Wyniki 1-3 spośród 3 dla zapytania: authorDesc:"Bin ZHOU"

Research on the Mechanism of Pin-to-Pin ESD to SCB Initiators

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By ESD experiment, SEM-EDXA and firing experiment, the electrostatic-response characteristic of SCB was studied and the electrical explosion performance after ESD was measured. Results show that surface-damage of bridge is not obviously visible when lower than 25kV, but part of samples coated with explosive fire; the V-type angles start to be damaged at 25kV. After ESD, the function time and firing energy required decrease significantly. 25kV is the critical damage-voltage of the bridge. When less than 25kV, the electrical energy can only make the polysilicon melting and at 25kV, the temperature reaches the boiling point of silicon to generate plasma. Streszczenie. Analizowano odpowiedź elektrostatyczną i parametry inicjatora eksplozji. Uszkodzenia mostka są nie zawsze widoczne jeśli napięcie jest poniżej 25 kV. Dlatego stwierdzono że napięcie 25 kV jest krytyczne, poniżej powoduje topienie polisilikonu, ale powyżej skutkuje tworzeniem się plazmy. (Badania mechanizmu wyładowania elektrostatycznego w inicjatorach półprzewodnikowych SCB) Keywords: initiator; semiconductor bridge; electrostatic discharge; SEM-EDXA Słowa kluczowe: wyładowanie elektrostatyczne ESB, inicjator wyładowania. Introduction The safety of energetic materials is a research hotspot in recent years. Many scholars are devoting themselves to studying the appropriate description of the response in the complex electromagnetic conditions. The initiating explosive devices are the most sensitive components in weapons and ammunition. Therefore, because of the electrostatic, electric explosive devices(EED) are often failure or accidental detonation in use. And the human-body electrostatic is the most important, frequent and dangerous factor in the electrostatic hazards of EED. Semiconductor bridge (SCB) initiator is a transducer. Under the effect of high electrical energy, the power transforms into thermal power. Then the doped polysilicon layer vaporises and generates high[...]

Research on Damage Mechanism of SCB Initiators under RF

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In order to elucidate the response characteristic of semiconductor bridge(SCB) initiators under radio frequency(RF), RF measurement system was used to test the RF sensitivity of SCBs, after that the energy stored in a 22μF was used to activate the SCB. It is inferred from the results of Bruceton-method firing experiment that RF energy does not damage the SCB chip, but can lead to the accidental ignition of SCB initiators or change the color of normal lead styphnate(NLS). RF can also passivate SCB significantly and the all-fire voltage increases from 6.71V to 7.72V. The experimental data of X-ray photoelectron spectroscopy(XPS) analysis, directly indicated that heat generated by RF changes the valence of Pb in NLS from +2 to +4. The decomposition of NLS is responsible for the loss in sensitivity of SCBs. The research results provide a theoretical guidance for the electromagnetic compatibility(EMC) design of SCB initiators. Streszczenie. W artykule opisano badanie oddziaływania sygnałów częstotliwości radiowej (ang. Radio Frequency) na zapalniki zbudowane z mostka półprzewodnikowego. Przedstawiono omówienie teoretyczne oraz wyniki badań eksperymentalnych. (Mechanizm uszkodzenia mostkowego zapalnika półprzewodnikowego pod wpływem fal radiowych) Keywords: initiator, SCB, RF, NLS, XPS, EMC Słowa kluczowe: Zapalnik, SCB, RF, NLS, XPS, EMC Introduction SCB is an energy-exchange device used in explosive devices. SCB initiator comprises SCB and the primary explosive which is a kind of sensitive energetic material. It attracted people’s attention in the mid-1980s [1]. Generally, it is desired that SCB provides highly reliability ignition while requiring less energy input. By passing an electrical current, the polysilicon bridge of SCB module is heated to generate high temperature. After that, the temperature causes the vaporization of polysilicon film and obtains plasma. Subsequently, the primary explosive around SCB chip is ignited[...]

Speech Enhancement by Short-Time Spectrum Estimation with Multivariate Laplace Speech Model

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The paper presents a new short-time spectrum estimation algorithm for speech enhancement. A novel multivariate Laplace speech model is utilized to characterize the dependencies between adjacent DFT coefficients of speech, based on which a minimum mean-square error (MMSE) estimator of speech spectral components is derived. Moreover, the speech presence uncertainty is incorporated to modify the MMSE estimator. Experimental results show that the developed algorithm achieves better noise suppression and lower speech distortion compared to the existing speech enhancement methods. Streszczenie. W artykule przedstawiono nowy algorytm estymacji krótkookresowego spektrum głosu do poprawy dźwięku mowy. Wykorzystano wieloczynnikowy model Laplace'a w celu scharakteryzowania zależności pomiędzy składnikami DFT dźwięku mowy. Na tej podstawie obliczane jest minimum błędu średnio-kwadratowego dla estymatora. Wyniki eksperymentalne potwierdzają ulepszoną skuteczność eliminacji zakłóceń mowy, w porównaniu ze stosowanymi metodami. (Wieloczynnikowy model mowy Laplace'a w estymatorze spektrum krótkookresowego, na potrzeby polepszenia dźwięku) Keywords: speech enhancement; minimum mean-square error (MMSE); multivariate Laplace distribution. Słowa kluczowe: polepszenie dźwięku mowy, minimum błędu średniokwadratowego, wieloczynnikowy rozkład Laplace'a. 1 Introduction Speech enhancement plays an important role in speech processing systems and is very useful in many applications such as speech communication and automatic speech recognition. As speech signal is often corrupted by noise during acquisition or transmission, the underlying goal of speech enhancement is to obtain the noise-free speech from the corrupted speech. Although various approaches to this problem have been adopted during the last decades, it is still one of the most fundamental, widely studied, and largely unsolved problems in speech processing. Single channel speech enhan[...]

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