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961.
The study was undertaken to evaluate the effects of malathion and chlorpyrifos on acetylcholinesterase (AChE), esterase (EST) activity and antioxidant system after topical application with different concentration to Oxya chinensis. The results showed that malathion and chlorpyrifos inhibited EST, AChE activity and increased malondialdehyde (MDA) contents. A change in superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione peroxidase (GPx), and glutathione reductase (GR) activity combined with reduced glutathione (GSH) and total glutathione (tGSH) contents was found in O. chinensis after malathion and chlorpyrifos treatments. Malathion and chlorpyrifos increased SOD and CAT activity compared with the control. With the concentrations increasing, SOD and CAT activity showed the similar tendency, namely, SOD and CAT activity increased at the lower concentrations and decreased at the higher concentrations. The results showed that malathion and chlorpyrifos decreased significantly GR activity. GST and GPx activity at the studied concentrations of chlorpyrifos was lower than that of the control. However, no significance was observed. GPx and GST activity in malathion treated grasshoppers showed a biphasic response with an initial increase followed by a decline in its activity. Malathion and chlorpyrifos decreased GSH contents and the ratio of GSH/GSSG. The present findings indicated that the toxicity of malathion and chlorpyrifos might be associated with oxidative stress. 相似文献
962.
963.
Liting Yang Chunlan Dai Lijun Ma Shaoquan Lin 《Journal of Polymers and the Environment》2011,19(1):189-195
The conjugated soybean oil was synthesized through the isomerization reaction of soybean oil to transformed the structure
of linoleic acid into conjugated linoleic acid structure, and Rhodium complexes (RhCl(Pph3)3) was used as catalyst. The efficiency on the conjugation of catalyst RhCl (Pph3)3, tin dichloride dehydrate (SnCl2·2H2O) and triphenylphosphine (Pph3) were evaluated. The results showed when RhCl(Pph3)3, SnCl2·2H2O and Pph3 are 9.25, 9.0 and 13.1 mg in 100 g soybean oil respectively, the highest conversion of conjugation achieved 96%. The free
radical copolymerization of conjugated soybean oil with acrylonitrile (AN) and dicyclopentadiene (DCP) was studied. AIBN was
used as the initiator. FT-IR and 1H-NMR results indicates that the conjugated soybean oil with AN and DCP did occur free radical copolymerization with the initiator
AIBN. The product is light yellow powder. The thermal properties of the soy-based copolymer were investigated by TG and DSC.
The initial degradation temperature of polymers is higher then 250 °C. 相似文献
964.
Phosphorus flows and use efficiencies in production and consumption of wheat, rice, and maize in China 总被引:5,自引:0,他引:5
Increasing fertilizer phosphorus (P) application in agriculture has greatly contributed to the increase of crop yields during the last decades in China but it has also increased P flows in food production and consumption. The relationship between P use efficiency and P flow is not well quantified at national level. In present paper we report on P flows and P use efficiencies in rice, wheat, and maize production in China using the NUFER model. Conservation strategies for P utilization and the impact of these strategies on P use efficiency have been evaluated. Total amounts of P input to wheat, rice, and maize fields were 1095, 1240, and 1128 Gg, respectively, in China, approximately 80% of which was in chemical fertilizers. The accumulation of P annually in the fields of wheat, rice, and maize was 29.4, 13.6, and 21.3 kg ha−1, respectively. Phosphorus recovered in the food products of wheat, rice, and maize accounted for only 12.5%, 13.5%, and 3.8% of the total P input, or 3.2%, 2.6%, and 0.9% of the applied fertilizer P, respectively. The present study shows that optimizing phosphorus flows and decreasing phosphorus losses in crop production and utilization through improved nutrient management must be considered as an important issue in the development of agriculture in China. 相似文献
965.
