检索结果-南通市图书馆

Delving into the dissimilarities in electrochemical performance and underlying mechanisms for sodium and potassium ion storage in N-doped carbon-encapsulated metallic Cu_(2)Se nanocubes

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第8期95卷 336-347,I0008页

作者： Xinyu Wang yanan xu Xiaofeng Liu Lei Tan Huaiqiang Gu Xin Du Dan Li College of Chemistry Zhengzhou UniversityZhengzhou 450001HenanChina Green Catalysis Center College of ChemistryZhengzhou UniversityZhengzhou 450001HenanChina Institute of Theoretical Physics Lanzhou UniversityLanzhou 730000GansuChina School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000GansuChina Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin 300071China State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources College of ChemistryXinjiang UniversityUrumqi 830046XinjiangChina

The large volumetric variations experienced by metal selenides within conversion reaction result in inferior rate capability and cycling stability,ultimately hindering the achievement of superior electrochemical ***,metallic Cu_(2)Se encapsulated with N-doped carbon(Cu_(2)Se@NC)was prepared using Cu_(2)O nanocubes as templates through a combination of dopamine polymerization and hightemperature *** unique nanocubic structure and uniform N-doped carbon coating could shorten the ion transport distance,accelerate electron/charge diffusion,and suppress volume variation,ultimately ensuring Cu_(2)Se@NC with excellent electrochemical performance in sodium ion batteries(SIBs)and potassium ion batteries(PIBs).The composite exhibited excellent rate performance(187.7 mA h g^(-1)at 50 A g^(-1)in SIBs and 179.4 mA h g^(-1)at 5 A g^(-1)in PIBs)and cyclic stability(246,8 mA h g^(-1)at 10 A g^(-1)in SIBs over 2500 cycles).The reaction mechanism of intercalation combined with conversion in both SIBs and PIBs was disclosed by in situ X-ray diffraction(XRD)and ex situ transmission electron microscope(TEM).In particular,the final products in PIBs of K_(2)Se and K_(2)Se_(3)species were determined after discharging,which is different from that in SIBs with the final species of Na_(2)*** density functional theory calculation showed that carbon induces strong coupling and charge interactions with Cu_(2)Se,leading to the introduction of built-in electric field on heterojunction to improve electron ***,the theoretical calculations discovered that the underlying cause for the relatively superior rate capability in SIBs to that in PIBs is the agile Na~+diffusion with low energy barrier and moderate adsorption *** findings offer theoretical support for in-depth understanding of the performance differences of Cu-based materials in different ion storage systems.

关键词： Cu_(2)Se nanocubes DFT calculations Ion storage mechanism Potassium ion batteries Sodium ion batteries

Effect of chemical regulators on the recovery of leaf physiology,dry matter accumulation and translocation,and yield-related characteristics in winter wheat following dry-hot wind

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第1期23卷 108-121页

作者： yanan xu Yue Wu Yan Han Jiqing Song Wenying Zhang Wei Han Binhui Liu Wenbo Bai Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesBeijing 100081China Institute of Dryland Farming Research Hebei Academy of Agriculture and Forestry SciencesHengshui 053000China Shandong General Station of Agricultural Technology Extension Jinan 250100China

Dry-hot wind stress causes losses in wheat productivity in major growing regions worldwide,especially winter wheat in the Huang-Huai-Hai Plain of China,and both the occurrence and severity of such events are likely to increase with global climate *** investigate the recovery of physiological functions and yield formation using a new noncommercial chemical regulator(NCR)following dry-hot wind stress,we conducted a three-year field experiment(2018-2021)with sprayed treatments of tap water(control),monopotassium phosphate(CKP),NCR at both the jointing and flowering stages(CFS),and NCR only at the jointing stage(FSJ)or flowering stage(FSF).The leaf physiology,biomass accumulation and translocation,grain-filling process,and yield components in winter wheat were *** the single spraying treatments,the FSJ treatment was beneficial for the accumulation of dry matter before anthesis,as well as larger increases in the maximum grain-filling rate and mean grain-filling *** FSF treatment performed better in maintaining a high relative chlorophyll content as indicated by the SPAD value,and a low rate of excised leaf water loss in flag leaves,promoting dry matter accumulation and the contribution to grain after anthesis,prolonging the duration of grain filling,and causing the period until the maximum grain-filling rate reached *** CFS treatment was better than any other treatments in relieving the effects of dry-hot *** exogenous NCR treatments significantly increased grain yields by 12.45-18.20% in 2018-2019,8.89-13.82% in 2019-2020,and 8.10-9.00% in *** conventional measure of the CKP treatment only increased grain yield by 6.69% in *** CFS treatment had the greatest mitigating effect on yield loss under dry-hot wind stress,followed by the FSF and FSJ treatments,and the CKP treatment only had a minimal *** summary,the CFS treatment could be used as the main chemical control measure for wheat stress resistance and yield

