المؤلفون: Ruffa, I, Davis, TA, Cappellari, M, Bureau, MG, Elford, J, Iguchi, S, Lelli, F, Liang, F-H, Liu, L, Lu, A, Sarzi, M, Williams, TG

الوصف: We present a CO dynamical estimate of the mass of the super-massive black hole (SMBH) in three nearby early-type galaxies: NGC 0612, NGC 1574 and NGC 4261. Our analysis is based on Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 3-6 observations of the 12CO(2-1) emission line with spatial resolutions of 14 − 58 pc (0.01″ − 0.26″). We detect disc-like CO distributions on scales from ≲ 200 pc (NGC 1574 and NGC 4261) to ≈10 kpc (NGC 0612). In NGC 0612 and NGC 1574 the bulk of the gas is regularly rotating. The data also provide evidence for the presence of a massive dark object at the centre of NGC 1574, allowing us to obtain the first measure of its mass, MBH = (1.0 ± 0.2) × 108 M⊙ (1σ uncertainty). In NGC 4261, the CO kinematics is clearly dominated by the SMBH gravitational influence, allowing us to determine an accurate black hole mass of (1.62 ± 0.04) × 109 M⊙ (1σ uncertainty). This is fully consistent with a previous CO dynamical estimate obtained using a different modelling technique. Signs of non-circular gas motions (likely outflow) are also identified in the inner regions of NGC 4261. In NGC 0612, we are only able to obtain a (conservative) upper limit of MBH ≲ 3.2 × 109 M⊙. This has likely to be ascribed to the presence of a central CO hole (with a radius much larger than that of the SMBH sphere of influence), combined with the inability of obtaining a robust prediction for the CO velocity curve. The three SMBH mass estimates are overall in agreement with predictions from the MBH − σ* relation.

العلاقة: https://ora.ox.ac.uk/objects/uuid:7b2eb7bb-44e6-434f-a212-601fa35a4ebaTest; https://doi.org/10.1093/mnras/stad1119Test

الإتاحة: https://doi.org/10.1093/mnras/stad1119Test
https://ora.ox.ac.uk/objects/uuid:7b2eb7bb-44e6-434f-a212-601fa35a4ebaTest

المؤلفون: Choi, W, Liu, L, Bureau, M, Cappellari, M, Davis, TA, Gensior, J, Liang, F-H, Lu, A, Williams, TG, Chung, A

الوصف: We present high spatial resolution (≈24 pc) Atacama Large Millimeter/sub-millimeter Array 12CO(2-1) observations of the central region of the nearby barred spiral galaxy NGC 5806. NGC 5806 has a highly structured molecular gas distribution with a clear nucleus, a nuclear ring, and offset dust lanes. We identify 170 spatially and spectrally resolved giant molecular clouds (GMCs). These clouds have comparable sizes (Rc) and larger gas masses, observed linewidths (σobs, los), and gas mass surface densities than those of clouds in the Milky Way disc. The size–linewidth relation of the clouds is one of the steepest reported so far ($\sigma _{\mathrm{obs,los}}\propto R_{\mathrm{c}}^{1.20}$), the clouds are on average only marginally bound (with a mean virial parameter 〈αvir〉 ≈ 2), and high velocity dispersions are observed in the nuclear ring. These behaviours are likely due to bar-driven gas shocks and inflows along the offset dust lanes, and we infer an inflow velocity of ≈120 km s−1 and a total molecular gas mass inflow rate of ≈5 M⊙ yr−1 into the nuclear ring. The observed internal velocity gradients of the clouds are consistent with internal turbulence. The number of clouds in the nuclear ring decreases with azimuthal angle downstream from the dust lanes without clear variation of cloud properties. This is likely due to the estimated short lifetime of the clouds (≈6 Myr), which appears to be mainly regulated by cloud–cloud collision and/or shear processes. Overall, it thus seems that the presence of the large-scale bar and gas inflows to the centre of NGC 5806 affect cloud properties.

