期刊文献+
共找到623篇文章
< 1 2 32 >
每页显示 20 50 100
Periodic Variation Studies of the Two Short Period W UMa-type Eclipsing Binaries: LX Lyn and V0853 Aur
1
作者 Xu zhang bin zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第1期273-284,共12页
In this paper,new light curves(LCs) of contact eclipsing binary(CEB) systems LX Lyn and V0853 Aur are presented and analyzed by using the 2015 version of the Wilson-Devinney(W-D) code.In order to explain their asymmet... In this paper,new light curves(LCs) of contact eclipsing binary(CEB) systems LX Lyn and V0853 Aur are presented and analyzed by using the 2015 version of the Wilson-Devinney(W-D) code.In order to explain their asymmetric LCs,cool starspots on the components were employed.It is suggested that their fill-out degrees are f=12.0%(LX Lyn) and f=26.3%(V0853 Aur).At the same time,we found that LX Lyn is a W-type eclipsing binary(EB) with an orbital inclination of i=84°.88 and a mass ratio of q=2.31.V0853 Aur is also a W-type CEB with a mass ratio of q=2.77 and an orbital inclination of i= 79°.26.Based on all available times of light minimum,their orbital period changes are studied by using the O-C method.The O-C diagram of LX Lyn reveals a cyclic oscillation with a period of about 14.84 yr and an amplitude of 0.0019 days,which can be explained by the light-travel time effect(LTTE) due to the presence of a third body with a minimum mass of0.06M_⊙.For V0853 Aur,it is discovered that the O-C diagram of the system also shows a cyclic oscillation with a period of 9.64 yr and an amplitude of 0.03365 days.The cyclic oscillation of V0853 Aur can be attributed to the LTTE by means of a third body with a mass no less than 3.77M_⊙.The third body may play an important role in the formation and evolution of these systems. 展开更多
关键词 stars:activity (stars:)binaries(including multiple):close (stars:)binaries:eclipsing (stars:)brown dwarfs stars:evolution stars:formation
下载PDF
Phase engineering of Ni-Mn binary layered oxide cathodes for sodiumion batteries
2
作者 Feifei Hong Xin Zhou +9 位作者 Xiaohong Liu Guilin Feng Heng zhang Weifeng Fan bin zhang Meihua Zuo Wangyan Xing Ping zhang Hua Yan Wei Xiang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期501-511,共11页
Nickel-manganese binary layered oxides with high working potential and low cost are potential candidates for sodium-ion batteries,but their electrochemical properties are highly related to compositional diversity.Dive... Nickel-manganese binary layered oxides with high working potential and low cost are potential candidates for sodium-ion batteries,but their electrochemical properties are highly related to compositional diversity.Diverse composite materials with various phase structures of P3,P2/P3,P2,P2/O3,and P2/P3/O3 were synthesized by manipulating the sodium content and calcination conditions,leading to the construction of a synthetic phase diagram for Na_(x)Ni_(0.25)Mn_(0.75)O_(2)(0.45≤x≤1.1).Then,we compared the electrochemical characteristics and structural evolution during the desodiation/sodiation process of P2,P2/P3,P2/03,and P2/P3/O3-Na_(x)Ni_(0.25)Mn_(0.75)O_(2).Among them,P2/P3-Na0.75Ni0.25Mn0.75O2exhibits the best rate capability of 90.9 mA h g^(-1)at 5 C,with an initial discharge capacity of 142.62 mA h g^(-1)at 0.1 C and a capacity retention rate of 78.25%after 100 cycles at 1 C in the voltage range of 2-4.3 V.The observed superior sodium storage performance of P2/P3 hybrids compared to other composite phases can be attributed to the enhanced Na^(+)transfer dynamic,reduction of the Jahn-teller effect,and improved reaction reversibility induced by the synergistic effect of P2 and P3 phases.The systematic research and exploration of phases in Na_(x)Ni_(0.25)Mn_(0.75)O_(2)provide new sights into high-performance nickel-manganese binary layered oxide for sodium-ion batteries. 展开更多
关键词 Phase engineering Ni-Mn layered oxide CATHODE Sodium-ion batteries
下载PDF
Construction and Verification of an RNA-Binding Protein-Associated Prognostic Model for Gliomas 被引量:1
3
作者 Peng PENG Zi-rong CHEN +4 位作者 Xiao-lin zhang Dong-sheng GUO bin zhang Xi-miao HE Feng WAN 《Current Medical Science》 SCIE CAS 2023年第1期156-165,共10页
