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ABSTRACT: A novel conjugated polymer PIDTT-quinoxaline (Qx) based on the coplanar thieno[3,2-b]thiophene-phenylene-thieno[3,2-b]thiophene structure is synthesized and evaluated as an electron-donor material for bulk-heterojunction polymer solar cells (BHJ PSCs). The absorption spectra, electrochemical, charge transport, and film morphology properties as well as theoretical modeling of PIDTT-Qx are investigated to understand its intrinsic structure-property relationship. As expected, this polymer with an extended π-conjugated backbone exhibits a narrow-bandgap and board absorption spectrum for enhanced light harvesting. BHJ PSCs (ITO/PEDOT:PSS/polymer:PC71 BM/interlayer/Al) afford a maximum power conversion efficiency of 5.05% with an open-circuit voltage of 0.84 V, a short-circuit current density of 11.26 mA cm(-2) , and a fill factor of 53.4%. These results demonstrate the potential of PIDTT-Qx as an efficient electron-donor material for BHJ PSCs.
Macromolecular Rapid Communications 03/2013; · 4.60 Impact Factor
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Chinese medical journal 03/2013; 126(5):991-992. · 0.86 Impact Factor
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ABSTRACT: We report the prediction of temperature-dependent diffusion coefficients of
interstitial hydrogen, deuterium, and tritium atoms in $\alpha$-Ti using
transition state theory. The microscopic parameters in the pre-factor and
activation energy of the impurity diffusion coefficients are obtained from
first-principles total energy and phonon calculations including the full
coupling between the vibrational modes of the diffusing atom with the host
lattice. The dual occupancy case of impurity atom in the hcp matrix are
considered, and four diffusion paths are combined to obtain the final diffusion
coefficients. The calculated diffusion parameters show good agreement with
experiments. Our numerical results indicate that the diffusions of deuterium
and tritium atoms are slower than that of the hydrogen atom at temperatures
above 425 K and 390 K, respectively.
02/2013;
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ABSTRACT: PURPOSE: To evaluate the effectiveness and safety of minimally invasive percutaneous nephrolithotomy (mPCNL) without nephrostomy drainage tubes. METHODS: We prospectively enrolled 32 eligible patients with kidney stones at our hospital. Patients were randomly assigned to a conventional mPCNL group (ureteric Double-J stents and nephrostomy drainage tubes) or a tubeless mPCNL group (ureteric catheter but no drainage tubes). A single experienced surgeon performed all operations. RESULTS: At baseline, the two groups had similar age, maximum stone diameter, and gender distribution. There were no significant differences in operation time, presence of postoperative fever, stone clearance, and level of postoperative serum hemoglobin. However, the tubeless mPCNL group had significantly shorter hospital stays (3 vs. 4 days, p = 0.032) and significantly less back pain (5 patients vs. 14 patients, p = 0.003) than the conventional mPCNL group. CONCLUSIONS: No significant differences were found between conventional and tubeless mPCNL in safety issues and stone clearance rate. However, patients treated with tubeless mPCNL had shorter hospitalization stays and were less likely to experience back pain.
World Journal of Urology 08/2012; · 2.41 Impact Factor
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ABSTRACT: A recent inelastic x-ray scattering study [Manley et al., Phys. Rev. B 85,
132301 (2012)] reveals that the phonon dispersion curves of PuO2 is
considerably consistent with our previous density functional +$U$ results
[Zhang et al., Phys. Rev. B 82, 144110 (2010)]. Here in the present work, using
the same computational methods, we further obtain the phonon dispersion curves
for \alpha-Pu2O3. We find that the Pu-O bonding is weaker in \alpha-Pu2O3 than
in fluorite PuO2, and subsequently a frequency gap appears between the
vibrations of oxygen and plutonium atoms. Based on the phonon dispersion curves
and Helmholtz free energies of PuO2 and \alpha-Pu2O3, we systematically
calculate the reaction energies for the transformations between Pu, PuO2, and
\alpha-Pu2O3. It is revealed that the thermodynamic equilibrium of the system
is dependent on temperature as well as on the chemical environment. High
temperature and insufficient oxygen environment are in favor of the formation
of \alpha-Pu2O3.
