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Effects of Different Padding on Air Quality in Broiler House and Growth Physiological Index of Broilers 被引量:1
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作者 刘雪兰 张燕 +5 位作者 阎佩佩 井庆川 魏祥法 刘瑞亭 石天虹 武彬 《Agricultural Science & Technology》 CAS 2015年第12期2764-2769,共6页
[Objective] This study aimed to investigate the effects of different padding on ammonia concentration in broiler house and growth performance and blood indi- cators of broilers. [Method] A total of 480 one-day-old 817... [Objective] This study aimed to investigate the effects of different padding on ammonia concentration in broiler house and growth performance and blood indi- cators of broilers. [Method] A total of 480 one-day-old 817 broilers were selected. They were randomly divided into four groups with different paddings, and each group was in triplicate. The weights of broilers and feed were weighed weekly. The growth performance of broilers was determined. On day 30, the ammonia concentra- tions in broiler houses were determined. On day 35, 6 broilers were randomly se- lected from each group, and their vein blood was sampled. In the sampled vein blood, the concentrations of ammonia, glucose, globulin, serum total protein and urea nitrogen were determined. [Result] There were significant differences in ammo- nia concentration among broiler houses laid with different paddings (P〈0.05). The ammonia concentration in group 1 was significantly lower than those in group 3 and group 4 (P〈0.05). No significant difference was found in ammonia concentrations in broiler houses between group 2 and group 3 (P〉0.05). The ammonia concentration in group 4 was significantly higher than those in group1, group 2 and group 3 (,0〈 0.05). There were also significant differences in blood indicators among different groups (P〈0.05). The blood ammonia, blood glucose and serum urea nitrogen con- centrations in group 1 were significantly lower than those in other groups (P〈0.05), the serum total protein concentration was significantly higher than those in group 3 and group 4 (P〈0.05), and the serum globulin concentration was significantly higher than those in group 2, group 3 and group 4 (P〈0.05). Significant differences were observed in feed intake, body weight gain and slaughter weight between different groups (P〈0.05), but there were no significant differences in feed to grain ratio (P〉 0.05). [Conclusion] Under the experimental conditions, the padding of Chinese medicine residue showed better effect on reducing ammonia concentration in broiler house, which was conducive to play of production potential of broilers. 展开更多
关键词 Chinese medicine residue PADDING Ammonia concentration Production performance Blood indicators
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关于理想气体反应K~■_c的特殊性和K~■_c应用于过渡态理论中错误的纠正
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作者 周中行 《浙江化工》 CAS 2018年第5期20-24,共5页
主要论述理想气体分别在等温等压下反应和在等温等容下反应的标准平衡常数K~■分别选择不同浓标P~■,C~■时四种不同标准平衡常数对温度变化响应的差异性,由此看出K~■_c的特殊性。进行了严密的理论推导,并深入分析了造成这种差异的原... 主要论述理想气体分别在等温等压下反应和在等温等容下反应的标准平衡常数K~■分别选择不同浓标P~■,C~■时四种不同标准平衡常数对温度变化响应的差异性,由此看出K~■_c的特殊性。进行了严密的理论推导,并深入分析了造成这种差异的原因。并对四种不同标准平衡常数在过渡态理论的应用中得出的四种活化能和四种速率常数长期以来的错误进行了纠正。 展开更多
关键词 准平衡常数 范特霍夫方程 浓标 等压 等容 过渡态 速率常数 活化能
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Tissue-specific bioaccumulation and oxidative stress responses in juvenile Japanese flounder (Paralichthys olivaceus) exposed to mercury 被引量:8
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作者 黄伟 曹亮 +3 位作者 叶振江 林龙山 陈全震 窦硕增 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第4期569-579,共11页
To understand mercury (Hg) toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder (Paralichthys olivaceus) and assessed the effects on growth and antioxidant responses. After Hg exposu... To understand mercury (Hg) toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder (Paralichthys olivaceus) and assessed the effects on growth and antioxidant responses. After Hg exposure (control, 5, 40, and 160 gg/L Hg) for 28 d, fish growth was significantly reduced. The accumulation of Hg in fish was dose-dependent and tissue-specific, with the maximum accumulation in kidney and liver, followed by gills, hone, and muscle. Different antioxidants responded differently to Hg exposure to cope with the induction of lipid peroxidation (LPO), which was also tissue-specific and dose- dependent. As Hg concentration increased, superoxide dismutase (SOD) and catalase (CAT) activities increased significantly, whereas glutathione S-transferase (GST) activity and glutathione (GSH) levels decreased significantly in the gills. SOD and glutathione peroxidase (GPx) activities and the GSH level increased significantly in the liver. SOD activity and GSH levels increased significantly, but CAT activity decreased significantly with an increase in Hg concentration in the kidney. LPO was induced significantly by elevated Hg in the gills and kidney but was least affected in the liver. Therefore, oxidative stress biomarkers in gills were more sensitive than those in the liver and kidney to Hg exposure. Thus, the gills have potential as bioindicators for evaluating Hg toxicity in juvenile flounder. 展开更多
