Typical application scenarios,such as vehicle to grid(V2G)and frequency regulation,have imposed significant long-life demands on lithium-ion batteries.Herein,we propose an advanced battery life-extension method employ...Typical application scenarios,such as vehicle to grid(V2G)and frequency regulation,have imposed significant long-life demands on lithium-ion batteries.Herein,we propose an advanced battery life-extension method employing bidirectional pulse charging(BPC)strategy.Unlike traditional constant current charging methods,BPC strategy not only achieves comparable charging speeds but also facilitates V2G frequency regulation simultaneously.It significantly enhances battery cycle ampere-hour throughput and demonstrates remarkable life extension capabilities.For this interesting conclusion,adopting model identification and postmortem characterization to reveal the life regulation mechanism of BPC:it mitigates battery capacity loss attributed to loss of lithium-ion inventory(LLI)in graphite anodes by intermittently regulating the overall battery voltage and anode potential using a negative charging current.Then,from the perspective of internal side reaction,the life extension mechanism is further revealed as inhibition of solid electrolyte interphase(SEI)and lithium dendrite growth by regulating voltage with a bidirectional pulse current,and a semi-empirical life degradation model combining SEI and lithium dendrite growth is developed for BPC scenarios health management,the model parameters are identified by genetic algorithm with the life simulation exhibiting an accuracy exceeding 99%.This finding indicates that under typical rate conditions,adaptable BPC strategies can extend the service life of LFP battery by approximately 123%.Consequently,the developed advanced BPC strategy offers innovative perspectives and insights for the development of long-life battery applications in the future.展开更多
In this paper,ambient IoT is used as a typical use case of massive connections for the sixth generation(6G)mobile communications where we derive the performance requirements to facilitate the evaluation of technical s...In this paper,ambient IoT is used as a typical use case of massive connections for the sixth generation(6G)mobile communications where we derive the performance requirements to facilitate the evaluation of technical solutions.A rather complete design of unsourced multiple access is proposed in which two key parts:a compressed sensing module for active user detection,and a sparse interleaver-division multiple access(SIDMA)module are simulated side by side on a same platform at balanced signal to noise ratio(SNR)operating points.With a proper combination of compressed sensing matrix,a convolutional encoder,receiver algorithms,the simulated performance results appear superior to the state-of-the-art benchmark,yet with relatively less complicated processing.展开更多
Grapevine is one of the most economically important crops worldwide.However,the previous versions of the grapevine reference genome tipically consist of thousands of fragments with missing centromeres and telomeres,li...Grapevine is one of the most economically important crops worldwide.However,the previous versions of the grapevine reference genome tipically consist of thousands of fragments with missing centromeres and telomeres,limiting the accessibility of the repetitive sequences,the centromeric and telomeric regions,and the study of inheritance of important agronomic traits in these regions.Here,we assembled a telomere-to-telomere(T2T)gap-free reference genome for the cultivar PN40024 using PacBio HiFi long reads.The T2T reference genome(PN_T2T)is 69 Mb longer with 9018 more genes identified than the 12X.v0 version.We annotated 67%repetitive sequences,19 centromeres and 36 telomeres,and incorporated gene annotations of previous versions into the PN_T2T assembly.We detected a total of 377 gene clusters,which showed associations with complex traits,such as aroma and disease resistance.Even though PN40024 derives from nine generations of selfing,we still found nine genomic hotspots of heterozygous sites associated with biological processes,such as the oxidation–reduction process and protein phosphorylation.The fully annotated complete reference genome therefore constitutes an important resource for grapevine genetic studies and breeding programs.展开更多
Objective: The aim of this study was to investigate the prevalence of sarcopenia(SP) and its relationship with gut microbiota alterations in patients with hematological diseases before and after hematopoietic stem cel...Objective: The aim of this study was to investigate the prevalence of sarcopenia(SP) and its relationship with gut microbiota alterations in patients with hematological diseases before and after hematopoietic stem cell transplantation(HSCT).Methods: A total of 108 patients with various hematological disorders were selected from Peking University People’s Hospital. SP was screened and diagnosed based on the 2019 Asian Sarcopenia Diagnosis Strategy. Physical measurements and fecal samples were collected, and 16S rRNA gene sequencing was conducted. Alpha and beta diversity analyses were performed to evaluate gut microbiota composition and diversity.Results: After HSCT, significant decreases in calf circumference and body mass index(BMI) were observed,accompanied by a decline in physical function. Gut microbiota analyses revealed significant differences in the relative abundance of Enterococcus, Bacteroides, Blautia and Dorea species before and after HSCT(P<0.05). Before HSCT, sarcopenic patients had lower Dorea levels and higher Phascolarctobacterium levels than non-sarcopenia patients(P<0.01). After HSCT, no significant differences in species abundance were observed. Alpha diversity analysis showed significant differences in species diversity among the groups, with the highest diversity in the postHSCT 90-day group and the lowest in the post-HSCT 30-day group. Beta diversity analysis revealed significant differences in species composition between pre-and post-HSCT time points but not between SP groups. Linear discriminant analysis effect size(LEfSe) identified Alistipes, Rikenellaceae, Alistipes putredinis, Prevotellaceae defectiva and Blautia coccoides as biomarkers for the pre-HSCT sarcopenia group. Functional predictions showed significant differences in anaerobic, biofilm-forming and oxidative stress-tolerant functions among the groups(P<0.05).Conclusions: This study demonstrated a significant decline in physical function after HSCT and identified potential gut microbiota biomarkers and functional alterations associated with SP in patients with hematological disorders. Further research is needed to explore the underlying mechanisms and potential therapeutic targets.展开更多
