• Current Optics and Photonics
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• 제6권1호
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• pp.23-31
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• 2022

Heterodyne efficiency is an indicator to evaluate the performance of space coherent laser communication systems. It is affected by signal light and local oscillator (LO) light amplitude, phase and polarization state. In this paper, based on the common heterodyne efficiency, a heterodyne efficiency model that can reflect polarization aberration of optical system is proposed. The heterodyne efficiency is analyzed when the signal light and the LO light are linearly polarized or circularly polarized. For a coherent communication optical system, when the incident signal light is right-circularly polarized light and the incident LO light is 45° linear polarized light. Based on the three-dimensional ray tracing theory and the heterodyne efficiency proposed in this paper, the change of polarization states and the distribution of heterodyne efficiency of the signal light and LO light influenced by the optical system's polarization aberration are analyzed. Analysis shows that the heterodyne efficiency model proposed in this paper can be used to evaluate coherent communication systems and reflect the influence of optical system polarization aberration.

• Current Optics and Photonics
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• 제8권1호
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• pp.56-64
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• 2024

In response to the current situation where general methods cannot effectively compensate for the phase delay of ordinary optical mixers, a multi-layer spatial beam-splitting optical mixer is designed using total reflection triangular prisms and polarization beam splittings. The phase delay is generated by the wave plate, and the mixer can use the existing parallel plates in the structure to individually compensate for the phase of the four output beams. A mixer model is established based on the structure, and the influence of the position and orientation of the optical components on the phase delay is analyzed. The feasibility of the phase compensation method is simulated and analyzed. The results show that the mixer can effectively compensate for the four outputs of the optical mixer over a wide range. The mixer has a compact structure, good performance, and significant advantages in phase error control, production, and tuning, making it suitable for free-space coherent optical communication systems.

• Journal of Microbiology and Biotechnology
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• 제24권10호
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• pp.1346-1353
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• 2014

In the present study, an anthraquinone derivative, questinol was successfully isolated from the broth extract of the marine-derived fungus Eurotium amstelodami for the first time. The structure of questinol was determined based on the analysis of the MS and NMR spectral data as well as comparison of those data with the published data. Moreover, the anti-inflammatory effect of questinol in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells was investigated. The results showed that questinol did not exhibit cytotoxicity in LPS-stimulated RAW 264.7 cells up to $200{\mu}M$. Questinol could significantly inhibit NO and $PGE_2$ production at indicated concentrations. Questinol was also found to inhibit the production of pro-inflammatory cytokines, including TNF-${\alpha}$, IL-1${\beta}$, and IL-6. Furthermore, the western blot analysis showed that questinol suppressed the expression level of iNOS in a dose-dependent manner. However, questinol could slightly inhibit the expression of COX-2 at the concentration of $200{\mu}M$. Therefore, our study suggests that questinol might be selected as a promising agent for the prevention and therapy of inflammatory disease.

• Journal of Ginseng Research
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• 제41권3호
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• pp.411-418
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• 2017

Background: Recently, protein from ginseng was studied and used for the treatment of several kinds of diseases. However, the effect of ginseng total protein (GTP) on proliferation and wound healing in fibroblast cells remains unclear. Methods: In this study, cell viability was analyzed using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. Cell cycle distribution was analyzed by flow cytometer. The levels of transforming growth factor ${\beta}1$, vascular endothelial growth factor, and collagens were analyzed by enzyme-linked immunosorbent assay and immunofluorescence staining. The expressions of cyclin A, phosphorylation of extracellular signal-related kinase (p-ERK1/2), and ERK1/2 were analyzed by Western blotting. Results: Our results showed that GTP promoted cell proliferation and increased the percentage of cells in S phase through the upregulation of cyclin A in NIH/3T3 cells. We also found that GTP induced the secretion of type I collagen, and promoted the expression of other factors that regulate the synthesis of collagen such as transforming growth factor ${\beta}1$ and vascular endothelial growth factor. In addition, the phosphorylation of ERK1/2 at Thr202/Tyr204 was also increased by GTP. Conclusion: Our studies suggest that GTP promoted proliferation and secretion of collagen in NIH/3T3 cells by activating the ERK signal pathway, which shed light on a potential function of GTP in promoting wound healing.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.160.5-160
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• 2001

In the paper, a cruise control system developed for the automobile with automated mechanical transmission (AMT) is introduced. After the AMT is concisely depicted, the paper details the functions, the points of the work, the principle of operation and the design course of the cruise control system.

