Xihua Yang - Academia.edu (original) (raw)

Papers by Xihua Yang

BMC Cancer

Background Mesenchymal circulating tumor cells (M-CTCs) may be related to tumor progression, and ... more Background Mesenchymal circulating tumor cells (M-CTCs) may be related to tumor progression, and Ki67 expression is known to be involved in tumor proliferation. The aim of the present study was to explore the relationship between M-CTCs and Ki67 in hepatocellular carcinoma (HCC) and their ability to predict prognosis. Methods Peripheral blood samples were obtained from 105 HCC patients before radical surgery. CTCs were isolated using CanPatrol enrichment and classified via in situ hybridization. Ki67 expression in HCC tissue was assessed through immunohistochemistry. Potential relationships of M-CTC, Ki67 with clinicopathological factors and prognosis were evaluated. Overall survival (OS) was analyzed using the Kaplan–Meier method and Cox regression. The prognostic efficacy of M-CTC, Ki67 and both together (M-CTC + Ki67) was assessed in terms of time-dependent receiver operating characteristic (ROC) curves and Harrell's concordance index. Results Of the 105 patients, 50 were pos...

The Indian Journal of Agricultural Sciences

Climate warming shows great diurnal variations with higher warming rate at nighttime, and consequ... more Climate warming shows great diurnal variations with higher warming rate at nighttime, and consequently causes significant impacts on rice growth and grain yield. The objective of this study was to determine the effects of asymmetric warming (all-day warming, AW; daytime warming from 7:00 to 19:00, DW; and nighttime warming from 19:00 to 7:00, NW; and a control, CK) on rice growth characteristics andyield. Two bucket warming experiments were performed in Nanjing in Jiangsu Province, China under Free Air Temperature Increases (FATI) in 2013 and 2014.< The daily mean temperatures in the rice canopy in the AW, DW and NW plots were 2.0°C, 1.1°C and 1.3°C higher, respectively, than those in the CK plots. Asymmetric warming reduced the maximum tillers and effective tillers in the order CK>DW>NW>AW. In the AW, DW and NW treatments, the effective tillers were decreased by18.57%-37.77% in both years. Asymmetric warming also decreased plant height, the Absolute Growth Rate (AGR)...

The Department of Environment, Climate Change and Water NSW (DECCW) has compiled CEMSYS Modelled ... more The Department of Environment, Climate Change and Water NSW (DECCW) has compiled CEMSYS Modelled Wind Erosion on behalf of the Department of Environment, Water, Heritage and the Arts in good faith, exercising all due care and attention. DECCW does not accept responsibility for any inaccurate or incomplete information supplied by third parties. No representation is made about the accuracy, completeness or suitability of the information in this publication for any particular purpose. DECCW shall not be liable for any damage which may occur to any person or organisation taking action or not on the basis of this publication. This document is subject to revision without notice and it is up to the reader to ensure that the latest version is being used. Readers should seek appropriate advice when applying the information to their specific needs.

Remote Sensing, 2020

Remote sensing technology has been widely used to estimate fractional vegetation cover (FVC) at g... more Remote sensing technology has been widely used to estimate fractional vegetation cover (FVC) at global and regional scales. Accurate and consistent field spectral measurements are required to develop and validate spectral indices for FVC estimation. However, there are rarely any experimental studies to determine the appropriate times for field spectral measurements, and the existing guidelines or references are rather general or inconsistent, it is still not agreed upon and detailed experiments are missing for a local research. In this experiment, five groundcover objects were measured continuously from 07:30 a.m. to 17:30 p.m. local time in three consecutive sunny days using a portable spectrometer. The coefficients of variation (CV) were applied to investigate the reflectance variation at wavelengths corresponding to MODIS satellite channels and the derived spectral indices used to estimate FVC, including photosynthetic vegetation (PV) and non-photosynthetic vegetation (NPV). The ...

Remote Sensing, 2020

The Tibetan Plateau has been undergoing accelerated warming over recent decades, and is considere... more The Tibetan Plateau has been undergoing accelerated warming over recent decades, and is considered an indicator for broader global warming phenomena. However, our understanding of warming rates with elevation in complex mountain regions is incomplete. The most serious concern is the lack of high-quality near-surface air temperature (Tair) datasets in these areas. To address this knowledge gap, we developed an automated mapping framework for the estimation of seamless daily minimum and maximum Land Surface Temperatures (LSTs) for the Tibetan Plateau from the existing MODIS LST products for a long period of time (i.e., 2002–present). Specific machine learning methods were developed and linked with target-oriented validation and then applied to convert LST to Tair. Spatial variables in retrieving Tair, such as solar radiation and vegetation indices, were used in estimation of Tair, whereas MODIS LST products were mainly focused on temporal variation in surface air temperature. We valid...

