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1.
本文利用KDV方程所对应的线性方程解所具有的光滑效应及压缩映像原理,得到了Hirota-Satsuma系统初值问题的局部和整体适定性结果. 相似文献
2.
The vibronic vapour phase photoacoustic spectrum of Br2 in the wavelength region 505–541 nm (19796–18480 cm−1) has been recorded using microphone as well as pump-probe method. Discrete vibronic bands superimposed on a monotonically
increasing continuum background towards the dissociation limit results from the overlapping B
3Π
0u
/+
← X
1Σ
g
/+
and 1Π1u
← X
1Σ
g
/+
electronic transitions. Vibronic bands originating from υ″=0 have been used to estimate the relative rate of non-radiative relaxation as a function of the excited state B
3Π0u
vibrational quantum number υ′. A comparison with the optical absorption spectroscopy of Br2 leads to the identification of three broad spectral regions between 505 and 541 nm (19796 and 18480 cm−1) on the basis of different non-radiative relaxation processes. 相似文献
3.
Ress DK Baytas SN Wang Q Muñoz EM Tokuzoki K Tomiyama H Linhardt RJ 《The Journal of organic chemistry》2005,70(20):8197-8200
A sTn double C-glycoside, sTn analogue 2, was synthesized using samarium chemistry developed in our laboratory. Complications in the oxidation reaction affording aldehyde acceptor were overcome by double protection of amide and the use of a room-temperature ionic liquid as solvent. Studies are underway to conjugate the sTn double C-glycoside hapten 2 to KLH carrier protein for biological evaluation as a vaccine. 相似文献
4.
Baytas SN Wang Q Karst NA Dordick JS Linhardt RJ 《The Journal of organic chemistry》2004,69(20):6900-6903
The chemoenzymatic regioselective acylation of Neu5Ac followed by SmI2-mediated C-glycosylation on a solid support is described for five C-glycosides. This method should facilitate the construction of combinatorial libraries of inhibitors of neuraminidase activity and hemagglutinin interaction as potential antiviral agents. 相似文献
5.
Xing Zhang Demetria M. Dickinson Lei Lin Matthew Suflita Sultan Baytas Robert J. Linhardt 《Tetrahedron letters》2019,60(13):911-915
Heparan sulfate tetrasaccharide 2 was efficiently prepared in seven steps through chemoenzymatic synthesis. A monosaccharide 5, N-acetyl-α-d-glucosamine- O-methylglycoside (GlcNAc-OMe), was successfully used as an acceptor in a heparosan synthase (pmHS2)-catalyzed glycosylation reaction. This avoided the multi-step synthesis of a more complex disaccharide acceptor 3, greatly simplifying the route to tetrasaccharide target 2. This approach provides a critical tetrasaccharide intermediate for subsequent chemoenzymatic transformation to fondaparinux and its analogues. 相似文献
6.
The Darcy flow model with the Boussinesq approximation is used to investigate numerically the natural convection inside an
inclined wavy cavity filled with a porous medium. Finite Element Method is used to discretize the governing differential equations
with non-staggered variable arrangement. Results are presented for
and
, where ϕ, Ra, A and λ correspond to the cavity inclination angle, Rayleigh number, aspect ratio and surface waviness parameter, respectively.
Stream and isotherm lines representing the corresponding flow and thermal fields, and local and average Nusselt numbers distribution
expressing the rate of heat transfer are determined and shown on graphs and tables. A good agreement is observed between the
present results and those known from the open literature. The flow and thermal structures found to be highly dependent on
surface waviness for inclination angles less than 45°, especially for high Rayleigh numbers. 相似文献
7.
Calculated free convection flows and heat transfer are presented for concentric spherical annular sectors, filled with a porous medium. Two isothermal walls and an adiabatic radial wall at the sector angle define the sectors. The governing equations (in the stream function and temperature formulation) are solved numerically using ADI (alternative direction implicit) finite-difference method. Over the range of geometric parameters examined, the obtained results for spherical annuli and low Rayleigh number Ra. As Ra increases, multicellular flows develop for small values of the aspect ratio parameter . In addition, analytical solutions of the governing equations were obtained for small values of Ra (1) and it was shown that these solutions agree well with those obtained numerically. Significant differences in the local heat transfer rates on the inner and outer walls of the spherical annuli were observed from these solutions. 相似文献
8.
Ki Hwan Bae 《中国化学快报》2009,20(11):1321-1323
Phytochemical study on the BuOH-soluble fraction of the stem bark of Populus davidiana resulted in the isolation of a new salicin derivative(1),named davidianoside.The structure was elucidated on the basis of extensive physicochemical and spectroscopic analyses. 相似文献
9.
10.
From the transport studies in the bilayer manganites LaSr2−x
Ca
x
Mn2O7, we have found the variable-range hopping model proposed by Viret et al to be inadequate to describe the transport of charge in these materials. The polarons appear to hop to their nearest neighbors
with an activation energy, which in part is dependent on the magnetic interactions in the lattice. 相似文献