32 results on '"Huang, Shengli"'
Search Results
2. Interfacial regulation of the semiconductor heterostructure for enhanced photoelectrochemical and photocatalytic performances
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Lan, Jinshen, Qu, Shanzhi, Long, Peng, Wang, Youshun, Ma, Mengwei, Zheng, Yifan, Guo, Shengshi, Huang, Shengli, Zhan, Huahan, Li, Shuping, and Kang, Junyong
- Published
- 2024
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3. Interfacial charge transfer of MoS2/ZnO/Ag2S nanotube array for efficient photocatalytic performance
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Qu, Shanzhi, Wan, Jing, Ye, Xiaofang, Lan, Jinshen, Fei, Yuchen, Yan, Jinjian, Zheng, Yifan, Ma, Mengwei, Zheng, Xuanli, Kong, Lijing, Guo, Shengshi, Huang, Rao, Huang, Shengli, Li, Shuping, and Kang, Junyong
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- 2024
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4. Facile construction of nanowires via etching process to increase heterostructure area for efficient photocatalysis
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Qu, Shanzhi, Lan, Jinshen, Wan, Jing, Fei, Yuchen, Ye, Xiaofang, Guo, Shengshi, Huang, Shengli, Li, Shuping, and Kang, Junyong
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- 2023
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5. Enhanced photocatalytic performance of TiO2 nanowires by substituting noble metal particles with reduced graphene oxide
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Fei, Yuchen, Ye, Xiaofang, Al-Baldawy, Aseel Shaker, Wan, Jing, Lan, Jinshen, Zhao, Jingtian, Wang, Ziyun, Qu, Shanzhi, Hong, Rongdun, Guo, Shengshi, Huang, Shengli, Li, Shuping, and Kang, Junyong
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- 2022
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6. Photocatalytic activity of molybdenum disulfide nanotube arrays with different wall thicknesses under visible light
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He, Yilin, Lan, Jinshen, Qu, Shanzhi, Ma, Mengwei, Zheng, Yifan, Zheng, Xuanli, Guo, Shengshi, Huang, Shengli, Li, Shuping, and Kang, Junyong
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- 2024
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7. Long-range collectivity in small collision systems with two- and four-particle correlations at STAR
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Huang, Shengli
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- 2019
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8. Structural anomalies induced by the metal deposition methods in 2D silver nanoparticle arrays prepared by nanosphere lithography
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Huang, Shengli, Yang, Qianqian, Zhang, Chunjing, Kong, Lingqi, Li, Shuping, and Kang, Junyong
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- 2013
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9. Measurements of identified particle anisotropic flow in Cu + Au and U + U collisions by PHENIX experiment
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Huang, Shengli
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- 2013
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10. Reconstructing satellite images to quantify spatially explicit land surface change caused by fires and succession: A demonstration in the Yukon River Basin of interior Alaska
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Huang, Shengli, Jin, Suming, Dahal, Devendra, Chen, Xuexia, Young, Claudia, Liu, Heping, and Liu, Shuguang
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- 2013
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11. Demonstration of a conceptual model for using LiDAR to improve the estimation of floodwater mitigation potential of Prairie Pothole Region wetlands
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Huang, Shengli, Young, Claudia, Feng, Min, Heidemann, Karl, Cushing, Matthew, Mushet, David M., and Liu, Shuguang
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- 2011
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12. Size effect on morphology and optical properties of branched ZnO/Si nanowire arrays
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Yang, Qianqian, Li, Dingguo, Yu, Binbin, Huang, Shengli, Wang, Jiayuan, Li, Shuping, and Kang, Junyong
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- 2016
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13. High photocatalytic performance of ferroelectric AgNbO3 in a doping state.
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Jiang, Lei, Huang, Xiaohua, Zhou, Yi, Huang, Shengli, Wang, Yiwei, Wang, Zijian, Sun, Dong, Lin, Hongyi, and Cheng, Zaijun
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ELECTRIC fields ,VISIBLE spectra ,HYDROXYL group ,METHYLENE blue ,RHODAMINE B ,HETEROJUNCTIONS ,SILVER phosphates - Abstract
The pure AgNbO 3 photocatalyst with intrinsic electric field has aroused much interest due to its potential in promoting photocatalytic activity, but the performance was generally restricted by its relative fast recombination of photo-induced charges. Herein, Ag (1–3 x) Nd x NbO 3 (x = 0, 0.01, 0.02, 0.03, 0.04, 0.05) powders with good crystalline structures were prepared by conventional solid-state reaction. The photocatalytic capacity of AgNbO 3 powders was observably improved by Nd
3+ doping due to the enhanced separation of photogenerated charges. In contrast to the pristine one, the photocatalytic efficiency of Ag (1–3 x) Nd x NbO 3 with x = 0.02 (ANN002) raised to 2.78 times (98.6% within 30 min) and the corresponding reaction rate constant increased to 9.87 times (0.1905 min−1 within 15 min) under visible light. The built-in electric field arising from the ferroelectricity of ANN002 may effectively restrain the recombination of photogenerated electron–hole pairs. The superoxide radicals (· O 2- ), holes (h+ ) and hydroxyl radicals (· OH) are involved in the rhodamine B (RhB) degradation activity, and · O 2- and h+ play the major part. Besides, ANN002 achieved the complete RhB degradation under sunlight within 15 min and was able to degrade two other pollutants (methylene blue and tetracycline) under visible light within 30 min, indicating its potential application in photocatalytic field. [Display omitted] • Nd doping remarkably improved the catalytic activity of AgNbO 3 for RhB degradation. • The kinetic reaction rate of ANN002 was 9.87 times of the pure one in visible light. • The built-in electric field and reactive radicals affected the catalytic activity. • The RhB solution was completely degraded by ANN002 within 15 min under sunlight. • ANN002 also possessed high photocatalytic performance for MB and TC degradation. [ABSTRACT FROM AUTHOR]- Published
- 2023
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14. Hierarchical ZnO/Si nanowire arrays as an effective substrate for surface-enhanced Raman scattering application.
