A controllable interface design and manufacturing strategy for embossed glass hierarchical nano-lens

Constructing nanostructured surfaces on the macro/micro-scale optical lens is of great importance in the improvement of light transmittance, reflection, and surface functionality of optical devices. In this paper, a flexible and novel material interface design and manufacturing method for hierarchical macro/nano optical glass lenses is proposed. To verify the feasibility of the presented manufacturing strategy, the deformation history and flow driving mechanism of multiscale structured surfaces during second hot embossing were studied by simulations and experiments. The results showed that solid-like glass preform exhibits a higher nanoscale deformation resistance and elastic recovery, which can reduce the distortion levels of the nanostructured surface. At small scales, molecular confinement greatly reduces the tectonic deformation of nanostructured surface at relatively low applied heat and pressure. However, beyond a specific thermal energy threshold, nanostructured convex surfaces are easily compressed into a smooth flattened surface. By collaborative control of embossing conditions, the nano-surface integrity of multiscale structured surface can be ensured during second hot embossing. Compared to the smooth macroscale optical lens, the hierarchical macro/nano glass lens exhibited better optical transmittance and antireflection properties. The proposed design and manufacturing strategy provides a facile and flexible solution for building the hierarchical macro/micro/nanostructure functional optics

Quantifying relative contributions of biotic interactions to bacterial diversity and community assembly by using community characteristics of microbial eukaryotes

Biotic interactions are known as a major control on microbial diversity. However, biotic interactions have rarely been quantified in an adequate manner, often leaving much residual variation unexplained in microbial biogeographic studies. Herein, we propose a holistic approach to disentangle the relative importance of inter-domain interactions in shaping microbial diversity by incorporating community-level characteristics. Taking coastal bacterioplankton on a regional scale as an example, we designated a range of community characteristics of pico- and nanoeukaryotes derived from metabarcoding and flow cytometric data as inter-domain interacting proxies, which were then considered in statistical modeling. We found that the bacterial diversity indices and community structure were much more accurately explained by a number of eukaryotic characteristics than by the measured environmental variables and/or spatial variables alone, as were the richness, relative abundances, and assemblage structures of major bacterial taxa. In co-occurrence networks, the nodes of characteristics that had more edges (links) were frequently the best explanatory variables for bacterial diversity indices. Over 70% of total variation in bacterial community structure could be explained by three categories of biotic interactions: parasitism (27%), fungi-bacterial competition (32%), and trophic structure and bacterivory (13%). This study showcases a methodological framework to infer different types of inter-domain interactions at play, and stresses the importance of non-grazing interacting processes in shaping bacterial diversity and community assembly

Comparative analysis of multi-energy complementary optimization schemes for regional integrated energy system considering wind power consumption

In order to select a more economical wind power consumption scheme for RIES （regional integrated energy system）， the electricity-gas multi-energy complementarity optimization models considering the reuse of waste heat from power to gas （P2G） reaction and the electric-thermal multi energy complementary optimization model of air source heat pump （ASHP） are established based on the principle of multi-energy complementarity. Taking account of the investment and maintenance cost of P2G and ASHP， the RIES multi-energy complementary economic dispatch model is established with the goal of minimizing the overall operating cost of the system. Constraints of energy supply and demand balance and various unit operation constraints are considered. The optimization software CPLEX is used to solve various models. The example calculation results show that the scheme considering the reuse of waste heat from P2G reaction can reduce the configuration capacity of P2G and increase the operation benefit of the system. On condition of the same consumption rate of wind power， the electric-thermal multi-energy complementary optimization model with ASHP is superior in economy and overall energy efficiency

Distinct seasonality of chytrid-dominated benthic fungal communities in the neritic oceans (Bohai Sea and North Yellow Sea)

Benthic fungal diversities in Bohai Sea and North Yellow Sea were investigated using pyrosequencing of 18S rDNA. Overall, Chytridiomycota dominated, followed by Basidiomycota, Ascomycota and Cryptomycota, in terms of alpha diversities and relative abundance. The beta diversity of benthic fungi showed a significant seasonality but no regional differences, accounted for by contrasting relative abundances of Chytridiomycota and Basidiomycota. Significantly seasonal changes in Chytridiomycota and Basidiomycota assemblage structure were also observed, but not for Ascomycota and Cryptomycota. Environmental filtering was more important than water depth and geographic distance in shaping the distribution of benthic fungi in the neritic oceans. The overall fungal beta diversity co-varied with concentration of chlorophyll a, pH, and salinity, distance from land, and water depth. The assemblage structure of benthic Chytridiomycota, Basidiomycota, Ascomycota and Cryptomycota co-varied with different sets of environmental parameters, suggesting their niche differentiations in the coastal sediments. (C) 2017 Elsevier Ltd and British Mycological Society. All rights reserved

