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11.
Sun-Kuk Kim Jeong Tai Kim Hee-Cheul Kim Kyong-Yop Rhee John Kathi 《Journal of Macromolecular Science: Physics》2013,52(4):750-756
Miscibility studies of unsaturated polyester resin (UPR) blends with two different thermoplastics—polystyrene (PS) and polycarbonate (PC), in a common solvent, chloroform, were carried out by viscosity, ultrasonic velocity, density, and refractive index methods. Two interaction parameters, μ and α were calculated using viscosity data for these blends. The positive interaction parameter values (μ and α > 0) obtained for the UPR/PS blend and the negative interaction parameter values (μ and α < 0) obtained for the UPR/PC blend indicate that the former is a miscible blend and the latter is an immiscible blend. These results were further confirmed by the ultrasonic velocity, density, and refractive index measurements. 相似文献
12.
A. Hussain C.W. Ahn H.J. Lee I.W. Kim J.S. Lee S.J. Jeong S.K. Rout 《Current Applied Physics》2010,10(1):305-310
We have fabricated lead-free Bi0.5(Na0.75K0.25)0.5TiO3 (BNKT) ceramics by a conventional process (CP) and reactive templated grain growth (RTGG) methods. The effect of grain orientation on structure, dielectric, complex impedance and electrical properties was investigated. The phase formation and grain morphology of BNKT ceramics were examined by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. High dielectric constant and low dielectric loss was observed for grain oriented (textured) BNKT ceramics. Complex impedance, temperature dependent ac and dc conductivity were performed to explore the conduction behavior of the prepared BNKT ceramics. 相似文献
13.
Characterization of mitochondria isolated from normal and ischemic hearts in rats utilizing atomic force microscopy 总被引:1,自引:0,他引:1
Lee GJ Chae SJ Jeong JH Lee SR Ha SJ Pak YK Kim W Park HK 《Micron (Oxford, England : 1993)》2011,42(3):299-304
Mitochondria play critical roles in both the life and the death of cardiac myocytes. Various factors, such as the loss of ATP synthesis and increase of ATP hydrolysis, impairment in ionic homeostasis, formation of reactive oxygen species (ROS), and release of proapoptotic proteins are related to the generation of irreversible damage. It has been proposed that the release of cytochrome c is caused by a swelling of the mitochondrial matrix triggered by the apoptotic stimuli. However, there is a controversy about whether or not the mitochondria, indeed, swell during apoptosis. The major advantages of atomic force microscopy (AFM) over conventional optical and electron microscopes for bio-imaging include the fact that no special coating and vacuum are required and imaging can be done in all environments--air, vacuum or aqueous conditions. In addition, AFM force-distance curve measurements have become a fundamental tool in the fields of surface chemistry, biochemistry, and material science. In this study, we used AFM to observe the morphological and property changes in heart mitochondria that were isolated from a rat myocardial infarction model. From the shape parameters of the mitochondria in the AFM topographic image, it seemed that myocardial infarction caused the mitochondrial swelling. Also, the results of force-distance measurements showed that the adhesion force of heart mitochondria was significantly decreased by myocardial in infarction. Therefore, we suggested that myocardial infarction might be the cause of mitochondrial swelling and the changes in outer membrane of heart mitochondria. 相似文献
14.
15.
Chunyan Cao Hyun Kyoung Yang Byung Kee Moon Jung Hyun Jeong Kwang Ho Kim 《Optics Communications》2011,284(23):5453-5456
By controlling the pH values of prepared solutions, the 10 mol% Ce3+, 5 mol% Tb3+ co-doped KGdF4 (synthesized with pH = 3) and the 10 mol% Ce3+, 5 mol% Tb3+ co-doped GdF3 (synthesized with pH = 1) submicro/nanocrystals have been synthesized based on a citric acid assisted hydrothermal method. For comparison, the samples synthesized by co-precipitation method (without hydrothermal treatment) with pH = 3 and 1 were also collected. The X-ray diffraction data illustrate that the hydrothermal treated KGdF4 sample crystallizes in the cubic phase and the GdF3 sample crystallizes in the orthorhombic phase. However, the samples synthesized by co-precipitation method with pH = 3 and 1 are both cubic phase KGdF4. The field emission scanning electron microscopy images suggest that the hydrothermal treated KGdF4 submicro/nanocrystals present spherical morphology and the GdF3 submicrocrystals are rhombic-shaped. And the photoluminescence excitation and emission spectra as well as the luminescent dynamic curves demonstrate the difference in optical properties of the two hydrothermal treated samples. 相似文献
16.
