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91.
In this paper an alternative approach for measurement of στ product for 4
F
3/2→4
I
11/2 transition of Nd3+ doped YVO4 crystal is reported. In this method a microchip laser is formed by keeping a small piece of the sample in plane-plane resonator
and a diode laser (808 nm) is used for pumping. The pump power induced thermal lensing effect is used to make the cavity stable.
The cavity mode area is estimated by measuring the thermal lens focal length at the threshold and the average pump area is
measured by Gaussian fit to the intensity profiles of the pump beam. The value of στ product of Nd:YVO4 crystal obtained by this method is within 10% of the reported values. The advantage of this method is that it is a simple
method for direct measurement of στ product of laser crystals. 相似文献
92.
Cheol Mun Myung-Sun Choi Han-Kyu Park 《Vehicular Technology, IEEE Transactions on》2001,50(5):1312-1317
The bit error rate (BER) performance and the characteristics of a two-dimensional (2-D) RAKE receiver operating in a correlated frequency-selective Nakagami-fading environment are analyzed. Correlated fading between array elements whose fading statistics are identical across the same RAKE branch, as well as an arbitrary number of RAKE-branches with arbitrary finding statistics, are assumed. We derived an approximated signal-to-noise ratio (SNR) statistics for one RAKE branch with correlated multiple antennas, which is extended to that for multiple RAKE branches with arbitrary fading statistics, i.e., a 2-D RAKE receiver. The receiver's performance and characteristics are analyzed using the cumulative distribution function of the SNR at the 2-D RAKE receiver output and the BER under various conditions, Numerical results show that the improvement In performance of the 2-D RAKE receiver is brought about by the average SNR and diversity gains, which are identified by two parameters specifying the gamma distribution of SNR 相似文献
93.
Demonstration of Time‐ and Wavelength‐Division Multiplexed Passive Optical Network Based on VCSEL Array
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Sil‐Gu Mun Eun‐Gu Lee Jie Hyun Lee Heuk Park Sae‐Kyoung Kang Han Hyub Lee Kwangok Kim Kyeong‐Hwan Doo Hyunjae Lee Hwan Seok Chung Jong Hyun Lee Sangsoo Lee Jyung Chan Lee 《ETRI Journal》2016,38(1):9-17
We demonstrate a time‐ and wavelength‐division multiplexed passive optical network system employing a vertical‐cavity surface‐emitting laser array–based optical line terminal transceiver and a tunable bidirectional optical subassembly–based optical network terminal transceiver. A packet error–free operation is achieved after a 40 km single‐mode fiber bidirectional transmission. We also discuss an arrayed waveguide grating, a photo detector array based on complementary metal–oxide–semiconductor photonics technologies, and low‐cost key devices for deployment in access networks. 相似文献
94.
Observation of insulating–insulating monoclinic structural transition in macro‐sized VO2 single crystals [Phys. Status Solidi RRL 5, No. 3, R107–R109 (2011)]
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Bongjin Simon Mun Kai Chen Youngchul Leem Catherine Dejoie Nobumichi Tamura Martin Kunz Zhi Liu Michael E. Grass Changwoo Park Joonseok Yoon Y. Yvette Lee Honglyoul Ju 《固体物理学:研究快报》2015,9(3):206-206
In our article, we reported the observation of monoclinic M2 to M1 structural phase transition in VO2 single crystal near the temperature of ~49 °C. However, the re‐examination of Laue patterns reveals that previously defined monoclinic M1 and M2 phases can be interpreted as monoclinic M2 and triclinic T phases instead. Careful experimental geometry calibration and further refinement of the lattice parameter ratios and angles show that monoclinic M2 and triclinic T phases fit better with the experimental data. On the other hand, our previous misidentification of the insulating phases does NOT affect the conclusions of our article. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
95.
Seungyeon Lee Sora Mun You-Rim Lee Jiyeong Lee Hee-Gyoo Kang 《Molecules (Basel, Switzerland)》2022,27(24)
Ergothioneine, which is a naturally occurring metabolite, generally accumulates in tissues and cells subjected to oxidative stress, owing to its structural stability at physiological pH; therefore, it has been attracting attention in various biomedical fields. Ergothioneine has also been suggested as a potential forensic marker, but its applicability has not yet been quantitatively validated. In this study, quantitative analysis of ergothioneine in bloodstains was conducted to estimate the age of bloodstains and that of bloodstain donors. Blood from youth and elderly participants was used to generate bloodstains. After extracting metabolites from the bloodstains under prevalent age conditions, ergothioneine levels were quantified by mass spectrometry via multiple reaction monitoring. The concentration of ergothioneine in day 0 bloodstains (fresh blood), was significantly higher in the elderly group than in the youth group, but it did not differ by sex. Statistically significant differences were observed between the samples from the two age groups on days 0, 5 and 7, and on days 2 and 3 compared with day 0. The findings suggest that ergothioneine can be used to estimate the age of bloodstains and of the donor; it could be useful as a potential marker in reconstructing crime scenes. 相似文献
96.