Land Degradation & Development, 2020

The cover‐management factor (C‐factor) is used in the revised universal soil loss equation to rep... more The cover‐management factor (C‐factor) is used in the revised universal soil loss equation to represent the effect of vegetation cover and its management practices on hillslope erosion. Remote sensing has been widely used to estimate vegetation cover and the C‐factor, but most previous studies only used the photosynthetic vegetation (PV) or green vegetation indices (VI, e.g., normalized difference VI) for estimating the C‐factor and the important non‐PV (NPV) component was often ignored. In this study, we developed a new technique to estimate monthly time‐series C‐factor using the fractional vegetation cover (FVC) including both PV and NPV, and weighted by monthly rainfall erosivity ratio. The monthly FVC was derived from the moderate resolution imaging spectroradiometer and LANDSAT data with field validation. We conducted the case‐study over China's Loess Plateau and analysed the spatiotemporal variations of FVC and the C‐factor and their impacts on erosion over the Plateau. Ou...

International Journal of Climatology, 2019

The Australian Alpine region is highly vulnerable to extreme climate events such as heavy rainfal... more The Australian Alpine region is highly vulnerable to extreme climate events such as heavy rainfall and snow falls, these events subsequently impact rainfall erosivity and hillslope erosion in the region. In this study, the relationship between extreme rainfall indices (ERIs) and rainfall erosivity was examined across the Alpine region in New South Wales (NSW) and Australian Capital Territory (ACT) and the surrounding areas including Murray and Murrumbidgee and South East and Tablelands (SET). Rainfall erosivity, hillslope erosion, and their changes were estimated in the future periods using the revised universal soil loss equation and the NSW/ACT Regional Climate Modeling (NARCliM) projections. Results from the study demonstrate a good relationship between ERIs (especially Rx5Day) and rainfall erosivity. The rainfall erosivity and hillslope erosion are projected to increase about 2 and 8% for the near future (2020-2039), further increase to 8 and 18% for the far future (2060-2079) in the Alpine region assuming the groundcover is maintained at the current condition. The change in rainfall erosivity and erosion risk is highly uneven in space and in season with the highest erosion risk in summer with an increase about 33% in the next 50 years. The highest erosion risk area is predicted within SET (maximum rate 19.95 Mg ha −1 year −1), but on average, the ACT has the highest erosion rate, which is above 1.36 Mg ha −1 year −1 in all periods. The snowmelt in spring in the Alpine region is estimated to increase the rainfall erosivity by 13% in the baseline period, up to 24% in the near future, but far less (about 1%) in the far future due to predicted temperature rise and less snow available in the Alpine region in the next 50 years.

Hydrological Processes, 2018

The Loess Plateau has been experiencing large‐scale land use and cover changes (LUCCs) over the p... more The Loess Plateau has been experiencing large‐scale land use and cover changes (LUCCs) over the past 50 years. It is well known about the significant decreasing trend of annual streamflow and sediment load in the catchments in this area. However, how surface run‐off and sediment load behaved in response to LUCC at flood events remained a research question. We investigated 371 flood events from 1963 to 2011 in a typical medium‐sized catchment within the Plateau in order to understand how LUCC affected the surface run‐off generation and sediment load and their behaviours based on the analysis of return periods. The results showed that the mean annual surface run‐off and sediment load from flood events accounted for 49.6% and 91.8% of their mean annual totals. The reduction of surface run‐off and associated sediment yield in floods explained about 85.0% and 89.2% of declines in the total annual streamflow and sediment load, respectively. The occurrences of flood events and peak sedimen...

Journal of Geographical Sciences, 2019

It is of great significance to quantify sediment load changing with erosion processes for improvi... more It is of great significance to quantify sediment load changing with erosion processes for improving the precision of soil loss prediction. Indoor rainfall experiments were conducted in 2 rainfall intensities (90 mm•h-1 and 120 mm•h-1), four slope gradients (17.60%, 26.80%, 36.40%, 46.60%) and 2 slope lengths (5 m, 10 m). Erosion processes are divided into five stages. Results show that sediment yield is mainly sourced from rill erosion, contributing from 54.60% to 95.70% and the duration of which is extended by slope gradients. Sediment load and sediment concentration are significantly different along erosion stages, with the highest values in rill development stage (S IV). Surface flow velocities (interrill and rill) demonstrate less significant differences along erosion stages. Rainfall intensity increases sediment load in all stages, with up to 12.0 times higher when changing from 90 to 120 mm•h-1. There is an increasing trend for sediment load and sediment concentration with the rising slope gradient, however, fluctuations existed with the lowest values on 26.80% and 36.40%, respectively, among different treatments. The slope gradient effects are enhanced by rainfall intensity and slope length. Results from this study are important for validating and improving hillslope erosion modelling at each erosion stage.

