The preparation of a novel polydopamine-graft-poly(2-methyl-2-oxazoline) protein-resistant coating and its applications in protein separation

A novel polydopamine-graft-poly(2-methyl-2-oxazoline)(PDA-g-PMOXA) coating was prepared by immobilizing poly(2-methyl-2-oxazoline)(PMOXA) onto material surfaces through polydopamine (PDA) anchored coating for the first time.And then,the chemical composition,hydrophilicity,and protein-resistant properties of the PDA-g-PMOXA coating were studied using X-ray photoelectron spectroscopy(XPS),contact angel(CA) test,surface plasmon resonance(SPR),and quartz crystal microbalance with dissipation(QCM-D) measurement.Finally,the coating was applied to the capillary inner surface for protein separation by capillary electrophoresis(CE).     

各向异性本构关系在板料成形数值模拟中的应用

对几种能表达面内各向异性的屈服准则Hill、Barlat-Lian、Barlat进行了比较。以弹性变形服从各向同性广义虎克定律的情况下，给出了基于张量算法推导的弹塑性本构关系的一般表达式，并由此导出了相应屈服准则的弹塑性本构关系的显式表达。借助ABAQUS软件本构模块用户子程序接口，分别实现了这些屈服准则在ABAQUS的嵌入。以模拟方形盒的拉延过程为例，分析了不同的屈服准则在板料成形过程数值模拟中的应用。模拟结果表明，基于弹塑性本构关系一般表达所列出的相应屈服准则的显式表达式是正确的；在采用壳元来模拟板料成形时，采用Barlat准则的模拟结果和采用Barlat-Lian准则的结果差别不大。     

Design studies on the 4π γ-ray calorimeter for the ETF experiment at HIRFL-CSR

A high detection efficiency calorimeter which is used to detect γ-rays with energies from 1 MeV up to 10 MeV as well as light charged particles has been proposed. Design of the geometry, results of the crystal tests and Monte Carlo simulations are presented in this paper. The simulation results confirm that the calorimeter can obtain high detection efficiency and good energy resolution with the current designed geometry. And the calorimeter is competent for the future External Target Facility (ETF) experiments.     

Double perovskite oxides Sr_2Mg_(1-x)Fe_xMoO(6-δ) for catalytic oxidation of methane

The double perovskite oxides Sr2Mg1-xF exMoO6-δ were investigated as catalysts for the methane oxidation.The structural properties of catalysts were characterized in detail by X-ray diffraction,X-ray photoelectron spectroscopy and X-ray absorption spectroscopy.The catalytic property was strongly influenced by the Fe substitution.The relation between catalytic performance and the degree of Fe substitution was examined with regard to the structure and surface characteristics of the mixed oxides.The Fe-containing catalysts exhibited higher activity attributable to the possible(Fe2+,Mo6+) and (Fe3+,Mo5+)valency pairs,and the highest activity was observed for Sr2Mg0.2Fe0.8MoO6-δ.The enhancement of the catalytic activity may be correlated with the Fe-relating surface lattice oxygen species and was discussed in view of the presence of oxygen vacancies.     

Recent progress in the application of microfluidic systems and gold nanoparticles in immunoassays

Immunoassays are useful for many bioassays. Many new techniques and materials are introduced into the immunoassay to improve the efficiency. This paper reviews recent progress in the application of microfluidic systems and gold nanoparticles in immunoassay. The micro/nano technologies and materials can offer good sensitivity, fast detection, cost-effectiveness and easy signal readout. In particular, the miniaturization of microfluidics and colorimetric assays based on gold nanoparticles have dramatically im...     

谷氨酸低分子量有机凝胶的药物控制释放行为

低分子量的有机胶凝剂组装形成的有机凝胶可应用于药物缓释体系.本研究中,使用亲水的钙黄绿素和疏水的布洛芬为模型分子,研究其在谷氨酸衍生物有机凝胶体系中的缓释行为.研究表明,与药物分子与有机胶凝剂简单混合的体系相比,亲水或疏水的药物分子在有机凝胶体系中的释放速度显著减缓.SEM的研究发现药物粒子嵌入在有机凝胶的三维网络中,因此,有机凝胶的三维网络结构可认为是实现药物缓慢释放的基质,药物分子从网络中的释放受限导致了其从有机凝胶中的缓释行为.     

含可脱除侧基的功能化微凝胶及其在药物释放中的应用

环境敏感微凝胶由于其对外界刺激的快速响应能力在药物传输和释放领域得到广泛的关注.本文报道了一种侧链含可脱除基团的温敏微凝胶,并探讨了其在药物释放中的潜在应用.通过分子设计,合成出含侧链N-叔丁氧羰基(N-Boc)的疏水单体N-(N-叔丁氧羰基-乙二胺)甘氨酸二肽甲基丙烯酰胺(BEMAGG),然后将其与N-异丙基丙烯酰胺(NIPAAm)沉淀共聚合直接得到侧链含Boc基团的微凝胶MG-Boc.通过浊点法、粒径和Zeta电位测定研究了微凝胶中Boc基团在酸中的脱除过程及其对微凝胶性能的影响,研究表明Boc基团的脱除显著影响微凝胶的体积相转变温度、粒径和Zeta电位.对盐酸阿霉素药物的释放研究表明,释放明显依赖于释放介质的pH值.该响应性的微凝胶在药物控制释放领域具有潜在的应用前景.     

Synthesis and shape memory behavior study of hyperbranched poly(urethane-tetrazole)

A novel hyperbranched poly(urethane-tetrazole)(HPUTZ) was synthesized via the A2+BB2' approach using hexadiisocyanate(HDI) and 3-(bis-(2-hydroxyethyl)) aminopropyltetrazole(HAPTZ).The molecular structure was characterized by FTIR and 1H NMR spectroscopy.The number average molecular weight was measured to be 1.05×104 g/mol with a polydispersity of 1.27 by GPC analysis.The HPUTZ was further cured by the semi-adduct(PEG-IPDI) from polyethylene glycol(PEG) reacting with isophorone diisocyanate(IPDI) to form th...     

Instrumentation of coherent X-ray imaging and the primary experimental results

Coherent X-ray microscopy has advanced towards higher-energy, more brilliant sources over the past decade since its demonstrations, and many advancements have been made towards optimizing this imaging technique. Here we present both the experimental instrument for obtaining diffraction patterns and the primary reconstruction of yeast cell 2D projection. In addition, the characteristics of the existing optics at BL29XUL of SPring-8 Facility and the method of image reconstruction are discussed.     

不同重力条件下管内冷凝现象研究进展

本文对不同重力环境中水平管内冷凝气液两相流动与传热现象的研究现状进行了全面评介, 重点关注于航天应用中的小管径、低流量和以氨为工质的情形,以及部分重力条件下冷凝现象中的重力效应. 冷凝现象中管壁四周液膜的存在,导致水平管内冷凝气液两相流与沸腾或绝热气液两相流在构型上存在着明显的不同, 表面张力的作用增大,向波状和分层流转换所对应的临界Bond数也随之增大, 进而使小管径、低流量水平管内冷凝气液两相流动与传热现象中的重力效应减弱,甚至可以忽略不计. 实验发现该情形中摩擦压降要小于基于常规气液两相流实验数据的经验关联式的预测结果, 而更接近光滑环状流情形; 对冷凝两相传热系数的预测,只有采用基于空隙率与界面剪切率相互耦合的模型, 才能够给出较好的结果.