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861.
862.
本文主要对近30年来营口地震台记录的海城7.3级地震的余震观测资料进行分析,按不同的震级进行统计,分别作出M-T图和N-T图,可供今后监测工作参考。 相似文献
863.
阻抑动力学光度法测定痕量邻二硝基苯 总被引:2,自引:0,他引:2
研究发现,在盐酸介质中,痕量邻二硝基苯能灵敏地阻抑溴酸钾氧化甲基红褪色的反应。研究了该阻抑褪色反应的最佳条件,建立了一种测定痕量邻二硝基苯的新方法。该方法线性范围为0.0~0.16μg,检测限为1.15×10-10gmL。用于环境水样中邻二硝基苯的测定,结果满意。 相似文献
864.
ADMS仿真模拟在总量控制中的应用 总被引:1,自引:0,他引:1
ADMs是新一代的大气扩散模型,用来评估空气污染扩散的问题。抚顺市2004年采取了大气污染治理措施并使用ADMs模型予以评估。仿真模拟的结果表明各项措施的效果并不和治理时的投资成比例,也不和污染物的削减总量成比例.说明治理过程中的科学性和经济性不够理想,也表明总量控制方针在实施中有许多实际问题需要解决。 相似文献
865.
简要回顾了海上溢油污染概况,介绍了国内外溢油鉴别方法:气相色谱法、气相色谱-质谱法、荧光光谱法、红外光谱法等,指出了未来海上溢油指纹鉴别技术的发展方向。 相似文献
866.
Nitrous oxide emissions from black soils with different pH 总被引:1,自引:0,他引:1
N2O fluxes as a function of incubation time from soil with different available N contents and pH were determined. Cumulative carbon dioxide (CO2) emissions were measured to indicate soil respiration. A 144-hr incubation experiment was conducted in a slightly acidic agricultural soil (pHH2O 5.33) after the pH was adjusted to four different values (3.65, 5.00, 6.90 and 8.55). The experiments consisted of a control without added N, and with NH4+-N and NO3--N fertilization. The results showed that soil pH contributed significantly to N2O flux from the soils. There were higher N2O emissions in the period 0-12 hr in the four pH treatments, especially those enhanced with N-fertilization. The cumulative N2O-N emission reached a maximum at pH 8.55 and was stimulated by NO3--N fertilization (70.4 μg/kg). The minimum emissions appeared at pH 3.65 and were not stimulated by NO3--N or NH4+-N fertilization. Soil respiration increased significantly due to N-fertilization. Soil respiration increased positively with soil pH (R2 = 0.98, P < 0.01). The lowest CO2-C emission (30.2 mg/kg) was presented in pH 3.65 soils without N-fertilization. The highest CO2-C emissions appeared in the pH 8.55 soils for NH4+-N fertilization (199 mg/kg). These findings suggested that N2O emissions and soil respiration were significantly influenced by low pH, which strongly inhibits soil microbial nitrification and denitrification activities. The content of NO3--N in soil significantly and positively affected the N2O emissions through denitrification. 相似文献
867.
The emissions of NO2 and HONO from the KNO3 photolysis in the presence of TiO2 were measured using a round-shape reactor coupled to a NOx analyzer. TiO2 played important roles in the emission flux density of NO2 (RNO2) and HONO (RHONO), depending on crystal structures and mass ratios of TiO2. RNO2 and RHONO significantly decreased with increasing the rutile and anatase mass ratios from 0 to 8 and 0.5 wt.%, respectively. Nevertheless, with further increasing the anatase mass ratio to 8 wt.%, there was an increase in RNO2 and RHONO. RNO2 on KNO3/TiO2/SiO2 had positive correlation with the KNO3 mass (1–20 wt.%), irradiation intensity (80–400 W/m2) and temperature (278–308 K), while it had the maximum value at the relative humidity (RH) of 55%. RHONO on KNO3/TiO2/SiO2 slightly varied with the KNO3 mass and temperature, whereas it increased with the irradiation intensity and RH. In addition, the mechanism for NO2 and HONO emissions from the nitrates photolysis and atmospheric implications were discussed. 相似文献
868.
Haotian Hao Yili Wang Baoyou Shi Kun Han Yuan Zhuang Yan Kong Xin Huang 《环境科学学报(英文版)》2018,30(11):107-116
Dye wastewater containing heavy metal ions is a common industrial effluent with complex physicochemical properties.The treatment of metal–dye binary wastewater is difficult.In this work,a novel in-situ ferrite process(IFP) was applied to treat Methylene Blue(MB)–Cu(II)binary wastewater,and the operational parameters were optimized for MB removal.Results showed that the optimum operating conditions were OH/M of 1.72,Cu~(2+)/Fe~(2+)ratio of 1/2.5,reaction time of 90 min,aeration intensity of 320 mL/min,and reaction temperature of40°C.Moreover,the presence of Ca~(2+)and Mg~(2+)moderately influenced the MB removal.Physical characterization results indicated that the precipitates yielded in IFP presented high surface area(232.50 m2/g) and a multi-porous structure.Based on the Langmuir model,the maximum adsorption capacity toward MB was 347.82 mg/g for the precipitates produced in IFP,which outperformed most other adsorbents.Furthermore,IFP rapidly sequestered MB with removal efficiency 5 to 10 times greater than that by general ferrite adsorption,which suggested a strong enhancement of MB removal by IFP.The MB removal process by IFP showed two different high removal stages,each with a corresponding removal mechanism.In the first brief stage(5 min),the initial high MB removal(~95%)was achieved by predominantly electrostatic interactions.Then the sweep effect and encapsulation were dominant in the second longer stage. 相似文献
869.
重大生态工程规划设计的理论探讨 总被引:1,自引:2,他引:1
生态问题已成为阻碍我国经济社会可持续发展的主要屏障,解决生态问题的主要途径是实施生态治理工程。我国开展的诸多生态治理工程以退耕还林还草工程最为典型,由于相关理论研究长期滞后于生产实践需求导致该工程在推进过程中“边实施、边调整、边总结”。论文剖析了退耕还林还草工程不同阶段出现的问题以及国家采取的相应对策。通过理论分析指出生态问题是经济社会系统内部矛盾的外在表现,生态治理工程既要解决生态退化及危害,又要解决诱发生态问题的经济社会内部矛盾;生态工程设计需要生态学、经济学、社会学等相关学科的理论支撑。重大生态工程设计之初需要考虑技术储备、工程成本、成果稳定性(经济社会系统内部矛盾解决程度)、推广性、综合效益、政策及法律法规搭配等问题以达到“内外兼治”的效果,避免因“边实施、边调整、边总结”带来的工程风险和浪费,最终保障工程目标的实现。 相似文献
870.