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991.
烟花爆竹用氧化剂的研究进展 总被引:3,自引:0,他引:3
在调查研究的基础上,分析、总结、研讨用于烟花爆竹的氧化剂的历史、现状及发展方向。分析和讨论氯酸盐类、高氯酸盐类、硝酸盐类以及金属氧化物等氧化剂的物化性质、燃爆性能及各自用于烟火剂的优缺点。研究指出:将不同类型的氧化剂复合使用,当选择的组分及搭配的比例合适时,不仅能使各种氧化剂充分发挥其优点,而且还将产生一些新的实际的性能。同时提出:复合氧化剂是配制燃放效果好、安全性能高、价格低廉的烟花爆竹氧化剂的发展方向。 相似文献
992.
The paper summarises the results to determine the fluxes of different N-compounds within the atmosphere and an aquatic and a terrestrial ecosystems, in Hungary. In the exchange processes of N-compounds between atmosphere and various ecosystems the deposition dominates. The net deposition fluxes are -730, -1270 and -1530 mg Nm(-2)yr(-1) for water, grassland, and forest ecosystems, respectively. For water, the main source of nitrogen compounds is the wet deposition. Ammonia gas is close to the equilibrium between the water and the air. For grassland the dry flux of nitric acid and ammonia is also an important term beside the wet deposition. Dry deposition to terrestrial ecosystems is roughly two times higher than wet deposition. A total of 8-10% of the nitrates and NH(x) deposited to terrestrial ecosystems are re-emitted into the air in the form of nitrous oxide (N2O) greenhouse gas. 相似文献
993.
994.
Hrönn Jörundsdóttir Karin Löfstrand Jörundur Svavarsson Anders Bignert Åke Bergman 《Chemosphere》2013
Data on distribution, concentration and trends of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) is scarce in biota from the sub-Arctic region of the Atlantic. The present study is an investigation on PBDE and HBCD concentrations in eggs from seven marine bird species from Iceland, i.e. common eider (Somateria mollissima), arctic tern (Sterna paradisaea), guillemot (Uria aalge), fulmar (Fulmarus glacialis), lesser black-backed gull (Larus fuscus), great black-backed gull (Larus marinus) and great skua (Stercorarius skua). Concentrations of sum PBDEs ranged from 44 ng g−1 fat in eider eggs to 2400 ng g−1 fat in great skua eggs. The contribution of different PBDE congeners to the sum concentration differed between species. Concentration of HBCDs (sum of α−,β− and γ−HBCD) ranged from 1.3 ng g−1 fat in arctic tern eggs to 41 ng g−1 fat in great black-backed gull. PCA on PBDE and HBCD shows different trends between the two BFR groups, further indicating different sources/usage. Investigations on any potential health or population effects of environmental pollutants on the great skua are advised since both the PBDE and HBCD concentrations are high. 相似文献
995.
996.
通过对乌鲁木齐市新装修居室空气连续6个月的追踪监测,分析新装修居室甲醛、总挥发性有机物浓度的动态变化规律。结果表明,室内甲醛的浓度随装修竣工后时间的增加呈现降低趋势,但到第6个月为止,绝大部分住户室内空气甲醛浓度依然超标。总挥发性有机物的浓度降低趋势较为明显,到第5个月时,绝大部分住户室内空气总挥发性有机物浓度达到国家标准限值的要求。室内空气甲醛浓度的降低是一个长期缓慢的过程,居室内甲醛污染对人体健康的危害应引起人们的足够重视。 相似文献
997.
Perfluorinated compounds (PFCs) are a group of anthropogenic chemicals containing diverse functional groups and chain lengths. They are known to be persistent and bioaccumulative explaining their worldwide environmental presence. The toxicological information on these chemicals is still incomplete and insufficient to assess their environmental impact and structure-activity relationship. In the present study, the developmental effects of PFOS (perfluorooctane sulfonate, C8), PFOA (perfluorooctanoic acid, C8), PFBS (perfluorobutane sulfonate, C4) and PFBA (perfluorobutanoic acid, C4) were evaluated in zebrafish embryos (Danio rerio). The different chain lengths and functional groups of the selected chemicals made it possible to determine the structure-activity relationship of these compounds. PFCs with longer chain lengths (C8) tend to be more toxic than PFCs with shorter chain lengths (C4). Comparison based on the functional groups of compounds with the same chain length indicates that PFCs with a sulfonate group have a larger toxic potential than the ones with a carboxyl group. Furthermore, exposure to the different PFCs resulted in some general effects, such as deformations of the tail and an uninflated swim bladder, as well as in more specific effects which might be related to the structure of the tested chemicals. Oedemas and effects on length could only be detected in 8-carbon PFCs while malformations of the head were a more specific action of the sulfonated PFCs. Effects on hatching rate and success were found in PFOA exposed embryos and heart rates were affected after exposure to PFOS, PFOA and PFBS. 相似文献
998.
Sergio Jarque Mireia Bartrons Joan O. Grimalt 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1392-1398
The biomarker of xenobiotic exposure cytochrome p450A1 (Cyp1A) was used to analyze the biological response to chemical pollution in Salmo trutta (brown trout) from nine high mountain European lakes in Norway, Tatras, Tyrol, and central Pyrenees. Hepatic Cyp1A mRNA levels correlated both with the reciprocal of absolute annual average air temperatures of the sampled lakes and with muscle concentrations of several hydrophobic organohalogen compounds (OC), including chlorinated polychlorobiphenyls (PCB), DDE, and DDT. The correlation between Cyp1A expression and OC content was observed across the whole temperature range (between −0.7 °C and +6.2 °C), but also in the absence of any thermal gradient. We concluded that airborne pollutants accumulate in high mountain lake fish at concentrations high enough to increase Cyp1A expression, among other possible effects. As geographical distribution of semi-volatile OC is strongly influenced by air temperatures, future climate modifications will potentially enhance their physiological effects in lake ecosystems. 相似文献
999.
K. Srinivasan H.P. Ramesh R. Radhakrishnamurty 《Journal of environmental science and health. Part. B》2013,48(4-5):453-466
Abstract Dietary administration of β‐ and α‐hexachlorocyclohexane (HCH) to albino rats caused an abnormal excessive excretion of glucose in the urine, blood glucose level being nearly normal. Occurrence of glucosuria was also accompanied by increased excretions of the two low‐threshold compounds ‐ creatinine and urea, their levels in blood being normal. The interference of HCH isomers with renal function as evidenced by biochemical data was also indicated by histopathological lesions observed in the kidney sections, viz., hypertrophy and degeneration of the renal tubular epithelia. 相似文献
1000.
土壤中挥发性有机污染物现场快速监测技术应用进展 总被引:1,自引:0,他引:1
在总结我国突发性环境事故发生现状的基础上,提出了我国环境现场快速监测工作缺少规范化管理,以及标准监测技术方法不完善等问题。探讨了土壤中挥发性有机污染物快速监测技术的研究进展,重点讨论了检测管,手持式气体检测器,便携式气相色谱(配置光离子化检测器、氢火焰离子化检测器或串/并联检测器)及便携式气相色谱-质谱等技术在快速检测土壤中挥发性有机污染物方面的性能特点与应用情况,并对我国建立土壤中挥发性有机污染物现场快速监测标准方法提出了建议。 相似文献