Yin-shan 陰山 Mountains and Tiande-jun 天徳軍 in the Late Tang Period: On the basis of 羽032 Document from Dunhuang.

This paper discusses the conditions pertaining in the vicinity of the Yinshan mountain range during the late Tang period through an examination of 羽032, a document discovered at Dunhuang. It begins by establishing that this document is a record kept by an emissary from Shazhou 沙州 (present-day Dunhuang) who in the early 850s reached the Yinshan Mountains, evidence for which is the fact the place names appearing in the document conform to late Tang usage and what is known of the political situation surrounding Dunhuang during this period of time. From it, this paper points to the fact that in the 850s a post road ran east-west along the southern foothills of the Yinshan Mountains, and that this post road was established primarily for the use of Uighur emissaries traveling back and forth to the Tang court from their homeland in the Mongolian Plateau. The paper further demonstrates that Tiande-jun was a place where emissaries from the north would be sure to visit as it was located in the western Yinshan region where travelers from the Mongolian plateau would arrive, and that because of this facilities called guan 館 for welcoming the official emissaries were established at this site

Northern China and the First Turkic Qaghanate in the late Sui to early Tang dynasty

This research analyzes historical sources such as epitaphs and classical Chinese texts, to focus on political tendencies among both the nomadic tribes of the First Turkic Qaghanate and warlords in northern China in the late Sui to the early Tang dynasty. The analysis reveals that the Zhishi 執失, a powerful Turkic tribe, was split by allegiances to both the Qaghanate and the Tang, so that while Zhishi Sili 執失思力 played a key role as a chief vassal of Xieli Qaghan 頡利可汗, Sili’s father, Zhishi Wu 執失武, formed a cavalry corps under Li Shimin 李世民. On the other hand, of the warlords that maintained spheres of influence in northern China, those with only relatively limited power, such as Zhang Changsun 張長遜, Guo Zihe 郭子和, and Wan Junzhang 苑君璋, swore their allegiance to both the Türks and the Tang at the same time. Both the Türks and the Tang felt it to be dangerous that these warlords pledged their allegiance to the other side, and sometimes carried out attacks or executions when they ascertained that this was the case. Conversely, there were also cases in which they encouraged the warlords to betray the other side. It is thought that both the Türk nomadic tribes and those warlords with minor spheres of influence sought to survive by shifting between both sides

Identification of excitonic phonon sideband by photoluminescence spectroscopy of single-walled carbon-13 nanotubes

We have studied photoluminescence (PL) and resonant Raman scatterings of single-walled carbon nanotubes (SWNTs) consisting of carbon-13 (SW13CNTs) synthesized from a small amount of isotopically modified ethanol. There was almost no change in the Raman spectra shape for SW13CNTs except for a downshift of the Raman shift frequency by the square-root of the mass ratio 12/13. By comparing photoluminescence excitation (PLE) spectra of SW13CNTs and normal SWNTs, the excitonic phonon sideband due to strong exciton-phonon interaction was clearly identified with the expected isotope shift

Heat conduction of single-walled carbon nanotube isotope-superlattice structures: A molecular dynamics study

Heat conduction of single-walled carbon nanotubes (SWNTs) isotope-superlattice is investigated by means of classical molecular dynamics simulations. Superlattice structures were formed by alternately connecting SWNTs with different masses. On varying the superlattice period, the critical value with minimum effective thermal conductivity was identified, where dominant physics switches from zone-folding effect to thermal boundary resistance of lattice interface. The crossover mechanism is explained with the energy density spectra where zone-folding effects can be clearly observed. The results suggest that the critical superlattice period thickness depends on the mean free path distribution of diffusive-ballistic phonons. The reduction of the thermal conductivity with superlattice structures beats that of the one-dimensional alloy structure, though the minimum thermal conductivity is still slightly higher than the value obtained by two-dimensional random mixing of isotopes.Comment: 7 Pages, 5 figures, accepted to Phys. Rev.

Electrothermal flow in Dielectrophoresis of Single-Walled Carbon Nanotubes

We theoretically investigate the impact of the electrothermal flow on the dielectrophoretic separation of single-walled carbon nanotubes (SWNT). The electrothermal flow is observed to control the motions of semiconducting SWNTs in a sizeable domain near the electrodes under typical experimental conditions, therefore helping the dielectrophoretic force to attract semiconducting SWNTs in a broader range. Moreover, with the increase of the surfactant concentration, the electrothermal flow is enhanced, and with the change of frequency, the pattern of the electrothermal flow changes. It is shown that under some typical experimental conditions of dielectrophoresis separation of SWNTs, the electrothermal flow is a dominating factor in determining the motion of SWNTs.Comment: 5 pages, 4 figures, Submitted to PR

Cross-polarized optical absorption of single-walled nanotubes probed by polarized photoluminescence excitation spectroscopy

Cross-polarized absorption peaks of isolated single-walled carbon nanotubes were observed by a polarized photoluminescence excitation (PLE) spectroscopy. Using a simple theory for PL anisotropy, the observed PLE spectra are decomposed into 'pure' components of the photoexcitation for incident light polarized parallel and perpendicular to the SWNT axis. For several (n, m) SWNTs, distinct peaks corresponding to perpendicular excitation were observed. The measured transition energies for perpendicular excitations were blue-shifted compared to the qualitative values predicted within a single-particle theory. The results indicate a smaller exciton binding energy for perpendicular excitations than for parallel excitations.Comment: 7 pages, 5 figures, submitted to Phys. Rev.

The Türk Leaders and Li Shimin: The Loose-rein Control of Türks during the Taizong Period of Tang

This paper investigates the process by which regional commanders were selected during the early period of Tang Chinese "loose-rein" rule over Turkic tribes following the defeat of the First Türk Qaghanate 突厥第一可汗国 in 630. On the basis of this investigation, it demonstrates that the even before Li Shimin ascended the throne as Emperor Taizong 太宗, the second Tang emperor, these commanders had been selected from among the men who had rallied to his support in his campaigns to pacify northern China (Shi Shanying 史善應, Shi Danai 史大奈), or from Türks who had become his allies or formed other personal relationships with him (Ashina Shibobi 阿史那什鉢苾, Ashina Zhong 阿史那忠, Ashina Shimo 阿史那思摩, and Ashina Sunishi 阿史那蘇尼失). Only one among them, Kang Sumi 康蘇密, remains a mystery due to inadequate historical source materials. This research has confirmed that the loose-rein policy of control of the Türks throughout Taizong\u27s reign was conducted principally by these commanders selected at the beginning. But, since a number of these individuals had been of low rank or status during the First Türk Qaghanate, they were unable to gain the support of the Turkic people, and this system of rule collapsed for a time. However, from the reign of Gaozong 高宗onward, a more realistic system of control was initiated, and the loose-reign policy attained its most perfected state