Phân tích tư tưởng của nhân dân qua đoạn thơ: Những người vợ nhớ chồng… Những cuộc đời đã hóa sông núi ta trong Đất nước của Nguyễn Khoa Điềm
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The effect of washing stabilized and unstabilized blown extruded films of low-density polyethylene (LDPE) used for greenhouse coverings naturally weathered in a sub-Saharan facility at Ghardaïa (Algeria) for 19 and 6 months, respectively, was studied. A comparison between unwashed and daily washed samples was done. The changes in the films’ properties were followed at regular intervals using various characterization methods (physicochemical and mechanical). Although in both cases the chemical species formed due to the weathering were qualitatively the same, they essentially differed in their concentrations, namely they were higher for the washed samples than for the unwashed ones.
Nội dung trích xuất từ tài liệu:
The effect of washing on stabilized and unstabilized low-density polyethylene films naturally weathered in a sub-Saharan region (Ghardaïa, Algeria)
