Search

The utilization of coal gasification slag currently has become a central issue in both coal and environmental science. Coal gasification slag has been used as raw materials to synthesize the porous materials. However, for the synthesis of these materials, the high temperature was needed, and not all coal gasification slag could be converted to. This work developed a new strategy to graded synthesis of MCM-41 and carbon/zeolite composite from coal gasification fine residue (CGFR) under mild conditions. By this way, graded preparations of valuable porous materials from CGFR could realize the efficient conversion and utilization of CGFR. The synthesized MCM-41 exhibited highly ordering feature with hexagonal arrays and the straight 1D channels. The MCM-41 zeolite had large surface areas and narrow pore diameter distribution. The different synthesis conditions of MCM-41 from CGFR, such as acidification process, gel pH, crystallization temperature and crystallization time were discussed. As to the synthesized carbon/zeolite composite, it presented a P-type zeolite with the flower-like shape on the substrate of carbon with low degree graphitization. The carbon/zeolite composite had the total specific surface area of 189.27 m2 g−1 and exhibited thermal stability below 300 °C. Meanwhile, the synthesis of carbon/zeolite composite with different alkali dissolution time was also investigated. Besides, the adsorption experiments of toxic crystal violet in water indicated that these two porous materials had potential applications in adsorption and removal of harmful pollutants. • MCM-41 and carbon/zeolite composite were staged synthesized from CGFR. • MCM-41 with large BET of 1013 m2 g−1 exhibited five characteristics diffraction peaks. • The carbon/zeolite composite with BET of 189.27 m2 g−1 had good thermal stability. • MCM-41 and carbon/zeolite composite had good performance for crystal violet remove. [ABSTRACT FROM AUTHOR]

During early embryogenesis, mammary glands are derived from surface ectoderm and their morphogenesis is controlled by mammary stem cells (MaSCs) and epithelial-mesenchymal transition (EMT). Mammary anlagen stage (E13.5–15.5) is an important stage for fetal mice to achieve EMT dependent mammary morphogenesis. And the characteristics of mammary anlagen repopulating cell population (MaRC) should be identified for understanding its stemness at earlier embryonic stage. Here we quantify and characterize MaSCs proportion at mammary anlagen stage. Compared with adult mouse mammary gland, our data revealed that E14.5 mammary anlagen exhibit higher stem cell activities. Then we purified mammary anlagen cell populations depending on the expression levels of CD24 and CD49f in mouse mammary anlagen, and identified an unique MaRC population (Lin-CD24medCD49f+) by real-time PCR, transplantation and mammosphere forming assays. In addition, by comparing with adult MaSC (Lin-CD24+CD29hi) and differentiated mammary anlagen cells, we find that E14.5 mouse MaRC population exhibit gene expression programs related to mesenchymal properties. To further identify the cell types of E14.5 mouse MaRC population, the expressions of K8, K14, K18, e-cadherin, n-cadherin and vimentin in mammary anlagen Lin-CD24medCD49f + cells were detected by immunofluorescence assay. These findings verified that the undifferentiated E14.5 mouse MaRC population is a heterogeneous population with mesenchymal property, which is associated with cell stemness and mammary duct morphogenesis. [ABSTRACT FROM AUTHOR]

• Identifying common responses of microbial functional genes to elevated CO 2 (eCO 2) • Nitrogen (N) fixation, carbon fixation and decomposition genes increased under eCO 2. • Plant biomass, soil carbon (C) decomposition and soil moisture increased under eCO 2. • Potential molecular biomarkers of global change for predicting ecosystem functions. • Increasing soil C, soil N and net primary productivity in future eCO 2 environments. Atmospheric CO 2 concentration is increasing, largely due to anthropogenic activities. Previous studies of individual free-air CO 2 enrichment (FACE) experimental sites have shown significant impacts of elevated CO 2 (eCO 2) on soil microbial communities; however, no common microbial response patterns have yet emerged, challenging our ability to predict ecosystem functioning and sustainability in the future eCO 2 environment. Here we analyzed 66 soil microbial communities from five FACE sites, and showed common microbial response patterns to eCO 2 , especially for key functional genes involved in carbon and nitrogen fixation (e.g., pcc/acc for carbon fixation, nifH for nitrogen fixation), carbon decomposition (e.g., amyA and pulA for labile carbon decomposition, mnp and lcc for recalcitrant carbon decomposition), and greenhouse gas emissions (e.g., mcrA for methane production, norB for nitrous oxide production) across five FACE sites. Also, the relative abundance of those key genes was generally increased and directionally associated with increased biomass, soil carbon decomposition, and soil moisture. In addition, a further literature survey of more disparate FACE experimental sites indicated increased biomass, soil carbon decay, nitrogen fixation, methane and nitrous oxide emissions, plant and soil carbon and nitrogen under eCO 2. A conceptual framework was developed to link commonly responsive functional genes with ecosystem processes, such as pcc/acc vs. soil carbon storage , amyA/pulA/mnp/lcc vs. soil carbon decomposition, and nifH vs. nitrogen availability, suggesting that such common responses of microbial functional genes may have the potential to predict ecosystem functioning and sustainability in the future eCO 2 environment. [ABSTRACT FROM AUTHOR]

