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Stable Carbon and Oxygen Isotopes of Pedogenic Carbonates in Ustic Vertisols: Implications for Paleoenvironmental Change 被引量:4
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作者 HUANG Cheng-Min WANG Cheng-Shan TANG Ya 《Pedosphere》 SCIE CAS CSCD 2005年第4期539-544,共6页
Pedogenic carbonates, found extensively in arid and semiarid regions, are important in revealing regional climatic and environmental changes as well as the carbon cycle. In addition, stable carbon and oxygen isotopic ... Pedogenic carbonates, found extensively in arid and semiarid regions, are important in revealing regional climatic and environmental changes as well as the carbon cycle. In addition, stable carbon and oxygen isotopic compositions of pedogenic carbonates have been used to rebuild paleoecology (biomass and vegetation) and to estimate paleotemperature and paleoprecipitation during past geological time. By utilizing the stable carbon and oxygen isotopic compositions (δ13C and (δ18O) of secondary nodules in Ustic Vertisols, this study looked into the climatic and environmental changes in the dry valleys of the Yuanmou Basin, Yunnan Province, in southwestern China. The results showed that during the early Holocene, a warm-humid or hot-humid climate existed in the Yuanmou Basin, but since then fluctuations in climate have occurred, with a dry climate prevailing. A highly significant correlation (r = 0.92, n = 9) between δ13C and δ18O values of carbonates illustrated that there had been a continual shifting between cold-humid and warm-dry climates in southwestern China including the Yuanmou Basin since the early Holocene. 展开更多
关键词 CARBON isotopic composition OXYGEN pedogenic carbonates Ustic Vertisols
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Heavy metals leaching in bottom ash and fly ash fractions from industrial-scale BFB-boiler for environmental risks assessment 被引量:2
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作者 Risto POYKIO Mikko MAKELA +2 位作者 Gary WATKINS Hannu NURMESNIEMI OUi DAHL 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第1期256-264,共9页
The bottom ash and fly ash from the co-combustion of wood residues and peat at a bubbling fluidised bed boiler(296 MW) contained only quartz(SiO_2), microcline(KAl Si_3O_8) and albite(NaAlSi_3O_8). Thus, X-ray... The bottom ash and fly ash from the co-combustion of wood residues and peat at a bubbling fluidised bed boiler(296 MW) contained only quartz(SiO_2), microcline(KAl Si_3O_8) and albite(NaAlSi_3O_8). Thus, X-ray powder diffraction(XRD) was not useful for clarifying the difference in the release of associated heavy metals from ash matrices. In order to assess the release of heavy metals from ashes under changing environmental conditions, they were sequentially extracted and fractionated by the BCR-procedure into acid soluble/exchangeable(CH_3COOH), reducible(NH_2OH-HCl) and oxidizable(H_2O_2/CH_3COONH_4) phases. The CH_3 COOH extractable fraction in conjunction with the total heavy metals concentrations were used to calculate the risk assessment code values for heavy metals leaching from the ash matrix. The leaching studies indicate that the heavy metals in the bottom ash and fly ash are bound to different fractions with different strengths. From the environmental and utilization perspectives, heavy metals in ashes posed different levels of environmental contamination risk. Only As in the bottom ash posed a very high risk. High risk metals were Cd in the bottom ash as well as As, Cd and Se in the fly ash. 展开更多
关键词 bottom ash fly ash BCR extraction heavy metals risk assessment code
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Energy consumption,indoor environmental quality,and benchmark for office buildings in Hainan Province of China 被引量:1
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作者 孔祥飞 吕石磊 +1 位作者 辛亚娟 吴薇 《Journal of Central South University》 SCIE EI CAS 2012年第3期783-790,共8页
With rapid economy growth,building energy consumption in China has been gradually increased.The energy consumption and indoor environmental quality of 51 office buildings in Hainan Province,a hot and humid area,were s... With rapid economy growth,building energy consumption in China has been gradually increased.The energy consumption and indoor environmental quality of 51 office buildings in Hainan Province,a hot and humid area,were studied through collection of verified data in site visits and field tests.The result revealed that,electricity accounted for 99.79% of the total energy consumption,natural gas 0.17%,and diesel 0.04%.The air conditioning dominated the energy use with a share of 43.18%,equipment in the