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Background and aims: The frequent occurrence of extreme rainfall events results in soils experiencing drying–rewetting (DRW) cycles. Such rewetting can lead to a surge in soil CO2 emissions; however, the main regulatory factors involved in this priming effect are unclear. Methods: In this study, we conducted a meta-analysis using data extracted from 43 published papers, to determine the direct regulatory factors involved in the priming effect of soil CO2. Results: The results indicated that the priming effect of rewetting on soil CO2 emissions was influenced by ecosystem type, soil properties, climatic factors, and the number of DRW cycles. The priming effect was the highest in cropland but the lowest in grassland when taking flux values observed before rewetting as the control group. It was also greater in acidic soils (pH < 6.5) and soils with a high clay fraction (clay ≥ 30%) than in other soils. The effect size (lnRR) of soil CO2 emissions was exponentially related to the mean annual precipitation (MAP), and decreased with increases in MAP. In DRW experiments, the priming effect of the first rewetting on soil CO2 emissions was the largest, an effect that gradually decreased with the number of DRW cycles, before disappearing completely. Most importantly, soil moisture influenced the peak time and the pulse time of the priming effect: the greater the change in soil moisture, the longer the peak time duration; the higher the maximum soil moisture content after rewetting, the longer the pulse time duration; and the lower the initial soil moisture content, the bigger the priming effect. Conclusion: Generally, physical mechanisms, especially soil moisture, directly regulate the CO2 priming effect during DRW cycles. Thus, this study provides a theoretical basis for assessing and predicting the impact of future precipitation changes on soil carbon cycling. Future studies should also carefully monitor any changes in soil microorganisms in response to changes in soil moisture during DRW cycles, because these appear to be significantly involved in CO2 release from soils. [ABSTRACT FROM AUTHOR]

Ethylene Propylene Diene Monomer (EPDM) composites filled with 0–400 phr PbWO 4 (PWO) were prepared by conventional process using a two-roll mill. Surface treatment of the fillers coated with KH570 was conducted to enhance the wettability and lubrication of fillers in the polymer matrix. According to SEM images and mechanical test, both micro- and submicro-fillers disperse homogeneously in the matrix, and adhesion of submicro-fillers to the matrix is stronger than that of micro-fillers. The submicro-PWO composites had better tensile strength and elongation at break than those composites containing micro-PWO powder, but a relatively higher hardness. The photon shielding test was performed to determine the radiation shielding properties of these composites, which showed that attenuation of gamma-rays for the submicro-PWO composites was substantially enhanced compared to micro-PWO reinforced composites. [ABSTRACT FROM AUTHOR]

Abstract Boron carbide (B 4 C) is an important type of neutron radiation shielding material with relatively high efficiency due to the high content of 10B element. Incorporation of B 4 C particles into polymer to prepare high-performance neutron radiation shielding material has become more and more important for the safe operation of nuclear power in the defense industry and nuclear power plant. The polyimide/B 4 C composite films with different micro-sized B 4 C contents were successfully prepared by in-situ polymerization. Silane coupling agent KH550 was employed to functionalize B 4 C particles to improve the dispersion of B 4 C particles in the polyimide matrix with strengthened interfacial interaction. As shown that the micro-sized B 4 C functional particles can be well dispersed in the BPDA/ODA polyimide matrix. With the B 4 C content increase, thermal stability of the polyimide/B 4 C composite films can be significantly improved, even mechanical properties partly declined. Meanwhile, the polyimide/B 4 C composite films exhibit good thermal neutron radiation shielding properties. The neutron permeability I/I 0 changes exponentially with the change of B 4 C content. When the B 4 C content is increased to 30 wt%, the polyimide/B 4 C composite films show optimum properties combination with thermal decomposition temperature (T d 10) of 622 °C, neutron permeability (I/I 0) of 0.24 (800 μm in thickness), and tensile strength of 406 MPa. The composite thus shows great potential for use in applications which require materials with high thermal stability and neutron radiation shielding ability, such as fusion reactor system and nuclear waste disposal. [ABSTRACT FROM AUTHOR]

Soil microbial communities play important roles in biogeochemical cycles and ecosystem functioning. However, how tree and grass species affect soil microbial structure and functions in semi-arid regions is poorly understood. In this study, we used sequencing of representative genes and bioinformatic analysis to compare the soil bacterial and fungal communities and their functional groups among legume and non-legume broad-leaved plantations, conifer plantations, artificial grassland, and adjacent farmland in a semi-arid area of Northern China. We found that soil bacterial diversity and abundance were significantly increased by legume plantations, especially Robinia pseudoacacia , compared to farmland. Soil bacterial communities were dominated by K-strategists in plantation soils and by r-strategists in farmland and grassland soils. Soil fungal communities showed contrasting patterns between Ascomycetes and Basidiomycota across treatments, and the highest abundance of nutrient indicator taxa Mortierellomycota was observed in plantation soils. Functional analysis revealed that afforestation altered the capacity of soil bacteria for organic compound mineralization and C and N cycling, and that different plant species enriched different types of ectomycorrhizal and saprophytic fungi. Moreover, we found that plantations and grasslands formed more connected but less complex and stable bacterial co-occurrence networks than farmland, and that conifer plantations increased the closeness of soil fungal networks compared to broad-leaved plantations. Our results suggest that tree and grass species play a key role in shaping the soil microbial community structure and functional groups, and provide valuable information for choosing suitable tree and grass species for ecosystem restoration and management in semi-arid regions. [ABSTRACT FROM AUTHOR]

Key message: Through the histological, physiological, and transcriptome-level identification of the abscission zone of Pennisetum alopecuroides ‘Liqiu’, we explored the structure and the genes related to seed shattering, ultimately revealing the regulatory network of seed shattering in P. alopecuroides. Pennisetum alopecuroides is one of the most representative ornamental grass species of Pennisetum genus. It has unique inflorescence, elegant appearance, and strong stress tolerance. However, the shattering of seeds not only reduces the ornamental effect, but also hinders the seed production. In order to understand the potential mechanisms of seed shattering in P. alopecuroides, we conducted morphological, histological, physiological, and transcriptomic analyses on P. alopecuroides cv. ‘Liqiu’. According to histological findings, the seed shattering of ‘Liqiu’ was determined by the abscission zone at the base of the pedicel. Correlation analysis showed that seed shattering was significantly correlated with cellulase, lignin, auxin, gibberellin, cytokinin and jasmonic acid. Through a combination of histological and physiological analyses, we observed the accumulation of cellulase and lignin during ‘Liqiu’ seed abscission. We used PacBio full-length transcriptome sequencing (SMRT) combined with next-generation sequencing (NGS) transcriptome technology to improve the transcriptome data of ‘Liqiu’. Transcriptomics further identified many differential genes involved in cellulase, lignin and plant hormone-related pathways. This study will provide new insights into the research on the shattering mechanism of P. alopecuroides. [ABSTRACT FROM AUTHOR]

Microstructural and textural characteristics of Zr702 and Zr-2.5Nb alloys before and after rolling (50% reduction in thickness) were characterized and compared by employing electron channel contrast imaging and electron backscatter diffraction techniques, with underlying reasons for the differences between them explored. Results show that the starting microstructure of the Zr702 is mainly comprised of well-equiaxed α-Zr grains while the Zr-2.5Nb presents a typical dual-phase microstructure featured by bulk α grains enclosed by thin β-Zr films. After the 50% rolling, plastic deformation readily occurs through the active operation of prismatic and pyramidal slip in both the Zr alloys. Most grains are found to be elongated along rolling direction with a few less-deformed grains also present (more evident in the rolled Zr702). The β-Zr preexisting in Zr-2.5Nb alloy is softer than α-Zr and could thus be deformed more easily, allowing fewer plastic strains to be accommodated by the α grains. The starting Zr702 has a typical bimodal basal texture that is essentially unchanged after the 50% rolling. The majority of grains in the starting Zr-2.5Nb show scattered orientations with their c-axes away from normal directions (ND). After the same rolling, however, c-axes of most α-grains in the Zr-2.5Nb alloy are aligned to be close to transverse direction or ~30° from the ND (ring-like distribution), different from that of the Zr702. It is demonstrated that the formation of such textural features is related to the preexisting thin β films in the Zr-2.5Nb alloy, in addition to the slip deformation. • Plastic deformation readily occurs through active slip in Zr702 and Zr-2.5Nb alloys after 50% rolling. • Fewer strains are accommodated by α grains in rolled Zr-2.5Nb due to presence of soft β phase. • A few less-deformed grains with c//ND exist in both the rolled Zr alloys. • Major textural characteristics are hardly changed in the Zr702 before and after rolling. • Distinct textural characteristics are developed in the 50%-rolled Zr-2.5Nb. [ABSTRACT FROM AUTHOR]

