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Measurement of Concentration of Sorbent Particles and Water Droplets in Hydration Desulfurization Reactor with PIV
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作者 赵长遂 吴树志 +3 位作者 刘现卓 肖军 陆勇 王式民 《Journal of Southeast University(English Edition)》 EI CAS 2002年第1期88-91,共4页
Vortexing limestone injection into furnace combined with calcium lime hydration in the downstream is the most promising technology for controlling SO 2 emission. Particle imaging velocimetry (PIV) is used to measure ... Vortexing limestone injection into furnace combined with calcium lime hydration in the downstream is the most promising technology for controlling SO 2 emission. Particle imaging velocimetry (PIV) is used to measure the gas liquid solid three phase flow field in a reactor. By image processing based on newly developed software, the number concentrations of sorbent particles and water droplets are presented. The measuring results are very helpful for better understanding the desulfurization mechanism and optimizing configurational and operational parameters in the hydration reactor. 展开更多
关键词 particle image velocimetry DESULFURIZATION particle water droplet concentration
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Impact of fertilization on chestnut growth, N and P concentrations in runoff water on degraded slope land in South China 被引量:8
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作者 ZENG Shu-cai CHEN Bei-guang +1 位作者 JIANG Cheng-ai WU Qi-tang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第7期827-833,共7页
Growing fruit trees on the slopes of rolling hills in South China was causing serious environmental problems because of heavy application of chemical fertilizers and soil erosion. Suitable sources of fertilizers and p... Growing fruit trees on the slopes of rolling hills in South China was causing serious environmental problems because of heavy application of chemical fertilizers and soil erosion. Suitable sources of fertilizers and proper rates of applications were of key importance to both crop yields and environmental protection. In this article, the impact of four fertilizers, i.e., inorganic compound fertilizer, organic compound fertilizer, pig manure compost, and peanut cake (peanut oil pressing residue), on chestnut (Castanea mollissima Blume) growth on a slope in South China, and on the total N and total P concentrations in runoff waters have been investigated during two years of study, with an orthogonal experimental design. Results show that the organic compound fertilizer and peanut cake promote the heights of young chestnut trees compared to the control. In addition, peanut cake increases single-fruit weights and organic compound fertilizer raises single-seed weights. All the fertilizers increased the concentrations of total N and total P in runoff waters, except for organic compound fertilizer, in the first year experiment. The observed mean concentrations of total N varied from 1.6 mg/L to 3.2 mg/L and P from 0.12 mg/L to 0.22 mg/L, which were increased with the amount of fertilizer applications, with no pattern of direct proportion. On the basis of these experiment results, organic compound fertilizer at 2 kg/tree and peanut cake at 1 kg/tree are recommended to maximize chestnut growth and minimize water pollution. 展开更多
关键词 CHESTNUT FERTILIZATION N concentration P concentration runoff water South China
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Effects of nitrate concentration in interstitial water on the bioremediation of simulated oil-polluted shorelines 被引量:5
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作者 XIA Wen-xiang LI Jin-cheng SONG Zhi-wen SUN Ying-jie 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第12期1491-1495,共5页
Nutrient addition has been proved to be an effective strategy to enhance oil biodegradation in marine shorelines. To determine the optimal range of nutrient concentrations in the bioremediation of oil-polluted beaches... Nutrient addition has been proved to be an effective strategy to enhance oil biodegradation in marine shorelines. To determine the optimal range of nutrient concentrations in the bioremediation of oil-polluted beaches, nitrate was added to the simulated shoreline models in the initial concentration of 1, 5 and 10 mg/L. Whenever the NO3-N concentration declined to 70% of its original value, additional nutrients were supplemented to maintain a certain range. Results showed adding nutrients increased the oil biodegradation level, the counts of petroleum degrading bacteria (PDB) and heterotrophic bacteria (HB), and the promoted efficiency varied depending on the concentration of nitrate. Oil degradation level in 5 mg/L (NO3-N) group reached as much as 84.3% accompanied with the consistently highest counts of PDB; while in l mg/L group oil removal efficiency was only 35.2%, and the numbers of PDB and HB were relatively low compared to the other groups supplemented with nutrients. Although counts of HB in the 10 mg/L group were remarkable, lower counts of PDB resulted in poorer oil removal efficiency (70.5%) compared to 5 mg/L group. Furthermore, it would need more NO3-N (0.371 mg) to degrade 1 mg diesel oil in the 10 mg/L group than in the 5 mg/L group (0.197 mg). In conclusion, Nitrate concentration in 5 mg/L is superior to l and 10 mg/L in the enhancement of diesel oil biodegradation in simulated shorelines. 展开更多