العلاقة: https://ora.ox.ac.uk/objects/uuid:4ce4ea21-7e42-4c57-9db5-c8c7be7caf1dTest; https://doi.org/10.1093/mnras/stad1211Test

الإتاحة: https://doi.org/10.1093/mnras/stad1211Test
https://ora.ox.ac.uk/objects/uuid:4ce4ea21-7e42-4c57-9db5-c8c7be7caf1dTest

المؤلفون: Lu, A, Boyce, H, Haggard, D, Bureau, M, Liang, F-H, Liu, L, Choi, W, Cappellari, M, Chemin, L, Chevance, M, Davis, TA, Drissen, L, Elford, JS, Gensior, J, Kruijssen, JMD, Martin, T, Masse, E, Robert, C, Ruffa, I, Rousseau-Nepton, L, Sarzi, M, Savard, G, Williams, TG

الوصف: The star formation efficiency (SFE) has been shown to vary across different environments, particularly within galactic starbursts and deep within the bulges of galaxies. Various quenching mechanisms may be responsible, ranging from galactic dynamics to feedback from active galactic nuclei (AGNs). Here, we use spatially resolved observations of warm ionized gas emission lines (Hβ, [O iii] λλ4959,5007, [N ii] λλ6548,6583, Hα and [S ii] λλ6716,6731) from the imaging Fourier transform spectrograph SITELLE at the Canada-France-Hawaii Telescope (CFHT) and cold molecular gas (12CO(2-1)) from the Atacama Large Millimeter/sub-millimeter Array (ALMA) to study the SFE in the bulge of the AGN-host galaxy NGC 3169. After distinguishing star-forming regions from AGN-ionized regions using emission-line ratio diagnostics, we measure spatially resolved molecular gas depletion times (τdep 1/SFE) with a spatial resolution of ≈100 pc within a galactocentric radius of 1.8 kpc. We identify a star-forming ring located at radii 1.25 ± 0.6 kpc with an average τdep of 0.3 Gyr. At radii <0.9 kpc, however, the molecular gas surface densities and depletion times increase with decreasing radius, the latter reaching approximately 2.3 Gyr at a radius ≈500 pc. Based on analyses of the gas kinematics and comparisons with simulations, we identify AGN feedback, bulge morphology and dynamics as the possible causes of the radial profile of SFE observed in the central region of NGC 3169.

العلاقة: https://ora.ox.ac.uk/objects/uuid:f91736a9-c5d9-4412-a02c-435497bf0278Test; https://doi.org/10.1093/mnras/stac1583Test

الإتاحة: https://doi.org/10.1093/mnras/stac1583Test
https://ora.ox.ac.uk/objects/uuid:f91736a9-c5d9-4412-a02c-435497bf0278Test

المؤلفون: Davis, TA, Gensior, J, Bureau, MG, Cappellari, M, Choi, W, Elford, JS, Kruijssen, JMD, Lelli, F, Liang, F-H, Liu, L, Ruffa, I, Saito, T, Sarzi, M, Schruba, A, Williams, TG

الوصف: We use high-resolution maps of the molecular interstellar medium (ISM) in the centres of eighty-six nearby galaxies from the millimetre-Wave Interferometric Survey of Dark Object Masses (WISDOM) and Physics at High Angular Resolution in Nearby GalaxieS (PHANGS) surveys to investigate the physical mechanisms setting the morphology of the ISM at molecular cloud scales. We show that early-type galaxies tend to have smooth, regular molecular gas morphologies, while the ISM in spiral galaxy bulges is much more asymmetric and clumpy when observed at the same spatial scales. We quantify these differences using non-parametric morphology measures (Asymmetry, Smoothness and Gini), and compare these measurements with those extracted from idealised galaxy simulations. We show that the morphology of the molecular ISM changes systematically as a function of various large scale galaxy parameters, including galaxy morphological type, stellar mass, stellar velocity dispersion, effective stellar mass surface density, molecular gas surface density, star formation efficiency and the presence of a bar. We perform a statistical analysis to determine which of these correlated parameters best predicts the morphology of the ISM. We find the effective stellar mass surface (or volume) density to be the strongest predictor of the morphology of the molecular gas, while star formation and bars maybe be important secondary drivers. We find that gas self-gravity is not the dominant process shaping the morphology of the molecular gas in galaxy centres. Instead effects caused by the depth of the potential well such as shear, suppression of stellar spiral density waves and/or inflow affect the ability of the gas to fragment.

