检索结果-南通市图书馆

Formation behavior of anodic TiO_2 nanotubes in fluoride containing electrolytes

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2009年第4期19卷 842-845页

作者： Byung-Gwan LEE jin-Wook CHOI Seong-Eun LEE Yong-Soo JEONG han-Jun oh Choong-Soo CHI School of Advanced Materials Engineering Kookmin University Korea Institute of Materials Science Department of Materials Science Han seo University

TiO2 nanotube layers can be formed with titanium in the electrolytes containing fluoride by electrochemical *** role of fluoride ion,the crystallinity of the anodic oxide,and the chemical state were *** results show the anodic film is composed of oxide and a little amount of *** presence of F- ions leads to chemical dissolution of Ti oxide layer and prevents hydroxide ***,chemical dissolution rate increases with increasing the fluoride content in the range of 0-2%(in mass fraction) because F- ions in electrolyte attack the interface and allow the ions of the electrolyte to easily penetrate into the *** as-anodized TiO2 nanotubes exhibit an amorphous *** treated nanotubes are composed of mixtures of the anatase and rutile phases.

关键词： TiO2纳米管阳极氧化处理氟离子电解质行为二氧化钛化学溶解电化学方法

Functionalization of carbon nanotubes and other nanocarbons by azide chemistry

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2010年第3期2卷 213-226页

作者： jin han Chao Gao MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang University

Following the conventional carbon allotropes of diamond and graphite,fullerene,carbon nanotubes(CNTs) and graphene as 0D,1D and 2D graphitic macromolecules have been discovered recently in succession,declaring the unlimited potential of carbon-based nanomaterials and *** CNTs exhibit significant potential applications in advanced materials and other fields due to their extraordinary mechanical strength and electrical/thermal conductivity properties,their low solubility,poor wettability and bad dispersibility in common solvents and solid matrices have limited their processing and ***,the attempt to achieve wettable/processable CNTs by functionalization has attracted increasing attention in both scientific and industrial *** recent years,azide chemistry has been demonstrated as a powerful means to covalently modify *** consists of two major approaches:click chemistry and nitrene chemistry,which both involve the usage of various azide *** former one is based on highly reactive and stereospecifical Cu(I) catalyzed azide-alkyne cycloaddition reaction;the latter one is based on the electrophilic attack to unsaturated bonds of CNTs with nitrenes as reactive intermediates formed from thermolysis or photolysis of *** this mini-review paper,the azide chemistry to functionalize CNTs is highlighted and the corresponding functionalization routes to build CNT-based complex structures are also ***,covalent functionalizations of other graphitic nanomaterials such as fullerence and graphene,via azide chemistry,are commented briefly.

关键词： Carbon nanotubes Functionalization Click chemistry Nitrene chemistry Nanocomposites Fullerene Graphene

Investigation of the level spectra of nuclei in the northeast region of doubly magic^(40)Ca with intruder orbit g_(9/2)

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2023年第6期34卷 115-123页

作者： jin-Zhong han Shuai Xu Amir Jalili han-Kui Wang School of Physics and Telecommunication Engineering Zhoukou Normal UniversityZhoukou466000China Department of Physics Zhejiang SCI-TECH UniversityHangzhou310018China School of Physics Nankai UniversityTianjin300071China School of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai200240China

This study utilizes large-scale shell model calculations with the extended pairing and multipole–multipole force model(EPQQM)to investigate low-lying states in the nuclei of^(42)Ca,^(42)Sc,and^(42−44)*** model space in this study includes the fp shell as well as the intruder g_(9/2)orbit,which accurately reproduces the positive parity levels observed in the aforementioned nuclei and predicts high energy states with negative parity coupled with the intruder g_(9/2).The study further predicts two different configurations in^(43)Ti at around 6 MeV,specificallyπf_(7/2)^(2)νg_(9/2)andπf_(7/2)g_(9/2)νf_(7/2),both of which involve the intruder orbit g_(9/2).The levels coupled with the intruder g_(9/2)in^(44)Ti are predicted to lie between 7 and 11 *** inclusion of the intruder orbit g_(9/2)is crucial for the exploration of high energy states in the northeast region of the doubly magic nucleus^(40)Ca.

关键词： Shell model Doubly magic Level structure

Oxidation behavior of artificial magnetite pellets

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2017年第6期24卷 603-610页

作者： han-quan Zhang jin-tao Fu School of Resource and Civil Engineering Wuhan Institute of Technology Wuhan 430205 China Western Mining Company Xi’ning 810001 China

The oxidation behavior of artificial magnetite pellets was investigated through measurements of the oxidation degree and mineralogical analysis. The results show that artificial magnetite pellets are much easier to oxidize than natural magnetite. The oxidation is controlled through two different reaction mechanisms. The oxidation of artificial magnetite is dominated by internal diffusion, with an activation energy of 8.40 kJ/mol, at temperatures less than 800°C, whereas it is controlled by chemical reaction, with a reaction activation energy of 67.79 kJ/mol, at temperatures greater than 800°C. In addition, factors such as the oxygen volume fraction and the pellet diameter strongly influence the oxidation of artificial magnetite: a larger oxygen volume fraction and a smaller pellet diameter result in a much faster oxidation process.

