1,721,031 research outputs found
Chasing the China wind: a musical journey
No full textIn this documentary, Chen-Yu was to explore the musical memories of Post-90s Generation across Taiwan, Hong Kong, China, and the UK. This film presents that the way audiences engage with China Wind music reflects a constant negotiation of Chineseness that takes place in both the creation and consumption of music. In the meantime, popular music helps the post-90s audience creating their identities along the way to discovering and defining ‘selves’ while imagining themselves being or not being Chinese
George Harrison: the story of the Beatles and Indian music
No full textThis film was produced for a concert taking place at the Royal Liverpool Philharmonic Hall in June 2017. The concert evolved from research that Dr. Mike Jones and Mr. John Ball have been organically working on for years. Through their work, they identified the previously unrecognised Indian musicians recorded on the track ‘Within You Without You’ on The Beatles’ seminal album, Sgt Pepper and Lonely Heart Club Band
Design and applications of low-temperature barium titanate-based conductive oxides
No full text目前已知同時具有高導電率、高強度和化學穩定性以及成本便宜的實用導電陶瓷材料，其實為數相當稀少。本論文主要針對鈦酸鋇(BaTiO3，以下表示時簡稱BT)添加氧化釔(Y2O3)或是Zr3Y(97mol.% ZrO2 + 3mol.% Y2O3)之鈦酸鋇陶瓷之導電現象研究，並找出使鈦酸鋇具有導電性需要之添加成分範圍和所需製程。在鈦酸鋇系統中，添加不同含量之Y2O3至鈦酸鋇中，或是添加不同含量之Zr3Y至鈦酸鋇中。製程方面皆採用一般常見之乾壓製程，燒結溫度範圍為1340℃-1500℃之間，觀察不同含量之添加物及燒結溫度不同會如何影響鈦酸鋇之導電性質。並找出可以使鈦酸鋇具導電性質所需添加之摻雜劑(Dopant)含量範圍，建立一個完整的成分和製程系統。即找出在低溫時，具有導電性質之鈦酸鋇導電陶瓷，例如鈦酸鋇添加Zr3Y之系統中，Zr3Y之添加量需在1-5wt% 間。和能夠表現出導電性所需之燒結溫度。並從所有可導電和不導電的成分中，各挑選二種成分，針對其導電的機制做進一步之分析。
在鈦酸鋇添加Y2O3之系統中，添加量低之BT-0.1wt%Y2O3系統，其導電性明顯優於一般之鈦酸鋇陶瓷，但是當含量增加至1wt% Y2O3時，導電性又回復到一般之介電材料之高電阻率，導電性差之絕緣體性質。而添加Zr3Y系統，BT-0.5wt% Zr3Y系統之導電性類似BT-1wt% Y2O3系統之絕緣體性質，電阻率高，導電性差。然而當添加Zr3Y至5wt% 時，BT-5wt% Zr3Y系統之導體現象又再次出現，導電性質和BT-0.1wt% Y2O3類似，由此可知，測量其電性發現，只要有添加Y2O3成分，即有可能出現導電性，但含量過少或是過多，都會使得導電性消失，在添加Zr3Y之鈦酸鋇系統中也是如此。
由於試片添加摻雜物之含量較低才能出現導電性，像是BT-0.1wt% Y2O3和BT-5wt% Zr3Y，因此在XRD、SEM、或是TEM分析上，無法找到以Zr或是Y為基底之第二相。因此，設計了其他有關電性方面的實驗，像是高溫導電或是同樣燒結溫度但改至還原氣氛下燒結以觀察其電性方面性質的改變，當試片改至還原氣氛下燒結時，通的是95% 氮氣+5% 氫氣，由於試片外環境的氧含量過低，內部之氧會擴散至外部，因此從缺陷方程式可以知道會產生氧空缺，留下自由電子。且添加之釔因為離子大小可同時取代鈦酸鋇中之鋇或是鈦原子。當替代了BaTiO3中之A-site(Ba site)，為正三價之釔取代了正二價之鋇，使得材料多帶正電，因此會多出自由電子，屬於donor-doped BaTiO3，這種由donor-doped產生導電性主要是利用多餘的自由電子來產生導電性(n-type conductivity)，因此在還原氣氛下燒結之試片，再次量測電性時，會發現在還原氣氛下燒結之試片，其導電性明顯提升。
相對地，BT-0.5wt% Zr3Y成分，在換算過後，其氧化釔的含量為所有試片中最少，經過高溫燒結後，並不具導電性，推論為在添加時，釔佔據在BaTiO3中之B-site(Ti site)，由正三價取代正四價，造成材料帶負電，因此會產生電洞來補償，電洞仍能使得材料的導電性提升(p-type conductivity)，此種鈦酸鋇稱為acceptor-doped BaTiO3， 但由於acceptor-doped造成之導電性需要較高的能量才能躍遷，因此在室溫時，熱活能(thermal energy)較低，電洞無法克服束縛，所以導電性沒有表現出來，經由高溫導電實驗發現，BT-0.5wt% Zr3Y之試片，的確有隨著溫度的上升使得導電性跟著提升。而另一不導電之成分為BT-1wt% Y2O3, 當添加過量的氧化釔時，可能會使得導電機制再次回到室溫時不會表現的電洞導電機制(p-type conductivity)，所以添加過量時，導電性沒有隨添加的含量增加而提升，經由高溫導電實驗可知，當升高溫度時，的確會造成材料之導電性提升。因此有關探討鈦酸鋇陶瓷中導電的機制，回歸到最原始之電子電洞理論，和材料中之缺陷有極大的關係。The conductivities of barium titanate (BaTiO3) systems doped with yittrium oxide (Y2O3) and Zr3Y (97mol.% ZrO2:3mol.%Y2O3)are studied in this thesis. Different amounts of Y2O3 and Zr3Y were added to study their influences on conductivity. Conventional oxide-mixing methods were adopted to produce the BaTiO3-based ceramics. The sintering temperature for the ceramics was varied in between 1340-1500℃ to study the influence of sintering temperature on conductivity.
