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51.
52.
Veysel T. Yilmaz Omer Andac Yildiray Topcu William T. A. Harrison 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(3):271-272
In the title complex, [Cu(C7H4NO3S)2(C2H7NO)2], the CuII centre lies on an inversion centre and exhibits octahedral coordination, with the two ethanolamine (Hea) and two saccharinate [sac; anionic 1,2-benzisothiazol-3(2H)-one 1,1-dioxide] ligands in a trans configuration. The bidentate Hea ligands bridge axial and equatorial positions and the sac anions occupy equatorial sites around the distorted octahedral copper(II) centre [Cu—O = 2.3263 (16), Cu—NHea = 1.9923 (16) and Cu—Nsac = 2.1776 (16) Å]. 相似文献
53.
The proposed decision model, based on Analytic Network Process (ANP), has been developed in order to determine the dynamics
of the Global System for Mobile Communications (GSM) market. In accordance with the sequence of ANP, first of all, the problem
was structured and modeled. At the next step, a quantitative analysis was conducted with the customers in order to assess
the importance of the related factors and forecast the market shares of the Turkish mobile communication operators. The forecasted
market share values were compared with actual ones for the validation of the decision model. The assessed importance of the
factors in a valid model would be a potential competitive advantage for the mobile operators. 相似文献
54.
采用密度泛函理论B3LYP与6—311++G方法研究了硼簇Bn(n=13~20)的电子和几何结构、总能量、结合能、谐波频率、点对称性、电荷分布、偶极矩、化学键以及最高分了占据轨道和最低分子占轨道能量差.此外,借助第一和第二能级差确定最稳定的硼簇尺寸.研究表明硼簇几乎所有的物理性质有尺寸依赖性,双环管状结构的B20具有最高平均结合能.内有一原子的二十面体结构的B13不具有稳定构型,这种结构转变为开放式笼状.B20出现二维到三维的结构转变.Mulliken分析表明电荷分布有x-z和y-z平面对称.硼簇的平面稳定性可以通过离域键(π键和σ键)以及多中心键来解释. 相似文献
55.
In this study, a new, sensitive, and rapid assay was developed to quantitatively measure the proteolytic enzyme activity using the surface-enhanced Raman scattering (SERS) probe. Two different shapes of gold nanoparticles, gold nanosphere and nanorod particles were produced. SERS label, comprising self-assembled monolayers (SAMs) of Raman reporter molecule (5,5-Dithiobis (2-Nitrobenzoic acid), DTNB), was coated on the surface of the nanoparticles. Two different SERS-based analysis platforms were designed using gold-coated glass slide and polystyrene microtiter plate. The calibration curves were obtained by plotting the intensity of the SERS signal of symmetric NO2 stretching of DTNB at 1326 cm−1vs. the protease concentration. The effects of nanoparticle geometry and assay platform on the protease assay were investigated and the best working combination of the parameters was selected as rod shaped SERS probe and gold-coated glass slide. The correlation between the protease activity and SERS signal was found to be linear within the range of 0.1-2 mU/mL (R2 = 0.979). The limit of detection (LOD) and limit of quantification (LOQ) values of the validated method were found as 0.43 and 1.30 mU/mL, respectively. The intra-day and inter-day precisions of the method, as relative standard deviation (RSD), were determined as 2.5% and 3.6%, respectively. The developed method was successfully applied for quantitative analysis of the commercial enzyme preparate that is used in cheese making process. It was also used for investigation of substrate specificity of protease enzyme towards the casein and bovine serum albumin. The proposed method has a flexibility to try different substrates for the detection of various enzyme activities. 相似文献
56.
Sevgi Haman Bayar Christoph Krafft Semra de Jürgen Popp Gunseli Guven Zafer C. Cehreli Elif Hilal Soylu 《Journal of Raman spectroscopy : JRS》2012,43(1):6-15
Human dentin specimens were treated with two different etch‐and‐rinse adhesives, Single Bond 2 (SB2) and Prime & Bond NT (PBNT), and two composite resins, TPH and P60. Cross‐sectional samples, approximately 1 mm thick, were analyzed with Raman line mapping and imaging across the dentin–adhesive–composite interface. The integrated intensities of selected bands associated with adhesive, organic material, composite and hydroxyapatite of dentin were calculated to determine the distribution of adhesive infiltration into demineralized dentin. The results were compared with the enamel‐adhesive composite interface. The demineralized zone was smaller in the enamel‐adhesive interface than in the dentin–adhesive interface. The region of collagen‐adhesive crosslinking was wider in the PBNT adhesive than in the SB2 adhesive. However, a gap at the dentin–PBNT composite interface, which was not observed at the dentin–SB2 composite interface, might compromise the dentin–restoration bond. K‐means cluster analysis of the Raman images confirmed the findings. The ultrastructure of the dentin–resin interface was studied using scanning electron microscopy. Small‐angle X‐ray scattering was also applied to reveal and quantify fine‐scale structural features. SB2 adhesive was found to diffuse more into demineralized dentin along with greater nanosized aggregations in the hybrid layer. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
57.
