检索结果-南通市图书馆

Ni-catalyzed cross-electrophile alkyl-alkyl coupling reactions

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年

作者： Li-Xu you Lan tian Chun-Ling Guo Shun-Xi Li yu-Cheng Liu yu-Long Li Wei Shu College of Chemistry and Environmental Engineering Key Laboratory of Green Catalysis of Higher Education Institutes of Sichuan Sichuan University of Science and Engineering Guangming Advanced Research Institute Shenzhen Grubbs Institute Department of Chemistry and Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and Technology

Introducing saturated carbon-carbon bonds into organic molecules significantly increases the three-dimensional configuration,thus altering the physical and chemical properties as well as the functions of molecules. Transition-metal-catalyzed carboncarbon cross-couplings represent one of the most straightforward, efficient and modular alternatives to build saturation in a single step. However, the efficient construction of alkyl-alkyl bonds remains a formidable challenge due to the precise manipulation of multiple alkyl metallic intermediates as well as associated competitive side reactions and selectivity control. Over the past years, Ni-catalyzed cross-coupling under reductive conditions has gained more and more attention for alkyl-alkyl crosscoupling partially attributing to the low-valent state of metal centers under reducing conditions, which suppresses the competitive β-hydride elimination process, thus facilitating the formation of alkyl-alkyl bonds. In this review, the initiative and progress of Ni-catalyzed cross-electrophile alkyl-alkyl cross-coupling, including the efforts in racemic and enantioselective formation of alkyl-alkyl bonds, have been summarized and discussed. Moreover, the challenges and further opportunities in this area have also been discussed.

关键词：

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

羊舌氏家风与叔向文学活动的文学史意义

西北师大学报（社会科学版） 2021年第1期58卷 68-78页

作者：赵逵夫田有余西北师范大学文学院甘肃兰州730070

晋国叔向以博学多识、工于辞令而闻名,《左传》《国语》记载了其文学活动。叔向善于赋诗、引诗,其诗学活动助力了《诗》的经典生成。叔向的言辞观表现为"辞不可以已"、须合乎礼制、"信而有征"等,其言辞观是儒家政教功用论文学思想的先... 详细信息

晋国叔向以博学多识、工于辞令而闻名,《左传》《国语》记载了其文学活动。叔向善于赋诗、引诗,其诗学活动助力了《诗》的经典生成。叔向的言辞观表现为"辞不可以已"、须合乎礼制、"信而有征"等,其言辞观是儒家政教功用论文学思想的先声。叔向的外交文辞、政论文辞、论谏文辞有很高的思想和文学价值。以叔向为代表的春秋卿大夫们的文化、文学活动,是战国诸子著书立说活动的上源,也为屈原、宋玉等卿大夫文学家的活动开了先河。

关键词：叔向卿大夫辞令创作文学史意义

Dip2a regulates stress susceptibility in the basolateral amygdala

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第6期20卷 1735-1748页

作者： Jing Li Zixuan He Weitai Chai Meng tian Huali yu Xiaoxiao He Xiaojuan Zhu Key Laboratory of Molecular Epigenetics Ministry of Education Institute of Genetics and CytologyNortheast Normal UniversityChangchunJilin ProvinceChina

Dysregulation of neurotransmitter metabolism in the central nervous system contributes to mood disorders such as depression, anxiety, and post–traumatic stress disorder. Monoamines and amino acids are important types of neurotransmitters. Our previous results have shown that disco-interacting protein 2 homolog A(Dip2a) knockout mice exhibit brain development disorders and abnormal amino acid metabolism in serum. This suggests that DIP2A is involved in the metabolism of amino acid–associated neurotransmitters. Therefore, we performed targeted neurotransmitter metabolomics analysis and found that Dip2a deficiency caused abnormal metabolism of tryptophan and thyroxine in the basolateral amygdala and medial prefrontal cortex. In addition, acute restraint stress induced a decrease in 5-hydroxytryptamine in the basolateral amygdala. Additionally, Dip2a was abundantly expressed in excitatory neurons of the basolateral amygdala, and deletion of Dip2a in these neurons resulted in hopelessness-like behavior in the tail suspension test. Altogether, these findings demonstrate that DIP2A in the basolateral amygdala may be involved in the regulation of stress susceptibility. This provides critical evidence implicating a role of DIP2A in affective disorders.

关键词： 5-hydroxytryptamine acute restraint stress basolateral amygdala CaMKII neurons DIP2A metabolomics neurotransmitters principal component analysis stress susceptibility tryptophan

基于HyperWorks的干式变压器公路运输方案优化设计

在线全文

学校读者我要写书评

暂无评论

变压器 2018年第5期55卷 21-25页

作者：朱天佑余雄刘玲海南金盘智能科技股份有限公司海南海口570216

利用有限元分析软件HyperWorks对一台干式变压器进行了随机振动仿真,分析了变压器在公路运输机械环境条件下的失效结构,通过对比实际运输情况,验证了随机振动仿真分析的正确性。

关键词：干式变压器公路运输振动仿真

Advances in the Development of Gradient Scaffolds Made of Nano‑Micromaterials for Musculoskeletal Tissue Regeneration

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第3期17卷 455-500页

作者： Lei Fang Xiaoqi Lin Ruian Xu Lu Liu yu Zhang Feng tian Jiao Jiao Li Jiajia Xue Beijing Laboratory of Biomedical Materials Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China State Key Laboratory of Organic‑Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029People’s Republic of China School of Biomedical Engineering Faculty of Engineering and ITUniversity of Technology SydneySydneyNSW 2007Australia

The intricate hierarchical structure of musculoskeletal tissues,including bone and interface tissues,necessitates the use of complex scaffold designs and material structures to serve as tissue-engineered *** has led to growing interest in the development of gradient bone scaffolds with hierarchical structures mimicking the extracellular matrix of native tissues to achieve improved therapeutic *** on the anatomical characteristics of bone and interfacial tissues,this review provides a summary of current strategies used to design and fabricate biomimetic gradient scaffolds for repairing musculoskeletal tissues,specifically focusing on methods used to construct compositional and structural gradients within the *** latest applications of gradient scaffolds for the regeneration of bone,osteochondral,and tendon-to-bone interfaces are ***,the current progress of testing gradient scaffolds in physiologically relevant animal models of skeletal repair is discussed,as well as the challenges and prospects of moving these scaffolds into clinical application for treating musculoskeletal injuries.

