1,724,085 research outputs found
Bei ju lun.
No full text章泯著.Includes bibliographical references.Copy 3-4 printed in 1940.Zhang Min zhu
Xi ju lun.
No full text章泯著.Includes bibliographical references.Copy 4-6 printed in 1940.Zhang Min zhu
Applications of metal nitride nanostructures in stabilising high energy and high capacity battery systems
No full textApplications of metal nitride nanostructures in stabilising high energy and high capacity battery systems were investigated. Sol-gel synthesis routes using tetrakis(dimethylamido)titanium(IV) and a propylamine or ammonia cross linking agent, followed by thermal treatment under NH3 or H2+N2,were developed to produce TiN powders of small crystallite size (<10 nm). The TiN with good conductivity were coated on LiFePO4 cathodes in lithium-ion batteries, which exhibited significantly improved electrochemical performance with a discharge capacity of 159 mA h g-1 at 0.1 C, that is~93% of the theoretical capacity. A literature review of various synthetic routes such as solid-state reactions, hydrothermal/solvothermal synthesis and sol-gel process to produce LiCoPO4 was performed, and various strategies such as surface modification, ion doping, size reduction and morphology control to improve the electrochemical performance of LiCoPO4 were summarised. Olivine-structured LiCoPO4 was prepared via a facile solvothermal synthesis, using various ratios of water/diethylene glycol co-solvent, followed by thermal treatment under Ar, air, 5%H2/N2 or NH3.The LiCoPO4 prepared after heating in Ar exhibited high initial discharge capacity of 147 mA h g-1 at0.1 C with capacity retention of 70% after 40 cycles. This is attributed to the enhanced electronic conductivity of LiCoPO4 due to the presence of Co2P after firing under Ar. In addition, Li4Ti5O12 synthesized via solid-state reaction with 2% Li excesses were found to have minimum TiO2 impurities, which delivered an initial capacity of 165 mA h g-1. TiN were coated onto Li4Ti5O12 anodes in lithium-ion batteries, which exhibited improved initial capacity of 174 mA h g-1. Finally, nanostructured TiN were prepared by a cross-linked sol-gel method with HDA or P123 as a surfactant, or evaporation induced self-assembly method with PEO-b-PS as a surfactant, and heated under NH3 at a variety of processing conditions. Mesoporous TiN with worm-like morphology and pore size of ~20 nm were obtained, and selected TiN samples have been used as host materials for sulfur cathodes in lithium-sulfur batteries
Core-shell structured LiFePO<sub>4</sub>/C nanocomposite battery material for lithium production from brines
No full textThe development of affordable and environmentally friendly methods to produce lithium is urgently required to cope with the accelerating growth of the lithium battery market. Battery materials such as LiFePO4 can be used to selectively sequestrate lithium from brine natural resources, thus producing a high-purity lithium salt for battery manufacture, but the long-term stability of the material is currently not sufficient for practical applications. Here, we report, for the first time, the development of a nanosized core-shell structured LiFePO4/C material for applications in lithium production from brines. This LiFePO4/C with a LiFePO4-core (∼123 nm size) covered by a pinhole-free carbon shell (∼5 nm thickness) was prepared via solvothermal synthesis, and the carbon content was optimised to 5 wt%. The optimal core-shell structured LiFePO4/C material exhibits a lithium extraction capacity of ca. 160 mA h g-1 at C/10 and ca. 130 mA h g-1 at 1C, and >87% capacity retention after 50 cycles of lithium sequestration and release at C/10 in synthetic brines. This excellent electrochemical performance is attributed to the homogenous nanosizing of the LiFePO4 particles as well as the full coverage of the carbon coating, which provides effective protection by preventing the direct contact of LiFePO4 with the brines, thus stopping the surface degradation reactions that compromise the long-term stability. A direct comparison with three commercial LiFePO4 materials demonstrates that, while similar performance is obtained in non-aqueous lithium-ion batteries, for lithium production applications, core-shell nanostructuring is crucial to achieve high capacity and preserve the material's longevity
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dataset for article 'Core-Shell Structured LiFePO4/C Nanocomposite Battery Material for Lithium Production from Brines'
No full textThis dataset supports the publication:
AUTHORS: Min Zhang, Nuria Garcia-Araez
TITLE: Core-Shell Structured LiFePO4/C Nanocomposite Battery Material for Lithium Production from Brines
JOURNAL: Electrochimica Acta
PAPER DOI: 10.1016/j.electacta.2024.144686
This dataset contains:
Data shown in figures 1, 2, 4, 4, 5, 6, 7, S1, S2, S3, S4, S5, S6, S7 and S8 </span
Xi ju dao yan ji chu.
No full text(美)布士沃斯原著, 章泯譯述, 新演劇社主編.本電子書乃根據《香港版權條例(第528章)》而複製, 並只可在大學圖書館系統內的獨立電子書系統上使用.(Mei) Bushiwosi yuan zhu, Zhang Min yi shu, Xin yan ju she zhu bian.Ben dian zi shu nai gen ju "Xianggang ban quan tiao li (Di 528 zhang)" er fu zhi, bing zhi ke zai da xue tu shu guan xi tong nei de du li dian zi shu xi tong shang shi yong
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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