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51.
Disruption of auditory feedback such as masking has been shown to influence vocal production. A reliable finding is an increase in intensity level; an increase in fundamental frequency (F0) is a less robust finding. Research is lacking concerning the effects of auditory masking on measures of phonatory stability such as jitter and harmonics-to-noise ratio (HNR). This study investigated changes in intensity, F0, jitter, and HNR in 22 normally speaking college aged women. Subjects produced the vowel /a/ under three conditions: no masking level (0-dB ML), 50-dB ML, and 80-dB ML. Significant differences between conditions emerged for intensity; means for the other measures were not significantly different. Intraindividual differences between conditions for each variable are discussed in the framework of auditory versus kinesthetic feedback. 相似文献
52.
Preliminary findings are presented regarding Visi-Pitch settings in relation to automatically derived perturbation values (jitter). Jitter values were estimated from sustained phonation of /a/ at each of four filter settings for three subjects using Visi-Pitch. Data were compared to values obtained by hand measuring the same signals and employing Koike's formula. Results indicated that the magnitude of difference between jitter estimated by Visi-Pitch and hand measurement was small. Findings support the use of the manufacturer's recommended filter settings as opposed to alternative settings suggested by Karnell. 相似文献
53.
Four acoustic measures were taken from voice recordings of 121 children between the ages of 64 and 134 months. Acoustic parameters were measured on a sustained neutral /a/ vowel, produced imitatively at normal pitch and loudness. Samples were analyzed for fundamental frequency, jitter, shimmer, and signal-to-noise ratio (SNR). Data are presented to characterize effects of age, sex, height, and weight on these acoustic parameters. Results indicate statistically significant relationships between frequency and sex, with higher frequencies for girls. Also significant is a positive relationship between shimmer and height and a negative relationship between SNR and height. 相似文献
54.
Head extension with protruded tongue is the position for video-laryngoscopy and simultaneous glottographic recordings including photoglottographic signals. This study investigated the effect of head extension and tongue protrusion on the measures of fundamental frequency, frequency perturbation (jitter), and amplitude perturbation (shimmer). Acoustic signals recorded during sustained vowels were obtained from 49 women and 66 men with no speech or voice disorders in different head-tongue positions. Head extension was associated with increased fundamental frequency and decreased shimmer. In men, head extension did not appear to affect jitter. When the tongue was protruded, head extension tended to lower jitter. For both genders, tongue protrusion was associated with decreased fundamental frequency with head extension. In the men, tongue protrusion tended to increase shimmer when the head was in the neutral position. In the women, tongue protrusion was associated with increased jitter and increased shimmer and was most evident in the head-neutral position. These findings supported a physical linkage hypothesis of the relationship between vocal tract configuration and vocal fold vibration, suggesting that head-tongue position must be taken into account when comparing voice measures. 相似文献
55.
56.
Reticent speakers differ from nonreticent speakers in vocal characteristics, such as fundamental frequency, frequency range, fluency, and intensity, which prompt negative impressions on the part of listeners. Waveform and spectrographic analyses were performed on the vocal cues of 19 reticent and nonreticent subjects (57 speech samples). Statistically significant differences were found in fluency between reticent and nonreticent speech. Reticent male speakers also showed significantly higher F0, whereas reticent female speakers demonstrated narrower frequency range. Identification and analysis of these characteristics are required for effective remediation. 相似文献
57.
对大功率延迟触发器中使用的氢闸流管的栅极点火特性,特别是延迟时间分散度做了比较细致的研究,对延迟时间做了理论计算,理论和实验符合得很好。本实验所用的延迟触发器输出电压幅度为3kV,电阻性负载的输出功率为十分之几兆瓦,最大时延50μs,改进型RC延迟器的时间分散度小于70ns,LC延迟触发器的时间分散度小于20ns。最后对进一步提高延迟时间的稳定性提出了若干改进措施。 相似文献
58.
This study examined intraproduction variability in jitter measures from elderly speakers' sustained vowel productions and tried to determine whether mean jitter levels (percent) and intraspeaker variability on jitter measures are affected significantly by the segment of the vowel selected for measurement. Twenty-eight healthy elderly men (mean age 75.6 years) and women (mean age 72.0 years) were tape recorded producing 25 repeat trials of the vowels /i/, /a/, and /u/, as steadily as possible. Jitter was analyzed from two segments of each vowel production: (a) the initial 100 cycles after 1 s of phonation, and (b) 100 cycles from the most stable-appearing portion of the production. Results indicated that the measurement point selected for jitter analysis was a significant factor both in the mean jitter level obtained and in the variability of jitter observed across repeat productions. 相似文献
59.
设计了用于脉冲功率装置的4 MV水介质同轴 三平板型输出开关。该脉冲功率装置将由24路相同的独立模块组成,每路模块由Marx发生器、中间储能器、激光触发气体开关、脉冲形成线、水介质脉冲输出开关、脉冲传输线等组成。水介质脉冲输出开关是同轴 三平板结构水介质多通道自击穿开关,由输入输出电极、预脉冲屏蔽板和连接部件组成。进行了有预脉冲屏蔽板结构和无预脉冲屏蔽板结构的自击穿水开关实验研究。有预脉冲屏蔽板结构开关的输入、输出电极都是半球电极,直径分别是8 cm和5 cm;无预脉冲屏蔽板结构开关为针 板结构,输入电极为平板电极,输出电极为直径3 cm的电极棒。Marx发生器充电70 kV,开关的击穿电压为3 MV,放电电流为450 kA。在3 MV等级的击穿电压下,有预脉冲屏蔽板结构开关的抖动约6 ns,没有预脉冲屏蔽板结构开关的抖动减小至3 ns。 相似文献
60.