期刊文献+
共找到13,524篇文章
< 1 2 250 >
每页显示 20 50 100
Studies for Intervention and Effect Assessment on Arsenism 被引量:2
1
作者 Yajuan Xia Kegong Wu +3 位作者 Zhiwei Guo Weihong Yang Yanhong Li Jun Liu 《Journal of Water Resource and Protection》 2013年第8期42-45,共4页
Chronic exposed to high arsenic via drinking water is worldwide public health problem. A large number of epidemiological studies showed that exposed to arsenic cause the human body skin lesions and also induce cancer,... Chronic exposed to high arsenic via drinking water is worldwide public health problem. A large number of epidemiological studies showed that exposed to arsenic cause the human body skin lesions and also induce cancer, cardiovascular and other kind of diseases. So arsenism not only affect the person’s work capability and life quality but also result in economic losses and mental suffering. How to prevent and control the effects of high arsenic? What intervention is more important and necessary for arsenism? How to scientifically assess the interventions effect of short-term and long-term? Through a systematic follow-up investigation in different high arsenic regions in Inner Mongolia, the environmental arsenic and human body internal arsenic exposure were analyzed, the clinical characteristics and signs of arsenism patients were examined. We established the evaluation system of intervention and control measures for population exposed to high arsenic. This evaluation system and control measures included government and exposed population. For government, change water supply and keep it work well and health education is very important. For exposed population, improving the diet and treating the symptoms or signs related to arsenic is more necessary. Arsenic in human body such as nail or urine sample arsenic must be reduced to normal value and this index show that the subject if still or not expose to high arsenic. 展开更多
关键词 EXPOSED to arsenIC INTERVENTION ASSESSMENT
下载PDF
Measuring the Accessibility of Safe Drinking-water: From Millennium Development Goals Experience to Sustainable Development Goals Prospects
2
作者 Léandre Ngogang Wandji 《Journal of Environmental Science and Engineering(A)》 2017年第12期587-593,共7页
The access to safe drinking-water is a global priority for sustainable development, as it has been recognized within the MDGs (Millennium Development Goals). Although the MDG’s target of halving the proportion of p... The access to safe drinking-water is a global priority for sustainable development, as it has been recognized within the MDGs (Millennium Development Goals). Although the MDG’s target of halving the proportion of people without sustainable access to safe drinking-water was met in 2010, the measurement method of the monitoring and evaluation indicator used ignored certain elements including the quality of water that should be underlined. Starting with a review of drinking-water and improved water source concepts, this study examines the limitations of measuring access to safe drinking-water in the context of the MDGs, and learns from the lessons to ensure a better performance in achieving the SDGs (Sustainable Development Goals). 展开更多
关键词 SDGs MDGS drinking-water improved water source water quality
下载PDF
Nutrient-Induced Growth of Coliform and HPC Bacteria in Drinking-Water Pipes
3
作者 Patrick Asamoah Sakyi Roland Asare +1 位作者 Chris Anani Samuel Boakye Dampare 《Journal of Environmental Protection》 2012年第6期508-517,共10页