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Huang, Shengli, He, Bing, Yan, Xiaolan, Khan, Imran, Wang, Jiayuan, Gao, Mengyao, Lan, Jinshen, Li, Shuping, and Kang, Junyong
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NANOWIRES , *ZINC oxide , *ELECTROMAGNETISM , *NANOPARTICLES , *SEMICONDUCTORS - Abstract
Hierarchical arrays of ZnO/Si nanowires were prepared through very convenient two-step solution method on silicon substrates. The tree-like nanowire structures showed high crystal quality, where well aligned Si nanowires were grown vertical to the substrate surface, whereas uniform assembly of branched ZnO nanowires was grown normal to the Si nanowires (backbones). Raman analysis indicated that among all the specimens having identical chemical compositions and dimensions but different forms (thin films or nanowires), Ag-decorated hierarchical arrays of ZnO/Si nanowires possessed the highest intensity peak in surface enhanced Raman scattering spectra. Such arrays demonstrated exceptional ability of detecting Rhodamine 6 G, limiting to a value as low as 1×10 −8 mol/L and an enhancement factor up to 1.5 × 10 4 . Both, experimental designing and band structure analysis indicated that electromagnetic effect of the localized surface plasmon resonance of Ag nanoparticles caused eight times enhancement, whereas chemical effect of hierarchical arrays of ZnO/Si nanowires played a more critical role in the high Raman sensitivity. Our results would be helpful to better understand the enhancement mechanisms and meanwhile, could be extended for further potential applications of hierarchical semiconducting nanowires. [ABSTRACT FROM AUTHOR]
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- 2018
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15. F3: Simulating spatiotemporal forest change from field inventory, remote sensing, growth modeling, and management actions.
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Huang, Shengli, Ramirez, Carlos, McElhaney, Marcus, and Evans, Kirk
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FOREST management ,FOREST succession ,FOREST surveys ,TREE growth ,REMOTE sensing - Abstract
Contemporary forest management requires highly-detailed, spatially-contiguous, multi-temporal, and scenarios-comparable forest conditions. Field inventories and individual-tree models often contain highly-detailed data and allow for long-term complex scenarios comparison, but the information is only at sampled locations and lacks complete spatial coverage. Forest landscape models (FLMs) provide landscape-level spatiotemporal data, but the details that are important to land managers are often lost in the generalized outputs. We developed a modeling framework, F 3 , to integrate FIA (Forest Inventory and Analysis) plots, the Forest Vegetation Simulator (FVS), and FastEmap (Field And SatelliTe for Ecosystem MAPping) to simulate spatiotemporal forest change under natural succession and vegetation management. F 3 extrapolates the details of forest inventory plots and individual-tree model outputs to a spatially-contiguous landscape by fusing tree-list field measurements, individual tree growth and yield models, remote sensing and environmental geospatial datasets. F 3 allows for area-specific management action simulations. F 3 compares FVS results with field measurements for temporal accuracy assessment and uses a leave-one-out cross-validation for spatial accuracy assessment. F 3 adopts parallel computation techniques to implement the modeling in an automatic and efficient manner. The proof of concept of F 3 was demonstrated in Tahoe National Forest (TNF) showing spatiotemporal changes on six forest structural metrics (quadratic mean diameter, basal area, biomass, habitat suitability index, canopy cover, and coarse woody debris) under natural succession, regeneration-cut, and thinning scenarios for the years 2014–2114 at a 30 m resolution. F 3 can be used for initializing FLMs and for analyzing a wide range of ecosystem services; however, the under-representation of certain forest types in the FIA plot data set, the modeling bias from FVS, and choice of FastEmap covariates contribute to major uncertainties in the framework. [ABSTRACT FROM AUTHOR]
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- 2018
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16. Effect of chromium interlayer deposition on periodic silver nanoparticle array structure fabricated by nanosphere lithography
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Huang, Shengli, Kong, Lingqi, Zhang, Chunjing, Wu, Yan, and Zhu, Xianfang
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- 2011
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17. Modeling spatially explicit fire impact on gross primary production in interior Alaska using satellite images coupled with eddy covariance.
