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 22?F 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.
PL
W artykule opisano badanie oddziaływania sygnałów częstotliwości radiowej (ang. Radio Frequency) na zapalniki zbudowane z mostka półprzewodnikowego. Przedstawiono omówienie teoretyczne oraz wyniki badań eksperymentalnych.
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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.
PL
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.
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The structure of each part of a diagonal compressor directly affects its overall performance and internal flow. We introduce the Reynolds-averaged Navier-Stokes flow simulation for unit calculation on the whole system including a diagonal impeller, a vaneless diffuser and a volute. By analyzing different flow chromatograms of specific sections, we can compare the configuration of three types of diffusers and volutes and the meridian flow status of the corresponding diagonal compressors which serves as a basis for the impeller flow path as well as for its matching designs. Considering the interference between the rotor and the upstream and downstream stillness body, this thesis analyzes how the vaneless diffuser meridian flow path, the volute flow path and its section secondary flow affect the upstream rotor flow. Both the calculation and experimental data on the rotor outlet are compared, as well as the calculated numerical value of the meridian plane streamline distribution and the diffuser velocity distribution, upstream and downstream, coincides with the designed numerical value. Without changing the conventional quasi-three-dimensional design system, the thesis applies the annulus wall boundary layer theory and the velocity distribution diagram to sweep and skew the leading edge of the airfoil. A performance test shows that the leading edge skewed-swept diagonal rotor can better improve the stall characteristic in a low flow rate area and expand the surge margin, compared with conventional diagonal rotor. It can also efficiently restrain the low-momentum fluid conglomeration near the wall region and reduce the secondary flow loss by sweeping and skewing the blade properly. The purpose of the thesis is to make a contribution to optimizing the overall structure design of diagonal compressors and to study further the complex internal flow between the leading edge skewed-swept diagonal rotor and the cover.
In order to screen differentially expressed genes during caste differentiation induced by pollen, larvae of Apis mellifer ligustica were developed in an incubator under controlled temperature and relative humidity until emergence. Worker bee morphology was induced by addition of water-soluble extracts from pollen in larval diets. After all of the developmental periods, the external characters and developmental degree of ovaries were evaluated to confirm the caste of new adults. Transcripts from larvae of developing queens and workers were profiled by differential-display RT-PCR analysis and differentially expressed fragments were reconfirmed by dot-blot assay. Our results showed that caste differentiation was triggered by the intake of pollen extracts. Six transcript-derived fragments were isolated and three of them are reported for the first time. We conclude that differential display is a feasible approach to identifying differentially expressed genes. The identification of up-regulated caste-differentiation-related genes provided interesting clues about the activation of biochemical steps relevant to this progress.
Canine mammary tumors are the most common neoplasms in intact female dogs. The surgery cannot always solve the problem, chemotherapy are recommend to these patients. However, chemotherapy could always fail because of multidrug resistance (MDR). Through stepwise increasing 5-Fluorouracil (5-FU) concentration in the culture medium, a 5-FU-resistant canine mammary tumor cell line CMT7364/5-FU was established to disclose the molecular mechanism of the drug resistance. Cell morphology, cell sensitivity to drugs, growth curves, expression of proteins, and chemo-sensitivity in vivo were compared between the parental cell line and resistant cell line. As compared it to its parental cell line (CMT7364), CMT7364/5-FU showed different morphology, cross-resistant to other chemo-drugs and a prolonged population doubling time (PDT). The drug efflux pump proteins (ABCB1 and ABCG2) in CMT7364/5-FU were up-regulated. In vivo, the similar result revealed that CMT7364/5-FU cell line was more resistant to 5-FU. In conclusion, a 5-FU-resistant canine mammary tumor cell line (CMT7364/5-FU) was successfully established, it can serve as a good model for researching the mechanism of MDR and screening effective agents to reverse drug resistance.
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