Sound radiation characteristics of a box-type structure

The finite element and boundary element methods are employed in this study to investigate the sound radiation characteristics of a box-type structure. It has been shown [T.R. Lin, J. Pan, Vibration characteristics of a box-type structure, Journal of Vibration and Acoustics, Transactions of ASME 131 (2009) 031004-1–031004-9] that modes of natural vibration of a box-type structure can be classified into six groups according to the symmetry properties of the three panel pairs forming the box. In this paper, we demonstrate that such properties also reveal information about sound radiation effectiveness of each group of modes. The changes of radiation efficiencies and directivity patterns with the wavenumber ratio (the ratio between the acoustic and the plate bending wavenumbers) are examined for typical modes from each group. Similar characteristics of modal radiation efficiencies between a box structure and a corresponding simply supported panel are observed. The change of sound radiation patterns as a function of the wavenumber ratio is also illustrated. It is found that the sound radiation directivity of each box mode can be correlated to that of elementary sound sources (monopole, dipole, etc.) at frequencies well below the critical frequency of the plates of the box. The sound radiation pattern on the box surface also closely related to the vibration amplitude distribution of the box structure at frequencies above the critical frequency. In the medium frequency range, the radiated sound field is dominated by the edge vibration pattern of the box. The radiation efficiency of all box modes reaches a peak at frequencies above the critical frequency, and gradually approaches unity at higher frequencies

Construction of network entrepreneurial platform leadership characteristics model: based on the grounded theory

With the embedding of internet technology, the entrepreneurial model has been gradually developing from  traditional single linear channel into network platform with symbiotic multi-platform. Platform leadership is the most important part of the new one and has been caught greatest attention. This paper put forward a new conception of network entrepreneurial platform leadership innovatively. By the integrated use of the Classical Grounded theory, the Procedure Grounded Theory and the Construction Grounded Theory, it adopted the normative research process of open coding, axial coding and selective coding to refine 34 concept—multi-node interactive, cross-level coupling relationship, etc, and formed  11 fundamental categories which include platform leadership power, network organization entrepreneurial mode, etc. Then, we analyzed the interactions between categories, based on which, a double-level and three-type-characteristics model were ultimately built. The study was finished by both two methods of statistical software and manual operation. In order to improve the reliability and validity of the study, it invited another coder to test the category subordination collaboratively, and used matched group to test the theoretical saturation.

Reconstruction of compressed spectral imaging based on global structure and spectral correlation

In this paper, a convolution sparse coding method based on global structure characteristics and spectral correlation is proposed for the reconstruction of compressive spectral images. The proposed method uses the convolution kernel to operate the global image, which can better preserve image structure information in the spatial dimension. To take full exploration of the constraints between spectra, the coefficients corresponding to the convolution kernel are constrained by the norm to improve spectral accuracy. And, to solve the problem that convolutional sparse coding is insensitive to low frequency, the global total-variation (TV) constraint is added to estimate the low-frequency components. It not only ensures the effective estimation of the low-frequency but also transforms the convolutional sparse coding into a de-noising process, which makes the reconstructing process simpler. Simulations show that compared with the current mainstream optimization methods (DeSCI and Gap-TV), the proposed method improves the reconstruction quality by up to 7 dB in PSNR and 10% in SSIM, and has a great improvement in the details of the reconstructed image

Stereotypical Images of STEM Professionals and STEM Career Interests in Chinese Elementary School Students

This study investigated stereotypical images of STEM professions and STEM career interest in Chinese elementary school students. The relationships between stereotypical images of STEM professionals and STEM career interests were also determined. Data for this study was gathered from two elementary schools in China, forming a convenience sample of 318 students enrolled from 3rd to 6th grade. Quantitative data of stereotypes about STEM professionals’ social skills, positive images of STEM professionals, views on STEM implications for society, and STEM career interests were gathered by a questionnaire with Likert scale. Follow-up structured interviews were performed with 12 participants. Elementary school students had strong stereotypes about STEM professionals’ social skills, slightly deep positive image of STEM professionals, and very positive views on STEM implications for society. However, their STEM career interests were not very high. Besides, elementary school students’ stereotypes about STEM professionals’ social skills have minor negative effects on their STEM career interests. Their positive image of STEM professionals and views on STEM implications for society have significant correlation with their STEM career interests

High reward enhances perceptual learning.

