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Attribution of the Tibetan Plateau to northern drought

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National Science Review 2020年第3期7卷 489-492页

作者： Yuzhi liu yaohui li Jianping Huang Qingzhe Zhu Shanshan Wang Key Laboratory for Semi-Arid Climate Change of the Ministry of Education Lanzhou University Institute of Arid Meteorology China Meteorology Administration

The Tibetan Plateau (TP), which is located in Asia and has an average elevation of over 4000 m, acts as a raised source of heat [1] and an isolated region of humidity in the atmosphere [2]. The TP serves as a ‘world ... 详细信息

关键词： Attribution of the Tibetan Plateau to northern drought

Turbulence Intensity and Turbulent Kinetic Energy Parameters over a Heterogeneous Terrain of Loess Plateau

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Advances in Atmospheric Sciences 2015年第9期32卷 1291-1302页

作者： YUE Ping ZHANG Qiang WANG Runyuan li yaohui WANG Sheng Key Laboratory of Arid Climatic Change and Reducing Deserter of Gansu Province Institute of Arid MeteorologyChina Meteorological Administration

A deep understanding of turbulence structure is important for investigating the characteristics of the atmospheric boundary layer,especially over heterogeneous *** the present study,turbulence intensity and turbulent kinetic energy（TKE）parameters are analyzed for different conditions with respect to stability,wind direction and wind speed over a valley region of the Loess Plateau of China during December 2003 and January *** purpose of the study is to examine whether the observed turbulence intensity and TKE parameters satisfy Monin–Obukhov similarity theory（MOST）,and analyze the wind shear effect on,and thermal buoyancy function of,the TKE,despite the terrain *** results demonstrate that the normalized intensity of turbulence follows MOST for all stability in the horizontal and vertical directions,as well as the normalized TKE in the horizontal *** shear effect of the wind speed in the Loess Plateau region is strong in winter and could enhance turbulence for all stability *** daytime,the buoyancy and shear effect together constitute the generation of TKE under unstable *** night,the contribution of buoyancy to TKE is relatively small,and mechanical shearing is the main production form of turbulence.

关键词： heterogeneous terrain turbulence intensity turbulent kinetic energy Monin–Obukhov similarity function

Proteomic analysis of effects of Chinese herbs to calm the liver and suppress hyperactive yang in a rat migraine model

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Neural Regeneration Research 2008年第5期3卷 494-497页

作者： Jianjun Hu Zeqi Chen Guangwei Zhong Wei li yaohui Yin Institute of Integrated Traditional Chinese and Western Medicine Xiangya Hospital Central South University Changsha 410008 HunanProvince China

BACKGROUND： The expression of ubiquitin and energy-associated protein can provoke migraines. Studies have suggested that expression is closely linked to ＂hyperactivity of liver-yang theory＂ in Traditional Chinese Medicine （TCM）, as well as the function of periphery sympathetic nerve medulla. OBJECTIVE： To observe proteomic changes in a rat migraine model with regard to hyperactivity of liver-yang when treated with Chinese herbs to calm the liver and suppress hyperactive yang compound. DESIGN, TIME AND SETTING： A randomized controlled study. This study was performed at the laboratory of Institute of Integrated Traditional Chinese and Western Medicine, Institute of Human Reproduction and Stem Cell Engineering and Key Laboratory of Cancer Proteomics of Ministry of Health, Xiangya Hospital Affiliated to Central South University between September 2006 and July 2007. MATERIALS： Thirty, male, healthy, Sprague-Dawley rats, aged eight weeks, were included in the final analysis. Aconite, to calm the liver and suppress hyperactive yang compound, was provided by the Dispensary of Traditional Chinese medicine, Xiangya Hospital, Central South University. A physiological electronic stimulator, type SDQ-1, was provided by Bengbu Practical Institute of Technology. The left trigeminal ganglion was localized and stimulated for 10 minutes, and the rats were orally administered an aconite concoction to establish a rat migraine model with hyperactivity of liver-yang. METHODS： Rats were randomly divided into a normal control group, model group, and TCM treatment group, with 10 rats in each group. The TCM treatment group was orally treated to calm the liver and suppress the hyperactive yang compound once a day for 28 days. In contrast, the model group and normal group were orally administered the same amount of distilled water once a day for 28 days. MAIN OUTCOME MEASURES： The total proteins from adrenal glands of the three groups were separated by two-dimensional gel electrophoresis （2-DE