Objective To construct and verificate an RNA-binding protein(RBP)-associated prognostic model for gliomas using integrated bioinformatics analysis.Methods RNA-sequencing and clinic pathological data of glioma patients... Objective To construct and verificate an RNA-binding protein(RBP)-associated prognostic model for gliomas using integrated bioinformatics analysis.Methods RNA-sequencing and clinic pathological data of glioma patients from The Cancer Genome Atlas(TCGA)database and the Chinese Glioma Genome Atlas database(CGGA)were downloaded.The aberrantly expressed RBPs were investigated between gliomas and normal samples in TCGA database.We then identified prognosis related hub genes and constructed a prognostic model.This model was further validated in the CGGA-693 and CGGA-325 cohorts.Results Totally 174 differently expressed genes-encoded RBPs were identified,containing 85 down-regulated and 89 up-regulated genes.We identified five genes-encoded RBPs(ERI1,RPS2,BRCA1,NXT1,and TRIM21)as prognosis related key genes and constructed a prognostic model.Overall survival(OS)analysis revealed that the patients in the high-risk subgroup based on the model were worse than those in the low-risk subgroup.The area under the receiver operator characteristic curve(AUC)of the prognostic model was 0.836 in the TCGA dataset and 0.708 in the CGGA-693 dataset,demonstrating a favorable prognostic model.Survival analyses of the five RBPs in the CGGA-325 cohort validated the findings.A nomogram was constructed based on the five genes and validated in the TCGA cohort,confirming a promising discriminating ability for gliomas.Conclusion The prognostic model of the five RBPs might serve as an independent prognostic algorithm for gliomas. 展开更多
关键词 bioinformatics analysis GLIOMA prognostic model RNA-binding protein
下载PDF
Comparison of short-term toxicity of 14 common phycotoxins(alone and in combination)to the survival of brine shrimp Artemia salina
4
作者 Yuting zhang Shanshan Song +7 位作者 bin zhang Yang zhang Miao Tian Ziyi Wu Huorong Chen Guangmao Ding Renyan Liu Jingli Mu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第2期134-141,共8页
Toxic harmful algal blooms(HABs)can cause deleterious effects in marine organisms,threatening the stability of marine ecosystems.It is well known that different strains,natural populations and growth conditions of the... Toxic harmful algal blooms(HABs)can cause deleterious effects in marine organisms,threatening the stability of marine ecosystems.It is well known that different strains,natural populations and growth conditions of the same toxic algal species may lead to different amount of phycotoxin production and the ensuing toxicity.To fully assess the ecological risk of toxic HABs,it is of great importance to investigate the toxic effects of phycotoxins in marine organisms.In this study,the short-term toxicity of 14 common phycotoxins(alone and in combination)in the marine zooplankton Artemia salina was investigated.The 48 h LC_(50)of the 14 phycotoxins varied from 0.0193µg/mL to 2.415µg/mL.The most potent phycotoxin was azaspiracids-3(AZA3;with a LC_(50)of 0.0193µg/mL),followed by azaspiracids-2(AZA2;0.0226µg/mL),pectenotoxin-2(PTX2;0.0460µg/mL)and dinophysistoxin-1(DTX1;0.0818µg/mL).For the binary exposure,okadaic acid(OA)induced potential additive effects with DTX1,probably due to their similar structure(polyether fatty acid)and mode of action(attacking the serine/threonine phosphoprotein phosphatases).On the other hand,OA showed potential antagonistic effects with PTX2,which might be accounted for by their activation on the detoxification activity of cytochrome P450 activity.In addition,DTX1 induced potential synergetic effects with saxitoxin(STX),yessotoxin(YTX)or PTX2,suggesting the hazard potency of the mixtures of DTX1 and other phycotoxins(like STX,YTX and PTX2)with regard to the ecological risk.These results provide valuable toxicological data for assessing the impact of phycotoxins on marine planktonic species and highlight the potential ecological risk of toxic HABs in marine ecosystems. 展开更多
关键词 LC_(50) harmful algal blooms binary exposure ecological risk
下载PDF
New Photometric Investigations of G-type Contact Binary TU Boo
5
作者 Jing-jing Wang Meng Guo +1 位作者 Lin-qiao Jiang bin zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第4期103-109,共7页
Two sets of CCD photometric observations for contact binary TU Boo were obtained in 2020 and 2021.Different from its asymmetric light curves published from the literature,our BVRcIc-band curves show that the heights o... Two sets of CCD photometric observations for contact binary TU Boo were obtained in 2020 and 2021.Different from its asymmetric light curves published from the literature,our BVRcIc-band curves show that the heights of maximum are almost equal.These distortions of light curves possibly indicate that the components were active in past 25 yr,but they were stable in the last two years.For total-eclipse binary TU Boo,due to some star-spots on the surface of the components,the physical structure obtained by many investigators are different.Therefore,the symmetric multi-color light curves in 2020,2021 are important for understanding configuration and evolution of this system.By using the Wilson–Devinney program,it is confirmed that TU Boo is an A-type shallow-contact binary with the temperature difference ofΔT=152 K and fill-out of f=14.67%.In the O−C diagram of orbital period analysis,a cyclic oscillation superimposed on a continuous decrease was determined.The long-term decreasing is often explained by the mass transfer from the more massive star to less massive one,this system will evolve into a deeper contact binary with time.The cyclic oscillations computed from much more CCD times of light minimum maybe result from the light-travel time effect via the presence of a third body.These characters of structure,evolution and ternary belong to typical A-type W UMa binaries with spectral G. 展开更多