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Huang, Shengli, Liu, Heping, Dahal, Devendra, Jin, Suming, Welp, Lisa R., Liu, Jinxun, and Liu, Shuguang
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WILDFIRES , *PRIMARY productivity (Biology) , *CLIMATE change , *LANDSAT satellites , *REMOTE sensing , *PHOTOSYNTHETICALLY active radiation (PAR) , *LAND cover ,INTERIOR Alaska (Alaska) - Abstract
Abstract: In interior Alaska, wildfires change gross primary production (GPP) after the initial disturbance. The impact of fires on GPP is spatially heterogeneous, which is difficult to evaluate by limited point-based comparisons or is insufficient to assess by satellite vegetation index. The direct prefire and postfire comparison is widely used, but the recovery identification may become biased due to interannual climate variability. The objective of this study is to propose a method to quantify the spatially explicit GPP change caused by fires and succession. We collected three Landsat images acquired on 13 July 2004, 5 August 2004, and 6 September 2004 to examine the GPP recovery of burned area from 1987 to 2004. A prefire Landsat image acquired in 1986 was used to reconstruct satellite images assuming that the fires of 1987–2004 had not occurred. We used a light-use efficiency model to estimate the GPP. This model was driven by maximum light-use efficiency (Emax) and fraction of photosynthetically active radiation absorbed by vegetation (FPAR). We applied this model to two scenarios (i.e., an actual postfire scenario and an assuming-no-fire scenario), where the changes in Emax and FPAR were taken into account. The changes in Emax were represented by the change in land cover of evergreen needleleaf forest, deciduous broadleaf forest, and shrub/grass mixed, whose Emax was determined from three fire chronosequence flux towers as 1.1556, 1.3336, and 0.5098gC/MJ PAR. The changes in FPAR were inferred from NDVI change between the actual postfire NDVI and the reconstructed NDVI. After GPP quantification for July, August, and September 2004, we calculated the difference between the two scenarios in absolute and percent GPP changes. Our results showed rapid recovery of GPP post-fire with a 24% recovery immediately after burning and 43% one year later. For the fire scars with an age range of 2–17years, the recovery rate ranged from 54% to 95%. In addition to the averaging, our approach further revealed the spatial heterogeneity of fire impact on GPP, allowing one to examine the spatially explicit GPP change caused by fires. [Copyright &y& Elsevier]
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- 2013
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18. Integration of Palmer Drought Severity Index and remote sensing data to simulate wetland water surface from 1910 to 2009 in Cottonwood Lake area, North Dakota
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Huang, Shengli, Dahal, Devendra, Young, Claudia, Chander, Gyanesh, and Liu, Shuguang
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DROUGHTS , *SIMULATION methods & models , *REMOTE sensing , *WATER temperature , *WETLANDS , *METEOROLOGICAL precipitation , *ATMOSPHERIC models - Abstract
Abstract: Spatiotemporal variations of wetland water in the Prairie Pothole Region are controlled by many factors; two of them are temperature and precipitation that form the basis of the Palmer Drought Severity Index (PDSI). Taking the 196km2 Cottonwood Lake area in North Dakota as our pilot study site, we integrated PDSI, Landsat images, and aerial photography records to simulate monthly water surface. First, we developed a new Wetland Water Area Index (WWAI) from PDSI to predict water surface area. Second, we developed a water allocation model to simulate the spatial distribution of water bodies at a resolution of 30m. Third, we used an additional procedure to model the small wetlands (less than 0.8ha) that could not be detected by Landsat. Our results showed that i) WWAI was highly correlated with water area with an R2 of 0.90, resulting in a simple regression prediction of monthly water area to capture the intra- and inter-annual water change from 1910 to 2009; ii) the spatial distribution of water bodies modeled from our approach agreed well with the water locations visually identified from the aerial photography records; and iii) the R2 between our modeled water bodies (including both large and small wetlands) and those from aerial photography records could be up to 0.83 with a mean average error of 0.64km2 within the study area where the modeled wetland water areas ranged from about 2 to 14km2. These results indicate that our approach holds great potential to simulate major changes in wetland water surface for ecosystem service; however, our products could capture neither the short-term water change caused by intensive rainstorm events nor the wetland change caused by human activities. [Copyright &y& Elsevier]
- Published
- 2011
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19. Measurement and modeling of CO2 solubility in NaCl brine and CO2–saturated NaCl brine density.
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Yan, Wei, Huang, Shengli, and Stenby, Erling H.
