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31.
As a major pollutant source to urban receiving waters, the non-point source pollution from urban runoff needs to be well studied and effectively controlled. Based on monitoring data from urban runoff pollutant sources, this article describes a systematic estimation of total pollutant loads from the urban areas of Beijing. A numerical model was developed to quantify main pollutant loads of urban runoff in Beijing. A sub-procedure is involved in this method, in which the flush process influences both the quantity and quality of stormwater runoff. A statistics-based method was applied in computing the annual pollutant load as an output of the runoff. The proportions of pollutant from point-source and non-point sources were compared. This provides a scientific basis for proper environmental input assessment of urban stormwater pollution to receiving waters, improvement of infrastructure performance, implementation of urban stormwater management, and utilization of stormwater. 相似文献
32.
次贷危机影响了我国的经济和财政态势,经济增长放缓使得财政的收支压力逐步凸显,风险增大。本文采用在国际上得到广泛采纳的风险指标法对我国当前的财政风险状况进行了度量,结论是短期内风险虽有所增加,但仍处在可控范围内;中长期则需要对政策作出适当调整,以降低未来的风险。 相似文献
33.
34.
介绍了热电联产成本的两种计算方法,指出了两种计算方法的局限性.对热电联产节能效果进行了量化分析,在按热量法对供热比计算的基础上,提出了修正热量法.此方法体现了热电联产的优越性,为发电企业增加了经济效益. 相似文献
35.
改革开放以来,由于各种原因使得我国地区之间的经济发展水平和收入水平有了很大的差距。对于这些差距,我们可以通过对人均经济收入、人均财政收入、城镇居民可支配收入、农民人均纯收入、人均国际收入等五个指标的分析中详细地看到。从客观性和可行性的意义上讲,西部地区要在短时期内消除这些差距,是根本不可能的。因此,作为西部地区来讲,应该选择实事求是的态度,既要正视这些差距的长期存在,又要通过体制创新、政策创新、战略创新等,努力探索试图缩小差距的途径和对策。 相似文献
36.
This article studies the role of risk arbitrageurs in takeoversand the source of their advantage. We show how the presenceof arbitrageurs affects the value of the target shares, sincearbitrageurs are more likely to tender. Therefore an arbitrageurhas the informational advantage of knowing he bought shares.In equilibrium, the number of arbitrageurs buying shares andthe price they pay are determined endogenously. We also presentseveral empirical implications, including the relationship amongtrading volume, takeover premium, liquidity of the shares, andthe number of risk arbitrageurs investing in one particulardeal. 相似文献
37.
本文不仅总结了当前主要的实证研究文献提出的我国通货膨胀的种种成因,而且对每种原因给予了比较分析和新的实证分析,并在此基础上尝试进行了综合分析,以得出一些有益的结论。 相似文献
38.
Water treatment using TiO2 semiconductor as a durable heterogeneous photocatalyst has been the focus of environmentalists in recent years. Currently, we developed an inexpensive and highly efficient approach for synthesizing nitrogen-doped TiO2 with lower band-gap energy that can respond to visible light. Doping on the molecular scale led to an enhanced nitrogen concentration of up to 21.8%. Reflectance measurements showed the synthesized N-doped TiO2 nanoparticles are catalytically active with the absorbance that extends into the visible region up to 600 nm. The water purification potential of this new class of compound was evaluated by studying the photodegradation of Acid Orange 7 (AO7) and E. coli. Experiments were conducted to compare the photocatalytic activities of N-doped TiO2 nanocatalysts and commercially available Degussa P25 power under identical solar light exposure. N-doped TiO2 demonstrated superior photocatalytic activities in both chemical compound degradation and bactericidal reactions. The result of this study shows the potential of applying new generations of catalyst for wastewater purification and disinfection. 相似文献
39.
根据在农村通自来水工程实践中积累的经验,提出并较好地解决了农村供水工程的评价标准,设计供水时间的确定,输配水管网设计中的优化等问题,对建好、管好和用好农村自来水工程具有一定的帮助作用. 相似文献
40.
We investigate the effects of analysts' affiliation and reputation on dealers' market making activities. We find that for a given stock, dealers who have affiliated analysts covering the stock quote and trade more aggressively than those who do not have any affiliated analysts. More important, the reputation of affiliated analysts plays an additional role in the affiliated dealer's quote and trade behavior. Dealers with affiliated star analysts post more aggressive quotes and have larger market shares than dealers with affiliated nonstar analysts. Although dealers who post more aggressive quotes also induce affiliated star analysts to cover the stocks, the positive effect of analyst reputation on the affiliated dealers' quote aggressiveness remains significant and robust after controlling for potential endogenous and simultaneous problems. 相似文献