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使(C_6H_5COCHCOC_6H_5)_2Eu·OCOCH_3与C_5H_5Na反应得到了一种热稳定性高,对氧和水都不敏感的黄褐色固体化合物,其熔点为230—232℃。经元素分析及分子量测定,其分子式为(C_6H_5COCHCOC_6H_5)_2EuC_5H_5。 测定了此化合物的紫外吸收光谱和红外吸收光谱,结果表明,其分子结构式可能为(C_6H_5COCHCOC_6H_5)_2Eu-η′C_5H_5。 相似文献
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利用原位红外光谱技术研究了常压下CO和CH3ONO多相催化合成草酸二甲酯的反应.发现在草酸二甲酯生成的同时还存在副反应,副产物NO继续与CO反应生成CO2和N2O.铜在合金催化剂中起辅助作用,铜分散把,使CO桥式吸附减少,线式吸附增多.主反应与CO桥式吸附无关,而副反应却依赖于CO的桥式吸附.CO线式吸附具有更高的反应活性. 相似文献
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为实现大型物理实验现场复杂多样的仪器控制,分析了物理实验的特点、过程、环境及仪器控制功能需求,利用虚拟仪器技术、计算机网络技术和数据库技术,建立了一套集成硬件和软件的综合控制管理信息系统,实现记录系统中示波器状态远程批量设置及波形数据自动采集、控制探测系统的高压电源并发加压或退压、保障各测试项目间测试仪器之间时间关联、监控UPS电量和远端现场图片或视频状态。给出了系统的关键的设计思路,列举了某型示波器控制的通用控制代码。结果表明,系统达到了一人总控或多人分权控制实验过程中多种多台仪器的目标,方便快捷地实现不同品牌不同类型示波器的相同功能。 相似文献
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A novel complex [Na(NIT-1'-MeBzIm)3]ClO4 (NIT-1'-MeBzIm = 2-{2'-[(1'- methyl)benzimidazolyl]}-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) has been prepared and structurally characterized by elemental analysis, IR spectra and X-ray diffraction methods. The title complex crystallizes in trigonal, space group P3 and Z = 2. Crystal data: C45H57ClN12NaO10, Mr = 984.47, a = 13.9411(8), b = 13.9411(8), c = 14.8622(16) A, γ= 120°, V= 2501.5(3) A^3, Dc = 1.307 g/cm^3, μ(MoKα) = 0.152 mm^-1, F(000) = 1038, R = 0.0637 and wR = 0.1813 for 1957 observed reflections with I 〉 2σ(I). X-ray analysis reveals that the Na(I) ion is six-coordinated with three NIT-1'-MeBzlm radicals. As we know, three radicals coordinating to the Na(I) ion in the main group by a chelate way is the first example. The Na(I) ion resides in a distorted octahedron with a facial configuration. Meanwhile, the intermolecular weak interactions result in a 2-D double layer conformation where the uncoordinated perchlorate anions are inserted in the packing space and take part in the H-bond interactions, and each complex is connected with six neighboring complexes and three perchlorate anions. 相似文献
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所谓复合最值就是在一群最大(小)值中求最值。其思考方法有以下几种。一、算术平均值法若M,m分别是变数a_1,a_2,…a_n中的最大者与最小者,则对a_1,a_2,…,a_n中任意几个数的算术平均值A均有 M≥A≥m。这虽是一个简单的事实,却应用广泛且易被人忽视。例1 求单位圆内接四边形的最短边的最大值。(82年上海中学数学竞赛试题) 解记圆内接四边形ABCD各边所对劣弧度数分别为AB,BC,CD,DA,则最短边所对劣弧度数小于等于故单位圆最短边的最大值为2sinπ/4=2~(1/2)。此时四 相似文献
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Three kinds of metal catalysts Ni/D_4, Ni-Mn/D_4, Ni-Mn-La/D_4, wrapped in organosilicon compound were prepared by metal vapor synthesis. Their feature was characterized with XRD, TEM, XPS, FMR and static magnetic measurement. The metal particle size in catalysts was less than 3.5 am. The results of XPS showed that the metals in the catalysts existed in zero and other valent state. Inner metal, as an organosilicon compound folded around the metal particle, was protected from oxidation. FMR and static magnetic measuremeat revealed that metal particles were spheroidal and of superparamagnetism. Of all the caralysts the catalytic activity of Ni-Mn-La/D_4 was the highest in hydrogenating furfuraldehyde into furfuralcohol. 相似文献
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碧冬茄的挥发性化学成份鉴定及其驱蚊活性研究初报 总被引:1,自引:0,他引:1
碧冬茄的挥发性化学成份鉴定及其驱蚊活性研究初报么恩云,李正名,平霄飞,施红林,毕富春,王文丽(元素有机化学国家重点实验室,南开大学元素有机化学研究所天津300071)杨瑞华(南开大学生物系天津300071)在天然植物中蕴藏着极其丰富的生理活性物质。近... 相似文献