| 1. |
- Bo, Qi-Bing, et al.
(författare)
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Simple directed material design through in situ substitution of proton with Cu+ ions
- 2009
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Ingår i: Journal of Inorganic and Organometallic Polymers and Materials. - : Springer Science and Business Media LLC. - 1574-1443 .- 1574-1451. ; 19:4, s. 485-493
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Tidskriftsartikel (refereegranskat)abstract
- A new inorganic-organic hybrid material (C10H8N2H)2(Mo8O26) · 2NH4 (1) was prepared under solvothermal conditions (H2O/ethanol), which was then used as a starting material in the synthesis of another material, (C10H8N2Cu)2(Mo8O26) · 2NH4 (2). Each compound has been characterized by single-crystal X-ray diffraction, X-ray powder diffraction, elemental analysis, thermogravimetric analysis, fluorescence, FT-IR, and bond valence sum calculations. The comparative study focuses on the transformation and structural change between 1 and 2, which arises from the simple substitution of the proton in 1 with the Cu+ ions. The other surprising feature is that Cu+ ions can not only directly be used to substitute the proton of 1 but also ameliorate its photoluminescence property. It means that 1 appears to have recognizable functional protons in the solid-state structure and, hence, can very well be considered as an ideal precursor agent to design the functional materials with special architectures and photoactive properties.
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| 2. |
- Bo, Qi-Bing, et al.
(författare)
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A new family of 3D 3d-4f heterometallic frameworks comprising 1D inorganic lanthanide ladders and organic Cu-bipyridine chains
- 2008
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Ingår i: CrystEngComm. - : Royal Society of Chemistry (RSC). - 1466-8033. ; 10:2, s. 232-238
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Tidskriftsartikel (refereegranskat)abstract
- A new family of the 3D heterometallic coordination polymers [{Ln2(SO4)2(H2O)2(pydc)2Cu2 (bpy)2·2(H2O)}]n (Ln = Sm ( 1), Eu ( 2), Gd ( 3), Tb ( 4) and Dy ( 5); pydc = 2,6-pyridine-dicarboxylate anion; bpy= 4,4-bipyridine) have successfully been synthesized under solvothermal conditions (H2O/ethanol). All the coordination polymers obtained were characterized by elemental analysis, FT-IR analysis, differential thermal analysis/thermogravimetry (DTA/TG), fluorescent spectra and single crystal X-ray diffraction analysis. The most intriguing structural feature is that all the compounds exhibit 3D frameworks with 1D inorganic lanthanide ladders and organic CuI-bipyridine chains, which represent two types of 3d/4f coordination polymers (form I: Ln = Sm and Eu; form II: Ln = Gd, Tb and Dy) as the result of a so-called gadolinium break effect. Additionally, compounds 2 and 4 showed the characteristic emission spectra of the EuIII and TbIII ions, respectively, and appeared to have good fluorescence properties, while 1, 3 and 5 emitted fluorescence resembling CuI complexes. To our knowledge, the investigation of the
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| 3. |
- Larsson, Anders, et al.
(författare)
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A Development Platform for Distributed User Interfaces
- 2007
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Ingår i: Proceedings of the Nineteenth InternationalConference on Software Engineering & Knowledge Engineering (SEKE’2007). - 1891706209 ; , s. 704-704
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Konferensbidrag (refereegranskat)abstract
- Developing user interfaces for a heterogeneous environment is a difficult challenge. Partial distribution of the user interface is an event harder one. Specifically providing developers with means of describing and controlling how components move around as devices are included or removed We present an approach to overcome these challenges, by combining ontologies with reasoning engines. Our tool MaDoE uses Protégé in combination with Jess to exemplify this in a simulated home setting. Our approach allows system developers to take advantage of the formal knowledge in the ontologies as well harnessing the power of rules inside the expert system when they design distributed user interfaces.
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| 4. |
- Li, Bo, et al.
(författare)
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Experimental and numerical study of a conical turbulent partially premixed flame
- 2009
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Ingår i: Proceedings of the Combustion Institute. - : Elsevier BV. - 1540-7489. ; 32, s. 1811-1818
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Tidskriftsartikel (refereegranskat)abstract
- The structure and dynamics of a turbulent partially premixed methane/air flame in a conical burner were investigated using laser diagnostics and large-eddy simulations (LES). The flame structure inside the cone was charecterized in detail using LES based on a two-scalar flamelet model, with the mixture fraction for the mixing field and level-set G-function for the partially premixed flame front propagation. In addition, planar laser induced florescence (PLIF) of CH and chemiluminiscence imaging with high speed video were performed through a glass cone. CH and CH2O PLIF were also used to examine the flame structures above the cone. It is shown that in the entire flame the CH layer remains very thin, whereas the CH2O layer is rather thick. The flame is stabilized inside the cone a short distance above the nozzle. The stabilization of the flame can be simulated by the triple-flame model but not the flamelet-quenching model. The results show that flame stabilization in the cone is a result of premixed flame front propagation and flow reversal near the wall of the cone which is deemed to be dependent on the cone angle. Flamelet based LES is shown to capture the measured CH structures whereas the predicted CH2O structure is some-what thinner than the experiments.
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| 5. |
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| 6. |
- Li, Zhongshan, et al.
