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71.
The mechanisms of photoluminescence excitation of Mn2+ ions in ZnS crystals have been investigated on the basis of complex analysis of the temperature dependences of the photoluminescence and photoluminescence-excitation spectra of ZnS:Mn crystals. The activation energy of a manganese luminescence center was estimated at Ea = 0.17 ± 0.05 eV. It is shown that Ea represents an energy band with a width ΔEa = 0.1 eV, within which a manganese luminescence center can experience radiationless recombination. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 6, pp. 788–793, November–December, 2005.  相似文献   
72.
《Composite Interfaces》2013,20(8-9):617-629
A carboxylic gel-type resin, poly-4-vinylpyridine-methacrylic acid-N, N'-methylenebisacrylamide is designed and synthesized in order to be able to incorporate both FeIII and, potentially, also AuIII in its polymer framework. Along with the gradual substitution of H+ with Na+, of Na+ with Fe3+/3 and after a very controlled and gradual precipitation of FeIII as oxihydroxides induced by the hydrolysis of urea directly inside the nanoporous domains of the metalated resin particles, an organic-inorganic composite is obtained. The material is characterized with TGA, ESEM, XRMA and Mössbauer spectroscopy.  相似文献   
73.
A non-contact measuring method on electrostatic potential by using α-ray ionization is proposed. In this method potential of a charged material is estimated from ionic current flowing through an ion collector attached with a small 241Am source. As hade electrode surrounding the collector has a function of adjusting sensitivity and potential up to 50 kV was measured with precision of 1 kV.  相似文献   
74.
Carrier free radioactive 54Mn and 59Fe enjoy favoured position in industrial, agricultural and medical applications [1]. The main methods used for their isolation from suitable irradiated targets are mainly based on solvent extraction [2] or ion exchange [3].  相似文献   
75.
Doxycycline can coordinate with europium (III) to form europium (III)-doxycycline complex, which can emit the fluorescence characteristic peak of europium (III) at 617 nm in alkaline solution, and the experiment proved that the fluorescence intensity could be further enhanced in the presence of silver nanoparticles and surfactant alkylphenols polyoxyethylene. So this method was applied to detect doxycycline content in duck meat in this research. First, 390 and 617 nm were selected as the optimum excitation wavelength and optimum emission wavelength by three-dimensional fluorescence spectrometry, respectively. Second, the experimental conditions were optimized through single factor experiment. Lastly, the samples of doxycycline concentration range of 0.05–12 mg/L were analyzed under the optimum experimental conditions. A good linear relationship between the doxycycline concentration and the fluorescence intensity was obtained, and the determination coefficient and the root mean squared error of prediction were 0.9982 and 0.4363 mg/L, respectively. This research showed that it was feasible to achieve the rapid detection of doxycycline content in duck meat by using silver nanoparticles and alkylphenols polyoxyethylene enhanced the fluorescence of europium complex.  相似文献   
76.
X-ray analysis and magnetic properties have been studied for the system Co0.6Zn0.4MnxFe2-xO4. The bulk density, X-ray density and porosity were also studied. It was found that the lattice constant decreased with increasing manganese concentration x. The X-ray density, the bulk density and porosity do depend on the manganese content. The magnetic susceptibility and the activation energies were found to be increased with increasing percentage of the manganese ions while the dc conductivity decreased.  相似文献   
77.
将三价铑离子配合物用于催化甲亚胺内盐与取代的丙烯酰胺之间的氧化偶联反应,实现了三取代的吡唑化合物的合成.在这个过程中,取代的丙烯酰胺的烯烃发生了C-H键活化.此类反应和用丙烯酸酯时的反应具有不同的选择性.  相似文献   
78.
The selective catalytic oxidation (SCO) of NO was studied on a catalyst consisting of iron-manganese oxide supported on mesoporous silica (MPS) with different Mn/Fe ratios. Effects of the amount of manganese and iron, oxygen, and calcination temperature on NO conversion were also investigated. It was found that the Mn-Fe/MPS catalyst with a Mn/Fe molar ratio of 1 showed the highest activity at the calcination temperature of 400 °C. The results showed that over this catalyst, NO conversion reached 70% under the condition of 280 °C and a space velocity of 5000 h-1. SO2 and H2O had no adverse impact on the reaction activity when the SCO reaction temperature was above 240 °C. In addition, the SCO activity was suppressed gradually in the presence of SO2 and H2O below 240 °C, and such an effect was reversible after heating treatment.  相似文献   
79.
A novel one-dimensional chain manganese(Ⅱ) compound [Mn(trz)2Cl][phthH], (trz=1,2,4-triazole, phthH=hydrogen phthalate), 1, was synthesized and structurally characterized. It crystallizes in monoclinic system, space group P2 /c with a=1.381 1(11) nm, b=0.815 5(7) nm, c=0.735 4(6) nm, β=94.667(15)°, V=0.825 5(12) nm3. It consists of one dimensional cationic manganese(Ⅱ) chain and uncoordinated hydrogen phthalate anions. The manganese(Ⅱ) ions are bridged with two 1,2,4-traizoles and one chloride anion along the cationic chain, in which the weak antiferromagnetic exchange occurs between manganese(Ⅱ) atoms. CCDC: 267461.  相似文献   
80.
Eu-TTA体系测定条件的优化及其在小麦代谢研究 中的应用   总被引:4,自引:0,他引:4  
曾福礼  吴翚  安宜  邓汝温  王怀公 《化学学报》2000,58(8):1063-1066
研究了铕(Ⅲ)-TTA(邻-噻吩甲酰三氟丙酮)体系在有机溶剂和邻菲啰啉衍生物存在下的荧光性质,发现醇类有机溶剂能使Eu(Ⅲ)-TTA体系荧光强度大幅度提高;三种邻菲啰啉衍生物中,4,7-二苯基-2,9-二甲基-1,10-邻菲啰啉的加入也能提高体系灵敏度。优化了反应条件,并用此法研究了小麦根施Eu^3^+数天后,Eu^3^+在根和叶片细胞膜和细胞内的分布定位,为稀土元素的植物代谢研究提供了一种重要的辅助研究手段。  相似文献   
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