Remote Sensing, 2018

In this study, simple dust detection and intensity estimation methods using Himawari-8 Advanced H... more In this study, simple dust detection and intensity estimation methods using Himawari-8 Advanced Himawari Imager (AHI) data are developed. Based on the differences of thermal radiation characteristics between dust and other typical objects, brightness temperature difference (BTD) among four channels (BT 11-BT 12 , BT 8-BT 11 , and BT 3-BT 11) are used together for dust detection. When considering the thermal radiation variation of dust particles over different land cover types, a dynamic threshold scheme for dust detection is adopted. An enhanced dust intensity index (EDII) is developed based on the reflectance of visible/near-infrared bands, BT of thermal-infrared bands, and aerosol optical depth (AOD), and is applied to the detected dust area. The AOD is retrieved using multiple temporal AHI observations by assuming little surface change in a short time period (i.e., 1-2 days) and proved with high accuracy using the Aerosol Robotic Network (AERONET) and cross-compared with MODIS AOD products. The dust detection results agree qualitatively with the dust locations that were revealed by AHI true color images. The results were also compared quantitatively with dust identification results from the AERONET AOD and Ångström exponent, achieving a total dust detection accuracy of 84%. A good agreement is obtained between EDII and the visibility data from National Climatic Data Center ground measurements, with a correlation coefficient of 0.81, indicating the effectiveness of EDII in dust monitoring.

IEEE Transactions on Geoscience and Remote Sensing, 2018

CATENA, 2018

It is widely recognized that vegetation restoration plays a key role in controlling soil erosion ... more It is widely recognized that vegetation restoration plays a key role in controlling soil erosion in China's Loess Plateau. However, the effects of vegetation types on soil erosion on steep slopes of the Loess Plateau are not yet fully understood. In this study, we carried out our experiments on surface runoff and soil loss monitoring at nine runoff plots with different vegetation types over a nine-year period from 2008 to 2016 to evaluate the effects of vegetation and rainfall on soil erosion. We classified forty-three rainfall events into three rainfall types based on a rainfall concentration index and further analyzed the sensitivities of the runoff and soil loss to these rainfall types. The results indicated that the grassland (Bothriochloa ischaemum L.) and shrubland (Sea-buckthorn) with high ground cover had a lower runoff depth and soil loss compared to the forestlands with poor ground cover with an average reduction of 50% in annual runoff depth and 92% in annual soil loss. Comparison of the mean runoff coefficient and soil loss in the three rainfall types demonstrated that rainfall events with high intensity and short duration caused more surface runoff and soil loss under all vegetation types. A power function fitted well in the runoff-soil loss relationship and the result showed that the grassland and shrubland had a smaller magnitude term which reflects less soil susceptibility to erosion. The research implies that the ground cover is an important factor in controlling soil and water loss and vegetation measures with high ground cover should be strongly recommended for soil erosion control on the Loess Plateau. It is helpful for vegetation restoration strategy and conserving soil and water on steep slopes of this area.

Global change biology, Jun 28, 2017

Climate change threatens global wheat production and food security, including the wheat industry ... more Climate change threatens global wheat production and food security, including the wheat industry in Australia. Many studies have examined the impacts of changes in local climate on wheat yield per hectare, but there has been no assessment of changes in land area available for production due to changing climate. It is also unclear how total wheat production would change under future climate when autonomous adaptation options are adopted. We applied species distribution models to investigate future changes in areas climatically suitable for growing wheat in Australia. A crop model was used to assess wheat yield per hectare in these areas. Our results show that there is an overall tendency for a decrease in the areas suitable for growing wheat and a decline in the yield of the northeast Australian wheat belt. This results in reduced national wheat production although future climate change may benefit South Australia and Victoria. These projected outcomes infer that similar wheat-growin...

Understanding and mitigating against the impact of land use change and groundwater extraction on ... more Understanding and mitigating against the impact of land use change and groundwater extraction on groundwater dependant ecosystems (GDE) requires information on the distribution and environmental water needs of these ecosystems. Conventional field based techniques for determining plant water use and plant stress are very labour intensive and time consuming. In this study, we proposed an alternative method using multi-temporal satellite images and the application of the Surface Energy Balance Algorithm for Land (SEBAL). Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+) images were used to derive land surface temperatures and evapotranspiration (ET) for the targeting ecosystems and species. The radiative transfer model (MODTRAN 4.1) was used with atmospheric profile data to atmospherically correct the Landsat data. Vegetation indices and surface temperature were derived from the satellite images and used to estimate fractional vegetation cover, leaf area index (LAI), emi...

Advances in Meteorology, 2015

This paper presents spatial interpolation techniques to produce finer-scale daily rainfall data f... more This paper presents spatial interpolation techniques to produce finer-scale daily rainfall data from regional climate modeling. Four common interpolation techniques (ANUDEM, Spline, IDW, and Kriging) were compared and assessed against station rainfall data and modeled rainfall. The performance was assessed by the mean absolute error (MAE), mean relative error (MRE), root mean squared error (RMSE), and the spatial and temporal distributions. The results indicate that Inverse Distance Weighting (IDW) method is slightly better than the other three methods and it is also easy to implement in a geographic information system (GIS). The IDW method was then used to produce forty-year (1990–2009 and 2040–2059) time series rainfall data at daily, monthly, and annual time scales at a ground resolution of 100 m for the Greater Sydney Region (GSR). The downscaled daily rainfall data have been further utilized to predict rainfall erosivity and soil erosion risk and their future changes in GSR to ...

