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91.
Extended Bis(benzothia)quinodimethanes and Their Dications: From Singlet Diradicaloids to Isoelectronic Structures of Long Acenes 下载免费PDF全文
Dr. Shaoqiang Dong Dr. Tun Seng Herng Dr. Tullimilli Y. Gopalakrishna Dr. Hoa Phan Zheng Long Lim Pan Hu Prof. Richard D. Webster Prof. Jun Ding Prof. Chunyan Chi 《Angewandte Chemie (International ed. in English)》2016,55(32):9316-9320
Extended bis(benzothia)quinodimethanes and their dications were synthesized as stable species. The neutral compounds mainly have a quinoidal structure in the ground state but show increased diradical character with extension of the central quinodimethane unit. The dications exhibit similar electronic absorption spectra, NMR spectra, NICS values, and diatropic ring currents to their aromatic all‐carbon acene analogues and thus can be regarded as genuine isoelectronic structures of pentacene, hexacene, and heptacene, respectively. Our research gave some insights into the design and synthesis of stable longer acene analogues. 相似文献
92.
Stepanov S. I. Hoa Nguyen Thi Yen Chekmarev A. M. Tsivadze A. Y. 《Doklady Chemistry》2021,496(2):32-37
Doklady Chemistry - The isomolar series method was used to identify the regions of synergistic extraction of praseodymium and neodymium from low-acid nitrate solutions containing ammonium nitrate... 相似文献
93.
Hoa T.M. Pham T. Kulrattanarak R.G.M. van der Sman C.G.P.H. Schroen R.M. Boom P.M. Sarro 《Procedia Chemistry》2009,1(1):345-348
This paper presents the design, fabrication and testing of deterministic ratchets which are used for fractionation purpose. Ratchets with different configuration are prepared to determine particle trajectories with different sizes. Silicon based MEMS technology is used to fabricate devices containing arrays of obstacles with varying size, spacing and number. The arrays of high aspect ratio, 7-20μm wide, silicon pillars are defined and etched in 60 to 80μm deep microchannels using Deep Reactive Ion Etching (DRIE). The working modes of the ratchets are demonstrated using colloidal suspensions of latex particles which have an average diameter ranging between 2 and 6μm. 相似文献
94.
This paper addresses the problem of an adaptive synchronization of two chaotic Hindmarsh–Rose (HR) neurons coupled with a gap junction via a single control input. Two adaptive control approaches (i.e., a nonlinear control when the entire state variables are available and a linear feedback control when only the membrane potential is available) are proposed to guarantee the asymptotic synchronization of the state trajectories of two coupled HR neurons having unknown parameters. Numerical simulations demonstrating and verifying the effectiveness of the proposed control methods are provided. 相似文献
95.
Mesh generation in regions in Euclidean space is a central task in computational science, and especially for commonly used numerical methods for the solution of partial differential equations, e.g., finite element and finite volume methods. We focus on the uniform Delaunay triangulation of planar regions and, in particular, on how one selects the positions of the vertices of the triangulation. We discuss a recently developed method, based on the centroidal Voronoi tessellation (CVT) concept, for effecting such triangulations and present two algorithms, including one new one, for CVT-based grid generation. We also compare several methods, including CVT-based methods, for triangulating planar domains. To this end, we define several quantitative measures of the quality of uniform grids. We then generate triangulations of several planar regions, including some having complexities that are representative of what one may encounter in practice. We subject the resulting grids to visual and quantitative comparisons and conclude that all the methods considered produce high-quality uniform grids and that the CVT-based grids are at least as good as any of the others. 相似文献
96.
Amorphous soft magnetic ribbons Fe73.5−xCrxSi13.5B9Nb3Cu1 (x=1–5) have been fabricated by rapid quenching on a single copper wheel. The differential scanning calorimetry (DSC) patterns showed that the crystallization temperature of α-Fe(Si) phase is ranging from 542 to 569 °C, a little higher than that of pure Finemet (x=0). With the same annealing regime, the crystallization volume fraction as well as the particle size of α-Fe(Si) crystallites decreased with increasing Cr amount substituted for Fe in studied samples. Especially, the interesting fact is that the laminar structure of heat-treated ribbons on the surface contacted to copper wheel in the fabricating process has been firstly discovered and explained to be related to the existence of Cr in studied samples. The hysteresis loop measurement indicated that there is the pinning of displacement of domain walls. The giant magnetocaloric effect (GMCE) has been found in amorphous state of the samples. After annealing, the soft magnetic properties of investigated nanocomposite materials are desirably improved. 相似文献
97.
Ngoc Hoa Tran Huy Carine Compain Louis Ricard Franois Mathey 《Journal of organometallic chemistry》2002,650(1-2):57-58
Stabilised phosphorus ylides react with transient terminal phosphinidene complexes [RP---W(CO)5] (R=Ph, Me) to give products resulting from a formal insertion of P into a C---H bond via an initial nucleophilic attack of the ylidic carbon. 相似文献
98.
The quantitative assessment of single molecule diffusion trajectories by orthogonal regression analysis is reported. This analysis is broadly applicable to any single particle tracking experiments in which diffusion along one dimension (1D) is expected. It affords quantitative data on the (in plane) orientation of 1D trajectories, allowing for their absolute orientations to be determined. Histograms depicting the distribution of trajectory angles provide new physical insights into the degree of trajectory alignment, and by inference, materials order. Estimates of the errors in the trajectory angle and particle positioning along each trajectory are also obtained. The angle results are compared to those from single-step angle determinations. The advantages of the regression method include its simplicity and computational efficiency, and the ability to objectively differentiate between 1D and 2D/immobile trajectories. Its utility is demonstrated through analysis of single molecule diffusion trajectories in surfactant-templated mesoporous silica films as probed by wide-field fluorescence microscopy. The trajectory angle histograms obtained provide quantitative data on mean trajectory orientation and the degree of trajectory alignment in distinct populations and sample regions. Mesopore order was quantitatively assessed by implementation of an order parameter,
= 2 ≈ 0.9. The latter corresponds to an ≈14° average deviation of the individual trajectories from the mean trajectory (and mesopore) orientation in each domain. 相似文献
99.
Brotherton WS Guha PM Phan H Clark RJ Shatruk M Zhu L 《Dalton transactions (Cambridge, England : 2003)》2011,40(14):3655-3665
Rapid coupling reactions between 2,6-bis(azidomethyl)pyridine and terminal alkynes in the presence of 5 mol% Cu(OAc)(2)·H(2)O without the addition of a reducing agent afford tridentate ligands for first-row transition-metal ions. The chelation between Cu(II) and alkylated nitrogen atoms of the azido groups of 2,6-bis(azidomethyl)pyridine, as observed in the solid state, is credited for the acceleration of the azide-alkyne cycloaddition reactions. 相似文献
100.
A.T. Raghavender Nguyen Hoa Hong 《Journal of magnetism and magnetic materials》2011,323(16):2145-2147
Mn-ferrite nanoparticles having diameter in the range 17-45 nm were synthesized by modified co-precipitation method using metal nitrate solutions. Different concentrations of NaOH were found to affect the growth of particle size. Néel temperature (TN) was found to increase with increasing particle size. The obtained Néel temperature was higher than that of the bulk. The shift in the Néel temperature is described by the finite size-scaling theory [TN(d)−TN(bulk)]/TN(bulk)=(d/d0)−1/v, where d is particle size, v=0.6±0.1 and d0=1.7±0.1 nm. 相似文献