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81.
B. Jiang Zh. Gong M. Chen J. Li W. Liu Y. Pan 《Bulletin of the Russian Academy of Sciences: Physics》2012,76(6):643-647
Transparent Yb3x Y3(1 ? x )Al5O12 (x = 3, 5, 10 and 15%) ceramics were fabricated by solid-state reaction and vacuum sintering method with a mixture of commercial Al2O3, Y2O3 and Yb2O3 powders. Ethanol and 0.5 wt % tetraethoxysilane were doped. Transparent fully dense samples with grain sizes of several micrometers were obtained by sintered at 1750 K. The absorption spectra, emission spectra and fluorescence life time of these transparent Yb3x Y3(1 ? x )Al5O12 ceramics at room temperature have been measured and calculated. The air annealed effects of Yb3x Y3(1 ? x )Al5O12 ceramics have been compared with un-annealed Yb:YAG transparent ceramics which shows the difference of the Yb3+ ions between annealed and unannealed Yb:YAG ceramics is less than 1%. 相似文献
82.
B. Xu Y. B. Gong L. Wang C. L. Yang 《The European Physical Journal B - Condensed Matter and Complex Systems》2012,85(9):1-5
Recently, delay-induced coherence resonance (CR) in neuronal networks with fixed coupling strength has received much attention. In this paper, we study delay-induced CR in Newman-Watts neuronal networks with time-periodic coupling strength, mainly investigating how CR changes with the varying frequency of time-periodic coupling strength. We find that delay-induced CR become more frequent as the frequency is increased. When the frequency exceeds a threshold value, time delay can induce multiple CR more than for constant coupling strength. Furthermore, delay-induced CR occurs more abruptly and becomes more pronounced for time-periodic coupling strength than for constant coupling strength. These results show that delay-induced CR strongly depends on the coupling strength of neurons, and time delay can optimize spiking coherence more frequently and precisely in the presence of time-periodic coupling strength. This implies that time-periodic coupling strength could be more helpful for time delay to enhance and optimize the spiking coherence, and thus it may play a more efficient role in improving the time precision of information processing in neuronal networks. 相似文献
83.
Wireless Personal Communications - This paper presents an error detection algorithm for Lempel-Ziv-78 (LZ78) compressed data. LZ78 data compression involves dictionary coding and aims to compress... 相似文献
84.
Tunable Oxygen Activation for Catalytic Organic Oxidation: Schottky Junction versus Plasmonic Effects 下载免费PDF全文
Ming Gong Shan Zhou Jiahua Hu Min Zhi Yang You Song Bai Prof. Jun Jiang Prof. Qun Zhang Prof. Xiaojun Wu Prof. Yujie Xiong 《Angewandte Chemie (International ed. in English)》2014,53(12):3205-3209
The charge state of the Pd surface is a critical parameter in terms of the ability of Pd nanocrystals to activate O2 to generate a species that behaves like singlet O2 both chemically and physically. Motivated by this finding, we designed a metal–semiconductor hybrid system in which Pd nanocrystals enclosed by {100} facets are deposited on TiO2 supports. Driven by the Schottky junction, the TiO2 supports can provide electrons for metal catalysts under illumination by appropriate light. Further examination by ultrafast spectroscopy revealed that the plasmonics of Pd may force a large number of electrons to undergo reverse migration from Pd to the conduction band of TiO2 under strong illumination, thus lowering the electron density of the Pd surface as a side effect. We were therefore able to rationally tailor the charge state of the metal surface and thus modulate the function of Pd nanocrystals in O2 activation and organic oxidation reactions by simply altering the intensity of light shed on Pd–TiO2 hybrid structures. 相似文献
85.