关键词 mercury (Hg) ANTIOXIDANTS lipid peroxidation bioaccumulation of metal
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Distribution of nutrients and eutrophication assessment in the Bohai Sea of China 被引量:23
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作者 王修林 崔正国 +2 位作者 郭全 韩秀荣 王江涛 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2009年第1期177-183,共7页
Water samples were collected in 120 stations in the Bohai Sea of China to analyze the distribution of dissolved nutrients and assess the degree of eutrophication in August 2002. The result shows that the average conce... Water samples were collected in 120 stations in the Bohai Sea of China to analyze the distribution of dissolved nutrients and assess the degree of eutrophication in August 2002. The result shows that the average concentration of DIN increased and the PO4-P concentration sharply decreased compared to the previous data of corresponding period. The high concentrations of DIN and PO4-P occurred in coastal waters, especially in the bays and some river estuaries, while the high concentrations of SiO3-Si in the surface and middle depth occurred in the central area of the Bohai Sea. The average ratio of DIN/PO4-P was much higher than the Redfield Ratio (16:1). Apparently, PO4-P was one of the limiting nutrient for phytoplankton growing in the sea. The average concentrations of DON and DOP were higher than their inorganic forms. The results of eutrophication assessment show that 22.1% of all stations were classified as violating the concentration levels of the National Seawater Quality Standard (GB 3097-1997) for DIN and only 3.9% for PO4-R The average eutrophication index in the overall area was 0.21±0.22 and the high values occurred in Bohai Bay, Liaodong Bay and near the Yellow River estuary. This means that the state of eutrophication was generally mesotrophic in the Bohai Sea, but relatively worse in the bays, especially some river estuaries. 展开更多
关键词 eutrophication aassessment NUTRIENTS DISTRIBUTION Bohai Sea
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Effects of benzo(a)pyrene exposure on the antioxidant enzyme activity of scallop Chlamys farreri 被引量:4
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作者 潘鲁青 任加云 郑德斌 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2009年第1期43-53,共11页
Scallop Chlamys farreri was exposed to different concentrations of benzo(a)pyrene (BaP) (0.5 μg/L, 1.0 μg/L, 10.0 μg/L and 50.0 μg/L) for 30 days in seawater. The 7-ethoxyresorufin O-deethylase (EROD) activity was... Scallop Chlamys farreri was exposed to different concentrations of benzo(a)pyrene (BaP) (0.5 μg/L, 1.0 μg/L, 10.0 μg/L and 50.0 μg/L) for 30 days in seawater. The 7-ethoxyresorufin O-deethylase (EROD) activity was significantly induced, and increased with the increasing BaP concentration. The glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), Glutathione peroxidase (GPx) activities increased in short time at low concentration of BaP, and was significantly depressed at high concentrations. Scallop gill was more sensitive to BaP than the digestive gland, and the digestive gland was the main tissue to deal with oxyradicals. The contents of malondialdehyde (MDA) increased with the exposure time and there was a positive correlation (concentration-effect) between the MDA content and the concentration of BaP. The biomarkers determined in this experiment had important roles in detoxification, and showed great potential as biomarkers for oxidative stress. Controlled laboratory experiments designed to simulate field exposure scenarios are particularly useful in ascertaining biomarkers suitable for use with complex contaminant mixtures in the marine environment. 展开更多
关键词 benzo(a)pyrene Chlamysfarreri biomarkers BIOTRANSFORMATION detoxification mechanism
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The Relationship between Major Components of PM2.5 and Meteorological Factors in Urban Tokyo, Japan
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作者 Ping Li Hideo Hasegawa 《Journal of Environmental Science and Engineering(B)》 2017年第1期27-33,共7页
