瓷乐器声学机理的实验设计与研究

对瓷乐器的发声机理,瓷乐器的音高、音色的影响因素、音位排列进行研究,使学生在陶冶情操的同时,学习声音传感器对振动体固有频率的测量方法,提高对物理实验的兴趣.并对瓷乐器的生产和改良起到一定的借鉴作用.     

复杂谐波信号中响度和谱质心的相互影响——响度和谱质心辨别阈的实验研究

根据阈值测量实验和变化一致性测量实验,在单自变量干扰和双自变量干扰两种情况下量化分析响度和谱质心之间的交互关系。研究发现:(1)复杂谐波信号中谱质心对响度的影响强于响度对谱质心的影响;(2)声音的变化方向对被试判断响度和谱质心的阈值存在影响。研究结果进一步呈现了响度和谱质心的定量特征,为听觉属性交互关系的深入研究提供了新的思路。     

笙的簧片物理参数与音色相关性的初步研究

为了改善笙的声音品质,本文研究了笙的簧片物理尺度与笙的音色之间的相关性。在提出笙的物理模型并验证其有效性的基础上,固定音高,改变簧舌的厚度、长度以及缝隙宽度,合成一组笙的声样本。通过对偶比较法以及多维尺度法分析笙的音色空间,根据簧舌参数及音色特征量解释该音色空间的物理意义,并从发声原理比较簧舌参数对音色的作用。结果表明,音高一定时,簧舌宽度对音色的作用可忽略,厚度(及长度)和缝隙宽度对音色的作用相似,但影响方式不同。改变簧舌物理参数所形成的二维音色空间与声音的对数起振时间、频谱丰富性以及频谱不规则度有关。起振特征与频谱丰富性特征存在共变关系,通过改变这两个特征,能够改变音色的明亮度和柔软度。     

五种典型硝基苯胺类炸药的静电势与撞击感度的关系研究

利用HONDO程序包,采用从头算法对硝基苯胺类炸药的分子结构和电偶极矩等性质以及 C-NO2键中点静电势等进行计算,讨论了硝基苯胺类炸药C-NO2键中点静电势最大值Vmidmax与其实验撞击感度之间的关系.研究表明:对于硝基苯胺类炸药,不宜单独用C-NO2键中点静电势最大值Vmidmax来表征撞击感度的变化,但可以用静电势最大值Vmidmax与电偶极矩的积来确定其撞击感度的变化趋势,讨论了硝基和胺基的相对位置以及硝基和胺基的数目对这类炸药感度的影响.     

金融动力学的时空关联与大波动特性——兼谈中西方金融市场的对比研究

文章扼要地评述了金融物理学研究进展,介绍了文章作者在金融动力学时空关联方面的最新研究成果,特别关注中西方金融市场的对比研究.唯象理论研究表明,西方金融市场的价格收益率和波动率的时间关联显示杠杆效应,而中国金融市场则显示反杠杆效应;一种价格收益率和波动率的反馈相互作用可以解释杠杆和反杠杆效应的起源.西方金融市场的个体股票价格的交叉关联呈现标准的行业板块结构,而中国金融市场展示的是一种特殊的板块结构,如"ST板块"和"蓝筹板块"等.股票价格大波动可分为动力学内部产生的和外部事件诱导的两大类.金融动力学的时间反演不对称性,主要来源于外部事件诱导的大波动.     

金融动力学的时空关联与大波动特性——兼谈中西方金融市场的对比研究

文章扼要地评述了金融物理学研究进展,介绍了文章作者在金融动力学时空关联方面的最新研究成果,特别关注中西方金融市场的对比研究.唯象理论研究表明,西方金融市场的价格收益率和波动率的时间关联显示杠杆效应,而中国金融市场则显示反杠杆效应;一种价格收益率和波动率的反馈相互作用可以解释杠杆和反杠杆效应的起源.西方金融市场的个体股票价格的交叉关联呈现标准的行业板块结构,而中国金融市场展示的是一种特殊的板块结构,如“ST板块”和“蓝筹板块”等.股票价格大波动可分为动力学内部产生的和外部事件诱导的两大类.金融动力学的时间反演不对称性,主要来源于外部事件诱导的大波动.     

Perceived pitch of whispered vowels-relationship with formant frequencies: A preliminary study

To clarify the role of formant frequency in the perception of pitch in whispering, we conducted a preliminary experiment to determine (1.) whether speakers change their pitch during whispering; (2.) whether listeners can perceive differences in pitch; and (3.) what the acoustical features are when speakers change their pitch. The listening test of whispered Japanese speech demonstrates that one can determine the perceived pitch of vowel /a/ as ordinary, high, or low. Acoustical analysis revealed that the perception of pitch corresponds to some formant frequencies. Further data with synthesized whispered voice are necessary to confirm the importance of the formant frequencies in detail for perceived pitch of whispered vowels.     

Influence of pitch, loudness, and timbre on the perception of instrument dynamics

The effect of variations in pitch, loudness, and timbre on the perception of the dynamics of isolated instrumental tones is investigated. A full factorial design was used in a listening experiment. The subjects were asked to indicate the perceived dynamics of each stimulus on a scale from pianissimo to fortissimo. Statistical analysis showed that for the instruments included (i.e., clarinet, flute, piano, trumpet, and violin) timbre and loudness had equally large effects, while pitch was relevant mostly for the first three. The results confirmed our hypothesis that loudness alone is not a reliable estimate of the dynamics of musical tones.     

