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221.
采用硅胶柱色谱、制备薄层色谱、凝胶柱色谱和半制备高效液相色谱等方法,从海南暗罗根的乙酸乙酯部位中分离获得7个单体化合物,结构分别为:debilone(1),trans-Nferuloyltyramine (2),3,4,5-trimethoxybenzoic acid (3),p-hydroxybenzaldehyde (4),phydroxybenzoic acid(5),β-sitostenone(6),β-sitosterol(7),其中化合物11-5为首次从该植物中分离得到。 相似文献
222.
The global existence of solutions to a damped MHD system in Besov spaces is obtained. This research is motivated by the open question [Wu et al., J. Nonlinear Sci. 25 (2015), 157–192, Remark 5.1] on the possibility of extension to the existence of global small solutions from a potential Banach space to a Besov space. The present result positively confirms the open question. What is more, the initial data are not required to be uniformly small. 相似文献
223.
傅里叶变换投影栅线法测量大物体的变形 总被引:1,自引:0,他引:1
本文利用傅里叶变换投影栅线技术对大物体的离面变形进行了测量,分析了大物体的尺寸给测量过程带来的主要矛盾,讨论了方法的灵敏度和精度,用计算机数值模拟技术给出了大尺寸引起的频率变化所带来的误差。结果表明,傅里叶变换投影栅线技术可以用于大尺寸物体离面变形的精确测量。 相似文献
224.
在含能材料单轴、受限三轴动态压缩实验的基础上,提出一种将计算机数值模拟和实验数据相结合,估算实验系统中钢筒与试件间的库伦摩擦力,从而正确确定含能材料的动态三轴力学性能(弹性模量E,泊桑比ν,屈服限Y等)的方法。本方法用于TNT炸药受限三轴动态压缩实验,通过建立钢筒-试件的库伦摩擦有限元模型,采用ADINA通用程序进行动力分析,估算了摩擦力对实验数据的影响,获得了考虑摩擦力修正后的TNT三轴动态压缩响应,为含能材料三轴动态力学性能的确定提供了一种有效的方法。 相似文献
225.
When a surface is illuminated by laser, the field of diffusing reflective light can be described by Fresnel-Kirchhoff integration
in the region of Fresnel. If the correlation, before and after the change of intensity field, is analysed by statistical method,
three governing equations for variations of intensity field and speckle movement formulas can be obtained. In these equations,
the surface motion, deformation and wavelength change are all considered to cause the speckle movement.
The project supported by National Natural Science Foundation of China 相似文献
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227.
Diselenophosphate‐Induced Conversion of an Achiral [Cu20H11{S2P(OiPr)2}9] into a Chiral [Cu20H11{Se2P(OiPr)2}9] Polyhydrido Nanocluster
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Dr. Rajendra S. Dhayal Jian‐Hong Liao Dr. Xiaoping Wang Dr. Yu‐Chiao Liu Dr. Ming‐His Chiang Dr. Samia Kahlal Prof. Jean‐Yves Saillard Prof. C. W. Liu 《Angewandte Chemie (International ed. in English)》2015,54(46):13604-13608
A polyhydrido copper nanocluster, [Cu20H11{Se2P(OiPr)2}9] ( 2H ), which exhibits an intrinsically chiral inorganic core of C3 symmetry, was synthesized from achiral [Cu20H11{S2P(OiPr)2}9] ( 1H ) of C3h symmetry by a ligand‐exchange method. The structure has a distorted cuboctahedral Cu13 core, two triangular faces of which are capped along the C3 axis, one by a Cu6 cupola and the other by a single Cu atom. The Cu20 framework is further stabilized by 9 diselenophosphate and 11 hydride ligands. The number of hydride, phosphorus, and selenium resonances and their splitting patterns in multinuclear NMR spectra of 2H indicate that the chiral Cu20H11 core retains its C3 symmetry in solution. The 11 hydride ligands were located by neutron diffraction experiments and shown to be capping μ3‐H and interstitial μ5‐H ligands (in square‐pyramidal and trigonal‐bipyramidal cavities), as supported by DFT calculations on [Cu20H11(Se2PH2)9] ( 2H′ ) as a simplified model. 相似文献
228.
Susceptibility of Ureaplasma urealyticum to Methylene Blue‐Mediated Photodynamic Antimicrobial Chemotherapy: An in vitro Study
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Tinglu Ye Bancheng Chen Bo Yu Qili Zhong Guoxin Huang Xiaoping Hu Wei Zhang 《Photochemistry and photobiology》2015,91(4):917-922
The aim of this study was to detect the susceptibility of Ureaplasma urealyticum to methylene blue‐mediated photodynamic antimicrobial chemotherapy (PACT). Three U. urealyticum strains including the standard serotype 1 and 5, and a clinically collected strain were used in this study. Strains were first incubated in 96‐well culture plates in the presence of methylene blue with decreasing concentrations (from 1 to 0.015625 mg mL?1) for 20 or 60 min, and then submitted to irradiation with a light‐emitting diode laser with a power density of 100 mW cm?2 for 8, 17, 34 or 68 min. Regrowth of the strains was performed soon after irradiation. A significant inactivation effect was observed after PACT. Longer incubation time induced more extensive inactivation of U. urealyticum. No difference in response to PACT was observed between the two biovars of U. urealyticum. It was concluded that PACT had a significant inactivation effect on U. urealyticum, and it might be a promising alternative treatment for resistant U. urealyticum infections. 相似文献
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[Cu32(H)20{S2P(OiPr)2}12]: The Largest Number of Hydrides Recorded in a Molecular Nanocluster by Neutron Diffraction
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Dr. Rajendra S. Dhayal Jian‐Hong Liao Dr. Samia Kahlal Dr. Xiaoping Wang Dr. Yu‐Chiao Liu Dr. Ming‐Hsi Chiang Prof. Werner E. van Zyl Prof. Jean‐Yves Saillard Prof. C. W. Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(23):8369-8374
An air‐ and moisture‐stable nanoscale polyhydrido copper cluster [Cu32(H)20{S2P(OiPr)2}12] ( 1H ) was synthesized and structurally characterized. The molecular structure of 1H exhibits a hexacapped pseudo‐rhombohedral core of 14 Cu atoms sandwiched between two nestlike triangular cupola fragments of (2×9) Cu atoms in an elongated triangular gyrobicupola polyhedron. The discrete Cu32 cluster is stabilized by 12 dithiophosphate ligands and a record number of 20 hydride ligands, which were found by high‐resolution neutron diffraction to exhibit tri‐, tetra‐, and pentacoordinated hydrides in capping and interstitial modes. This result was further supported by a density functional theory investigation on the simplified model [Cu32(H)20(S2PH2)12]. 相似文献