In this study, a commercial cube-shaped open-celled cellulose sponge adsorbent was modified by in-situ co-precipitation of superparamagnetic iron oxide nanoparticles(SPION) and used to remove As(V) from aqueous soluti...In this study, a commercial cube-shaped open-celled cellulose sponge adsorbent was modified by in-situ co-precipitation of superparamagnetic iron oxide nanoparticles(SPION) and used to remove As(V) from aqueous solutions. Fe K-edge X-ray absorption spectroscopy(XAS) and TEM identified maghemite as the main iron phase of the SPION nanoparticles with an average size 13 nm. Batch adsorption experiments at 800 mg/L showed a 63% increase of adsorption capacity when loading 2.6 wt.% mass fraction of SPION in the cube-sponge.Experimental determination of the adsorption thermodynamic parameters indicated that the As(V) adsorption on the composite material is a spontaneous and exothermic process.As K-edge XAS results confirmed that the adsorption enhancement on the composite can be attributed to the nanoparticles loaded. In addition, adsorbed As(V) did not get reduced to more toxic As(Ⅲ) and formed a binuclear corner-sharing complex with SPION. The advantageous cube-shape of the sponge-loaded SPION composite together with its high affinity and good adsorption capacity for As(V), good regeneration capability and the enhanceddiffusion attributed to its open-celled structure make this adsorbent a good candidate for industrial applications.展开更多
This study was concerned on the influence of cooking liquor parameters i.e. active alkali （AA） and sulfidity, on the properties of pulp produced from Thai bamboo by means of multivariate analysis. The investigated p...This study was concerned on the influence of cooking liquor parameters i.e. active alkali （AA） and sulfidity, on the properties of pulp produced from Thai bamboo by means of multivariate analysis. The investigated pulp properties were cooking yield and viscosity. The experiments were performed according to a face centered cube experimental design. Then, multiple linear regression （MLR） of independent and dependent variables were conducted with SPSS software using least square method. In order to optimize process, Pareto-Optimality method was employed. The obtained regression models were characterized by both descriptive and predictive ability （R^2 ≥ 95% and Rcv^2 ≥ 93%） and allowed the kraft pulping process with an acceptable viscosity （ 1110- 1 190 ml/g） and a total yield about 50% at a sulfidity level of 20-30% with 18% AA. Results indicated that high sulfidity at a lower AA could get high viscosity and relatively low kappa number for pulps. Also oxygen delignification was studied in this research.展开更多
The growing demand for high-quality,temporally consistent satellite imagery for environmental monitoring and land use research has exposed a substantial data gap in China.Unlike the United States,which provides Analys...The growing demand for high-quality,temporally consistent satellite imagery for environmental monitoring and land use research has exposed a substantial data gap in China.Unlike the United States,which provides Analysis Ready Data(ARD)for Landsat imagery,Chinese researchers currently lack an equivalent resource,resulting in time-intensive data processing and potential research inaccuracies.In this study,we introduce the first seamless,annual Leaf-On Landsat composite data cube for China,covering 1985 to 2023.Leveraging the comprehensive image compositing approach,our dataset harmonizes images across multiple Landsat sensors and addresses key challenges such as cloud and shadow contamination,reflectance consistency,and the data gaps.Over this period,an average of 7.9% of data remained unavailable due to cloud/shadow cover and limited data accessibility.To address this,we applied segmented linear interpolation to generate proxies,which we validated for stability,achieving high consistency with actual Landsat references for both stable and dynamic pixel sequences(r=0.77 to 0.99,root mean square error[RMSE]=0.0043 to 0.0232).Additionally,representativeness assessments indicate a strong correlation between our composites and Landsat reference images(closest to day of year 225)(r=0.75 to 0.94,RMSE=0.025 to 0.063),confirming that these composites effectively capture seasonal vegetation conditions across diverse land cover types.This dataset is expected to help reduce preprocessing efforts for researchers and provide a solid basis for land use monitoring and environmental assessments across China.展开更多
