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991.
992.
Double bonds activated by the electron withdrawing group(s) are cleaved with the reagent system consisting of a hard Lewis acid and ethanethiol to give dithioacetals. 相似文献
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994.
Fumiya Togashi Takeshi Fujita Yasushi Ito Kazuhiro Nakahashi Yoshikazu Makino 《国际流体数值方法杂志》2005,48(8):801-818
Flows around the NAL jet‐powered experimental airplane with a small rocket booster under the fuselage are computed by solving the Euler equations using the overset unstructured grid method. The main objective of the present study is to evaluate the effect of a small rocket booster, which accelerates the airplane to supersonic speed, on the aerodynamic performance of the airplane during the ascent flight and the booster separation. Two unstructured meshes, one for the airplane and one for the booster, overlap. For the accurate separation simulation, the two bodies are in contact at first, and then the booster mesh is contact mesh is moved relative to the airplane mesh to evaluate flow interactions between two bodies. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
995.
Dibenzo[a,j]phenazine‐Cored Donor–Acceptor–Donor Compounds as Green‐to‐Red/NIR Thermally Activated Delayed Fluorescence Organic Light Emitters 下载免费PDF全文
Dr. Przemyslaw Data Piotr Pander Masato Okazaki Prof. Dr. Youhei Takeda Prof. Dr. Satoshi Minakata Prof. Dr. Andrew P. Monkman 《Angewandte Chemie (International ed. in English)》2016,55(19):5739-5744
A new family of thermally activated delayed fluorescence (TADF) emitters based on U‐shaped D‐A‐D architecture with a novel accepting unit has been developed. All investigated compounds have small singlet‐triplet energy splitting (ΔEST) ranging from 0.02 to 0.20 eV and showed efficient TADF properties. The lowest triplet state of the acceptor unit plays the key role in the TADF mechanism. OLEDs fabricated with these TADF emitters achieved excellent efficiencies up to 16 % external quantum efficiency (EQE). 相似文献
996.
Mahjouba Ben Nasr Kamel Kaabi Matthias Zeller Wataru Fujita Pedro Sid nio Pereira da Silva Cherif Ben Nasr 《中国化学快报》2016,27(6):896-900
The chemical preparation, crystal structure and infrared spectroscopic characterization of the triaqua(4-amino-6-methoxypyrimidine) cuprate(II) sulfate, [Cu(C_5H_7N_3)(H_2O)_3]SO_4, is reported. The compound crystallizes in the noncentrosymmetric orthorhombic space group P2_12_12_1 with lattice parameters a = 7.9025(3), b = 11.1189(4), c = 12.9720(4) , V = 1139.81(7) ~3 and Z = 4. The Cu(II) cation is fivecoordinated, in an early half-way between square pyramidal and trigonal bipyramidal fashion, by two nitrogen atoms of the 4-amino-6-methoxypyrimidine ligand and three water oxygen atoms. In the atomic arrangement, the organic ligands and the 5-connected Cu centers are linked with each other to give a 1-D corrugated hybrid chain running along the b-axis direction. The chains are interconnected by the SO_4~(2-) anions via O–H...O, O–H...S, C–H...O and N–H...O hydrogen bonds to form layers spreading parallel to the(011) plane. The vibrational absorption bands were identified by infrared spectroscopy. Quantitative measurements of the second harmonic generation(SHG) of a powdered sample at 1064 nm were performed and a relative efficiency of 5.2 times the KDP standard was observed. Magnetic properties were also defined to characterize the complex. Magnetic measurements revealed that this material had a onedimensional antiferromagnetic character. The magnetic parameters were g = 2.11 and 2J/k B = -36 K. 相似文献
997.
The unusual quantum Hall effect (QHE) in graphene is described in terms of the composite (c-) bosons, which move with a linear dispersion relation. The “electron” (wave packet) moves easier in the direction [1 1 0 c-axis] ≡ [1 1 0] of the honeycomb lattice than perpendicular to it, while the “hole” moves easier in [0 0 1]. Since “electrons” and “holes” move in different channels, the particle densities can be high especially when the Fermi surface has “necks”. The strong QHE arises from the phonon exchange attraction in the neighborhood of the “neck” surfaces. The plateau observed for the Hall conductivity and the accompanied resistivity drop is due to the superconducting energy gap caused by the Bose-Einstein condensation of the c-bosons, each forming from a pair of one-electron–two-fluxons c-fermions by phonon-exchange attraction. The half-integer quantization rule for the Hall conductivity: (1/2)(2P?1)(4e2/h), P=1,2,..., is derived. 相似文献
998.
Y. Yoshida Y. Ino K. Matsumuro T. Watanabe H. Fujita K. Hayakawa K. Yukihira K. Ogai K. Moriguchi Y. Harada H. Soejima 《Hyperfine Interactions》2016,237(1):130
A prototype Mössbauer Spectroscopic Microscope is applied for the feasibility study of 57Fe impurity diffusion in Si wafers. A 2nm- 57Fe deposited Si wafer is annealed at 430 °C for 1 hour, and subsequently the 1/3 area of the wafer is further grinded with an angle of 6 degrees to the original surface to get a higher depth resolution for the mapping. Subsequently, the mapping images for Fe\(_{\text {sub}}^{\mathrm {0}}\), Fe\(_{\text {int}}^{\mathrm {0}}\), and Fe\(_{\text {int}}^{\mathrm {+}}\) states are measured separately for the two different areas: one area (A) along the grinded surface, and the other (B) along the original wafer surface crossing through the 57Fe-deposition boundary. By integrating the mapping intensity the diffusivity of each Fe component along the two different directions can be evaluated and compared with an average Fe diffusivity in Si, which is measured by EDS mapping data obtained for the same area. 相似文献
999.
Y. Ino H. Soejima K. Hayakawa K. Yukihira K. Tanaka H. Fujita T. Watanabe K. Ogai K. Moriguchi Y. Harada Y. Yoshida 《Hyperfine Interactions》2016,237(1):13
A 3D-Mössbauer Spectroscopic Microscope is developed to evaluate Fe impurities in multi-crystalline Si solar cells, which combines the Mössbauer spectroscopic microscope with a scanning electron microscope (SEM), an electron beam induced current (EBIC), an electron backscatter diffraction (EBSD), and an electron energy analyzer (HV-CSA). In addition, a new moving-coil-actuator with a liner encoder of 100 nm-resolution is incorporated for the operations with both a constant velocity and a constant acceleration mode successfully with the same precision as that obtained by the conventional transducers. Furthermore, a new multi-capillary X-ray lens is designed to achieve a γ-ray spot size less than 100 μm in diameter. The new microscope provides us to investigate the space correlation between Fe impurities and the lattice defects such as grain boundaries in multi-crystalline Si solar cells. 相似文献
1000.
We show a new direction to expand the applicability of the complex basis function method for calculating photoionization cross sections through the imaginary part of the frequency-dependent polarizability. Based on the variational stability of the frequency-dependent polarizability, we made nonlinear optimizations of complex orbital exponents in basis functions representing continuum wave functions, and obtained fairly accurate results for H atom with only one or two complex basis functions particularly with dipole velocity gauge. Results were almost independent of whether Slater-type or Gaussian-type orbitals are used, implying the applicability to general many electron problems. The method was also applied to the (1)S (1s)(2) --> (1)P (1s)(1)(kp)(1) cross section of He atom and the optimized complex orbital exponents were related to those of H atom through the scaling property. The nonlinear optimizations have converged smoothly and the cross sections were in excellent agreement with experiment throughout wide photon energies, which suggest the effectiveness of the approach for many-electron systems. 相似文献