|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Effects of spatial distribution of soil parameters on soil moisture retrieval from passive microwave remote sensing显示文摘In this paper,we studied the effect of spatial distribution of soil parameters on passive soil moisture retrieval at pixel scale.First,we evaluated the forward microwave emission model and soil moisture retrieval algorithm accuracy through the observa-tion of field experiments.Then,we used soil parameters in different spatial distribution patterns,including random,normal,and uniform distribution,to determine the different levels of heterogeneity on soil moisture retrieval,in order to seek the rela-tionship between heterogeneity and soil moisture retrieval error.Finally,we conducted a controlled heterogeneity effect ex-periment measurements using a Truck-mounted Multi-frequency Radiometer(TMMR) to validate our simulation results.This work has proved that the soil moisture retrieval algorithm had a high accuracy(RMSE=0.049 cm3 cm 3) and can satisfy the need of this research.The simulation brightness temperatures match well with observations,with RMSE=9.89 K.At passive microwave remote sensing pixel scale,soil parameters with different spatial distribution patterns could have different levels of error on soil moisture estimation.Overall,we found that soil moisture with a random distribution in a satellite pixel scale can cause the largest error,with a normal distribution being the second,and a uniform distribution the least due to the smallest het-erogeneity. | ZHANG Tao ZHANG LiXin JIANG LingMei ZHAO ShaoJie ZHAO TianJie LI YunQing | 2012 | Science China Earth Sciences2012，55，8： | 5 |
| 2 | Assessing the ecological vulnerability of protected areas by using Big Earth Data显示文摘The ecological vulnerability of global protected areas(PAs)is linked to the 2030 United Nations Sustainable Development Goals.We developed a novel degree of ecological vulnerability(DEV)index based on Big Earth Data to assess the ecological vulnerability of PAs.This is a transparent,repeatable,large-scale and rapid assessment method.We applied the method to case studies of International Union for Conservation of Nature(IUCN)PAs in the basins of the Aral Sea,the Caspian Sea,the Black Sea and the Lake Baikal.Between 2001 and 2015,the spatial pattern of ecological vulnerability in the study area was relatively stable.The Caspian Sea basin and protected landscape/seascape(category V)showed high ecological vulnerability,while the Black Sea basin and wilderness areas(category Ib)showed low ecological vulnerability.Big Earth Data shows great vitality in PAs ecological vulnerability assessment.Strengthening international cooperation is an important means to break the bottleneck of ecological environment and resource endowment in these important international basins. | Yaomin Zheng Shudong Wang Yue Cao Jinlian Shi Yi Qu Liping Li Tianjie Zhao Zhenguo Niu Rui Yang Peng Gong | 2021 | International Journal of Digital Earth2021，14，11： | 3 |
| 3 | The discovery of surface runoff in the megadunes of Badain Jaran Desert,China,and its significance显示文摘The Badain Jaran Desert exhibits the greatest difference in altitude of all of the world's deserts.On the slopes of megadunes in the desert,there are physical and chemical deposits produced by surface runoff.In addition,we have observed rarely-seen infiltration-excess surface runoff in the megadune depressions as well as spring streams at the base of megadunes.We used electron microscopy,energy spectrum analysis,infiltration experiments,moisture content determinations and grain-size analysis to study the mineral and chemical composition of the runoff precipitates,and grain-size of the deposits associated with the runoff,together with the hydrological balance in the megadune area,and the atmospheric precipitation mechanism responsible for groundwater recharge and for supplying water to lakes.The observations of shallow runoff and infiltration-excess surface runoff indicate the occurrence of strong and effective precipitation in summer,which would provide an important source for groundwater recharge.Several lines of evidence,such as the physical and chemical deposits resulting from shallow subsurface runoff,spring streams,infiltration-excess runoff,and gravity capillary water with a