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Towards a semi-empirical model of the sea ice thickness based on hyperspectral remote sensing in the Bohai Sea

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Acta Oceanologica Sinica 2017年第1期36卷 80-89页

作者： YUAN Shuai GU Wei liu chengyu XIE Feng National Marine Environmental Monitoring Center State Oceanic Administration State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Key Laboratory of Spatial Active Opto-electronic Techniques Shanghai Institute of Technical PhysicsChinese Academy of Sciences

Sea ice thickness is one of the most important input parameters for the prevention and mitigation of sea ice disasters and the prediction of local sea environments and climates. Estimating the sea ice thickness is currently the most important issue in the study of sea ice remote sensing. With the Bohai Sea as the study area, a semiempirical model of the sea ice thickness（SEMSIT） that can be used to estimate the thickness of first-year ice based on existing water depth estimation models and hyperspectral remote sensing data according to an optical radiative transfer process in sea ice is proposed. In the model, the absorption and scattering properties of sea ice in different bands（spectral dimension information） are utilized. An integrated attenuation coefficient at the pixel level is estimated using the height of the reflectance peak at 1 088 nm. In addition, the surface reflectance of sea ice at the pixel level is estimated using the 1 550–1 750 nm band reflectance. The model is used to estimate the sea ice thickness with Hyperion images. The first validation results suggest that the proposed model and parameterization scheme can effectively reduce the estimation error associated with the sea ice thickness that is caused by temporal and spatial heterogeneities in the integrated attenuation coefficient and sea ice surface. A practical semi-empirical model and parameterization scheme that may be feasible for the sea ice thickness estimation using hyperspectral remote sensing data are potentially provided.

关键词： Bohai Sea sea ice thickness hyperspectral remote sensing semi-empirical model

Characteristics of the sea ice reflectance spectrum polluted by oil spills based on field experiments in the Bohai Sea

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Acta Oceanologica Sinica 2017年第1期36卷 73-79页

作者： CHAO Jinlong liu chengyu LI Ying LIN Xia YAN Yu Institute of Geography Science Taiyuan Normal University Yuci 030619 China State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Beijing 100875 China Key Laboratory of Spatial Active Opto-electronic Technologies Shanghai Insitute of Technical Physics Chinese Academy of Sciences Shanghai 200083 China National Marine Environmental Monitoring Center State Oceanic Administration Dalian 116023 China Institute of City and Environment Liaoning Normal University Dalian 116029 China

Oil spilled on the sea ice surface in the Bohai Sea of China is studied through the field measurements of the reflectance of a simulated sea ice-oil film mixed pixel. The reflection characteristics of sea ice and oil film are also analyzed. It is found that the mixed pixel of sea ice and oil film is a linear mixed pixel. The means of extracting sea ice pixels containing oil film is presented using a double-band ratio oil-film sea-ice index（DROSI） and a normalized difference oil-film sea-ice index（NDOSI） through the analysis of the reflectance curves of the sea iceoil film pixel for different ratios of oil film. The area proportion of the oil film in the sea ice-oil film pixel can be accurately estimated by the average reflectance of the band of 1 610–1 630 nm, and the volume of the spilled oil can be further estimated. The method of the sea ice-oil film pixel extraction and the models to estimate the proportion of oil film area in the sea ice-oil film pixel can be applied to the oil spill monitoring of the ice-covered area in the Bohai Sea using multispectral or hyperspectral remote sensing images in the shortwave infrared band（1 500–1 780 nm）.

关键词： remote sensing sea ice the Bohai Sea of China oil spill mixed pixel

On the surface roughness characteristics of the land fast sea-ice in the Bohai Sea

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Acta Oceanologica Sinica 2014年第7期33卷 97-106页

作者： liu chengyu CHAO Jinlong GU Wei LI Lantao XU Yingjun State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Shanghai Institute of Technical Physics Chinese Academy of Sciences Academy of Ministry of Civil Affairs and Ministry of Education for Disaster Reduction and Emergency Management Beijing Normal University

The surface roughness characteristics （e.g., height and slope） of sea ice are critical for determining the parameters of an electromagnetic scattering, a surface emission and a surface drag coefficients. It is also important in identifying various ice types, retrieval ice thickness, surface temperature and drag coefficients from remote sensing data. The point clouds （a set of points which are usually defined by X, Y, and Z coordinates that represents the external surface of an object on earth） of land fast ice in five in situ sites in the eastern coast Bohai Sea were measured using a laser scanner-Trimble GX during 2011-2012 winter season. Two hundred and fifty profiles selected from the point clouds of different samples have been used to calcu- late the height root mean square, height skewness, height kurtosis, slope root mean square, slope skewness and slope kurtosis of them. The root mean square of the height, the root mean square of the slope and the correlation length are about 0.090, 0.075 and 11.74 m, respectively. The heights of 150 profiles in three sites manifest the Gaussian distribution and the slopes of total 250 profiles distributed exponentially. In addition, the fractal dimension and power spectral density profiles were calculated. The results show that the fractal dimension of land fast ice in the Bohai Sea is about 1.132. The power spectral densities of 250 profiles can be expressed through an exponential autocorrelation function.

