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Abstract Graphene nanoribbons have many extraordinary electrical properties and are the candidates for semiconductor industry. In this research, we propose a design of Coved GNRs with periodic structure ranged from 4 to 8 nm or more, of which the size is within practical feature sizes by advanced lithography tools. The carrier transport properties of Coved GNRs with the periodic coved shape are designed to break the localized electronic state and reducing electron–phonon scattering. In this way, the mobility of Coved GNRs can be enhanced by orders compared with the zigzag GNRs in same width. Moreover, in contrast to occasional zero bandgap transition of armchair and zigzag GNRs without precision control in atomic level, the Coved GNRs with periodic edge structures can exclude the zero bandgap conditions, which makes practical the mass production process. The designed Coved-GNRs is fabricated over the Germanium (110) substrate where the graphene can be prepared in the single-crystalline and single-oriented formants and the edge of GNRs is later repaired under "balanced condition growth" and we demonstrate that the propose coved structures are compatible to current fabrication facility.

IntroductionMonoecy is usually interpreted as an important evolutionary route of the plant sexual system from hermaphroditism to dioecy. This floral mechanism can effectively reduce self-interference during the reproductive process, and the services provided by pollinators may play an essential role in monoecious species; however, relevant research is still lacking. Thus, we aimed to determine whether monoecious plants could effectively avoid self-interference and promote the evolution of monoecy under the service of pollinators.MethodsHere, we successfully performed manipulation experiments to test self-compatibility, pollinator behavior, and self-interference between male and female functions in Akebia trifoliata, a typical monoecious species.ResultsWe demonstrated that experimental self-pollination did not yield any fruit, and supplemental pollination significantly increased fruit set and fruit weight compared to natural pollination, suggesting that this species is completely self-incompatible and experiences strong pollen limitation. Simultaneous self- and cross-pollination and self-pollination prior to cross-pollination significantly reduced reproductive fitness, but self-pollination after cross-pollination did not, indicating self-interference in this plant. Moreover, both male flower probing preference and switching modes within inflorescences by pollinators successfully reinforced self-interference and were also responsible for decreasing reproductive fitness in A. trifoliata.DiscussionIn summary, pollinator-mediated self-interference significantly reduced selfing, providing potential dynamics for the maintenance and evolution of monoecy.

Porphyry-type molybdenum deposits, many of which are in China, supply most of the World's molybdenum. Of particular importance are the molybdenum deposits located in the Qinling-Dabie region that are responsible for more than half of China's molybdenum production. A feature that distinguishes this suite of deposits from the better-known Climax and Endako sub-types of porphyry molybdenum deposits is their formation from CO2-rich magmatic-hydrothermal fluids. The role of CO2, if any, in the transport of molybdenum by these fluids, however, is poorly understood. We conducted experiments on the partitioning of molybdenum between H2O-CO2, H2O-NaCl, and H2O-NaCl-CO2 fluids and a felsic melt at 850 °C and 100 and 200 MPa. Here we show that the exsolution of separate (immiscible) brine and vapor leads to the very high brine DMo values needed for efficient extraction of Mo from the magmas forming Dabie-type porphyry molybdenum deposits. Direct exsolution of immiscible CO2 vapour and brine from magma greatly enriches the brine in molybdenum, a likely factor in the genesis of the Dabie-type porphyry deposits that supply much of the World's molybdenum [ABSTRACT FROM AUTHOR]

Abstract Background Light availability may have direct effects on reproduction through resource availability, and indirect effects on female reproduction by influencing plant-pollinator interactions. Floral display size, pollinator visitation per flower, resource and pollen limitation of fruit and seed production were quantified in a forested patch and an adjacent open patch of two populations of the perennial herb Hosta ventricosa. Results Plants in the open patch produced significantly larger floral displays than those in the forested patch in both populations. Floral display size had a positive effect on pollinator visitation rate per flower in one population, but no effect in the other. Plants in the open patch received approximately 8–11 times more visitation rates and produced significantly more fruit and seeds per flower than those in the forested patch. However, supplemental pollination resulted in significantly more fruit and seed production per flower compared to natural pollination in the forested patch but not in the open patch in one population, and did not enhance fruit and seed production in either the forested or the open patch in the other. In both populations, supplementally pollinated plants in the open patch produced significantly more fruit and seeds per flower than supplementally pollinated plants in the forested patch. Conclusions In H. ventricosa, local variation in light conditions could affect pollinator activity and influence female reproduction through resource availability; however differences in the degree of pollen limitation between local habitats were found to be population-specific.

Antimony (Sb) has been widely used in products such as fire retardants, glass, rubber, paint, ceramics and semiconductors. It is found throughout igneous rocks but can be enriched in sedimentary rocks such as abysmal clays, shales and clastic rocks. Sb commonly occurs in magmatic sulfide deposits related to gabbroic rocks, sulfide deposits related to granitic rocks, clastic rocks and carbonate rocks hosted in stratified W-Sb-Hg deposits, and hydrothermal Pb-Zn deposits. The analytical method of high precision determination of Sb isotopes is now available. Samples are commonly digested with different types of acids, and Sb is separated and concentrated by cation exchange column combined with Thiol cotton fiber or both anion and cation exchange columns. Sb isotopes are determined by MC-ICP-MS coupled with hydride generation. The mass discrimination of equipment is commonly corrected by sample standard bracketing, using In and Sn internal standards. Different geological reservoirs have variable Sb isotope compositions (up to 18‱), with seawater of about 3.7‱, silicate rocks of 0.9‱ to 2.9‱, and sulfides (stibnite, sphalerite, pyrite, marcasite) of -1.9‱ to 16.9‱. Moreover, stibnites from different countries have different Sb isotope compositions. Glass from different places of production also shows different Sb isotope compositions. Sb isotopes will fractionate up to about 9‱ and 4‱ during oxide-reduction process (or sulfide precipitation) and inorganic absorption process, respectively. Therefore, Sb isotopes may serve as a geochemical tracer, which play an important role in indicating the source of ore-forming materials, portraying the ore-forming process and revealing the ore-forming mechanism. This isotope system can also be used to trace heavy metal pollution and can be used in archaeology.