电视机内有“声响”算不算有故障

仔细的人们可能会注意到．电视机在不用时或者在使用时．有时会发出一些异常的声响，不免会引起人们担忧，是不是电视机出了毛病?如能对照下列几种情形进行判别，就不难为你除去心头的疑虑。

朱光潜的诗歌“声响学”思想

在《诗论》中,美学家朱光潜把诗歌的声音节奏和视觉意象看得同等重要,由于诗歌"意象学"已经有许多论述,因而他有针对性地提出诗歌"声响学"思想,旨在加强诗歌声音节奏方面的建设。朱光潜认为,诗歌创作首先要解决语言的音义协调问题,同时,诗歌"声响学"在新旧诗体的转换方面也具有一定的启示意义。

Optimal Ultrasonic Extraction of Pachyman from Jiuzihe Poria cocos

This study was conducted to extract pachyman to the greatest degree with ultrasonic technology, and to determine the content of pachyman by the phe-nol-sulfuric acid method, so as to choose the optimal technique of ultrasonic extrac-tion of pachyman. Firstly, the ultrasonic power, extraction time and solid-to-liquid ra-tio were investigated by ultrasonic extraction method. Then, on this basis, a respon-sible surface experiment was designed, to select the optimal process conditions ac-cording to the index of pachyman yield. The optimized ultrasonic water extraction conditions were as fol ow： ultrasonic power of 100 W, extraction time of 30 min, and solid-to-liquid ratio at 1：40. The Oxford cup method was used to study the an-timicrobial activity of pachyman. lt was found that pachyman could significantly in-hibit Bacilus subtilis_and Staphylococcus aureus.

《汉语大词典》补三例——以方言和文献为据

《汉语大词典》当补收"看笑声"和"响快"二词,并给"恭敬"增加义项。本文提供现代汉语方言和历代文献两方面的证据。

传统民宅戏楼声学特性测量

A comprehensive acoustical test was conducted in the traditional Ch ine se in-house theater, the theater of Shi`s residence in Tianjin. The measured pa rameters include reverberation time, clarity, lateral reflectance and IACC. Prim ary analysis was done with the test result.

程迥《古韵通式》及古音说通考

宋代学者程迥,著《古韵通式》一书,从《文选》中摘出五十余例古诗文协韵的例子,总结出古人诗文协韵的方式,所谓“四声互用,切响通用”,与吴棫古韵通转说相呼应欢?关于“切响”问题后人误解者甚多,至今无确解。本文立足于文献考证,对“切响”问题着重进行了考释,可澄清其中一些是非问题。

Superparticles Formed by Amphiphilic Tadpole-like Single Chain Polymeric Nanoparticles and Their Application as an Ultrasonic Responsive Drug Carrier

Herein, we report self-assembly of tadpole-like single chain polymeric nanoparticles （TPPs） and the ultrasonic response of the resultant superparticles. The TPPs are with an intramolecularly crosslinked poly（2-（methacryloyloxy）ethyl pent-4-ynoate）-rpoly（hydroxyethyl methacrylate） （PMAEP-r-PHEMA） chain as the ＂head＂ and a poly（2- （dimethylamino）ethyl methacrylate （PDMAEMA） linear chain as the ＂tail＂, and are pre- pared simply and emciently by Glaser-coupling of the pendant alkynes in the PMAEP-r- PHEMA block in the common solvent methanol. The formation of the TPPs was confirmed by gel permeation chromatograph, nuclear magnetic resonance spectroscopy, dynamic light scattering, static dynamic scattering, and transmission electron microscopy. In aqueous solution, the amphiphilic TPPs could self-assemble into regular superparticles, driven by aggregation of the hydrophobic ＂heads＂. Since in the structure there is no chain entanglement and the embedding of PDMAEMA chains disturb close-packing of the ＂heads＂, the superpartieles are responsive to a low-energy ultrasonic vibration, as evidenced by greatly enhanced release of the functional molecules from the superparticles by treatment of a low-energy ultrasound. Therefore, the superparticles should be very promising in the use as the drug carriers that can be manipulated from a long distance, considering that ultrasonic energy can be focused at a small area in a relatively long distance from the ultrasound-radiating source.