We conducted a study on a model drinking water distribution system to evaluate the impact of nutrient in the form of sodium acetate on the growth and survival of coliform and heterotrophic plate count (HPC) bacteria f... We conducted a study on a model drinking water distribution system to evaluate the impact of nutrient in the form of sodium acetate on the growth and survival of coliform and heterotrophic plate count (HPC) bacteria for a maximum of 21 days residence time of water in pipes. Our results show that, besides the nutrient added and the absence of any additional source of contamination and additional supply of nutrient, there was significant growth of the above mentioned bacteria in the pipes and bottles for a couple of days, after which the bacterial population began to decrease. The results indicate that the bacteria used the nutrient to grow and multiply until the nutrient was totally consumed and became depleted in the bulk water phase, after which the bacterial population reached a near stationary level and subsequently declined. This suggests the death of some of the bacteria and their dead cells were used by other bacteria for growth and survival. Using a detection limit of 3.3 CFU/100 mL for the coliforms, the study shows that after sometime, no bacteria were found in the water phase of the pipe, however, the biofilm in the pipes still harbored some of the bacteria. The results have revealed that the bacteria also have the tendency to move from the water phase to the biofilm since the latter provides a more suitable environment for bacteria to thrive on and grow, thus prolonging their survival in the system. 展开更多
关键词 COLIFORM HPC BACTERIA NUTRIENT drinking-water Pipes Biofilm Bacterial Growth
下载PDF
Recycling arsenic-containing bio-leaching residue after thermal treatment in cemented paste backfill:Structure modification,binder properties and environmental assessment
4
作者 Dengfeng Zhao Shiyu Zhang Yingliang Zhao 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第10期2136-2147,共12页
The substantial arsenic(As)content present in arsenic-containing bio-leaching residue(ABR)presents noteworthy environ-mental challenges attributable to its inherent instability and susceptibility to leaching.Given its... The substantial arsenic(As)content present in arsenic-containing bio-leaching residue(ABR)presents noteworthy environ-mental challenges attributable to its inherent instability and susceptibility to leaching.Given its elevated calcium sulfate content,ABR exhibits considerable promise for industrial applications.This study delved into the feasibility of utilizing ABR as a source of sulfates for producing super sulfated cement(SSC),offering an innovative binder for cemented paste backfill(CPB).Thermal treatment at varying temperatures of 150,350,600,and 800℃ was employed to modify ABR’s performance.The investigation encompassed the examination of phase transformations and alterations in the chemical composition of As within ABR.Subsequently,the hydration characteristics of SSC utilizing ABR,with or without thermal treatment,were studied,encompassing reaction kinetics,setting time,strength development,and microstructure.The findings revealed that thermal treatment changed the calcium sulfate structure in ABR,consequently impacting the resultant sample performance.Notably,calcination at 600℃ demonstrated optimal modification effects on both early and long-term strength attributes.This enhanced performance can be attributed to the augmented formation of reaction products and a densified micro-structure.Furthermore,the thermal treatment elicited modifications in the chemical As fractions within ABR,with limited impact on the As immobilization capacity of the prepared binders. 展开更多
关键词 cemented paste backfill bio-leaching residue arsenic immobilization binder hydration CALCINATION
下载PDF
Distribution and Contamination of Arsenic in Fish, Gastropods and Bivalves in the Aby and Tendo Lagoons in East of Ivory Coast
5
作者 Kouakou Serge Kouassi Stéphane Jean Claon +3 位作者 Kossonou Roland N’Guettia Séri Kipré Laurent Dakouo Guei Jokebed Djaman Allico Joseph 《Journal of Environmental Protection》 2024年第3期246-264,共19页