Chemical composition of very metal-poor(VMP)stars can provide observational constraints on current models of nucleosynthesis and the chemical evolution of the Galaxy.It has been found that the scatter of[Na/Fe]versus[...Chemical composition of very metal-poor(VMP)stars can provide observational constraints on current models of nucleosynthesis and the chemical evolution of the Galaxy.It has been found that the scatter of[Na/Fe]versus[Fe/H]in VMP stars is very large in contrast with most other elements.Moreover,a negative slope in[Na/Fe]versus[Fe/H]was found for giants,which is very unlikely according to the theory of nucleosynthesis.For the sample of93 VMP stars in the metallicity range-4.25<[Fe/H]<-1.64 we obtained NLTE sodium abundances using the line profile fitting method by employing accurate atmospheric parameters determined when taking into account NLTE line formation for both FeⅠand FeⅡ.Originally selected from the LAMOST low-resolution spectral database,the spectra of stars were obtained with the High Dispersion Spectrograph of the Subaru Telescope.For 57turn-off stars in metallicity domain-3.04<[Fe/H]<-1.64,we obtained mean[Na/Fe]=-0.29±0.14 and positive slope 0.09±0.06.For 21 giants distributed over metallicity-3.59<[Fe/H]<-2.19,we found mean[Na/Fe]=-0.35±0.1 and positive slope 0.07±0.07.Our[Na/Fe]trend is lower by~0.2 dex,compared to the modern GCE model.We believe the GCE model should be adjusted,by considering the associated scatter.Twelve stars in our sample are found to be outliers,with too low or too high Na abundances.展开更多
The sixth generation(6G)mobile networks will reshape the world by offering instant,efficient,and intelligent hyper-connectivity,as envisioned by the previously proposed Ubiquitous-X 6G networks.Such hyper-massive and ...The sixth generation(6G)mobile networks will reshape the world by offering instant,efficient,and intelligent hyper-connectivity,as envisioned by the previously proposed Ubiquitous-X 6G networks.Such hyper-massive and global connectivity will introduce tremendous challenges into the operation and management of 6G networks,calling for revolutionary theories and technological innovations.To this end,we propose a new route to boost network capabilities toward a wisdom-evolutionary and primitive-concise network(WePCN)vision for the Ubiquitous-X 6G network.In particular,we aim to concretize the evolution path toward the WePCN by first conceiving a new semantic representation framework,namely semantic base,and then establishing an intelligent and efficient semantic communication(IE-SC)network architecture.In the IE-SC architecture,a semantic intelligence plane is employed to interconnect the semantic-empowered physical-bearing layer,network protocol layer,and application-intent layer via semantic information flows.The proposed architecture integrates artificial intelligence and network technologies to enable intelligent interactions among various communication objects in 6G.It features a lower bandwidth requirement,less redundancy,and more accurate intent identification.We also present a brief review of recent advances in semantic communications and highlight potential use cases,complemented by a range of open challenges for 6G.展开更多
In MEC-enabled vehicular network with limited wireless resource and computation resource,stringent delay and high reliability requirements are challenging issues.In order to reduce the total delay in the network as we...In MEC-enabled vehicular network with limited wireless resource and computation resource,stringent delay and high reliability requirements are challenging issues.In order to reduce the total delay in the network as well as ensure the reliability of Vehicular UE(VUE),a Joint Allocation of Wireless resource and MEC Computing resource(JAWC)algorithm is proposed.The JAWC algorithm includes two steps:V2X links clustering and MEC computation resource scheduling.In the V2X links clustering,a Spectral Radius based Interference Cancellation scheme(SR-IC)is proposed to obtain the optimal resource allocation matrix.By converting the calculation of SINR into the calculation of matrix maximum row sum,the accumulated interference of VUE can be constrained and the the SINR calculation complexity can be effectively reduced.In the MEC computation resource scheduling,by transforming the original optimization problem into a convex problem,the optimal task offloading proportion of VUE and MEC computation resource allocation can be obtained.The simulation further demonstrates that the JAWC algorithm can significantly reduce the total delay as well as ensure the communication reliability of VUE in the MEC-enabled vehicular network.展开更多
With the evolution of cellular networks,6G is a promising technology to provide ubiquity of communications,computing,control,and consciousness(UC4)for“human⁃machine⁃thing⁃genie”and build a ubiquitous intelligent mob...With the evolution of cellular networks,6G is a promising technology to provide ubiquity of communications,computing,control,and consciousness(UC4)for“human⁃machine⁃thing⁃genie”and build a ubiquitous intelligent mobile society.Genie,which can act as the artificial intelligence assistance for 6G users,is the key enabler to realize the unprecedented transformation from mobile Internet to network of intelligence.While Internet of Things(IoT)is the digital nervous system,genie acts like the brain of the overall system.Supported by 6G,IoT will step into the Artificial Intelligence of Things(AIoT)era and the AIoT networks have the abilities of intelligent perception,intelligent analysis,and intelligent control.In this paper,the concept of Ubiquitous⁃X is introduced,which is considered as the fundamental architecture of 6G network,and the definition and architecture of AIoT under Ubiquitous⁃X is also presented.Several major technical challenges posed by the service requirements of novel AIoT applications are pinpointed,including massive and intelligent connectivity,efficient computing,security,privacy,authentication,high scalability and efficiency.Potential enabling technologies to support seamless service experiences across terminals to realize AIoT are introduced as well.展开更多
Dy：Lu2O3 was grown by the float-zone （Fz） method. According to the absorption spectrum, the Judd-Ofelt （JO） parameters Ω2, Ω4, and Ω6 were calculated to be 4.86 × 10-20 cm2, 2.02 × 10-20 cm2, and 1.7...Dy：Lu2O3 was grown by the float-zone （Fz） method. According to the absorption spectrum, the Judd-Ofelt （JO） parameters Ω2, Ω4, and Ω6 were calculated to be 4.86 × 10-20 cm2, 2.02 × 10-20 cm2, and 1.76 ×10-20 cm2, respectively. The emission cross-section at 574 nm corresponding to the 4F9/2 →6H13/2 transition was calculated to be 0.53 ×10 20 cm2. The yellow （4F9/2 →6H13/2 transition） to blue （4F9/2 →6H15/2 transition） intensity ratio ranges up to 12.9. The fluorescence lifetime of the 4F9/2 energy level was measured to be 112.1 μs. These results reveal that Dy：Lu2O3 is a promising material for use in yellow lasers.展开更多
