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131.
Basheer C Balaji G Chua SH Valiyaveettil S Lee HK 《Journal of chromatography. A》2011,1218(5):654-661
A novel on-site sample preparation approach for the organophosphorus pesticides (OPPs) using functional polymer-coated fibers with a portable agitation device has been developed and demonstrated. In this approach, a handheld battery-operated electric toothbrush was used to provide agitation of the sample solution at the sampling site to facilitate extraction. A functional conjugated polymer (2-(9,9-bis(6-bromo-2-ethylhexyl)9-H-fluoren-2-yl)benzene-1,4-diamine) was coated on commercial Technora fibers (each strand consisted of 1000 filaments, each of diameter ca. 9.23μm) which were then used for extraction. After extraction, the fibers were brought back to the laboratory in an icebox. The analytes were subsequently desorbed by organic solvent and the extract was analysed by gas chromatography-mass spectrometry. Six OPPs, triethylphosphorothiolate, thionazin, sulfotep, phorate, disulfoton and parathion were used as model compounds. Experimental parameters such as extraction time, desorption time, types of polymer fibers and fiber coatings as well the nature of desorption solvent were optimized in the laboratory prior to its on-site application of the procedure. Using optimum extraction conditions calibration curves were linear with correlation coefficient of 0.9748-0.9998 over the concentration range of 0.1-10μgl(-1). The method detection limits (at a signal-to-noise ratio of 3) were in the range of 0.3-30.3ngl(-1), which were lower than what could be achieved with solid-phase extraction performed at the laboratory. The proposed method was evaluated for the on-site extraction of OPPs in seawater samples. 相似文献
132.
Chua SS Stefszky MS Mow-Lowry CM Buchler BC Dwyer S Shaddock DA Lam PK McClelland DE 《Optics letters》2011,36(23):4680-4682
We report on the performance of a dual-wavelength resonant, traveling-wave optical parametric oscillator to generate squeezed light for application in advanced gravitational-wave interferometers. Shot noise suppression of 8.6±0.8 dB was measured across the detection band of interest to Advanced LIGO, and controlled squeezing measured over 5900 s. Our results also demonstrate that the traveling-wave design has excellent intracavity backscattered light suppression of 47 dB and incident backscattered light suppression of 41 dB, which is a crucial design issue for application in advanced interferometers. 相似文献
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The mixings of d(R) quarks, hidden from view in the standard model (SM), are naturally the largest if one has an Abelian flavor symmetry. With supersymmetry (SUSY) their effects can surface via d(R) squark loops. Squark and gluino masses are at TeV scale, but they can still induce effects comparable to SM in B(d) (or B(s)) mixings, while D0 mixing could be close to recent hints from data. In general, CP phases would be different from SM, as may be indicated by recent B factory data. Presence of nonstandard soft SUSY breakings with large tanbeta could enhance b-->dgamma (or sgamma) transitions. 相似文献
137.
低温陈化超声波共沉淀法制得SO42-/ZrO2-La2O3前驱体, 经H2SO4处理, 在不同温度下焙烧得到纳米晶催化剂SO42-/ZrO2-La2O3;用Hammett指示剂法测定其酸性. 用XRD、BET、TEM、IR和XPS对样品进行表征,其催化活性用醋酸和甘油的酯化反应进行了评价. 结果表明经超声波搅拌和低温(-15 ºC)陈化,650 ºC焙烧4 h得到的固体超强酸表现出较高催化活性. 相似文献
138.
A tunable erbium-doped fiber ring laser employing an all -polarization- maintaining fiber loop filter with certain birefringence is proposed and demonstrated. The lasing frequencies can be selected by properly adjusting the polarization controller in the cavity. 相似文献
139.
Tomoaki Masuzawa Masanori Onishi Ichitaro Saito Takatoshi Yamada Angel T. T. Koh Daniel H. C. Chua Shuichi Ogawa Yuji Takakuwa Yusuke Mori Tatsuo Shimosawa Ken Okano 《固体物理学:研究快报》2013,7(7):473-476
High‐sensitivity ultraviolet (UV) photodetection has been attempted by utilizing the carrier multiplication effect in amorphous selenium. The prototype photodetector presented in this Letter showed an extremely high sensitivity to UV light, so that up to 1000 carriers are generated per incident photon. This result should lead to the development of an ultrahigh‐sensitivity photodetector that can be used for spectrometric applications covering the visible to UV region. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
140.
Heng Huat Chan Kok Seng Chua Patrick Solé 《Transactions of the American Mathematical Society》2003,355(4):1505-1520
In this paper, properties of the functions , and are derived. Specializing at and , we construct two new quadratic iterations to . These are analogues of previous iterations discovered by the Borweins (1987), J. M. Borwein and F. G. Garvan (1997), and H. H. Chan (2002). Two new transformations of the hypergeometric series are also derived.