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Maria Madjarova Mitsugu Kakuta Takashi Obi Masahiro Yamaguchi Nagaaki Ohyama 《Optical Review》1998,5(3):143-151
Pseudo-random properties of a class of two-dimensional (2-D) 5-neighborhood cellular automata (CA), built around nonlinear (OR, AND) and linear (XOR) Boolean functions are studied. The site values at each step of the 2-D CA evolution are taken in parallel and form pseudo-random sequences, which satisfy the criteria established for pseudo random number generator (PRNG): long period, excellent random qualities, single bit error propagation (avalanche criteria), easy and fast generation of the random bits. A block-scheme for secure Stream Cipher based on 2-D CA is proposed. The 2-D CA based PRNG algorithm has simple structure, use space-invariant and local interconnections and can be easily realized in very large scale integration or parallel optoelectronic architectures. 相似文献
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Properties of as prepared or nanoengineered III-V semiconductor surfaces provide attractive means for photonic detection of different adsorbants from surrounding gaseous or liquid environments. To be practical, this approach requires that the surface is made selectively sensitive (functionalized) to targeted species. In addition, such surface has also to stay stable over extended period of time to make it available for rapid testing. Numerous reports demonstrate attractive properties of GaAs for sensing applications. One of the most fundamental issues relevant to these applications concerns the ability to functionalize chemically, or biologically, the surface of GaAs. The most studied method of GaAs surface functionalization is based on formation of self-assembled monolayers (SAMs) of various n-alkanethiols, HS-(CH2)n-T (T = CH3, COOH, NH2, etc.). In spite of multi-year research concerning this issue, it has only been recently that a comprehensive picture of SAMs formation on GaAs and an understanding of the natural limitation of the SAM-GaAs interface in some bio-chemical sensing architectures has begun to emerge. 相似文献
15.
Tamara Alhilfi Pierre Chambon Steve P. Rannard 《Journal of polymer science. Part A, Polymer chemistry》2020,58(10):1426-1438
Ambient temperature-initiated anionic polymerization has generated branched polystyrenes of varying molecular weights and architectures by inclusion of a distyryl branching comonomer into a conventional sec-Butylithium-initiated polymerization of styrene. Primary chain length control within the branched polymers, and restriction of the branching points to varying segments of the primary chains, led to variations of glass transition temperature with no direct correlation to the branched polymer molecular weight but a strong relationship to the length of individual chains comprising the branched macromolecules. 相似文献
16.
《无机化学与普通化学杂志》2018,644(18):1084-1090
Reaction of a imidazole phenol ligand 4‐(imidazlo‐1‐yl)phenol (L) with 3d metal salts afforded four complexes, namely, [Ni(L)6] · (NO3)2 ( 1 ), [Cu(L)4(H2O)] · (NO3)2 · (H2O)5 ( 2 ), [Zn(L)4(H2O)] · (NO3)2 · (H2O) ( 3 ), and [Ag2(L)4] · SO4 ( 4 ). All complexes are composed of monomeric units with diverse coordination arrangements and corresponding anions. All the hydroxyl groups of monomeric cations are used as hydrogen‐bond donors to form O–H ··· O hydrogen bonds. However, the coordination habit of different metal ions produces various supramolecular structures. The NiII atom shows octahedral arrangement in 1 , featuring a 3D twofold inclined interpenetrated network through O–H ··· O hydrogen bond and π–π stacking interaction. The CuII atom of 2 displays square pyramidal environment. The O–H ··· O hydrogen bond from the [Cu(L)4(H2O)]2+ cation and lattice water molecule as well as π–π stacking produce one‐dimensional open channels. NO3– ions and lattice water molecules are located in the channels. 3 is a 3D supramolecular network, in which ZnII has a trigonal bipyramid arrangement. Two different rings intertwined with each other are observed. The AgI in 4 has linear and triangular coordination arrangements. The mononuclear units are assembled into a 1D chain by hydrogen bonding interaction from coordination units and SO42– anions. 相似文献
17.