Lagoons are ecosystems for biodiversity and the livelihoods of coastal communities. The main objective of the study was to analyze the variability of arsenic concentrations in gastropods and bivalves in the Aby and Te... Lagoons are ecosystems for biodiversity and the livelihoods of coastal communities. The main objective of the study was to analyze the variability of arsenic concentrations in gastropods and bivalves in the Aby and Tendo lagoons, taking into account spatial, seasonal and hydrological variations. The study was carried out in four stages spread over two successive hydroclimatic cycles, including two seasons during the rainy season and two more during the dry season. The samples were taken in two areas of the Aby and Tendo lagoons. Arsenic levels were measured by ICP-MS. The results showed that mean arsenic concentrations in the muscles of organisms in Aby Lagoon ranged from 0.01 to 1.26 μg As/g, with a mean and median of 0.17 and 0.06 μg As/g, respectively. Fish had the highest levels of arsenic, followed by crustaceans, while molluscs and plants had lower and comparable concentrations of As. Arsenic concentrations in tilapia and jawbones varied significantly between sites and seasons, with higher concentrations at Tendo and during the rainy season. Arsenic concentrations in gastropods and bivalves were significantly higher than those of other species, with averages of 0.74 and 1.03 mg As/kg, respectively. 展开更多
关键词 arsenIC Pollution FISH GASTROPODS LAGOONS Health Effect
下载PDF
Roles of Aqueous Extract of Marigold on Arsenic-Induced Oxidative Damage in Pancreatic Islet β-Cells
6
作者 Zongqin Mei Jiao Dai +2 位作者 Guofen Liu Zuoshun He Shiyan Gu 《Journal of Biosciences and Medicines》 2024年第5期19-34,共16页
Roles of Marigold extracts (ME) on arsenic trioxide (ATO)-induced oxidative damage to pancreatic β-cells need to be further elucidated. In this study, NIT-1 cells were treated with different concentrations of and/or ... Roles of Marigold extracts (ME) on arsenic trioxide (ATO)-induced oxidative damage to pancreatic β-cells need to be further elucidated. In this study, NIT-1 cells were treated with different concentrations of and/or ATO, following by the cell viability was detected by CCK8 assay. Then, intracellular reactive oxygen species (ROS) levels, lipid peroxide (MDA) contents and superoxide dismutase (SOD) activity were measured with a fluorescence probe method and colorimetric assay, respectively. The apoptosis rate and morphology was detected and observed with hoechst 33,258 staining assay. The mRNA levels and protein expressions of nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were measured by real-time fluorescence quantitative polymerase chain reaction and protein immunoblotting assay, respectively. Our results indicated that Co-treatment with ME and ATO exacerbated the cell viability decreasing reduced by ATO, while the addition of ME after ATO treatment effectively promote the recovery of ATO reduced survival rates. The ATO group increased apoptosis (P P β-cells by modulating the activation of the Nrf2 signaling pathway. 展开更多
关键词 arsenic Trioxide Marigold Extracts Nuclear Factor E2-Related Factor 2 Oxidative Damage
下载PDF
Arsenic and fluoride co-enrichment of groundwater in the loess areas and associated human health risks:A case study of Dali County in the Guanzhong Basin
7
作者 Rui-ping Liu Fei Liu +5 位作者 Hua-qing Chen Yu-ting Yang Hua Zhu You-ning Xu Jian-gang Jiao Refaey M El-Wardany 《China Geology》 CAS CSCD 2024年第3期445-459,共15页
This study aims to reveal the occurrence and origin of typical groundwater with high arsenic and fluoride concentrations in the loess area of the Guanzhong Basin—a Neogene faulted basin.Key findings are as follows:(1... This study aims to reveal the occurrence and origin of typical groundwater with high arsenic and fluoride concentrations in the loess area of the Guanzhong Basin—a Neogene faulted basin.Key findings are as follows:(1)Groundwater samples with high arsenic and fluoride concentrations collected from the loess area and the terraces of the Weihe River accounted for 26%and 30%,respectively,of the total samples,with primary hydrochemical type identified as HCO_(3)-Na.The karst and sand areas exhibit relatively high groundwater quality,serving as preferred sources for water supply.It is recommended that local governments fully harness groundwater in these areas;(2)groundwater with high arsenic and fluoride