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91.
青藏铁路建设中高寒缺氧及保障问题的研讨 总被引:2,自引:1,他引:1
“高寒缺氧”是青藏铁路建设面临的主要难题之一,青藏铁路沿线自然条件恶劣、海拔高、气压低,含氧量低,缺氧严重会导致急性高原病严重影响人体健康和劳动能力,同时含氧量低会造成机械功率降低。为保障高原施工人员和铁路建设者的健康和安全,降低机械设备的功率损耗,在青藏铁路的设计和建设中,必须采取高原劳动卫生和劳动保护措施、选用可靠度高、维修量少的运营设备,建立起适合高原特点的管理体制、机构及合理的用工制度等技术保障措施,提供坚强有力的医疗卫生保障,从而提高劳动效率,降低劳动强度、缩短工期,保护员工的安全与健康。 相似文献
92.
Mary E. McAfee 《Journal of the American Water Resources Association》1980,16(4):690-696
ABSTRACT: Two small cold water reservoirs with stable water levels were compared with two reservoirs scheduled for complete drawdown to determine the effects of drawdown on invertebrate abundance and fish abundance and density. An extensive literature review supplemented the results with other applicable information. No conclusive evidence of effects of drawdown on invertebrates or fish was found. Characteristics of a reservoir and its drainage basin which obscure or lessen drawdown effects are discussed. Analysis and observation of drawdown procedures showed that duration and scheduling of draw-down periods are important in determining whether drawdown will be harmful to fauna in a given reservoir. 相似文献
93.
Ronald L. Wycoff Udai P. Singh 《Journal of the American Water Resources Association》1980,16(3):463-470
ABSTRACT: This paper describes the Continuous Stormwater Pollution Simulation System (CSPSS) as well as a site-specific application of CSPSS to the Philadelphia urban area and its receiving water, the Delaware Estuary. Conceptually, CSPSS simulates the quantity and quality or urban stormwater runoff, combined sewer overflow, municipal and industrial waste water effuent, and upstream flow on a continuous basis for each time step in the simulation period. In addition, receiving water dissolved oxygen, suspended solids, and lead concentrations resulting from these pollutant sources may be simulated. However, only rceiving water dissolved oxygen (DO) response is considered in this paper. The continuous Do receiving water response model was calibrated to existing conditions usinv observed data at Chester, Pennsylvnia, located on the Delaware Estuary approximately 10 miles down stream from the study area. Average annual pollutant loads to the receiving water were estimated for all major sources and receiving water quality improvements resulting from removal of various portions of these pollutant loads were estimated by application of the calibrated stimultion model. It was found that the removal of oxygen-demanding pollutants from combined sewer overflow and urban stormwater runoff would result in relatively minor improvements in the overall dissoved oxygen resources of the Delaware Estuary; whereas. removal of oxygen demanding pollutants from waste water treatment plant effluent would result in greater improvemens. The results of this investigation can be used along with appropriate economic techniques to identify the most cost-effective mix of point and nonpoint source pollution control measures. 相似文献
94.
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96.
J. J. M. Cuppen G. F. Wiegertjes H. W. J. Lobee H. F. J. Savelkoul M. A. Elmusharaf A. C. Beynen H. N. A. Grooten W. Smink 《The Environmentalist》2007,27(4):577-583
A hypothesis is proposed how Low Frequency Electromagnetic Field (LF EMF) exposure can stimulate an immune response, based
on recent insights in immunology. We hypothesize that the Immunent EMF treatment induces mild stress to cells, which then
produce cytokines that function as alarms or so called danger signals for the immune system. In this way EMF treatment takes
the place of multiplying pathogens, and the damage these cause, in the triggering of an immune response. In a first series
of experiments in␣vitro common carp head kidney-derived phagocytes were used to determine ROS production as a measure for
immune activation. Exposure to LF EMF signals (200–5,000 Hz) at 5 μT or 1.5 mT led to 42 or 33% increase in immune activity,
respectively, compared to negative control values. EMF could also additionally stimulate chemically pre-stimulated samples
up to 18% (5 μT) or 22% (1.5 mT). Significance of increase in ROS production in the total series was: p < 0.0001. In a second series of experiments in␣vitro commercial goldfish were used. Groups of fish were housed under equal
conditions in at least four control tanks and 8–16 EMF-exposed tanks. Exposure was done with a predominantly vertical field
at field strengths (rms) between 0.15 and 50 μT. Without treatment mortality was about 50% after 18 days, while the treatment
at 5 μT reduced it to 20% on average. At field strengths 0.15, 0.5, 1.5, 5, 15 and 50 μT an equally strong effect was found.
Reducing the field strength to 0.05, 0.06, 0.01 and 0.003 μT showed a gradually decreasing effect, which only at 0.003 μT
is no longer statistically significant. Finally, in␣vitro experiments were done with 560 commercial broiler chickens exposed
to infection pressure from coccidiosis. EMF exposure at 6.5 μT reduced intestinal lesions by 40% and improved feed conversion
by 8%. 相似文献
97.
98.
低温等离子体及其在废气处理中的应用 总被引:15,自引:0,他引:15
介绍了等离子体的概念及分类、低温等离子体的产生方法,概述了低温等离子体处理烟道气有机废气的应用研究进展情况,并指出了今后低温等离子体处理废气的应用研究方向。 相似文献
99.
云南稻核心种质苗期与孕穗期耐冷性特点及关系分析 总被引:2,自引:1,他引:1
以544份云南地方稻核心种质为材料,在昆明自然低温(苗期平均5.5~12.3℃,孕穗期平均17.8℃)冷害下,按籼粳、稻作区进行云南稻核心种质苗期耐冷性与孕穗期耐冷性的特点及关系研究.结果表明:(1)苗期耐冷性与孕穗期耐冷性密切相关,苗期耐冷性强的材料表现为孕穗期株高、剑叶长和宽、穗颈长、穗下节长、1~2节长、穗长较长、穗粒数较多,耐冷性较强.通过对苗期耐冷性的严格选择,可以间接获得孕穗期耐冷性较强的材料.(2)苗期和孕穗期耐冷性在籼粳间、稻作区间差异明显.籼粳间均表现为粳稻强于籼稻;稻作区间苗期耐冷性为滇中一季籼粳稻区和滇南单双季籼稻区最强,滇中一季籼粳稻区和滇西北高寒粳稻区孕穗期耐冷性较强,揭示了水稻苗期与穗期耐冷性的形成演化机制存在一致性和差异性. 相似文献
100.
低温等离子体技术在环境工程中的研究进展 总被引:11,自引:0,他引:11
低温等离子体技术是一种用来处理环境污染问题的高新技术。介绍了低温等离子体的概念和去除污染物的机理,阐述了该技术在国内外环境工程中的应用现状,分析其存在的问题,并指出今后的发展方向。 相似文献