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392 results on '"Lin, L. H."'

1. High resolution observations of 12CO and 13CO(3--2) toward the NGC 6334 extended filament

Author

Neupane, S., Wyrowski, F., Menten, K. M., Urquhart, J., Colombo, D., Lin, L. -H., and Garay, G.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
Abstract

NGC 6334 is a giant molecular cloud complex with elongated filamentary structure, harbouring OB-stars, HII regions and star forming clumps. To study the emission and velocity structure of the gas in the extended NGC 6334 region, we made observations of the 12CO and 13CO (J=3-2) lines with the APEX telescope. The data provides a spatial resolution of 20 arcsec (~0.16 pc) and sensitivity of ~0.4 K at a spectral resolution of 0.25 km/s. Our observations reveal in the extended NGC 6334 region a connected velocity coherent structure of ~-3.9 km/s over ~80 pc parallel to the galactic plane. The NGC 6334 complex has two connected velocity structures at velocities ~ -9.2 km/s (the bridge features) and ~-20 km/s (the Northern Filament, NGC 6334-NF). We observed local velocity fluctuations at smaller spatial scales along the filament tracing local density enhancement and infall. We investigated the 13CO emission and velocity structure around HII regions and found that most HII regions show signs of molecular gas dispersal from the center and intensity enhancement at their outer radii. Overall NGC 6334 exhibits sequential star formation from west to east. Located in the west, the GM-24 region exhibits bubbles within bubbles and is at a relatively evolved stage of star formation. The NGC 6334 central ridge is undergoing global gas infall and exhibits two gas bridge features possibly connected to the cloud-cloud collision scenario of the NGC 6334-NF and the NGC 6334 main gas component. The relatively quiescent eastern filament (EF1 - G352.1) is a hub-filament in formation which shows the kinematic signature of global gas infall onto the filament. Our observations highlight the important role of H II regions in shaping the molecular gas emission and velocity structure as well as the overall evolution of the molecular filaments in NGC 6334., Comment: 38 pages, 21 figures, Accepted for publication in A&A

Published
2024

2. A search for cloud cores affected by shocked carbon chain chemistry in L1251

Author

Liu, Xunchuan, Wu, Y., Zhang, C., Chen, X., Lin, L. -H., Qin, S. -L., Liu, T., Henkel, C., Wang, J., Liu, H. -L., Yuan, J., Yuan, L. -X., Li, J., Shen, Z. -Q., Li, D., Esimbek, J., Wang, K., Li, L. -X., Kim, Kee-Tae, Zhu, L., Madones, D., Inostroza, N., Meng, F. -Y., Zhang, Tianwei, Tatematsu, K., Xu, Y., Ju, B. -G., Kraus, A., and Xu, F. -W.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics
Abstract

We searched for shocked carbon chain chemistry (SCCC) sources with C$_3$S abundances surpassing those of HC$_5$N towards the dark cloud L1251, using the Effelsberg telescope at K-band (18 -- 26\,GHz). L1251-1 and L1251-3 are identified as the most promising SCCC sources. The two sources harbor young stellar objects. We conducted mapping observations towards L1251-A, the western tail of L1251, at $\lambda$ $\sim$3\,mm with the PMO 13.7 m and the NRO 45 m telescopes in lines of C$_2$H, N$_2$H$^+$, CS, HCO$^+$, SO, HC$_3$N and C$^{18}$O as well as in CO 3--2 using the JCMT. The spectral data were combined with archival data including Spitzer and Herschel continuum maps for further analysis. Filamentary sub-structures labeled as F1 to F6 were extracted in L1251, with F1 being associated with L1251-A hosting L1251-1. The peak positions of dense gas traced by HCO$^+$ are misaligned relative to those of the dust clumps. Episodic outflows are common in this region. The twisted morphology of F1 and velocity distribution along L1251-A may originate from stellar feedback. SCCC in L1251-1 may have been caused by outflow activities originated from the infrared source IRS1. The signposts of ongoing SCCC and the broadened line widths of C$_3$S and C$_4$H in L1251-1 as well as the distribution of HC$_3$N are also related to outflow activities in this region. L1251-1 (IRS1) together with the previously identified SCCC source IRS3 demonstrate that L1251-A is an excellent region to study shocked carbon chain chemistry., Comment: 32 pages, 15 figures

Published
2021
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9. A Search for Cloud Cores Affected by Shocked Carbon Chain Chemistry in L1251