关键词 diesel oil 0# BIOREMEDIATION nutrient concentration interstitial water
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Determination of triazine herbicide residues in water samples by on-line sweeping concentration in micellar electrokinetic chromatography 被引量:2
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作者 Shuai Hua Zhang Yuan Yuan Yang Dan Dan Han Chun Wang Xin Zhou Xiao Huan Zang Zhi Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2008年第12期1487-1490,共4页
A new method for the determination of atrazine, simazine and prometryn in water samples by on-line sweeping concentration technique in micellar electrokinetic chromatography (MEKC) was developed. Various parameters ... A new method for the determination of atrazine, simazine and prometryn in water samples by on-line sweeping concentration technique in micellar electrokinetic chromatography (MEKC) was developed. Various parameters affecting sample enrichment and separation efficiency were systematically studied. Compared with the conventional MEKC method, up to 60-200-fold improvement in concentration sensitivity was achieved in terms of peak height by using this sweeping injection technique. The compound strychnine was used as the internal standard for the improvement of the experimental reproducibility. The limits of detection (S/ N = 3:1) for atrazine, simazine and prometryn were 9, 10 and 0.5 ng mL-1, respectively. This method has been successfully applied to the analysis of atrazine, simazine and prometryn in lake, steam and ground water. 展开更多
关键词 Triazine herbicides On-line concentration MEKC SWEEPING water samples
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Synthesis of Water Utilization System Using Concentration Interval Analysis Method ( Ⅰ ) Non-Mass-Transfer-Based Operation 被引量:3
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作者 刘永健 袁希钢 罗祎青 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第3期361-368,共8页
A strategy for water and wastewater minimization is developed for continuous water utilization systems involving fixed flowrate(non-mass-transfer-based)operations,based on the fictitious operations that is introduced ... A strategy for water and wastewater minimization is developed for continuous water utilization systems involving fixed flowrate(non-mass-transfer-based)operations,based on the fictitious operations that is introduced to represent the water losing and/or generating operations and a modified concentration interval analysis(MCIA) technique.This strategy is a simple,nongraphical,and noniterative procedure and is suitable for the quick yields of targets and the identification of pinch point location.Moreover,on the basis of the target method,a heuristic-based approach is also presented to generate water utilization networks,which could be demonstrated to be optimum ones. The proposed approaches are illustrated with example problems. 展开更多
关键词 water minimization water utilization network targeting method concentration interval table
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Freeze Concentration of Proteins in Antarctic Krill Wash Water 被引量:1
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作者 QI Xiangming XU Jing +2 位作者 ZHAO Kuo GUO Hui MA Lei 《Journal of Ocean University of China》 SCIE CAS CSCD 2017年第6期1109-1114,共6页
Water-washing removes fluoride from Antarctic krill but produces large volumes of wash water containing water-soluble proteins and fluoride. The freeze concentration method was tested to determine if it could be used ... Water-washing removes fluoride from Antarctic krill but produces large volumes of wash water containing water-soluble proteins and fluoride. The freeze concentration method was tested to determine if it could be used to recover water-soluble proteins while leaving the fluoride in solution. After freezing and thawing the wash water, protein and fluoride contents of the thawed fractions were determined to explore the melting regularity of components in the wash water. The highest concentration factors of protein and fluoride were obtained after 80 min of