In this research, the main purpose is to estimate the variation of PM2.5 mass concentration and study the influence of meteorological characteristics on major components of PM2.5 concentrations in urban Tokyo, Japan. ... In this research, the main purpose is to estimate the variation of PM2.5 mass concentration and study the influence of meteorological characteristics on major components of PM2.5 concentrations in urban Tokyo, Japan. The results shown that the annual mean mass concentration of PM2.5 in urban Tokyo was higher than JEQS (Japanese Environmental Quality Standard) of the MOEJ (Ministry of the Environment Japan) (15 μg/m^3), and 41.1% of the daily PM2.5 mass concentration exceeded the annual JEQS concentration during observation period. The major components of PM2.5 including SO4^2-, NO3^-, NH4^+, OC and EC were tightly related to the meteorological conditions, the correlations results shown that the wind speed and relative humidity had significant correlations with major components of PM2.5 than the other meteorological factors. Higher relative humidity, windless and less rainfall conditions were favorable for elimination of PM2.5 concentration. Higher temperature was beneficial to the formation of SO42", but higher temperature and stronger sunshine duration were not conducive to the formation of NO3^-. 展开更多
关键词 PM2.5 major components meteorological factors.
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Effect of Sources and Concentrations of Soybean Phosphatidylcholine on Diluted Goat Semen Equilibrated at 4 ℃ 被引量:1
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作者 N. Phutikanit E. Sangkrachang J. Suwimonteerabutr J. Singlor 《Journal of Agricultural Science and Technology(A)》 2011年第8期1170-1173,共4页
The objective of the present study was to determine the proper sources and concentrations of soybean lecithin (phosphatidylcholine, PC) to be used as substitute for hen egg yolk in extender for preserving goat semen... The objective of the present study was to determine the proper sources and concentrations of soybean lecithin (phosphatidylcholine, PC) to be used as substitute for hen egg yolk in extender for preserving goat semen. Two sources of soybean lecithin (20% and 95% soybean phosphatidylcholine; PC20 and PC95) and three concentrations (1%, 2% and 3% v/v) of PC20 and PC95 supplemented in Tris-citric acid-fructose (TCF) extender were tested. The TCF extender supplemented with 20% hen egg yolk was used as a control. Fresh semen samples were collected from 3 goats by artificial vagina. Seminal plasma was removed by centrifugation and sperm pellets were pooled together and divided into 7 groups according to types of extender. The diluted semen samples were kept at 4 ℃ (equilibration). The semen qualities including progressive motility, sperm viability, sperm plasma membrane integrity and tail abnormalities were evaluated before dilution and after 4 hrs equilibration. It was found that the progressive motility of equilibrated semen in egg yolk and PC20 extenders were higher than those in PC95 extender (P 〈 0.05). Sperm viability was lower in 1% and 2% PC95 extender compared to other extenders (P 〈 0.05). PC20 extender maintained the sperm membrane integrity and normal tail morphology at low temperature better than egg yolk and PC95 (P 〈 0.05). It can be concluded that 20% soybean phosphatidylcholine supplemented in TCF extender at 1%-3% (v/v) is as effective as hen egg yolk to preserve goat semen during equilibration at 4 ℃ for 4 hrs . 展开更多
关键词 Goat semen semen extender soybean lecithin PHOSPHATIDYLCHOLINE EQUILIBRATION
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Air Quality Legislation and Standards in the European Union: Background, Status and Public Participation 被引量:4
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作者 Marco GEMMER XIAO Bo 《Advances in Climate Change Research》 SCIE 2013年第1期50-59,共10页
In order to improve air quality, the European Union introduced the New Air Quality Directive in 2008 and set its Member States strict targets on air pollution concentrations for the most harmful and challenging substa... In order to improve air quality, the European Union introduced the New Air Quality Directive in 2008 and set its Member States strict targets on air pollution concentrations for the most harmful and challenging substances, such as fine particles. The law enforcement relies on a monitoring and reporting system to inform the European Commission and the public, for it is the citizens' right to be informed about harmful air quality. With sectoral measures, air quality could be improved in the past 20 years, but some emissions concentrations have stagnated in recent years and emissions temporarily exceed thresholds in nearly half of the Member States. The European Emission Inventory allows the commission to identify the substances, areas, and times of exceedances, and to implement sectoral measures leading to air quality improvements, all of which have to be made available publicly. This manuscript introduces the air quality legislation and reviews the quality of European air for recent years. 展开更多
