24 research outputs found

    Study on the Concept of Per Capita Cumulative Emissions and Allocation Options

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    Global long-term emission reduction targets need well defined options for equitable allocation of greenhouse gas emissions. Scholars from developing countries put forward the concept of equitable per capita cumulative emission rights. There are four possible operational definitions resulting from this concept. These potential options for allocation of emission rights are expressed with mathematical equations. Through simple simulation, this paper reveals the advantages, disadvantages and characteristics of each option. Yu, S., X. Gao, C. Ma, et al., 2011: Study on the concept of per capita cumulative emissions and allocation options. Adv. Clim . Change Res ., 2 (2), doi: 10.3724/SP.J.1248.2011.00079

    Theoretical Investigation of HER and OER Electrocatalysts Based on the 2D R-graphyne Completely Composed of Anti-Aromatic Carbon Rings

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    Based on the DFT calculations, two-dimensional (2D) R-graphyne has been demonstrated to have high stability and good conductivity, which can be conducive to the relevant electrocatalytic activity of the material. Different from the poor graphene, R-graphyne, which is completely composed of anti-aromatic structural units, can exhibit certain HER catalytic activity. In addition, doping the TM atoms in Group VIIIB can be considered an effective strategy to enhance the HER catalytic activity of R-graphyne. Particularly, Fe@R-graphyne, Os@R-graphyne, Rh@R-graphyne and Ir@R-graphyne can exhibit higher HER catalytic activities due to the formation of more active sites. Usually, the shorter the distance between the TM and C atoms is, the better the HER activity of the C-site is. Furthermore, doping Ni and Rh atoms of Group VIIIB can significantly improve the OER catalytic performance of R-graphyne. It can be found that ΔGO* can be used as a good descriptor for the OER activities of TM@R-graphyne systems. Both Rh@R-graphyne and Ni@R-graphyne systems can exhibit bifunctional electrocatalytic activities for HER/OER. In addition, all the relevant catalytic mechanisms are analyzed in detail. This work not only provides nonprecious and highly efficient HER/OER electrocatalysts, but also provides new ideas for the design of carbon-based electrocatalysts

    The linkage between longitudinal sediment routing systems and basin types in the northern South China Sea in perspective of source-to-sink

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    Using bathymetric and seismic data, this study describes the morpho-sedimentary features in Qiongdongnan basin and southwest Taiwan collision basin, northern South China Sea and reveals the linkages between sediment routing system and basin types. The modern Central Canyon in the Qiongdongnan basin is located along the rift margin, and subparallel to the shelf-break southeast of Hainan Island. The modern Central Canyon develops along the basin axis (i.e., Xisha Trough) and longitudinally transports sediments eastward which are mainly supplied by northern continental slope. The Penghu Canyon in the southwest Taiwan collision basin is located along the collision boundary parallel to the strike of the adjacent uplifted Taiwan orogen. The Penghu Canyon develops along the tilting basin axis transporting sediments longitudinally southward to the deep-sea basin and Manila Trench. The Penghu Canyon is supplied with sediments from both flank Kaoping and South China Sea slopes where tributary canyons and channels transport sediments down-slope and feed the axial canyon

    Comparison of Soybean Transformation Efficiency and Plant Factors Affecting Transformation during the Agrobacterium Infection Process

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    The susceptibility of soybean genotype to Agrobacterium infection is a key factor for the high level of genetic transformation efficiency. The objective of this study is to evaluate the plant factors related to transformation in cotyledonary nodes during the Agrobacterium infection process. This study selected three genotypes (Williams 82, Shennong 9 and Bert) with high transformation efficiency, which presented better susceptibility to Agrobacterium infection, and three low transformation efficiency genotypes (General, Liaodou 16 and Kottman), which showed a relatively weak susceptibility. Gibberellin (GA) levels and soybean GA20ox2 and CYP707A2 transcripts of high-efficiency genotypes increased and were higher than those of low-efficiency genotypes; however, the opposite performance was shown in abscisic acid (ABA). Higher zeatin riboside (ZR) content and DNA quantity, and relatively higher expression of soybean IPT5, CYCD3 and CYCA3 were obtained in high-efficiency genotypes. High-efficiency genotypes had low methyl jasmonate (MeJA) content, polyphenol oxidase (PPO) and peroxidase (POD) activity, and relatively lower expression of soybean OPR3, PPO1 and PRX71. GA and ZR were positive plant factors for Agrobacterium-mediated soybean transformation by facilitating germination and growth, and increasing the number of cells in DNA synthesis cycle, respectively; MeJA, PPO, POD and ABA were negative plant factors by inducing defence reactions and repressing germination and growth, respectively