particular areas 26.90%,equipment in the office rooms 11.95%,lighting system 8.67%,general service system 7.57%,and miscellaneous items 1.73%.Statistical method including six indicators obtained the energy consumption benchmark with upper limit of 98.31 kW-h/m2 and lower limit of 55.26 kW-h/m2.According to ASHRAE standard(comfortable standard) and GB/T 18883-2002(acceptable standard),the indoor environmental quality of 51 sampled office buildings was classified into three ranks:good,normal and bad.With benchmark of building energy consumption combined with indoor environmental quality,it was found that only 3.92% of sampled buildings can be identified as the best performance buildings with low energy consumption and advanced indoor environmental quality,and the buildings classified into normal level accounted for the maximum ratio. 展开更多
关键词 building energy consumption BENCHMARK indoor environmental quality energy use index Hainan Province
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Space-Earth Integration Observation Based Environmental Emergency Monitoring and Management System Design 被引量:3
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作者 Tao Xie Rui Liu Qiuhong Hu 《环境科学前沿(中英文版)》 2013年第3期17-23,共7页
关键词 摘要 编辑部 编辑工作 读者
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Dealuminated Hβ zeolite for selective conversion of fructose to furfural and formic acid 被引量:1
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作者 Rui Li Qixuan Lin +3 位作者 Junli Ren Xiaobao Yang Yingxiong Wang Lingzhao Kong 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第2期311-320,共10页
The fructose-to-furfural transformation is facing major challenges in the selectivity and high efficiency. Herein, we have developed a simple and effective approach for the selective conversion of fructose to furfural... The fructose-to-furfural transformation is facing major challenges in the selectivity and high efficiency. Herein, we have developed a simple and effective approach for the selective conversion of fructose to furfural using Hβ zeolite modified by organic acids for dealuminization to regulate its textural and acidic properties. It was found that citric acid-dealuminized Hβ zeolite possessed high specific surface areas, wide channels and high Brønsted acid amount, which facilitated the selective conversion of fructose to furfural with a maximum yield of 76.2% at433 K for 1 h in the γ-butyrolactone(GBL)-H_(2)O system, as well as the concomitant formation of 83.0% formic acid. The^(13)C-isotope labelling experiments and the mechanism revealed that the selective cleavage of C1–C2 or C5–C6 bond on fructose was firstly occurred to form pentose or C5 intermediate by weak Brønsted acid, which was then dehydrated to furfural by strong Brønsted acid. Also this dealuminized Hβ catalyst showed the great recycling performance and was active for the conversion of glucose and mannose. 展开更多
关键词 FRUCTOSE Dealuminated-Hb zeolite Selective conversion FURFURAL
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Environmental Exposure to Lead, Vanadium, Copper and Selenium: Possible Implications in the Development of Autism Spectrum Disorders
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作者 A. O. Akinade I. O. Omotosho +1 位作者 I. A. Lagunju M. A. Yakubu 《Neuroscience & Medicine》 2019年第3期247-258,共12页
Human exposure to toxic metals is on the increase especially in the developing world;this is compounded by the almost unavoidable application of the metals domestically and industrially and their implication in severa... Human exposure to toxic metals is on the increase especially in the developing world;this is compounded by the almost unavoidable application of the metals domestically and industrially and their implication in several genetic defects, aging and some chronic illnesses including Autism Spectrum Disorders (ASD). This study investigated the concentration of toxic metals (Pb and V) and micro-essential elements (Cu and Se) in children with ASD and controls in Nigeria towards establishing their possible associations with the aetiopathogenesis of ASD. Eight children clinically diagnosed by Paediatric Neurologist and Child Psychiatrist for ASD using DMS-IV and fifteen apparently healthy children (age range 2 - 12 years) were recruited as cases and controls respectively. Plasma levels of Pb, V, Cu and Se were analyzed using Induction ICP-MS. Results were analyzed using students t-test. The mean plasma lead and vanadium levels were (7.92 ± 1.30 μg/dl;1.07 ± 0.22 μg/dl) and (6.83 ± 0.72 μg/dl;2.59 ± 0.48 μg/dl) in children with ASD and in controls respectively. The result showed that blood lead level in ASD was slightly increased but not significant when compared with control (p < 0.433). On the other hand, plasma vanadium concentration in ASD was significantly reduced (1.07 ± 0.22 μg/dl) when compared with control (2.59 ± 0.48 μg/dl) (P < 0.038). Mean plasma copper was similar in all participants (1.98 ± 0.13, 2.23 ± 0.12) but selenium concentrations were significantly reduced (0.37 ± 0.05 mg/L;0.57 ± 0.02 mg/L) in ASD relative to controls respectively. Given the physiological functions of vanadium and selenium, the observed reduced levels of the two elements in children with ASD may account for the speech and other neurological dysfunctions of the brain in ASD. 展开更多
