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951.
952.
Qiang Zhou Ming-Lai Fu Bao-Ling Yuan Hao-Jie Cui Jian-Wen Shi 《Journal of nanoparticle research》2011,13(12):6661-6672
The semiconductor quantum dots (QDs) can be very efficient to tune the response of photocatalyst of TiO2 to visible light. In this study, CdS QDs formed in situ with about 8 nm have been successfully deposited onto the surfaces
of TiO2 nanotubes (TNTs) to form TNTs/CdS QDs nanocomposites by use of a simple bifunctional organic linker, thiolactic acid. The
diffuse reflectance spectroscopy (DRS) spectra of as prepared samples showed that the absorption edge of the TNTs/CdS composite
is extended to visible range, with absorption edge at 530 nm. The photocatalytic activity and stability of TNTs/CdS were also
evaluated for the photodegradation of rhodamine B. The results showed that when TNTs/CdS QDs was used, photocatalytic degradation
of RhB under visible light irradiation reached 91.6%, higher than 45.4 and 30.5% for P25 and TNTs, respectively. This study
indicated that the TNTs/CdS QDs nanocomposites were superior catalysts for photodegradation under visible light irradiation
compared with TNTs and P25 samples, which may find wide application as a powerful photocatalyst in environmental field. 相似文献
953.
954.
提出了一种研究混响室问题的理论分析方法,从理想混响室的离散概率模型出发,采用蒙特卡罗模拟来获得室内电磁场量及其相关物理量的概率统计特性。运用该方法获得了混响室内若干场量(均为归一化值)的概率密度函数、室内一段均匀无耗单导体传输线的负载平均耦合截面及负载电流响应模值的概率分布,所得结果与已有文献给出的结果(包括由解析公式计算或测量所得的结果)吻合良好。由于蒙特卡罗方法的普适性,采用该方法可以获得任意待分析参量的全部概率统计特性(只要样本数足够大)。同时该方法无需针对具体混响室进行,只要在其测试区域能较好地与理想混响室的基本概率模型相吻合,就能给出较精确的计算结果,且其计算量远远小于基于全波分析的蒙特卡罗方法。 相似文献
955.
Xiaoyan Zhou Zhaozhu Zhang Xuehu MenJin Yang Xianghui XuXiaotao Zhu Qunji Xue 《Applied Surface Science》2011,258(1):285-289
A superhydrophobic polyaniline (PANI) film has been fabricated by using a facile one-step spraying method. The PANI was synthesized via in situ doping polymerization in the presence of perfluorooctanoic acid (PFOA) as the dopant. The water contact angle of this superhydrophobic surface reaches to 156°. Both the surface chemical compositions and morphological structures were analyzed. A granular morphology of PANI with a moderate amount of nanofibers was obtained. Moreover, a rapid surface wettability transition between superhydrophobicity and superhydrophilicity can be observed when it is doped with PFOA and de-doped with base. The mechanism for this tunable wettability has been discussed in detail. 相似文献
956.
The present work reports a simple and time-saving method to fabricate cupric stearate film on zinc substrate by a solution-immersion process. Superhydrophobic surfaces are conventionally prepared employing two steps: roughening a surface and lowering its surface energy. The fabrication of superhydrophobic cupric stearate surface is reported using a one-step process by immersing a zinc plate coated with copper into the stearic acid solution, simplifying the complexity of two different steps involved in the conventional methods. The surface of the zinc plate coated with copper is found to be covered with low surface energy cupric stearate film providing the water contact angle of 160 ± 1° with the rolling off properties. In addition, the damaged superhydrophobic surface can restore superhydrophobicity property by immersing the surface into the stearic acid solution again. 相似文献
957.
Simultaneous measurement of curvature and temperature based on PCF-based interferometer and fiber Bragg grating 总被引:2,自引:0,他引:2
Yan Zhou Wenjun Zhou Chi Chiu Chan Li-Yang Shao Xinyong Dong 《Optics Communications》2011,284(24):5669-5672
A sensor head consisting of a photonic crystal fiber (PCF)-based Mach-Zehnder interferometer (MZI) and a fiber Bragg grating (FBG) is proposed and experimentally demonstrated for simultaneous measurement of curvature and temperature. The MZI fabricated by splicing a short length of PCF between two single-mode fibers with the air-hole structure that completely collapsed near the splicing points, is sensitive to fiber bending and surrounding temperature, while the FBG is only sensitive to the later. Simultaneous measurement of curvature and temperature is therefore obtained. Sensitivities of 4.06 nm/m− 1 and 6.30 pm/°C are achieved experimentally for curvature and temperature, respectively. And the corresponding resolutions are 5.2 × 10− 4 m− 1 and 1.25 °C for curvature and temperature, respectively, based on the wavelength measurement resolution of 10 pm. 相似文献
958.
The results of an experimental study of quantum correction of electron-electron interaction (EEI) to the conductivity of two-dimensional electron gas (2DEG) in an undoped heterostructure are reported. A small but significant decrease of the Hall slope with the increase of temperature was discovered. This is not due to the increase of electron concentration as temperature increases but to the EEI effect. Both diffusion and ballistic contributions of EEI to the conductivity of 2DEG were observed. As the temperature increases, the negative diffusion EEI correction to the conductivity increases in an absolute value while the ballistic EEI correction reduces to a renormalization of the transport mobility. 相似文献
959.
960.
采用高温熔融法制备了Yb3+/Er3+掺杂的氟氧化物发光微晶玻璃,确定了最佳熔化温度(1 100℃)和退火温度(440℃,480℃)。测定得到基质玻璃的透过率为85%,掺入稀土后,透过率有所下降,并出现了稀土离子的特征吸收峰。980 nm半导体激光器(LD)激发下样品的上转换发射光谱存在4个明显的发射峰,分别为410,532,546和656 nm,对应于2H9/2→4I15/2,2H11/2→4I15/2,4S3/2→4I15/2和4F9/2→4I15/2跃迁。研究了不同Yb3+/Er3+(摩尔分数)和Er3+浓度对上转换发光强度的影响,当Yb3+∶Er3+=4∶1、Er3+摩尔分数为1.5%时,上转换发光强度达到最高。根据发光强度与泵浦功率之间的关系,确定了上转换发射均为双光子过程。讨论了Yb3+,Er3+离子间的能量传递,建立了上转换发光机制。 相似文献