关键词 (stars:)binaries eclipsing-stars solar-type-stars individual(TU Boo)
下载PDF
两种不同形貌纳米Cu_(2)(Salen)_(2)的制备与表征综合实验设计
6
作者 苑娟 张彬 +1 位作者 吴金萍 王梦凡 《大学化学》 CAS 2024年第10期420-425,共6页
分别采用反溶剂沉淀法和溶剂热法制备了两种不同形貌的Cu_(2)(Salen)_(2)纳米材料,通过红外光谱(IR)、X射线粉末衍射(XRD)和扫描电子显微镜(SEM)等手段对其进行了结构和形貌表征,并利用Olex2软件对该配合物的分子结构和配位情况进行了... 分别采用反溶剂沉淀法和溶剂热法制备了两种不同形貌的Cu_(2)(Salen)_(2)纳米材料,通过红外光谱(IR)、X射线粉末衍射(XRD)和扫描电子显微镜(SEM)等手段对其进行了结构和形貌表征,并利用Olex2软件对该配合物的分子结构和配位情况进行了展示。本实验内容涉及有机合成、配位化学、纳米材料制备与表征、晶体结构分析软件应用等,将基础理论知识与现代科技手段有机统一,兼顾基础的同时,注重创新能力和综合素质的培养。本实验将前沿科研成果转化到实验教学实践中,使二者相互促进,形成良性循环。 展开更多
关键词 综合实验 Cu_(2)(Salen)_(2) 纳米材料 反溶剂沉淀法 溶剂热法 合成与表征
下载PDF
火焰原子吸收光谱法检测烟梗草木灰中的钾含量
7
作者 史梦瑶 苏康乐 +2 位作者 路庆明 张斌 徐晓文 《大学化学》 CAS 2024年第10期255-260,共6页
使用火焰原子吸收光谱法测量废弃烟梗中钾离子的含量,并与其他常见农作物钾素含量做对比,为废弃烟梗的再利用提供一定的解决思路。通过自主设计并进行实验,能够培养学生独立思考和解决实际问题的能力,强化对理论与实践二者间联系的理解... 使用火焰原子吸收光谱法测量废弃烟梗中钾离子的含量,并与其他常见农作物钾素含量做对比,为废弃烟梗的再利用提供一定的解决思路。通过自主设计并进行实验,能够培养学生独立思考和解决实际问题的能力,强化对理论与实践二者间联系的理解,进一步了解并正视能源和环境问题,充分发挥知识育人和实践育人的作用。 展开更多
关键词 烟梗 钾含量 原子吸收光谱 自主设计实验
下载PDF
New Record Ocean Temperatures and Related Climate Indicators in 2023 被引量:1
8
作者 Lijing CHENG John ABRAHAM +31 位作者 Kevin E.TRENBERTH Tim BOYER Michael EMANN Jiang ZHU Fan WANG Fujiang YU Ricardo LOCARNINI John FASULLO Fei ZHENG Yuanlong LI bin zhang Liying WAN Xingrong CHEN Dakui WANG Licheng FENG Xiangzhou SONG Yulong LIU Franco RESEGHETTI Simona SIMONCELLI Viktor GOURETSKI Gengxin CHEN Alexey MISHONOV Jim REAGAN Karina VON SCHUCKMANN Yuying PAN Zhetao TAN Yujing ZHU Wangxu WEI Guancheng LI Qiuping REN Lijuan CAO Yayang LU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第6期1068-1082,共15页
The global physical and biogeochemical environment has been substantially altered in response to increased atmospheric greenhouse gases from human activities.In 2023,the sea surface temperature(SST)and upper 2000 m oc... The global physical and biogeochemical environment has been substantially altered in response to increased atmospheric greenhouse gases from human activities.In 2023,the sea surface temperature(SST)and upper 2000 m ocean heat content(OHC)reached record highs.The 0–2000 m OHC in 2023 exceeded that of 2022 by 15±10 ZJ(1 Zetta Joules=1021 Joules)(updated IAP/CAS data);9±5 ZJ(NCEI/NOAA data).The Tropical Atlantic Ocean,the Mediterranean Sea,and southern oceans recorded their highest OHC observed since the 1950s.Associated with the onset of a strong El Niño,the global SST reached its record high in 2023 with an annual mean of~0.23℃ higher than 2022 and an astounding>0.3℃ above 2022 values for the second half of 2023.The density stratification and spatial temperature inhomogeneity indexes reached their highest values in 2023. 展开更多
关键词 ocean heat content SALINITY STRATIFICATION global warming CLIMATE
下载PDF
High-dose dexamethasone regulates microglial polarization via the GR/JAK1/STAT3 signaling pathway after traumatic brain injury
9
作者 Mengshi Yang Miao Bai +10 位作者 Yuan Zhuang Shenghua Lu Qianqian Ge Hao Li Yu Deng Hongbin Wu Xiaojian Xu Fei Niu Xinlong Dong bin zhang Baiyun Liu 《Neural Regeneration Research》 SCIE CAS 2025年第9期2611-2623,共13页
Although microglial polarization and neuroinflammation are crucial cellular responses after traumatic brain injury,the fundamental regulatory and functional mechanisms remain insufficiently understood.As potent anti-i... Although microglial polarization and neuroinflammation are crucial cellular responses after traumatic brain injury,the fundamental regulatory and functional mechanisms remain insufficiently understood.As potent anti-inflammato ry agents,the use of glucoco rticoids in traumatic brain injury is still controversial,and their regulatory effects on microglial polarization are not yet known.In the present study,we sought to determine whether exacerbation of traumatic brain injury caused by high-dose dexamethasone is related to its regulatory effects on microglial polarization and its mechanisms of action.In vitro cultured BV2 cells and primary microglia and a controlled cortical impact mouse model were used to investigate the effects of dexamethasone on microglial polarization.Lipopolysaccharide,dexamethasone,RU486(a glucocorticoid receptor antagonist),and ruxolitinib(a Janus kinase 1 antagonist)were administered.RNA-sequencing data obtained from a C57BL/6 mouse model of traumatic brain injury were used to identify potential targets of dexamethasone.The Morris water maze,quantitative reverse transcription-polymerase chain reaction,western blotting,immunofluorescence and confocal microscopy analysis,and TUNEL,Nissl,and Golgi staining were performed to