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61.
Dong Mok Shin Seung Uk Son Bog Ki Hong Young Keun Chung Sung-Ho Chun 《Journal of molecular catalysis. A, Chemical》2004,210(1-2):35-46
A variety of neutral palladium(II) complexes [Pd(L–L)Cl2] containing 1,3-di(2-pyridyl)propane (1), 1,3-bis(2-pyridyl)-2-pentylpropane (2), 1,3-bis(2-pyridyl)-2-phenylpropane (3a), 1,3-bis(2-pyridyl)-2-tolylpropane (4), and 1,3-bis(2-pyridyl)-2-ferrocenylpropane (5) as chelate ligands (L–L) have been synthesized. The crystal structures of 1,3-diphenyl-2,4-di-pyridin-2-yl-butan-1-ol (3b), 5, [(2)PdCl2], [(4)PdCl2], and [(5)PdCl2] have been determined and show a square planar geometry at palladium(II). The neutral complexes were tested in the polymerization of norbornene and copolymerization of norbornene with norbornene derivatives. The complex bearing the pentyl group exhibited high reactivity to give up to 5.9×105 in molecular weight for the homopolymerization. When [(4)PdCl2] or [(5)PdCl2] was used as a catalyst, homopolymers insoluble at 150 °C in trichlorobenzene were obtained. However, copolymerization of norbornene with norbornene derivatives 8a–d catalyzed by [(4)PdCl2] gave soluble copolymers with molecular weights up to 5.1×105. 相似文献
62.
M.K. Wu F.C. Hsu K.W. Yeh T.W. Huang J.Y. Luo M.J. Wang H.H. Chang T.K. Chen S.M. Rao B.H. Mok C.L. Chen Y.L. Huang C.T. Ke P.M. Wu A.M. Chang C.T. Wu T.P. Perng 《Physica C: Superconductivity and its Applications》2009,469(9-12):340-349
An overview of the recent development of the superconducting FeSe1?x and related compounds is presented. Methods to synthesize high purity polycrystalline samples, single crystals and thin films with preferred orientation are described. In addition to the synthesis of FeSe and FeSeTe, the effects of various partial chemical substitutions on Fe and Se/Te site are described. It was found that the effects of chemical doping to the Se-site or Fe-site are rather different. Ionic size of the dopant is found to play a critical role on the occurrence of superconductivity. We also review the physical properties, including transport, magnetic, and thermal properties. There exist interesting transport anomalies in the resistivity at low temperature, and it was found that a structural distortion at low temperature is critical to the occurrence of superconductivity in these materials. However, the exact origin of these observed anomalies is not clear, and the exact pairing symmetry in FeSe-based superconductors is also still in question. 相似文献
63.
Young Sun Mok Sung Won Ham In-Sik Nam 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1998,26(5):1566-1574
A mathematical model was proposed to describe the behaviour of the removal of nitrogen oxides (NOx) in a positive pulsed corona discharge reactor. The proposed model takes into account radical production at each pulsing and subsequent radical utilization for NOx removal. The production efficiencies of radicals such as O, OH, H, and N were derived by considering direct electron impact on dissociation of gaseous molecules, followed by excitation transfer reactions of excited oxygen atoms. The production efficiencies of those species were used for the model calculations. The proposed model could adequately predict the experimental data. Of the active species present, the ozone (O3) produced by the reaction of O radical with oxygen was found to play the crucial role in oxidation of NO to NO2 , both theoretically and experimentally 相似文献
64.
Ahn JH Jung SH Kim JA Song SB Kwon SJ Kim KR Rhee SD Park SD Lee JM Kim SS Cheon HG 《Chemical & pharmaceutical bulletin》2005,53(8):1048-1050
In the continuation of efforts to modify the structure of our novel DP-IV inhibitors, a series of pyrazolidine derivatives with heteroaryl urea was synthesized and evaluated for their ability to inhibit dipeptidyl peptidase IV (DP-IV). 相似文献
65.
Laser-induced fluorescence spectrum of TiS in the 769-863 nm region has been recorded and analyzed. The TiS molecule was produced using the technique of laser vaporization/reaction with supersonic cooling. Twenty-one weak subbands have been assigned as being due to b(1)Pi-X(3)Delta, B(3)Pi(0)-X(3)Delta(1), and C(3)Delta-X(3)Delta transitions. Strong evidence shows that the b(1)Pi state is responsible for perturbing the v = 0, 1, and 2 levels of the C(3)Delta(1) subband. The molecular constants of the b(1)Pi state have been determined as follows: T(e) = 10 589.47 cm(-1), omega(e) = 542.14 cm(-1), omega(e)x(e) = 3.16 cm(-1), B(e) = 0.19568 cm(-1), and alpha(e) = 0.00085 cm(-1). The spin-orbit interaction between the b(1)Pi (v = 2 and 3) and C(3)Delta (v = 1 and 2) levels is discussed in terms of configuration interaction occurring between the b(1)Pi from the 11varsigma(1) 5pi(1) configuration and the (1)Pi from the 5pi(1) 1delta(1) configuration, and the C(3)Delta state from 12varsigma(1) 1delta(1) configuration. Copyright 2000 Academic Press. 相似文献
66.
67.
Experimental determinations of the frequency dependence of the anharmonic self-energy shift and damping of the q ? 0 transverse optic mode in KBr at 300 and 100 K are presented. The room temperature measurements of the damping function are shown to be in good agreement with recent calculations by Bruce which include a contribution from a term reflecting the three phonon density of states. 相似文献
68.
69.
S. M. Rao M. K. Wu J. K Srivastava B. H. Mok N. Y. Yen H. Y. Lin H. Y. Tang M. C. Ling H. L. Liu 《Crystal Research and Technology》2006,41(9):859-864
Single crystals of Sr2YRu1‐xCuxO6 (x = 0 ‐ 0.4) have been grown from PbO‐PbF2 based solutions in the temperature range 1150 – 1350°C. A silicon carbide heating element furnace (with a recrystallized alumina tube lining) in a vertical configuration was used to grow the crystals in platinum crucibles. Conditions for the stable growth of big crystals have been investigated. The morphology of the crystals containing Cu was found to change from octahedral to cube octahedral as the growth temperature is increased from 1150 to 1350°C. Crystals measuring up to 4.5 mm across and 2.5 mm thick have been grown from 1250°C. The incorporation of Cu into the crystals was ascertained by EDS and x‐ray diffraction analysis. A diamagnetic transition which increased in magnitude and temperature with x was observed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献