Showing papers by "Zhong Chen published in 2002"
TL;DR: In this article, the fracture toughness of the film and the delamination toughness have been estimated from controlled buckling experiments on the substrate and the film under both tension and compression, and design to maximize the flexibility of the device is discussed.
266 citations
TL;DR: In this article, the performance of the effective core potentials of LanL2DZ and CRENBL basis sets for metal atoms were compared to 3-21G all-electron basis set.
Abstract: The 19F NMR chemical shieldings of solid-state alkaline-earth-metal fluorides MF2 (M = Be, Mg, Ca, Sr, Ba) and alkali-metal fluorides MF (M = Li, Na, K, Rb, Cs) were systematically studied by the gauge-independent atomic orbital (GIAO) method at the level of density functional theory (DFT). The 6-311+G(d) basis set was used for the inspected fluoride ion. The performance of the effective core potentials (ECP) of LanL2DZ and CRENBL basis sets for metal atoms were compared to 3-21G all-electron basis set. The role of d polarization functions for metal atoms is investigated. The results show that the clusters [FMg3F9]4-, [FM4F6]+ (M = Ca, Sr, Ba), and [FM6]5+ (M = Li, Na, K, Rb, Cs) used to model the bulk solids are reasonable. The electrons in the next outermost shell of metal atoms have significant influence on the 19F NMR calculations and should be treated as valence electrons together with the electrons in the outermost shell, while the remaining electrons can be represented by the ECP of CRENBL basis se...
23 citations
TL;DR: To optimize timing parameters in an intermolecular double‐quantum coherence imaging pulse sequence for overall image signal‐to‐noise ratio (SNR) and blood oxygenation level‐dependent (BOLD) sensitivity for brain functional imaging.
Abstract: Purpose
To optimize timing parameters in an intermolecular double-quantum coherence (iDQC) imaging pulse sequence for overall image signal-to-noise ratio (SNR) and blood oxygenation level-dependent (BOLD) sensitivity for brain functional imaging.
Material and Methods
Fresh human blood was measured under different oxygenation conditions, and human brain functional magnetic resonance (fMR) images in three normal volunteers were obtained, using iDQC techniques at 1.5 T. The dependence of SNR and BOLD sensitivity was measured as a function of time delays after the iDQC evolution period.
Results
A time delay after the iDQC evolution period τ can be adjusted either to refocus the dephasing accumulated during τ, thus increasing SNR, with full rephasing occurring at delay = ±2τ (for iDQC order n = ±2), or to enhance BOLD effects with consequent reduced image SNR at delay = 0.
Conclusion
Image SNR and BOLD sensitivity often impose different requirements for iDQC image sequence design and timing parameter selections. It is therefore important to select properly relevant parameters for different applications. J. Magn. Reson. Imaging 2002;16:733–740. © 2002 Wiley-Liss, Inc.
17 citations
TL;DR: In this paper, the 19 F NMR chemical shieldings of MF 2 (M=Zn, Cd, Pb), MF 3 (M =Al, Ga, In), and SnF 4 were studied by the GIAO-B3LYP method.
13 citations
TL;DR: In this paper, a blue-emitting conjugated polymer, poly[(4-decylthiophene-2,5-diyl)(2,2′-biphenyl), was synthesized via reductive coupling polymerization using nickel(0) as the catalyst in place of FeCl3-oxidative polymerization.
1 citations