人耳听阈曲线的测定实验设计

为了医学生物理实验的改革创新,我实验室引进了BD-Ⅱ-116型听觉实验仪,为学生开设＂人耳听阈曲线的测定＂的医用物理实验,在此给出声强级、听阈曲线、响度等概念,设计目的、实验器材、实验原理、实验内容与步骤等,学生通过本实验掌握了实验理论,同时对医学内容也有了一定了解。     

利用实验曲线计算液体比热容的方法

电热法测液体比热容的实验中，由于量热器系统并非一个真实的绝热系统，在低于外界环境温度和高于外界环境温度时，量热器和外界环境之间存在不等的热量交换；同时由于量热器的散热系数是一未知的常数，对其散热不能进行修正，导致实验结果和标准值之间有较大的偏差．本文介绍的利用实验曲线计算液体比热容的方法，可以消除由于散热对实验的影响，得到比较准确的实验结果．一、计算原理由热力学第一定律可知，待测液体在外界环境温度T0附近在dt时间内所吸收的热量dQ应等于它从电热丝吸收的热量式中V、I分别为加热电阻丝两端的电压及其中的…     

如何选择弗兰克-赫兹实验的工作参量

分析了弗兰克-赫兹管中灯丝电压VF、第一栅极电压VG1K、拒斥电压VG2A对实验曲线的影响,进而探讨弗兰克-赫兹实验的最佳实验条件,得到了一些有价值的规律,对实验有一定的指导作用。     

关于Michelson—Morley实验曲线的分析

一、引言 1887年,迈克耳孙同莫雷合作,更新了他在1881年所设计的干涉仪,进行了一项测量地球上“以太风”的著名实验,试图证实绝对静止“以太”的许在。同年秋,他们联合署名发表了题为“论地球与光以太的相对运动”的论文,将这项实验及其结果公诸于世。在这篇论文中,记载了他们由实验观测值和预期理论值画出的曲线(图1)。     

物理实验的计算机模拟

我们通过第二课堂、毕业实习等方式,参与物理实验计算机模拟课件的研制.通过这种实践活动有效地培养了集体主义和协作精神、科学态度和钻研精神,综合素质得到提高.下面是一些体会.     

利用Origin软件对大学物理实验数据进行曲线分析的两个实例

通过两个具体的实验例子介绍Origin软件对数据曲线进行分析的一些功能,以便更好地运用Origin软件于大学物理实验数据曲线分析中。     

椭圆偏振光直接实验证的数据处理方法

从理论上分析了大学物理吉有关在椭圆偏振光实验里得不到椭圆曲线的原因,提出了得到椭圆曲线的数据处理方法。     

2006年高考电学实验的考查特点及趋势

2006年高考中对实验的考查仍然以电学为主，力学为辅．总体上说，电学实验又以电阻的测量为主线，围绕测量电源的电动势和内阻以及小灯泡的伏安特性曲线为主要的测量而设计题目．通过三种方式考查考生对电阻测量的认识：首先，也是最主要的，能够从题目给出实验原理中选取合理的，并采取合理的实验步骤来实施测量；其次，像往年一样，能够结合题中实验器材设计出合理的实验原理；最后，使用多用电表测量电阻，如重庆和天津卷考题．分析全国卷和各自主命题省份的考卷，2006年电学实验又呈现下面的四个特点．     

用自制仪器测热敏电阻的特性曲线

随着教育条件的不断改善，学生实验仪器正在向着集成化、智能化方向发展，仪器外观漂亮，价格昂贵操作简便，造成学生做实验时动手的机会越来越少．由于很多物理量的变化被智能化以数字的形式表现出来，不利于学生对实验现象的理解与基本能力的培养．教育部对基础实验教学的目标是：基本知识、基本方法、基本技能方面得到严格而系统的训练，因此，实验仪器越简单、越暴露、越直观对学生的“三基”培养效果应该就越好．     

快速电子验证相对论效应实验中几个问题的分析

快速电子验证相对论实验是近代物理实验中一个极其重要的实验，本对实验得到的能谱曲线中的两个峰作了详细分析，并证明该实验不仅可以用来验证相对论，也可以用来验证全同粒子的不可分辨性以及X射线特征谱线与入射电子能量无关，只与靶材料有关的理论。     

Elements of reality,Lorentz invariance,and the product rule

Recently various gedankenexperiments have been formulated which argue that the assumption that elements of reality are Lorentz invariant cannot be reconciled with standard quantum mechanics. Two of these gedankenexperiments were subsequently analyzed using the notion of pre- and postselected quantum systems, and it was claimed that elements of reality can be made Lorentz invariant if the product rule of standard quantum mechanics is abandoned. In this paper we show that the apparent violations of the product rule in these gedankenexperiments are not as significant as they appeared to be in the previous analysis. We conclude that the problems with Lorentz invariance which arise in these gedankenexperiments are essentially unrelated to the product rule violations.     

