investigate approaches that can make 2D materials with better functionality by studying the energetic ., Engineering Chemically-Exfoliated Large-Area Two-Dimensional MoS2 Nanolayers with Porphyrins for Improved
ERIC Educational Resources Information Center
Dervin, Fred; Gao, Minghui
2012-01-01
"Happy Chinese" or kuaile hanyu is an educational melodrama produced by the Chinese TV channel CCTV in 2009. Aiming to improve foreign learners' Chinese language skills, the plot revolves around Susan, an American, staying with her former Chinese classmate's family. "Happy Chinese" proposes both language and cultural learning.…
ERIC Educational Resources Information Center
Hsiao, Ya Ping; Broeder, Peter
2014-01-01
Twitter is becoming increasingly popular as a medium for language learning. This study explores self-directed learning via social interactions that use Twitter as an interactive learning environment. The participants in this study were thirty university students of Chinese as a foreign language at levels 1 and 2 of the "Hanyu Shuiping…
ERIC Educational Resources Information Center
Chung, Kevin K. H.
2007-01-01
The influence of different instructional presentations upon meaning and pronunciation acquisition in character learning was examined. High school students learned to identify a series of characters in terms of their associated pinyin and English translation prompts. Acquisition was shown to proceed more rapidly when the Chinese character was…
Pressure-induced transition in the grain boundary of diamond
NASA Astrophysics Data System (ADS)
Chen, J.; Tang, L.; Ma, C.; Fan, D.; Yang, B.; Chu, Q.; Yang, W.
2017-12-01
Equation of state of diamond powder with different average grain sizes was investigated using in situ synchrotron x-ray diffraction and a diamond anvil cell (DAC). Comparison of compression curves was made for two samples with average grain size of 50nm and 100nm. The two specimens were pre-pressed into pellets and loaded in the sample pressure chamber of the DAC separately to minimized differences of possible systematic errors for the two samples. Neon gas was used as pressure medium and ruby spheres as pressure calibrant. Experiments were conducted at room temperature and high pressures up to 50 GPa. Fitting the compression data in the full pressure range into the third order Birch-Murnaghan equation of state yields bulk modulus (K) and its pressure derivative (K') of 392 GPa and 5.3 for 50nm sample and 398GPa and 4.5 for 100nm sample respectively. Using a simplified core-shell grain model, this result indicates that the grain boundary has an effective bulk modulus of 54 GPa. This value is similar to that observed for carbon nanotube[1] validating the recent theoretical diamond surface modeling[2]. Differential analysis of the compression cures demonstrates clear relative compressibility change at the pressure about 20 GPa. When fit the compression data below and above this pressure separately, the effect of grain size on bulk modulus reverses in the pressure range above 20 GPa. This observation indicates a possible transition of grain boundary structure, likely from sp2 hybridization at the surface[2] towards sp3like orbital structure which behaves alike the inner crystal. [1] Jie Tang, Lu-Chang Qin, Taizo Sasaki, Masako Yudasaka, Akiyuki Matsushita, and Sumio Iijima, Compressibility and Polygonization of Single-Walled Carbon Nanotubes under Hydrostatic Pressure, Physical Review Letters, 85(9), 1187-1198, 2000. [2] Shaohua Lu, Yanchao Wang, Hanyu Liu, Mao-sheng Miao, and Yanming Ma, Self-assembled ultrathin nanotubes on diamond (100) surface, Nature
EDITORIAL: Close contact Close contact
NASA Astrophysics Data System (ADS)
Demming, Anna
2010-07-01
means to produce nanoscale device elements, such as carbon nanotube transistors [5] and high-density memory crossbar circuits [6]. Recently, the use of scanning tunnelling microscopes has broached a new field of research, which is currently attracting enormous interest—single molecule detection. In issue 25 of Nanotechnology researchers in Houston reported unprecedented sensitivities using localized surface plasmon resonance shifts of gold bipyramids to detect concentrations of substances down to the single molecule level [7]. In issue 26 a collaboration of researchers from the US and Czech Republic describe a different approach, namely tunnelling recognition. In their topical review they describe hydrogen-bond mediated tunnelling and the associated experimental methods that facilitate the detection of single molecules in a tunnel junction using chemically functionalized electrodes [8]. The nanoworld depicted by scanning probe microgaphs over 20 years ago may have looked as extraterrestrial as any science fiction generated alien terrain, but though study and analysis these nano-landscapes have become significantly less alien territory. The work so far to unveil the intricacies of electronic contact has been a story of progress in investigating this new territory and manipulating the mechanisms that govern it to formulate new devices and delve deeper into phenomena at the nanoscale. References [1] Binning G, Rohrer H, Gerber Ch and Weibel E 1982 Phys. Rev. Lett. 49 57-61 [2] X D Cui, X Zarate, J Tomfohr, O F Sankey, A Primak, A L Moore, T A Moore, D Gust, G~Harris and S M Lindsay 2002 Nanotechnology 13 5-14 [3] Martin C A, van Ruitenbeek J M and van der Zant S J H 2010 Nanotechnology 21 265201 [4] Davis J J and Hanyu Y 2010 Nanotechnology 21 265302 [5] Tans S J, Verschueren A R M and Dekker C 1998 Nature 393 49-52 [6] Chen Y, Jung G-Y, Ohlberg D A A, Li X, Stewart D R, Jeppesen J O, Nielsen K A, Stoddart J F and Williams R S 2003 Nanotechnology 14 462-8 [7] Mayer K M