Based on TM image data in 1989, 1995, 1999, 2003, 2006 and 2009 of Yanchi County of Ningxia, the land use date of Yanchi County in each year were extracted supported by RS and GIS technology, and used to analyze the d...Based on TM image data in 1989, 1995, 1999, 2003, 2006 and 2009 of Yanchi County of Ningxia, the land use date of Yanchi County in each year were extracted supported by RS and GIS technology, and used to analyze the dynamic change of land use. The land use data were studied for estimating the change of ecosystem services value caused by the land use change of Yanchi County, using the evaluation method of China terrestrial ecosystem services value. The results showed that the changes of land use were obvious during 1989 to 2009. The area of woodland and construction land had an increasing tendency; grassland area changed from decreasing to increasing, which was in contrary to farmland and un-used land areas (from increasing to decreasing); water area fluctuated slightly. The ecosystem services value of Yanchi County had an increasing tendency during 1989 to 1995, because the increasing woodland area had took the major role in raising the total ecosystem services value. The grassland accounted for a large proportion of the total ecosystem service value of Yanchi County, with its contribution rate from 49.8% to 60.4%. And the composition of the ecosystem services value of Yanchi County happened benign change for the increasing contribution rate of woodland. The ecosystem services value sensitivity index of each land use type was less than 1, indicating that the ecosystem services value of Yanchi County lacks flexibility on its service value index, and the research results are reliable.展开更多
The nanostructure of the catalytic electrode has a great effect on the performance of direct metha- nol fuel cells (DMFCs), including catalyst utilization, precious metal loading, water balance, and oxygen mass tran...The nanostructure of the catalytic electrode has a great effect on the performance of direct metha- nol fuel cells (DMFCs), including catalyst utilization, precious metal loading, water balance, and oxygen mass transfer. In this work, ordered arrays of platinum nanorods with different diameters were directly grown onto microporous layers by electrodeposition via a sacrificial template, and were used as the catalytic cathode for passive DMFCs. The use of these ordered electrodes led to a dramatic decrease in cathode polarization behavior. The maximum power density of passive DMFCs fabricated with catalytic electrodes of 200 and 100 am Pt nanorod arrays were 17.3 and 12.0 mW/cm2, respectively. The obtained improvement in performance was ascribed to the fact that the ordered nanostructured electrode not only increased the electrochemically active surface area and the catalyst utilization, but also enhanced oxygen mass transfer and water balance in the system.展开更多
Yolk‐shell structured nanoparticles are of immense scientific and technological interests because of their unique architecture and myriad of applications.This review summarizes recent progresses in the use of yolk‐s...Yolk‐shell structured nanoparticles are of immense scientific and technological interests because of their unique architecture and myriad of applications.This review summarizes recent progresses in the use of yolk‐shell structured nanoparticles as nanoreactors for various chemical reactions.A very brief overview of synthetic strategies is provided with emphasis on recent research progress in the last five years.Catalytic applications of these yolk‐shell structured nanoreactors are then discussed by covering photocatalysis,methane reforming and electrochemical conversion.The state of the art research and perspective in future development are also highlighted.展开更多
The pollution of aquatic ecosystem by heavy metals has assumed serious proportions due to their toxicity and accumulative behavior. The toxicity metal is dependent on its chemical form and therefore removal of metal i...The pollution of aquatic ecosystem by heavy metals has assumed serious proportions due to their toxicity and accumulative behavior. The toxicity metal is dependent on its chemical form and therefore removal of metal is more meaningful than the estimation of its concentrations. In this study, the batch experiments were carried out under 30℃ to study the effect of pH, initial Cr concentration, adsorbent dose and contact time on the removal of Cr (lII). The maximum adsorption efficiency (99%) was observed when 1.5 g of pond mud was used for removal ofCr (Ⅲ) from test solution containing 150 mg·Cr / 100 ml. The optimal pH and contact time recorded during the study were 6 and 10.0, respectively.展开更多
