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991.
Following the approach of Carlet et al. (2011) [9], we construct a class of infinite-dimensional Frobenius manifolds underlying the Toda lattice hierarchy, which are defined on the space of pairs of meromorphic functions with possibly higher-order poles at the origin and at infinity. We also show a connection between these infinite-dimensional Frobenius manifolds and the finite-dimensional Frobenius manifolds on the orbit space of extended affine Weyl groups of type A defined by Dubrovin and Zhang.  相似文献   
992.
We get a new inequality on the Hodge number $h^{1,1}(S)$ of fibred algebraic complex surfaces $S$ , which is a generalization of an inequality of Beauville. Our inequality implies the Arakelov type inequalities due to Arakelov, Faltings, Viehweg and Zuo, respectively.  相似文献   
993.
This research proposes a solution framework based on discrete-event simulation, sequential bifurcation (SB) and response surface methodology (RSM) to address a multi-response optimization problem inherent in an auto parts supply chain. The objective is to identify the most efficient operating setting that would maximize the logistics performance after the expansion of the assembly plant’s capacity due to market growth. In the proposed framework, we first construct a comprehensive simulation as a platform to model the physical flow of the auto parts operations. We then apply the SB to identify the most important factors that influence system performance. To determine the optimal levels of these key factors, we employ RSM to develop metamodels that best describe the relationship between key decision variables and the multiple system responses. We adapt the Derringer–Suich’s desirability function to find the optimal solution of the metamodels. Computational study shows that our method enables the greatest improvement on system performance. The proposed method helps the case firm develop insights into system dynamics and to optimize the operating condition. It realizes the performance objective of the auto parts supply chain without the need for additional fiscal investment.  相似文献   
994.
In this article, a decoupling scheme based on two‐grid finite element for the mixed Stokes‐Darcy problem with the Beavers‐Joseph interface condition is proposed and investigated. With a restriction of a physical parameter α, we derive the numerical stability and error estimates for the scheme. Numerical experiments indicate that such two‐grid based decoupling finite element schemes are feasible and efficient. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1066–1082, 2014  相似文献   
995.
Study of fine-particle media, because of their high sorption capacities, is of particular importance for the use as backfill materials in waste repository design, and because argillaceous formations are particularly suitable as host rock formations. In this study, sorption and retardation characteristics of strontium in fine-particle media were studied to evaluate the distribution coefficient (K d ) and retardation factor (R d ) of this radioactive element in fine-particle media, which was comprised of selected particles with a diameter less than 1 mm from a candidate site to dispose very low level waste (VLLW). The results indicated that K d values of strontium under different initial concentrations ranged between 20 and 110. Values of strontium R d measured from column experiments ranged between 36 and 102, with the corresponding K d values, determined from solving the inverse problem of R d calculating formula, ranging between 5 and 20. In conclusion, the K d value of Sr from the batch tests was found to be higher than these from the column experiments.  相似文献   
996.
Bright funnels : A series of dendritic systems, which are capable of funneling energy from the periphery to the core, have been synthesized. The photophysical properties of dendrimers have been determined. Selective excitation of the donor leads to an efficient energy transfer (>90 %) to the acceptor. The approach provides a facile synthesis for the modification of near‐infrared BF2‐Azadipyrromethenes.

  相似文献   

997.
欧阳歆  张祚  阳年发 《有机化学》2010,30(1):120-123
薄荷基溴和新薄荷基溴是一类非常有用的不对称合成中间体。以L-薄荷醇为原料,通过与不同的溴化剂反应高立体选择性地得到薄荷基溴和和新薄荷基溴。当L-薄荷醇与盐酸和无水溴化锌反应时高立体选择性地得到薄荷基溴,当L-薄荷醇与三溴化磷反应时高立体选择性地得到新薄荷基溴.  相似文献   
998.
Five new copper(I)/silver(I) complexes containing 2-aminopyridine, [Cu(μ-Cl)(2-Apy)(PPh3)]2(1), [Ag(μ-Cl)(2-Apy)(PPh3)]2(2), [Ag(μ-Br)(2-Apy)PPh3)]2(3), [Ag(μ-ONO2)(2-Apy)(PPh3)]2(4), [Ag(μ-ONO2)(2-Apy)(AsPh3)]2(5) have been synthesised for the first time. Complexes 15 are obtained by the reactions of MX (MX = CuCl for 1; M = Ag for 2–5; X = Cl, Br for 23; X = NO3 for 4–5) with the monodentate ligands EPh3 (E = P for 14; E = As for 5) and 2-Apy in the molar ratio of 1:1:2 in the mixed solvent of CH2Cl2 and MeOH. Complexes 15 are characterised by IR and X-ray diffraction. In 15, chloride, bromide and nitrate ions bridge two metal atoms to form dinuclear complexes containing the parallelogram cores M2X2 (M = Cu, Ag).  相似文献   
999.
Geometries, frequencies, and energies of the 12B1, 12A2, 12B2, 22B1, 22B2, and 12A1, of the C6H5Br+ ion were calculated by using CASSCF and CASPT2 methods in conjunction with an ANO‐RCC basis. The CASPT2//CASSCF adiabatic excitation energies and CASPT2 relative energies for the six states are in good agreement with experiment. The X, A, B, C, and D electronic states of the C6H5Br+ ion were assigned to be X2B1, A2A2, B2B2, C2B1, and D2B2 based on the CASSCF and CASPT2 calculations. The assignment on the D state of the C6H5Br+ ion is different from the previously published works. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010  相似文献   
1000.
Asymmetric ring‐opening reactions of N‐Boc‐azabenzonorbornadiene with N‐substituted piperazine nucleophiles in the presence of 5 mol% of [Rh(COD)Cl]2 and 10 mol% of chiral ligand, (R,S)‐PPF‐P‐t‐Bu2, gave the corresponding 1,2‐diamine product in moderate to excellent yields (up to 95%) with reasonable enantiomeric excesses (up to 70% ee). The results showed that the nature of ligands had significant influence on the yields and the enantiomeric excesses.  相似文献   
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