排序方式: 共有3条查询结果,搜索用时 31 毫秒
1
1.
Depth of field effects in laser sheet imaging were considered for droplet sizing of a pre-swirl spray. A pre-swirl spray is
formed before the hollow-cone type main-swirl spray from a D.I. gasoline injector, and shows transient characteristics with
high axial velocity. A microscopic imaging technique was applied to obtain high spatial resolution LIF tomograms of the pre-swirl
spray. A 1 mm thick Nd:YAG laser sheet was used as a light source to make the LIF tomograms that were imaged using a high-resolution
CCD camera. The droplet sizing of the pre-swirl spray was carried out using an image processing technique. In the image processing
procedure, the laser sheet-straddling large-sized droplets were carefully taken into account to remove the errors caused by
the depth of field effects from the limited thickness and the energy distribution of the laser sheet. The mean intensity of
the individual droplets and the line profile of the LIF signal around the droplet edge were inspected to screen the laser
sheet-straddling large-sized droplets. In order to consider the effects of the size-dependent LIF signal intensity, the size-classified
or ensemble-averaged mean intensity of the individual droplets was introduced. The mean droplet sizes such as AMD and SMD
were calculated using only screened droplets, and they slightly increase before considering the depth of field effects. 相似文献
2.
单细胞凝胶电泳技术检测小鼠成纤维细胞DNA的氧化损伤及修复 总被引:1,自引:0,他引:1
目的观察小鼠成纤维细胞由过氧化氢(H2O2)引起的DNA损伤及其修复,并详细介绍单细胞凝胶电泳技术。方法培养NIH3T3细胞,H2O2造成细胞氧化损伤,单细胞凝胶电泳技术(SCGE,Comet Assay)检测细胞DNA的损伤情况。结果①建立了H2O2致NIH3T3细胞DNA损伤的分级图谱;②H2O2引起的小鼠成纤维细胞DNA单链断裂与H2O2的浓度呈依赖性关系;③细胞在除去H2O2后15 min已出现明显修复,多数修复可在1 h内完成,但少数修复可能需要较长时间才能完成。结论单细胞凝胶电泳技术是一种简便、敏感的检测DNA氧化损伤的方法。 相似文献
3.
Tran Hong Ha Osami Nishida Hirotsugu Fujita Harano Wataru 《Journal of Marine Science and Technology》2010,15(3):271-279
Marine diesel engines are major sources of air pollution. They emit a large amount of pollutants, including diesel particulate
matter (DPM), carbon oxide (CO
x
), unburned hydrocarbons (HC), nitrogen oxide (NO
x
), sulfur oxide (SO
x
), and other products of combustion. Among these, DPM may cause respiratory and mutagenic diseases in humans, including lung
and bladder cancer (see Donaldson et al. J Aerosol Sci 29:553–560, 1998). In this study, experiments were performed with an
electrostatic water-spraying scrubber (EWSS) to evaluate its effectiveness for the collection of mass- and number-based DPM
emissions from a marine diesel engine. The results show that the collection efficiency of the scrubber increases as the engine
load increases due to an increase in the large DPM concentration and an increase in the amount of DPM collected by the charged
droplets. The effect of water spraying performance on DPM collection at constant engine load was investigated experimentally.
The strength of the electrical attraction between the charged water droplets and the charged DPM within the scrubber led to
a significant increase in total DPM collection efficiency (up to 4–7 times). In addition, the total DPM collection efficiency
was found to be directly related to the corona power, the electrical properties of water, water spraying performance and engine
load. The EWSS appears to be a promising alternative method for controlling mass-based as well as number-based DPM emissions. 相似文献
1