Plastic shear significantly reduces the phase transformation (PT) pressure when compared to hydrostatic conditions. Here, a paradoxical result was obtained: PT of graphitelike hexagonal boron nitride (hBN) to superhard wurtzitic boron nitride under pressure and shear started at about the same pressure ( approximately 10 GPa) as under hydrostatic conditions. In situ x-ray diffraction measurement and modeling of the turbostratic stacking fault concentration (degree of disorder) and PT in hBN were performed. Under hydrostatic pressure, changes in the disorder were negligible. Under a complex compression and shear loading program, a strain-induced disorder was observed and quantitatively characterized. It is found that the strain-induced disorder suppresses PT which compensates the promotion effect of plastic shear. The existence of transformation-induced plasticity (TRIP) was also proved during strain-induced PT. The degree of disorder is proposed to be used as a physical measure of plastic straining. This allows us to quantitatively separate the conventional plasticity and transformation-induced plasticity. Surprisingly, it is found that TRIP exceeds the conventional plasticity by a factor of 20. The cascade structural changes were revealed, defined as the reoccurrence of interacting processes including PTs, disordering, conventional plasticity, and TRIP. In comparison with hydrostatic loading, for the same degree of disorder, plastic shear indeed reduces the PT pressure (by a factor of 3-4) while causing a complete irreversible PT. The analytical results based on coupled strain-controlled kinetic equations for disorder and PT confirm our conclusions. 相似文献
58.
A new phenolic ester 2-( p-hydroxyphenyl)ethyl eicosaheptanoic acid ester (1) and a known one hexacosylferulate (2) were isolated from the acetone extract of Salvia microphylla. In addition, two sesquiterpenes beta-eudesmol (3) and 8alpha-hydroxy-beta-eudesmol (4), a diterpene carnosic acid 12-methyl ether (12-methoxycarnosic acid) (5), three triterpenes erithrodiol 3-acetate, oleanolic acid, lupeol and beta-sitosterol were obtained as known compounds from this plant extract. The structures of the isolated compounds were elucidated by spectroscopic methods, including one- and two- dimensional 1H- and 13C-NMR and MS spectroscopies. The selected compounds were tested for antimicrobial activity against standard bacterial strains, and only carnosic acid 12-methyl ether showed antimicrobial activity against S. aureus at 78 microg mL(-1). 相似文献
59.
Magnetic Nanoparticles: Hierarchically Structured Magnetic Nanoconstructs with Enhanced Relaxivity and Cooperative Tumor Accumulation (Adv. Funct. Mater. 29/2014) 下载免费PDF全文
Ayrat Gizzatov Jaehong Key Santosh Aryal Jeyarama Ananta Antonio Cervadoro Anna Lisa Palange Matteo Fasano Cinzia Stigliano Meng Zhong Daniele Di Mascolo Adem Guven Eliodoro Chiavazzo Pietro Asinari Xuewu Liu Mauro Ferrari Lon J. Wilson Paolo Decuzzi 《Advanced functional materials》2014,24(29):4562-4562
60.
The use of particle formulations with antifouling surface properties attracts increasing interest in several biotechnological applications. Majority of these studies utilize a poly(ethylene glycol) coating to render the corresponding surface nonrecognizable to biological macromolecules. Herein, we report a simple way to prepare novel antifouling colloids composed of oligo(ethylene glycol) backbones via surfactant-free emulsion polymerization. Monodisperse cross-linked poly(ethylene glycol) ethyl ether methacrylate particles were characterized by dynamic light scattering and transmission electron microscopy. The effects of monomer, cross-linker and initiator on particle characteristics were investigated. More importantly, a prominent blockage of bovine serum albumin adsorption was obtained for the poly(ethylene glycol)-based sub-micron (~200 nm) particles when compared with similar-sized poly(methyl methacrylate) counterparts. 相似文献