The recent increase in patent granted in China prompts for an analysis of the various strategies which are certainly developed by Chinese applicants in that field. An analysis (APA Automatic Patent Analysis) has bee...The recent increase in patent granted in China prompts for an analysis of the various strategies which are certainly developed by Chinese applicants in that field. An analysis (APA Automatic Patent Analysis) has been done in several fields which have different impacts on the Chinese economy. We chose four different subjects: solar panels; photovoltaic panels; fireworks; and honeysuckle. These areas go from deep international concern to only Chinese interest. We analyzed in the different ratios between Chinese priority patents, Chinese patents extended to other countries, Patent extended from other countries to China and Chinese utility models. The results show clearly that various directions are followed depending on the economic importance of the field and also the pressure of the competition inside and outside China. In this context the strategic dependence (number of patents extended to China by other countries) was examined for each of the fields. We also show that in the domain where the man power is important such as fireworks the number of utility models is important. This suggests that utility models are used to spread in that field minor innovations. In the fields such as honeysuckle many applicants are the same that the inventors and the involvement of universities larger than in other fields. These two fields more or less centered on Chinese domestic aspects only a few patents (not for Honeysuckle) are extended to other countries. The impact of foreign patents in these two fields is quasi nil. In other domains such as photovoltaic panel the triadic patents (extension to US JP EP) are examined its show that if some Chinese patents are extended to other countries there are also an important numbers of foreign patents extended to China. This also suggests that in these most critical subjects, China develops a sort of technological protection barrier from domestic patents. This underlines a strategy on attack and defense in that field.展开更多
Solid oxide fuel cells (SOFCs) are considered to be one of the most important clean,distributed resources. However,SOFCs present a challenging control problem owing to their slow dynamics,nonlinearity and tight operat...Solid oxide fuel cells (SOFCs) are considered to be one of the most important clean,distributed resources. However,SOFCs present a challenging control problem owing to their slow dynamics,nonlinearity and tight operating constraints. A novel data-driven nonlinear control strategy was proposed to solve the SOFC control problem by combining a virtual reference feedback tuning (VRFT) method and support vector machine. In order to fulfill the requirement for fuel utilization and control constraints,a dynamic constraints unit and an anti-windup scheme were adopted. In addition,a feedforward loop was designed to deal with the current disturbance. Detailed simulations demonstrate that the fast response of fuel flow for the current demand disturbance and zero steady error of the output voltage are both achieved. Meanwhile,fuel utilization is kept almost within the safe region.展开更多
A general method for facile kinetics-controlled growth of aligned arrays of mesocrystalline SnO2 nanorods on arbitrary substrates has been developed by adjusting supersaturation in a unique ternary solvent system comp...A general method for facile kinetics-controlled growth of aligned arrays of mesocrystalline SnO2 nanorods on arbitrary substrates has been developed by adjusting supersaturation in a unique ternary solvent system comprising acetic acid, ethanol and water. The hydrolysis processes of Sn(IV) as well as the nucleation and growth of SnO2 crystals were carefully controlled in the mixed solvents, leading to an exclusively heterogeneous nucleation on a substrate and the subsequent growth into mesocrystalline nanorod arrays. In particular, aligned arrays of hierarchically structured, [001]-oriented mesocrystalline SnO2 nanorods with four {110} lateral facets can be readily grown on Ti foil as well as many other inert substrates such as fluoride-doped tin oxide (FTO), Si, graphite, and polytetrafluoroethylene (Teflon). Due to the unique combination of the mesocrystalline structure and the one-dimensional nanoarray structure, the obtained mesocrystalline SnO2 nanorod arrays grown on metallic Ti substrate exhibited an excellent rate performance with a high initial Coulombic efficiency of 65.6% and a reversible capacity of 720 mA.h/g at a charge/discharge rate of 10 C (namely, 7,820 mA/g) when used as an anode material for lithium-ion batteries.展开更多