Miscanthus spp. show excellent application prospects due to its bioenergy potential and multiple ecological services. Annual N export with biomass harvest from Miscanthus, even without fertilizer supplement, do not reduce soil N levels. The question arises regarding how Miscanthus can maintain stable soil N levels. Metagenomic strategies were used to reveal soil N‐cycling‐related microbiome and their functional contributions to processes of soil N‐cycling based on the comparison among the bare land, cropland, 10‐year Miscanthus × giganteus, and 15‐year Miscanthus sacchariflorus fields. The results showed that, after long‐term cropland‐to‐Miscanthus conversion (LCMC), 16 of 21 bacterial phyla and all the archaeal phyla exhibited significant changes. Soil microbial denitrification and nitrification functions were significantly weakened, and N fixation (NF) was significantly enhanced. The biosynthesis of amino acids, especially alanine, aspartate, and glutamate metabolism, in soil N‐cycling‐related microbiome was dramatically promoted. The genus Anaeromyxobacter contributed largely to the NF process after LCMC. Variations in the soil available potassium, available N, organic C, and total N contents drove a functional shift of soil microbiome from cropland to Miscanthus pattern. We conclude that Miscanthus can recruit Anaeromyxobacter communities to enhance NF benefiting its biomass sustainability and soil N balance. [ABSTRACT FROM AUTHOR]

Switchgrass (Panicum virgatum L.) shows great bioenergy potential and provides multiple ecological services. However, its severe seed shedding causes biomass waste and seed diffusion risk. Questions arise as to the production performance of switchgrass after panicle removal (PR), which remains unknown. We revealed switchgrass growth responses to PR and illustrated physiological reasons. Compared to the untreated switchgrass, PR significantly stimulated stem elongation (32.13%) and increased tiller number (39.70%), as well as aboveground biomass (24.69%). Importantly, PR significantly increased contents of nonstructural carbohydrates (NSCs) in the stem, which was directly beneficial to the ethanol conversion, and in the rhizome and root. The chlorophyll contents, net photosynthetic efficiency, and photochemical quantum efficiencies of flag leaf increased significantly. PR switchgrass allocated more assimilates into the stem, root, rhizome, and NSCs. Activities of phosphoenolpyruvate carboxylase, ribulose-1, 5-diphosphate carboxylase, sucrose phosphate synthase (SPS) in flag leaf and adenosine diphosphate glucose pyrophosphorylase (AGPase) and SPS in the stem and rhizome all increased significantly. In contrast, activities of the AGPase in flag leaf and sheath decreased significantly. Contents of zeatin nucleoside, gibberellins, and indoleacetic acid in flag leaf, stem, and rhizome all increased. Abscisic acid contents in flag leaf and stem decreased significantly while increased significantly in the rhizome. In conclusion, growth-promoting hormones delayed plant senescence, enhanced leaf photosynthesis, and enhanced vegetative growth through regulating assimilates-metabolism-related enzymes, which increased biomass accumulation in PR switchgrass. This work provided new insights for yield and digestibility improvement in switchgrass through field management practices, hormones regulation, or genetic modification strategies. [Display omitted] • Panicle removal (PR) retarded plant senescence in switchgrass. • PR increased biomass dry weights of switchgrass. • PR increased contents of nonstructural carbohydrates in stem, root and rhizome. • AGPase and SPS facilitated storage and transport of C assimilates in PR switchgrass. • Growth promoting hormones played critical roles in delaying plant senescence. [ABSTRACT FROM AUTHOR]

Different vegetation restoration methods may affect the soil's physicochemical properties and microbial communities. However, it is not known how the microbial network's complexity of the bacterial and fungal communities respond to short-term vegetation restoration. We conducted a short-term ecological restoration experiment to reveal the response of the soil's microbial community and microbial network's stability to initial vegetation restoration during the restoration of the degraded grassland ecosystem. The two restoration methods (sowing alfalfa (Medicago sativa, AF) and smooth brome (Bromus inermis, SB)) had no significant effect on the alpha diversity of the fungal community, but the SB significantly increased the alpha diversity of the soil surface bacterial community (p < 0.01). The results of NMDS showed that the soil's fungal and bacterial communities were altered by a short-term vegetation restoration, and they showed that the available phosphorus (AP), available potassium (AK), and nitrate nitrogen (nitrate-N) were closely related to changes in bacterial and fungal communities. Moreover, a short-term vegetation restoration significantly increased the complexity and stability of fungi ecological networks, but the opposite was the case with the bacteria. Our findings confirm that ecological restoration by sowing may be favorable to the amelioration of soil fungi complexity and stability in the short-term. Such findings may have important implications for soil microbial processes in vegetation recovery. [ABSTRACT FROM AUTHOR]

A kind of silicone rubber (SR)/carbon fiber (CF)@polydopamine (PDA) flexible composites were prepared in this work. CF was modified by oxidative self‐polymerization of dopamine (DA), and the effect of DA concentration on properties of SR/CF@PDA composites was researched. The transverse fiber bundle tests have shown that SR/CF@PDA‐1.5 has the best interfacial bonding performance. Compared with SR/CF, tensile strength and elongation at break of SR/CF@PDA‐1.5 were increased by 61.7% and 68.4%, respectively. Results indicate that the interfacial bonding of SR/CF@PDA composites was effectively improved due to the adhesion properties of PDA. Moreover, the rough surface of CF@PDA also enhanced the interface interaction through physical "interlocking." When being compared to other surface modification process, dopamine‐modified carbon fiber is cost effective, "green" and highly efficient. SR/CF@PDA with an excellent interfacial bonding and flexibility is a kind of wrapping material for protection of special precision instruments. [ABSTRACT FROM AUTHOR]

In this work, two Nb(Ta)TiZr medium-entropy alloy (MEA) coatings were fabricated successfully on a commercially pure Zr sheet by pulsed laser cladding. Their phase constitutions, microstructural characteristics, chemical compositions and grain orientations were well characterized and analyzed by using X-ray diffraction (XRD), electron channeling contrast (ECC) imaging, energy dispersive spectrometry (EDS) and electron backscatter diffraction (EBSD) techniques, with hardness and wear resistance measured and correlated with the microstructural characteristics as well. Results show that irregular-shaped bulk grains (BCC solid-solution phase) are formed in the two Nb(Ta)TiZr MEA coatings (cladding zones), both of which have a thickness of ∼800 μm with good metallurgical bonding to the substrate. After adding Ta, grains in the MEA coating are slightly refined. The phase constitutions in both the coatings agree with calculations based on several theoretical parameters. Hardness tests show that the NbTiZr and the NbTaTiZr coatings have hardnesses of 360 ± 18 HV and 430 ± 28 HV, respectively, ∼1.8 times and ∼2.2 times that of the substrate (196 ± 4 HV). This can be ascribed to combined effects of grain refinement strengthening, solid solution strengthening with denser low angle boundaries in the MEA coatings. Specific wear rates of the NbTiZr and the NbTaTiZr coatings are only ∼17% and ∼6% of that of the substrate, respectively, indicating markedly improved wear resistance. This is demonstrated to be closely related to complete oxide films easily formed on the coatings with oxidation and abrasive wear mechanisms. • Two Nb(Ta)TiZr MEA coatings were prepared on a pure Zr sheet by pulsed laser cladding. • The MEA coatings have a thickness of ∼800 μm and consist of irregular-shaped BCC phase. • Hardness and wear resistance of both MEA coatings are greatly improved compared to the substrate. • Their superior properties are related to grain refinement, solid solution and denser low angle boundaries. [ABSTRACT FROM AUTHOR]

The recretohalophyte Karelinia caspia is of forage and medical value and can remediate saline soils. We here assess the contribution of primary/secondary metabolism to osmotic adjustment and ROS homeostasis in Karelinia caspia under salt stress using multi‐omic approaches. Computerized phenomic assessments, tests for cellular osmotic changes and lipid peroxidation indicated that salt treatment had no detectable physical effect on K. caspia. Metabolomic analysis indicated that amino acids, saccharides, organic acids, polyamine, phenolic acids, and vitamins accumulated significantly with salt treatment. Transcriptomic assessment identified differentially expressed genes closely linked to the changes in above primary/secondary metabolites under salt stress. In particular, shifts in carbohydrate metabolism (TCA cycle, starch and sucrose metabolism, glycolysis) as well as arginine and proline metabolism were observed to maintain a low osmotic potential. Chlorogenic acid/vitamin E biosynthesis was also enhanced, which would aid in ROS scavenging in the response of K. caspia to salt. Overall, our findings define key changes in primary/secondary metabolism that are coordinated to modulate the osmotic balance and ROS homeostasis to contribute to the salt tolerance of K. caspia. [ABSTRACT FROM AUTHOR]

