Enhanced Raman Scattering by Polystyrene Microspheres and Application for Detecting Molecules Adsorbed on Au Single Crystal Surface

利用在样品表面上组装聚苯乙烯微球,可以使得表面拉曼信号得到增强.系统考察了增强效应与微球粒子尺寸的依赖关系,发现当微球直径为3.00μm时,拉曼信号的增强效应最强,可以达到约5倍的增强.进一步利用聚苯乙烯微球的增强效应,获得了单层吸附在Au(111)表面上具有共振增强效应的异氰基孔雀石绿分子的拉曼信号,得到约20倍的信号净增强,相当于约3个数量级的拉曼增强效应,表明利用这种方法可以显著提高单晶表面吸附分子的检测灵敏度.这种增强效应主要是由于激光在透明微球的作用下,在微球底部产生纳米光束流,从而形成高度局域化的电磁场,使拉曼散射过程得到极大的增强.初步探讨了两种类型样品表面获得不同的增强效应的原因.By assembling polystyrene microsphores on a sample surface, the surface Raman signalcould be enhanced. The dependence of the enhancement effect on the size of microparticles was systematically investigated and it was found that microparticles with a diameter of 3.00 μm showed the highest enhancement of ca 5 folds. By utilizing the enhancement effect of the microspheres, the surface Raman intensity of malachite green isothiocyanate (MGITC) adsorbed on Au(111) surface could be enhanced by 20 folds, indicating that this method could effectively improve the detection sensitivity of surface Raman spectroscopy for the adsorbed species on single crystal surface. The later signal increment corresponds to the Raman enhancement effect of nearly 3 orders of magnitude. The enhancement effect is mainly owing to the formation of nanojets when a laser is focused on the microspheres of appropriate diameter. The formation of nanojets will lead to the highly localized electromagnetic field, which will then significantly enhance the Raman process in the nanojets. The main reason for obtaining different enhancements on two types of samples was analyzed.国家自然科学基金(20673086,20825313);; 教育部新世纪优秀人才计划(NCET-05-0564);; 国家重点基础研究发展规划(973)项目(2007CB935603)资

Experimental Study of the Abalone Shell on Cataract induced by Oxidative Stress

目的研究石决明提取物对体外培养的晶状体氧化应激性白内障形成的作用及机制。方法离体培养小鼠晶状体,应用不同浓度的石决明提取物预孵育晶状体24h后,加入1mm过氧化氢,继续培养3小时后恢复正常培养,72小时后观察小鼠晶状体混浊程度,测定晶状体组织培养液中的乳酸脱氢酶(LDH)含量,晶状体组织中还原型谷胱甘肽(GSH)含量及超氧化物歧化酶(SOD)活力。结果石决明提取物在1~2 mg/ml浓度范围内减轻氧化应激造成的晶状体混浊,减少晶状体LDH的释放,提高组织内GSH含量和SOD活力。结论石决明提取物可减轻氧化应激白内障的形成,其作用主要与石决明提取物提高内源性抗氧化系统有关。Objective To study the effect of the abalone shell extract on oxidative stress induced cataract formation and its mechanism in cultured mouse lens in vitro. Methods The cultured mouse lens were pretreated with the abalone shell extract in different concentrations for24 hours,and then 1mm hydrogen peroxide was added and continued incubating for 3 hours,and they were changed to normal culture media.After 72 hours,the opacity of each lens was observed under an anatomical microscope,the content of lactate dehydrogenase( LDH)leakages,the content of the reduced glutathione( GSH) and activity of superoxide dismutase( SOD) in lens tissue were assayed. Results Abalone shell extract in the concentration range of 1 ~ 2 mg / ml reduced the lens opacity caused by oxidative stress,alleviated the release of LDH,and increased GSH content and SOD activity in cultured lens. Conclusion Abalone shell extract can alleviate the oxidative stress induced cataract formation,and this effect is mainly related to its improvement of the endogenous antioxidant system in lens.2012年福建省卫生厅中医药科研专项课题(No.WST201210);; 2013年福建省卫生厅中医药科研专项课题(No.wzhw201302);; 2014年厦门市科技局科技惠民项目课题(No.3502Z20144030

