8,218 research outputs found
Turbulent convection model in the overshooting region: II. Theoretical analysis
Turbulent convection models are thought to be good tools to deal with the
convective overshooting in the stellar interior. However, they are too complex
to be applied in calculations of stellar structure and evolution. In order to
understand the physical processes of the convective overshooting and to
simplify the application of turbulent convection models, a semi-analytic
solution is necessary.
We obtain the approximate solution and asymptotic solution of the turbulent
convection model in the overshooting region, and find some important properties
of the convective overshooting:
I. The overshooting region can be partitioned into three parts: a thin region
just outside the convective boundary with high efficiency of turbulent heat
transfer, a power law dissipation region of turbulent kinetic energy in the
middle, and a thermal dissipation area with rapidly decreasing turbulent
kinetic energy. The decaying indices of the turbulent correlations ,
, and are only determined by the parameters of the
TCM, and there is an equilibrium value of the anisotropic degree .
II. The overshooting length of the turbulent heat flux is
about ().
III. The value of the turbulent kinetic energy at the convective boundary
can be estimated by a method called \textsl{the maximum of diffusion}.
Turbulent correlations in the overshooting region can be estimated by using
and exponentially decreasing functions with the decaying indices.Comment: 32 pages, 9 figures, Accepted by The Astrophysical Journa
On Red Culture Education under the Background of Youth Education in Higher Vocational Colleges
Red culture is a unique socioculture formed by the Chinese Communist Party in the revolutionary practice, and plays the role of propagating positive energy in the course of China’s development. Under the background of youth education in higher vocational colleges, the development of red culture education can promote the development of Ideological and political education in higher vocational colleges, cultivate the socialist core values of students, and continue the struggle spirit of the Chinese nation, so that students in China become ideal and ambitious new young people in the new era to strive for the early realization of the great rejuvenation of the Chinese nation. To this end, this article aims to study the education of red culture under the background of youth education in higher vocational colleges, and hope to provide some suggestions for the development of Ideological and political education in higher vocational colleges.
Keywords: higher vocational colleges, youth education background, red culture educatio
Contextual modeling of hand written Chinese character for recognition. II. Discriminative training
This is an extension of a companion paper entitled 'Contextual Modeling of Hand Written Chinese Character for Recognition (I) - A Comparative Study' which is also submitted to this conference for presentation. In this investigation, contextual models are discriminatively trained using a gradient projection technique. Both open test and close test recognition rates are substantially upgraded when compared with the results of the decision directed training algorithm reported in the other paper.published_or_final_versio
A discrete contextual stochastic model for the off-line recognition of handwritten Chinese characters
We study a discrete contextual stochastic (CS) model for complex and variant patterns like handwritten Chinese characters. Three fundamental problems of using CS models for character recognition are discussed, and several practical techniques for solving these problems are investigated. A formulation for discriminative training of CS model parameters is also introduced and its practical usage investigated. To illustrate the characteristics of the various algorithms, comparative experiments are performed on a recognition task with a vocabulary consisting of 50 pairs of highly similar handwritten Chinese characters. The experimental results confirm the effectiveness of the discriminative training for improving recognition performance.published_or_final_versio
KDM2B/FBXL10 targets c-Fos for ubiquitylation and degradation in response to mitogenic stimulation.
KDM2B (also known as FBXL10) controls stem cell self-renewal, somatic cell reprogramming and senescence, and tumorigenesis. KDM2B contains multiple functional domains, including a JmjC domain that catalyzes H3K36 demethylation and a CxxC zinc-finger that recognizes CpG islands and recruits the polycomb repressive complex 1. Here, we report that KDM2B, via its F-box domain, functions as a subunit of the CUL1-RING ubiquitin ligase (CRL1/SCF(KDM2B)) complex. KDM2B targets c-Fos for polyubiquitylation and regulates c-Fos protein levels. Unlike the phosphorylation of other SCF (SKP1-CUL1-F-box)/CRL1 substrates that promotes substrates binding to F-box, epidermal growth factor (EGF)-induced c-Fos S374 phosphorylation dissociates c-Fos from KDM2B and stabilizes c-Fos protein. Non-phosphorylatable and phosphomimetic mutations at S374 result in c-Fos protein which cannot be induced by EGF or accumulates constitutively and lead to decreased or increased cell proliferation, respectively. Multiple tumor-derived KDM2B mutations impaired the function of KDM2B to target c-Fos degradation and to suppress cell proliferation. These results reveal a novel function of KDM2B in the negative regulation of cell proliferation by assembling an E3 ligase to targeting c-Fos protein degradation that is antagonized by mitogenic stimulations
UAV-Assisted Wireless Powered Cooperative Mobile Edge Computing:Joint Offloading, CPU Control, and Trajectory Optimization
This article investigates the unmanned-aerial-vehicle (UAV)-enabled wireless powered cooperative mobile edge computing (MEC) system, where a UAV installed with an energy transmitter (ET) and an MEC server provides both energy and computing services to sensor devices (SDs). The active SDs desire to complete their computing tasks with the assistance of the UAV and their neighboring idle SDs that have no computing task. An optimization problem is formulated to minimize the total required energy of UAV by jointly optimizing the CPU frequencies, the offloading amount, the transmit power, and the UAV’s trajectory. To tackle the nonconvex problem, a successive convex approximation (SCA)-based algorithm is designed. Since it may be with relatively high computational complexity, as an alternative, a decomposition and iteration (DAI)-based algorithm is also proposed. The simulation results show that both proposed algorithms converge within several iterations, and the DAI-based algorithm achieve the similar minimal required energy and optimized trajectory with the SCA-based one. Moreover, for a relatively large amount of data, the SCA-based algorithm should be adopted to find an optimal solution, while for a relatively small amount of data, the DAI-based algorithm is a better choice to achieve smaller computing energy consumption. It also shows that the trajectory optimization plays a dominant factor in minimizing the total required energy of the system and optimizing acceleration has a great effect on the required energy of the UAV. Additionally, by jointly optimizing the UAV’s CPU frequencies and the amount of bits offloaded to UAV, the minimal required energy for computing can be greatly reduced compared to other schemes and by leveraging the computing resources of idle SDs, the UAV’s computing energy can also be greatly reduced
AutoDeconJ: a GPU accelerated ImageJ plugin for 3D light field deconvolution with optimal iteration numbers predicting
Light field microscopy is a compact solution to high-speed 3D fluorescence
imaging. Usually, we need to do 3D deconvolution to the captured raw data.
