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1.
沈崤 《物理》1990,19(6):321-325
本文介绍了声学发展的概况和它与其它学科的关系,阐述了在经典声学基础上发展起来的现代声学体系,讨论了现代声学中主要分支学科的内容和80年代现代声学的进展,最后指出了由于数字技术和微处理机的应用,声学中的理论工作,实验测量技术,以及为改善听闻条件的高保真录声、放声技术,已出现一个新的飞跃.根据作者在中国科学技术大学研究生院开圾的“近代声学”课程的讲稿整理而成.  相似文献   

2.
李启虎 《物理》1992,21(11):678-682
综述了水声学及水声信号处理的历史发展概况及它们在军事及民用方面的重要作用,介绍了与水声信号处理有关的换能器、布阵理论、波束成形理论、卡尔曼滤波、自适应滤波、目标识别、专家系统等课题,同时介绍水声信号处理中的一些现代技术,如FFT,Zoom FFT,LOFAR,DEMON及高分辨力谱分析的基本知识。  相似文献   

3.
项端祈 《应用声学》2002,21(1):40-45
我国建筑学声在近20年间,无论在科研、设计、声学材料(结构)的研制、生产和应用方面均有较大的发展。在厅堂音质设计的个别领域还取得了突破性的进展。本文就上述几方面作概要的介绍。  相似文献   

4.
汪德昭 《物理》1991,20(5):257-261
本文对声学技术在海洋探测、海洋开发以及海洋学研究工作中的地位、作用、应用现状和前景作了阐述,同时也对我国科学工作者在这方面作出的成就和贡献作了扼要介绍.  相似文献   

5.
天然气水化合物的声学探测进展   总被引:1,自引:0,他引:1       下载免费PDF全文
天然水合物是一种未来的新型能源,与此相关的研究正日益成为能源勘探领域的热点。本文对 天然水合物及其特点、分布和探测技术进行了简要的介绍,在此基础上从声学技术研究角度出发, 介绍了声波测井、地震探测、海底地貌声波检测技术等在探测天然水合物中的应用;并探讨了声学方 法和技术在评价天然水合物储层方面的研究内容、进展和侧重点。  相似文献   

6.
声纳技术的应用及其最新进展   总被引:4,自引:0,他引:4  
王炳和  李宏昌 《物理》2001,30(8):491-495
声纳技术是声学检测新技术在水下介质中的具体应用,文章简要阐述了声纳技术的原理,方法及其发展历史,介绍了声纳技术在军事和非军事方面的主要应用及其最新进展。  相似文献   

7.
环境噪声学进展   总被引:5,自引:0,他引:5       下载免费PDF全文
本文简要地回顾了30年来中国环境噪声学的发展,并从飞机噪声、地面运输噪声、环境噪声影响与评价以及工业噪声控制四个方面介绍了近年来环境噪声学的进展。  相似文献   

8.
汪云九  周昌乐 《物理》2007,36(7):501-506
文章介绍了物理学理论和技术在研究意识问题中的应用进展。首先列出意识活动的一些主要特性,其次介绍新的仪器技术在确定意识的脑功能定位上的研究成果。最后介绍物理学的理论(特别是量子理论)在解释意识的机制上的作用,介绍信息理论在意识复杂性计算方面的应用。  相似文献   

9.
声学是一门具有广泛应用性的学科,涉及到人类生产、生活及社会活动的各个方面;同时声学又是一门具有很强交叉渗透性的学科,与各种新学科、新技术相互作用,相互促进,不断地吸收、应用和发展新的思想,增强了声学的生命力、竞争力和学术与艺术魅力.本文从科学、技术与艺术等几个方面,介绍了声学的学科发展,特别是在科学与技术上的新的研究方向与进展.  相似文献   

10.
多极子阵列声波成像测井已经成为测井中主要方法之一,在地层评价与油气田开发中有重要作用。在已有理论与数值模拟的基础上,经过近十年的技术攻关,我们已经在多极阵列声波成像仪器制造、测试与数值处理等主要关键技术方面都取得了长足的进展,具体包括高温正交偶极子发射换能、高温低频单极子换能器、声系测试、多极子阵列声波测井高温电路及仪器集成、资料处理及解释等主要方面。所研制的仪器及资料处理方法,经过与国外同类仪器的测井结果进行了对比分析,验证了所研发的仪器的可靠性和处理方法的正确性,这些关键技术为我国声学测井仪器装备技术研发和快速发展打下了基础,提供了技术支撑。  相似文献   

11.
J.C. Owen 《Annals of Physics》1979,118(2):373-413
A variational wave function is constructed for a system of fermions interacting with a spin dependent potential. The correlations due to the repulsive core of the potential are described by a spin independent Jastrow product ansatz and the correlations due to the longer range part of the potential, which are assumed to be spin dependent, are described by an independent pair ansatz. A cluster expansion is derived for the variational energy and a set of hypernetted chain (HNC) equations obtained to sum the cluster series in terms of the elementary diagrams. Neglecting the elementary diagrams, the HNC equations are solved numerically for the spin dependent potential, V3, in neutron matter. The introduction of spin dependent correlations is found to give a small lowering of the variational energy in the HNC approximation. The results are very sensitive to an accurate treatment of the many-body terms within the HNC approximation, however, and it is shown that additional approximations can easily lead to an exaggeration of the effect of the spin dependent correlations.  相似文献   