Studies of perceptual learning have revealed a great deal of plasticity in adult humans. In this study, we systematically investigated the effects and mechanisms of several forms (trial-by-trial, block, and session rewards) and levels (no, low, high, subliminal) of monetary reward on the rate, magnitude, and generalizability of perceptual learning. We found that high monetary reward can greatly promote the rate and boost the magnitude of learning and enhance performance in untrained spatial frequencies and eye without changing interocular, interlocation, and interdirection transfer indices. High reward per se made unique contributions to the enhanced learning through improved internal noise reduction. Furthermore, the effects of high reward on perceptual learning occurred in a range of perceptual tasks. The results may have major implications for the understanding of the nature of the learning rule in perceptual learning and for the use of reward to enhance perceptual learning in practical applications

Fibroblast Growth Factor-10 (FGF-10) Mobilizes Lung-resident Mesenchymal Stem Cells and Protects Against Acute Lung Injury.

FGF-10 can prevent or reduce lung specific inflammation due to traumatic or infectious lung injury. However, the exact mechanisms are poorly characterized. Additionally, the effect of FGF-10 on lung-resident mesenchymal stem cells (LR-MSCs) has not been studied. To better characterize the effect of FGF-10 on LR-MSCs, FGF-10 was intratracheally delivered into the lungs of rats. Three days after instillation, bronchoalveolar lavage was performed and plastic-adherent cells were cultured, characterized and then delivered therapeutically to rats after LPS intratracheal instillation. Immunophenotyping analysis of FGF-10 mobilized and cultured cells revealed expression of the MSC markers CD29, CD73, CD90, and CD105, and the absence of the hematopoietic lineage markers CD34 and CD45. Multipotency of these cells was demonstrated by their capacity to differentiate into osteocytes, adipocytes, and chondrocytes. Delivery of LR-MSCs into the lungs after LPS injury reduced the inflammatory response as evidenced by decreased wet-to-dry ratio, reduced neutrophil and leukocyte recruitment and decreased inflammatory cytokines compared to control rats. Lastly, direct delivery of FGF-10 in the lungs of rats led to an increase of LR-MSCs in the treated lungs, suggesting that the protective effect of FGF-10 might be mediated, in part, by the mobilization of LR-MSCs in lungs

Effect of berbamine hydrochloride on the absorption of berberine hydrochloride in an in situ single-pass intestinal perfusion system in rats

Purpose: To investigate the intestinal absorption characteristics of berberine hydrochloride (BBH) under different perfusion conditions in rats.Methods: Based on the in situ single-pass intestinal perfusion model of rats, HPLC was used to determine the content of berberine hydrochloride in solution after perfusion under different conditions. The absorption rate constant (Ka), effective permeability coefficient (Papp) and cumulative absorption per unit area (Q) under different perfusion conditions were analyzed by one-way ANOVA.Results: The Papp and Ka of BBH in perfusion solution at pH 7.4 were greater than those in perfusion solution at pH 6 and 8. There was no significant difference (p > 0.05) in Papp and Ka of duodenum, jejunum and ileum at high, medium and low concentrations of berberine hydrochloride perfusion solution. The Q increased linearly with increase of mass concentration of perfusion solution. The Ka and Papp of BBH in duodenum, jejunum, and ileum of BBH and berbamine hydrochloride (BAH) combined at different ratios were higher than those of BBH control group at the same BBH concentration, but absorption of BBH in the ratio B40:A50 and B30:A20 groups was highest. In the ratio of B40:A50 ratio, B30:A20 ratio group or the same concentration's BBH group, Ka and Papp of BBH decreased in the order of jejunum > duodenum > ileum.Conclusion: Berberine hydrochloride is absorbed in neutral environment of pH 7.4. The intestinal absorption mechanism of BBH is passive diffusion, and jejunum is the best intestinal segment for absorption. BAH promotes the absorption of BBH

Control-A-Video: Controllable Text-to-Video Generation with Diffusion Models

This paper presents a controllable text-to-video (T2V) diffusion model, named Video-ControlNet, that generates videos conditioned on a sequence of control signals, such as edge or depth maps. Video-ControlNet is built on a pre-trained conditional text-to-image (T2I) diffusion model by incorporating a spatial-temporal self-attention mechanism and trainable temporal layers for efficient cross-frame modeling. A first-frame conditioning strategy is proposed to facilitate the model to generate videos transferred from the image domain as well as arbitrary-length videos in an auto-regressive manner. Moreover, Video-ControlNet employs a novel residual-based noise initialization strategy to introduce motion prior from an input video, producing more coherent videos. With the proposed architecture and strategies, Video-ControlNet can achieve resource-efficient convergence and generate superior quality and consistent videos with fine-grained control. Extensive experiments demonstrate its success in various video generative tasks such as video editing and video style transfer, outperforming previous methods in terms of consistency and quality. Project Page: https://controlavideo.github.io