Integrative cancer therapies, Jan 2, 2015

To assess the antitumor effects of protosappanin B extracted from Lignum Sappan. Lignum Sappan wa... more To assess the antitumor effects of protosappanin B extracted from Lignum Sappan. Lignum Sappan was sequentially extracted by boiling water and ethyl acetate. The resulting extract was separated by column chromatography, to yield protosappanin B. The compound was then identified by thin-layer chromatography, high-performance liquid chromatography, elemental analysis, and spectrometry (infrared and ultraviolet). The effects on tumor cell viability and growth of purified protosappanin B were evaluated in vitro by trypan blue exclusion and MTT assays, respectively. And the effects of protosappanin B were assessed in vivo, on H22 mouse liver cancer cell invasion and the survival of tumor-bearing mice. Protosappanin B (2 mg/mL) reduced the viability of human bladder cancer T24 cells and mouse bladder cancer BTT cells in a time-dependent manner (P < .05) and significantly inhibited the growth of the human colon cancer cell lines HCT-116 and SW-480. IC50 values of 21.32, 26.73, and 76.53...

Climate Research, 2015

Identifying climatic drivers that dominate in determining crop yield variations at a regional sca... more Identifying climatic drivers that dominate in determining crop yield variations at a regional scale is important for predicting regional crop production. In this study, a statistical method was used to quantify the relationship between reported shire wheat yields and climate factors during the wheat-growing season across the New South Wales (NSW) wheat belt in eastern Australia from 1922 to 2000. The results show that recent climatic trends have increased wheat yield by 8.5 to 21.2% in 4 different climatic regions of NSW over the last few decades: In the eastern slopes, growing season maximum and minimum temperatures and number of heat stress days (> 34°C) were identified as the dominant climatic factors affecting wheat yield, accounting for 36% of its variation. The wheat yield variation in the remaining 3 regions were as follows: 41% in the northern region from maximum temperature, pre-growing season rainfall (December to April), and number of frost days (< 2°C); 47% in the south from rainfall, temperature, and number of frost and heat stress days; while in southwest NSW, rainfall was the main factor responsible for 31% of the variation. Frost was less important in the eastern slopes because farmers manage frost occurrence by sowing late and using late-flowering cultivars. However, the opposite occurs in the northern parts of the wheat belt where farmers sow earlier and select shortseason varieties to avoid heat stress, but thereby expose their crops to possible frost conditions. Understanding the impact of climate variations on crop yield is important for developing sustainable agricultural production under future climate change.

Soil Science and Plant Nutrition, 2014

Climate warming exhibits strong diurnal variations, with higher warming rates being observed at n... more Climate warming exhibits strong diurnal variations, with higher warming rates being observed at nighttime, which significantly affects rice (Oryza sativa L.) growth and grain yield. The objective of this study was to determine the effects of asymmetric warming (all-day warming, AW; daytime warming from 07:00 to 19:00, DW; nighttime warming from 19:00 to 07:00, NW, and a control, CK) on rice nitrogen (N) dynamics and productivity. Two rice bucket warming experiments were performed in Nanjing in Jiangsu Province, China, using the free air temperature increase (FATI) technique. The daily mean temperatures in the rice canopy in the AW, DW and NW plots were 2.0, 1.1 and 1.3ºC higher than those in the rice canopy in the CK plots, respectively. The results indicated that the total N accumulation of rice was 8.27-40.53% higher in the warming treatment than in the control during the jointing, anthesis and maturity stages. However, there was no significant difference detected among the three warming treatments. The warming treatment substantially decreased N translocation efficiency, leading to the retention of more N in the plant stems during grain filling. The warming treatment also decreased the N harvest index, N utilization efficiency based on grain yield and N utilization efficiencies based on biomass in both growing seasons. The warming treatment significantly increased the aboveground biomass (9.26-16.18%) in the jointing stage but decreased it (2.75-9.63%) in the maturity stage. Although DW increased the carbon (C) gain by photosynthesis and NW increased the C loss by night respiration, the daytime higher-temperature treatment affected rice photosynthesis and reduced its photosynthetic rate and product. This effect may be one of the primary reasons for the insignificant difference in the aboveground biomass between the DW and NW treatments. In the AW, DW and NW plots, the grain yield was reduced by an average of 10.07, 5.05 and 7.89%, respectively, across both years. The effective panicles and grains per spike tended to decrease in the warmed plots, whereas irregular changes in the 1000-grain weight were observed. Our results suggest that under the anticipated climate warming, rice productivity would further decline in the Yangtze River Basin.

World Review of Science, Technology and Sustainable Development, 2010

Journal of Nonlinear Optical Physics & Materials, 2006

Conical emission is investigated for Ti :sapphire femtosecond laser pulses propagating in water. ... more Conical emission is investigated for Ti :sapphire femtosecond laser pulses propagating in water. The colored rings can be observed in the forward direction due to the constructive and destructive interference of transverse wavevector, which are induced by the spatio-temporal gradient of the free-electron density. With increasing input laser energy, due to filamentation and pulse splitting induced by the plasma created by multiphoton excitation of electrons from the valence band to the conduction band, the on-axis spectrum of the conical emission is widely broadened and strongly modulated with respect to input laser spectrum, and finally remains fairly constant at higher laser energy due to intensity clamping in the filaments.

