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41.
In this work, zinc oxide/tin oxide (ZnO/SnO2) heterostructured nanomaterials were synthesized by hydrothermal method. Transmission electron microscopy, scanning electron
microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction measurements revealed that the product was composed
of ZnO nanowires and SnO2 nanobranches. The novel ZnO/SnO2 heterostructured nanocrystals were for the first time used as a supporting matrix to explore a novel immobilization and biosensing
platform of redox proteins. UV–visible absorption investigation indicated that hemoglobin (Hb) intercalated well in the ZnO/SnO2 heterostructured nanocrystals retained its native structure. Comparative experiments have confirmed that the ZnO/SnO2-based biosensor not only had enhanced direct electron transfer capacity but also displayed excellent electrocatalytic properties
such as higher sensitivity and wider linear range to the detection of hydrogen peroxide in comparison with the ZnO- and SnO2-based biosensors. 相似文献
42.
Wenzeng Duan Yudao Ma Fuyan He Lei Zhao Jianqiang Chen Chun Song 《Tetrahedron: Asymmetry》2013,24(5-6):241-248
Three novel planar chiral N-heterocyclic carbene silver and rhodium complexes based on [2.2]paracyclophane have been prepared. These could be used as catalysts/precatalysts for the asymmetric 1,2-addition of organoboronic acids to aldehydes. We optimized the reaction conditions and have applied ultrasonic irradiation in the asymmetric arylation for the first time. Under ultrasound irradiation, the combination of planar chiral NHC–Ag complex 5 and RhCl3 can achieve higher catalytic activities in the asymmetric addition of organoboronic acids to aldehydes. 相似文献
43.
Peng Liu Jianqiang Liu Dongju Zhang Changqiao Zhang 《International journal of quantum chemistry》2010,110(9):1583-1593
A very recent laser ablation‐molecular beam experiment shows that an Al+ ion can react with a single methylamine (MA, CH3NH2) or dimethylamine (DMA, (CH3)2NH) molecule to form a 1:1 ion–molecule complex Al+[CH3NH2] or Al+[(CH3)2NH)], whereas a dehydrogenated complex ion Cu+[CH3N] or Cu+[C2H5N] is detected, respectively, in the similar reaction for a Cu+ ion. Here, we show a comparative density functional theory study for the reactivities of the Al+ and Cu+ ions toward MA and DMA to reveal the intrinsic mechanism. It is found that the interactions of the Al+ ion with MA and DMA are mostly electrostatic, leading to the direct ion–molecule complexes, Al+? NH2CH3 and Al+? NH( CH3)2, in contrast to the non‐negligible covalent character in the corresponding Cu+‐containing complexes, Cu+? NH2CH3 and Cu+? NH( CH3)2. The general dehydrogenation mechanism for MA and DMA promoted by the Cu+ ion has been shown, and the preponderant structures contributing to the mass spectra of the product ions Cu+[CH3N] and Cu+[C2H5N] are rationalized as Cu+? NHCH2 and Cu+? N( CH2)( CH3). The presumed dehydrogenation reactions are also discussed for the Al+‐containing systems. However, the involved barriers are found to be too high to be overcome at low energy conditions. These results have rationalized all the experimental observations well. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 相似文献
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为研究使用不同形状光斑触发光导开关对光电导特性的影响,研制了12 mm间隙的半绝缘砷化镓光导开关,在不同的偏置电压下,使用波长为1 064 nm的不同能量的激光触发光导开关并进行了光电导测试。使用了不同形状的光斑(包括面状、线状和点状光斑)触发光导开关并进行了光电导特性的比较,讨论了触发光参数对光导开关特性的影响。对处于开关电极间不同位置的线状光斑触发特性进行了比较,结果显示,本征光电导和非本征光电导情况下光斑位置对光电流的影响正好相反。 相似文献
47.
在激光惯性约束核聚变(ICF)精确打靶中,对激光束变换、整形和控制要求苛刻,通过数字在线操控技术能够在线实现激光系统的自动校准,而频率变换是数字在线操控技术中的关键一环。在不进行逼近迭代计算的情况下,基于可逆的傅里叶变换和龙格-库塔算法,对神光II终端靶场系统中负单轴晶体KDP的"I+II"类频率变换的逆问题进行了探讨和相应的算法研究,并给出了对应的模拟计算结果。最后,与神光装置运行的实验数据进行比对,验证了频率变换逆问题算法的正确性和稳定性。 相似文献
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A new three-dimensional (3D) optical fluorescent tomographic imaging scheme is proposed with structured illumination and spatial Fourierdomain decomposition methods for the first time. In this spatial Fourier-decomposition optical fluorescence tomography (SF-OFT), the intensity of focused excitation light from an objective lens is modulated to be a cosine function along the optical axis of the system. For a given position in a two-dimensional (2D) raster scanning process, the spatial frequency of the cosine function along the optical axis sweeps in a proper range while a series of fluorescence intensity are detected accordingly. By making an inverse discrete cosine transformation of these recorded intensity profiles, the distribution of fluorescent markers along the optical axis of a focused laser beam is obtained. A 3D optical fluorescent tomography can be achieved with this proposed SF-OFT technique with a simple 2D raster scanning process. 相似文献
50.
In this paper, the supersonic chemically reacting mixing layer is simulated with the third order ENN scheme, based on the
Navier-Stokes equations, containing transport equations of all species. The numerical results show that the thickness of mixing
layer increases gradually along the flow direction, and that the Kelvin-Helmholtz instabilities may not exist in mixing layer
flows.
The project supported by the National Natural Science Foundation of China 相似文献