关键词 air quality European Union public participation standards
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Chemical Contamination and Radiological Risk Assessment of Water Sources in Richards Bay
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作者 Felix. B. Masok Paulus L. Masiteng +1 位作者 Risimati D. Mavunda Peane P. Maleka 《Journal of Physical Science and Application》 2016年第5期8-13,共6页
South Africa is pronounced a dry country. Though KwaZulu-Natal has a higher rain fall than most part of the country, it has recorded cases of austere droughts. The present study was aimed at examining the quality of w... South Africa is pronounced a dry country. Though KwaZulu-Natal has a higher rain fall than most part of the country, it has recorded cases of austere droughts. The present study was aimed at examining the quality of water within Richards Bay precinct in relation to South African target water quality range (TWQR). Fifty water samples were collected from five water sources (effluent, stream, Mzingazi River, Indian Ocean and Esikawini drinking tap water) and analyzed using ICP-MS technique to determine the concentrations of some traced metals i.e., Fe, Cu, T1, Zn, Pb, Cr, and Ni. The main impurities were found to be Cd, Mn and As with concentrations of 2.21 × 10^0mg. l-1, 7.19 × 10-1mg.l-1and 2.72 ×10-3mg. 1-1 respectively. The surface gross alpha contamination of mineral stores within the facilities ranges from 1.00 × 10-4 ± 1.5 × 10-2 Bq.cm-2 to 1.45× 10-2 ±4.20 ×10-3Bq.cm-2 with a mean concentration of 1.15 × 10-2 ±1.36 ×10-2Bq.cm-2while the gross beta contamination ranges from 1.00 ×10-3 ± 1.14 × 10-ZBq, cm-2 to 4.15 × 10-2 ± 2.17 × 10-2Bq. cm-2 with a mean concentration of 2.15 ×10-2 ±1.80×10-2Bq. cm-2. The result indicated that the water quality was acceptable. 展开更多
关键词 Water heavy metals contamination.
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Radial Non-uniformity Index Research on High-density,High-flux CFB Riser with Stratified Injection 被引量:3
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作者 Geng Qiang Wang Lu +3 位作者 Li Zhichao Li Chunyi Liu Yibin You Xinghua 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第4期64-72,共9页
A high-density, high-flux circulating fluidized bed (CFB) riser (100 mm in ID and 10.614 m in height) was ap- plied in a wide range of operating conditions (with solid fluxes up to 400 kg/m2s and superficial gas ... A high-density, high-flux circulating fluidized bed (CFB) riser (100 mm in ID and 10.614 m in height) was ap- plied in a wide range of operating conditions (with solid fluxes up to 400 kg/m2s and superficial gas velocities up to 12 m/s) to examine its radial non-uniformity dynamics. The solids holdup was determined through the use of a fiber-optic probe at 11 axial levels. The results indicated that under all operating conditions, the high superficial gas velocity and low solid flux- es maintained a low radial non-uniformity index (RNI). The high-density/flux CFB riser had several unique characteristics, so that the peak of the radial solids holdup profile occurred at a position with r/R=0.8. The RNI and solids holdup at the cross-sectional position had a good logarithmic relationship at the low-density condition (with a mean solids holdup of 〈0.2), and the RNI decreased when the mean solids holdup exceeded 0.2. Investigation of the dynamics of stratified injec- tion revealed that the feed ratio had an important effect on G, and on solids holdup distribution. A novel "〈" shaped axial solids holdup profile was found. Gs decreased sharply when the up-flow feed ratio exceeded 0.5, and RNI was lowest when the up-flow feed ratio was 1. 展开更多
关键词 fluidization high density/flux CFB riser radial non-uniformity index stratified injection feed ratio
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Heavy metals accumulation effect in rabbit body fluids after smoking 被引量:2
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作者 钟狂飚 桂明 +3 位作者 朱立勇 李维 管茶香 郭方遒 《Journal of Central South University》 SCIE EI CAS 2011年第5期1408-1412,共5页