BMC Cancer

Background Mesenchymal circulating tumor cells (M-CTCs) may be related to tumor progression, and ... more Background Mesenchymal circulating tumor cells (M-CTCs) may be related to tumor progression, and Ki67 expression is known to be involved in tumor proliferation. The aim of the present study was to explore the relationship between M-CTCs and Ki67 in hepatocellular carcinoma (HCC) and their ability to predict prognosis. Methods Peripheral blood samples were obtained from 105 HCC patients before radical surgery. CTCs were isolated using CanPatrol enrichment and classified via in situ hybridization. Ki67 expression in HCC tissue was assessed through immunohistochemistry. Potential relationships of M-CTC, Ki67 with clinicopathological factors and prognosis were evaluated. Overall survival (OS) was analyzed using the Kaplan–Meier method and Cox regression. The prognostic efficacy of M-CTC, Ki67 and both together (M-CTC + Ki67) was assessed in terms of time-dependent receiver operating characteristic (ROC) curves and Harrell's concordance index. Results Of the 105 patients, 50 were pos...

The Indian Journal of Agricultural Sciences

Climate warming shows great diurnal variations with higher warming rate at nighttime, and consequ... more Climate warming shows great diurnal variations with higher warming rate at nighttime, and consequently causes significant impacts on rice growth and grain yield. The objective of this study was to determine the effects of asymmetric warming (all-day warming, AW; daytime warming from 7:00 to 19:00, DW; and nighttime warming from 19:00 to 7:00, NW; and a control, CK) on rice growth characteristics andyield. Two bucket warming experiments were performed in Nanjing in Jiangsu Province, China under Free Air Temperature Increases (FATI) in 2013 and 2014.< The daily mean temperatures in the rice canopy in the AW, DW and NW plots were 2.0°C, 1.1°C and 1.3°C higher, respectively, than those in the CK plots. Asymmetric warming reduced the maximum tillers and effective tillers in the order CK>DW>NW>AW. In the AW, DW and NW treatments, the effective tillers were decreased by18.57%-37.77% in both years. Asymmetric warming also decreased plant height, the Absolute Growth Rate (AGR)...

The Department of Environment, Climate Change and Water NSW (DECCW) has compiled CEMSYS Modelled ... more The Department of Environment, Climate Change and Water NSW (DECCW) has compiled CEMSYS Modelled Wind Erosion on behalf of the Department of Environment, Water, Heritage and the Arts in good faith, exercising all due care and attention. DECCW does not accept responsibility for any inaccurate or incomplete information supplied by third parties. No representation is made about the accuracy, completeness or suitability of the information in this publication for any particular purpose. DECCW shall not be liable for any damage which may occur to any person or organisation taking action or not on the basis of this publication. This document is subject to revision without notice and it is up to the reader to ensure that the latest version is being used. Readers should seek appropriate advice when applying the information to their specific needs.

Remote Sensing, 2020

Remote sensing technology has been widely used to estimate fractional vegetation cover (FVC) at g... more Remote sensing technology has been widely used to estimate fractional vegetation cover (FVC) at global and regional scales. Accurate and consistent field spectral measurements are required to develop and validate spectral indices for FVC estimation. However, there are rarely any experimental studies to determine the appropriate times for field spectral measurements, and the existing guidelines or references are rather general or inconsistent, it is still not agreed upon and detailed experiments are missing for a local research. In this experiment, five groundcover objects were measured continuously from 07:30 a.m. to 17:30 p.m. local time in three consecutive sunny days using a portable spectrometer. The coefficients of variation (CV) were applied to investigate the reflectance variation at wavelengths corresponding to MODIS satellite channels and the derived spectral indices used to estimate FVC, including photosynthetic vegetation (PV) and non-photosynthetic vegetation (NPV). The ...

Remote Sensing, 2020

The Tibetan Plateau has been undergoing accelerated warming over recent decades, and is considere... more The Tibetan Plateau has been undergoing accelerated warming over recent decades, and is considered an indicator for broader global warming phenomena. However, our understanding of warming rates with elevation in complex mountain regions is incomplete. The most serious concern is the lack of high-quality near-surface air temperature (Tair) datasets in these areas. To address this knowledge gap, we developed an automated mapping framework for the estimation of seamless daily minimum and maximum Land Surface Temperatures (LSTs) for the Tibetan Plateau from the existing MODIS LST products for a long period of time (i.e., 2002–present). Specific machine learning methods were developed and linked with target-oriented validation and then applied to convert LST to Tair. Spatial variables in retrieving Tair, such as solar radiation and vegetation indices, were used in estimation of Tair, whereas MODIS LST products were mainly focused on temporal variation in surface air temperature. We valid...