thawing, such as 1.48 ± 0.06 and 1.35 ± 0.04 times, respectively. The free amino-nitrogen(FAN) content and sodium dodecyl sulfate-polyacrylamide gel electrophoresis pattern results revealed that the highest concentrations of all ingredients were obtained after 80 min of the process. The degree of hydrolysis of all fractions from the thawing process fluctuated in a narrow range around 12% during the entire process, indicating that the thawing order did not change with various proteins or time during the entire thawing course. These results demonstrate that the freeze concentration method can be used to concentrate protein solutions, even those with fluoride. It was concluded that condensation was achieved and no ingredient could be separated, regardless of fluoride, amino acids, or different proteins in the water. 展开更多
关键词 ANTARCTIC KRILL freeze concentration WASH water PROTEIN extraction FLUORIDE
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Suspended sediment concentration mapping based on the MODIS satellite imagery in the East China inland, estuarine, and coastal waters 被引量:2
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作者 YANG Xianping SOKOLETSKY Leomd +1 位作者 WEI Xiaodao SHEN Fang 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第1期39-60,共22页
The purpose of this research is to improve the retrieval accuracy for the suspended sediment concentration(SSC) from in situ and satellite remote sensing measurements in turbid East China estuarine and coastal waters.... The purpose of this research is to improve the retrieval accuracy for the suspended sediment concentration(SSC) from in situ and satellite remote sensing measurements in turbid East China estuarine and coastal waters. For this aim, three important tasks are formulated and solved: 1) an estimation of remote-sensing reflectance spectra R_(rs)(λ) after atmospheric correction; 2) an estimation of R_(rs)(λ) from the radiometric signals above the air-water surface; and 3) an estimation of SSC from R_(rs)(λ). Six different models for radiometric R_(rs)(λ) determination and 28 models for SSC versus R_(rs)(λ) are analyzed based on the field observations made in the Changjiang River estuary and its adjacent coastal area. The SSC images based on the above-mentioned analysis are generated for the area. 展开更多
关键词 ocean optics turbid estuarine and coastal waters remote-sensing reflectance suspended sediment concentration atmospheric correction
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Effect of water-sediment regulation and its impact on coastline and suspended sediment concentration in Yellow River Estuary 被引量:7
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作者 Hai-bo Yang En-chong Li +1 位作者 Yong Zhao Qiu-hua Liang 《Water Science and Engineering》 EI CAS CSCD 2017年第4期311-319,共9页
Implementation of the water-sediment regulation(WSR) scheme, mainly focused on solving the sedimentation problems of reservoirs and the lower reaches of the Yellow River, has inevitably influenced the sediment distrib... Implementation of the water-sediment regulation(WSR) scheme, mainly focused on solving the sedimentation problems of reservoirs and the lower reaches of the Yellow River, has inevitably influenced the sediment distribution and coastal morphology of the Yellow River Estuary.Using coastline delineation and suspended sediment concentration(SSC) retrieval methods, this study investigated water and sediment changes,identified detailed inter-annual and intra-annual variations of the coastline and SSC in the normal period(NP: 1986-2001, before and after the flood season) and WSR period(WSRP: 2002-2013, before and after WSR). The results indicate that(1) the sedimentation in the low reaches of the Yellow River turned into erosion from 2002 onward;(2) the inter-annual coastline changes could be divided into an accretion stage(1986-1996), a slow erosion stage(1996-2002), and a slow accretion stage(2002-2013);(3) an intra-annual coastline extension occurred in the river mouth in most years of the WSRP; and(4) the mean intra-annual accretion area was 0.789 km^2 in the NP and 4.73 km2 in the WSRP,and the mean SSC increased from 238 mg/L to 293 mg/L in the NP and from 192 mg/L to 264 mg/L in the WSRP. 展开更多
关键词 COASTLINE Suspended SEDIMENT concentration water-sediment REGULATION REMOTE sensing YELLOW River ESTUARY
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Long-term operation optimization of circulating cooling water systems under fouling conditions
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作者 Jiarui Liang Yong Tian +3 位作者 Shutong Yang Yong Wang Ruiqi Yin Yufei Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第1期255-267,共13页