Aim: Planted forests are becoming increasingly common world‐wide for a variety of reasons, including water conservation and carbon sequestration, although the effects of tree plantations on biodiversity are unclear with respect to whether planted ecosystems are "green deserts" or valuable habitats for biodiversity. Location: Global. Time period: 1980–2020. Taxa studied: Flora, fauna and microorganisms. Methods: By conducting a meta‐analysis of 361 observations from 138 sites world‐wide, we explored the global patterns and associated drivers of biodiversity responding to tree plantations by comparing biodiversity levels in plantations and adjacent habitats (primary or secondary forests). Results: Overall, the biodiversity (species richness) and abundance across multitrophic levels in tree plantations were lower than those in primary forests, reached similar values to secondary succession, but varied with plantation and management regimes. Specifically, the biodiversity across multitrophic levels in reforestation was higher than that in afforestation; the biodiversity in mixed, native species and unmanaged plantations was higher than that in monoculture, exotic species and managed plantations. The diversity of vertebrates, invertebrates and plants in reforestation was lower than that in primary forests, whereas belowground biodiversity in reforestation showed no difference from primary forests. Invertebrate diversity in reforestation was lower than that in secondary succession, whereas plant diversity was higher than that in secondary succession. Moreover, the biodiversity in reforestation increased with reforestation age. Furthermore, structural equation models showed that aboveground faunal diversity in reforestation was driven by canopy coverage and plant diversity and that reforestation affected belowground biodiversity mainly by changing soil organic carbon. Main conclusions: Our findings suggest that reforestation by planting mixed native species will be more beneficial to biodiversity. We reveal that biodiversity in intensively managed plantations is significantly lower than that in restoration‐oriented plantations. We highlight that primary forests are not replaceable, but that planted forests might be a reliable way to restore biodiversity rapidly. [ABSTRACT FROM AUTHOR]

Background and aims: Many meadows are experiencing severe degradation due to the effects of global climate change and other human-related activity, especially overgrazing. The impact of grazing may however vary in different sites, but the dynamics and mechanisms associated with grazing-related meadow degradation on soil microbial biomass structure and function in different locations are still unclear.To address this we examined three alpine meadows with different grazing sites in northwest China, which included grazing in winter and summer, in each of which there were four degradation gradients, varying from no degradation to severe degradation.At the Maqin site, grazing during the summer resulted in higher concentrations of microbial carbon (MBC), nitrogen (MBN), and phosphorus (MBP) compared to grazing during winter. Undegraded meadows (ND) also had higher MBC concentrations compared to low (LD), medium (MD), or severely degraded (SD) ones at the three sites. However, the homeostasis analysis revealed that the elemental stoichiometries were strictly controlled, despite significant degradation-related effects on the concentrations of MBC, MBN, and MBP, indicating relatively stable coupling relationships among C, N, and P.The random forest and partitioning variation analyses showed that edaphic factors play the more important roles in regulating microbial biomass and elemental composition in the different sites. Overall, these results suggest that the effects of degradation on soil microbial biomass concentrations and the stoichiometries are context dependent, particularly with regard to the impact of background soil properties, demonstrating that site conditions must be considered when predicting how grassland ecosystems will respond to grazing-related degradation.Methods: Many meadows are experiencing severe degradation due to the effects of global climate change and other human-related activity, especially overgrazing. The impact of grazing may however vary in different sites, but the dynamics and mechanisms associated with grazing-related meadow degradation on soil microbial biomass structure and function in different locations are still unclear.To address this we examined three alpine meadows with different grazing sites in northwest China, which included grazing in winter and summer, in each of which there were four degradation gradients, varying from no degradation to severe degradation.At the Maqin site, grazing during the summer resulted in higher concentrations of microbial carbon (MBC), nitrogen (MBN), and phosphorus (MBP) compared to grazing during winter. Undegraded meadows (ND) also had higher MBC concentrations compared to low (LD), medium (MD), or severely degraded (SD) ones at the three sites. However, the homeostasis analysis revealed that the elemental stoichiometries were strictly controlled, despite significant degradation-related effects on the concentrations of MBC, MBN, and MBP, indicating relatively stable coupling relationships among C, N, and P.The random forest and partitioning variation analyses showed that edaphic factors play the more important roles in regulating microbial biomass and elemental composition in the different sites. Overall, these results suggest that the effects of degradation on soil microbial biomass concentrations and the stoichiometries are context dependent, particularly with regard to the impact of background soil properties, demonstrating that site conditions must be considered when predicting how grassland ecosystems will respond to grazing-related degradation.Results: Many meadows are experiencing severe degradation due to the effects of global climate change and other human-related activity, especially overgrazing. The impact of grazing may however vary in different sites, but the dynamics and mechanisms associated with grazing-related meadow degradation on soil microbial biomass structure and function in different locations are still unclear.To address this we examined three alpine meadows with different grazing sites in northwest China, which included grazing in winter and summer, in each of which there were four degradation gradients, varying from no degradation to severe degradation.At the Maqin site, grazing during the summer resulted in higher concentrations of microbial carbon (MBC), nitrogen (MBN), and phosphorus (MBP) compared to grazing during winter. Undegraded meadows (ND) also had higher MBC concentrations compared to low (LD), medium (MD), or severely degraded (SD) ones at the three sites. However, the homeostasis analysis revealed that the elemental stoichiometries were strictly controlled, despite significant degradation-related effects on the concentrations of MBC, MBN, and MBP, indicating relatively stable coupling relationships among C, N, and P.The random forest and partitioning variation analyses showed that edaphic factors play the more important roles in regulating microbial biomass and elemental composition in the different sites. Overall, these results suggest that the effects of degradation on soil microbial biomass concentrations and the stoichiometries are context dependent, particularly with regard to the impact of background soil properties, demonstrating that site conditions must be considered when predicting how grassland ecosystems will respond to grazing-related degradation.Conclusion: Many meadows are experiencing severe degradation due to the effects of global climate change and other human-related activity, especially overgrazing. The impact of grazing may however vary in different sites, but the dynamics and mechanisms associated with grazing-related meadow degradation on soil microbial biomass structure and function in different locations are still unclear.To address this we examined three alpine meadows with different grazing sites in northwest China, which included grazing in winter and summer, in each of which there were four degradation gradients, varying from no degradation to severe degradation.At the Maqin site, grazing during the summer resulted in higher concentrations of microbial carbon (MBC), nitrogen (MBN), and phosphorus (MBP) compared to grazing during winter. Undegraded meadows (ND) also had higher MBC concentrations compared to low (LD), medium (MD), or severely degraded (SD) ones at the three sites. However, the homeostasis analysis revealed that the elemental stoichiometries were strictly controlled, despite significant degradation-related effects on the concentrations of MBC, MBN, and MBP, indicating relatively stable coupling relationships among C, N, and P.The random forest and partitioning variation analyses showed that edaphic factors play the more important roles in regulating microbial biomass and elemental composition in the different sites. Overall, these results suggest that the effects of degradation on soil microbial biomass concentrations and the stoichiometries are context dependent, particularly with regard to the impact of background soil properties, demonstrating that site conditions must be considered when predicting how grassland ecosystems will respond to grazing-related degradation. [ABSTRACT FROM AUTHOR]