العلاقة: https://ora.ox.ac.uk/objects/uuid:006a789c-5a19-4dfc-89ca-9352b06adb88Test; https://doi.org/10.1093/mnras/stac600Test

الإتاحة: https://doi.org/10.1093/mnras/stac600Test
https://ora.ox.ac.uk/objects/uuid:006a789c-5a19-4dfc-89ca-9352b06adb88Test

المؤلفون: Abdurro'uf, Accetta, K, Aerts, C, Aguirre, VS, Ahumada, R, Ajgaonkar, N, Ak, NF, Alam, S, Prieto, CA, Almeida, A, Anders, F, Anderson, SF, Andrews, BH, Anguiano, B, Aquino-Ortiz, E, Aragon-Salamanca, A, Argudo-Fernandez, M, Ata, M, Aubert, M, Avila-Reese, V, Badenes, C, Barba, RH, Barger, K, Barrera-Ballesteros, JK, Beaton, RL, Beers, TC, Belfiore, F, Bender, CF, Bernardi, M, Bershady, MA, Beutler, F, Bidin, CM, Bird, JC, Bizyaev, D, Blanc, GA, Blanton, MR, Boardman, NF, Bolton, AS, Boquien, M, Borissova, J, Bovy, J, Brandt, WN, Brown, J, Brownstein, JR, Brusa, M, Buchner, J, Bundy, K, Burchett, JN, Bureau, M, Burgasser, A, Cabang, TK, Campbell, S, Cappellari, M, Carlberg, JK, Wanderley, FC, Carrera, R, Cash, J, Chen, Y-P, Chen, W-H, Cherinka, B, Chiappini, C, Choi, PD, Chojnowski, SD, Chung, H, Clerc, N, Cohen, RE, Comerford, JM, Comparat, J, da Costa, L, Covey, K, Crane, JD, Cruz-Gonzalez, I, Culhane, C, Cunha, K, Dai, YS, Damke, G, Darling, J, Davidson, JW, Davies, R, Dawson, K, De Lee, N, Diamond-Stanic, AM, Cano-Diaz, M, Sanchez, HD, Donor, J, Duckworth, C, Dwelly, T, Eisenstein, DJ, Elsworth, YP, Emsellem, E, Eracleous, M, Escoffier, S, Fan, X, Farr, E, Feng, S, Fernandez-Trincado, JG, Feuillet, D, Filipp, A, Fillingham, SP, Frinchaboy, PM, Fromenteau, S, Galbany, L, Garcia, RA, Garcia-Hernandez, DA, Ge, J, Geisler, D, Gelfand, J, Geron, T, Gibson, BJ, Goddy, J, Godoy-Rivera, D, Grabowski, K, Green, PJ, Greener, M, Grier, CJ, Griffith, E, Guo, H, Guy, J, Hadjara, M, Harding, P, Hasselquist, S, Hayes, CR, Hearty, F, Hill, L, Hogg, DW, Holtzman, JA, Horta, D, Hsieh, B-C, Hsu, C-H, Hsu, Y-H, Huber, D, Huertas-Company, M, Hutchinson, B, Hwang, HS, Ibarra-Medel, HJ, Chitham, JI, Ilha, GS, Imig, J, Jaekle, W, Jayasinghe, T, Ji, X, Johnson, JA, Jones, A, Jonsson, H, Katkov, I, Khalatyan, A, Kinemuchi, K, Kisku, S, Knapen, JH, Kneib, J-P, Kollmeier, JA, Kong, M, Kounkel, M, Kreckel, K, Krishnarao, D, Lacerna, I, Lane, RR, Langgin, R, Lavender, R, Law, DR, Lazarz, D, Leung, HW, Leung, H-H, Lewis, HM, Li, C, Li, R, Lian, J, Liang, F-H, Lin, L, Lin, Y-T, Lin, S, Lintott, C, Long, D, Longa-Pena, P, Lopez-Coba, C, Lu, S, Lundgren, BF, Luo, Y, Mackereth, JT, de la Macorra, A, Mahadevan, S, Majewski, SR, Manchado, A, Mandeville, T, Maraston, C, Margalef-Bentabol, B, Masseron, T, Masters, KL, Mathur, S, McDermid, RM, Mckay, M, Merloni, A, Merrifield, M, Meszaros, S, Miglio, A, Di Mille, F, Minniti, D, Minsley, R, Monachesi, A, Moon, J, Mosser, B, Mulchaey, J, Muna, D, Munoz, RR, Myers, AD, Myers, N, Nadathur, S, Nair, P, Nandra, K, Neumann, J, Newman, JA, Nidever, DL, Nikakhtar, F, Nitschelm, C, O'Connell, JE, Garma-Oehmichen, L, de Oliveira, GLS, Olney, R, Oravetz, D, Ortigoza-Urdaneta, M, Osorio, Y, Otter, J, Pace, ZJ, Padilla, N, Pan, K, Pan, H-A, Parikh, T, Parker, J, Peirani, S, Ramirez, KP, Penny, S, Percival, WJ, Perez-Fournon, I, Pinsonneault, M, Poidevin, F, Poovelil, VJ, Price-Whelan, AM, Queiroz, AB de A, Raddick, MJ, Ray, A, Rembold, SB, Riddle, N, Riffel, RA, Riffel, R, Rix, H-W, Robin, AC, Rodriguez-Puebla, A, Roman-Lopes, A, Roman-Zuniga, C, Rose, B, Ross, AJ, Rossi, G, Rubin, KHR, Salvato, M, Sanchez, SF, Sanchez-Gallego, JR, Sanderson, R, Rojas, FAS, Sarceno, E, Sarmiento, R, Sayres, C, Sazonova, E, Schaefer, AL, Schiavon, R, Schlegel, DJ, Schneider, DP, Schultheis, M, Schwope, A, Serenelli, A, Serna, J, Shao, Z, Shapiro, G, Sharma, A, Shen, Y, Shetrone, M, Shu, Y, Simon, JD, Skrutskie, MF, Smethurst, R, Smith, V, Sobeck, J, Spoo, T, Sprague, D, Stark, D, Stassun, KG, Steinmetz, M, Stello, D, Stone-Martinez, A, Storchi-Bergmann, T, Stringfellow, GS, Stutz, A, Su, Y-C, Taghizadeh-Popp, M, Talbot, MS, Tayar, J, Telles, E, Teske, J, Thakar, A, Theissen, C, Tkachenko, A, Thomas, D, Tojeiro, R, Toledo, HH, Troup, NW, Trump, JR, Trussler, J, Turner, J, Tuttle, S, Unda-Sanzana, E, Vazquez-Mata, JA, Valentini, M, Valenzuela, O, Vargas-Gonzalez, J, Vargas-Magana, M, Alfaro, PV, Villanova, S, Vincenzo, F, Wake, D, Warfield, JT, Washington, JD, Weaver, BA, Weijmans, A-M, Weinberg, DH, Weiss, A, Westfall, KB, Wild, V, Wilde, MC, Wilson, JC, Wilson, RF, Wilson, M, Wolf, J, Wood-Vasey, WM, Yan, R, Zamora, O, Zasowski, G, Zhang, K, Zhao, C, Zheng, Z, Zhu, K

