Software defined intelligent satellite-terrestrial integrated networks:Insights and challenges

Satellite-Terrestrial integrated Networks(STNs)have been advocated by both academia and industry as a promising network paradigm to achieve service continuity and ubiquity.However,STNs suffer from problems including poor flexibility of network architecture,low adaptability to dynamic environments,the lack of network intelligence,and low resource utilization.To handle these challenges,a Software defined Intelligent STN(SISTN)architecture is introduced.Specifically,the hierarchical architecture of the proposal is described and a distributed deployment scheme for SISTNs controllers is proposed to realize agile and effective network management and control.Moreover,three use cases in SISTNs are discussed.Meanwhile,key techniques and their corresponding solutions are presented,followed by the identification of several open issues in SISTNs including compatibility with existing networks,the tradeoff between network flexibility and performance,and so on.

Surface plasmon resonance effect of Ag nanoparticles for improving the photocatalytic performance of biochar quantum-dot/Bi_4Ti_3O_(12) nanosheets

Herein,we report a novel ternary material comprised of Ag nanoparticles and carbon quantum dots(CDs),which are co-loaded using 2D Bi4Ti3O12(BIT)sheets.In this system,Ag can be applied as excited electron-hole pairs in the Bi4Ti3O12 by transferring the plasmonic energy from the metal to the semiconductor.The surface plasmon resonance of Ag can promote the electron transfer properties of the CDs,thereby improving the separation efficiency of the electron-hole pairs.Meanwhile,the CDs can act as an electron buffer to decrease the recombination rate of the electron hole.Moreover,CDs are prepared using a biomaterial,which can provide a chemical group to enhance the electron transfer and connection.The synergistic effects of CDs,Ag,and BIT enable the design of a photocatalytic application with a remarkably improved efficiency and operational stability.

Channel Estimation for Reconfigurable Intelligent Surface Assisted Wireless Communication Systems in Mobility Scenarios

Reconfigurable intelligent surface(RIS)can manipulate the wireless propagation environment by smartly adjusting the amplitude/phase in a programmable panel,enjoying the improved performance.The accurate acquisition of the instantaneous channel state information(CSI)in the cascaded RIS chain makes an indispensable contribution to the performance gains.However,it is quite challenging to estimate the CSI in a time-variant scenario due to the limited signal processing capability of the passive elements embedded in a RIS pannel.In this work,a channel estimation scheme for the RIS-assisted wireless communication system is proposed,which is demonstrated to perform well in a time-variant scenario.The cascaded RIS channel is modeled as a state-space model based upon the mobility situations.In addition,to fully exploit the time correlation of channel,Kalman filter is employed by taking the prior information of channels into account.Further,the optimal reflection coefficients are derived according to the minimum mean square error(MMSE)criterion.Numerical results show that the proposed methods exhibit superior performance if compared with a conventional channel estimation scheme.

RPA3 is transcriptionally activated by YY1 and its depletion enhances radiosensitivity of triple-negative and HER2-positive breast cancer

RPA3(Replication Protein A3)(14 kD)is a part of the canonical heterotrimeric replication protein A complex(RPA/RP-A).This study aimed to explore the functional role of RPA3 and the mechanisms of its dysregulation in breast cancer.Data from the Cancer Genome Atlas(TCGA)-breast cancer patients and GSE75688 were utilized for gene expression and survival analysis.Breast cancer cell lines MDA-MB-231 and SK-BR-3 were used for in-vitro cell studies.Clonogenic assay and immunofluorescent staining ofγ-H2AX were performed to examine radiation-induced cytotoxicity.Systemic correlation analysis was performed to identify potential transcription factors(TFs)regulating RPA3 expression.ChIP-qPCR and dual-luciferase assay were conducted to verify the transcriptional activating effect of YY1 on RPA3 expression.Bioinformatic analysis showed that RPA3 expression was upregulated in breast cancer.Its upregulation was associated with poor survival of basal-like and HER2+cases.RPA3 inhibition by siRNA reduced colony formation and increasedγ-H2AX foci formation after irradiation in MDA-MB-231 and SK-BR-3 cells.RPA3 expression was transcriptionally activated by YY1 via promoter binding in the two cell lines.Both RPA3 and YY1 expression were positively correlated with their gene-level copy numbers.RPA3 might serve as a potential target for radio-sensitization in basal-like and HER2+breast cancer.

