检索结果-南通市图书馆

Polyimide covalent organic frameworks as efficient solid-state Li^(+) electrolytes

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第5期67卷 1647-1652页

作者： Xu liu Shi Wang Siqi liu chengfang liu Xiangchun Li Jian Wu Dazhi Li Shihao Xu Chongyang liu Wen-Yong Lai State Key Laboratory of Organic Electronics and Information Displays(SKLOEID) Institute of Advanced Materials(IAM)School of Chemistry and Life SciencesNanjing University of Posts&TelecommunicationsNanjing 210023China

Covalent organic frameworks(COFs) are attractive porous crystalline materials with extremely high stability, easy functionalization, and open channels, which are expected to be unique ion conductors/transporters in lithium ion batteries(LIBs). Despite recent advances, low ion conductivity and low transference number, resulting in low charging/discharging rate, low energy density, and short battery life, are the main issues that limit their direct application as solid electrolytes in LIBs. Here, we designed and synthesized a novel polyimide COF, namely, TAPA-PDI-COF, with abundant C=O groups, which has been successfully employed as high-performance solid electrolytes by doping TAPA-PDI-COF and succinonitrile(SN). Both the well-defined nanochannels of COFs and SN confined in the well-aligned channels restricted the free migration of anions, while C=O on COFs and CN groups of SN enhanced Li^(+) transport, thus achieving a high ion conductivity of 0.102 m S cm^(-1)at 80 °C and a high lithium-ion transference number of 0.855 at room temperature. According to density functional theory(DFT)calculations, Li-ion migration mainly adopted in-plane transport rather than the axial pathway, which may be due to the shorter hopping distances in the planar pathway. The results suggest an effective strategy for the design and development of all-solidstate ionic conductors for achieving high-performance LIBs.

关键词： lithium ion batteries(LIBs) covalent organic frameworks(COFs) solid-state ion conductors solid-state electrolytes ion conductivity

Single-Component Color-Tunable Smart Organic Emitters with Simultaneous Multistage Stimuli-Responsiveness and Multimode Emissions

在线全文

学校读者我要写书评

暂无评论

Research 2024年第2期2023卷 719-728页

作者： Yu Yan chengfang liu Jianzhong Fan Yusheng Li Huanling liu Qian Wang Xiangchun Lil Junfeng Li Wen-Yong Lai State Key Laboratory of Organic Electronics and Information Displays(SKLOEID) Institute of Advanced Materials(IAM)School of Chemistry and Life SciencesNanjing University of Posts&Telecommunications9 Wenyuan RoadNanjng 210023China Shandong Province Key Laboratory of Medical Physics and Image Processing Technology School of Physics and ElectronicsShandong Normal UniversityJinan 250358China

Achieving color-tunable emission in single-component organic emitters with multistage stimuli-responsiveness is of vital significance for intelligent optoelectronic applications,but remains enormously ***,we present an unprecedented example of a color-tunable single-component smart organic emitter(DDOP)that simultaneously exhibits multistage stimuli-responsiveness and multimode *** based on a highly twisted amide-bridged donor-tcceptor-donor structure has been found to facilitate intersystem crossing,form multimode emissions,and generate multiple emissive species with multistage *** pristine crystalline powders exhibit abnormal excitation-dependent emissions from a monomer-dominated blue emission centered at 470 nm to a dimer-dominated yellow emission centered at 550 nm through decreasing the ultraviolet(UV)excitation wavelengths,whereas DDOP single crystals show a wide emission band with a main emission peak at 585 nm when excited at different *** emission behaviors of pristine crystalline powders and single crystals are different,demonstrating emission features that are closely related to the aggregation *** work has developed color-tunable single-component organic emitters with simultaneous multistage stimuli-responsiveness and multimode emissions,which is vital for expanding intelligent optoelectronic applications,including multilevel information encryption,multicolor emissive patterns,and visual monitoring of UV wavelengths.

关键词： donor excitation Smart

从“幼有所育”迈向“幼有优育”,推动农村学前教育高质量发展

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

华中农业大学学报（社会科学版） 2024年第4期 164-165页

作者：刘承芳北京大学现代农学院/中国农业政策研究中心北京100871

学前教育作为经济发展的关键组成部分,与人力资本积累和经济社会发展密切相关。大量研究表明,学前教育作为全生命周期人力资本积累最早的一个阶段,不仅涉及知识的传授,还包括社会技能的培养、学习动机的激发以及解决问题能力的提升。这... 详细信息

学前教育作为经济发展的关键组成部分,与人力资本积累和经济社会发展密切相关。大量研究表明,学前教育作为全生命周期人力资本积累最早的一个阶段,不仅涉及知识的传授,还包括社会技能的培养、学习动机的激发以及解决问题能力的提升。这些技能和素养不仅对个人成年后的职业发展和社会参与影响深远,而且与国家的创新能力和国际竞争力也息息相关。此外,学前教育还有助于不同社会经济背景的儿童实现起点公平,缩小差距。可见,高质量的学前教育不仅是新时代实现人的全面发展的重要基础,更是国家实现经济社会高质量发展的重要基石。