Concentration of heavy metals in blood and urine of rabbit after inhaling three different kinds of cigarette was studied through the animal passive smoking pattern. The samples were prepared by nitric acid solution di... Concentration of heavy metals in blood and urine of rabbit after inhaling three different kinds of cigarette was studied through the animal passive smoking pattern. The samples were prepared by nitric acid solution digestion and determination of seven kinds of heavy metals including Hg, Se, Sn, Pb, Cd, Ni and Cr was performed by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The ICP-AES method was established with good precision and accuracy, relative standard deviation (n=6) was between 2.9% and 5.9%, and the recovery was in the range of 95.0%-104.2%. Concentration of six heavy metals increases in some extent in blood and urine after period of smoking and the increasing of heavy metals in blood and urine all shows time dependence. Significantly higher heavy metal levels are observed in the blood and urine of the cigarette inhaling rabbits in the exposed group. The concentration of six kinds of heavy metals in the blood of the rabbit increases after 16 weeks exposing to cigarette smoking. Three times of rig, ten times of Se and trace amount ofPb, Cd, Ni and Cr are detected in the blood after 16 weeks of smoking. For urine samples, about three times of Hg, two times of Se, five times of Pb and trace amount of Cd are detected after 16 weeks of inhalation of cigarette. Comparatively, higher concentration of heavy metals are detected after inhaling of Nise cigarette. 展开更多
关键词 inductively coupled plasma-atomic emission spectrometry BLOOD URINE heavy metal element
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Electrochemical Determination of Dapoxetine HCI in Biological Fluids Using Coated Wire Electrode
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作者 Amani Salim Alturiqi 《Journal of Chemistry and Chemical Engineering》 2016年第6期277-282,共6页
Coated wire sensor for potentiometric determination ofDAP (dapoxetine HCI) in pure form and in biological fluidsbased on DAP-TPB (dapoxetine-tetraphenyl borate) as the sensing element in the presence of DOP (dioc... Coated wire sensor for potentiometric determination ofDAP (dapoxetine HCI) in pure form and in biological fluidsbased on DAP-TPB (dapoxetine-tetraphenyl borate) as the sensing element in the presence of DOP (dioctylphthalate) as the plasticizing solvent mediator was prepared. The best performance was obtained with a membrane composition of 10.0% (w/w) ion-pair, 45.0% DOP (w/w) and 45.0% PVC (w/w). The electrode showed a Nemstian response (with a slope of 58.70 mV decade-1) for the concentration range of 4.2 × 10-5-1.0 ×10-2 mol/L. It illustrates a relatively fast response time in the whole concentration range (-15 s) in a pH range of 3.0-7.5. The selectivity coefficients were determined in relation to several inorganic and organic species. DAP is determined successfully in pure solutions and in biological fuids using the standard additions and petentiometric titrations methods. 展开更多
关键词 DAP coated wire electrode biological fluids.
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Spectrophotometric Error Due to Uncertainty in Reading the Signal
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作者 Mavroudis A. Demertzis Anastasios I. Palios Alexandru V. Calin Cristina-Ioana M. Vijdeluc George A.Chrysafis 《Journal of Chemistry and Chemical Engineering》 2012年第7期585-590,共6页
Based upon the standard deviations for the intercept and the slope of a linear regression line, as well as by differentiating both Beer's law and a linear relationship between transmittance and concentration at high ... Based upon the standard deviations for the intercept and the slope of a linear regression line, as well as by differentiating both Beer's law and a linear relationship between transmittance and concentration at high transmission, it is proved that the relative spectrophotometric error of a measurement becomes greater as the sample concentration only decreases. Further, it is demonstrated that the present knowledge with regard to the error in absorption spectrophotometry is necessary to be reexamined. The total scale of transmittance can literally be used for measurements, unfolding workable dynamic ranges about two orders of magnitude lower than usually and thus absorption spectrophotometry can efficiently compete with other methods of analysis with respect to detection limits. 展开更多
关键词 Spectrophotometric error transmittance uncertainty sensitive spectrophotometry transmittance noise.