Excitation-emission matrix (EEM) fluorescence spectroscopy is a powerful tool for the characterization of dissolved organic matter (DOM) in wastewater systems. It is of particular value if its utility could be extended by connecting the spectral features to hydrophobicity, one of the fundamental physicochemical properties of DOM. In this study, we employed a DAX-8 resin column to fractionate the hydrophobic/philic components of DOM and determine the relative degree of hydrophobicity by adjusting the critical retention factor (k' cr , the ratio of treated water sample volume to column volume). A higher k' cr would result in a higher hydrophobicity of the column effluent. At different k' cr values (5, 10, 25, 50, 100, and 200), the EEM characteristics of the obtained DOM components were inspected, including overall properties (average fluorescence per total organic carbon and UV absorbance), regional properties (fluorescence regional integration (FRI) and its secondary parameters), and energy-related properties (energy level of the excited states, Stokes shift for relaxation of the excited states, and fluorescence lifetime). In case studies of a wastewater membrane bioreactor and an oxidation ditch, plenty of the EEM properties varied significantly with log k' cr (r > 0.9, p < 0.05). The average fluorescence per UV absorbance (reflecting quantum yield), fluorescence proportion at Stokes shift ≥ 1.1 μm−1, and some secondary FRI parameters presented the best linear fitting with log k' cr , suggesting a smooth variation of the π-conjugated structures with the relative degree of DOM hydrophobicity. This may help to further understand the relationship between EEM fingerprints and DOM hydrophobicity. Image 1 • Fluorescence EEM fingerprints vary with the relative degree of DOM hydrophobicity. • Critical retention factor (k' cr) of DAX column regulates the relative hydrophobicity. • A set of intensity, wavelength and energy parameters are explored from EEM spectra. • Fluorescence quantum yield, excitation energy, and Stokes shift correlate with k' cr. • Some EEM parameters exhibit good linear regression with log k' cr , with R2 > 0.95. [ABSTRACT FROM AUTHOR]

Systemic lupus erythematosus (SLE) is a complex multi-system autoimmune disease. Detection of anti-nuclear antibodies (ANA) is fundamental for the diagnosis of SLE. In the present study, we found that the level of core fucosylation catalyzed by α1,6-fucosyltransferase (Fut8) is markedly up-regulated on immunoglobulin G (IgG) in the sera of SLE patients detected by Aspergillus oryzae lectin (AOL) blot. In sandwich Dot enzyme-linked immunosorbent assay (Dot-ELISA), the core fucosylation level was also found significantly increased in the sera from SLE patients with a higher ANA titer. To establish a rapid and sensitive laboratory test for the diagnosis of SLE, we prokaryotically expressed AOL and C3-D1-C3-D2-C3 of protein G (SpG3), and generate AOL-conjugated colloid gold immunochromatographic strips (ICS). The detection limit of core fucosylated IgG was 10 μg/mL for AOL-conjugated colloid gold ICS. As well as indirect immunofluorescence, the AOL-conjugated colloid gold ICS showed reliable results in the serum of 39 SLE patients. Our results indicated that the AOL-conjugated colloid gold ICS could serve as a rapid test for the detection of ANA and suspected cases of SLE. [ABSTRACT FROM AUTHOR]