For the Y2O3-doped BaTiO3 system, the conductivity is at the highest when the BaTiO3 is doped with 0.1wt%Y2O3. The conductivity decreases significantly when the Y2O3 content increases to 1wt%. For the Zr3Y-doped BaTiO3 system, the conductivity with 5wt%Zr3Y doping is similar to that with 0.1wt% Y2O3 doping. Furthermore, if the Zr3Y doping is less than 0.5wt%, the conductivity is low. It is therefore concluded that in both the Y2O3-and Zr3Y-doped BaTiO3 systems, the dominant factor for the conductivity is the amount of yittrium doping. The origin of conductivity for the Y2O3-and Zr3Y-doped BaTiO3 system is investigated by studying the evolution of conductivity at different temperatures and reducing atmospheres. Donor-doped and acceptor-doped BaTiO3 systems are therefore defined. It is found that the room-temperature conductivity of BaTiO3 is governed by the amounts of its chemical defects, such as free electrons, electron holes, oxygen vacancies, and cation vacancies.摘要 i
Abstract iii
目錄 v
第一章、緒論 1
1.1簡介 1
1.2研究目的 2
1.3論文架構 2
第二章 文獻回顧 5
2.1 鐵電材料（Ferroelectric materials） 5
2.2 BaTiO3 8
2.3 BaTiO3之導電機制 11
2.3.1 控制價數半導體(Controlled-valence semiconductor) 11
2.3.2 氧分壓對BaTiO3導電之影響 12
2.4離子大小對佔據晶格原子的影響 19
2.5添加物對鈦酸鋇性質之影響 19
2.5.1燒結溫度對添加氧化釔至鈦酸鋇中導電性之影響 19
2.5.3添加氧化釔和氧化鋯至鈦酸鋇中對介電性質之影響 21
第三章 材料製備與使用儀器 27
3.1 材料製備 27
3.1.1 BaTiO3 添加氧化鋯和氧化釔 27
3.1.2 BaTiO3 添加Y2O3 27
3.2 X-ray 繞射分析 30
3.3崩潰電壓量測 30
3.4 LCR電性量測 32
3.5 EPMA 32
3.6掃瞄式電子顯微鏡 32
3.7穿透式電子顯微鏡 32
3.8 高溫導電量測電性性質 33
3.9 還原氣氛燒結下之LCR電性性質 33
四、結果與討論 35
4.1 鈦酸鋇添加不同比例之氧化鋯與氧化釔 35
4.2崩潰電場 35
4.3 LCR量測性質 36
4.4 密度與顏色 51
4.5 XRD 51
4.6高溫導電電性量測 53
4.7還原氣氛燒結下之LCR電性性質 61
4.8 SEM分析 64
4.9 EPMA 69
4.10 TEM 75
4.10.1 BT-0.1Y2O3 75
4.10.2 BT-5Zr3Y 76
五、結論 81
5.1 研究結果 81
5.2未來研究方向 83
參考文獻 8
Convertible Bond Offering and Institutional Factors - the International Evidence
No full text本篇論文探討金融市場發展、總體經濟環境、及投資人權利保障等制度性因子對於可轉債發行動機的影響，並且透過跨國的公司財務資訊以橫斷面時間序列迴歸法進行分析。股票市場發展及銀行體系規模對於可轉債有負向影響，此結果支持金融市場發展會降低資訊及監督成本，進而降低可轉債發行動機；然而，當銀行體系吸收過多存款，銀行會放鬆對企業的監督，反而提高可轉債發行動機以控制可能的資產替代問題。經濟發展及公司舉債利率水準對於可轉債發行有負向效果，而物價膨脹率對於可轉債則是有正向效果。另外，當投資人權利保障越好，企業越傾向發行可轉債。實證結果不但支持過去可轉債用來解決代理問題、破產成本、資訊不對稱及降低資金成本等動機外，我們也發現制度性因子對於可轉債發行動機的影響效果對於已開發國家較有解釋能力。