08/2012;
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ABSTRACT: Free-standing 3D macroscopic polyaniline (PANi)-carbon nanotube (CNT)-nickel fiber hybrids have been developed, and they deliver high specific capacitance (725 F g(-1) at 0.5 A g(-1)) and high energy density at high rates (~22 W h kg(-1) at 2000 W kg(-1), based on total electrode mass) with good cyclability.
Nanoscale 04/2012; 4(9):2867-9. · 5.91 Impact Factor
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ABSTRACT: Galvanic deposition of Au onto a thin-sheet sinter-locked 8 μm Ni-fiber delivers a high-performance Au/Ni-fiber catalyst for alcohol oxidation, due to the unique combination of excellent heat conductivity, remarkable low-temperature activity, and good stability/regenerability. The special NiO@Au ensembles formed during the reaction contribute to promoting the low-temperature activity.
Chemical Communications 09/2011; 47(34):9642-4. · 6.17 Impact Factor
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ABSTRACT: Novel microfibrous-structured silver catalysts were developed for gas-phase selective oxidation of mono-/aromatic-/di-alcohols. Sinter-locked three-dimensional microfibrous networks consisting of 5 vol % 8-μm-Ni (or 12-μm-SS-316L) fibers and 95 vol % void volume were built up by the papermaking/sintering processes. Silver was then deposited onto the surface of the sinter-locked fibers by incipient wetness impregnation method. At relatively low temperatures (e.g., 380°C), the microfibrous-structured silver catalysts provided quite higher activity/selectivity compared to the electrolytic silver. The microfibrous Ag/Ni-fiber offered much better low-temperature activity than the Ag/SS-fiber. The interaction at Ag particles and Ni-fiber interface not only visibly increased the active/selective sites of Ag+ ions and Agnδ+ clusters but also significantly promoted their low-temperature reducibility and ability for O2 activation. In addition, the microfibrous structure provided a unique combination of large void volume, entirely open structure, high thermal conductivity and high permeability. © 2009 American Institute of Chemical Engineers AIChE J, 2010
AIChE Journal 10/2009; 56(6):1545 - 1556. · 2.26 Impact Factor
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ABSTRACT: An aerobic oxidative removal of mercaptans from gasoline in the absence of liquid base has been demonstrated for gasoline sweetening over CuZnAl catalyst. This process could proceed at large WHSV of gasoline (50–70 h−1) with >95% mercaptan conversion at 150°C (or 300°C) using an O2/S molar ratio of 20–40. At 150°C, dimerization of mercaptans occurred dominantly to form their disulfides. At 300°C, deep oxidation of the mercaptans to SO2 was the dominant process in the first tens of hours, but it decreased then with prolonged time on stream and meanwhile the dimerization increased. The spent catalyst could be restored to its fresh activity level only through a calcination treatment in air. This process was also demonstrated to be effective and efficient for sweetening of a real cracking gasoline. © 2009 American Institute of Chemical Engineers AIChE J, 2009
AIChE Journal 08/2009; 55(12):3214 - 3220. · 2.26 Impact Factor
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ABSTRACT: A series of CuZnAl oxide-composite catalysts were prepared via decomposition of CuZnAl hydrotalcite-like compounds (HTLcs). The catalysts derived from CuZnAl HTLcs (Cu: 37%, Zn: 15%, Al: 48% mol; using metal nitrate or acetate precursors) at 600°C provided excellent activity and stability for the methanol steam reforming. CuZnAl HTLcs were almost decomposed completely at 600°C to form highly dispersed CuO with large specific surface area while forming CuAl2O4 spinel that played a key role in separating and stabilizing the nano-sized Cu and ZnO during the reaction. The CuZnAl catalyst prepared from metal acetates could highly convert H2O/MeOH (1.3/1, mol/mol) mixture into hydrogen with only ∼0.05% CO at 250°C or ∼0.005% at 210°C. It is evidenced that the former afforded stronger Cu-ZnO interaction, which might be the intrinsic reason for the significant promotion of catalyst selectivity. © 2009 American Institute of Chemical Engineers AIChE J, 2009
AIChE Journal 03/2009; 55(5):1217 - 1228. · 2.26 Impact Factor
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ABSTRACT: A series of CuZnAl oxide−composite catalysts have been prepared via decomposition of CuZnAl hydrotalcite-like compounds (HTLcs: Cu 37%, Zn 15%, Al 48% mol) at various temperatures and examined for use with aerobic oxidative desulfurization (AODS) of gasoline-range organosulfur compounds in iso-octane. It shows that catalytically relevant properties of HTLcs-derived CuZnAl catalysts and their performance for AODS reaction can be significantly controlled by HTLcs decomposition temperatures. At 600 °C, CuZnAl HTLcs can be decomposed completely to form highly dispersed CuO with large specific surface area while forming a small amount of CuAl2O4 spinel phase, and meanwhile, improved CuO−ZnO interaction and promoted catalyst reducibility/reoxidizability can be obtained. By taking the above beneficial properties, this HTLcs-derived CuZnAl catalyst is quite active and selective for aerobically oxidizing organosulfur compounds to SO2 at 300 °C and atmospheric pressure. Thiophene is not so reactive as mercaptan, organic sulfide, benzothiophene, and dibenzothiophene. Adsorptive oxidation of thiophene previously observed on Pt/CeO2 catalyst is likewise detectable on this HTLcs-derived CuZnAl catalyst by means of in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), but it hardly happens to paraffinic, olefinic, and aromatic hydrocarbon molecules.
