细胞三维动态培养微器件的设计与制作

细胞培养是进行细胞研究的基础,为了在细胞体外培养时提供一种近似于体内的微环境,设计了一种可供细胞三维动态培养的微器件。首先设计了用于输运流体的微通道网络,培养池对称布置于微通道网络中,通过一系列\"多进多出\"型微通道分别与进样口和出样口相连。利用Comsol软件中的层流物理场和多孔介质物理场耦合对培养池内的流场进行仿真,通过比较流场的均一性和稳定性优化微通道网络结构。然后,采用静电直写技术在培养池内集成聚己内酯(PCL)三维支架,构建细胞三维培养空间。最后,封合微器件,检测微器件培养池内的流体流动情况,并进行细胞实验。实验结果表明,\"2×2\"型微器件培养池内的流体稳定性和均一性较好;PCL三维支架的纤维间距400μm,纤维直径80μm,孔隙率64%,细胞存活率达到90%以上。该细胞三维动态培养微器件更好地模拟了生物体内细胞生存所需的微环境,培养池内的细胞生长良好,满足设计要求。国家自然科学基金资助项目(No.51475079,No.51375076

柿竹园多通道微震监测系统的建立及其应用

在柿竹园多金属矿床,由于大量集中采空区群的存在,采矿生产过程中地压现象显现严重,安全生产受到严重威胁。为此,公司与长沙矿山研究院合作,在优化采矿工艺的基础上,先后建立了多种常规地压监测系统,并从加拿大ESG公司引进地压监测设备,于2008年11月建立了国内矿山最大通道的全数字型微震监测系统。详细介绍了微震监测系统的建立、优化及其现场应用情况,论述了多通道微震监测技术在矿山地压灾害防治方面所展示的优势和效果

The Time Dependent Red Shift Phenomenon of Visible Electroluminescence of Porous Silicon

本文着重研究了多孔硅（ＰｏｒｏｕｓＳｉｌｉｃｏｎ，简称ＰＳ）在阴极偏压下过硫酸铵溶液中电压调制的电致发光（Ｅｌｅｃｔｒｏｌｕｍｉｎｅｓｃｅｎｃｅ，简称ＥＬ）现象．发现在定电压下，随极化时间的增长电致发光强度减小并伴随着光谱红移现象．通过红外、拉曼、ＡＦＭ及光电化学等手段对电致发光的淬灭机制进行了研究，结果表明，在电致发光过程中强氧化剂向多孔硅注入空穴使ＰＳ表面氧化，导致小粒径的硅晶逐渐被剥落，造成光谱高能部分首先淬灭并出现随时间变化的电致发光红移现象．这些结果支持量子限制效应在多孔硅液相电致发光中起着重要作用The electroluminescence (EL) of ntype porous silicon (PS) in a persulphate solution under cathodic polarization was studied. A significant red shift in the luminescence spectra with the increase of polarization time, as well as a blue shift with the increase of cathodic polarization, have been found. FTIR, MicroRaman, AFM and photoelectrochemical techniques have been used to investigate the structure of PS before and after the electroluminescence emission. All these results show that the surface of PS has been oxidized by the persulphate during the EL emission, and accompanied by the stripping of small silicon nanocrystallite, which leades to the red shift of the electroluminescence spectrum. Both of the voltagetunable electroluminescence and the timedependent red shift of the EL spectra support that quantum confinement effect (QCE) plays an important role in the electroluminescence in liquid contact.作者联系地址：北京大学化学与分子工程学院智能材料研究中心Author's Address: Center for Intelligent Materials Research, College of Chem. and Molecular Engineering,Peking Univ., Beijing 10087

Further Evidence for Surface Properties of Porous Silicon Resulting in Electroluminescence

用荧光分光光度法现场监测多孔硅在阳极偏压下于溶液中的电致发光行为 ,该电致发光行为主要取决于多孔硅本身的表面性质 .将电致发光实验后的多孔硅样品再次电解 ,并再次进行电致发光实验 ,发现其发光性能明显改善 ;实验表明 ,多孔硅在阳极偏压下的液相电致发光机制是由表面的Si_H键氧化向导带注入电子 ,并与阳极偏压注入的价带空穴进行复合而发光 ;此外 ,还发现了多孔硅于溶液中在阳极偏压下电压调制的可见光发射行为 ,并以量子限制效应对该现象进行了解释The electroluminescence of porous silicon in solutions at positive biases was investigated by luminescence spectrometer. The electroluminescence of porous silicon in solutions mainly depended on its surface properties. The elelctroluminescence was much enhanced when the sample of porous silicon was electrolyzed once again which had undergone an electroluminescence test. The tests of both cyclic voltammetry and the luminescence of the sample of porous silicon prepared by repeated electrolysis provided further evidence that the electroluminescence of porous silicon in solutions at positive biases stemmed from the oxidation of Si_H on the surface of porous silicon. The voltage tunable emitting for porous silicon in formic acid_sodium formate solution at positive biases was revealed, which could be explained with the quantum confinement effect.作者联系地址：北京大学化学与分子工程学院,北京大学化学与分子工程学院,北京大学化学与分子工程学院,北京大学化学与分子工程学院 北京100871.中国科学院研究生院化学学部,北京,100039 ,北京100871 ,北京100871 ,北京100871Author's Address: 1.College of Chemistry and Molecular Engineering, Peking University, Beijing 100871; 2.Chemistry Department of Graduate School of Chinese Academic Sciences,