moisture content of 3-6%,demonstrate that precipitation reaches the base of the megadunes through infiltration and subsequently becomes groundwater.The chemical deposits,such as newly-formed calcite and gypsum,and gray-black physical deposits,as well as different stages in the development of fan-shaped landforms resulting from shallow subsurface runoff,indicate that groundwater recharge in the area is the result of long-term precipitation,rather than intermittent individual major rainfall events.Fine sand layers with a low infiltration capacity lead to subsurface runoff emerging at the ground surface.Five factors play an important role in maintaining a positive water balance and in replenishing groundwater via rainfall:effective rainfall as a water source,the high infiltration capacity of the sands enabling rainfall to rapidly become capillary water in the dunes,low evapotranspiration rates due to the sparse vegetation,the fact that the depth of the sand layer influenced by evaporation is shallow enough to maximize the deep infiltration of rainfall,and rapidly-moving gravity capillary water in the sandy dunes.These five factors together constitute a mechanism for groundwater recharge from rainfall,and explain the origin of the groundwater and lakes in the area.Our findings represent a significant advance in research on the hydrological cycle,including groundwater recharge conditions and recharge mechanisms,in this desert region. | ZHAO JingBo MA YanDong LUO XiaoQing YUE DaPeng SHAO TianJie DONG ZhiBao | 2017 | Science China Earth Sciences2017，60，4： | 3 |
| 4 | Discovery and study of silver sulfate mineral in S_5 from the eastern suburb of Xi'an显示文摘The paleosol samples from the fifth layer of the loess profile at Renjiapo in the eastern suburb of Xi'an are observed and analyzed using electron microscope and energy spectrum. Minerals such as AgSO4 and molybdenum, which are rare to find and can indicate typical dry climate environment, are found in this layer of paleosol. Secondary mineral is usually granular form of ellipsoidal and crystallization, and has the characteristics of chemical precipitating crystallization of apertures and fracture. Molybdenum minerals have the characteristics of colloidal substances. There are two kinds of secondary minerals. One is silver sulfate mineral and the other is silver oxide mineral. The movement of secondary silver, molybdenum and cobalt minerals, new clay mineral, Fe2O3 and Al2O3 indicates that S5 has experienced strong chemical weathering and mineral dissolution during its development. Silver, molybdenum, and cobalt can be released from primary minerals. During that period, the precipitation was abundant in Xi'an where soil reached an acidity stage of chemical weathering. At the later development stage of paleosol in the lowest part of S5, warm and wet monsoon climate had changed to dry and non-monsoon climate. In the period of the formation of AgSO4, which is easier to dissolve than CaSO4, a dry and non-monsoon climate was present in the Guanzhong Plain. Strong evaporation resulted in the accumulation of SO42-in the soil water solution and the formation of AgSO4. At that time, summer monsoon of East Asia was weak and did not cross Qinling Mountains to reach Guanzhong Plain. And at that time, the precipitation in Xi'an was less than 300 mm, and it was drier then in Xi'an than at present in Lanzhou. | ZHAO JingBo CAO JunJi SHAO TianJie LIU Rui YUE YingLi DU Juan | 2012 | Science China Earth Sciences2012，55，3： | 2 |
| 5 | Vertical distribution of soil moisture and surface sandy soil wind erosion for different types of sand dune on the southeastern margin of the Mu Us Sandy Land,China显示文摘Soil moisture is a critical state affecting a variety of land surface and subsurface processes. We report investigation results of the factors controlling vertical variation of soil moisture and sand transport rate of three types of dunes on the southeastern margin of the Mu Us Sandy Land. Samples were taken from holes drilled to a depth of 4 m at different topographic sites on the dunes, and were analyzed for soil moisture, grain-size distribution and surface sediment discharge. The results show that:(1) The average soil moisture varies in different types of dunes, with the following sequences ordered from highest to lowest: in the shrubs-covered dunes and the trees-covered dunes the sequence is from inter-dunes lowland to windward slope to leeward slope. The average moisture in the bare-migratory sand dunes is sequenced from inter-dunes lowland to leeward slope to windward slope.