排序方式: 共有56条查询结果,搜索用时 312 毫秒
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《Process Safety and Environmental Protection》2014,92(6):637-644
In China, more than 2.65 million coal mine workers are exposed to coal dust. Every year, new pneumoconiosis cases amount to 25,000, among which 6000 cases die of this disease. The figure is twice the death toll in production safety accidents. Occupational diseases seriously endanger life and health of coal mine workers, and restrict the healthy growth of the coal industry.The paper presented a study of foam–sol-based coal dust control. This was an experimental study of characteristics of foam–sol-based coal dust control, which features dust capture, suppression, and isolation. Comparative wettability experiments were carried out to determine contact angles of water, aqueous foam, and foam–sol solution. A new foam–sol generating system with a conical diffuser outlet was proposed.The experiment results clearly showed that the foam–sol features dust capture, suppression, and isolation. The wettability of the aqueous foam solution was better than the foam–sol solution, but the foam–sol technology had the better ability to capture the airborne dust, suppress the static dust and enclose the dust source, due to the excellent surface viscosity, strong cohesiveness and less volatile property. The paper concluded that the foam–sol could greatly improve the dust control efficiency and did not have main deficiencies that the aqueous foam technology had. 相似文献
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五滚柱式定向离合器是一种广泛用于机床、汽车、飞机及其他机械的装置。五滚柱式定向离合器的外环形状很不规则 ,其接触应力的计算为国内外工程界的难题之一。笔者采用弹性力学方法计算出了其接触应力 ,并用光弹性实验技术验证 ,理论计算的应力与实测结果基本吻合 相似文献
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优势微生物强化水解—多级接触氧化工艺处理屠宰废水 总被引:2,自引:0,他引:2
结合工程实例,本文对优势微生物强化水解—多级接触氧化处理屠宰废水工艺及设计体会进行了讨论。设计进水COD、BOD5、SS、NH3-N、动植物油为2300~2700mg/L、900~1300mg/L、600~800mg/L、100~120mg/L、70~90mg/L,出水为90mg/L、20mg/L、60mg/L1、0mg/L1、0 mg/L。实际运行结果表明:主要出水指标COD、BOD5、SS、NH3-N、动植物油的去除率分别可达到97.9%、98.6%、93.7%、93.4%、90.7%。该工艺具有占地少、建设成本低、运行可靠、稳定达标、剩余污泥少、运行成本低、维护简便等优点。 相似文献
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Structure of the social network and its influence on transmission dynamics in a honeybee colony 总被引:4,自引:3,他引:1
Dhruba Naug 《Behavioral ecology and sociobiology》2008,62(11):1719-1725
Infectious processes in a social group are driven by a network of contacts that is generally structured by the organization
arising from behavioral and spatial heterogeneities within the group. Although theoretical models of transmission dynamics
have placed an overwhelming emphasis on the importance of understanding the network structure in a social group, empirical
data regarding such contact structures are rare. In this paper, I analyze the network structure and the correlated transmission
dynamics within a honeybee colony as determined by food transfer interactions and the changes produced in it by an experimental
manipulation. The study demonstrates that widespread transmission in the colony is correlated to a lower clustering coefficient
and higher robustness of the social network. I also show that the social network in the colony is determined by the spatial
distribution of various age classes, and the resulting organizational structure provides some amount of immunity to the young
individuals. The results of this study demonstrates how, using the honeybee colony as a model system, concepts in network
theory can be combined with those in behavioral ecology to gain a better understanding of social transmission processes, especially
those related to disease dynamics. 相似文献
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Prem Kumar Bikkina 《International Journal of Greenhouse Gas Control》2011,5(5):1259-1271
This work presents contact angle measurements for CO2–water–quartz/calcite systems at general sequestration pressure and temperature conditions (200–3000 psig and 77–122 °F). The effect of drop volume, repeated exposure of the substrates to dense water saturated CO2, pressure and temperature on the contact angles is examined. In the 1st measurement cycle, the contact angles for the quartz substrate varied from 46 to 48° and 47 to 46° for gaseous (water saturated) CO2 and liquid (water saturated) CO2 respectively, at 77 °F. For calcite substrate, these values varied from 45 to 48° and 42 to 40°, respectively. Remarkably, this work highlights a characteristic permanent shift in the contact angle data with repeated exposure to dense, water saturated, CO2. The contact angle data trends after repeated exposure to the dense, water saturated CO2 varied from 89 to 91° and 85 to 80° for the quartz substrate for gaseous (water saturated) CO2 and liquid (water saturated) CO2 respectively, at 77 °F. For calcite substrates, these values varied from 60 to 59° and 54 to 48°, respectively. This important observation has serious implications towards the design and safety issues, as a permanent positive contact angle shift indicates lower CO2 retention capabilities of sequestration sites due to a reduction in the capillary pressure. It is further confirmed that the permanent shift in the contact angle is due to surface phenomena. With an increase in temperature (from 77 to 122 °F), the contact angle shift is reduced from about 45° to about 20° for quartz substrates. Other observations in the contact angle data with respect to pressure are in good agreement with the trends reported in the literature. 相似文献
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《Journal of Manufacturing Processes》2014,16(2):183-189
The reported investigation is related to laser beam braze-welding technology for dissimilar aluminum–copper interconnects for Li-ion battery assembly. The correlation between the brittle and high-resistivity intermetallic compounds and the electrical contact resistance showed that a thin intermetallic layer is highly desirable. It was proved that highest shear strength and lowest contact resistance can be achieved within the same parameter set which is of particular interest to battery electrical vehicle applications requiring both high mechanical reliability and electrical performance.A study on the weld seam layout further showed that two parallel weld seams with optimized spacing and overlap design provide lowest contact resistance. 相似文献