concentrations in the loess area and the alluvial plain of rivers in Dali County is primarily distributed within the Guanzhong Basin,which represents the drainage zone of groundwater;(3)arsenic and fluoride in groundwater originate principally from natural and anthropogenic sources;(4)the human health risk assessments reveal that long-term intake of groundwater with high arsenic and fluoride concentrations pose cancer or non-cancer risks,which are more serious to kids compared to adults.This study provides a theoretical basis for the prevention and treatment of groundwater with high arsenic and fluoride concentrations in loess areas. 展开更多
关键词 arsenIC FLUORIDE GROUNDWATER Cancer risk Kid and adult Human health risk assessment Hydrogeological survey engineering Environmental geological survey engineering Loess areas
下载PDF
Feasibility Evaluation of Using Biochar-based Permeable Reactive Barrier for the Remediation of Mercury and Arsenic Composite Polluted Water Bodies
8
作者 Dilixiati·Abulizi 《Asian Agricultural Research》 2024年第5期15-19,共5页
This study employed a modified biochar material to construct a permeable reactive barrier(PRB)for the treatment of water bodies polluted with mercury and arsenic.The experimental results demonstrated that the addition... This study employed a modified biochar material to construct a permeable reactive barrier(PRB)for the treatment of water bodies polluted with mercury and arsenic.The experimental results demonstrated that the addition of goethite-modified biochar significantly enhanced the remediation efficiency of As(III),achieving a maximum removal rate of 100%.Conversely,pure biochar exhibited high efficiency in the removal of Hg(II),with a maximum removal rate approaching 100%.Furthermore,the pH level of the water significantly influenced the adsorption efficiency of heavy metal ions,with the optimal removal performance observed at a pH of 6.0.The PRB system demonstrated excellent removal rates under low concentrations of heavy metals.However,as the concentration increased,the remediation efficiency exhibited a slight decrease.In summary,the findings of this study provide compelling evidence for the use of modified biochar in the construction of PRBs for the remediation of mercury and arsenic-polluted water bodies.Furthermore,the study reveals the mechanism by which pH and heavy metal concentration influence remediation efficiency. 展开更多
关键词 BIOCHAR Goethite-modified biochar Permeable reactive barrier(PRB) Mercury and arsenic pollution Remediation efficiency
下载PDF
Removal and stabilization of arsenic from anode slime by forming crystal scorodite 被引量:20
9
作者 闵小波 廖映平 +4 位作者 柴立元 杨志辉 熊珊 刘琳 李青竹 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第4期1298-1306,共9页
A process was proposed for removing and stabilizing arsenic(As) from anode slime. The anode slime with high arsenic concentration was pretreated by circular alkaline leaching process. Then, the arsenic in the leaching... A process was proposed for removing and stabilizing arsenic(As) from anode slime. The anode slime with high arsenic concentration was pretreated by circular alkaline leaching process. Then, the arsenic in the leaching solution can be further precipitated as a form of scorodite crystalline(FeAsO4·2H2O). In the precipitating arsenic reaction, in which ferrous ions were oxidized by air gas, the effects of acidity(p H), reaction temperature, air flow rate, initial concentration of arsenic and initial molar ratio of Fe(II) to As(V) on arsenic precipitation were investigated. The results showed that sufficiently stable crystal scorodite could be achieved under the condition of initial arsenic concentration of 10 g/L, pH 3.0-4.0, Fe/As molar ratio of 1.5, the temperature of 80-95 °C, and the air flow rate higher than 120 L/h. Under the optimal condition, more than 78% of arsenic could be precipitated as a form of scorodite crystalline. The As leaching concentration of the precipitates was less than 2.0 mg/L and the precipitates may be considered to be safe for disposal. 展开更多
