检索结果-南通市图书馆

Chemically doped macroscopic graphene fibers with significantly enhanced thermoelectric properties

在线全文

学校读者我要写书评

暂无评论

Nano Research 2018年第2期11卷 741-750页

作者： Weigang Ma Yingjun Liu Shen Yan Tingting Miao shaoyi shi Zhen Xu Xing Zhang Chao Gao Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering Mechanics Tsinghua University Beijing China MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province Zhejiang University Hangzhou China Department of Thermal Engineering Tsinghua University Beijing China Key Laboratory of Process Fluid Filtration and Separation College of Mechanical and Transportation Engineering China University of Petroleum-Beijing Beijing China

Flexible wearable electronics, when combined with outstanding thermoelectric properties, are promising candidates for future energy harvesting systems. Graphene and its macroscopic assemblies （e.g., graphene-based fibers and films） have thus been the subject of numerous studies because of their extraordinary electrical and mechanical properties. However, these assemblies have not been considered suitable for thermoelectric applications owing to their high intrinsic thermal conductivity. In this study, bromine doping is demonstrated to be an effective method for significantly enhancing the thermoelectric properties of graphene fibers. Doping enhances phonon scattering due to the increased defects and thus decreases the thermal conductivity, while the electrical conductivity and Seebeck coefficient are increased by the Fermi level downshift. As a result, the maximum figure of merit is 2.76 ~ 10~, which is approximately four orders of magnitude larger than that of the undoped fibers throughout the temperature range. Moreover, the room temperature power factor is shown to increase up to 624 btW.m-l.K-2, which is higher than that of any other material solely composed of carbon nanotubes and graphene. The enhanced thermoelectric properties indicate the promising potential for graphene fibers in wearable energy harvesting systems.

关键词： macroscopic graphene fiber bromine doping thermoelectric properties thermal conductivity electrical conductivity Seebeck coefficient

Systematic characterization of transport and thermoelectric properties of a macroscopic graphene fiber

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

Nano Research 2016年第11期9卷 3536-3546页

作者： Weigang Ma Yingjun Liu Shen Yan Tingting Miao shaoyi shi Mincheng Yang Xing Zhang Chao Gao Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering Mechanics Tsinghua University Beijing 100084 China MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and Engineering Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province Zhejiang University Hangzhou 310027 China Department of Thermal Engineering Tsinghua University Beijing 100084 China Key Laboratory of Process Fluid Filtration and Separation College of Mechanical and Transportation Engineering China University ot Petroleum Beijing Beijing 102249 China

Graphene, a two-dimensional material with extraordinary electrical, thermal, and elastic performance, is a potential candidate for future technologies. However, the superior properties of graphene have not yet been realized for graphenederived macroscopic structures such as graphene fibers. In this study, we systematically investigated the temperature （T ）-dependent transport and thermoelectric properties of graphene fiber, including the thermal conductivity （A）, electrical conductivity （o）, and Seebeck coefficient （S）. A increases from 45.8 to 149.7 W·m^-1·K^-1 and then decreases as T increases from 80 to 290 K, indicating the boundary-scattering and three-phonon Umklapp scattering processes. σ increases with T from 7.1 × 10^4 to 1.18 × 10^5 S·m^-1, which can be best explained by the hopping mechanism. S ranges from -3.9 to 0.8 μV·K^-1 and undergoes a sign transition at approximately 100 K.

关键词： macroscopic graphene fiber thermoelectric properties thermal conductivity electrical conductivity Seebeck coefficient

Silkworm Silk Fibers with Multiple Reinforced Properties Obtained through Feeding Ag Nanowires

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

Advanced Fiber Materials 2022年第3期4卷 547-555页

作者： Haojie Lu Muqiang Jian Zhe Yin Kailun Xia shaoyi shi Mingchao Zhang Huimin Wang Xiaoping Liang Weigang Ma Xing Zhang Yingying Zhang Key Laboratory of Organic Optoelectronics and Molecular Engineering of the Ministry of Education Department of ChemistryTsinghua UniversityBeijing 100084China Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China

