含聚醚间隔链的扩链脲改性环氧树脂/双氰双胺固化体系性能研究

合成了一系列含不同分子量聚环氧丙烷 (PPG)柔性间隔链的扩链脲 ,系统考察了扩链脲改性环氧树脂E 5 1/双氰双胺 (dicy)固化体系的固化反应活性、动态力学行为、冲击性能和断裂面形态结构 ,并对体系的冲击性能、形态结构与动态力学行为之间的关系进行了探讨 .结果表明 ,改性体系固化反应活性明显提高 ,固化反应表观活化能降低 ,固化反应峰顶温度从 190℃降低至 14 0℃ ,固化反应的表观活化能由 14 5 5kJ/mol降至 70～ 80kJ mol;改性体系冲击强度明显提高 ,其中所含PPG柔性链分子量为 10 0 0的扩链脲改性的E 5 1/dicy体系冲击强度较未改性的E 5 1/dicy体系提高了 8倍 ,其冲击试样断裂面的形态具有明显的韧性断裂特征 ,微观两相网络结构的存在导致了改性体系冲击强度显著提高     

High diastereoselective synthesis of spiro-isoxazolonechromans via domino oxa-Michael/1,6-addition reactions of ortho-hydroxyphenylsubstituted para-quinone methides with unsaturated isoxazolones

A mild Et₃N-catalyzed novel domino oxa-Michael/1,6-addition reaction of ortho-hydroxyphenylsubstituted p-QMs and unsaturated isoxazolones is described. Various new spiro-isoxazolonechromans were obtained in good yields (up to 89%) with excellent diastereoselectivities (>99:1 dr). The structure of the new compound 3a was determined by single crystal X-ray analysis.     

Preparation of Nano-Sized γ-Al2O3 Supported Iron Catalyst for Fischer-Tropsch Synthesis by Solvated Metal Atom Impregnation Methods

Two types of small iron clusters supported on γ-Al2O3-RT(dehydroxylated at room temperature) and γ-Al2O3-800 (dehydroxylated at 800 ℃) were prepared by solvated metal atom impregnation (SMAI) techniques. The iron atom precursor complex, bis(toluene)iron(0) formed in the metal atom reactor, was impregnated into γ-Al2O3 having different concentrations of surface hydroxyl groups to study the effect of surface hydroxylation on the crucial stage of iron cluster formation. Catalysts prepared in this way were characterized by TEM, M(o)ssbauer, and chemisorption measurements, and the results show that higher concentration of surface hydroxyl groups of γ-Al2O3-RT favors the formation of more positively charged supported iron cluster Fen/γ-Al2O3-RT, and the lower concentration of surface hydroxyl groups of γ-Al2O3-800 favors the formation of basically neutral supported iron cluster Fen/γ-Al2O3-800. The measured results also indicate that the higher concentration of surface hydroxyl groups causes the rapid decomposition of precursor complex, bis(toluene)iron(0), and favors the formation of relatively large iron cluster. Consequently, these two types of catalysts show different catalytic properties in Fischer-Tropsch reaction. The catalytic pattern of Fen/γ-Al2O3-RT in F-T reaction is similar to that of the unreduced α-Fe2O3 and that of Fen/γ-Al2O3-800 is similar to that of the reduced α-Fe2O3.     

Potential‐Responsive Surfaces for Manipulation of Cell Adhesion,Release, and Differentiation

In living systems, interfacial molecular interactions control many biological processes. New stimuli‐responsive strategies are desired to provide versatile model systems that can regulate cell behavior in vitro. Described here are potential‐responsive surfaces that control cell adhesion and release as well as stem cell differentiation. Cell adhesion can be modulated dynamically by applying negative and positive potentials to surfaces functionalized with tailored monolayers. This process alters cell morphology and ultimately controls behavior and the fate of the cells. Cells can be detached from the electrode surface as intact clusters with different geometries using electrochemical potentials. Importantly, morphological changes during adhesion guide stem cell differentiation. The higher accessibility of the peptide under a positive applied potential causes phenotypic changes in the cells that are hallmarks of osteogenesis, whereas lower accessibility of the peptide promoted by negative potentials leads to adipogenesis.     

石墨烯和氧化石墨烯的表面功能化改性

石墨烯和氧化石墨烯由于特殊的电子、光学、力学性能已成为当今科学研究的热点.重点综述了近年来石墨烯和氧化石墨烯的表面功能化改性研究进展.首先介绍了石墨烯、氧化石墨烯的基本结构与性质.然后将表面功能化分为非共价键结合改性、共价键结合改性和元素掺杂改性.非共价键结合的功能化改性分为四类：π-π键相互作用、氢键作用、离子键作用以及静电作用.共价键结合的功能化改性分为四类：碳骨架功能化、羟基功能化、羧基功能化和环氧基功能化.元素掺杂改性分为N、B、P等不同元素的掺杂功能化.总结了石墨烯、氧化石墨烯基体与改性分子的相互作用和反应类型,以及改性产物的性能与应用.最后对石墨烯和氧化石墨烯在表面功能化改性方面的发展前景作了展望和预测.     