关键词 TOXIC and ESSENTIAL Metals AUTISM Spectrum DISORDER Children Aetiopathogenesis
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Magma Mixing Genesis of the Mafic Enclaves and Related Granitoids in the Kan Granite-Gneiss Complex of Central Côte d’Ivoire: Evidence from Geology, Petrology and Geochemistry
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作者 Koffi Raoul Teha Koffi Kossonou Jean-Marie Pria +3 位作者 Koffi Joseph Brou Alain Nicaise Kouamelan Marc Ephrem Allialy Souad M’Rabet 《Open Journal of Geology》 CAS 2024年第8期760-786,共27页
The mafic enclaves from Paleoproterozoic domain are considered to be the results of large-scale crust-mantle interaction and magma mixing. In this paper, petrography, mineralogy and geochemistry were jointly used to d... The mafic enclaves from Paleoproterozoic domain are considered to be the results of large-scale crust-mantle interaction and magma mixing. In this paper, petrography, mineralogy and geochemistry were jointly used to determine the origin of the mafic enclaves and their relationship with the host granitoids of the Kan granite-gneiss complex. This study also provides new information on crust-mantle interactions. The mafic enclaves of the Kan vary in shape and size and have intermediate chemical compositions. The diagrams used show a number of similarities in the major elements (and often in the trace elements) between the mafic enclaves and the host granitoids. Geochemical show that the Kan rock are metaluminous, enriched in silica, medium to high-K calc-alkaline I-type granite. The similarities reflect a mixing of basic and acid magma. Mafic enclaves have a typical magmatic structure, which is characterized by magma mixing. The genesis of these rocks is associated with the context of subduction. They result from the mixing of a mafic magma originating from the mantle and linked to subduction, and a granitic magma (type I granite) that arises from the partial melting of the crust. 展开更多
关键词 Magma Mixing Mafic Microgranular Enclaves Host Granitoids Kan Granite-Gneiss Complex West Africa
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Gross Alpha and Beta Activities and Related Lifetime Risks Assessment Due to Ingestion of Drinking Water from Different Sources in the District of Abidjan, Cote d’Ivoire
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作者 Ponaho Claude Kezo Issa Konate Dabo Salif Ignace Agba 《World Journal of Nuclear Science and Technology》 CAS 2024年第1期86-96,共11页
Drinking good quality water is essential for better health. It is therefore essential to assess the radiological quality of all water consumed in the District of Abidjan in order to prevent related hazards. Thus, the ... Drinking good quality water is essential for better health. It is therefore essential to assess the radiological quality of all water consumed in the District of Abidjan in order to prevent related hazards. Thus, the objective of this study was to assess the risk of cancer due to the ingestion of alpha and beta emitting radionuclides in the different types of water consumed in the region. A total of 63 water samples with 43 tap water samples, 5 bottled mineral water and 15 sachet water samples was collected and taken to GAEC laboratory for analysis. The low background Gas-less Automatic Alpha/Beta counting system (Canberra iMatic<sup>TM</sup>) was used to determine alpha and beta activity concentrations. Activity concentrations of both gross alpha and gross beta obtained in water sample were respectively lower than the WHO recommended limits of 0.1 Bq/l and 1 Bq/l. Also, the annual effective dose and total equivalent effective dose found in mineral bottled water samples were higher than in other types of water. The assessment of radiological lifetime risk has shown values of cancer risk due to ingestion alpha and beta emitters lower than recommended limit. These results indicate that there is no health hazard associated to consumption of water in the District of Abidjan. 展开更多
关键词 Gross Alpha and Beta Activities Drinking Water Effective Dose Radiological Lifetime Risks
