49 research outputs found

    基于生态系统管理理念在地方海岸带综合管理中的融合与体现

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    随着经济的发展,越来越多的人在海岸带地区生活和工作,由此带来的一系列资源利用和环境污染问题,也给海岸带带来了巨大的压力,协调海岸带地区经济发展和生态维护之间的关系已成为全球可持续发展的巨大挑战之一。ICM已经成为解决海岸带资源利用与生态环境矛盾的有效工具,而EbM理念的融合对ICM的实施产生了积极的效果。在简要介绍厦门ICM体制的基础上,重点介绍其将EbM理念应用于ICM的具体做法和典型案例

    中華家政學會第六屆年會紀盛

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    The studies of microstructures and magnetic properties in ferromagnetic/antiferromagnetic bilayers and [Cu/Co] thin films

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    The exchange bias of CoFe/(Co,Fe)O and Mn-oxide/FePt bilayers, and the magnetic properties of Cu/Co thin films are studied in this thesis. In Part I, we investigate the effects of ion-beam bombardment on the exchange bias in CoFe/(Co,Fe)O bilayers using single crystalline MgO substrates. Results show that the ion-beam bombardment altered the magnitude of the effective anisotropy field for bilayers grown on an MgO(110) substrate and shifted the easy-plane direction for bilayers grown on an MgO(100) substrate. Our results reflect that the choice of substrate and bombardment conditions provide an efficient route for tuning both the effective unidirectional and uniaxial magnetic anisotropies in magnetic thin films. In Part II, we investigate the exchange coupling between the bottom FePt layer and the different structures of capped Mn-oxide layers in Mn-oxide/FePt bilayers. Results show that the magnetization reversal of the soft FePt layer is strongly influenced by the capped Mn-oxide layer (Mn, MnO, and Mn3O4), as revealed by the enhanced coercivities in the Mn-oxide/FePt bilayers. The typical temperature dependence of magnetization between the zero-field-cooling (ZFC) and field-cooling (FC) curves is observed in an Mn-oxide (8% O2/Ar)/FePt bilayer exhibiting a blocking temperature (TB ≈ 120 K) close to the TN of MnO. However, the Mn/FePt bilayer exhibited unusual the temperature dependence of M on T, implying an intermixing between the Mn and FePt interfaces. This in turn resulted in the formation of interfacial antiferromagnetic FeMn and may give rise to a high irreversibility temperature (Tirr ≈ 400 K), compared to the almost identical ZFC and FC curves in Mn-oxide (21% and 30% O2/Ar)/FePt bilayers that are attributed to the weaker exchange coupling with FePt. In Part III, we examine Cu/Co thin films are grown on SiO2 substrates using a reactive ion-beam deposition technique. The polycrystalline Cu/Co thin films formed as a result of intermixing. The Cu/Co thin films consisted of metallic Cu, Co, CuCo, and the oxides Cu2O and CoO. Magnetometry results show that the ferromagnetic and superparamagnetic behaviors strongly depend on the measuring temperature and the amount of cobalt. However, a much reduced magnetization onset temperature, Ton., which depended on the amount of cobalt in the film, is observed.本論文利用雙離子束濺鍍系統製備(1)CoFe/(Co,Fe)-oxide長在MgO(100),(110)單晶基板上經由離子束轟擊(VEH= 130V);(2)藉由不同氧含量改變Mn-oxide/FePt與 (3)[Cu/Co]薄膜之微結構與磁性質的研究。