关键词：学前教育人力资本积累解决问题能力全生命周期社会经济背景起点公平缩小差距创新能力

基于各向异性梯度约束的裂缝弱度贝叶斯反演方法

在线全文

学校读者我要写书评

暂无评论

石油物探 2024年第3期63卷 645-653页

作者：刘成芳魏华动刘瑞中国石油化工股份有限公司西北油田分公司新疆乌鲁木齐830011

发育定向排列垂直裂缝的油气储层可以等效为具有水平对称轴的横向各向同性(HTI)介质,裂缝的发育程度可以用裂缝弱度参数来刻画。在贝叶斯理论的框架下,利用方位地震振幅差异,提出了一种基于各向异性梯度的裂缝弱度AVAZ反演方法。首先,... 详细信息

发育定向排列垂直裂缝的油气储层可以等效为具有水平对称轴的横向各向同性(HTI)介质,裂缝的发育程度可以用裂缝弱度参数来刻画。在贝叶斯理论的框架下,利用方位地震振幅差异,提出了一种基于各向异性梯度的裂缝弱度AVAZ反演方法。首先,基于线性滑动模型理论求取干裂缝的法向与切向弱度之间的相关性,推导了各向异性梯度与裂缝弱度的关系式。其次,利用叠前地震数据提取HTI介质AVO各向异性梯度属性,构建了裂缝弱度参数的初始模型,为后续裂缝参数反演提供更加准确的先验约束信息。为了提高储层的裂缝预测精度,利用方位地震数据振幅差异,消除了背景介质的干扰。最后,开展基于贝叶斯理论的AVAZ叠前反演,实现了HTI介质储层裂缝弱度的估算。该方法的优势在于能够获得较为准确的初始模型,突出裂缝参数在反演过程中的贡献。模型和实际地震数据的应用结果与测井解释结果以及地质认识吻合较好,表明该方法具有良好的稳定性与可行性,是一种可靠的裂缝型储层预测方法。

关键词：裂缝型储层预测裂缝型油气藏 HTI介质贝叶斯反演各向异性梯度裂缝弱度

在线全文

学校读者我要写书评

暂无评论

数字经济背景下的乡村交易和产业转型

中国农村经济 2024年第6期 2-24页

作者：刘守英郑旭媛刘承芳中国人民大学经济学院福建农林大学经济与管理学院北京大学现代农学院北京大学中国农业政策研究中心

本文基于中国乡村社会“差序格局”的特征事实,分析了数字经济背景下中国乡村交易内涵的演变以及产业转型的逻辑,并基于可得数据开展相关实证研究。研究结果表明,长期以来在乡土中国熟人社会中形成的局限于信任半径内的交易习惯,限制了... 详细信息

本文基于中国乡村社会“差序格局”的特征事实,分析了数字经济背景下中国乡村交易内涵的演变以及产业转型的逻辑,并基于可得数据开展相关实证研究。研究结果表明,长期以来在乡土中国熟人社会中形成的局限于信任半径内的交易习惯,限制了乡村产业规模的扩张与市场价值的实现。数字经济的兴起,一方面,能够从地域、品牌、口碑和直觉等方面提高陌生人之间的信任程度,拓展乡村的交易半径与信任经济的范畴,有助于乡村交易的内涵从“熟人社会的人际交易”向“熟悉社会的非人际交易”转变;另一方面,数字技术可以通过发挥在信息传递、商品流通和资金流动方面的优势,推动乡村传统产业的智能化升级、产业链延长和服务业拓展,从而促进乡村产业从“土”到“特”的转型升级。

关键词：熟人社会数字经济乡村交易乡村产业转型

同方期刊数据库

区域民族文化在湖南高职院校汽车专业实践与应用——以湖南邵阳蓝印花布课程为例

在线全文

学校读者我要写书评

暂无评论

时代汽车 2024年第11期 73-75页

作者：刘承芳韦萧萧湖南汽车工程职业学院湖南株洲412001

本文以湖南邵阳蓝印花布课程为例,探讨了区域民族文化在湖南高职院校汽车专业实践与应用。文章首先介绍了湖南邵阳蓝印花布的概述,然后阐述了该课程在汽车专业实践中的应用,包括课程设计、教学内容、教学方法等方面。最后,通过实例分析... 详细信息

本文以湖南邵阳蓝印花布课程为例,探讨了区域民族文化在湖南高职院校汽车专业实践与应用。文章首先介绍了湖南邵阳蓝印花布的概述,然后阐述了该课程在汽车专业实践中的应用,包括课程设计、教学内容、教学方法等方面。最后,通过实例分析,展示了湖南邵阳蓝印花布在汽车设计中的应用。本文旨在通过探讨区域民族文化在高职教育中的应用,为高职教育提供新的思路和方法,促进高职教育的创新发展。

关键词：区域民族文化湖南高职院校汽车专业实践与应用

维普期刊数据库博看期刊

Implementation of Teacher Training in China and Its Policy Implications

在线全文

学校读者我要写书评

暂无评论

China & World Economy 2016年第3期24卷 86-104页

作者： Hongyan liu chengfang liu Fang Chang Prashant Loyalka PhD candidate Center for Experimental Economics in Education Shaanxi Normal University China. Associate Professor School of Advanced Agricultural Sciences Peking University China. Assistant Professor Center for Experimental Economics in Education Shaanxi Normal University China. Associate Professor Freeman Spogli Institute for International Studies Stanford University USA.

