Diffusion characteristics of a T-type microchannel with different configurations and inlet angles.

A series of symmetrical and asymmetrical microfluidic T-sensors with different inlet angles were fabricated to study the mixing characteristics of a T-type microstructure for generating concentration gradient. Computational fluid dynamics (CFD) simulations showed that the concentration gradient, transition zone and diffusion length were different for various configurations and inlet angles. Quick mix and sharp concentration gradient occurred in the asymmetrical structure with large inlet angle. The observed concentration gradients in the fabricated microchannel were consistent with the theoretical prediction. In this microstructure, stagnant zone and z-direction diffusion also affected the concentration gradient. Based on the simulation results, the microfluidic structure was optimized to generate desired concentration gradient for a cell-based study.     

磁性固体超强酸SO42-/ZrO2-Al2O3-Fe3O4的制备与性能研究

利用化学共沉淀法将磁性基质与固体酸组装制备磁性纳米固体超强酸催化剂，利用XRD、Raman、TG-DSC、M?ssbauer、TEM、HRTEM等手段对样品性质进行表征。结果表明：磁性基质的引入赋予固体超强酸以超顺磁性；Fe₃O₄、Al₂O₃粒子弥散在ZrO₂基质中，烧结过程中阻碍了扩散传质的进行以及晶界移动，抑制了ZrO₂晶体生长，稳定了四方晶相(T-ZrO₂)；样品粒径分布集中，平均约为32 nm；HRTEM显示T-ZrO₂晶体生长取向于(101)方向，晶面间距d(101)=0.29 nm；Hammett指示剂法测得经600 ℃焙烧后产物的酸强度H_o＜-13.8，酸强度大于浓硫酸(H_o=-11.93)。以柠檬酸三丁酯的合成作为磁性固体超强酸SO₄^2-/ZrO₂-Al₂O₃-Fe₃O₄催化剂的探针反应，结果表明外磁场的引入提高了柠檬酸的转化率。     

Synthesis and characterization of perfluorohexylated poly(3,4-ethylenedioxythiophene)

The perfluorohexylated 3,4-ethylenedioxythiophene 5 was prepared via Mitsunobu reaction of perfluorohexylatyed diol 2 with diethyl 3,4-dihydroxythiophenedicarboxylate followed by decarboxylation. The polymerization of 5 was conducted with both oxidative chemical and electrochemical polymerizations. The polymers were characterized by cyclic voltammogram, UV, IR, TGA and DSC.     

C9‐Iridoids from Scrophularia buergeriana

Four new iridoids, buergerinins B–E ( 1 – 4 ), along with three known iridoids, were isolated from the roots of Scrophularia buergeriana. Their structures were identified on the basis of spectroscopic analysis.     

Photopolymerization induced by a benzophenone derivative photoinitiator

A benzophenone derivative photoinitiator, HBP-TDI-HQ-TDI-HBP （HTCTH）, was synthesized based on 4-hydroxy benzophenone （HBP）, toluene-2,4-diisocyanate （TDI） and hydroquinone （HQ）. HTCTH was a more effective photoinitiator which had longer wavelength absorption in the UV-vis absorption spectra than the low molecular counterpart benzophenone （BP）. It showed that both rate of polymerization （Rp） and final conversion （P） increased with increase of amine and HTCTH concentration in photopolymerization.     

离子液体中用Heck反应合成2-取代萘烯丙醇化合物

利用Heck反应, 在离子液体、金属钯或镍、碱和膦配体反应体系中, 由卤代萘与烯丙醇反应, 制得了高收率和高选择性的2-取代萘烯丙醇化合物. 该方法原料便宜易得、操作简单、反应体系可循环使用. 并讨论了醋酸镍替代醋酸钯、不同膦配体、溶剂及碱对反应转化率的影响. 通过核磁共振、红外光谱、质谱和元素分析对产物的结构进行了表征.     

Chemiluminescence Determination of Benzoic Acid Using A Solid-Phase Verdigris Reactor

Benzoicacidisacommonadditiveusedwidelyasfoodpreservativeandplasticizer.Itcouldpromoteseverereactiontoallergicpopulationevenatlowconcentrationlevel1.Routinemethodsfortheassayofbenzoicacidincludeschromatographic2-6,spectrophotometry7,8,capillaryelectrophoresis9-13andelectrochemicaltitration14.Stokes15etal.monitoredairbornebenzoicacidbasedonsurface-enhancedRamanscatteringtechniques.Thereisalsoreportonamicrobialsensorusingpseudomonasforbenzoicacidandtheirderivativesinaqua16.Interestofusinglumines…     

MOLECULAR ENGINEERING STUDIES ON NONTHROMBOGENIC BIOMATERIALS——A NOVEL CLASS OF NONTHROMBOGENIC BIOMATERIALS WITH ZWITTERIONIC STRUCTURE OF CARBOXYBETAINES

N,N-dimethyl-N-methacryloyloxyethyl-N-carboxyethyl ammonium (DMMCA) was graft-copolymerized onto the surface of segmented poly(ether urethane) (SPEU) and PE film. The carboxybetaine structure on SPEU and PE film surfaces was confirmed by ATR-FTIR, XPS and water contact angle measurements. Through the experiments with platelet adhesion and protein adhesion assay in vitro, the two materials studied, including poly-DMMCA gel, all show excellent nonthrombogenicity. This confirms once again that the zwitterionic molecular structure on the surfaces of materials is essential for improving their nonthrombogenicity and biocompatibility.     

足球分子及有关碳笼的电子结构

本文评述了激光气化产生的碳原子簇的电子结构和活性。足球分子具有球面芳香性。我们用INDO/2和INDO/CI系列方法。研究了足球分子及其异构体的电子结构和UV谱。足球分子的计算结果是只有一条低频带(366.4nm),与实验结果(386.0nm)符合得很好。     

反胶束笼对纳米氯化银反应性能的微环境限定

研究了反映束中直径为１０￣１７ｎｍ的ＡｇＣｌ微料与亚甲基蓝之间的作用，比较了阴离子型和非离子型表面活性剂组成的反胶束微环境的影响，讨论了亚甲基蓝在粒子上的吸附，二聚体形成的钠米ＡｇＣｌ粒子对亚甲基蓝荧光猝灭机制。