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本文分析了危险废物所产生的危害及分类管理的原则,并探讨了分类管理危险废物时存在的问题,从而论证了分类管理危险废物的必性。 相似文献
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近几年,广西建设投资呈快速增长之势。在这种建设环境的刺激下,商品混凝土行业的发展异常活跃。本文结合市场调查,分析了广西商品混凝土行业现状,并指出了行业目前存在的主要问题,最后对行业发展提出了相应的建议。 相似文献
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聚氨酯基复合材料是近年来新研发出的新型复合材料,其具有良好的力学性能及可加工性,广泛应用于电力及建筑领域.目前国内对其的相关报道主要集中对0°、90°、±45°铺层方向上,对小角度夹角聚氨酯基复合材料力学性能分析鲜有报道,做了大量验证性的试验,系统地研究了小角度聚氨酯基复合材料的基本力学性能,为电力杆塔的合理设计提供可靠的数据支持. 相似文献
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In this paper,a novel method called fuzzy diffusion maps (FDM) is proposed to evaluate cartoon similarity,which is critical to the applications of cartoon recognition,cartoon clustering and cartoon reusing.We find that the features from heterogeneous sources have different influence on cartoon similarity estimation.In order to take all the features into consideration,a fuzzy consistent relation is presented to convert the preference order of the features into preference degree,from which the weights are calculated.Based on the features and weights,the sum of the squared differences (L2) can be calculated between any cartoon data.However,it has been demonstrated in some research work that the cartoon dataset lies in a low-dimensional manifold,in which the L2 distance cannot evaluate the similarity directly.Unlike the global geodesic distance preserved in Isomap,the local neighboring relationship preserved in Locally Linear Embedding,and the local similarities of neighboring points preserved in Laplacian Eigenmaps,the diffusion maps we adopt preserve diffusion distance summing over all paths of length connecting the two data.As a consequence,this diffusion distance is very robust to noise perturbation.Our experiment in cartoon classification using Receiver Operating Curves shows fuzzy consistent relation’s excellent performance on weights assignment.The FDM’s performance on cartoon similarity evaluation is tested on the experiments of cartoon recognition and clustering.The results show that FDM can evaluate the cartoon similarity more precisely and stably compared with other methods. 相似文献
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对于具有淤沙复盖可冲性河床的浑水河流来说,在许多问题中,如悬移质分布或河床稳定等,河床质的组成是一个主要因素。倘若说冲积河流的水力特点可由它的河床质的组成来代表是不会过分的。不过河床质的科学研究目前尚属初期阶段,即使测验成果也不多;除开在美国密士失必河流域对于河床质组成有较多的研究,并且能提供研究河流动力学的一些有用材料(1935年美国水道试验)以来,在中国任何河流实际上尚无资料。本文论及长江下游,包括海口以上约1300公里的干流河段以及几个支流所采集的河床质的机械分析成果,虽采样不多,但已足以说时长江下游水系河床质的一般特性了。 相似文献
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