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Highly porous nature of a primitive asteroid revealed by thermal imaging 期刊论文
NATURE, 2020, 579 (7800) : 518-522
作者:  Quinn, Robert A.;  Melnik, Alexey, V;  Vrbanac, Alison;  Fu, Ting;  Patras, Kathryn A.;  Christy, Mitchell P.;  Bodai, Zsolt;  Belda-Ferre, Pedro;  Tripathi, Anupriya;  Chung, Lawton K.;  Downes, Michael;  Welch, Ryan D.;  Quinn, Melissa;  Humphrey, Greg;  Panitchpakdi, Morgan;  Weldon, Kelly C.;  Aksenov, Alexander;  da Silva, Ricardo;  Avila-Pacheco, Julian;  Clish, Clary;  Bae, Sena;  Mallick, Himel;  Franzosa, Eric A.;  Lloyd-Price, Jason;  Bussell, Robert;  Thron, Taren;  Nelson, Andrew T.;  Wang, Mingxun;  Leszczynski, Eric;  Vargas, Fernando;  Gauglitz, Julia M.;  Meehan, Michael J.;  Gentry, Emily;  Arthur, Timothy D.;  Komor, Alexis C.;  Poulsen, Orit;  Boland, Brigid S.;  Chang, John T.;  Sandborn, William J.;  Lim, Meerana;  Garg, Neha;  Lumeng, Julie C.;  Xavier, Ramnik J.;  Kazmierczak, Barbara, I;  Jain, Ruchi;  Egan, Marie;  Rhee, Kyung E.;  Ferguson, David;  Raffatellu, Manuela;  Vlamakis, Hera;  Haddad, Gabriel G.;  Siegel, Dionicio;  Huttenhower, Curtis;  Mazmanian, Sarkis K.;  Evans, Ronald M.;  Nizet, Victor;  Knight, Rob;  Dorrestein, Pieter C.
收藏  |  浏览/下载:102/0  |  提交时间:2020/05/13

Carbonaceous (C-type) asteroids(1) are relics of the early Solar System that have preserved primitive materials since their formation approximately 4.6 billion years ago. They are probably analogues of carbonaceous chondrites(2,3) and are essential for understanding planetary formation processes. However, their physical properties remain poorly known because carbonaceous chondrite meteoroids tend not to survive entry to Earth'  s atmosphere. Here we report on global one-rotation thermographic images of the C-type asteroid 162173 Ryugu, taken by the thermal infrared imager (TIR)(4) onboard the spacecraft Hayabusa2(5), indicating that the asteroid'  s boulders and their surroundings have similar temperatures, with a derived thermal inertia of about 300 J m(-2) s(-0.5) K-1 (300 tiu). Contrary to predictions that the surface consists of regolith and dense boulders, this low thermal inertia suggests that the boulders are more porous than typical carbonaceous chondrites(6) and that their surroundings are covered with porous fragments more than 10 centimetres in diameter. Close-up thermal images confirm the presence of such porous fragments and the flat diurnal temperature profiles suggest a strong surface roughness effect(7,8). We also observed in the close-up thermal images boulders that are colder during the day, with thermal inertia exceeding 600 tiu, corresponding to dense boulders similar to typical carbonaceous chondrites(6). These results constrain the formation history of Ryugu: the asteroid must be a rubble pile formed from impact fragments of a parent body with microporosity(9) of approximately 30 to 50 per cent that experienced a low degree of consolidation. The dense boulders might have originated from the consolidated innermost region or they may have an exogenic origin. This high-porosity asteroid may link cosmic fluffy dust to dense celestial bodies(10).


Thermal imaging data obtained from the spacecraft Hayabusa2 reveal that the carbonaceous asteroid 162173 Ryugu is an object of unusually high porosity.


