22,177 research outputs found
Program Notes of Cheng-Hsin Kuo\ue2s Violin Recital
No full textThis report is the program notes of Cheng-Hsin Kuo\ue2s Violin Recital, which was performed at Chiang Kai-shek Chateau in National Sun Yat-sen University on December 9, 2019. The repertoires of the recital include Johann Sebastian Bach\ue2s Partita for Solo Violin in D Minor, BWV 1004: Chaconne, Niccol\uc3\ub2 Paganini\ue2s 24 Caprices for Solo Violin, Op. 1 No. 13, Johannes Brahms\ue2 Violin Sonata in G Major, Op. 78, and Henryk Wieniawski\ue2s Polonaise Brillante in A Major, Op. 21. The program notes will present the lives of the four composers, as well as the background and music styles of the four compositions, so that the performer can further understand the content of the works, and interpret them with more conviction
On the Sobolev quotient of three-dimensional CR manifolds
Get PDFWe exhibit examples of compact three-dimensional CR manifolds of positive Webster class, Rossi spheres, for which the pseudo-hermitian mass as defined in [CMY17] is negative, and for which the infimum of the CR-Sobolev quotient is not attained. To our knowledge, this is the first geometric context on smooth closed manifolds where this phenomenon arises, in striking contrast to the Riemannian case
On the variation of the Einstein-Hilbert action in pseudohermitian geometry (with an appendix by Xiaodong Wang)
Get PDFMinimal surfaces in pseudohermitian geometry
Get PDFWe consider surfaces immersed in three-dimensional pseudohermitian manifolds. We define the notion of (p-)mean curvature and of the associated (p-)minimal surfaces, extending some concepts previously given for the (flat) Heisenberg group. We interpret the p-mean curvature not only as the tangential sublaplacian of a
defining function, but also as the curvature of a characteristic
curve, and as a quantity in terms of calibration geometry.
As a differential equation, the p-minimal surface equation is degenerate (hyperbolic and elliptic). To analyze the singular set (where the (p-)area
integrand vanishes),
we formulate some {\em extension} theorems, which describe how the
characteristic curves meet the singular set. This allows us to classify the entire solutions to this equation and to solve a
Bernstein-type problem (for graphs over the -plane) in the Heisenberg group . In , identified with the Euclidean space , the p-minimal surfaces are classical ruled surfaces with the rulings generated by Legendrian lines. We also prove a
uniqueness theorem for the Dirichlet problem under a condition on the size of the singular set in two dimensions, and generalize to
higher dimensions without any size control condition.
We also show that there are no closed, connected, smoothly immersed
constant p-mean curvature or p-minimal surfaces of genus greater than one in the standard
This fact continues to hold when is replaced by a general pseudohermitian 3-manifold
Studies on the growth and opto-eletronic properties of low-dimensional II-VI semiconductors
No full text低維度半導體已廣泛地被應用在光電半導體產業，並在學術研究上引起很大的注意。在此論文中，我們將會呈現在三種不同的二六族半導體奈米結構系統其特有的光電性質。在一維CdSe奈米結構成長方面，我們發現經由改變MOCVD系統中的磊晶參數，可在一次的製程中同時生長出不同形狀、不同晶體結構的一維CdSe。在矽太陽能電池的研究中，利用乾蝕刻所製作的錐狀表面提供了極佳的抗反射效果；將CdSe或CdTe的量子點灑在已做好的電池上，發現其功率可分別提升約兩成與四成，而這樣的結果歸因於量子點在光吸收與電子（或電洞）傳輸上皆有所助益。在ZnTe/ZnSe的研究中，我們發現在ZnSe中加入少量Te（δ-doped Te）或者成長ZnTe量子點，會分別形成等電子中心與type-II 的能帶結構，所觀察到的螢光光譜和時間解析螢光光譜皆有很大的差異。Low-dimensional semiconductors systems have attracted much attention recently because they have many interesting properties and can have many potential technological applications. In this thesis we present our studies on the optical and electrical properties of three different II-VI semiconductor nanostructure systems. In the growth of one-dimensional CdSe nanostructures, different shapes and crystalline structures of one-dimensional CdSe were fabricated in a single process successfully by changing the growth parameters with a MOCVD system. In the study of Si solar cell, the efficiency of the solar cells was enhanced about 20 % or 40 % by spraying CdSe or CdTe quantum dots on the surfaces of textured Si wafer. The enhancement was attributed to the contribution of quantum dots in photo absorption and electron (or hole) transport. In the study on ZnTe/ZnSe system, the results demonstrate that there are two different mechanisms responsible for the green PL emission in ZnSeTe system and our growth methods provide a way of selecting one of the two mechanisms for the green light emission in this system.Chapter 1 Introduction.1 Growth and characterization of one-dimensional CdSe nanostructures …….. 1.2 Texturing Si surface with reactive ion etching and the effect of addingCdSe and CdTe quantum dots on the efficiency of solar cell …….…............. 2.3 Isoelectronic centers and type-II quantum dots: Mechanisms for the green band emission in ZnSeTe alloy …………………………………………….... 