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101.
本文将标准加入法运用于分光光度分析中,排除了废水氨氮测定中复杂的基体干扰,操作简便,结果准确,适合于单个或小批量水样的直接测定。 相似文献
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A spore germination-based concept and its transformation into a field level prototype for monitoring aflatoxin M1 (AFM1) in milk was developed. Initially, 15 strains of Bacillus spp. procured from different culture collection were screened for AFM1 sensitivity using spot assay and marker strain showing inhibition at 0.5 ppb was selected based upon maximum zone of inhibition. The selected strain B. megaterium 2949 was further screened for different enzymes activities and subsequently its spores were produced to an extent of 73.13% ± 3.197% in newly developed sporulation medium containing beef extract (0.0075% ± 0.0004%), yeast extract (0.015% ± 0.001%), peptone (0.0375% ± 0.0016%), and sodium chloride (0.0375% ± 0.0018%). A spore germination-based concept/ assay was optimized by immobilizing spores in eppendorf with pretreated milk (80°C/15 min) containing germinant and chromogenic substrate followed by incubation at 37°C. The appearance of sky blue color within real time of 45 min indicated spores germination and release of specific marker enzyme such as acetyl esterase and its specific action on chromogenic substrate which demonstrates absence of AFM1 in milk. However, if there was no color change, presence of AFM1 at 0.5 ppb MRL was denoted by Codex. The developed concept on AFM1 detection was validated and a correlation of 0.97 was established with AOAC approved Charm 6602 and ELISA at Codex MRL with minimal false positive and negative results. The cost effective test has potential application in dairy farms, manufacturing, and R&D units for routine monitoring of AFM1 in milk. 相似文献
104.
The purpose of this study is to shed light on the connection between income, dwelling type, tenure type and city living, in terms of both a household’s energy saving behaviours and direct residential energy consumption. This study employs data from the Household Energy Consumption Survey, Australia. Using a seemingly unrelated regression (SUR) system of equations the results reveal some key mechanisms which may allow householders to realise lower levels of energy consumption and hence lower carbon emissions. The results indicate that there are characteristics unique to living in a city that are linked to higher levels of direct residential energy consumption. On a number of measures (e.g. household income, tenure type and dwelling type), the results point to a lower likelihood of engaging in energy saving behaviours in cities. Also, depending on the number of energy saving behaviours, these actions have the potential to more than offset higher direct residential energy consumption of householders residing in separate houses. Coupled with these findings renters, a more vulnerable social group, are found to be significantly disadvantaged, suffering from a much lower adaptive capacity. Specifically, householders who rent their home are 77% less likely to have solar electricity. A result which may reflect differences in access to opportunity. Further, householders who rent are less likely to engage in energy saving actions. A finding which may reflect difference in ontological security and the greater psychological burden associated with undertaking energy saving behaviours (a barrier) borne by renters not shared with home owners. 相似文献
105.
武钢三烧区域改建了二台大连三洋蒸汽型双效溴化锂吸收式制冷机。叙述了该改建项目的主机选型、参数选定、设计特点等。 相似文献
106.
This paper aims to identify the main driving force for changes of total primary energy consumption in Beijing during the period of 1981-2005. Sectoral energy use was investigated when regional economic structure changed significantly. The changes of total primary energy consumption in Beijing are decomposed into production effects, structural effects and intensity effects using the additive version of the logarithmic mean Divisia index (LMDI) method. Aggregate decomposition analysis showed that the major contributor of total effect was made by the production effect followed by the intensity effect, and the structural effect was relatively insignificant. The total and production effects were all positive. In contrast, the structural effect and intensity effect were all negative. Sectoral decomposition investigation indicated that the most effective way to slow down the growth rate of total primary energy consumption (TPEC) was to reduce the production of the energy-intensive industrial sectors and improving industrial energy intensity. The results show that in this period, Beijing's economy has undergone a transformation from an industrial to a service economy. However, the structures of sectoral energy use have not been changed yet, and energy demand should be increasing until the energy-intensive industrial production to be reduced and energy intensity of the region reaches a peak. As sequence energy consumption data of sub-sectors are not available, only the fundamental three sectors are considered: agriculture, industry and service. However, further decomposition into secondary and tertiary sectors is definitely needed for detailed investigations. 相似文献
107.
This article analyzes China's coal consumption changes since 1991 and proportion change of coal consumption to total energy consumption. It is argued that power, iron and steel, construction material, and chemical industries are the four major coal consumption industries, which account for 85% of total coal consumption in 2005. Considering energy consumption composition characteristics of these four industries, major coal demand determinants, potentials of future energy efficiency improvement, and structural changes, etc., this article makes a forecast of 2010s and 2020s domestic coal demand in these four industries. In addition, considering such relevant factors as our country's future economic growth rate and energy saving target, it forecasts future energy demands, using per unit GDP energy consumption method and energy elasticity coefficient method as well. Then it uses other institution's results about future primary energy demand, excluding primary coal demand, for reference, and forecasts coal demands in 2010 and 2020 indirectly. After results comparison between these two methods, it is believed that coal demands in 2010 might be 2620-2850 million tons and in 2020 might be 3090-3490 million tons, in which, coal used in power generation is still the driven force of coal demand growth. 相似文献
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110.
Simultaneous photocatalytic reduction of poisonous Cr(VI) and Ni(II) ions, coupled with photocatalytic oxidation of sodium dodecyl benzene sulfonate (SDBS) were studied with a trace amount of commercial titania nanoparticles and by means of a direct-photo-irradiation reactor. The co-presence of metal ions and SDBS causes metal ions reduction as well as SDBS oxidation to enhance and energy efficiency to improve. XRD, XPS and FTIR analysis were used to characterize TiO2 particles before and after usage with the aim of evaluating the mechanism of reactions. The effect of major operating parameters, pH and temperature, was investigated. Under conditions of [Cr(VI)]0 = [Ni(II)]0 = 5 mg/L, [SDBS]0 = 10 mg/L, [TiO2] = 40 mg/L, pH 6 and T = 35 °C; the removal efficiencies of 55.4%, 71.2% and 57.2% were obtained, respectively, for Cr(VI) and Ni(II) reduction, as well as for SDBS oxidation, after 110 min operation. The relevant kinetic model jointed with the Arrhenius equation was introduced. Pseudo-first-order reactions are relevant. Energy consumption (electrical and thermal) evaluations revealed that operations at higher temperatures provide significant cost reduction. Meantime, a criterion was proposed for a consistent assessment of this kind of processes. 相似文献