The production of graded cubic boron nitride (cBN) tool materials starting with cBN-TiC-Al-Co mixture and having a three-layer symmetrical graded structure were obtained by high temperature high pressure method. In the first part, the design model which proposed a component gradient of cBN varied from 4 vol% to 10 vol% accompanied with Al and Co varied from 2 vol% to 5 vol% between the surface and interior was presented. Afterwards, the rationality of the graded structures were verified by the thermal residual stress analysis in the composites. In the second part, the relationships between the mechanical properties and the thickness ratio, sintering temperature, holding time as well as the component gradient were investigated. The significant gradients of the elements of Al and Co were detected in the graded cBN composites. When the temperature converted from 1350 °C to 1550 °C, the liquid phase sintering and reaction process were confirmed, leading to the formation of AlN, AlB 2 and Co 2 B. The excellent samples with a thickness ratio of 0.3 and a cBN gradient of 6 vol% acquired a homogeneous microstructure with no obvious defects under a pressure of 5.8 GPa at 1500 °Cfor 10 min. The optimum mechanical properties were achieved a flexural strength of 710 MPa and a hardness of 36.5 GPa, which was higher than that of the monolithic material with a cBN content of 80 vol%. The crack deflection and bridging played the main role in the toughening mechanism, reflecting a significant contribution of the residual stress to the mechanical properties. • The graded structure was introduced to the cBN cutting tool material to improve the strength and toughness, acquiring a flexural strength of 710 MPa and a hardness of 36.5 GPa. • The residual stress induced by the graded structure was the main toughening and strengthening mechanism, characterized by crack bridging and deflection. [ABSTRACT FROM AUTHOR]

• More susceptible topsoil temperature to warming in alpine steppe than swamp meadow. • Greater thermal changes in alpine steppe than swamp meadow, linked to soil moisture. • Warming postponed frozen onset and reduced frozen days in alpine steppe. • Active layer in alpine steppe distinctly thickened by warming compared to control. Soil thermal regime in permafrost regions is sensitive to climate change and may cause vast ecological consequences under future warming scenarios. However, there still lacks a systematic evaluation on the effect of warming on soil thermodynamics in the different ecosystems of permafrost regions. This study investigated the alterations of soil thermodynamics in alpine swamp meadow and alpine steppe under experimental warming by open-top chambers in permafrost regions of the central Tibetan Plateau. The results showed that air temperature increased significantly with an annual mean increase of 1.4 °C under warming. Compared to alpine swamp meadow, soil thermodynamics represented by soil temperature, soil thermal parameters, soil freeze-thaw process and active layer thickness in alpine steppe was more susceptible to warming. Specifically, soil temperature at 5–40 cm depths increased more in alpine steppe than alpine swamp meadow under warming, especially at topsoil (5–20 cm). Moreover, the increase in soil temperature at topsoil was greater during cold season than warm season. Greater alterations of soil thermal parameters were likely because soil moisture content reduced more in alpine steppe. Regarding soil freeze-thaw process, warming significantly postponed the onset of completely frozen stage and reduced the completely frozen days in alpine steppe. Active layer thickness in alpine steppe distinctly increased by 46 cm on average and showed an increasing trend under warming from 2009 to 2011. Overall, vegetation coverage and soil moisture content were responsible for the different responses of soil thermodynamics to experimental warming. The study has important implications for future scenarios as permafrost and grassland degradation may intensify under climate warming. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N 2 O) is an important greenhouse gas contributing to global climate change. Emissions of N 2 O from acidic forests are increasing rapidly; however, little is known about the mechanisms driving these emissions. We analyzed soil samples from a high N 2 O emission area (HEA, 224–601 μg N m−2 h−1) and an adjacent low emission area (LEA, 20–30 μg N m−2 h−1) of a highly acidified forest. HEA showed similar carbon and nitrogen (N) pools and microbial biomass to LEA, but significantly higher moisture and extractable nutrients than LEA did. GeoChip 4 detected 298 gene families (unadjusted P < 0.05; 94, adjusted P < 0.05) showing significantly different structures between HEA and LEA. Both areas had highly diverse N cycling functional genes. However, HEA had higher relative abundances of nor , P450nor, and archaeal nitrifier nirK , which provided evidence for the importance of denitrifiers in N 2 O emission. HEA also showed significantly higher relative abundances of lignin- and cellulose-degrading genes, oxygen-limitation-response genes and denitrifier ppk , but lower abundances of N- and phosphorus (P) -limitation-response genes especially denitrifier pstS , corresponding to the higher moisture and extractable nutrients conducive to denitrification. The moisture, extractable nutrients and pH explained over 50% variation in microbial communities, and extractable P appeared as the key factor driving community variation and consequently regulated N 2 O production. N 2 O emission in highly acidified forest soils was related to the diverse N functional genes, especially denitrification genes, and was affected by soil properties. Unlabelled Image • N 2 O emission rates were high in the TSP forest but also diverse in different sites. • Nitrogen cycling function genes were diverse in acidified forest soils. • Functional genes in denitrifiers were positively correlated to N 2 O emission. • Phosphorus showed significant influence on microbial gene communities. [ABSTRACT FROM AUTHOR]