Although there are deep neural network methods that can accelerate the
reconstruction process, the model is not universally applicable for all system
parameters. Here, we develop AutoDeconJ, a GPU accelerated ImageJ plugin for
4.4x faster and accurate deconvolution of light field microscopy data. We
further propose an image quality metric for the deconvolution process, aiding
in automatically determining the optimal number of iterations with higher
reconstruction accuracy and fewer artifact
Policy assessments for the carbon emission flows and sustainability of Bitcoin blockchain operation in China
The growing energy consumption and associated carbon emission of Bitcoin mining could potentially undermine global sustainable efforts. By investigating carbon emission flows of Bitcoin blockchain operation in China with a simulation-based Bitcoin blockchain carbon emission model, we find that without any policy interventions, the annual energy consumption of the Bitcoin blockchain in China is expected to peak in 2024 at 296.59 Twh and generate 130.50 million metric tons of carbon emission correspondingly. Internationally, this emission output would exceed the total annualized greenhouse gas emission output of the Czech Republic and Qatar. Domestically, it ranks in the top 10 among 182 cities and 42 industrial sectors in China. In this work, we show that moving away from the current punitive carbon tax policy to a site regulation policy which induces changes in the energy consumption structure of the mining activities is more effective in limiting carbon emission of Bitcoin blockchain operation
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Seismic performance of a load-bearing prefabricated composite wall panel structure for residential construction
To improve both seismic performance and thermal insulation of low-rise housing in rural areas of China, this study proposes a load-bearing prefabricated composite wall panel structure that achieves appropriate seismic performance and energy efficiency using field-assembled load-bearing prefabricated composite wall panels. A 1:2 scale prototype built using load-bearing prefabricated composite wall panel is subjected to quasi-static testing so as to obtain damage characteristics, load-bearing capacity and load–displacement curves in response to a simulated earthquake. As a result, seismic performance indicators of load-bearing capacity, deformation and energy-dissipating characteristics, are assessed against the corresponding seismic design requirements for rural building structures of China. Experimental results indicate that the earthquake-resistant capacity of the prototype is 68% higher than the design value. The sample has a ductility factor of 4.7, which meets the seismic performance requirement mandating that the ductility factor of such concrete structures should exceed 3. The design can be further optimized to save the consumption of material. This shows that the load-bearing prefabricated composite wall panel structure developed here has decent load-bearing capacity, ductility and energy dissipation abilities, a combination of which is in line with the seismic design code. A new construction process proposed here based on factory prefabrication and field assembly leads to a considerable reduction of energy consumption. </jats:p
TfR Binding Peptide Screened by Phage Display Technology - Characterization to Target Cancer Cells
Purpose: To screen an hTfR affinity peptide and investigate its activity in vitro.Methods: hTfR affinity phage clones were screened from 7-mer phage display library, and their binding ability evaluated by enzyme-linked immunosorbent assay (ELISA). A competitive assay was performed to discover the peptide BP9 (BP9) binding site on the cells. The inhibitory effect of BP9 on the cells was determined using thiazolyl blue (MTT) assay. EGFP-BP9 fusion protein was expressed in E. coli, and its binding and localization on cells were determined by fluorescence microscopy and confocal microscopy, respectively.Results: After three rounds of panning, recovery efficiency was 48-fold higher than that of the first round. The peptide BP9 sharing 2 identical amino acids to Tf showed high-affinity to hTfR, and possessed strong proliferation inhibition ratio on different tumour cells of 70 % (HepG2 cells)/77 % (SMMC-7221 cells) at a concentration of 0.1 mM, and 85 % (HepG2 cells)/81 % (SMMC-7221 cells) at a concentration of 0.001 mM for 48 h. The recombinant protein EGFP–BP9 could bind to tumour cells andgain entry via the endocytic pathway.Conclusion: BP9 can bind to TfR and inhibit the proliferation of the tumour cells over-expressing TfR. The DNA sequence coding for BP9 was able to target the macromolecule to combine with TfR. BP9 may possess potential applications in cancer therapy.Keywords: Peptide, hTfR, Transferrin receptor, Phage display technology, Enhanced green fluorescence protein, Target, Cancer cell
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