关键词： Gradient scaffolds Musculoskeletal tissues Advanced manufacturing Biomaterials Tissue regeneration

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

击实试验结果分析及应用

山西建筑 2010年第6期36卷 112-113页

作者：田玉友天津南环铁路有限公司

介绍了击实试验的目的和适用范围,具体阐述了击实试验的方法,并对试验结果进行了分析,总结了解决同一层填土使用什么样压实标准这一问题的几种办法,进而提出建议以保证试验的准确性。

关键词：击实试验含水率干密度方法路基

在线全文

学校读者我要写书评

暂无评论

仰泳双手双脚重叠并拢滑行技术的运动学分析

南京体育学院学报（自然科学版） 2016年第6期15卷 49-52,64页

作者：由天宇南京体育学院江苏南京210014

双手双脚重叠并拢滑行技术是一种逐渐发展普及的游泳技术,也是在仰泳项目中国际优秀运动员所使用的技术。通过对6名江苏省优秀仰泳运动员进行双手双脚重叠并拢滑行技术训练教学,并对滑行、出发、转身后滑行成绩和技术进行比较分析,证实... 详细信息

双手双脚重叠并拢滑行技术是一种逐渐发展普及的游泳技术,也是在仰泳项目中国际优秀运动员所使用的技术。通过对6名江苏省优秀仰泳运动员进行双手双脚重叠并拢滑行技术训练教学,并对滑行、出发、转身后滑行成绩和技术进行比较分析,证实该技术的效果,探寻仰泳项目中该技术形成的最佳途径与方法。研究主要使用影像解析分析方法对主要运动学指标进行分析,结果表明使用该技术能显著提高蹬边滑行、出发滑行成绩,也能提高转身滑行成绩,且该技术的运用不影响整体技术发挥,表明双手双脚重叠并拢滑行技术是一种科学有效的仰泳滑行技术。有必要在训练比赛中推广该技术,同时在日常训练比赛中加强系统训练,并注意结合运动员个人特点进行针对性教学,尤其是转身中的技术运用。

关键词：游泳滑行技术双手双脚重叠并拢压差助力

在线全文

学校读者我要写书评

暂无评论

气体扩散电极的电流密度分布研究

电源技术 2016年第5期40卷 1011-1012,1016页

作者：由天宇徐献芝李清宇中国科学技术大学安徽合肥230027

为探究气体扩散电极中小孔电极电流密度与反应速度及传质的关系,用数值计算的方法,给出了氧电极不同反应速度下的小孔电极电流密度分布。首先根据相关参数,估算出反应的最大传质速度,而后给出了当反应速度大于,等于及小于最大传质速度... 详细信息

为探究气体扩散电极中小孔电极电流密度与反应速度及传质的关系,用数值计算的方法,给出了氧电极不同反应速度下的小孔电极电流密度分布。首先根据相关参数,估算出反应的最大传质速度,而后给出了当反应速度大于,等于及小于最大传质速度时的电流密度分布。发现当反应速度等于及大于最大传质速度时,电流密度分布不变,且反应集中于三相交界线附近;当反应速度小于最大传质速度时,电流密度分布随反应速度的减小而改变。

关键词：气体扩散电极小孔电极电流密度分布集中反应区域

Homologous CoS2 interface with directed electron transfer and strong chloridion repulsion for efficient seawater oxidation

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年

作者： yuan tian Jiang-Bo Chen Jie Ying Ge tian yu-Xuan Xiao Yi Lu Si-Ming Wu Wei Geng Ling Shen Xiao-yu Yang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing and School of Materials Science and Engineering and Shenzhen Research Institute & Laoshan Laboratory Wuhan University of Technology School of Chemical Engineering and Technology Sun Yat-Sen University National Energy Key Laboratory for New Hydrogen-Ammonia Energy Technologies Foshan Xianhu Laboratory

Seawater electrolysis is a highly promising method to produce high energy density hydrogen,especially in dry areas that have scarce freshwater ***,application of seawater electrolysis is confronted by two major problems associated with catalysts employed for the anodic oxygen evolution reaction （OER） including the competitive hypochlorite evolution reaction（HCER） and strong chloridion （Cl–） triggered *** studies aimed at overcoming these problems,a facile method has been developed to synthesize a homologous CoS2heterojunction as an OER *** to a difference in work functions at the interface and increased electron density,this material has directed electron transfer and strong chloridion repulsion properties,*** have shown that CoS2achieves low overpotentials of 289 and 322 mV at 10 mA cm-2current density in respective alkaline （1 M KOH） and alkaline simulated seawater ***,the outstanding stability of CoS2is reflected in a negligible decline in activity during promotion of the OER for 100 *** of density functional theory calculations reveal that the homologous CoS2heterojunction promotes directed electron transport for optimizing adsorption/desorption of reactive species and heightens the Cl-adsorption energy for strongly repulsing Cl-,phenomena that enhance OER performance in alkaline simulated seawater.

关键词：