排序方式: 共有57条查询结果,搜索用时 31 毫秒
41.
Teerapon Pirom Thidarat Wongsawa Thanaporn Wannachod Niti Sunsandee Ura Pancharoen Soorathep Kheawhom 《Chemical Papers》2017,71(7):1291-1302
Amoxicillin was removed from aqueous solutions using hollow fibre supported liquid membrane system (HFSLM). After evaluation of the influencing variables, the highest permeation coefficient of amoxicillin reached 2.778 × 10?4 ms?1 when the length of hollow fibres was 15 cm and the operating time was 60 min. Then, the reaction flux models of extraction and stripping were calculated. Thereafter, the modelling results were compared with the experimental data at standard deviations of 2.07 and 3.19%. In the comparison of carrier and diluent, the best conditions were achieved when Aliquat 336 and 1-Decanol were used. Results showed that amoxicillin extraction and stripping were of first and zero reaction orders; their reaction rate constants were 0.0344 min?1 and 0.0445 mg/L·min, respectively. 相似文献
42.
Kwon HJ Kakugo A Ura T Okajima T Tanaka Y Furukawa H Osada Y Gong JP 《Langmuir : the ACS journal of surfaces and colloids》2007,23(11):6257-6262
We show that F-actins form three-dimensional giant network under uni-directional diffusion of polycations, at a dilute actin concentration (0.01 mg/mL) that only bundles are formed by homogeneous mixing with polycations. The mesh size of the actin network depends on polycation concentration and ionic strength, while bundle thickness of network depends only on ionic strength, which indicates that actin network is formed through nucleation-growth mechanism. The mesh size and the bundle thickness are determined by nucleus concentration and nucleus size, respectively. The atomic force microscopy measurement correlates the elasticity of the actin network, E, with the mesh size, xi, as E approximately xi-1, while the bundle thickness, D dependence of E cannot be described by a simple scaling relation. E approximately D6.5 when D is small and E approximately D0.1 when D is large. Our study on the self-assembly of actin network under asymmetric polycation condition would provide the crucial insight into the organization of biopolymers in polarized condition of cell. 相似文献
43.
The chemistry of a novel zerovalent Ru complex, Ru(eta6-cot)(eta2-dmfm)2 (1) (cot=1,3,5-cyclooctatriene; dmfm=dimethyl fumarate), is reviewed with a focus on its reactivity toward phosphines, amines, and H2O, as well as arenes and p-quinones. A variety of novel zerovalent Ru complexes were synthesized from Ru(eta6-cot)(eta2-dmfm)2 (1), and it was shown that the complexes preferably bear both electron-donating and -accepting ligands simultaneously to exhibit thermodynamic stability. The first isolable zerovalent Ru aqua complexes were successfully prepared, and in these complexes, the generation of a chiral center on the O atom of the coordinated H2O was disclosed. In addition, the characteristic catalytic activity of 1 in organic synthesis was considered by reviewing recently developed novel reactions: (i) dimerization of 2,5-norbornadiene to pentacyclo[6.6.0.0(2,6).0(3,13).0(10,14)]tetradeca-4,11-diene (PCTD), (ii) intramolecular hydroamination of aminoalkynes to cyclic imines, (iii) formal [4+2] cycloaddition of alkynes with dmfm to trans-4-cyclohexene-1,2-dicarboxylates, and (iv) co-dimerization of dihydrofurans with alpha,beta-unsaturated esters to 2-alkylidenetetrahydrofurans. The products obtained here are expected to be used as novel functional organic monomers. 相似文献
44.
Ema T Ura N Eguchi K Ise Y Sakai T 《Chemical communications (Cambridge, England)》2011,47(21):6090-6092
Chiral diporphyrin receptor 1, which has a macrocyclic cavity to sandwich aromatic guest molecules via double π-π stacking interactions, enabled the naked-eye detection of an aromatic explosive as well as chiral discrimination in NMR. 相似文献
45.
The virtual object and image are introduced in order to apply the usual lens formula to an electrostatic lense accompaning pre- and/or electric fields. In case of the uniform electric field, their positions are simply expressed as a function of the accelerating or decelerating potential ratio. 相似文献
46.
47.
