The practical assessment of errors in sound intensity measurement

Many sources of error in two transducer sound intensity measurements have been discussed in the literature. Many of these errors are difficult to assess in a practical situation, but two in particular can be calculated. These are the error associated with phase mis-match and random error. The use of the known phase mis-match is discussed as regards its use in evaluating the quality of a particular measurement, and the use of coherence is discussed as regards its use in calculating random error.     

中性K介子系统唯象理论的修正

研究中性K介子系统的唯象理论,传统上采用的是建立在Wigner–Weisskopf近似基础上的有效哈密顿量理论.为了对此系统进行更精确地描述,采用了不作Wigner–Weisskopf近似的态演化矩阵,得到了描述此系统CP和CPT破坏的4个复参数(有效哈密顿量理论用2个复参数描述),并估计出实验精确到10^－14时,必须采用这种严格地描述,而不能再近似用有效哈密顿量理论.     

Shaping coherence function of sources used in low-coherent measurement techniques

In low-coherent measurement techniques coherence function of the source affects metrological parameters of the designed system. Hence, in many applications, it is necessary to use some techniques to change the shape of coherence function of the source. It is possible to do so by the use of optic, mechanic and electronic methods. In this article, author analyses the possibilities of shaping the coherence function of the optic source by the use of optic methods. The result of theoretical investigation and simulations will show that the use of the source with shaped coherence function can improve the metrological parameters of the designed system.     

低视力和眼镜式低视力助视器

本文阐述了低视力的概念,分析了低视力增视的光学原理,介绍了一种国内最新研制成功的远近两用系列和专用近用系列眼镜式助视器,并以若干临床病例说明了该助视器的使用效果。     

The use of acoustic cues for phonetic identification: effects of spectral degradation and electric hearing

Although some cochlear implant (CI) listeners can show good word recognition accuracy, it is not clear how they perceive and use the various acoustic cues that contribute to phonetic perceptions. In this study, the use of acoustic cues was assessed for normal-hearing (NH) listeners in optimal and spectrally degraded conditions, and also for CI listeners. Two experiments tested the tense/lax vowel contrast (varying in formant structure, vowel-inherent spectral change, and vowel duration) and the word-final fricative voicing contrast (varying in F1 transition, vowel duration, consonant duration, and consonant voicing). Identification results were modeled using mixed-effects logistic regression. These experiments suggested that under spectrally-degraded conditions, NH listeners decrease their use of formant cues and increase their use of durational cues. Compared to NH listeners, CI listeners showed decreased use of spectral cues like formant structure and formant change and consonant voicing, and showed greater use of durational cues (especially for the fricative contrast). The results suggest that although NH and CI listeners may show similar accuracy on basic tests of word, phoneme or feature recognition, they may be using different perceptual strategies in the process.     

Acoustic features of objects matched by an echolocating bottlenose dolphin

The focus of this study was to investigate how dolphins use acoustic features in returning echolocation signals to discriminate among objects. An echolocating dolphin performed a match-to-sample task with objects that varied in size, shape, material, and texture. After the task was completed, the features of the object echoes were measured (e.g., target strength, peak frequency). The dolphin's error patterns were examined in conjunction with the between-object variation in acoustic features to identify the acoustic features that the dolphin used to discriminate among the objects. The present study explored two hypotheses regarding the way dolphins use acoustic information in echoes: (1) use of a single feature, or (2) use of a linear combination of multiple features. The results suggested that dolphins do not use a single feature across all object sets or a linear combination of six echo features. Five features appeared to be important to the dolphin on four or more sets: the echo spectrum shape, the pattern of changes in target strength and number of highlights as a function of object orientation, and peak and center frequency. These data suggest that dolphins use multiple features and integrate information across echoes from a range of object orientations.     

Use and Abuse of Entropy in Biology: A Case for Caliber

Here, I discuss entropy and its use as a tool in fields of biology such as bioenergetics, ecology, and evolutionary biology. Statistical entropy concepts including Shannon’s diversity, configurational entropy, and informational entropy are discussed in connection to their use in describing the diversity, heterogeneity, and spatial patterning of biological systems. The use of entropy as a measure of biological complexity is also discussed, and I explore the extension of thermodynamic entropy principles to open, nonequilibrium systems operating in finite time. I conclude with suggestions for use of caliber, a metric similar to entropy but for time-dependent trajectories rather than static distributions, and propose the complementary notion of path information.     

