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181.
Pb(Zr0.4Ti0.6)O3 film prepared by sol-gel spin coating on a Pt/Ti/SiO2/Si substrate is applied to ferroelectric capacitors with Pt or Ru as the top electrode. For the Pt/PZT/Pt and Ru/PZT/Pt ferroelectric capacitors, although with the same ferroelectric film, different top electrode materials incur different properties of PZT capacitors, such as fatigue, leakage, remanent and saturated polarization, except the similar crystal orientations of the PZT film. After 10^10 switch cycles, the remanent polarizations of the Ru/PZT/Pt and Pt/PZT/Pt capacitors decrease to 70% and 84%, respectively. The leakage current density of the latter increases obviously at positive bias after 108 switch cycles, compared with the former. Different materials for the top electrode bring different conditions at the PZT/top electrode interface. The influence of oxygen-vacancy concentration at the PZT/electrode interface and the influence of oxides of the electrode material at the PZT/electrode interface to charge injection can explain the difference of properties of the PZT capacitors with Pt or Ru as the top electrodes. 相似文献
182.
We demonstrated a diode-pumped vertical external cavity surface emitting laser with simple plane-concave cavity. When the pump power at a wavelength of 811.6 nm is 1.5 W, the maximum output power is 40.4 mW at the wavelength of 1005.8 nm. The optical-optical conversion efficiency is 2.7%. . 相似文献
183.
A passive mode-locked diode-pumped self-frequency-doubling Yb:YAB laser with a low modulation depth semiconductor saturable absorber mirror operating at 374 MHz is demonstrated. The measured pulse duration is 1.98 ps at the wavelength of 1044 nm. The maximum average power reaches 45 mW. 相似文献
184.
185.
This paper proposed a ray-tracing model for the Martinez stretcher, derived the calculation formulae for the stretcher of a grating-spherical mirror system and discussed the error for the total dispersion resulted from the spatial dispersion. The calculated results show that the error could be ignored for the beam returned to the stretcher for the second pass in the wavelength range of 750 nm and 850 nm. 相似文献
186.
187.
A compact Er:fiber ring laser operated at a fundamental repetition rate of 325 MHz is reported.Two gain fibers with opposite dispersion are employed to shorten the fiber laser cavity for high repetition rate and soliton-like pulse generation without losing gain and compactness.The spectral bandwidth of the output pulse is 24 nm and the direct pulse duration is 123 fs without extra-cavity compression,which are values near the transform-limited range. 相似文献
188.
Numerical simulation for characterizing femtosecond optical pulses with the SPIDER algorithm
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In this article based on the spectral phase interferometry for direct electric-field reconstruction (SPIDER), the femtosecond pulses with various phase characters are numerically simulated. The spectral phases and amplitudes of the transform-limited pulse, the linear chirped pulse, the cubic dispersion pulse, the quartic dispersion pulse, the self-phase modulation pulse and the pulses with the combination of different chirped characters are retrieved. These characterized pulses are applicable to the real-time measurement as samples for diagnosing the chirped characters of pulses quickly. 相似文献
189.
二茂钛二甘氨酸盐酸盐与DNA作用机理的研究 总被引:5,自引:0,他引:5
二氯二茂钛是一种活性很高的抗肿瘤药物,对它的抗肿瘤机理目前尚无定论.我们用核磁共振方法研究二氯二茂钛与单核苷酸的成键特点时发现[1],二氯二茂钛与核苷酸的成键方式既不同于顺铂,又不同于二氯二茂钼、二氯二茂钒等,表明其抗肿瘤机理可能与顺铂有明显不同.由于二氯二茂钛在水中的溶解度不大,故妨碍了对它与DNA作用机理的进一步研究.最近,二氯二茂钛与甘氨酸形成的配合物──二茂钛二甘氨酸盐酸盐,已被成功地合成出来[2].由于它极易溶于水,且其酸性配体为氨基酸,因此研究该化合物的抗肿瘤活性及其与DNA的作用特点,对了… 相似文献
190.