次声试验系统及次声对人体生理功能影响的试验方法

研制了一种在试验室内可提供次声环境的次声舱,测量的次声波特性曲线和其空间均匀性表明,在6~20Hz频率范围内的试验结果是令人满意的。设计的次声对人体生理功能影响的试验研究方法具有可行性。     

Robust adaptive matched field processing with sector eigenvector constraints

Standard adaptive beamforming or matched field processing requires accurate replica fields finely gridded over the search parameter space for localization with sidelobe control. This paper presents an Adaptive Matched Field Processing (AMFP) algorithm, which aims at gaining robustness for the environmental mismatch, and simultaneously reducing the real-time computational load. The new method integrates the merits of several AMFP beam-formers with neighboring location constraints, environmental perturbation constraints and sector focusing constraints. The robustness and effectiveness of the suggested algorithm has been illustrated through the numerical simulation and the experimental Mediterranean benchmark shallow-water data.     

The acoustic characteristics of clause, sentence and paragraph boundaries in Chinese Putonghua

The acoustic and perceptive characteristics of discourse units, including clauses, simple sentences, compound sentences and paragraphs, were studied. The acoustic characteristics were based on the analysis of a speech corpus consisted of ten monologues. The Perceived Boundary Strength (PBS) of the monologues was labeled on a five-point scale by 25 participants. The main results are as follows: (1) There is a significant difference in the PBS of clauses (corresponding to intonational phrase), sentences (including simple sentences and compound sentences) and paragraphs. But the PBS of simple sentences and compound sentences is the same, and the pitch reset and pause are also not significantly different between these two kinds of boundaries. (2) The pitch-based cue used to distinguish clauses, sentences and paragraphs appears to be the difference between pre- and post-boundary syllables, but not simply the pitch value of either syllable alone. (3) Declination mainly occurs within intonational phrases, whereas there is no consistent global declination in sentences or in paragraphs. (4) Pauses are longer and more varied at the boundary of larger discourse units. Moreover, there is a significant positive correlation between pause duration and degree of pitch reset at clause boundaries, but not at sentence or paragraph boundaries.     

《光谱学与光谱分析》2007年征订启事

The authors achieved the temporal coherent control in an Er^3＋ doped telluride glass, one kind of disordered solids. The upconversion at 670 nm was modulated and the dephasing time was simulated as 300 fs. Moreover, the photon echo signal gave the dephasing time due to the phonon interaction. The agreement between the two data indicates that the interaction between the wavepacket and the phonon leads to the fast disappearance of wavepackets interference, which is helpful for the tech- nique to be applied to the disordered solids.     

氧分子离子第一负带系（b^4∑g^——α^4Пu）（2，6）带的光谱测量与分析

采用光外差-速度调制分子离子吸收光谱技术，在近红外波段13170-13500cm^-1范围内，对氧分子离子第一负带（b^4∑g^--α^4Пu）（2，6）带进行测量和分析，有关第一负带（2,6）带光谱测量尚未见文献报道．本文简述了光外差-速度调制光谱技术的特点，同时给出了对复杂四重态跃迁谱带的分析，运用非线性最小二乘拟合获得了该跃迁上下态精确的分子常数。     

基于偏振特性对石英玻璃和绿漆涂层的反演

物质的偏振特性与其复折射率、表面粗糙度以及观测几何条件有关,为了应用偏振探测技术实现对目标的定量反演,本文首先对两种典型目标(绿漆涂层和石英玻璃)的偏振特性进行了实验测定,并对偏振度与探测天顶角的关系进行了分析。利用实验数据并基于描述目标偏振特性的PG模型首次在考虑了粗糙度的影响下,对目标的折射率、消光系数进行了定量反演,最后将反演结果与参考结果进行比较。结果表明,石英玻璃的折射率相对误差为4.944 9%,绿漆涂层的折射率与消光系数的相对误差分别为11%和21.558 9%。该方法在考虑表面粗糙度的条件下能够更精确地测定物质的复折射率,同时也为偏振技术应用于目标定量反演提供了依据。     

CCD摄像系统镜头的畸变测量

从畸变定义出发,讨论了畸变数学模型,介绍了精密测角法与比长法综合测量畸变的原理。通过放大率法标定出CCD探测器的像素距离当量,通过质心法求出点目标的质心,质心与原点的像素距离乘以像素距离当量得到精确长度。利用正切函数求出绝对畸变值,用最小二乘法解多组数据超定方程,求出拟和公式的系数。实际计算和数据处理结果表明：畸变数学模型在中视场范围内拟合效果很好。     

Hawking Radiation from Topological Kerr Anti-de-Sitter Black Hole with One Rotational Parameter via Covariant Anomalies

Using anomalous viewpoint, we study the Hawking radiation from a kind of topological Kerr Anti-de-Sitter （Kerr-AdS） black hole with one rotational parameter. We employ the covariant gauge and gravitational anomalies. The result supports the Robinson-Wilczek opinion and shows that the Hawking temperature can be correctly determined by cancelling covariant gauge and gravitational anomalies at the horizon.     

Fuzzy Impulsive Control of Permanent Magnet Synchronous Motors

The permanent magnet synchronous motors （PMSMs） may experience chaotic behaviours with systemic parameters falling into a certain area or under certain working conditions, which threaten the secure and stable operation of motor-driven. Hence, it is important to study the methods of controlling or suppressing chaos in PMSMs. In this work, the Takagi-Sugeno （T-S） fuzzy impulsive control model for PMSMs is established via the T-S modelling methodology and impulsive technology. Based on the new model, the control conditions of asymptotieal stability and exponential stability for PMSMs have been derived by the Lyapunov method. Finaily, an illustrated example is also given to show the effectiveness of the obtained results.     

Sudden Death of Entanglement between Two Atoms with Initial Tripartite Entangled State in the Tavis--Cummings Model

We study the entanglement dynamics of two atoms with initial tripartite entangled W-like state in the Tavis-Cummings model. We find that the entanglement evolvement is sensitive not only to the entanglement degree of the initial state but also to the concrete form of the initial state. The so-called sudden death effect occurs only for some initial states.