关键词： preparation stress foliar spraying grain-filling remobilization

Carbon nanocages bridged with graphene enable fast kinetics for dual-carbon lithium-ion capacitors

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第3期9卷 573-583页

作者： Shani Li yanan xu Wenhao Liu xudong Zhang Yibo Ma Qifan Peng Xiong Zhang Xianzhong Sun Kai Wang Yanwei Ma Institute of Electrical Engineering Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China Innovation Academy for Green Manufacture Beijing100190China Beijing Institute of Technology Beijing100081China School of Materials Science and Engineering Zhengzhou UniversityZhengzhou450001China

Lithium-ion capacitors(LICs) combining the advantages of lithium-ion batteries and supercapacitors are considered a promising nextgeneration energy storage device. However, the sluggish kinetics of battery-type anode cannot match the capacitor-type cathode, restricting the development of LICs. Herein, hierarchical carbon framework(HCF) anode material composed of 0D carbon nanocage bridged with 2D graphene network are developed via a template-confined synthesis process. The HCF with nanocage structure reduces the Li^(+) transport path and benefits the rapid Li^(+) migration, while 2D graphene network can promote the electron interconnecting of carbon nanocages. In addition, the doped N atoms in HCF facilitate to the adsorption of ions and enhance the pseudo contribution, thus accelerate the kinetics of the anode. The HCF anode delivers high specific capacity, remarkable rate capability. The LIC pouch-cell based on HCF anode and active HCF(a-HCF) cathode can provide a high energy density of 162 Wh kg^(-1) and a superior power density of 15.8 kW kg^(-1), as well as a long cycling life exceeding 15,000cycles. This study demonstrates that the well-defined design of hierarchical carbon framework by incorporating 0D carbon nanocages and 2D graphene network is an effective strategy to promote LIC anode kinetics and hence boost the LIC electrochemical performance.

关键词： Hierarchical carbon framework Nanocage ZIF Graphene Lithium-ion capacitors

Supramolecular Bonding Competition Enabled Nanostructure Evolution and Mechanical Reinforcement

在线全文

学校读者我要写书评

暂无评论

CCS Chemistry 2024年第1期6卷 157-164页

作者： Yuting Wang Peng Meng Aidan Brock yanan xu Hang Meng Zixuan Liu Kan Zhang John McMurtrie Jingsan xu School of Chemistry and Physics and Centre for Materials Science Queensland University of TechnologyBrisbaneQueensland 4000 Central Analytical Research Facility Institute for Future EnvironmentsQueensland University of TechnologyBrisbaneQueensland 4000 State Key Laboratory of Superhard Materials Department of Materials Science and Key Laboratory of Automobile MaterialsMOEJilin UniversityChangchun 130012

In this work,competition between different supramolecular interactions is investigated based on a fibrous crystal composed of hydrogen-bonded cyanuric acid(CA)and amidinothiourea(ADT).Melamine(M)is found to prevail over ADT and bond to CA due to its stronger triple H-bonding affiliation,forming hollow microtubes assembled by oriented CAM crystalline arrays,as guided by the directionality of peripheral hydrogen ***,competitive interaction between hydrogen bonding and ionic/covalent bonding is demonstrated by mixing Ag+ions with the CA-ADT fibers,where sulfur atoms are abstracted from ADT molecules to produce Ag_(2)S *** in situ-formed Ag_(2)S serves as a binding glue to generate CA-ADT/Ag_(2)S composites with significantly enhanced mechanical strength compared to the pristine CA-ADT fiber pellet.

