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我国高技术产品出口的障碍与对策分析 总被引:1,自引:0,他引:1
本文在分析了我国高技术产品出口障碍的基础上,提出了促进高技术产品出口的指导思想和战略目标,并重点研究了鼓励利用外资与技术转让的政策和鼓励出口的政策。 相似文献
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东昆仑尕林格铁矿床成因年代学及Hf同位素制约 总被引:14,自引:0,他引:14
尕林格矿床发育大量与铁多金属成矿关系密切的花岗闪长岩、石英二长岩、石英二长闪长岩和石英闪长岩体.LA-ICP-MS锆石U-Pb年代学表明石英二长闪长岩的年龄为228.3土0.5 Ma,石英二长岩的年龄为234.4±0.6 Ma.地球化学特征也较为相似,SiO2质量分数中等(58.4%~64.3%),w(FeOT)/w(MgO)偏低(0.62~1.38),A/CNK值(0.52~0.86)<1,轻稀土富集,轻重稀土分馏明显,中等—强烈的负Eu异常(δEu为0.33~0.82),富集Rb,Th等大离子亲石元素,明显亏损高场强元素(Sr,P,Nb,Ta,Ti等),w(Rb)/w(Sr)为0.12~0.39,具有壳幔混合Ⅰ型花岗岩的特征.锆石Hf同位素组成表明,石英二长闪长岩的εHf(t)为-4.15~3.44,T2DM为1042~1523 Ma;石英二长岩εHf(t)为-5.06~1.7,T2DM为1157~1587 Ma,二者具有相同的岩浆来源,可能为壳幔混合岩浆作用的结果.综合研究认为尕林格铁矿床中三叠世岩体为东昆仑218~242 Ma俯冲—碰撞转换阶段,地幔底侵古老陆壳,幔源基性岩浆与壳源花岗质岩浆发生不同程度混合作用的产物,中高温岩浆流体与围岩发生水—岩反应是矽卡岩型矿体形成的主要因素. 相似文献
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The scales on the surface of yak hair fiber act as barriers during the dyeing process. In order to solve the scale problem and to improve the dyeability of yak hair, yak hair fiber was treated by microwave low temperature plasma (MLTP) in this study. The weight loss and the dyeing properties of the yak hair fiber modified by MLTP were investigated. Scanning Electron Microscopy (SEM) photographs were taken to observe the changes in the surface shape of yak hair fiber before and after treatment. Results showed that after MLTP treatment, the scale structure of yak hair was weakened and damaged greatly and the noticeable changes on the surface shape took place. At the same time, a significant improvement in dyeing properties of yak hair fiber was exhibited. 相似文献
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从设计、材料、施工角度进行分析,提出采取控制混凝土的收缩应力及温差应力,控制混凝土坍落度,以达到控制混凝土的收缩,控制高层建筑泵送混凝土裂缝的目的。 相似文献