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951.
道路交通事故再现不仅是交通事故责任鉴定和原因分析的重要方法,也是交通事故防治的重要内容。在详细介绍国内外事故再现计算机仿真技术的基础上,分析目前事故再现系统开发中事故现场数据采集技术、碰撞前后速度估算的技术、碰撞过程进行模拟的虚拟现实技术的研究现状与存在的问题,提出进一步优化的方向,进而达到完善交通事故模拟再现的目的。最后指出我国交通事故再现技术进一步研究的内容和发展趋势。 相似文献
952.
通过对典型商贸市场的实地调研,依据历年商贸市场火灾事故统计数据,采用将统计方法与专家评分相结合的方法,运用系统安全及模糊数学的相关理论,提出了商贸市场火灾风险评估方法,从而为商贸市场的安全管理及火灾风险评价提供了切实可行的参考依据。 相似文献
953.
954.
杨辉 《中国个体防护装备》2007,(6):36-38
据最新研究表明.用户的满意程度和企业的盈利能力与产品和服务的质量紧密相关。较高的产品质量和服务质量,能使用户满意,同时也能维持较高的价格。因此,质量改进方案通常会增加企业的盈利能力。 相似文献
955.
956.
Xiaoying Yang Benedykt Dziegielewski 《Journal of the American Water Resources Association》2007,43(1):160-169
Abstract: Thermoelectric power generation is responsible for the largest annual volume of water withdrawals in the United States although it is only a distant third after irrigation and industrial sectors in consumptive use. The substantial water withdrawals by thermoelectric power plants can have significant impacts on local surface and ground water sources, especially in arid regions. However, there are few studies of the determinants of water use in thermoelectric generation. Analysis of thermoelectric water use data in existing steam thermoelectric power plants shows that there is wide variability in unitary thermoelectric water use (in cubic decimeters per 1 kWh) within and among different types of cooling systems. Multiple‐regression models of unit thermoelectric water use were developed to identify significant determinants of unit thermoelectric water use. The high variability of unit usage rates indicates that there is a significant potential for water conservation in existing thermoelectric power plants. 相似文献
957.
对乌鲁木齐市燃煤点派数量、耗煤量、污染物的排放量以及在各功能区的分布分别进行了统计分析,对污染物的排放量在不同高度空间的分布也进行了统计分析,从而得出了确切的结论并提出了相应的建议。 相似文献
958.
Contamination of oxygen-consuming organics (OCOs) was one of the most serious problems in the Yellow River of China. This
study was conducted to analyze monitoring of the data on OCOs contamination for the river in 1980 and during 1992–1999 as
well as examining the effect of suspended solids (SS) on chemical oxygen demand (CODMn) and biochemical oxygen demand (BOD5) of river water. Several significant results have arisen from the study. First, CODMn and BOD5 of the river water showed an increasing trend from the upper to the lower reaches of the mainstream. BOD5 values of river water in 1992 were significantly higher than those in 1980 and showed an increasing trend during 1992–1999.
Second, OCOs in river water of the mainstream was attributed mainly to point sources; the ratio of point to non-point sources
of BOD5 was about 2.81. The load from point sources showed an increasing trend during 1992–1998. In contrast, the load from non-point
sources manifested a decreasing trend during this period; this was caused by the decreasing trend of SS content in river water.
The total load of BOD5 from point and non-point sources displayed an increasing trend during 1992–1998. Third, as the humic substances in SS can
hardly be biologically oxidized in natural conditions but can be oxidized by chemical oxidants such as potassium permanganate,
CODMn was not suitable for being regarded as a parameter reflecting the pollution degree of OCOs in river water with a high SS
content. 相似文献
959.
通过间歇处理和连续处理实验,探讨微波技术对沼液中四环素类抗生素和激素喹乙醇去除的效果。结果表明,沼液在微波间歇处理中,最优反应时间为40min。此条件下沼液中喹乙醇、土霉素、四环素和金霉素的去除率分别达到26%、49%、48%和70%;微波可显著提高可生化性,BOD5/COD值达到0.37。微波一好氧处理系统中COD与氨氮的去除率分别达到91%和93%,明显优于单独好氧处理。沼液微波连续处理中,最优HRT为90min,此时喹乙醇、土霉素、四环素和金霉素的去除率分别达到24%、45%、50%和74%;BOD5/COD值达到0.34。微波.好氧处理系统中COD与氨氮的去除率均为90%,优于单独好氧处理效果。 相似文献
960.
Ambient levels of phosphine (PH3) in the air, phosphine emission fluxes from paddy fields and rice plants, and the distribution of matrix-bound phosphine (MBP) in paddy soils were investigated throughout the growing stages of rice. The relationships between MBP and environmental factors were analyzed to identify the principal factors determining the distribution of MBP. The phosphine ambient levels ranged from 2.368 ± 0.6060 ng m−3 to 24.83 ± 6.529 ng m−3 and averaged 14.25 ± 4.547 ng m−3. The highest phosphine emission flux was 22.54 ± 3.897 ng (m2 h)−1, the lowest flux was 7.64 ± 4.83 ng (m2 h)−1, and the average flux was 14.17 ± 4.977 ng (m2 h)−1. Rice plants transport a significant portion of the phosphine emitted from the paddy fields. The highest contribution rate of rice plants to the phosphine emission fluxes reached 73.73% and the average contribution was 43.00%. The average MBP content of 111.6 ng kg−1fluctuated significantly in different stages of rice growth and initially increased then decreased with increasing depth. The peak MBP content in each growth stage occurred approximately 10 cm under the surface of paddy soils. Pearson correlation analyses and stepwise multiple regression analysis showed that soil temperature (Ts), acid phosphatase (ACP) and total phosphorus (TP) were the principal environmental factors, with correlative rankings of Ts > ACP > TP. 相似文献