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431.
高玉良 《新疆大学学报(理工版)》2000,17(1):10-15
给出由等价关系的提升确定的商拓扑与超拓扑,距离拓扑之间的相等或同胚的新结果,建立了映射与其提升在拓扑熵方面的联系,关于连续映射的提升本文减弱了文「6」中相应定理的条件。 相似文献
432.
We study the quasilinear elliptic problem with multivalued terms.We consider the Dirichlet problem with a multivalued term appearing in the equation and a problem of Neumann type with a multivalued term appearing in the boundary condition. Our approach is based on Szulkin's critical point theory for lower semicontinuous energy functionals. 相似文献
433.
The relationship of lung pressure, fundamental frequency, peak airflow, open quotient, and maximal flow declination rate to vocal intensity for a normal speaking, young male control group and an elderly male group was investigated. The control group consisted of 17 healthy male subjects with a mean age of 30 years and the elderly group consisted of 11 healthy male subjects with a mean age of 77 years. Data were collected at three levels of vocal intensity: soft, comfortable, and loud, corresponding to 25%, 50%, and 75% of dynamic range, respectively. Phonational threshold pressure and lung pressure were obtained using the intraoral technique. The oral airflow waveform was inverse filtered to provide an approximation to the glottal airflow waveform from which measures of fundamental frequency, peak airflow, open quotient, and maximal flow declination rate were determined. Excess lung pressure was calculated as lung pressure minus estimated phonational threshold pressure. The results show for both groups an increase in sound pressure level across the conditions, with corresponding increases in lung pressure, excess lung pressure, fundamental frequency, peak airflow, and maximal flow declination rate. Open quotient decreased with increasing vocal intensity. Lung pressure, sound pressure level, and peak airflow were all found to be significantly greater for the control group than for the elderly group at each condition. Open quotient was found to be significantly lower in the control group than in the elderly group at each condition. No significant difference was observed for excess lung pressure, phonational threshold pressure, fundamental frequency, or maximal flow declination rate between the two groups. These results show that a difference in vocal intensity does exist between young and elderly voices and that this difference is the result of differences in lung pressure, peak airflow, and open quotient. 相似文献
434.
Regular monomorphisms in the category of Hausdorff frames are characterized by means of a naturally defined closure operator; this is used also to characterize the epimorphisms. Further it is shown that for spatial (strongly) Hausdorff frames the regular monomorphisms do not generally coincide with the quotients, and do not generally compose. Also, an additional property (under which regular monomorphisms do compose) is briefly studied. 相似文献
435.
直觉模糊正规子群与直觉模糊商群 总被引:5,自引:0,他引:5
在直觉模糊子群的基础上 ,引入直觉模糊正规子群与直觉模糊商群概念 ,并讨论了它们的一些性质 ,最后研究了群同态下 ,直觉模糊正规子群的对应关系 相似文献
436.
学龄儿童智商与微量元素含量关系研究 总被引:4,自引:0,他引:4
黄建香 《广东微量元素科学》2001,8(8):24-27
为了解头发微量元素含量与学龄儿童智商之间的关系,本文测定了深圳市某小学570名7-13岁低智商儿童和正常儿童的IQ值及其头发中七种元素(I、Zn、Fe、Cu、Ca、Mn、Pb)的含量,并对低智商儿童及正常儿童头发中的元素含量作了比较。结果表明,低智商儿童头发碘、锌、钙的含量显著低于正常儿童头发中的含量,而发铅则显著高于正常儿童的含量。说明儿童智商高低与机体碘、锌、钙以及铅的含量有密切关系。 相似文献
437.
离散变量框架结构的可靠性优化 总被引:1,自引:0,他引:1
以框架结构系统的可靠性分析为基础,给出离散变量框架结构可靠性优化的相对差商方法及迭代格式,并用算例证明了该法的有效性及实用性。 相似文献
438.
For the complete algebra of two-dimensional Töplitz operators with measurable bounded symbols, we establish conditions necessary for the Fredholm property of the operators and prove results on the separation of singularities of the symbols. As a corollary, conditions sufficient for the Fredholm property are established for operators with symbols satisfying local conditions of sectorial type. 相似文献
439.
The normalized amplitude quotient (NAQ), defined as the ratio between the peak-to-peak amplitude of the flow pulse and the negative peak amplitude of the differentiated flow glottogram and normalized with respect to period time, has been shown to be related to glottal adduction. Glottal adduction, in turn, affects mode of phonation and hence perceived phonatory pressedness. The relationship between NAQ and perceived phonatory pressedness was analyzed in a material collected from a professional female singer and singing teacher who sang a triad pattern in breathy, flow, neutral, and pressed phonation in three different loudness conditions (soft, middle, loud). In addition, she also sang the same triad pattern in four different styles of singing, classical, pop, jazz, and blues, in the same three loudness conditions. A panel of experts rated the degree of perceived phonatory press along visual analogue scales. Comparing the obtained mean rated pressedness ratings with the mean NAQ values for the various triads showed that about 73% of the variation in perceived pressedness could be accounted for by variations of NAQ. 相似文献
440.
In this paper we consider the formally symmetric differential expressionM [.] of any order (odd or even) ≥ 2. We characterise the dimension of the quotient spaceD(T
max)/D(T
min) associated withM[.] in terms of the behaviour of the determinants det [[f
rgs](∞)] where 1 ≤n ≤ (order of the expression +1); here [fg](∞) = lim [fg](x), where [fg](x) is the sesquilinear form in f andg associated withM. These results generalise the well-known theorem thatM is in the limit-point case at ∞ if and only if [fg](∞) = 0 for everyf, g ε the maximal domain Δ associated withM. 相似文献