Paddy fields in the southeastern basin of Dianchi Lake have rapidly changed to greenhouses since 1999. A total of 61 surface soil samples, including 43 greenhouse soils, 12 upland soils, and 6 paddy soils, were collec...Paddy fields in the southeastern basin of Dianchi Lake have rapidly changed to greenhouses since 1999. A total of 61 surface soil samples, including 43 greenhouse soils, 12 upland soils, and 6 paddy soils, were collected from a flat lowland area mainly used for agricultural production fields in the southeastern basin of Dianchi Lake. Analyses of the soil samples indicated that the greenhouse soils were characterized by a lower organic matter content, lower pH, and higher soluble nutrients than the paddy soils in the area. The lower organic matter content of the greenhouse soils was ascribed to environmental or management factors rather than the clay content of the soil. Accumulation of soluble nutrients, especially inorganic N, was due to over-application of fertilizers, which also caused soil acidification. The average amount of readily available N, P, and K accumulated in the greenhouse soils was estimated to be equal to or higher than the annual input of these nutrients as a fertilizer, indicating that a reduction in fertilizer application was possible and recommended. In contrast, a very low available Si content was observed in the paddy soils, suggesting the need for Si application for rice production.展开更多
Besides grid-to-vehicle(G2 V) and vehicle-to-grid(V2 G) functions, the battery of an electric vehicle(EV) also has the specific feature of mobility. This means that EVs not only have the potential to utilize the stora...Besides grid-to-vehicle(G2 V) and vehicle-to-grid(V2 G) functions, the battery of an electric vehicle(EV) also has the specific feature of mobility. This means that EVs not only have the potential to utilize the storage of cheap electricity for use in high energy price periods, but can also transfer energy from one place to another place. Based on these special features of an EV battery, a new EV energy scheduling method has been developed and is described in this article. The approach is aimed at optimizing the utilization EV energy for EVs that are regularly used in multiple places. The objective is to minimize electricity costs from multiple meter points. This work applies real data in order to analyze the effectiveness of the method. The results show that by applying the control strategy presented in this paper at locations where the EVs are parked, the electricity cost can be reduced without shifting the demand and lowering customer's satisfaction. The effects of PV size and number of EVs on our model are also analyzed in this paper. This model has the potential to be used by energy system designers as a new perspective to determine optimal sizes of generators or storage devices in energy systems.展开更多
TiO2-NaYF4:Er^3+/Yb^3+-C3N4 composite photoanodes were successfully designed for the first time. The photoelectric conversion efficiency of TiO2-NaYF4:Er^3+/Yb^3+ C3N4 composite cell can result an efficiency of ...TiO2-NaYF4:Er^3+/Yb^3+-C3N4 composite photoanodes were successfully designed for the first time. The photoelectric conversion efficiency of TiO2-NaYF4:Er^3+/Yb^3+ C3N4 composite cell can result an efficiency of 7.37%, which is higher than those of pure TiO2 cell and TiO2-C3N4 composite cell. The enhancement of the efficiency can be attributed to the synergetic effect of NaYF4:Er^3+/Yb^3+ and C3N4. Elec- trochemical impedance spectroscopy analysis revealed that the interfacial resistance of the TiO2-dyelI3^-/I^- electrolyte interface of TiO2-NaYF4:Er^3+/Yb^3+-C3N4 composites cell was much smaller than that of pure TiO2 cell. In addition, the TiO2-NaYF4:Er^3+/Yb^3+-C3N4 composite cell had longer electron recombination time and shorter electron transport time than that of pure TiO2 cell.展开更多
Soil erosion and loss of soil nutrients have been a crucial environment threat in Southwest China. The land use and its impact on soil qualities continue to be highlighted. The present study was conducted to compare s...Soil erosion and loss of soil nutrients have been a crucial environment threat in Southwest China. The land use and its impact on soil qualities continue to be highlighted. The present study was conducted to compare soil erosion under four land use types(i.e.,forestland, abandoned farmland, tillage, and grassland) and their effects on soil organic carbon(SOC), total nitrogen(TN) and total phosphorus(TP) in the Shuanglong catchment of the Dianchi Lake watershed, China. There were large variations in the erosion rate and the nutrient distributions across the four land use types. The erosion rates estimated by137 Cs averaged 2 133 t km-2year-1under tillage and abandoned farmland over the erosion rate of non-cultivated sites, and the grasslands showed a net deposition. For all sites, the nutrient contents basically decreased with the soil depth. Compared with tillage and abandoned farmland, grassland had the highest SOC and TN contents within 0–40 cm soil layer, followed by forestland. The significant correlations between137 Cs, SOC and TN were observed. The nutrient loss caused by erosion in tillage was the highest. These results suggested that grassland and forestland would be beneficial for SOC and TN sequestration over a long-term period because of their ability to reduce the loss of nutrients by soil erosion. Our study demonstrated that reduction of nutrient loss in the red soil area could be made through well-managed vegetation restoration measures.展开更多
