Advanced solar energy utilization technology requires high-grade energy to achieve the most efficient application with compact size and least capital investment recovery period. Concentrated solar ...power (CSP) technology has the capability to meet thermal energy and electrical demands. Benefits of using CSP technology with parabolic trough collector (PTC) system include promising cost-effective investment, mature technology, and ease of combining with fossil fuels or other renewable energy sources. This review first covered the theoretical framework of CSP technology with PTC system. Next, the detailed derivation process of the maximum theoretical concentration ratio of the PTC was initially given. Multiple types of heat transfer fluids in tube receivers were reviewed to present the capability of application. Moreover, recent developments on heat transfer enhancement methods for CSP technology with PTC system were highlighted. As the rupture of glass covers was frequently observed during application, methods of thermal deformation restrain for tube receivers were reviewed as well. Commercial CSP plants worldwide with PTC system were presented, including those that are in operation, under construction, and announced. Finally, possible further developments of CSP plants with PTC system were outlined. Besides, suggestions for future research and application guidance were also illustrated.
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•An amphiphilic particles ODS catalyst was successfully prepared.•The stable Pickering emulsion was formed in bi-phase ODS system.•Impressive desulfurization performance was achieved ...in model oil and real oil.•Demulsification of the system was easily achieved by centrifugation.•The catalyst could be recycled for 5 times with little catalytic inactivation.
Phosphotungstic active component (PW12O403−) was supported on the bi-component carbon-organosilica Janus particles to prepare an amphiphilic catalyst for oxidative desulfurization, and it was analyzed by a series of characterization. Its catalytic performance in different systems including n-octane/acetonitrile, n-octane/BimPF6, n-octane/BimBF4, n-octane/methanol, and n-octane/water, was evaluated. According to the results, the stable Pickering emulsion was formed in n-octane/acetonitrile system which exhibited the best desulfurization performance, corresponding to the final desulfurization ratio of 99.86%. Compared with the conventional bi-phase system using H3PW12O40 as catalyst, the desulfurization ratio was sharply increased. Besides, the prepared amphiphilic catalyst could be easily recovered by centrifugation, which was unattainable for the conventional amphiphilic heteropoly acid catalyst. The desulfurization ratio could achieve above 98% even after the catalyst was reused for 5 times. Due to its excellent catalytic performance for the model oil with different initial sulfur content and different sulfur-containing compounds, good recyclability, and outstanding selectivity, the prepared catalyst was evaluated for real oil desulfurization, and a satisfactory result was achieved. The excellent desulfurization performance was attributed to the micrometer-scale droplets formed in Pickering emulsion to result in good mixing.
Phylogeography has been one major focus of evolutionary biology in recent years, with many important advances in Chinese species. In this issue, we collected 11 phylogeographic studies of plants by ...Chinese laboratories. We further synthesized the main findings and patterns emerging from these and previous phylogeographic studies in China and asked where phylogeographic research should be directed in the coming years. Numerous examples have shown that phylogeographic patterns in China did not show an expected expansion–contraction pattern at large scale, mirroring the geological records showing that no unified ice sheet had developed in China during the Quaternary Period. Instead, regional expansions and intraspecific divergences are very common in most studied species during the Quaternary oscillations. Different intraspecific lineages or alleles (haplotypes) were detected in multiple localized refugia, from where regional or local expansions are likely to have started. Hybridizations and introgressions are frequent between intraspecific lineages or between different species. We also reviewed computational methods for phylogeographic analyses. Despite the great progress made in recent years, there remains much to discover about the spatial–temporal dimensions and underlying speciation mechanisms of Chinese plants. Phylogeographic studies represent a key knot that connects the genus phylogeny (macroevolution) and speciation and adaptation (microevolution). Therefore, we advocate that: (i) phylogeographic studies of plants in China should be directed to the closely related species or a monophyletic group (for example, a genus or a section) in the coming years; and (ii) population genetic data based on direct sequencing multiple loci, especially those from nuclear genome and statistical tests should be widely adopted and enforced. The recovered intraspecific divergences and phylogeographic patterns of multiple‐species may allow us to better understand the high plant diversity in China and set up concrete hypotheses for studying plant speciation and diversification mechanisms in this region.