The key technologies involved in the evolution of the Cloud-based Radio Access Network(C-RAN) are discussed in this paper. Taking the Frameless Network Architecture(FNA) as a starting point, a cell-lessbased network t...The key technologies involved in the evolution of the Cloud-based Radio Access Network(C-RAN) are discussed in this paper. Taking the Frameless Network Architecture(FNA) as a starting point, a cell-lessbased network topology for a multi-tier Heterogeneous Network(Het Net) and ultra-dense network is proposed. The FNA network topology modeling is researched with centralized processing and distributed antenna deployments. The Antenna Element(AE) is released as a new dimensional radio resource that is included in the centralized Radio Resource Management(RRM) processes. This contributes to the on-demand user-centric serving-set associations with cell-edge effect elimination. The Control Plane(CP) and User Plane(UP) separation and adaptation are introduced for energy efficiency improvements. The centralized RRM and different optimization goals are discussed for fully exploring the merits from the centralized computing of C-RAN. Considering the complexity, near-optimal approaches for specific users' Quality-of-Service(Qo S) requirements are addressed. Finally, based on the research highlighted above, the way forward of C-RAN evolution is discussed.展开更多
The crystal growth,x-ray diffraction pattern,absorption spectrum,emission spectrum,and fluorescence lifetime of a Tb：Lu2O3 single crystal were studied.Excited at 483 nm,the peak absorption cross-section was calculate...The crystal growth,x-ray diffraction pattern,absorption spectrum,emission spectrum,and fluorescence lifetime of a Tb：Lu2O3 single crystal were studied.Excited at 483 nm,the peak absorption cross-section was calculated to be 3.5×10（-22）cm2,and the full width at half maximum was found to be 2.85 nm.The Judd-Ofelt（J-O）intensity parameters 2,4,and 6 were computed to be 3.79×10（-20）cm2,1.30×10（-20）cm2,and 1.08×10（-20）cm2,with a spectroscopic quality factor 4/6 being 1.20.The emission cross-sections of green emission around 543 nm and yellow emission around 584 nm were calculated to be 9.43×10（-22）cm2 and 1.32×10（-22）cm2,respectively.The fluorescence lifetimeτexp of -5D4 was fitted to be 1.13 ms.The data suggest that the Tb：Lu2O3 crystal could be a potential candidate for green and yellow laser operation.展开更多
The 0.6 at.%Pr^(3+)-doped CaF_(2)-YF_(3)crystal was successfully grown by the temperature gradient technique(TGT).X-ray diffraction analysis showed that the grown crystal still had cubic structure.The absorption spect...The 0.6 at.%Pr^(3+)-doped CaF_(2)-YF_(3)crystal was successfully grown by the temperature gradient technique(TGT).X-ray diffraction analysis showed that the grown crystal still had cubic structure.The absorption spectrum,emission spectrum,Judd-Ofelt analysis and fluorescence decay curve at room temperature were discussed.The fluorescence lifetime of Pr:CaF_(2)-YF_(3)crystal was 45.46µs,and theσem·τof ^(3)P0→^(3)H_(6) and ^(3)P0→^(3)F_(2) transitions were calculated to be 80.92×10^(−20) cm^(2)·µs and 388.7×10^(−20) cm^(2)·µs,respectively.The FWHMs are 20.1 nm and 6.8 nm,which are higher than those of Pr:LiYF_(4),Pr:LiLuF_(4),Pr:LiGdF_(4) and Pr:BaY_(2)F_(8) crystals.The results show that the Pr:CaF_(2)-YF_(3)crystal is expected to achieve 605 nm orange light and 642 nm red light laser operation.展开更多
Reinforcement learning can be modeled as markov decision process mathematically.In consequence,the interaction samples as well as the connection relation between them are two main types of information for learning.How...Reinforcement learning can be modeled as markov decision process mathematically.In consequence,the interaction samples as well as the connection relation between them are two main types of information for learning.However,most of recent works on deep reinforcement learning treat samples independently either in their own episode or between episodes.In this paper,in order to utilize more sample information,we propose another learning system based on directed associative graph(DAG).The DAG is built on all trajectories in real time,which includes the whole connection relation of all samples among all episodes.Through planning with directed edges on DAG,we offer another perspective to estimate stateaction pair,especially for the unknowns to deep neural network(DNN)as well as episodic memory(EM).Mixed loss function is generated by the three learning systems(DNN,EM and DAG)to improve the efficiency of the parameter update in the proposed algorithm.We show that our algorithm is significantly better than the state-of-the-art algorithm in performance and sample efficiency on testing environments.Furthermore,the convergence of our algorithm is proved in the appendix and its long-term performance as well as the effects of DAG are verified.展开更多
[Objective] The paper was to understand the physiological, enzymatic and molecular changes of Acipenser schrencki induced by heat exposure. [Method] The effects of heat exposure on A. schrencki were investigated. The ...[Objective] The paper was to understand the physiological, enzymatic and molecular changes of Acipenser schrencki induced by heat exposure. [Method] The effects of heat exposure on A. schrencki were investigated. The temperature was increased from(18± 0.5) ℃ by 0.08 ℃/min and respectively kept at(32±0.5) ℃ for 2, 4 and 6 h. The respiration rate, related biochemical indicators and heat shock protein 70(Hsp 70) mR-NA expression were investigated. [Result] At(32±0.5) ℃, the activities of total protein, albumin, globulin, urea nitrogen, ceatinine, malondialde-hyde, aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase fluctuated dramatically from 2 h to 6 h. Meanwhile, the respi-ration rate and Hsp 70 m RNA expression in heart, liver and spleen were significantly increased from 2 h to 6 h. In comparison, the lower respira-tion rate and tiny fluctuations in activities of biochemical indicators were consistent with the lower Hsp 70 expression. [Conclusion] During the process of heat stress, A. schrencki seems to be sensitive to such temperature, and manifests generally consistent gill breathing, biochemical indica-tors and Hsp70 gene expression, implying better heat tolerance.展开更多
根据国际电信联盟关于IMT-2030愿景,第6代移动通信系统(the 6th generation mobile networks,6G)的覆盖服务需求将从单场景覆盖向多场景覆盖扩展,6G基础设施的部署也将逐步从2D覆盖向3D覆盖扩展、从局部覆盖向全球覆盖扩展、从中低频段...根据国际电信联盟关于IMT-2030愿景,第6代移动通信系统(the 6th generation mobile networks,6G)的覆盖服务需求将从单场景覆盖向多场景覆盖扩展,6G基础设施的部署也将逐步从2D覆盖向3D覆盖扩展、从局部覆盖向全球覆盖扩展、从中低频段融合使用向更高频段按需开启.上述需求使得6G在提升容量的同时,需要进一步考虑无线覆盖扩展需求.本文针对如何在6G网络结构时空尺度跨度大、全场景业务需求差异大、超密集覆盖能耗大等关键挑战下实现容量和能效约束下的覆盖能力扩展这一重大科学问题,首先提出了面向6G无线覆盖扩展的智能柔性组网架构;其次研究了面向6G无线覆盖扩展的关键技术,包括面向6G广域覆盖的多维立体空天地覆盖扩展技术、面向深度覆盖的超密集异构覆盖扩展技术和面向6G平滑度覆盖的超高速移动覆盖扩展技术;接着分析了基于语义通信的覆盖扩展技术;最后给出了6G全场景无线覆盖扩展仿真验证,通过定义6G无线覆盖扩展技术指标体系,进行了典型场景的覆盖性能仿真验证.展开更多