investigate our hypothesis.High-throughput sequencing results showed that arginase 1,a marker of M2 microglia,was significantly downregulated in the dexamethasone group compared with the traumatic brain injury group at3 days post-traumatic brain injury.Thus dexamethasone inhibited M1 and M2 microglia,with a more pronounced inhibitory effect on M2microglia in vitro and in vivo.Glucocorticoid receptor plays an indispensable role in microglial polarization after dexamethasone treatment following traumatic brain injury.Additionally,glucocorticoid receptor activation increased the number of apoptotic cells and neuronal death,and also decreased the density of dendritic spines.A possible downstream receptor signaling mechanism is the GR/JAK1/STAT3 pathway.Overactivation of glucocorticoid receptor by high-dose dexamethasone reduced the expression of M2 microglia,which plays an antiinflammatory role.In contrast,inhibiting the activation of glucocorticoid receptor reduced the number of apoptotic glia and neurons and decreased the loss of dendritic spines after traumatic brain injury.Dexamethasone may exe rt its neurotoxic effects by inhibiting M2 microglia through the GR/JAK1/STAT3 signaling pathway. 展开更多
关键词 apoptosis BV2 microglia DEXAMETHASONE glucocorticoid receptor GLUCOCORTICOIDS innate immune system microglial polarization neuroinflammation primary microglia traumatic brain injury
下载PDF
Early identification of stroke through deep learning with multi-modal human speech and movement data
10
作者 Zijun Ou Haitao Wang +9 位作者 bin zhang Haobang Liang Bei Hu Longlong Ren Yanjuan Liu Yuhu zhang Chengbo Dai Hejun Wu Weifeng Li Xin Li 《Neural Regeneration Research》 SCIE CAS 2025年第1期234-241,共8页
Early identification and treatment of stroke can greatly improve patient outcomes and quality of life.Although clinical tests such as the Cincinnati Pre-hospital Stroke Scale(CPSS)and the Face Arm Speech Test(FAST)are... Early identification and treatment of stroke can greatly improve patient outcomes and quality of life.Although clinical tests such as the Cincinnati Pre-hospital Stroke Scale(CPSS)and the Face Arm Speech Test(FAST)are commonly used for stroke screening,accurate administration is dependent on specialized training.In this study,we proposed a novel multimodal deep learning approach,based on the FAST,for assessing suspected stroke patients exhibiting symptoms such as limb weakness,facial paresis,and speech disorders in acute settings.We collected a dataset comprising videos and audio recordings of emergency room patients performing designated limb movements,facial expressions,and speech tests based on the FAST.We compared the constructed deep learning model,which was designed to process multi-modal datasets,with six prior models that achieved good action classification performance,including the I3D,SlowFast,X3D,TPN,TimeSformer,and MViT.We found that the findings of our deep learning model had a higher clinical value compared with the other approaches.Moreover,the multi-modal model outperformed its single-module variants,highlighting the benefit of utilizing multiple types of patient data,such as action videos and speech audio.These results indicate that a multi-modal deep learning model combined with the FAST could greatly improve the accuracy and sensitivity of early stroke identification of stroke,thus providing a practical and powerful tool for assessing stroke patients in an emergency clinical setting. 展开更多
关键词 artificial intelligence deep learning DIAGNOSIS early detection FAST SCREENING STROKE
下载PDF
Evaluating soil acidification risk and its effects on biodiversity–ecosystem multifunctionality relationships in the drylands of China
11
作者 Lan Du Shengchuan Tian +5 位作者 Nan Zhao bin zhang Xiaohan Mu Lisong Tang Xinjun Zheng Yan Li 《Forest Ecosystems》 SCIE CSCD 2024年第2期162-171,共10页
Background:Soil acidifcationn caused by anthropogenic activities may aft soil biochemical cydling,bidiversity,productivity,and multiple eosystem-related functions in drylands.However,to date,such information is lackin... Background:Soil acidifcationn caused by anthropogenic activities may aft soil biochemical cydling,bidiversity,productivity,and multiple eosystem-related functions in drylands.However,to date,such information is lacking to support this hypothesis.Methods Based on a transect survey of 78 naturally assembled shrub communities,we caloulated acid deposition flux in Northwest China and evaluated its likely ecological ffets by testing three altemnative hypotheses,namely:.nidche complementarity,mass ratio,and vegetation quantity hypotheses Rao's quadratic entopy and community-weighted mean traits were employed to represent the complementary aspect of niche complementarity and mass ratio effects,respectively.Resulbs:We observed that in the past four decades,the concentrations of exchangeable base cations in soil in Northwest China have