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71.
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73.
Transdisciplinarity: Context, contradictions and capacity 总被引:1,自引:0,他引:1
74.
Analysis of firm investment behavior during 1982–1993 shows that the Tax Reform Act of 1986 (TRA 86) Public Law No. 99-514 substantially affects both purchases and leases of depreciable assets. The changes in the regular corporate income tax rules are shown to lower asset acquisition. The effect of the alternative minimum tax (AMT) is found to vary with the debt share in firms’ capital structure and with the frequency of AMT exposure during the life of the assets acquired. On average, TRA86 depresses asset purchases less for firms that are subject to the AMT: AMT somewhat mitigates the negative effects of the regular tax rules. 相似文献
75.
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
76.
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
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78.
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
79.
There are four ecologically important river catchments that contain candidate Special Areas of Conservation (cSACs) under the Habitats Directive in the Lake District National Park located in the North of England. These are the rivers Ehen, Kent, Derwent and Eden. For each cSAC, there are defined ecological criteria that include water quality targets to protect the designated species. Stretches of the riverine cSACs in each catchment are failing to meet these and other water quality targets. The Environment Agency commissioned a study of each catchment to provide the underpinning scientific knowledge to allow it to deliver its statutory obligations under the Habitats Directive. SIMCAT river water quality models were produced and used to predict the water quality impacts resulting from a number of water quality planning scenarios aimed at achieving full compliance with the Habitats Directive and other national and EEC water quality targets. The results indicated that further controls on effluent discharges will allow the majority of targets to be met but other sources of pollution will also need to be controlled. The outcome of the study also recognised that water quality improvements alone will not necessarily produce the required improvement to the ecological interest features in each cSAC. 相似文献
80.
E Persson M Ljunggren J la Cour Jansen R Strube L J?nsson 《Water science and technology》2006,53(12):139-147
A Discfilter with 10 and 18 microm filter openings, respectively, was placed in parallel to a flotation plant for separation of biological flocs from a post-denitrifying Kaldnes Moving Bed Process, the last treatment step at the municipal wastewater treatment plant at Sj?unda, Malm?, Sweden. The effluent concentrations from the 10 and 18 microm filter were 2-5 and 2-8 mg SS L(-1), respectively, which is comparable to, or better than, the flotation plant. Comparison with experiences from activated sludge plants shows that the Discfilter works especially well after the Kaldnes process. Particle size distribution (PSD) studies show that particles larger than the filter openings of 10 and 18 microm are separated with approximately 90% efficiency, whereas most of the smaller particles pass the filter. This fact indicates that the major particle separation mechanism is physical blocking. These findings point to the possibility of improving the prediction of the separation efficiency by combining measurements of turbidity and suspended solids with particle size analysis. 相似文献