    Tetrathiafulvalene-based covalent organic frameworks for ultrahigh iodine capture

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    International audienceTo safeguard the development of nuclear energy, practical techniques for capture and storage of radioiodine are of critical importance but remain a significant challenge. Here we report the synergistic effect of physical and chemical adsorption of iodine in tetrathiafulvalene-based covalent organic frameworks (COFs), which can markedly improve both iodine adsorption capacity and adsorption kinetics due to their strong interaction. These functionalized architectures are designed to have high specific surface areas (up to 2359 m2 g−1) for efficient physisorption of iodine, and abundant tetrathiafulvalene functional groups for strong chemisorption of iodine. We demonstrate that these frameworks achieve excellent iodine adsorption capacity (up to 8.19 g g−1), which is much higher than those of other materials reported so far, including silver-doped adsorbents, inorganic porous materials, metal–organic frameworks, porous organic frameworks, and other COFs. Furthermore, a combined theoretical and experimental study, including DFT calculations, electron paramagnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy, reveals the strong chemical interaction between iodine and the frameworks of the materials. Our study thus opens an avenue to construct functional COFs for a critical environment-related application

    Iodine Adsorption in Tetrathiafulvalene-Based Covalent Organic Frameworks

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    To safeguard the development of nuclear energy, practical techniques for capture and storage of radioiodine are of critical importance but remains a significant challenge. Here we report the synergistic effect of physical and chemical adsorption of iodine in tetrathiafulvalene-based covalent organic frameworks (COFs), which can markedly improve both iodine adsorption capacity and adsorption kinetics due to their strong interaction. These functionalized architectures are designed to have high specific surface areas (up to 2359 m2 g−1) for efficient physisorption of iodine, and abundant tetrathiafulvalene functional groups for strong chemisorption of iodine. We demonstrate that these frameworks achieve excellent iodine adsorption capacity (~ 8.15 g g-1) and adsorption kinetics (~ 0.69 g g-1 h-1), which are much higher than other materials reported so far, including silver-doped adsorbents, inorganic porous materials, metal−organic frameworks, porous organic frameworks, and other COFs. Furthermore, a combined theoretical and experimental study, including DFT calculations, electron paramagnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy, reveals the strong chemical interaction between iodine and framework of material. Our study thus opens an avenue to construct functional COFs for a critical environment-related application. </p

    Iodine Adsorption in Tetrathiafulvalene-Based Covalent Organic Frameworks

    No full text
    To safeguard the development of nuclear energy, practical techniques for capture and storage of radioiodine are of critical importance but remains a significant challenge. Here we report the synergistic effect of physical and chemical adsorption of iodine in tetrathiafulvalene-based covalent organic frameworks (COFs), which can markedly improve both iodine adsorption capacity and adsorption kinetics due to their strong interaction. These functionalized architectures are designed to have high specific surface areas (up to 2359 m2 g−1) for efficient physisorption of iodine, and abundant tetrathiafulvalene functional groups for strong chemisorption of iodine. We demonstrate that these frameworks achieve excellent iodine adsorption capacity (~ 8.15 g g-1) and adsorption kinetics (~ 0.69 g g-1 h-1), which are much higher than other materials reported so far, including silver-doped adsorbents, inorganic porous materials, metal−organic frameworks, porous organic frameworks, and other COFs. Furthermore, a combined theoretical and experimental study, including DFT calculations, electron paramagnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy, reveals the strong chemical interaction between iodine and framework of material. Our study thus opens an avenue to construct functional COFs for a critical environment-related application. </p
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