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951.
双重网格技术是将有限元计算用网格与材料质点网格分开,通过两层网格的信息传递,可将有限元网格上的位移、速率、应变速率映射到材料质点网格上去.采用这种方法,避免了大变形中需多次重新生成网格的问题,大大缩短了上机时间,同时还能直观反映各质点从变形开始到变形结束时的位移. 相似文献
952.
Lu WJ Wang HT Nie YF Wang ZC Huang DY Qiu XY Chen JC 《Journal of environmental science and health. Part. B》2004,39(5-6):871-887
A lab-scale composting experiment was carried out using vegetable and flower stalks waste to study the effectiveness of ligno-cellulolytic microorganisms (LCMs) obtained from the previous isolation on composting process, especially on enhancement of biodegradation rate of these organic materials. The addition of LCMs to compost showed promised to be a valuable asset by rendering timely benefits in efficiency, maturity, and quality of the composting. This was evidenced by a significant increase of temperature, O2 consumption and CO2 emission, and population density of LCMs in compost mass compared with that of biotic (addition of culture of horse feces) and abiotic (1% molasses amendment) treatments, as well as control trial. The phytotoxicity assay showed that the substrate became mature after 60 days' composting. The LCMs inoculation enhanced the biodegradation of the composting materials as evidenced by an increasing screening ratio (1.2 cm sieve pore) of 34.5% in the treated trail, compared with that of control, which elucidated that big advantage of adding selected inoculants over other treatment, and screening ratio is a reasonable index to compare the quality of different compost. However, the inoculation seemed to have no significant effect on the moisture content, pH, and the final organic carbon of the composting materials. 相似文献
953.
将正交实验法用于湿式烟气脱硫装置离心式除水器脱水性能实验中,通过对实验数据的方差分析,确定了除水器各结构参数对脱水性能影响的显著水平及最佳结构参数,实现了除水器的优化设计。 相似文献
954.
本文分析了赤水市山地丘陵气候的垂直变化规律,根据各气侯观测资料和温度垂直分布模型,推算出不同海拔高度各温度要素值。根据热量条件指标的自然分异和果树分布的实际情况,划分出不同农业气候层的高度,并对主要果树在赤水地区种植的适宜高度进行了气候适宜性分析,提出了不同农业气候层次的果树发展方向。 相似文献
955.
江汉平原的芦苇土壤资源和开发利用 总被引:4,自引:0,他引:4
丘华昌 《长江流域资源与环境》1994,3(2):132-135
研究了江汉平原芦苇土壤资源的分布特点,形成条件与肥力性质,所得结果指出了这些土壤资源开发利用中应注意的问题,为提高这些土壤资源的生产力并加以开发利用提出了一些建议。 相似文献
956.
Parameter determination to calculate water environmental capacity in
Zhangweinan Canal Sub-basin in China 总被引:1,自引:0,他引:1
Zhangweinan canal sub-basin (ZWN) has the most serious water resource shortage and water pollution problems in north of China. To calculate the water environmental capacity in ZWN, determination methods for design flow rates and degradation coeffcients were discussed in this study. Results showed that 90% and 50% hydrological guarantee flow rates were suitable to be the design flow rates for rainy and dry seasons, respectively. Degradation coeffcients of CODMn and NH3-N were 0.25 day−1 and 0.15 day−1 for branch streams and 0.5 day−1 and 0.25 day−1 for mainstreams, respectively in ZWN. With one-dimensional water quality simulation model, water environmental capacities were calculated to be 82,139 tons/yr for CODMn and 2394 tons/yr for NH3-N in ZWN. 相似文献
957.
Yong Qiu He Jing Hanchang Shi 《Frontiers of Environmental Science & Engineering in China》2010,4(3):301-310
Perfluorinated compounds (PFCs) are ubiquitously distributed in the environment mainly as perfluorocarboxylic acids (PFCAs)
and perfluoroalkyl sulfonates (PFASs). In this paper, six PFCAs and two PFASs were quantified in surface and tap water samples
from 12 sites around Lake Taihu near Shanghai City in East China. Predominant PFCs were perfluorooctanoic acid (PFOA) and
perfluorooctane sulfonate (PFOS), of which the concentration ranges were 6.8–206 and 1.2–45 ng·L−1, the geometric means were 35.3 and 9.4 ng·L−1, and the median (quartile range) values were 31.4 (34.4) and 10.4 (10.7) ng·L−1, respectively. Other PFCs were also detected but in much lower concentrations than PFOA. The sources of the PFCs were expected
to be direct industrial discharges in the Lake Taihu area, and this area was also a possible source of PFCs contaminations
in Shanghai district in the downstream. PFCs distributions were found different in the upstream, downstream and north part
of Lake Taihu. Occurrences of PFCs in the tap water in Lake Taihu area indicated their exposure to the local people. A brief
estimation of the environmental risks by PFCs implied no acute or immediate risks from PFCs to local human health, but chronic
risks from PFOA in the tap water should be considered in the downstream regions. 相似文献
958.
铝合金电镀环评中污染防治措施若干问题的探讨 总被引:1,自引:0,他引:1
针对铝合金电镀环境影响评价中废水分类、水质特征及污染防治措施等问题进行了讨论,同时结合作者的工作实践,对电镀废水分类原则、处理工艺及其可靠性进行了分析,并提出了一系列适用于国家新颁布的《电镀污染物排放标准》(GB21900-2008)的工艺措施。 相似文献
959.
从某高矿化度含油废水中筛选得到两株有效去除废水中有机物的高效降解菌株L1和Yj。通过VITEKTWO鉴定系统初步鉴定,得出LI为放射型根瘤菌(Rhizobium radiobacter)Yj为少见罗尔斯顿茼(Ralstonia paucula)。研究得到两株菌在pH为7、温度为40℃时生物量最大,两株菌在此条件培养下以1:1质量比复配投加对含油废水的有机物降解率在3h达39%,在6h达53%,提高了生物法处理含油废水的降解效率。 相似文献
960.