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141.
Herein, a novel sensitive pseudobienzyme electrocatalytic DNA biosensor was proposed for mercury ion (Hg2+) detection by using autonomously assembled hemin/G-quadruplex DNAzyme nanowires for signal amplification. Thiol functionalized capture DNA was firstly immobilized on a nano-Au modified glass carbon electrode (GCE). In presence of Hg2+, the specific coordination between Hg2+ and T could result in the assembly of primer DNA on the electrode, which successfully triggered the HCR to form the hemin/G-quadruplex DNAzyme nanowires with substantial redox probe thionine (Thi). In the electrolyte of PBS containing NADH, the hemin/G-quadruplex nanowires firstly acted as an NADH oxidase to assist the concomitant formation of H2O2 in the presence of dissolved O2. Then, with the redox probe Thi as electron mediator, the hemin/G-quadruplex nanowires acted as an HRP-mimicking DNAzyme that quickly bioelectrocatalyzed the reduction of produced H2O2, which finally led to a dramatically amplified electrochemical signal. This method has demonstrated a high sensitivity of Hg2+ detection with the dynamic concentration range spanning from 1.0 ng L−1 to 10 mg L−1 Hg2+ and a detection limit of 0.5 ng L−1 (2.5 pM) at the 3Sblank level, and it also demonstrated excellent selectivity against other interferential metal ions. 相似文献
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144.
Drag amplification of long flexible riser models undergoing multi-mode VIV in uniform currents 总被引:2,自引:0,他引:2
Measurement data of long flexible riser models are used to study the drag amplification due to multi-mode vortex induced vibration (VIV). The riser model was towed in a towing tank, and vibration along its length was measured indirectly at a set of discrete points using accelerometers, along with the total drag and lift forces on the model. These data were used to fit expressions for the drag amplification taking into account the spatial variation of the vibration amplitude along the riser length. The results were compared with the existing empirical expression used in the VIV analysis tool SHEAR7 as well as other test data. It was found that the expression in SHEAR7 agrees well with the test data. However, for larger vibration amplitudes, it appears to under-predict the drag amplification. 相似文献
145.
增益饱和在啁啾脉冲放大中的影响 总被引:5,自引:0,他引:5
研究了增益饱和在啁啾脉冲放大中的影响,发现由于增益饱和在存在,压缩后脉冲的信噪比会下降,而且展宽器附加的色散也会降低输出的信噪比,这种降低对应着一定的光谱畸变。通过对展宽/压缩器作用的分析,提示了啁啾脉冲放大中光谱与光强的内在联系,提出利用非共振放大来修正光谱畸变提高放大压缩后的信噪比。 相似文献
146.
Hai Ming Yu Liu Hui Nie Baorui Ren Jianping Xie Jingren Qian 《Chinese Journal of Lasers》1993,2(5):393-397
Amplification of spontaneous emission(ASE) in 4m Nd~(3 )-doped fiber pumped by Ti : Al~2O_3 tunable laser is studied theoretically and experimentally. The output of 2.64mW from ASE source pumped at 833 nm is obtained and the experimental results of ASE source are compared with that of Nd~(3 )-doped fiber ring laser. 相似文献
147.
148.
Xiaopeng Zhao David G. Schaeffer Carolyn M. Berger Daniel J. Gauthier 《Nonlinear dynamics》2007,48(4):381-389
Various authors have shown that, near the onset of a period-doubling bifurcation, small perturbations in the control parameter
may result in much larger disturbances in the response of the dynamical system. Such amplification of small signals can be
measured by a gain defined as the magnitude of the disturbance in the response divided by the perturbation amplitude. In this
paper, the perturbed response is studied using normal forms based on the most general assumptions of iterated maps. Such an
analysis provides a theoretical footing for previous experimental and numerical observations, such as the failure of linear
analysis and the saturation of the gain. Qualitative as well as quantitative features of the gain are exhibited using selected
models of cardiac dynamics. 相似文献
149.
Kong Hong Jin Lee Jae Yong Shin Yun Sup Byun Jae Oh Park Hee Su Kim Hyogun 《Optical Review》1997,4(2):277-283
Beam recombination characteristics were numerically investigated in array laser amplification using stimulated Brillouin scattering phase conjugation. To clarify the effect of piston errors due to imperfect phase locking, spatial intensity profiles of the beam recombination output were calculated in both the near and the far field on the basis of Rayleigh-Sommerfeld diffraction theory. The analyses indicate that piston errors are seriously detrimental to the quality of a beam recombination output and should be eliminated by a proper phase locking. It is also found that the gap between the beam splitting-combining wedges has a negligible effect.Presented at 1996 International Workshop on Interferometry (IWI ‘96), August 27-29, Saitama, Japan. 相似文献
150.
Jianping Lu Xiaoyin Hong Bing Wu Peiqing Wang Yongqi Chen 《Journal of photochemistry and photobiology. A, Chemistry》1997,110(3):313-316
Development-free vapor photolithography (DFVP) is a unique all-dry pattern transfer technique, which is based on the reaction of SiO2 with HF vapor under a polymer film in the presence of accelerators at a temperature of above 100°C. In this paper, we found that the etching reaction could be catalyzed by superacids. Based on this discovery, a novel, chemically amplified, development-free vapor photolithography technique was developed, and has benn successfully applied to power electronic device manufacture. 相似文献