Land degradation causes serious environmental problems in many regions of the world, and although it can be effectively assessed and monitored using a time series of rainfall and a normalized difference vegetation ind...Land degradation causes serious environmental problems in many regions of the world, and although it can be effectively assessed and monitored using a time series of rainfall and a normalized difference vegetation index （NDVI） from remotely-sensed imagery, dividing human-induced land degradation from vegetation dynamics due to climate change is not a trivial task. This paper presented a multilevel statistical modeling of the NDVI-rainfall relationship to detect human-induced land degradation at local and landscape scales in the Ordos Plateau of Inner Mongolia, China, and recognized that anthropogenic activities result in either positive （land restoration and re-vegetation） or negative （degradation） trends. Linear regressions were used to assess the accuracy of the multi- level statistical model. The results show that： （1） land restoration was the dominant process in the Ordos Plateau between 1998 and 2012; （2） the effect of the statistical removal of precipitation revealed areas of human-induced land degradation and improvement, the latter reflecting successful restoration projects and changes in land man- agement in many parts of the Ordos; （3） compared to a simple linear regression, multilevel statistical modeling could be used to analyze the relationship between the NDVI and rainfall and improve the accuracy of detecting the effect of human activities. Additional factors should be included when analyzing the NDVI-rainfall relationship and detecting human-induced loss of vegetation cover in drylands to improve the accuracy of the approach and elimi- nate some observed non-significant residual trends.展开更多
In situ microscale distributions of 02, H2S, pH and redox potential in sediments of Hongfeng Lake, SW China, were investigated using the powerful microsensor technique. Our results show that O2 was depleted within the...In situ microscale distributions of 02, H2S, pH and redox potential in sediments of Hongfeng Lake, SW China, were investigated using the powerful microsensor technique. Our results show that O2 was depleted within the top 3.9 mm in surface sediments, and H2S was subsequently detected at -6.0 mm depth, and reached its maximum concentrations at -25 mm. The degradation of organic matter and reduction of sulfate might be the major pathways of producing H2S in sediments, pH rapidly reduced in surface layers mainly due to H＋ release in the oxidation of organic matter. Eh also decreased sharply in surface sediments, probabl indicating the coexistence of Fe and Mn oxides with O2 in aerobic region. Furthermore, the programme of PROFILE was applied to model the 02 gradient, and good fit was obtained between the simulative values and the factual values both in sediments and in the diffusive boundary layer （DBL）. The results indicate that the depth-integrated O2 consumption rates within sediments were 0.083 and 0.134 nmol·m-3·s-1 in site S1 and site S2, respectively. In addition, there were distinct DBL in two sediment profiles, with 1.2 mm thickness in S1 and 0.9 mm thickness in S2. The diffusive fluxes of O2 within the DBL were 67.13 nmol·m-2·s-1 in S1 and 88.54 nmol·m-2·s-1 in S2.展开更多
Typical wastes from nickel plating operations include excess drag-out solution. An electrochemical approach was made to recover the nickel and remove the organic pollutants from the spent electroless nickelplating bat...Typical wastes from nickel plating operations include excess drag-out solution. An electrochemical approach was made to recover the nickel and remove the organic pollutants from the spent electroless nickelplating bath. An electrolyte cell which was constructed by the cathode of porous nickel foam and the anode of Ti/RuO2 was used. During electrolysis, the nickel ion was electrodeposited at the cathode and the oxidation of the organics in the hath was conducted at the anode. The current （i） , time （t） , temperature （T） and pH of the solution affected the recovery efficiency of nickel with constant potential electrolysis. With the optimum experimental conditions of pH=7.6, i = 0.45 A. T = 65℃ andt = 2 h, the concentration of nickel ion was reduced from 2.09 g/L to 0. 053 g/L and the recovery rate of nickel, the current efficiency and the consumed energy wer 97.5%, 17. 1%, 12.2 kWh/kg Ni, respectively. Meanwhile, total organic carbon （TOC） of the bath was reduced from 5 800 mg/L to 152.5 mg/L and the removal efficiency of TOC was 97.3%. The recovery rate of nickel could keep to about 97% when eleetrodeposit was used to recover nickel for 40 hours in a laboratol.w batch reactor containing the spent bath. Dull nickel containing phosphorus was obtained on the cathode.展开更多