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SOLUBILITY ,CARBON sequestration ,GEOTHERMAL brines ,PHASE equilibrium ,EQUATIONS of state ,SALINITY - Abstract
Abstract: Phase equilibrium for CO
2 –NaCl brine is of general interest to many scientific disciplines and technical areas. The system is particularly important to CO2 sequestration in deep saline aquifers and CO2 enhanced oil recovery, two techniques discussed intensively in recent years due to the concerns over climate change and energy security. This work is an experimental and modeling study of two fundamental properties in high pressure CO2 –NaCl brine equilibrium, i.e., CO2 solubility in NaCl brine and CO2 –saturated NaCl brine density. A literature review of the available data was presented first to illustrate the necessity of experimental measurements of the two properties at high pressures. An experimental method for measuring high pressure CO2 solubility in NaCl brine was then developed. With the method, CO2 solubilities in 0, 1, and 5m NaCl brines were measured at 323, 373, and 413K from 5 to 40MPa. The corresponding density data at the same conditions were also measured. For solubility, two models used in the Eclipse simulator were tested: the correlations of Chang et al. and the Søreide and Whitson equation of state (EoS) model. The latter model was modified to improve its performance for high salinity brine. In the density modeling, the correlations of Chang et al., Garcia''s correlation, and five different EoS models were tested. Among these models, Garcia''s correlation and the ePC-SAFT EoS generally give satisfactory agreement with the experimental measurements. An analysis was also made to show that dissolution of CO2 increases the brine density only if the apparent mass density of CO2 in brine is higher than the brine density at the same conditions. [Copyright &y& Elsevier]- Published
- 2011
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20. Fusing optical and radar data to estimate sagebrush, herbaceous, and bare ground cover in Yellowstone
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Huang, Shengli, Potter, Christopher, Crabtree, Robert L., Hager, Stacey, and Gross, Peggy
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REMOTE sensing in earth sciences , *MULTISENSOR data fusion , *SAGEBRUSH , *SYNTHETIC apertures , *RADAR in aeronautics , *AIRBORNE Visible/Infrared Imaging Spectrometer (AVIRIS) , *INFORMATION processing , *STATISTICAL correlation - Abstract
Abstract: The arid and semi-arid sagebrush–grass ecosystem occupies a substantial portion of rangelands in the western United States. Using remote sensing techniques to map the percent of sagebrush, grass/forb, and bare ground components is necessary for forage production estimation and natural resource management over large areas. However optical data have significant deficiencies in these ecosystems because of exposed bright soil, spectrally-indeterminate vegetation, and a large dead vegetation component. Radar data also have deficiencies caused by factors such as antenna pattern calibration, local incidence angle (LIA), soil moisture, and surface roughness. With the complementary vegetation information gained from optical data and radar data, these two datasets were fused to estimate 10-m sagebrush, grass, and bare ground percent cover in the non-forested areas of Yellowstone National Park, which is a representative native western rangeland ecosystem of the US. The datasets were processed to resolve the issues of antenna pattern calibration and LIA effect. Peak green Landsat, late fall Airborne Visible and Infrared Imaging Spectrometer (AVIRIS), and Airborne Synthetic Aperture Radar (AirSAR) data were fused in this analysis. AVIRIS, Landsat, AirSAR and elevation data were used to segment the study area into two main subcategories of “pure grass” and “mixed sagebrush and grass”. Landsat Tasseled Cap Greenness (LTCG) was used to retrieve bare land and grass percentages in pure grass areas. In the areas with mixed grass and sagebrush, standardized LTCG and radar C vv were used to derive the vegetation cover percentage, and the ratio of standardized LTCG and radar L hv was further used to calculate the relative abundance of sagebrush and grass. Comparison between the field and remote sensing estimations shows the correlation coefficients were 0.838, 0.746, and 0.830 for bare land, grass, and sagebrush, respectively. When grouped into three discrete categories of “low”, “medium”, and “high”, the overall accuracies were 79.4%, 75.9%, and 77.6%, respectively. Our study shows the potential for application of global spaceborne C- and L-band radar and optical data fusion for large-area rangeland monitoring. [Copyright &y& Elsevier]
- Published
- 2010
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21. Estimating the quantity and quality of coarse woody debris in Yellowstone post-fire forest ecosystem from fusion of SAR and optical data
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Huang, Shengli, Crabtree, Robert L., Potter, Christopher, and Gross, Peggy
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COARSE woody debris , *WOOD quality , *FOREST fires , *FOREST ecology , *SYNTHETIC aperture radar , *MULTISENSOR data fusion , *ESTIMATION theory , *FOREST biomass , *FOREST regeneration , *NUTRIENT cycles - Abstract
