Combined optical fiber interferometric sensors for the detection of acoustic emission

A type of combined optical fiber interferometric acoustic emission sensor is proposed. The sensor can be independent on the laser source and make light interference by matching the lengths of two arms,so it can be used to monitor the health of large structure. Theoretical analyses indicate that the system can be equivalent to the Michelson interferometer with two optical fiber loop reflectors,and its sensitivity has been remarkably increased because of the decrease of the losses of light energy. PZT is powered by DC regulator to control the operating point of the system,so the system can accurately detect feeble vibration which is generated by ultrasonic waves propagating on the surface of solid. The amplitude and the frequency of feeble vibration signal are obtained by detecting the output light intensity of interferometer and using Fourier transform technique. The results indicate that the system can be used to detect the acoustic emission signals by the frequency characteristics.

Studies on Persian Passion Play （ta＇ziya）： An Annotated Bibliography

Persian Passion Play （Ta＇ziya）, the most important Shiite religious ritual, performed by non-professional actors and musicians, is based on the martyrdom of the third Shiite Imam, Husein, and his companions at Karbala （in 680）. This paper aims to introduce a wide range of sources, both books and articles, on the history, music, actors, and arrangements of ta＇ziya performance in Iran from 1971 onwards. It includes a number of titles of ta＇ziya manuscripts, and the place of performance. The article contains traveler accounts from sixteen century onwards and the translations of ta＇ziya texts in European languages.

An Intelligent Household Heart Rate Meter

The measuring instrument which uses Sunplus SPCE061A MCU as the controller is a practical intelligent household heart rate meter.It can serve all people timely and effectively to detect the heart rate.It rings some voice alarm if the HRV is abnormal.Then it is decided whether to see a doctor at a convenient time for further diagnosis.The instrument has a feature of voice guidance that can save keyboard steps,which extends the scope of use.All people,old and young,the blind and the deaf,can use it by themselves.

Portable Distortion Degree of Measuring Apparatus

Distortion is a technical indicator in the field of voice signal processing. The design is a portable distortion degree tester, based on Field-Progranmmble Gate Array （FleA, EP2C20） as the cote, using harmonic analysis method which better solve the distortion problem of acctwacy. It can achieve the signal transformation from the time-domain to the frequency-donkain, and is widely used for signal spectrum analysis. All the componets used in the design are low power, high perf-, low drift and industrial grade compionents. The reference voltage sources of ADC and DAC have identical performance of high stability, high precision. The dtr.k is the precise stable clock with FPGA temperature compensation. This project can get the cost-effective, high-precision, low power and portable design goals.

路上的风景

'辉儿,桂花美吗?'仪一仪个熟悉仪而又苍仪老的声仪音从远仪方飘过,仪又像来仪自四面仪八方,仪这声音仪在浓郁的妖娆的甜香之中,惊起阵阵涟漪。他猛地一回头,映入眼帘的却只有金灿灿仪的桂花仪,这秋仪天的精仪灵。他仪呆住了仪,是被这仪灵动的仪桂花所仪打动?仪抑或是仪想起了什么?他缓缓低下头,望着手中的黑白照片。'沙沙……沙沙……'这是秋风拂过树叶的声音,也拂过了他的心头,直击心底最柔软的部分。

Acquirement and enhancement of remote speech signals

To address the challenges of non-cooperative and remote acoustic detection, an all-fiber laser Doppler vibrometer(LDV) is established. The all-fiber LDV system can offer the advantages of smaller size, lightweight design and robust structure, hence it is a better fit for remote speech detection. In order to improve the performance and the efficiency of LDV for long-range hearing, the speech enhancement technology based on optimally modified log-spectral amplitude(OM-LSA) algorithm is used. The experimental results show that the comprehensible speech signals within the range of 150 m can be obtained by the proposed LDV. The signal-to-noise ratio(SNR) and mean opinion score(MOS) of the LDV speech signal can be increased by 100% and 27%, respectively, by using the speech enhancement technology. This all-fiber LDV, which combines the speech enhancement technology, can meet the practical demand in engineering.

Improving optomechanical gyroscopes by coherent quantum noise cancellation processing

Coherent quantum noise cancellation(CQNC) method is used to beat standard quantum limit(SQL) for improving the performance of quantum optomechanical gyroscopes. The protocol for realizing CQNC is achieved by constructing an effective negative mass mechanical oscillator, which is simulated by an ancillary cavity. This oscillator shows an antiresponse relative to that of a real mechanical oscillator. Thus, the optomechanical back-action noise is counteracted or restrained, and we could increase our signal by increasing the coupling strength without increasing the noise.

“重音说”与《仪礼音义》之“重音”

今本《经典释文》的同一词条中,存在两个或两个以上的音注同时为该词头出相同音的“重音”现象,自上世纪80年代以来,这个问题就广受学界关注,提出了“录存”“存疑”等解释。本文主要以邵荣芬先生指出的《仪礼音义》中的31条“重音”为考察对象,从校勘、音韵、训诂及语音发展史等角度,结合《经典释文》内部出音体例,全面梳理这些“重音”,指出绝大部分“重音”不可靠,并复原出其引音前、后的特殊情况。