Given the escalating impact of climate change on agriculture and food security,gaining insights into the evolutionary dynamics of climatic adaptation and uncovering climate-adapted variation can empower the breeding o...Given the escalating impact of climate change on agriculture and food security,gaining insights into the evolutionary dynamics of climatic adaptation and uncovering climate-adapted variation can empower the breeding of climate-resilient crops to face future climate change.Alfalfa(Medicago sativa subsp.sativa),the queen of forages,shows remarkable adaptability across diverse global environments,making it an excellent model for investigating species responses to climate change.In this study,we performed population genomic analyses using genome resequencing data from 702 accessions of 24 Medicago species to unravel alfalfa’s climatic adaptation and genetic susceptibility to future climate change.We found that interspecific genetic exchange has contributed to the gene pool of alfalfa,particularly enriching defense and stress-response genes.Intersubspecific introgression between M.sativa subsp.falcata(subsp.falcata)and alfalfa not only aids alfalfa’s climatic adaptation but also introduces genetic burden.A total of 1671 genes were associated with climatic adaptation,and 5.7%of them were introgressions from subsp.falcata.By integrating climate-associated variants and climate data,we identified populations that are vulnerable to future climate change,particularly in higher latitudes of the Northern Hemisphere.These findings serve as a clarion call for targeted conservation initiatives and breeding efforts.We also identified preadaptive populations that demonstrate heightened resilience to climate fluctuations,illuminating a pathway for future breeding strategies.Collectively,this study enhances our understanding about the local adaptation mechanisms of alfalfa and facilitates the breeding of climate-resilient alfalfa cultivars,contributing to effective agricultural strategies for facing future climate change.展开更多
Structural variations(SVs)are a feature of plant genomes that has been largely unexplored despite their significant impact on plant phenotypic traits and local adaptation to abiotic and biotic stress.In this study,we ...Structural variations(SVs)are a feature of plant genomes that has been largely unexplored despite their significant impact on plant phenotypic traits and local adaptation to abiotic and biotic stress.In this study,we employed woolly grape(Vitis retordii),a species native to the tropical and subtropical regions of East Asia with both coastal and inland habitats,as a valuable model for examining the impact of SVs on local adaptation.We assembled a haplotype-resolved chromosomal reference genome for woolly grape,and conducted population genetic analyses based on whole-genome sequencing(WGS)data from coastal and inland populations.The demographic analyses revealed recent bottlenecks in all populations and asymmetric gene flow from the inland to the coastal population.In total,1,035 genes associated with plant adaptive regulation for salt stress,radiation,and environmental adaptation were detected underlying local selection by SVs and SNPs in the coastal population,of which 37.29% and 65.26% were detected by SVs and SNPs,respectively.Candidate genes such as FSD2,RGA1,and AAP8 associated with salt tolerance were found to be highly differentiated and selected during the process of local adaptation to coastal habitats in SV regions.Our study highlights the importance of SVs in local adaptation;candidate genes related to salt stress and climatic adaptation to tropical and subtropical environments are important genomic resources for future breeding programs of grapevine and its rootstocks.展开更多
Inbreeding depression refers to the reduced performance arising from increased homozygosity,a phenomenon that is the reverse of heterosis and exists among plants and animals.As a natural self-pollinated crop with stro...Inbreeding depression refers to the reduced performance arising from increased homozygosity,a phenomenon that is the reverse of heterosis and exists among plants and animals.As a natural self-pollinated crop with strong heterosis,the mechanism of inbreeding depression in rice is largely unknown.To understand the genetic basis of inbreeding depression,we constructed a successive inbreeding population from the F_(2)to F_(4)generation and observed inbreeding depression of all heterotic traits in the progeny along with the decay of heterozygosity in each generation.The expected depression effect was largely explained by 13 QTLs showing dominant effects for spikelets per panicle,11 for primary branches,and 12 for secondary branches,and these loci constitute the main correlation between heterosis and inbreeding depression.However,the genetic basis of inbreeding depression is also distinct from that of heterosis,such that a biased transmission ratio of alleles for QTLs with either dominant or additive effects in four segregation distortion regions would result in minor effects in expected depression.Noticeably,two-locus interactions may change the extent and direction of the depression effects of the target loci,and overall interactions would promote inbreeding depression among generations.Using an F_(2:3)variation population,the actual performance of the loci showing expected depression was evaluated considering the heterozygosity decay in the background after inbreeding.We found inconsistent or various degrees of background depression from the F_(2)to F_(3)generation assuming different genotypes of the target locus,which may affect the actual depression effect of the locus due to epistasis.The results suggest that the genetic architecture of inbreeding depression and heterosis is closely linked but also differs in their intrinsic mechanisms,which expand our understanding of the whole-genome architecture of inbreeding depression.展开更多
基金supported by the National Natural Science Foundation of China(52177217)。
文摘Typical application scenarios,such as vehicle to grid(V2G)and frequency regulation,have imposed significant long-life demands on lithium-ion batteries.Herein,we propose an advanced battery life-extension method employing bidirectional pulse charging(BPC)strategy.Unlike traditional constant current charging methods,BPC strategy not only achieves comparable charging speeds but also facilitates V2G frequency regulation simultaneously.It significantly enhances battery cycle ampere-hour throughput and demonstrates remarkable life extension capabilities.For this interesting conclusion,adopting model identification and postmortem characterization to reveal the life regulation mechanism of BPC:it mitigates battery capacity loss attributed to loss of lithium-ion inventory(LLI)in graphite anodes by intermittently regulating the overall battery voltage and anode potential using a negative charging current.Then,from the perspective of internal side reaction,the life extension mechanism is further revealed as inhibition of solid electrolyte interphase(SEI)and lithium dendrite growth by regulating voltage with a bidirectional pulse current,and a semi-empirical life degradation model combining SEI and lithium dendrite growth is developed for BPC scenarios health management,the model parameters are identified by genetic algorithm with the life simulation exhibiting an accuracy exceeding 99%.This finding indicates that under typical rate conditions,adaptable BPC strategies can extend the service life of LFP battery by approximately 123%.Consequently,the developed advanced BPC strategy offers innovative perspectives and insights for the development of long-life battery applications in the future.
