582 research outputs found

    OH-Ď€ HYDROGEN BOND IN THE COMPLEX OF STYRENE-WATER: A ROTATIONAL STUDY

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    The rotational spectra of the styrene-water complex has been investigated by using the pulsed jet Fourier transform microwave spectroscopic technique. Styrene has two π\pi systems which can act as the proton acceptor and link with water through the OH-π\pi hydrogen bond. Ab initio calculations suggested that the vinyl π\pi system is favored to form such a hydrogen bond. In contrast, the experimental evidences of four isotopologues pointed out that the water O-H group prefers to link to the benzene π\pi system. The internal rotation of water around its symmetry axis splits all the rotational transitions into two component line with a relative intensity ration of 1:3

    Non-Covalent Interaction: Revealed by Rotational Spectroscopy

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    The pulsed jet Fourier transform microwave spectroscopy have been applied to several molecular complexes involving H2O, freons, methane, carboxylic acids, and rare gas. The obtained results showcase the suitability of this technique for studying the intermolecular interactions. The rotational spectra of three water adducts of halogenated organic molecules, i.e. chlorotrifluoroethylene, isoflurane and alfa,alfa,alfa,-trifluoroanisole, have been investigated. It has been found that, the halogenation of the partner molecules definitely changes the way in which water will link to the partner molecule. Quadrupole hyperfine structures and/or the tunneling splittings have been observed in the rotational spectra of difluoromethane-dichloromethane, chlorotrifluorometane-fluoromethane, difluoromethane-formaldehyde and trifluoromethane-benzene. These features have been useful to describe their intermolecular interactions (weak hydrogen bonds or halogen bonds), and to size the potential energy surfaces of their internal motions. The rotational spectrum of pyridine-methane pointed out that methane prefers to locate above the ring and link to pyridine through a C-H•••π weak hydrogen bond, rather than the C-H•••n interaction. This behavior, typical of complexes of pyridine with rare gases, suggests classifying CH4, in relation to its ability to form molecular complexes with aromatic molecules, as a pseudo rare gas. The conformational equilibria of three bi-molecules of carboxylic acids, acrylic acid-trifluoroacetic acid, difluoroacetic acid-formic acid and acrylic acid-fluoroacetic acid have been studied. The increase of the hydrogen bond length upon H→D isotopic substitution (Ubbelohde effect) has been deduced from the elongation of the carboxylic carbons C•••C distance. The van der Waals complex tetrahydrofuran-krypton shows that the systematic doubling of the rotational lines has been attributed to the residual pseudo-rotation of tetrahydrofuran in the complex, based on the values of the Coriolis coupling constants, and on the type (mu_b) of the interstate transitions

    A survey on energy justice: a critical review of the literature

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    The increasing scarcity of resources and the escalating complexity of reality make the fairness ensuring in energy activities even more difficult. In this context, energy justice, as an emerging cross-field, tries to provide solutions based on practical problems. In the face of the surge of energy justice publications, it is necessary to review them in time, so that we can comprehend the significant achievements and the research directions worthy of further exploration. With the help of visualization tools, this paper conducts a comprehensive quantitative analysis of 1,910 energy justice publications. Based on the results, we reach the following main conclusions: (1) The energy justice publications have only emerged rapidly in recent years; (2) The research hotspots are closely related to the renewable energy transition; (3) The distribution of prominent contributors in this field is relatively concentrated. The main contribution of this study is to comprehensively display the essential characteristics of the literature in this field, such as the evolutions of research themes and the performances of research contributors in different dimensions, so as to provide readers with an effective way to understand the knowledge structure in this field, and help related researchers rationally examine the existing results

    Virtual Accessory Try-On via Keypoint Hallucination

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    The virtual try-on task refers to fitting the clothes from one image onto another portrait image. In this paper, we focus on virtual accessory try-on, which fits accessory (e.g., glasses, ties) onto a face or portrait image. Unlike clothing try-on, which relies on human silhouette as guidance, accessory try-on warps the accessory into an appropriate location and shape to generate a plausible composite image. In contrast to previous try-on methods that treat foreground (i.e., accessories) and background (i.e., human faces or bodies) equally, we propose a background-oriented network to utilize the prior knowledge of human bodies and accessories. Specifically, our approach learns the human body priors and hallucinates the target locations of specified foreground keypoints in the background. Then our approach will inject foreground information with accessory priors into the background UNet. Based on the hallucinated target locations, the warping parameters are calculated to warp the foreground. Moreover, this background-oriented network can also easily incorporate auxiliary human face/body semantic segmentation supervision to further boost performance. Experiments conducted on STRAT dataset validate the effectiveness of our proposed method

    Heat Transfer Correlations for Supercritical Water in Vertically Upward Tubes

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    Supercritical pressure water (SCW) has been widely used in many engineering fields and industries, such as fossil fuel-fired power plants, newly developed Gen-IV nuclear power plants and so forth. Heat transfer characteristics of SCW are of great importance for both design and safe operation of the related systems. Many heat transfer correlations have been developed in the history for predicting the heat transfer characteristics of SCW. However, the prediction accuracy of the existing correlations is less than satisfactory, especially in the cases with deteriorated heat transfer (DHT) because of the severe and quick variation in thermal physical properties of SCW in the vicinity of the fluids’ pseudo critical point. It is very necessary to develop new correlations for the heat transfer of SCW to meet the engineering requirements for satisfactory prediction of the heat transfer behavior of SCW. In this chapter, experimental data on heat transfer of SCW are extensively collected from published literatures, and the performance of the existing heat transfer correlations for SCW are reviewed and quantitatively evaluated against the collected experimental data, and then a new heat transfer correlation for SCW with high prediction accuracy is proposed

    Decorin-mediated inhibition of colorectal cancer growth and migration is associated with E-cadherin in vitro and in mice.

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    Previous studies have shown that decorin expression is significantly reduced in colorectal cancer tissues and cancer cells, and genetic deletion of the decorin gene is sufficient to cause intestinal tumor formation in mice, resulting from a downregulation of p21, p27(kip1) and E-cadherin and an upregulation of β-catenin signaling [Bi,X. et al. (2008) Genetic deficiency of decorin causes intestinal tumor formation through disruption of intestinal cell maturation. Carcinogenesis, 29, 1435-1440]. However, the regulation of E-cadherin by decorin and its implication in cancer formation and metastasis is largely unknown. Using a decorin knockout mouse model (Dcn(-/-) mice) and manipulated expression of decorin in human colorectal cancer cells, we found that E-cadherin, a protein that regulates cell-cell adhesion, epithelial-mesenchymal transition and metastasis, was almost completely lost in Dcn(-/-) mouse intestine, and loss of decorin and E-cadherin accelerated colon cancer cell growth and invasion in Dcn(-/-) mice. However, increasing decorin expression in colorectal cancer cells attenuated cancer cell malignancy, including inhibition of cancer cell proliferation, promotion of apoptosis and importantly, attenuation of cancer cell migration. All these changes were linked to the regulation of E-cadherin by decorin. Moreover, overexpression of decorin upregulated E-cadherin through increasing of E-cadherin protein stability as E-cadherin messenger RNA and promoter activity were not affected. Co-immunoprecipitation assay showed a physical binding between decorin and E-cadherin proteins. Taken together, our results provide direct evidence that decorin-mediated inhibition of colorectal cancer growth and migration are through the interaction with and stabilization of E-cadherin
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