• Food Science and Biotechnology
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• 제17권1호
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• pp.118-122
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• 2008

The use of tartary buckwheat flour as a source of dietary rutin has been limited because of the enzymatic degradation of rutin during the dough-making process, which results in a bitter taste. A variety of pretreatment regimes, including heating, steaming, boiling, and extruding, were evaluated in relation to the inactivation of the rutin-degrading enzyme responsible for rutin loss and color change during dough-making. Steaming (120 see), boiling (90 see) buckwheat grains, or extruding (180 rpm/min at $140^{\circ}C$) the flour resulted in the retention of >85% of the original rutin and eliminated the bitter taste in the hydrated flours. In contrast, dry heating at $140^{\circ}C$ for 9 min or microwaving at 2,450 MHz for 3 min did not reduce the rutin loss, and the bitter taste remained. Unlike in the flour, the rutin degradation in water-soaked grains was insignificant at room temperature. Moreover, the samples treated by steaming, boiling, or extrusion were darker and more reddish in color.

• Journal of the Optical Society of Korea
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• 제20권2호
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• pp.251-256
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• 2016

The prediction of thermal effects in lithography projection objective plays a significant role in the real-time dynamic compensation of thermal aberrations. For the illuminated lithography projection objective, this paper applies finite element analysis to get the temperature distribution, surface deformation and stress data. To improve the efficiency, a temperature distribution function model is proposed to use for the simulation of thermal aberrations with the help of optical analysis software CODE V. SigFit is approved integrated optomechanical analysis software with the feature of calculating OPD effects due to temperature change, and it is utilized to prove the validation of the temperature distribution function. Results show that the impact of surface deformation and stress is negligible compared with the refractive index change; astigmatisms and 4-foil aberrations dominate in the thermal aberration, about 1.7 λ and 0.45 λ. The system takes about one hour to reach thermal equilibrium and the contrast of the imaging of dense lines get worse as time goes on.

• The Korean Journal of Ceramics
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• 제3권3호
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• pp.187-190
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• 1997

The aluminum-magnesium (Al-Mg) aklloys have been proved to be an effective solvent for synthesis of cubic-phase boron nitride (cBN) from hexagonal-phase boron nitride (hBN) at the conditions of high pressures and high temperatures (HP/HT). Various kinds of hBN powders having different crystallinity have been tested for cBN synthesis with Al-Mg solvents. The conversion ratio from hBN to cBN and the shape of synthesized cBN crystals appeared to be affected strongly by chemical composition and added amount of Al-Mg solvents as well as crystallinity of BN powders. As the magnesium content increased in the Al-Mg solvents, the conversion ratio increased and the size of cBN crystals became larger. The crystal facets developed well in the specimens with solvents having high Mg content. It was observed that a hBNlongrightarrowcBN transformation occurred more easily in the specimens having well crystallized hBN powders. Amorphous BN having much $B_2O_3$ impurity exhibited a low threshold temperature for transformation to cBN, which was attributed to crystallization of amorphous BN to well crystallized hBN prior to transformation into cBN with help of $B_2O_3$.

• Structural Engineering and Mechanics
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• 제52권5호
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• pp.903-918
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• 2014

Large space structures may have resonant low eigenvalues and often these appear with closely-spaced natural frequencies. Owing to the coupling among modes with closely-spaced natural frequencies, each eigenvector corresponding to closely-spaced eigenvalues is ill-conditioned that may cause structural instability. The subspace to an invariant subspace corresponding to closely-spaced eigenvalues is well-conditioned, so a method is presented to design the feedback control law of intelligent structures with closely-spaced eigenvalues in this paper. The main steps are as follows: firstly, the system with closely-spaced eigenvalues is transformed into that with repeated eigenvalues by the spectral decomposition method; secondly, the computation for the linear combination of eigenvectors corresponding to repeated eigenvalues is obtained; thirdly, the feedback control law is designed on the basis of the system with repeated eigenvalues; fourthly, the system with closely-spaced eigenvalues is regarded as perturbed system on the basis of the system with repeated eigenvalues; finally, the feedback control law is applied to the original system, the first order perturbations of eigenvalues are discussed when the parameter modifications of the system are introduced. Numerical examples are given to demonstrate the application of the present method.

• Current Optics and Photonics
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• 제1권5호
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• pp.538-543
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• 2017

Progressive addition lenses (PAL) have very wide application in the modern glasses market. The unique progressive surface can make a lens have progressive refractive power, which can meet the human eye's different needs for distance-vision and near-vision. According to the national glasses fabrication standard, the difference between actual optical power after fabrication and nominal design value should be less than 0.1D over the lens effective area. The optical power distribution of PAL is determined directly by the surface. Consequently, the surface processing accuracy requirement is proposed. Beginning from the surface expressions of progressive addition lenses, the relationship equations between the surface sag and optical power distribution are derived. They are demonstrated through tolerance analysis and test of an example progressive addition lens with addition of 2.09D (5.46D-7.55D). The example addition surface is fabricated under given accuracy by a single-point diamond ultra-precision machine. The optical power of the PAL example is tested with a focal-meter after fabrication. The optical power addition difference between test result and design nominal value is 0.09D, which is less than 0.1D. The derived relationship between the surface error and optical power is verified from the PAL example simulation and test result. It can provide theoretical tolerance analysis proof for the PAL surface fabricating process.