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Catalyst–Support Interaction in Polyaniline‑Supported Ni_(3)Fe Oxide to Boost Oxygen Evolution Activities for Rechargeable Zn‑Air Batteries
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作者 Xiaohong Zou Qian Lu +8 位作者 Mingcong Tang Jie Wu Kouer Zhang Wenzhi Li Yunxia Hu Xiaomin Xu Xiao Zhang Zongping Shao Liang An 《Nano-Micro Letters》 SCIE EI CAS 2025年第1期176-190,共15页
Catalyst–support interaction plays a crucial role in improving the catalytic activity of oxygen evolution reaction(OER).Here we modulate the catalyst–support interaction in polyaniline-supported Ni_(3)Fe oxide(Ni_(3... Catalyst–support interaction plays a crucial role in improving the catalytic activity of oxygen evolution reaction(OER).Here we modulate the catalyst–support interaction in polyaniline-supported Ni_(3)Fe oxide(Ni_(3)Fe oxide/PANI)with a robust hetero-interface,which significantly improves oxygen evolution activities with an overpotential of 270 mV at 10 mA cm^(-2)and specific activity of 2.08 mA cm_(ECSA)^(-2)at overpotential of 300 mV,3.84-fold that of Ni_(3)Fe oxide.It is revealed that the catalyst–support interaction between Ni_(3)Fe oxide and PANI support enhances the Ni–O covalency via the interfacial Ni–N bond,thus promoting the charge and mass transfer on Ni_(3)Fe oxide.Considering the excellent activity and stability,rechargeable Zn-air batteries with optimum Ni_(3)Fe oxide/PANI are assembled,delivering a low charge voltage of 1.95 V to cycle for 400 h at 10 mA cm^(-2).The regulation of the effect of catalyst–support interaction on catalytic activity provides new possibilities for the future design of highly efficient OER catalysts. 展开更多
关键词 Catalyst-support interaction Supported catalysts HETEROINTERFACE Oxygen evolution reaction Zn-air batteries
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Heavy metal availability and impact on activity of soil microorganisms along a Cu/Zn contamination gradient 被引量:21
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作者 WANG Yuan-peng SHI Ji-yan +2 位作者 LIN Qi CHEN Xin-cai CHEN Ying-xu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第7期848-853,共6页
All the regulations that define a maximum concentration of metals in the receiving soil are based on total soil metal concentration. However, the potential toxicity of a heavy metal in the soil depends on its speciati... All the regulations that define a maximum concentration of metals in the receiving soil are based on total soil metal concentration. However, the potential toxicity of a heavy metal in the soil depends on its speciation and availability. We studied the effects of heavy metal speciation and availability on soil microorganism activities along a Cu/Zn contamination gradient. Microbial biomass and enzyme activity of soil contaminated with both Cu and Zn were investigated. The results showed that microbial biomass was negatively affected by the elevated metal levels. The microbial biomass-C (Cmic)/organic C (Corg) ratio was closely correlated to heavy metal stress. There were negative correlations between soil microbial biomass, phosphatase activity and NH4NO3 extractable heavy metals. The soil microorganism activity could be predicted using empirical models with the availability of Cu and Zn. We observed that 72% of the variation in phosphatase activity could be explained by the NH4NO3-extractable and total heavy metal concentration. By considering different monitoring approaches and different viewpoints, this set of methods applied in this study seemed sensitive to site differences and contributed to a better understanding of the effects of heavy metals on the size and activity of microorganisms in soils. The data presented demonstrate the relationship between heavy metals availability and heavy metal toxicity to soil microorganism along a contamination gradient. 展开更多
关键词 heavy metals AVAILABILITY SPECIATION ACTIVITY soil microorganism
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Changes in Phosphorus Fractions, pH, and Phosphatase Activity in Rhizosphere of Two Rice Genotypes 被引量:18
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作者 LI Yong-Fu LUO An-Cheng +1 位作者 WEI Xing-Hua YAO Xu-Guo 《Pedosphere》 SCIE CAS CSCD 2008年第6期785-794,共10页