研究結果顯示(1) CoFe/(Co,Fe)-oxide底層經由21% O2/Ar氧含量轟擊下(Co,Fe)O為岩鹽結構,磁性質方面,藉由離子束轟擊過後,室溫下明顯發現矯頑磁力(Hc)的下降與磁滯曲線形狀的改變。經由場冷卻降至低溫(180K和50K),低溫下有明顯交換偏壓(Hex)產生,並且交換偏壓大小與轟擊跟單晶基板相關。MvsT曲線結果顯示,不同的單晶基板導致MvsT曲線的改變,並且離子束轟擊過後造成不可逆溫度(Tirr)的下降,可以得知單晶基板與適當的轟擊能量可以改變CoFe/(Co,Fe)O磁晶異相性和上層鈷鐵的磁矩排列並導致交換偏壓的變化。(2)Mn-oxide/FePt雙層薄膜結果顯示,軟磁FePt的磁化翻轉強烈受到上層Mn-oxide(Mn,MnO,Mn3O4)的影響,典型的MvsT曲線可以從Mn-oxide(8%)發現,並且阻隔溫度(T¬B)~120K接近MnO的尼爾溫度(TN)。然而Mn(0%)/FePt雙層薄膜異常的MvsT曲線意味著Mn與FePt之間的界面相互混合(intermixing)產生部分的FeMn結構。(3) [Cu/Co]多層薄膜研究結果顯示,從TEM橫結面結果判斷Cu/Co薄膜為相互混合的情況,並且與XRD,TEM繞射環與XPS可以發現有Co,Cu,CuCo,Cu2O與少量的CoO存在,這意味著輔助離子槍在轟擊薄膜的過程中有少量的氧含量導致薄膜有部分的氧化物存在。磁性質結果顯示,隨著不同的Co含量的改變,會有超順磁與鐵磁的現象轉換。低溫180K下,部分超順磁受到熱震動的影響降低轉變成鐵磁性,MvsT行為可以發現隨著Co含量的提高而導致上升了磁化起始溫度(Ton.),這可能是隨著不同的Co含量導致CuCo量的改變進而影響到Ton.,然而TB~ 50K並無隨任何Co含量有任何變化。此外XacvsT曲線更可以印證出多種不同的相存在導致的變化。Contents Chapter 1 Introduction 1 1.1 Background 1 1.2 Possible applications based on the exchange bias phenomenon 2 1.2.1 GMR and TMR 2 1.2.2 Magnetic Random Access Memory (MRAM) 4 1.3 Motivation 5 1.4 Review of earlier work on the exchange bias phenomenon 6 1.4.1 M vs T behavior 6 1.4.2 Ion-beam bombardment effect 8 1.4.3 Interfacial uncompensated antiferromagnetic spins 9 1.4.4 Diluted antiferromagnets in exchange bias 10 1.5 Related work by our research group 11 1.6 Material selection 12 1.7 References for the first chapter 16 Chapter 2 Basic Concepts 19 2.1 Magnetic anisotropy 19 2.2 Theoretical models of the exchange bias phenomenon 21 2.2.1 Ideal interface 24 2.2.2 Random interface 26 2.2.3 Planar AF domain wall 27 2.2.4 Perpendicular interfacial coupling 28 2.2.5 Frozen interface 29 2.2.6 Domain state 30 2.2.7 Thermally induced spontaneous magnetization reversal 32 2.3 References for the second chapter 33 Chapter 3 Experimental equipment 35 3.1 Experimental flowchart 35 3.2 Dual ion-beam deposition (DIBD) technique 35 3.3 Characterizations 39 3.3.1 X-Ray Diffractometer (XRD) 39 3.3.2 Transmission Electron Microscopy (TEM) 41 3.3.3 X-ray Photoelectron Spectroscopy (XPS) 43 3.3.4 Vibrating Sample Magnetometer (VSM) 45 3.4 References for the third chapter 46 Chapter 4 Results and discussion 47 4-1 The exchange bias field in CoFe/(Co,Fe)O bilayers using ion-beam bombardment and single crystalline substrates 47 4.1.1 XRD spectra 47 4.1.2 TEM 49 4.1.3 XPS 52 4.1.4 Magnetic hysteresis loop results at room temperature and low temperature 56 4.1.5 Magnetothermal behavior (Magnetization vs Temperature) 64 4-2 Exchange coupling effects in FePt/Mn-oxide bilayers with different O2/Ar ratios 70 4.2.1 XRD spectra 70 4.1.2 TEM 73 4.2.3 Magnetic hysteresis loops at room temperature and low temperature 75 4.2.4 Magnetothermal behavior (Magnetization vs Temperature) 83 4-3 The microstructure and magnetism of Cu-Co thin films modified by deposition processes 85 4.3.1 XRD spectra 85 4.3.2 TEM 87 4.3.3 XPS 94 4.3.4 Magnetic hysteresis loop results at 298 K and 180 K and magnetothermal behavior. 96 4.4 References for the fourth chapter 105 Chapter 5 Conclusions 106 Curriculum Vitae 10

