Surface coatings and surficial sediments were obtained in four natural waters in Xianghai Wetland in China to study the role of surface coatings and surficial sediments in controlling the transporting and cycling of h...Surface coatings and surficial sediments were obtained in four natural waters in Xianghai Wetland in China to study the role of surface coatings and surficial sediments in controlling the transporting and cycling of heavy metals in aquatic environments. Pb and Cd adsorption to the surface coatings and surficial sediments were measured under controlled laboratory conditions(mineral salts solution with defined speciation, ionic strength 0 05 mol/L, 25℃ and pH 6 0 for surface coatings; and 0 005 mol/L CaCl 2 solution, 25℃ and pH 6 0 for surficial sediments). The Langmuir adsorption isotherm was applied to estimate equilibrium coefficients of Pb and Cd adsorption to the surface coatings and surficial sediments, and the component analyses of surface coatings and surficial sediments were also carried out. Correlation analyses between the maximum adsorption of Pb and Cd(Г max ) and the components in the surface coatings and surficial sediments suggested that there was a statistically significant trend for Pb and Cd adsorption(Г max ) to the surface coatings to increase with increasing in contents of Fe and Mn oxides in the surface coatings and surficial sediments. And the metal adsorption abilities of surface coatings were much stronger than those of surficial sediments, highlighting that in the same water, i.e. at the same pH and initial metal concentrations, the metals(such as lead and cadmium) in supernatant were feasible to be adsorbed by surface coatings than surficial sediments. The more importance of surface coatings than surficial sediments for adsorbing and cycling of heavy metals in aquatic environments was evidenced.展开更多
Based on data of questionnaire and field survey and two developing models of Business As Usual (BAU) and the Intensive Urbanization (IU), this article, taking Wuwei City, a medium size city and typical oasis arid area...Based on data of questionnaire and field survey and two developing models of Business As Usual (BAU) and the Intensive Urbanization (IU), this article, taking Wuwei City, a medium size city and typical oasis arid area in Gansu Province with very vulnerable and sensitive natural environment but long history of oasis economy, as an example, evaluated the sustainability of its environment and analyzed the scenarios of Wuwei’s household energy consumption, waste discharge in transportation industry, primary industry, secondary industry, tertiary industry, by the integration of the systematical dynamics model Stella and Polestar language to simulate the future development of the research area. The results showed that, first, the developing model of IU was propitious to Wuwei City named for oasis economy and vulnerable natural environment. The strategy of "Intensive Urbanization" can change the structure of energy utilization, and improve the efficiency of energy utilization. Second, the proportion of domestic energy consumption will decrease with industrialization and economic development, while that of tertiary industry, secondary industry and transportation will gradually grow up according to strategy of "Intensive Urbanization". Third, the Wuwei City is facing a severe eco-environmental crisis under the conventional patterns of development and a better future under a sustainable urbanization scenario, in the next 10 to 20 years. The different developing trends were clarified and the relative countermeasures were put forward for the policy makers according to the driving forces.展开更多
Catalytic wet air oxidation(CWAO) was employed to reduce the organic compounds in landfill leachate and the effects of temperature, oxygen pressure, catalyst dosage, and concentration of the organic compounds on the T...Catalytic wet air oxidation(CWAO) was employed to reduce the organic compounds in landfill leachate and the effects of temperature, oxygen pressure, catalyst dosage, and concentration of the organic compounds on the TOC and COD Cr removal rates were studied. The degradation kinetics of landfill leachate was also investigated and an exponential experiential model consisting of four influential factors was established to describe the reduction of the organic compounds in the landfill leachate. Meanwhile, the GC-MS technique was used