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991.
Cui Hua XUE Qi Ming MU Shu Hua CHEN* The Faculty of chemistry Sichuan University Chengdu 《中国化学快报》2001,(5)
Molecular tweezers is a novel type of artificial receptors, which not only offer the advantage of efficient construction but also their surfaces can be tailored for specific applications. The clefts of molecular tweezers are particularly effective in regard to complementarity with substrates since functional groups attached to the interior of the cleft converge on substrates held inside1. So, in recent years, the molecular tweezers receptors have attracted more and more attention in molecular … 相似文献
992.
SinceTangetaldevelopedanoveltWo-layerorganicelectr0luminescentdevice(OELD)inl987successfully',OELDhasattractedmuchinterestall0verthew0rId.ltisregardedas"havingbr0ughtthethirdrev0luti0ntoflatpaneldisplay"',becauseithass0manyadvantagessuperiort0CathodeRayTube(CRT)andLiquidCrystalDevice(LCD).Ithasl0wdrivenvoltage(lO0,000cd/m=),highluminescentefficiency(l5lIn/w),goodstability(50,000h),andithassimplestructureandiseasytofabricate'.ComparedtoinorganicELD,OELDiseasie… 相似文献
993.
994.
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996.
Ming‐Liang Tong Xiao‐Ming Chen Seik Weng Ng 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):e374-e375
The Cu atom in the title complex {[Cu(C10H8N2)(C12H8N2)(ClO4)2]·H2O}n, has an N4O2 octahedral coordination geometry, the Cu atoms being bridged by the bipyridine and chelated by the phenanthroline heterocycles. Adjacent molecules are linked into a zigzag chain running along the c axis of the monoclinic unit cell. The chains are connected through lattice water molecules to produce a layer structure. 相似文献
997.
Li Feng Zhi‐Ming Li Zhen‐Xia Chen Yong‐Sheng Tan Lin‐Hong Weng Feng‐Gang Tao 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o680-o681
The title compound, C38H32BrNO6, is a new photochromic tetrahydroazepinoisoquinoline (THAI). The longest spiro bond [1.589 (4) Å] can be broken very easily by UV light, leading to ring opening. This explains the photochromic behaviour. 相似文献
998.
Ming Xia LI Yan Ming WANG Ru Ru CHEN* Research Institute of Elemento-Organic Chemistry Nankai University Tianjin Pittsburgh University Medical Center Pittsburgh PA U. S. A 《中国化学快报》2001,(6)
The chiral diols ((,(,((,((-Tetraaryl-1,3-dioxolane-4,5-dimethanols) have been used for the formation of cyclic titanates and similar derivatives of Mg, Al and Zr. These complexes of oxophilic metal centers were employed in catalytic and stiochiometric enantioselective reactions such as enantioselective addition reactions of carbon-centered nucleophiles to aldehydes1, [2+2] cycloadditions2, and Diels-Alder reactions3. So far, the two hydrogen atoms of all this type of diols are in trans form… 相似文献
999.
Many applications of histogram-based techniques for the purposes of image enhancement are well known. However, these techniques often fail to produce satisfactory results for a broad variety of low-contrast images (e.g., X-ray images). In this paper, we propose a new form of histogram for image contrast enhancement. The input image is first divided into several equal-sized regions according to the intensities of gradients, their corresponding statistical values of gray levels are then modified respectively, and finally the processed histogram for the whole image is obtained by the summation of all the weighted values of regions. The fundamental characteristic of this new form of histogram is that the amplitudes of its components can objectively reflect the contribution of the gray levels to the representation of image information. Accordingly, this new histogram is called gray-level information histogram. The performance of many histogram-based enhancement techniques might be improved dramatically using the proposed histogram. Testing on the X-ray images validates the effectiveness of the new histogram. 相似文献
1000.