Abstract: The Coarse Woody Debris (CWD) quantity, defined as biomass per unit area (t/ha), and the quality, defined as the proportion of standing dead logs to the total CWD quantity, greatly contribute to many ecological processes such as forest nutrient cycling, tree regeneration, wildlife habitat, fire dynamics, and carbon dynamics. However, a cost-effective and time-saving method to determine CWD is not available. Very limited literature could be found that applies remote sensing technique to CWD inventory. In this paper, we fused the wall-to-wall multi-frequency and multi-polarization Airborne Synthetic Aperture Radar (AirSAR) and optical Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) to estimate the quantity and quality of CWD in Yellowstone post-fire forest ecosystem, where the severe 1988 fire event resulted in high spatial heterogeneity of dead logs. To relate backscatter values to CWD metrics, we first reduced the terrain effect to remove the interference of topography on AirSAR backscatter. Secondly, we removed the influence of regenerating sapling by quadratic polynomial fitting between AVIRIS Enhanced Vegetation Index (EVI) and different channels backscatters. The quantity of CWD was derived from P hh and P hv, and the quality of CWD was derived from P hh aided by the ratio of L hv and P hh. Two maps of Yellowstone post-fire CWD quantity and quality were produced. The calculated CWD quantity and quality were validated by extensive field surveys. Regarding CWD quantity, the correlation coefficient between measured and predicted CWD is only 0.54 with mean absolute error up to 29.1 t/ha. However, if the CWD quantity was discretely classified into three categories of “≤60”, “60–120”, and “≥120”, the overall accuracy is 65.6%; if classified into two categories of “≤90” and “≥90”, the overall accuracy is 73.1%; if classified into two categories of “≤60” and “≥60”, the overall accuracy is 84.9%. This indicates our attempt to map CWD quantity spatially and continuously achieved partial success; however, the general and discrete categories are reasonable. Regarding CWD quality, the overall accuracy of 5 types (Type 1—standing CWD ratio ≥40%; Type 2—15%≤standing CWD ratio <40%; Type 3—7%≤standing CWD ratio<15%; Type 4—3%≤standing CWD ratio <7%; Type 5—standing CWD ratio <3%) is only 40.32%. However, when type 1, 2, 3 are combined into one category and type 4 and 5 are combined into one category, the overall accuracy is 67.74%. This indicates the partial success of our initial results to map CWD quality into detailed categories, but the result is acceptable if solely very coarse CWD quality is considered. Bias can be attributed to the complex influence of many factors, such as field survey error, sapling compensation, terrain effect reduction, surface properties, and backscatter mechanism understanding. [Copyright &y& Elsevier]
- Published
- 2009
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22. Molecular vibrations of the layered-perovskite cobalt oxides characterized by infrared and Raman spectroscopies coupled with crystal structure refinement
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Huang, Shengli, Ruan, Keqing, Pang, Zongqiang, Lv, Zhangming, Wu, Huiyan, Shen, Zhaochuan, Cao, Liezhao, and Li, Xiaoguang
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SPECTRUM analysis , *OXIDE minerals , *TRANSITION metals , *RAMAN spectroscopy - Abstract
Abstract: Molecular vibrations of the polycrystalline Nd2−x Sr x CoO4 are systematically characterized by powdered x-ray diffraction, Raman scattering and infrared spectra at different dopings as well as at different temperatures. Structural refinements reveal that all the specimens crystallize in the K2NiF4 structure with space group as is also confirmed by the phonon bands of Raman scattering and infrared transmittance. The frequency shifts of the phonon bands are found to be very well consistent with the elongation and/or contraction of the bond lengths. Moreover, for Nd0.75Sr1.25CoO4, the phonon bands of the Raman active modes seem to retrace the evolutions of magnetic and structural temperature. [Copyright &y& Elsevier]
- Published
- 2007
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23. Analysis of sapling density regeneration in Yellowstone National Park with hyperspectral remote sensing data
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Potter, Christopher, Li, Shuang, Huang, Shengli, and Crabtree, Robert L.
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LODGEPOLE pine , *REMOTE sensing , *DATA analysis , *REGRESSION analysis , *PLANTS , *REGENERATION (Biology) , *STATISTICAL correlation , *AIRBORNE Visible/Infrared Imaging Spectrometer (AVIRIS) - Abstract