    Applications of biosensing technology in marine monitoring

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    21世纪是海洋开发的世纪,我国将更加关注在可持续发展前提下的海洋资源的合理开发和海洋环境保护,特别是更多地关注近海生态环境的监测和保护。用于海洋监测的生物传感器技术是一种基于生物敏感元件对污染物的生理、生化、细胞反应而建立起来的海洋生物监测技术,有很高的灵敏度,并可与生物个体的生长、繁殖、代谢、存活等指标直接联系起来,从而有可能就污染对生物种群、群落乃至整个生态系统的影响做出评价和预测

    一种锂离子电池的电极粘结剂、其制备方法及使用方法

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    本发明提供一种锂离子电池的电极粘结剂,该粘结剂是一种以含芳香苯环为主链,含氟磺酰亚胺锂为侧链的锂离子聚合物。与现有的技术相比,本发明的粘结剂与纳米硅等高能量密度活性物质形成共配合桥接,具有良好的粘合性,能够适应因充放电过程中活性物质体积变化而产生的应力影响,同时该粘结剂具有良好的锂离子导电性,从而有效解决了现有粘结剂的锂离子电导率低而影响锂离子电池充放电性能,尤其是在大倍率充放电下导致电池容量迅速衰减的问题,因此在全固态聚合物锂离子电池、凝胶态聚合物锂离子电池,一体化聚合物锂离子电池等中具有良好的应用前景

    一种高硫含量碳硫锂离子电池材料的制备方法及其应用

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    本发明公开一种高硫含量碳硫锂离子电池材料的制备方法及其应用。该方法是将单质硫加入到反应容器内,注入六氯丁二烯于100~300℃、0~15 MPa压力条件下密闭反应,后处理后离心、沉淀水洗,干燥得初品;在惰性气体保护下,管式炉热处理30 min~4h即可。高硫含量新型碳硫材料在锂离子电池中的应用。本发明方法极其简单,原料来源丰富,制备出的高硫含量新型碳硫分子材料,碳原子和硫原子以化学键的形式结合,其中硫元素的含量占该材料的质量百分比可达10﹪~80﹪。碳硫原子通过化学键相互结合,硫原子在材料中得到均匀分散,使得在充放电过程中能与锂离子充分接触并反应,极大地提高了锂离子电池的比容量和循环性能

    一种支化结构型聚氟磺酰亚胺阴离子锂盐及其合成方法与应用

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    本发明公开一种支化结构型聚氟磺酰亚胺阴离子锂盐及其合成方法与应用。此聚合物为具有星形与树形结构的聚阴离子锂盐聚合物,其分子结构如式(Ⅰ)所示,此结构的构建方法,是选择不同多酚类或多元醇类为底物,将含氟单体与底物在缚酸剂作用下缩合反应,再通过锂盐进行锂离子交换得到目标分子。与一维直链的含氟烷基磺酰亚胺结构聚合物相比,本发明的支化结构聚合物具有更好的电导率,并且与高电化学活性的正负极材料有良好的相容性,高锂离子迁移数(t+>0.9),以及高电化学窗口(>6V),并有良好的充放电性能与寿命
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