Random laser based on waveguided plasmonic gain channels

A waveguide-plasmonic scheme is constructed by coating the matrix of randomly distributed gold nanoisland structures with a layer of dye-doped polymer, which provides strong feedback or gain channels for the emission from the dye molecules and enables successful running of a random laser. Excellent overlap of the plasmonic resonance of the gold nanoislands with the photoluminescence spectrum of the dye molecules and the strong confinement mechanism provided by the active waveguide layer are the key essentials for the narrow-band and low-threshold operation of this random laser. This kind of feedback configuration potentially enables directional output from such random lasers. The flexible solution-processable fabrication of the plasmonic gold nanostructures not only enables easy realization of such a random laser but also provides mechanisms for the tuning and multicolor operation of the laser emission.     

Detection of Epstein-Barr virus infection in gastric carcinomas using quantum dot-based fluorescence in-situ hybridization

Quantum dots were proposed as new fluorochromes for use in fluorescence in-situ hybridization. EBV-encoded small RNA, the most abundant viral product in latently infected cells, was detected by quantum dot fluorescence in-situ hybridization in paraffin-embedded tissue sections of gastric carcinoma. An indirect FISH approach using quantum dots streptavidin conjugates as secondary reporters and digoxigenin labeled EBV-encoded small RNA oligonucleotide probes as detectable molecules was employed. Quantum dot fluorescence in-situ hybridization offered a slightly higher sensitivity in detecting EBV-encoded small RNA in gastric carcinoma than chromogenic in-situ hybridization. Statistical analyses showed that the detected EBV-associated gastric carcinoma was not associated with any clinicopathological parameters of the Chinese gastric carcinoma patients investigated in this study.     

Photocatalytic bactericidal mechanism of nanoscale TiO2 films on Escherichia coli

Two kinds of nanoscale TiO2 films were prepared by magnetron sputtering and screen printing methods, respectively. Results show that both phase composition and specific surface area of the film affect the photocatalytic bactericidal efficiency. Time-series in situ atomic force microscopy (AFM) observation were further used to characterize the cellular responses of Escherichia coli (E. coli) in photocatalytic process. Some nanosized patches were found on the bacterial surface in the forepart of photocatalytic reaction. It suggested that the photocatalytic attack induced the self-protection of bacteria at first. Subsequently, some cracks on the surface and the enlargement of cell body indicated that the cell wall was damaged and lost its structure supporting function, and it eventually led to the death of bacteria.     

Origin of the unusually high dibenzothiophene concentrations in Lower Ordovician oils from the Tazhong Uplift, Tarim Basin, China

The origin of the unusually high dibenzothiophene (DBT) concentrations in Lower Ordovician oils from the Tazhong Uplift,Tarim Basin was studied by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS).The most abundant sulfur compounds in the oils are S 1 species with doublebond equivalent (DBE) values of 1-19 and 11-48 carbon atoms.The range of the number of carbon atoms in the sulfur compounds detected by the FT-ICR MS (S 1 species with DBE=9) is about ten times larger than that for sulfur compounds detected by GC/MS (DBTs).This suggests that FT-ICR MS is a much better approach than GC/MS for characterization of DBTs in crude oils.The abundance of S 1 species with DBE=1-8 decreased with increasing thermal maturity,while the abundance of S 1 species with DBE=9 (primarily DBTs) increased.Therefore,thermal maturity is an important factor in the formation of oils with high DBT concentrations.Unusually high abundances of S 1 species with low DBE values (1-8),which include sulfide,thiophene and benzothiophene,were observed in several oils,especially the TZ83 (O 1) oil with high or very high thermal maturity.Thermochemical sulfate reduction (TSR) was thought to be the reason for the high abundance of these low DBE compounds in deep reservoirs,and thermochemical sulfate reduction could affect the distribution and composition of DBTs in the oils.According to the results of FT-ICR MS analysis,there are no signs that TSR is occurring or has occurred recently for most of the Lower Ordovician oils.     

