http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Yoon, K.,Hwang, G.,Chung, J.,Kim, H.g.,Kwon, O.,Kihm, K.D.,Lee, J.S. Pergamon Press ; Elsevier Science Ltd 2014 Carbon Vol.76 No.-
Despite the importance of the accurate measurement of the thermal conductivity of graphene, deviations in previous data are still quite large due to the low signal-to-noise ratio in the measurement of graphene temperature, the uncertainties in the measurement of the heat dissipation, and the influence of the polymeric residues. Herein, we improve signal-to-noise ratio by using null point scanning thermal microscopy, which profiles temperature quantitatively with nanoscale spatial resolution (~50nm), independently of both the heat flux through the air and the variation of the sample surface properties. Also, we control and monitor the heat generation rate accurately by heating the suspended graphene bridge electrically. Furthermore, we prevent the disturbance of the thermal conductivity caused by the polymeric residues by using polydimethylsiloxane stamping method, which leaves much less residue than using polymethylmethacrylate. The thermal conductivity values of graphene, whose length and width are 3.6 and 5.52μm, respectively, were measured as 2430+/-190, 2150+/-170, and 2100+/-160W/mK at the peak temperatures of 335, 361, and 366K, respectively, with much smaller error range compared to the previously reported values. The measured values exceed the highest value (~2000W/mK at room temperature) obtained for graphite.
Phase-sensitive imaging of diffracted light by single nanoslits: measurements from near to far field
Kihm, Hyun-woo,Kihm, Q. H.,Kim, D. S.,Ahn, K. J.,Kang, J. H. The Optical Society 2010 Optics express Vol.18 No.15
<P>We perform phase-sensitive imaging of optical wavefront emanating from a single nanoslit and propagating into free space by using scattering type near-field scanning optical microscope combined with an optical interferometer. By analyzing polarization resolved optical amplitudes and phases, the propagation directions of surface waves are determined and the phase difference between two orthogonal polarization components of the surface wave are discussed for increasing distance from the slit.</P>
Optical Tracking of Three-Dimensional Brownian Motion of Nanoparticles
C. K. Choi,K. D. Kihm 한국가시화정보학회 2005 한국가시화정보학회지 Vol.3 No.1
Novel optical techniques are presented for three-dimensional tracking of nanoparticles; Optical Serial Sectioning Microscopy (OSSM) and Ratiometric Total Internal Reflection Fluorescent Microscopy (R-TIRFM). OSSM measures optically diffracted particle images, the so-called Point Spread Function (PSF), and determines the defocusing or line-of-sight location of the imaged particle measured from the focal plane. The line-of-sight Brownian motion detection using the OSSM technique is proposed in lieu of the more cumbersome two-dimensional Brownian motion tracking on the imaging plane as a potentially more effective tool to nonintrusively map the temperature fields for nanoparticle suspension fluids. On the other hand, R-TIRFM is presented to experimentally examine the classic theory on the near-wall hindered Brownian diffusive motion. An evanescent wave field from the total internal reflection of a 488-㎚ bandwidth of an argon-ion laser is used to provide a thin illumination field of an order of a few hundred nanometers from the wall. The experimental results show good agreement with the lateral hindrance theory, but show discrepancies from the normal hindrance theory. It is conjectured that the discrepancies can be attributed to the additional hindering effects, including electrostatic and electro-osmotic interactions between the negatively charged tracer particles and the glass surface.
Optical Tracking of Three-Dimensional Brownian Motion of Nanoparticles
Choi C. K.,Kihm K.D. The Korean Society of Visualization 2005 한국가시화정보학회지 Vol.3 No.1
Novel optical techniques are presented for three-dimensional tracking of nanoparticles; Optical Serial Sectioning Microscopy (OSSM) and Ratiometric Total Internal Reflection Fluorescent Microscopy (R-TIRFM). OSSM measures optically diffracted particle images, the so-called Point Spread Function (PSF), and dotermines the defocusing or line-of-sight location of the imaged particle measured from the focal plane. The line-of-sight Brownian motion detection using the OSSM technique is proposed in lieu of the more cumbersome two-dimensional Brownian motion tracking on the imaging plane as a potentially more effective tool to nonintrusively map the temperature fields for nanoparticle suspension fluids. On the other hand, R-TIRFM is presented to experimentally examine the classic theory on the near-wall hindered Brownian diffusive motion. An evanescent wave field from the total internal reflection of a 488-nm bandwidth of an argon-ion laser is used to provide a thin illumination field of an order of a few hundred nanometers from the wall. The experimental results show good agreement with the lateral hindrance theory, but show discrepancies from the normal hindrance theory. It is conjectured that the discrepancies can be attributed to the additional hindering effects, including electrostatic and electro-osmotic interactions between the negatively charged tracer particles and the glass surface.
Park, T.-Y.S.,Kihm, J.-H.,Kang, I.,Choi, D.K. THE PALEONTOLOGICAL SOCIETY 2014 Journal of paleontology Vol.88 No.2
The Order Asaphida was grouped by the presence of a ventral median suture and a globular protaspis. The Superfamily Trinucleoidea has been assigned to the Order Asaphida, based on the recognition of a globular protaspis in the Ordovician representatives of the group, and the presence of a ventral median suture in the middle Cambrian genus Liostracina which has been regarded as a primitive sister-group to the post-Cambrian trinucleoideans. Recent studies demonstrate that the ventral median suture and the globular protaspis could have evolved multiple times in the trilobite evolutionary history, casting doubt on the traditional concept of the Order Asaphida. Inclusion of the Trinucleoidea into the Order Asaphida, therefore, has to be tested. It has recently been revealed that Liostracina simesi Jago and Cooper, 2005 did not possess a Ventral median suture, implying that there could have been variable types of ventral suture within the genus Liostracina. Here we report the ontogeny of Liostracina tangwangzhaiensis n. sp. from the Cambrian Series 3 (middle Cambrian) strata of Shandong Province of North China. The material for this study includes protaspides, which are of flat, benthic morphology, contrasting to the globular protaspid morphology of the Ordovician trinucleoideans. The benthic protaspid morphology of L. tangwangzhaiensis indicates an independent evolution of the globular protaspis within the Superfamily Trinucleoidea. Together with the variable types of ventral suture within the genus Liostracina, the benthic protaspid morphology of Liostracina leads us to propose that the Superfamily Trinucleoidea be excluded from the Order Asaphida.