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11.
为研究在电流辅助成形时脉冲电流的电流密度、占空比和脉冲频率3个因素对6016-T4铝合金板材力学性能的影响规律,设计了3因素5水平的正交实验。实验表明,对6016-T4铝合金力学性能影响的主次因素是:电流密度>占空比>脉冲频率。在此基础上,选用主次2个因素,即电流密度和脉冲频率,使用控制变量法进行进一步的实验研究。实验结果表明,电流密度对6016-T4铝合金力学性能影响较大,改变电流密度的同时带来了明显的焦耳热效应,该效应对材料有明显的软化作用,降低了材料的流动应力,但是,同时也降低了铝合金板的伸长率,这是因为过大的电流密度加剧了试样的主应变演化,进而促进了试样的断裂。而脉冲频率的变化对6016-T4铝合金板材的力学性能影响很小,这也印证了正交实验的结论。 相似文献
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Zhao Chen Xiaojing Zhang Yongpeng Ma Shilei Li Qi Pang Haoxu Wang Gaochao Sun 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2020,95(12):3252-3260
The appearance of heavy metals in wastewater brings a major burden to wastewater treatment plants, due to the high toxicity to microorganisms. Several commonly used heavy metals, including Zn(II), Cd(II), Hg(II), and Pb(II) were adopted to clear the individual and joint toxicity to the completely autotrophic nitrogen removal over nitrite (CANON) process in six sequencing batch reactors. The obtained results suggested that the nitrogen removal performances were transiently inhibited, but rapidly recovered. The restoration period under the stress of Hg(II) and Pb(II) was shorter than that under Zn(II), Cd(II), and the joint heavy metals. During the long-term exposure, Cd(II) in 1mg L−1 slightly inhibited the nitrogen removal, while Zn(II), Hg(II), Pb(II), and mixture showed a negligible impact on CANON process. The defense of extracellular polymeric substances (EPS), the good adaptability of functional bacteria, and the inducement of resistant genera by heavy metals all contributed to the robustness and stability of CANON process. Therefore, it is feasible to treat nitrogenous wastewater containing low heavy metals using CANON process. © 2020 Society of Chemical Industry 相似文献
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Ebbe Toftgaard Poulsen Agnete Larsen Alen Zollo Arne L. J?rgensen Kristian W. Sanggaard Jan J. Enghild Carmela Matrone 《International journal of molecular sciences》2015,16(12):29446-29453
The Amyloid Precursor Protein (APP) has been extensively studied for its role as the precursor of the β-amyloid protein (Aβ) in Alzheimer’s disease (AD). However, our understanding of the normal function of APP is still patchy. Emerging evidence indicates that a dysfunction in APP trafficking and degradation can be responsible for neuronal deficits and progressive degeneration in humans. We recently reported that the Y682 mutation in the 682YENPTY687 domain of APP affects its binding to specific adaptor proteins and leads to its anomalous trafficking, to defects in the autophagy machinery and to neuronal degeneration. In order to identify adaptors that influence APP function, we performed pull-down experiments followed by quantitative mass spectrometry (MS) on hippocampal tissue extracts of three month-old mice incubated with either the 682YENPTY687 peptide, its mutated form, 682GENPTY687 or its phosphorylated form, 682pYENPTY687. Our experiments resulted in the identification of two proteins involved in APP internalization and trafficking: Clathrin heavy chain (hc) and its Adaptor Protein 2 (AP-2). Overall our results consolidate and refine the importance of Y682 in APP normal functions from an animal model of premature aging and dementia. Additionally, they open the perspective to consider Clathrin hc and AP-2 as potential targets for the design and development of new therapeutic strategies. 相似文献
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Relations between asphaltene content,viscosity reduction rate of heavy oil and ultrasonic parameters
Ultrasonic treatment could decrease the viscosity of heavy oil and previous study on had focused on one heavy oil sample and involved less on the influence of asphaltene content. This study examined the effect of asphaltene content on viscosity reduction rate by ultrasonication. A comparison on samples with various asphaltene content and vibration parameter was made. The results showed that the optimal vibration frequency might decrease as the asphaltene content increased, whereas the optimal vibration intensity and the optimal treatment time were suggested to be enlarged. A semi-quantitative correlation was matched, which helped for numerical simulation about ultrasonic treatment. 相似文献
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《Oil and Energy Trends》2019,44(9):31-39
Current data of world oil demand. This includes international bunkers and refinery fuel. Updated on a monthly basis. Current data of oil demand from counties such as Canada, the United States of America, Japan, OECD Europe, Belgium, France, Germany, Italy, Netherlands, Spain, Sweden, the United Kingdom, Australia, Mexico, Republic of Korea, and Turkey. Updated on a monthly basis. Current data for crude oil and refined product stocks in Canada, Chile, Mexico, the United States (Western Hemisphere), France, Germany, Italy, Netherlands, Spain, the United Kingdom and Other Europe (Europe), Japan, Republic of Korea, Other Pacific (Asia-Pacific), and Total OECD (Table 12.1) Current data for refined product stocks in the OECD Western Hemisphere, OECD Europe, OECD Asia-Pacific and Total OECD. Products include gasoline, diesel and gasoil, and heavy fuel oil. Updated on a monthly basis (Table 12.2). 相似文献
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为了深入研究与控制重轨钢中大尺寸MnS夹杂物,针对目前热力学计算MnS析出行为问题,提出在应用时需要根据实际条件做相应的选择进行计算。在比较了目前几个常用的热力学数据后,基于U75V钢中MnS夹杂物形成过程,建立了适合计算MnS夹杂物析出的分段计算方法。研究表明,采用FactSage 6.4商业软件计算MnS析出温度为1 631 K,与平衡热力学参数计算的结果1 694 K相差63 K。该方法可准确预测MnS的析出行为,降低了热力学分析MnS析出的难度。在1 473、1 573 和1 673 K 3个温度下固溶硫质量分数分别为0.000 67%、0.001 67%和0.010 8%。在铸坯轧制之前的开坯和保温温度为1 563 K时,需要将钢中硫质量分数降低到0.001 67%以下,才能有效控制大尺寸的MnS夹杂物。 相似文献
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为了提升大断面球墨铸铁综合力学性能,通过复合添加微量合金元素铜、锑、锡、钼对大断面球墨铸铁进行微合金化处理,借助金相显微镜(OM)、扫描电子显微镜(SEM)及力学性能测试等手段,研究了Cu Sb Sn Mo复合微合金化大断面球墨铸铁微观组织和力学性能。结果表明,试验球墨铸铁具有良好的综合力学性能。大断面球墨铸铁中添加铜、锑、锡、钼后优化了材料的组织结构,基体组织为珠光体+少量牛眼状铁素体;试样石墨组织细小、圆整,分布均匀。同时,合金元素的复合加入使得其抗拉强度达到800 MPa以上,硬度约为280HB,伸长率达到5%以上。拉伸断口分析表明,微合金化大断面球墨铸铁断裂模式以解理断裂为主,伴有少量的塑性变形。 相似文献
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