Author

Liu, X-C, Wu, Y., Zhang, C., Chen, X., Lin, L-H, Qin, S-L, Liu, T., Henkel, C., Wang, J., Liu, H-L, Yuan, J., Yuan, L-X, Li, J., Shen, Z-Q, Li, D., Esimbek, J., Wang, K., Li, L-X, Kim, Kee-Tae, Zhu, L., Madones, D., Inostroza-Pino, N., Meng, F-Y, Zhang, T., Tatematsu, K., Xu, Y., Ju, B-G, Kraus, A., Xu, F-W, Liu, X-C, Wu, Y., Zhang, C., Chen, X., Lin, L-H, Qin, S-L, Liu, T., Henkel, C., Wang, J., Liu, H-L, Yuan, J., Yuan, L-X, Li, J., Shen, Z-Q, Li, D., Esimbek, J., Wang, K., Li, L-X, Kim, Kee-Tae, Zhu, L., Madones, D., Inostroza-Pino, N., Meng, F-Y, Zhang, T., Tatematsu, K., Xu, Y., Ju, B-G, Kraus, A., and Xu, F-W

Abstract

We searched for shocked carbon chain chemistry (SCCC) sources with C3S abundances surpassing those of HC5N toward the dark cloud L1251, using the Effelsberg telescope at the K band (18-26 GHz). L1251-1 and L1251-3 are identified as the most promising SCCC sources. The two sources harbor young stellar objects. We conducted mapping observations toward L1251-A, the western tail of L1251, at lambda similar to 3 mm with the Purple Mountain Observatory 13.7 m and the Nobeyama Radio Observatory 45 m telescopes in lines of C2H, N2H+, CS, HCO+, SO, HC3N, and (CO)-O-18 as well as in CO 3-2 using the James Clerk Maxwell Telescope (JCMT). The spectral data were combined with archival data including Spitzer and Herschel continuum maps for further analysis. Filamentary substructures labeled as F1-F6 were extracted in L1251, with F1 being associated with L1251-A hosting L1251-1. The peak positions of dense gas traced by HCO+ are misaligned relative to those of the dust clumps. Episodic outflows are common in this region. The twisted morphology of F1 and velocity distribution along L1251-A may originate from stellar feedback. SCCC in L1251-1 may have been caused by outflow activities originated from the infrared source IRS1. The signposts of ongoing SCCC and the broadened line widths of C3S and C4H in L1251-1 as well as the distribution of HC3N are also related to outflow activities in this region. L1251-1 (IRS1) together with the previously identified SCCC source IRS3 demonstrate that L1251-A is an excellent region to study SCCC.

Published
2021

13. A Search for Cloud Cores Affected by Shocked Carbon Chain Chemistry in L1251

Author

Liu, X.-C., primary, Wu, Y., additional, Zhang, C., additional, Chen, X., additional, Lin, L.-H., additional, Qin, S.-L., additional, Liu, T., additional, Henkel, C., additional, Wang, J., additional, Liu, H.-L., additional, Yuan, J., additional, Yuan, L.-X., additional, Li, J., additional, Shen, Z.-Q., additional, Li, D., additional, Esimbek, J., additional, Wang, K., additional, Li, L.-X., additional, Kim, Kee-Tae, additional, Zhu, L., additional, Madones, D., additional, Inostroza-Pino, N., additional, Meng, F.-Y., additional, Zhang, T., additional, Tatematsu, K., additional, Xu, Y., additional, Ju, B.-G., additional, Kraus, A., additional, and Xu, F.-W., additional

Published
2021
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32. Hot Carriers in CVD-Grown Graphene Device with a Top h-BN Layer

Author

Chuang, C., primary, Mineharu, M., additional, Matsumoto, N., additional, Matsunaga, M., additional, Liu, C.-W., additional, Wu, B.-Y., additional, Kim, Gil-Ho, additional, Lin, L.-H., additional, Ochiai, Y., additional, Watanabe, K., additional, Taniguchi, T., additional, Liang, C.-T., additional, and Aoki, N., additional

Published
2018
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33. Photoluminescence origins of the porous silicon nanowire arrays.

Author

Lin, L. H., Sun, X. Z., Tao, R., Li, Z. C., Feng, J. Y., and Zhang, Z. J.

Subjects
*PHOTOLUMINESCENCE, *NANOWIRES, *NANOSTRUCTURED materials, *ELECTROLESS plating, *NUCLEAR excitation
Abstract

We investigate the photoluminescence (PL) behavior of the porous silicon nanowire (PSiNW) arrays synthesized via metal-assisted electroless etching method on the n-Si (100) substrate. Two PL bands with different origins dependent on the post-chemical treatments were detected. The red emission band, the peak position of which is insensitive to temperature and excitation source, is considered to originate from the excitons localized at the interface between the Si nanostructure and the oxide layer. An anomalous blue shift of the near-infrared PL band was observed when the temperature increased from 80 to 290 K. The maximum intensity appears around 160 K and the emission energy is strongly dependent on the excitation energy and power. The triplet-singlet state transition is introduced to explain the PL behavior for this emission band. The absorption spectra are also induced to confirm the PL origins. [ABSTRACT FROM AUTHOR]

Published
2011
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34. Photoluminescence characterization of GaInNAs/GaAs quantum well carrier dynamics.