decreased significantly to the extent of having faced the risk of depletion,whereas changes in the calium carbonate content and pH of soil were not significant.Adid deposition primani ly increased the aboweground biomass and shrub density in shrublands but had no sigmificant effect on shrub richness and ecasystem multifunctionality(EMF),indicating that acid deposition had positive but weak ecological effects on dryland ecosystems.Community wd ghted mean of functional traits(representing the mass ratio hypothesis)correlated negatively with EMF,whereas both Rao's quadratic entropy(representing the niche complementarity hypothesis)and aboveground biomass(representing the vegetation quantity hypothesis)correlated positively but insignifcantly with EMF.These biodiversity-EMF relationships highlight the fragility and instability of drylands relative to forest ecasystems.Concuions:The findings from this study serve as important reference points to understand the ris of soil acidification in arid regions and its impacts on biodiversity-EMF relationships. 展开更多
关键词 Soil acidification risk BIODIVERSITY Ecosystem multifunctionality Niche complementarity hypothesis Mass ratio hypothesis Vegetation quantity hypothesis
下载PDF
Uncertainty and sensitivity analysis of in-vessel phenomena under severe accident mitigation strategy based on ISAA-SAUP program
12
作者 Hao Yang Ji-Shen Li +2 位作者 Zhi-Ran zhang bin zhang Jian-Qiang Shan 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第1期108-123,共16页
The phenomenology involved in severe accidents in nuclear reactors is highly complex.Currently,integrated analysis programs used for severe accident analysis heavily rely on custom empirical parameters,which introduce... The phenomenology involved in severe accidents in nuclear reactors is highly complex.Currently,integrated analysis programs used for severe accident analysis heavily rely on custom empirical parameters,which introduce considerable uncertainty.Therefore,in recent years,the field of severe accidents has shifted its focus toward applying uncertainty analysis methods to quantify uncertainty in safety assessment programs,known as“best estimate plus uncertainty(BEPU).”This approach aids in enhancing our comprehension of these programs and their further development and improvement.This study concentrates on a third-generation pressurized water reactor equipped with advanced active and passive mitigation strategies.Through an Integrated Severe Accident Analysis Program(ISAA),numerical modeling and uncertainty analysis were conducted on severe accidents resulting from large break loss of coolant accidents.Seventeen uncertainty parameters of the ISAA program were meticulously screened.Using Wilks'formula,the developed uncertainty program code,SAUP,was employed to carry out Latin hypercube sampling,while ISAA was employed to execute batch calculations.Statistical analysis was then conducted on two figures of merit,namely hydrogen generation and the release of fission products within the pressure vessel.Uncertainty calculations revealed that hydrogen production and the fraction of fission product released exhibited a normal distribution,ranging from 182.784 to 330.664 kg and from 15.6 to 84.3%,respectively.The ratio of hydrogen production to reactor thermal power fell within the range of 0.0578–0.105.A sensitivity analysis was performed for uncertain input parameters,revealing significant correlations between the failure temperature of the cladding oxide layer,maximum melt flow rate,size of the particulate debris,and porosity of the debris with both hydrogen generation and the release of fission products. 展开更多
关键词 Gen-III PWR Severe accident mitigation Wilks’formula HYDROGEN Fission products Uncertainty and sensitivity analysis
下载PDF
Boosting rate performance of layered lithium-rich cathode materials by oxygen vacancy induced surface multicomponent integration
13
作者 Youyou Fang Yuefeng Su +7 位作者 Jinyang Dong Jiayu Zhao Haoyu Wang Yun Lu bin zhang Hua Yan Feng Wu Lai Chen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期250-262,共13页
The rapid development of electric vehicles and portable energy storage systems demands improvements in the energy density and cost-effectiveness of lithium-ion batteries,a domain in which Lithium-rich layered cathode(... The rapid development of electric vehicles and portable energy storage systems demands improvements in the energy density and cost-effectiveness of lithium-ion batteries,a domain in which Lithium-rich layered cathode(LLO)materials inherently excel.However,these materials face practical challenges,such as low initial Coulombic efficiency,inferior cycle/rate performance,and voltage decline during cycling,which limit practical application.Our study introduces a surface multi-component integration strategy that incorporates oxygen vacancies into the pristine LLO material Li1.2Mn_(0.6)Ni_(0.2)O_(2).This