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Analysis of Nitrates and Nitrites in Groundwater of Ilorin Environs
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作者 Oluwadurotimi O. Akiwumi Omodele. A. Eletta Oluyemi Odebunmi 《Journal of Environmental Science and Engineering(A)》 2012年第5期656-662,共7页
The levels of nitrates and nitrites in drinking water from two local government areas in Ilorin, Kwara State were determined using HACH DR/EL 5 Spectrnphotometer over a period of four months. The average mean concentr... The levels of nitrates and nitrites in drinking water from two local government areas in Ilorin, Kwara State were determined using HACH DR/EL 5 Spectrnphotometer over a period of four months. The average mean concentration of nitrate (NO3-N) in borehole is 0.185 mg/L and for nitrites (NO2-N) is 0.044 mg/L. The mean concentration in well for the nitrate (NOs-N) is 0.915 mg/L and for nitrites is 0.087 mg/L. The observed means as well as the highest single-point values for both nitrates and nitrites in groundwater are well below WHO (World Health Organisation) MCL (maximum contaminant level) of 10.0 mg/L nitrate as NO3-N and 3.0 mg/L nitrite as NO2-N. The values are also below the NSDWQ's (Nigerian Standard for Drinking Water Quality) maximum permitted level of 50 mg/L nitrate as NO3-N and 0.2 mg/L nitrite as NO2-N. 展开更多
关键词 NSDWQ METHEMOGLOBINEMIA BOREHOLES wells MCL (maximum contaminant level).
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Technical Procedure Determination of Thoron Indoor Concentration by LR-115 Type II
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作者 Nguyen Thi Thu Ha Frinh Van Giap Le Dinh Cuong 《Journal of Environmental Science and Engineering(B)》 2016年第3期109-114,共6页
Thoron (Rn-220) is an invisible, odorless radioactive gas and nine times heavier than air. Purpose of project is to set up procedure to determine Rn-220 concentration which has been carried out in laboratory using S... Thoron (Rn-220) is an invisible, odorless radioactive gas and nine times heavier than air. Purpose of project is to set up procedure to determine Rn-220 concentration which has been carried out in laboratory using Solid State Nuclear Track Detector (SSNTD) based passive detector technique. In this study, technical procedure has been applied in Karlsruhe diffusion chamber and LR-115, Type II strippable (Kodak Pathe, France) detector. The results have investigated how LR-115 work for Rn-220 by using Monazite ore to simultaneously measure Rn-222 and Rn-220. To carry out experiment, Karlsruhe diffusion chamber is used to with and without Poly-Ethylene (PE) membrane. Karlsruhe diffusion chamber with PE membrane only detect Rn-222, without PE membrane detect total Rn-222 and Rn-220. Precision evaluation by duplicate measure at 8 cm detector-source distance with relative standard deviation is less than 2.54%. Testing technical procedure, detectors have been sent to National Institute of Radiological Science (NIRS) for Rn-220 calibration exposure. After detectors have been calibration exposure at NIRS, it carried out all the following steps of procedure which set up at laboratory in 1NST, Vietnam. Finally, calibration factor calculated is 0.21 (tracks-cm2/Bq·m3·h) and constructed curve between integrated Tn-220 concentration and tracks density with factor R2 = 0.975. 展开更多
关键词 LR-115 type-II (SSNTDs) Rn-220 spark counter.
