30 research outputs found

    A Knowledge Mapping Analysis of Digital Photogrammetry Research Using CiteSpace

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    In order to clearly understand the current status and application trends of digital photogrammetry domestic and overseas research, taking the core journals of Web of Science as the data source, using bibliometric methods and CiteSpace to carry out statistical analysis of the relevant literature of digital photogrammetry research. The results show that since 2011, the research literature on digital photogrammetry has shown a steady growth year by year.  Digital photogrammetry is most closely related to the three disciplines of geology, earth science integration, and physical geography; countries such as the United States, the United Kingdom, Italy, and China publish the most papers, and these countries have strong research capabilities. Lane SN and Chandler JH have been shared with a high number of citations, who are representative scholars in this field; Digital photogrammetry contains multiple research directions. This article studies the research hotspots and frontiers of digital photogrammetry through keyword co-occurrence analysis and mutation detection analysis

    REAL-TIME MONITORING DEFORMATION OF BUILDING USING PHOTOGRAPHY DYNAMIC MONITORING SYSTEM

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    The spatial structure building is a type of building system; it is necessary to monitor deformation to determine its stability and robustness. Under the dynamic deformation of structures, it is challenging to determine appropriate zero image (the reference image) if we use the PST-IM- MP (photograph scale transformation-image matching-motion parallax) method to obtain the deformation of structures. This paper offers the Z-MP (zero-centered motion parallax) method to solve these problems and offers PDMS (Photography Dynamic Monitoring System) based on the digital photography system to monitor the dynamic deformation of the tennis stadium located in Jinan Olympic Sports Center. The results showed that the spatial structures of the tennis stadium were robust, and the deformations were elastic and within the permissible value. Compared with the PST-IM-MP method, the Z-MP method is more suitable for deformation monitoring structures under real-time deformation. This paper indicates PDMS has advantages of the simplicity of operations, automation, and the ability of non-contact dynamic deformation monitoring for multiple points in a short period. In the future, it will have broader application prospects

    Leucine Carboxyl Methyltransferase Downregulation and Protein Phosphatase Methylesterase Upregulation Contribute Toward the Inhibition of Protein Phosphatase 2A by α-Synuclein

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    The pathology of Parkinson’s disease (PD) is characterized by intracellular neurofibrillary tangles of phosphorylated α-synuclein (α-syn). Protein phosphatase 2A (PP2A) is responsible for α-syn dephosphorylation. Previous work has demonstrated that α-syn can regulate PP2A activity. However, the mechanisms underlying α-syn regulation of PP2A activity are not well understood. In this study, we found that α-syn overexpression induced increased α-syn phosphorylation at serine 129 (Ser129), and PP2A inhibition, in vitro and in vivo. α-syn overexpression resulted in PP2A demethylation. This demethylation was mediated via downregulated leucine carboxyl methyltransferase (LCMT-1) expression, and upregulated protein phosphatase methylesterase (PME-1) expression. Furthermore, LCMT-1 overexpression, or PME-1 inhibition, reversed α-syn-induced increases in α-syn phosphorylation and apoptosis. In addition to post-translational modifications of the catalytic subunit, regulatory subunits are involved in the regulation of PP2A activity. We found that the levels of regulatory subunits which belong to the PPP2R2 subfamily, not the PPP2R5 subfamily, were downregulated in the examined brain regions of transgenic mice. Our work identifies a novel mechanism to explain how α-syn regulates PP2A activity, and provides the optimization of PP2A methylation as a new target for PD treatment

    MAGNESIUM SULFATE ATTACK RESISTANCE OF SCM-MODIFIED CEMENT-BASED MATERIALS

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    Sulfate attack is one of the main concerns of cement-based materials. In this research, the magnesium sulfate attack resistivity of cement-based materials modified with nano silica (NS) and supplementary cementitious materials (SCMs) i.e., silica fume (SF), fly ash (FA) and ground granulated blast-furnace slag (GGBS) was studied up to 500 days. The effects of the initial curing time (7 and 28 days) on the mechanical property and volume stability of the cement mortars under magnesium sulfate attack were studied. The results showed that the NS has a better capability of improving the magnesium sulfate attack resistivity of the cement mortar compared with traditional supplementary materials, and a longer initial curing time contributed to the higher resistivity. The higher pozzolanic reactivity of NS led to a denser structure of the cement mortar and retarded the magnesium sulfate attack process. FA-added samples had poor resistance to magnesium sulfate attack due to the low pozzolanic reactivity. The resistance of the GGBS-added samples to magnesium sulfate attack was moderate among the samples

    Facile Synthesis of Nanoporous Amorphous Silica on Silicon Substrate

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    Large-scale nanoporous amorphous silica nanostructure is fabricated via a simply etched approach and effective thermal evaporation process. The nanoporous amorphous silica was synthesized by a general and scalable process via etching by metal particles on the silica sheets. In this study, we elucidated how a nanoporous structure was performed and the addition of indium is the key factor that determined the formation of the nanoporous structures. The morphology and the sizes of the porous structure could be tunable by the sizes and the shape of the metal. We discovered a promising optical property in the as-synthesized nanostructures, which have a photoluminescence in an intensive ultraviolet emission as well as a broad visible emission at room temperature

    The investigation of structure and IR spectra for hydrated potassium ion clusters K

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    The hydration of K+(H2O)n has been widely studied and believe to be important for understanding solvent properties in biological and chemical systems. However, understanding the structure and the spectrum information K+(H2O)n with changing n is limited. Here, we investigated the clusters K+(H2O)n=1–16 and further studied the IR spectrums of the most stable clusters with density functional theory. The configuration, bond length, vibration frequency were given out. It shows that K+(H2O)8(H2O)n, a distorted square antiprism in inner layer, is the main configuration with hydration distance rK - OI 0.296 nm when the hydration number n is bigger than 8. The saturated hydration number is 8 in the first hydration layer and the water molecules of the second hydration sphere have little effect on the inner ones when n> 8. A detailed classification about the hydrated water molecules was made according to the role of acceptor or donor hydrogen bonding in clusters. The vibration frequency of the different kinds of water molecules were also detailly identified. The results are valuable for further determination of the K+(H2O)n clusters in aqueous solutions
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