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41.
高精度红外光点位置检测分析系统是基于光电位置敏感器件、立体测量学研制而成的运动物体分析系统。它能快速、准确地测出运动物体各特征点的瞬时位置,并在此基础上进行分析计算,给出三维坐标及针对具体应用领域的特征曲线和参数。该系统可应用于人体运动检测、外科手术定位等领域。 相似文献
42.
Power spectral analysis of the electroencephalographic and hemodynamic correlates of propofol anesthesia in the rat: Intravenous infusion 总被引:2,自引:0,他引:2
Peter P. C. Tan Ming-Hwang Shyr Chen-Hsein Yang Terry B. J. Kuo Wynn H. T. Pan Samuel H. H. Chan 《Neuroscience letters》1993,160(2):205-208
Based on the tail-flick response to noxious thermal stimuli, we determined in the present study that effective antinociception could be achieved in adult male Sprague-Dawley rats 15 min after intravenous infusion of propofol at 60 mg/kg/h. Simultaneous power spectral analysis of the electroencephalographic (EEG) and systemic arterial pressure signals further revealed a concomitant depression of the activity of all EEG frequency bands (δ, θ, , β), alongside hypotension, negative inotropic and chronotropic actions, and attenuated baroreceptor reflex and vasomotor activity. These effects were congruent with a plasma concentration of propofol in the arterial blood of 1.70 ± 0.13 μg/ml, as determined by high-performance liquid chromatography. 相似文献
43.
一个快速稳定的分割系统是研究神经元干细胞变化的基础,为完善此系统,针对多连接边缘模糊的细胞分割提取问题,根据曲线进化原理,我们提出了一种基于水平集方法的改进的几何活动轮廓算法。此算法能自动解决图像的拓扑变化,并能获得更加真实的细胞轮廓边缘。将此方法应用于神经元干细胞的序列图像分割,实验结果证明了此算法的有效性与准确性。 相似文献
44.
传统中医艾灸疗法的热辐射光谱特性的研究 总被引:6,自引:0,他引:6
采用间接测量方法研究传统中医艾灸热辐射光谱的特性,即采用光电色度计测量自燃状态下艾条的三刺激值,并在计算出色度坐标基础上,使用内插法得到艾条的色温,最后由plank公式计算得到艾条热辐射光谱特性。由测量结果得知自燃状态下艾条的热辐射光谱主要是以靠近近红外的远红外为主的光谱,其中包含可见光成份,其谱峰大约在2、8μm。 相似文献
45.
Recent electrophysiological experiments have shown that brain norepinephrine (NE) neurons in the locus coeruleus (LC) are activated by cutaneous thermal stimuli of both non-noxious and noxious character. In the present study the LC neuronal response to thermal stimuli was used to evaluate cutaneous thermal sensitivity in capsaicin-treated rats, a treatment that is described to cause impaired thermoregulation. Capsaicin treatment, of neonates as well as of adult rats, caused a reduced responsiveness of brain LC neurons to thermal stimuli. The results suggest that a reduction in peripheral thermal afferent transmission may be one mechanism underlying the capsaicin-induced thermoregulatory dysfunction. 相似文献
46.
Jean‐Marie Raquez Philippe Dege Ramani Narayan Philippe Dubois 《Macromolecular chemistry and physics.》2004,205(13):1764-1773
Summary: Various poly(ε‐caprolactone‐block‐1,4‐dioxan‐2‐one) (P(CL‐block‐PDX)) block copolymers were prepared according to the living/controlled ring‐opening polymerization (ROP) of 1,4‐dioxan‐2‐one (PDX) as initiated by in situ generated ω‐aluminium alkoxides poly(ε‐caprolactone) (PCL) chains in toluene at 25 °C. 1 1H NMR, PCS and TEM measurements have attested for the formation of colloids attributed to a growing PPDX core surrounded by a solvating PCL shell during the polymerization of PDX promoted by ω‐Al alkoxide PCL chains in toluene. The thermal behavior of the P(CL‐block‐PDX) copolymers was studied by DSC; showing two distinct melting temperatures (as well as two glass transition temperatures) similar to those of the respective homopolyesters. Finally, the thermal degradation of the P(CL‐block‐PDX) block copolymers was investigated by TGA simultaneously coupled to a FT‐IR spectrometer and a mass spectrometer for evolved gas analysis (EGA). The degradation occurred in two consecutive steps involving a first unzipping depolymerization of the PPDX blocks followed by the degradation of the PCL blocks via both ester pyrolysis and unzipping reactions.
