1,255 research outputs found
The politics of fashion: perceptions of power in female clothing and ornamentation as reflected in the sixteenth-century Chinese novel Jin Ping Mei
No full textThis thesis examines issues of female power and influence in sixteenth-century China focusing on how women and their roles were perceived in the changing social environment of the mid-late Ming dynasty. Using aspects of a New Historicist approach, information from contemporary literary and historical sources are analysed alongside each other. With its emphasis on the lives of women and preoccupation with the description of material objects, the late Ming novel Jin Ping Mei forms an important element in the thesis. China in the sixteenth century saw expanding urbanisation, the emergence of a new wealthy merchant class, increasing visibility of women and a questioning of traditional morality. Fashion consciousness, as one of the most conspicuous aspects of the new material culture, is a possible indicator of these trends. Traditional Western theories contend that fashion began in the particular context of Renaissance Europe. However, this study argues that a similar fashion awareness existed in China too, and was manifested in a competitive striving for social status, in this case specifically among women. In contrast to previous studies which downplayed the impact women had on defining traditional Chinese culture, this thesis demonstrates how women and their sartorial choices began to redefine the boundaries of material culture, influencing literati discourse which, in turn, re- influenced female behaviour
Correlating structural and electrical characteristics of threading dislocations in GaN-on-Si heterostructures and p-n diodes by multiple microscopy techniques
No full textStructural and electrical properties of a- and a +c-type threading dislocations in metal-organic vaporphase epitaxy-grown Si-doped GaN (0001) are determined by combining multiple scanning probe microscopy approaches. The analysis examines the space-charge region (SCR) formed around dislocation cores and clarifies the role it plays in influencing the local recombination, the surface-potential characteristic, and even the conductivity. Direct evidence of the SCR is obtained from a differential capacitance (dC/dV) measurement at dislocation sites on the (0001) surface. Experimental dC/dV (V) measurement results supported by technology computer-aided design calculations of capacitance, accounting for the theoretical deep levels related to different atom-core structures of the identified dislocations, reveal quantitative differences in their respective trap densities. This study is extended to p-n GaN vertical diodes to analyze the doping distribution across active layers. Through a correlated cross-section investigation combining electron-channeling contrast-imaging microscopy, the underlying dislocations within the depth limited by the screening of their SCRs are found to severely impact the homogeneity of the cross-section dC/dV contrast in the low-doped n-type drift layer of the diodes. This raises serious concerns regarding any quantification efforts by differential capacitance measurements in GaN on Si, where the dislocation density is in the order of 10(9) cm(-2)
Darqan Sigülengge, Altan Khan’s emissary to Ming China, 1570-1571
No full textDrawing from recently published Mongolian and Chinese sources of the Ming period such as Altan Khan’s biography and “The Memorials of Ministry of Army” (Bingbu zoushu), the author clarifies the identity of Darqan Sigülengge — Da-er-han Shou-ling-ge in Chinese —, an emissary of Altan Khan in the negociations with officials of Ming China in 1570-1571, of Toγuci Taisi, an official of Altan Khan, and of Buciγdai alias Bao Chongde.S’appuyant sur des sources chinoises et mongoles de la période Ming récemment publiées, telles que la biographie d’Altan Khan et les « Mémoires [au trône] du Ministère des Armées », l’auteur clarifie l’identité de Darqan Sigülengge — Da-er-han Shou-ling-ge en chinois —, un émissaire d’Altan Khan dans les négociations avec les fonctionnaires de la Chine des Ming en 1570-1571, de Toγuci Taisi, fonctionnaire d’Altan Khan, et de Buciγdai alias Bao Chongde
Structural and electrical properties of Pr1-xaexmno3 (ae = sr, ba)
No full textBulk samples of Pr1-xAExMnO3 (AE = Sr, Ba) were prepared through conventional
solid state method. XRD analysis shows that Pr0.67Sr0.33MnO3 (PSMO) and
Pr0.67Ba0.33MnO3 (PBMO) exhibited single phase orthorhombic structure with space
group of Pnma and Imma, respectively. The lattice parameters (a,b,c), Mn-O-Mn bond
angle and volume of the structure increased when smaller Sr atom was replaced with
bigger Ba atom. SEM micrograph shows different grain size with 1.6?m for PBMO and
9.1?m for PSMO. The metal-insulator transition temperature, Tp was found different
where PBMO show double Tp value (150K, 182K), where PSMO give single Tp value
of 286K. The difference is believed to be due to the different phases of the surface and
core of the grain. Typical polycrystalline type of MR behavior (intrinsic accompany
with extrinsic MR effect) is observed. However, the intrinsic effect is more dominant in
both cases. In this study, substitution of various atomic radius in Pr site greatly
influences the structural and electrical properties in Pr0.67(Ba, Sr)0.33MnO3 system
Origin of leakage current in vertical GaN devices with nonplanar regrown p-GaN
