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931.
932.
WE Lu ML Zheng WQ Chen ZS Zhao XM Duan 《Physical chemistry chemical physics : PCCP》2012,14(34):11930-11936
We have successfully prepared gold nanoparticles (AuNPs) with flower-like and spherical morphology through multi-photon photoreduction (MPR) of an aqueous solution of HAuCl(4) and (2-hydroxyethyl) trimethylammonium glycinate ([HETMA][Gly]) ionic liquid (IL) through the use of a femtosecond laser. The results of (1)H NMR and UV-Vis absorption indicated that AuNPs were produced from the photoreduction of the [Gly]-Au(iii) complex. Spherical AuNPs of about 2.5 nm were obtained on the solution when irradiated for 2 h, then aggregated into flower-like AuNPs of several tens of nanometers assisted by the IL with an increase in the irradiation time. Furthermore, precipitates of spherical AuNPs with the size of around 15 nm were formed after being irradiated for 6 h. The mechanisms of the MPR reaction and controlled growth of AuNPs have also been discussed. 相似文献
933.
Shi W Ji X Wei M Evans DG Duan X 《Langmuir : the ACS journal of surfaces and colloids》2012,28(18):7119-7124
A fluorescent logic gate was fabricated based on calcein/layered double hydroxide ultrathin films (UTFs) via alternate assembly technique, which exhibits high stability, reversibility, and resettability. The logic gate was manipulated by utilizing pH value, Hg(2+) and Cl(-) ion as inputs, and the fluorescence emission of the (calcein/LDH)(16) UTF as output, serving as a three-input logic gate that combines the YES and INHIBIT operation. 相似文献
934.
含1,3,4-噻二唑环吡唑并[3,4-d]嘧啶类化合物的合成及生物活性 总被引:1,自引:0,他引:1
通过5-氨基-4-氰基-1-苯基吡唑与甲酸发生环合、再经氯化和芳香族亲核取代反应,合成了12种新的含1,3,4-噻二唑环吡唑并[3,4-d]嘧啶类化合物.目标化合物的结构经红外光谱、核磁共振氢谱、质谱和元素分析方法予以确认.初步的生物活性测定试验表明,在50 mg/L浓度下,大部分目标化合物对小麦纹枯病菌(Rhizoctonia cerealis)表现出较好的杀菌活性,其中化合物5b,5d和5j的抑菌率超过90%. 相似文献
935.
以α-氨基酸与邻苯二胺在微波辐射下反应合成了α-氨基取代苯并咪唑(1~5).1-(1H-苯并[d]咪唑-2-基)乙胺(1)与溴丁烷反应可形成单丁基、二丁基、三丁基取代产物1a~1d,1的氨基经Boc保护,N-烷基化后制备咪唑环上的N-烷基化产物1i~1g.制备的氨基取代咪唑与Ru(II)化合物原位组成催化体系,考察了其在取代苯乙酮的氢转移反应中的催化活性.结果表明RuCl2(PPh3)3与各配体组成的催化剂均有较好的催化活性,含有NH2基团的α-氨基取代苯并咪唑化合物参与的催化体系催化活性最好,TOF(Turnover frequency)可达到40200 h-1. 相似文献
936.
Chen Xu Zhen Li Lu-Meng Duan Zhi-Qiang Wang Wei-Jun Fu Xin-Qi Hao Mao-Ping Song 《Transition Metal Chemistry》2012,37(4):373-378
N-4,6-dimethyl-2-pyrimidinylimidazole 1 and its hydroxyethyl derivative 1-(2-hydroxyethyl)-3-(4,6-dimethyl-2-pyrimidinyl)imidazolium chloride 2 have been synthesized and characterized. The attempted synthesis of bis(N-heterocyclic carbene)palladium complexes via the direct reaction of 2 with Pd(OAc)2 results in the unexpected formation of a bis(N-arylimidazole) palladium complex 3. Additionally, the analogous bis(N-methylimidazole) palladium complex 4 has also been synthesized by the above method. Compounds 1–4 were characterized by elemental analysis, IR, and 1H NMR. Additionally, their crystal structures have been determined by X-ray diffraction. Complexes 3 and 4 were found to be efficient catalysts for the Suzuki reaction. 相似文献
937.
938.
We demonstrated continuous-wave (CW) and Q-switched operation of a Tm,Ho:YAP ring laser at 77 K. The maximum CW output power of 2 W at 2130.7 nm was obtained under the incident pump power of 12 W, corresponding to a slope efficiency of 23% and an optical-to-optical efficiency of 16.7%. For the Q-switched regime the maximum output energy of 5 mJ with the pulse width of 160 ns at the repetition rate of 100 Hz was achieved, corresponding to a peak power of 31.25 kW. 相似文献
939.
Xueqiang Zhang Yongqing Huang Xiaofeng Duan Xinye Fan Qi Wang Xia Zhang Bing Shen Wei Wang Xiaomin Ren 《Optics Communications》2012,285(21-22):4338-4343
To meet the requirement of the dense wavelength-division-multiplexed (DWDM) system and optoelectronic integrated circuit, we design a Si-Based InGaAs photodetector, which is fabricated by bonding InGaAs/InP photodetector on a Si-Based dielectric film Fabry–Perot filter. The photodetector can exhibit an extremely good flat-top and steep-edge spectral response through designing the structure of Si-Based dielectric film Fabry–Perot filter. The simulation result of phtodetector demonstrates that the spectral response linewidth, ?at-top and steep-edge characteristics of these photodetectors are suitable to be used in 50 GHz, 100 GHz, 200 GHz DWDM system. 相似文献
940.
Potassium lithium tantalate niobate single crystals doped with erbium ions are grown by top-seeded solution growth method. The crystals are characterized by X-ray diffraction and differential thermal analysis. The refractive indices of the crystal are measured using ellipsometry method and fitted by Sellmeier equation. The as-grown crystals are tetragonal phase tungsten bronze-type structure with Curie temperature of 271.3 °C. Characteristic Er3 + absorption bands are observed from 350 to 1100 nm in ultraviolet–visible-near infrared absorption spectra. These crystals emit brightly green and red upconversion fluorescence under 975 nm LD laser excitation, and the steady state upconversion spectra are obtained at room temperature. The red emission intensity increases as the erbium ions concentration increases in crystals. Processes of excited state absorption and energy transfer are responsible for upconversion luminescence. The emission intensities are quadratic dependences on pump power from pump power dependence analyses and deduction of transition rate equation model. 相似文献