to detect the components of the organic intermediates for the inference of the decomposition mechanisms of the organic compounds in landfill leachate. The results reveal that the reaction temperature and the catalyst dosage are the most important factors affecting the degradation reaction of the organic compounds and that the principal intermediates confirmed by GC-MS are organic acids at a percentage of more than 88% with no aldehydes or alcohols detected. The decomposition mechanisms of the organic compounds in landfill leachate were inferred based on the GC-MS information as follows: the activated gas phase O 2 captured the hydrogen of the organic pollutants to produce free radicals, which then initiated the catalytic reaction. So most of the organic compounds were oxidized into CO 2 and H 2O ultimately. In general, catalytic wet air oxidation over catalyst Co 3O 4/Bi 2O 3 was a very promising technique for the treatment of landfill leachate.展开更多
This paper firstly analyzes the property of the low frequency electromagnetic wave, which can penetrate many types of non-metallic materials, and the ability of Ultra-Wide Band (UWB) impulse signal which has high rang...This paper firstly analyzes the property of the low frequency electromagnetic wave, which can penetrate many types of non-metallic materials, and the ability of Ultra-Wide Band (UWB) impulse signal which has high range resolution. Then the methods are discussed for conducting surveillance through walls, detecting and locating the moving persons behind the partitions. The schematic diagram of Through-Wall Detecting Radar (TWDR) and the models of moving target are shown and the principle of detecting the moving target is also provided with coherent superimposing technique on a range gate. Finally an algorithm for estimating the location of targets is given. The performance of TWDR is validated by the experiments of penetrating a wood block, a red brick wall and a reinforced concrete wall.展开更多
The solvent extraction of uranium(VI) and europium(III) from nitric acid solution was studied with pi- colinamide dissolved in ethylene dichloride. The distribution ratios of U(VI) and Eu(III) as a function of aqueous...The solvent extraction of uranium(VI) and europium(III) from nitric acid solution was studied with pi- colinamide dissolved in ethylene dichloride. The distribution ratios of U(VI) and Eu(III) as a function of aqueous HNO3 concentration , extractant concentration in organic phase and temperature as well as the salting-out agent con- centration have been measured. The experiment results show that picolinamide has higher extractability for U(VI) than for Eu(III). The composition of extracted species, equilibrium constants and enthalpies of extraction reaction have also been presented.展开更多
Objective:to study the effect of coixenolide (CXL) on irradiation of human nasophyaryngeal carcinoma cell line CNE-2Z in the absence of oxygen,Methods: Microcolony formation assay was used for determining the sensitiv...Objective:to study the effect of coixenolide (CXL) on irradiation of human nasophyaryngeal carcinoma cell line CNE-2Z in the absence of oxygen,Methods: Microcolony formation assay was used for determining the sensitivity of CNE-2Z to γ-ray in vitro,Results:When CNE-2Z was treated with 10^-7--10^-6 mol/L of CXL,CXL shifted the radiation dose-survival curve to the left,with the decrease of D0,Dq and N values,Radiation dose reduced 10.07%-35.69% at D37 level,the sensitizing enhancement ratios(SER) were 1.07-1.43 and 1.16-1.72 at D0 and Dq levels respectively.Conclusion:CXL increase susceptibility of CNE-2Z to ray under hypoxic condition by the mechanism of inhibiting its sublethal damgae repair.Subject words Nasopharyngeal neoplasm;Coixenolide;Radiosensitzation;Hypoxic irradiation.展开更多
Objective. To study the effect of ecdysterone (ECR) on beta - amyloid peptide fragment 25-35 ( Aβ25-35 )-induced PC12 cell cytotoxicity, and further to expore its mechanism. Methods: PC12 survial was monitored by LDH...Objective. To study the effect of ecdysterone (ECR) on beta - amyloid peptide fragment 25-35 ( Aβ25-35 )-induced PC12 cell cytotoxicity, and further to expore its mechanism. Methods: PC12 survial was monitored by LDH release and 3-(4, 5-dimethylthiazol-yl-2, 5-diphenyhetrazolium bromide (MTT) assays. The content of malondi-展开更多
