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71.
Zhennan Wu Qiaofeng Yao Osburg Jin Huang Chai Nan Ding Wen Xu Shuangquan Zang Jianping Xie 《Angewandte Chemie (International ed. in English)》2020,59(25):9934-9939
Aggregation‐induced emission (AIE) provides an efficient strategy to synthesize highly luminescent metal nanoclusters (NCs), however, rational control of emission energy and intensity of metal NCs is still challenging. This communication reveals the impact of surface AuI‐thiolate motifs on the AIE properties of Au NCs, by employing a series of water‐soluble glutathione (GSH)‐coordinated Au complexes and NCs as a model ([Au10SR10], [Au15SR13], [Au18SR14], and [Au25SR18]?, SR=thiolate ligand). Spectroscopic investigations show that the emission wavelength of Au NCs is adjustable from visible to the near‐infrared II (NIR‐II) region by controlling the length of the AuI‐SR motifs on the NC surface. Decreasing the length of AuI‐SR motifs also changes the origin of cluster luminescence from AIE‐type phosphorescence to Au0‐core‐dictated fluorescence. This effect becomes more prominent when the degree of aggregation of Au NCs increases in solution. 相似文献
72.
A combination of fluorobenziodoxole (FBX) and BF3 ? OEt2 in cyclopentyl methyl ether promotes regio‐ and stereoselective addition of benziodoxole and methoxy groups to alkynes. This difunctionalization reaction tolerates a variety of functionalized internal and terminal alkynes to afford trans‐β‐alkoxyvinylbenziodoxoles, which represent versatile precursors to stereochemically well‐defined multisubstituted vinyl ethers. The reaction is proposed to involve cleavage of the I?F bond of FBX by BF3, followed by electrophilic activation of the alkyne by the resulting cationic IIII species that triggers the nucleophilic addition of the ethereal oxygen. 相似文献
73.
Shufang Wang Huiling Li Kun Zhao Songqing Zhao Mingjing Chen Jingchun Chen Jianglong Wang Guangsheng Fu 《Applied Physics A: Materials Science & Processing》2011,105(2):407-410
A heterojunction was fabricated by growing a layer of Bi2Sr2Co2O
y
thin film on the 0.7 wt% Nb-doped SrTiO3 substrate. Such heterojunction showed good rectifying characteristics over a wide temperature range, and its transport mechanism
under the forward bias can be attributed to a space charge limited conduction mechanism via defects near the interface of
the heterojunction. Photovoltaic properties of the heterojunction were studied by using both continuous-wave and pulsed irradiations
and the results can be well explained by the photovoltaic effect of a p–n junction. 相似文献
74.
Ying Wang Yousong GuShou Peng Wanyu Ding Hualin Wang Weiping Chai 《Applied Surface Science》2011,257(18):8044-8047
Transparent conducting Al-doped ZnO (ZnO:Al, AZO) thin films with good optical and electrical characteristics were prepared by direct current pulse magnetron sputtering. Textured surfaces of AZO films were obtained by etching with NaOH solution successfully and the effect of substrate temperature on the surface texture was investigated. The surface is covered with craters after etching with 5% NaOH solution, and the crater diameter decreases gradually as substrate temperature increases. For AZO film deposited at 270, the crater diameters is 0.5-1 μm, which is an effective surface texture for light trapping. 相似文献
75.
利用直流脉冲磁控溅射方法在室温下通过改变O2流量制备具有不同晶体结构的N掺杂TiO2薄膜,利用台阶仪、X射线光电子能谱仪、X射线衍射仪、紫外-可见分光光度计等设备对薄膜沉积速率、化学成分、晶体结构、禁带宽度等进行分析.结果表明:所制备的薄膜元素配比约为TiO1.68±0.06N0.11±0.01,N为替位掺杂,所有样品退火前后均未形成Ti—N相结构,N掺杂TiO2薄膜的沉积速率、晶体结构等主要依赖于O2流量.在O2流量为2 sccm时,N掺杂TiO2薄膜沉积速率相对较高,薄膜为非晶态结构,但薄膜内含有锐钛矿(anatase)和金红石(rutile)相晶核,退火后薄膜呈anatase和rutile相混合结构,禁带宽度仅为2.86 eV.随着O2流量的增加,薄膜沉积速率单调下降,退火后样品禁带宽度逐渐增加.当O2流量为12 sccm时,薄膜为anatase相择优生长,退火后呈anatase相结构,禁带宽度为3.2 eV.综合本实验的分析结果,要在室温条件下制备晶态N掺杂TiO2薄膜,需在高O2流量(>10 sccn)条件下制备.