关键词 SCORODITE anode slime arsenIC ferric arsenate arsenic stabilization
下载PDF
Leaching behavior of metals from high-arsenic dust by NaOH-Na_2S alkaline leaching 被引量:23
10
作者 郭学益 易宇 +1 位作者 石靖 田庆华 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第2期575-580,共6页
Arsenic is selectively extracted from high-arsenic dust by NaOH-Na2S alkaline leaching process. In the leaching arsenic process, the effects of alkali-to-dust ratio, sodium sulfide addition, leaching temperature, leac... Arsenic is selectively extracted from high-arsenic dust by NaOH-Na2S alkaline leaching process. In the leaching arsenic process, the effects of alkali-to-dust ratio, sodium sulfide addition, leaching temperature, leaching time and liquid-to-solid ratio on metals leaching efficiencies were investigated. The results show that the arsenic can be effectively separated from other metals under the optimum conditions of alkali/dust mass ratio of 0.5, sodium sulfide addition of 0.25 g/g, leaching temperature of 90 ℃, leaching time of 2 h, and liquid-to-solid ratio of 5:1 (mL/g). Under these conditions, the average leaching efficiencies of arsenic, antimony, lead, tin and zinc are 92.75%, 11.68%, 0.31%, 29.75% and 36.85%, respectively. The NaOH-Na2S alkaline leaching process provides a simple and highly efficient way to remove arsenic from high-arsenic dust, leaving residue as a suitable lead resource. 展开更多
关键词 high arsenic dust alkaline leaching leaching behavior arsenIC
下载PDF
Determination of arsenic speciation in secondary zinc oxide and arsenic leachability 被引量:9
11
作者 李玉虎 刘志宏 +3 位作者 赵忠伟 李启厚 刘智勇 曾理 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第5期1209-1216,共8页
The species of arsenic in secondary zinc oxide generated from fuming furnace were investigated. The results revealed that there are mainly three types of secondary zinc oxide based on three arsenic species. The main p... The species of arsenic in secondary zinc oxide generated from fuming furnace were investigated. The results revealed that there are mainly three types of secondary zinc oxide based on three arsenic species. The main phase of As is As2O3 in type Ⅰ, zinc arsenite (Zn(AsO2)2) in type Ⅱ and lead arsenate (Pb(As206), Pb4As2O9) in type Ⅲ, respectively. Selective leaching of zinc oxide of type Ⅱ was carried out. The leaching rate of As kept at 65%-70% with 30 g/L NaOH and L/S ratio of 3 at 20 ℃ for 1 h, while the losses of Pb and Zn were both below 1%. 展开更多
关键词 secondary zinc oxide arsenic species alkali leaching arsenic removal
下载PDF
Extraction of arsenic from arsenic-containing cobalt and nickel slag and preparation of arsenic-bearing compounds 被引量:12
12
作者 余国林 张盈 +3 位作者 郑诗礼 邹兴 王晓辉 张懿 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第6期1918-1927,共10页
The arsenic extraction from the arsenic-containing cobalt and nickel slag,which came from the purification process of zinc sulfate solution in a zinc smelting factory,was investigated.The alkaline leaching method was ... The arsenic extraction from the arsenic-containing cobalt and nickel slag,which came from the purification process of zinc sulfate solution in a zinc smelting factory,was investigated.The alkaline leaching method was proposed according to the mode of occurrence of arsenic in the slag and its amphoteric characteristic.The leaching experiments were conducted in the alkaline aqueous medium,with bubbling of oxygen into the solution,and the optimal conditions for leaching arsenic were determined.The results showed that the extraction rate of arsenic was maximized at 99.10%under the optimal conditions of temperature 140 ℃,NaOH concentration 150 g/L,oxygen partial pressure 0.5 MPa,and a liquid-to-solid ratio 5:1.Based on the solubilities of As2O5,ZnO and PbO in NaOH solution at 25 ℃,a method for the separation of As in the form of sodium arsenate salt from the arsenic-rich leachate via cooling crystallization was established,and the reaction medium could be fully recycled.The crystallization rate was confirmed to reach 88.9%(calculated on