Objective: To explore the mechanism of Ecdysterone (ECR) in prevention of learning and memory dysfunction of the rats induced by β-amyloid peptide ( Aβ25-35 ). Methods: Ninety Wistar male rats were randomly divided ...Objective: To explore the mechanism of Ecdysterone (ECR) in prevention of learning and memory dysfunction of the rats induced by β-amyloid peptide ( Aβ25-35 ). Methods: Ninety Wistar male rats were randomly divided into five groups, the control group, the model group, the treated groups (ECR 4mg·kg^-1 and ECR 8mg·kg-1 and展开更多
Aim: To study the effect of Ecdysterone (ECR) on the expression of Tau from the cerebral cortice and hippocampus and behaviors in passive avoidance reaction and spatial discrimination of the mice induced by overload a...Aim: To study the effect of Ecdysterone (ECR) on the expression of Tau from the cerebral cortice and hippocampus and behaviors in passive avoidance reaction and spatial discrimination of the mice induced by overload aluminum salt.Methods Fourty-five NIH mice were randomly divided into five groups, the control group, the model group, the展开更多
文摘Surface coatings and surficial sediments were obtained in four natural waters in Xianghai Wetland in China to study the role of surface coatings and surficial sediments in controlling the transporting and cycling of heavy metals in aquatic environments. Pb and Cd adsorption to the surface coatings and surficial sediments were measured under controlled laboratory conditions(mineral salts solution with defined speciation, ionic strength 0 05 mol/L, 25℃ and pH 6 0 for surface coatings; and 0 005 mol/L CaCl 2 solution, 25℃ and pH 6 0 for surficial sediments). The Langmuir adsorption isotherm was applied to estimate equilibrium coefficients of Pb and Cd adsorption to the surface coatings and surficial sediments, and the component analyses of surface coatings and surficial sediments were also carried out. Correlation analyses between the maximum adsorption of Pb and Cd(Г max ) and the components in the surface coatings and surficial sediments suggested that there was a statistically significant trend for Pb and Cd adsorption(Г max ) to the surface coatings to increase with increasing in contents of Fe and Mn oxides in the surface coatings and surficial sediments. And the metal adsorption abilities of surface coatings were much stronger than those of surficial sediments, highlighting that in the same water, i.e. at the same pH and initial metal concentrations, the metals(such as lead and cadmium) in supernatant were feasible to be adsorbed by surface coatings than surficial sediments. The more importance of surface coatings than surficial sediments for adsorbing and cycling of heavy metals in aquatic environments was evidenced.
基金Under theauspicesofKey Program of the National Natural Science Foundation of China (No .90102013) and KeyInnovationSub-projectof Chinese Academy of Sciences(No .KZCX1-10-07-04 )
文摘Based on data of questionnaire and field survey and two developing models of Business As Usual (BAU) and the Intensive Urbanization (IU), this article, taking Wuwei City, a medium size city and typical oasis arid area in Gansu Province with very vulnerable and sensitive natural environment but long history of oasis economy, as an example, evaluated the sustainability of its environment and analyzed the scenarios of Wuwei’s household energy consumption, waste discharge in transportation industry, primary industry, secondary industry, tertiary industry, by the integration of the systematical dynamics model Stella and Polestar language to simulate the future development of the research area. The results showed that, first, the developing model of IU was propitious to Wuwei City named for oasis economy and vulnerable natural environment. The strategy of "Intensive Urbanization" can change the structure of energy utilization, and improve the efficiency of energy utilization. Second, the proportion of domestic energy consumption will decrease with industrialization and economic development, while that of tertiary industry, secondary industry and transportation will gradually grow up according to strategy of "Intensive Urbanization". Third, the Wuwei City is facing a severe eco-environmental crisis under the conventional patterns of development and a better future under a sustainable urbanization scenario, in the next 10 to 20 years. The different developing trends were clarified and the relative countermeasures were put forward for the policy makers according to the driving forces.