基金financially supported by the MINECO ministry of Spain (No. CTM2015–65414-C2–1-R)the Innovation Found for Competitiveness of the Chilean Economic Development Agency (CORFO, No. es 13CEI2–21839)+1 种基金the China scholarship council for the fellowship (No. 201708110179)funding support from the European Union’s Horizon 2020 research and innovation program under the Marie Sk?odowska-Curie grant agreement (No. 665919)。
文摘In this study, a commercial cube-shaped open-celled cellulose sponge adsorbent was modified by in-situ co-precipitation of superparamagnetic iron oxide nanoparticles(SPION) and used to remove As(V) from aqueous solutions. Fe K-edge X-ray absorption spectroscopy(XAS) and TEM identified maghemite as the main iron phase of the SPION nanoparticles with an average size 13 nm. Batch adsorption experiments at 800 mg/L showed a 63% increase of adsorption capacity when loading 2.6 wt.% mass fraction of SPION in the cube-sponge.Experimental determination of the adsorption thermodynamic parameters indicated that the As(V) adsorption on the composite material is a spontaneous and exothermic process.As K-edge XAS results confirmed that the adsorption enhancement on the composite can be attributed to the nanoparticles loaded. In addition, adsorbed As(V) did not get reduced to more toxic As(Ⅲ) and formed a binuclear corner-sharing complex with SPION. The advantageous cube-shape of the sponge-loaded SPION composite together with its high affinity and good adsorption capacity for As(V), good regeneration capability and the enhanceddiffusion attributed to its open-celled structure make this adsorbent a good candidate for industrial applications.
文摘This study was concerned on the influence of cooking liquor parameters i.e. active alkali （AA） and sulfidity, on the properties of pulp produced from Thai bamboo by means of multivariate analysis. The investigated pulp properties were cooking yield and viscosity. The experiments were performed according to a face centered cube experimental design. Then, multiple linear regression （MLR） of independent and dependent variables were conducted with SPSS software using least square method. In order to optimize process, Pareto-Optimality method was employed. The obtained regression models were characterized by both descriptive and predictive ability （R^2 ≥ 95% and Rcv^2 ≥ 93%） and allowed the kraft pulping process with an acceptable viscosity （ 1110- 1 190 ml/g） and a total yield about 50% at a sulfidity level of 20-30% with 18% AA. Results indicated that high sulfidity at a lower AA could get high viscosity and relatively low kappa number for pulps. Also oxygen delignification was studied in this research.
基金supported in part by the National Science Foundation for Distinguished Young Scholars of China under Grant 42225107the National Key Research and Development Program of China under Grant 2022YFB3903402the National Natural Science Foundation of China under Grant 42171409 and Grant 42171410.
文摘The growing demand for high-quality,temporally consistent satellite imagery for environmental monitoring and land use research has exposed a substantial data gap in China.Unlike the United States,which provides Analysis Ready Data(ARD)for Landsat imagery,Chinese researchers currently lack an equivalent resource,resulting in time-intensive data processing and potential research inaccuracies.In this study,we introduce the first seamless,annual Leaf-On Landsat composite data cube for China,covering 1985 to 2023.Leveraging the comprehensive image compositing approach,our dataset harmonizes images across multiple Landsat sensors and addresses key challenges such as cloud and shadow contamination,reflectance consistency,and the data gaps.Over this period,an average of 7.9% of data remained unavailable due to cloud/shadow cover and limited data accessibility.To address this,we applied segmented linear interpolation to generate proxies,which we validated for stability,achieving high consistency with actual Landsat references for both stable and dynamic pixel sequences(r=0.77 to 0.99,root mean square error[RMSE]=0.0043 to 0.0232).Additionally,representativeness assessments indicate a strong correlation between our composites and Landsat reference images(closest to day of year 225)(r=0.75 to 0.94,RMSE=0.025 to 0.063),confirming that these composites effectively capture seasonal vegetation conditions across diverse land cover types.This dataset is expected to help reduce preprocessing efforts for researchers and provide a solid basis for land use monitoring and environmental assessments across China.