Effects of different pull-out loading rates on mechanical behaviors and acoustic emission responses of fully grouted bolts

Due to the influence of mining disturbance stress,it is of great significance to better understand the bearing characteristics of fully grouted bolts under different pull-out loading rates.For this purpose,a series of laboratory pull-out tests were conducted to comprehensively investigate the effects of different pull-out loading rates on the mechanical performance and failure characteristics of fully grouted bolts.The results show that the mechanical performance of the anchored specimen presents obvious loading rate dependence and shear enhancement characteristics.With the increase of the pull-out loading rates,the maximum pull-out load increases,the displacement and time corresponding to the maximum pull-out load decrease.The accumulated acoustic emission(AE)counts,AE energy and AE events all decrease with the increase of the pull-out loading rates.The AE peak frequency has obvious divisional distribution characteristics and the amplitude is mainly distributed between 50-80 dB.With the increase of the pull-out loading rates,the local strain of the anchoring interface increases and the failure of the anchoring interface transfers to the interior of the resin grout.The accumulated AE counts are used to evaluate the damage parameter of the anchoring interface during the whole pull-out process.The analytical results are in good agreement with the experimental results.The research results may provide guidance for the support design and performance monitoring of fully grouted bolts.

Bionic covert anti-reverberation active sonar detection method based on imitating whale whistles

The disguised covert detection method that imitates whale calls has received great attention in recent years because it can solve the traditional problem of the trade-off between long-range detection and covert detection.However,under strong reverberation conditions,traditional echo signal processing methods based on matched filtering will be greatly disturbed.Based on this,a disguised sonar signal waveform design is proposed based on imitating whale calls and computationally efficient anti-reverberation echo signal processing method.Firstly,this article proposed a disguised sonar signal waveform design method based on imitating whale calls.This method uses linear frequency modulation(LFM)signals to replace LFM-like segments in real whale calls,and extracts the envelope of the real whale call’s LFM-like segment to modify the LFM signal.Secondly,this article proposed an echo signal processing method of fractional Fourier transform(FrFT)based on target echo locating of synchronization signals.This method uses the synchronization signal to locate the target echo,and determines the step-size interval of the FrFT based on the information carried by the synchronization signal.Compared with the traditional FrFT,this method effectively reduces the amount of calculation and also improves the anti-reverberation ability.Finally,the excellent performance of the proposed method is verified by simulation results.

Effect of Correlation of Two Dichotomous Noises on Stochastic Resonance

The effect of the correlation of two dichotomous noises on stochastic resonance is investigated for a linear stochastic system subject to a periodic oscillatory signal. It is found that, the correlation between the two dichotomous noises can not only affect the appearance of the stochastic resonance phenomenon, but also the distinctness of the stochastic resonance phenomenon. There is an optimal value of the correlation, at which the stochastic resonance phenomenon is most distinct. In addition, the correlation between the two dichotomous noises can also cause the movement of the peak of stochastic resonance. Finally, two stochastic resonances caused by two correlated multiplicative dichotomous noises can be found in this system.

Research on the coefficient of sound absorption in turbid water

China’s coastal waters are turbid and the properties of the seabed are complex. This negatively impacts the performance of underwater detection equipment. The properties of sound absorption in turbid water are not well understood. In this paper, the coefficient of sound absorption in turbid water was measured by the reverberation technique. All work was done in a reverberation barrel made of seamless aluminum. First, pure water was poured into the reverberation barrel and its reverberation time measured. Next, various concentrations of turbid water were poured into the barrel and their reverberation time measured. After all data had been gathered, the coefficient of sound absorption in turbid water of different concentrations was calculated. From this we determined a law of sound absorption in turbid water as summarized in the paper.