文摘In this paper,ambient IoT is used as a typical use case of massive connections for the sixth generation(6G)mobile communications where we derive the performance requirements to facilitate the evaluation of technical solutions.A rather complete design of unsourced multiple access is proposed in which two key parts:a compressed sensing module for active user detection,and a sparse interleaver-division multiple access(SIDMA)module are simulated side by side on a same platform at balanced signal to noise ratio(SNR)operating points.With a proper combination of compressed sensing matrix,a convolutional encoder,receiver algorithms,the simulated performance results appear superior to the state-of-the-art benchmark,yet with relatively less complicated processing.
基金This work was supported by the National Natural Science Fund for Excellent Young Scientists Fund Program(Overseas)to Y.Z.,the National Key Research and Development Program of China(grant 2019YFA0906200)the Agricultural Science and Technology Innovation Program(CAAS-ZDRW202101)+1 种基金the Shenzhen Science and Technology Program(grant KQTD2016113010482651)the BMBF-funded de.
文摘Grapevine is one of the most economically important crops worldwide.However,the previous versions of the grapevine reference genome tipically consist of thousands of fragments with missing centromeres and telomeres,limiting the accessibility of the repetitive sequences,the centromeric and telomeric regions,and the study of inheritance of important agronomic traits in these regions.Here,we assembled a telomere-to-telomere(T2T)gap-free reference genome for the cultivar PN40024 using PacBio HiFi long reads.The T2T reference genome(PN_T2T)is 69 Mb longer with 9018 more genes identified than the 12X.v0 version.We annotated 67%repetitive sequences,19 centromeres and 36 telomeres,and incorporated gene annotations of previous versions into the PN_T2T assembly.We detected a total of 377 gene clusters,which showed associations with complex traits,such as aroma and disease resistance.Even though PN40024 derives from nine generations of selfing,we still found nine genomic hotspots of heterozygous sites associated with biological processes,such as the oxidation–reduction process and protein phosphorylation.The fully annotated complete reference genome therefore constitutes an important resource for grapevine genetic studies and breeding programs.
基金supported by Grant National Key R&D Program of China (No.2020YFC2005600 and No.2020YFC2005605)。
文摘Objective: The aim of this study was to investigate the prevalence of sarcopenia(SP) and its relationship with gut microbiota alterations in patients with hematological diseases before and after hematopoietic stem cell transplantation(HSCT).Methods: A total of 108 patients with various hematological disorders were selected from Peking University People’s Hospital. SP was screened and diagnosed based on the 2019 Asian Sarcopenia Diagnosis Strategy. Physical measurements and fecal samples were collected, and 16S rRNA gene sequencing was conducted. Alpha and beta diversity analyses were performed to evaluate gut microbiota composition and diversity.Results: After HSCT, significant decreases in calf circumference and body mass index(BMI) were observed,accompanied by a decline in physical function. Gut microbiota analyses revealed significant differences in the relative abundance of Enterococcus, Bacteroides, Blautia and Dorea species before and after HSCT(P<0.05). Before HSCT, sarcopenic patients had lower Dorea levels and higher Phascolarctobacterium levels than non-sarcopenia patients(P<0.01). After HSCT, no significant differences in species abundance were observed. Alpha diversity analysis showed significant differences in species diversity among the groups, with the highest diversity in the postHSCT 90-day group and the lowest in the post-HSCT 30-day group. Beta diversity analysis revealed significant differences in species composition between pre-and post-HSCT time points but not between SP groups. Linear discriminant analysis effect size(LEfSe) identified Alistipes, Rikenellaceae, Alistipes putredinis, Prevotellaceae defectiva and Blautia coccoides as biomarkers for the pre-HSCT sarcopenia group. Functional predictions showed significant differences in anaerobic, biofilm-forming and oxidative stress-tolerant functions among the groups(P<0.05).Conclusions: This study demonstrated a significant decline in physical function after HSCT and identified potential gut microbiota biomarkers and functional alterations associated with SP in patients with hematological disorders. Further research is needed to explore the underlying mechanisms and potential therapeutic targets.
