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研究了微波场中T型分子筛的结晶过程。考察了微波加热体系中合成参数如合成时间、溶胶组成、反应压力和模板剂用量对分子筛晶化的影响。微波加热的主要优点是减少合成时间,无模板剂的溶胶在普通加热条件下的晶化时间需要120 h,而在微波场中则仅需要20~25 h。另一方面,由于微波的快速加热特性促进了稳定相钙十字沸石的生成,从而减小了次稳定相T型分子筛的结晶区间。在未添加模板剂条件时,100 ℃下微波水热合成T型分子筛的结晶区间为:20≤nSiO2/nAl2O3≤22和0.31≤ nM2O/nSiO2≤0.33(其中M2O=Na2O+K2O, nNa/nK=3和nM2O/nSiO2=11.70)。在普通加热和微波加热合成体系中,添加模板剂均能扩大结晶区间,同时还可以进一步减少合成时间。 相似文献
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Generalized oscillator strengths for some higher valence-shell excitations of krypton atom 下载免费PDF全文
The valence-shell excitations of krypton atom have been
investigated by fast electron impact with an angle-resolved
electron-energy-loss spectrometer. The generalized oscillator
strengths for some higher mixed valence-shell excitations in 4d,
4f, 5p, 5d, 6s, 6p, 7s $\leftarrow$ 4p of krypton atom have
been determined. Their profiles are discussed, and the generalized
oscillator strengths for the electric monopole and quadrupole
excitations in $5\p \leftarrow 4\p$ are compared with the calculations
of Amusia \it et al. (\it Phys. Rev. A \textbf67
022703 (2003)). The differences between the experimental results and
theoretical calculations show that more studies are needed. 相似文献
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Experimental research on spectrum and imaging of continuous-wave terahertz radiation based on interferometry 下载免费PDF全文
A system for measuring terahertz spectrum is proposed based on optical interferometer theory, and is experimentally demonstrated by using a backward-wave oscillator as the terahertz source. A high-resolution, high-precision interferometer is constructed by using a pyroelectric detector and a chopper. The results show that the spectral resolution is better than 1 GHz and the relative error of frequency is less than 3%. The terahertz energy density distribution is calculated by an inverse Fourier transform and tested to verify the feasibility of the interferometric approach. Two kinds of carbon-fiber composites are imaged. The results confirm that the interferometer is useful for transmission imaging of materials with different thickness values. 相似文献
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利用KC-5直线型吸烟机同时捕集主、侧流烟气,固相萃取预处理烟气样品,以ZORBAX SB-C18柱(150 mm×4.6mm,5 μm)作色谱柱,V(乙腈):V(水)=75:25作流动相,激发波长380 nm,发射波长413 nm,高效液相色谱-荧光检测法测定加入丹参、白芍和淫羊藿提取物前后卷烟主、侧流烟气中苯并[a]芘(BaP)含量的变化.结果表明,①该法的回收率为93.70%,RSD1.67%,检测限0.62 ng/mL;②丹参、白芍和淫羊藿提取液可使卷烟的主、侧流烟气中BaP含量分别降低35.80%、20.39%、21.71%和11.11%、14.69%、10.97%,且BaP的降低量与总粒相物(TPM)之间不存在明显的相关性. 相似文献
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