STUDY ON MAGNETIC FIELD-INDUCED 0RIENTATI0N OF A CHIRAL SIDE-CHAIN LIQUID CRYSTAL POLYACRYLATE USING INFRARED DICHROISM

Magnetic field-induced orientation of a chiral side chain liquid crystalline polyacrylate(P-11) was studied by using IR dichroism. For the investigated P-11, it has been shown thatthe magnetic alignment takes place over the entire temperature range between its meltingpoint and clearing point and the orientation level is strongly temperature-dependent, thedevelopment with time of the magnetic orieatation follows an exponeotial-type relation,and the smectic phase state influences the thermal relaxation process in the absence of themagnetic field.     

Shear-induced band texture of side group liquid crystalline polymers

The shear-induced band texture of conventional end-on fixed side group liquid crystalline polymers (LCPs) has been investigated by using polarizing optical microscopy (POM), small angle light scattering (SALS) and infra-red dichroism techniques. The band spacing is about 1 μm, which increases very slightly on increasing the temperature of shearing and is independent of shearing rate within the range studied. The band texture is not seen to exhibit an interchange of dark and bright bands on rotation of the sample with respect to the polarizer/analyser, but a typical periodical structure is reflected by the SALS patterns of the band texture. The relaxation behaviour of the bands indicates that the band texture formed here is the result of the orderly aligning of domains exhibiting the focal-conic texture, and this is totally different from the case of main chain LCPs where the band texture is substantially an optical effect of the periodic zigzag or sinusoidal structure of parallel aligned microfibrils. Infra-red dichroism and rotating parallel-plate shearing measurements show that the axes of the backbone of the polymer tend to orient in the shearing direction and the end-on fixed mesogenic side groups tend to align perpendicular to the shearing direction.     

Assembly of ϵ-Keggin Polyoxometalate from Molecular Crystal to Zeolitic Octahedral Metal Oxide

Zeolitic octahedral metal oxides are inorganic crystalline microporous materials with adsorption and redox properties. New ϵ-Keggin nickel molybdate–based zeolitic octahedral metal oxides have been synthesized. ³¹P NMR spectroscopy shows that reduction of Mo^VI-based molybdates forms an ϵ-Keggin polyoxometalate that immediately transfers to the solid phase. Investigation of the formation process indicates that a low Ni concentration, insoluble reducing agent, and long synthesis time are the critical factors for obtaining the zeolite octahedral metal oxides rather than the ϵ-Keggin polyoxometalate molecule. The synthesized zeolitic nickel molybdate with Na⁺ is used as the adsorbent, which effectively separates C₂ hydrocarbon mixtures.     

熊果酸-3’-取代丙醇酯衍生物的合成及抗肿瘤活性研究

熊果酸与1,3-二溴丙烷反应制得中间体熊果酸-3’-溴代丙醇酯(1),含溴醇酯1与含氮化合物反应,合成了系列熊果酸含氮衍生物2a～2j,均未见文献报道,其结构经1H NMR,13C NMR,IR,MS确认.初步的抗肿瘤生物活性研究表明,部分化合物的抗肿瘤活性与熊果酸相比均有提高,其中化合物2e具有更强的抑制活性.     

豆腐果苷-喹啉和黄酮衍生物的合成及镇静活性研究

以L-脯氨酸为有机催化剂一步合成了豆腐果苷-喹啉酮(2),在此基础上合成了一系列豆腐果苷-喹啉衍生物3a～3c,4和5a～5c;以苄溴、豆腐果苷、邻羟基苯乙酮,氨基脲盐酸盐、羟胺盐酸盐、甲氧基胺盐酸盐为原料合成出豆腐果苷-黄酮衍生物8和9a～9c.产物结构经1H NMR,IR和HRMS确认.初步生物活性测试结果表明5b和9b具有较好的镇静催眠活性.     

2-(4-β-D-吡喃阿洛糖苷-苯基)-5-取代芳基-1,3,4-噁二唑的合成及镇静活性研究

以豆腐果苷为原料, 与取代苯甲酰肼反应生成中间体4-β-D-吡喃阿洛糖苷-苯甲醛取代苯甲酰腙(2a～2g), 在溴作催化剂的条件下发生关环反应, 合成了一系列豆腐果苷类似物3a～3g. 所有化合物结构经IR, ¹H NMR以及MS谱得以证实. 初步药理实验结果表明, 化合物3a, 3c, 3f与豆腐果苷相比有更好的镇静活性.     

A delay-induced predator–prey model with Holling type functional response and habitat complexity

Nonlinear Dynamics - A delay-induced predator–prey system with the effect of habitat complexity and Holling type functional response is proposed. The dynamical behaviors of the presented...     

Photooxidation of a Twisted Isoquinolinone

Understanding the oxidation mechanism and positions of twistacenes and twistheteroacenes under ambient conditions is very important because such knowledge can guide us to design and synthesize novel, larger stable analogues. Herein, we demonstrated for the first time that a twisted isoquinolinone can decompose under oxygen and light at room temperature. The as‐decomposed product 1 was fully characterized through conventional methods as well as single‐crystal structure analysis. Moreover, the physical properties of the as‐obtained product were carefully investigated and the possible formation mechanism was proposed.     

二元酸茄尼醇烷基5-氟尿嘧啶二酯衍生物的合成及其抗肿瘤活性研究

以茄尼醇为原料与4种不同的酸酐反应,然后再与N-烷羟基-替加氟反应,得到12个新的目标化合物.其结构经IR,1H NMR,MS确认.初步的体外抗肿瘤实验结果表明,目标化合物具有一定抗肿瘤活性.     

2DNMR鉴定吗啉付产物的结构

本文用~H—NMR,反门控定量~(13)C—NMR,异核丁—分解2D、同核化学位移相关2D、异核化学位移相关2D等技术,鉴定了二种未见报道的吗啉付产物结构。