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Influence of Mechanical Grinding on the Interface Characteristics of Rice/Wheat Straws
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作者 Dingguo Zhou Peixing Wei 《Journal of Agricultural Science and Technology(B)》 2013年第5期369-376,共8页
The mechanical grinding method was used to make rice and wheat straw flakes and the properties of the interface of straws before and after grinding were evaluated. The particle boards were prepared using two kinds of ... The mechanical grinding method was used to make rice and wheat straw flakes and the properties of the interface of straws before and after grinding were evaluated. The particle boards were prepared using two kinds of straw flakes, respectively and their physical and mechanical properties were investigated. The results showed that the rice straw was easier to be broken when compared with wheat straw and the inner surface of cells in grinded straws was exposed remarkably. The characteristic peaks of lignin and cellulose on the surface of wheat straw were more significant than rice straw. The free-radical concentrations of straws were increased dramatically after being grinded with heating in the range from I00 ~C to 200 ~C. The surface free energy of straws was also improved after being grinded and the value in wheat straw was higher than that of rice straw, which implies that wheat straw was easier to be bonded than rice straw. The physical and mechanical properties of two kinds of straw particle boards could achieve the requirements of Chinese National Standards of GB 4897.3-2003, while wheat straw particle boards had better properties than those made from rice straws. 展开更多
关键词 Rice straw wheat straw surface free radicals surface free energy mechanical grinding method.
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Trends of surface ozone based on hourly concentrations in the Beijing–Tianjin–Hebei region during 2017–2021
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作者 Xiaoyan Wang Huihui Zheng +3 位作者 Bing Liu Shuyan Xie Yonghai Huang Shuai Wang 《Atmospheric and Oceanic Science Letters》 2024年第6期26-32,共7页
As a typical secondary air pollutant,surface ozone has been monitored routinely since 2013 in China.Most studies on the spatiotemporal variation of ozone have been centered around the daily maximum 8-h average,with li... As a typical secondary air pollutant,surface ozone has been monitored routinely since 2013 in China.Most studies on the spatiotemporal variation of ozone have been centered around the daily maximum 8-h average,with little attention paid to the trends of hourly ozone,especially hourly ozone exceedances.Focusing on hourly ozone exceedances and peak values,the spatiotemporal trends of hourly ozone at 77 sites in 13 cities of the Beijing-Tianjin-Hebei(BTH)region during 2017-2021 were analyzed in this study.The number of hours with exceedances(N_(H200))in 2019 was nearly three times that of 2021.On a five-year average,the percentage of cumulative NH200 in June accounted for up to 40.5%of all hourly exceedances.Cities in central Hebei Province had the highest cumulative annual N_(H200).June had the highest average hourly ozone exceeded multiples of 0.158.The top two cities with the highest average exceeded multiple were Tangshan(0.166)and Beijing(0.158).Tangshan and Xingtai ranked as the top two in terms of the mean of the 10 highest daily maximum ozone concentrations(MTDM),with 286.74 and 285.37μg m^(−3),respectively.The gap between the MTDM and the daily maximum of hourly ozone averaged over all sites had narrowed to 97.88μg m^(−3) in 2021,much lower than that in other years,which indicated that the stability and convergence of ozone pollution in BTH region had been enhanced in 2021 to some extent. 展开更多
关键词 Surface ozone Hourly concentration Ozone exceedance Peak value Beijing-tianjin-hebei region
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The vertical distribution characteristics of integral turbulence statistics in the atmospheric boundary layer over an urban area in Beijing 被引量:7
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作者 LIU Yang LIU HuiZhi WANG Lei 《Science China Earth Sciences》 SCIE EI CAS CSCD 2017年第8期1533-1545,共13页
Turbulence data(2008–2012) from a 325 m meteorological tower in Beijing, which consisted of three layers(47,140, and 280 m), was used to analyze the vertical distribution characteristics of turbulent transfer over Be... Turbulence data(2008–2012) from a 325 m meteorological tower in Beijing, which consisted of three layers(47,140, and 280 m), was used to analyze the vertical distribution characteristics of turbulent transfer over Beijing city according to similarity theory. The conclusions were as follows.(1) Normalized standard deviations of wind speeds/ui * were plotted as a function only of a local stability parameter. The values under near-neutral conditions were 2.15, 1.61, and 1.19 at 47 m, 2.39, 1.75,and 1.21 at 140 m, and 2.51, 1.77, and 1.30 at 280 m, showing a clear increase with height. The normalized standard deviation of wind components fitted the 1/3 law under unstable stratification conditions and decreased with height under both stable and unstable conditions.