排序方式: 共有18条查询结果,搜索用时 15 毫秒
1.
N4-Benzoylcytosine 1-(methyl 2,3,4-tri-O-acetyl--D-glucopyranosiduronate) has been obtained with a yield of 70% by the glycosylation of the trimethylsilyl derivative of N4-benzoylcytosine with methyl 1,2,3,4-tetra-O-acetyl--D-glucopyranuronate in the presence of three equivalents of SnCl4 as condensing agent. Cytosine 1-(-D-glucopyranosiduronamide) (IV) — the amide of pentopyranic acid — has been synthesized in practically quantitative yield by the ammonolysis of the nucleoside (I).Peat Institute, Academy of Sciences of the Belorussian SSR, Minsk. Institute of Bioorganic Chemistry, Academy of Sciences of the Belorussian SSR, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 617–619, September–October, 1983. 相似文献
2.
Frédérin abwergel Jacques Herbert Ballly Herbert Ballly H Beirao da Veiga VA Solonnikov 《偏微分方程通讯》2013,38(9-10):1323-1358
We study a class of stationary transport equation with nonlocal low-order tems We obtain the existence and uniqueness of a solution in sobolev spaces 相似文献
3.
4.
非线性涡黏性系数模型和代数应力模型联系了线性涡黏性系数湍流模型和完整的微分
雷诺应力模型.随着它们受到日益关注,其形式也越来越多样化.本篇综述的目的是对这些模
型加以总结并比较它们之间的共同点及不同之处,指出它们与完整微分雷诺应力模型之间的
关系,以及相对于线性涡黏性系数模型而言它们在预报流场上所具有的优势. 相似文献
5.
M. M. Khalisov K. I. Timoshchuk A. V. Ankudinov T. E. Timoshenko 《Technical Physics》2017,62(2):310-313
Peak force measurements with the aid of atomic force microscopy are used to quantitatively map nanomechanical properties of intact erythrocytes of rats under conditions that are close to physiological conditions. Erythrocytes that are immobilized on the substrate preliminary processed using poly-L-lysine predominantly exhibit plane shape. However, cells may also exhibit stepwise transformation to semispherical objects with an increase in volume and hardening. Possible reasons for such transformations are discussed. 相似文献
6.
A definition of a wave aberration as a phase shift upon composition of light waves in the image of a point is given using
the concept of point eikonal. An expression that determines the total differential of a wave aberration function is obtained
and the condition of its integrability is determined. The sequence of the wave aberration function definition at the known
functions of the meridional and sagittal components of lateral aberration is presented. 相似文献
7.
Hussein YH Anderson N Lian TT Abdou IM Strekowski L Timoshchuk VA Vaghefi MM Netzel TL 《The journal of physical chemistry. A》2006,110(13):4320-4328
The goal of this work is to produce high yields of long-lived AQ(*-)/dA(*+) charge transfer (CT) excited states (or photoproducts). This goal fits within a larger context of trying generally to produce high yields of long-lived CT excited states within DNA nucleoside conjugates that can be incorporated into DNA duplexes. Depending upon the energetics of the anthraquinonyl (AQ) (3)(pi,pi) state as well as the reduction potentials of the subunits in particular anthraquinonyl-adenine conjugates, CT quenching of the AQ (3)(pi,pi*) state may or may not occur in polar organic solvents. In MeOH, bis(3',5'-O-acetyl)-N(6)-(anthraquinone-2-carbonyl)-2'-deoxyadenosine (AQCOdA) behaves as intended and forms a (3)(AQ(*-)/dA(*+)) CT state with a lifetime of 3 ns. However, in nonpolar THF the AQ(*-)/dA(*+) CT states of AQCOdA are too high in energy to be formed, and in DMSO a (1)(AQ(*-)/dA(*+)) CT state is formed but lives only 6 ps. Although the lowest energy excited state for AQCOdA in MeOH is a (3)(AQ(*-)/dA(*+)) CT state, for N(6)-(anthraquinone-2-methylenyl)-2'-deoxyadenosine (AQMedA) in the same solvent it is a (3)(pi,pi*) state. Changing the linking carbonyl in AQCOdA to methylene in AQMedA makes the anthraquinonyl subunit harder to reduce by 166 mV. This raises the energy of the (3)(AQ(*-)/dA(*+)) CT state above that of the (3)(pi,pi*) in AQMedA. The conclusion is that anthraquinonyl-dA conjugates will not have lowest energy AQ(*-)/dA(*+) CT states in polar organic solvents unless the anthraquinonyl subunit is also substituted with an electron-withdrawing group that raises the AQ-subunit's reduction potential above that of AQ. A key finding in this work is that the lifetime of the (3)(AQ(*-)/dA(*+)) CT excited state (ca. 3 ns) is ca. 500-times longer than that of the corresponding (1)(AQ(*-)/dA(*+)) CT excited state (ca. 6 ps).' 相似文献
8.
Using the method of singular integral equations we solve a two-dimensional problem of the theory of elasticity for an infinite plate containing an elastic inclusion of arbitrary configuration and a system of curvilinear incisions. The numerical solution is found by the method of mechanical quadratures for the case of an elliptic inclusion and a single polygonal crack.Translated fromMatematicheskie Metody i Fiziko-Mekhanicheskie Polya, Issue 27, 1988, pp. 93–98. 相似文献
9.
10.