关键词： supramolecular interaction hydrogen bonds chemical bond competition hollow crystal array organic-inorganic composite

A neural m^(6)A pathway regulates behavioral aggregation in migratory locusts

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2024年第6期67卷 1242-1254页

作者： Xianliang Huang Qing Li yanan xu Ang Li Shanzheng Wang Yusheng Chen Chunrui Zhang Xia Zhang Hailin Wang Cong Lv Baofa Sun Shaoqin Li Le Kang Bing Chen School of Life Science Institutes of Life Science and Green DevelopmentHebei UniversityBaoding 071002China College of Plant Science and Technology Huazhong Agricultural UniversityWuhan 430070China State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijing 100101China Institute of Health Sciences Anhui UniversityHefei 230601China Beijing Institute of Genomics Chinese Academy of SciencesBeijing 100101China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing100101China

RNA N6-methyladenosine(m^(6)A),as the most abundant modification of messenger RNA,can modulate insect behaviors,but its specific roles in aggregation behaviors remain ***,we conducted a comprehensive molecular and physiological characterization of the individual components of the methyltransferase and demethylase in the migratory locust Locusta *** results demonstrated that METTL3,METTL14 and ALKBH5 were dominantly expressed in the brain and exhibited remarkable responses to crowding or *** individual knockdown of methyltransferases(i.e.,METTL3 and METTL14)promoted locust movement and conspecific attraction,whereas ALKBH5 knockdown induced a behavioral shift toward the solitary ***,global transcriptome profiles revealed that m^(6)A modification could regulate the orchestration of gene expression to fine tune the behavioral aggregation of *** summary,our in vivo characterization of the m^(6)A functions in migratory locusts clearly demonstrated the crucial roles of the m^(6)A pathway in effectively modulating aggregation behaviors.

关键词： RNA methylation N^(6)-methyladenosine transcriptional orchestration aggregation behavior Locusta migratoria

在线全文

学校读者我要写书评

暂无评论

虚拟现实技术在智能插秧机中的应用

农机化研究 2024年第5期46卷 201-205页

作者：徐亚楠郑州升达经贸管理学院郑州451191

为进一步提升我国智能插秧机的作业效率与插植准确度,基于虚拟现实技术理念针对其结构设计及作业控制展开研究。在充分理解智能插秧机的结构组成与作业要求实现的基础上,运用VR控制理念,建立VR可视化设计模型平台,融入北斗定位及VR矩阵... 详细信息

为进一步提升我国智能插秧机的作业效率与插植准确度,基于虚拟现实技术理念针对其结构设计及作业控制展开研究。在充分理解智能插秧机的结构组成与作业要求实现的基础上,运用VR控制理念,建立VR可视化设计模型平台,融入北斗定位及VR矩阵元素等核心技术,形成完整的智能插秧机作业系统,并展开有效性的插秧作业试验。试验结果表明:将虚拟现实技术应用于智能插秧机,实现了插秧作业性能的整体提升,在VR可视化的监测与调偏功能运用下,控制准确率相对提高了8.83%,合格率相对提高了6.76%,秧苗利用率亦得到明显提升,对于插秧装备的无人化和智能化及多范围、多地区推广起到了积极作用,可为类似农机装备的优化创新提供很好的思路与方向。

关键词：智能插秧机虚拟现实可视化设计控制准确率插秧合格率

维普期刊数据库博看期刊

在线全文

学校读者我要写书评

暂无评论

天然皂苷在阿尔茨海默病作用及机制研究进展

中国实验方剂学杂志 2024年第13期30卷 240-249页

作者：徐亚南柳成刚黑龙江中医药大学基础医学院哈尔滨150040

阿尔茨海默病(AD)是一种神经退行性疾病,其主要特征是记忆和认知功能的进行性下降。尽管在过去几十年里对AD的研究取得了一些进展,但其确切病因仍然不清楚,目前尚无可靠的治疗方法。这引起了对新型治疗策略的迫切需求,特别是对不良反应... 详细信息

阿尔茨海默病(AD)是一种神经退行性疾病,其主要特征是记忆和认知功能的进行性下降。尽管在过去几十年里对AD的研究取得了一些进展,但其确切病因仍然不清楚,目前尚无可靠的治疗方法。这引起了对新型治疗策略的迫切需求,特别是对不良反应小、疗效好的神经保护药物的需求。天然植物提取物中的是一类甾体或三萜皂苷类化合物,具有多种药理活性,被认为在AD的预防和治疗中具有巨大的潜力。研究表明,天然皂苷可能通过多种途径发挥作用,包括减少淀粉样蛋白β肽的沉积、抑制Tau蛋白的异常磷酸化、调节氧化应激、减少炎症反应及抑制细胞凋亡等。特别是,一些含有天然皂苷成分的中药制剂已经显示出在AD治疗中的潜在优势,具有重要的临床应用前景。该文综述了天然植物提取后的皂苷类化合物在AD防治方面的研究进展,并对其作用机制进行了深入探讨。通过对这些研究的综合分析,揭示了皂苷在AD治疗中的潜在机制,旨在为新型治疗药物的研发提供了重要参考,并期待未来能够通过进一步的研究和临床实验,充分挖掘其在AD治疗中的潜力,并为患者提供更有效的治疗选择。