How to Comprehensively Utilize the Discarded Fresh Tobacco Leaf ?

This paper aims to explore comprehensive utilization way of discarded fresh tobacco leaf. Based on modern tobacco demands on green,environmental protection and sustainable development,as well as actual situation of biogas production facility in some villages of local tobacco area,this paper selects Longwan Village of Fengshiyan Town as the experimental site and explores the rational way of discarded fresh tobacco leaf biogas fermentation. Results show that cutting and fermentation of discarded fresh tobacco leaf before adding into biogas digester is conductive to improving p H in fermentation process,reducing crust amount,and effectively improving biogas production amount and rate. The study can provide reference for effective processing and rational utilization of discarded fresh tobacco leaf.

河南省农村互助养老发展困境与策略研究

近些年来,我国人口老龄化趋势不断加剧,农村地区更不例外。随着农村地区大力实施乡村振兴政策,如何面对人口老龄化以及人口老龄化带来的负面影响成为了一项重要课题,其中互助养老就是一种有益实践且十分具有研究价值,互助养老如何高质量发展也是实施乡村振兴战略的内在要求。本篇文章首先针对互助养老进行了文献的梳理,主要选取了我国的人口大省河南省为例,通过对河南省人口老龄化的现状进行分析,发现当地互助养老发展的困境主要集中于主体参与程度低、政府支持力度有限、基础设施不完善、发展的体制机制不够完善等方面,进一步针对性地提出了优化路径来推动农村互助养老健康可持续发展,在一定程度上也有助于提升老年人的老年生活质量、提升生活幸福感。

Interference management in 6G space and terrestrial integrated networks: Challenges and approaches

The Space-Terrestrial Integrated Network(STIN)is considered to be a promising paradigm for realizing worldwide wireless connectivity in sixth-Generation(6G)wireless communication systems.Unfortunately,excessive interference in the STIN degrades the wireless links and leads to poor performance,which is a bottleneck that prevents its commercial deployment.In this article,the crucial features and challenges of STIN-based interference are comprehensively investigated,and some candidate solutions for Interference Management(IM)are summarized.As traditional IM techniques are designed for single-application scenarios or specific types of interference,they cannot meet the requirements of the STIN architecture.To address this issue,we propose a self-adaptation IM method that reaps the potential benefits of STIN and is applicable to both rural and urban areas.A number of open issues and potential challenges for IM are discussed,which provide insights regarding future research directions related to STIN.

Joint uplink and downlink resource allocation for low-latency mobile virtual reality delivery in fog radio access networks

Fog radio access networks(F-RANs),in which the fog access points are equipped with communication,caching,and computing functionalities,have been anticipated as a promising architecture for enabling virtual reality(VR)applications in wireless networks.Although extensive research efforts have been devoted to designing efficient resource allocation strategies for realizing successful mobile VR delivery in downlink,the equally important resource allocation problem of mobile VR delivery in uplink has so far drawn little attention.In this work,we investigate a mobile VR F-RAN delivery framework,where both the uplink and downlink transmissions are considered.We first characterize the round-trip latency of the system,which reveals its dependence on the communication,caching,and computation resource allocations.Based on this information,we propose a simple yet efficient algorithm to minimize the round-trip latency,while satisfying the practical constraints on caching,computation capability,and transmission capacity in the uplink and downlink.Numerical results show that our proposed algorithm can effectively reduce the round-trip latency compared with various baselines,and the impacts of communication,caching,and computing resources on latency performance are illustrated.