从预防事故和消除隐患的角度改进实验室安全工作

从预防实验室事故和消除安全隐患的角度,分析归纳出安全意识淡薄、安全知识缺乏、安全条例执行不到位、工作人员心理疲劳等导致实验室事故和安全隐患的深层次原因,以及这些原因之间的相互影响,并从安全教育教学、人事考核、实验室团队建设、信息化建设等方面对实验室安全工作提出相应的改进对策与建议

The Size and Shape Effects on the Optical Properties of Gold Nanoparticles

【中文文摘】纳米尺度的金属及半导体呈现出特殊的光学、电学及磁学性质,采用近年发展起来的离散偶极近似(DDA)的方法,我们分析了金纳米粒子的尺寸及形状对其光学性质的影响。粒子周围介质的影响在文中亦作了分析。计算结果显示,金纳米粒子的等离子体吸收带同时受到粒子尺寸和形状的影响,但来自形状的影响更为明显。与米氏理论及扩展的甘氏理论相比较,DDA方法在粒子尺寸不再远小于入射光波长的时候更准确,并能应用于任何形状的纳米粒子。理论计算与实验结果能较好的吻合。 【英文文摘】Metals and semiconductors exhibit unusual optical, electronic, and magnetic properties at the nanometer scale. Based on the newly developed method, discrete dipole approximation (DDA), the dependence of the optical properties of the gold nanoparticles on the size and shape was analyzed. The effects of the surrounding medium were also taken into consideration in the calculation. The calculated results show that the plasmon absorption band depends on both the size and shape of the gold noanoparticles. However , the influence of the shape is more significant . Compared to the Mieps theory and the extension , Gansp theory , the DDA method is more accurate when the dimensions of the particles are not much smaller than the wavelength of the incident light and can be applied to particles of any shape. The theoretical results are in good agreement with the experimental data.国家自然科学基金项目,批准号为 :20003008,2983306

Enhanced Raman Scattering by Polystyrene Microspheres and Application for Detecting Molecules Adsorbed on Au Single Crystal Surface

By assembling polystyrene microsphores on a sample Surface, the surface Raman signal Could be enhanced. The dependence of the enhancement effect on the size of microparticles was systematically investigated and it was found that microparticles with a diameter of 3.00 mu m showed the highest enhancement of ca 5 folds. By utilizing the enhancement effect of the microspheres. the surface Raman intensity of malachite green isothiocyanate (MGITC) adsorbed on Au(111) surface could be enhanced by 20 folds, indicating that this method could effectively improve the detection sensitivity of surface Raman spectroscopy for the adsorbed species on single crystal surface. The later signal increment corresponds to the Raman enhancement effect of nearly 3 orders of magnitude. The enhancement effect is mainly owing to the formation of nanojets when a laser is focused on the microspheres of appropriate diameter. The formation of nanojets will lead to the highly localized electromagnetic field, which will then significantly enhance the Raman process in the nanojets. The main reason for obtaining different enhancements on two types of samples was analyzed

Surface-Enhanced Raman Scatting Substrates Fabricated by Combining Chemical Assembly and Electrodeposition Methods

采用一种结合化学组装和电化学沉积制备均匀而且具有强SERS基底的方法,研究了沉积电位对组装在ITO表面的金纳米粒子形貌的影响,发现在-0.04 V下沉积5 min可以得到形貌均匀的纳米粒子.利用现场电化学紫外-可见吸收光谱来监控电化学沉积过程,发现沉积一定时间后,紫外-可见吸收谱在600~700 nm区间出现新峰,表明粒子间发生了有效的电磁场耦合.对制备的基底进行拉曼成像,结果表明,基底的均匀性很好,最强点与最弱点的d信号差小于20%,符合商品化基底的要求.We reported a method to prepare SERS substrates with a high and uniform SERS activity by combining chemical assembly and electrochemical deposition methods.We systematically investigated the effect of the electrode potential on the surface morphology of the Au nanoparticles on the ITO surface.It is found that Au nanoparticles with very uniform structure and proper electromagnetic coupling can be obtained by electrodeposition at-0.04 V(vs.SCE) for 5 min.In situ electrochemical UV-Vis absorption spectroscopy was used to monitor the deposition process by measuring the absorption spectra.A new peak between 600 and 700 nm was observed in the UV spectra during the electrochemical deposition process,which can be used as a measurement of whether and how the electromagnetic field of nanoparticles couples.SERS mapping was performed to demonstrate that the substrate was very uniform with a signal deviation less than 20%,meeting the standard for commercial SERS substrates.国家自然科学基金(批准号:20673086);; 教育部博士点基金(批准号:20040384010);; 新世纪优秀人才支持计划项目(批准号:NCET-05-0564);; 国家“九七三”计划(批准号:2007CB935603)资

