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- Zhang, S. N., et al.
(författare)
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The high energy cosmic-radiation detection (HERD) facility onboard China's Space Station
- 2014
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9780819496126
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Konferensbidrag (refereegranskat)abstract
- The High Energy cosmic-Radiation Detection (HERD) facility is one of several space astronomy payloads of the cosmic lighthouse program onboard China's Space Station, which is planned for operation starting around 2020 for about 10 years. The main scientific objectives of HERD are indirect dark matter search, precise cosmic ray spectrum and composition measurements up to the knee energy, and high energy gamma-ray monitoring and survey. HERD is composed of a 3-D cubic calorimeter (CALO) surrounded by microstrip silicon trackers (STKs) from five sides except the bottom. CALO is made of about 104 cubes of LYSO crystals, corresponding to about 55 radiation lengths and 3 nuclear interaction lengths, respectively. The top STK microstrips of seven X-Y layers are sandwiched with tungsten converters to make precise directional measurements of incoming electrons and gamma-rays. In the baseline design, each of the four side SKTs is made of only three layers microstrips. All STKs will also be used for measuring the charge and incoming directions of cosmic rays, as well as identifying back scattered tracks. With this design, HERD can achieve the following performance: energy resolution of 1% for electrons and gamma-rays beyond 100 GeV, 20% for protons from 100 GeV to 1 PeV; electron/proton separation power better than 10-5; effective geometrical factors of >3 m2sr for electron and diffuse gamma-rays, >2 m2sr for cosmic ray nuclei. R and D is under way for reading out the LYSO signals with optical fiber coupled to image intensified CCD and the prototype of one layer of CALO.
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2. |
- Callaway, EM, et al.
(författare)
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A multimodal cell census and atlas of the mammalian primary motor cortex
- 2021
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 598:7879, s. 86-102
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Tidskriftsartikel (refereegranskat)abstract
- Here we report the generation of a multimodal cell census and atlas of the mammalian primary motor cortex as the initial product of the BRAIN Initiative Cell Census Network (BICCN). This was achieved by coordinated large-scale analyses of single-cell transcriptomes, chromatin accessibility, DNA methylomes, spatially resolved single-cell transcriptomes, morphological and electrophysiological properties and cellular resolution input–output mapping, integrated through cross-modal computational analysis. Our results advance the collective knowledge and understanding of brain cell-type organization1–5. First, our study reveals a unified molecular genetic landscape of cortical cell types that integrates their transcriptome, open chromatin and DNA methylation maps. Second, cross-species analysis achieves a consensus taxonomy of transcriptomic types and their hierarchical organization that is conserved from mouse to marmoset and human. Third, in situ single-cell transcriptomics provides a spatially resolved cell-type atlas of the motor cortex. Fourth, cross-modal analysis provides compelling evidence for the transcriptomic, epigenomic and gene regulatory basis of neuronal phenotypes such as their physiological and anatomical properties, demonstrating the biological validity and genomic underpinning of neuron types. We further present an extensive genetic toolset for targeting glutamatergic neuron types towards linking their molecular and developmental identity to their circuit function. Together, our results establish a unifying and mechanistic framework of neuronal cell-type organization that integrates multi-layered molecular genetic and spatial information with multi-faceted phenotypic properties.
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3. |
- Zhang, S. -N, et al.
(författare)
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Introduction to the high energy cosmic-radiation detection (HERD) facility onboard China's future space station
- 2017
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Ingår i: Proceedings of Science. - : Sissa Medialab Srl.
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Konferensbidrag (refereegranskat)abstract
- The High Energy cosmic-Radiation Detection (HERD) facility is one of several space astronomy payloads onboard China's Space Station, which is planned for operation starting around 2025 for about 10 years. The main scientific objectives of HERD are searching for signals of dark matter annihilation products, precise cosmic electron (plus positron) spectrum and anisotropy measurements up to 10 TeV, precise cosmic ray spectrum and composition measurements up to the knee energy, and high energy gamma-ray monitoring and survey. HERD is composed of a 3-D cubic calorimeter (CALO) surrounded by microstrip silicon trackers (STKs) from five sides except the bottom. CALO is made of about 7,500 cubes of LYSO crystals, corresponding to about 55 radiation lengths and 3 nuclear interaction lengths, respectively. The top STK microstrips of six X-Y layers are sandwiched with tungsten converters to make precise directional measurements of incoming electrons and gamma-rays. In the baseline design, each of the four side STKs is made of only three layers microstrips. All STKs will also be used for measuring the charge and incoming directions of cosmic rays, as well as identifying back scattered tracks. With this design, HERD can achieve the following performance: energy resolution of 1% for electrons and gamma-rays beyond 100 GeV and 20% for protons from 100 GeV to 1 PeV; electron/proton separation power better than 10-5; effective geometrical factors of >3 m2sr for electron and diffuse gamma-rays, >2 m2sr for cosmic ray nuclei. R&D is under way for reading out the LYSO signals with optical fiber coupled to image intensified IsCMOS and CALO prototype of 250 LYSO crystals.
