摘要 :
Polymer-stabilized liposome systems and non-polymer-stabilized (conventional) liposome systems were investigated for particle size, lipid assoication, micropolarity, and migration of a fluoresent probe between lipid bilayers. The ...
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Polymer-stabilized liposome systems and non-polymer-stabilized (conventional) liposome systems were investigated for particle size, lipid assoication, micropolarity, and migration of a fluoresent probe between lipid bilayers. The size difference between the two types of liposome systems prepared with identical procedure was determined using light scattering method. NMR spectroscopic analysis using deuterium-labeled lipids showed that under the set conditions all lipids in both Polymer-stabilized and conventional liposome systems become associated. Environmental micropolarity assessment of Pyrene showed that the probe localizes within the lipid bilayers of both polymer-stabilized and conventional liposome Systems. Further investigation revealed that the bilayers of both systems were mobile enough to permit migration of the Probe into neighboring unlabeled liposome bilayers.
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摘要 :
According to methodology of damage mechanics, the conservative integral, stress and strain concentration factors and closed form solution of fatigue crack initi- ation lives of notched plates are established. For aluminum alloy, t...
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According to methodology of damage mechanics, the conservative integral, stress and strain concentration factors and closed form solution of fatigue crack initi- ation lives of notched plates are established. For aluminum alloy, the agreement be- tween the results of theoretical predictions and those by experiments is satifactory. This method is very time - saving and a lot of experimental work can be Substituted. So this method is in engineering practice.
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A recombinant thermostable β-galactosidase from Bacillus stearothermophilus was immobilized onto chi-tosan using Tris(hydroxymethyl)phosphine (THP) and glutaraldehyde, and a packed bed reactor was utilized to hydrolyze lactose in...
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A recombinant thermostable β-galactosidase from Bacillus stearothermophilus was immobilized onto chi-tosan using Tris(hydroxymethyl)phosphine (THP) and glutaraldehyde, and a packed bed reactor was utilized to hydrolyze lactose in milk. The thermostability and enzyme activity of THP-immobilized 3-galactosidase during storage was superior to that of free and glutar-aldehyde-immobilized enzymes. The THP-immobilized β-galactosidase showed greater relative activity in the presence of Ca~(2+) than the free enzyme and was stable during the storage at 4℃ for 6 wk, whereas the free enzyme lost 31% of the initial activity under the same storage conditions. More than 80% of lactose hydrolysis in milk was achieved after 2 h of operation in the reactor. Therefore, THP-immobilized recombinant thermostable β-galactosidase from Bacillus stearothermophilus has the potential for application in the production of lactose-hydrolyzed milk.
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We report measurements of the atomic form factor of lithium, beryllium, and aluminum single crystals at low-momentum transfers (Q=1.6-50 nm~(-1)) from the intensity of phonons observed by inelastic x-ray scattering. Comparing to H...
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We report measurements of the atomic form factor of lithium, beryllium, and aluminum single crystals at low-momentum transfers (Q=1.6-50 nm~(-1)) from the intensity of phonons observed by inelastic x-ray scattering. Comparing to Hartree-Fock calculations,
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The Fe-projected vibrational density of states g(E) in nanoscale ~(57)Fe/M multilayers, where M=Cr, Co, Cu, Pd, or Ag was measured by nuclear resonant inelastic x-ray scattering. With decreasing Fe thickness, the high-energy phono...
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The Fe-projected vibrational density of states g(E) in nanoscale ~(57)Fe/M multilayers, where M=Cr, Co, Cu, Pd, or Ag was measured by nuclear resonant inelastic x-ray scattering. With decreasing Fe thickness, the high-energy phonon peak of Fe near 36 meV
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Sliding crack model is employed to simulate the strength of rock material under dynamic triaxial compressive loads. Stress intensity factor of crack array considered is estimated by pseudo-traction method. A dynamic crack growth c...
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Sliding crack model is employed to simulate the strength of rock material under dynamic triaxial compressive loads. Stress intensity factor of crack array considered is estimated by pseudo-traction method. A dynamic crack growth criterion is used in the analysis. The simulated strengths of a granite obtained by the sliding crack model agree with the experimental resu1ts.
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We report the study of temperature- and magnetic-field dependent in-plane tunneling conductance on the electron-doped Nd_(1. 85)Ce_(0.15)CuO_(4-y). and Pr_(1-x)LaCe_xCuO(4-y) single crystals. The previously reported normal state g...
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We report the study of temperature- and magnetic-field dependent in-plane tunneling conductance on the electron-doped Nd_(1. 85)Ce_(0.15)CuO_(4-y). and Pr_(1-x)LaCe_xCuO(4-y) single crystals. The previously reported normal state gap (NSG) Δ_(ps) and superconducting gap Δ_(sc) were observed simultaneously in superconducting state. Combined with an investigation on the evolution of low-energy spectral weight with temperature, our data present evidence for electron-doped cuprates that Δ_(ps)and Δ_(sc) are most possibly two different energy scales with very different field dependencies, and that superconductivity is condensed from the residual quasiparticle density of states (DOS) of the NSG state.
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ZnO films were grown under different oxygen partial pressures by metal organic chemical vapor deposition on the substrates of Corning glass. We investigated the quality of the films by SIEMENS D8 X-ray diffractometer. The surface ...
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ZnO films were grown under different oxygen partial pressures by metal organic chemical vapor deposition on the substrates of Corning glass. We investigated the quality of the films by SIEMENS D8 X-ray diffractometer. The surface morphology of the films were observed by Digital Nanoscope IIIa AFM with normal silicon nitride tip in the contact mode. The hall effect measurements were carried out with indium ohmic contact. The transmission spectrum of the films were measured. The transmission ratio is larger than 80% in the region above the wavelength of 385nm, and sharply decreased under 10% below the wavelength of 375 nm.
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Carrier recombination lifetime measurements and analyses based on Shockley-Read-Hall, radiative, and Auger recombination mechanisms were utilized to characterize the material quality of HgCdTe grown by molecular beam epitaxy. The ...
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Carrier recombination lifetime measurements and analyses based on Shockley-Read-Hall, radiative, and Auger recombination mechanisms were utilized to characterize the material quality of HgCdTe grown by molecular beam epitaxy. The Auger recombination mechanism employed in this analysis is in the theoretical framework according to Beattie and Landsberg [Proc. R. Soc. London, Ser. A 249, 16 (1959)], which we independently re-evaluated using the electronic band structures computed with a 14-band k·p methodology and direct evaluations of the transition rates. The Levenberg-Marquette method was used to fit the temperature-dependent carrier recombination lifetimes as measured by the photoconductive decay technique. Based on the above methods, carrier recombination lifetime measurements were developed as a routine characterization technique.
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Relationships between melt heat treatment and undercooling of al1oy melts were clarified with Bi_95Sb_5 through four-factor, three-level orthogonal experiments. The results show that the cooling rate plays the most important role ...
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Relationships between melt heat treatment and undercooling of al1oy melts were clarified with Bi_95Sb_5 through four-factor, three-level orthogonal experiments. The results show that the cooling rate plays the most important role in the undercooling of Bi_95Sb_5, alloy melts. Undercooling as large as l21 K was obtained in the bulk Bi_95Sb_5, alloy melt. It is presently the highest undercooling of this alloy system. A metastable phase with tetragonal structure was found in the Bi_95Sb_5, alloy with undercooling of l2l K.
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