海原—六盘山地区活动构造的活动时间厘定:来自光释光测年的限定

海原-六盘山地区位于现今青藏高原东北部,该地区活动构造的研究不仅可以为地震安全评价提供依据,也可以为第四纪青藏高原的扩展提供限定.在野外地质调查的基础上,运用光释光定年技术,限定研究区活动构造的活动时间.研究显示,海原-六盘山断裂和香山-天景山断裂在晚第四纪存在剧烈活动,产生了如角度不整合(夷平面)、褶皱和断层构造.这些结果表明,研究区应该作为地震安全评价的重点关注区域,同时也显示青藏高原东北部在晚第四纪存在持续的扩展.</p

Surface-enhanced Raman scatting substrates fabricated by combining chemical assembly and electrodeposition methods

We reported a method to prepare SERS substrates with a high and uniform SERS activity by combining chemical assembly and electrochemical deposition methods. We systematically investigated the effect of the electrode potential on the surface morphology of the Au nanoparticles on the ITO surface. It is found that An nanoparticles with very uniform structure and proper electromagnetic coupling can be obtained by electrodeposition at -0.04 V (vs. SCE) for 5 min. In situ electrochemical UV-Vis absorption spectroscopy was used to monitor the deposition process by measuring the absorption spectra. A new peak between 600 and 700 nm was observed in the UV spectra during the electrochemical deposition process, which can be used as a measurement of whether and how the electromagnetic field of nanoparticles couples. SERS mapping was performed to demonstrate that the substrate was very uniform with a signal deviation less than 20%, meeting the standard for commercial SERS substrates

Biomass Structure and Energy Distribution of Phyllostachys heterocycla cv. pubescens Population

研究了福建省永春县毛竹种群的生物量结构、能量分布 ,研究结果表明 :(1)永春毛竹种群的现存生物量为6 474.874g/m2 ,其中地上部分为 46 76 .6 39g/m2 ,占 72 .2 3% ;地下部分为 1798.2 35g/m2 ,占 2 7.77% ;其各组分分别为 :杆 3736 .2 0 0 g/m2 、枝 772 .0 6 9g/m2 、叶 16 8.370 g/m2 、竹蔸 10 5 9.115 g/m2 、鞭根 739.12 0 g/m2 ;(2 )毛竹种群生物量在Ⅰ至Ⅳ度的分配为 :5 .12 % ,40 .5 2 % ,39.82 % ,14.5 4% ;(3)毛竹种群的能量现存量为 12 46 89.5 76kJ/m2 ,其中地上部为 912 18.36 1kJ/m2 (占 73.16 % ) ,地下部为 334 71.2 15kJ/m2 (占 2 6 .84% ) ;(4 )能量现存量在Ⅰ至Ⅳ度的分配为 :5 .0 8% ,40 .38% ,39.80 % ,14.74% .Biomass structure and energy distribution of Phyllostachys heterocycla cv. pubescens population in Yongchun county, Fujian were discussed in this paper. The results showed as follows:(1)the standing crop of biomass in the Phyllostachys heterocycla cv. pubescens population was 6 474.874 g/m 2, in which the biomass of above-ground was 4 676.639 g/m 2 (accounting for 72.23%), and that of below-ground was 1 798.235 g/m 2 (27.77%), respectively; the biomass of various components of population was 3 736.200 g/m 2 for stem, 772.069 g/m 2 for branch, 168.370 g/m 2for leaf, 1 059.115 g/m 2 for rhizome and 739.120 g/m 2 for roots, respectively.(2)the biomass components fromⅠto Ⅳ age was 5.12%, 40.52%, 39.82% and 14.54%, respectively.(3)the standing crop of energy was 124 689.576 kJ/m 2 , in which above-ground and below-ground comprised 91 218.361 kJ/m 2 (accounting for 73.16%) and 33 471.215 kJ/m 2 (26.84%), respectively.(4)the standing crop of energy from Ⅰto Ⅳ age was 5.08%, 40.38%, 39.80% and 14.74%, respectively.福建省自然科学基金 (B0 110 0 0 7)资助项