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401.
基于Linux平台的电话语音邮件系统 总被引:1,自引:0,他引:1
通过CTI(电脑语音)技术将电话语音与电子邮件相结合,提出并实现了一个基于Linux平台的电话语音邮件系统,并对原理和各功能模块的实现方法进行了论述。该系统通过Internet和现今十分普及的电信网相连接,提供了一个全方位的交叉的通信平台,拓宽了E-mail的应用领域。 相似文献
402.
Maria Sdersten PhD Svante Granqvist Britta Hammarberg Annika Szabo 《Journal of voice》2002,16(3):356-371
Preschool teachers are at risk for developing voice problems such as vocal fatigue and vocal nodules. The purpose of this report was to study preschool teachers' voice use during work. Ten healthy female preschool teachers working at daycare centers (DCC) served as subjects. A binaural recording technique was used. Two microphones were placed on both sides of the subject's head, at equal distance from the mouth, and a portable DAT recorder was attached to the subject's waist. Recordings were made of a standard reading passage before work (baseline) and of spontaneous speech during work. The recording technique allowed separate analyses of the level of the background noise, and of the subjects' voice sound pressure level, mean fundamental frequency, and total phonation time. Among the results, mean background noise level for the ten DCCs was 76.1 dBA (range 73.0-78.2), which is more than 20 dB higher than what is recommended where speech communication is important (50-55 dBA). The subjects spoke on an average of 9.1 dB louder (p < 0.0001), and with higher mean fundamental frequency (247 Hz) during work as compared to the baseline (202 Hz) (p < 0.0001). Mean phonation time for the group was 17%, which was considered high. It was concluded that preschool teachers do have a highly vocally demanding profession. Important steps to reduce the vocal loading for this occupation would be to decrease the background noise levels and include pauses so that preschool teachers can rest their voices. 相似文献
403.
Susanna Simberg Eeva Sala Jyrki Tuomainen Jaana Sellman Anna-Maija Rnnemaa 《Journal of voice》2006,20(1):97-109
Previous studies of students studying to be teachers have indicated that these students commonly have voice disorders. Ideally, voice disorders should be treated before students start their work as teachers, but the resources for this treatment are often limited. This study examines whether group voice therapy is effective for teacher students. Accordingly, 20 teacher students with mild voice disorders received group voice therapy (in three small groups), whereas 20 students with similar voice disorders served as a control group and consequently did not receive voice therapy. Two out of three outcome measures (perceptual evaluation of voice quality and a questionnaire on the occurrence of vocal symptoms) indicated significant changes in the treatment group compared with the control group. No differences between groups were noted in the laryngeal status. The results suggest that group voice therapy seems to be an effective method to treat students with mild voice disorders. 相似文献
404.
The nasal cavity and its related structures make significant contributions to human phonation, especially the resonance of voice spectra. The voice spectra of the nasal consonant-vowel (CV), [md:], in the subjects with nasal obstruction were obtained and were compared with the spectra of the same CV vocalized by the same subjects after topical nasal decongestion treatment with 1:1000 epinephrine solution. Results revealed that the intensity damping was more marked in the high-frequency area (>1600 Hz) after the nasal decongestion. Moreover, the intensities of the spectral valleys damped more than the spectral peaks, especially the spectral valley of 1000-2700 Hz. Therefore, a more complex spectral pattern was formed by the resultant uneven damping effect after nasal decongestion. The nasal cavity plays an important role in the formation of spectral peaks and valleys, and such engraved voice spectra may also characterize nasal voices like the nasal CV [md:] demonstrated in our study. 相似文献
405.
Effects of charge trapping in gamma irradiated and accelerated aged low-density polyethylene 总被引:1,自引:0,他引:1
The effects of gamma irradiation in air and accelerated aging of low-density polyethylene (LDPE) were studied through dielectric loss (tan δ) analysis in the temperature range from 25 to 325 K and using thermally stimulated discharge current (TSDC) measurements. The radiation-induced oxidation was observed using IR spectroscopy. The influence of radiation dose and accelerated aging on the intensities and the positions of the γ and β dielectric relaxation maxima were correlated with maxima of TSDC measurements, and found to be strongly dependent upon the changes in the microstructure of the amorphous phase and on the surface of the crystallites induced by oxidation and crosslinking. 相似文献
406.