Fouling caused by excess metal ions in hard water can negatively impact the performance of the circulating cooling water system(CCWS)by depositing ions on the heat exchanger's surface.Currently,the operation optim... Fouling caused by excess metal ions in hard water can negatively impact the performance of the circulating cooling water system(CCWS)by depositing ions on the heat exchanger's surface.Currently,the operation optimization of CCWS often prioritizes short-term flow velocity optimization for minimizing power consumption,without considering fouling.However,low flow velocity promotes fouling.Therefore,it's crucial to balance fouling and energy/water conservation for optimal CCWS long-term operation.This study proposes a mixed-integer nonlinear programming(MINLP)model to achieve this goal.The model considers fouling in the pipeline,dynamic concentration cycle,and variable frequency drive to optimize the synergy between heat transfer,pressure drop,and fouling.By optimizing the concentration cycle of the CCWS,water conservation and fouling control can be achieved.The model can obtain the optimal operating parameters for different operation intervals,including the number of pumps,frequency,and valve local resistance coefficient.Sensitivity experiments on cycle and environmental temperature reveal that as the cycle increases,the marginal benefits of energy/water conservation decrease.In periods with minimal impact on fouling rate,energy/water conservation can be achieved by increasing the cycle while maintaining a low fouling rate.Overall,the proposed model has significant energy/water saving effects and can comprehensively optimize the CCWS through its incorporation of fouling and cycle optimization. 展开更多
关键词 Computer simulation Circulating water system FOULING concentration cycle OPTIMIZATION Variable frequency drive
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Study on copper complexing ligand concentrations in several China's coastal waters
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作者 GONG Haidong ZHANG Zhengbin LIU Chunying LIU Liansheng 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2006年第1期64-77,共14页
Copper complexing ligand concentrations in the Daya Bay, Qingdao coast, Jiaozhou Bay, South China Sea and Huanghe Estuary waters were determined by the anodic stripping voltammetry technique. The distribution regulari... Copper complexing ligand concentrations in the Daya Bay, Qingdao coast, Jiaozhou Bay, South China Sea and Huanghe Estuary waters were determined by the anodic stripping voltammetry technique. The distribution regularity and the relationship with other parameters were discussed. The results were as follows: Copper complexing ligand concentrations of the South China Sea were a little higher than those of other sea areas, and they were apparently higher than those of the ocean. Compared with the subsurface layer (SSL) in the sea surface microlayer copper complexing ligand concentrations showed an enrichment phenomenon, of which the mechanism is similar to dissolved organic matter. The metal complexing ligand concentration profiles of the South China Sea showed that the value in the sea surface was the highest, then it decreased with depth accruing, and a higher value appeared at the bottom. Copper complex- ing ligand concentrations were higher than those of cadmium and lead. Ligands in each sea area exhibited a complicated property. In short, the distribution regularity of copper complexing ligand concentrations in China's coastal waters was consistent with that of other regions in the world. Meanwhile, the positive relationship between the copper complexing ligand concentrations and biological oxygen demand, chemical oxygen demand, dissolved organic carbon, and viscosity were found clearly. 展开更多
关键词 copper complexing ligand concentrations China' s coastal waters distribution regularity RELATIONSHIP
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Statistical characteristics of chlorophyll-a concentration in Hong Kong's coastal waters
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作者 CHEN Xiaoling, Yok Sheung Li, LI Zhilin(1. Dept. of Civil and Structural Engineering, The Hong Kong Polytechnic University, Hong Kong, China 2. National Laboratory for Information Engineering in Surveying, Mapping and Remote Sensing (LIESMARS), Wuhan Uni 《Journal of Geographical Sciences》 SCIE CSCD 2002年第3期331-342,共12页