The Biological Fate of a Novel Anticancer Drug Candidate TNBG-5602: Metabolic Profile,Interaction with CYP450, and Pharmacokinetics in Rats

TNBG-5602, a novel anticancer drug candidate, may induce the expression of PPARγ, causing targeted lipotoxicity in cancer tissues. In this study, the in vivo metabolism in rats, in vitro metabolism in recombinant cytochromes, molecular docking for the CYP binding site, and pharmacokinetics in rats were explored to better understand TNBG-5602′s in vivo fate and behavior. Thirteen metabolites were identified using a high-resolution mass spectrometry method, and metabolizing pathways of TNBG-5602 were proposed. Results suggest that TNBG-5602 could be metabolized by CYP450s, while CYP2D6 may play an important role in its in vivo metabolism. The main metabolizing sites of TNBG-5602 are the amino group on the side chain and rings A and E in the molecule. TNBG-5602 is a potent CYP2D6 inhibitor, with an IC₅₀ value of 2.52 μM. An interaction responsible for its metabolism is formed by the NH on the side chain bonding with the ASP301 on the CYP2D6. The pharmacokinetics in rats after a single intravenous administration were fitted to a two-compartment model. The clearance was 0.022 L min⁻¹, and the elimination half-life was 710.9 min. The distribution volume of the peripheral compartment was 1.88-fold that of the central compartment, while the K₁₂ was 1.5-fold that of K₂₁. In conclusion, these studies have not only revealed the metabolizing pathways of TNBG-5602 using in vivo and in vitro methodology, but they have also provided the pharmacokinetic characteristics of TNBG-5602 in rats. The results suggest that TNBG-5602 has good drug developability in terms of pharmacokinetic behaviors.     

纳米晶粒TiO2多孔微球的合成与表征

 钛酸四丁酯经酸性水解得到TiO2溶胶，将溶胶与苯酚混合后加入到正庚烷分散介质中，再滴加甲醛水溶液，通过反相悬浮聚合和溶胶－凝胶过程制备了聚合物与TiO2的复合微球．对复合微球进行焙烧处理，使聚合物分解，从而得到由纳米TiO2晶粒组成的多孔微球．以示差扫描量热法、热重分析、X射线衍射、扫描电子显微镜和氮吸附等方法对TiO2多孔微球的物理性质进行了表征．结果表明，所得TiO2多孔微球主要由锐钛型TiO2纳米晶粒组成，晶粒尺寸为20～30nm；TiO2多孔微球的直径为200～500μm，比表面积为87．40m2／g，平均孔径为8．65nm，孔径的分布具有单分散特征．     

功能基化介晶高聚物增韧环氧树脂性能研究——材料断裂面形态结构与力学性能的关系

在系统研究含介晶基团的高聚物ＬＣＥＵＰＰＧ增韧环氧树脂Ｅ ５１／双氰双胺（ｄｉｃｙ）固化体系固化反应活性、反应机制、动态力学行为及冲击性能的基础上,以扫描电镜（ＳＥＭ）为手段,对材料断裂面的形态结构进行了研究,并对体系的形态结构与动态力学行为、冲击性能之间的关系进行了探讨．结果表明,改性后材料断裂面的形态均呈微观两相网络结构,明显不同于未改性体系,正是由于两相网络结构的存在,导致了改性体系的冲击强度大幅度提高．     

咪唑封端聚氨酯予聚体改性环氧树脂E-51/双氰双胺固化体系性能研究

以聚丙二醇PPG10 0 0、甲苯二异氰酸酯 (TDI)、咪唑为原料 ,合成了咪唑封端的聚氨酯予聚体 ,简称扩链脲TIEU .利用DSC、粘弹谱仪、冲击试验机及扫描电镜 (SEM)等手段对TIEU改性的环氧树脂E 5 1/双氰双胺(dicy)固化体系的反应活性、动态力学行为、冲击性能、断裂面形态结构进行了系统研究 .实验结果表明 ,改性后的E 5 1 dicy体系反应活性明显提高 ,固化反应的表观活化能由未改性体系的 131kJ mol降至 75～ 80kJ mol.与咪唑促进体系比较结果显示 ,两种固化反应的促进机制具有一定的差异 .另外与未改性体系相比 ,经过改性的环氧树脂体系冲击强度提高 2～ 3倍 ,而玻璃化温度和模量基本不变 ,冲击断面呈韧性断裂     

任意双偶阶幻方构造规律的研究

本文着力于任意双偶阶幻方构造规律的研究。在文中，作者引入一个新概念，即所谓四阶传递幻方基，并借助电子计算机构造出造型优美的任意双偶阶幻方且阶数不封顶。