关键词： migraine liver yang hyperactivity adrenal glands pacifying liver

Impact of Sky Conditions on Net Ecosystem Productivity over a “Floating Blanket” Wetland in Southwest China

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Advances in Atmospheric Sciences 2024年第2期41卷 355-368页

作者： Yamei SHAO Huizhi liU Qun DU Yang liU Jihua SUN yaohui li Jinlian li State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100029China Yunnan Meteorological Observatory Kunming 530100China College of Aviation Meteorology Civil Aviation Flight University of ChinaGuanghan 618307China Meteorological Bureau of Tengchong County Baoshan 679100China

Based on eddy covariance(EC) measurements during 2016–20, the effects of sky conditions on the net ecosystem productivity(NEP) over a subtropical “floating blanket ” wetland were investigated. Sky conditions were divided into overcast, cloudy, and sunny conditions. On the half-hourly timescale, the daytime NEP responded more rapidly to the changes in the total photosynthetic active radiation(PARt) under overcast and cloudy skies than that under sunny skies. The increase in the apparent quantum yield under overcast and cloudy conditions was the greatest in spring and the least in summer. Additionally, lower atmospheric vapor pressure deficit(VPD) and moderate air temperature were more conducive to enhancing the apparent quantum yield under cloudy skies. On the daily timescale, NEP and the gross primary production(GPP) were higher under cloudy or sunny conditions than those under overcast conditions across seasons. The daily NEP and GPP during the wet season peaked under cloudy skies. The daily ecosystem light use efficiency(LUE) and water use efficiency(WUE) during the wet season also changed with sky conditions and reached their maximum under overcast and cloudy skies, respectively. The diffuse photosynthetic active radiation(PAR_d) and air temperature were primarily responsible for the variation of daily NEP from half-hourly to monthly timescales, and the direct photosynthetic active radiation(PAR_b) had a secondary effect on NEP. Under sunny conditions, PAR_b and air temperature were the dominant factors controlling daily NEP. While daily NEP was mainly controlled by PAR_d under cloudy and overcast conditions.

关键词： diffuse radiation eddy covariance NEP controlling factors wetland path analysis

Effects of Updated RegCM4 Land Use Data on Near-Surface Temperature Simulation in China

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Journal of Meteorological Research 2018年第5期32卷 758-767页

作者： Yulong REN yaohui li Zhaoxia PU Tiejun ZHANG Haixia DUAN Wei WANG Institute of Arid Meteorology of China Meteorological Administration(CMA) Key Laboratory of Arid Climatic Change and Disaster Reduction of Gansu Province and CMALanzhou 730020China Department of Atmospheric Sciences University of UtahUtah 84112USA

Biogeophysical effects of land use and land cover （LULC） changes play a significant role in modulating climate on various spatial scales. In this study, a set of recent LULC products with a spatial resolution of 500 m was developed in China for update in RegCM4 （regional climate model version 4）. Two sets of comparative numerical experiments were conducted to study the effects of LULC changes on near-surface temperature simulation. The results show that after LULC changes, areas of crops and mixed woodlands as well as urban areas increase over entire China, accom- panied with greatly expanded mixed farming and forests/field mosaics in southern China, and reduced areas of 1） ir- rigated crops and short grasses in northern China and the Tibetan Plateau, and 2） semi-desert and desert in northwest-em China. Improvements in the LULC data clearly result in more accurate simulations of the near-surface temperat-ure. Specifically, increasing latent heat and longwave albedo due to enhanced LULC in certain areas lead to reduc-tion in land surface temperature （LST）, while changes in shortwave albedo and sensible heat also exert a great influ- ence on the LST. Overall, these parameter adjustments reduce the biases in near-surface temperature simulation.

