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(Fe4Cr4Ni)9 C4的晶体结构 总被引:3,自引:0,他引:3
(Fe, Cr, Ni)9C4是一种(Fe, Cr, Ni)与C化合而成的金属碳化物矿物, 产于西藏罗布莎蛇绿岩块铬铁矿床中. 经晶体结构测定确定其晶体化学式为: (Fe4.12Cr3.84Ni0.96)8.92C3.70, 简化的化学分子式为(Fe4Cr4Ni)9C4. 该矿物属六方晶系, 空间群为P63 m c, Z = 6, 计算比重Dx = 7.089 g/cm3. Fe, Cr, Ni各有其不同的晶体化学位置, 配位数近似于12, 形成带折皱的堆积层与平的堆积层的互层结构. 部分金属原子具有缺位结构. Fe, Cr, Ni原子间的键长为0.2525~0.2666 nm, C与Fe, Cr, Ni 原子之间的距离为0.1893~0.2169 nm. C的配位数为6, 充填于Fe, Cr, Ni金属原子间构成三方柱配位多面体. 该配位多面体以共角顶或共棱方式相互连接构成了一种新型的金属碳化物结构. 相似文献
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通过对试样进行强度测试后,在高倍电镜和能谱仪上对金刚石界面金属面碳化物的微观结构和含量的观察,分析,测量其表面金属碳化物面积,计算出不同添加剂所生成的金属碳化物在不同浓度和粒度的金刚石中所生成强度的排序,从而确定不同金属碳化物及其物理力学性能的差异,为金刚石制品的生产与开发提供理论依据。 相似文献
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韩丽君 《中国海洋湖沼学报》2003,21(2):171-179
Measurements of three chlorofluorocarbons(CFCs) :trichlorofluoromethane (CFC-11),dichlorodifluoromethane (CFC-12) and trichlorotrifluoroethane (CFC-113), along with methyl chloroform (CH3CCl3) and carbon tetrachloride (CCl4) were made in water samples from Lake Washington,using Electron Capture-Gas Chromatography (EC-GC).The samples were collected in mid-autumn, a period when the lake‘‘‘‘‘‘‘‘s upper layer undergoes rapid cooling,At the time of sam-pling,a strong vertical temperature gradient was present in the lake,with surface temperatures of -14℃,and near bottom(50 meters) temperatures of -8℃ ,The concentrations of dissolved CFC-12 and CFC-11 increased with depht ,as expected from the higher solubilities of these gases at lower temperatures ,Atmospheric measurements made at the sampling site at the time of the cruise ,showed that CFC-11 and CFC-12 saturations in the near surface samples were 100% and 106%,respectively,For the deepest sample (52 meters)CFC-11 and CFC-12 saturations were 102% and 126%,Because the surface layer of the lake respondes to changes in atmospheric CFCs on a time scale of several weeks ,the highere than equilibrium concentrations of CFC-12 observed at the time of sampling may reflect earlier episodes of elevated levels of atmospheric CFC-12 in this urban area.High concentrations of dissolved CFCs in runoff or industrial effluent might also lead to elevated CFC levels in the lake. The cold ,deep water of Lake Wahington is realtively isolated from the effects of surface gas exchange except during winter ,and the supersaturations observed in the deep layer may reflect pe-riods of elevated atmospheric CFC-12 levels from the previous winter season.These results were compared to summertime profiles of CFC-11 and CFC-12 made in 1994. 相似文献
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当今,国内外十分重视金刚石表面处理技术,它可以用少量投资和简单的工艺方法,使金刚石性能得到改善。常用的处理技术有:①电镀法;②真空镀法;③扩散渗覆法;④气相沉积法;⑤离子镀法;⑥化学镀法。 相似文献
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正2014年11月12日,中美两国发布《中美气候变化联合声明》,宣布清洁能源发展合作与温室气体减排方面的双边协议:美国计划于2025年实现在2005年基础上减排26%~28%的全经济范围减排目标并将努力减排28%;中国计划2030年左右CO2排放达到峰值且将努力早日达峰,并计划到2030年非化石能源占一次能源消费比重提高到20%左右。中美两国新的减排目标为2015年气候谈判做出了重要的承诺,以合作的方式寻求建立互信和促进全球能源转型,为国际应对气候变化行动注入新的活力。中美两国减排目标的确定是根据现有政策措施开展密集的碳减排成本效应分析。中美两国新的减排承 相似文献
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通过对不同试样进行物理力学性能测试,在高倍电镜下,对金刚石界面及微区进行观察分析和测量,显微照片证明,在界面处,金刚石中的碳原子和胎体中的金属原子(Zr、Ti)分别向对方扩散,从而形成了一层金属碳化物,实现了金刚石与胎体金属之间的真正焊接。分析了碳化物过渡层的形成过程和机理。 相似文献