Facile Assembly of Benzo[b]naphtho[2,3‐d]azocin‐6(5 H)‐ones by a Palladium‐Catalyzed Double Carbometalation 下载免费PDF全文
The palladium‐catalyzed reaction of 2‐alkynylanilines with 2‐(2‐bromobenzylidene)cyclobutanone as an efficient route to 7,8‐dihydrobenzo[b]naphtho[2,3‐d]azocin‐6(5 H)‐ones was developed. The fused eight‐membered ring was constructed conveniently. During the reaction process, double carbometalation was involved, which resulted in excellent selectivity with the formation of three new bonds. This transformation is highly efficient and leads to fused polycycles in good to excellent yields with good functional group tolerance. 相似文献
86.
An efficient and easy sample pretreatment methodology was proposed for the detection of photoinitiator 4‐methylbenzophenone from milk before high‐performance liquid chromatography. Appropriate conditions for demulsification were studied. The parameters affecting cloud point extraction, such as concentration of Tween‐20, electrolyte salt, equilibration temperature, and time, have been investigated. When the spiked level was 200–1000 μg/kg, the average addition standard recovery was 99.14–105.98% with the optimum cloud point extraction conditions (concentration of Tween‐20, 138 g/L; mass of anhydrous sodium sulfate, 0.75 g; equilibration temperature, 65°C; equilibration time, 30 min). To decrease the detection limits, further work about the organic solvent, shaking time, and ultrasonic parameters was carried. When the spiked level was 10–100 μg/kg, the average addition standard recovery was 70.40–106.91% with the optimum cloud point extraction and enrichment conditions (optimum cloud point extraction conditions; volume of cyclohexane, 30 mL; shaking time, 20 min; time of ultrasonic, 20 min; temperature of ultrasonic bath, 45°C). 相似文献
87.
88.
Jian-Chang He Sheng-Hua Gu Di Liu Qing Zhang En-Fu Feng Yuan-Yuan Gong Gui-Li Xu 《Chromatographia》2008,68(11-12):1009-1012
A sensitive and reproducible liquid chromatographic method with UV detection was described for the determination of helicidum in beagle dog plasma. Sample preparation was accomplished through protein precipitation with 15% perchloric acid and chromatographic separation was performed on a reversed phase C18 column at 30 °C. Mobile phase consisted of a mixture of acetonitrile–water at a flow rate of 1.0 mL min?1. Wavelength was set at 270 nm. The method was applied to a pharmacokinetic study of two formulations of helicidum. No statistical difference in the t 1/2 (AUC0–5, AUC0–∞) between the two formulations were observed. The t max of helicidum ODTs is significantly shorter than that of conventional tablets (0.84 h vs. 1.33 h, P< 0.05). 相似文献
89.
S. Landsberger A. Massicotte J. Braisted S. Gong 《Journal of Radioanalytical and Nuclear Chemistry》2008,276(1):193-197
Arctic pollution is a problem of great concern, because its characteristics (transportation, assimilation into the environment,
etc.) are complex and not fully understood. Detection of elemental constituents has been undertaken through the use of neutron
activation analysis and Compton suppression (to lower the detection limits for radionuclides characteristic of mainly single
gamma-ray emission) to discover possible pollutant sources. The goal of this project was to perform a feasibility study to
determine the suitability of neutron activation analysis (NAA) to evaluate cadmium concentrations on air filters collected
in the Arctic. 相似文献
90.
以单分散亲水性交联聚甲基丙烯酸环氧丙酯-甲基丙烯酸乙二醇双酯(PGMA/EDMA)树脂为载体,制备新型L-羟脯氨酸聚合物键合高效手性配体交换固定相。该固定相在配体交换分离模式下,以0.2mol/LNaAc和0.1mmol/LCu(Ac)2水溶液(pH5.2)为流动相,柱温为30℃~50℃,对衍生和非衍生的D,L-氨基酸和α-羟基酸等9种手性化合物进行了高效液相色谱拆分。详细考察了流动相pH值、温度、流速和进样量对手性分离的影响,选择了合适的色谱分离条件。结果表明,所拆分的9种手性化合物,有5种手性化合物能得到基线分离,最好的分离因子α=2.32。 相似文献