关键词：阿尔茨海默病三萜皂苷甾体皂苷作用机制

脉冲电场辅助碳素钢极薄带拉伸变形的本构模型和微观组织演变

在线全文

学校读者我要写书评

暂无评论

机械工程学报 2024年第6期60卷 245-260页

作者：任忠凯李赫许雅楠程前冯浩王涛太原理工大学机械与运载工程学院太原030024 太原理工大学先进金属复合材料成形技术与装备教育部工程研究中心太原030024 中国重型机械研究院股份公司西安710018

08AL碳素钢极薄带材在微机电及微系统领域有着广泛的应用前景,但随着厚度的减小其塑性变形能力成为掣肘其应用的痛点。将脉冲电场集成到08AL碳素钢极薄带拉伸试验中,探究拉伸变形中电致塑性效应对极薄带变形能力和微观组织演变的影响规... 详细信息

08AL碳素钢极薄带材在微机电及微系统领域有着广泛的应用前景,但随着厚度的减小其塑性变形能力成为掣肘其应用的痛点。将脉冲电场集成到08AL碳素钢极薄带拉伸试验中,探究拉伸变形中电致塑性效应对极薄带变形能力和微观组织演变的影响规律。基于试验结果,建立一种改进的Johnson-Cook本构模型,用来定量分析电致塑性效应中焦耳热效应和非热效应对材料流动应力的影响规律。基于材料硬化子程序VUMAT开发电场辅助拉伸有限元模型,分析不同成形参数下的应力和应变特性,并确定试样微观结构表征的位置。试验结果表明,在施加1.50 A/mm^(2)的电流时,试样抗拉强度较室温拉伸降低16.5%,伸长率提高32.1%。此外,微观表征结果表明,在平均电流密度为1.50 A/mm^(2)的条件下,极薄带在塑性变形阶段不断细化晶粒并促进晶内和晶界处位错滑移,使其变形抗力降低,塑性性能提高。因此,脉冲电场辅助08AL碳素钢极薄带变形,有望显著提高其成形极限,拓宽其应用领域。

关键词： 08AL碳素钢脉冲电流 Johnson-Cook本构模型微观表征抗拉强度

Ni_(3)Al基高温合金的成分设计及室温性能

在线全文

学校读者我要写书评

暂无评论

金属热处理 2024年第3期49卷 209-214页

作者：滕宗延许雅南王轶农刘林徐朝晖大连理工大学材料科学与工程学院辽宁大连116024

为改善Ni_(3)Al基高温合金的室温性能,基于“团簇加连接原子模型”对Ni_(3)Al基合金进行了成分设计,考察了合金的显微组织、力学性能和耐蚀性。结果表明,退火前后合金均由β相、α相和基体γ′相组成。1050℃×24 h退火后Ni5Co5Cr2Al2.5... 详细信息

为改善Ni_(3)Al基高温合金的室温性能,基于“团簇加连接原子模型”对Ni_(3)Al基合金进行了成分设计,考察了合金的显微组织、力学性能和耐蚀性。结果表明,退火前后合金均由β相、α相和基体γ′相组成。1050℃×24 h退火后Ni5Co5Cr2Al2.5Ti1.5合金中β相和α相在基体中分布均匀,不仅使其呈现出更优的力学性能(最大压缩率为29.35%,屈服强度为1796 MPa,硬度为546.35 HV),还诱导合金发生电偶腐蚀,增强了合金的钝化效果,使合金呈现出更好的耐蚀性(阻抗为7.74×10^(4)Ω,自腐蚀电位为-0.055 V(vs SCE),自腐蚀电流密度为5.93×10^(-7)A/cm^(2))。本文所设计合金的室温力学性能和耐蚀性与Ni_(3)Al相比均有显著改善,为高温合金的成分设计提供了新的研究思路。

关键词： Ni_(3)Al基合金团簇加连接原子模型退火处理显微组织