Miscanthus spp. are increasingly cultivated in cropland worldwide due to their bioenergy potential and multiple ecological services. Effects of long‐term cropland‐to‐Miscanthus conversion without N fertilizer on soil microbiome and N cycling largely remain unknown. We aimed to explore the effects of Miscanthus conversion on soil microbiome and N cycling over a 15‐year period. We analyzed diversity, composition, and abundance of bacterial and archaeal communities using 16S rRNA amplicon sequencing, and abundances of N‐cycling‐related genes using quantitative polymerase chain reaction of 0–10 cm soils collected from bare land, cropland, 10‐year Miscanthus × giganteus, and 15‐year Miscanthussacchriflorus land in Beijing. Conversion decreased soil sand and micro‐aggregate proportion, nitrate N (NiN), available phosphorus levels, conductivity, temperature, and pH, while increasing proportion of soil clay and macro‐aggregate (MAA), soil organic C (SOC), available N (AN), exchangeable Mg2+ (EMg2+), and available potassium (AK) contents as well as microbial C/N. Consequently, diversity, composition, and abundance of soil bacterial community exhibited larger changes than those values of archaeal community after conversion. Soil AP, EMg2+, AK, and SOC were key factors in shifting microbiome from the cropland to Miscanthus pattern. Moreover, abundances of bacterial and archaeal communities and the N fixer gene nifH increased, whereas that of the bacterial ammonia monooxygenase gene decreased. The copies of other N‐cycling‐related genes in the two Miscanthus lands seemed similar to those values of cropland. The nifH copies negatively correlated with soil NiN and positively correlated with AN, EMg2+, ECa2+, SOC, AK, and MAA. We conclude that changes in soil microbiome pattern induced by the variation of soil properties enhance microbial N fixation potential, maintaining stable N levels and robust N cycling with lower N leakage risk after conversion. These results should inspire farmers and governments to large‐scale use Miscanthus on marginal cropland in Northern China. [ABSTRACT FROM AUTHOR]

Hydrogen generation and accumulation in confined spaces poses safety concerns due to its reactivity with oxygen to form explosions and the ability to embrittle metals. Various organic getters have been developed to eliminate hydrogen and minimize these undesired effects; however, these getters are usually powders with low molecular weights and are difficult to apply in complex structures. Polymer getters exhibit the promising features required for confined space applications, where could be readily processed into various shapes and forms. Unfortunately, polymer getters are relatively unexplored and their recorded performances are far from satisfactory. In this work, we report the preparation and characterization of novel vinyl polysiloxane getters. Starting from a methyl vinyl silicone oil prepared by ring-opening polymerization, polysiloxane getters in versatile forms that are adaptable to various environments are prepared by adding Pd/C and then curing. Combined with the thermal and radiation stability of polysiloxane, not only will these new getters be applicable in future applications in the electronic and nuclear industries as hydrogen scavengers, they also serve as platform for further development of polymer getters with superior properties. [ABSTRACT FROM AUTHOR]

Cover cropping is widely used for soil management in vineyards. But few studies have compared the effect of different cover cropping management methods on soil properties and fungal communities in vineyards. Therefore, we examined the effects of traditional management (shallow tillage to remove weeds), cover with single species (two treatments covered with different herbages), cover with mixed species (two combination treatments named M1 and M2 respectively), and cover with a crop on soil physicochemical properties and fungal community structure in a vineyard in northern China in 2020 and 2021. Soil total carbon and mineral nitrogen increased under Carex lanceolata Boott, Medicago sativa L., M1, and M2 covers but decreased under Glycine max (L.) Merr. Compare to traditional management. Soil organic carbon content increased under Carex lanceolata Boott, Medicago sativa L., M1, and M2, with increasing planting time. Cover cropping management had a minor effect on fungal diversity in the short term. Effects on beneficial and pathogenic fungi varied with cover type. With a cover of Glycine max (L.) Merr, the abundance of Fusarium brachygibbosum , a pathogen that affects grape production, increased, but that of Chaetomium , a genus that inhibits pathogens, also increased. With a cover of Carex lanceolata Boott, the abundance of Didymella glomerata , another pathogen that affects grape production, increased, but that of Metarhizium , an entomopathogenic fungus, also increased. Compared with Carex lanceolata Boott, covers with mixed species (M1 and M2) showed minor effects on soil pathogens, so covers with mixed species could benefit the vineyards more than other cover cropping management in North China. • Cover cropping management can improve soil carbon and nitrogen in vineyard. • Cover cropping management has impacts on grape productivity-related fungi. • SOC is the major drivers of fungal diversity and Didymella glomerata. [ABSTRACT FROM AUTHOR]

Background: Carex L. is one of the largest genera in the Cyperaceae family and an important vascular plant in the ecosystem. However, the genetic background of Carex is complex and the classification is not clear. In order to investigate the gene function annotation of Carex, RNA-sequencing analysis was performed. Simple sequence repeats (SSRs) were generated based on the Illumina data and then were utilized to investigate the genetic characteristics of the 79 Carex germplasms. Results: In this study, 36,403 unigenes with a total length of 41,724,615 bp were obtained and annotated based on GO, KOG, KEGG, NR databases. The results provide a theoretical basis for gene function exploration. Out of 8776 SSRs, 96 pairs of primers were randomly selected. One hundred eighty polymorphic bands were amplified with a polymorphism rate of 100% based on 42 pairs of primers with higher polymorphism levels. The average band number was 4.3 per primer, the average distance value was 0.548, and the polymorphic information content was ranged from 0.133 to 0.494. The number of observed alleles (Na), effective alleles (Ne), Nei's (1973) gene diversity (H), and the Shannon information index (I) were 2.000, 1.376, 0.243, and 0.391, respectively. NJ clustering divided into three groups and the accessions from New Zealand showed a similar genetic attribute and clustered into one group. UPGMA and PCoA analysis also revealed the same result. The analysis of molecular variance (AMOVA) revealed a superior genetic diversity within accessions than between accessions based on geographic origin cluster and NJ cluster. What's more, the fingerprints of 79 Carex species are established in this study. Different combinations of primer pairs can be used to identify multiple Carex at one time, which overcomes the difficulties of traditional identification methods. Conclusions: The transcriptomic analysis shed new light on the function categories from the annotated genes and will facilitate future gene functional studies. The genetic characteristics analysis indicated that gene flow was extensive among 79 Carex species. These markers can be used to investigate the evolutionary history of Carex and related species, as well as to serve as a guide in future breeding projects. [ABSTRACT FROM AUTHOR]

Thermally conductive and electrically insulating polyamide 6 (PA6) matrix quaternary composites were prepared by hot press molding and injection molding, respectively. The quaternary composites were composed of zero-dimensional aluminum oxide particle, one-dimensional silicon carbide whisker, two-dimensional flake graphite, and PA6 resin matrix. Morphology, structure, density, thermal conductivity, volume electrical resistivity, and tensile strength of two types of composites were characterized by scanning electron microscopy, X-ray diffractometer, thermal conductivity tester, high resistance micro-current tester, and tensile tester. The results showed that crystallinity, thermal conductivity, density, and tensile strength of hot press molding samples were superior to those of samples made by injection molding method. This is due to that hot press molding method can provide higher molding pressure and longer annealing time than injection molding. The mechanism could be explained that the performances of the composites were promoted by increasing molding pressure and annealing time. [ABSTRACT FROM AUTHOR]

Abstract A kind of silicone rubber (SR)/paraffin (Pa)@silicon dioxide (SiO 2) composite form-stable phase change material (PCM) was developed in this paper. Pa@SiO 2 was obtained by choosing Pa as PCM core microencapsulated in SiO 2 shell based on tetraethoxysilane (TEOS) and γ-aminopropyl triethoxysilane (APTES) as precursors, then Pa@SiO 2 microencapsules were embedded in SR matrix to fabricate SR/Pa@SiO 2 composites. The SiO 2 shell can provide a barrier for the melted Pa and meanwhile have reinforcing effect on SR as inorganic filler. The in-situ modification of SiO 2 shell using APTES owing to the amino groups can not only prevent agglomeration, but also increase interfacial bonding between Pa@SiO 2 with SR. The thermal and mechanical properties of the form-stable PCMs were characterized by differential scanning calorimetry (DSC) and mechanical tests. The results showed that the thermal and mechanical properties of SR/Pa@SiO 2 composites were better than those of SR/Pa and SR/Pa/SiO 2. Leakage test was conducted by heating the prepared composites over the melting temperature of Pa. The SR/Pa@SiO 2 composites were found as form-stable PCM with low leakage rate. The phase change latent heat of the SR/Pa@SiO 2 composites was up to 92.39 J g−1 and the composites can be used for thermal energy storage. Highlights • Developed a novel and efficient process for amino terminated paraffin (Pa)@SiO 2 microencapsules. • The Pa@SiO 2 microencapsules were embedded in silicone rubber (SR) matrix to fabricate SR/Pa@SiO 2 composites. • The SiO 2 shell can provide a barrier for the melted Pa and meanwhile have reinforcing effect on SR as inorganic filler. • The phase change latent heat of the SR/Pa@SiO 2 composites was up to 92.39 J g−1. [ABSTRACT FROM AUTHOR]

