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| 1 | A high-resolution small animal SPECT system developed at Tsinghua显示文摘An SPECT system dedicated to small animal imaging shall be of a millimeter spatial resolution or even better.This study was aimed at achieving 0.5-mm spatial resolution for a small animal SPECT system at low cost.It was developed from a single-head clinical SPECT scanner,with a seven-pinhole collimator and a four-degree-offreedom motion control stage.Several key techniques were developed,including high-resolution image reconstruction algorithm,high accuracy geometrical calibration method,and optimized system matrix derivation scheme.The system matrix was derived from Monte-Carlo simulation and de-noised by fitting each point spread function to a two dimensional Gaussian function.Experiments of point source and ultra micro hot rod phantom were conducted.With a spatial resolution of 0.5-0.6 mm,this system provides a practical way for low-cost high-resolution animal imaging on a clinic SPECT system. | DAI Tiantian MATianyu LIU Hui CUI Junjian WEI Qingyang LIU Yaqiang WANG Shi | 2011 | Nuclear Science and Techniques2011，22，6： | 3 |
| 2 | A chromosome-level genome assembly provides insights into Cornus wilsoniana evolution, oil biosynthesis, and floral bud development显示文摘Cornus wilsoniana W.is a woody oil plant with high oil content and strong hypolipidemic effects,making it a valuable species for medicinal,landscaping,and ecological purposes in China.To advance genetic research on this species,we employed PacBio together with Hi-C data to create a draft genome assembly for C.wilsoniana.Based on an 11-chromosome anchored chromosome-level assembly,the estimated genome size was determined to be 843.51 Mb.The N50 contig size and N50 scaffold size were calculated to be 4.49 and 78.00 Mb,respectively.Furthermore,30474 protein-coding genes were annotated.Comparative genomics analysis revealed that C.wilsoniana diverged from its closest species∼12.46 million years ago(Mya).Furthermore,the divergence between Cornaceae and Nyssaceae occurred>62.22 Mya.We also found evidence of whole-genome duplication events and whole-genome triplicationγ,occurring at∼44.90 and 115.86 Mya.We further inferred the origins of chromosomes,which sheds light on the complex evolutionary history of the karyotype of C.wilsoniana.Through transcriptional and metabolic analysis,we identified two FAD2 homologous genes that may play a crucial role in controlling the oleic to linoleic acid ratio.We further investigated the correlation between metabolites and genes and identified 33 MADS-TF homologous genes that may affect f lower morphology in C.wilsoniana.Overall,this study lays the groundwork for future research aimed at identifying the genetic basis of crucial traits in C.wilsoniana. | Zhenxiang He Haoyu Chao Xinkai Zhou Qingyang Ni Yueming Hu Ranran Yu Minghuai Wang Changzhu Li Jingzhen Chen Yunzhu Chen Yong Chen Chunyi Cui Liangbo Zhang Ming Chen Dijun Chen | 2023 | Horticulture Research2023，10，11： | 0 |
| 3 | Application of Activated Alumina Powders in Corundum Castables显示文摘There are many brands of activated alumina powders in the market and the products from different manufacturers exist subtle differences. In this work, four brands of activated alumina powder which are the mainstream products in China with the same marked particle size of 2-3 μm were added to corundum castables to investigate the effect of different activated alumina powder on properties of corundum castables. It is found that the multi-peak distribution, round-shape particle,low impurities content of alumina powder are of great benefit to the improvement of the overall performance of castables.Obvious CA6 frame structure formed in castables matrix is conductive to improving the thermal shock resistance and high temperature strength of castables. One kind of domestic alumina micropowder studied in this work has good application value and prospect in corundum castables because of the excellent comprehensive performance. | LI Youqi DING Jinxing CUI Qingyang ZHAO Jizeng | 2019 | China's Refractories2019，28，2： | 0 |
| 4 | Relation Between Sintering Reactivity of Matrix and Thermal Shock Resistance of Ultra-low Cement Bonded Corundum-spinel Castables for Fired Purging Plugs显示文摘Purging plugs installed in the bottom of steel ladles are widely used for the secondary refining of high quality steel grades. The dynamic service conditions and temperature gradients caused by the cold inert gas blown through the plug during stirring create a strong thermal shock impact on the materials. This can affect its service life and restrict the safety and efficiency of steel making if the plug fails during use. In this work,the influence of the particle size distribution( PSD) and amount of reactive alumina on the sintering behavior of ultra-low cement bonded corundum-spinel based castables was investigated on lab scale. The relationship between sintering reactivity of matrix and thermal shock resistance of castables was evaluated in detail. Results show that the sintering of castables can be intensified by using finer reactive alumina. However, excessive sintering of the castable through finer reactive alumina is negative for thermal shock resistance. The microstructure characterization reveals that castables with more intense sintering show denser matrix structure,which is less effective inhampering crack propagation and therefore results in decline of their thermal shock resistance. | ZHANG Ju LONG Bin ZHOU Yunpeng Andreas BUHR WANG Feng CUI Qingyang XIE Guofeng DING Dafei JIA Quanli YE Guotian | 2018 | China's Refractories2018，27，4： | 0 |