We study the institutional factors of financial markets development, macroeconomic conditions, and investor rights protection which affect convertible bond (CB) offering by using the panel regression approach with international firm-level data. The results suggest that the stock market development and the size of the bank sector reduce information costs and then lower the motivation of convertible bond offering. However, an over-sized deposit economy may weaken the bank’s monitoring and need additional convertible bonds as complements to control the possible asset substitution problem. The economic growth rates and interest rate levels are negatively related to convertible bond offering while inflation has a positive relation with convertible bond offering. Additionally, both shareholder and creditor rights protection have positive effect on convertible bond offering. The empirical evidence of institutional effects supports the fact that convertible bonds can control agency problems, information asymmetry, financial distress costs, and lower costs of capital. We also notice that the explanatory power of institutional factors is stronger for developed countries than for emerging countries.Contents
Introduction …………………………………………………… 1
Section ⅠConvertible Bond Offering Theory and Institutional Factor Hypotheses ………………………… 5
1.A. Firm-specific convertibles offering theories …… 5
2.B. Institutional factors hypotheses ………………… 10
Section Ⅱ Data Source and Description ……………… 25
2.A. Institutional data source ………………………… 25
2.B. Data description ……………………………………… 28
2.C. Time-series trend of data …………………………… 32
Section Ⅲ Methodology and Institutional Effects …… 36
3.A. Panel data methodology ……………………………… 36
3.B. Empirical results of institutional factors ……… 37
Section Ⅳ Panel Regressions by Controlling Firm-specific Factors
and Sub-sample Results ………………… 43
4.A. Effects of firm-specific factors …………………… 43
4.B. Empirical results by controlling firm-specific factors …… 49
4.C. Sub-sample empirical evidence ……………………… 52
Section Ⅴ Conclusions ….…………………………………… 54
Reference ……………………………………………………… 57
Figures …………………………………………………………. 62
Tables ………………………………………………………… 68
Contents of Figures and Tables
Figure 1 ………………………………………………………. 62
Figure 2 ……………………………………………………… 62
Figure 3 ……………………………………………………… 64
Figure 4 ……………………………………………………… 65
Figure 5 ……………………………………………………… 66
Table 1 ……………………………………………………… 68
Table 2 ……………………………………………………… 69
Table 3 ……………………………………………………… 71
Table 4 ……………………………………………………… 74
Table 5 ……………………………………………………… 75
Table 6 ……………………………………………………… 76
Table 7 ……………………………………………………… 77
Table 8 ……………………………………………………… 78
Table 9 ……………………………………………………… 8
Integrated Optimization Model to Manage Risk of Transporting Hazardous Materials on Railroad Networks
No full textGoing 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
sj-docx-1-wso-10.1177_17474930231174227 – Supplemental material for Severe lupus flare is associated with a much higher risk of stroke among patients with SLE
No full textSupplemental material, sj-docx-1-wso-10.1177_17474930231174227 for Severe lupus flare is associated with a much higher risk of stroke among patients with SLE by Kuo-Cheng Chang, Ching-Heng Lin, Po-Lin Chen, Yu-Hsuan Wu, Chung-Wei Hou and Jin-An Huang in International Journal of Stroke</p
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