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1.
Low-temperature combustion synthesis of CuCr2O4 spinel powder for spectrally selective paints 总被引:1,自引:0,他引:1
Geng Qingfen Zhao Xin Gao Xianghu Yang Shengrong Liu Gang 《Journal of Sol-Gel Science and Technology》2012,61(1):281-288
CuCr2O4 spinel powder with high quality black hue, investigated as solar-absorbing pigment for spectrally selective paint, was synthesized
by an environmental friendly sol–gel combustion process using citric acid as the fuel and metal nitrates as oxidizers. Single-phase
CuCr2O4 spinel crystals were obtained after heat treatment of the as-burnt powder at a low temperature (600 °C) and the average crystallite
size of the CuCr2O4 powders increased with the calcining temperature. Morphological analysis of powders calcined at various temperatures was
done by field emission scanning electron microscopy. CuCr2O4 powder calcined at 700 °C was chosen as pigment to fabricate thickness sensitive spectrally selective paint coatings by simple
spray-coating technique. For the sake of comparison, the as-burnt powder composed of mixed metal oxides (i.e., CuO and Cr2O3) was also used as pigment. The results reveal that the spinel CuCr2O4 based paint coatings exhibit much higher spectral selectivity (α
s = 0.88–0.91, ε
100 = 0.27–0.35) which is depending on the coating thicknesses than that of coatings using as-burnt powder as pigment (α
s = 0.83–0.88, ε
100 = 0.60–0.66). The CuCr2O4-based paint coatings showed no visible degradation after 600 h of condensation test and the performance criterion value is
0.04, indicating that the coatings have excellent long term stability. 相似文献
2.
When surface plasmon resonance is excited in Kretschmann configuration, the maximum Goos–Hänchen shift occurs at the resonant angle which is associated with the minimum value of reflectivity, but the maximum angular shift occurs at two incident angles beside the resonant angle. When the reflected beam is detected at Rayleigh range, the maximum net lateral shift of the reflected beam does not encounter the resonant angle and its magnitude is lager than that of Goos–Hänchen shift. Numerical simulation shows that theory agrees well with numerical results when the beam width is large enough. 相似文献
3.
A new oligothiophene-based sensor 3 TH for monitoring Hg2+ has been designed and synthesized based on the intramolecular charge transfer (ICT) mechanism. The 3 TH shows the significant specificity toward Hg2+ through “naked-eye” colorimetric detection as well as via ratiometric fluorescence enhancement response with low detection limit of 62 nM. In addition, sensor 3 TH shows high selectivity and sensitivity for Hg2+ with fast response in a suitable pH range. Moreover, the 3 TH-based test strips was used to conveniently detect Hg2+ ions in water. Furthermore, considering its good ‘‘turn-on’’ fluorescent sensing behavior and low cell cytotoxicity, 3 TH was successfully applied to detect and image Hg2+ in real water samples and living cells, which shows great potentials for application in environmental and biological systems. 相似文献
4.
Synthesis and Characterization of Diorganocobalt Chlorides by Aliphatic Vinylic C–Cl Bond Activation
Qingfen Niu Shumiao Zhang Xiaoyan Li Hongjian Sun Olaf Fuhr Dieter Fenske 《无机化学与普通化学杂志》2016,642(15):866-869
Three diorganocobalt chlorides [CoClMe(PMe3)2–{(C5H6)–CH=O}] ( 4 ), [CoClMe(PMe3)2–{(C6H8)–CH=O}] ( 5 ), and [CoClMe(PMe3)2–{(C6H7Memeta)–CH=O}] ( 6 ) were synthesized through cyclometalation reactions with aldehyde as an anchoring group involving aliphatic vinylic C–Cl bond activation. Complexes 4 – 6 were characterized by IR and NMR spectroscopy. The crystal and molecular structures of complexes 4 and 5 were determined by single‐crystal X‐ray diffraction. Complexes 4 – 6 are stable in solution at room temperature, but they decompose at above 30 °C affording C,C‐couplings products with the formation of [Co(PMe3)3Cl]. The results of this work will be important for people to deepen the understanding of the C–Cl bond activation mechanism. 相似文献
5.
