −4 atm•m 3 •mol −1 ) during the ISD process. Compounds such as phenols, which have relatively high volatilization and condensation rates, deserve the most attention as potential contaminants in the distilled water. Meanwhile, other compounds that are more volatile than phenol condensed less in distilled water. Adding an activated carbon adsorbent or a photothermal oxidant is a promising strategy to effectively mitigate the distillation of contaminants and ensure water safety. These results fill the knowledge gap in understanding the transport of volatile and semivolatile compounds in ISD for the treatment of complex source waters.

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The water-water cycle which may be helpful for dissipating the excitation pressure over electron transport chain and minimizing the risk of photoinhibition and photodamage was investigated in rice after 10-d P-deficient treatment. Net photosynthetic rate decreased under P-deficiency, thus the absorption of photon energy exceeded the energy required for CO 2 assimilation. A more sensitive response of effective quantum yield of photosystem 2 (Φ PS2 ) to O 2 concentration was observed in plants that suffered P starvation, indicating that more electrons were transported to O 2 in the P-deficient leaves. The electron transport rate through photosystem 2 (PS 2) (J f ) was stable, and the fraction of electron transport rate required to sustain CO 2 assimilation and photorespiration (J g /J f ) was significantly decreased accompanied by an increase in the alternative electron transport (J a /J f ), indicating that a considerable electron amount had been transported to O 2 during the water-water cycle in the P-deficient leaves. However, the fraction of electron transport to photorespiration (J o /J f ) was also increased in the P-deficient leaves and it was less sensitive than that of water-water cycle. Therefore, water-water cycle could serve as an efficient electron sink. The higher non-photochemical fluorescence quenching (q N ) in the P-deficient leaves depended on O 2 concentration, suggesting that the water-water cycle might also contribute to non-radiative energy dissipation. Hence, the enhanced activity of the water-water cycle is important for protecting photosynthetic apparatus under P-deficiency in rice.Additional key words: Oryza sativa, net photosynthetic rate, stomatal conductance, intercellular CO 2 concentration, photosystem 2, chlorophyll a fluorescence, non-photochemical and photochemical quenching, photorespiration.

BackgroundStyrax tonkinensis is a great potential biofuel as the species contains seeds with a particularly high oil content. Understanding the nutrient distribution in different parts of the fruit is imperative for the development and enhancement of S. tonkinensis as a biodiesel feedstock.MethodsFrom 30 to 140 days after flowering (DAF), the development of S. tonkinensis fruit was tracked. The morphology change, nutrient content, and activity of associated enzymes in the continuum of the pericarp, seed coat, and kernel were analyzed.ResultsBetween 30 and 70 DAF, the main locus of dry matter deposition shifted from the seed coat to the kernel. The water content within the pericarp remained high throughout development, but at the end (130 DAF later) decreased rapidly. The water content within both the seed coat and the kernel consistently declined over the course of the fruit development (30–110 DAF). Between 70 and 80 DAF, the deposition centers for sugar, starch, protein, potassium, and magnesium was transferred to the kernel from either the pericarp or the seed coat. The calcium deposition center was transferred first from pericarp to the seed coat and then to the kernel before it was returned to the pericarp. The sucrose to hexose ratio in the seed coat increased between 30 and 80 DAF, correlating with the accumulation of total soluble sugar, starch, and protein. In the pericarp, the sucrose to hexose ratio peaked at 40 and 100 DAF, correlating with the reserve deposition in the following 20–30 days. After 30 DAF, the chlorophyll concentration of both the pericarp and the seed coat dropped. The maternal unit (the pericarp and the seed coat) in fruit showed a significant positive linear relationship between chlorophyll b/a and the concentration of total soluble sugar. The potassium content had significant positive correlation with starch (ρ = 0.673, p = 0.0164), oil (ρ = 0.915, p = 0.000203), and protein content (ρ = 0.814, p = 0.00128), respectively. The concentration of magnesium had significant positive correlation with starch (ρ = 0.705, p = 0.0104), oil (ρ = 0.913, p = 0.000228), and protein content (ρ = 0.896, p = 0.0000786), respectively. Calcium content had a significant correlation with soluble sugar content (ρ = 0.585, p = 0.0457).ConclusionsDuring the fruit development of S. tonkinensis, the maternal unit, that is, the pericarp and seed coat, may act a nutrient buffer storage area between the mother tree and the kernel. The stage of 70–80 DAF is an important time in the nutrient distribution in the continuum of the pericarp, seed coat, and kernel. Our results described the metabolic dynamics of the continuum of the pericarp, seed coat, and kernel and the contribution that a seed with high oil content offers to biofuel.

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For the application of high-pressure air injection (HPAI) in light oil reservoirs, low-temperature oxidation (LTO) behavior is the main concerned factor affecting the recovery performance. In a previous study, we have investigated the thermal behavior of Keke Ya light crude oil (Tarim Basin, China) by thermogravimetry (TG)/differential thermogravimetry (DTG) and differential thermal analysis (DTA) tests. In this paper, sensitivity studies on the LTO behavior of crude oil in porous media have been addressed and the influences of factors such as pressure, oxidation time, water saturation (S w), and clays on the oxidation behavior of crude oil in porous media are investigated by oxidation tube experiments. All experiments are carried out at 85 °C. Gas chromatography is employed to investigate the effluent gas composition and hydrocarbon distribution of the oxidized oil. In addition, the apparent hydrogen/carbon (H/C) ratio calculated from the effluent gas composition is used to analyze the exothermic degree of crude oil during the oxidation process in porous media. In the last part of this paper, we introduce a two-step process LTO model (oxygen addition reaction and carbon–carbon bond stripping reaction) to further investigate the mechanism of oxidation behavior. Some key factors affecting the HPAI performance are discussed.