Land Degradation & Development, 2020

The cover‐management factor (C‐factor) is used in the revised universal soil loss equation to rep... more The cover‐management factor (C‐factor) is used in the revised universal soil loss equation to represent the effect of vegetation cover and its management practices on hillslope erosion. Remote sensing has been widely used to estimate vegetation cover and the C‐factor, but most previous studies only used the photosynthetic vegetation (PV) or green vegetation indices (VI, e.g., normalized difference VI) for estimating the C‐factor and the important non‐PV (NPV) component was often ignored. In this study, we developed a new technique to estimate monthly time‐series C‐factor using the fractional vegetation cover (FVC) including both PV and NPV, and weighted by monthly rainfall erosivity ratio. The monthly FVC was derived from the moderate resolution imaging spectroradiometer and LANDSAT data with field validation. We conducted the case‐study over China's Loess Plateau and analysed the spatiotemporal variations of FVC and the C‐factor and their impacts on erosion over the Plateau. Ou...

International Journal of Climatology, 2019

The Australian Alpine region is highly vulnerable to extreme climate events such as heavy rainfal... more The Australian Alpine region is highly vulnerable to extreme climate events such as heavy rainfall and snow falls, these events subsequently impact rainfall erosivity and hillslope erosion in the region. In this study, the relationship between extreme rainfall indices (ERIs) and rainfall erosivity was examined across the Alpine region in New South Wales (NSW) and Australian Capital Territory (ACT) and the surrounding areas including Murray and Murrumbidgee and South East and Tablelands (SET). Rainfall erosivity, hillslope erosion, and their changes were estimated in the future periods using the revised universal soil loss equation and the NSW/ACT Regional Climate Modeling (NARCliM) projections. Results from the study demonstrate a good relationship between ERIs (especially Rx5Day) and rainfall erosivity. The rainfall erosivity and hillslope erosion are projected to increase about 2 and 8% for the near future (2020-2039), further increase to 8 and 18% for the far future (2060-2079) in the Alpine region assuming the groundcover is maintained at the current condition. The change in rainfall erosivity and erosion risk is highly uneven in space and in season with the highest erosion risk in summer with an increase about 33% in the next 50 years. The highest erosion risk area is predicted within SET (maximum rate 19.95 Mg ha −1 year −1), but on average, the ACT has the highest erosion rate, which is above 1.36 Mg ha −1 year −1 in all periods. The snowmelt in spring in the Alpine region is estimated to increase the rainfall erosivity by 13% in the baseline period, up to 24% in the near future, but far less (about 1%) in the far future due to predicted temperature rise and less snow available in the Alpine region in the next 50 years.

Hydrological Processes, 2018

The Loess Plateau has been experiencing large‐scale land use and cover changes (LUCCs) over the p... more The Loess Plateau has been experiencing large‐scale land use and cover changes (LUCCs) over the past 50 years. It is well known about the significant decreasing trend of annual streamflow and sediment load in the catchments in this area. However, how surface run‐off and sediment load behaved in response to LUCC at flood events remained a research question. We investigated 371 flood events from 1963 to 2011 in a typical medium‐sized catchment within the Plateau in order to understand how LUCC affected the surface run‐off generation and sediment load and their behaviours based on the analysis of return periods. The results showed that the mean annual surface run‐off and sediment load from flood events accounted for 49.6% and 91.8% of their mean annual totals. The reduction of surface run‐off and associated sediment yield in floods explained about 85.0% and 89.2% of declines in the total annual streamflow and sediment load, respectively. The occurrences of flood events and peak sedimen...

Journal of Geographical Sciences, 2019

It is of great significance to quantify sediment load changing with erosion processes for improvi... more It is of great significance to quantify sediment load changing with erosion processes for improving the precision of soil loss prediction. Indoor rainfall experiments were conducted in 2 rainfall intensities (90 mm•h-1 and 120 mm•h-1), four slope gradients (17.60%, 26.80%, 36.40%, 46.60%) and 2 slope lengths (5 m, 10 m). Erosion processes are divided into five stages. Results show that sediment yield is mainly sourced from rill erosion, contributing from 54.60% to 95.70% and the duration of which is extended by slope gradients. Sediment load and sediment concentration are significantly different along erosion stages, with the highest values in rill development stage (S IV). Surface flow velocities (interrill and rill) demonstrate less significant differences along erosion stages. Rainfall intensity increases sediment load in all stages, with up to 12.0 times higher when changing from 90 to 120 mm•h-1. There is an increasing trend for sediment load and sediment concentration with the rising slope gradient, however, fluctuations existed with the lowest values on 26.80% and 36.40%, respectively, among different treatments. The slope gradient effects are enhanced by rainfall intensity and slope length. Results from this study are important for validating and improving hillslope erosion modelling at each erosion stage.