基金supported by the National Key Technology R&D Program of China(2012BAD16B02)National Forestry Public Welfare Industry Research of China(201004018)~~
文摘Based on TM image data in 1989, 1995, 1999, 2003, 2006 and 2009 of Yanchi County of Ningxia, the land use date of Yanchi County in each year were extracted supported by RS and GIS technology, and used to analyze the dynamic change of land use. The land use data were studied for estimating the change of ecosystem services value caused by the land use change of Yanchi County, using the evaluation method of China terrestrial ecosystem services value. The results showed that the changes of land use were obvious during 1989 to 2009. The area of woodland and construction land had an increasing tendency; grassland area changed from decreasing to increasing, which was in contrary to farmland and un-used land areas (from increasing to decreasing); water area fluctuated slightly. The ecosystem services value of Yanchi County had an increasing tendency during 1989 to 1995, because the increasing woodland area had took the major role in raising the total ecosystem services value. The grassland accounted for a large proportion of the total ecosystem service value of Yanchi County, with its contribution rate from 49.8% to 60.4%. And the composition of the ecosystem services value of Yanchi County happened benign change for the increasing contribution rate of woodland. The ecosystem services value sensitivity index of each land use type was less than 1, indicating that the ecosystem services value of Yanchi County lacks flexibility on its service value index, and the research results are reliable.
基金supported by the National Basic Research Program of China(973 Program,2012CB932800)the National Natural Science Founda-tion of China(21533005,21276158,21303243,51506213)
文摘The nanostructure of the catalytic electrode has a great effect on the performance of direct metha- nol fuel cells (DMFCs), including catalyst utilization, precious metal loading, water balance, and oxygen mass transfer. In this work, ordered arrays of platinum nanorods with different diameters were directly grown onto microporous layers by electrodeposition via a sacrificial template, and were used as the catalytic cathode for passive DMFCs. The use of these ordered electrodes led to a dramatic decrease in cathode polarization behavior. The maximum power density of passive DMFCs fabricated with catalytic electrodes of 200 and 100 am Pt nanorod arrays were 17.3 and 12.0 mW/cm2, respectively. The obtained improvement in performance was ascribed to the fact that the ordered nanostructured electrode not only increased the electrochemically active surface area and the catalyst utilization, but also enhanced oxygen mass transfer and water balance in the system.
文摘Yolk‐shell structured nanoparticles are of immense scientific and technological interests because of their unique architecture and myriad of applications.This review summarizes recent progresses in the use of yolk‐shell structured nanoparticles as nanoreactors for various chemical reactions.A very brief overview of synthetic strategies is provided with emphasis on recent research progress in the last five years.Catalytic applications of these yolk‐shell structured nanoreactors are then discussed by covering photocatalysis,methane reforming and electrochemical conversion.The state of the art research and perspective in future development are also highlighted.
文摘The pollution of aquatic ecosystem by heavy metals has assumed serious proportions due to their toxicity and accumulative behavior. The toxicity metal is dependent on its chemical form and therefore removal of metal is more meaningful than the estimation of its concentrations. In this study, the batch experiments were carried out under 30℃ to study the effect of pH, initial Cr concentration, adsorbent dose and contact time on the removal of Cr (lII). The maximum adsorption efficiency (99%) was observed when 1.5 g of pond mud was used for removal ofCr (Ⅲ) from test solution containing 150 mg·Cr / 100 ml. The optimal pH and contact time recorded during the study were 6 and 10.0, respectively.
