101 research outputs found

    In-depth understanding of the morphology effect of α-Fe2O3 on catalytic ethane destruction

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    Shape effects of nanocrystal catalysts in different reactions have attracted remarkable attention. In the present work, three types of α-Fe2O3 oxides with different micromorphologies were rationally synthesized via a facile solvothermal method and adopted in deep oxidation of ethane. The physicochemical properties of prepared materials were characterized by XRD, N2 sorption, FE-SEM, HR-TEM, FTIR, in situ DRIFTS, XPS, Mössbauer spectroscopy, in situ Raman, electron energy loss spectroscopy, and H2-TPR. Moreover, the formation energy of oxygen vacancy and surface electronic structure on various crystal faces of α-Fe2O3 were explored by DFT calculations. It is shown that nanosphere-like α-Fe2O3 exhibits much higher ethane destruction activity and reaction stability than nanocube-like α-Fe2O3 and nanorod-like α-Fe2O3 due to larger amounts of oxygen vacancies and lattice defects, which greatly enhance the concentration of reactive oxygen species, oxygen transfer speed, and material redox property. In addition to this, DFT results reveal that nanosphere-like α-Fe2O3 has the lowest formation energy of oxygen vacancy on the (110) facet (Evo (110) = 1.97 eV) and the strongest adsorption energy for ethane (−0.26 eV) and O2 (−1.58 eV), which can accelerate the ethane oxidation process. This study has deepened the understanding of the face-dependent activities of α-Fe2O3 in alkane destruction

    Laying Bare: Agamben, Chandler, and The Responsibility to Protect

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    This paper demonstrates the hidden similarities between Raymond Chandler’s prototypical noir The Big Sleep, and the United Nations Responsibility to Protect (R2P) document. By taking up the work of philosopher Giorgio Agamben, this paper shows that the bare life produces the form of protection embodied by Philip Marlowe in Chandler’s novel and by the United Nations Security Council in R2P. Agamben’s theorizing of the extra-legal status of the sovereign pertains to both texts, in which the protector exists outside of the law. Philip Marlowe, tasked with preventing the distribution of pornographic images, commits breaking-and-entering, withholding evidence, and murder. Analogously, R2P advocates for the Security Council’s ability to trespass laws that safeguard national sovereignty in order to prevent “bare” atrocities against human life. As Agamben demonstrates, the extra-legal position of the protector is made possible by “stripping bare” human life. This paper also gestures towards limitations of Agamben’s thought by indicating, through a comparison of these two texts, that bare life produces states of exception as the object of protection rather than punishment

    The emerging oilseed crop Sesamum indicum enters the “Omics” era

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    Sesame (Sesamum indicum L.) is one of the oldest oilseed crops widely grown in Africa and Asia for its high-quality nutritional seeds. It is well adapted to harsh environments and constitutes an alternative cash crop for smallholders in developing countries. Despite its economic and nutritional importance, sesame is considered as an orphan crop because it has received very little attention from science. As a consequence, it lags behind the other major oil crops as far as genetic improvement is concerned. In recent years, the scenario has considerably changed with the decoding of the sesame nuclear genome leading to the development of various genomic resources including molecular markers, comprehensive genetic maps, high-quality transcriptome assemblies, web-based functional databases and diverse daft genome sequences. The availability of these tools in association with the discovery of candidate genes and quantitative trait locis for key agronomic traits including high oil content and quality, waterlogging and drought tolerance, disease resistance, cytoplasmic male sterility, high yield, pave the way to the development of some new strategies for sesame genetic improvement. As a result, sesame has graduated from an “orphan crop” to a “genomic resource-rich crop.” With the limited research teams working on sesame worldwide, more synergic efforts are needed to integrate these resources in sesame breeding for productivity upsurge, ensuring food security and improved livelihood in developing countries. This review retraces the evolution of sesame research by highlighting the recent advances in the “Omics” area and also critically discusses the future prospects for a further genetic improvement and a better expansion of this crop. (RĂ©sumĂ© d'auteur

    Caplak, Tidak Hanya Membuat Gatal

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    CAPLAK, TIDAK HANYA MEMBUAT GATA