Abstract A series of paraffin/expanded graphite (EG) composites with various mass fraction were prepared. The microscopic geometry configuration, thermal conductivity and saturation sorption capacity of EG were obtained. In this paper, a method based on the experiments of EG pores was proposed for constructing geometric models. The geometric model constructed by this method has obvious anisotropy and has been employed in the calculation. Furthermore, the numerical results of thermal conductivity indicate anisotropy of a single-pore. Moreover, it had been observed by experiment that the anisotropy is weakened and transformed to isotropy in the process of combining geometric models with a large number of single pores. The final numerical results agree well with the experiments, which validates the precision and reliability of the proposed model. The increasement of thermal conductivity is also calculated and discussed during the phase change process of paraffin/EG. Highlights • A method of EG pores was proposed for constructing geometric models which has obvious anisotropy. • The SEM micrograph and saturation sorption capacity are employed to build the geometric models of EG pores. • Effective thermal conductivity during non-phase change process and the phase change process was calculated. • The numerical results agree well with the experiments. [ABSTRACT FROM AUTHOR]

A novel kind of paraffin-based shape-stable phase change materials (SSPCMs) was prepared by introducing paraffin into reduced graphene oxide (rGO)/carbon nanotubes (CNTs) aerogel via vacuum-assisted impregnation method. The effects of ratio of rGO to CNTs in 3D network structure on morphology, structure and property of paraffin-based SSPCMs were investigated. The rGO/CNTs 3D network structure with high thermal conductivity, served as thermally conductive skeleton together. In particular, CNTs was used as a secondary heat conductive filler, which could be well dispered in the SSPCMs to conduct heat synergistically. The SSPCMs exhibited high thermal conductivity and excellent shape-stability. And the thermal conductivity of SSPCMs can be regulated by adjusting the ratio of rGO to CNTs in aerogels. These results indicate that 3D rGO/CNTs aerogels have advantages as thermally conductive skeleton, and can endow phase transition materials with stable shape, so as to realize the application of phase change materials in the field of heat dissipation. [ABSTRACT FROM AUTHOR]

Graphene encapsulating paraffin (paraffin@graphene) microcapsules were fabricated by electrostatic interaction-based self-assembly. An aqueous dispersion of graphene sheets charged with cation, were mixed with a water-based emulsion containning negatively charged paraffin droplet spheres to form self-assembled microcapsules. The morphology of the microcapsules was characterized by scanning electron microscope (SEM). Results show that the microcapsules with a well-defined spherical structure were prepared successfully. Differential scanning calorimeter (DSC) results indicate that the phase change latent heat are all above 200 J g−1. With a graphene mass fraction of 8 wt%, the thermal conductivity of the fabricated composites can reach 1.73 W m−1 K−1. Attributing to the interlocking of graphene with each other, the microcapsules enable lock the paraffin in the shell thus successfully avoiding its leakage during phase change process. The prepared phase change microcapsules are expected to apply in energy storage field. [ABSTRACT FROM AUTHOR]

Paraffin, due to its linear chain and saturated hydrocarbons with low thermal conductivity, is difficult to transfer energy effectively. Using amphiphilicity of graphene oxide (GO), Pickering emulsion of paraffin@GO was obtained and then paraffin@graphene microencapsulated phase change materials (MEPCMs) were achieved by chemical reduction through adding hydrazine hydrate. Thermally conductive PCMs with segregated structure were constructed by hot compression of paraffin@graphene microencapsules. Scanning electronic microscopy, differential scanning calorimetry and thermal conductivity test were used to characterize microstructure and thermal properties of MEPCMs. Meanwhile, the effect of graphene on the phase change latent heat and phase transition temperature was investigated. Results indicated that GO did not react with paraffin during the process of chemical reduction and the obtained MEPCMs were regular spheres. These MEPCMs had paraffin content of 99% or even more. Graphene working as shell materials increased the phase change latent heat of paraffin from 227.6 to 232.4 J/g, without affecting the phase transition temperature. The hot-compress molding makes graphene shell form segregated structure with more thermal pathways, further enhancing thermal conductivity. The segregated-structure PCMs with high latent heat and thermal conductivity can be applied in energy storage field. [ABSTRACT FROM AUTHOR]

In the research of wide-range light-absorbing coordination polymers, to enhance intermolecular or intramolecular charge transfer (CT) and decrease the electron transition excitation energy, a dedicatedly designed novel pyridine diketopyrrolopyrrole (DPP) ligand with strong electron-withdrawing unit were introduced into the Zn, Cu and 1,4-benzenedicarboxylic acid (BDC) based coordination frameworks and porous coordination polymers DPP-Zn(BDC) and DPP-Cu(BDC) were obtained, respectively. By comparing study with physically-mixed samples DPP + Zn(BDC) and DPP + Cu(BDC), a fresh light-absorbing peak around 720 nm is observed and makes the samples exhibit a wide-range absorption in the range of 200–1400 nm and gives another experimental evidence for the research of charge transfer effect in naphthalenediimide-based metal-organic framework Zn 2 (NDC) 2 (DPNI) (J. Phys. Chem. Lett. 2013, 4, 453–458). The tremendous red-shift of absorbing onset wavelength could be ascribed to the enhanced intermolecular or intramolecular CT due to electron-withdrawing DPP ligands. At the mean time slow-photon effect is also discussed. The materials have been also characterized through powder XRD, FT-IR, SEM, XPS, solution-state spectra techniques and etc. This study underscores the importance of analyzing the extended structure for interpreting photophysical data based on the potential factors: CT, slow photon, or J-coupling. Moreover the research work might inspire the construction of light-responsive coordination polymers or metal-organic frameworks (MOFs) for charge or electron transfer. [ABSTRACT FROM AUTHOR]

Switchgrass is a photoperiod-sensitive energy grass suitable for growing in the marginal lands of China. We explored the effects of extended photoperiods of low-irradiance light (7 μmol·m-2·s-1, no effective photosynthesis) on the growth, the biomass dry weight, the biomass allocation, and, especially, the stem digestibility and cell wall characteristics of switchgrass. Two extended photoperiods (i.e., 18 and 24 h) were applied over Alamo. Extended light exposure (18 and 24 h) resulted in delayed heading and higher dry weights of vegetative organs (by 32.87 and 35.94%, respectively) at the expense of reducing the amount of sexual organs (by 40.05 and 50.87%, respectively). Compared to the control group (i.e., natural photoperiod), the yield of hexoses (% dry matter) in the stems after a direct enzymatic hydrolysis (DEH) treatment significantly increased (by 44.02 and 46.10%) for those groups irradiated during 18 and 24 h, respectively. Moreover, the yield of hexoses obtained via enzymatic hydrolysis increased after both basic (1% NaOH) and acid (1% H2SO4) pretreatments for the groups irradiated during 18 and 24 h. Additionally, low-irradiance light extension (LILE) significantly increased the content of non-structural carbohydrates (NSCs) while notably reducing the lignin content and the syringyl to guaiacyl (S/G) ratio. These structural changes were in part responsible for the observed improved stem digestibility. Remarkably, LILE significantly decreased the cellulose crystallinity index (CrI) of switchgrass by significantly increasing both the arabinose substitution degree in xylan and the content of ammonium oxalate-extractable uronic acids, both favoring cellulose digestibility. Despite this LILE technology is not applied to the cultivation of switchgrass on a large scale yet, we believe that the present work is important in that it reveals important relationships between extended day length irradiations and biomass production and quality. Additionally, this study paves the way for improving biomass production and digestibility via genetic modification of day length sensitive transcription factors or key structural genes in switchgrass leaves. [ABSTRACT FROM AUTHOR]

The surface characterization and electrostatic property of Hybrid Pennisetum (HP) after alkaline sulfite pretreatment were explored for enhanced enzymatic hydrolysability. The O/C ratio in HP increased from 0.34 to 0.60, and C1 concentration decreased from 62.5% to 31.6%, indicating that alkaline sulfite pretreatment caused poorer lignin but richer carbohydrate on HP surface. Zeta potential and sulfur element analysis indicated that more enzymes would preferably adsorb on the carbohydrate surface of alkaline sulfite pretreated HP because the lignin was sulfonated, which facilitated the decrease of non-productive adsorption. Glucose yield of alkaline sulfite pretreated HP reached to 100% by synergistic action of cellulase and xylanase in the hydrolysis, which was significantly higher than that of NaOH pretreated, and the concentration of glucose released was 1.52 times higher. The results suggested that alkaline sulfite pretreatment had potential for improving the HP hydrolysability, and the surface characterization and electrostatic property facilitated the enzymatic digestibility. [ABSTRACT FROM AUTHOR]

