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981.
Matveeva EG Gryczynski I Malicka J Gryczynski Z Goldys E Howe J Berndt KW Lakowicz JR 《Journal of fluorescence》2005,15(6):865-871
We compared plastic (polycarbonate) and high-quality glass support materials for gold-coated slides, when performing a model
immunoassay against rabbit IgG using fluorescently labeled (AlexaFluor-647) anti-rabbit IgG, and detecting surface plasmon-coupled
emission (SPCE) signals. Both, glass and plastic slides were simultaneously coated with a 48-nm layer of gold and protected
with a 10-nm layer of silica. The maximum SPCE signal of AlexaFluor-647 was only two- to three-fold smaller on plastic slides
than on glass slides. A small difference in the SPCE angles on glass (θ
F = 55°) and plastic (θ
F = 52.5°) slides was observed and can be explained with a slightly smaller refractive index of the plastic. We have not found
any difference in the angle distribution (sharpness of the fluorescence signal at optimal SPCE angle) for the plastic slide
compared to the glass slide. The kinetics of binding was monitored on the plastic slide as well as on the glass slide. Optically
dense samples, a 4% red blood cell suspension and a 15% hemoglobin solution, are causing a reduction in the immunoassay SPCE
signal by approximately 15% and three times, respectively, and the percentage of the reduction is the same for plastic and
for glass slides. We believe that plastic substrates can be readily used in any SPCE assay, with only marginally lower total
signal compared to high-quality glass slides. 相似文献
982.
Presaturation utilizing relaxation gradients and echoes is an extremely easy and effective approach to solvent suppression in solution state nuclear magnetic resonance spectroscopy. The experiment produces flat baselines, excellent phase properties, and highly selective suppression that betters that of commonly used sequences. Furthermore, the only parameter that needs adjusting is the presaturation power, making it easy to implement even for non spectroscopists. Considering these factors, we envisage the approach will have wide spread applications. 相似文献
983.
Self-similar models are important in general relativity and other fundamental theories. In this paper we shall discuss the
“similarity hypothesis”, which asserts that under a variety of physical circumstances solutions of these theories will naturally
evolve to a self-similar form. We will find there is good evidence for this in the context of both spatially homogenous and
inhomogeneous cosmological models, although in some cases the self-similar model is only an intermediate attractor. There
are also a wide variety of situations, including critical phenomena, in which spherically symmetric models tend towards self-similarity.
However, this does not happen in all cases and it is important to understand the prerequisites for the conjecture. 相似文献
984.
We have investigated the influence of the dispersion of optical constants on the spectral properties of multilayer interference
systems, in the spectral characteristics of which the suppression of the high-reflection bands of the 5th, 6th, and 7th orders
is observed. Examples of realization of synthesized interference filters are given, and special features of their manufacturing
are considered.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 5, pp. 684–688, September–October, 2005. 相似文献
985.
A method for determining ropivacaine in human plasma using highly selective molecular imprint-based solid phase extraction
and LC–MS analysis was developed. The imprinted extraction material was prepared using a structural analogue of ropivacaine
as the template. The efficient sample cleanup achieved allowed single MS mode operation and analytical separation under isocratic
conditions with a total separation time of less than two minutes. The absence of ion suppression was confirmed for both the m/z of ropivacaine and the m/z of the internal standard. The solid phase extraction protocol was optimised for elution of ropivacaine in a small volume
of aqueous-rich solvent suitable for injection into a reversed phase LC–MS system. The final method measured trace levels
of ropivacaine in human plasma with a limit of quantification of 2.5 nmol/L and interassay accuracy and precision of 101.7–104.4%
and 2.1–7.2%, respectively. 相似文献
986.
987.
Ultrafast Dynamics of Defect-Assisted Carrier Capture in MoS2 Nanodots Investigated by Transient Absorption Spectroscopy 下载免费PDF全文
Da Ke Lai-zhi Sui Dun-li Liu Jian-qiu Cui Yun-feng Zhang Qing-yi Li Su-yu Li Yuan-fei Jiang An-min Chen Jun-ling Song Ming-xing Jin 《化学物理学报(中文版)》2018,31(3):277-283
MoS2 nanodots are emerging as promising semiconductor materials for optoelectronic devices. However, most of the recent attention is focused on the fabrication of MoS2 nanodots, and the survey for exciton dynamics of MoS2 nanodots remains less explored. Herein, we use femtosecond transient absorption spectroscopy to investigate the carrier dynamics of MoS2 nanodots. Our results show that defect-assisted carrier recombination processes are well consistent with the observed dynamics. The photo-excited carriers are captured by defects with at least two different capture rates via Auger scattering. Four processes are deemed to take part in the carrier relaxation. After photoexcitation, carrier cooling occurs instantly within ~0.5 ps. Then most of carriers are fast captured by the defects, and the corresponding time constant increases from ~4.9 ps to ~9.2 ps with increasing pump fluence, which may be interpreted by saturation of the defect states. Next a small quantity of carriers is captured by the other kinds of defects with a relatively slow carrier capture time within ~65 ps. Finally, the remaining small fraction of carriers relaxes via direct interband electron-hole recombination within ~1 ns. Our results may lead to deep insight into the fundamentals of carrier dynamics in MoS2 nanodots, paving the way for their further applications. 相似文献
988.