8 research outputs found

    Effects of Different Conditions of Water Cooling at High Temperature on the Tensile Strength and Split Surface Roughness Characteristics of Hot Dry Rock

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    To investigate the effects of the different conditions of water cooling at high temperature on the tensile strength and split surface roughness characteristics of hot dry rock in the Songliao Basin, the physical characteristics, tensile strength, and split surface roughness of granite under different conditions of water cooling at high temperature were studied. In addition, the relationship between tensile strength and split surface roughness under different conditions of water cooling at high temperature was established. The results showed the following: (1) as the rock temperature increased, the number of water injection cycles increased or the water injection temperature decreased, the mechanical properties of the specimen weakened, and the roughness of the split surface increased. The threshold for the effect of the rock temperature on the split surface roughness of granite was 300°C. At 400°C, the tensile strength greatly decreased. At 600°C, the tensile strength, height mean square error (MSE), fluctuation difference, roughness coefficient, and roughness profile index of the specimen were 0.21, 2.51, 2.57, 8.92, and 1.06 times those at 100°C, respectively. After five heating-cooling cycles, the tensile strength, height MSE, fluctuation difference, roughness coefficient, and roughness profile index of the specimen were 0.57, 1.33, 1.49, 1.29, and 1.01 times those after one cycle, respectively. (2) The roughness angle calculated using the root mean square of the first derivative of the profile was always greater than that derived using the roughness profile index. In addition, the higher the temperature, the lower the water temperature, the more high-temperature-water cooling cycles, the greater the difference between the above two calculations. (3) When the tensile strength varies, the factors affecting the variation in the height MSE and surface roughness were in the following descending order: rock temperature, number of heating-cooling cycles, and water temperature. In addition, the higher the tensile strength, the lower the roughness coefficient. This study is expected to provide a reference for the selection of different conditions of water cooling at high temperature for thermal recovery in the Songliao Basin

    Wind Tunnel Tests and Numerical Simulations of Wind-Induced Snow Drift in an Open Stadium and Gymnasium

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    A long-span sports centre generally comprises multiple stadiums and gymnasiums, for which mutual interference effects of wind-induced snow motion are not explicitly included in the specifications of various countries. This problem is addressed herein by performing wind tunnel tests and numerical simulations to investigate the snow distribution and mutual interference effect on the roofs of long-span stadiums and gymnasiums. The wind tunnel tests were used to analyse the influences of the opening direction (0°, 90°, 180°, and 270°) and spacing (0.3 L, 0.5 L, 1 L, 1.5 L, 2 L, and 2.5 L, where L is the gymnasium span) of the stadium and gymnasium. The wind tunnel tests and numerical simulations were used to analyse the influence of the wind direction angle (from 0° to 315°, there are a total of eight groups in 45° intervals). The following results were obtained. The stadium opening had a significant effect on the snow distribution on the surface of the two structures. An even snow distribution was obtained when the stadium opened directly facing the gymnasium, which corresponded to the safest condition for the structures’ surfaces. As the spacing between the buildings increased, the interference effect between the two structures was reduced. The interference was negligible for a spacing of 2 L. The stadium had the most significant amplification interference effect on the gymnasium for a wind direction angle of 45°, which was extremely unfavourable to the safety of the structure. The most favourable wind direction angle was 270°, where there were both amplification interference and blockage interference

    The SLC Family Are Candidate Diagnostic and Prognostic Biomarkers in Clear Cell Renal Cell Carcinoma

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    Clear cell renal cell carcinoma (ccRCC) is the most common lethal subtype of renal cancer, and changes in tumor metabolism play a key role in its development. Solute carriers (SLCs) are important in the transport of small molecules in humans, and defects in SLC transporters can lead to serious diseases. The expression patterns and prognostic values of SLC family transporters in the development of ccRCC are still unclear. The current study analyzed the expression levels of SLC family members and their correlation with prognosis in ccRCC patients with data from Oncomine, Gene Expression Profiling Interactive Analysis (GEPIA), The Cancer Genome Atlas (TCGA), cBioPortal, the Human Protein Atlas (HPA), the International Cancer Genome Consortium (ICGC), and the Gene Expression Omnibus (GEO). We found that the mRNA expression levels of SLC22A6, SLC22A7, SLC22A13, SLC25A4, SLC34A1, and SLC44A4 were significantly lower in ccRCC tissues than in normal tissues and the protein expression levels of SLC22A6, SLC22A7, SLC22A13, and SLC34A1 were also significantly lower. Except for SLC22A7, the expression levels of SLC22A6, SLC22A13, SLC25A4, SLC34A1, and SLC44A4 were correlated with the clinical stage of ccRCC patients. The lower the expression levels of SLC22A6, SLC22A13, SLC25A4, SLC34A1, and SLC44A4 were, the later the clinical stage of ccRCC patients was. Further experiments revealed that the expression levels of SLC22A6, SLC22A7, SLC22A13, SLC25A4, SLC34A1, and SLC44A4 were significantly associated with overall survival (OS) and disease-free survival (DFS) in ccRCC patients. High SLC22A6, SLC22A7, SLC22A13, SLC25A4, SLC34A1, and SLC44A4 expression predicted improved OS and DFS. Finally, GSE53757 and ICGC were used to revalidate the differential expression and clinical prognostic value. This study suggests that SLC22A6, SLC22A7, SLC22A13, SLC25A4, SLC34A1, and SLC44A4 may be potential targets for the clinical diagnosis, prognosis, and treatment of ccRCC patients

    Emergence of quantum confinement in topological kagome superconductor CsV3Sb5

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    Abstract Quantum confinement is a restriction on the motion of electrons in a material to specific region, resulting in discrete energy levels rather than continuous energy bands. In certain materials, quantum confinement could dramatically reshape the electronic structure and properties of the surface with respect to the bulk. Here, in the recently discovered kagome superconductors CsV3Sb5, we unveil the dominant role of quantum confinement in determining their surface electronic structure. Combining angle-resolved photoemission spectroscopy (ARPES) measurement and density-functional theory simulation, we report the observations of two-dimensional quantum well states due to the confinement of bulk electron pocket and Dirac cone to the nearly isolated surface layer. The theoretical calculations on the slab model also suggest that the ARPES observed spectra are almost entirely contributed by the top two layers. Our results not only explain the disagreement of band structures between the recent experiments and calculations, but also suggest an equally important role played by quantum confinement, together with strong correlation and band topology, in shaping the electronic properties of this material
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