18 research outputs found

    A New Approach of Loading and Routing Decision for FMS

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    柔性是柔性制造系统(FMS)的一个基本优点,但这一基本优点却往往被人们所忽视,许多现在运行的FMS不是缺乏柔性,就是没能充分利用可获得的柔性来提高生产效率柔性制造系统的负荷分配和路径规划问题正是这种柔性的一个主要方面.然而,路径规划决策却往往被忽视.其中一个主要原因就是人们仍不能从传统的生产管理概念中解放出来.本文在明确概念区分的基础上,提出了一种柔性制造系统的负荷分配和路径规划的线性规划模型,其主要特点是将负荷分配和路径规划问题有机地结合起来,并通过仿真实验验证并分析了此方法对FMS性能上的影响。</p

    高效薄层色谱测定湛江等鞭金藻培养过程脂质变化

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    【目的】研究湛江等鞭金藻(Isochrysis zhangjiangensis)由氮元素丰富至限制培养过程中脂质成分的变化.【方法】利用高效薄层色谱(HPTLC)分离分析微藻中脂质.【结果】随着培养基中营养物质的消耗,细胞逐渐处于胁迫状态,在这种状态下,细胞大量积累贮存脂质—甘油三脂(TAG),组成生物膜系统的单半乳糖甘油二脂(MGDG)、硫代异鼠李糖甘油二脂(SQDG)、磷脂酰甘油(PG)和磷脂酰胆碱(PC)含量降低,而游离脂肪酸(FFA)、甘油二脂(DAG)、双半乳糖甘油二脂(DGDG)、磷脂酰肌醇(PI)和磷脂酰乙醇胺(PE)则相对稳定.【结论】HPTLC可作为一种简便、可靠的微藻中脂质分离分析方法,为研究微藻油脂代谢途径以及甘油三脂(TAG)的调控积累提供有效手段

    短程硝化/厌氧氨氧化/全程硝化工艺处理焦化废水

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    通过对短程硝化和厌氧氨氧化工艺的研究,开发了短程硝化/厌氧氨氧化/全程硝化(O1/A/O2)生物脱氮新工艺并用于焦化废水的处理。控制温度为(35&plusmn;1)℃、DO为2.0~3.0mg/L,第一级好氧连续流生物膜反应器在去除大部分有机污染物的同时还实现了短程硝化。考察了HRT、DO和容积负荷对反应器运行效果的影响。结果表明,当氨氮容积负荷为0.13~0.22gNH 4+-N/(L.d)时,连续流反应器能实现短程硝化并有效去除氨氮。通过控制一级好氧反应器的工艺参数,为厌氧反应器实现厌氧氨氧化(ANAMMOX)创造条件。结果表明,在温度为34℃、pH值为7.5~8.5、HRT为33 h的条件下,经过115 d成功启动了厌氧氨氧化反应器。在进水氨氮、亚硝态氮浓度分别为80和90 mg/L左右、总氮负荷为160 mg/(L.d)时,对氨氮和亚硝态氮的去除率最高分别达86%和98%,对总氮的去除率为75%。最后在二级好氧反应器实现氨氮的全程硝化,进一步去除焦化废水中残留的氨氮、亚硝态氮和有机物。O1/A/O2工艺能有效去除焦化废水中的氨氮和有机物等污染物,正常运行条件下的出水氨氮&lt;15 mg/L、亚硝态氮&lt;1.0 mg/L,COD降至124~186 mg/L,出水水质优于A/O生物脱氮工艺的出水水质

    Biogenic silica in the surface sediment of the Bohai Sea

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    The 103-surface sediment samples collected from the Bohai Sea were extracted by 0.1 mol/LHCl and 1%Na_2CO_3 sequentially for the analysis of biogenic silica. The results showed that biogenic silica contents were in the range of 7.3~54.7 g/kg, with an average of 31.5 g/kg. The measured contents of the biogenic silica were higher than other reported values in the same study area. This might be the result of different extraction methods that were employed in the studies, the extraction by 0.1 mol/L HCl may dissolve the oxides plaque coated on the biogenic silica in the sediment and therefore increase the release of the biogenic silica. Spatial distributions of the biogenic silica were characterized using geographic information system(GIS)and the spatial heterogeneity of the biogenic silica was observed in the surface sediments of the Bohai Sea. The highest content located along the coastal marine of Hebei province, in contrast to the lowest content located in the Laizhou Bay. This suggested long-term terrestrial input of nutrient substances and frequent disturbance by the input of the Yellow River sediments may govern the abundance and distribution of biogenic silica in this area. Principal component analysis indicated the contents of biogenic silica had a significantly(P < 0.01)positive correlation with the contents of clay, fine sand, total organic nitrogen, and organic carbon in the sediment of the Bohai Sea, which further confirmed the effects of grain size and nutrient substance on the accumulation of biogenic silica in the sediment

    曹妃甸围填海土壤重金属积累的磁化率指示研究

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    环境磁学方法在土壤重金属污染识别中被广泛运用,其具有简单、快速、无破坏性和灵敏度高的特点.本研究以北方典型的围填海区——曹妃甸工业区土壤为例,开展土壤磁化率对重金属积累的指示研究.根据研究区的土地功能规划特征,将研究区土壤分为工业区土壤、生活区土壤以及自然滩涂和湿地土壤共3类.共采集35个表土(0~10 cm)样品和3个土壤剖面柱状样,分析土壤中的磁化率(χlf)、铁(Fe_2O_3)含量及重金属(Cr、Ni、Cu、Zn、As、Pb、Mn、V)元素含量.结果表明:工业区表土磁化率和重金属含量空间分异性较高,受工业生产的影响明显;工业区和生活区剖面中0~20cm的表层土壤中,各重金属均出现不同程..
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