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21.
The mechanism of the slowly opened Q-switch operation was investigated thoroughly. Maximum energy extraction from the resonator
could be optimized, and the smallest output beam divergence could be achieved. In this article, we present a detailed analysis
that has numerically verified the mode-selection mechanism in the slowly opened Q-switch operation, and the degree of the
smaller output laser beam divergence that has been achieved. The mechanism of the slowly opened Q-switch operation is the
inherent advantage of the passive saturable absorber in this operation. We can use the maximum energy extraction and the smallest
output beam divergence results of the slowly opened Q-switch operation to design and optimize various passive saturable absorbers:
plastic dye sheets, LiF:F2− color center crystals, Cr4+: YAG crystals, RG1000 color glass filters, and the single crystal semiconductor saturable absorber wafers that are in developed
in our microchip laser systems. 相似文献
22.
本文研究DNA的两两序列比时,提出了基于快速沃尔什变换的新方法。经过计算模拟分析可知,比对的时间复杂度和空间复杂度明显降低. 相似文献
23.
J. A. M. Janssen 《Journal of statistical physics》1989,57(1-2):187-198
The master equation for a complex chemical reaction cannot always be reduced to a simpler master equation, even if there are fast and slow individual reaction steps. Nevertheless the elimination of intermediates can be carried out with the help of the-expansion. This is illustrated with a well-known complex reaction: the dissociation of N2O5. It is shown that the intrinsic fluctuations in the N2O5 decay are larger than those implied by the master equation suggested by the macroscopic rate law. 相似文献
24.
用铜(Ⅱ)—L—精氨酸配体交换薄层色谱拆分氨基酸对映体 总被引:2,自引:0,他引:2
报道了一种新的配体交换薄层色谱拆分氨基酸对映体的方法。以醋酸铜-L-精氨酸的络合物为配体交换剂,用浸渍的方法吸附在硅胶薄层板上,制成配体交换薄层,用PRISMA优化法选择出展开剂的最佳组成为:甲醇/乙腈/四氢呋喃/水=80:8.2:5.8:6,在此色谱条件下,十对氨基酸对映体得到良好的分离,D-和L-氨基酸的相对比移值在1.09-2.40之间。文中对配体交换薄层的制备方法,样品的分子结构及色谱行为 相似文献
25.
Jun Fan Wei‐Guang Zhang Min‐Yu Tan Yu Tang Wei‐Sheng Liu Ning Tang Kai‐Bei Yu 《中国化学》2004,22(6):508-511
The La(III) complex with a new amide‐type tripodal ligand,2,2′.2″‐nitrilotris{[(2′‐benzylaminofomyl)‐phenoxylethyl)amine (L), was synthesized and characterized by X‐ray crystallographic analysis. Crystal data: C48H55.50LaN7O18.75, Mr=1169.40, monoclinic. space group, P21/n, a= 1.0644(3) nm. b=2.3889(5) nm, c= 2.1917(5) nm, β=90.65°, V=5.573(2) nm3, Z=1, Dc=1.394 g°cm?3, R1=0.0487, wR [1>2s?(I)]=0.1266. The results reveal that each La(III) ion binds to 9 oxygen atoms, three of which belong to carbonyl groups from three tripodal ligands and six to three bidentate nitrate groups and a two‐dimensional sheet of 4.82 networks is assembled by metal‐ligand coordination interaction. L, a heptadentate compound, merely acts as a tridentate bridging spacer due to its steric hindrance and links the La(III) ions as three‐connected nodes. 相似文献
26.
本文通过异氰酸酰化反应合成了含有脲基的苯乙炔新型配体及以它作为辅助配体的4′-(对甲基苯基)-6-苯基-2,2′-二联吡啶铂(II)络合物,初步研究了铂(II)络合物的光物理性质,发现由于脲基的存在,当浓度大于3.32×10-5mol/L时铂(II)络合物能够发生分子间簇集. 相似文献
27.
O. N. Babkina O. M. Chukanova E. E. Faingol"d N. M. Bravaya 《Russian Chemical Bulletin》2004,53(4):785-790
Quantitative characteristics of changes in the energy of charge transfer from -bonded ligands to metal are presented for the series of structurally similar ansa-metallocene complexes of IVB Group elements. The changes are caused by the solvation effect, replacement of -bonded chlorine ligands by methyl groups and of bridging ethylene groups by dimethylsilylene moieties, introduction of the methyl substituent into position 2 and phenyl substituent into position 4 of the indenyl system, variation of the transition metal in metallocene, and formation of complexes with polymethylalumoxane (MAO) at different AlMAO/Zr ratios. These effects are found to be additive. 相似文献
28.
Marta Filizola Maria Carteni-Farina Juan J. Perez 《Journal of computer-aided molecular design》1999,13(4):397-407
3D models of the opioid receptors , and were constructed using BUNDLE, an in-house program to build de novo models of G-protein coupled receptors at the atomic level. Once the three opioid receptors were constructed and before any energy refinement, models were assessed for their compatibility with the results available from point-site mutations carried out on these receptors. In a subsequent step, three selective antagonists to each of three receptors (naltrindole, naltrexone and nor-binaltorphamine) were docked onto each of the three receptors and subsequently energy minimized. The nine resulting complexes were checked for their ability to explain known results of structure-activity studies. Once the models were validated, analysis of the distances between different residues of the receptors and the ligands were computed. This analysis permitted us to identify key residues tentatively involved in direct interaction with the ligand. 相似文献
29.
Suyun Jie Tianzhu Zhang Jiutong Chen Dongbing Liu Wei Chen 《Journal of organometallic chemistry》2005,690(7):1739-1749
A series of bridged bis(pyridinylimino) ligands were efficiently synthesized through the condensation reaction of 4,4′-methylene-bis(2,6-disubstituted aniline) with 2-pyridinecarboxaldehyde or 2-benzoylpyridine. They reacted with (DME)NiBr2 to form dinuclear Ni(II) complexes. All resultant compounds were characterized by elemental analysis, IR spectra as well as the single-crystal X-ray diffraction to confirm the structures of ligands and complexes. Activated with methylaluminoxane (MAO), these nickel complexes showed considerably good activities for ethylene oligomerization and polymerization. Their catalytic activities and the properties of PEs obtained were depended on the arched environment of ligand and reaction conditions. 相似文献
30.
XU Xing-Youa MA Wei-Xinga GAO Jiana LIU Qing-Liangb a 《结构化学》2002,21(5):473-476
1 INTRODUCTION Macrocyclic ligands and their metal complexes have received much attention due to their applications in ion transport, ion separation and as models in biomimic researches[1~7]. The synthetic methods of macrocyclic ligands and their metal complexes are mainly divided into three kinds[8]. The first one is synthesizing free ligand, then forming the metal complexes; the second is template synthesis; and the third is synthesizing the end-off or side-off precursor ligand, then c… 相似文献