基金funded by the National Natural Science Foundation of China(NSFC,Grant Nos.11988101 and 11890694)the National Key R&D Program of China No.2019YFA0405502。
文摘Chemical composition of very metal-poor(VMP)stars can provide observational constraints on current models of nucleosynthesis and the chemical evolution of the Galaxy.It has been found that the scatter of[Na/Fe]versus[Fe/H]in VMP stars is very large in contrast with most other elements.Moreover,a negative slope in[Na/Fe]versus[Fe/H]was found for giants,which is very unlikely according to the theory of nucleosynthesis.For the sample of93 VMP stars in the metallicity range-4.25<[Fe/H]<-1.64 we obtained NLTE sodium abundances using the line profile fitting method by employing accurate atmospheric parameters determined when taking into account NLTE line formation for both FeⅠand FeⅡ.Originally selected from the LAMOST low-resolution spectral database,the spectra of stars were obtained with the High Dispersion Spectrograph of the Subaru Telescope.For 57turn-off stars in metallicity domain-3.04<[Fe/H]<-1.64,we obtained mean[Na/Fe]=-0.29±0.14 and positive slope 0.09±0.06.For 21 giants distributed over metallicity-3.59<[Fe/H]<-2.19,we found mean[Na/Fe]=-0.35±0.1 and positive slope 0.07±0.07.Our[Na/Fe]trend is lower by~0.2 dex,compared to the modern GCE model.We believe the GCE model should be adjusted,by considering the associated scatter.Twelve stars in our sample are found to be outliers,with too low or too high Na abundances.
基金the National Key Research and Development Program of China(2019YFC1511302)in part by the National Natural Science Foundation of China(61871057)in part by the Fundamental Research Funds for the Central Universities(2019XD-A13).
文摘The sixth generation(6G)mobile networks will reshape the world by offering instant,efficient,and intelligent hyper-connectivity,as envisioned by the previously proposed Ubiquitous-X 6G networks.Such hyper-massive and global connectivity will introduce tremendous challenges into the operation and management of 6G networks,calling for revolutionary theories and technological innovations.To this end,we propose a new route to boost network capabilities toward a wisdom-evolutionary and primitive-concise network(WePCN)vision for the Ubiquitous-X 6G network.In particular,we aim to concretize the evolution path toward the WePCN by first conceiving a new semantic representation framework,namely semantic base,and then establishing an intelligent and efficient semantic communication(IE-SC)network architecture.In the IE-SC architecture,a semantic intelligence plane is employed to interconnect the semantic-empowered physical-bearing layer,network protocol layer,and application-intent layer via semantic information flows.The proposed architecture integrates artificial intelligence and network technologies to enable intelligent interactions among various communication objects in 6G.It features a lower bandwidth requirement,less redundancy,and more accurate intent identification.We also present a brief review of recent advances in semantic communications and highlight potential use cases,complemented by a range of open challenges for 6G.
基金This work was supported in part by the National Key R&D Program of China under Grant 2019YFE0114000in part by the National Natural Science Foundation of China under Grant 61701042+1 种基金in part by the 111 Project of China(Grant No.B16006)the research foundation of Ministry of EducationChina Mobile under Grant MCM20180101.
文摘In MEC-enabled vehicular network with limited wireless resource and computation resource,stringent delay and high reliability requirements are challenging issues.In order to reduce the total delay in the network as well as ensure the reliability of Vehicular UE(VUE),a Joint Allocation of Wireless resource and MEC Computing resource(JAWC)algorithm is proposed.The JAWC algorithm includes two steps:V2X links clustering and MEC computation resource scheduling.In the V2X links clustering,a Spectral Radius based Interference Cancellation scheme(SR-IC)is proposed to obtain the optimal resource allocation matrix.By converting the calculation of SINR into the calculation of matrix maximum row sum,the accumulated interference of VUE can be constrained and the the SINR calculation complexity can be effectively reduced.In the MEC computation resource scheduling,by transforming the original optimization problem into a convex problem,the optimal task offloading proportion of VUE and MEC computation resource allocation can be obtained.The simulation further demonstrates that the JAWC algorithm can significantly reduce the total delay as well as ensure the communication reliability of VUE in the MEC-enabled vehicular network.
基金National Key Research and Development Project of China(Grant No.2018YFB2100202).
文摘With the evolution of cellular networks,6G is a promising technology to provide ubiquity of communications,computing,control,and consciousness(UC4)for“human⁃machine⁃thing⁃genie”and build a ubiquitous intelligent mobile society.Genie,which can act as the artificial intelligence assistance for 6G users,is the key enabler to realize the unprecedented transformation from mobile Internet to network of intelligence.While Internet of Things(IoT)is the digital nervous system,genie acts like the brain of the overall system.Supported by 6G,IoT will step into the Artificial Intelligence of Things(AIoT)era and the AIoT networks have the abilities of intelligent perception,intelligent analysis,and intelligent control.In this paper,the concept of Ubiquitous⁃X is introduced,which is considered as the fundamental architecture of 6G network,and the definition and architecture of AIoT under Ubiquitous⁃X is also presented.Several major technical challenges posed by the service requirements of novel AIoT applications are pinpointed,including massive and intelligent connectivity,efficient computing,security,privacy,authentication,high scalability and efficiency.Potential enabling technologies to support seamless service experiences across terminals to realize AIoT are introduced as well.
基金Project supported by the Fund of Key Laboratory of Optoelectronic Materials Chemistry and Physics,Chinese Academy of Sciences(Grant No.2008DP173016)the National Key Research and Development Program of China(Grant No.2016YFB1102202)the National Key Research and Development Program of China(Grant No.2016YFB0701002)
文摘Dy：Lu2O3 was grown by the float-zone （Fz） method. According to the absorption spectrum, the Judd-Ofelt （JO） parameters Ω2, Ω4, and Ω6 were calculated to be 4.86 × 10-20 cm2, 2.02 × 10-20 cm2, and 1.76 ×10-20 cm2, respectively. The emission cross-section at 574 nm corresponding to the 4F9/2 →6H13/2 transition was calculated to be 0.53 ×10 20 cm2. The yellow （4F9/2 →6H13/2 transition） to blue （4F9/2 →6H15/2 transition） intensity ratio ranges up to 12.9. The fluorescence lifetime of the 4F9/2 energy level was measured to be 112.1 μs. These results reveal that Dy：Lu2O3 is a promising material for use in yellow lasers.