A rhizobox experiment with two phosphorus (P) treatments, zero-P (0 mg P kg-1) and plus-P (100 mg P kg-1) as Ca(H2PO4)2·H2O, was conducted to study the chemical and biochemical properties in the rhizosphere of tw... A rhizobox experiment with two phosphorus (P) treatments, zero-P (0 mg P kg-1) and plus-P (100 mg P kg-1) as Ca(H2PO4)2·H2O, was conducted to study the chemical and biochemical properties in the rhizosphere of two rice genotypes (cv. Zhongbu 51 and Pembe) different in P uptake ability and their relationship with the depletion of soil P fractions. Plant P uptake, pH, phosphatase activity, and soil P fractions in the rhizosphere were measured. Both total dry weight and total P uptake of Pembe were significantly (P < 0.05) higher than those of Zhongbu 51 in the zero-P and plus-P treatments. Significant depletions of resin-Pi, NaHCO3-Pi, NaHCO3-Po, and NaOH-Pi, where Pi stands for inorganic P and Po for organic P, were observed in the rhizosphere of both Zhongbu 51 and Pembe under both P treatments. Pembe showed a greater ability than Zhongbu 51 in depleting resin-Pi, NaHCO3-Pi, NaHCO3-Po, NaOH-Pi, and NaOH- Po in the rhizosphere. HCl-Pi and residual-P were not depleted in the rhizosphere of both genotypes, regardless of P treatments despite significant acidification in the rhizosphere of Pembe under zero-P treatment. Higher acid phosphatase (AcPME) activity and alkaline phosphatase (AlPME) activity were observed in the rhizosphere of both Zhongbu 51 and Pembe compared to the corresponding controls without plant. AcPME activity was negatively (P < 0.01) correlated to NaHCO3-Po concentration in the rhizosphere of both Zhongbu 51 and Pembe, suggesting that AcPME was associated with the mineralization of soil organic P. 展开更多
关键词 PHOSPHATASE phosphorus fractions RHIZOSPHERE rice genotypes soil pH
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CO2 hydrogenation to methanol over Cu/CeO2 and Cu/ZrO2 catalysts:Tuning methanol selectivity via metal-support interaction 被引量:21
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作者 Weiwei Wang Zhenping Qu +1 位作者 Lixin Song Qiang Fu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第1期22-30,I0002,共10页
Copper-based catalysts for CO2 hydrogenation to methanol are supported on ZrO2 and CeO2,respectively.Reaction results at 3.0 MPa and temperatures between 200 and 300°C reveal that Cu catalysts supported on ZrO2 a... Copper-based catalysts for CO2 hydrogenation to methanol are supported on ZrO2 and CeO2,respectively.Reaction results at 3.0 MPa and temperatures between 200 and 300°C reveal that Cu catalysts supported on ZrO2 and CeO2 exhibit better activity and selectivity than pure Cu catalyst due to Cu-support(ZrO2 and CeO2)interaction.Combining the structural characterizations with in-situ diffuse reflectance infrared Fourier transform spectroscopy(in-situ DRIFTS),Cu/CeO2 shows the higher methanol selectivity due to the formation of main carbonates intermediates,which are closely related with the oxygen vacancies over Cu/CeO2.In contrast,bicarbonate and carboxyl species are observed on Cu/ZrO2,which originates from the hydroxyl groups presented on catalyst surfaces.Difference in CO2 adsorption intermediates results in the distinct methanol selectivity over the two catalysts. 展开更多
关键词 CO_2 hydrogenation Methanol selectivity In-situ DRIFTS CeO_2 ZrO_2
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Temperature effect on aerobic denitrification and nitrification 被引量:11
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作者 XIE Shu guang ZHANG Xiao jian WANG Zhan sheng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2003年第5期669-673,共5页
Nitrogen loss without organic removal in biofilter was observed and its possible reason was explained. A lower hydraulic loading could improve aerobic denitrification rate. Aerobic denitrification was seriously affect... Nitrogen loss without organic removal in biofilter was observed and its possible reason was explained. A lower hydraulic loading could improve aerobic denitrification rate. Aerobic denitrification was seriously affected by low temperature(below 10℃). However, nitrification rate remained high when the temperature dropped from 15℃ to 5℃. It seemed the autotrophic biofilm in BAF could alleviate the adverse effect of low temperature. 展开更多
关键词 aerobic denitrification NITRIFICATION BIOFILTER temperature effect
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Water and Energy Consumption by Agriculture in the Minqin Oasis Region 被引量:11
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作者 LI Cheng WANG Yue QIU Guo-yu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2013年第8期1330-1340,共11页
