Mathematics simulation and experiments of continuous casting with strip feeding in mold

Steel strip feeding technology can reduce the degree of superheat of the molten steel, change the solidification order of the molten steel; raise the equiaxed crystal rate of the slab and improve the continuous casting quality. The paper establishes the mathematical model of heat transfer and temperature field of casting billet of steel strip feeding in continuous casting mold. Results show that if Plate Billet is 1 000 mm × 220 mm and the steel strip is 100 mm × 3 mm, feeding position of parallel is 250 mm from the narrow side. When the feeding speed is 3,6 m/min, the superheat degree can be reduced by 5 °C, and the solidification length can be reduced by 2,9 m. When the feeding speed is 6 m/min, the superheat degree can be reduced by about 9 °C, and the solidification length can be reduced by 3,7 m. The results of the test in a steel plant are in good agreement with the experimental results

Multifractal analysis of complex networks

Complex networks have recently attracted much attention in diverse areas of science and technology. Many networks such as the WWW and biological networks are known to display spatial heterogeneity which can be characterized by their fractal dimensions. Multifractal analysis is a useful way to systematically describe the spatial heterogeneity of both theoretical and experimental fractal patterns. In this paper, we introduce a new box covering algorithm for multifractal analysis of complex networks. This algorithm is used to calculate the generalized fractal dimensions $D_{q}$ of some theoretical networks, namely scale-free networks, small world networks and random networks, and one kind of real networks, namely protein-protein interaction networks of different species. Our numerical results indicate the existence of multifractality in scale-free networks and protein-protein interaction networks, while the multifractal behavior is not clear-cut for small world networks and random networks. The possible variation of $D_{q}$ due to changes in the parameters of the theoretical network models is also discussed.Comment: 18 pages, 7 figures, 4 table

Propagation Modes of 3D Scour below a Submarine Pipeline in Oblique Steady Currents and Waves

This paper presents experimental results on 3D scour propagation along a pipeline under oblique-incidence currents and waves. Different modes of 3D scour propagation were discovered after the local scour was initiated below the pipeline. These modes include scour propagation throughout the whole pipeline, onset of scour at multiple locations due to piping, termination of scour propagation induced by backfill and no scour propagation. The critical conditions for these scour propagation modes were determined in terms of flow incident angle, embedment depth and Shields parameter (or KC number)

Comparison of anal function and quality of life after conformal sphincter preservation operation and intersphincteric resection of very low rectal cancer: a multicenter, retrospective, case-control analysis

Purpose: Conformal sphincter preservation operation (CSPO) is a sphincter preservation operation for very low rectal cancers. Compared to intersphincteric resection (ISR), CSPO retains more dentate line and distal rectal wall, and also avoids damaging the nerves in the intersphincteric space. This study aimed to compare the postoperative anal function and quality of life between the CSPO and ISR. Method: Patients with low rectal cancer undergoing CSPO (n = 117) and ISR (n = 66) were included from Changhai and Huashan Hospital, respectively, between 2011 and 2020. A visual analog scale (range 0–10) was utilized to evaluate satisfaction with anal function and quality of life. The anal function was evaluated with Wexner scores and low anterior resection syndrome (LARS) score. Quality of life was evaluated with the EORTC QLQ-C30 and QLQ-CR38. Results: The CSPO group had more male patients (65.8% vs. 50%, p = 0.042), more preoperative chemoradiotherapy (33.3% vs. 10.6%, p < 0.001), lower tumor position (3.45 ± 1.13 vs. 4.24 ± 0.86 cm, p < 0.001), and more postoperative chemotherapy (65% vs. 13.6%, p < 0.001) compared to the ISR group. In addition, CSPO patients had shorter postoperative stay (6.63 ± 2.53 vs. 7.85 ± 4.73 days, p = 0.003) and comparable stoma reversal rates within 1 year after surgery (92.16% vs. 96.97%, p = 0.318). Multivariable analysis showed that CSPO significantly contributed to higher satisfaction with anal function (beta = 1.752, 95% CI 0.776–2.728) and with quality of life (beta = 1.219, 95% CI 0.374–2.064), but not to Wexner, LARS score, or EORTC QLQ-C30 and QLQ-CR38. Conclusion: CSPO improved the satisfaction with anal function and quality of life but utilized more preoperative chemoradiotherapy. CSPO may be an alternative choice for patients with very low rectal cancers in better physical health and with higher requirements for anal function and quality of life

Application of a Double Aza-Michael Reaction in a ‘Click, Click, Cy-Click’ Strategy: From Bench to Flow

The development of a ‘click, click, cy-click’ process utilizing a double aza-Michael reaction to generate functionalized 1,2,5-thiadiazepane 1,1-dioxides is reported. Optimization in flow, followed by scale out of the inter-/intramolecular double aza-Michael addition has also been realized using a microwave-assisted, continuous flow organic synthesis platform (MACOS). In addition, a facile one-pot, sequential strategy employing in situ Huisgen cycloaddition post-double aza-Michael has been accomplished, and is applicable to library synthesis

Theory of Exciton Recombination from the Magnetically Induced Wigner Crystal

We study the theory of itinerant-hole photoluminescence of two-dimensional electron systems in the regime of the magnetically induced Wigner crystal. We show that the exciton recombination transition develops structure related to the presence of the Wigner crystal. The form of this structure depends strongly on the separation $d$ between the photo-excited hole and the plane of the two-dimensional electron gas. When $d$ is small compared to the magnetic length, additional peaks appear in the spectrum due to the recombination of exciton states with wavevectors equal to the reciprocal lattice vectors of the crystal. For $d$ larger than the magnetic length, the exciton becomes strongly confined to an interstitial site of the lattice, and the structure in the spectrum reflects the short-range correlations of the Wigner crystal. We derive expressions for the energies and the radiative lifetimes of the states contributing to photoluminescence, and discuss how the results of our analysis compare with experimental observations.Comment: 10 pages, no figures, uses Revtex and multicol.st