In this paper seven of the ten Water Control Zones (WCZs) in Hong Kong's coastal waters with monthly or bi-weekly sampling data of 17 parameters collected at 37 monitoring stations from 1988 to 1999 were selected ... In this paper seven of the ten Water Control Zones (WCZs) in Hong Kong's coastal waters with monthly or bi-weekly sampling data of 17 parameters collected at 37 monitoring stations from 1988 to 1999 were selected to analyze the spatial and temporal variations of chlorophyll-a and its influencing factors. Cluster analysis was employed to group the monitoring stations based on the structure of the data set. Multiple step regression was employed to determine the significant influencing factors of chlorophyll-a level. The results suggest that all the monitoring stations could be grouped into two clusters. Cluster Ⅰ with frequent red tide incidents comprises two WCZs which are semi-enclosed bays. Cluster Ⅱ with less red tide occurrence comprises the other five WCZs in an estuarine environment in the west. For both clusters, the organic contents indicator, BODS, was a common significant influencing factor of the chlorophyll-a level. Nitrogen and light penetration condition related to turbidity, total volatile solids and suspended solids had more influence on the cholophyll-a level in Cluster Ⅰ than in Cluster Ⅱ, while phosphorus and oceanographic conditions associated with salinity, temperature, dissolved oxygen and pH were more important in Cluster Ⅱ than in Cluster Ⅰ. Generally, there was a higher average chlorophyll-a level in winter and autumn in a year. The chlorophyll-a level was much higher in Cluster Ⅰ than in Cluster Ⅱ among all seasons. Although the chlorophyll-a concentration had great variations from place to place in Hong Kong's coastal waters, it seemed to have a common long term fluctuation period of 8-10 years with a high-low-high variation in the period in the whole region, which might be influenced by other factors of global scale. 展开更多
关键词 Hong Kong's coastal waters chlorophyll-a concentration spatial-temporal variations
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Effect of elevated ambient CO_2 concentration on water use efficiency of Pinus sylvestriformis
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作者 韩士杰 张军辉 +3 位作者 王琛瑞 邹春静 周玉梅 王晓春 《Journal of Forestry Research》 SCIE CAS CSCD 1999年第4期209-210,共2页
Pinus Syvestfiformis is an important species as an indicator of global climate changes in Changbai Mountain, China. The water use efficiency (WUE) of this species (11 -year old ) was studied on response to elevated Co... Pinus Syvestfiformis is an important species as an indicator of global climate changes in Changbai Mountain, China. The water use efficiency (WUE) of this species (11 -year old ) was studied on response to elevated Co, concentration at 500±μLL' L-1 by directly injecting CO2 into the canopy under natural condition in 1998-1999. The results showed that the elevated Co, concentration reduced averagely stomatal opening, stomatal conductance and stomatal density to 78%, 80% and 87% respectively, as compared to normal ambient. The elevated Co, reduced the transpiration and enhances the water use efficiency (WUE) of plant. 展开更多
关键词 Pinus sylvestriformis water Use Efficiency (WUE) Elevated CO_2 concentration
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Influence of water vapor concentration on discharge dynamics and reaction products of underwater discharge within a He/H2O-filled bubble at atmospheric pressure
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作者 Shengran MA Wen YAN +3 位作者 Zhenhua BI Hongzhi WANG Ying SONG Dezhen WANG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2020年第8期129-136,共8页
In this study,a two-dimensional fluid model is proposed to simulate the underwater discharge in a He/H2O-filled bubble at atmospheric pressure.The molar fraction of water vapor is varied in the range of 0.01%-1%to inv... In this study,a two-dimensional fluid model is proposed to simulate the underwater discharge in a He/H2O-filled bubble at atmospheric pressure.The molar fraction of water vapor is varied in the range of 0.01%-1%to investigate the dependence of discharge dynamics and reaction products on water vapor concentration(WVC).The numerical results show that most properties of the discharge sensitively depend on the WVC.The increase of WVC leads to an increase in the electron density and discharge propagation velocity,which is attributed to Penning ionization between He*and H2O.The main positive ion switches from He+to H2O+,while the WVC increases from 0.01%to 1%.The dominant reactive oxygen species is OH,whose peak density is about two orders of magnitude higher than that of O.Besides,the densities of OH and O radicals increase with the increasing WVC.It is shown that the formation mechanism of O radicals is significantly affected by the WVC.The dominant reaction creating O radicals changes from the charge exchange between He2+and H2O to the electron impact dissociation of H2O as the WVC increases from 0.01%to 1%.This study is helpful for better understanding the application of non-thermal plasmas discharges in water,such as biomedical,environmental engineering. 展开更多