基金supported by the National High Technology Research and Development Program of China No.2014AA01A701Nature and Science Foundation of China under Grants No.61471068,61421061+2 种基金Beijing Nova Programme No.Z131101000413030International Collaboration Project No.2015DFT10160National Major Project No.2016ZX03001009-003
文摘The key technologies involved in the evolution of the Cloud-based Radio Access Network(C-RAN) are discussed in this paper. Taking the Frameless Network Architecture(FNA) as a starting point, a cell-lessbased network topology for a multi-tier Heterogeneous Network(Het Net) and ultra-dense network is proposed. The FNA network topology modeling is researched with centralized processing and distributed antenna deployments. The Antenna Element(AE) is released as a new dimensional radio resource that is included in the centralized Radio Resource Management(RRM) processes. This contributes to the on-demand user-centric serving-set associations with cell-edge effect elimination. The Control Plane(CP) and User Plane(UP) separation and adaptation are introduced for energy efficiency improvements. The centralized RRM and different optimization goals are discussed for fully exploring the merits from the centralized computing of C-RAN. Considering the complexity, near-optimal approaches for specific users' Quality-of-Service(Qo S) requirements are addressed. Finally, based on the research highlighted above, the way forward of C-RAN evolution is discussed.
基金Project supported by the National Natural Science Foundation of China(Grant No.61621001)the National Key Research and Development Program of China(Grant Nos.2016YFB1102202 and 2016YFB0701002)+1 种基金the Fundamental Research Funds for the Central Universities,Chinathe help of MOE Key Laboratory of Advanced Micro-Structured Materials and School of Physical Science and Technology,Guangxi University
文摘The crystal growth,x-ray diffraction pattern,absorption spectrum,emission spectrum,and fluorescence lifetime of a Tb：Lu2O3 single crystal were studied.Excited at 483 nm,the peak absorption cross-section was calculated to be 3.5×10（-22）cm2,and the full width at half maximum was found to be 2.85 nm.The Judd-Ofelt（J-O）intensity parameters 2,4,and 6 were computed to be 3.79×10（-20）cm2,1.30×10（-20）cm2,and 1.08×10（-20）cm2,with a spectroscopic quality factor 4/6 being 1.20.The emission cross-sections of green emission around 543 nm and yellow emission around 584 nm were calculated to be 9.43×10（-22）cm2 and 1.32×10（-22）cm2,respectively.The fluorescence lifetimeτexp of -5D4 was fitted to be 1.13 ms.The data suggest that the Tb：Lu2O3 crystal could be a potential candidate for green and yellow laser operation.
基金supported by the National Natural Science Foundation of China(Grant Nos.61805177,61861136007,and 61621001).
文摘The 0.6 at.%Pr^(3+)-doped CaF_(2)-YF_(3)crystal was successfully grown by the temperature gradient technique(TGT).X-ray diffraction analysis showed that the grown crystal still had cubic structure.The absorption spectrum,emission spectrum,Judd-Ofelt analysis and fluorescence decay curve at room temperature were discussed.The fluorescence lifetime of Pr:CaF_(2)-YF_(3)crystal was 45.46µs,and theσem·τof ^(3)P0→^(3)H_(6) and ^(3)P0→^(3)F_(2) transitions were calculated to be 80.92×10^(−20) cm^(2)·µs and 388.7×10^(−20) cm^(2)·µs,respectively.The FWHMs are 20.1 nm and 6.8 nm,which are higher than those of Pr:LiYF_(4),Pr:LiLuF_(4),Pr:LiGdF_(4) and Pr:BaY_(2)F_(8) crystals.The results show that the Pr:CaF_(2)-YF_(3)crystal is expected to achieve 605 nm orange light and 642 nm red light laser operation.
基金This work is supported by the National Key Research and Development Program of China,2018YFA0701603 and Natural Science Foundation of Anhui Province,2008085MF213.
文摘Reinforcement learning can be modeled as markov decision process mathematically.In consequence,the interaction samples as well as the connection relation between them are two main types of information for learning.However,most of recent works on deep reinforcement learning treat samples independently either in their own episode or between episodes.In this paper,in order to utilize more sample information,we propose another learning system based on directed associative graph(DAG).The DAG is built on all trajectories in real time,which includes the whole connection relation of all samples among all episodes.Through planning with directed edges on DAG,we offer another perspective to estimate stateaction pair,especially for the unknowns to deep neural network(DNN)as well as episodic memory(EM).Mixed loss function is generated by the three learning systems(DNN,EM and DAG)to improve the efficiency of the parameter update in the proposed algorithm.We show that our algorithm is significantly better than the state-of-the-art algorithm in performance and sample efficiency on testing environments.Furthermore,the convergence of our algorithm is proved in the appendix and its long-term performance as well as the effects of DAG are verified.
基金Supported by the Project of Science and Technology Innovation(CXCZ2017331)Natural Science Foundation of Fujian Province(2021J01085 and 2020J01539)National Innovation and En-trepreneurship Program for College Students(202110389008)。
文摘[Objective] The paper was to understand the physiological, enzymatic and molecular changes of Acipenser schrencki induced by heat exposure. [Method] The effects of heat exposure on A. schrencki were investigated. The temperature was increased from(18± 0.5) ℃ by 0.08 ℃/min and respectively kept at(32±0.5) ℃ for 2, 4 and 6 h. The respiration rate, related biochemical indicators and heat shock protein 70(Hsp 70) mR-NA expression were investigated. [Result] At(32±0.5) ℃, the activities of total protein, albumin, globulin, urea nitrogen, ceatinine, malondialde-hyde, aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase fluctuated dramatically from 2 h to 6 h. Meanwhile, the respi-ration rate and Hsp 70 m RNA expression in heart, liver and spleen were significantly increased from 2 h to 6 h. In comparison, the lower respira-tion rate and tiny fluctuations in activities of biochemical indicators were consistent with the lower Hsp 70 expression. [Conclusion] During the process of heat stress, A. schrencki seems to be sensitive to such temperature, and manifests generally consistent gill breathing, biochemical indica-tors and Hsp70 gene expression, implying better heat tolerance.