Abstract: The density of lodgepole pine (Pinus contorta) sapling regeneration was mapped in areas burned during the 1988 wildfires across Yellowstone National Park (YNP), Wyoming, USA. Hyperspectral image analysis and field measurements were combined across the entire YNP extent. Airborne Visible Infrared Imaging Spectrometer (AVIRIS) image data from 2006 were used to compute ten different vegetation indices (VI). The ten VIs were combined to build multiple regression models for predicting and mapping post-fire sapling density. Four different forms of regression modeling were applied to derive the highest possible prediction accuracy (correlation coefficient of R 2 =0.83). Pine sapling regeneration 19years after large-scale wildfires showed a high level of variability in patch density (ranging from 14/100ha to 57/100ha), whereas sapling density measured previously from the first decade following wildfire was more uniform (10/100ha to 21/100ha). The ecosystem-level clumpiness index showed major shifts in aggregation of different sapling density classes, and was consistent with an overall decrease in estimated sapling density of nearly 50% between 1998 and 2007. This analysis revealed important succession patterns and processes in post-fire forest regeneration for the Greater Yellowstone Area (GYA). [Copyright &y& Elsevier]
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- 2012
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24. Nanostructural instability of single-walled carbon nanotubes during electron beam induced shrinkage
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Zhu, Xianfang, Li, Lunxiong, Huang, Shengli, Wang, Zhanguo, Lu, Gao Qing (Max), Sun, Chenghua, and Wang, Lianzhou
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NANOSTRUCTURED materials , *CARBON nanotubes , *ELECTRON beams , *TRANSMISSION electron microscopes , *SIMULATION methods & models , *CRYSTAL lattices , *FORCE & energy - Abstract
Abstract: The diameter of a single-walled carbon nanotube shrunk at an increasingly faster rate under electron beam irradiation in a transmission electron microscope. The relationship between the radius of the single-walled carbon nanotube and the irradiation time demonstrates that the shrinkage is much faster than that predicted by current simulations. The results indicate that a curvature effect on the nanoscale and an energetic beam-induced soft mode and lattice instability effect, which were underestimated or neglected in the existing simulations are the primary driving force for the shrinkage. [Copyright &y& Elsevier]
- Published
- 2011
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25. Electrical transport and magnetic properties of the Ruddlesden–Popper phases Sr3Fe2−x Ru x O7 ()
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Lv, Zhangming, Ruan, Keqing, Huang, Shengli, Wu, Huiyan, Cao, Liezhao, and Li, Xiaoguang
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ELECTROMAGNETIC induction , *MAGNETIC properties , *MATHEMATICAL physics , *X-ray diffraction - Abstract
Abstract: The Ru-doped Ruddlesden–Popper (RP)-type compounds Sr3Fe2−x Ru x O7 (, 0.3, 0.6, 1.0 and 1.4) were synthesized and checked by X-ray diffraction (XRD). The doping dependencies of unit cell parameters, resistivity () and magnetization were studied. Further, hysteresis measurements were done on the sample . Resistance measurements indicate that all the samples are insulators and electric transport properties fit the two-dimensional variable range hopping (VRH) model very well. Magnetism measurements show that a spin-glass state exists in all the measured samples when the temperature is lower than about 25 K. The temperature dependencies of the inverse molar magnetic susceptibility indicate that weak ferromagnetism occurs at a much higher temperature than that of glassy transition. [Copyright &y& Elsevier]
- Published
- 2006
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26. Regioselective sulfation of Artemisia sphaerocephala polysaccharide: Solution conformation and antioxidant activities in vitro.
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Wang, Junlong, Yang, Wen, Tang, YinYing, Xu, Qing, Huang, Shengli, Yao, Jian, Zhang, Ji, and Lei, Ziqiang
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POLYSACCHARIDES , *REGIOSELECTIVITY (Chemistry) , *SOLUTION (Chemistry) , *ANTIOXIDANTS , *HYDROGEN bonding , *SUBSTITUTION reactions - Abstract
Regioselective modification is an effective approach to synthesize polysaccharides with different structure features and improved properties. In this study, regioselective sulfation of Artemisia sphaerocephala polysaccharide (S RS ASP) was prepared by using triphenylchloromethane (TrCl) as protecting precursor. The decrease in fractal dimension ( d f ) values (1.56–2.04) of S RS ASP was observed in size-exclusion chromatography combined with multi angle laser light scattering (SEC-MALLS) analysis. Compared to sample substituted at C-6, S RS ASP showed a more expanded conformation of random coil, which was attributed to the breakup of hydrogen bonds and elastic contributions. Circular dichroism (CD), methylene blue (MB) and congo red (CR) spectrophotometric method and atomic force microscopy (AFM) results confirmed the conformational transition and stiffness of the chains after sulfation. S RS ASP exhibited enhanced antioxidant activities in the DPPH, superoxide and hydroxyl radical scavenging assay. Sulfation at C-2 or C-3 was favorable for the chelation which might prevent the generation of hydroxyl radicals. It concluded that the degree of substitution and substitution position were the factors influencing biological activities of sulfated polysaccharides. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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27. Plasmonic properties and sensor application of the Ag nanocaps.