Research on Stability Evaluation of Perilous Rock on Soil Slope Based on Natural Vibration Frequency

Perilous rock instability on the soil slope brings a substantial threat to project operation and even people’s lives. The buried depth of the perilous rock is a challenge to deal with and primarily determines its stability, and the indirect rapid identification of its buried depth is the key to its stability evaluation. The paper aims to find a new and quick method to measure the buried depth of perilous rock on the soil slope and to solve the hard-to-measure buried depth stability evaluation. When the damping ratio is less than one, and the deformation is linear elastic throughout the amplitude range, the potentially perilous rock vibration model may reduce to a multi-degree-of-freedom vibration one. By theoretical deduction, a quantitative relationship is established among the perilous rock mass, the basement response coefficient, the buried depth of the perilous rock, and the natural horizontal vibration frequency. In addition, the accuracy of this relationship is confirmed via numerous indoor experiments, showing that the horizontal vibration frequency of the perilous rock model in one dimension increases as the buried depth increases. Finally, based on the natural vibration frequency and guided by the limit balance model, a stability evaluation model of the perilous rock on the soil slope is constructed. Hence, the example shows that the method is feasible. The research findings are of vital significance for the stability evaluation of the perilous rock on the soil slope and give a novel approach and theoretical foundation for quick identification and monitoring

Spatiotemporal distributions and environmental drivers of diversity and community structure of nosZ-type denitrifiers and anammox bacteria in sediments of the Bohai Sea and North Yellow Sea, China

Denitrification and anammox processes are major nitrogen removal processes in coastal ecosystems. However, the spatiotemporal dynamics and driving factors of the diversity and community structure of involved functional bacteria have not been well illustrated in coastal environments, especially in human-dominated ecosystems. In this study, we investigated the distributions of denitrifiers and anammox bacteria in the eutrophic Bohai Sea and the northern Yellow Sea of China in May and November of 2012 by constructing clone libraries employing nosZ and 16S rRNA gene biomarkers. The diversity of nosZ-denitrifier was much higher at the coastal sites compared with the central sites, but not significant among basins or seasons. Alphaproteobacteria were predominant and prevalent in the sediments, whereas Betaproteobacteria primarily occurred at the site near the Huanghe (Yellow) River estuary. Anammox bacteria Candidatus Scalindua was predominant in the sediments, and besides, Candidatus Brocadia and Candidatus Kuenenia were also detected at the site near the Huanghe River estuary that received strong riverine and anthropogenic impacts. Salinity was the most important in structuring communities of nosZ-denitrifier and anammox bacteria. Additionally, anthropogenic perturbations (e.g. nitrogen overloading and consequent high primary productivity, and heavy metal discharges) contributed significantly to shaping community structures of denitrifier and anammox bacteria, suggesting that anthropogenic activities would influence and even change the ecological function of coastal ecosystems

Dynamics and Distribution of Marine Synechococcus Abundance and Genotypes during Seasonal Hypoxia in a Coastal Marine Ranch

Marine Synechococcus are an ecologically important picocyanobacterial group widely distributed in various oceanic environments. Little is known about the dynamics and distribution of Synechococcus abundance and genotypes during seasonal hypoxia in coastal zones. In this study, an investigation was conducted in a coastal marine ranch along two transects in Muping, Yantai, where hypoxic events (defined here as the dissolved oxygen concentration <3 mg L-1) occurred in the summer of 2015. The hypoxia occurred in the bottom waters from late July and persisted until late August. It was confined at nearshore stations of the two transects, one running across a coastal ranch and the other one outside. During this survey, cell abundance of Synechococcus was determined with flow cytometry, showing great variations ranging from 1 x 10(4) to 3.0 x 10(5) cells mL(-1), and a bloom of Synechococcus occurred when stratification disappeared and hypoxia faded out outside the ranch. Regression analysis indicated that dissolved oxygen, pH, and inorganic nutrients were the most important abiotic factors in explaining the variation in Synechococcus cell abundance. Diverse genotypes (mostly belonged to the sub-clusters 5.1 and 5.2) were detected using clone library sequencing and terminal restriction fragment length polymorphism analysis of the 16S-23S rRNA internal transcribed spacer region. The richness of genotypes was significantly related to salinity, temperature, silicate, and pH, but not dissolved oxygen. Two environmental factors, temperature and salinity, collectively explained 17% of the variation in Synechococcus genotype assemblage. With the changes in population composition in diverse genotypes, the Synechococcus assemblages survived in the coastal hypoxia event and thrived when hypoxia faded out

The habitat differentiation, dynamics and functional potentials of bacterial and micro-eukaryotic communities in shrimp aquaculture systems with limited water exchange