To prevent the agglomeration of silicon carbide whiskers (SiC w) in photosensitive ceramic paste, a butanone-ethanol azeotropic solvent is employed to facilitate the dispersion of alumina particles, SiC whiskers and UV resins. Moreover, SiC w /Al 2 O 3 ceramic pastes, with 5–15 vol % SiC w , are prepared by using ball milling, stirring and distillation processes. The mixture of butanone-ethanol solvent and resins can be effectively separated at 70 °C without weakening the polymerization of UV resin. Moreover, an empirical equation is established to evaluate the relationship between SiC w content, aspect ratio and viscosity of resulting ceramic paste. The 15 vol % SiC w /Al 2 O 3 composite ceramic, with SiC w aspect ratio of 50, renders higher resistance to liquid flow and results in a high viscosity of 30,000 mPa s at the shear rate of 30 s−1. Furthermore, a modified equation is established to predicate the curing depth of ceramic pastes with different amounts of SiC w , where 15 vol % SiC w /Al 2 O 3 composite results in higher light scattering properties, leading to lowest C d of ∼0.061 mm. Finally, the complex-shaped SiC w /Al 2 O 3 ceramic component, prepared by SL 3D printing technology, debinding and sintering processes, exhibited a superior fracture toughness of 7.1 ± 1.20 MPa m1/2 and a higher hardness of 17.6 ± 0.78 GPa. • A novel technology was proposed for preparing a 50 vol% SiC w /Al 2 O 3 photosensitive paste. • The dispersing process can effectively prevent the agglomeration of SiC whiskers. • 5-15 vol% SiC w contents influence on the pastes corresponding properties were evaluated. • Complex SiC w /Al 2 O 3 part with 7.1 ± 1.20 MPa m1/2 was 3D printed and sintered. [ABSTRACT FROM AUTHOR]

The front cover artwork is provided by the Huang Group at the Institute of Advanced Materials (IAM) at Nanjing University of Posts and Telecommunications (China). The image shows how comprehensive performances of deep‐blue organic light‐emitting diodes can be achieved through Friedel–Crafts arylmethylation of a fluorophore. Read the full text of the Communication at10.1002/cptc.201900268. [ABSTRACT FROM AUTHOR]

