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81.
82.
电化学强化脱氮中反硝化菌对活性炭纤维电极电化学反应影响初步研究 总被引:4,自引:0,他引:4
研究固定反硝化菌活性炭纤维电极的阴极极化行为及其硝酸盐氮脱除率,考察了活性炭纤维电极电化学强化脱氮系统中生物过程对电化学过程的影响。实验表明,反硝化过程影响电极电化学反应,参数表观交换电流密度可用来表征体系反硝化菌的反硝化能力,新定义了生物效益量,其变化率与硝酸盐氮脱除率相关性良好。 相似文献
83.
84.
Eco-Efficiency of Electric and Electronic Appliances: A Data Envelopment Analysis (DEA) 总被引:2,自引:0,他引:2
Y. Barba-Gutiérrez B. Adenso-Díaz S. Lozano 《Environmental Modeling and Assessment》2009,14(4):439-447
Several papers have studied the eco-efficiency of manufacturing systems to address strategic socioeconomic issues in the context
of sustainability analysis. Their goal has been to take into account not only environmental impact aspects throughout the
whole life cycle but also to incorporate the associated economic value as well, thus, giving a comprehensive vision of both
factors. This paper focuses on different commonplace household electric appliances, comparing their eco-efficiency computed
using a data envelopment analysis model. We consider the retail price as a measure of the product’s economic value and the
ecopoint LCA score as the assessment of its environmental impact. We conclude that cell phones and the bulky analyzed appliances
have the highest eco-efficiency scores, whereas the rest would require a more environmentally friendly redesign and/or an
increase in their perceived value to improve their eco-efficiency. 相似文献
85.
During their seasonal runs in the Okavango and other freshwater bodies in southern Africa, the sharptooth catfish, Clarias gariepinus, specialises on the bulldog, Marcusenius macrolepidotus, as its main prey. We examined whether the catfish can locate bulldogs by detecting their pulse-type electric organ discharges
(EODs). The electrosensory threshold for single-cycle, monopolar square-wave pulses was exceedingly low (down to 13 μVp–p/cm for 4-ms pulses) in trained, food-rewarded sharptooth catfish (n=4), confirming the results of Lissmann and Machin who were, however, unable to identify a biological function. Other stimulus
pulse waveforms (single-cycle, monopolar as well as bipolar sine-wave pulses) were also effective stimuli according to their
spectral low-frequency energy contents (0– 30 Hz). Male bulldogs display an EOD pulse approximately 10× the duration of female
EODs (≈0.5 ms). The C. gariepinus threshold for field-recorded playbacks of a male bulldog EOD (of long duration) was 103 μVp–p/cm, whereas the brief female and juvenile EODs were not detected (using intensities of natural EODs). EODs of other mormyrids
were detected when either monopolar or of long duration. Signal source amplitude increased linearly with standard length (SL)
in bulldogs. Signal reach, as calculated from signal source amplitude and receiver sensitivity, is up to 150 cm for a large
male bulldog (SL 27.5 cm), and 83 cm for a male that has just turned sexually mature (SL 12.6 cm). Therefore, most bulldogs
eaten by catfish are probably male, in agreement with the size distribution of bulldogs found in catfish stomachs. These results
suggest that sharptooth catfish rely heavily on their acute electrical sense during hunting, and an important function for
electroreception in an African catfish has been identified.
Received: 13 December 1999 / Revised: 20 April 2000 / Accepted: 20 May 2000 相似文献
86.
87.
为了加快大气降尘样品的蒸发速度和报出数据的及时,经过分析总结,得出蒸发样品的步骤为:先电热套蒸发再水浴蒸发最后用电热板蒸发,这样既可以节省时间,又可以节约能耗,避免样品在空气中放置时间过长,空气中的尘粒进入样品中,影响样品测定的结果。 相似文献
88.
Eun-Hee Kim 《Journal of Environmental Economics and Management》2011,61(3):311-326
Although mandatory disclosure programs have been studied extensively, strategic voluntary environmental disclosures by firms are not well understood. We study the motivations for and impacts of firms' strategic disclosure of greenhouse gas reductions to the US government. We first model firms' joint abatement and disclosure decisions, incorporating both economic and political incentives. We then use data from the Department of Energy's Voluntary Greenhouse Gas Registry to compare reported reductions to actual emissions. We find that participants in the program engage in highly selective reporting: in the aggregate, they increase emissions over time but report reductions. In contrast, non-participants decrease emissions over time. Participants tend to be large firms facing strong regulatory pressure; pressure from environmental groups reduces the likelihood of participation, suggesting such groups viewed the program as a form of greenwash. Participating in the 1605(b) program had no significant effect on a firm's changes in carbon intensity over time. 相似文献
89.
电动助力转向装置是汽车上一种新的助力转向系统装置 ,近年来在国内外发展迅速 ,由于它采用了可编程电子控制装置 ,在带来灵活性的同时也存在着安全隐患。在分析这种产品特殊性的基础上 ,笔者结合电子控制装置的特点 ,指出了事关安全性的因素 ,提出了处理安全性的措施 ,并讨论了几个事关安全性的具体问题。研究结果表明 :现有标准不能够满足电动助力转向装置安全性的需要 ;并提出了对电动助力转向装置进行安全性测评的思想。研究工作对电动助力转向装置的开发以及评价具有参考意义。 相似文献
90.
Experimental study on thermal runaway risk of 18650 lithium ion battery under side-heating condition
To simulate the heat transfer process between lithium-ion batteries (LIBs), an electric heater with the same size and shape as LIB in this work is used to trigger thermal runaway event. The effect of state of charge (SOC), the power of heater, the cell spacing on thermal behavior of LIB was investigated as well the amount of transferred heat between the heater and LIB was calculated. The results indicate that 50% SOC is an unstable state for LIB, that a stronger jet flame becomes more likely when the SOC of LIB is higher than 50%. Additionally, the increased spacing, lower heating power and SOC can contribute to mitigate the severity of thermal runaway behavior. Further, the dominant path of heat transfer between the heater and LIB will also vary with operating conditions. The heat conduction through air is the main heat transfer path in tests with lower heating power. However, heat radiation will replace heat conduction as the primary heat transfer mode when there is a large temperature difference between the heater and LIB in tests with higher heating power. Understanding the leading heat transfer path between LIBs can provide valuable guidelines for the safety design of lithium-ion battery modules. 相似文献