12.
MP2/aug-cc-pVDZ calculations have been used to provide information on the three ternary systems comprising one HNC and two HF molecules. The binding distances, frequency shifts, and interaction energies in these systems have been analysed to study the cooperativity of hydrogen bond in these systems. The cooperativity of hydrogen bond in HNC–HF–HF trimer is larger than that in HF–HF–HNC trimer. The result indicates that the proton acceptor HNC plays a more important role in enhancing the cooperativity of hydrogen bond. Many-body interaction analyses have also been performed for these ternary systems.  相似文献   

13.
本文提出了语音信号的一种时域-频域-能量表示,并给出了算法,可用于孤立词语音识别,这种时域-频域-能量表示有两个特点,基于短时能量梯度的非线性时间规正,可保留语音信号频域的过滤特性,丢掉其稳态特性,计算量小,适于实时应用。  相似文献   

14.
本文提出了语音信号的一种时域─频域─能量表示,并给出了算法,可用于孤立词语音识别.这种时域─频域─能量表示有两个特点:基于短时能量梯度的非线性时间规正,可保留语音信号频域的过渡特性,丢掉其稳态特性;计算量小,适于实时应用.  相似文献   

15.
A two-component system of penetrable particles interacting via a gaussian core potential is considered, which may serve as a crude model for binary polymer solutions. The pair structure and thermodynamic properties are calculated within the random phase approximation (RPA) and the hypernetted chain (HNC) integral equation. The analytical RPA predictions are in semi-quantitative agreement with the numerical solutions of the HNC approximation, which itself is very accurate for gaussian core systems. A fluid-fluid phase separation is predicted to occur for a broad range of potential parameters. The pair structure exhibits a nontrivial clustering behaviour of the minority component. Similiar conclusions hold for the related model of parabolic core mixtures, which is frequently used in dissipative particle dynamics (DPD) simulations.  相似文献   

16.
Ab initio calculations using a minimum basis of Slater orbitals have been carried out on the molecules HCN and HNC with optimization of geometry. The predicted geometry of HNC is compatible with an observed radio-emission line which has been attributed to this molecule. The reaction profile for the internal migration of the proton has been calculated. The transition state is approximately T shaped with an activation energy from HNC of 251 kJ/mole.  相似文献   

17.
B. HRIBAR  V. VLACHY  O. PIZIO 《Molecular physics》2013,111(19):3093-3103
A theoretical study is reported of a quenched-annealed system where both components were modelled as size symmetric +1: ?1 primitive model electrolytes. The partly quenched system was studied by using the replica Ornstein-Zernike (ROZ) integral equation theory in the hypernetted chain (HNC) approximation and grand canonical Monte Carlo (GCMC) simulations. The primary interest was the excess Gibbs free energy (logarithm of the mean activity coefficient) of the adsorbed electrolyte and an expression for this quantity, valid within the ROZ/HNC formalism, was derived. The effects of the concentration of matrix ions, pre-quenching conditions, and the electrolyte and solvent conditions (concentration, temperature, dielectric constant) on the structure and thermodynamics of the adsorbed electrolyte were examined. The numerical results indicated that the mean activity of the adsorbed electrolyte differs substantially from the corresponding quantity for the bulk electrolyte. The excess chemical potential depends strongly on the concentration of charged obstacles and matrix preparation, and also on the temperature and dielectric constant of the annealed electrolyte solution. Newly generated computer simulation results for the structural and thermodynamic parameters, obtained by the grand canonical Monte Carlo method, were used to assess the validity of the ROZ/HNC approximation. It was shown that the ROZ/HNC theory yields good agreement with the computer simulations.  相似文献   

18.
The hypernetted chain (HNC) equation for the one-component plasma is corrected by including a single-parameter expression for the bridge graphs whose functional form ensures that the correct long-wavelength limit of the HNC results is retained. The parameter is chosen to improve the short-range behaviour.  相似文献   

19.
The emission spectrum of HNC has been measured from 400 to 4100 cm(-1). The HNC was observed as an equilibrium mixture of HCN and HNC in a fused quartz cell heated to 1370 K. The three fundamental bands and many hot bands of HNC were measured with resolutions ranging from 0.006 cm(-1) for the lowest fundamental to 0.033 cm(-1) for the other two. High rotational levels up to J=62 were observed as well as vibrational levels up to v(2)=5. Now all the quadratic contributions to the vibrational and rotational term values have been determined, as well as some higher order terms. Copyright 2001 Academic Press.  相似文献   

20.
A composite auditory model for processing speech sounds   总被引:2,自引:0,他引:2  
A composite inner-ear model, containing the middle ear, basilar membrane (BM), hair cells, and hair-cell/nerve-fiber synapses, is presented. The model incorporates either a linear-BM stage or a nonlinear one. The model with the nonlinear BM generally shows a high degree of success in reproducing the qualitative aspects of experimentally recorded cat auditory-nerve-fiber responses to speech. In modeling fiber population responses to speech and speech in noise, it was found that the BM nonlinearity allows bands of fibers in the model to synchronize strongly to a common spectral peak in the stimulus. A cross-channel correlation algorithm has been devised to further process the model's population outputs. With output from the nonlinear-BM model, the cross-channel correlation values are appreciably reduced only at those channels whose CFs coincide with the formant frequencies. This observation also holds, to a large extent, for noisy speech.  相似文献   

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