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871.
Jamie YuLing Han Timothy Thatt Yang Tan Joachim Say Chye Loo 《Journal of nanoparticle research》2011,13(8):3441-3454
The aim of this study was to investigate the feasibility of the inverse micelles (IM) technique in producing protein-loaded
calcium phosphate nanoparticles (CaP NPs), and to compare this technique with the conventional co-precipitation (co-ppt) technique.
In this study, bovine serum albumin and lysozyme were used as model proteins. The results show that CaP NPs produced by IM
were shown to be spherical and homogenous in size of ~50 nm. Protein loading efficiency of the IM technique was shown to be
much higher than CaP NPs synthesized through co-ppt technique. X-ray photoelectron spectroscopy shows that proteins were not adsorbed onto the surface of IM-synthesized CaP NPs, which suggested
that the proteins were entrapped within the particle matrix. Release studies show that protein release was more rapid at lower
pH conditions (pH 5 and 6) than at physiological pH of 7.4. A burst release was observed for co-ppt CaP NPs, while a continuous
release of protein was observed for IM-produced CaP NPs. This study shows the superiority of the IM technique in preparing
pH responsive CaP NPs as nano-carriers. 相似文献
872.
L. Tan L. W. Liu Y. F. Sun 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,61(1):161-169
A theoretical study is carried out for the cavity
cooling of a Λ-type three-level atom in a high-finesse
optical cavity driven by a weakly field. Analytical expressions
for the friction, diffusion coefficients and the equilibrium
temperature are obtained by using the Heisenberg equations, then
they are calculated numerically and shown graphically as functions
of the controlling parameters. For a suitable choice of these
parameters, the dynamics of the cavity field interaction with the
Λ-type three-level atom introduces a sisyphus cooling
mechanism yielding lower temperature than the one of the two-level
atom, avoiding the problems induced by spontaneous emission. 相似文献
873.
The single-molecule surface-enhanced Raman scattering(SERS) spectra of Rhodamine 6G(R6G) in an aqueous environment under non-resonance conditions are studied.Series of spectra are recorded in timemapping mode,and intensity fluctuations of SERS signals and spectral diffusion are observed.The correlations between the presence frequency of SERS spectra and number of hot spots as well as the quantity of molecules in scattering volume are examined thoroughly.The results indicate that only molecules located at hot spots produce good signal-to-noise ratio Raman spectra and the origin of fluctuating SERS signals are mainly ascribed to the movement of hot spots. 相似文献
874.
Morphology evolution of prior β grains of laser solid forming (LSF) Ti-xAl-yV (x 11,y 20) alloys from blended elemental powders is investigated. The formation mechanism of grain morphology is revealed by incorporating columnar to equiaxed transition (CET) mechanism during solidification. The morphology of prior β grains of LSF Ti-6Al-yV changes from columnar to equiaxed grains with increasing element V content from 4 to 20 wt.-%. This agrees well with CET theoretical prediction. Likewise, the grain morphology of LSF Ti-xAl-2V from blended elemental powders changes from large columnar to small equiaxed with increasing Al content from 2 to 11 wt.-%. The macro-morphologies of LSF Ti-8Al-2V and Ti-11Al-2V from blended elemental powders do not agree with CET predictions. This is caused by the increased disturbance effects of mixing enthalpy with increasing Al content, generated in the alloying process of Ti, Al, and V in the molten pool. 相似文献
875.
Y.?Tan C.?Zhang F.?ChenEmail author F.-Q.?Liu D.?Jaque Q.-M.?Lu 《Applied physics. B, Lasers and optics》2011,103(4):837-840
We report on the generation of continuous wave lasers at a wavelength of ∼1064 nm in a Nd:YAG ceramic waveguide at room temperature.
The waveguide was fabricated by using 6 MeV carbon ion implantation at a fluence of 3×1014 ions/cm2. Laser operation has been realized with a slope efficiency as high as ∼11%. The pump threshold of an 808-nm laser beam for
the waveguide laser oscillation is 19.5 mW. 相似文献
876.
Li-ion rechargeable batteries based on polymer electrolytes are of great interest for solid state electrochemical devices
nowadays. Many studies have been carried out to improve the ionic conductivity of polymer electrolytes, which include polymer
blending, incorporating plasticizers and filler additives in the electrolyte systems. This paper describes the effects of
incorporating nano-sized MnO2 filler on the ionic conductivity enhancement of a plasticized polymer blend PMMA–PEO–LiClO4–EC electrolyte system. The maximum conductivity achieved is within the range of 10−3 S cm−1 by optimizing the composition of the polymers, salts, plasticizer, and filler. The temperature dependence of the polymer
conductivity obeys the VTF relationship. DSC and XRD studies are carried out to clarify the complex formation between the
polymers, salts, and plasticizer. 相似文献
877.
Zhongkui Tan Vijay Patel Konstantin K. Likharev Dong Su Yimei Zhu 《Applied Physics A: Materials Science & Processing》2011,103(2):293-300
We have studied resistive bistability (memory) effects in junctions based on metal oxides, with a focus on sample-to-sample
reproducibility, which is necessary for the use of such junctions as crosspoint devices of hybrid CMOS/nanoelectronic circuits.
Few-nm-thick layers of NbO
x
, CuO
x
and TiO
x
have been formed by thermal and plasma oxidation, at various deposition and oxidation conditions, both with and without rapid
thermal post-annealing. The resistive bistability effect has been observed for all these materials, with particularly high
endurance (over 103 switching cycles) obtained for single-layer TiO2 junctions, and the best reproducibility reached for multi-layer junctions of the same material. Fabrication optimization
has allowed us to improve the OFF/ON resistance ratio to about 103, but the sample-to-sample reproducibility is so far lower than that required for large-scale integration. 相似文献
878.
基于稀疏非负矩阵分解和支持向量机的海洋溢油近红外光谱鉴别分析 总被引:2,自引:0,他引:2
提出一种海洋溢油近红外光谱特征提取与种类鉴别新方法.海面溢油种类鉴别对现场应急处置方案的制定和可疑溢油源的追踪具有重要意义.采用傅里叶变换近红外光谱仪测定汽油、柴油、煤油三类模拟海洋溢油样本的近红外光谱,基于稀疏非负矩阵分解算法对光谱进行特征提取,采用五重交义检验,对210个样本进行训练,建立基于支持向量机的溢油光谱定... 相似文献
879.
全反射傅里叶变换成像光谱仪ARFTIS(all-reflection Fourier transform imaging spectrometer)是基于FT成像光谱理论的一种新型仪器,它不但具有高光谱分辨率特点,而且还具有宽波段、无色差的特点,特别适合应用在宽波段成像的遥感领域.目前常用的光谱定标方法有单色法、平均法... 相似文献
880.