process involves a brief citric acid treatment followed by calcination,aiming to explore rate-dependent degradation behavior.The induced surface oxygen vacancies can reduce surface oxygen partial pressure and diminish the generation of O_(2)and other highly reactive oxygen species on the surface,thereby facilitating the activation of Li ions trapped in tetrahedral sites while overcoming transport barriers.Additionally,the formation of a spinel-like phase with 3D Li+diffusion channels significantly improves Li^(+)diffusion kinetics and stabilizes the surface structure.The optimally modified sample boasts a discharge capacity of 299.5 mA h g^(-1)at a 0.1 C and 251.6 mA h g^(-1)at a 1 C during the initial activation cycle,with an impressive capacity of 222.1 mA h g^(-1)at a 5 C.Most notably,it retained nearly 70%of its capacity after 300 cycles at this elevated rate.This straightforward,effective,and highly viable modification strategy provides a crucial resolution for overcoming challenges associated with LLO materials,making them more suitable for practical application. 展开更多
关键词 Lithium-ion battery Layered lithium rich cathode Surface multicomponent integration Rate-dependent degradation and Li^(+) diffusion kinetics
下载PDF
Impact of T_(i)/T_(e )ratio on ion transport based on EAST H-mode plasmas
14
作者 刘建文 臧庆 +14 位作者 梁云峰 陈佳乐 邬潇河 Alexander KNIEPS 扈嘉辉 金仡飞 张斌 储宇奇 刘海庆 吕波 段艳敏 李妙辉 陈颖杰 龚先祖 the EAST Team 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第4期68-78,共11页
At the EAST tokamak, the ion temperature(T_(i)) is observed to be clamped around 1.25 keV in electron cyclotron resonance(ECR)-heated plasmas, even at core electron temperatures up to 10 keV(depending on the ECR heati... At the EAST tokamak, the ion temperature(T_(i)) is observed to be clamped around 1.25 keV in electron cyclotron resonance(ECR)-heated plasmas, even at core electron temperatures up to 10 keV(depending on the ECR heating power and the plasma density). This clamping results from the lack of direct ion heating and high levels of turbulence-driven transport. Turbulent transport analysis shows that trapped electron mode and electron temperature gradient-driven modes are the most unstable modes in the core of ECR-heated H-mode plasmas. Nevertheless, recently it was found that the T_(i)/T_(e)ratio can increase further with the fraction of the neutral beam injection(NBI) power, which leads to a higher core ion temperature(Ti0). In NBI heating-dominant H-mode plasmas, the ion temperature gradient-driven modes become the most unstable modes.Furthermore, a strong and broad internal transport barrier(ITB) can form at the plasma core in high-power NBI-heated H-mode plasmas when the T_(i)/T_(e)ratio approaches ~1, which results in steep core Teand Tiprofiles, as well as a peaked neprofile. Power balance analysis shows a weaker Teprofile stiffness after the formation of ITBs in the core plasma region, where Ticlamping is broken,and the core Tican increase further above 2 keV, which is 80% higher than the value of Ticlamping in ECR-heated plasmas. This finding proposes a possible solution to the problem of Ticlamping on EAST and demonstrates an advanced operational regime with the formation of a strong and broad ITB for future fusion plasmas dominated by electron heating. 展开更多
关键词 ion temperature clamping TRANSPORT neutral beam injection STIFFNESS internal transport barrier
下载PDF
ST-LaneNet: Lane Line Detection Method Based on Swin Transformer and LaneNet
15
作者 Yufeng Du Rongyun zhang +3 位作者 Peicheng Shi Linfeng Zhao bin zhang Yaming Liu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第1期130-145,共16页
The advancement of autonomous driving heavily relies on the ability to accurate lane lines detection.As deep learning and computer vision technologies evolve,a variety of deep learning-based methods for lane line dete... The advancement of autonomous driving heavily relies on the ability to accurate lane lines detection.As deep learning and computer vision technologies evolve,a variety of deep learning-based methods for lane line detection have been proposed by researchers in the field.However,owing to the simple appearance of lane lines and the lack of distinctive features,it is easy for other objects with similar local appearances to interfere with the process of detecting lane lines.The precision of lane line detection is limited by the unpredictable quantity and diversity of lane lines.To address the aforementioned challenges,we propose a novel deep learning approach for lane line detection.This method leverages the Swin Transformer in conjunction with LaneNet(called ST-LaneNet).The experience results showed that the true positive detection rate can reach 97.53%for easy lanes and 96.83%for difficult lanes(such as scenes with severe occlusion and extreme lighting conditions),which can better accomplish the objective of detecting lane lines.In 1000 detection samples,the average detection accuracy can reach 97.83%,the average inference time per image can reach 17.8 ms,and the average number of frames per second can reach 64.8 Hz.The programming scripts and associated models for this project can be accessed openly at the following GitHub repository:https://github.com/Duane 711/Lane-line-detec tion-ST-LaneNet. 展开更多