基金Program Foundation for Environmental Protection of 2 0 0 2 by Jilin Province Environm ental ProtectionBureau
文摘Catalytic wet air oxidation(CWAO) was employed to reduce the organic compounds in landfill leachate and the effects of temperature, oxygen pressure, catalyst dosage, and concentration of the organic compounds on the TOC and COD Cr removal rates were studied. The degradation kinetics of landfill leachate was also investigated and an exponential experiential model consisting of four influential factors was established to describe the reduction of the organic compounds in the landfill leachate. Meanwhile, the GC-MS technique was used to detect the components of the organic intermediates for the inference of the decomposition mechanisms of the organic compounds in landfill leachate. The results reveal that the reaction temperature and the catalyst dosage are the most important factors affecting the degradation reaction of the organic compounds and that the principal intermediates confirmed by GC-MS are organic acids at a percentage of more than 88% with no aldehydes or alcohols detected. The decomposition mechanisms of the organic compounds in landfill leachate were inferred based on the GC-MS information as follows: the activated gas phase O 2 captured the hydrogen of the organic pollutants to produce free radicals, which then initiated the catalytic reaction. So most of the organic compounds were oxidized into CO 2 and H 2O ultimately. In general, catalytic wet air oxidation over catalyst Co 3O 4/Bi 2O 3 was a very promising technique for the treatment of landfill leachate.
基金Supported by the National 863 Program (No.2001AA132020).
文摘This paper firstly analyzes the property of the low frequency electromagnetic wave, which can penetrate many types of non-metallic materials, and the ability of Ultra-Wide Band (UWB) impulse signal which has high range resolution. Then the methods are discussed for conducting surveillance through walls, detecting and locating the moving persons behind the partitions. The schematic diagram of Through-Wall Detecting Radar (TWDR) and the models of moving target are shown and the principle of detecting the moving target is also provided with coherent superimposing technique on a range gate. Finally an algorithm for estimating the location of targets is given. The performance of TWDR is validated by the experiments of penetrating a wood block, a red brick wall and a reinforced concrete wall.
文摘The solvent extraction of uranium(VI) and europium(III) from nitric acid solution was studied with pi- colinamide dissolved in ethylene dichloride. The distribution ratios of U(VI) and Eu(III) as a function of aqueous HNO3 concentration , extractant concentration in organic phase and temperature as well as the salting-out agent con- centration have been measured. The experiment results show that picolinamide has higher extractability for U(VI) than for Eu(III). The composition of extracted species, equilibrium constants and enthalpies of extraction reaction have also been presented.
基金This project was supported by Guangdong provincial natural science foundation (No.970839) and Guangdong provincial administrati
文摘Objective:to study the effect of coixenolide (CXL) on irradiation of human nasophyaryngeal carcinoma cell line CNE-2Z in the absence of oxygen,Methods: Microcolony formation assay was used for determining the sensitivity of CNE-2Z to γ-ray in vitro,Results:When CNE-2Z was treated with 10^-7--10^-6 mol/L of CXL,CXL shifted the radiation dose-survival curve to the left,with the decrease of D0,Dq and N values,Radiation dose reduced 10.07%-35.69% at D37 level,the sensitizing enhancement ratios(SER) were 1.07-1.43 and 1.16-1.72 at D0 and Dq levels respectively.Conclusion:CXL increase susceptibility of CNE-2Z to ray under hypoxic condition by the mechanism of inhibiting its sublethal damgae repair.Subject words Nasopharyngeal neoplasm;Coixenolide;Radiosensitzation;Hypoxic irradiation.
文摘Objective. To study the effect of ecdysterone (ECR) on beta - amyloid peptide fragment 25-35 ( Aβ25-35 )-induced PC12 cell cytotoxicity, and further to expore its mechanism. Methods: PC12 survial was monitored by LDH release and 3-(4, 5-dimethylthiazol-yl-2, 5-diphenyhetrazolium bromide (MTT) assays. The content of malondi-
文摘Objective: To explore the mechanism of Ecdysterone (ECR) in prevention of learning and memory dysfunction of the rats induced by β-amyloid peptide ( Aβ25-35 ). Methods: Ninety Wistar male rats were randomly divided into five groups, the control group, the model group, the treated groups (ECR 4mg·kg^-1 and ECR 8mg·kg-1 and
文摘Aim: To study the effect of Ecdysterone (ECR) on the expression of Tau from the cerebral cortice and hippocampus and behaviors in passive avoidance reaction and spatial discrimination of the mice induced by overload aluminum salt.Methods Fourty-five NIH mice were randomly divided into five groups, the control group, the model group, the