Action semantics: A unifying conceptual framework for the selective use of multimodal and modality-specific object knowledge

Our capacity to use tools and objects is often considered one of the hallmarks of the human species. Many objects greatly extend our bodily capabilities to act in the physical world, such as when using a hammer or a saw. In addition, humans have the remarkable capability to use objects in a flexible fashion and to combine multiple objects in complex actions. We prepare coffee, cook dinner and drive our car. In this review we propose that humans have developed declarative and procedural knowledge, i.e. action semantics that enables us to use objects in a meaningful way. A state-of-the-art review of research on object use is provided, involving behavioral, developmental, neuropsychological and neuroimaging studies. We show that research in each of these domains is characterized by similar discussions regarding (1) the role of object affordances, (2) the relation between goals and means in object use and (3) the functional and neural organization of action semantics. We propose a novel conceptual framework of action semantics to address these issues and to integrate the previous findings. We argue that action semantics entails both multimodal object representations and modality-specific sub-systems, involving manipulation knowledge, functional knowledge and representations of the sensory and proprioceptive consequences of object use. Furthermore, we argue that action semantics are hierarchically organized and selectively activated and used depending on the action intention of the actor and the current task context. Our framework presents an integrative account of multiple findings and perspectives on object use that may guide future studies in this interdisciplinary domain.     

用光速测量仪探究蔗糖溶液折射率与浓度的关系

实验应用现有的CG-V型光速测量仪,对其测量光速的光路进行改进,测量不同浓度蔗糖溶液的折射率,并利用计算机软件（Excel）对实验的测量数据进行分析处理,得出蔗糖溶液折射率与浓度的定量关系,并加以验证,使学生能掌握光速测量仪的使用,更深刻了解透明液体折射率与浓度之间的关系。     

Spectroscopic temperature determination of aluminum monoxide in laser ablation with 266-nm radiation

We report time-resolved measurements of diatomic aluminum monoxide spectra in the study of laser ablation by the use of frequency-quadrupled 266 nm Nd:YAG laser radiation. Spectroscopic temperatures of 3432(35) K and 3329(13) K are obtained at a delay time of 20mu, respectively, by the use of the modified diatomic Boltzmann plot and by the use of the Nelder-Mead algorithm in the fitting of the recorded spectrum.     

Ultrasound in contemporary physiotherapy practice

The use of therapeutic ultrasound as an element of physiotherapy practice is well established, but the nature of that practice has changed significantly over the last 20 years. This paper aims to review the rationale and range of applications for which this modality is employed in current practice. Whereas in the past, its primary use was as a thermal modality, it is argued that currently, it is the ‘non-thermal’ aspects of the intervention that are most commonly employed. The predominant use of therapeutic ultrasound is in relation to tissue repair and soft tissue lesion management, where the evidence would support its application in the inflammatory, proliferative and remodelling phases. The clinical outcomes appear to be dose dependent, and whilst this paper does not detail dose related clinical decision making, the broad issues are considered. The future possibilities for the use of the modality are reviewed, and although outside the immediate remit of this paper, the use of therapeutic ultrasound in fracture management is briefly considered.     

NMR detection of8Li and27Si polarized by the tilted foil technique

Nuclear spin polarization created by use of the beam-tilted-foil interaction, was studied by use of asymmetric β decay and NMR detection.     

用伏安法测电阻的讨论

用伏安法测电阻时，待测电阻(Rx)在何值范围内采用内接法，Rx在何值范围内采用外接法。本就此进行讨论。     

Holographic interferometry and the fractional Fourier transformation

The fractional Fourier transform (FRT) is shown to be of potential use in analyzing the motion of a surface by use of holographic interferometry. The extra degree of freedom made available by the use of the FRT allows information regarding both translational and tilting motion to be obtained in an efficient manner.     

Use of Speech Recognition Software: A Vocal Endurance Test for the New Millennium?

Speech recognition software for the personal or office computer is a relatively new area of technology. As the number of these products has increased so has use of this software. Some individuals will employ speech recognition systems due to difficulty with the conventional keyboard and mouse interface: others will use it for perceived efficiency or simply novelty. Regardless of the reason for use of this technology, the voice demands associated with extended or frequent use can be high, placing the user at risk for vocal difficulties. This paper reviews the case of an individual referred to our multidisciplinary voice care program for evaluation and treatment of vocal difficulties that began secondary to utilization of speech recognition software. We discuss medical and vocal histories, examination findings, treatment, and treatment outcomes.