Two kinds of carbon aerogels, graphene aerogels (GA) and carbon nanotubes-graphene aerogels (CGA), were prepared by modified hydrothermal method. The form-stable phase change materials (PCMs) were fabricated by adsorbing paraffin into carbon aerogels. Morphology, structure, form stability and thermal property were characterized by scanning electron microscope (SEM),in situX-ray diffraction (in situXRD) and differential scanning calorimeter (DSC). The results showed that GA presented wrinkled surface textures with curling edges, and carbon nanotubes (CNTs) were interspersed or attached to GA sheets. The phase transition temperature and the phase change enthalpy of the GA/paraffin PCM composite were 48.7 °C and 223.2 J/g, respectively. Thermal and mechanical properties of PCM composites achieved a qualitative leap with the adding of carbon aerogels. The PCM composites had a thermal conductivity of about 2.182 W/m K at the carbon aerogels loading fraction of 2 wt%. The form-stable PCM composites with high thermal conductivity and high enthalpy could be promising for thermal energy storage applications in construction field. [ABSTRACT FROM PUBLISHER]

Novel microencapsulated phase change materials (MEPCMs) with high encapsulation capacity and enhanced leakage-prevention performance were prepared by in situ polymerization. For these MEPCMs, paraffin and melamine-formaldehyde resin (MF) are respectively used as core and shell, and graphene oxide (GO) nanosheets, which can be seen as extra protective screen, are situated at the interface between the core and the shell. Effects of GO on morphology, microstructure and properties of MEPCMs were characterized by scanning electronic microscopy (SEM), laser diffraction particle analyzer, atomic force microscopy (AFM), Fourier transformation infrared spectroscopy (FTIR), X-ray diffractometry (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TG) and paraffin leakage rate test. The results show that the fabricated MEPCMs with GO nanosheets have gradual increasing average diameters from 6.32 to 15.89 μm with an increase content of GO, while the size of MEPCMs without GO is 5.63 μm. When the time of leakage rate test is 50 h, the MEPCMs prepared with 0.5 mg/mL GO aqueous dispersion have considerably high encapsulation ratio of 93.9 wt.%, and the leakage rate is reduced by 93.1% compared with those without GO. The high encapsulation capacity and enhanced leakage-prevention performance might be highly attractive for the application of MEPCMs. [ABSTRACT FROM AUTHOR]

Switchgrass ( Panicum virgatum L.) has been developed into a major herbaceous bioenergy crop for the production of cellulosic biofuels in North America and many counties in European. As cultivar selection has a major impact on the ultimate biomass productivity, we evaluated the adaptability and yield potential of 12 switchgrass cultivars including both upland and lowland ecotypes from 2010 to 2013 in the Beijing region, Northern China. Plant height was measured after anthesis, but phytomer number and tiller density were investigated at harvest. One single autumn harvest was carried out each year and biomass yields were determined. It was found that the lowland cultivars ‘Alamo’, ‘Kanlow’ and ‘NewYork’ produced the most biomass for their better performances in number of phytomers per tiller and mass per phytomer, though upland cultivars had higher tiller density. ‘Cave-in-rock’ and ‘Trailblazer’ had better biomass production among the upland cultivars and they were also recommended for planting together with lowland ones for their excellent cold tolerance in this region. [ABSTRACT FROM AUTHOR]

Pennisetum species are widely used as ornamental grasses and may be a valuable genetic resource for their breeding to broaden its genetic basis. At present, new ornamental Pennisetum cultivars are primarily bred via somaclone, which increases the number of variants. It is difficult to estimate whether the suspected variants are authentic in genetic features by morphological traits because of their many limitations. Moreover, although the phylogenetic classification of the Pennisetum genus has been approved in some morphological and cytological studies, genetic evidence is lacking. In the present study, we developed 15 specific simple sequence repeat (SSR) markers with a large amount of polymorphisms and strong distinguishing abilities for Pennisetum ornamental grasses using magnetic bead enrichment. These markers, together with the other 11 reported polymorphic SSRs, were further used for the identification of a broad collection of 55 Pennisetum samples, including nine original taxa and 46 suspected variants. After comparing the genetic characteristics between each variant and its corresponding original taxon, we verified 20 suspected variants that possess the potential to become new, commercially desirable cultivars. The nine original taxa and the 20 verified variants were identified based on the polymorphisms of six core loci, and unique molecular identities with 15 denary digits for each taxon were further established. The rationality of the traditional phylogenetic classification system of the Pennisetum genus was further verified using 147 polymorphic alleles. The present study promotes the protection, registration, breeding, and international communication of Pennisetum ornamental grasses. [ABSTRACT FROM AUTHOR]

A novel composites based on ethylene-propylene-diene monomer (EPDM) rubber for gamma shielding were prepared by using carbon blacks (CB) and ball milled PbWO (PWO) powder as fillers. The microstructure of ball milled PWO powder which has a uniform morphology in these composites was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD). The mechanical and shielding tests were performed to determine mechanical and radiation attenuation properties, respectively. The results show these materials exhibit excellent mechanical and radiation-resistance properties. [ABSTRACT FROM AUTHOR]

1-ethyl-3-methylimidazolium acetate ([EMIM] AC) pretreatment at moderate temperatures (60 °C and 75 °C) was evaluated for improving hydrolysability of Chinese pennisetum, a leading candidate as an energy crop, for bioethanol production. The pretreatment caused slight carbohydrate and lignin loss but significantly changed the material physicochemical characters, such as crystallinity and surface structure. Both changes exhibited positive effects on improving the enzymatic digestibility of the Chinese pennisetum. It was observed that approximately 90% of the cellulose and 50% of the xylan in the Chinese pennisetum after pretreatment at 75 °C were converted to fermentable monosaccharides by the combined cellulases and endo-xylanase. The results suggested that Chinese pennisetum could be effectively pretreated with ([EMIM] AC) pretreatment at moderate temperatures, and the high hydrolysis yield of fermentable sugars from pretreated Chinese pennisetum could be achieved by the synergistic action of accessory xylanase in enzymatic hydrolysis by cellulases. [ABSTRACT FROM AUTHOR]

Thermally conductive form-stable phase change materials (FSPCMs) were prepared by using ethylene-vinyl acetate (EVA), paraffin, expanded graphite (EG) and carbon fiber (CF) as row materials. Two-dimensional EG and one-dimensional CF were used as thermally conductive fillers. Paraffin and EVA were phase change material (PCM) and supporting material, respectively. Differential scanning calorimetry (DSC) and leakage rate testing results indicated that FSPCMs owned the melting temperature of 45.63 °C and the latent heat of 167.4 J/g. The prepared material had a small leakage rate which was less than 2%. Scanning electron microscope (SEM) results shown that EG and CF possessed excellent compatibility in FSPCMs. In-situ X-ray diffraction (XRD) tests demonstrated that the crystal behaviors of paraffin and EVA were changed with the phase transformation. Thermal conductivity results shown that thermal conductivity of FSPCMs in horizontal orientation was higher than that in longitudinal orientation. EG and CF have synergistic enhancement to thermal conductivity of FSPCMs. [ABSTRACT FROM AUTHOR]

The effects of aqueous ammonia pretreatment on structural properties and hydrolysabilities of Chinese Pennisetum and Hybrid Pennisetum were investigated. Aqueous ammonia pretreatment increased cellulose crystallinities and hydrolysabilities of Chinese Pennisetum and Hybrid Pennisetum. Compared with Chinese Pennisetum, Hybrid Pennisetum showed better enzymatic digestibility. Xylanase supplementation was more effective than the increase of cellulase loadings in the hydrolysis of aqueous ammonia pretreated Chinese Pennisetum and Hybrid Pennisetum. After supplementation of 2 mg of xylanase/g dry matter to 5 FPU of cellulases/g dry matter, the hydrolysis yields of cellulose of aqueous ammonia pretreated Chinese Pennisetum and Hybrid Pennisetum were 92.3–95.4%, and the hydrolysis yields of xylan were 86.9–94.2%. High hydrolysability and low dosage of enzyme loadings together with the advantages of high yield and widely distribution demonstrated the potential of Chinese Pennisetum and Hybrid Pennisetum for the production of platform sugars. [ABSTRACT FROM AUTHOR]