文摘根据国际电信联盟关于IMT-2030愿景,第6代移动通信系统(the 6th generation mobile networks,6G)的覆盖服务需求将从单场景覆盖向多场景覆盖扩展,6G基础设施的部署也将逐步从2D覆盖向3D覆盖扩展、从局部覆盖向全球覆盖扩展、从中低频段融合使用向更高频段按需开启.上述需求使得6G在提升容量的同时,需要进一步考虑无线覆盖扩展需求.本文针对如何在6G网络结构时空尺度跨度大、全场景业务需求差异大、超密集覆盖能耗大等关键挑战下实现容量和能效约束下的覆盖能力扩展这一重大科学问题,首先提出了面向6G无线覆盖扩展的智能柔性组网架构;其次研究了面向6G无线覆盖扩展的关键技术,包括面向6G广域覆盖的多维立体空天地覆盖扩展技术、面向深度覆盖的超密集异构覆盖扩展技术和面向6G平滑度覆盖的超高速移动覆盖扩展技术;接着分析了基于语义通信的覆盖扩展技术;最后给出了6G全场景无线覆盖扩展仿真验证,通过定义6G无线覆盖扩展技术指标体系,进行了典型场景的覆盖性能仿真验证.
基金supported by the earmarked fund for CARS(CARS-34)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(ASTIP-IAS14)the Science Fund Program for Distinguished Young Scholars of the National Natural Science Foundation of China(Overseas)to Yongfeng Zhou.
文摘Given the escalating impact of climate change on agriculture and food security,gaining insights into the evolutionary dynamics of climatic adaptation and uncovering climate-adapted variation can empower the breeding of climate-resilient crops to face future climate change.Alfalfa(Medicago sativa subsp.sativa),the queen of forages,shows remarkable adaptability across diverse global environments,making it an excellent model for investigating species responses to climate change.In this study,we performed population genomic analyses using genome resequencing data from 702 accessions of 24 Medicago species to unravel alfalfa’s climatic adaptation and genetic susceptibility to future climate change.We found that interspecific genetic exchange has contributed to the gene pool of alfalfa,particularly enriching defense and stress-response genes.Intersubspecific introgression between M.sativa subsp.falcata(subsp.falcata)and alfalfa not only aids alfalfa’s climatic adaptation but also introduces genetic burden.A total of 1671 genes were associated with climatic adaptation,and 5.7%of them were introgressions from subsp.falcata.By integrating climate-associated variants and climate data,we identified populations that are vulnerable to future climate change,particularly in higher latitudes of the Northern Hemisphere.These findings serve as a clarion call for targeted conservation initiatives and breeding efforts.We also identified preadaptive populations that demonstrate heightened resilience to climate fluctuations,illuminating a pathway for future breeding strategies.Collectively,this study enhances our understanding about the local adaptation mechanisms of alfalfa and facilitates the breeding of climate-resilient alfalfa cultivars,contributing to effective agricultural strategies for facing future climate change.
基金supported by the Science Fund Program for Distinguished Young Scholars of the National Natural Science Foundation of China(Overseas)to Yongfeng ZhouNational Natural Science Foundation of China(Nos.32300191,32372662)+1 种基金Guangxi University,Bama Institute of Integration of Industry and Education,postgraduate joint training project(Project Nos.20210020,20210039)the National Key Research and Development Program of China(grants 2023YFF1000100 and 2023YFD2200700).
文摘Structural variations(SVs)are a feature of plant genomes that has been largely unexplored despite their significant impact on plant phenotypic traits and local adaptation to abiotic and biotic stress.In this study,we employed woolly grape(Vitis retordii),a species native to the tropical and subtropical regions of East Asia with both coastal and inland habitats,as a valuable model for examining the impact of SVs on local adaptation.We assembled a haplotype-resolved chromosomal reference genome for woolly grape,and conducted population genetic analyses based on whole-genome sequencing(WGS)data from coastal and inland populations.The demographic analyses revealed recent bottlenecks in all populations and asymmetric gene flow from the inland to the coastal population.In total,1,035 genes associated with plant adaptive regulation for salt stress,radiation,and environmental adaptation were detected underlying local selection by SVs and SNPs in the coastal population,of which 37.29% and 65.26% were detected by SVs and SNPs,respectively.Candidate genes such as FSD2,RGA1,and AAP8 associated with salt tolerance were found to be highly differentiated and selected during the process of local adaptation to coastal habitats in SV regions.Our study highlights the importance of SVs in local adaptation;candidate genes related to salt stress and climatic adaptation to tropical and subtropical environments are important genomic resources for future breeding programs of grapevine and its rootstocks.
基金supported by the National Key Research and Development Program of China(2022YFF1002100)the National Natural Science Foundation of China(31991223,32341031,32170622,31821005)+2 种基金the Hubei Key R&D Program(2020BBA034)the Hubei Key R&D Program in Hongshan Lab(2021hszd005,2022hszd017)the Fundamental Research Founds for the Central Universities(2662023PY002).
文摘Inbreeding depression refers to the reduced performance arising from increased homozygosity,a phenomenon that is the reverse of heterosis and exists among plants and animals.As a natural self-pollinated crop with strong heterosis,the mechanism of inbreeding depression in rice is largely unknown.To understand the genetic basis of inbreeding depression,we constructed a successive inbreeding population from the F_(2)to F_(4)generation and observed inbreeding depression of all heterotic traits in the progeny along with the decay of heterozygosity in each generation.The expected depression effect was largely explained by 13 QTLs showing dominant effects for spikelets per panicle,11 for primary branches,and 12 for secondary branches,and these loci constitute the main correlation between heterosis and inbreeding depression.However,the genetic basis of inbreeding depression is also distinct from that of heterosis,such that a biased transmission ratio of alleles for QTLs with either dominant or additive effects in four segregation distortion regions would result in minor effects in expected depression.Noticeably,two-locus interactions may change the extent and direction of the depression effects of the target loci,and overall interactions would promote inbreeding depression among generations.Using an F_(2:3)variation population,the actual performance of the loci showing expected depression was evaluated considering the heterozygosity decay in the background after inbreeding.We found inconsistent or various degrees of background depression from the F_(2)to F_(3)generation assuming different genotypes of the target locus,which may affect the actual depression effect of the locus due to epistasis.The results suggest that the genetic architecture of inbreeding depression and heterosis is closely linked but also differs in their intrinsic mechanisms,which expand our understanding of the whole-genome architecture of inbreeding depression.