Water used in agriculture consumes much energy, mainly due to pumping water for irrigation, but the water-energy nexus is always neglected in arid and semi-arid areas. Based on hydrological observation data, irrigatio... Water used in agriculture consumes much energy, mainly due to pumping water for irrigation, but the water-energy nexus is always neglected in arid and semi-arid areas. Based on hydrological observation data, irrigation data and socio- economic data over the past 50 yr, this study has derived a detailed estimate of greenhouse gas (GHG) emissions from agricultural water use in the Minqin Oasis. Results show that the decreasing water supply and increasing demand for agriculture has caused severe water deficits over the past 50 yr in this region. The groundwater energy use rate rose by 76% between 1961 and 2009 because of the serious decline in groundwater levels. An increase in pump lift by an average 1 m would cause GHG emission rates to rise by around 2%. Over the past 10 yr, the GHG emissions from groundwater accounted for 65-88% of the total emissions from agricultural water. GHG emissions for diverted water varied from 0.047 to 0.074 Mt CO2e as the water input increased. Long distance conveyance and high pump lifts need more electricity input than groundwater abstraction does. Government policies have had a favorable effect on total emissions by reducing water abstraction. But groundwater depletion, exacerbated by a growing population and an expansion in arable land, remains the principal energy-water nexus challenge in the region. In response to the increasing water-energy crisis, energy-saving irrigation technology, matching to cost efficiencies, and better coordination between different infrastructural agencies could be feasible ways of rendering the water and energy sectors more sustainable over the long term. 展开更多
关键词 WATER ENERGY IRRIGATION EMISSIONS Minqin Oasis
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Effects of Evapotranspiration on Mitigation of Urban Temperature by Vegetation and Urban Agriculture 被引量:10
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作者 QIU Guo-yu LI Hong-yong +3 位作者 ZHANG Qing-tao CHEN Wan LIANG Xiao-jian LI Xiang-ze 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2013年第8期1307-1315,共9页
The temperature difference between an urban space and surrounding non-urban space is called the urban heat island effect (UHI). Global terrestrial evapotranspiration (ET) can consume 1.4803x1023joules (J) of ene... The temperature difference between an urban space and surrounding non-urban space is called the urban heat island effect (UHI). Global terrestrial evapotranspiration (ET) can consume 1.4803x1023joules (J) of energy annually, which is about 21.74% of the total available solar energy at the top of atmosphere, whereas annual human energy use is 4.935× 1020 J, about 0.33% of annual ET energy consumption. Vegetation ET has great potential to reduce urban and global temperatures. Our literature review suggests that vegetation and urban agricultural ET can reduce urban temperatures by 0.5 to 4.0℃. Green roofs (including urban agriculture) and water bodies have also been shown to be effective ways of reducing urban temperatures. The cooling effects on the ambient temperature and the roof surface temperature can be 0.24-4.0℃ and 0.8-60.0℃, respectively. The temperature of a water body (including urban aquaculture) can be lower than the temperature of the surrounding built environment by between 2 and 6℃, and a water body with a 16 m2 surface area can cool up to 2 826 m3 of nearby space by 1℃. Based on these findings, it can be concluded that the increase of evapotranspiration in cities, derived from vegetation, urban agriculture, and water body, can effectively mitigate the effect of urban heat islands. 展开更多
关键词 EVAPOTRANSPIRATION urban heat island VEGETATION TEMPERATURE
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Semivolatile organic compounds, organochlorine pesticides and heavy metals in sediments and risk assessment in Huaihe River of China 被引量:9
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作者 HUANG Hong OU Wen-hua WANG Lian-sheng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第2期236-241,共6页
The concentrations of semivolatile organic compounds, organochlorine pesticides and heavy metals in sediments from Jiangsu reach of Huaihe River, China, were presented. The organic compounds were extracted by acetone... The concentrations of semivolatile organic compounds, organochlorine pesticides and heavy metals in sediments from Jiangsu reach of Huaihe River, China, were presented. The organic compounds were extracted by acetone: n-hexane using a Soxhlet apparatus and concentrations were performed using HP6890 gas chromatography coupled by FID and ECD detector. The total contents of 8 heavy metals by inductively coupled plasma atomic emission spectrometry or cold-vapor/atomic absorption spectrometry were developed. 30 semivolatile organic compounds were detected, including substituted benzenes, phenols, phthalates and polycyclic aromatic hydrocarbons, from 0.01 to 3.01 mg/kg. 16 organochlorine pesticides were almost detected and from 0.010 to 2.339 μg/kg. Concentrations of major metals were 50 mg/kg or less, mean level of mercury was only 0.055 mg/kg. Compared to sediment quality guidelines (SQGs), concentrations of some semivolatilc organic compounds were high enough to cause possible toxic effects to living resources. The organochlorine pesticides presented relatively low, lower than threshold effect concentrations (TECs), harmful effects on sediment-dwelling organisms were not expected. Chromium posed probable toxic effects to the living resources, other heavy metals had no threat temporarily according to SQGs. 展开更多