(2) The normalized standard deviation of temperature fitted the.1/3 law in the free convection limit, but was quite scattered with different characteristics under near-neutral conditions. The normalized standard deviations of humidity and the CO2 concentration fitted the.1/3 law under unstable conditions, and remained constant under near-neutral and stable stratification. The normalized standard deviation of scalars, i.e., temperature, humidity, and CO2 concentration, all increased with height.(3) Compared with momentum, and the water vapor and CO2 concentrations, the turbulence correlation coefficient for heat was smaller under near-neutral conditions, but larger under both stable and unstable conditions. A dissimilarity between heat, and the water vapor and CO2 concentrations was observed in urban areas. The relative correlation coefficients between heat and each of momentum, humidity, and CO2 concentration(|rwT/ruw|, |rwT/rwc| and |rwT/ruq|) in the lower layers were always larger than in higher layers, except for the relative correlation coefficient between heat and humidity in an unstable stratification. Therefore, the ratio between heat and each of momentum, humidity, and CO2 concentration decreased with height. 展开更多
关键词 Urban boundary layer Local similarity theory Integral turbulence statistics
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Heavy Metal Contamination of Agricultural Soils in Taiyuan, China 被引量:20
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作者 LIU Yong WANG Huifeng +1 位作者 LI Xiaoting LI Jinchang 《Pedosphere》 SCIE CAS CSCD 2015年第6期901-909,共9页
To evaluate the current state of the environmental quality of agricultural soils in Taiyuan City, a hotspot for China's industrial development, the concentrations of 8 heavy metals in soils were investigated by me... To evaluate the current state of the environmental quality of agricultural soils in Taiyuan City, a hotspot for China's industrial development, the concentrations of 8 heavy metals in soils were investigated by means of extensive sampling in farmlands, forestlands,and grasslands in the city. Statistical analyses and spatial distribution maps were used to identify the most significant heavy metal pollutants. The mean concentrations of As, Cd, Cu, Hg, Pb, Zn, Ni, and Cr were slightly higher than their background values in Taiyuan's topsoil, but were lower than the maximum permissible concentrations in the Chinese Environmental Quality Standard for agricultural soils. Farmland soils in Taiyuan had the highest average Cd, Cu, Hg, Pb, Zn, and Cr concentrations, but the As and Ni concentrations did not differ significantly among the farmland, forestland, and grasslands. Soil contamination by Cd, Cu, Hg, Pb,Zn, and Cr was mainly derived from farming practices, especially the use of sewage water for irrigation. In contrast, As and Ni might derive mainly from the soil parent material. The identification of heavy metal sources in agricultural soils may provide a basis for taking appropriate action to protect soil quality. 展开更多
关键词 environmental pollution farming practices sewage irrigation soil parent material soil quality
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Mn-doped ZnS quantum dots/methyl violet nanohybrids for room temperature phosphorescence sensing of DNA 被引量:2
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作者 HE Yu YAN XiuPing 《Science China Chemistry》 SCIE EI CAS 2011年第8期1254-1259,共6页
Mn-doped ZnS quantum dots/methyl violet nanohybrids were explored to develop a novel room temperature phosphorescence (RTP) sensor for the detection of DNA. Methyl violet (MV) as the electron acceptors was adsorbed on... Mn-doped ZnS quantum dots/methyl violet nanohybrids were explored to develop a novel room temperature phosphorescence (RTP) sensor for the detection of DNA. Methyl violet (MV) as the electron acceptors was adsorbed on the surface of the quantum dots (QDs) to quench the RTP of the Mn-doped ZnS QDs through an electron-transfer process under excitation. The addition of DNA recovered the RTP signal of the Mn-doped ZnS QDs due to the binding of MV with DNA and the removal of MV from the surface of the Mn-doped ZnS QDs. Under the optimal conditions, the enhanced RTP intensity of the Mn-doped ZnS QDs/MV nanohybrids linearly increased with the concentration of DNA from 0.08 to 12 mg L-1 with the detection limit of 33.6 μg L-1. The relative standard deviation for eleven replicate detections of the reagent blank was 3.7%. The developed method was applied to the detection of DNA in spiked urine samples with recoveries of 96%-103% without interference from nonspecific fluorescence. 展开更多
关键词 room temperature phosphorescence quantum dots photoinduced electron transfer sensor DNA
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