•The continuous-feed pyrolysis of polyethylene in porous media was investigated.•Oil quality can be improved by using more porous media with smaller pore size.•Aromatics will be present in the oil ...when the temperature exceeds 520 °C.•Gas-carrying speed exceeding 130 mL/min will eliminate aromatics in the oil.
This study investigates the pyrolysis of polyethylene waste in a continuous-feed mode to provide novel insights into recycling waste plastics. Alumina (Al2O3) porous media has been introduced into the pyrolysis reactor to study its effect on continuous-feeding plastic waste pyrolysis. The pyrolysis product yields, oil fractions, and gas components have been determined under varying porous media structures, i.e., thickness and pore size, and operating parameters, i.e., temperature and gas-carrying velocity. To the best of our knowledge, it is the first attempt to investigate the influence of porous media pore size on the thermal decomposition of waste polyolefin in continuous feeding mode. The results reveal that higher thicknesses and smaller pore sizes of porous media can enhance the properties of pyrolysis oil with lower heavy fractions (>C20). The aromatization of light olefins is triggered when the temperature exceeds 520 °C, resulting in a rapid increase in light fraction (<C12) in pyrolysis oil. Moreover, the gas-carrying velocity determines the pyrolysis product distribution by regulating the volatiles' residence time.
Eight Dawson‐type polyoxometalates were successfully prepared and used in an octanal/air oxidative desulfurization (ODS) system for model oil. Among which, the classical 2:18 polyoxometalate ...K6α‐P2W18O62·14H2O exhibited the best catalytic performance with a sulfur removal ratio of 99.63%. Then, K6α‐P2W18O62·14H2O was supported on graphene oxide (GO) to afford K6P2W18O62/GO using the hydrothermal method. Due to the in situ adsorption of the supported catalysts in the ODS process, the sulfur removal ratio was 96.10% without extraction treatment. Compared with the octanal/air ODS system using pure GO as an adsorbent for the oxidation products, the sulfur removal ratio increased from 89.21 to 96.10%, and the n‐octanal/S molar ratio decreased from 24 to 4. To facilitate the recycling of the catalyst and avoid catalyst loss, K6α‐P2W18O62·14H2O was supported on magnetic graphene oxide (mGO) to afford K6P2W18O62/mGO. The results showed that the supported catalyst could be easily recovered with the aid of an external magnetic field, while maintaining high catalytic activity during five cycles of reuse with little catalyst loss. Furthermore, all the prepared materials were analyzed by a series of characterizations, and the reaction mechanism of the studied system was proposed through contrast tests and GC‐MS characterization analysis.
In situ ultra‐deep desulfurization of fuel oil was achieved by the combination of catalytic air oxidation and adsorption.
Radiative cooling is a passive means of cooling that does not require the consumption of additional energy and has broad application potential. While experimental spectral measurements have been ...conducted, the daylighting of buildings, photovoltaic (PV) cells, and vehicles has seldom been considered. Here, we use spectrum-selective coatings to resolve the competing demands of daylighting (or appearance) and radiative cooling. A simple liquid blade-coating method that was inexpensive, convenient, and scalable was used to achieve radiative cooling with ultrahigh transmittance in visible light and excellent cooling performance. Resonant polar dielectric SiO2 microparticles with optimized volumetric fractions and diameters were randomly mixed into an acrylic resin and manually bladed at room temperature with natural evaporation drying. Spectrometry results showed that a mean visible light transmittance >91.3% was achieved, which was much higher than reported in previous studies; a mean emittance >93.7% within the “atmospheric window” was also reached. Over four days testing of a silver-plated aluminum sheet in a populous area at sea level, we achieved a maximum sub-ambient decrease in temperature of ~8.7 °C and a maximum cooling power of 108.49 W/m2.