• Superimposition of magmatic events led to various styles of mineralization in the Zijinshan ore district. • The involvement of mantle materials was critical for the formation of the early Cu-Au deposits. • More crustal materials and highly evolved magmas were the key in the formation of the late stage of Ag-Pb-Zn mineralization. • The extension triggered melting of the metasomatized mantle to form ore-forming magmas. Volcanic–subvolcanic rocks and associated Cu-Au-Ag-Pb-Zn mineralization within the Zijinshan ore district, located in the southwestern part of Fujian Province, represent a large metallogenic district within the southeastern coastal volcanic belt of China. This study presents new whole-rock geochemical, Sr–Nd–Hf isotopic, and zircon trace element data for igneous rocks within the Zijinshan area. Combining these new data with previously published geochronological results allows to constrain the magmatic and hydrothermal history and to understand the ore-related geological setting. Our results provide evidence of multi-stage metallogenic events within the Zijinshan district that can be roughly divided into early stage Cu-dominant (ca. 105–102 Ma) and late-stage Pb-Zn-enriched Ag-polymetallic (ca. 95–92 Ma) mineralization. Igneous rocks associated with the early stage of mineralization are enriched in the large ion lithophile elements (LILEs), depleted in the high field strength elements (HFSEs) with negative Nb, Ta and Ti anomalies, and have relatively high Mg# (35.9–63.5), low initial 87Sr/86Sr (0.7065–0.7088), relatively depleted εNd(t) and εHf(t) values (-3.6 to −2.3 and −5.04 to 0.85, respectively), and younger two-stage Hf model ages (1.4–1.1 Ga), suggesting that the components from metasomatized mantle were incorporated. The zircons in these early stage rocks are with elevated Ce4+/Ce3+ values (358–1029) indicating the high oxygen fugacity. In comparison, the igneous rocks associated with the late stage of mineralization have high initial 87Sr/86Sr values (0.7071–0.7103), enriched εNd(t) and εHf(t) values (−6.6 to −5.5 and −8.92 to −4.15, respectively), and older two-stage Hf model ages (1.7–1.4 Ga), that are indicative of formation from magmas that incorporated ancient crustal material. The late-stage igneous rocks contain zircons with low Ce4+/Ce3+ values (20–387) that are indicative of low oxygen fugacity conditions. Besides, the late stage ore-related igneous rocks are of high silica contents with highly evolved chemical signatures, indicative of intensive fractionation processes. The diverse metal endowments may be attributed to different sources, oxygen fugacity and magmatic evolution levels of the ore-related magmas. The Cretaceous magmas in Zijinshan were likely generated under an extensional setting. The lithospheric extension triggered partial melting of the fertile metasomatized subcontinental mantle, incorporating a large amount of mantle-derived components and generated the early Cu-Au-Mo mineralization. Later, a local and temporary shift to the more compressional environment would weaken the contribution of mantle. More ancient crustal materials were incorporated in the late stage and the magmas underwent intensive fractional crystallization, leading to the generation of Ag-polymetallic mineralization in the Zijinshan ore district. [ABSTRACT FROM AUTHOR]

• Molybdenite samples yield first Re-Os age of 111.31 ± 0.70 Ma. • Alteration type and depth control trace element distribution in sulfides. • Different trace element characteristics indicate distinct sulfide genesis. • Pyrite and digenite dominantly carry primary Au whereas bornite and digenite carry primary Ag. • The Zijinshan Cu-Au deposit formed in different hydrothermal system from the adjacent Luoboling porphyry Cu-Mo system. The Zijinshan Cu-Au deposit, located in Fujian Province, is the largest high-sulfidation epithermal (HSE) deposit in Southeastern China and is usually regarded as a major part of the porphyry Cu system in the Zijinshan ore field. Molybdenite samples collected from the Cu mineralization zone yield a first weighted mean Re-Os age of 111.31 ± 0.70 Ma, which is explained as the time of dickite-alunite alteration. Combining the newly reported muscovite 40Ar-39Ar and zircon U-Pb ages (~113 Ma), the mineralization of Zijinshan is likely to initiate before ca. 110 Ma. This result is obviously older than the Re-Os age of the adjacent Luoboling porphyry Cu-Mo deposit (~105 Ma). Pyrite, chalcopyrite, bornite, digenite, and covellite collected from the deep potassic, middle phyllic and upper epithermal zones are used to conduct LA-ICP-MS trace element analysis. The spatial zonings of mineralization and alteration and the regular variations of trace elements in sulfides at vertical direction imply a potentially complete transition from porphyry to epithermal mineralization and the deep origin of ore-forming fluids. Mineralogical and trace element characteristics indicate that the chalcopyrite formed in both stages, whereas bornite is the product of epithermal mineralization, rather than a porphyry stage residue. The majority of digenite and covellite has hypogene genesis. Pyrite and digenite in the epithermal zone are major carriers of primary Au. Au in pyrite is Te-Bi related and exists as solid solutions or different-sized telluride and Bi-sulfosalt inclusions. Compared to As, Te and Bi played more important roles to scavenge Au and Ag and achieve the primary Au enrichment. Differently, Au in digenite is independently locked in digenite lattice. Bornite and digenite are good carriers of primary Ag, which mainly exists as solid solutions. The high sulfidation state stage is the major period for concentrations of primary Au and Ag. The upward increase of Au in primary sulfides of HSE Cu zone implies that the distribution pattern of upper Au enrichment and lower Cu enrichment is not only caused by supergene process, but is also controlled by hypogene trend. Based on the mineralization and alteration zonings, the spatial variation of trace elements and the presented Re-Os age, the ore-forming fluids of the Zijinshan Cu-Au deposit most likely originate from deep region, rather than from the adjacent Luoboling porphyry deposit. The Zijinshan and the Luoboling deposits should belong to two independent hydrothermal systems. [ABSTRACT FROM AUTHOR]