In this work, we investigated resistive switching behavior of CrO<sub>x</sub> thin films grown by using sputtering technique. Conventional I-V measurements obtained from Ag/CrO<sub>x</sub>/Pt/T...In this work, we investigated resistive switching behavior of CrO<sub>x</sub> thin films grown by using sputtering technique. Conventional I-V measurements obtained from Ag/CrO<sub>x</sub>/Pt/Ti/SiO<sub>2</sub>/Si structures depict the bipolar switching behavior, which is controlled by formation/dissolution processes of Ag conducting filaments through electrochemical redox reaction under external electric field driven. Conductive atomic force microscopy (C-AFM) technique provides the valuable mapping images of existing Ag filaments at low resistance state as well as the characteristics of filament distributions and diameters. This study also reveals that where the higher amplitude of topography is, the easier possibility of forming conducting filament paths is on CrO<sub>x</sub> surface films.展开更多
Exploring the spatial zoning of urban territories and their ecological effects under different decision preferences is an important approach to promote the sustainable utilization of regional resources.This paper cons...Exploring the spatial zoning of urban territories and their ecological effects under different decision preferences is an important approach to promote the sustainable utilization of regional resources.This paper constructs an index system for evaluating the suitability of territorial space development from the perspectives of urban development,agricultural production,and ecological conservation.It predicts and simulates the trade-offs between territorial space development and protection in Ezhou under different decision preferences using the Analytic Hierarchy Process(AHP) and Ordered Weighted Averaging(OWA) method.The modified equivalent factor method is used to analyze the ecosystem service values of different functional areas.The results indicate the following:(1) the preferences of decision-makers considerably influence the level of territorial space suitability.Higher(lower)levels of concern for risk result in more optimistic(pessimistic) evaluators,and this affects the priority given to ecological protection(development and utilization).(2) Under the ecological priority scenario,the status quo scenario and development priority scenario,there are significant differences in regional suitability levels.The ecological priority scenario gives high importance to ecological protection,resulting in the absolute protection of the Liangzi lake area,with 42.59% of Liangzihu district considered unsuitable for development.In contrast,the development orientation scenario designates Echeng district,an economic and political center,as highly suitable for development,with over 60% of the area available for development.(3) The total value of ecosystem services in Ezhou city was 213.355 billion yuan in 2018.Ecosystem service values were mainly provided by the water area in the permanently unsuitable development zone,leading to a mismatch between the supply and demand of ecosystem services under different scenarios.展开更多
Lanmuchangite is a new thallium hydrous sulfate from the oxidation zone hosting rich thallium ore bodies in the Lanmuchang thallium(mercury) ore deposit, Xinren County, Guizhou Province, China. This new mineral is nam...Lanmuchangite is a new thallium hydrous sulfate from the oxidation zone hosting rich thallium ore bodies in the Lanmuchang thallium(mercury) ore deposit, Xinren County, Guizhou Province, China. This new mineral is named after the locality where it was discovered. The mineral is associated with melanterite, pickeringite, potassium alum, jarosite, gypsum, arsenic blane, sulphur and some unknown minerals. The aggregates of lanmuchangite range from 2 to 10 mm in size. In general, the aggregates are compact and massive in form and are composed of anhedral granular crystals measuring in size from 40 to 90μm, but the single crystal grains show distinct boundaries. Parallel columnar aggregates are occasionally seen, which are composed of subhedral to euhedral columnar crystals ranging in size from 15 to 65μm. White, light yellow to white in color, glassy in luster and transparent. Hv-{mess.