关键词 UNDERwater discharge water vapor concentration production and loss mechanisms fluid simulation
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Effects of water phase concentration on the emulsion polymerization of polyaniline
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作者 PAN Chun yue 1,CHEN Zhen hua 2,HUANG Yong li 1,HUANG Ke long 1 (1.College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China 2.Department of Materials Science and Engineering, Central South University, Cha 《Journal of Central South University of Technology》 2001年第2期140-142,共5页
The emulsion polymerization of aniline in three phase system of xylene functionalized protonic acid water was carried out using (NH 4) 2S 2O 4 as oxidant. The influences of water phase concentration on the viscosity, ... The emulsion polymerization of aniline in three phase system of xylene functionalized protonic acid water was carried out using (NH 4) 2S 2O 4 as oxidant. The influences of water phase concentration on the viscosity, conductivity, transmittance of polyaniline(PAN) latex and its powders were studied. The results show that the properties of PAN prepared through the emulsion polymerization are influenced by the amount of water used in the polymerization. The morphology of PAN varies with the water phase concentration used in the polymerization, which may result in the change of properties of PAN latex and its powders. When the volume fraction of water (φ) is about 20% 30%, the prepared PAN powder has higher conductivity, and the PAN latex has appropriate viscosity and particle size. The consumption of xylene was reduced at high φ value. 展开更多
关键词 POLYANILINE emulsion polymerization water concentration PROPERTY
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Agrochemical Concentration Level in Zaria Dam Reservoir and Ground Waters in the Environs
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作者 J. A. Tanko E. A. Oluwadamisi I. Abubakar 《Journal of Environmental Protection》 2012年第2期225-232,共8页
This study examines the effect of agrochemical used for faming in the Galma Dam area on the quality of water in the reservoir and well water around the reservoir. Nine sampling points upstream of the Galma Dam were ra... This study examines the effect of agrochemical used for faming in the Galma Dam area on the quality of water in the reservoir and well water around the reservoir. Nine sampling points upstream of the Galma Dam were randomly se- lected for the study. Also, six hand dug wells in use by adjacent communities were identified for ground water samples. The study covered the period July to September 2011. All measurements were in accordance with the Standard Methods for the Examination of Water and Wastewater. The parameters measured and their mean concentrations from the reser- voir are in the order of: Chlorides (0.600 - 0.900 mg/l);Nitrates (0.009 - 0.019 mg/l);Bicarbonates;0.444 - 1.900 mg/l);Total Phosphates (0.173 - 3.077 mg/l);Sulphates (0.617 - 3.587 mg/l);and pH (6.4 - 7.5). For the well water samples, the results ranged from 1.58 - 3.10 mg/l;0.14 - 0.03 mg/l;0.60 - 2.73 mg/l;0.08 - 1.89 mg/l;0.33 - 2.66 mg/l and 6.05 - 7.0 respectively in the order previously listed. The results were statistically analyzed using ANOVA at 95% confidence level. Chlorides showed no significant variation between sampling points but significant variation with dates of sam- pling for surface and well waters. Nitrates variations with both sampling points and dates of sampling were insignificant. Bicarbonates variations with sampling points and dates of sampling were highly significant. Total Phosphates and Sul- phates variations with sampling points and dates of sampling were insignificant and significant respectively. pH values variations with sampling points and dates of sampling were insignificant and highly significant respectively. Generally, the mean concentrations are within the WHO maximum limits of the parameters in drinking water and recommenda- tions were made regarding the use of agrochemicals for farming in the area. 展开更多
关键词 Surface and GROUND water Qualities Agrochemicals Mean concentration LEVELS
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Levels of Radon Activity Concentration in Thermal Waters of Bosnia and Herzegovina 被引量:1
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作者 Amela Kasic Ema Hankic Amira Kasumovic Feriz Adrovic 《材料科学与工程(中英文B版)》 2013年第8期539-544,共6页
关键词 放射性氡 波斯尼亚 温泉水 浓度 活度 放射性气体 环境保护局 健康问题
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Effects of Ionic Concentrations on Survival and Growth in Polyculture of Litopenaeus vannamei with Oreochromis niloticus in Low Salinity Water