关键词 SEDIMENT semivolatile organic compounds organochlorinc pcsticidcs heavy mctals sediment quality guiedlines Huaihe River
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Impact of Climate and Land-Use Changes on Water Security for Agriculture in Northern China 被引量:10
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作者 QIU Guo-yu YIN Jin Shu Geng 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第1期144-150,共7页
North China is the most important food basket of China, where the majority of wheat and corn are produced. Most crops grown in North China are irrigated, thus water security is food security. Since the 1980s, drying h... North China is the most important food basket of China, where the majority of wheat and corn are produced. Most crops grown in North China are irrigated, thus water security is food security. Since the 1980s, drying has been frequently observed, as shown by a reduction in precipitation, cutoff in riverflow, and shrinkage of lakes. This increase in drying cannot be explained by climate change alone. We propose that intensive land-use in this area in recent decades has had a significant impact. The objectives of the study are to develop a quantitative model of the concurrent processes of climate change and land-use in North China, and to estimate the relative contributions of each on the observed drying. We integrated relevant socioeconomic data, land-use data, and climate data in the model, and carried out a detailed multi-temporal (decade, year, day) analysis. Results showed that land-use has greatly changed since 1999. This change is mainly associated with an extremely important 1999 national policy of "returning farmland and grazing land to forest and grassland". We found an interesting interaction between climate change and land use policy on riverflow, runoff, and evapotranspiration. During 1970s and 1980s, climate change explained more than 80%, while the land-use change explained only 10% of the riverflow change. The relative contributions were 45 and 45% in the 1980s-1990s and 35 and 55% in the 1990s-2000s respectively for climate change and land-use change. Since the 1990s land-use change has also contributed more to runoff change than climate change. The opposite trend was found for changes in evapotranspiration. Water availability for agriculture in northern China is simultaneously stressed by extensive changes in land-use and rapid climate change. Adaptation of ecological principles, such as the "returning farmland/grazing land to forest and grassland" policy, and other adjustments of economic developmental strategies can be effective tools to mitigate the water shortage problem in northern China and promote sustainable agricultural and food development. 展开更多
关键词 water resources climate change land-use DRYNESS riverflow sustainable development
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A statistical analysis of spatiotemporal variations and determinant factors of forest carbon storage under China's Natural Forest Protection Program 被引量:9
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作者 Shengnan Wu Jiaqi Li +5 位作者 Wangming Zhou Bernard Joseph Lewis Dapao Yu Li Zhou Linhai Jiang Limin Dai 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第2期410-419,共10页
The Natural Forest Protection Program(NFPP)is one of the key ecological forestry programs in China.It not only facilitates the improvement of forest ecological quality in NFPP areas,but also plays a significant role i... The Natural Forest Protection Program(NFPP)is one of the key ecological forestry programs in China.It not only facilitates the improvement of forest ecological quality in NFPP areas,but also plays a significant role in increasing the carbon storage of forest ecosystems.The program covers 17 provinces,autonomous regions,and municipalities with correspondingly diverse forest resources and environments,ecological features,engineering measures and forest management regimes,all of which affect