Chebyshev Biorthogonal Multiwavelets and Approximation

In this paper, we construct Chebyshev biorthogonal multiwavelets, and use this multiwavelets to approximate signals (functions). The convergence rate for signal approximation is derived. The fast signal decomposition and reconstruction algorithms are presented. The numerical examples validate the theoretical analysis.

Unidirectional rotation of circles driven by chiral active particles

The dynamics of two-dimensional rigid circles filled with chiral active particles are investigated by employing the overdamped Langevin dynamics simulations. Unidirectional rotation of rigid circles is observed, and the rotational angular velocity（ω） relies mainly on the length（l）, the number（nB）, and tilt angle（γ） of boards, and the angular velocity（ω）and area fraction（ρ） of chiral active particles. There are optimum values for these parameters at which the average angular velocity of circle reaches its maximum. The center-of-mass mean square displacement for circles drops by about two orders of magnitude for large angular velocity ω of chiral active particles with oscillations in the short-time regime. Our work demonstrates that nanofabricated objects with suitable designs immersed in a bath of chiral active particles can extract and rectify energy in a unidirectional motion.

科学数据跨境流动治理的现状、思考与展望

伴随着数据密集型科学研究范式的兴起,科学数据已成为传播速度最快、影响面最宽、开发利用潜力最大的战略性、基础性科技资源,各国对科学数据的管理、共享和综合利用的需求与日俱增.在百年变局加速演进、大国科技博弈愈加激烈、开放科学持续推进以及我国加快构建具有全球竞争力的开放创新生态背景下,科学数据跨境流动逐步成为影响科学研究和学术交流的重要因素之一.

DVsc:An Automated Framework for Efficiently Detecting Viral Infection from Single-cell Transcriptomics Data

Single-cell RNA sequencing(scRNA-seq)has emerged as a valuable tool for studying cellular heterogeneity in various fields,particularly in virological research.By studying the viral and cellular transcriptomes,the dynamics of viral infection can be investigated at a single-cell resolution.However,limited studies have been conducted to investigate whether RNA transcripts from clinical samples contain substantial amounts of viral RNAs,and a specific computational framework for efficiently detecting viral reads based on scRNA-seq data has not been developed.Hence,we introduce DVsc,an open-source framework for precise quantitative analysis of viral infection from single-cell transcriptomics data.When applied to approximately 200 diverse clinical samples that were infected by more than 10 different viruses,DVsc demonstrated high accuracy in systematically detecting viral infection across a wide array of cell types.This innovative bioinformatics pipeline could be crucial for addressing the potential effects of surreptitiously invading viruses on certain illnesses,as well as for designing novel medicines to target viruses in specific host cell subsets and evaluating the efficacy of treatment.DVsc supports the FASTQ format as an input and is compatible with multiple single-cell sequencing platforms.Moreover,it could also be applied to sequences from bulk RNA sequencing data.DVsc is available at http://62.234.32.33:5000/DVsc.

社会计算与社会智能:机遇与挑战

本文梳理了社会计算与社会智能诞生的时代背景,对社会计算、社会智能、计算社会科学等概念进行了辨析,提出了当前社会计算中的八大挑战问题,分别是数据伦理与数据治理、开源平台建设与管理、人与社会的重构、基于认知科学的人工智能、复杂系统建模和分析、仿真系统建设与研究、因果推理与因果发现、全球公共危机管理。在此基础上进一步提出了社会计算研究范式的转变,认为,社会计算研究范式是继实验科学、理论科学、计算科学、数据密集型的探索科学后的新研究范式,即社会科学和计算科学高度交叉融合的研究范式。

Absorption and scattering effects of Maalox,chlorophyll, and sea salt on a micro-LED-based underwater wireless optical communication [Invited]

In this work,a blue gallium nitride(GaN)micro-light-emitting-diode(micro-LED)-based underwater wireless optical communication(UWOC)system was built,and UWOCs with varied Maalox,chlorophyll,and sea salt concentrations were studied.Data transmission performance of the UWOC and the influence of light attenuation were investigated systematically.Maximum data transmission rates at the distance of 2.3 m were 933,800,910,and 790 Mbps for experimental conditions with no impurity,200.48 mg/m3 Maalox,12.07 mg/m3 chlorophyll,and 5 kg/m3 sea salt,respectively,much higher than previously reported systems with commercial LEDs.It was found that increasing chlorophyll,Maalox,and sea salt concentrations in water resulted in an increase of light attenuation,which led to the performance degradation of the UWOC.Further analysis suggests two light attenuation mechanisms,e.g.,absorption by chlorophyll and scattering by Maalox,are responsible for the decrease of maximum data rates and the increase of bit error rates.Based on the absorption and scattering models,excellent fitting to the experimental attenuation coefficient can be achieved,and light attenuation by absorption and scattering at different wavelengths was also investigated.We believe this work is instructive apply UWOC for practical applications.