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71.
激光晶体YAG中Er3+的辐射跃迁 总被引:2,自引:0,他引:2
本文讨论和分析了激光晶体YAG中Er3+离子的激光上能级的4S3/2、4I11/2和4I13/2辐射跃迁的有关因素。 相似文献
72.
1.INTRODUCTION[()-227.3()]Endotoxinislipopolysaccharide(LPS)derivedfromthecellmembranesofgram-negativebacteria.Endotoxincancausefebrilereactionsinanimalswithsymptomsofhighfever,vasodilation,diarrheaandfetalshockwheninjectedeveninaverysmallamount[1].Iftheconcentrationofendotoxininpatients?bloodishighenoughitcancauseseveresepsis,whichisamajorcauseofdeathinpatientsandcontinuestohaveahighmortalitydespiteappropriatesurgery,potentantibiotic,andintensivesupportivetherapy[2~5].LipidAisthemaintox… 相似文献
73.
L. C. Lew Yan Voon C. Galeriu M. Willatzen 《Physica E: Low-dimensional Systems and Nanostructures》2003,18(4):547-549
We argue that the two-dimensional elliptic quantum dot problem with finite barrier cannot be exactly solved, contrary to a recent assertion (van den Broek and Peeters, Physica E 11 (2001) 345. We also prove it explicitly by numerically calculating the correct energy spectrum. 相似文献
74.
In mononuclear HgI2[(C5H4N)3N], mercury is tetrahedrally coordinated by two nitrogen atoms of a tris(2‐pyridyl)amine ligand and two iodides. The coordination moieties are connected by weak intermolecular Hg(II)···I interactions to give a one‐dimensional structure. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
75.
XiWenHE HongShengGUO YuMeiJIA 《中国化学快报》2003,14(9):979-982
In order to obtain mechanically stable membrane for practical application, the imprinted polymer was synthesized in the pores of polyfluoromembrane, the binding and transport ability of the membrane were studied. 相似文献
76.
77.
LiuYuqi LiZhigang YahYakun 《Acta Mechanica Solida Sinica》2004,17(1):58-64
By using the Finite Element Inverse Approach based on the Hill quadratic anisotrop-ically yield criterion and the quadrilateral element, a fast analyzing software-FASTAMP for the sheet metal forming is developed. The blank shapes of three typical stampings are simulated and compared with numerical results given by the AUTOFORM software and experimental results, respectively. The comparison shows that the FASTAMP can predict blank shape and strain distribution of the stamping more precisely and quickly than those given by the traditional methods and the AUTOFORM. 相似文献
78.
79.
Xin‐Gui Li Run‐Feng Chen Mei‐Rong Huang Mei‐Fang Zhu Qun Chen 《Journal of polymer science. Part A, Polymer chemistry》2004,42(9):2073-2092
A new series of copolymers was synthesized through the oxidative polymerization of pyrrole (PY) and o‐phenetidine (PHT) with inorganic oxidants in acidic media. The polymerization parameters including the mixing method of the oxidant with the comonomer, the comonomer ratio, the time, the temperature, the oxidant, the organic medium, and the acid were systematically optimized for the synthesis of copolymers with high yields, intrinsic viscosities, and solubility. The resultant copolymers were characterized by elemental analysis, infrared, ultraviolet–visible, solution high‐resolution 1H NMR and solid‐state high‐resolution 13C NMR, circular dichroism spectroscopy, and cyclic voltammetry. The results showed that the PY observed content in the copolymers was much higher than the PY feed content. The regular variation of the polymerization yield, intrinsic viscosity, solubility, macromolecular structure, and electroactivity of the resulting polymers with the comonomer ratio, together with the complete solubility of a PY/PHT (10/90) polymer in highly polar solvents, indicated the formation of real random copolymers containing both PY and PHT units rather than a mixture of two homopolymers. However, the polymers containing more than 59 mol % PY were not homogeneous copolymers consisting of soluble and insoluble parts. A semiquantitative relationship between the polymerization yield or solubility of the copolymers and the polarity index of the organic solvents was examined. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2073–2092, 2004 相似文献
80.
Chun‐Yan Hong Ye‐Zi You Cai‐Yuan Pan 《Journal of polymer science. Part A, Polymer chemistry》2004,42(19):4873-4881
Well‐defined diblock and triblock copolymers composed of poly(N‐isopropylacrylamide) (PNIPAM) and poly(ethylene oxide) (PEO) were successfully synthesized through the reversible addition–fragmentation chain transfer polymerization of N‐isopropylacrylamide (NIPAM) with PEO capped with one or two dithiobenzoyl groups as a macrotransfer agent. 1H NMR, Fourier transform infrared, and gel permeation chromatography instruments were used to characterize the block copolymers obtained. The results showed that the diblock and triblock copolymers had well‐defined structures and narrow molecular weight distributions (weight‐average molecular weight/number‐average molecular weight < 1.2), and the molecular weight of the PNIPAM block in the diblock and triblock copolymers could be controlled by the initial molar ratio of NIPAM to dithiobenzoate‐terminated PEO and the NIPAM conversion. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4873–4881, 2004 相似文献