No full textThis work demonstrates large-area vertical GaN-on-GaN Schottky barrier diodes (SBDs) with different p-GaN terminations fabricated by the p-GaN regrowth on planar and nonplanar n-GaN structures and studies the leakage current in these regrown p-GaN terminations. The SBDs with planar p-GaN terminations demonstrate a higher breakdown voltage than the non-terminated SBDs. In contrast, the SBDs with nonplanar regrown terminations exhibit a significantly higher leakage current, which agrees with the tunneling behavior. The microscopic current mapping and local current-voltage (I-V) spectra are acquired using conductive atomic force microscopy (C-AFM) in the nonplanar regrown junction region. The local leakage currents and conduction types are derived from the I-V characteristics of the Schottky barrier between the metalized C-AFM tip and GaN. The dominant leakage path is revealed to be the tunneling across the Schottky barrier to the regrowth sidewall assisted by high-concentration interfacial impurities, followed by current flow along the regrowth sidewall. An ∼0.7 μm-wide n-type compensation layer is found next to the non-polar regrowth sidewall, which does not directly induce a major leakage path but moves the p-GaN away from the regrowth interface, thus weakening the p-GaN depletion of the sidewall interfacial impurities as well as facilitating the formation of a crowded electric field and tunneling at the Schottky contact to the regrowth region.link_to_subscribed_fulltex
Lateral p-GaN/2DEG junction diodes by selective-area p-GaN trench-filling-regrowth in AlGaN/GaN
No full textThis work demonstrates a lateral p-n junction diode formed between the two-dimensional electron gas (2DEG) and the selective-area regrown p-GaN in AlGaN/GaN. Benefiting from the in-plane 2DEG channel, this p-GaN/2DEG diode can directly characterize the current conduction and voltage blocking characteristics of the regrown sidewall p-n junction, which has been regarded as the key building block of future high-voltage GaN power devices. Control samples with planar regrown p-n junctions are first used to optimize the regrowth conditions. The planar junction characteristics show considerable improvement by adding the Mg pre-flow (Cp2Mg) before the p-GaN regrowth, which is attributed to the Mg out-diffusion beyond the regrowth interface. A record high ratio between the Mg concentration and the maximum impurity (C, Si, O) spike at the regrowth interface is demonstrated. Using the optimal regrowth conditions, the fabricated p-GaN/2DEG junction diodes show excellent rectifying behavior with an on/off ratio of over 5 × 107 in both large-area devices and the multi-finger devices with 1 μm-wide finger trenches. A breakdown voltage over 100 V is demonstrated, where the peak electric field is estimated to be at least 2.5 MV/cm at the sidewall junction. These results not only suggest that p-GaN trench-filling regrowth is a viable approach for selective-area p-type doping in GaN power devices but also open a door for the development of unconventional GaN devices based on p-GaN/2DEG junctions.link_to_subscribed_fulltex
Gu jing jie hui han : fu xiao xue hui han /
No full textv. 1. Zheng shi Zhou yi zhu. Lu shi Zhou yi shu -- v. 2-6. Zhou yi ji jie -- v. 7. Zhou yi kou jue yi -- v. 8-9. Yi wei ba zhong -- v. 10-11. Shang shu da zhuan -- v. 12-13. Han shi wai zhuan. Mao shi cao mu niao shou chong yu shu -- v. 14-16. Chun qiu fan lu -- v. 17-23. Chun qiu shi li -- v. 24-26. Chun qiu ji zhuan zuan li -- v. 27. Chun qiu wei zhi -- v. 28-29. Chun qiu ji zhuan bian yi -- v. 30-33. Lun yu yi shu -- v. 34. Lun yu bi jie. Zheng zhi -- v. 35. Fang yan -- v. 36. Shi ming -- v. 37. Guang ya -- v. 38. Kuang miu zheng su -- v. 39-40. Ji jiu pian -- v. 41-44. Shuo wen jie zi -- v. 45-51. Shuo wen xi zhuan -- v. 52-53. Shuo wen zhuan yun pu -- v. 54-56. Yu pian -- v. 57. Gan lu zi shu. Wu jing wen zi. Jiu jing zi yang -- v. 58-62. Guang yun (Zhang shi ke ben) -- v. 63-64. Guang yun (Ming Nei fu ben).Mode of access: Internet
Superjunction Power Transistors With Interface Charges: A Case Study for GaN
No full textRecent progress in p-GaN trench-filling epitaxy has shown promise for the demonstration of GaN superjunction (SJ) devices. However, the presence of n-type interface charges at the regrowth interfaces has been widely observed. These interface charges pose great challenges to the design and performance evaluation of SJ devices. This work presents an analytical model for SJ devices with interface charges for the first time. In our model, two approaches are proposed to compensate interface charges, by the modulation of the SJ doping or the SJ geometry. Based on our model, an analytical study is conducted for GaN SJ transistors, revealing the design windows and optimal values of doping concentration and pillar width as a function of interface charge density. Finally, TCAD simulation is performed for vertical GaN SJ transistors, which validated our analytical model. Our results show that, with optimal designs, interface charges would only induce small degradation in the performance of GaN SJ devices. However, with the increased interface charge density, the design windows for pillar width and doping concentration become increasingly narrow and the upper limit in the pillar width window reduces quickly. When the interface charge density exceeds cm−2, the design window of pillar width completely falls into the sub-micron range, indicating significant difficulties in fabrication. Vertical GaN SJ transistors with interface charges retain great advantages over conventional GaN power transistors, but have narrower design windows and require different design rules compared to ideal GaN SJ devices
POLYMERIZATION OF MONOMERS IN MICROEMULSIONS FOR FORMING POROUS POLYMERIC MATERIALS
No full textPh.DDOCTOR OF PHILOSOPH
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