Signal modulating noise effect in bistable stochastic resonance systems and its analog simulation

The effect of signal modulating noise in bistable stochastic resonance systems was studied theoretically and experimentally. A mathematical analysis was made on the bistable stochastic resonance model with small system parameters. An analogue circuit was designed to perform the effect. The effect of signal modulating noise was shown in the analog simulation experiment. The analog experiment was conducted for two sinusoidal signals with different frequencies. The results show that there are a sinusoidal component corresponding to the input sinusoidal signal and a noise component presented as a Wiener process corresponding to the input white noise in the system output. By properly selecting system parameters, the effect of signal modulating noise can be manifested in the system output.

A simple algorithm to calculate the pulsed sound field of a wide-band linear phased array

A simple algorithm using an impulse response for a rectangular piston element is discussed. The impulse response of linear phased array is obtained hv stumming the impulse responses of rectangular piston elements with different delay times. The output response of the linear wide-band array is equal to the convolution of impulse response functions with wide-band pulse exeiting signal. Sound field distributions and impulse responses of three kinds of transducers are compared. The results can be used to optimize the parameters of the linear phased array transducers used in uhrasonie imaging in nondestructive testing （NDT）.

Numerical Analysis and Comparison of the Fan Ducted Discharge Equipment Acoustics

In order to cut down excessive experiments, acoustic response of the different fan ducted discharge (equipment) was studied based on numerical method. The sound pressure level(SPL) in each component of a duct-plenum-reverberant room model was drawn and SPL deviation was analyzed. The trends of the curves were explained by the diffracti on and end reflection at the duct discharge. Models with different room dimensions, duct lengths, duct cross sections, duct locations and duct elbow were constructed, and their response was analyzed and compared. The results show that the SPL curves are smooth in the duct discharge cross section, but seriously fluctuant in the reverberant room; SPL in the duct discharge is only sensitive to duct dimensions, while that of the reverberant room is regularly influenced by all the dimension and arrangement factors. Small room and short duct help to increase room SPL. Elbow has an indistinct influence on all the components’ sound field. Finally, suggestion to reduce the deviation of experiment results was proposed.

Response evaluation of chemotherapy in metastatic colorectal cancer by contrast enhanced ultrasound

AIM： To evaluate whether contrast enhanced ultra- sound （CEUS） might also be used for response predic- tion and early response evaluation in patients receiving bevacizumab based chemotherapy for metastasized colorectal cancer.METHODS： Thirty consecutive patients with non prima- ry resectable liver metastases from colorectal cancer underwent CEUS before treatment （CEUS date 1） and before the second （CEUS date 2） and fourth （CEU5 date 3） cycle of bevacizumab based chemotherapy. Three parameters [PEAK, Time to peak （l-I-P） and RISE RATE]were correlated with radiological response.RESULTS： For neoadjuvant purpose a reduction of tu- mour mass was required to assume clinical response. Based on these response criteria there was a significant （P 〈 0.001） correlation in TTP between metastases of responders （9.08 s） and non-responders （14.76 s） ar- chived on CEUS date 1. By calculating a standardized quotient （metastases divided by normal liver tissue） we were able to define a cut off, predicting response with a sensitivity of 92.3 % and a specificity of 100 %. To reflect a palliative intention only those patients with progressive disease were classified as non-responders. In this stetting -FI-P was also significantly （P 〈 0.01） dif- ferent between responders and non-responders. In con- trast, Peak and Rise rate did not show any significant difference between responder and non-responder. CONCLUSION： CEUS might serve as a surrogate mark- er to predict treatment response in patients with me- tastasized colorectal cancer who receive antiangiogenic therapy.

Ultrasonic plastification speed of polymer and its influencing factors

The melt filling difficulty in micro cavity is one of the main challenges for micro-injection molding (MIM). An approach employing ultrasound in MIM was proposed. The approach was extensively studied through experiments with a home-made experimental ultrasonic plastification device. The results of the experiments show that polymer ultrasonic plastification speed increases with ultrasonic supply voltage and plastification pressure. When the ultrasonic supply voltage is 200 V and the plastification pressure is 2.0 MPa, the polymer ultrasonic plastification speed reaches the maximum value of 0.111 1 g/s. The results also indicate that the ultrasonic cavitation effect is the most significant effect of all the three effects during polymer ultrasonic plastification process.