文摘The recent increase in patent granted in China prompts for an analysis of the various strategies which are certainly developed by Chinese applicants in that field. An analysis (APA Automatic Patent Analysis) has been done in several fields which have different impacts on the Chinese economy. We chose four different subjects: solar panels; photovoltaic panels; fireworks; and honeysuckle. These areas go from deep international concern to only Chinese interest. We analyzed in the different ratios between Chinese priority patents, Chinese patents extended to other countries, Patent extended from other countries to China and Chinese utility models. The results show clearly that various directions are followed depending on the economic importance of the field and also the pressure of the competition inside and outside China. In this context the strategic dependence (number of patents extended to China by other countries) was examined for each of the fields. We also show that in the domain where the man power is important such as fireworks the number of utility models is important. This suggests that utility models are used to spread in that field minor innovations. In the fields such as honeysuckle many applicants are the same that the inventors and the involvement of universities larger than in other fields. These two fields more or less centered on Chinese domestic aspects only a few patents (not for Honeysuckle) are extended to other countries. The impact of foreign patents in these two fields is quasi nil. In other domains such as photovoltaic panel the triadic patents (extension to US JP EP) are examined its show that if some Chinese patents are extended to other countries there are also an important numbers of foreign patents extended to China. This also suggests that in these most critical subjects, China develops a sort of technological protection barrier from domestic patents. This underlines a strategy on attack and defense in that field.
基金Projects(51076027,51036002) supported by the National Natural Science Foundation of ChinaProject(20090092110051) supported by the Doctoral Fund of Ministry of Education of China
文摘Solid oxide fuel cells (SOFCs) are considered to be one of the most important clean,distributed resources. However,SOFCs present a challenging control problem owing to their slow dynamics,nonlinearity and tight operating constraints. A novel data-driven nonlinear control strategy was proposed to solve the SOFC control problem by combining a virtual reference feedback tuning (VRFT) method and support vector machine. In order to fulfill the requirement for fuel utilization and control constraints,a dynamic constraints unit and an anti-windup scheme were adopted. In addition,a feedforward loop was designed to deal with the current disturbance. Detailed simulations demonstrate that the fast response of fuel flow for the current demand disturbance and zero steady error of the output voltage are both achieved. Meanwhile,fuel utilization is kept almost within the safe region.
文摘A general method for facile kinetics-controlled growth of aligned arrays of mesocrystalline SnO2 nanorods on arbitrary substrates has been developed by adjusting supersaturation in a unique ternary solvent system comprising acetic acid, ethanol and water. The hydrolysis processes of Sn(IV) as well as the nucleation and growth of SnO2 crystals were carefully controlled in the mixed solvents, leading to an exclusively heterogeneous nucleation on a substrate and the subsequent growth into mesocrystalline nanorod arrays. In particular, aligned arrays of hierarchically structured, [001]-oriented mesocrystalline SnO2 nanorods with four {110} lateral facets can be readily grown on Ti foil as well as many other inert substrates such as fluoride-doped tin oxide (FTO), Si, graphite, and polytetrafluoroethylene (Teflon). Due to the unique combination of the mesocrystalline structure and the one-dimensional nanoarray structure, the obtained mesocrystalline SnO2 nanorod arrays grown on metallic Ti substrate exhibited an excellent rate performance with a high initial Coulombic efficiency of 65.6% and a reversible capacity of 720 mA.h/g at a charge/discharge rate of 10 C (namely, 7,820 mA/g) when used as an anode material for lithium-ion batteries.
基金Supported by the JSPS KAKENHI,Japan(No.21255007)
文摘Paddy fields in the southeastern basin of Dianchi Lake have rapidly changed to greenhouses since 1999. A total of 61 surface soil samples, including 43 greenhouse soils, 12 upland soils, and 6 paddy soils, were collected from a flat lowland area mainly used for agricultural production fields in the southeastern basin of Dianchi Lake. Analyses of the soil samples indicated that the greenhouse soils were characterized by a lower organic matter content, lower pH, and higher soluble nutrients than the paddy soils in the area. The lower organic matter content of the greenhouse soils was ascribed to environmental or management factors rather than the clay content of the soil. Accumulation of soluble nutrients, especially inorganic N, was due to over-application of fertilizers, which also caused soil acidification. The average amount of readily available N, P, and K accumulated in the greenhouse soils was estimated to be equal to or higher than the annual input of these nutrients as a fertilizer, indicating that a reduction in fertilizer application was possible and recommended. In contrast, a very low available Si content was observed in the paddy soils, suggesting the need for Si application for rice production.