Figure Radiative cooling blade coating with ultrahigh visible light transmittance and emission within an “atmospheric window”. Display omitted
•Competing demands of daylighting (or appearance) and radiative cooling is resolved.•Low cost liquid blade-coating method is developed for radiative cooling.•Visible light transmittance>91.3% and emittance>93.7% in atmospheric window.•Over four days testing, a maximum sub-ambient decrease in temperature of ~8.7 °C.•Over four days testing, the maximum radiative cooling power is 108.49 W/m2
•The high concentrations of PE (2.0%, 5.0% and 10.0%) increased the peak viscosity.•The CS-PE mixtures exhibited a pseudoplastic and shear-thinning behavior.•Pectin promoted a remarkable reduction in ...the fraction of RDS.•The PE decreased the hydrolysis rate of CS with lower values of C∞ and k.
In this paper, the effects of pectin (PE) with different concentrations on the pasting, rheological and digestibility properties of corn starch (CS) were evaluated. The Rapid Visco-Analyzer results showed that the peak viscosity was decreased with the concentrations of PE (0.5% and 1.0%) and then increased when the concentration of PE exceeded 2.0%. PE resulted in lower breakdown and setback values of CS. Rheological results revealed that the CS and CS-PE mixtures exhibited a pseudoplastic and shear-thinning behavior. The storage modulus (G′) and loss modulus (G″) of CS were increased with increasing PE concentrations from 2.0% to 10.0%. PE resulted in a decrease in the starch susceptibility to α-amylase and promoted a remarkable reduction (P < 0.05) in the fraction of rapidly digested starch. The hydrolysis kinetic analysis suggested a decelerating effect of pectin on the hydrolysis rate of CS with lower values of equilibrium hydrolysis percentage (C∞) and kinetic constant (k).
Geographical variation in the interacting traits of plant–pollinator mutualism can lead to local adaptive differentiation. We tested Darwin’s hypothesis of reciprocal selection as a key driving force ...for the evolution of floral traits of an alpine ginger (Roscoea purpurea) and proboscis length of a tabanid fly (Philoliche longirostris).
We documented the pattern of trait variation in R. purpurea and P. longirostris across five populations. At each site, we quantified pollinator-mediated selection on floral display area, inflorescence height and corolla length of R. purpurea by comparing selection gradients for flowers exposed to natural pollination and to supplemental hand pollination. Reciprocal selection between plant and fly was examined at two sites via the relationship between proboscis length and nectar consumption (fly benefit) and corolla length and pollen deposition (plant benefit).
Local corolla tube length was correlated with local fly proboscis length among the five sites. We found strong linear selection imposed by pollinators on corolla tube length at all sites, but there was no consistent relationship of fitness to inflorescence height or floral display area. Selection between corolla length and proboscis length was reciprocal at the two experimental sites examined.
The geographical pattern of trait variation and the evidence of selection is consistent with a mosaic of local, species-specific reciprocal selection acting as the major driving force for the evolution of corolla length of R. purpurea and proboscis length of P. longirostris.
A two-marker combination of plastid rbcL and matK has previously been recommended as the core plant barcode, to be supplemented with additional markers such as plastid trnH–psbA and nuclear ribosomal ...internal transcribed spacer (ITS). To assess the effectiveness and universality of these barcode markers in seed plants, we sampled 6,286 individuals representing 1,757 species in 141 genera of 75 families (42 orders) by using four different methods of data analysis. These analyses indicate that (i) the three plastid markers showed high levels of universality (87.1–92.7%), whereas ITS performed relatively well (79%) in angiosperms but not so well in gymnosperms; (ii) in taxonomic groups for which direct sequencing of the marker is possible, ITS showed the highest discriminatory power of the four markers, and a combination of ITS and any plastid DNA marker was able to discriminate 69.9–79.1% of species, compared with only 49.7% with rbcL + matK; and (iii) where multiple individuals of a single species were tested, ascriptions based on ITS and plastid DNA barcodes were incongruent in some samples for 45.2% of the sampled genera (for genera with more than one species sampled). This finding highlights the importance of both sampling multiple individuals and using markers with different modes of inheritance. In cases where it is difficult to amplify and directly sequence ITS in its entirety, just using ITS2 is a useful backup because it is easier to amplify and sequence this subset of the marker. We therefore propose that ITS/ITS2 should be incorporated into the core barcode for seed plants.
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