(2) Vegetation form and surface coverage affect the range of soil moisture of different types of dunes in the same topographic position. The coefficient of variation of soil moisture for shrubs-covered dunes is higher than that of other types of dune.(3) The effect of shrubs on dune soil moisture is explained in terms of the greater ability of shrubs to trap fine-grained atmospheric dust and hold moisture.(4) The estimated sand transport rates over sand dunes with sparse shrubs are less than those over bare-migratory dunes or sand dunes with sparse trees, indicating that shrubs are more effective in inhibiting wind erosion in the sandy land area. | ChaoFeng Fu JingBo Zhao FanMin Mei TianJie Shao Jun Zuo | 2015 | Research in Cold and Arid Regions2015，7，6： | 2 |
| 6 | Observations and geophysical value-added datasets for cold high mountain and polar regions显示文摘The Earth’s cold regions,in particular,the Arctic,Antarctic,and High-Mountain Asia(HMA),are dominated by the changing cryosphere and have inherently fragile environ-ments(Guo,2018;Kulmala,2018;Guo et al.,2020;Li et al.,2020;Yao et al.,2022;Group on Earth Observations(GEO),2022).Warming has reshaped the regions where the cryo-sphere is located;it has also been affecting water availability in lowland downstream areas,opening up northern sea routes,and affecting the stability of roads and infrastruc-ture in permafrost rich areas(Pulliainen et al.,2019).Changes in the phase of water and its consequences have thus had a major impact on the environment and the lives of billions of people. | Yubao Qiu Hanna K.Lappalainen Tao Che Stein Sandven Tianjie Zhao | 2022 | Big Earth Data2022，6，4： | 1 |
| 7 | Assessing the active-passive approach at variant incidence angles for microwave brightness temperature downscaling显示文摘The Terrestrial Water Resources Satellite(TWRS)campaign is a planned Chinese candidate satellite mission,and a one-dimensional synthetic aperture technology will be used,resulting in variant incidence angles for collecting synchronous active-passive observations at L-band,which would make brightness temperature(T_(b))downscaling especially challenging when aiming to improve the spatial resolution of soil moisture measurements.In this study,two active-passive T_(b) downscaling algorithms,the time-series regression(TSR)and spectral analysis(SA)algorithms,are assessed comprehensively based on airborne experimental datasets.The results with data collected during the Soil Moisture Experiment 2002(SMEX02)showed that both approaches could provide a reliable downscaled T_(b) at the same incidence angle.Based on the ground and airborne active-passive observations under variant incidence angles from the Soil Moisture Experiment in the Luan River(SMELR)it can be shown that the linear relationship between T_(b) andσis still robust under the case of variant incidence angles,and T_(b)(both h-and v-pol)is better correlated toσvv for most cases thanσhh.Both downscaling approaches can be applied to active-passive observations under varying incidence angles.Moreover,SA method performed better than the TSR method according to the lower RMSE values and higher correlation. | Peng Guo Tianjie Zhao Jiancheng Shi Hongxin Xu Xiuwei Li Shengda Niu | 2021 | International Journal of Digital Earth2021，14，10： | 1 |
| 8 | Esti- mate of phase transition water content in freeze-thaw process using microwave radiometer 显示文摘 | Zhang Lixin Zhao Tianjie Jiang Lingmei | 2010 | IEEE Transac- tions on Geoscience and Remote Sensing2010，48，12： | 1 |