So far no successful artificial hybridizations among ornamental grasses in the Pennisetum Rich. (Poaceae) genus that are widely applied in landscape design have been reported because of unclear genetic backgrounds and uncertain evolutionary and genetic relationships among one another, severely restricting the number of ornamental cultivars and their gardening utility. The present study aims to reveal genetic backgrounds and relationships for nine Pennisetum ornamental grasses via karyotype diversity analysis; discuss the morphological classification system proposed in previous studies on morphological, chromosomal and genomic levels; and verify the chromosomal evolution of Pennisetum genus using the combined karyotypic and genomic data. Our results indicated that (1) traditional morphological classification system of Pennisetum genus is reasonable, both from the morphological and cytological points of view; (2) hybridization among Pennisetum alopecuroides , P. alopecuroides ‘Little Bunny’, P. alopecuroides ‘Moudry’ and P. orientale may be easier to obtain a hit; (3) chromosomes with lower basic chromosome number are more asymmetry than those chromosomes with higher basic chromosome number, and taxa with different basic chromosome numbers may have experienced different way of speciation; and (4) chromosomal evolution in Pennisetum genus progressed from a symmetrical to an asymmetrical order in the course of evolution; and the structure of the genome of Pennisetum species involved in the reduction of chromosome number and an increase in their sizes and DNA contents. The present study guides the breeding programs and genome projects of Pennisetum ornamental grasses practically, and provides references for the evolutionary studies on Pennisetum genus theoretically. [ABSTRACT FROM AUTHOR]

In this study, tassels of Cave-in-Rock (upland) and Alamo (lowland) were removed at or near tassel emergence to explore its effects on biomass production and quality. Tassel-removed (TR) Cave-in-Rock and Alamo both exhibited a significant (P<0.05) increase in plant heights (not including tassel length), tiller number, and aboveground biomass dry weight (10% and 12%, 30% and 13%, 13% and 18%, respectively by variety) compared to a control (CK) treatment. Notably, total sugar yields of TR Cave-in-Rock and Alamo stems increased significantly (P<0.05 or 0.01) by 19% and 19%, 21% and 14%, 52% and 18%, respectively by variety, compared to those of control switchgrass under 3 treatments by direct enzymatic hydrolysis (DEH), enzymatic hydrolysis after 1% NaOH pretreatment (EHAL) and enzymatic hydrolysis after 1% H2SO4 pretreatment (EHAC). These differences were mainly due to significantly (P<0.05 or 0.01) higher cellulose content, lower cellulose crystallinity indexes (CrI) caused by higher arabinose (Ara) substitution in xylans, and lower S/G ratio in lignin. However, the increases of nitrogen (N) and sulphur (S) concentration negatively affects the combustion quality of switchgrass aboveground biomass. This work provides information for increasing biomass production and quality in switchgrass and also facilitates the inhibition of gene dispersal of switchgrass in China. [ABSTRACT FROM AUTHOR]

Abstract: Biological soil crusts (BSCs) are extensively developed and commonly regarded as a kind of vegetation in desertification areas around the world. The natural recovery process of BSCs after disturbance and their long-term impacts on the soil water conditions are important but not well understood. In order to provide more insights into this problem, we set up two treatments including BSCs (natural BSCs without disturbance) and disturbed BSCs (the top 30mm of surface soil, including the BSC layer, was severely disturbed and completely removed) in a semi-arid environment on the Loess Plateau of China. Over the succeeding years, the natural recovery process of BSCs was qualitatively described and the soil water content at 0–90cm depth of the two treatments was consecutively monitored. The results showed the following: (1) it is possible to recover natural moss-dominated BSCs after severe disturbance under natural conditions, and the recovery process to BSC full-coverage took approximately three years; (2) the BSC disturbance greatly decreased soil water content by up to 18% and the effects gradually weakened with time; (3) the BSC disturbance decreased surface soil water content (0–70cm) by up to 24% but increased deep soil water content (80–90cm) by up to 13%; and (4) the BSC disturbance decreased soil water storage at 0–90cm by 7.8mm, 4.4mm, 8.0mm, and 4.9mm in the second, third, fourth, and seventh years, respectively. We concluded that the BSC disturbance degraded soil water conditions in the three to four years following the disturbance. Therefore, the artificial destruction of natural moss-dominated BSCs in a semi-arid region on the Loess Plateau of China should not be recommended as a land management practice for the improvement of soil water conditions. [Copyright &y& Elsevier]

Reference evapotranspiration (ET0) is the basic parameter for the vegetation evapotranspiration calculation, the regional water balance analysis, and the water resources management. The ET0 models have different adaptability for different regions because of the difference in meteorological conditions among regions. Measurement using lysimeter is the classical method for ET0 model evaluation in European and American areas, but is seldom used in China, and no research reported for North China. Assessment of four ET0 models, Penman-Monteith (FAO-56), Hargreaves-Samani, Priestley-Taylor, and Penman-van Bavel were conducted in Beijing using tall fescue (Festuca arundinacea L.) turf evapotranspiration measurement by auto-weighing lysimeter during the growing season (April - October) of 2012. Two lysimeters were established in cold-season grass tall fescue for standard ET0. The weather station (Dynamet, Dynamax Co. Ltd.) was set up in the experiment site to measure and record automatically the meteorological data of air temperature, air relative humidity, solar radiation and wind speed at 2 meter height above ground for the ET0 calculation by the models. The linear regression and the root-mean-square error (RMSE) and the index of agreement (d) were used for assessing the prediction accuracy of the different models. The results indicated that the solar radiation showed a linear relationship (R2=0.95, p=2.72×10-7) with the monthly reference evapotranspiration, indicating that the solar radiation energy was the main force to drive water from the vegetation to the atmosphere in SPAC system. The accuracy of the models declined with the time scale. The models showed different deviations in ET0 calculation because of the different parameters input. The monthly ET0 was underestimated by Priestley-Taylor model but overestimated by Penman-Monteith, Hargreaves-Samani and Penman-van Bavel models. For the daily ET0, Hargreaves-Samani and Penman-van Bavel models had a slight overestimation with the rate of 1.0167 and 1.0526, respectively, but Penman-Monteith and Priestley-Taylor models had an underestimation with the rate of 0.8204 and 0.7593, respectively. For the timely ET0, Priestley-Taylor had the lowest value among the models, while other models resulted in different values under different weather conditions. The overall estimation for the ET0 at the monthly, daily, and hourly scales showed that the Penman-van Bavel equation was the most precise method for calculating reference evapotranspiration, with a RMSE of 0.63 mm/d and a d-index of 0.96 (monthly), a RMSE of 1.43 mm/d and a d-index of 0.89 (daily), a RMSE of 0.087 mm/h and a d-index of 0.87 (hourly). The calculating accuracy of Penman-Monteith model was a little lower than that of Penman-van Bavel with a d-index of 0.73-0.93. [ABSTRACT FROM AUTHOR]

• ZjNYC1 was localized in the chloroplasts and interacts with ZjNOL in vivo. • Overexpression of ZjNYC1 accelerated the degradation of chlorophyll, and promoted senescence. • Integrated analysis of JIP-test and RNA-seq revealed ZjNYC1 negatively affected the integrity and functionality of photosystem. Chlorophyll plays essential roles in photosynthesis and its degradation should be regulated precisely. Chlorophyll b reductase encoded by the gene NYC1 is responsible for catalyzing chlorophyll b degradation and maintaining the stability of photosystems. Although NYC1s have been characterized in many plants, their function in the photosynthetic machinery and the underlying regulatory mechanisms at the whole transcriptome level remain elusive. In this study, the ZjNYC1 gene was cloned from the important warm-season turfgrass Zoysia japonica. Analysis of the subcellular localization revealed that ZjNYC1 was localized in the chloroplasts, and results of the bimolecular fluorescence complementation (BiFC) assay indicated that ZjNYC1 could interact in vivo with the NYC1-like protein, ZjNOL. Overexpression of ZjNYC1 accelerated the degradation of chlorophyll, and promoted senescence with accumulation of ABA and reactive oxygen species (ROS) in Arabidopsis. Expression of ZjNYC1 rescued the stay-green phenotype of the Arabidopsis nyc1 mutant. An integrated analysis of chlorophyll fluorescence test (JIP-test) and RNA-sequencing revealed that ZjNYC1 negatively affected the efficiency of the PSII, PSI, and the intersystem electron transport chain. Furthermore, the Calvin cycle and photorespiration were suppressed, but ABA and ethylene synthesis and signal transduction pathways were activated in the transgenic lines. Collectively, these results demonstrated that ZjNYC1 plays important roles in accelerating chlorophyll degradation and senescence, and caused negative affect on the integrity and functionality of the photosystems. [ABSTRACT FROM AUTHOR]