| 5 | MEIC-global-CO_(2):A new global CO_(2)emission inventory with highly-resolved source category and sub-country information显示文摘CO_(2)emission inventory provides fundamental data for climate research and emission mitigation.Currently,most global CO_(2)emission inventories were developed with energy statistics from International Energy Agency(IEA)and were available at country level with limited source categories.Here,as the first step toward a high-resolution and dynamic updated global CO_(2)emission database,we developed a data-driven approach to construct seamless and highly-resolved energy consumption data cubes for 208 countries/territories,797 sub-country administrative divisions in 29 countries,42 fuel types,and 52 sectors,with the fusion of activity data from 24 international statistics and 65 regional/local statistics.Global CO_(2)emissions from fossil fuel combustion and cement production in 1970–2021 were then estimated with highly-resolved source category(1,484 of total)and sub-country information(797 of total).Specifically,73%of global CO_(2)emissions in 2021 were estimated with sub-country information,providing considerably improved spatial resolution for global CO_(2)emission accounting.With the support of detailed information,the dynamics of global CO_(2)emissions across sectors and fuel types were presented,representing the evolution of global economy and progress of climate mitigation.Remarkable differences of sectoral contribution were found across sub-country administrative divisions within a given country,revealing the uneven distribution of energy and economic structure among different regions.Our estimates were generally consistent with existing databases at aggregated level for global total or large emitters,while large discrepancies were observed for middle and small emitters.Our database,named the Multiresolution Emission Inventory model for Climate and air pollution research(MEIC)is publicly available through http://gffzz6c575fb1d0a54d36h9fp5owq665bb6ou0.ffgz.tsg.suse.edu.cn with highly-resolved information and timely update,which provides an independent carbon emission accounting data source for climate research. | Ruochong XU Dan TONG Qingyang XIAO Xinying QIN Cuihong CHEN Liu YAN Jing CHENG Can CUI Hanwen HU Wenyu LIU Xizhe YAN Huaxuan WANG Xiaodong LIU Guannan GENG Yu LEI Dabo GUAN Kebin HE Qiang ZHANG | 2024 | Science China Earth Sciences2024，67，2： | 0 |
| 6 | Rhodium catalyzed asymmetric synthesis of Chiraphos derivatives显示文摘Herein,we report a highly efficient versatile synthetic route to Chiraphos derivatives through Rh/Ph-bod catalyzed asymmetric addition of aryl boronic acids to phosphinyl dienes.Various substituted phosphinyl dienes,both on the parent skeleton and the phosphine atoms,were well tolerated with this method and provided chiral phosphine oxides in satisfied yield and up to 95%ee.The corresponding Chiraphos derivative displayed an advantage over Chiraphos in the representative Pd-catalyzed asymmetric 1,4-addition reaction. | Ying-Ying Sun Bin Zhang Liangbin Yu Ranran Cui Qingyang Zhao Qing-Wei Zhang | 2022 | Chinese Chemical Letters2022，33，12： | 0 |
| 7 | The effect of nitrogen on the compressibility and conductivity of iron at high pressure显示文摘Although nitrogen in the Earth’s interior has attracted significant attention recently,it remains the most enigmatic of the light elements in the Earth’s core.In this work,synchrotron X-ray diffraction(XRD)and electrical conductivity experiments were conducted on iron nitrides(Fe_(2)N and Fe_(4)N)in diamond anvil cells(DACs)up to about 70 GPa at ambient temperature.These results show that iron nitrides are stable up to at least 70 GPa.From the equation of state(EOS)parameters,iron nitrides are more compressible than iron carbides.Moreover,using the van der Pauw method and Wiedemann-Franz law,the electrical and thermal conductivity of samples were determined to be much lower than that of iron carbides.The conductivities of Fe_(2)N and Fe_(4)N were similar at 20–70 GPa,suggesting no evident effects by varying the N stoichiometries in iron nitrides.Iron nitrides are less dense and conductive but more compressible than carbides at 0–70 GPa.This study indicates that less nitrogen than carbon can explain geophysical phenomena in the deep Earth,such as the density deficit. | Yukai Zhuang Xiaowan Su Nilesh P.Salke Zhongxun Cui Qingyang Hu Dongzhou Zhang Jin Liu | 2021 | Geoscience Frontiers2021，12，2： | 0 |
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