| 1. |
- Zhang, Shi-Li, et al.
(författare)
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Abnormal anti-Stokes Raman scattering of carbon nanotubes
- 2002
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 66:3
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Tidskriftsartikel (refereegranskat)abstract
- Abnormal anti-Stokes Raman scattering (AASR) was unambiguously observed in carbon nanotubes (CNT's). In contrast to traditional Raman scattering theory, the absolute value of the Raman frequency of the anti-Stokes peak is not the same as that of the corresponding Stokes peak. It was demonstrated that AASR scattering originates from the unique nanoscale cylindrical structure of CNT's that can be considered naturally as a graphite structure with an intrinsic defect from its rolling. The double-resonance Raman scattering theory was applied to interpret the scattering mechanism of the AASR phenomenon successfully and quantitatively.
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| 2. |
- Sun, S. G., et al.
(författare)
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Studies on a series of rhenium(I) bipyridyl photosensitive dyes
- 2004
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Ingår i: Youji huaxue. - 0253-2786. ; 24:8, s. 953-956
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Tidskriftsartikel (refereegranskat)abstract
- A series of rhemium(I) 2,2'-bipyridyl complexes [fac-(4,4'-di-COOEt-bpy)Re(CO)(3)(Xpy)PF6] (bpy = 2, 2'-bipyridine; py = pyridine; X = 3-methyl, 3-hydroxy, 3-amino, H) were synthesized. Their electrochemical properties, ground state electronic spectra and emission spectra were studied in acetonitrile. As the X group became more electron donating from H to 3-methyl, 3-hydroxy or 3-amino, the Re(II/I) oxidation potentials declined, the MLCT absorption maximum of the complex was changed little, the emission maximum blue-shifted, and the emission intensity and the fluorescence lifetime were decreased.
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| 3. |
- Zhou, J., et al.
(författare)
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Self-excited piezoelectric microcantilever for gas detection
- 2003
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Ingår i: Microelectronic Engineering. - 0167-9317 .- 1873-5568. ; 69:1, s. 37-46
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Tidskriftsartikel (refereegranskat)abstract
- Design, fabrication and results from theoretical and experimental studies on the self-excited piezoelectric microcantilever are presented in this paper. Theoretical studies have been carried out to design the microcantilever and have been extended to harmonic analysis using the finite element technique. Silicon microfabrication has been successfully completed to create microcantilever devices. Experimental studies have been performed to obtain the resonance frequencies. Applied as a mass-sensitive sensor, the microcantilever has a sensitivity of - 0.0024%/ppm and a minimum mass loading of 3.5 x 10(-9) g with the help of a zeolite sensitive layer to freon.
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| 4. |
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| 5. |
- Ji, Xiaoyan, et al.
(författare)
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Activity coefficients of HCl in the HCl + NH4Cl + H2O systems at 298.15 and 313.15 K
- 2000
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Ingår i: Journal of Chemical and Engineering Data. - : American Chemical Society (ACS). - 0021-9568 .- 1520-5134. ; 45:1, s. 29-33
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Tidskriftsartikel (refereegranskat)abstract
- Using the ion-selective electrode method with a concentrated electrolyte solution added continuously, the mean activity coefficients of HCl in the HCl + NH4Cl + H2O system were experimentally measured at 298.15 and 313.15 K and at five molality fractions of NH4Cl (y2 = mNH4Cl/(mHCl + mNH4Cl) from 0.1 to 0.9. The measurements were made by an electrochemical cell using a H glass ion-selective electrode and a chloride solid-state ion-selective electrode. It was found that the influence of NH4+ on the H glass ion-selective electrode could be neglected up to 1.3 molkg-1, and this pair of ion-selective electrodes was suitable for determining the activity coefficients of HCl in the system. A new set of Pitzer mixing parameters, correlated from the experimental results, was used to calculate the activity coefficients for HCl in the system from 293.15 to 313.15 K up to 3.0 molkg-1.