"电场生物学效应"引入大学物理实验教学的探讨

为培养学生创新意识和能力,实现物理实验教学现代化,本文介绍了将“电场生物学效应”科研工作中取得的部分成果引入大学物理实验教学的一些尝试。     

Acoustical characteristics of water sounds for soundscape enhancement in urban open spaces

The goal of the present study is to characterize water sounds that can be used in urban open spaces to mask road traffic noise. Sounds and visual images of a number of water features located in urban open places were obtained and subsequently analyzed in terms of psychoacoustical metrics and acoustical measures. Laboratory experiments were then conducted to investigate which water sound is appropriate for masking urban noise. The experiments consisted of two sessions: (1) Audio-only condition and (2) combined audio-visual condition. Subjective responses to stimuli were rated through the use of preference scores and 15 adjectives. The results of the experiments revealed that preference scores for the urban soundscape were affected by the acoustical characteristics of water sounds and visual images of water features; Sharpness that was used to explain the spectral envelopes of water sounds was proved to be a dominant factor for urban soundscape perception; and preferences regarding the urban soundscape were significantly related to adjectives describing "freshness" and "calmness."     

The power of thought experiments

According to popular opinion, thought experiments are limited in scope, since no novel empirical results could be expected to be produced by thought alone. Yet consider the spectacular 16th century experiment by Stevin. leading to the discovery of the principles of the resolution and combination of forces. He conducted no experiments, for he derived his novel and highly important conclusions by several steps of ingenious reasoning alone. To understand why mental experiments may serve as very effective scientific tools. we need to explicate carefully their underlying mechanism. Thought experiments invariably involve the widely debated notion of counterfactual conditionals. A variety of historical examples are offered designed to illustrate the nature of thought experiments, their associated counterfactual conditionals. as well a the nature of the vital link between the two.     

Evoked magnetoencephalographic responses to omission of a tone in a musical scale

The musical scale is a basis for melodies and can be a simple melody by itself. The present study investigated magnetoencephalographic (MEG) responses to omissions of one tone out of the C major scale. The tone preceding the omitted "target" tone was either prolonged or repeated. In another series, the tone after the target tone was repeated. In "normal" oddball experiments, the complete C major scale was presented more frequently than an incomplete scale lacking one tone, and in "reverse" oddball experiments, the roles were exchanged. In the normal oddball experiments, omission of any tone produced a response significantly different in amplitude from the standard response in the group of non-musicians, although the responses differed depending on the types of omission. The leading tone (B in the C major scale) was shown to elicit a large response when omitted and also when its presence was emphasized. The Reverse oddball experiments showed that repeated presentation of an incomplete scale lacking one tone temporarily reduced the influence of the complete scale but could not even temporarily replace it working as "standard." In addition, an auxiliary study was done to see possible influence of rhythmic variations.     

“猫眼效应”影响因素的分析与验证

以自制透镜组、水准仪和加农炮瞄准镜为例,对影响"猫眼反射效应"回波的主要因素进行实验验证,实验结果表明:在近距离实验室条件下,"猫眼"效应受光学系统中反射面离焦、扫描光束的入射角影响很大。     

A dual-mode microwave resonator for double electron-electron spin resonance spectroscopy at W-band microwave frequencies

We present a dual-mode resonator operating at/near 94 GHz (W-band) microwave frequencies and supporting two microwave modes with the same field polarization at the sample position. Numerical analysis shows that the frequencies of both modes as well as their frequency separation can be tuned in a broad range up to GHz. The resonator was constructed to perform pulsed ELDOR experiments with a variable separation of "pump" and "detection" frequencies up to Δν=350 MHz. To examine its performance, test ESE/PELDOR experiments were performed on a representative biradical system.     

The role of perceived speaker identity in F0 normalization of vowels

In the experiments reported here, perceived speaker identity was controlled by manipulating the fundamental frequency (F0) range of carrier phrases in which speech tokens were embedded. In the first experiment, words from two "hood"-"hud" continua were synthesized with different F0. The words were then embedded in synthetic carrier phrases with intonation contours which reduced perceived speaker identity differences for test items with different F0. The results indicated that when perceived speaker identity differences were reduced, the effect of F0 on vowel identification was also reduced. Experiment 2 indicated that when items presented in carrier phrases are matched for speaker identity and F0 with items in isolation, there is no effect for presentation in a carrier phrase. Experiment 3 involved the presentation of vowels from the "hood"-"hud" continuum in two different intonational contexts which were judged to have been produced by different speakers, even though the F0 of the test word was identical in the two contexts. There was a shift in identification as a result of the intonational context which was interpreted as evidence for the role of perceived identity in vowel normalization. Overall, the experiments suggest that perceived speaker identity is a better predictor of vowel normalization effects than is intrinsic F0. This indicates that the role of F0 in vowel normalization is mediated through perceived speaker identity.