珠江口盆地白云深水区沉积充填演化及控制因素分析

白云深水区在新生代经历了裂谷断陷、断拗、热沉降拗陷等构造演化阶段,相应发育了裂谷断陷期文昌组多个半地堑陆相河湖沉积,断拗期恩平组大型湖盆沉积、从断拗向热沉降拗陷过渡的珠海组海相浅水陆架一陆坡深水沉积,以及23.8 Ma之后的热沉降拗陷期海相陆坡内盆地深水沉积,形成了独特的多个盆地叠置的沉积充填模式和断陷-断坳-坳陷的三层盆地结构,从而在时间和空间上构成了有利的生储盖组合条件.构造演化、古地理、物源供给条件和相对海平面变化等多种因素控制了白云深水区的沉积充填演化;发生于23.8～21.0 Ma的白云运动,是白云深水区裂后海相沉积充填的主控因素,使得古珠江的物源体系和陆架坡折带发生迁移,形成了珠海组海退进积型与珠江组-韩江组海侵加积型层序组合,这两个层序组合均发育大规模深水扇砂岩.     

基于TMS320VC5509DSP的FIR数字滤波器的实现

FIR数字滤波器广泛应用于实时数字信号处理领域.本文介绍了FIR数字滤波器的结构、特点及设计方法,并采用窗函数法设汁了FIR滤波器.利用TMS320VC5509 DSP芯片强大的数字信号处理功能实现了该滤波器.实验表明,此数字滤波器工作稳定,能够满足实时的滤波处理功能.     

循环经济理论在机械零件失效修复中的运用

前瞻性地以节约和环保的高新技术修复失效报废的机械零件,符合国家发展循环经济的政策。本文从循环经济的基本概念入手,阐述机械零件修复再利用的实质体现循环经济的基本原则。     

热连轧活套系统的自适应自抗扰控制研究

在热连轧活套系统工作点附近建立了活套高度与张力的近似线性化耦合模型。用两个并行自抗扰控制器对活套系统进行解耦与控制,用单神经元方法对自抗扰控制器的重要参数进行在线修正以提高控制器的自适应性。仿真结果显示了本文算法的可行性与有效性。     

中国传统豆豉溶栓活性的初步研究

豆豉中含有一种具溶栓功能的活性物质,利用纤维蛋白平板法对14种传统豆豉产品的溶栓活性物质进行研究。结果表明,豆豉提取物的溶栓活性为0.326～161.972尿激酶单位/mL。永川毛霉型豆豉提取物表现出最大的活性,达161.972尿激酶单位/mL,曲霉豆豉与辣豆豉活性较小。     

Detection of Panax quinquefolius in Panax ginseng using 'subtracted diversity array'

BACKGROUND: Food adulteration remains a major global concern. DNA fingerprinting has several advantages over chemical and morphological identification techniques. DNA microarray‐based fingerprinting techniques have not been used previously to detect adulteration involving dried commercial samples of closely related species. Here we report amplification of low‐level DNA obtained from dried commercial ginseng samples using the Qiagen^? REPLI‐g^® Kit. Further, we used a subtracted diversity array (SDA) to fingerprint the two ginseng species, Panax ginseng and Panax quinquefolius, that are frequently mixed for adulteration. RESULTS: The two ginseng species were successfully discriminated using SDA. Further, SDA was sensitive enough to detect a deliberate adulteration of 10% P. quinquefolius in P. ginseng. Thirty‐nine species‐specific features including 30 P. ginseng‐specific and nine P. quinquefolius‐specific were obtained. This resulted in a feature polymorphism rate of 10.5% from the 376 features used for fingerprinting the two ginseng species. The functional characterization of 14 Panax species‐specific features by sequencing revealed one putative ATP synthase, six putative uncharacterized proteins, and two retroelements to be different in these two species. CONCLUSION: SDA can be employed to detect adulterations in a broad range of plant samples. Copyright © 2011 Society of Chemical Industry