基金supported by the China Scholarship Council and Donghua University Graduate Student Degree Thesis Innovation Fund Project (Grant No. CUSF-DH-D-2013059)
文摘Besides grid-to-vehicle(G2 V) and vehicle-to-grid(V2 G) functions, the battery of an electric vehicle(EV) also has the specific feature of mobility. This means that EVs not only have the potential to utilize the storage of cheap electricity for use in high energy price periods, but can also transfer energy from one place to another place. Based on these special features of an EV battery, a new EV energy scheduling method has been developed and is described in this article. The approach is aimed at optimizing the utilization EV energy for EVs that are regularly used in multiple places. The objective is to minimize electricity costs from multiple meter points. This work applies real data in order to analyze the effectiveness of the method. The results show that by applying the control strategy presented in this paper at locations where the EVs are parked, the electricity cost can be reduced without shifting the demand and lowering customer's satisfaction. The effects of PV size and number of EVs on our model are also analyzed in this paper. This model has the potential to be used by energy system designers as a new perspective to determine optimal sizes of generators or storage devices in energy systems.
基金supported by the National Natural Science Foundation of China (21471050 and 21501052)the China Postdoctoral Science Foundation (2015M570304)+2 种基金the Postdoctoral Science Foundation of Heilongjiang Province (LBH-TZ06019)Heilongjiang Province Natural Science Foundation (ZD201301)the Science Foundation for Excellent Youth of Harbin City of China (2016RQQXJ099)
文摘TiO2-NaYF4:Er^3+/Yb^3+-C3N4 composite photoanodes were successfully designed for the first time. The photoelectric conversion efficiency of TiO2-NaYF4:Er^3+/Yb^3+ C3N4 composite cell can result an efficiency of 7.37%, which is higher than those of pure TiO2 cell and TiO2-C3N4 composite cell. The enhancement of the efficiency can be attributed to the synergetic effect of NaYF4:Er^3+/Yb^3+ and C3N4. Elec- trochemical impedance spectroscopy analysis revealed that the interfacial resistance of the TiO2-dyelI3^-/I^- electrolyte interface of TiO2-NaYF4:Er^3+/Yb^3+-C3N4 composites cell was much smaller than that of pure TiO2 cell. In addition, the TiO2-NaYF4:Er^3+/Yb^3+-C3N4 composite cell had longer electron recombination time and shorter electron transport time than that of pure TiO2 cell.
基金supported by the National Natural Science Foundation of China(Nos.41273102,41030751 and 41273103)
文摘Soil erosion and loss of soil nutrients have been a crucial environment threat in Southwest China. The land use and its impact on soil qualities continue to be highlighted. The present study was conducted to compare soil erosion under four land use types(i.e.,forestland, abandoned farmland, tillage, and grassland) and their effects on soil organic carbon(SOC), total nitrogen(TN) and total phosphorus(TP) in the Shuanglong catchment of the Dianchi Lake watershed, China. There were large variations in the erosion rate and the nutrient distributions across the four land use types. The erosion rates estimated by137 Cs averaged 2 133 t km-2year-1under tillage and abandoned farmland over the erosion rate of non-cultivated sites, and the grasslands showed a net deposition. For all sites, the nutrient contents basically decreased with the soil depth. Compared with tillage and abandoned farmland, grassland had the highest SOC and TN contents within 0–40 cm soil layer, followed by forestland. The significant correlations between137 Cs, SOC and TN were observed. The nutrient loss caused by erosion in tillage was the highest. These results suggested that grassland and forestland would be beneficial for SOC and TN sequestration over a long-term period because of their ability to reduce the loss of nutrients by soil erosion. Our study demonstrated that reduction of nutrient loss in the red soil area could be made through well-managed vegetation restoration measures.