مصطلحات موضوعية: QB Astronomy

الوصف: This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 survey that publicly releases infrared spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the subsurvey Time Domain Spectroscopic Survey data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey subsurvey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated value-added catalogs. This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper surveys.

وصف الملف: text

العلاقة: https://researchonline.ljmu.ac.uk/id/eprint/18145/1/The%20seventeenth%20data%20release%20of%20the%20sloan%20digital%20sky%20surveys%20-%20complete%20release%20of%20MaNGA%20MaStar%20and%20APOGEE-2%20data.pdfTest; Abdurro'uf, , Accetta, K, Aerts, C, Aguirre, VS, Ahumada, R, Ajgaonkar, N, Ak, NF, Alam, S, Prieto, CA, Almeida, A, Anders, F, Anderson, SF, Andrews, BH, Anguiano, B, Aquino-Ortiz, E, Aragon-Salamanca, A, Argudo-Fernandez, M, Ata, M, Aubert, M, Avila-Reese, V, Badenes, C, Barba, RH, Barger, K, Barrera-Ballesteros, JK, Beaton, RL, Beers, TC, Belfiore, F, Bender, CF, Bernardi, M, Bershady, MA, Beutler, F, Bidin, CM, Bird, JC, Bizyaev, D, Blanc, GA, Blanton, MR, Boardman, NF, Bolton, AS, Boquien, M, Borissova, J, Bovy, J, Brandt, WN, Brown, J, Brownstein, JR, Brusa, M, Buchner, J, Bundy, K, Burchett, JN, Bureau, M, Burgasser, A, Cabang, TK, Campbell, S, Cappellari, M, Carlberg, JK, Wanderley, FC, Carrera, R, Cash, J, Chen, Y-P, Chen, W-H, Cherinka, B, Chiappini, C, Choi, PD, Chojnowski, SD, Chung, H, Clerc, N, Cohen, RE, Comerford, JM, Comparat, J, da Costa, L, Covey, K, Crane, JD, Cruz-Gonzalez, I, Culhane, C, Cunha, K, Dai, YS, Damke, G, Darling, J, Davidson, JW, Davies, R, Dawson, K, De Lee, N, Diamond-Stanic, AM, Cano-Diaz, M, Sanchez, HD, Donor, J, Duckworth, C, Dwelly, T, Eisenstein, DJ, Elsworth, YP, Emsellem, E, Eracleous, M, Escoffier, S, Fan, X, Farr, E, Feng, S, Fernandez-Trincado, JG, Feuillet, D, Filipp, A, Fillingham, SP, Frinchaboy, PM, Fromenteau, S, Galbany, L, Garcia, RA, Garcia-Hernandez, DA, Ge, J, Geisler, D, Gelfand, J, Geron, T, Gibson, BJ, Goddy, J, Godoy-Rivera, D, Grabowski, K, Green, PJ, Greener, M, Grier, CJ, Griffith, E, Guo, H, Guy, J, Hadjara, M, Harding, P, Hasselquist, S, Hayes, CR, Hearty, F, Hill, L, Hogg, DW, Holtzman, JA, Horta, D, Hsieh, B-C, Hsu, C-H, Hsu, Y-H, Huber, D, Huertas-Company, M, Hutchinson, B, Hwang, HS, Ibarra-Medel, HJ, Chitham, JI, Ilha, GS, Imig, J, Jaekle, W, Jayasinghe, T, Ji, X, Johnson, JA, Jones, A, Jonsson, H, Katkov, I, Khalatyan, A, Kinemuchi, K, Kisku, S, Knapen, JH, Kneib, J-P, Kollmeier, JA, Kong, M, Kounkel, M, Kreckel, K, Krishnarao, D, Lacerna, I, Lane, RR, Langgin, R, Lavender, R, Law, DR, Lazarz, D, Leung, HW, Leung, H-H, Lewis, HM, Li, C, Li, R, Lian, J, Liang, F-H, Lin, L, Lin, Y-T, Lin, S, Lintott, C, Long, D, Longa-Pena, P, Lopez-Coba, C, Lu, S, Lundgren, BF, Luo, Y, Mackereth, JT, de