Preparation of poly(ethylene glycol)-modified poly(amido amine) dendrimers encapsulating gold nanoparticles and their heat-generating ability 总被引:2,自引:0,他引:2
Haba Y Kojima C Harada A Ura T Horinaka H Kono K 《Langmuir : the ACS journal of surfaces and colloids》2007,23(10):5243-5246
Loading of HAuCl4 in poly(amido amine) G4 dendrimers having poly(ethylene glycol) (PEG) grafts at all chain ends and subsequent reduction with NaBH4 yielded PEG-modified dendrimers encapsulating gold nanoparticles (Au NPs) of ca. 2 nm diameter. The Au NPs held in the dendrimers were stable in aqueous solutions and dissolved readily, even after freeze-drying. Despite their small particle size, the heat-generating ability of Au NPs held in the dendrimer was comparable to that of widely used Au NPs with ca. 11 nm diameter under visible light irradiation. The observed excellent colloidal stability, high heat-generating ability and their biocompatible surface confirm that the PEG-modified dendrimers encapsulating Au NPs are a promising tool for photothermal therapy and imaging. 相似文献
48.
Tatchanok Prapasawat Anchaleeporn Waritswat Lothongkum Ura Pancharoen 《Chemical Papers》2014,68(2):180-189
This paper reports on the enantioseparation of racemic phenylalanine or D-phenylalanine and Lphenylalanine via a hollow fibre-supported liquid membrane (HFSLM) and the results are compared with the mathematical model. The enantioseparation results, of 80 % and 73 %, showed the highest extraction and stripping of l-phenylalanine from the feed phase and the enantiomeric excess (% ee) of 60 % from 6 mmol L?1 of initial rac-phenylalanine in the feed solution. The optimum parameters were feed solution at pH 5, 6 mmol LL?1 of O,O′-dibenzoyl-(2S,3S)-tartaric acid ((+)-DBTA) as the extractant in octanol as the liquid membrane, and deionised water as the stripping solution. Equal flow-rates of feed and stripping solutions of 100 mL minL?1 were adjusted in a batch operation mode for 50 min at ambient temperature. From the calculation, the equilibrium constants of extraction (K ex) and mass transfer coefficients in the feed phase (k f) and in the liquid membrane phase (k m) were found to be 1.81 L mmol?2, 3.50 × 10?2 cm s?1, and 1.40 × 10?2 cm s?1, respectively. Finally, the change in concentrations of d,l-phenylalanine over time in the feed and stripping solutions by mathematical model were estimated and compared with the experimental results. The values thus calculated were in agreement with the experimental data with the average deviation of approximately 3 %. 相似文献
49.
The effectiveness and usefulness of further enhancing the shock resolution of a second‐order accurate scheme for open‐channel flows by using an adaptive grid is investigated. The flux‐difference‐splitting (FDS) scheme based on the Lax–Wendroff numerical flux is implemented on a fixed as well as on a self‐adjusting grid for this purpose. The grid‐adjusting procedure, developed by Harten and Hyman, adjusts the grid by averaging the local characteristic velocities with respect to the signal amplitude in such a way that a shock always lies on a mesh point. This enables a scheme capable of perfectly resolving a stationary shock to capture a shock that moves from mesh point to mesh point. The Roe's approximate Jacobian is used for conservation and consistency, while theoretically sound treatment for satisfying entropy inequality conditions ensures physically realistic solutions. Details about inclusion of source terms, often left out of analyses for the homogeneous part of governing equations, are also explained. The numerical results for some exacting problems are compared with analytical as well as experimental results for examining improvements in resolution of discontinuities by the adaptive grid. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
50.
Takashi Kakue Mitsuo Kuwamura Yuki Shimozato Tatsuki Tahara Yasuhiro Awatsuji Kenzo Nishio Shogo Ura Toshihiro Kubota Osamu Matoba 《Optical Review》2011,18(1):180-183
We propose an in-line color digital holography that can suppress a 0th-order diffraction image and a conjugate image. This
technique reconstructs the image of an object from two holograms that are formed at two different distances from the object
for each primary color. We numerically simulated the proposed technique and confirmed that it enabled the reconstruction of
higher-quality images of an object than the Fresnel transform alone, which is the simplest reconstruction algorithm in digital
holography. The effectiveness of the proposed technique was also quantitatively shown by evaluating the reconstructed images
using root-mean-square errors. Thus, it was confirmed that the proposed technique was capable of recording and reconstructing
both three-dimensional information and color information of an object. 相似文献