Silkworm silk fbers have been woven into textiles for thousands of years,because of their attractive luster,good mechanical properties,excellent biocompatibility,and large-scale *** the development of human society,preparation of silk fbers with modifed or enhanced properties are highly desirable for potential applications in structural materials and smart ***,we realized the reinforcement of multiple properties of silk fbers by feeding silkworms with Ag nanowire(Ag NW)modifed *** obtained silk fbers show obviously enhanced comprehensive mechanical properties,including improved tensile strength,elongation at break,tensile modulus,and toughness,which are increased by 37.2%,37.6%,68.3%,and 69.8%,***,compared with unmodifed silk,the electrical conductivity and thermal conductivity of modifed silk fbers are improved by 246.4%and 32.1%,*** analysis on the components and structure shows that the incorporated Ag NWs lead to increased content of random coil/α-helix,improved orientation of crystallites,and increased content of Ag compared to pristine silk fbers,which may contribute to the enhanced mechanical,electrical,and thermal properties.

关键词： Silkworm silk fber Ag nanowire Mechanical properties Electrical property Thermal property

发生、演进与差异:马克思主义工农联盟理论研究

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

当代世界社会主义问题 2020年第2期 22-31页

作者：肖存良史少毅复旦大学马克思主义学院上海200433

马克思主义工农联盟理论的内在差异可以从阶层分析和联合策略两个方面进行考察。马克思恩格斯认为农民各阶层具有“两头大中间小”的特点,中间阶层必然消亡,农业无产阶级是城市无产阶级“天然的同盟者”。列宁将中农放在重要地位,但俄... 详细信息

马克思主义工农联盟理论的内在差异可以从阶层分析和联合策略两个方面进行考察。马克思恩格斯认为农民各阶层具有“两头大中间小”的特点,中间阶层必然消亡,农业无产阶级是城市无产阶级“天然的同盟者”。列宁将中农放在重要地位,但俄国形势的变化使列宁联合中农的策略在“积极联合”与“消极联合”之间多次摇摆。此外,列宁还将工农联盟理论拓展到了工人与农民经济关系的层面,将工农联盟的形式拓展为发达资本主义国家无产阶级与殖民地国家农民阶级的联合。毛泽东的工农联盟理论强调对中农坚持“团结”与“联合”的策略,对富农的联合策略则经历了从“中立”到“削弱”再到“联合”的转变。

关键词：工农联盟阶层分析联合策略马克思主义

饲料中添加氯化胆碱对草鱼成鱼生长、脂肪沉积和脂肪代谢酶活性的影响

在线全文

学校读者我要写书评

暂无评论

中国水产科学 2010年第3期17卷 527-535页

作者：朱瑞俊李小勤谢骏冷向军田娟史少奕上海海洋大学省部共建水产种质资源发掘与利用教育部重点实验室中国水产科学研究院珠江水产研究所

选用初始体质量为(314.7±9.9)g的草鱼(Ctenophary ngodon idella)240尾,随机分成4组,每组3个重复,每重复20尾鱼,分别饲喂氯化胆碱添加量为0%(对照组)、0.2%、0.4%和0.6%(占饲料的质量分数)的4组饲料(粗蛋白、粗脂肪含量分别为28.01%和4... 详细信息

选用初始体质量为(314.7±9.9)g的草鱼(Ctenophary ngodon idella)240尾,随机分成4组,每组3个重复,每重复20尾鱼,分别饲喂氯化胆碱添加量为0%(对照组)、0.2%、0.4%和0.6%(占饲料的质量分数)的4组饲料(粗蛋白、粗脂肪含量分别为28.01%和4.54%),胆碱实测含量分别为1010mg/kg、2516mg/kg、4184mg/kg、5852mg/kg,养殖77d后,考察氯化胆碱对草鱼成鱼生长性能、脂肪沉积及脂肪代谢酶活性的影响。结果表明,与对照组相比较,添加0.4%和0.6%氯化胆碱可显著提高鱼体增重率(P<0.05)、特定生长率(P<0.05),降低饲料系数(P<0.05);添加0.2%～0.6%氯化胆碱可显著降低肝胰脏和全鱼脂肪含量(P<0.05);添加0.4%和0.6%氯化胆碱,肌肉脂肪含量显著下降(P<0.05);添加0.2%～0.6%氯化胆碱可显著提高血清甘油三酯和总胆固醇含量(P<0.05),添加0.4%和0.6%氯化胆碱可显著降低肝胰脏甘油三酯和总胆固醇含量(P<0.05);在脂肪代谢酶方面,添加0.2%～0.6%氯化胆碱可显著提高前肠脂肪酶活性(P<0.05),添加0.6%氯化胆碱显著提高脂蛋白脂酶活性(P<0.05),添加0.4%～0.6%氯化胆碱可显著升高肝脂酶和总脂酶活性(P<0.05)。综上所述,适量添加胆碱能改善草鱼成鱼生长性能,提高饲料利用率,降低肝胰脏、全鱼和肌肉的脂肪含量,提高脂肪代谢酶活性。建议草鱼实用饲料中氯化胆碱添加量为0.4%～0.6%。