Jong Min Oh Hyun-Jae Jang Myung-Gyun Kang Seul-Ki Mun Daeui Park Su-Jin Hong Min Ha Kim Soo-Young Kim Sung-Tae Yee Hoon Kim 《Molecules (Basel, Switzerland)》2023,28(1)
Thirteen compounds were isolated from the Canavalia lineata pods and their inhibitory activities against human monoamine oxidase-A (hMAO-A) and -B (hMAO-B) were evaluated. Among them, compounds 8 (medicarpin) and 13 (homopterocarpin) showed potent inhibitory activity against hMAO-B (IC50 = 0.45 and 0.72 µM, respectively) with selectivity index (SI) values of 44.2 and 2.07, respectively. Most of the compounds weakly inhibited MAO-A, except 9 (prunetin) and 13. Compounds 8 and 13 were reversible competitive inhibitors against hMAO-B (Ki = 0.27 and 0.21 µM, respectively). Structurally, the 3-OH group at A-ring of 8 showed higher hMAO-B inhibitory activity than 3-OCH3 group at the A-ring of 13. However, the 9-OCH3 group at B-ring of 13 showed higher hMAO-B inhibitory activity than 8,9-methylenedioxygroup at the B-ring of 12 (pterocarpin). In cytotoxicity study, 8 and 13 showed non-toxicity to the normal (MDCK) and cancer (HL-60) cells and moderate toxicity to neuroblastoma (SH-SY5Y) cell. Molecular docking simulation revealed that the binding affinities of 8 and 13 for hMAO-B (−8.7 and −7.7 kcal/mol, respectively) were higher than those for hMAO-A (−3.4 and −7.1 kcal/mol, respectively). These findings suggest that compounds 8 and 13 be considered potent reversible hMAO-B inhibitors to be used for the treatment of neurological disorders. 相似文献
97.
Dr. Mostakim SK Dr. Soumitra Barman Shounik Paul Ratnadip De Dr. S. S. Sreejith Dr. Helge Reinsch Dr. Maciej Grzywa Dr. Norbert Stock Prof. Dr. Dirk Volkmer Dr. Shyam Biswas Prof. Dr. Soumyajit Roy 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(12):4098-4107
A Zr-based metal-organic framework has been synthesized and employed as a catalyst for photochemical carbon dioxide reduction coupled with water oxidation. The catalyst shows significant carbon dioxide reduction property with concomitant water oxidation. The catalyst has broad visible light as well as UV light absorption property, which is further confirmed from electronic absorption spectroscopy. Formic acid was the only reduced product from carbon dioxide with a turn-over frequency (TOF) of 0.69 h−1 in addition to oxygen, which was produced with a TOF of 0.54 h−1. No external photosensitizer is used and the ligand itself acts as the light harvester. The efficient and selective photochemical carbon dioxide reduction to formic acid with concomitant water oxidation using Zr-based MOF as catalyst is thus demonstrated here. 相似文献
98.
Se Hwan Mun Peter Sang Uk Park Kyung-Hyun Park-Min 《Experimental & molecular medicine》2020,52(8):1239
Colony-stimulating factor 1 receptor (CSF1R, also known as c-FMS) is a receptor tyrosine kinase. Macrophage colony-stimulating factor (M-CSF) and IL-34 are ligands of CSF1R. CSF1R-mediated signaling is crucial for the survival, function, proliferation, and differentiation of myeloid lineage cells, including osteoclasts, monocytes/macrophages, microglia, Langerhans cells in the skin, and Paneth cells in the intestine. CSF1R also plays an important role in oocytes and trophoblastic cells in the female reproductive tract and in the maintenance and maturation of neural progenitor cells. Given that CSF1R is expressed in a wide range of myeloid cells, altered CSF1R signaling is implicated in inflammatory, neoplastic, and neurodegenerative diseases. Inhibiting CSF1R signaling through an inhibitory anti-CSF1R antibody or small molecule inhibitors that target the kinase activity of CSF1R has thus been a promising therapeutic strategy for those diseases. In this review, we cover the recent progress in our understanding of the various roles of CSF1R in osteoclasts and other myeloid cells, highlighting the therapeutic applications of CSF1R inhibitors in disease conditions.Subject terms: Osteoimmunology, Cell signalling, Targeted bone remodelling, Differentiation 相似文献
99.
Wireless Personal Communications - A super-connected society is emerging in which things and things or people and things communicate with each other through the Internet of Things. Since devices in... 相似文献
100.
Chang-Joo Kim Young-Su Kim Goo-Young Jeong Jae-Kyung Mun Hyuck-Jae Lee 《ETRI Journal》1996,17(4):25-35
This paper derives the symbol error probability for quadrature amplitude modulation(QAM) with L-fold space diversity in Rayleigh fading channels. Two combining techniques, maximal ratio combining(MRC) and selection combining(SC), are considered. The formula for MRC space diversity is obtained by averaging the symbol error probability of M-ary QAM in an additive white Gaussian noise(AWGN) channel over a chi-square distribution with 2L degrees of freedom. The obtained formula overcomes the limitations of the earlier work, which has been limited only to deriving the symbol error rate(SER) of QAM with two branch MRC space diversity. The formula for SC space diversity is obtained by averaging the symbol error probability of M-ary QAM in an AWGN channel over the distribution of the maximum signal-to-noise ratio among all of the diversity channels for SC space diversity. No analysis for QAM with SC space diversity has been reported yet. Analytical results show that the probability of error decreases with the order of diversity. We can also see that the incremental diversity gain per additional branch decreases as the number of branches becomes larger. On the other hand, the performance of 16 QAM with MRC becomes much better than that of SC as the number of branches becomes larger. By giving the order of diversity, L, and the number of signal points, M, we have been able to obtain the SER performance of QAM with general space diversity. These results can be used to determine the order of diversity to achieve the desired SER in land mobile communication system employing QAM modulation. 相似文献