对RuIrSnLa四元金属氧化物涂层的组成进行了研究.采用均匀设计、偏最小二乘回归(PLS)与灰色关联度分析相结合的方法,以使用寿命、伏安电量、析氯电位、析氧电位及析氧析氯电位差为考察指标,对电化学性能的影响因素进行了主次分析,并对涂层配方进行了优选.结果表明:Ir对提高阳极的使用寿命影响最大.其次是Ru,Sn是提高析氧电位的主要元素,而La对提高阳极电催化活性,降低析氯电位及增大析氧析氯电位差起着主要作用,PLS分析认为,La对阳极稳定性呈负效应.采用偏最小二乘回归与灰色关联度相结合的分析方法,可以优势互补,为多元金属氧化物涂层的成分设计和理论研究提供依据. 相似文献
6.
Ying Xue Yanwu Zhai Prof. Dr. Kebin Zhou Lei Wang Haina Tan Qingfen Luan Prof. Dr. Xin Yao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(35):11115-11122
Cerium oxide (CeO2) nanoparticles display excellent antioxidant properties by scavenging free radicals. However, some studies have indicated that they can cause an adverse response by generating reactive oxygen species (ROS). Hence, it is important to clarify the factors that affect the oxidant/antioxidant activities of CeO2 nanoparticles. In this work, we report the effects of different buffer anions on the antioxidant activity of CeO2 nanoparticles. Considering the main anions present in the body, Tris‐HCl, sulfate, and phosphate buffer solutions have been used to evaluate the antioxidant activity of CeO2 nanoparticles by studying their DNA protective effect. The results show that CeO2 nanoparticles can protect DNA from damage in Tris‐HCl and sulfate systems, but not in phosphate buffer solution (PBS) systems. The mechanism of action has been explored: cerium phosphate is formed on the surface of the nanoparticles, which interferes with the redox cycling between Ce3+ and Ce4+. As a result, the antioxidant activity of CeO2 nanoparticles is greatly affected by the external environment, especially the anions. These results may provide guidance for the further practical application of CeO2 nanoparticles. 相似文献
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A novel one‐pot approach for the preparation of 2‐mercaptobenzaldehyde, 2‐mercaptocyclohex‐1‐enecarboxaldehydes and 3‐mercaptoacrylaldehydes [(Z)‐3‐mercapto‐2‐methyl‐3‐phenylacrylaldehyde, 3‐mercapto‐3‐(o‐tolyl)acrylaldehyde)] starting from ortho‐bromobenzaldehyde, 2‐chlorocyclohex‐1‐enecarbaldehydes, (Z)‐3‐chloro‐2‐methyl‐3‐phenylacrylaldehyde and 3‐chloro‐3‐(o‐tolyl)acrylaldehyde is reported. The reaction of sulfur with the Grignard reagent of the acetal for the protection of the aldehyde group affords the title compounds through hydrolysis with dilute hydrochloric acid in high yields. 相似文献
10.
Xiangmin Liu Pengfei Zhu Zonglin Yan Jiangwen Wu Qingfen Yang 《Optics Communications》2008,281(2):273-277
The accurate reflection coefficient of prism waveguide coupler that takes coherence property of incident light into account is obtained at first. Based on the reflection coefficient, the effect of coherence property of incident light on prism coupling is discussed in this work. It is shown that extra damping in waveguide caused by the coherence property is larger for high-order resonant mode than that for low-order mode. For 100 fs Gaussian pulses incidence, the reflected spectra at different resonant modes are obtained theoretically and experimentally, which show that coherence property has a strong effect on prism coupling at high-order modes. 相似文献