35 research outputs found

    Exceptional capture of methane at low pressure by an iron‐based metal‐organic framework

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    The selective capture of methane (CH4) at low concentrations and its separation from N2 are extremely challenging owing to the weak host-guest interactions between CH4 molecules and any sorbent material. Here, we report the exceptional adsorption of CH4 at low pressure and efficient separation of CH4/N2 by MFM-300(Fe). MFM-300(Fe) shows a very high uptake for CH4 of 0.85 mmol g−1 at 1 mbar and 298 K and a record CH4/N2 selectivity of 45 for porous solids, representing a new benchmark for CH4 capture and CH4/N2 separation. The excellent separation of CH4/N2 by MFM-300(Fe) has been confirmed by dynamic breakthrough experiments. In situ neutron powder diffraction, and solid-state nuclear magnetic resonance and diffuse reflectance infrared Fourier transform spectroscopies, coupled with modelling, reveal a unique and strong binding of CH4 molecules involving Fe-OH···CH4 and C···phenyl ring interactions within the pores of MFM-300(Fe), thus promoting the exceptional adsorption of CH4 at low pressure

    Improvement of the high-accuracy O 17 ( p , α ) N 14 reaction-rate measurement via the Trojan Horse method for application to O 17 nucleosynthesis

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    The ^{17}\text{O}(p,\ensuremath{\alpha})^{14}\text{N} and ^{17}\text{O}(p,\ensuremath{\gamma})^{18}\text{F} reactions are of paramount importance for the nucleosynthesis in a number of stellar sites, including red giants (RGs), asymptotic giant branch (AGB) stars, massive stars, and classical novae. In particular, they govern the destruction of 17O^{17}\text{O} and the formation of the short-lived radioisotope 18F^{18}\text{F}, which is of special interest for \ensuremath{\gamma}-ray astronomy. At temperatures typical of the above-mentioned astrophysical scenario, T=0.01T=0.01--0.1 GK for RG, AGB, and massive stars and T=0.1T=0.1--0.4 GK for a classical nova explosion, the ^{17}\text{O}(p,\ensuremath{\alpha})^{14}\text{N} reaction cross section is dominated by two resonances: one at about ERcm=65{E}_{R}^{cm}=65 keV above the 18F^{18}\text{F} proton threshold energy, corresponding to the EX=5.673{E}_{X}=5.673 MeV level in 18F^{18}\text{F}, and another one at ERcm=183{E}_{R}^{cm}=183 keV (EX=5.786({E}_{X}=5.786 MeV). We report on the indirect study of the ^{17}\text{O}(p,\ensuremath{\alpha})^{14}\text{N} reaction via the Trojan Horse method by applying the approach recently developed for extracting the strength of narrow resonance at ultralow energies. The mean value of the strengths obtained in the two measurements was calculated and compared with the direct data available in literature. This value was used as input parameter for reaction-rate determination and its comparison with the result of the direct measurement is also discussed in the light of the electron screening effect

    Transcriptome analysis to identify candidate genes related to mammary gland development of Bactrian camel (Camelus bactrianus)

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    IntroductionThe demand for camel milk, which has unique therapeutic properties, is increasing. The mammary gland is the organ in mammals responsible for the production and quality of milk. However, few studies have investigated the genes or pathways related to mammary gland growth and development in Bactrian camels. This study aimed to compare the morphological changes in mammary gland tissue and transcriptome expression profiles between young and adult female Bactrian camels and to explore the potential candidate genes and signaling pathways related to mammary gland development.MethodsThree 2  years-old female camels and three 5  years-old adult female camels were maintained in the same environment. The parenchyma of the mammary gland tissue was sampled from the camels using percutaneous needle biopsy. Morphological changes were observed using hematoxylin-eosin staining. High-throughput RNA sequencing was performed using the Illumina HiSeq platform to analyze changes in the transcriptome between young and adult camels. Functional enrichment, pathway enrichment, and protein–protein interaction networks were also analyzed. Gene expression was verified using quantitative real-time polymerase chain reaction (qRT-PCR).ResultsHistomorphological analysis showed that the mammary ducts and mammary epithelial cells in adult female camels were greatly developed and differentiated from those in young camels. Transcriptome analysis showed that 2,851 differentially expressed genes were obtained in the adult camel group compared to the young camel group, of which 1,420 were upregulated, 1,431 were downregulated, and 2,419 encoded proteins. Functional enrichment analysis revealed that the upregulated genes were significantly enriched for 24 pathways, including the Hedgehog signaling pathway which is closely related to mammary gland development. The downregulated genes were significantly enriched for seven pathways, among these the Wnt signaling pathway was significantly related to mammary gland development. The protein–protein interaction network sorted the nodes according to the degree of gene interaction and identified nine candidate genes: PRKAB2, PRKAG3, PLCB4, BTRC, GLI1, WIF1, DKK2, FZD3, and WNT4. The expression of fifteen genes randomly detected by qRT-PCR showed results consistent with those of the transcriptome analysis.DiscussionPreliminary findings indicate that the Hedgehog, Wnt, oxytocin, insulin, and steroid biosynthesis signaling pathways have important effects on mammary gland development in dairy camels. Given the importance of these pathways and the interconnections of the involved genes, the genes in these pathways should be considered potential candidate genes. This study provides a theoretical basis for elucidating the molecular mechanisms associated with mammary gland development and milk production in Bactrian camels