}=94-124 kg/mm+2, Hm={3.1}-{3.4}, density={2.22} g/cm+3. Under the polarization microscope the mineral is colorless and homogeneous, with N-{meas.}={1.495}. It is easily water-soluble. The average chemical composition is: Tl-2O={33.25}, Al-2O-3={8.07}, SO-3={25.19}, SiO-2={0.10}, K-2O={0.35}, CaO={0.08}, MgO={0.06}, FeO={0.04} and H-2O={33.46} [the crystal water (H-2O) was measured by thermogravimetery (TG) while the other composition were determined by electron microprobe], totaling {100.60%}. The empirical formula is (Tl-{1.00}K-{0.05})-{1.05} (Al-{1.01}Si-{0.01}Ca-{0.01}Mg-{0.01})-{1.04}-{2.01}·{11.88} H-2O and the simplified formula is TlAl-2·12H-2O. The compatibility of lanmuchangite is {-0.03} and its value falls within the range of {±0.020}-{±0.039}, so the compatibility is excellent. Its TG curve demonstrated that the crystal water was lost (i.e., dewatering) in stages at 101, 130 and 230℃. At the temperature of 243℃ the process of dewatering came to the end and the sum of lost crystal water reaches {33.30} wt%. IR spectroscopic analysis showed that the absorption bands 3374-3147 cm+{-1} and 1655-1648 cm+{-1} are due to tensile and bending vibration of crystal water molecules (H-2O) whereas those at 1131 cm+{-1} and 605 cm+{-1} are attributed to tensile and bending vibration of group +{2-}. Lanmuchangite is of the isometric system, with space group=Pa3, a={12.212(5)}, v=1821(2)+3, and Z=4. The strongest diffraction lines from the X-ray power diffraction data are {4.314}(100, 220), {2.801}(70, 331), {7.03}(54, 111), {2.731}(35, 420), {6.11}(27, 200), {3.524}(24, 222), {3.676}(22, 311), {3.051}(22, 400), {2.350}(21, 511), {3.263}(20, 321), {2.494}(20, 422), {1.932}(19, 620).展开更多
In order to extract the boundary of rural habitation, based on geographic name data and basic geographic information data, an extraction method that use polygon aggregation is raised, it can extract the boundary of th...In order to extract the boundary of rural habitation, based on geographic name data and basic geographic information data, an extraction method that use polygon aggregation is raised, it can extract the boundary of three levels of rural habitation consists of town, administrative village and nature village. The method first extracts the boundary of nature village by aggregating the resident polygon, then extracts the boundary of administrative village by aggregating the boundary of nature village, and last extracts the boundary of town by aggregating the boundary of administrative village. The related methods of extracting the boundary of those three levels rural habitation has been given in detail during the experiment with basic geographic information data and geographic name data. Experimental results show the method can be a reference for boundary extraction of rural habitation.展开更多
基金National Basic Research Program of China (2012CB722201)National Natural Science Foundation of China (30970504, 31060320)National Science and Technology Support Program (2011BAC07B01)
文摘Land degradation causes serious environmental problems in many regions of the world, and although it can be effectively assessed and monitored using a time series of rainfall and a normalized difference vegetation index （NDVI） from remotely-sensed imagery, dividing human-induced land degradation from vegetation dynamics due to climate change is not a trivial task. This paper presented a multilevel statistical modeling of the NDVI-rainfall relationship to detect human-induced land degradation at local and landscape scales in the Ordos Plateau of Inner Mongolia, China, and recognized that anthropogenic activities result in either positive （land restoration and re-vegetation） or negative （degradation） trends. Linear regressions were used to assess the accuracy of the multi- level statistical model. The results show that： （1） land restoration was the dominant process in the Ordos Plateau between 1998 and 2012; （2） the effect of the statistical removal of precipitation revealed areas of human-induced land degradation and improvement, the latter reflecting successful restoration projects and changes in land man- agement in many parts of the Ordos; （3） compared to a simple linear regression, multilevel statistical modeling could be used to analyze the relationship between the NDVI and rainfall and improve the accuracy of detecting the effect of human activities. Additional factors should be included when analyzing the NDVI-rainfall relationship and detecting human-induced loss of vegetation cover in drylands to improve the accuracy of the approach and elimi- nate some observed non-significant residual trends.
