Comparing the consistency and distinctiveness of speech produced in quiet and in noise

The study investigated whether properties of speech produced in noise (Lombard speech) were more distributed (thus potentially more distinct) and/or more consistent than those from speech produced in quiet. This was examined for auditory tokens by measuring vowel space dispersion and by determining the consistency of formant production across repeated instances. Vowel space was not expanded for speech produced in noise; there was a tendency for formants to be produced more consistently in noise (with less variation in formant frequency across repeated instances) but this was not a secure effect. The distinctiveness and consistency of Lombard visual speech were also examined using motion capture data. Relative distinctiveness was determined by comparing the amount of mouth and jaw motion for speech produced in noise and quiet; relative consistency by comparing the size of correlations for motion produced across repeated instances in the noise or in quiet conditions. Mouth, and jaw motion was larger for speech in noise, however there was no greater association between the movement measures for repeated instances of speech in noise compared to in quiet. We also examined whether the correlation between auditory and motion properties was greater for speech produced in noise than in quiet. It was found that the association between speech RMS energy and jaw motion was greater for speech in noise. The results show that although Lombard speech affects both auditory and visible articulatory properties in ways likely to enhance speech perception it does not increase production consistency.     

Facile synthesis of magnesium oxide nanoplates via chemical precipitation

Magnesium oxide (MgO) nanoplates, which have a thickness of about 10–20 nm and a length of up to 100 nm, are synthesized via chemical precipitation using ammonia hydroxide as precipitator in the presence of a nonionic surfactant polyethylene glycol (PEG 400). The morphologies and structures of the synthesized nanoplates have been characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Furthermore, the mechanism for the formation of the nanoplates has been preliminarily discussed. It is believed that the capping molecule of PEG 400, which inhibits crystal growth along the (001) direction due to its selective adsorption, plays a critical role in the formation of the plate-like nanostructures.     

C-axis oriented polycrystalline BaNi2GdxFe16-xO27 (x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5) for the application of self-biased circulator at K band

The grains of oriented W-type hexaferrite BaNi₂Gd_xFe_16-xO₂₇ (BaW) where x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 grew uniformly along their c-axis perpendicular to the sample plane, which meant high remanence ratio of BaW. When Gd³⁺ substitution content was x = 0.0, the corresponding remanence ratio reached as high as 0.90. When x = 0.2, the oriented BaW simultaneously possessed high saturation magnetization (M_s= 58.36 emu/g), high coercivity (H_c = 1527 Oe), high remanence ratio (M_r/M_s = 0.85), relatively low magnetocrystalline anisotropy field (H_a = 10,253 Oe) and low ferromagnetic resonance linewidth (ΔH = 624 Oe). These characteristics indicated the material was suitable for the design of self-biased circulator operated at K band. Based on the BaW material, self-biased double Y-junction microstrip circulator was designed and realized well circulatory function at K band.     

Social media and student learning behavior: Plugging into mainstream music offers dynamic ways to learn English

The purpose of this study demonstrates how social media enables mainstream English songs to be extended into the classroom as teaching material for learning English as a second language. Students thrive under such fun conditions and enjoyable activities, improving their listening skills and bettering their control of the English language by learning common, everyday phrases most useful for modern day English communication. The teaching procedure, approach and course of events during the learning activity is described. Researchers such as Berk (2009) emphasize the use of video clips from TV movies, YouTube, and mtvU in the classroom as a systematic teaching tool to improve learning in college courses. Similarly, this paper would like to advance the idea that learning English mainstream songs can be a ubiquitous form of learning since the involvement of technology is omnipresent, and the ease of implementing it into the classroom is readily attainable.     

低温条件下光学厚度对Tm3+:YAG 材料光谱烧孔孔深的影响

通过理论与实验研究了光学厚度对Tm3+:YAG 材料光谱烧孔孔深的影响.提出了一种用于分析光学厚度对光谱烧孔孔深影响的新模型.该模型从理论上推导了烧孔孔深与光学厚度的关系.根据提出的理论模型,当温度大于4 K时,通过选择合适的光学厚度可以使光谱烧孔孔深得到最大值.最后通过使用合适的激光与Tm3+:YAG 材料所形成的光谱烧孔实验证明了实验结果与理论分析是相一致的.     

Fabrication tolerance analysis of grating mask for pattern-specific off-axis illumination

In this paper, the effectiveness of grating mask proposed previously was evaluated for line and space patterns, and its fabrication tolerance was analyzed with aerial image simulation. The structure of grating mask was determined from the local features of Cr patterns. It was verified that grating mask could provide locally matched oblique illumination for specific patterns written on the Cr mask. When the fabrication errors of ±10% were randomly introduced into both the widths and the phases of phase gratings in the grating mask, the resulting aerial image showed the CD variation of 15.5%. In order to reduce CD variation to 5% and less, width and phase errors should be maintained to be less than 3.2% and 7.2%, respectively.     

Electrical pumped energy up-conversion: A non-linear electroluminescence process mediated by triplet-triplet annihilation

Excitons dominate the optoelectronic properties of organic devices. Normal organic light-emitting devices (OLEDs) generally linearly use exciton to generate electroluminescence (EL), in which one photon is produced from per exciton. Eliminating bi-excitons quenching is of great concern for efficient devices. Here, we have theoretically and experimentally investigated a non-linear EL process mediated by triplet-triplet annihilation (TTA) in rubrene/C₆₀-based OLEDs. This non-linear EL process realizes the electrically pumped up-conversion by promoting two low-energy triplet excitons into one high-energy exciton, thus extremely lowering the working voltage of resulting OLEDs. It is clearly seen that this up-conversion EL intensity essentially exhibits two distinct regimes at different current densities, i.e. a quadratic dependence at low current density where mono-triplet decay is dominant, and a linear dependence at high current density where bi-triplet decay becomes dominant. These results further our understanding of the non-linear optoelectronic process. In particular, our results demonstrate that energetically utilizing the TTA provides possibility of fabricating low-driving voltage, high efficiency OLEDs via non-linear EL process.     

Optimization of a-Si:H absorber layer grown under a low pressure regime by plasma-enhanced chemical vapor deposition: Revisiting the significance of the p/i interface for solar cells

In this study, we revisited the significance of the p/i interface for hydrogenated amorphous silicon (a-Si:H) solar cells. Initially, intrinsic and extrinsic (p and n type) a-Si:H layers were grown in a low pressure regime (0.5–0.1 Torr) using the conventional RF plasma-enhanced chemical vapor deposition process and their opto-electronic properties were optimized for the fabrication of p–i–n a-Si:H solar cells. Subsequently, we obtained new insights in terms of the activation energy and band gap at the p/i interface in these solar cells. The absorber layers deposited at pressures of 0.23 Torr and 0.53 Torr had the highest photosensitivity with a band absorption edge at ~700 nm. Furthermore, the photosensitivity was shown to be correlated with the estimated diffusion length, which effectively defined the carrier transport within the solar cell layers. Moreover, the cell efficiency increased from 1.53% to 5.56% due to the improved p/i interface as well as the higher photosensitivity of the intrinsic/absorber layer.