02/2009;
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ABSTRACT: A novel non-metallic salt, 1-butyl-3-methylimidazolium tosylate ([bmim][OTs]) dissolved in the ambient temperature ionic liquid of 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), was found to be the efficient catalyst for acetylation with the advantages of good recyclability, avoidance of metal contamination,
mild reaction conditions, and wide availability for substrates (alcohols, phenols, and amines), could completely replace organic
bases, metal Lewis acids, or metallic triflates to fulfill acetylation by a nucleophilic catalytic mechanism, which was supported by 13C NMR analysis.
Monatshefte fuer Chemie/Chemical Monthly 05/2008; 139(6):633-638. · 1.53 Impact Factor
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ABSTRACT: In the multi-functionalized ionic liquid compositions (MFILC), composed of 1-n-butyl-2-diphenylphosphino-3-methylimidazolium
hexafluorophosphate, [BDPPMIM]PF6), 1-(2-piperid-1-yl-ethyl)-3-methylimidazolium hexafluorophosphate, [PEMIM]PF6), and 1-n-butyl-3-methylimidazolium
hexafluorophosphate ([BMIM]PF6), PdCl2 served as an efficient catalyst for Heck reactions of aryl iodides and bromides. The
built-up PdCl2-MFILC, including stoichiometrically consumed base of [PEMIM]PF6, could be reused at least for seven cycles
without activity loss.
Catalysis Letters 02/2008; 121(3):331-336. · 2.24 Impact Factor
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ChemSusChem 02/2008; 1(4):302-6. · 6.83 Impact Factor
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ABSTRACT: The ionic manganese porphyrins, composed of trimethylbenzylammonium cations and S-containing anions, were designed to mimic
cytochrome P450. S-containing anions could function as the stoichiometric axial ligands and counterions dually. Such ionic
catalysts showed good catalytic performance in alkene epoxidation as compared with their neutral counterparts, in terms of
activity, epoxide selectivity, and recyclability.
Catalysis Letters 01/2008; 124(3):334-339. · 2.24 Impact Factor
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ABSTRACT: A new imidazolium IL-supported diol has been synthesized and used as a phosphine-free ligand for palladium catalyzed Heck
reaction, which was proved to be a convenient and economical system due to its efficiency, non-toxicity and recyclability.
