Synthesis of new chiral fluorescent sensors and their applications in enantioselective discrimination

Five novel sensors (R,R)-3–6 and (S, S)-6 were synthesized and developed for enantioselective recognition of chiral compounds. Sensor 6 with two thiourea groups and steric π-conjugation frameworks could discriminate different chiral substrates, including acidic compounds, basic compounds, and neutral compounds. These results disclosed that the outstanding performance of enantioselective discrimination could be attributed to the thiourea group which acted as a hydrogen-bonding donor and the bulky steric moiety of the hosts which provided appropriate chiral environment. This result will be of great practical value in the designation of chiral sensors and high-throughput assay of chiral products.     

Suffruyabiosides A and B, two new monoterpene diglycosides from moutan cortex

Two new monoterpene diglycosides, suffruyabiosides A and B, and seven known compounds 3-9 were isolated from Moutan Cortex (root cortex of Paeonia suffruticosa Andrews). The structures were elucidated on the basis of 2D NMR spectral data. Suffruyabiosides A and B are rare monoterpene diglycosides, including a cellobiose in the molecules. Salicylpaeoniflorin (4) had a antiproliferation effect similar to paeoniflorin (3) on human lung adenocarcinoma epitherial A549 cells. Galloylpaeoniflorin (8) and salicylpaeoniflorin (4) revealed a more pronounced radical scavenging effect than a-tocopherol (positive control). An increase in the number of phenolic hydroxyl groups produced a more effective radical scavenging effect [8 > mudanpioside E (6) > oxypaeoniflorin (5)]. Comparison of the effects of 4 and 5 showed that o-substitution with a phenolic hydroxyl group was more effective than p-substitution. The results suggest that salicylpaeoniflorin (4) may be useful as a cytotoxic and a radical scavenging agent.     

Exact stationary wave patterns in three coupled nonlinear Schrödinger/Gross–Pitaevskii equations

The evolution of a Bose–Einstein condensate (BEC) with an internal degree of freedom, i.e., spinor BEC, is governed by a system of three coupled mean-field equations. The system admits the application of the inverse scattering transform and Hirota bilinear method under appropriate conditions, which makes it possible to generate exact analytical solutions relevant to physical applications. Here, we produce six families of exact periodic solutions, directly constructed in terms of Jacobi elliptic functions. Solitary-wave limit forms, obtained from these solutions in the long-wave limit, are presented too.     

不同初始磁场对激波冲击R22重气柱过程影响的数值模拟

基于磁流体动力(magneto-hydrodynamic,MHD)方程,采用CTU+CT方法,对在不同初始磁场作用下的平面入射激波与磁化R22重质气柱作用过程进行了数值研究。数值结果清晰地描述了不同初始磁场条件时激波诱导R22气柱界面不稳定性的过程,揭示了磁场控制界面不稳定性的机理。另外,还分析了磁感应强度对界面不稳定性的影响,发现在磁场较小时,涡层附着于界面,但随着磁感应强度的增大,平均涡量随之增大,涡层与界面逐渐分离,最终更好地抑制了界面不稳定性。同时,还发现平均涡度拟能随着磁感应强度的增大而减小,而垂直磁场比平行磁场更能降低平均涡度拟能,因而平均涡度拟能可较好地反映磁场对不稳定性的影响效果。     

On a new algorithm of constructing solitary wave solutions for systems of nonlinear evolution equations in mathematical physics

ＩｎｔｒｏｄｕｃｔｉｏｎＳｏｌｖｉｎｇｎｏｎｌｉｎｅａｒｅｑｕａｔｉｏｎｓｉｓａｌｗａｙｓａｖｅｒｙｉｎｔｅｒｅｓｔｉｎｇｓｕｂｊｅｃｔｆｏｒｍａｔｈｅｍａｔｉｃｉａｎａｎｄｐｈｙｓｉｃｉａｎ ,ｉｎｐａｒｔｉｃｕｌａｒ,ｓｏｌｉｔａｒｙｗａｖｅｓｏｌｕｔｉｏｎｓｆｏｒｎｏｎｌｉｎｅａｒｅｑｕａｔｉｏｎｓａｒｅｏｆｂｏｔｈｔｈｅｏｒｅｔｉｃａｌａｎｄｐｒａｃｔｉｃａｌｉｍｐｏｒｔａｎｃｅ.Ｒｅｃｅｎｔｌｙ ,Ｙａｎ[1]ｏｂｔａｉｎｅｄａｔｒａｎｓｆｏｒｍａｔｉｏｎｄｉｒｅｃｔｌｙｆｒｏｍｔｈｅｆａｍｏ…     

变形色散水波方程的Auto-B(a)cklund变换、多孤子解和有理分式解

利用未知数变换并借助Mathematica软件,给出了变形色散水波方程的Auto-B(a)cklund变换以及它与热传导方程和线性方程之间的Darboux变换.进而用此变换,获得了变形色散水波方程的多孤子解、有理分式解及其他精确解.这种思路也适用于其他的非线性方程.     

Energetic study of diastereoselective thio-Claisen rearrangement

Molecular simulation is applied to explain the diastereoselective thio-Claisen rearrangement results of various S-allyl γ-hydroxy ketene dithioacetals. We show that the experimental results of Sreekumar et al. in the absence and in the presence of zeolite catalyst can be rationalized in terms of the energetics of the steric of the reactant and the transition-state structure and of the non-bonding interactions of zeolite–reactant and zeolite–transition-state structure. The procedures used can successfully identify optimum products for a given diastereoselective thio-Claisen rearrangement.     

Research on Thermal Effect of Window of High Power Fast Axial Flow CO2 Laser

Because of the thermal effect of window of high power fast axial flow (CO2 laser, the coupler will be distorted and become a convex lens. In this paper, the thermal distorted coupler is taken as a quasi-lens ABCD system, and through experiment and theoretical analysis, relations between the position of the output beam waist, the beam waist size, divergence angle, and the output power are given.     

分析电镜Cliff-Lorimer 因子测量及薄标样标准化探讨

采用电子探针矿物标样,即均匀性和稳定性符合显微定量分析要求的国标样品,制备成适于分析电镜（ＡＥＭ）成分分析的薄样品,测量了一组Ｃｌｉｆ－Ｌｏｒｉｍｅｒ（ＣＬ）因子,考察了用不同型号的分析电镜分析时ＣＬ因子的变化,提出了仪器校正因子ＫＩ＝εＢ／εＡ,对原子序数小于２０的较轻元素其ＣＬ应考虑作ＫＩ校正;作者建议采用易于制成薄晶片的黑云母标样来统一不同分析条件下的ＣＬ因子,并应建立适于分析电镜定量分析的无机薄标样通用技术条件。     

含镓、锡的铝合金在碱性溶液中的阳极行为

铝的电极电位负,为一1．66V（VS．SHE）,电化当量高（298Ah／g）是一种理想的阳板材料．但是由于铝在空气和水中表面形成一层致密的氧化膜,使其在中性溶液中处于钝化状态．而在酸性或碱性溶液中铝表面氧化膜就会被溶解破坏,与水直接反应,腐蚀中途难以中止．这一直是影响铝作为阳板材料应用和深入研究的障碍,特别是对铝阳极活化溶解机理的研究进展缓慢．虽然目前人们在铝中添加Ga、In、11、Zn、Sn、Mg、Hg等元素,研制出各种铝合金阳极,提高了铝阳极活化性能,但是这些研究本质上仍属于经验性的．到1983年Despic等人提出了“场…