    Insight into the AP2/ERF transcription factor superfamily in sesame and expression profiling of DREB subfamily under drought stress

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    Background. Sesame is an important oilseed crop mainly grown in inclement areas with high temperatures and frequent drought. Thus, drought constitutes one of the major constraints of its production. The AP2/ERF is a large family of transcription factors known to play significant roles in various plant processes including biotic and abiotic stress responses. Despite their importance, little is known about sesame AP2/ERF genes. This constitutes a limitation for drought-tolerance candidate genes discovery and breeding for tolerance to water deficit. Results. One hundred thirty-two AP2/ERF genes were identified in the sesame genome. Based on the number of domains, conserved motifs, genes structure and phylogenetic analysis including 5 relatives species, they were classified into 24 AP2, 41 DREB, 61 ERF, 4 RAV and 2 Soloist. The number of sesame AP2/ERF genes was relatively few compared to that of other relatives, probably due to gene loss in ERF and DREB subfamilies during evolutionary process. In general, the AP2/ERF genes were expressed differently in different tissues but exhibited the highest expression levels in the root. Mostly all DREB genes were responsive to drought stress. Regulation by drought is not specific to one DREB group but depends on the genes and the group A6 and A1 appeared to be more actively expressed to cope with drought. Conclusions. This study provides insights into the classification, evolution and basic functional analysis of AP2/ERF genes in sesame which revealed their putative involvement in multiple tissue-/developmental stages. Out of 20 genes which were significantly up- /down-regulated under drought stress, the gene AP2si16 may be considered as potential candidate gene for further functional validation as well for utilization in sesame improvement programs for drought stress tolerance. (Résumé d'auteur

    Long-lived charge separation following pump-wavelength-dependent ultrafast charge transfer in graphene/WS2 heterostructures

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    Van der Waals heterostructures consisting of graphene and transition metal dichalcogenides have shown great promise for optoelectronic applications. However, an in-depth understanding of the critical processes for device operation, namely, interfacial charge transfer (CT) and recombination, has so far remained elusive. Here, we investigate these processes in graphene-WS2 heterostructures by complementarily probing the ultrafast terahertz photoconductivity in graphene and the transient absorption dynamics in WS2 following photoexcitation. We observe that separated charges in the heterostructure following CT live extremely long: beyond 1 ns, in contrast to ~1 ps charge separation reported in previous studies. This leads to efficient photogating of graphene. Furthermore, for the CT process across graphene-WS2 interfaces, we find that it occurs via photo- thermionic emission for sub-A-exciton excitations and direct hole transfer from WS2 to the valence band of graphene for above-A-exciton excitations. These findings provide insights to further optimize the perform ance of optoelectronic devices, in particular photodetection

    Long-Lived Charge Separation Following Pump-Energy Dependent Ultrafast Charge Transfer in Graphene/WS2_2 Heterostructures

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    Van der Waals heterostructures consisting of graphene and transition metal dichalcogenides (TMDCs) have recently shown great promise for high-performance optoelectronic applications. However, an in-depth understanding of the critical processes for device operation, namely interfacial charge transfer (CT) and recombination, has so far remained elusive. Here, we investigate these processes in graphene-WS2_2 heterostructures, by complementarily probing the ultrafast terahertz photoconductivity in graphene and the transient absorption dynamics in WS2_2 following photoexcitation. We find that CT across graphene-WS2_2 interfaces occurs via photo-thermionic emission for sub-A-exciton excitation, and direct hole transfer from WS2_2 to the valence band of graphene for above-A-exciton excitation. Remarkably, we observe that separated charges in the heterostructure following CT live extremely long: beyond 1 ns, in contrast to ~1 ps charge separation reported in previous studies. This leads to efficient photogating of graphene. These findings provide relevant insights to optimize further the performance of optoelectronic devices, in particular photodetection

    NÀyttötutkintomestariksi Oulussa

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    Videolla kerrotaan, miten nÀyttötutkintomestarikoulutus toteutetaan Oulussa. Videossa tuodaan esille muun muassa osaamisen tunnistamisen ja tunnustamisen sekÀ henkilökohtaistamisen kÀsitteet
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