| 9 | Controlling the strontium-doping in calcium phosphate microcapsules through yeastregulated biomimetic mineralization显示文摘Yeast cells have controllable biosorption on metallic ions during metabolism.However,few studies were dedicated to using yeast-regulated biomimetic mineralization process to control the strontium-doped positions in calcium phosphate microcapsules.In this study,the yeast cells were allowed to pre-adsorb strontium ions metabolically and then served as sacrificing template for the precipitation and calcination of mineral shell.The pre-adsorption enabled the microorganism to enrich of strontium ions into the inner part of the microcapsules,which ensured a slow-release profile of the trace element from the microcapsule.The co-culture with human marrow stromal cells showed that gene expressions of alkaline phosphatase and Collagen-I were promoted.The promotion of osteogenic differentiation was further confirmed in the 3D culture of cell-material complexes.The strategy using living microorganism as‘smart doping apparatus’to control incorporation of trace element into calcium phosphate paved a pathway to new functional materials for hard tissue regeneration. | Miaojun Huang Tianjie Li Ting Pan Naru Zhao Yongchang Yao Zhichen Zhai Jiaan Zhou Chang Du Yingjun Wang | 2016 | Regenerative Biomaterials2016，3，5： | 1 |
| 10 | A new soil freeze/thaw discriminant algorithm using AMSR-E passive microwave imagery显示文摘 | Zhao Tianjie Zhang Lixin Jiang Lingmei | 2011 | Hydrological Processes2011，25，11： | 1 |
| 11 | Electro-optic properties of sol-gel derived PZT and PLZT thin films显示文摘 | Teowee G Simpson J T Zhao Tianji | 1995 | Microelectronic Engineering1995，29，14： | 1 |
| 12 | Parameterization of the freeze/thaw discriminant function algorithm using dense in-situ observation network data显示文摘The near-surface soil freeze–thaw(FT)transition is an important factor affecting land-atmosphere exchanges,hydrology and carbon cycles.Thus,effectively monitoring the temporal–spatial changes of soil FT processes is crucial to climate change and environment research.Several approaches have been developed to detect the soil FT state from satellite observations.The discriminant function algorithm(DFA)uses temperature and emissivity information from Advanced Microwave Scanning Radiometer Enhanced(AMSR-E)passive microwave satellite observations.Although it is well validated,it was shown to be insufficiently robust for all land conditions.In this study,we use in-situ observed soil temperature and AMSR-E brightness temperature to parameterize the DFA for soil FT state detection.We use the in-situ soil temperature records at 5 cm selected from available dense networks in the Northern Hemisphere as a reference.Considering the distinction between ascending and descending orbits,two different sets of parameters were acquired for each frequency pair.The validation results indicate that the overall discriminant accuracy of the new function can reach 90%.We further compared the Advanced Microwave Scanning Radiometer 2 discriminant results using the new function to the Soil Moisture Active Passive freeze/thaw product,and a reasonable consistency between them was found. | Pingkai Wang Tianjie Zhao Jiancheng Shi Tongxi Hu Alexandre Roy Yubao Qiu Hui Lu | 2019 | International Journal of Digital Earth2019，12，8： | 1 |
| 13 | Time-varying baseline error correction method for ground-based micro-deformation monitoring radar显示文摘In recent years, ground-based micro-deformation monitoring radar has attracted much attention due to its excellent monitoring capability. By controlling the repeated campaigns of the radar antenna on a fixed track, ground-based micro-deformation monitoring radar can accomplish repeat-pass interferometry without a space baseline and thus obtain highprecision deformation data of a large scene at one time. However, it is difficult to guarantee absolute stable installation position in every campaign. If the installation position is unstable, the stability of the radar track will be affected randomly, resulting in time-varying baseline error. In this study, a correction method for this error is developed by analyzing the error distribution law while the spatial baseline is unknown. In practice, the error data are first identified by frequency components, then the data of each one-dimensional array(in azimuth direction or range direction) are grouped based on numerical distribution period, and finally the error is corrected by the nonlinear model established with each group.This method is verified with measured data from a slope in southern China, and the results show that the method can effectively correct the time-varying baseline error caused by rail instability and effectively improve the monitoring data accuracy of groundbased micro-deformation radar in short term and long term. | LEI Tianjie WANG Jiabao HUANG Pingping TAN Weixian QI Yaolong XU Wei ZHAO Chun | 2022 | Journal of Systems Engineering and Electronics2022，33，4： | 0 |