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Wang, Ziyun, Zheng, Xuanli, Gao, Mengyao, Zhao, Jintian, Lan, Jinshen, Ye, Xiaofang, Wan, Jing, Fei, Yuchen, Guo, Shengshi, Wu, Yuanfei, Huang, Shengli, Li, Shuping, and Kang, Junyong
- Subjects
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SERS spectroscopy , *POLARITONS , *SURFACE enhanced Raman effect , *PLASMONICS , *PLASMA instabilities , *FINITE difference time domain method - Abstract
Plasmonic properties of the Ag nanocaps were analyzed by the finite-difference time-domain method, in addition to the fabrication and sensor application of the two-dimensional Ag nanocap arrays. The thickness limitation for the light penetration of the nanocaps was revealed. The evolution of the plasma modes with the shell thickness and structure of the nanocaps was illustrated. The hemisphere nanocap was found to own the strongest absorption intensity and field enhancement. The sensing ability of the fabricated Ag hemisphere nanocap arrays was evaluated by the Raman spectrum of the rhodamine 6G and methylene blue molecules. The ordered arrays displayed improved light absorption with intense plasmon coupling, resulting in the strong surface-enhanced Raman scattering with an enhanced factor 15 folds of the nanosphere arrays, which suggested that the metal nanocaps might be promising for biochemical sensor application. The ordered nanocaps owned strong light absorption and confined electric field around with enormous plasmon coupling, resulting in the improved surface-enhanced Raman scattering with an enhanced factor 15 folds of the ordered nanospheres. [Display omitted] • A certain thickness limitation for the light penetration of the Ag nanocaps was revealed. • The evolution of the plasma modes with the shell thickness of the caps was illustrated. • The development of the plasma modes with the cap structure was illustrated. • The Ag nanocap arrays confined electric field around the nanocaps with strong plasmon coupling. • The Ag nanocap arrays achieved an enhanced factor as large as 15 folds of the Ag/PS nanosphere arrays. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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28. A modeling and spatio-temporal analysis framework for monitoring environmental change using NPP as an ecosystem indicator
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Crabtree, Robert, Potter, Christopher, Mullen, Randall, Sheldon, Jennifer, Huang, Shengli, Harmsen, Joshua, Rodman, Ann, and Jean, Cathie
- Subjects
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REMOTE sensing in environmental monitoring , *SPATIO-temporal variation , *SPATIAL analysis (Statistics) , *GLOBAL environmental change , *PRIMARY productivity (Biology) measurement , *BIOINDICATORS , *AUTOREGRESSION (Statistics) , *GEOGRAPHIC information systems - Abstract
We present and describe a modeling and analysis framework for monitoring protected area (PA) ecosystems with net primary productivity (NPP) as an indicator of health. It brings together satellite data, an ecosystem simulation model (NASA–CASA), spatial linear models with autoregression, and a GIS to provide practitioners a low-cost, accessible ecosystem monitoring and analysis system (EMAS) at landscape resolutions. The EMAS is evaluated and assessed with an application example in Yellowstone National Park aimed at identifying the causes and consequences of drought. Utilizing five predictor covariates (solar radiation, burn severity, soil productivity, temperature, and precipitation), spatio-temporal analysis revealed how landscape controls and climate (summer vegetation moisture stress) affected patterns of NPP according to vegetation functional type, species cover type, and successional stage. These results supported regional and national trends of NPP in relation to carbon fluxes and lag effects of climate. Overall, the EMAS provides valuable decision support for PAs regarding informed land use planning, conservation programs, vital sign monitoring, control programs (fire fuels, invasives, etc.), and restoration efforts. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
29. Carbon clathrates as strong lightweight structures.
- Author
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Zhu, Jinghui, Xu, Ke, Zhang, Zhisen, Cao, Xuezheng, Huang, Shengli, and Wu, Jianyang
- Subjects
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YOUNG'S modulus , *AB-initio calculations , *ELECTROMECHANICAL devices , *TENSILE strength , *CLATHRATE compounds , *CARBON , *SHEAR strain - Abstract
• Type-I-C 46 , Type-II-C 34 and Type-H-C 34 carbon clathrates show distinct anisotropy in their tensile Young's moduli and ideal tensile/shear strengths, but isotropy in the shear Young's moduli. • Maximum ideal tensile strength of carbon clathrates can exceed that of heavyweight diamond under <111> directional load, and shear Young's moduli are comparable to that of diamond • Those carbon clathrates are intrinsically indirect semiconductors, and their electronic properties can be greatly dictated by mechanical tension and shear strains. Clathrates are fully- sp 3 cage-like three dimensional (3D) structures that offer unique mechanical and electronic properties. Here, the mechanical properties of Type-I-C 46 , Type-II-C 34 and Type-H-C 34 carbon clathrates under uniaxial and shear loads are examined by means of ab initio calculations. It is predicted that those carbon clathrates show distinct anisotropy in their ideal tensile/shear strengths and critical tensile/shear strains, but isotropy in the shear Young's moduli. Intriguingly, their maximum ideal tensile strengths exceed that of heavyweight diamond under <111> directional load, and their shear Young's moduli are comparable to that of diamond. Those carbon clathrates show distinct deformability in their critical load-bearing bond configurations, resulting in their distinct mechanical properties. Moreover, all investigated carbon clathrates are intrinsically indirect semiconductors, and their electronic properties can be greatly tuned by tension and shear strains. As a consequence, carbon clathrates can be potentially utilized as lightweight strong engineering structures and in electromechanical devices. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