la Macorra, A, Mahadevan, S, Majewski, SR, Manchado, A, Mandeville, T, Maraston, C, Margalef-Bentabol, B, Masseron, T, Masters, KL, Mathur, S, McDermid, RM, Mckay, M, Merloni, A, Merrifield, M, Meszaros, S, Miglio, A, Di Mille, F, Minniti, D, Minsley, R, Monachesi, A, Moon, J, Mosser, B, Mulchaey, J, Muna, D, Munoz, RR, Myers, AD, Myers, N, Nadathur, S, Nair, P, Nandra, K, Neumann, J, Newman, JA, Nidever, DL, Nikakhtar, F, Nitschelm, C, O'Connell, JE, Garma-Oehmichen, L, de Oliveira, GLS, Olney, R, Oravetz, D, Ortigoza-Urdaneta, M, Osorio, Y, Otter, J, Pace, ZJ, Padilla, N, Pan, K, Pan, H-A, Parikh, T, Parker, J, Peirani, S, Ramirez, KP, Penny, S, Percival, WJ, Perez-Fournon, I, Pinsonneault, M, Poidevin, F, Poovelil, VJ, Price-Whelan, AM, Queiroz, AB de A, Raddick, MJ, Ray, A, Rembold, SB, Riddle, N, Riffel, RA, Riffel, R, Rix, H-W, Robin, AC, Rodriguez-Puebla, A, Roman-Lopes, A, Roman-Zuniga, C, Rose, B, Ross, AJ, Rossi, G, Rubin, KHR, Salvato, M, Sanchez, SF, Sanchez-Gallego, JR, Sanderson, R, Rojas, FAS, Sarceno, E, Sarmiento, R, Sayres, C, Sazonova, E, Schaefer, AL, Schiavon, R, Schlegel, DJ, Schneider, DP, Schultheis, M, Schwope, A, Serenelli, A, Serna, J, Shao, Z, Shapiro, G, Sharma, A, Shen, Y, Shetrone, M, Shu, Y, Simon, JD, Skrutskie, MF, Smethurst, R, Smith, V, Sobeck, J, Spoo, T, Sprague, D, Stark, D, Stassun, KG, Steinmetz, M, Stello, D, Stone-Martinez, A, Storchi-Bergmann, T, Stringfellow, GS, Stutz, A, Su, Y-C, Taghizadeh-Popp, M, Talbot, MS, Tayar, J, Telles, E, Teske, J, Thakar, A, Theissen, C, Tkachenko, A, Thomas, D, Tojeiro, R, Toledo, HH, Troup, NW, Trump, JR, Trussler, J, Turner, J, Tuttle, S, Unda-Sanzana, E, Vazquez-Mata, JA, Valentini, M, Valenzuela, O, Vargas-Gonzalez, J, Vargas-Magana, M, Alfaro, PV, Villanova, S, Vincenzo, F, Wake, D, Warfield, JT, Washington, JD, Weaver, BA, Weijmans, A-M, Weinberg, DH, Weiss, A, Westfall, KB, Wild, V, Wilde, MC, Wilson, JC, Wilson, RF, Wilson, M, Wolf, J, Wood-Vasey, WM, Yan, R, Zamora, O, Zasowski, G, Zhang, K, Zhao, C, Zheng, Z, Zheng, Z and Zhu, K (2022) The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar, and APOGEE-2 Data. Astrophysical Journal Supplement Series, 259 (2). ISSN 0067-0049