the basis of Na3AsO4) upon a direct cooling of the hot leachate down to room temperature.On the basis of redox potentials,the sodium arsenate solution could be further reduced by sulfur dioxide(SO2) gas to arsenite,at a reduction yield of 92%under the suitable conditions.Arsenic trioxide with regular octahedron shape could be prepared successfully from the reduced solution,and further recycled to the purification process to purify the zinc sulfate solution.Also,sodium arsenite solution obtained after the reduction of arsenate could be directly used to purify the zinc sulfate solution.Therefore,the technical scheme of alkaline leaching with pressured oxygen,cooling crystallization,arsenate reduction by SO2 gas,and arsenic trioxide preparation,provides an attractive approach to realize the resource utilization of arsenic-containing cobalt and nickel slag. 展开更多
关键词 arsenic-containing cobalt and nickel slag alkaline leaching cooling crystallization sodium arsenate arsenic trioxide
下载PDF
Reduction and deposition of arsenic in copper electrolyte 被引量:3
13
作者 周文科 彭映林 +2 位作者 郑雅杰 马玉天 崔涛 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第12期2772-2777,共6页
The influences of temperature, H2SO4 concentration, CuSO4 concentration, reaction time and SO2 flow rate on the reduction of arsenic(V) with SO2 were studied and the deposition behavior of arsenic (III) under the ... The influences of temperature, H2SO4 concentration, CuSO4 concentration, reaction time and SO2 flow rate on the reduction of arsenic(V) with SO2 were studied and the deposition behavior of arsenic (III) under the effect of concentration and co-crystallization was investigated in copper electrolyte. The results indicate that reduction rate of arsenic (V) decreases with increasing temperature and H2SO4 concentration, but increases with increasing SO2 flow rate and reaction time, and it can reach 92% under appropriate conditions that reaction temperature is 65 °C, H2SO4 concentration is 203 g/L, CuSO4 concentration is 80 g/L, reaction time is 2 h and SO2 gas flow rate is 200 mL/min. To remove arsenic in the copper electrolyte, arsenic (V) is reduced to trivalence under the appropriate conditions, the copper electrolyte is concentrated till H2SO4 concentration reaches 645 g/L, and then the removal rates of As, Cu, Sb and Bi reach 83.9%, 87.1%, 21.0% and 84.7%. The XRD analysis shows that crystallized product obtained contains As2O3 and CuSO4·5H2O. 展开更多
关键词 copper electrolyte arsenic (V) REDUCTION sulfur dioxide CONCENTRATION arsenic trioxide
下载PDF
Determination of Arsenic and Mercury in Soil by Microwave Digestion and Hidride GenerationAtomic Fluorescence Spectrometry 被引量:5
14
作者 王天顺 杨玉霞 +5 位作者 牙禹 莫磊兴 范业赓 廖洁 黄东亮 谭宏伟 《Agricultural Science & Technology》 CAS 2013年第4期651-653,共3页
[Objective] The aim was to develop a rapid, simple method for determina- tion of arsenic and mercury in soil samples by atomic fluorescence spectrometry. [Method] The method for determination of As and Hg in soil by c... [Objective] The aim was to develop a rapid, simple method for determina- tion of arsenic and mercury in soil samples by atomic fluorescence spectrometry. [Method] The method for determination of As and Hg in soil by combined atomic fluorescence spectrometry and microwave digestion was used. [Result] The concentration curve was linear within the range of 0-80.0μg/L of As and 0-8.0 μg/L of Hg, and the detection limits of As and Hg was 0.036 μg/L and 0.015 μg/L, respectively. The precision for elevenfold determination of As at 40.0 ug/L level and Hg at 4.0μg/L level were 1.1% and 2.2%(RSD), respectively. Recoveries of 103.0%-106.6% for As and 90.0%-95.0% for Hg were obtained for there soil samples. [Conclusion] The proposed method has the advantages of simple operation, high sensitivity, and high efficiency; it was successfully used for determination of As and Hg in soil samples. 展开更多
关键词 Microwave digestion Atomic fluorescence spectrometry arsenIC MERCURY SOIL
下载PDF
Effect of arsenic on spatial pattern of radial oxygen loss and iron plaque formation in rice 被引量:1