关键词： sea ice roughness statistical parameters fractal dimension spectral density

MacroH2A1.1 cooperates with EZH2 to promote adipogenesis by regulating Wnt signaling

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Journal of Molecular Cell Biology 2017年第4期9卷 325-337页

作者： Danyang Wan chengyu liu Yu Sun Wenjun Wang Kun Huang Ling Zheng Hubei Key Laboratory of Cell Homeostasis College of Life Sciences Wuhan University Wuhan 430072 China Tongji School of Pharmacy Huazhong University of Science and Technology Wuhan 430030 China

White adipocytes play important roles in many physiological processes, including energy storage, endocrine signaling, and inflammatory responses. Understanding the molecular mechanisms of adipocyte formation （adipogenesis） provides insights into therapeutic approaches against obesity and its related diseases. Many transcriptional Factors and epigenetic enzymes are known to regulate adipogenesis; however, whether histone variants play a role in this process is unknown. Here we found that macroH2A1.1 （mH2A1.1）, a variant of histone H2A, was upregulated during adipocyte differentiation in 3T3-L1 ceils and in the white adipose tissue of obese mice. Ablation of mH2A1.1 activated Wnt/β-catenin signaling pathway, while overexpression of mH2A1.1 showed opposite effects. We farther found that mH2A1.1 regulated Wnt/β-catenin signaling pathway by cooperating with EZH2, a histone H3K27 methyltrans- ferase, thus led to accumulation of H3K27me2 and H3K27me3 on the promoters of Wnt genes. Mutations in the macro-domain, mH2A1.1G224E, and mH2A1.1G314E, not only impaired adipogenesis, but also impaired the binding ability of mH2A1.1 to EZH2 and the enrichments of H3K27me2 and H3K27me3 on the promoters of Wnt genes. Together, our study reveals a novel regulatory role of mH2A1.1 in adipogenesis and obesity, which provides new insights in white fat development.

关键词： adipogenesis EZH2 H3K27me2/me3 macroH2A1.1 Wnt/β-catenin signaling

The actin motor protein OsMYA1 associates with OsExo70H1 and contributes to rice secretory defense by modulating OsSyp121 distribution

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Journal of Integrative Plant Biology 2024年第9期66卷 2058-2075页

作者： Yuan‐Bao Li chengyu liu Ningning Shen Shuai Zhu Xianya Deng Zixuan liu Li‐Bo Han Dingzhong Tang State Key Laboratory of Ecological Control of Fujian‐Taiwan Crop Pests Key Laboratory of Ministry of Education for GeneticsBreeding and Multiple Utilization of CropsPlant Immunity CenterFujian Agriculture and Forestry UniversityFuzhou 350002China College of Agriculture Fujian Agriculture and Forestry UniversityFuzhou 350002China College of Life Sciences Fujian Agriculture and Forestry UniversityFuzhou 350002China School of Future Technology Fujian Agriculture and Forestry UniversityFuzhou 350002China

Magnaporthe oryzae(***)is a devastating hemibiotrophic *** biotrophic invasive hyphae(IH)are enclosed in the extrainvasive hyphal membrane produced by plant cells,thus generating a front line of the battlefield between the pathogen and the host *** plants,defense-related complexes such as proteins,callose-rich materials and vesicles,are directionally secreted to this interface to confer defense responses,but the underlying molecular mechanism is poorly *** this study,we found that a Myosin gene,Myosin A1(OsMYA1),contributed to rice *** OsMYA1 knockout mutant exhibited decreased resistance to *** ***1 localizes to the actin cytoskeleton and surrounds the IH of ***1 interacts with an exocyst subunit,OsExo70H1,and regulates its accumulation at the plasma membrane(PM)and pathogen–plant ***,OsExo70H1 interacted with the rice syntaxin of the plants121 protein(OsSyp121),and the distribution of OsSyp121 to the PM or the pathogen–plant interface was disrupted in both the OsMYA1 and OsExo70H1 ***,these results not only reveal a new function of OsMYA1 in rice blast resistance,but also uncover a molecular mechanism by which plants regulate defense against *** by OsMYA1-initiated vesicle secretory pathway,which originates from the actin cytoskeleton to the PM.