关键词：草鱼成鱼氯化胆碱生长脂肪沉积脂肪代谢酶

改进的Burnett法测定N_2-CO_2-CHClF_2体系的压缩因子和维里系数

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

南京工业大学学报（自然科学版） 1989年第2期22卷 8-14页

作者：江绍毅王延儒时钧南京化工学院化学工程系

对DH81型压缩因子计及其数据处理方法进行改造与完善,形成一套完整的能比较精确测量流体PVT性质的改进Burnett法,用以测定含N_2、CO_2、CHClF_2体系在293.15K下的压缩因子和维里系数,其中含CHClF_2体系的有关数据未见文献报导。

关键词：压缩因子第二维里系数

在线全文

学校读者我要写书评

暂无评论

基于C#的电能质量分析智能校准方法

仪器仪表标准化与计量 2015年第6期 43-45页

作者：牛佳佩林振华石劭毅王晓东广东省计量科学研究院广州市510405

由于电能质量分析仪校准项目多,传统手动校准效率较低,校准数据不能直接生成校准原始记录或校准证书,手工录入数据存在效率低、易错问题;对此,本文提出一种基于C#的智能校准方法进行解决,实验结果显示可节约时间70%以上,校准数据准确可靠。

关键词：电能质量分析仪智能校准自组合校准项

在线全文

学校读者我要写书评

暂无评论

夏谷营养特性的初步研究

莱阳农学院学报 1988年第2期 24-28页

作者：赵镭程绍义隋方功史全文郭立忠莱阳农学院农学系

夏谷出苗时就可吸收土壤养分。出苗后第29天和第49天为吸氮的高峰期。对磷钾的吸收动态基本与氮相吻合,但对磷的吸收直线增长期稍早于氮,对钾的吸收到出苗后第64天即可达到最大值,夏谷抽穗后,穗部氮磷的含量与茎叶及根部氮磷含量呈负相关。

关键词：夏谷营养特性吸收强度

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

贵州瓮安复向斜含铝岩系层序特征及层位归属

现代矿业 2022年第4期38卷 30-35页

作者：蒙信礼马晓旻刘兴金梁国礼李艳桃施少亿贵州省有色金属和核工业地质勘查局物化探总队贵州省有色金属和核工业地质勘查局核资源地质调查院

贵州瓮安复向斜新查明了一批赋存于栖霞组之下的铝土矿,层位归属尚存争议。通过对以往调查资料对比分析指出:前人在该区所获孢粉材料未统计孢粉谱、未建立孢粉图式,达不到进行地层对比的规范要求;已鉴定出的孢粉组分存在多种年轻分子,... 详细信息

贵州瓮安复向斜新查明了一批赋存于栖霞组之下的铝土矿,层位归属尚存争议。通过对以往调查资料对比分析指出:前人在该区所获孢粉材料未统计孢粉谱、未建立孢粉图式,达不到进行地层对比的规范要求;已鉴定出的孢粉组分存在多种年轻分子,不足以证明含铝岩组属九架炉组。准确划定层位归属,对铝土矿成矿规律研究、成矿图件编制以及古地理环境、古植物群落、地质构造演化分析等有重要意义。

关键词：含铝岩系层位梁山组瓮安复向斜