基金supported by the National Natural Science Foundation of China (Nos.41173125 and 41403113)
文摘In situ microscale distributions of 02, H2S, pH and redox potential in sediments of Hongfeng Lake, SW China, were investigated using the powerful microsensor technique. Our results show that O2 was depleted within the top 3.9 mm in surface sediments, and H2S was subsequently detected at -6.0 mm depth, and reached its maximum concentrations at -25 mm. The degradation of organic matter and reduction of sulfate might be the major pathways of producing H2S in sediments, pH rapidly reduced in surface layers mainly due to H＋ release in the oxidation of organic matter. Eh also decreased sharply in surface sediments, probabl indicating the coexistence of Fe and Mn oxides with O2 in aerobic region. Furthermore, the programme of PROFILE was applied to model the 02 gradient, and good fit was obtained between the simulative values and the factual values both in sediments and in the diffusive boundary layer （DBL）. The results indicate that the depth-integrated O2 consumption rates within sediments were 0.083 and 0.134 nmol·m-3·s-1 in site S1 and site S2, respectively. In addition, there were distinct DBL in two sediment profiles, with 1.2 mm thickness in S1 and 0.9 mm thickness in S2. The diffusive fluxes of O2 within the DBL were 67.13 nmol·m-2·s-1 in S1 and 88.54 nmol·m-2·s-1 in S2.
文摘Typical wastes from nickel plating operations include excess drag-out solution. An electrochemical approach was made to recover the nickel and remove the organic pollutants from the spent electroless nickelplating bath. An electrolyte cell which was constructed by the cathode of porous nickel foam and the anode of Ti/RuO2 was used. During electrolysis, the nickel ion was electrodeposited at the cathode and the oxidation of the organics in the hath was conducted at the anode. The current （i） , time （t） , temperature （T） and pH of the solution affected the recovery efficiency of nickel with constant potential electrolysis. With the optimum experimental conditions of pH=7.6, i = 0.45 A. T = 65℃ andt = 2 h, the concentration of nickel ion was reduced from 2.09 g/L to 0. 053 g/L and the recovery rate of nickel, the current efficiency and the consumed energy wer 97.5%, 17. 1%, 12.2 kWh/kg Ni, respectively. Meanwhile, total organic carbon （TOC） of the bath was reduced from 5 800 mg/L to 152.5 mg/L and the removal efficiency of TOC was 97.3%. The recovery rate of nickel could keep to about 97% when eleetrodeposit was used to recover nickel for 40 hours in a laboratol.w batch reactor containing the spent bath. Dull nickel containing phosphorus was obtained on the cathode.
文摘In this work, we investigated resistive switching behavior of CrO<sub>x</sub> thin films grown by using sputtering technique. Conventional I-V measurements obtained from Ag/CrO<sub>x</sub>/Pt/Ti/SiO<sub>2</sub>/Si structures depict the bipolar switching behavior, which is controlled by formation/dissolution processes of Ag conducting filaments through electrochemical redox reaction under external electric field driven. Conductive atomic force microscopy (C-AFM) technique provides the valuable mapping images of existing Ag filaments at low resistance state as well as the characteristics of filament distributions and diameters. This study also reveals that where the higher amplitude of topography is, the easier possibility of forming conducting filament paths is on CrO<sub>x</sub> surface films.
基金National Natural Science Foundation of China,No.71974070,No.41501593。
文摘Exploring the spatial zoning of urban territories and their ecological effects under different decision preferences is an important approach to promote the sustainable utilization of regional resources.This paper constructs an index system for evaluating the suitability of territorial space development from the perspectives of urban development,agricultural production,and ecological conservation.It predicts and simulates the trade-offs between territorial space development and protection in Ezhou under different decision preferences using the Analytic Hierarchy Process(AHP) and Ordered Weighted Averaging(OWA) method.The modified equivalent factor method is used to analyze the ecosystem service values of different functional areas.The results indicate the following:(1) the preferences of decision-makers considerably influence the level of territorial space suitability.Higher(lower)levels of concern for risk result in more optimistic(pessimistic) evaluators,and this affects the priority given to ecological protection(development and utilization).(2) Under the ecological priority scenario,the status quo scenario and development priority scenario,there are significant differences in regional suitability levels.The ecological priority scenario gives high importance to ecological protection,resulting in the absolute protection of the Liangzi lake area,with 42.59% of Liangzihu district considered unsuitable for development.In contrast,the development orientation scenario designates Echeng district,an economic and political center,as highly suitable for development,with over 60% of the area available for development.(3) The total value of ecosystem services in Ezhou city was 213.355 billion yuan in 2018.Ecosystem service values were mainly provided by the water area in the permanently unsuitable development zone,leading to a mismatch between the supply and demand of ecosystem services under different scenarios.