关键词： artificial magnetite pellets oxidation reaction mechanisms

Microgravity may help future organ/tissue manufacture

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2016年第8期59卷 850-853页

作者： jin han Jianwu Dai State Key Laboratory of Molecular Developmental Biology Institute of Genetics and Developmental Biology Chinese Academy of Sciences Beijing 100101China

Stem cells are a group of multipotent or pluripotent cells which could differentiate into specialized cells or could self-renew to duplicate themselves. During the body devel- oping period, stem cells differentiated into specialized cells to build the whole body. In the adult organisms, stem cells live in seclusion and are ready to repair the injuries of tis- sues. Within one tissue, stem cells could differentiate in to all types of somatic cells of the tissue, for example,

关键词： manufacture specialized pluripotent differentiate duplicate renew repair themselves ready injuries

Generation of Interstellar Class Ⅱ 7_2-8_1A^+ and 7_2-8_1A^-Methanol Masers

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Astronomy and Astrophysics 2007年第6期7卷 803-808页

作者： han-Ping Liu jin Sun Department of Physics Beijing Normal University Beijing 100875 Department of Astronomy Beijing Normal University Beijing 100875

New methanol maser lines at 72 → 63A^-（86.6 GHz） and 72 → 63A^＋（86.9 GHz） together with two candidate methanol maser lines at 72 → 81A-（80.99GHz） and 72→81A^＋（111.29GHz） have been detected in W3（oh）. We use a pumping mechanism, i.e., methanol masers without population inversion, to explain the formation of weak methanol masers of 72 → 81A^＋ and 72→ 81A^-. We explain well why the line-shape of the transition 72 → 81A^＋ is not typical. A similar argument can be applied to the A-type level system 72A^-, 63A^- and 81A^-, as well as to the 72 → 81A^- 80.99 GHz masers.

关键词： pumping mechanism -- Class II methanol sources -- maser without inversion-- coherent microwave field

Inflammation: a mechanism of depression?

在线全文

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2014年第3期30卷 515-523页

作者： Qiu-Qin han jin Yu Department of Integrative Medicine and Neurobiology State Key Laboratory of Medical Neurobiology Institutes of Brain Science Shanghai Medical College Fudan University

In recent decades, major depression has become more prevalent and research has shown that immune activation and cytokine production may be involved. This review is mainly focused on the contribution of inflammation to depression. We first briefly introduce the inflammatory biomarkers of depression, then discuss the sources of cytokines in the brain, and finally describe the neuroimmunological mechanisms underlying the association between inflammation and depression.

关键词： depression inflammation cytokines hypothalamic-pituitary-adrenal axis 5-HT neuroplasticity

A compiled catalog of rotation measures of radio point sources

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2014年第8期14卷 942-958页

作者： Jun Xu jin-Lin han National Astronomical Observatories Chinese Academy of Sciences University of Chinese Academy of Sciences

We compiled a catalog of Faraday rotation measures （RMs） for 4553 extragalactic radio point sources published in literature. These RMs were derived from multi-frequency polarization observations. The RM data are compared to those in the NRAO VLA Sky Survey （NVSS） RM catalog. We reveal a systematic uncertainty of about 10.0± 1.5rad m^-2 in the NVSS RM catalog. The Galactic foreground RM is calculated through a weighted averaging method by using the compiled RM catalog together with the NVSS RM catalog, with careful consideration of uncertainties in the RM data. The data from the catalog and the interface for the Galactic foreground RM calculations are publicly available on the webpage： http：//***/RM/.

关键词： catalogs -- polarization -- radio continuum ISM -- ISM magnetic fields

Voltage-induced material removal mechanism of copper for electrochemical-mechanical polishing applications

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2009年第B9期19卷 262-265页

作者： Sang-Jun han Yong-jin SEO Nano-Information Material ＆ Device Laboratory Daebul University Chonnam 526-702 Korea School of Fusion Technology Daebul University Chonnam 526-702 Korea

The current-voltage (I-V) curves, such as linear sweep voltammetry (LSV) and cyclic voltammetry (CV), were employed to evaluate the effect of electrolyte concentration on the electrochemical reaction trend. From the I-V curve, the electrochemical states of active, passive, transient and trans-passive region could be characterized. And then, the mechanism of the process of voltage-induced material removal in electrochemical mechanical polishing (ECMP) of copper was investigated. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyses were used to observe the surface profile. Finally, the oxidation and reduction processes of the Cu surface were monitored by the repetition of anodic and cathodic potential from cyclic voltammetry (CV) method in acid-and alkali-based electrolyte.

关键词：电化学机械抛光材料去除机理铜电极电压诱导线性扫描伏安法扫描电子显微镜循环伏安法