| 14 | Remote sensing experiments for earth system science显示文摘The Earth system is an integrated system that can be divided into six main subsystems:geosphere,atmosphere,hydrosphere,cryosphere,biosphere,and anthrosphere.These subsystems are interconnected through the flows of global energy,water,and carbon,which are fundamental constituent cycles within the Earth system.To improve our predictive understanding of the subsystem on our changing planet,there is a need to better represent these subsystems through modelling and observations.The central role of these fundamental cycles has prompted scientific institutions or meteorological centers to develop digital platforms dedicated to the integration,modelling,and assimilation of Earth observation data,e.g.,Big Earth Data Science Engineering(Guo,Li,and Qiu 2020). | Tianjie Zhao Michael H.Cosh Alexandre Roy Xihan Mu Yubao Qiu Jiancheng Shi | 2021 | International Journal of Digital Earth2021，14，10： | 0 |
| 15 | Association of DNA methylation/demethylation with the functional outcome of stroke in a hyperinflammatory state显示文摘Inflammation is closely related to stroke prognosis, and high inflammation status leads to poor functional outcome in stroke. DNA methylation is involved in the pathogenesis and prognosis of stroke. However, the effect of DNA methylation on stroke at high levels of inflammation is unclear. In this study, we constructed a hyperinflammatory cerebral ischemia mouse model and investigated the effect of hypomethylation and hypermethylation on the functional outcome. We constructed a mouse model of transient middle cerebral artery occlusion and treated the mice with lipopolysaccharide to induce a hyperinflammatory state. To investigate the effect of DNA methylation on stroke, we used small molecule inhibitors to restrain the function of key DNA methylation and demethylation enzymes. 2,3,5-Triphenyltetrazolium chloride staining, neurological function scores, neurobehavioral tests, enzyme-linked immunosorbent assay, quantitative reverse transcription PCR and western blot assay were used to evaluate the effects after stroke in mice. We assessed changes in the global methylation status by measuring DNA 5-mc and DNA 5-hmc levels in peripheral blood after the use of the inhibitor. In the group treated with the DNA methylation inhibitor, brain tissue 2,3,5-triphenyltetrazolium chloride staining showed an increase in infarct volume, which was accompanied by a decrease in neurological scores and worsening of neurobehavioral performance. The levels of inflammatory factors interleukin 6 and interleukin-1 beta in ischemic brain tissue and plasma were elevated, indicating increased inflammation. Related inflammatory pathway exploration showed significant overactivation of nuclear factor kappa B. These results suggested that inhibiting DNA methylation led to poor functional outcome in mice with high inflammation following stroke. Further, the effects were reversed by inhibition of DNA demethylation. Our findings suggest that DNA methylation regulates the inflammatory response in stroke and has an important role in the functional outcome of hyperinflammatory stroke. | Yubo Wang Ling Zhang Tianjie Lyu Lu Cui Shunying Zhao Xuechun Wang Meng Wang Yongjun Wang Zixiao Li | 2024 | Neural Regeneration Research2024，19，10： | 0 |
| 16 | Mediating Mesenchymal Stem Cells Responses and Osteopontin Adsorption via Oligo(ethylene glycol)-amino Mixed Self-assembled Monolayers显示文摘Oligo(ethylene glycol)(-OEG) and amino(-NH_2) mixed self-assembled monolayers(SAMs) were employed as model substrates to investigate the effect of charge density on the fate of mesenchymal stem cells(MSCs) and osteopontin(OPN) adsorption. We found that all surfaces presenting-NH_2 groups favored cell responses regardless of the surface charge. Meanwhile, OPN adsorption could remain stable on the mixed SAMs over a certain range of charge densities. Our work provides some insights into cell responses and protein adsorption to surface charge. | Lijing Hao Tianjie Li Naru Zhao Fuzhai Cui Chang Du Yingjun Wang | 2016 | Journal of Materials Science & Technology2016，32，9： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员