文摘Lanmuchangite is a new thallium hydrous sulfate from the oxidation zone hosting rich thallium ore bodies in the Lanmuchang thallium(mercury) ore deposit, Xinren County, Guizhou Province, China. This new mineral is named after the locality where it was discovered. The mineral is associated with melanterite, pickeringite, potassium alum, jarosite, gypsum, arsenic blane, sulphur and some unknown minerals. The aggregates of lanmuchangite range from 2 to 10 mm in size. In general, the aggregates are compact and massive in form and are composed of anhedral granular crystals measuring in size from 40 to 90μm, but the single crystal grains show distinct boundaries. Parallel columnar aggregates are occasionally seen, which are composed of subhedral to euhedral columnar crystals ranging in size from 15 to 65μm. White, light yellow to white in color, glassy in luster and transparent. Hv-{mess.}=94-124 kg/mm+2, Hm={3.1}-{3.4}, density={2.22} g/cm+3. Under the polarization microscope the mineral is colorless and homogeneous, with N-{meas.}={1.495}. It is easily water-soluble. The average chemical composition is: Tl-2O={33.25}, Al-2O-3={8.07}, SO-3={25.19}, SiO-2={0.10}, K-2O={0.35}, CaO={0.08}, MgO={0.06}, FeO={0.04} and H-2O={33.46} [the crystal water (H-2O) was measured by thermogravimetery (TG) while the other composition were determined by electron microprobe], totaling {100.60%}. The empirical formula is (Tl-{1.00}K-{0.05})-{1.05} (Al-{1.01}Si-{0.01}Ca-{0.01}Mg-{0.01})-{1.04}-{2.01}·{11.88} H-2O and the simplified formula is TlAl-2·12H-2O. The compatibility of lanmuchangite is {-0.03} and its value falls within the range of {±0.020}-{±0.039}, so the compatibility is excellent. Its TG curve demonstrated that the crystal water was lost (i.e., dewatering) in stages at 101, 130 and 230℃. At the temperature of 243℃ the process of dewatering came to the end and the sum of lost crystal water reaches {33.30} wt%. IR spectroscopic analysis showed that the absorption bands 3374-3147 cm+{-1} and 1655-1648 cm+{-1} are due to tensile and bending vibration of crystal water molecules (H-2O) whereas those at 1131 cm+{-1} and 605 cm+{-1} are attributed to tensile and bending vibration of group +{2-}. Lanmuchangite is of the isometric system, with space group=Pa3, a={12.212(5)}, v=1821(2)+3, and Z=4. The strongest diffraction lines from the X-ray power diffraction data are {4.314}(100, 220), {2.801}(70, 331), {7.03}(54, 111), {2.731}(35, 420), {6.11}(27, 200), {3.524}(24, 222), {3.676}(22, 311), {3.051}(22, 400), {2.350}(21, 511), {3.263}(20, 321), {2.494}(20, 422), {1.932}(19, 620).
文摘In order to extract the boundary of rural habitation, based on geographic name data and basic geographic information data, an extraction method that use polygon aggregation is raised, it can extract the boundary of three levels of rural habitation consists of town, administrative village and nature village. The method first extracts the boundary of nature village by aggregating the resident polygon, then extracts the boundary of administrative village by aggregating the boundary of nature village, and last extracts the boundary of town by aggregating the boundary of administrative village. The related methods of extracting the boundary of those three levels rural habitation has been given in detail during the experiment with basic geographic information data and geographic name data. Experimental results show the method can be a reference for boundary extraction of rural habitation.