关键词:
2薄膜')" href="#">N掺杂TiO2薄膜
磁控溅射
化学配比
晶体结构 相似文献
76.
对认知无线网络中的频谱进行有效分配是实现动态频谱接入的关键技术.考虑3次用户对频谱的需求和分配的公平性,给出了频谱分配的数学模型,并将其转换为以最大化网络收益为目标的带约束优化问题,进而提出一种采用混沌量子克隆优化求解的认知无线网络频谱分配算法, 并证明了该算法以概率1收敛.最后,通过仿真实验比较了本文算法与颜色敏感图着色算法、基于遗传算法的频谱分配、基于量子遗传算法的频谱分配的性能.结果表明:本文算法性能较优, 能更好地实现网络收益最大化.
关键词:
混沌量子克隆算法
认知无线网络
频谱分配 相似文献
77.
Bao-Shan Chai Chang-Ling Liu Hui-Chao Li Shao-Wu Liu Ying Xu Yu-Quan Song Jun-Biao Chang 《中国化学快报》2014,25(1):137-140
Pyriminostrobin, a new acaricide, was discovered in our previous studies. Because introducing fluorine into organic compounds can increase bioactivity, pyriminostrobin was modified as a series of strobilurin-pyrimidine derivatives for biological screening. The compounds were characterized by 1H NMR, MS and elemental analysis. Preliminary bioassays demonstrated that compounds 7e and 7i exhibited significant control against Tetranychus cinnabarinus (Boisd.) at 0.625 mg L^-1, and their acaricidal potencies were higher than pyriminostrobin in a greenhouse. The relationship between structure and acaricidal activity was also studied. 相似文献
78.
Yaxi Liu Ruo Yuan Yaqin Chai Chenglin Hong Kaige Liu Shu Guan 《Mikrochimica acta》2009,167(3-4):217-224
An immunosensor has been fabricated for direct amperometric determination of carcinoembryonic antigen. It is based on a biocompatible composite film composed of porous chitosan (pChit) and gold nanoparticles (GNPs). Firstly, a pChit film was formed on a glassy carbon electrode by means of electrodeposition. Then, thionine as a redox probe was immobilized on the pChit film modified electrode using glutaraldehyde as a cross-linker. Finally, GNPs were adsorbed on the electrode surface to assemble carcinoembryonic antibody (anti-CEA). The surface morphology of the pChit films was studied by means of a scanning electron microscope. The immunosensor was further characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical behaviors and factors influencing the performance of the resulting immunosensors were studied in detail. Results showed that the pChit films can enhance the surface coverage of antibodies and improve the sensitivity of the immunosensor. Under optimal conditions, the immunosensor was highly sensitive to CEA with a detection limit of 0.08 ng·mL?1 at three times the background noise and linear ranges of 0.2~10.0 ng·mL?1 and 10.0~160 ng·mL?1. Moreover, the immunosensor exhibited high selectivity, good reproducibility and stability. 相似文献
79.
Simple azetidines are synthesized in good to excellent yields and high purity via cyclization of 3-(ammonio)propyl sulfates derived from primary amines and the cyclic sulfate of 1,3-propanediol. A feature of this methodology includes the accelerated synthesis of azetidines in water under the influence of microwave-assisted heating. 相似文献
80.
H. Zhang Z. F. Chai W. Y. Qing H. C. Chen 《Journal of Radioanalytical and Nuclear Chemistry》2009,281(1):23-26
Cyclic neutron activation analysis method was conducted for determination of Se in food samples. High accuracy and good precision
were proved by analyzing certified reference materials (CRMs) of chicken (GBW10018), rice (GBW10010) and cabbage (GBW10014).
The detection limits for the three CRMs reached 0.16, 0.66 and 1.2 ng after 6 cycles at the 161.9 keV γ-peak from 77mSe, under a neutron flux of 9.0 × 1011 n cm−2 s−1 and the conditions of 30 s irradiation, 2 s decay, 30 s counting and 2 s waiting, significantly lower than those of conventional
neutron activation analysis without any cycles, which were 0.94, 3.6 and 4.3 ng, respectively. 相似文献