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| 6. |
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| 7. |
- Ji, Xiaoyan, et al.
(författare)
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Mean activity coefficients of NaCl in (sodium chloride + sodium bicarbonate + water) fromT = (293.15 to 308.15) K
- 2001
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Ingår i: Journal of Chemical Thermodynamics. - : Elsevier BV. - 0021-9614 .- 1096-3626. ; 33, s. 1107-1119
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Tidskriftsartikel (refereegranskat)abstract
- The mean activity coefficients of NaCl in (sodium chloride + sodium bicarbonate + water) were determined experimentally in the temperature range 293.15 K to 308.15 K at four NaHCO3 molality fractions (0.1, 0.3, 0.5, and 0.7). The measurements were made with an electrochemical cell, using a Na+ glass ion-selective electrode and a Cl- solid-state ion-selective electrode. The experimental values reported by Butler and Huston are found to be higher than those calculated from the Pitzer equation using the existing parameters while the experimental results of this work are close to the calculated values, up to an NaHCO3 molality fraction of 0.5. At the NaHCO3 molality fraction of 0.7, the experimental data are much lower than the calculated values, implying that the interference of HCO3- on the Na+ glass ion-selective electrode can only be neglected up to a molality fraction of NaHCO3 of 0.5, an observation which is consistent with that of Butler and Huston.
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| 8. |
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| 9. |
- Li, H. Y., et al.
(författare)
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Properties of a dinuclear Mn(III,III) complex with a tri-phenolate ligand N4O3 (3-) and a new complex containing a ligand covalently linked to ruthenium tris-bipyridine
- 2004
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Ingår i: Huaxue xuebao. - 0567-7351. ; 62:9, s. 916-922
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Tidskriftsartikel (refereegranskat)abstract
- A new high valent complex [Mn-2(III, III)L(mu-OAc)(2)].PF6 (2a) was prepared, where L was the trianion of 2, 6-bis {[(2-hydroxy-5-tert-butylbenzyl) (pyridyl-2-methyl)-amino]-methyl}-4-methylphenol, which contains two additional phenolate groups and two tert-butyl groups compared to its parent [Mn-2(II, II)(bpmp)(mu-OAc)(2)].ClO4 (1). These improvements narrowed the disparity between the new model and (Mn)(4) cluster (OEC in nature). Moreover, L was modified to be covalently linked with Ru(II) tris-bipyridine through an amide bond to construct a complex 2b for the study of photoinduced electron transfer (PET). UV-vis, IR, emission spectra and electrochemistry were used to investigate their photochemistry properties. The results showed that 2b has good photochemistry properties and the E-1/2 of Ru3+/Ru2+ was higher than those of phenol(+)/phenol and Mn(III, IV)/Mn(III, III). After coordination of manganese ions, the electron transfer process in the model complex conforms to the basic principles of electron donor side of photosystem II (PS II) in nature.
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| 10. |
- Lindgren, A. C., et al.
(författare)
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Characterization of strained Si/Si1-xGex/Si heterostructures annealed in oxygen or argon
- 2002
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 91:5, s. 2708-2712
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Tidskriftsartikel (refereegranskat)abstract
- The strained Si/Si1-xGex/Si layer heterostructure heat treated from 700 degreesC to 950 degreesC in Ar (annealing) or O-2-C2H2Cl2 (oxidation) was characterized using high-resolution x-ray diffraction in combination with Rutherford backscattering. Only small changes to the structure are observed up to 800 degreesC, within the resolution limits of diffraction and backscattering. Severe strain relaxation occurs at 950 degreesC and the heterostructure tends to relax more during annealing in Ar than during oxidation in O-2-C2H2Cl2. The strain relaxation is mainly caused by interdiffusion of Si and Ge rather than formation of misfit dislocations. Diffusion of Si interstitials generated during oxidation into the heterostructure is suggested as the cause responsible for the less pronounced interdiffusion of Si and Ge in the oxidized samples.
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