We propose the remote multiplexing of holograms with random patterns from a multimode fiber bundle used as the reference beams. The random pattern reference beam is characterized by the superposition and concatenation of propagation modes of multimode fiber and free space. For angle, shift, and wavelength remote multiplexing we compare two methods of laser coupling to the fiber bundle, i.e., direct coupling and lens coupling. A theoretical discussion that uses mode orthogonality is provided to describe multiplexing characteristics, and the theory is verified by experimental results. These remote-multiplexing methods can be applied to general multimode waveguide arrays for construction of compact and integrated optical systems in which multiplexing can be controlled remotely. 相似文献
17.
Dongshin Myung Yumin Lee Jaeyeon Lee Hak Ki Yu Jong‐Lam Lee Jeong Min Baik Woong Kim Myung Hwa Kim 《固体物理学:研究快报》2010,4(12):365-367
We present the synthesis of highly crystalline metallic rhenium trioxide (ReO3) nanowires via a simple physical vapor transport at 300 °C for the first time. Based on HRTEM, the ReO3 nanowires exhibit a core of perfect cubic perovskite‐type single crystal structure with a shell of thin amorphous and disordered structures of less than 2 nm in the near surface layers. Possibly this is due to proton intercalation induced by the surface reaction of single crystal ReO3 with water.
18.
In this study, poly(?-caprolactone)-based polyurethane (PCL-PU) nanofibers containing Ag nanoparticles for use in antimicrobial nanofilter applications were prepared by electrospinning 8 wt% PCL-PU solutions containing different amounts of AgNO3 in a mixed solvent consisting of DMF/THF (7/3 w/w). The average diameter of the pure PCL-PU nanofibers was 560 nm and decreased with increasing concentration of AgNO3. The PCL-PU nanofiber mats electrospun with AgNO3 exhibited higher tensile strength, tensile modulus, and lower elongation than the pure PCL-PU nanofiber mats. Small Ag nanoparticles were produced by the reduction of Ag+ ions in the PCL-PU solutions. The average size and number of the Ag nanoparticles in the PCL-PU nanofibers were considerably increased after being annealed at 100 °C for 24 h. They were all sphere-shaped and evenly distributed in the PCL-PU nanofibers, indicating that the PCL-PU chains stabilized the Ag nanoparticles well. 相似文献
19.
Rechtsman MC Jeong HC Chaikin PM Torquato S Steinhardt PJ 《Physical review letters》2008,101(7):073902
A photonic quasicrystal consists of two or more dielectric materials arranged in a quasiperiodic pattern with noncrystallographic symmetry that has a photonic band gap. We use a novel method to find the pattern with the widest TM-polarized gap for two-component materials. Patterns are obtained by computing a finite sum of density waves, assigning regions where the sum exceeds a threshold to a material with one dielectric constant, epsilon1, and all other regions to another, epsilon0. Compared to optimized crystals, optimized quasicrystals have larger gaps at low constrasts epsilon1/epsilon0 and have gaps that are much more isotropic for all contrasts. For high contrasts, optimized hexagonal crystals have the largest gaps. 相似文献
20.
A double lambda four-level system could be implemented with biexcitonic transitions on GaAs quantum well. We observed that the phase dependent biexcitonic transition could be explained by interference between one-photon and three-photon transition in a double lambda four-level system. An ultralow-light switch pulse could control 80% of biexcitonic absorption, which demonstrated all-optical switching with biexcitonic double lambda system. 相似文献