3.4 References……………………………………………………………………...5hapter 2 Experimental Details and Theoretical Background .1 Quantum confinement effect …………………………………………….........9.2 δ-doped Te/ZnSe ……………………………………..…………………...... 13.3 MOCVD ………………………………………………………………......... 13.4 Texture and passivation of Si solar cell’s surface …………………...…....... 17.5 Reactive ion etching (RIE) ……………………………….….……..…......... 21.6 Photoluminescence (PL) ………………………………….......………......... 22.7 Time-resolved Photoluminescence (TRPL) ................................................... 24.8 Scanning Electron Microscopy (SEM) ………..…………...….………........ 30.9 I-V measurement …………………………………...….………..….............. 33.10 References……………………………………………………………………....36hapter 3 Sample preparation .1 One-dimensional CdSe nanostructures grown by MOCVD .......................... 37.2 Si solar cell textured by RIE ...…………………………………………....... 39.3 CdSe and CdTe quantum dots ...……............................................................ 40.4 δ-doped Te/ZnSe and ZnTe QDs/ZnSe grown by MOCVD ...…….............. 42.5 References…………………………………………………………………....45hapter 4 Growth and characterization of one-dimensional CdSe nanostructures.1 Introduction .……........................................................................................... 46.2 Experiment .……............................................................................................ 47.3 Result and discussion ..................................................................................... 47.4 conclusion ...................................................................................................... 59.5 References………………………………………………………………….…62hapter 5 Texturing Si surface with reactive ion etching and the effect of adding CdSe and CdTe quantum dots on the efficiency of solar cell..1 Introduction .................................................................................................... 64.2 Experiment ..................................................................................................... 64.3 Result and discussion .......................................................................................65.4 Conclusion ..................................................................................................... 78.5 References…………………………………………………………………....79hapter 6 Isoelectronic centers and type-II quantum dots: Mechanisms for the green band emission in ZnSeTe alloy.1 Introduction .................................................................................................... 80.2 Experiment ..................................................................................................... 80.3 Result and discussion ..................................................................................... 81.4 Conclusion ..................................................................................................... 87.5 References………………………………………………………………..…..89hapter 7 Conclusions...........................................................................9
Inspiration provided to biomechatronics engineering education from the experience of biomedical engineering education
No full textThe political role of the people's liberation army 1949-1973
Get PDFThis thesis is to study the political role of the People's Liberation Army from the approach of structure and function. The framework of the thesis consists of three major parts, first, the influence of Chinese traditional political culture on, and the formation of, the political role of the PL A; second, the influence of domestic political struggles and external military conflicts on the development of the political role of the PLA; and the third, the analysis of the transition of the PLA's political role from the structure and personnel arrangements of the CCPCC Within the above-mentioned three scopes, this thesis make a thorough discussion on the following: (1) The relationship between the structure of the PRC and the formation of the PLA's political role; (2) How has ideology influenced the army's political role; (3) What is Mao's viewpoint and his influence on the development of the army's political role; (4) What is the link between the army and the party, and how has this developed; (6) What accounts for the expansion of the PLA's political functions; (7) What is the influence of political factional struggles on the PLA's political role; (8) Is it political institution or military institution that controls the recruitment of the military elite; (9) What are the disparities between the military elite in handling international conflicts and what are their political considerations; (10) What is the Party's position in the army; (11) How have the Party’s important meetings and personnel arrangements influenced the rise and fall of the PLA's political role
Work Fatigue in a Hospital Setting: The Experience at Cheng Hsin General Hospital