Schematic interface of sound creation for computer animators

As an audiovisual medium, computer animations require superior image quality and professional soundtrack to lead audiences into their fascinating virtual world. Without sound, the impact of storytelling is reduced or the story is even not under- standable. Despite the importance of sound, most animators are unfamiliar with sound editing software. Limited budget projects such as independent or student works have difficulty hiring sound professionals to create tailor-made soundtrack. Therefore, we need a suitable sound tool to express their individual ideas. In this paper, we propose an approach using schematic for both computer animation and sound. Our approach provides (1) physical simulation on sound through animation parameters and (2) a new channel for animators to add aesthetic values in sound through their experience of using schematics in existing animation software. We demonstrate our idea through several examples, such as Doppler shift, obstacle effect, importance, energetic, and sputtering effect.

Study on Transient Properties of Levitated Object in Near-Field Acoustic Levitation

A new approach to the study on the transient properties of the levitated object in near-field acoustic levitation （NFAL） is presented. In this article, the transient response characteristics, including the levitated height of an object with radius of 24 mm and thickness of 5 mm, the radial velocity and pressure difference of gas at the boundary of clearance between the levitated object and radiating surface （squeeze film）, is calculated according to severa/velocity amplitudes of radiating surface. First, the basic equations in fluid areas on Arbitrary Lagrange--Euler （ALE） form are numericaJly solved by using streamline upwind petrov gaJerkin （SUPG） finite elements method. Second, the formed a/gebraic equations and solid control equations are solved by using synchronous alternating method to gain the transient messages of the levitated object and gas in the squeeze film. Through theoretical and numerical analyses, it is found that there is a oscillation time in the transient process and that the response time does not simply increase with the increasing of velocity amplitudes of radiating surface. More investigations in this paper are helpful for the understanding of the transient properties of levitated object in NFAL, which are in favor of enhancing stabilities and responsiveness of levitated object.

Optimal design of butterfly-shaped linear ultrasonic motor using finite element method and response surface methodology

A new method for optimizing a butterfly-shaped linear ultrasonic motor was proposed to maximize its mechanical output. The finite element analysis technology and response surface methodology were combined together to realize the optimal design of the butterfly-shaped linear ultrasonic motor. First, the operation principle of the motor was introduced. Second, the finite element parameterized model of the stator of the motor was built using ANSYS parametric design language and some structure parameters of the stator were selected as design variables. Third, the sample points were selected in design variable space using latin hypercube Design. Through modal analysis and harmonic response analysis of the stator based on these sample points, the target responses were obtained. These sample points and response values were combined together to build a response surface model. Finally, the simplex method was used to find the optimal solution. The experimental results showed that many aspects of the design requirements of the butterfly-shaped linear ultrasonic motor have been fulfilled. The prototype motor fabricated based on the optimal design result exhibited considerably high dynamic performance, such as no-load speed of 873 ram/s, maximal thrust of 27.5 N, maximal efficiency of 43%, and thrust-weight ratio of 45.8.

Optimization of Response Surface of Ultrasonic-assisted Extraction of Rizhao Black Tea

[ Objectivel The aim was to determine the optimal technology for ultrasonic-assisted extraction of black tea was determined. [ Methed] Taking Black Tea as materials, the Box-Behnken response surface design method of tea polyphenols ultrasonic-assisted extraction process optimi- zation was applied. The regression optimization model of the ethanol volume fraction, ultrasonic time, and ultrasonic temperature, ethyl acetate extract stalling time and tea polyphenols was established. [ Result] The influence of four factors on the black tea polyphenol solvents affecting size was as follows： ultrasonic time 〉 ethanol volume fraction 〉 stalling extraction time 〉 ultrasound temperature. The best extraction process was ultrasonic time 80 min, volume fraction of 88.99% ethanol, extraction time 89.97 min, ultrasonic temperature of 80℃. At the optimized technical parameters, the black tea phenolic extraction yield can be as high as 73.50%. [ Conclusion] The study provided theoretical basis for the development of tea leaves and black tea.