15
作者 吴川 黄柳 +4 位作者 薛生国 潘炜松 邹奇 William Hartley 莫竞瑜 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第2期413-419,共7页
The effects of different arsenic (As) treatments on spatial pattern of radial oxygen loss (ROL), iron (Fe) plaque formation and As accumulation in rice were investigated using three rice genotypes, planted under... The effects of different arsenic (As) treatments on spatial pattern of radial oxygen loss (ROL), iron (Fe) plaque formation and As accumulation in rice were investigated using three rice genotypes, planted under greenhouse conditions. Arsenic was applied to soil at 50 and 100 mg/kg, with untreated soil used as a control having an average As concentration of 8.5 mg/kg. It was demonstrated that the ratio of ROL in root tips to that at the root base slightly decreased with increasing As concentration, suggesting that the spatial ROL patterns in these groups may be shifted from the “tight” barrier towards the “partial” barrier form. Furthermore, increasing As concentration led to a increase in Fe plaque formation on root surfaces. In addition, root As concentrations of genotypes in 50 and 100 mg/kg As treatments were significantly higher than that of control treatment (P〈0.05). Grain As concentration of genotype Nanyangzhan (with lower ROL) was significantly higher (P〈0.05) than that of genotype CNT87059-3 with higher ROL. 展开更多
关键词 arsenIC iron plaque RICE spatial pattern of ROL
下载PDF
Dissolved Inorganic Arsenic in the Yellow Sea and the East China Sea—Distributions and Seasonal Variations 被引量:2
16
作者 任景玲 刘素美 张经 《Marine Science Bulletin》 CAS 2009年第1期24-36,共13页
The distributions and seasonal variations of total dissolved inorganic arsenic (TDIAs, [TDIAs] = [As^5+]+[As^3+]) and arsenite (As3.) in the Yellow Sea and East China Sea are presented hero based on the observa... The distributions and seasonal variations of total dissolved inorganic arsenic (TDIAs, [TDIAs] = [As^5+]+[As^3+]) and arsenite (As3.) in the Yellow Sea and East China Sea are presented hero based on the observations of 9 cruises carried out in 2000 - 2003. The study area covers a broad range of hydrographic and chemical properties. The emphasis is put on a southeast transect from Changjiang Estuary to the Ryukyu Islands (i.e. PN section) in the East China Sea to discuss the impact of terrestdal input on the marginal seas of China. Arsenic species (TDlAs and arsenite) are determined by selective hydride generation - atomic fluorescence spectrometry (HG-AFS). TDIAs concentrations were high in the coastal area of Changjiang Estuary and decreased slightly towards the shelf region. High concentratiOns of TDIAs were also existed in the near bottom layer of shelf edge of the East China Sea which indicated another source of arsenic from the incursion of Kuroshio Waters. The seasonal variations of TDIAs in the study area depend on the hydrographic stages of Changjiang and the incursion intensity of Kuroshio Waters. Arsenite showed opposite distributions with TDIAs, with higher concentrations appeared at the surface layer of shelf region, which was positive correlated with the chlorophyll a. Biological conversion of arsenate into arsenite was hypothesized for the observed distribution pattern and its seasonal variations. The stoichoimetric ratios of As to P were estimated to be about 2×10^3 at PN Section in summer. The concentrations of dissolved arsenic in the Yellow Sea and East China Sea were comparable with other areas in the world. 展开更多
关键词 dissolved arsenic SPECIES Yellow Sea and East China Sea distributions and seasonal variations
下载PDF
ARSENAL25%SL防除非耕地杂草研究 被引量:1
17
作者 沈国辉 石鑫 +1 位作者 杨烈 王学鹗 《农药科学与管理》 CAS 2001年第6期14-16,共3页
2年的田间试验结果证明 ,ARSENAL25%SL是防除非耕地杂草的优秀除草剂 ,它不仅可有效地防除出苗后的一年生和多年生单、双子叶杂草 ,对未出土的杂草有明显的封杀作用 ,ARSENAL25%SL750~1000ml/hm2 药后60d的总防效高达99.2%~100% ,持... 2年的田间试验结果证明 ,ARSENAL25%SL是防除非耕地杂草的优秀除草剂 ,它不仅可有效地防除出苗后的一年生和多年生单、双子叶杂草 ,对未出土的杂草有明显的封杀作用 ,ARSENAL25%SL750~1000ml/hm2 药后60d的总防效高达99.2%~100% ,持效期为90~120d,因而一次用药可保证长时间无草。 展开更多