• The interactive roles of organic, inorganic and biological fouling were quantified. • Organic-inorganic, organic-bio and organic-inorganic-bio synergies were prominent. • Organics can also cause fouling individually but inorganic and biofoulants cannot. • Fouling was delineated into three stages by statistical analysis of foulant features. • Fouling control may be targeted more accurately on foulant type or fouling stage. The dynamic process of membrane fouling was characterized during relatively long-term (30 d) continuous nanofiltration (NF) of a real wastewater secondary effluent, with the roles of organic, inorganic and biological foulants quantified via statistical analyses. The analyses were based on time-series data of physical properties (morphology, roughness, hydrophilicity and charge), chemical compositions (X-ray and infrared responses) and biomass (adenosine triphosphate, ATP) on the membrane surface during fouling evolution. The individual and interactive contributions of organic factor (typical functional groups), inorganic factor (Ca as a representative) and biological factor (ATP amount) to fouling were quantified via multiple linear regression coupled with variance partitioning analysis. About 78% of the variance of filtration resistance can be explained by these factors, among which 16% was contributed by individual effect of organics (via e.g. physical adsorption), 21% by organic-inorganic binary effect (in the form of e.g. Ca-complex), 13% by organic-biological binary effect (organics as the nutrient/product of microorganisms), and 24% by organic-inorganic-biological ternary interaction. Organic matter was universally involved in these effects. The interrelations among fouling factors, foulant layer properties and filtration time were comprehensively explored via redundancy analysis, which clearly delineated the fouling evolution into three major stages: Stage I (0–1 d) for initial fouling mainly due to rapid organic adsorption; Stage II (1–10 d) mainly for the gradual growth of Ca-organic combined fouling; and Stage III (10–30 d) for the eventual maturation of biofouling. These may provide foundations for a targeted fouling control based on foulant type or fouling stage. [ABSTRACT FROM AUTHOR]

• The bionic optimization method based on leaf veins can effectively improve the efficiency of piezoelectric energy harvesters. • The dicotyledonous vein configuration is an ideal biomimetic prototype of piezoelectric leaves. • A piezoelectric sheet with non-uniformly distributed stiffeners may have some quasi- bistable states. In this paper, we analyze the energy harvesting capacity of different piezoelectric elements with bionic stiffeners derived from venation growth algorithm (VGA) that have the prototypes of dicotyledonous plant leaf venations. Three types of polyvinylidene fluoride (PVDF) leaves are designed and fabricated. The contours of these models are isosceles triangle, isosceles trapezoid and 60° sector that correspond to the palmate leaf, pinnate leaf and ginkgo leaf, respectively. In wind tunnel tests, the PVDF leaves are connected with a cylinder bluff body by a double-layer beam and driven by the vortex-induced vibration in the wind flow after crossing the cylinder. The performances of energy harvester are evaluated by the open circuit voltage and output power. Through some control group test, the influence of the contours of leaves was proved to be negligible. Experiment results show that the maximum output power can reach 0.855μW for the model with pinnate venation at the wind speed of 11 m/s with a power density of 3.29μW/cm3. In this condition, the open circuit RMS (root mean square) voltage is 1.695 V and also the best performance of our models. Furthermore, the experimental results indicate that the energy harvesting capacity of PVDF models with bionic veins is 2–3 times higher than the traditional reinforced structure with orthogonal stiffeners. From these studies, it is confirmed that the bionic reinforced structure can significantly improve the efficiency of piezoelectric energy harvesters operating on wind-induced vibration principle. At present, the dicotyledonous vein configuration has proved to be the best prototype, which can be obtained by venation growth algorithm (VGA). [ABSTRACT FROM AUTHOR]