关键词： cytoskeleton plant defense mechanism rice blast vesicle delivery

Microseismic observations reveal that internal waves intensify seabed methane release

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Science China Earth Sciences 2024年第10期67卷 3186-3203页

作者： Zhaoyang TIAN Yonggang JIA Junjiang ZHU Tian CHEN Hui WANG Chunsheng JI chengyu liu Longyu LU Manchao HE Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China Frontiers Science Center for Deep Ocean Multispheres and Earth System Key Lab of Submarine Geosciences and Prospecting TechniquesMOE and College of Marine GeosciencesOcean University of ChinaQingdao 266100China Guangzhou Marine Geological Survey China Geological SurveyGuangzhou 511458China Shandong Earthquake Agency Jinan 250014China State Key Laboratory for Tunnel Engineering China University of Mining and Technology(Beijing)Beijing 100083China

Internal waves transport material and energy from the upper water column to the deep ocean, disturbing seabed sediments and resulting in phenomena such as seabed erosion and changes in topography. On the northern slope of the South China Sea and in many coastal margins worldwide, the zones with internal wave action closely overlap with areas where natural gas hydrates are present. However, due to significant differences in the spatial and temporal scales, understanding the influence of internal waves on methane releases from deep seabeds is challenging. In this study, in situ observations of seabed microseismicity and internal waves are conducted at water depths of 655 meters and 1450 meters in the Pearl River Canyon of the South China Sea. The microseismicity caused by internal waves and seabed methane releases is identified, and a method to establish the correlation between internal waves and seabed methane releases through the use of microseismic recordings is proposed, aiming to obtain direct observational evidence of internal waves intensifying seabed methane releases. The results show that internal waves and seabed methane releases generate significant microseismic signals, indicating the continuous influence of internal waves on the deep seabed of the northern slope of the South China Sea and revealing active methane release phenomena on the seabed. At both long and short time scales, internal waves increase the frequency of seabed methane releases by 4.2 times and 2.4 times, respectively, while also enhancing the intensity of these releases. These changes are influenced by the alterations in seabed flow velocity, pressure, and temperature that are induced by internal wave activities. This study emphasizes that microseismic signals are effective carriers of information for multiscale geological processes on seabeds and suggests that internal waves exacerbate marine geological hazards and contribute to global climate change by intensifying seabed methane relea

关键词： Internal waves Seabed methane release Microseismic observation Ocean bottom seismometer Northern slope of the South China Sea

Encapsulated carbon nanotube array as a thermal interface material compatible with standard electronics packaging

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Nano Research 2023年第8期16卷 11389-11400页

作者： Ruixiang Bai Yangbing Wei Jiyuan Xu Xiaobo Li Menglin Li Ziwen Zou Xinyan Huang chengyu liu Yiwei Sun Menglong Hao Key Laboratory of Energy Thermal conversion and control of Ministry of Education National Engineering Research Center of Power Generation Control and SafetySchool of Energy and EnvironmentSoutheast UniversityNanjing 210096China School of Materials Science and Engineering School of Energy and EnvironmentSoutheast UniversityNanjing 210096China Nanjing Research Institute of Electronics Technology Nanjing 210039China Research Centre for Fire Engineering Hong Kong Polytechnic UniversityKowloon 999077Hong KongChina State Key Laboratory of Bioelectronics School of Instrument Science and EngineeringSoutheast UniversityNanjing 210096China

Vertically aligned carbon nanotubes arrays(VACNTs)are a promising candidate for the thermal interface material(TIM)of next-generation electronic devices due to their attractive thermal and mechanical ***,the environment required for synthesizing VACNTs is harsh and severely incompatible with standard device packaging ***’extremely low in-plane thermal conductivity also limits its performance for cooling hot ***,using a transfer-and-encapsulate strategy,a two-step soldering method is developed to cap both ends of the VACNTs with copper microfoils,forming a standalone Cu-VACNTs-Cu sandwich TIM and avoiding the need to directly grow VACNTs on chip *** new TIM is fully compatible with standard packaging,with excellent flexibility and high thermal conductivities in both in-plane and through-plane *** mechanical compliance behavior and mechanism,which are critical for TIM applications,are investigated in depth using in situ *** thermal performance is further verified in an actual light emitting diode(LED)cooling experiment,demonstrating low thermal resistance,good reliability,and achieving a 17℃ temperature reduction compared with state-of-the-art commercial *** study provides a viable solution to VACNTs’longstanding problem in device integration and free-end contact resistance,bringing it much closer to application and solving the critical thermal bottleneck in next-generation electronics.