الإتاحة: https://doi.org/10.3847/1538-4365/ac4414Test
http://researchonline.ljmu.ac.uk/id/eprint/18145Test/
https://researchonline.ljmu.ac.uk/id/eprint/18145/1/The%20seventeenth%20data%20release%20of%20the%20sloan%20digital%20sky%20surveys%20-%20complete%20release%20of%20MaNGA%20MaStar%20and%20APOGEE-2%20data.pdfTest

المؤلفون: Liu, H Q, Kan, Y, Liu, Y, Zhang, W M, Shan, H Y, Wang, Y H, Liang, F H, Liu, X L

المصدر: IOP Conference Series: Earth and Environmental Science ; volume 346, issue 1, page 012012 ; ISSN 1755-1307 1755-1315

الوصف: Lingang wetland park is a newly built wetland park in Lingang district, Tianjin, China. The community composition, community structure, frequency of occurrence of arbor and shrub layer and dominant species of plant community in lingang wetland park were investigated. The results showed that the community of Lingang wetland park was mainly characterized by the structure of trees-shrubs-lawns, and the ratio of species and number of evergreen trees to deciduous trees was 2:15 and 1:23. Wetland park is rich in plant diversity, the dominance index at park's east gate and “qushuihuajing” were 0.8183 and 0.8152, which were far higher than other quadrants and the dominant species is golden elm. Among the tall trees, Ulmus pumila, Salix babylonica, Aureus locustae with the highest application frequency accounted for 23.8%. For shrubs, lonicera japonica, Euonymus japonicus and Lonicera maackii had the highest frequency of application. Festuca elata and Hemerocallis fulva had highest application frequency in lawns. They accounted for only 13.2% in herbs. It indicated that only several plants in the park have high frequencies.

الإتاحة: https://doi.org/10.1088/1755-1315/346/1/012012Test

المؤلفون: Shi, Y Y, Yang, J H, Liu, T, Zhang, Z W, Mu, K, Liang, F H, Liu, Y

المصدر: IOP Conference Series: Earth and Environmental Science ; volume 346, issue 1, page 012025 ; ISSN 1755-1307 1755-1315