Remote Sensing, 2018

In this study, simple dust detection and intensity estimation methods using Himawari-8 Advanced H... more In this study, simple dust detection and intensity estimation methods using Himawari-8 Advanced Himawari Imager (AHI) data are developed. Based on the differences of thermal radiation characteristics between dust and other typical objects, brightness temperature difference (BTD) among four channels (BT 11-BT 12 , BT 8-BT 11 , and BT 3-BT 11) are used together for dust detection. When considering the thermal radiation variation of dust particles over different land cover types, a dynamic threshold scheme for dust detection is adopted. An enhanced dust intensity index (EDII) is developed based on the reflectance of visible/near-infrared bands, BT of thermal-infrared bands, and aerosol optical depth (AOD), and is applied to the detected dust area. The AOD is retrieved using multiple temporal AHI observations by assuming little surface change in a short time period (i.e., 1-2 days) and proved with high accuracy using the Aerosol Robotic Network (AERONET) and cross-compared with MODIS AOD products. The dust detection results agree qualitatively with the dust locations that were revealed by AHI true color images. The results were also compared quantitatively with dust identification results from the AERONET AOD and Ångström exponent, achieving a total dust detection accuracy of 84%. A good agreement is obtained between EDII and the visibility data from National Climatic Data Center ground measurements, with a correlation coefficient of 0.81, indicating the effectiveness of EDII in dust monitoring.

IEEE Transactions on Geoscience and Remote Sensing, 2018

CATENA, 2018

It is widely recognized that vegetation restoration plays a key role in controlling soil erosion ... more It is widely recognized that vegetation restoration plays a key role in controlling soil erosion in China's Loess Plateau. However, the effects of vegetation types on soil erosion on steep slopes of the Loess Plateau are not yet fully understood. In this study, we carried out our experiments on surface runoff and soil loss monitoring at nine runoff plots with different vegetation types over a nine-year period from 2008 to 2016 to evaluate the effects of vegetation and rainfall on soil erosion. We classified forty-three rainfall events into three rainfall types based on a rainfall concentration index and further analyzed the sensitivities of the runoff and soil loss to these rainfall types. The results indicated that the grassland (Bothriochloa ischaemum L.) and shrubland (Sea-buckthorn) with high ground cover had a lower runoff depth and soil loss compared to the forestlands with poor ground cover with an average reduction of 50% in annual runoff depth and 92% in annual soil loss. Comparison of the mean runoff coefficient and soil loss in the three rainfall types demonstrated that rainfall events with high intensity and short duration caused more surface runoff and soil loss under all vegetation types. A power function fitted well in the runoff-soil loss relationship and the result showed that the grassland and shrubland had a smaller magnitude term which reflects less soil susceptibility to erosion. The research implies that the ground cover is an important factor in controlling soil and water loss and vegetation measures with high ground cover should be strongly recommended for soil erosion control on the Loess Plateau. It is helpful for vegetation restoration strategy and conserving soil and water on steep slopes of this area.

Global change biology, Jun 28, 2017

Climate change threatens global wheat production and food security, including the wheat industry ... more Climate change threatens global wheat production and food security, including the wheat industry in Australia. Many studies have examined the impacts of changes in local climate on wheat yield per hectare, but there has been no assessment of changes in land area available for production due to changing climate. It is also unclear how total wheat production would change under future climate when autonomous adaptation options are adopted. We applied species distribution models to investigate future changes in areas climatically suitable for growing wheat in Australia. A crop model was used to assess wheat yield per hectare in these areas. Our results show that there is an overall tendency for a decrease in the areas suitable for growing wheat and a decline in the yield of the northeast Australian wheat belt. This results in reduced national wheat production although future climate change may benefit South Australia and Victoria. These projected outcomes infer that similar wheat-growin...

Understanding and mitigating against the impact of land use change and groundwater extraction on ... more Understanding and mitigating against the impact of land use change and groundwater extraction on groundwater dependant ecosystems (GDE) requires information on the distribution and environmental water needs of these ecosystems. Conventional field based techniques for determining plant water use and plant stress are very labour intensive and time consuming. In this study, we proposed an alternative method using multi-temporal satellite images and the application of the Surface Energy Balance Algorithm for Land (SEBAL). Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+) images were used to derive land surface temperatures and evapotranspiration (ET) for the targeting ecosystems and species. The radiative transfer model (MODTRAN 4.1) was used with atmospheric profile data to atmospherically correct the Landsat data. Vegetation indices and surface temperature were derived from the satellite images and used to estimate fractional vegetation cover, leaf area index (LAI), emi...

Advances in Meteorology, 2015

This paper presents spatial interpolation techniques to produce finer-scale daily rainfall data f... more This paper presents spatial interpolation techniques to produce finer-scale daily rainfall data from regional climate modeling. Four common interpolation techniques (ANUDEM, Spline, IDW, and Kriging) were compared and assessed against station rainfall data and modeled rainfall. The performance was assessed by the mean absolute error (MAE), mean relative error (MRE), root mean squared error (RMSE), and the spatial and temporal distributions. The results indicate that Inverse Distance Weighting (IDW) method is slightly better than the other three methods and it is also easy to implement in a geographic information system (GIS). The IDW method was then used to produce forty-year (1990–2009 and 2040–2059) time series rainfall data at daily, monthly, and annual time scales at a ground resolution of 100 m for the Greater Sydney Region (GSR). The downscaled daily rainfall data have been further utilized to predict rainfall erosivity and soil erosion risk and their future changes in GSR to ...