Author

Ng, T. K., Yoon, S. F., Wang, S. Z., Lin, L.-H., Ochiai, Y., and Matsusue, T.

Subjects
PHOTOLUMINESCENCE, QUANTUM wells, GALLIUM arsenide, QUANTUM theory
Abstract

Variable temperature photoluminescence (PL) measurement of a thermal-annealed 6 nm GaInNAs/GaAs quantum well (QW) is carried out to understand its low-temperature carrier dynamic characteristics. It is found that the effect of carrier localization, which remained after a thermal anneal, is due possibly to a center characterized by a transition with activation energy of 13.7 meV below the e1 state. This result is deduced from fitting the integrated PL intensity versus the temperature data with a single-activation-energy model. A comparable value of 11 meV was also obtained between the low-energy (main localized state) and high-energy (e1 state) Gaussian functions used to fit the low-temperature PL spectrum. The localization effect in the thermal-annealed GaInNAs/GaAs QW is further confirmed by time-resolved PL measurements at 17 K, which showed emission-energy-dependent PL decay time characteristic for the low-energy regime (below 1.045 eV) and nearly constant decay time of about 0.14 ns at the high-energy regime, which corresponds to the e1-hh1 transition lifetime. The main localization center could form carrier traps that reduce the e1-hh1 PL transition efficiency. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2003
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36. Scientific Drilling / Workshop to develop deep-life continental scientific drilling projects

Author

Kieft, T. L., Onstott, T. C., Ahonen, L., Aloisi, V., Colwell, F. S., Engelen, B., Fendrihan, S., Gaidos, E., Harms, U., Head, I., Kallmeyer, J., Kiel Reese, B., Lin, L.-H., Long, P. E., Moser, D. P., H., Mills, Sar, P., Schulze-Makuch, D., Stan-Lotter, H., Wagner, D., Wang, P.-L., and We, F.

Abstract

The International Continental Scientific Drilling Program (ICDP) has long espoused studies of deep subsurface life, and has targeted fundamental questions regarding subsurface life, including the following: "(1) What is the extent and diversity of deep microbial life and what are the factors limiting it? (2) What are the types of metabolism/carbon/energy sources and the rates of subsurface activity? (3) How is deep microbial life adapted to subsurface conditions? (4) How do subsurface microbial communities affect energy resources? And (5) how does the deep biosphere interact with the geosphere and atmosphere?" (Horsfield et al., 2014) Many ICDP-sponsored drilling projects have included a deep-life component; however, to date, not one project has been driven by deep-life goals, in part because geomicrobiologists have been slow to initiate deep biosphere-driven ICDP projects. Therefore, the Deep Carbon Observatory (DCO) recently partnered with the ICDP to sponsor a workshop with the specific aim of gathering potential proponents for deep-life-driven ICDP projects and ideas for candidate drilling sites. Twenty-two participants from nine countries proposed projects and sites that included compressional and extensional tectonic environments, evaporites, hydrocarbon-rich shales, flood basalts, Precambrian shield rocks, subglacial and subpermafrost environments, active volcanotectonic systems, megafan deltas, and serpentinizing ultramafic environments. The criteria and requirements for successful ICDP applications were presented. Deep-life-specific technical requirements were discussed and it was concluded that, while these procedures require adequate planning, they are entirely compatible with the sampling needs of other disciplines. As a result of this workshop, one drilling workshop proposal on the Basin and Range Physiographic Province (BRPP) has been submitted to the ICDP, and several other drilling project proponents plan to submit proposals for ICDP-sponsored drilling workshops in 2016. (VLID)1731059

Published
2015

37. Identification and characterization of Xanthomonas albilineans causing sugarcane leaf scald in China using multilocus sequence analysis.

Author

Ntambo, M. S., Meng, J.‐Y., Rott, P. C., Royer, M., Lin, L.‐H., Zhang, H.‐L., and Gao, S.‐J.