This study describes the current teacher training system in China, including the prevalence of teacher training, the types of training, training content and the ways that training is delivered. The paper presents subjective evaluations of training for principaIs and teachers using four diverse datasets. The results show that the National Teacher Training Project OVTTP） deviates from official policy objectives in several respects. The subjects of training programs and training content are not fully compliant with policy objectives. In addition, training opportunities are offered to a smaller proportion of rural teachers than urban teachers. It is found that the proportion of teachers and principals satisfied with the NTTP is lower than that for other types of training. Therefore, measures should be taken to increase training opportunities for rural teachers and to ensure the quality of training for all teachers.

关键词： China program implementation teacher training

Wavelength-tunable organic semiconductor lasers based on elastic distributed feedback gratings

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 Semiconductors 2023年第3期44卷 68-75页

作者： chengfang liu He Lin Dongzhou Ji Qun Yu Shuoguo Chen Ziming Guo Qian Luo Xu liu Wenyong Lai State Key Laboratory for Organic Electronics and Information Displays(SKLOEID) Institute of Advanced Materials(IAM)Nanjing University of Posts&TelecommunicationsNanjing 210023China

Wavelength-tunable organic semiconductor lasers based on mechanically stretchable polydimethylsiloxane (PDMS) gratings were developed. The intrinsic stretchability of PDMS was explored to modulate the period of the distributed feedback gratings for fine tuning the lasing wavelength. Notably, elastic lasers based on three typical light-emitting molecules show com-parable lasing threshold values analogous to rigid devices and a continuous wavelength tunability of about 10 nm by mechanic-al stretching. In addition, the stretchability provides a simple solution for dynamically tuning the lasing wavelength in a spec-tral range that is challenging to achieve for inorganic counterparts. Our work has provided a simple and efficient method of fab-ricating tunable organic lasers that depend on stretchable distributed feedback gratings, demonstrating a significant step in the advancement of flexible organic optoelectronic devices.

关键词： stretchable electronics organic semiconductor lasers elastic lasers distributed feedback(DFB)gratings wavelength tunability

Zacopride selectively activates the Kir2.1 channel via a PKA signaling pathway in rat cardiomyocytes

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2013年第9期56卷 788-796页

作者： ZHANG Li liu QingHua liu chengfang ZHAI XuWen FENG QiLong XU RuiLing CUI XiangLi ZHAO ZhiQing CAO JiMin WU BoWei Department of Physiology and the Key Laboratory of Cellular Physiology Ministry of Education Shanxi Medical University Department of Pathophysiology Shanxi Medical University Department of Biomedical Sciences Mercer University School of Medicine Department of Physiology Institute of Basic Medical Sciences Chinese Academy of Medical Sciences School of Basic Medicine Peking Union Medical College

We recently reported that zacopride is a selective inward rectifier potassium current (IK1 ) channel agonist, suppressing ventricular arrhythmias without affecting atrial arrhythmias. The present study aimed to investigate the unique pharmacological properties of zacopride. The whole-cell patch-clamp technique was used to study IK1 currents in rat atrial myocytes and Kir2.x currents in human embryonic kidney (HEK)-293 cells transfected with inward rectifier potassium channel (Kir)2.1, Kir2.2, Kir2.3, or mutated Kir2.1 (at phosphorylation site S425L). Western immunoblots were performed to estimate the relative protein expression levels of Kir2.x in rat atria and ventricles. Results showed that zacopride did not affect the IK1 and transmembrane potential of atrial myocytes. In HEK293 cells, zacopride increased Kir2.1 homomeric channels by 40.7%±9.7% at 50 mV, but did not affect Kir2.2 and Kir2.3 homomeric channels, and Kir2.1-Kir2.2, Kir2.1-Kir2.3 and Kir2.2-Kir2.3 heteromeric channels. Western immunoblots showed that similar levels of Kir2.3 protein were expressed in rat atria and ventricles, but atrial Kir2.1 protein level was only 25% of that measured in the ventricle. In addition, 5-hydroxytryptamine (5-HT) 3 receptor was undetectable, whereas 5-HT 4 receptor was weakly expressed in HEK293 cells. The Kir2.1-activating effect of zacopride in these cells was abolished by inhibition of protein kinase A (PKA), but not PKC or PKG. Furthermore, zacopride did not activate the mutant Kir2.1 channel in HEK293 cells but selectively activated the Kir2.1 homomeric channel via a PKA-dependent pathway, independent to that of the 5-HT receptor.

关键词：离子通道 PKA 大鼠信号通路激活 HEK293细胞 5-HT受体内向整流钾通道