Articulatory asymmetries

Tongue contact patterns for /s/ and /l/ were investigated using dynamic palatography. Both spatial and temporal asymmetries were commonly found extending into the vocalic transitions for these consonants. Implications for the adequacy of tongue motion data taken in a single midsagittal plane are discussed, as well as for articulatory interpretation of speech signals and speaker recognition applications.     

Articulatory dynamics of loud and normal speech

A comparison was made between normal and loud productions of bilabial stops and stressed vowels. Simultaneous recordings of lip and jaw movement and the accompanying audio signal were made for four native speakers of Swedish. The stimuli consisted of 12 Swedish vowels appearing in an /i'b_b/ frame and were produced with both normal and increased vocal effort. The displacement, velocity, and relative timing associated with the individual articulators as well as their coarticulatory interactions were studied together with changes in acoustic segmental duration. It is shown that the production of loud as compared with normal speech is characterized by amplification of normal movement patterns that are predictable for the above articulatory parameters. In addition, it was observed that the acoustic durations of bilabial stops were shortened, whereas stressed vowels were lengthened during loud speech production. Two interpretations of the data are offered, viewing loud articulatory behavior as a response to production demands and perceptual constraints, respectively.     

Articulatory and acoustic adaptation to palatal perturbation

Previous work has established that speakers have difficulty making rapid compensatory adjustments in consonant production (especially in fricatives) for structural perturbations of the vocal tract induced by artificial palates with thicker-than-normal alveolar regions. The present study used electromagnetic articulography and simultaneous acoustic recordings to estimate tongue configurations during production of [s s? t k] in the presence of a thin and a thick palate, before and after a practice period. Ten native speakers of English participated in the study. In keeping with previous acoustic studies, fricatives were more affected by the palate than were the stops. The thick palate lowered the center of gravity and the jaw was lower and the tongue moved further backwards and downwards. Center of gravity measures revealed complete adaptation after training, and with practice, subjects' decreased interlabial distance. The fact that adaptation effects were found for [k], which are produced with an articulatory gesture not directly impeded by the palatal perturbation, suggests a more global sensorimotor recalibration that extends beyond the specific articulatory target.     

Detectors for monolithic optoelectronics

In this paper, we present data on the electrical characteristics and the optical response of photodetectors integrated on GaAs substrates with FET devices. We compare the differences between devices fabricated on globally implanted areas versus the undoped semi-insulating regions of the same wafer.     

Detectors for monolithic optoelectronics

In this paper, we present data on the electrical characteristics and the optical response of photodetectors integrated on GaAs substrates with FET devices. We compare the differences between devices fabricated on globally implanted areas versus the undoped semi-insulating regions of the same wafer.     

Photon Detectors are Catching Up

Over the last 10 years, we have seen a paradigm change in the approach towards detector developments for accelerator-based X-ray science. Until the last decade, scientists at light sources used or adapted detectors that had been developed for entirely different applications, such as astronomy or medical imaging. Undisputedly, these systems made it possible to do state-of-the-art science, and as long as the source brilliance kept increasing exponentially, new science and new areas developed. However, it is also beyond doubt that these adopted detection systems were not able to get the most out of the source potential. The few dedicated development projects that were undertaken never managed to have a significant impact.     

Articulatory correlates of stress and speaking rate in Swedish VCV utterances

Articulatory activity underlying changes in stress and speaking rate was studied by means of x-ray cinefilm and acoustic speech records. Two Swedish subjects produced vowel-consonant-vowel (VCV) utterances under controlled rate-stress conditions. The vowels were tense (i a u), and the consonants were the voiceless stops, notably (p). The spectral characteristics of the vowels were not significantly influenced by changes in the speaking rate. They were, however, significantly emphasized under stress. At the articulatory level, stressed vowels displayed narrower oral tract constrictions than unstressed vowels at the two speaking rates studied. At the faster speaking rate, vowel- and consonant-related gestures were coproduced to a greater extent than at the slower rate. The data, failing to produce evidence for an "undershoot" mechanism, support the view that dialect-specific correlates of stress are actively safeguarded by means of articulatory reorganization.     

多环型半导体探测器的研制

为了改进低能次级束逆运动学核反应角分布的测量，研制了空心的多环型半导体探测器，用来取代沿用多年的X-Y位置灵敏型半导体探测器. 论述了多环型探测器的优越性，介绍了其制作过程和工艺，给出了已研制成功的十一环探测器的性能测试结果.     

Articulatory movement characteristics of labial consonant productions by children and adults

One purpose of the present investigation was to attempt to better understand articulatory movement characteristics of children's speech, particularly as they might relate to the question of why acoustic measures of children's segment durations are often longer than those of adults. In order to address this issue and to consider other general characteristics of children's speech production development, a variety of data was obtained from three groups of children and from a group of adults using strain gauge instrumentation to monitor superior-inferior lip and jaw displacement and peak velocity. Results indicate that the children's peak velocity and articulatory displacement measures were in many respects quite similar to those of the adults, although certain differences were observed. For a number of measures, there were also few peak velocity or displacement differences observed among the three age groups of children, despite the fact that they spanned about a six-year age range. In general, it appears that even when children and adults produce consonant sounds that are perceptually "correct," articulatory differences can be observed among their productions.     

Dense Baryonic Matter and Neutron Detectors

Promising approaches and methods for studying nuclear matter at high baryonic densities and low temperatures are discussed.     

