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排序方式: 共有21条查询结果,搜索用时 343 毫秒
1.
用 S195柴油机为试验样机,采取在进气过程中吸入少量氢气的方法,通过台架试验及分析,探讨了用氢作为涡流室柴油机副燃料的可能性及其实用价值。结果表明,吸入副燃料氢能显著改善燃烧,提高发动机性能,但保证性能良好的许用吸氢量具有一定限度,并存在最佳值;用氢作副燃料时,仅需适当增大涡流室通道截面比,而无需变动燃烧系统其它参数,即可获得较好效果。  相似文献   
2.
介绍了湿喷钢纤维混凝土的工程特性及在布陇箐隧道中的应用,包括“湿喷法”钢纤维混凝土的力学性能指标、材料选择、配合比设计、现场试验、施工工艺等。  相似文献   
3.
针对某型电动喷枪存在噪声过大的问题,通过声压测试实验对电动喷枪5个工况下的A计权声压级进行分析,并对空载情况下的整枪1/3倍频程谱进行分析,得出壳体振动是产生电动喷枪噪声的主要原因。并将各噪声源分离出来,从而提出通过改变壳体结构减少振动的方法来降噪。  相似文献   
4.
The conservation of freshwater is of both global and national importance, and in the United States, agriculture is one of the largest consumers of this resource. Reduction of the strain farming puts on local surface or groundwater is vital for ensuring resilience in the face of climate change, and one possible option is to irrigate with a combination of freshwater and reclaimed water from municipal wastewater treatment facilities. However, this wastewater can contain pathogens that are harmful to human health, such as Legionella pneumophila, which is a bacterium that can survive aerosolization and airborne transportation and cause severe pneumonia when inhaled. To assess an individual adult's risk of infection with L. pneumophila from a single exposure to agricultural spray irrigation, a quantitative microbial risk assessment was conducted for a scenario of spray irrigation in central Illinois, for the growing seasons in 2017, 2018, and 2019. The assessment found that the mean risk of infection for a single exposure exceeded the safety threshold of 10–6 infections/exposure up to 1 km from a low-pressure irrigator and up to 2 km from a high-pressure irrigator, although no median risk exceeded the threshold for any distance or irrigator pressure. These findings suggest that spray irrigation with treated municipal wastewater could be a viable option for reducing freshwater consumption in Midwest farming, as long as irrigation on windy days is avoided and close proximity to the active irrigator is limited.  相似文献   
5.
为探究一种新型旋流式气化炉冷态流场分布特性及内部结构对其流场的影响,应用计算流体力学( CFD)软件 FLUENT对该气化炉进行三维数值模拟分析。采用RNG K-8湍流模型,通过多点测压实验,对模拟结果进行验证,并且 采用不同的开孔率及旋流片角度组合分析气化炉内部结构对其流场的影响。结果表明:模拟和测压实验结果较为一致; 旋流式气化炉内气流主要做螺旋上升运动;栅板开孔率大小主要影响气化炉内压降、轴向速度以及湍流强度;而旋流片 角度则主要影响切向速度及湍流强度分布。新型旋流式气化炉内部栅板旋流片结构可增加气化反应速率及反应停留 时间,有助于气化反应的进行。  相似文献   
6.
《Risk analysis》2018,38(7):1502-1517
Antimicrobial spray products are used by millions of people around the world for cleaning and disinfection of commonly touched surfaces. Influenza A is a pathogen of major concern, leading to up to 49,000 deaths and 114,000 hospitalizations per year in the United States alone. One of the recognized routes of transmission for influenza A is by transfer of viruses from surfaces to hands and subsequently to mucous membranes. Therefore, routine cleaning and disinfection of surfaces is an important part of the environmental management of influenza A. While the emphasis is generally on spraying hard surfaces and laundering cloth and linens with high temperature machine drying, not all surfaces can be treated in this manner. The quantitative microbial risk assessment (QMRA) approach was used to develop a stochastic risk model for estimating the risk of infection from indirect contact with porous fomite with and without surface treatment with an antimicrobial spray. The data collected from laboratory analysis combined with the risk model show that influenza A infection risk can be lowered by four logs after using an antimicrobial spray on a porous surface. Median risk associated with a single touch to a contaminated fabric was estimated to be 1.25 × 10−4 for the untreated surface, and 3.6 × 10−8 for the treated surface as a base case assumption. This single touch scenario was used to develop a generalizable model for estimating risks and comparing scenarios with and without treatment to more realistic multiple touch scenarios over time periods and with contact rates previously reported in the literature. The results of this study and understanding of product efficacy on risk reduction inform and broaden the range of risk management strategies for influenza A by demonstrating effective risk reduction associated with treating nonporous fomites that cannot be laundered at high temperatures.  相似文献   
7.
新型喷雾干燥烟气脱硫性能实验研究   总被引:1,自引:0,他引:1  
提出了一种新型喷雾干燥烟气脱硫工艺,实验研究了影响该工艺性能的主要运行因素,并进行了机理分析,研究结果为该工艺的推广设计提供参考依据。  相似文献   
8.
本文对在淬火油槽内用超声波振动提高油冷却能力的试验进行了研究。提出了用被迫对流和超声波振动同时作用于淬火油槽的方法。试验研究表明,用涡流喷射器作用淬火油槽,可显著提高油的冷却能力。  相似文献   
9.
本文对以铁和硝酸为主要原料制备大型合成氨厂铁基无硫无铬型CO高温变换催化剂的干燥方式进行了研究,探讨了喷雾干燥机的进口温度,固液比等对物料含水量的影响,并对普通箱式干燥和喷雾干燥方式对催化剂性能的影响进行了研究。  相似文献   
10.
作为消费社会资本平台的当代传媒   总被引:3,自引:1,他引:2  
李勇 《北方论丛》2009,(1):58-61
在生产社会向消费社会的转型过程中,媒介的作用不只表现在观念层面,还体现在基础层面.在这一层面,媒介文化生产可以直接转化为资本和现实生产力.具体来说,媒介不仅身体力行作为资本操演平台,更为重要的是,它鼓动社会各领域文化纷纷向资本与消费文化靠拢,并把这种靠拢塑型为普遍的价值趋向.这种普遍性价值趋同效应可以结合传播学的"内爆"理论加以阐释.  相似文献   
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