Wang Q Wang L Chen X Rao KM Lu SY Ma ST Jiang P Zheng D Xu SQ Zheng HY Wang JS Yu ZQ Zhang R Tao Y Yuan J 《Environmental science and pollution research international》2011,18(6):987-996
Background
Di-(2-ethylhexyl) phthalate (DEHP) is a common plasticizer used in industrial and diverse consumer products. Animal studies indicate DEHP caused developmental, reproductive, and hepatic toxicities. However, human studies of the potential effects of DEHP are limited.Methods
The exposed site with a history of over 20 years of waste plastic recycling was located in Hunan Province, China. The reference site without known DEHP pollution source was about 50 km far away from the exposed site. In this study, 181 workers working in plastic waste recycling and 160 gender?Cage matched farmers were recruited. DEHP concentrations in water and cultivated soil samples, serum thyroid-stimulating hormone, malondialdehyde (MDA), superoxide dismutase (SOD), urinary 8-hydroxy-2??-deoxyguanosine (8-OHdG), and micronuclei frequency in human capillary blood lymphocytes were analyzed.Results
Mean levels of DEHP were greater in environment at the recycling site than at reference site (industry wastewater for the exposed: 42.43 ??g/l; well water: 14.20 vs. 0.79 ??g/l, pond water: 135.68 vs. 0.37 ??g/l, cultivated soil: 13.07 vs. 0.81 mg/kg, p?0.05 for all). The workers had higher median levels of MDA (3.80 vs. 3.14 nmol/ml) and urinary 8-OHdG (340.37 vs. 268.18 ??mol/mol creatinine) and decreased SOD activities (112.15 vs. 123.82 U/ml) than the reference group (p?0.01 for all). Multivariate analysis revealed that the history of working in waste plastic recycling was an independent risk factor for the increased urinary 8-OHdG levels in the male workers (p?0.01).Conclusions
The occupational DEHP exposure might contribute to oxidative deoxyribonucleic acid damage in the male workers. 相似文献966.
Sixteen USEPA priority polycyclic aromatic hydrocarbons (PAHs) extracted by Soxhlet extraction (S-PAHs) with dichloromethane and routine accelerated solvent extraction (A-PAHs) with 1:1 toluene/methanol, respectively, were investigated in 24 soil samples from two cities in the center of the Pearl River Delta, South China. Polycyclic aromatic hydrocarbons, methylphenanthrene and perylene, in two soils, two sediments, and an immature oil shale were also sequentially extracted by accelerated solvent extraction (ASE) with each of four different organic solvents for three times. The A-PAHs' concentrations are 2.41 times the S-PAHs' concentrations. For sequential three ASEs, PAHs in the first extract account for 56 to 67% of their total concentrations in the sequential three extractions and toluene displays the best extraction performance among the four solvents. Diagnostic ratios of PAHs in Soxhlet extraction, routine ASE, and sequential ASE with each solvent for a given sample are very similar, suggesting their identical petrogenic and pyrogenic sources in the soils and sediments. But the PAH ratios for the shale have an obvious petrogenic origin. The perylene/5-ring PAH ratios indicate a diagenetic source, especially in the shale and sediments. The correlation analysis shows that A-PAHs/S-PAHs is better associated with the contents of total organic carbon (TOC) than those of black carbon (BC). The above results indicate the significant petrogenic origin of PAHs and the important effect of organic matter on their extraction and distribution in the investigated field soils/sediments. 相似文献
967.
968.
发制品行业是以人发、人造纤维等为原材料进行假发加工的行业。许昌市发制品的生产过程大致可分为两个阶段:漂染和前后处理。漂染过程用水量大,产生的废水难以处理。其中过酸、氧化、染色配置的溶液使用一次后直接排放,不符合清洁生产要求,且所排放的溶液可考虑中和多次利用。漂染过程水资源消耗量大,废水产生量大,没有考虑废水综合利用。按清洁生产的要求在以上环节可通过技术革新和设备改造得以改进。 相似文献
969.
水环境中有机污染物对藻类毒理性的探讨 总被引:2,自引:0,他引:2
近年来,环境中的有机污染物对生态环境的破坏日益加剧,并严重威胁到了人类的生存和发展。藻类作为初级生产者,是整个生态系统物质循环和能量流动的基础,因此研究水环境中有机污染物对藻类的毒理性,对于环境污染的监测具有深远的意义。就有机污染物对藻类的毒性机理、藻类对有机污染物的敏感度等问题的研究现状进行综述,并对藻类在环境监测方面的应用前景进行展望。 相似文献
970.
Agricultural ammonia emissions inventory and spatial distribution in the North China Plain 总被引:7,自引:0,他引:7
Y. Zhang A.J. Dore X.J. Liu W.Q. Ma J.N. Cape 《Environmental pollution (Barking, Essex : 1987)》2010,158(2):490-501
An agricultural ammonia (NH3) emission inventory in the North China Plain (NCP) on a prefecture level for the year 2004, and a 5 × 5 km2 resolution spatial distribution map, has been calculated for the first time. The census database from China's statistics datasets, and emission factors re-calculated by the RAINS model supported total emissions of 3071 kt NH3-N yr−1 for the NCP, accounting for 27% of the total emissions in China. NH3 emission from mineral fertilizer application contributed 1620 kt NH3-N yr−1, 54% of the total emission, while livestock emissions accounted for the remaining 46% of the total emissions, including 7%, 27%, 7% and 5% from cattle, pigs, sheep and goats, and poultry, respectively. A high-resolution spatial NH3 emissions map was developed based on 1 × 1 km land use database and aggregated to a 5 × 5 km grid resolution. The highest emission density value was 198 kg N ha−1 yr−1. 相似文献