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作者 K. Limhang C. Limsuwan +1 位作者 N. Chuchird W. Taparhudee 《Journal of Agricultural Science and Technology(A)》 2011年第8期1217-1220,共4页
A study comparative of rearing of the Pacific white shrimp (Litopenaeus vannamei) with the Nile tilapia (Oreochromis niloticus) in three earthen ponds (5,600 m^2) with the salinity ranged from 0.5-1.2 ppt and th... A study comparative of rearing of the Pacific white shrimp (Litopenaeus vannamei) with the Nile tilapia (Oreochromis niloticus) in three earthen ponds (5,600 m^2) with the salinity ranged from 0.5-1.2 ppt and three treatment ponds with salinity of 2-4 ppt by adding brine water into the ponds. Postlarvae 12 (PL12) of L. vannamei were stocked at density of 9 PL/m^2 and after one week the Nile tilapia fingerlings were stocked at density of I fish/m^2. Only pelleted feed were given to the fish during the 196-day rearing period. Shrimps were partially harvested by sieve net at day 80 and 120, and five days later PLI2 were stocked at the rate of 3 PL/m^2. After final harvesting at day 196, the production, body weight and survival from the treatment group were significantly higher (P 〈 0.05) than those of the control group. While the fish production body weight and survival rate from both groups were not significant differences (P 〉 0.051). The ionic concentration of six major ions (CI, SO42, Ca^2+, Na^+, Mg^2+ and K^+), salinity and hardness in the treatment ponds were significantly higher than those of the control ponds (P 〈 0.05). Moreover, the ionic profiles of the treatment ponds were similar to seawater at the salinity of 2 ppt while only 1 ppt in the control ponds. Results from the study indicated that in order to achieve good growth and survival rate of L. vannamei, brine water should be added into grow-out ponds prior to stocking and during the rearing: period to obtain and maintain the salinity not less than 2 ppt. 展开更多
关键词 Litopenaeus vannamei Oreochromis niloticus POLYCULTURE ionic concentration low salinity water
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Autonomous Changes in the Concentration of Water Vapor Drive Climate Change
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作者 William A. Van Brunt 《Atmospheric and Climate Sciences》 2020年第4期443-508,共66页
When compared to the average annual global temperature record from 1880, no published climate model posited on the assumption that the increasing concentration of atmospheric carbon dioxide is the driver of climate ch... When compared to the average annual global temperature record from 1880, no published climate model posited on the assumption that the increasing concentration of atmospheric carbon dioxide is the driver of climate change can accurately replicate the significant variability in the annual temperature record. Therefore, new principles of atmospheric physics are developed for determining changes in the average annual global temperature based on changes in the average atmospheric concentration of water vapor. These new principles prove that: 1) Changes in average global temperature are not driven by changes in the concentration of carbon dioxide;2) Instead, autonomous changes in the concentration of water vapor, <span style="white-space:nowrap;">Δ</span>TPW, drive changes in water vapor heating, thus, the average global temperature, <span style="white-space:nowrap;">Δ</span>T<sub>Avg</sub>, in accordance with this principle, <span style="white-space:normal;"><span style="white-space:nowrap;">Δ</span>T</span><span style="white-space:normal;"><sub>Avg</sub>=0.4<span style="white-space:normal;"><span style="white-space:nowrap;">Δ</span>TPW </span></span>the average accuracy of which is ±0.14%, when compared to the variable annual, 1880-2019, temperature record;3) Changes in the concentration of water vapor and changes in water vapor heating are not a feedback response to changes in the concentration of CO<sub>2</sub>;4) Rather, increases in water vapor heating and increases in the concentration of water vapor drive each other in an autonomous positive feedback loop;5) This feedback loop can be brought to a halt if the average global rate of precipitation can be brought into balance with the average global rate of evaporation and maintained there;and, 6) The recent increases in average global temperature can be reversed, if average global precipitation can be increased sufficiently to slightly exceed the average rate of evaporation. 展开更多
关键词 Carbon Dioxide Climate Change water Vapor Global Warming DRIVER Average Global Temperature Change in concentration water Vapor water Vapor Heating
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Radon (<sup>222</sup>Rn) Concentration in Fresh and Processed Coconut Water Using a RAD7 Detector