Detectors for nuclear resonant scattering experiments

Ferrite samples of Zn_0.5Cu_0.5Al _x Fe_2?x O₄, 0≤x≤1 were studied using Mössbauer, X-ray and infrared spectra. Mössbauer spectra taken at room temperature show signs of relaxation for all samples. The obtained spectra were analysed into two Zeeman magnetic patterns assigned to the tetrahedral A- and octahedral B-sites and a paramagnetic phase C (quadrupole doublet ΔE). ΔE and the doublet area, which increase with x and the oxygen parameter u are studied. The quadrupole shift is small and may be ignored within experimental error. The isomer shift of the B-sites increases, with x while that of the A-sites does not change. The hyperfine magnetic field of the A-site (H _A) is higher than that of the B-sites (H _B). H _B decreases for x≤0.8 and increases at x=1 while H _A decreases for x≤0.4 and increases for x>0.4. This behaviour is discussed. The cation distribution has been estimated. The linewidth of the outermost A and B-sites and the calculated magnetization have been studied as functions of x for all samples. The B-sites show a composite pattern that has been successfully analysed into separate components. The obtained hyperfine parameters are discussed. The oxygen parameter, the ionic radius and the metal-oxygen bonds of the A- and B-sites were calculated for all samples. The infrared spectra show three vibration bands υ₁, υ₂ and υ₄. The bands υ₁ and υ₂ show a shoulder, splitting and increasing overlap. Their behaviour has been discussed as a function of x. They show the same behaviour of magnetization and area ratio as the B- to A-sites. All parameters show a different behaviour at x=0.4, which is assigned to higher fraction of the Cu²⁺ ions in the A-site at this composition.     

M-Mode Color Doppler Ultrasonic Imaging of Vertical Tongue Movement During Articulatory Movement

To observe and estimate the movement of the tongue, ultrasonic investigation is the most harmless real-time monitoring procedure for analyzing articulatory movements. Color Doppler ultrasonic imaging is special in that it can only sample a moving target, and it can indicate the velocity and direction of the target by color and brightness in real time. This study assessed and demonstrated the validity of M-mode color Doppler ultrasonic imaging to observe the movements of the tongue during syllable repetition tasks performed by normal subjects and dysarthric patients, those affected by amyotrophic lateral sclerosis, cerebellar ataxia, Parkinsonism, and polymyopathy. When the transducer was set below the jaw, upward movement was indicated by a blue signal and downward movement was indicated by a red one on the screen of the ultrasound machine. We also measured the velocity of the tongue by contrast scale classified by 15 degrees. Thus, we could observe vertical tongue movement by a color-coded pattern after quantitative analysis. The Doppler signal patterns of normal subjects were verified by simultaneous video x-ray fluorography recordings. The findings for dysarthric patients corresponded well with previously reported features analyzed by other methods. Therefore, color Doppler ultrasonic imaging of the tongue is a useful procedure to researchers for clinical speech and voice studies.     

双面硅多条探测器的测试

介绍了由中国科学院近代物理研究所和北京大学微电子研究院联合研制的双面硅多条探测器的初步测试过程及测试结果。测试内容包括: 探测器的电特性、 能量分辨率、 二维能谱、 条间串扰（crosstalk）。在-25 V全耗尽偏压下, 各条的反向漏电流均小于10 nA, 对于5.486 MeV的α粒子, 正面各条的能力分辨率在1.5%左右, 条间串扰在6%左右; 背面各条能量分辨率稍差, 在3%左右, 其条间串扰在1%左右。同时对进口的Micron BB1直流耦合单边读出的双面硅条探测器做了相同测试, 并进行了性能对比。The testing of a doubled-sided multi-strip silicon detector manufactured by Institute of Modern Physics of CAS and Peking University were introduced. The electrical characteristics and energy resolution, two dimensional spectrum, crosstalk were presented. The reverse leak current of each strip is smaller than 10 nA under bias voltage of 25 V. The energy resolution of strips on the front side is about 1.5%, but a little worse for the backside strips, about 3%. The level of crosstalk is about 6% for the front side, 1% for the backside. Same tests were carried out on the commercial Micron BB1 detector and a comparison was presented.     

GaN基PIN结构X射线探测器

使用GaN基材料制备了PIN结构核辐射探测器,研究了探测器对x射线响应的多方面性能.在没有X射线照射时,探测器具有很小的漏电流,在-10 V时小于0.1nA.对探测器的X射线的响应时间特性进行了分析和模拟,给出了很好的物理机制解释.研究了信噪比随外加偏压的变化,并得到了最佳信噪比对应的工作电压为-20 V.     

Calibration of Photoelectric Pulsed Radiation Detectors

Russian Physics Journal - A method for calibrating a photodiode intended for high-intensity radiation pulse detection using continuous lighting lamps is described. The method is based on the use of...     

Articulatory tradeoffs reduce acoustic variability during American English /r/ production.

The American English phoneme /r/ has long been associated with large amounts of articulatory variability during production. This paper investigates the hypothesis that the articulatory variations used by a speaker to produce /r/ in different contexts exhibit systematic tradeoffs, or articulatory trading relations, that act to maintain a relatively stable acoustic signal despite the large variations in vocal tract shape. Acoustic and articulatory recordings were collected from seven speakers producing /r/ in five phonetic contexts. For every speaker, the different articulator configurations used to produce /r/ in the different phonetic contexts showed systematic tradeoffs, as evidenced by significant correlations between the positions of transducers mounted on the tongue. Analysis of acoustic and articulatory variabilities revealed that these tradeoffs act to reduce acoustic variability, thus allowing relatively large contextual variations in vocal tract shape for /r/ without seriously degrading the primary acoustic cue. Furthermore, some subjects appeared to use completely different articulatory gestures to produce /r/ in different phonetic contexts. When viewed in light of current models of speech movement control, these results appear to favor models that utilize an acoustic or auditory target for each phoneme over models that utilize a vocal tract shape target for each phoneme.