The alpine grassland on the Qinghai-Tibet Plateau covers an area of about 1/3 of China's total grassland area and plays a crucial role in regulating grassland ecological functions. Both environmental changes and irrational use of the grassland can result in severe grassland degradation in some areas of the Qinghai-Tibet Plateau. However, the magnitude and patterns of the physical and anthropogenic factors in driving grassland variation over northern Tibet remain debatable, and the interactive influences among those factors are still unclear. In this study, we employed a geographical detector model to quantify the primary and interactive impacts of both the physical factors (precipitation, temperature, sunshine duration, soil type, elevation, slope, and aspect) and the anthropogenic factors (population density, road density, residential density, grazing density, per capita GDP, and land use type) on vegetation variation from 2000 to 2015 in northern Tibet. Our results show that the vegetation index in northern Tibet significantly decreased from 2000 to 2015. Overall, the stability of vegetation types was sorted as follows: the alpine scrub > the alpine steppe > the alpine meadow. The physical factors, rather than the anthropogenic factors, have been the primary driving factors for vegetation dynamics in northern Tibet. Specifically, meteorological factors best explained the alpine meadow and alpine steppe variation. Precipitation was the key factor that influenced the alpine meadow variation, whereas temperature was the key factor that contributed to the alpine steppe variation. The anthropogenic factors, such as population density, grazing density and per capita GDP, influenced the alpine scrub variation most. The influence of population density is highly similar to that of grazing density, which may provide convenient access to simplify the study of the anthropogenic activities in the Tibet plateau. The interactions between the driving factors had larger effects on vegetation than any single factor. In the alpine meadow, the interaction between precipitation and temperature can explain 44.6% of the vegetation variation. In the alpine scrub, the interaction between temperature and GDP was the highest, accounting for 27.5% of vegetation variation. For the alpine steppe, the interaction between soil type and population density can explain 29.4% of the vegetation variation. The highest value of vegetation degradation occurred in the range of 448–469 mm rainfall in the alpine meadow, 0.61–1.23 people/km2 in the alpine scrub and –0.83–0.15 °C in the alpine steppe, respectively. These findings could contribute to a better understanding of degradation prevention and sustainable development of the alpine grassland ecosystem in northern Tibet. [ABSTRACT FROM AUTHOR]

In this paper, we report on a novel room-temperature air plasma jet array with a large cross section. There is no risk of glow-to-arc transitions. It is demonstrated that the air plasma plumes could merge together and produce a stable homogeneous glow. One hundred shots integrated photograph on dynamic of the air discharge is taken. The photograph reveals that the air plasma appears homogeneous. [ABSTRACT FROM PUBLISHER]

The mechanism of ZnO sulfidation with sulfur and iron oxide at high temperatures was studied. The thermodynamic analysis, sulfidation behavior of zinc, phase transformations, morphology changes, and surface properties were investigated by HSC 5.0 combined with FactSage 7.0, ICP, XRD, optical microscopy coupled with SEM-EDS, and XPS. The results indicate that increasing temperature and adding iron oxide can not only improve the sulfidation of ZnO but also promote the formation and growth of ZnS crystals. Fe2O3 captured the sulfur in the initial sulfidation process as iron sulfides, which then acted as the sulfurizing agent in the late period, thus reducing sulfur escape at high temperatures. The addition of carbon can not only enhance the sulfidation but increase sulfur utilization rate and eliminate the generation of SO2. The surfaces of marmatite and synthetic zinc sulfides contain high oxygen due to oxidation and oxygen adsorption. Hydroxyl easily absorbs on the surface of iron-bearing zinc sulfide (Zn1−xFexS). The oxidation of synthetic Zn1−xFexS is easier than marmatite in air. [ABSTRACT FROM AUTHOR]

Plants have an important impact on soil microbial communities and their functions. However, how plants determine the microbial composition and network interactions is still poorly understood. During a four-year field experiment, we investigated the functional gene composition of three types of soils (Phaeozem, Cambisols and Acrisol) under maize planting and bare fallow regimes located in cold temperate, warm temperate and subtropical regions, respectively. The core genes were identified using high-throughput functional gene microarray (GeoChip 3.0), and functional molecular ecological networks (fMENs) were subsequently developed with the random matrix theory (RMT)-based conceptual framework. Our results demonstrated that planting significantly (P < 0.05) increased the gene alpha-diversity in terms of richness and Shannon - Simpson's indexes for all three types of soils and 83.5% of microbial alpha-diversity can be explained by the plant factor. Moreover, planting had significant impacts on the microbial community structure and the network interactions of the microbial communities. The calculated network complexity was higher under maize planting than under bare fallow regimes. The increase of the functional genes led to an increase in both soil respiration and nitrification potential with maize planting, indicating that changes in the soil microbial communities and network interactions influenced ecological functioning. [ABSTRACT FROM AUTHOR]