光学萌芽时期的科学思维与中西文明对比

围绕科学教育的目的,通识课程“众说有光”模块基于中西方光学萌芽时期的发展史实现教学设计,引导学生了解人类历史早期不同社会群体对光学基本问题从主观认识向客观理解的演变过程,探究该时期光学理论体系的发展状况,思考中西文明对科学思维形成、研究方法演变等方面的影响,并从多学科的视角了解光学发展与人类文明的联系.     

The external frame function in the control of pitch, register, and singing mode: Radiographic observations of a female singer

This study investigates pitch control, register, and singing mode related movements of the laryngo-pharyngeal structures by radiographic methods. One trained female singer served as the subject. The results show that singing voice production involves complex movements in the laryngeal structures. Pitch related increase in the thyro-arytenoid distance (vocal fold length) is nonlinear, slowing down as pitch rises. Similar observations have been made earlier. At the highest pitches, a shortening of the distance can be seen, suggesting the use of alternative pitch control mechanisms. The various observations made support the existence of three registers in this trained female singing voice. Open and covered modes of singing seemed to be distinguishable on the basis of different amounts of inner and outer forces acting on the larynx. Therefore, caution must be exercised when generalizing from the results.     

火焰原子吸收法测定10种中成药中钠、铬、镍、锰和镁的含量

采用火焰原子吸收分光光度法测定10种中成药物中Na,CR,Ni,Mn和Mg五种金属元素的含量。结果显示，药物中金属元素含量丰富，但含量具有一定差异。其中含Na元素最多的是脑塞通；Mg元素含量最高的是中风回春片；Mn元素含量最高的是强力天麻杜仲丸；而消栓通络胶囊中Cr,Ni含量较高。测定结果为探讨中药微量元素与治疗脑血管疾病的关系提供了有用的数据。     

Effect of listening level and background noise on the subjective decay rate of room impulse responses: Using time-varying loudness to model reverberance

Room impulse responses (RIRs) are used very widely to characterize the acoustic conditions of rooms, such as in the derivation of reverberation time, early decay time and clarity index. This study investigates the subjective decay rate (or reverberance) of RIRs when directly listened to (rather than convolved with a dry signal such as speech or music). Through a subjective experiment, it investigates the effects of gain (or listening level) and background noise level on the reverberance of RIRs that had been measured in three concert auditoria. The task of the experiment was to match the decay rate of RIRs to that of a reference RIR by ear, by adjusting the RIRs’ exponential decay rate. Based on objective loudness modeling, gain should have a positive effect on reverberance, and background noise has a negative effect. This is confirmed in the results of the experiment. Furthermore, the objectively calculated loudness decay function provides an effective predictor of subjective decay rate, which performs better than conventional early decay time or reverberation time for the RIRs tested.     

Effects of a professional solo singer education on auditory and kinesthetic feedback—a longitudinal study of singers'' pitch control

The significance of auditory and kinesthetic feedback to pitch control in singing was described in a previous report of this project for students at the beginning of their professional solo singer education.(1) As it seems reasonable to assume that pitch control can be improved by training, the same students were reinvestigated after 3 years of professional singing education. As in the previous study, the singers sang an ascending and descending triad pattern with and without masking noise in legato and staccato and in a slow and a fast tempo. Fundamental frequency and interval sizes between adjacent tones were determined and compared with their equivalents in the equally tempered tuning. The average deviations from these values were used as estimates of intonation accuracy. Intonation accuracy was reduced by masking noise, by staccato as opposed to legato singing, and by fast as opposed to slow performance. The contribution of the auditory feedback to pitch control was not significantly improved after education, whereas the kinesthetic feedback circuit was improved in slow legato and slow staccato tasks. The results support the assumption that the kinesthetic feedback contributes substantially to intonation accuracy.     

The interaction of formant frequency and pitch in the perception of voice category and jaw opening in female singers

This study represents a first step toward understanding the contribution formant frequency makes to the perception of female voice categories. The effects of formant frequency and pitch on the perception of voice category were examined by constructing a perceptual study that used two sets of synthetic stimuli at various pitches throughout the female singing range. The first set was designed to test the effects of systematically varying formants 1 through 4. The second set was designed to test the relative effects of lower frequency formants (F1 and F2) versus higher frequency formants (F3 and F4) through construction of mixed stimuli. Generally, as the frequencies of all four formants decreased, perception of soprano voice category decreased at all but the highest pitch, A5. However, perception of soprano voice category also increased as a function of pitch. Listeners appeared to need agreement between all four formants to perceive voice categories. When upper and lower formants are inconsistent in frequency, listeners were unable to judge voice category, but they could use the inconsistent patterns to form perceptions about degree of jaw opening.     

治疗胃炎中成药物中锌、铜、铁、锰的含量分析

用原子吸收分光光度法测定了7种治疗胃炎中成药物中Zn,Cu,Fe,Mn的含量。结果表明,药物中Zn,Fe,Mn含量丰富,Cu元素含量较少。探讨了微量元素与胃炎发病因素的关系。它为探讨药物中微量元素与治疗胃肠道炎症的关系提供了有用的参考数据。     

Saturation mechanism in clarinet-like instruments, the effect of the localised non-linear losses

The question of what limits the amplitude of the oscillations of clarinet-like instruments is investigated. The study is based on numerical simulations in which two kind of losses are taken into account: linear losses and non-linear losses localised at the open end of the tube. The influence of the amount of losses on the saturation process and on the playing range of clarinet-like instruments is shown. Results are confirmed by experiments using an artificial mouth in which the non-linear losses are varied using several terminations with different geometries.