الوصف: In order to compare the salt tolerance of the three species of Nitraria, NaCl with different concentrations was used to stress the Nitraria seedlings. The results showed that salt treatment had different effects on the growth of Nitraria; The inhibiting effect of salt stress on the growth of plant height was in the order of Nitraria tangutorum Bobr>Nitraria roborowskii Kom>Nitraria sibirica Pall; Salt stress caused a rapid decrease in the number of leaves of Nitraria tangutorum Bobr and the number of leaves of Nitraria sibirica Pal rapidly decreased when the salt concentration was greater than 6%, while the relative number of leaves of Nitraria roborowskii Kom significantly decreased when the salt concentration was 15%; With the increase of salt concentration, the order of relative reduction of stem diameter was Nitraria tangutorum Bobr>Nitraria roborowskii Kom>Nitraria sibirica Pall; With the increase of salt concentration, the relative leaf area decreased significantly in the order of Nitraria tangutorum Bobr>Nitraria sibirica Pall>Nitraria roborowskii Kom; With the increase of salt concentration, there was no significant difference between the dry weight and fresh weight of Nitraria roborowskii Kom, but there were significant changes between Nitraria tangutorum Bobr and Nitraria sibirica Pal. According to the comprehensive membership function analysis, the salt tolerance of Nitraria roborowskii Kom was the best, followed by that of Nitraria sibirica Pal, and that of Nitraria tangutorum Bobr was the worst.

الإتاحة: https://doi.org/10.1088/1755-1315/346/1/012025Test

المؤلفون: Liu, Y, Liu, H Q, Liang, F H, Shi, Y Y, Liu, X L

المصدر: IOP Conference Series: Earth and Environmental Science ; volume 346, issue 1, page 012020 ; ISSN 1755-1307 1755-1315

الوصف: In order to explore the effect of using two different afforestation tree species to improve soil in coastal saline-alkali land, the method of combining field sampling and indoor analysis and test was adopted. The physical and chemical properties of soils planted with Rhus typhina and Robinia pseudoacacia forest were determined. The results showed that afforestation could improve soil structure, decrease soil bulk density and increase soil fertility. To reduce soil salinization, the soil physical and chemical indexes of Robinia pseudoacacia plantation were better than those of growing Rhus typhina forest, so the planting area of Robinia pseudoacacia plantation in Dagang area could be increased. Planting Rhus typhina forest could also improve the soil in this area, but its effect was lower than planting Robinia pseudoacacia plantation.

الإتاحة: https://doi.org/10.1088/1755-1315/346/1/012020Test

المؤلفون: Liang, F H, Liu, Y J, Yang, J H, Liu, Y, Shi, Y Y, Liu, H Q, Zhang, C

المصدر: IOP Conference Series: Earth and Environmental Science ; volume 346, issue 1, page 012022 ; ISSN 1755-1307 1755-1315

الوصف: In order to obtain the embryogenic callus of raspberry, the friable calluses of raspberry were used as materials to be treated by different time of starvation and desiccation, and were further cultivated and induced embryoid. By use of embryogenic observation, the embryogenic degree of callus could be determined. The results showed that the embryogenic degree of calluses which were treated by starvation for 6 days was the highest, and the desiccation treatment had no effect on embryogenic degree of calluses. Therefore, appropriate starvation treatment can facilitate the transformation of non-embryogenic callus into embryogenic callus. The results of this experiment could provide reference for callus embryogenesis induction of other plants.

الإتاحة: https://doi.org/10.1088/1755-1315/346/1/012022Test

المؤلفون: Liang, F H, Liu, Y, Shi, Y Y, Liu, H Q, Zhang, C

المصدر: IOP Conference Series: Earth and Environmental Science ; volume 346, issue 1, page 012023 ; ISSN 1755-1307 1755-1315

الوصف: In order to study the influence of the transparency and crown density of road green belts on particle dispersion, the green belts along Tinjing highway in Tianjin, China, were selected to study in this study and the green space was divided into four types, which respectively were the high crown density-high transparency green space, the low crown density-low transparency green space, the high crown density-low transparency green space and the low crown density-high transparency green space. The particle pollution concentration in sidewalk and green space was researched in the four types of green space. It was concluded that: in the sidewalk, the high crown density-high transparency green space was the most adverse to the diffusion of automobile exhaust pollutants because those contents of pm2.5, pm10 and dust were all the highest; in the green space, the high crown density-high transparency green space and the low crown density-low transparency green space were the most adverse to the diffusion of automobile exhaust pollutants because those contents of pm2.5, pm10 and dust were all the highest. So among the four types of green space, the high crown density-high transparency green space was the most adverse to pollutant diffusion.

الإتاحة: https://doi.org/10.1088/1755-1315/346/1/012023Test