Integrative cancer therapies, Jan 2, 2015

To assess the antitumor effects of protosappanin B extracted from Lignum Sappan. Lignum Sappan wa... more To assess the antitumor effects of protosappanin B extracted from Lignum Sappan. Lignum Sappan was sequentially extracted by boiling water and ethyl acetate. The resulting extract was separated by column chromatography, to yield protosappanin B. The compound was then identified by thin-layer chromatography, high-performance liquid chromatography, elemental analysis, and spectrometry (infrared and ultraviolet). The effects on tumor cell viability and growth of purified protosappanin B were evaluated in vitro by trypan blue exclusion and MTT assays, respectively. And the effects of protosappanin B were assessed in vivo, on H22 mouse liver cancer cell invasion and the survival of tumor-bearing mice. Protosappanin B (2 mg/mL) reduced the viability of human bladder cancer T24 cells and mouse bladder cancer BTT cells in a time-dependent manner (P < .05) and significantly inhibited the growth of the human colon cancer cell lines HCT-116 and SW-480. IC50 values of 21.32, 26.73, and 76.53...

Climate Research, 2015

Identifying climatic drivers that dominate in determining crop yield variations at a regional sca... more Identifying climatic drivers that dominate in determining crop yield variations at a regional scale is important for predicting regional crop production. In this study, a statistical method was used to quantify the relationship between reported shire wheat yields and climate factors during the wheat-growing season across the New South Wales (NSW) wheat belt in eastern Australia from 1922 to 2000. The results show that recent climatic trends have increased wheat yield by 8.5 to 21.2% in 4 different climatic regions of NSW over the last few decades: In the eastern slopes, growing season maximum and minimum temperatures and number of heat stress days (> 34°C) were identified as the dominant climatic factors affecting wheat yield, accounting for 36% of its variation. The wheat yield variation in the remaining 3 regions were as follows: 41% in the northern region from maximum temperature, pre-growing season rainfall (December to April), and number of frost days (< 2°C); 47% in the south from rainfall, temperature, and number of frost and heat stress days; while in southwest NSW, rainfall was the main factor responsible for 31% of the variation. Frost was less important in the eastern slopes because farmers manage frost occurrence by sowing late and using late-flowering cultivars. However, the opposite occurs in the northern parts of the wheat belt where farmers sow earlier and select shortseason varieties to avoid heat stress, but thereby expose their crops to possible frost conditions. Understanding the impact of climate variations on crop yield is important for developing sustainable agricultural production under future climate change.

Soil Science and Plant Nutrition, 2014

Climate warming exhibits strong diurnal variations, with higher warming rates being observed at n... more Climate warming exhibits strong diurnal variations, with higher warming rates being observed at nighttime, which significantly affects rice (Oryza sativa L.) growth and grain yield. The objective of this study was to determine the effects of asymmetric warming (all-day warming, AW; daytime warming from 07:00 to 19:00, DW; nighttime warming from 19:00 to 07:00, NW, and a control, CK) on rice nitrogen (N) dynamics and productivity. Two rice bucket warming experiments were performed in Nanjing in Jiangsu Province, China, using the free air temperature increase (FATI) technique. The daily mean temperatures in the rice canopy in the AW, DW and NW plots were 2.0, 1.1 and 1.3ºC higher than those in the rice canopy in the CK plots, respectively. The results indicated that the total N accumulation of rice was 8.27-40.53% higher in the warming treatment than in the control during the jointing, anthesis and maturity stages. However, there was no significant difference detected among the three warming treatments. The warming treatment substantially decreased N translocation efficiency, leading to the retention of more N in the plant stems during grain filling. The warming treatment also decreased the N harvest index, N utilization efficiency based on grain yield and N utilization efficiencies based on biomass in both growing seasons. The warming treatment significantly increased the aboveground biomass (9.26-16.18%) in the jointing stage but decreased it (2.75-9.63%) in the maturity stage. Although DW increased the carbon (C) gain by photosynthesis and NW increased the C loss by night respiration, the daytime higher-temperature treatment affected rice photosynthesis and reduced its photosynthetic rate and product. This effect may be one of the primary reasons for the insignificant difference in the aboveground biomass between the DW and NW treatments. In the AW, DW and NW plots, the grain yield was reduced by an average of 10.07, 5.05 and 7.89%, respectively, across both years. The effective panicles and grains per spike tended to decrease in the warmed plots, whereas irregular changes in the 1000-grain weight were observed. Our results suggest that under the anticipated climate warming, rice productivity would further decline in the Yangtze River Basin.

World Review of Science, Technology and Sustainable Development, 2010

Journal of Nonlinear Optical Physics & Materials, 2006

Conical emission is investigated for Ti :sapphire femtosecond laser pulses propagating in water. ... more Conical emission is investigated for Ti :sapphire femtosecond laser pulses propagating in water. The colored rings can be observed in the forward direction due to the constructive and destructive interference of transverse wavevector, which are induced by the spatio-temporal gradient of the free-electron density. With increasing input laser energy, due to filamentation and pulse splitting induced by the plasma created by multiphoton excitation of electrons from the valence band to the conduction band, the on-axis spectrum of the conical emission is widely broadened and strongly modulated with respect to input laser spectrum, and finally remains fairly constant at higher laser energy due to intensity clamping in the filaments.