(författare)
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Detection of HCl in a Premixed CH4/O-2/Ar Flame Seeded with CHCl3 Using Mid-IR Polarization Spectroscopy
- 2008
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Ingår i: Proceedings of the Ninth Asia-Pacific International Symposium on Combustion and Energy Utilization. - 9787506292849 ; , s. 222-226
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Konferensbidrag (refereegranskat)abstract
- Mid-infrared polarization spectroscopy (IRPS) was applied to detect HCl in flames. For the first time, sensitive and nonin trusive HCl detection with a manner of high spatial- and temporal-resolution in harsh reactive gas flow has been demonstrated in this work. In an atmospheric pressure premixed CH4/O-2/Ar flat flame, trace level HCl was prepared by seeding small amount chloroform through the Ar flow. IRPS HCl detection in the burnt region of the equivalent flame was pert formed by probing the fundamental ro-vibration transitions with a 3.2 mu m tunable pulsed laser produced through difference frequency mixing of a 1064 nm and a tunable 800 nm laser beams from a injection seeded Nd:YAG and a dye laser pumped by the second harmonic of the same Nd:YAG laser, respectively. High resolution IRPS excitation scans were recorded in the flames both with and without chloroform seeding. All the HCl rotation lines in the chosen spectral range were recognized among the dense lines from hot water, which was the majority species in the burnt region of the flat flame. The saturation behavior of the HCl IRPS was investigated by study the variation of the signal intensity with pumping laser pulse energy and the saturation pulse energy was found to be 250 mu J. in the setup. The dependence of the IRPS signal on the HCl number density was also investigated and a detection limit of less than 100 ppm in the atmospheric pressure flame was estimated based on the measurements. The potential interference from water lines related to the IRPS application was also investigated.
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| 7. |
- Li, Zhongshan, et al.
(författare)
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Spatially resolved trace detection of HCl in flames with mid-infrared polarization spectroscopy
- 2008
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Ingår i: Optics Letters. - 0146-9592. ; 33:16, s. 1836-1838
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Tidskriftsartikel (refereegranskat)abstract
- Sensitive and nonintrusive detection of HCl in reactive gas flows with high spatial and temporal resolution manner has for the first time (to our knowledge) been demonstrated using mid-infrared polarization spectroscopy (IRPS). Trace levels of HCl were prepared in an atmospheric pressure premixed CH4/O-2/Ar flat flame by seeding a small amount of chloroform into the Ar flow. Detection of HCl with IRPS in the burnt region of the stoichiometric flame was performed by probing the fundamental ro-vibration transitions with a 3.2 mu m tunable pulsed laser. The quantitative nature, the detection sensitivity, and the potential spectral interferences from water were investigated. (c) 2008 Optical Society of America.
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| 8. |
- Sun, Jie, et al.
(författare)
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Scanning electron microscopy observation of in-device InAs/AlAs quantum dots by selective etching of capping layers
- 2007
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Ingår i: Modern Physics Letters B. - 0217-9849. ; 21:14, s. 859-866
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Tidskriftsartikel (refereegranskat)abstract
- Self-assembled InAs/AlAs quantum dots embedded in a resonant tunneling diode device structure are grown by molecular beam epitaxy. Through the selective etching in a C6H8O7 center dot H2O-K3C6H5O7 center dot H2O-H2O2 buffer solution, 310 nm GaAs capping layers are removed and the InAs/AlAs quantum dots are observed by field-emission scanning electron microscopy. It is shown that as-fabricated quantum dots have a diameter of several tens of nanometers and a density of 10(10) cm(-2) order. The images taken by this means are comparable or slightly better than those of transmission electron microscopy. The undercut of the InAs/AlAs layer near the edges of mesas is detected and that verifies the reliability of the quantum dot images. The inhomogeneous oxidation of the upper AlAs barrier in H2O2 is also observed. By comparing the morphologies of the mesa edge adjacent regions and the rest areas of the sample, it is concluded that the physicochemical reaction introduced in this letter is diffusion limited.
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| 9. |
- Sun, Zhiwei, et al.
(författare)
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Four-wave mixing with non-resonant pump and resonant probe for OH detection in flames
- 2008
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Ingår i: Applied Physics B. - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 92:2, s. 287-293
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Tidskriftsartikel (refereegranskat)abstract
- A new type of two-color four-wave mixing spectroscopy is theoretically and experimentally demonstrated. By employing a non-resonant pumping and resonant probing scheme, OH radicals are detected in a laminar, atmospheric pressure methane/air flame as a proof-of-principle experiment. Two 532 nm laser beams from a multi-mode Nd:YAG laser are utilized to create an electrostrictive grating in the flame. A probe beam in resonance with the Q(1)( 5) rotational line belonging to the A(2)Sigma-X-2 Pi(1,0) band at 283 nm is employed to achieve species selective detection of OH radicals. In detail, in the present paper the coherence effects of the pump beams are investigated by changing the temporal delay between the two pump beams. A signal enhanced by a factor of 3 is obtained in the coherence range. Furthermore, the dependence of the signal intensity on the laser pulse energy of the pump and probe beams is studied in detail. At high pulse energies even for the pumping process a certain saturation behavior is observed. In general, the demonstrated four-wave mixing scheme is estimated to be superior in terms of the saturation limitation in comparison to the widely applied degenerate four-wave mixing, but still providing a high sensitivity and species selectivity due to the strong resonant signal enhancement.
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| 10. |
- Sun, Zhong-Xi, et al.
(författare)
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Effects of calcination temperature on the pore size and wall crystalline structure of mesoporous alumina
- 2008
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 319:1, s. 247-251
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, mesoporous alumina with different pore sizes and wall crystalline structures was synthesized at calcination temperatures over 550 °C. The characterization of the samples calcined at 550, 800, 1100, and 1300 °C, respectively, was performed using TEM, XRD, FTIR, TG/DTA, and N2 adsorption/desorption techniques. The correlation between pore size and wall crystalline structure on calcination temperature was systematically investigated.
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