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171.
Peidong Su Xiangyu Gao Junke Zhang Ridha Djellabi Bo Yang Qi Wu Zhen Wen 《Frontiers of Environmental Science & Engineering》2021,15(6):130
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电梯维护保养质量评价是一项评价指标多,指标间关系复杂,评判结论模糊的工作。应用灰色综合评价法对解决以上工作中的难点有很好的效果。本文介绍了灰色综合评价法的基本思想和原理,给出了灰色评价法指标体系的构造方法、计算过程以及关联系数计算公式的分辨系数选取原则。通过实例分析,得出电梯维护保养质量评价中应用灰色综合评价法的特点和要注意的事项。 相似文献
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China is the world's largest energy consumer, and coal accounts for a higher proportion of the country's total energy consumption, yet during its 12th five-year plan (2011–2015), the coal share among total energy consumption significantly decreased. Previous studies exploring energy performance typically used energy consumption as an input, but this lacks the analytical capacity for the structure of energy consumption. Thus, this study splits energy input into two different inputs, coal consumption and non-coal energy consumption, and based on their differences with other variables, uses the hybrid dynamic data envelopment analysis model to assess the energy performance of China's provincial industrial sector during the period 2011 to 2015. We then compare coal consumption's and non-coal consumption's rooms for improvement and conclude that provinces in eastern and central China should reduce the amount of coal consumption, thereby improving energy performance. Conversely, provinces in the western region should target a balance between energy utilization efficiency and coal consumption. 相似文献
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Guohua Su Yelin Huang Fengxiao Tan Xiaowei Ni Tian Tang Suhua Shi 《Marine Biology》2007,150(3):321-328
Mangrove forests, with their ecological significance and economic benefits, are vital inter-tidal wetland ecosystems. Lumnitzera littorea (Combreataceae) is a non-viviparous mangrove distributed in tropical Asia and North Australia. Due to natural and human impacts, populations of this species have been isolated, fragmented, and highly disturbed. In China, L. littorea is an endangered species, restricted to small regions of Hainan Island. The genetic composition of five populations of this species from the Indo-West Pacific (South China, Malay Peninsula, Sri Lanka, North Australia) was assessed using inter simple sequence repeat (ISSR) makers. At the species level, expected mean heterozygosity (He) was 0.240 with 75.6% of loci polymorphic (P). However, genetic variation was much lower at the population level (P = 37.1%, He = 0.118). A high coefficient of gene differentiation (Gst = 0.515) and low level of gene flow (Nm = 0.470) indicated significant genetic differentiation among populations. AMOVA also indicated that more than half the total variation (58.4%) was partitioned among populations. The high degree of differentiation observed among populations emphasizes the need for appropriate conservation measures that incorporate additional populations into protected areas, and achieve the restoration of separate, degraded populations. 相似文献
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铝盐最佳混凝形态及最佳pH范围研究 总被引:38,自引:3,他引:38
本文从理论上分析了铝盐的水解聚合过程,预测了铝盐混凝过程进行时的最佳混凝形态及最佳pH范围,并且通过实验手段分析说明了铝盐的最佳混凝形态,混凝特征及最佳pH范围,得到了较为一致的结果。 相似文献