排序方式: 共有27条查询结果,搜索用时 15 毫秒
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Washboard belt-like zinc selenide (ZnSe) nanostructures are successfully prepared by a simple chemical vapor deposi- tion (CVD) technology without catalyst. The phase compositions, morphologies and optical properties of the nanos- tructures are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmis- sion electron microscopy (HRTEM) and photoluminescence (PL) spectroscop, respectively. A vapor-liquid mecha- nism is proposed for the formation of ZnSe belt-like structures. Strong PL from the ZnSe nanostructure can be tuned from 462 nm to 440 nm with temperature varying from 1000 ℃ to 1200 ℃, and it is demonstrated that the washboard belt-like ZnSe nanostructures have potential applications in optical and sensory nanotechnology. This method is ex- pected to be applied to the synthesis of other II-VI groups or other group's semiconducting materials. 相似文献
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Fluorescent porous silicon was prepared as a stable biosensor chip substrate. The aminopropyltriethoxysilane (APTES) molecules are attached in the pores of the porous silicon with a crosslink method, and when the molecules are added into the chip, the fluorescence intensity is reduced according to the concentration of the APTES. Controlled experiments are also presented with the small molecule that cannot be covalently coupled, and the results show that this kind of sensor chip has better specificity. Compared with other conventional methods, this method is simple, quick and label-free. 相似文献
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In order to solve this problem, a new biological detection method is proposed, which makes use of the characteristics of optical transmission at the edge of the spectral band gap and sensitive to refractive index variation. When the probe light with wavelength at the edge of the Bragg band gap of porous silicon is incident on the surface of porous silicon, the change of refractive index caused by deoxyribonucleic acid (DNA) reaction in porous silicon will affect the detection light intensity transmitted from the porous silicon sensor. By analyzing the change of the average gray value of the transmitted light image, the concentration of the DNA can be obtained. 相似文献
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为了实现胡萝卜汁品牌的快速无损鉴别,文章以市售两种品牌的胡萝卜汁为研究对象,通过采集拉曼光谱,并结合支持向量机算法,建立了快速判断胡萝卜汁品牌的分类模型。两种品牌的胡萝卜汁光谱主要在1007 cm^-1,1157 cm^-1,1516 cm^-1这3个谱峰存在差异。先对拉曼光谱进行预处理,再选用蚁群优化算法进行特征选择,最后结合SVM构建分类模型。结果显示,相比SVM直接分类,模型ACO-SVM的最优分类准确率为96.67%,提高了2.5%;其分类时间为7.17 s,缩短了163.31 s。研究表明,基于拉曼光谱分析技术和模式识别算法构建的分类模型能够有效地鉴别胡萝卜汁品牌。 相似文献
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提出了一种在信息安全风险评估中采用层次分析方法进行风险的分析,而在风险的具体计算中采用模糊数学计算的信息安全风险评估模型。探索性的提出了一种改进的方法,把层次分析法与模糊数学计算结合起来,使得风险评估的结果得以量化,经实践证明,该模型可方便地应用于信息安全风险评估,使评估结果更科学、合理。最后辅以实例说明。 相似文献
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High-density CdS hollow nanospheres are successfully synthesized by a simple chemical vapor deposition technology.The crystal structure,compositional information,and morphological structure are characterized by X-ray diffraction(XRD),scanning electronic microscopy(SEM),transmission electronic microscopy(TEM),and energy-dispersive X-ray spectrometer(EDX).The results show that the as-prepared CdS hollow nanospheres have uniform size about 1-3 μm in diameter.The Kirkendall phenomenon is proposed for the formation of the CdS nanostructures.A strong emission located at 580 nm is observed. 相似文献