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黄河断流的不良影响及水资源利用对策 总被引:3,自引:0,他引:3
七十年代以来黄河流域频繁发生的断流现象,加剧了黄河水资源利用的供需矛盾,本文对黄河断流的现状,成因及其影响进行了全面分析,并系统地阐述了黄河流水资源利用现状及其存在的问题,在此基础上,提出了解决当前水资源供需矛盾的合理途径及建议。 相似文献
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利用高温固相烧结法制备了Sm3+掺杂的BaBPO5材料.利用X射线粉末衍射和Fourier红外光谱测试和分析晶体结构.通过两种方法实现了Sm3+到Sm2+的还原:一是在还原气氛中制备Sm2+掺杂的BaBPO5材料;二是利用X射线照射还原手段得到Sm2+.结果表明;在X射线的照射下,可有效地实现在BaBPO5基质中Sm3+→Sm2+的还原.发光和衰减测试效果表明:利用两种方法得到的Sm2+具有不同的发光特性.对Sm2+的发光稳定性和缺陷结构进行了分析:在488 nm的Ar+激光照射下,两种方法得到的Sm2+的发光强度均降低,即均具有光漂白作用,在BaBPO5之中Sm2+的发光和稳定性强烈地依赖于其制各方法. 相似文献
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某高铁三水铝石矿制备4^°A沸石半工业试验研究 总被引:1,自引:0,他引:1
介绍了利用我国呆滞矿高铁三水铝石制备4^°A沸石的半工业试验研究,讨论了整个工艺流程中主要的影响因素。说明表明,常压下对三水铝石的浸出可得到合格的铝酸钠溶液。经化学合成4^°A沸石,得到了高品质的4^°A沸石产品。工艺流程简单,经济效益显著,有广泛的市场前景。 相似文献
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New blue luminescence glass-ceramic samples were prepared in air by annealing of the Eu^3+-doped Li2O-BaO-B2O3 glass. The as-made glass samples only showed the sharp emission peaks assigned to the transitions of 5^D0-7^Fj (J=0, 1, 2, 3, 4) of Eu^3+ ions. The glass-ceramic samples gave a strong and broad emission band peaking at about 382 nm ascribed to the 5d-4f transition of Eu^2+ ions. The optical properties such as excitation and emission spectra, and the decay time of the Eu^2+ ions were investigated in the glasses or the glass-ceramics samples. The X-ray diffraction pattern showed that LiBan9O15 might be demonstrated to be the crystallites in the glass-ceramic, which contributed to the blue luminescence. SEM micrograph was investigated on the glass-ceramic samples obtained by crystallization of the glass matrix resulting in a mixture of poly-crystals. 相似文献
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The luminescence of Nd3+-doped in NaBi(WO4)2 single crystal was investigated from 10 K to room temperature.The excitation source was a pulsed dye laser in resonance into the(4G5/2+2G(1)7/2) levels of Nd3+ ions.Several blue emission bands in the up-conversion luminescence spectra corresponded to transitions from 2P1/2 to 4I9/2.Some violet bands corresponding to transitions of 4D3/2→(4I9/2,4I11/2,4I13/2) were also observed.For comparison,the luminescence spectra and decay curves excited by the pulsed 355 nm l... 相似文献
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介绍了利用我国呆滞矿高铁三水铝石制备4A°沸石的半工业试验研究,讨论了整个工艺流程中主要的影响因素。试验表明,常压下对三水铝石的浸出可得到合格的铝酸钠溶液。经化学合成4A°沸石,得到了高品质的4A°沸石产品。工艺流程简单,经济效益显著,有广阔的市场前景 相似文献