47.
Four heterocyclic methacrylates were investigated with respect to their loss tangent and activation energy using a dynamic mechanical thermal analyser over a limited frequency range of 0.033 to 90 Hz. The linear regression lines obtained showed an Arrhenius-type relationship between transition temperature and frequency. Their low activation energies in comparison to poly (methyl methacrylate) and bis-phenol A based methacrylates was thought to be a direct consequence of their low molecular weights. 相似文献
48.
We examined developmental differences in smooth pursuit eye tracking proficiency in a large sample of preadolescent, adolescent, and adult males. Smooth pursuit was quantified using general measures of oculomotor functioning and by examining the frequency and dynamic characteristics of specific saccadic events. Examination of age effects using general measures indicated that, by late adolescence, the smooth pursuit system reached adult levels of functioning. No significant differences were found between the adolescent and adult groups on most global measures. However, both groups had better eye tracking than the preadolescent group, suggesting that during preadolescence the oculomotor system is still developing and is not yet capable of optimal performance. Examination of the frequency and dynamic characteristics of the saccadic events yielded additional information regarding the nature of the smooth pursuit eye tracking differences of the three age groups. 相似文献
49.
Heat and water vapour transfer of protective clothing systems in a cold environment,measured with a newly developed sweating thermal manikin 总被引:1,自引:0,他引:1
Fukazawa T Lee G Matsuoka T Kano K Tochihara Y 《European journal of applied physiology》2004,92(6):645-648
A moveable sweating thermal manikin has recently been developed. Thermal and water-vapour resistances of three kinds of cold-protective clothing ensembles, laminated with polytetrafluoroethylene, polyurethane and without a laminate were measured, with the aid of the manikin in a cold environment of 5°C with a relative humidity of 70% and an air velocity of around 1.5 m s–1. Two sweating rates of 65 and 130 g m–2 h–1 were employed. Supplied heat fluxes in both of the sweat rates ranged from 350 W m–2 to 400 W m–2. To maintain a comfortable condition, the skin wettedness (w) (mean weighted value) had to be kept at 0.6. The measurements obtained from the manikin when testing the three ensembles were w=0.3 (approximately) for the low sweat rate and w0.6 for the high sweat rate, irrespective of the property differences among the ensembles. In addition, the condensation in the ensembles in comparison with those calculated from an analytical equation is discussed. Condensation mass fluxes in the ensembles obtained byexperiment and those from the calculation agreed sufficiently well. Thus, distribution of the condensation in the ensembles was estimated using the equation. 相似文献
50.
Drowsiness and increased tendency to fall asleep during daytime is still a generally underestimated problem. An increased
tendency to fall asleep limits the efficiency at work and substantially increases the risk of accidents. Reduced alertness
is difficult to assess, particularly under real life settings. Most of the available measuring procedures are laboratory-oriented
and their applicability under field conditions is limited; their validity and sensitivity are often a matter of controversy.
The spontaneous eye blink is considered to be a suitable ocular indicator for fatigue diagnostics. To evaluate eye blink parameters
as a drowsiness indicator, a contact-free method for the measurement of spontaneous eye blinks was developed. An infrared
sensor clipped to an eyeglass frame records eyelid movements continuously. In a series of sessions with 60 healthy adult participants,
the validity of spontaneous blink parameters was investigated. The subjective state was determined by means of questionnaires
immediately before the recording of eye blinks. The results show that several parameters of the spontaneous eye blink can
be used as indicators in fatigue diagnostics. The parameters blink duration and reopening time in particular change reliably
with increasing drowsiness. Furthermore, the proportion of long closure duration blinks proves to be an informative parameter.
The results demonstrate that the measurement of eye blink parameters provides reliable information about drowsiness/sleepiness,
which may also be applied to the continuous monitoring of the tendency to fall asleep.
Electronic Publication 相似文献