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991.
用硝酸盐分解法(N-法)和柠檬酸络合法(L-法)合成了La-Sr-Ni-O系复合氧化物.用XRD技术考察了样品组成、制备条件及灼烧气氛等对产物结构的影响.结果表明:按La_(1-x)Sr_xNiO_3计量比,用N-法合成只能形成四方体心K_2NiF_4结构的A_2BO_4型复合氧化物.而采用L-法,通过改变条件,在0.0≤x≤0.2范围内可形成菱形晶系钙钛矿结构的复合氧化物.另外,用L-法合成La_(2-x)Sr_xNiO_4系列样时发现,制备条件及灼烧温度、气氛对样品结晶态存在较大的影响,高温、空气氛下可形成高结晶态的K_2NiF_4结构复合氧化物.La_(2-x)Sr_xNiO_4体系CO催化氧化活性研究表明,随x(Sr~(2+)取代量)增加,CO的转化率增加. 相似文献
992.
Liyun Zhong Jiye Cai Yi Liu Honggao Tang Yuping Sun Jiaju Du 《Journal of Infrared, Millimeter and Terahertz Waves》1991,12(3):239-249
In this paper we study the room-temperature infrared transmission spectra (400–1600cm?1) and far-infrared diffuse reflection spectra (50–450cm?1) in Pb-doped Bi?Sr?Ca?Cu?O (2223) single phase (Tc=107k, sp1), multiphase (Tc=110k, sp2) and nonsuperconducting samples (sp3). The spectral features in superconductor are totally different from those in nonsuperconductor, which show the different crystal structure. The correlation existing between a factor group analysis of the phonons in (2223) and (2212) compounds affords a tentative assignment of ir-active modes in Pb-doped (2223) single phase by comparison with reported data in (2212) materials. The Cu?O stretching Eu vibration (605cm?1) of CuO2 layers is the characteristic vibrational mode related perovskitelike crystal structures. Two phonon coupling effect emerges in the infrared transmission spectra in Pb-doped superconductor. The Ca?O vibration A2u (254cm?1) might be related to superconductivity of Bi-based family. 相似文献
993.
Shiyang Zhu Rui Li Lee S.J. Li M.F. Du A. Singh J. Chunxiang Zhu Chin A. Kwong D.L. 《Electron Device Letters, IEEE》2005,26(2):81-83
Schottky-barrier source/drain (S/D) germanium p-channel MOSFETs are demonstrated for the first time with HfAlO gate dielectric, HfN-TaN metal gate and self-aligned NiGe S/D. The drain drivability is improved over the silicon counterpart with PtSi S/D by as much as /spl sim/5 times due to the lower hole Schottky barrier of the NiGe-Ge contact than that of PtSi-Si contact as well as the higher mobility of Ge channel than that of Si. 相似文献
994.
995.
Ji‐Min Du Hui‐Yi Zeng Zhen‐Chao Dong Guo‐Cong Guo Jin‐Shun Huang 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(7):m396-m397
The title compound, {[Cu4(C3H4NS2)4]·2H2O}n, was produced by diffusing a solution of 2‐mercaptothiazoline in tetrahydrofuran into a solution of CuCl in CH3CN at room temperature. The structure is characterized by self‐assembled one‐dimensional chains that are condensed from butterfly‐like [Cu(C3H4NS2)]4 tetrameric units via double S‐bridging at opposite ends. The Cu—Cu distances within the Cu4 butterfly cluster are in the range 2.7103 (10)–2.9764 (10) Å, while the shortest Cu?Cu intercluster distance is 3.468 (1) Å, much longer than the sum of the van der Waals radii. 相似文献
996.
997.
998.
Quasi-hereditary algebras can be viewed as a Lie theory approach to the theory of finite dimensional algebras. Motivated by the existence of certain nice bases for representations of semisimple Lie algebras and algebraic groups, we will construct in this paper nice bases for (split) quasi-hereditary algebras and characterize them using these bases. We first introduce the notion of a standardly based algebra, which is a generalized version of a cellular algebra introduced by Graham and Lehrer, and discuss their representation theory. The main result is that an algebra over a commutative local noetherian ring with finite rank is split quasi-hereditary if and only if it is standardly full-based. As an application, we will give an elementary proof of the fact that split symmetric algebras are not quasi-hereditary unless they are semisimple. Finally, some relations between standardly based algebras and cellular algebras are also discussed. 相似文献
999.
本文采用一种优化的硫化助熔剂方法合成了红外上转换材料,这种材料能够在室温下将红外光转换成可见光。这种新工艺在反应效率、生产成本、环境保护、工艺难度等方面均优于传统的热熔工艺。文章给出了红外上转换材料的激励光谱和发射光谱。 相似文献
1000.
Zilei Chen Hong Zhang Bing Liu Guosheng Yang Hassan Y. Aboul-Enein Wenbo Wang Ruiyan Ding Hongxia Du Huidong Li 《Chromatographia》2007,66(11-12):887-891
A rapid multi-residue method has been developed for the determination of 16 herbicides in garlic. The analytical procedure is based on prior microwave heating prevention of the generation of sulfur-containing compounds. The garlic samples which had been pretreated were extracted with acetonitrile and cleaned up by solid-phase extraction. The herbicide residues were detected by gas chromatography–mass spectrometry with selected ion monitoring. The recoveries of 16 herbicides ranged from 69.0 to 105.4% with the relative standard deviations (RSD) below 10.1%. The limit of quantification (LOQ) ranged from 0.003 to 0.015 mg kg?1. 相似文献