关键词： vertically aligned carbon nanotube arrays(VACNTs) sandwich structure thermal conductivity thermal interface materials(TIMs)

A wearable real-time telemonitoring electrocardiogram device compared with traditional Holter monitoring

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The Journal of Biomedical Research 2021年第3期35卷 238-246页

作者： Qin Shen Jianqing Li Chang Cui Xingyao Wang Hongxiang Gao chengyu liu Minglong Chen Department of Cardiology the First Affiliated Hospital of Nanjing Medical UniversityNanjingJiangsu 210029China School of Biomedical Engineering and Informatics Nanjing Medical UniversityNanjingJiangsu 211166China School of Instrument Science and Engineering Southeast UniversityNanjingJiangsu 210096China

Arrhythmias are very common in the healthy populations as well as patients with cardiovascular *** them,atrial fibrillation(AF)and malignant ventricular arrhythmias are usually associated with some clinical *** diagnosis of arrhythmias,particularly AF and ventricular arrhythmias,is very important for the treatment and prognosis of *** is a gold standard commonly recommended for noninvasive detection of paroxysmal ***,it has some shortcomings such as fixed detection timings,delayed report and inability of remote real-time *** deal with such problems,we designed and applied a new wearable 72-hour triple-lead H3-electrocardiogram(ECG)device with a remote cloud-based ECG platform and an expertsupporting *** this study,31 patients were recruited and 24-hour synchronous ECG data by H3-ECG and Holter were *** the H3-ECG group,ECG signals were transmitted using remote real-time modes,and confirmed reports were made by doctors in the remote expert-supporting system,while the traditional modes and detection systems were used in the Holter *** results showed no significant differences between the two groups in 24-hour total heart rate(HR),averaged HR,maximum HR,minimum HR,premature atrial complexes(PACs)and premature ventricular complexes(PVCs)(P>0.05).The sensitivity and specificity of capture and remote automatic cardiac events detection of PACs,PVCs,and AF by H3-ECG were 93%and 99%,98%and 99%,94%and 98%,***,the long-term limb triple-lead H3-ECG device can be utilized for domiciliary ECG self-monitoring and remote management of patients with common arrhythmia under medical supervision.

关键词： wearable ECG device Holter real-time remote ECG monitoring

A single-nucleus transcriptomic atlas of primate liver aging uncovers the pro-senescence role of SREBP2 in hepatocytes

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Protein & Cell 2024年第2期15卷 98-120页

作者： Shanshan Yang chengyu liu Mengmeng Jiang Xiaoqian liu Lingling Geng Yiyuan Zhang Shuhui Sun Kang Wang jian Yin Shuai Ma Si Wang Juan Carlos Izpisua Belmonte Weiqi Zhang Jing Qu Guang-Hui liu Advanced Innovation Center for Human Brain Protection and National Clinical Research Center for Geriatric Disorders Xuanwu Hospital Capital Medical UniversityBeijing 100053China State Key Laboratory of Membrane Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Aging Translational Medicine Center International Center for Aging and CancerBeijing Municipal Geriatric Medical Research CenterXuanwu HospitalCapital Medical UniversityBeijing 100053China State Key Laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China CAS Key Laboratory of Genomic and Precision Medicine Beijing Institute of GenomicsChinese Academy of Sciences and China National Center for BioinformationBeijing 100101China Xuanwu Hospital Capital Medical University Beijing 100053China University of Chinese Academy of Sciences Beijing 100049China Institute for Stem Cell and Regeneration Chinese Academy of SciencesBeijing 100101China Beijing Institute for Stem Cell and Regenerative Medicine Beijing 100101China Aging Biomarker Consortium Beijing 100101China Altos Labs Inc.San DiegoCA 94022USA

Aging increases the risk ofliver diseases and systemic susceptibility to aging-related ***,cell type-specific changes and the underlying mechanism of liver aging in higher vertebrates remain incompletely ***,we constructed the first single-nucleus transcriptomic landscape of primate liver aging,in which we resolved cell type-specific gene expression fluctuation in hepatocytes across three liver zonations and detected aberrant cell-cell interactions between hepatocytes and niche *** in-depth dissection of this rich dataset,we identifed impaired lipid metabolism and upregulation of chronic inflammation-related genes prominently associated with declined liver functions during *** particular,hyperactivated sterol regulatory element-binding protein(SREBP)signaling was a hallmark of the aged liver,and consequently,forced activation of SREBP2 in human primary hepatocytes recapitulated in vivo aging phenotypes,manifesting as impaired detoxification and accelerated cellular *** study expands our knowledge of primate liver aging and informs the development of diagnostics and therapeutic interventions for liver aging and associated diseases.

关键词： single-nucleus RNA sequencing liver hepatocytes aging senescence SREBP2