关键词 Autonomous driving Lane line detection Deep learning Swin transformer
下载PDF
Three anti-inflammatory polysaccharides from Lonicera japonica Thunb.:insights into the structure-function relationships
16
作者 Yu Liu Hongjing Dong +5 位作者 Dongxiao Sun-Waterhouse Wenwen Li bin zhang Jinqian Yu Zhichang Qiu Zhenjia Zheng 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第4期2197-2207,共11页
This study demonstrates the feasibility of producing three polysaccharides(neutral LJP-1,acidic LJP-2 and acidic LJP-3)with significant in vitro and in vivo anti-inflammatory activities from the flowers of Lonicera ja... This study demonstrates the feasibility of producing three polysaccharides(neutral LJP-1,acidic LJP-2 and acidic LJP-3)with significant in vitro and in vivo anti-inflammatory activities from the flowers of Lonicera japonica.The three polysaccharides differed in chemical composition,molecular weight(Mw)distribution,glycosidic linkage pattern,functional groups and morphology.They exhibited excellent protective effects(in a dose-dependent manner)in lipopolysaccharide-injured RAW264.7 macrophages and Cu SO4-damaged zebrafish via reducing NO production and inhibiting the overexpressions of inflammation-related transcription factors,inflammatory proteins and cytokines in the NF-κB/MAPK signaling pathways.Their antiinflammatory effects varied owing to their different molecular characteristics and chemical compositions.Overall,LJP-2 at 400μg/m L was the most effective.LJP-2 consisted mainly of→5)-α-L-Araf(1→,→4)-α-LGalp A(1→and→2)-α-L-Rhap(1→residues with terminal T-β-D-Glcp.Thus,honeysuckle flowers are good sources of anti-inflammatory polysaccharides,and precise fractionation enables the production of potent antiinflammatory agents for the development of functional foods and healthcare products. 展开更多
关键词 Honeysuckle polysaccharides FRACTIONATION Molecular characteristics Anti-inflammatory properties Structure-function relationship
下载PDF
Robust optimal dispatch strategy of integrated energy system considering CHP-P2G-CCS
17
作者 bin zhang Yihui Xia Xiaotao Peng 《Global Energy Interconnection》 EI CSCD 2024年第1期14-24,共11页
Integrated energy systems(IESs)can improve energy efficiency and reduce carbon emissions,essential for achieving peak carbon emissions and carbon neutrality.This study investigated the characteristics of the CHP model... Integrated energy systems(IESs)can improve energy efficiency and reduce carbon emissions,essential for achieving peak carbon emissions and carbon neutrality.This study investigated the characteristics of the CHP model considering P2G and carbon capture systems,and a two-stage robust optimization model of the electricity-heat-gascold integrated energy system was developed.First,a CHP model considering the P2G and carbon capture system was established,and the electric-thermal coupling characteristics and P2G capacity constraints of the model were derived,which proved that the model could weaken the electric-thermal coupling characteristics,increase the electric power regulation range,and reduce carbon emissions.Subsequently,a two-stage robust optimal scheduling model of an IES was constructed,in which the objective function in the day-ahead scheduling stage was to minimize the start-up and shutdown costs.The objective function in the real-time scheduling stage was to minimize the equipment operating costs,carbon emission costs,wind curtailment,and solar curtailment costs,considering multiple uncertainties.Finally,after the objective function is linearized with a ψ-piecewise method,the model is solved based on the C&CG algorithm.Simulation results show that the proposed model can effectively absorb renewable energy and reduce the total cost of the system. 展开更多
关键词 Combined heat and power Power-to-gas Carbon capture system Integrated energy system Robust optimization
下载PDF
Simulation of space heavy-ion induced primary knock-on atoms in bipolar devices
18
作者 张彬 姜昊 +5 位作者 徐晓东 应涛 刘中利 李伟奇 杨剑群 李兴冀 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期573-580,共8页
