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N,N-二甲基甲酰胺(DMF)废水处理研究进展 总被引:16,自引:0,他引:16
DMF是一种性能优良的有机溶剂和精细化工产品中间体,工业用途广泛,但DMF有毒性,难生物降解.在此综述了DMF废水的主要处理方法,包括生物降解、吸附、萃取、化学氧化、碱性水解等,分析了各种方法的优缺点及适用范围,并展望了DMF废水处理工业化应用的研究方向. 相似文献
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A fast and simple method for determination of α, β,γ-hexachlorocyclohexanes (HCHs) in water using activated carbon fibersolid phase microextraction(ACF-SPME) were studied. Results showed the performance of adsorption and desorption of three HCHs on ACF were excellent. A wide linear range from 10 to 100 μg/L and detection limits of the ng/L level were obtained using ACF-SPME with GC-MS in selected ion monitoring(SIM) acquisition mode. The proposed method was also successfully applied for determination of three HCHs in tap water. Compared to commercial fibers, ACF showed some advantages such as better resistance to solvents, higher thermal stability, longer lifetime and lower cost. The data demonstrated that GC-MS with ACF-SPME is well suitable for the analysis of HCHs in water. 相似文献
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基于道化学公司安全评价标准的计算机辅助方法 总被引:5,自引:0,他引:5
传统的安全评价手段已经不能满足对石油化工行业安全进行科学的综合评估的要求,本文在分析美国道化学公司火灾爆炸指数评价体系的基础上,把数据库与计算机技术应用于其中,提出了基于道安全评价标准的计算机辅助方法,为石化行业的安全评估提供了一种有效的工具。 相似文献
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Peter A. Benn Mitchell Sugarman M. Alba Greco Gloria Harris George B. Deguire Lillian Y. F. Hsu 《黑龙江环境通报》1982,2(4):309-312
The first prenatally diagnosed case of 49,XXXYY is reported. The pathological findings of the fetus included bilateral clinodactyly, decreased carrying angles (OO), and hypertelorism, slightly low set ears and mildly prominent forehead. A minimum of two independent non- disjunctional events are postulated for this polysomy to arise. 相似文献
758.
Jaroslav Hynt Miloslav imek Petr Br
ek Sren O. Petersen 《Agriculture, ecosystems & environment》2007,120(2-4):269-279
Cattle overwintering areas common in central Europe may represent significant point sources of the important greenhouse gases, nitrous oxide (N2O) and carbon dioxide (CO2). A 2-year field study was carried out in order to estimate the emissions of N2O and CO2 from soil in a cattle overwintering area located in the southwest of the Czech Republic. The measurements were performed at three sampling locations along a gradient of animal impact (severe, moderate, slight) to test the hypothesis that emissions of CO2 and N2O are positively related to the degree of impact. In addition to CO2 and N2O fluxes determined by using non-vented manual closed chambers, soil mineral nitrogen (NH4+ and NO3−), pH and temperature were determined to assess their regulatory role and impact on gas fluxes. The overwintering area was about 4 ha and it had been used for overwintering of about 90 cows since 1995. Deposition of animal excreta resulted in a significant accumulation of nitrogen in the soil during winter, but most of the N2O was emitted during a few short periods in spring and/or in late autumn. Maximum N2O fluxes of up to 2.5 mg N2O-N m−2 h−1 were recorded at the most impacted location near the animal house, where the highest concentrations of soil mineral nitrogen also occurred. The emissions of CO2 showed a completely different pattern to those of N2O, being correlated with soil temperature; the highest emissions thus occurred in June–July, while very low fluxes were found in winter. Emission values ranged from about 0 to 700 mg C-CO2 m−2 h−1. Furthermore, the effect of animal impact on CO2 emissions was opposite to that on N2O fluxes, as the highest CO2 fluxes were mostly recorded at the least impacted location, where respiration of plants most likely increased overall CO2 production. The results show that cattle overwintering areas are important sources of greenhouse gases, including N2O and CO2. Fluxes of these two gases are, however, differently distributed over the year, which also suggests that they are controlled by different environmental and soil factors. 相似文献
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Detecting forest landscape boundary between Mountain Birch and evergreen coniferous forest in the northern slope of Changbai Mountain 总被引:3,自引:0,他引:3
IntroductionLandscapeboundaries,ortransitionalzones ecotonesamongdifferentlandscapes,haveoftenbeenignoredorreducedtolinesonamapwhenecologistsstudied .Howeverlandscapeboundariesareinherentfeaturesoflandscapesandplayimportantrolesinecosystemsdynamics.Fora… 相似文献
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