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1.
滑坡相似材料试验结果优化分析研究 总被引:2,自引:0,他引:2
在运用模糊综合评判确定的滑坡相似材料试验配合比隶属度基础上,利用方差分析确定各因素的数学优化区间,结合变量有上下界的改进单纯形法,获得技术,经济上的最佳配合比,克服了统计优化理论不能在连续区间寻优的缺点,这对从事滑坡相似材料试验研究具有一定的实际意义。 相似文献
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Lime-induced chlorosis is a potential problem on most calcareous soils particularly in arid and semi-arid climates affecting most of the plants grown on them. Bicarbonates, phosphates, calcium, iron inactivation in plant tissue and organic anions have been held responsible as the mechanism leading to the disorder which is still not fully understood, and there is a lack of agreement as to the primary factor responsible for lime-induced chlorosis. To date, no hypothesis has adequately explained why chlorosis occurs on some high lime soils and not on others. Likewise, the nutrient ratios, K/Ca, P/Fe and Fe/Mn considered as diagnostic criteria for lime-induced chlorosis, have shown inconsistency. The presence of calcium carbonate, bicarbonate, calcium and imbalance of nutrient cations in the growth medium, injudicious addition of phosphates, quality of irrigation water, and other soil and plant factors have been held responsible for the disorder. Amelioration of lime-induced chlorosis by (i) acidification of calcareous soils, (ii) use of iron salts, (iii) use of synthetic iron chelates, and (iv) by management practices including the selection and development of varieties resistant to lime-induced iron chlorosis, is discussed. Suggestions for future research work are made. 相似文献
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The construction of dams significantly alters flow and sediment regimes with subsequent deleterious effects on the morphological and ecological character of rivers. Effective experimental floods can ameliorate the downstream geomorphic impacts of dams. The traditional view is that large floods are required to perform effective geomorphic work, and the geomorphic outcomes of small floods are often overlooked. Many river restoration frameworks do not consider small floods. Yet, there is evidence that the hydrological characteristics that ameliorate specific geomorphic impacts in a river are unique to each river, and a customised approach to setting the right mix of floods (including small experimental floods) is needed. In this study, we modify an existing flood effectiveness model developed for large floods, for determining the geomorphic effectiveness of small floods in a highly regulated Australian river. Two flood classes were added to the model (medium peak stream power and moderate total energy expenditure), and the flood power characteristics were rescaled to reflect the relative difference in the magnitude of the small floods and the magnitude of the geomorphic work performed. Using a step‐wise approach, this customised model determined the geomorphic effectiveness of small floods. The best flood for ameliorating the geomorphic impacts of flow regulation had medium to long duration (10 to 51 days), high peak unit stream power (77 to 123 Wm?2) and moderate to large total energy expenditure (78,600 to 342,320 × 103 J). This approach to determining flood effectiveness for small floods is applicable to other geomorphically impacted river channels downstream of dams and can be used to inform experimental flood releases for geomorphic outcomes. 相似文献
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确定保障能力薄弱环节对提高部队保障能力至关重要,目前保障能力薄弱环节确定有指标评估得分法和权重法两种方法,两种方法均存在一定的片面性。针对存在的问题,提出一种基于指标裕度空间和权重的求指标薄弱度的方法查找、确定保障能力薄弱环节,并且将集对分析的思想应用到指标优化和指标裕度空间的分析求取上,使指标薄弱度更加精确。最后结合某基层一级保障单位进行实例,运用Matlab软件仿真模型,进行保障能力指标薄弱度分析,并与目前存在的两种方法对比分析,实践证明所提出的方法更适用于保障能力薄弱环节的确定。 相似文献
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针对广州员村热电厂0号低压厂用变压器自动开关联锁自动投入不成功的现象,对0号低压厂用变压器的控制回路和联锁回路进行分析,查找问题原因并提出两种解决方法,经过比较分析,采用加装时间继电器KT,取消继电器K2的方法,可改进自动开关的储能功能,缩短备用电源自动投入时间,大大提高合闸可靠性。改造后,0号低压厂用变压器自动开关能正常合闸成功,保证了厂用电的安全。 相似文献
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文中提出光导纤维直径测量系统的新方法.就几种影响因素从理论和实验上对激光衍射法测量细丝直径进行精度分析,改进测量系统,并以正交CCD组为接收元件,解决传统测量方法中存在的不足. 相似文献
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