Bipolar junction transistors(BJTs) are often used in spacecraft due to their excellent working characteristics. However,the complex space radiation environment induces primary knock-on atoms(PKAs) in BJTs through coll... Bipolar junction transistors(BJTs) are often used in spacecraft due to their excellent working characteristics. However,the complex space radiation environment induces primary knock-on atoms(PKAs) in BJTs through collisions, resulting in hard-to-recover displacement damage and affecting the performance of electronic components. In this paper, the properties of PKAs induced by typical space heavy ions(C, N, O, Fe) in BJTs are investigated using Monte Carlo simulations. The simulated results show that the energy spectrum of ion-induced PKAs is primarily concentrated in the low-energy range(17eV–100eV) and displays similar features across all tested ions. The PKAs induced by the collision of energetic ions have large forward scattering angles, mainly around 88°. Moreover, the distribution of PKAs within a transistor as a function of depth displays a peak characteristic, and the peak position is linearly proportional to the incident energy at a certain energy range. These simulation outcomes serve as crucial theoretical support for long-term semiconductor material defect evolution and ground testing of semiconductor devices. 展开更多
关键词 Monte Carlo simulation primary knock-on atom(PKA) space-heavy ion radiation damage
下载PDF
Oxidation Evolution and Activity Origin of N-Doped Carbon in the Oxygen Reduction Reaction
19
作者 Jiaqi Wu Chuanqi Cheng +2 位作者 Shanshan Lu bin zhang Yanmei Shi 《Transactions of Tianjin University》 EI CAS 2024年第4期369-379,共11页
N-doped carbon materials,with their applications as electrocatalysts for the oxygen reduction reaction(ORR),have been extensively studied.However,a negletcted fact is that the operating potential of the ORR is higher ... N-doped carbon materials,with their applications as electrocatalysts for the oxygen reduction reaction(ORR),have been extensively studied.However,a negletcted fact is that the operating potential of the ORR is higher than the theoretical oxida-tion potential of carbon,possibly leading to the oxidation of carbon materials.Consequently,the infl uence of the structural oxidation evolution on ORR performance and the real active sites are not clear.In this study,we discover a two-step oxida-tion process of N-doped carbon during the ORR.The fi rst oxidation process is caused by the applied potential and bubbling oxygen during the ORR,leading to the oxidative dissolution of N and the formation of abundant oxygen-containing functional groups.This oxidation process also converts the reaction path from the four-electron(4e)ORR to the two-electron(2e)ORR.Subsequently,the enhanced 2e ORR generates oxidative H_(2)O_(2),which initiates the second stage of oxidation to some newly formed oxygen-containing functional groups,such as quinones to dicarboxyls,further diversifying the oxygen-containing functional groups and making carboxyl groups as the dominant species.We also reveal the synergistic eff ect of multiple oxygen-containing functional groups by providing additional opportunities to access active sites with optimized adsorption of OOH*,thus leading to high effi ciency and durability in electrocatalytic H_(2)O_(2) production. 展开更多
关键词 Oxygen reduction reaction N-doped carbon Reaction path Structural evolution Oxidation in reduction
下载PDF
The effect of Ti and Zr content on the structure,mechanics and energy-release characteristics of Ti—Zr—Ta alloys
20
作者 Jia-yu Meng Jing-zhi He +4 位作者 bin zhang Jin Chen Shun Li Dun Niu Yu Tang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期343-350,共8页
Energetic structural materials(ESMs)are a new type of structural materials with bearing and damage characteristics.In this work the microstructure,mechanical properties and energy release characteristics of multi-elem... Energetic structural materials(ESMs)are a new type of structural materials with bearing and damage characteristics.In this work the microstructure,mechanical properties and energy release characteristics of multi-element Ti-Zr-Ta alloys with good casting performance were studied.The microstructure of the Ti_(x)ZrTa alloys gradually change from BCC+HCP to single BCC structure with the increase of Ti.While the Ti_(2)Zr_(y)Ta alloys was still uniform and single BCC structure with the increase of Zr.The evolution of microstructure and composition then greatly affect the mechanical properties and energy-release characteristics of Ti-Zr-Ta alloys.The synergistic effect of dual phase structure increases the fracture strain of Ti_(x)ZrTa(x=0.2,0.5)with the Ti content decreases,while the fracture strain of Ti_(x)ZrTa(x=2.0,3.0,4.0)gradually increase with the Ti content increases caused by the annihilation of the obstacles for dislocation movement.And as Zr content increases,the fracture strain of Ti_(2)Zr_(y)Ta alloys decrease,then the oxidation reaction rate and fragmentation degree gradually increase.The higher oxidation rate and the lager exposed oxidation area jointly leads the higher releasing energy efficiency of Ti_(x)ZrTa alloys with low Ti content and Ti_(2)Zr_(y)Ta alloys with high Zr content. 展开更多
关键词 Energetic structural materials Ti-Zr-Ta Multi-element alloy Energy release characteristics
下载PDF
上一页 1 2 32 下一页 到第
使用帮助 返回顶部