30. Band engineering of ZnO/Si nanowire arrays in Z-scheme heterojunction for efficient dye photodegradation.
- Author
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Lan, Jinshen, He, Bing, Haw, Choonyian, Gao, Mengyao, Khan, Imran, Zheng, Rongsheng, Guo, Shengshi, Zhao, Jingtian, Wang, Ziyun, Huang, Shengli, Li, Shuping, and Kang, Junyong
- Subjects
- *
ELECTRON-hole recombination , *HETEROJUNCTIONS , *SEMICONDUCTOR junctions , *SILVER phosphates , *QUANTUM dots , *PHOTODEGRADATION - Abstract
ZnO/Si nanotrees were coated by Ag 2 S and In 2 S 3 nanoparticles. The built-in electric field of the heterojunctions induced electron-hole pair recombination in the conduction band of ZnO and valence bands of other semiconductors at the interfaces, which reduced charge recombination in the interior of the component semiconductors and improved redox ability. • Heterogeneous nanowire arrays were grown resulting in efficient dye photodegradation. • Introduction of quantum dots yielded a quarter resistance and 31-fold photocurrent. • The samples got efficiency of 62% and 55% in visible and UV light with recyclability. • Z-scheme heterojunctions played a critical role in the high photocatalytic activity. Hierarchical heterogeneous ZnO/Si nanowire arrays grown from metal-induced wet etching process on p-type silicon wafer were obtained and have been strategically sensitized by narrow bandgap semiconductors of In 2 S 3 nanosheets and Ag 2 S quantum dots via successive ionic layer adsorption and reaction technique. The photodegradation of methylene blue as catalyzed by the arrays was conducted under visible light and ultraviolet light. By introducing the coating layers, the specimens were found to achieve absorptivity higher than 94% and yield a quarter of the resistance and 31-fold of the photo-current as compared to the primary nanowire arrays. The photodegradation efficiency was improved from 48.9% to 62.0%, and 43.0% to 55.0%, respectively in visible light and ultraviolet light with an enhanced recyclability. Band structure analysis indicated that the coating brought different Z-scheme heterojunctions for efficient photocatalytic performance, while the function could only work in a given spectral range. These results would be helpful to better realize the photocatalytic mechanisms and meanwhile, could be extended to design heterogeneous semiconductor nanomaterials for their potential applications. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
31. Layer-by-layer assembly of Ag2S quantum dots-sensitized ZnO/SnO2 core-shell nanowire arrays for enhanced photocatalytic activity.
- Author
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Lan, Jinshen, Gao, Mengyao, Haw, Choonyian, Khan, Imran, Zhao, Jingtian, Wang, Ziyun, Guo, Shengshi, Huang, Shengli, Li, Shuping, and Kang, Junyong
- Subjects
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ATOMIC layer deposition , *SEMICONDUCTOR nanowires , *SILICON nanowires , *BAND gaps , *ULTRAVIOLET radiation , *ZINC oxide , *METHYLENE blue , *VISIBLE spectra - Abstract
• Ag 2 S-sensitized ZnO/SnO 2 core-shell nanowire arrays were successfully synthesized. • The absorptivity of the sample was larger than 95% in visible and UV range. • The photocurrent response of the sample reached 53.6-fold of the ZnO NW arrays. • The catalytic efficiency got 71.61% and 57.58% respectively in visible and UV range. • Mechanism of the effective photocatalysis was explored. Ag 2 S quantum dots-sensitized ZnO/SnO 2 core-shell nanowire arrays were successfully synthesized layer by layer through hydrothermal growth, atomic layer deposition, and successive ionic layer adsorption and reaction process. By introducing the two-layer semiconductors, the bandgap of ZnO component in the arrays was slightly modulated, while the light absorption was obviously improved with an absorptivity higher than 95% in visible and ultraviolet range. In contrast to the ZnO NW arrays, the photocurrent response of the ZnO/SnO 2 /Ag 2 S NW arrays for the visible light was improved from 0.42 μA to 22.5 μA, and the photodegradation efficiency of methylene blue was increased from 45.24% to 71.61%, and 42.61% to 57.58%, respectively in visible light and ultraviolet light. Band structure analysis indicated that the coating layer brought different staggered gaps and suitable band alignment for efficient photocatalytic performance, which could be extended to design heterogeneous semiconductor nanomaterials for their potential applications. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
32. Resonant light absorption and plasmon tunability of lateral triangular Au nanoprisms array.
- Author
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Gao, Mengyao, Zheng, Xuanli, Khan, Imran, Cai, Haoyuan, Lan, Jinshen, Liu, Jing, Wang, Jiayuan, Wu, Jianyang, Huang, Shengli, Li, Shuping, and Kang, Junyong
- Subjects
- *
SURFACE plasmon resonance , *FINITE difference time domain method , *THEORY of wave motion , *SURFACE enhanced Raman effect , *BREWSTER'S angle , *ELECTRIC fields , *REFRACTIVE index - Abstract
Optical characteristics and electric field distribution of triangular Au nanoprism in a unit and units array under polarized light irradiation were systematically studied by numerical simulation with finite difference time domain method. It is found that the plasmonic properties of the triangular nanoprism are dominated by the electric polarization rather than the wave propagation. The triangular nanoprism presents similar optical response with a strong dipole band under different wave propagations if the electric polarization vectors are parallel to the triangular cross section. The lateral triangular Au nanoprisms array possesses a large tunability of the plasmonic properties contributed from the combined influence of inter-particle distance, particles size, polarization angle and even environmental medium. From the plasmon band shift versus the refractive index, ultra-high local surface plasmon resonance sensitivity (509.96 nm/RIU, figure of merit = 5.55) is reached at ∼ 850 nm , making this array promising for biochemical sensing applications. • This work advanced a new nanostructure system in sensing application with its LSPR. • LSPR characteristics of the system were computed and illustrated. • The system demonstrated a sensitivity of 509.96 nm/RIU with a figure of merit of 5.55. • Mechanism of the optical and sensing properties of the system was explored. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
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