关键词： land use and land cover RegCM4 (regional climate model version 4) temperature simulation

Evaluation of the Forecast Accuracy of Near-Surface Temperature and Wind in Northwest China Based on the WRF Model

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Journal of Meteorological Research 2018年第3期32卷 469-490页

作者： Haixia DUAN yaohui li Tiejun ZHANG Zhaoxia PU Cailing ZHAO Yuanpu liU Northwestern Regional Center of Numerical Weather Prediction/Key Laboratory of Arid Climate Change and Disaster Reduction of China Meteorological Administration (CMA) and Gansu Province Institute of Arid Meteorology of CMA Department of Atmospheric Sciences The University of Utah

This study investigated the performance of the mesoscale Weather Research and Forecasting(WRF) model in predicting near-surface atmospheric temperature and wind for a complex underlying surface in Northwest China in June and December 2015. The spatial distribution of the monthly average bias errors in the forecasts of 2-m temperature and 10-m wind speed is analyzed first. It is found that the forecast errors for 2-m temperature and 10-m wind speed in June are strongly correlated with the terrain distribution. However, this type of correlation is not apparent in December, perhaps due to the inaccurate specification of the surface albedo and freezing-thawing process of frozen soil in winter in Northwest China in the WRF model. In addition, the WRF model is able to reproduce the diurnal variation in 2-m temperature and 10-m wind speed, although with weakened magnitude. Elevations and land-use types have strong influences on the forecast of near-surface variables with seasonal variations. The overall results imply that accurate specification of the complex underlying surface and seasonal changes in land cover is necessary for improving near-surface forecasts over Northwest China.

关键词： Weather Research and Forecasting(WRF) model complex terrain near-surface forecasts diurnal variation

Research on the Microstructure Construction Technology of Fully Degraded Polymer Vascular Stent Based on Electric Field Driven 3D Printing

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Fluid Dynamics & Materials Processing 2024年第11期20卷 2489-2508页

作者： Yanpu Chao Fulai Cao Hao Yi Shuai Lu yaohui li Hui Cen College of Mechatronics Xuchang UniversityXuchang461000China College of Mechanical Engineering Chongqing UniversityChongqing400044China State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing400044China

The so-called fourth-generation biodegradable vascular stent has become a research hotspot in thefield of bioengineering because of its good degradation ability and drug-loading ***,the preparationof polymer-degraded vascular stents is affected by known problem such as poor processflexibility,low formingaccuracy,large diameter wall thickness,limited complex pore structure,weak mechanical properties of radial support and high process *** this study,a deposition technique based on a high-voltage electric-field-driven continuous rotating jet is proposed to fabricate fully degraded polymer vascular *** experimental results showthat,due to the rotation of the deposition axis,the deposition direction of PCL(polycaprolactone)micro-jet isalways tangent to the surface of the deposition *** direction of the viscous drag force is also consistent withthe deposition direction of the *** is shown that by setting different rotation speeds of deposition axisωandlinear motion speeds of the nozzle V,the direction of rotation,pitch and angle of the individual printed spiralcurve can be precisely *** the process of multiple spiral curves matching the deposition forming thin walltube mesh,the mesh shape and size of the thin wall tube can be accurately controlled by changing the number ofmatching spiral curves and the size of the matching position bias ***,the characteristics of a PCLtubular stent sample(with uniform-size microfibers and mesh shape),fabricated under the appropriate processparameters are described in detail.

