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91.
胡秀峰 《宁波大学学报(理工版)》2008,21(3):399-402
室内设计是现代科技和文化艺术的综合产物,它不仅折射出鲜明的社会时代特征,而且还反映了人与自然的关系,创造一个符合人性诉求、让人的心理和生理都感到自然和谐的居住空间已成为现代家居设计发展的趋势.而利用自然的设计元素,注重以人为本,构建自然、建筑和人三者之间和谐统一是以回归自然为理念的室内设计的根本. 相似文献
92.
K. A. Lyssenko I. L. Odinets P. V. Kazakov M. P. Pasechnik M. Yu. Antipin 《Russian Chemical Bulletin》2005,54(3):560-565
Phenyl methylisopropoxyphosphorylformate was studied by high resolution X-ray diffraction. The chemical bonding in the vicinity of the phosphoryl group was studied by analyzing the deformation electron density, the Laplacian of the electron density, and the electron localization function. A P=O...C=O intermolecular contact was revealed and its nature was analyzed.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 553–558, March, 2005. 相似文献
93.
Bacterial cellulose (BC) is a natural material produced by Acetobacter xylinum, widely used in wound dressings due to the high water‐holding capacity and great mechanical strength. In this paper, a novel antimicrobial dressing made from BC/methylglyoxal (MGO) composite with a dip‐coating method inspired by naturally antimicrobial Manuka honey is proposed, which to our best knowledge, has not yet to be reported. Characterizations by scanning electron microscope and atomic force microscopy show the interconnected nanostructure of BC and MGO and increase surface roughness of the BC/MGO composite. Thermal analysis indicates high temperature stability of both BC and BC/MGO, while compared with BC, BC/MGO exhibits slightly weaker thermal stability possibly due to reduction of hydrogen bonding and increase of crystallinity. Mechanical test confirms the strong mechanical property of BC and BC/MGO nanocomposite. From the disk diffusion antimicrobial test, the BC/MGO nanocomposite with highest MGO concentration (4%) shows great zone inhibition diameter (around 14.3, 12.3, 17.1, and 15.5 mm against Micrococcus luteus, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli). Compared with other antimicrobial wound dressing composite materials, the proposed BC/MGO nanocomposite has among the greatest antimicrobial property against broad‐spectrum bacteria, making it a promising antimicrobial dressing in chronic wounds care. 相似文献
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对光波及电磁波衍射本性的认识和判断 总被引:3,自引:0,他引:3
本文明确指出: 边界衍射波具有 π位相跃变性质 ,它是物理存在. 当目前通用的基耳霍夫衍射积 分公式因限制条件不满足而碰到问题时 ,则以前种观点分析为准 . 相似文献
97.
Suyong Re Takashi Imai Jaewoon Jung Seiichiro Ten‐No Yuji Sugita 《Journal of computational chemistry》2011,32(2):260-270
Reversible phosphorylation of proteins is a post‐translational modification that regulates diverse biological processes. The molecular mechanism underlying phosphoryl transfer catalyzed by enzymes remains a subject of active debate. In particular, the nature of transition state (TS), whether it has an associative or dissociative character, has been one of the most controversial issues. Structural evidence supports associative TS, whereas physical organic studies point to a dissociative character. Here we perform hybrid quantum mechanics/molecular mechanics simulations for the reversible phosphorylation of phosphoserine phosphatase (PSP) to study the nature of the TS. Both phosphorylation and dephosphorylation reactions are investigated based on the two‐dimensional energy surfaces along phosphoryl and proton transfer coordinates. The structures of the active site at TS in both reactions reveal compact geometries, consistent with crystal structures of PSP with phosphate analogues. However, the electron density of the phosphoryl group in both TS structures slightly decreases compared with that in the reactant states. These findings suggest that the TS of PSP has a geometrically associative yet electronically dissociative character and strongly depends on proton transfer being coupled with phosphoryl transfer. Structure and literature database, which searches on phosphotransferases, suggest that such a hybrid TS is consistent with many structures and physical organic studies and likely holds for most enzymes catalyzing phosphoryl transfer. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011 相似文献
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Optical absorption, Electron Paramagnetic Resonance (EPR) studies are carried out on lead zinc phosphate glass systems doped with Cr3+ and VO2+. From optical absorption investigations the crystal-field parameters Dq, B and C are evaluated. EPR measurements on Cr3+ systems indicate that Cr3+ ions are located at sites with low symmetry. EPR spectra of vanadyl doped system revealed the characteristic nature of vanadyl ion. Spin-Hamiltonian and hyperfine values are evaluated for both the systems. Optical absorption spectra of vanadyl doped system revealed three bands that are characteristic of VO(II) ion in tetragonally distorted octahedral site. By correlating both EPR and optical data, the dipolar coupling constant (P) and Fermi-constant coupling parameter (κ) and molecular orbital coefficients β?2, eπ?2 are evaluated. Electron Paramagnetic Resonance and optical absorption studies showed that the chemical bonds of Cr3+ ions and VO2+ ions with the ligands have more covalent nature. From these studies it is also observed that lead spinals are playing major key role in sustaining the covalent nature of bonding. 相似文献