Microbes are important in not only driving matter cycling, modulating water quality, but also serving as food for animals in intensive aquaculture systems, in which artificial substrates in combination of biofloc technology can be applied to strengthen microbial values and animal production. However, the influence of micro-habitats created by these practices on water quality and microbial diversity and dynamics remains poorly understood. In this study, samples of three micro-habitats, the biofilms formed on immersed meshes, the suspended macro -aggregates, and the pond water were collected from limited-water-exchange ponds for rearing Litopenaeus van-namei during a period of 80 days. Using high-throughput sequencing of 16S and 18S rRNA genes and statistical analyses, we found that the community structures of both bacteria and micro-eukaryotes were similar between biofilms and macro-aggregates (ANOVA, P > 0.05), but significantly different from those in the water (P 0.05). Functionally, microbes in both biofilms and macro-aggregates exhibited higher potentials of organic matter degradation and nitrogen removal, supporting the usefulness of application of biofloc technology and biofilms in recycling waste and nutrients in the shrimp ponds with limited water exchange

Taxonomic Diversity of Pico-/Nanoeukaryotes Is Related to Dissolved Oxygen and Productivity, but Functional Composition Is Shaped by Limiting Nutrients in Eutrophic Coastal Oceans

Pico-/nanoeukaryotes (P/NEs) comprise both primary producers and bacterial predators, playing important biogeochemical and ecological roles in the marine microbial loop. Besides the difference in size, these small-sized fractions can be distinguished from microplankton by certain functional and ecological traits. Nevertheless, little information is available regarding patterns of their taxonomic and functional diversity and community composition along environmental gradients in coastal marine ecosystems. In this study, we applied high-throughput sequencing of 18S rRNA gene to assess the taxonomic species richness and community composition of P/NEs in surface waters of Bohai Sea and North Yellow Sea, northern China spanning a 600-km distance during summer and winter of 2011. The richness of operational taxonomic units (OTUs) formed a U-shaped relationship with concentration of chlorophyll a (Chl-a, a proxy of primary productivity), but a stronger, negative relationship with concentration of dissolved oxygen (DO). These two factors also significantly co-varied with the OTU-based community composition of P/NEs. The effect of geographic distance on community composition of P/NEs was negligible. Among the three functional groups defined by trophic traits, heterotrophs had the highest OTU richness, which exhibited a U-shaped relationship with both DO and Chl-a. The community of P/NEs was dominated by heterotrophs and mixotrophs in terms of read numbers, which showed a trade-off along the gradient of phosphate, but no significant changes along DO and Chl-a gradients, indicating functional redundancy. Similarly, the proportion of phototrophs was significantly and positively correlated with the concentration of silicate. Our results indicate that taxonomic and functional composition of P/NEs are decoupled on a regional scale, and limiting nutrients are important factors in modulating functional composition of these microorganisms in the studied area. These findings contribute toward gaining a better understanding of how diversity of small eukaryotes and their functions are structured in coastal oceans and the effect of environmental changes on the structuring process

Seagrass Colonization Alters Diversity, Abundance, Taxonomic, and Functional Community Structure of Benthic Microbial Eukaryotes

Seagrass form high productive ecosystems in coastal environments. However, the effects of these coastal plants on the structure and function of the belowground eukaryotic microbiome remain elusive. In this study, we characterized the community of microbial eukaryotes (microeukaryotes) in both vegetated and unvegetated sediments using 18S rRNA gene amplicon sequencing and quantitative PCR. Analysis of sequencing data showed that the eelgrass (Zostera marina) colonization decreased the alpha diversity indices of benthic microeukaryotes. Apicomplexa represented an average of 83% of reads across all samples, with a higher proportion at the vegetated sites. The taxonomic community structure was significantly different between these two types of sediments, for which the concentration of NH4+ in sediment porewater and salinity could account. Phylogenetic analyses of long 18S rRNA genes (around 1,030 bp) indicated these apicomplexan parasites are closely related to gregarine Lecudina polymorpha. Determination of 18S rRNA gene abundances provided evidence that the eelgrass markedly promoted the biomass of the gregarine and all microeukaryotes in the seagrass-colonized sediments and confirmed that the gregarine was hosted by a polychaete species. Significantly higher gene abundances of heterotrophs and mixotrophs were found at the vegetated sites, which could be explained by the finer sediments and short supply of dissolved inorganic nitrogen, respectively. The pigmented protists were more abundant in 18S rRNA gene copies at the lower and higher pH levels than at the intermediate. Nevertheless, the fractions of heterotrophs and phototrophs in the community were significantly related to porewater N:P ratio. These results indicate that seagrass colonization significantly induces an increase in overall biomass and a decrease in diversity of benthic microeukaryotes, making them more heterotrophic. This study also highlights that the hotspot of eukaryotic parasites could be linked with the high productivity of a natural ecosystem