Synthesis and Anti-HIV Activity of Trisubstituted （3＇R, 4＇R）-3＇,4＇-Di-O-（S）-camphanoyl-（＋）-c/s-khenactone （DCK） Analogs

To further explore the potential of DCK analogs as anti-HIV drug candidates, ten new tri-substituted （3＇R,4＇R）-3＇,4＇-di-O-（S）-camphanoyl-（＋）-cis-khellactone （DCK） derivatives （4-13） were designed, synthesized, and evaluated against HIV replication in MT4 cells and H9 lympho- cytes.     

Synthesis of Pyrrole-Imidazole Polyamide

Small molecules that target specific predetermined DNA sequences have the potential tocontrol gene expression'. Realization of the high affinity binding and specific recognitionof DNA sequences by organic molecules is one of the focuses of biological chemistry.The natural products netropsin and distamycin are N-methylpyrrole containing di- andtripeptides, with binding specificity at sites of successive A.T or T.A base pairs of DNAin the minor groove'. Recently, N-methylimidazole is intro…     

The Synthesis of 7-[1-Aza-2-(dimethylamino)vinyl]-4-methylhydroquinolin-2-ones and their Isomerism in Different Solvents

Interesting biological activities have been reported recently for 4-methylhydro-2H-pyrano [6,5-h]-chromen-2-ones and 4-methylhydro-2H-pyrano[6,5-h]quinolin-2-ones, including excellent anti-HIV activity with DCK derivatives1 and significant cytotoxic activity with 4,8,8-trimethylhydro-2H-pyrano[6,5-h]quinolin-2-one2. These results prompted us to synthesize two series of corresponding diaza three-ring heterocyclic analogs, trihydro- pyridino[2,3-h]quinolin-2-ones and hydropyridino[2,3-h]quino…     

Anionic Synthesis of Primary and Secondary Amine-Functionalized Polymers Using Imine Chemistry

There has been growing interest and research on new synthetic methods for thepreparation of well-defined polymers with chain-end functional groups[1～ 7] . Thesefunctional groups in polymers can participate in reversible ionic association;chainextension,branching,or crosslinking reactions with polyfunctional reagents;couplingand linking with reactive groups in other oligomer or polymer chains;and initiation ofpolymerization of other monomers[4～ 6] . The methodology of living anionic polyme-ri…     

结构型网格分块生成技术

构造了一种适用于模拟具有复杂几何特征的流动问题的结构型网格生成方法,该方法应用CAD技术中非均匀有理B样条(NURBS)曲面表达形式,根据给定物体的典型站位截面,首先对物体进行分片表面网格的构造与重构,同时根据物体几何特征及流场特性对绕流流场进行区域分解并构造其块边界,在此基础上再采用数值方法进行相应的分块网格生成,并给出了应用所建立的方法生成的几种天地往返运输系统流场网格.     

Total Nuclear Reaction Cross Section Induced by Halo Nuclei and Stable Nuclei

We develop a method for calculation of the total reaction cross sections induced by the halo nuclei and stable nuclei. This approach is based on the Glauber theory, which is valid for nuclear reactions at high energies. It is extended for nuclear reactions at low energies and intermediate energies by including both the quantum correction and Coulomb correction under the assumption of the effective nuclear density distribution. The calculated results of the total reaction cross section induced by stable nuclei agree well with 30 experimental data within 10 percent accuracy.The comparison between the numerical results and 20 experimental data for the total nuclear reaction cross section induced by the neutron halo nuclei and the proton halo nuclei indicates a satisfactory agreement after considering the halo structure of these nuclei, which implies quite digerent mean fields for the nuclear reactions induced by halo nuclei and stable nuclei. The halo nucleon distributions and the root-mean-square radii of these nuclei can be extracted from the above comparison based on the improved Glauber model, which indicates clearly the halo structures of these nuclei. Especially,it is clear to see that the medium correction of the nucleon-nucleon collision has little effect on the total reaction cross sections, induced by the halo nuclei due to the very weak binding and the very extended density distribution.     

低Mach数翼型绕流数值模拟的低耗散预处理格式

低Mach数流动中,基于可压缩流动的数值模拟算法存在严重的刚性问题,预处理方法可以有效地解决这一问题,但其计算结果不稳定．基于原有的预处理Roe格式,引入可调节参数,得到一种新的低耗散格式．该格式可以减弱边界层以及极低速区域的过度耗散,使得整个流场计算稳定．低Mach数、低Reynolds数定常圆柱绕流和低Mach数、高Reynolds数翼型(NACA0012和S809)绕流3个验证算例表明,带可调节参数的低耗散预处理方法正确可靠,是低速流动数值模拟的有效方法．     

拟变分包含及不动点问题公解的算法

介绍了一种新的迭代算法,在Hilbert空间的框架下,用以寻求具多值极大单调映象和逆-强单调映象的变分包含的解集与非扩张映象的不动点集的公共元．在适当的条件下,逼近于这一公共元的某些强收敛定理被证明．所得结果是新的,它不仅改进和推广了Korpelevich 的结果,而且也推广和改进了Iiduka和Takahashi,Takahashi和Toyoda,Nadezhkina和Takahashi及Zeng和Yao等人的最新结果．     

一个新的有自由面渗流问题的变分不等式提法

建立了一个新的有自由面渗流问题的变分不等式提法,提法通过将潜在出渗面上的边界条件提为Signorini型条件,从而从理论上消除了出渗点的奇性并解决了出渗点的定位问题．与其它变分不等式提法相比,该提法有更好的数值稳定性．