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5. |
- Ding, Hao, et al.
(författare)
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A specific requirement for PDGF-C in palate formation and PDGFR-alpha signaling.
- 2004
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Ingår i: Nat Genet. - 1061-4036. ; 36:10, s. 1111-6
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Tidskriftsartikel (refereegranskat)abstract
- PDGF-C is a member of the platelet-derived growth factor (PDGF) family, which signals through PDGF receptor (PDGFR) alphaalpha and alphabeta dimers. Here we show that Pdgfc(-/-) mice die in the perinatal period owing to feeding and respiratory difficulties associated with a complete cleft of the secondary palate. This phenotype was less severe than that of Pdgfra(-/-) embryos. Pdgfc(-/-) Pdgfa(-/-) embryos developed a cleft face, subepidermal blistering, deficiency of renal cortex mesenchyme, spina bifida and skeletal and vascular defects. Complete loss of function of both ligands, therefore, phenocopied the loss of PDGFR-alpha function, suggesting that both PDGF-A and PDGF-C signal through PDGFR-alpha to regulate the development of craniofacial structures, the neural tube and mesodermal organs. Our results also show that PDGF-C signaling is a new pathway in palatogenesis, different from, and independent of, those previously implicated.
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7. |
- Fan, H. W., et al.
(författare)
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Different moisture regimes during the last 150 years inferred from a tree-ring delta O-18 network over the transitional zone of the Asian summer monsoon
- 2022
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Ingår i: Journal of Hydrology. - 0022-1694. ; 613
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Tidskriftsartikel (refereegranskat)abstract
- The East Asian summer monsoon (EASM) and Indian summer monsoon (ISM) are two interactive climate systems dominating the moisture variability of Monsoon Asia. However, ISM-EASM interactions and their effects on regional moisture dynamics remain unclear. This study investigated the spatiotemporal characteristics of monsoon-related hydroclimate variability by establishing a new tree-ring oxygen isotope ratio (delta O-18(tree)) network of eight delta O-18(tree) records covering the last 150 years in southern China, which differs from previous studies that used data from individual sites. The delta O-18(tree) chronologies were found to be sensitive to regional hydroclimatic changes during the monsoon season. The delta O-18(tree) network indicated an east-west clustering pattern in the ISM-EASM transitional zone, which demonstrates an asynchrony in d18Otree variability in the west and east of this region. Regional variability of the west and east delta O-18(tree) modes reflected the different moisture signals, as indicated by their significant correlations with modern observations and paleo-delta O-18 records in disparate upstream regions of moisture transport (the Indochina Peninsula and Southeast China). This finding was confirmed by the east-west distinct pattern of spatial isotopic depletion of monsoon rainfall that originates from coastal areas of tropical oceans (Bay of Bengal and South China Sea) to the study area, as well as the consistent present-day pattern of atmospheric vapor transport during the monsoon season. In addition, the west and east modes exhibited stronger associations with ISM variability, whereas the east-west delta O-18(tree) gradient captured the EASM-related hydroclimatic signal, suggesting that summer moisture variability in the ISM-EASM transitional zone was regulated more by ISM than by EASM during the last 150 years. The relationships between delta O-18(tree) and large-scale ocean-atmosphere interaction modes revealed that the El Nino-Southern Oscillation (ENSO) dominantly modulates delta O-18(tree) variability across southern China.
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8. |
- Fan, H., et al.