regional carbon storage.In this study,volume of timber harvest,tending area,pest-infested forest,firedamaged forest,reforestation,and average annual precipitation,and temperature were evaluated as factors that influence carbon storage.We developed a vector autoregression model for these seven indicators and we studied the dominant factors of carbon storage in the areas covered by NFPP.Timber harvest was the dominant factorinfluencing carbon storage in the Yellow and Yangtze River basins.Reforestation contributed most to carbon storage in the state-owned forest region in Xinjiang.In state-owned forest regions of Heilongjiang and Jilin Provinces,the dominant factors were forest fires and forest cultivation,respectively.For the enhancement of carbon sequestration capacity,a longer rotation period and a smaller timber harvest are recommended for the Yellow and Yangtze River basins.Trees should be planted in stateowned forests in Xinjiang.Forest fires should be prevented in state-owned forests in Heilongjiang,and greater forest tending efforts should be made in the state-owned forests in Jilin. 展开更多
关键词 Forest carbon storage Influencing factors Natural forest protection program Variance decomposition Vector autoregression(VAR) model
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Photocatalytic remediation ofγ-hexachlorocyclohexane contaminated soils using TiO_2 and montmorillonite composite photocatalyst 被引量:5
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作者 ZHAO Xu QUAN Xie +2 位作者 CHEN Shuo ZHAO Hui-min LIU Yu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第3期358-361,共4页
TiO2 and montmorillonite composite photocatalysts were prepared and applied in degrading γ-hexachlorocyclohexane (γ-HCH) in soils. After being spiked with γ-HCH, soil samples loaded with the composite photocataly... TiO2 and montmorillonite composite photocatalysts were prepared and applied in degrading γ-hexachlorocyclohexane (γ-HCH) in soils. After being spiked with γ-HCH, soil samples loaded with the composite photocatalysts were exposed to UV-light irradiation. The results indicated that the photocatalytic activities of the composite photocatalysts varied with the content of TiO2 in the order of 10%〈70%〈50% 〈30%, Moreover, the photocatalytic activity of the composite photocatalysts with TiO2 content 30% was higher than that of the pure P25 with the same mass of TiO2. The strong adsorption capacity of the composite photocatalysts and quantum size effect may contribute to its increased photocatalytic activities. In addition, effect of dosage of composite photocatalysts and soil pH on γ-HCH photodegradation was investigated. Pentachlorocyclohexene, trichlorocyclohexene, and dichlorobenzene were detected as photodegradation intermediates, which were gradually degraded with the photodegradation evolution. 展开更多
关键词 TiO2 MONTMORILLONITE Γ-HCH soil surfaces composite photocatalysts
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Analysis of Atmospheric Boundary Layer Height Characteristics over the Arctic Ocean Using the Aircraft and GPS Soundings 被引量:13
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作者 DAI Cheng-Ying GAO Zhi-Qiu +1 位作者 WANG Qing CHENG Gang 《Atmospheric and Oceanic Science Letters》 2011年第2期124-130,共7页
Utilizing aircraft sounding data collected from the Surface Heat Budget of the Arctic Ocean (SHEBA, 1998) campaign, the authors evaluated commonly-used profile methods for Arctic ABL height estimation by validating ag... Utilizing aircraft sounding data collected from the Surface Heat Budget of the Arctic Ocean (SHEBA, 1998) campaign, the authors evaluated commonly-used profile methods for Arctic ABL height estimation by validating against the'true'ABL height from aircraft sounding profiles, where ABL height is defined as the top of the layer with significant turbulence. Furthermore, the best performing method was used to estimate ABL height from the one-year GPS soundings obtained during SHEBA (October 1997-October 1998). It was found that the temperature gradient method produces a reliable estimate of ABL height. Additionally, the authors determined optimal threshold values of temperature gradient for stable boundary layer (SBL) and convective boundary layer (CBL) to be 6.5 K/100 m and 1.0 K/100 m, respectively. The maximum ABL height during the year was 1150 m occurred in May. Median values of Arctic ABL height in May, June, July, and August were 400 m, 430 m, 180 m, and 320 m, respectively. Arctic ABL heights are clearly higher in the spring than in the summer. 展开更多
关键词 aircraft sounding Arctic boundary layer boundary layer height GPS sounding turbulence
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