Subjects
XANTHOMONAS albilineans, SUGARCANE leaf scald, SUGARCANE industry, PHYLOGENY, PHYTOPATHOGENIC microorganisms
Abstract

Xanthomonas albilineans is the causal agent of leaf scald, a disease that can cause considerable damage to sugarcane industries. This study analysed the phylogenetic relationship of 14 samples of X. albilineans from China and 13 reference strains retrieved from the GenBank database by multilocus sequence analysis (MLSA). To reach this goal, five housekeeping genes of X. albilineans were amplified from diseased leaves and sequenced: gyrB, abc, rpoD, atpD and glnA. Based on the concatenated sequence of these genes (4473 nt), the 14 samples of X. albilineans from China had 99.9–100% sequence identity with one another and with five strains of the pathogen from the French West Indies and the USA (Florida). The 27 samples or strains of X. albilineans were distributed in two distinct clades in the MLSA‐based phylogenetic tree. Clade 1 was formed by four strains of the pathogen from Fiji, Papua New Guinea and the USA. All the other strains from worldwide locations, including the 14 samples from China, were grouped in clade 2. This latter clade included all strains of the pathogen that were associated with outbreaks of leaf scald that have occurred over the last two decades, especially in the Caribbean islands and the USA. The very low diversity of X. albilineans in four Chinese provinces suggests recent spread of a single strain (from genetic group PFGE‐B) of the leaf scald pathogen within China. [ABSTRACT FROM AUTHOR]

Published
2019
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39. Measuring Recent Thymic Emigrants in Blood of Normal and HIV-1–Infected Individuals before and after Effective Therapy

Author

Zhang, L., Lewin, S. R., Markowitz, M., Lin, L. -H, Skulsky, E., Karanicolas, R., Yuxian, H., Xia, J., Tuttleton, S., Vesanen, M., Spiegel, H., Kost, R., Van Lunzen, J., Stellbrink, H. -J, Wolinsky, S., Borkowsky, W., Palumbo, P., Kostrikis, Leontios G., and Ho, David D.

Subjects
Aging, T-Lymphocytes, HIV Infections, Pathogenesis, Medical and Health Sciences, Polymerase Chain Reaction, 0302 clinical medicine, thymus, Cell Movement, 2.1 Biological and endogenous factors, Immunology and Allergy, Aetiology, Child, cell count, Gene Rearrangement, 0303 health sciences, antiretrovirus agent, T-cell receptor excision circles, pathogenesis, article, Thymus gland, drug therapy, 3. Good health, Infectious Diseases, priority journal, HIV/AIDS, t lymphocyte receptor, Original Article, lamivudine, Drug therapy, DNA, Circular, Infection, human immunodeficiency virus 1, Adult, thymus gland, stavudine, Adolescent, Anti-HIV Agents, Immunology, Recent Thymic Emigrant, Circular, t lymphocyte, human immunodeficiency virus infection, Biology, interleukin 2, Gene Rearrangement, T-Lymphocyte, nelfinavir, saquinavir, 03 medical and health sciences, Pharmacotherapy, Clinical Research, blood, Humans, controlled study, human, DNA Primers, 030304 developmental biology, Base Sequence, human cell, T-cell receptor, Case-control study, HIV, DNA, T lymphocyte, Gene rearrangement, age, T-Lymphocyte, Case-Control Studies, HIV-1, 030215 immunology
Abstract

The role of the thymus in HIV-1 pathogenesis remains unclear. We developed an assay to quantify the number of recent thymic emigrants in blood based on the detection of a major excisional DNA byproduct (termed α1 circle) of T cell receptor rearrangement. By studying 532 normal individuals, we found that α1 circle numbers in blood remain high for the first 1015 yr of life, a sharp drop is seen in the late teen years, and a gradual decline occurs thereafter. Compared with age-matched uninfected control individuals, α1 circle numbers in HIV-1-infected adults were significantly reduced however, there were many individuals with normal α1 circle numbers. In 74 individuals receiving highly active antiretroviral therapy, we found no appreciable effect on α1 circle numbers in those whose baseline values were already within the normal range, but significant increases were observed in those with a preexisting impairment. The increases in α1 circle numbers were, however, numerically insufficient to account for the rise in levels of naive T lymphocytes. Overall, it is difficult to invoke thymic regenerative failure as a generalized mechanism for CD4 lymphocyte depletion in HIV-1 infection, as α1 circle numbers are normal in a substantial subset of HIV-1- infected individuals. 190 725 732 Cited By :288

Published
1999

43. Workshop to develop deep-life continental scientific drilling projects

Author

Kieft, T. L., primary, Onstott, T. C., additional, Ahonen, L., additional, Aloisi, V., additional, Colwell, F. S., additional, Engelen, B., additional, Fendrihan, S., additional, Gaidos, E., additional, Harms, U., additional, Head, I., additional, Kallmeyer, J., additional, Kiel Reese, B., additional, Lin, L.-H., additional, Long, P. E., additional, Moser, D. P., additional, Mills, H., additional, Sar, P., additional, Schulze-Makuch, D., additional, Stan-Lotter, H., additional, Wagner, D., additional, Wang, P.-L., additional, Westall, F., additional, and Wilkins, M. J., additional

Published
2015
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