  
Surprising lack of sensitivity of biochemical limitation of photosynthesis of nine tree species to open-air experimental warming and reduced rainfall in a southern boreal forest 期刊论文
GLOBAL CHANGE BIOLOGY, 2019
作者:  Stefanski, Artur;  Bermudez, Raimundo;  Sendall, Kerrie M.;  Montgomery, Rebecca A.;  Reich, Peter B.
收藏  |  浏览/下载:24/0  |  提交时间:2019/11/27
B4WarmED  biochemical limitation  boreal forest  experimental warming  J(max)  rainfall reduction  V-cmax  
Modelled net carbon gain responses to climate change in boreal trees: Impacts of photosynthetic parameter selection and acclimation 期刊论文
GLOBAL CHANGE BIOLOGY, 2019, 25 (4) : 1445-1465
作者:  Stinziano, Joseph R.;  Bauerle, William L.;  Way, Danielle A.
收藏  |  浏览/下载:23/0  |  提交时间:2019/04/09
carbon cycle  J(max)  modelling  seasonality  thermal acclimation  V-cmax  
Using GRACE to Explain Variations in the Earth's Oblateness 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2019, 46 (1) : 158-168
作者:  Sun, Yu;  Riva, Riccardo;  Ditmar, Pavel;  Rietbroek, Roelof
收藏  |  浏览/下载:13/0  |  提交时间:2019/04/09
Earth'  s dynamic oblateness  J(2)  GRACE  C-20  geoid fingerprints  mass redistribution  
Relative Influence of Landscape Variables and Discharge on Suspended Sediment Yields in Temperate Mountain Catchments 期刊论文
WATER RESOURCES RESEARCH, 2018, 54 (7) : 5126-5142
作者:  Bywater-Reyes, Sharon;  Bladon, Kevin D.;  Segura, Catalina
收藏  |  浏览/下载:20/0  |  提交时间:2019/04/09
H  J  Andrews  suspended sediment yield  Oregon  LTER  long-term data  forest management  
Improving models of photosynthetic thermal acclimation: Which parameters are most important and how many should be modified? 期刊论文
GLOBAL CHANGE BIOLOGY, 2018, 24 (4) : 1580-1598
作者:  Stinziano, Joseph R.;  Way, Danielle A.;  Bauerle, William L.
收藏  |  浏览/下载:22/0  |  提交时间:2019/04/09
climate change  Eddy covariance  J(max)  modified Arrhenius equation  scaling  seasonality  temperature  V-cmax  
Short-term acclimation to warmer temperatures accelerates leaf carbon exchange processes across plant types 期刊论文
GLOBAL CHANGE BIOLOGY, 2017, 23 (11)
作者:  Smith, Nicholas G.;  Dukes, Jeffrey S.
收藏  |  浏览/下载:21/0  |  提交时间:2019/04/09
climate change  J(max)  photosynthesis  plant physiology  respiration  V-cmax  warming  
Impact of evapotranspiration process representation on runoff projections from conceptual rainfall-runoff models 期刊论文
WATER RESOURCES RESEARCH, 2017, 53 (1)
作者:  Guo, Danlu;  Westra, Seth;  Maier, Holger R.
收藏  |  浏览/下载:15/0  |  提交时间:2019/04/09
evapotranspiration  climate impact assessment  GR4J  AWBM  IHACRES  conceptual rainfall-runoff model  AET simulation  
'Zum Spielen und zum Tantzen', a Kinaesthetic Exploration of the Bach Cello Suites through Studies in Baroque Choreography 科技报告
来源:Center for International Climate and Environmental Research-Oslo (CICERO). 出版年: 2015
作者:  Dalen, Tormod
收藏  |  浏览/下载:19/0  |  提交时间:2019/04/05
J. S. Bach  cello suites  cello solo  baroque dance  la belle danse  HIP  body paradigm  kinaesthetic empathy  artistic research  dance tempo  dance character  melodic reduction  Taubert  Feuillet  Rameau  Pécour  Tomlinson  menuet  sarabande  bourrée  gavotte  gigue  courante  corrente  giga  allemande  VDP::Humanities: 000::Musicology: 110::Alternative musicology: 119  
Interactive Photochemistry in Earth System Models to Assess Uncertainty in Ozone and Greenhouse Gases. Final report 科技报告
来源:US Department of Energy (DOE). 出版年: 2014
作者:  Prather, Michael J.;  Hsu, Juno;  Nicolau, Alex;  Veidenbaum, Alex
收藏  |  浏览/下载:6/0  |  提交时间:2019/04/05
atmospheric radiation-chemistry-dynamics interaction  stratospheric ozone  linearized ozone scheme  tropopause  Fast-J  GPUs  uncertainty quantification