《Acta Crystallographica. Section C, Structural Chemistry》2018,74(7):789-796
Three new metal(II)–cytosine (Cy)/5‐fluorocytosine (5FC) complexes, namely bis(4‐amino‐1,2‐dihydropyrimidin‐2‐one‐κN3)diiodidocadmium(II) or bis(cytosine)diiodidocadmium(II), [CdI2(C4H5N3O)2], ( I ), bis(4‐amino‐1,2‐dihydropyrimidin‐2‐one‐κN3)bis(nitrato‐κ2O,O′)cadmium(II) or bis(cytosine)bis(nitrato)cadmium(II), [Cd(NO3)2(C4H5N3O)2], ( II ), and (6‐amino‐5‐fluoro‐1,2‐dihydropyrimidin‐2‐one‐κN3)aquadibromidozinc(II)–6‐amino‐5‐fluoro‐1,2‐dihydropyrimidin‐2‐one (1/1) or (6‐amino‐5‐fluorocytosine)aquadibromidozinc(II)–4‐amino‐5‐fluorocytosine (1/1), [ZnBr2(C4H5FN3O)(H2O)]·C4H5FN3O, ( III ), have been synthesized and characterized by single‐crystal X‐ray diffraction. In complex ( I ), the CdII ion is coordinated to two iodide ions and the endocyclic N atoms of the two cytosine molecules, leading to a distorted tetrahedral geometry. The structure is isotypic with [CdBr2(C4H5N3O)2] [Muthiah et al. (2001). Acta Cryst. E 57 , m558–m560]. In compound ( II ), each of the two cytosine molecules coordinates to the CdII ion in a bidentate chelating mode via the endocyclic N atom and the O atom. Each of the two nitrate ions also coordinates in a bidentate chelating mode, forming a bicapped distorted octahedral geometry around cadmium. The typical interligand N—H…O hydrogen bond involving two cytosine molecules is also present. In compound ( III ), one zinc‐coordinated 5FC ligand is cocrystallized with another uncoordinated 5FC molecule. The ZnII atom coordinates to the N(1) atom (systematic numbering) of 5FC, displacing the proton to the N(3) position. This N(3)—H tautomer of 5FC mimics N(3)‐protonated cytosine in forming a base pair (via three hydrogen bonds) with 5FC in the lattice, generating two fused R22(8) motifs. The distorted tetrahedral geometry around zinc is completed by two bromide ions and a water molecule. The coordinated and nonccordinated 5FCs are stacked over one another along the a‐axis direction, forming the rungs of a ladder motif, whereas Zn—Br bonds and N—H…Br hydrogen bonds form the rails of the ladder. The coordinated water molecules bridge the two types of 5FC molecules via O—H…O hydrogen bonds. The cytosine molecules are coordinated directly to the metal ion in each of the complexes and are hydrogen bonded to the bromide, iodide or nitrate ions. In compound ( III ), the uncoordinated 5FC molecule pairs with the coordinated 5FC ligand through three hydrogen bonds. The crystal structures are further stabilized by N—H…O, N—H…N, O—H…O, N—H…I and N—H…Br hydrogen bonds, and stacking interactions. 相似文献
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{[Pb3(CPIDA)2(H2O)3]·H2O}n1, {[Cd3(CPIDA)2(H2O)4]·5H2O}n2, [Cd(HCPIDA)(bpy)(H2O)]n3 (bpy=4,4′-bipyridine) and {[Co3(CPIDA)2(bpy)3(H2O)4]·2H2O}n4 were synthesized with N-(4-carboxyphenyl) iminodiacetic acid (H3CPIDA). In 1, the CPIDA3− ligands adopt chelating and bridging modes with Pb(II) to possess a 3D porous framework. In 2D-layer 2, the CPIDA3− ligands display a simple bridging mode with Cd(II). The 2D layers have parallelogram-shaped channels along a axis. With bpy ligands, the HCPIDA2− ligands in 3 show more abundant modes, but 3 still displays a 2D sheet on bc plane for the unidentate bpy molecules. However, in 3D-framework 4, the bpy ligands adopt bridging bidentate at a higher pH value and the CPIDA3− ligands show bis-bidentate modes with Co(II). Additionally, 2D correlation analysis of FTIR was introduced to ascertain the characteristic adsorptions location of the carboxylate groups with different coordination modes in 4 with thermal and magnetic perturbation. Compounds 1, 2 and 4 exhibit the fluorescent emissions at room temperature. 相似文献
19.
Xiujun Yu Hongxia Lu Qi Li Yunlong Zhao Liwei Zhang Bingbing Fan Deliang Chen Hailong Wang Hongliang Xu Rui Zhang 《Crystal Research and Technology》2011,46(11):1175-1180
Micro/nanostructured ZnSn(OH)6/ZnO composite architectures were synthesized through a simple one‐step hydrothermal method. Phase structure and morphology of the products were characterized by using X‐ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). ZnSn(OH)6 microcubes and ZnO nanorods with uniform size were interconnected to form the micro/nanostructured architectures. ZnO nanorods preferentially grow at edges and corners of the microcubes. Morphology of the products was susceptible to concentration of the reactants. With increasing reactant concentration, the ZnO nanorods grown on the surfaces of ZnSn(OH)6 microcubes disappeared. Meanwhile, the smooth surfaces of the ZnSn(OH)6 microcubes become coarsened and were etched to spherical outlines. Growth mechanism of the micro/nanostructured ZnSn(OH)6/ZnO composite architectures was discussed and thermal decomposition properties of the micro/nanostructured ZnSn(OH)6/ZnO composite architectures at high temperature were examined. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
20.
Fabrication of fibrous patterned architectures with controlled deposition and multidirectional alignment
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In recent years, the ability to produce nanofibrous patterned architectures by electrospinning has exposed a wide range of potential applications in biomedical and industrial fields. Directional alignment, controlled deposition, and density variation into the patterns are desirable for many applications such as tissue engineering scaffolds and micro/nano‐electronic devices. In this study, we introduce a versatile method for fabrication of various kinds of nanofibrous deposition patterns with the help of microprocessor based control system for switching collector electrodes. By controlling the concurrent activation time of two adjacent electrodes, we demonstrated that amount of fibers going into the pattern can be adjusted and alignment in electrospun fibers can be obtained. We also revealed that the deposition density of electrospun fibers in different areas of patterned architectures can be varied. This advanced technique can have a significant impact in enhancing the technology of electrospinning and can help develop new applications in health sciences and industrial sectors. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献