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作者 Orville N. Bignall Tyona Caldwell 《Natural Science》 2021年第9期425-436,共12页
Coconut water has several uses that are beneficial to humans, mainly because of its nutritional and medicinal properties. In this study coconut water samples were collected from the fresh mature coconuts and from pack... Coconut water has several uses that are beneficial to humans, mainly because of its nutritional and medicinal properties. In this study coconut water samples were collected from the fresh mature coconuts and from packaged processed coconut water to measure the radon concentrations in them. The results were used to estimate the annual effective radiation dose to the general adult population from ingestion of coconut water. The samples were analyzed for radon concentrations using the Durridge RAD-7 radon detector. The results of measured radon concentrations for the fresh mature coconut were ranged from 381.10 Bq·m<span lang="EN-US" style="font-size:9pt;font-family:Tahoma, sans-serif;"><sup>-3</sup></span> to 1716.80 Bq·m<span lang="EN-US" style="font-size:9pt;font-family:Tahoma, sans-serif;"><sup>-3</sup></span>. The results for packaged processed coconut samples ranged from 68.08 Bq·m<span lang="EN-US" style="font-size:9pt;font-family:Tahoma, sans-serif;"><sup>-3</sup></span> to 556.85 Bq·m<span lang="EN-US" style="font-size:9pt;font-family:Tahoma, sans-serif;"><sup>-3</sup></span>. The mean values for the samples were (1081.40 and 222.78) Bq·m<span lang="EN-US" style="font-size:9pt;font-family:Tahoma, sans-serif;"><sup>-3</sup></span> for the fresh and processed samples, respectively. The estimated mean annual effective doses (AED) due to ingestion of coconut water were 0.41 and 0.08 μSv·y<span lang="EN-US" style="font-size:9pt;font-family:Tahoma, sans-serif;"><sup>-1</sup></span> for fresh and processed samples, respectively. These values are significantly lower than the safe limits recommended by the World Health Organization and the European Commission of 0.1 mSv·y<span lang="EN-US" style="font-size:9pt;font-family:Tahoma, sans-serif;"><sup>-1</sup></span> and the maximum contamination level (MCL) of 11,000 Bq·m<span lang="EN-US" style="font-size:9pt;font-family:Tahoma, sans-serif;"><sup>-3</sup></span> by the United States Environmental Protection Agency and so do not constitute a risk to consumers of coconut water. 展开更多
关键词 Coconut water Radon concentration Cancer RAD7
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Zoning of Nitrite and Nitrate Concentration in Groundwater Using Geografic Information System (GIS), Case Study: Drinking Water Wells in Yazd City
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作者 Reza Ali Fallahzadeh Seyed Ali Almodaresi +6 位作者 Mohamad Mehdi Dashti Ahmad Fattahi Mojtaba Sadeghnia Hadi Eslami Rasoul Khosravi Roya Peirovi Minaee Mahmoud Taghavi 《Journal of Geoscience and Environment Protection》 2016年第3期91-96,共6页
Studies have demonstrated that the presence of nitrate and nitrite in drinking water can cause some disease such as cancer and blu baby in the infant. The Environmental Protection Agency (EPA) has since adopted the 10... Studies have demonstrated that the presence of nitrate and nitrite in drinking water can cause some disease such as cancer and blu baby in the infant. The Environmental Protection Agency (EPA) has since adopted the 10 mg/L standard as the maximum contaminant level (MCL) for nitrate-nitrogen and 1 mg/L for nitrite-nitrogen for regulated public water systems. Given the importance of nitrate and nitrite in drinking water as well as GIS ability in spatial analysis of various factors in the groundwater, this study aimed to evaluate concentration of nitrate and nitrite in the drinking water wells of Yazd using two IDW (Inverse Distance Weighting) and Kriging models. In this descriptive study, the applied data on the water quality of underground water of Yazd Environmental Health Office and the average annual nitrate and nitrite in 2015 were related to 24 wells in the studied area. The nitrate and nitrite rate in groundwater in wells was compared to the standard amount of Institute of Standard and Industrial Researches and then was analyzed via Arc GIS software using IDW and Kriging interpolation methods. The mean concentration of nitrate was 17.62 ± 3.08 mg/l and for nitrite was 0.011 ± 0.003 mg/l in the wells. In the all studied zone, the nitrate and nitrite rate was in the standard range according to the National Standard of Iran (No. 1053). In this study, Kriging interpolation method was more efficient than IDW method. 展开更多
关键词 Drinking water Nitrite and Nitrate concentration Geographic Information Systems INTERPOLATION
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