Catalysis Letters 10/2007; 119(1):154-158. · 2.24 Impact Factor
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ABSTRACT: Using a high-speed and low-cost papermaking technology combined with subsequent sintering process, sinter-locked three-dimensional microfibrous networks consisting of ∼2 vol % of 6-μm-diameter SS-316 microfibers were utilized to entrap ∼25 vol % of 100–200-μm-diameter porous Al2O3 support particulates. Nickel, a most active component for ammonia decomposition, was then dispersed onto the pore surface of the entrapped Al2O3 support particulates by incipient wetness impregnation method. The resulting microfibrous catalysts took advantage of large void volume, entirely open structure, high heat/mass transfer, good thermal stability, and unique form factors, thereby leading to good activity for ammonia decomposition and significant reduction of overall bed weight and volume. This composite bed reactor was capable of producing 215 sccm hydrogen over per cm3 bed volume with ammonia conversion of 99.5% at 650°C. © 2007 American Institute of Chemical Engineers AIChE J, 2007
AIChE Journal 05/2007; 53(7):1845 - 1849. · 2.26 Impact Factor
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ABSTRACT: A novel microfibrous composite bed reactor was developed and was demonstrated for high efficiency hydrogen production by the decomposition of ammonia at moderate temperatures in portable fuel cell power system applications. By using a high-speed and low-cost papermaking technology combined with a subsequent sintering process, sinter-locked three-dimensional microfibrous networks consisting of approximately 3 vol% 8 microm (dia.) nickel microfibers were utilized to entrap approximately 35 vol% 100-200 microm dia. porous Al(2)O(3) support particulates. A CeO(2) promoter and active Ni component were then dispersed onto the pore surface of the entrapped Al(2)O(3) support particulates by a stepwise incipient wetness impregnation method. The microfibrous structure took advantage of a large void volume, entirely open structure, high heat/mass transfer, high permeability, good thermal stability, and unique form factors. Addition of ceria significantly promoted the low-temperature activity of Ni/Al(2)O(3) catalyst particulates incorporated into the micorfibrous structure. The use of fine particles of catalyst significantly attenuated the intraparticle mass transport limitations. As a result, the present novel microfibrous composite bed reactor provided excellent activity and structure stability in ammonia decomposition, as well as low pressure drop and high efficiency reactor design. At a 90% conversion of a 145 sccm ammonia feed rate, the microfibrous entrapped Ni/CeO(2)-Al(2)O(3) catalyst composite bed could provide a 4-fold reduction of catalytic bed volume and a 5-fold reduction of catalytic bed weight (or 9-fold reduction of catalyst dosage), while leading to a reduction of reaction temperature of 100 degrees C, compared to a packed bed with 2 mm dia. Ni/CeO(2)-Al(2)O(3) catalyst pellets. This composite bed was capable of producing roughly 22 W of hydrogen power, with an ammonia conversion of 99% at 600 degrees C in a bed volume of 0.5 cm(3) throughout a 100 h continuous test. These initial and promising results established that the microfibrous nickel-based catalyst composites were effective for high efficiency production of hydrogen by ammonia decomposition, while achieving a significant reduction of overall catalytic bed weight and volume. We anticipate our assay to be a new point for small-scale hydrogen production, where the microfibrous catalytic reactors considered in isolation can satisfy several of the most fundamental criteria needed for useful operation.
Lab on a Chip 02/2007; 7(1):133-40. · 5.67 Impact Factor
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ABSTRACT: The first total synthesis of (+/-)-subincanadine F, a bioactive indole alkaloid structurally featuring a 1-azabicyclo[4.3.1]decane unit, has been realized from 1-(para-methoxybenzyl)tryptamine in six steps. The bridge-containing tetracyclic framework of subincanadine F was efficiently assembled by a SmI2-mediated ring opening followed by an acid-mediated Mannich reaction. In addition, the tetracyclic ketoester 6, a key intermediate potentially useful for synthesizing structurally related indole alkaloids as well, was obtained in one step from alpha,beta-diketoester 5.
The Journal of Organic Chemistry 01/2007; 71(25):9495-8. · 4.45 Impact Factor
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ABSTRACT: In this study, a microfibrous carrier consisting of 3 vol.% of 8 µm (diameter) glass fibers is used to entrap 45 vol.% of
150 to 250 µm (diameter) SiO2 support particulates. ZnO is then nanodispersed onto the support by impregnation at the loading of 17 wt.%. At equivalent
bed volumes, ZnO/SiO2-entrapped materials provide twofold longer breakthrough times for H2S (with a 67% reduction in sorbent loading) compared with packed beds of 1 to 2 mm commercial extrudates. Five-log reductions
in H2S concentration with up to 75% ZnO utilization at breakthrough are achieved. H2S concentrations from 60 to 2000 parts per million in volume (ppmv) can be reduced to as little as 0.6 ppmv at 400°C in 30%
H2O at a face velocity of 1.7 cm/s for layers as thin as 1.0 mm. At 500 to 600°C, ZnO/SiO2-entrapped materials provide much higher regenerability in air than do 1 to 2 mm commercial extrudates. The use of glass fibers
permits greater than 50 regeneration cycles.
Journal of Materials Engineering and Performance 01/2006; 15(4):439-441. · 0.86 Impact Factor