(författare)
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Different moisture regimes during the last 150 years inferred from a tree-ring δ18O network over the transitional zone of the Asian summer monsoon
- 2022
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Ingår i: Journal of Hydrology. - : Elsevier BV. - 0022-1694. ; 613
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Tidskriftsartikel (refereegranskat)abstract
- The East Asian summer monsoon (EASM) and Indian summer monsoon (ISM) are two interactive climate systems dominating the moisture variability of Monsoon Asia. However, ISM-EASM interactions and their effects on regional moisture dynamics remain unclear. This study investigated the spatiotemporal characteristics of monsoon-related hydroclimate variability by establishing a new tree-ring oxygen isotope ratio (δ18Otree) network of eight δ18Otree records covering the last 150 years in southern China, which differs from previous studies that used data from individual sites. The δ18Otree chronologies were found to be sensitive to regional hydroclimatic changes during the monsoon season. The δ18Otree network indicated an east–west clustering pattern in the ISM-EASM transitional zone, which demonstrates an asynchrony in δ18Otree variability in the west and east of this region. Regional variability of the west and east δ18Otree modes reflected the different moisture signals, as indicated by their significant correlations with modern observations and paleo-δ18O records in disparate upstream regions of moisture transport (the Indochina Peninsula and Southeast China). This finding was confirmed by the east–west distinct pattern of spatial isotopic depletion of monsoon rainfall that originates from coastal areas of tropical oceans (Bay of Bengal and South China Sea) to the study area, as well as the consistent present-day pattern of atmospheric vapor transport during the monsoon season. In addition, the west and east modes exhibited stronger associations with ISM variability, whereas the east–west δ18Otree gradient captured the EASM-related hydroclimatic signal, suggesting that summer moisture variability in the ISM-EASM transitional zone was regulated more by ISM than by EASM during the last 150 years. The relationships between δ18Otree and large-scale ocean–atmosphere interaction modes revealed that the El Niño-Southern Oscillation (ENSO) dominantly modulates δ18Otree variability across southern China. © 2022 Elsevier B.V.
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9. |
- Gou, Shaoqing, et al.
(författare)
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Passive design optimization of newly-built residential buildings in Shanghai for improving indoor thermal comfort while reducing building energy demand
- 2018
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788. ; 169, s. 484-506
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this paper is to optimize the passive design of newly-built residential buildings in hot summer and cold winter region of China for improving indoor thermal comfort while reducing building energy demand. In this respect, this paper investigates the performance of a representative apartment building in the city of Shanghai and evaluates the optimum solutions by using a developed optimization approach, which includes three major steps of 1) setting the model for multi-objective optimization, 2) sensitivity analysis for reducing the dimension of input variables, and 3) multi-objective optimization by using the Non-dominated Sorting Genetic Algorithm II (NSGA-II) coupled with the Artificial Neural Network (ANN), among which a novel indicator for evaluating the annual indoor thermal comfort of residential buildings of Shanghai named Comfort Time Ratio (CTR) is defined based on the modification of Szokolay's theory in terms of bioclimatic analysis, and the impacts of passive design variables on the indoor thermal comfort and building energy demand in terms of different directions are comprehensively investigated. Results of the multi-objective optimization indicate that the residential buildings of Shanghai have a great potential in comfort-improvement and energy-saving. A series of novel optimal passive design tactics for residential buildings in Shanghai are derived accordingly which could be easily understood and conveniently carried out by the architects in practice.
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12. |
- Wang, X. J., et al.
(författare)
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Contrasting characteristics, changes, and linkages of permafrost between the Arctic and the Third Pole
- 2022
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Ingår i: Earth-Science Reviews. - : Elsevier BV. - 0012-8252. ; 230
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Tidskriftsartikel (refereegranskat)abstract
- Permafrost degradation poses serious threats to both natural and human systems through its influence on ecological-hydrological processes, infrastructure stability, and the climate system. The Arctic and the Third Pole (Tibetan Plateau, TP hereafter) are the two northern regions on Earth with the most extensive permafrost areas. However, there is a lack of systematic comparisons of permafrost characteristics and its climate and ecoenvironment between these two regions and their susceptibility to disturbances. This study provides a comprehensive review of the climate, ecosystem characteristics, ground temperature, permafrost extent, and active-layer thickness, as well as the past and future changes in permafrost in the Arctic and the TP. The potential consequences associated with permafrost degradation are also examined. Lastly, possible connections between the two regions through land-ocean-atmosphere interactions are explored. Both regions have experienced dramatic warming in recent decades, characterized by Arctic amplification and elevation-dependent warming on the TP. Permafrost temperatures have increased more rapidly in the Arctic than on the TP, and will likely be reinforced under a future high emission scenario. Near-surface permafrost extents are projected to shrink in both regions in the coming decades, with a more dramatic decline in the TP. The active layer on the TP is thicker and has substantially deepened, and is projected to thicken more than in the Arctic. Widespread permafrost degradation increases geohazard risk and has already wielded considerable effects on the human and natural systems. Permafrost changes have also exerted a pronounced impact on the climate system through changes in permafrost carbon and land-atmosphere interactions. Future research should involve comparative studies of permafrost dynamics in both regions that integrate long-term observations, high-resolution satellite measurements, and advanced Earth System models, with emphasis on linkages between the two regions.
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