No full textWe aimed to investigate fatigue and its related factors in a medical professional population aged ≥30 years, as appraised by the implementation of an employee health screening program at Cheng Hsin General Hospital in Taipei, Taiwan. The study participants included a total of 2132 (400 males and 1732 females) healthy medical professionals enrolled in a teaching hospital who underwent physical verification in 2019. Demographic characteristics and fatigue information were collected. The overall prevalence of personal- and work-related fatigue in this study population was 41.4% and 39.1%, respectively. The prevalence of a high risk of work- or personal-related fatigue proved to be substantially greater (p-value for chi-square test <0.0001) than it was for a low or moderate risk of personal-related fatigue. Using multinominal logistic regression analysis, seniority and position were statistically significant in relation to a high risk of personal- and work-related fatigue. Personal- and work-related fatigue were found to be prevalent in physicians and nurses. Lower seniority was also related to severe personal- or work-related fatigue. Providing this population with controlled working environments and health improvements is important
Taiwan’s democratic progressive party and its mainland china policy
Get PDFTaiwan has successfully changed its political system from dictatorship into a democracy since the end of 1980s. Some people do not like 'Taiwan's democracy' -some candidates get elected by bribery in election, parliamentary fighting., but the majority of the Taiwanese people really enjoy their freedom in their homeland. They do know, at least, they have the right to oppose the government, no one would be shot by the national military force in a demonstration. The political systems are totally different between Taiwan and Mainland China, one is democracy, another is communism. Even the majority of the Taiwanese people are Chinese in ethnic origin, but their life experience are different over the past 50 years, it is difficult for any side to persuade the other side which one is better. Some Chinese Taiwanese people believe that they can have a better life, if their homeland—Taiwan can be really independent in the international community. Taiwan’s political opposition built Taiwan's first opposition party— Democratic Progressive Party (DPP) 13 years ago, and with the dream of establishing a new independent country on Taiwan. The establishment of the DPP is the result of the political opposition movement in Taiwan. Most of the members of the DPP have a strong Taiwanese identity, which is very different from the ruling KMT in Taiwan and the ruling CCP in China. The DPP gains more influence in Taiwan, the uncertainty across the Taiwan Straits increase at the same time. The DPP waited and saw between being the ruling party and establishing an independent country on Taiwan, finally it chose to complete the political aim of replacing the position of the KMT at present. The purpose of the study is to assess the DPP's policy-making in its Mainland China policy. I try to give a full picture of the policy-making process in the party. The most important factor in the formulation of the mainland China policy is the relationship between the factions within the DPP, therefore, I adopt the historical and document review approach on doing this study, and describe how the interaction between the factions worked and how they made the decisions on the policies? I found that the DPP will insist on its 'one Taiwan, one China' policy before becoming the ruling party in Taiwan. However, the DPP's insistence on the 'one China, one Taiwan' policy could bring conflicts across the Taiwan Straits and obstruct the possibility of replacing the ruling KMT's position. Hence the DPP tried to explain again the party's Taiwan independence platform, and to 'purify' the party’s ideology in order to achieve its present political aim. Because the cross-Straits relationship is still developing, the DPP's mainland policy would be affected by various factors across the Taiwan Straits. There is no final text of the DPP's mainland China policy at present. Therefore, I predict the future development of its China policy could tend in two ways. Firstly, if the cross-Straits exchanges increase, and Beijing reduces its hostility, the DPP's stand of 'one Taiwan, one China' will become more flexible, and it would keep on developing a more perfect China policy. Secondly, if the cross-Straits exchanges decrease, and Beijing increases the force of threatening to Taipei, the DPP's stand of 'one Taiwan, one China' policy will be more radical, even though it would not turn its back on the business affairs. At the end of this work, I suggest the DPP rethink its insistence on a Taiwanese independence position, this could not break Taiwan's isolation in international community, but could endanger Taiwan's security. As the factional fight has reduced the force of the DPP, to condense the powers of the party would be an important issue for the DPP
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