关键词 ARSNAL 防效 非耕地 杂草 除草 除草剂
下载PDF
黑磷/黑砷异质结纳米器件热电性质应力调控研究
18
作者 戎杙 邱乙峰 张蓓 《原子与分子物理学报》 CAS 北大核心 2025年第1期69-74,共6页
探索新型高性能低维热电纳米材料已成为国家重大发展策略.论文采用密度泛函理论结合非平衡态格林函数方法研究了由黑磷、黑砷纳米带构建异质结构在2%、4%、6%和8%四种拉伸应变作用下热电性能调控机理.研究结果表明,6%拉伸应变较其他情形... 探索新型高性能低维热电纳米材料已成为国家重大发展策略.论文采用密度泛函理论结合非平衡态格林函数方法研究了由黑磷、黑砷纳米带构建异质结构在2%、4%、6%和8%四种拉伸应变作用下热电性能调控机理.研究结果表明,6%拉伸应变较其他情形,能够更有效抑制声子输运行为;与此同时,拉伸应变对于器件的电子输运的调控效果并不明显.在费米能附近,黑磷/黑砷异质结纳米器件在6%拉伸应变调控下热电优值达到最大值2.31. 展开更多
关键词 黑磷 黑砷 异质结 应力 热电性质
下载PDF
Arsenic trioxide inhibites transgenic tumor necrosis factor-α promoter activity in vascular smooth muscle cells and THP-1 monocytes in vitro
19
作者 张卓琦 曹希传 黄永麟 《Journal of Chinese Pharmaceutical Sciences》 CAS 2007年第2期134-138,共5页
Aim This study was to evaluate the effect of arsenic trioxide (As2O3) on the transgenic TNF-α promoter activity in cultured vascular smooth muscle cells (VSMCs) and THP-1 monocytes. Methods Human TNF-α promoter ... Aim This study was to evaluate the effect of arsenic trioxide (As2O3) on the transgenic TNF-α promoter activity in cultured vascular smooth muscle cells (VSMCs) and THP-1 monocytes. Methods Human TNF-α promoter was constructed by reporter gene system and was transiently transfected into VSMCs and THP-1 in vitro. The promoter activity was tested by luciferase activity with or without LPS and Ang Ⅱ stimulation, before and after different dosage of As2O3 treatment. Results 1. TNF-α promoter effectively expressed in VSMCs and THP-1 compared with CMV promoter (58.3% and 80.9%, respectively). Both LPS and Ang Ⅱ significantly up-regulated TNF-α promoter activity (P〈0.05). 2. As2O3 significantly inhibited, both intact and LPS/Ang Ⅱ stimulated promoter activity, in a dose dependent manner (P〈0.05), and in both cell type. Conclusion These results manifested that, the inhibition effect of As2O3 on the activity of human TNF-α promoter indicated its potential inhibition on pro-inflammatory cytokine genes expression at transcriptional level and its potential anti-inflammatory property in the cardiovascular system. 展开更多
关键词 arsenic trioxide TNF-α promoter INFLAMMATION Smooth muscle cells VASCULAR MONOCYTES
下载PDF
Ascorbic Acid Promotes Arsenic-induced Cytotoxicity in Human Hepatocarcinoma Cells and Their Underlying Mechanisms
20
作者 吴辉文 吴向阳 陈锡慰 《Journal of Nanjing Medical University》 2004年第6期297-300,共4页
Objective: To study synergistic effect with Ascorbic acid(AA) on arsenic trioxide inducing human Hepatocarcinoma cell apoptosis, and provide theoretical basis for promoting human Hepatocarcinoma cell apoptosis induced... Objective: To study synergistic effect with Ascorbic acid(AA) on arsenic trioxide inducing human Hepatocarcinoma cell apoptosis, and provide theoretical basis for promoting human Hepatocarcinoma cell apoptosis induced by arsenic trioxide(AT). Methods: Human Hepatocarcinoma cell line BEL-7402 being cultured in vitro, the effect of AT and (or) AA on its growth inhibition and its two intracellular signal molecules was evaluated separately using MTT and Western blot. Results: AT at a few μmol/L concentration could suppress abnormal proliferation of human hepatocarcinoma cells, and initiate their apoptosis by activation of caspase-3, and activate extracellular-signal regulated kinases (ERKs), which were dependent on the dosage of AT conspicuously. The effect of AA on BEL-7402 was not significant; However, AA could effectively enhance AT-induced hepatocarcinoma cell apoptosis and lesion severity through activation of caspase-3 but not ERKs. Conclusion: Caspase-3 and ERKs proteins could involve in arsenic-induced hepatocarcinoma cell apoptosis and differentiation respectively as intracellular signaling molecules; The effect between AT and AA on hepatocarcinoma is synergistic, which further inhibits cell growth and induces apoptosis in human hepatocarcinoma cells through activation of caspase-3 but not ERKs. 展开更多
关键词 HEPATOCARCINOMA arsenic trioxide Ascorbic acid apoptosis CASPASE-3 extracellular-signal regulated kinases
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部