Shiyu Ma Wensheng Lu Jin Mu Fen Liu Long Jiang 《Colloids and surfaces. A, Physicochemical and engineering aspects》2008,324(1-3):9-13
A chitosan-based electrode filled with silver nanoparticles (AgNPs) and glucose oxidase (GOD) was used as an enzyme electrode to investigate the effect of aging process of AgNPs on the GOD activity. Freshly prepared AgNPs inhibit the GOD activity, however, the inhibitory effect decreased with the increase of aging time. After aged for a period of time, AgNPs showed enhancement effect on the GOD activity. The effect of aging was studied by the measurements of Ag+ ions concentration, zeta (ζ) potential and X-ray photoelectron spectroscopy (XPS). And the results indicated that the concentration of Ag+ ions in the silver sol decreased during the aging period (i.e. Ag+ ions converted to more inert silver metal Ag0). The effect of AgNPs on the GOD activity can be changed by controlling the aging time of AgNPs. This research provides a new and simple approach to mediate AgNPs property, which is of great value in potential application of AgNPs in biosensors and nanoscale devices. 相似文献
407.
This study concerns speaking voice quality in a group of male teachers (n = 35) and male actors (n = 36), as the purpose was to investigate normal and supranormal voices. The goal was the development of a method of valid perceptual evaluation for normal to supranormal and resonant voices. The voices (text reading at two loudness levels) had been evaluated by 10 listeners, for 15 vocal characteristics using VA scales. In this investigation, the results of an exploratory factor analysis of the vocal characteristics used in this method are presented, reflecting four dimensions of major importance for normal and supranormal voices. Special emphasis is placed on the effects on voice quality of a change in the loudness variable, as two loudness levels are studied. Furthermore, the vocal characteristics Sonority and Ringing voice quality are paid special attention, as the essence of the term "resonant voice" was a basic issue throughout a doctoral dissertation where this study was included. 相似文献
408.
409.
Miriam Sanz Brígida Fernández de Simón Estrella Cadahía Enrique Esteruelas Ángel Mª Muñoz Mª Teresa Hernández Isabel Estrella 《Analytica chimica acta》2012
Although oak wood is the main material used in cooperage, other species are being considered as possible sources of wood for the production of wines and their derived products. In this work we have compared the phenolic composition of acacia (Robinia pseudoacacia), chestnut (Castanea sativa), cherry (Prunus avium) and ash (Fraxinus excelsior and F. americana) heartwoods, by using HPLC-DAD/ESI-MS/MS (some of these data have been showed in previous paper), as well as the changes that toasting intensity at cooperage produce in each polyphenolic profile. Before toasting, each wood shows a different and specific polyphenolic profile, with both qualitative and quantitative differences among them. Toasting notably changed these profiles, in general, proportionally to toasting intensity and led to a minor differentiation among species in toasted woods, although we also found phenolic markers in toasted woods. Thus, methyl syringate, benzoic acid, methyl vanillate, p-hydroxybenzoic acid, 3,4,5-trimethylphenol and p-coumaric acid, condensed tannins of the procyanidin type, and the flavonoids naringenin, aromadendrin, isosakuranetin and taxifolin will be a good tool to identify cherry wood. In acacia wood the chemical markers will be the aldehydes gallic and β-resorcylic and two not fully identified hydroxycinnamic compounds, condensed tannins of the prorobinetin type, and when using untoasted wood, dihydrorobinetin, and in toasted acacia wood, robinetin. In untoasted ash wood, the presence of secoiridoids, phenylethanoid glycosides, or di and oligolignols will be a good tool, especially oleuropein, ligstroside and olivil, together verbascoside and isoverbascoside in F. excelsior, and oleoside in F. americana. In toasted ash wood, tyrosol, syringaresinol, cyclolovil, verbascoside and olivil, could be used to identify the botanical origin. In addition, in ash wood, seasoned and toasted, neither hydrolysable nor condensed tannins were detected. Lastly, in chestnut wood, gallic and ellagic acids and hydrolysable tannins of both the gallotannin and ellagitannin type, can be used as chemical markers. 相似文献
410.
Heiko Rieger 《Phase Transitions》2013,86(5-7):497-523
We present an overview of recent developments in the nonequilibrium dynamics of spin glasses. The prevailing theoretical pictures are described and discussed in light of numerical results and experimental observations. We focus on aging phenomena like waiting-time-dependent length scales, scaling of two-time quantities, more complex temperature protocols during aging, and the violation of the fluctuation–dissipation theorem. Finally, aging in quantum spin glass models coupled to a dissipative bath is discussed. 相似文献