    Dynamic Simulation and Analysis on Elevating Process of Elevating Equilibrator

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    The elevating equilibrator is used to control the elevating angel of the director of a rocket launcher. Based on an elevating equilibrator, a method for co-simulation is introduced with dynamic simulation software ADAMS and hydraulic simulation software EASY5. A three-dimensional model of the elevating equilibrator is developed with Solidworks and is imported into ADAMS. Furthermore, the hydraulic system model is established by EASY5. The interaction of mechanical system and hydraulic system is analyzed. The analysis indicates that the modeling method for co-simulation is effective and practical

    Dynamic Simulation and Analysis on Elevating Process of Elevating Equilibrator

    No full text
    The elevating equilibrator is used to control the elevating angel of the director of a rocket launcher. Based on an elevating equilibrator, a method for co-simulation is introduced with dynamic simulation software ADAMS and hydraulic simulation software EASY5. A three-dimensional model of the elevating equilibrator is developed with Solidworks and is imported into ADAMS. Furthermore, the hydraulic system model is established by EASY5. The interaction of mechanical system and hydraulic system is analyzed. The analysis indicates that the modeling method for co-simulation is effective and practical

    A Wind-Solar Hybrid Energy Harvesting Approach Based on Wind-Induced Vibration Structure Applied in Smart Agriculture

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    Solar energy harvesting devices are widely used in smart agriculture nowadays. However, when lighting conditions are weak, such as through the night or on cloudy days, efficiency decays a lot. Additionally, as time goes by, more and more dust and bird droppings accumulate on the panel, which decreases the performance significantly. This paper aims to overcome the disadvantages mentioned above, and a novel wind–solar hybrid energy harvesting approach is proposed with an oscillation-induced dust-cleaning function. A wind-induced vibration device is specially designed in order to generate electrical energy and/or clean the photovoltaic panel. While in good lighting conditions, the device could keep the panel in a stable state and optimize the photovoltaic power generation efficiency. Such a hybrid energy harvesting approach is called a “suppress vibration and fill vacancy” algorithm. The experimental platform of the proposed device is introduced, and both experimental and simulation results are attained, which prove that using this device, we could realize multiple purposes at the same time

    Computational Experiments: Virtual Production and Governance Tool for Metaverse

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    The metaverse, as an extension of the physical world, can be described as a highly immersive digital realm constructed with technologies such as mixed reality and digital modeling. It is rooted in decentralized principles and features novel economic forms, individual identities, and institutional systems. In this architecture, the entire social landscape is redefined under the logic of service, gradually becoming a service ecosystem operated and cooperated by numerous intelligent entities. To achieve sustainable and healthy development of the metaverse ecology, this paper first analyzes the operating logic of the metaverse from the perspective of the fusion of the cyber-physical-social tripartite world and the three typical complexity characteristics faced by it: evolutionary complexity, cognitive complexity, and regulatory complexity. Next, the paper focuses on introducing the idea and technical system of computational experiments as an analysis and governance tool for the metaverse service ecosystem. Then, it explores the integration of computational experiments and metaverse technology, including how computational experiments can be applied to the metaverse and how the metaverse can support computational experiments. Finally, the paper introduces the metaverse applications of computational experiments, covering fields such as industrial design, health care, social governance, and military reform
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