关键词： Electricfield driven micro-jet spiral curve polymer vascular stent

Impacts of Land-Use Data on the Simulation of Surface Air Temperature in Northwest China

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Journal of Meteorological Research 2018年第6期32卷 896-908页

作者： yaohui li Cailing ZHAO Tiejun ZHANG Wei WANG Haixia DUAN Yuanpu liU Yulong REN Zhaoxia PU Key Laboratory for Arid Climate Change and Disaster Reduction of Gansu Province Lanzhou Institute of Arid Meteorology/Northwestern Regional Center of Numerical Weather Prediction Key Open Laboratory for Arid Climate Change and Disaster Reduction of the China Meteorological Administration Department of Atmospheric Sciences University of Utah

This study examines the impacts of land-use data on the simulation of surface air temperature in Northwest China by the Weather Research and Forecasting(WRF) model. International Geosphere–Biosphere Program(IGBP) landuse data with 500-m spatial resolution are generated from Moderate Resolution Imaging Spectroradiometer(MODIS)satellite products. These data are used to replace the default U.S. Geological Survey(USGS) land-use data in the WRF model. Based on the data recorded by national basic meteorological observing stations in Northwest China, results are compared and evaluated. It is found that replacing the default USGS land-use data in the WRF model with the IGBP data improves the ability of the model to simulate surface air temperature in Northwest China in July and December 2015. Errors in the simulated daytime surface air temperature are reduced, while the results vary between seasons. There is some variation in the degree and range of impacts of land-use data on surface air temperature among seasons. Using the IGBP data, the simulated daytime surface air temperature in July 2015 improves at a relatively small number of stations, but to a relatively large degree; whereas the simulation of daytime surface air temperature in December 2015 improves at almost all stations, but only to a relatively small degree(within 1°C). Mitigation of daytime surface air temperature overestimation in July 2015 is influenced mainly by the change in ground heat flux. The modification of underestimated temperature comes mainly from the improvement of simulated net radiation in December 2015.

关键词： surface air temperature land-use data numerical simulation Northwest China

Regional and Global Land Data Assimilation Systems: Innovations,Challenges, and Prospects

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Journal of Meteorological Research 2019年第2期33卷 159-189页

作者： Youlong XIA Zengchao HAO Chunxiang SHI yaohui li Jesse MENG Tongren XU Xinying WU Baoqing ZHANG I.M.Systems Group at Environmental Modeling Center(EMC) National Centers for Environmental Prediction (NCEP)National Oceanic and Atmospheric Administration (NOAA) College of Water Sciences Beijing Normal University National Meteorological Information Center China Meteorological Administration Institute of Arid Meteorology China Meteorological Administration State Key Laboratory of Earth Surface Processes and Resource Ecology School of Natural ResourcesFaculty of Geographical Science Beijing Normal University Key Laboratory of Western China's Environmental Systems of Ministry of Education College of Earth and Environmental Sciences Lanzhou University

Since the North American and Global Land Data Assimilation Systems(NLDAS and GLDAS) were established in2004, significant progress has been made in development of regional and global LDASs. National, regional, projectbased, and global LDASs are widely developed across the world. This paper summarizes and overviews the development, current status, applications, challenges, and future prospects of these LDASs. We first introduce various regional and global LDASs including their development history and innovations, and then discuss the evaluation, validation, and applications(from numerical model prediction to water resources management) of these LDASs. More importantly, we document in detail some specific challenges that the LDASs are facing: quality of the in-situ observations, satellite retrievals, reanalysis data, surface meteorological forcing data, and soil and vegetation databases; land surface model physical process treatment and parameter calibration; land data assimilation difficulties; and spatial scale incompatibility problems. Finally, some prospects such as the use of land information system software, the unified global LDAS system with nesting concept and hyper-resolution, and uncertainty estimates for model structure,parameters, and forcing are discussed.

关键词： land data assimilation system (LDAS) regional and global LDASs in-situ observation satellite retrieval land surface model (LSM)