Abstract: Soil and water loss from sloping croplands is a major environmental problem that is attracting widespread attention across the world. Various soil protection techniques, such as terrace and contour tillage, have been used in recent years with limited results. Grass hedges and micro-basins are effective for reducing soil and water loss on sloping croplands in tropical and subtropical regions. However, grass hedges and micro-basins have not been adequately evaluated in temperate climatic regions (for example, in Northern China); thus, they would not be readily accepted by local farmers. In this study, the soil and water conservation effects of two native grass hedges (Pennisetum alopecuroides (Linn.) Spreng. and Arundinella hirta (Thunb.) C. Tanaka) and micro-basins were studied in the temperate regions of Northern China using simulated rainfall. The experiment included two parts: trial I and trial II. In trial I, three independent variables, including grass hedges (the Arundinella, the Pennisetum, and the control), slope gradient (5%, 10%, 15%, and 20%), and rainfall intensity (36mmh−1 and 63mmh−1) were considered. In trial II, the independent variables were changed to soil protective practice (the grass hedges, the micro-basins, and the control), slope gradient (5%, 10%, 15%, and 20%), and rainfall intensity (36mmh−1 and 63mm h−1). Next, the Vegetative Filter Strip Modeling System (VFSMOD) model was introduced to simulate the runoff and sediment intercepted by the grass hedges. Lastly, cost analysis was conducted based on the cost of labor and seeds or plants for the grass hedge and micro-basin trials. The use of Pennisetum hedges decreased the mean runoff and soil loss by 56% and 81%, the Arundinella hedges decreased the runoff and soil loss by 55% and 67%, and the micro-basins decreased the runoff and soil loss by 70% and 62%, respectively. Moreover, the runoff and sediment that passed through the grass hedges can be reasonably simulated with the VFSMOD model (the relative errors for runoff and sediment content were −19.1% and −14.6%, and the Nash–Sutcliffe efficiencies for runoff and sediment content were 0.91 and 0.85, respectively). Conversely, the grass hedges occupied 9% of the farmland in the study area and cost 5864 CNY per hectare. In addition, the micro-basins occupied 7% of the farmland and cost 3000 CNY per hectare. These results imply that grass hedges and micro-basins are cost-effective when compared with terraces, which cost more than 7401 CNY per hectare and typically occupy 18% of farmland. Overall, we conclude that the soil protective practices of using grass hedges or micro-basins are effective and efficient for decreasing soil and water loss on sloping croplands in temperate regions. Thus, these practices should be intensively recommended and used widely in similar climatic regions. [Copyright &y& Elsevier]

A strategy to combat the adverse effects of urbanization involves the installation of green roofs under different climatic conditions. The design and maintenance of green roof systems need to be tailored to the local climate. However, there is a scarcity of reports on the performance of plants under temperate monsoonal climatic conditions. This study follows the growth pattern of 28 species (18 non-succulent forbs and 10 succulents) grown at three substrate depths (10, 15, and 20 cm) over three years on an unirrigated extensive green roof, located in Beijing, China. The results of this study revealed that sustainable extensive green roof was realizable without irrigation in Beijing. In terms of plant adaptive strategies, the most successful plants in this study were the stress-tolerant species, followed by the ruderal species. While deeper substrate could facilitate the survival and performance of plants, substrate moisture content was more significant for the survival of plants in the dry and cold winter in Beijing. This study recommended the use of a substrate depth, which was at least 15 cm deep for unirrigated green roofs in Beijing. Unlabelled Image • A green roof research was conducted in a temperate monsoonal climate. • Stress-tolera\nt species and ruderal species performed well on unirrigated green roofs. • Substrate moisture content was vital for the plant survival in dry and cold winters. • Substrate depth should be at least 15 cm for unirrigated green roofs in Beijing. [ABSTRACT FROM AUTHOR]

Background: Carex L., a grass genus commonly known as sedges, is distributed worldwide and contributes constructively to turf management, forage production, and ecological conservation. The development of next-generation sequencing (NGS) technologies has considerably improved our understanding of transcriptome complexity of Carex L. and provided a valuable genetic reference. However, the current transcriptome is not satisfactory mainly because of the enormous difficulty in obtaining full-length transcripts. Results: In this study, we employed PacBio single-molecule long-read sequencing (SMRT) technology for whole-transcriptome profiling in Carex breviculmis. We generated 60,353 high-confidence non-redundant transcripts with an average length of 2302-bp. A total of 3588 alternative splicing events, and 1273 long non-coding RNAs were identified. Furthermore, 40,347 complete coding sequences were predicted, providing an informative reference transcriptome. In addition, the transcriptional regulation mechanism of C. breviculmis in response to shade stress was further explored by mapping the NGS data to the reference transcriptome constructed by SMRT sequencing. Conclusions: This study provided a full-length reference transcriptome of C. breviculmis using the SMRT sequencing method for the first time. The transcriptome atlas obtained will not only facilitate future functional genomics studies but also pave the way for further selective and genic engineering breeding projects for C. breviculmis. [ABSTRACT FROM AUTHOR]

Background: Carex L., a grass genus commonly known as sedges, is distributed worldwide and contributes constructively to turf management, forage production, and ecological conservation. The development of next-generation sequencing (NGS) technologies has considerably improved our understanding of transcriptome complexity of Carex L. and provided a valuable genetic reference. However, the current transcriptome is not satisfactory mainly because of the enormous difficulty in obtaining full-length transcripts. Results: In this study, we employed PacBio single-molecule long-read sequencing (SMRT) technology for whole-transcriptome profiling in Carex breviculmis. We generated 60,353 high-confidence non-redundant transcripts with an average length of 2302-bp. A total of 3588 alternative splicing events, and 1273 long non-coding RNAs were identified. Furthermore, 40,347 complete coding sequences were predicted, providing an informative reference transcriptome. In addition, the transcriptional regulation mechanism of C. breviculmis in response to shade stress was further explored by mapping the NGS data to the reference transcriptome constructed by SMRT sequencing. Conclusions: This study provided a full-length reference transcriptome of C. breviculmis using the SMRT sequencing method for the first time. The transcriptome atlas obtained will not only facilitate future functional genomics studies but also pave the way for further selective and genic engineering breeding projects for C. breviculmis. [ABSTRACT FROM AUTHOR]

In this study, silica aerogel microspheres were prepared through sol–gel method with tetraethyl orthosilicate as the silicon source. Thermal insulation coatings were prepared by mixing silica aerogel and acrylic emulsion. The relationships between the thermal conductivity and volume fractions, densities, sizes, and interfaces of silica aerogel microspheres were investigated through scanning electron microscopy and thermal conductivity analysis. The thermal insulation mechanism of composite coating was discussed in detail. Results showed that the aggregations prevented the decrease of thermal conductivity in the coating when the volume fraction of silica aerogel microspheres was lower than 30 %. However, the pores in the coating reduced the thermal conductivity when the volume fraction was higher than 30 %. The porosity of silica aerogel increased with the declining density, which improved the thermal insulation performance of silica aerogel and reduced the thermal conductivity of the coating. The thermal conductivity of the coating with large microspheres was lower than that with small microspheres at low volume fractions. However, the thermal conductivity of the coating with small silica aerogel microspheres was low because of their large interfacial thermal resistance at high volume fractions. Wetting agents were beneficial in improving the compatibility of hydrophobic aerogel microspheres and polymer, improving the volume fractions of silica aerogel microspheres in the coating, and reducing the thermal conductivity of the coating. [ABSTRACT FROM AUTHOR]

Highlights from the article: B Background: b Neuro-developmental disorders (NDDs) are common but severe pediatric diseases affecting a child's brain development and growth. Early intervention significantly improves patient's neuropsychological function, and early diagnosis is the key step for early intervention. Meanwhile, the genetic variants contributing to pediatric NDDs are complex including copy number variant (CNV) or single nucleotide variant (SNV), balanced or imbalanced chromosomal rearrangement, gene-disruption rearrangement or noncoding-region rearrangement, somatic/mosaic or germline variant.

Polyploidization is regularly regarded as an important tool for the generation of innovative germplasm resources and plant breeding. In this study, autopolyploid switchgrass lines were produced from calli derived from immature inflorescence of tetraploid switchgrass ( Panicum virgatum L.), both lowland cv. Alamo and Kanlow, and upland cv. Ranlow, through colchicine treatments. Ploidy levels of plantlets regenerated from the calli were screened by flow cytometry. Growth characteristics of the tetraploid and octoploid switchgrass cultivars were further investigated in a field experiment. Compared with the tetraploid plants of the three switchgrass cultivars, the corresponding octoploid plants showed significant reduction in plant height, number of tillers per plant and fresh matter, but an increase in leaf length and width. [ABSTRACT FROM AUTHOR]