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1.
为探究某加氢装置高压换热器管束腐蚀泄漏原因,利用Aspen Plus工艺模拟软件计算了冷低压分离器油相(简称冷低分油)中水质量分数分别为1%,2%,3%时,冷低分油系统的露点温度、氯化铵结晶温度、氯化铵潮解点温度和相对湿度。结果表明:相较于经验的露点温度预测方法,通过引入潮解点、划分系统“湿环境”温度范围判断氯化铵垢下腐蚀风险区域的方法与实际腐蚀案例更为切合;在3种油相含水条件下,换热器管束存在氯化铵垢下腐蚀的“湿环境”温度范围分别为:50~103 ℃,50~161 ℃,50~176 ℃;随着油相中含水量的提高,“湿环境”腐蚀区域逐渐向高温部位迁移,预计铵盐导致的垢下腐蚀将会愈加严重。 相似文献
2.
《Ceramics International》2022,48(4):5066-5074
We studied the morphological nature of various thin films such as silicon carbide (SiC), diamond (C), germanium (Ge), and gallium nitride (GaN) on silicon substrate Si(100) using the pulsed laser deposition (PLD) method and Monte Carlo simulation. We, for the first time, systematically employed the visibility algorithm graph to meticulously study the morphological features of various PLD grown thin films. These thin-film morphologies are investigated using random distribution, Gaussian distribution, patterned heights, etc. The nature of the interfacial height of individual surfaces is examined by a horizontal visibility graph (HVG). It demonstrates that the continuous interfacial height of the silicon carbide, diamond, germanium, and gallium nitride films are attributed to random distribution and Gaussian distribution in thin films. However, discrete peaks are obtained in the brush and step-like morphology of germanium thin films. Further, we have experimentally verified the morphological nature of simulated silicon carbide, diamond, germanium, and gallium nitride thin films were grown on Si(100) substrate by pulsed laser deposition (PLD) at elevated temperature. Various characterization techniques have been used to study the morphological, and electrical properties which confirmed the different nature of the deposited films on the Silicon substrate. Decent hysteresis behavior has been confirmed by current-voltage (IV) measurement in all the four deposited films. The highest current has been measured for GaN at ~60 nA and the lowest current in SiC at ~30 nA level which is quite low comparing with the expected signal level (μA). The HVG technique is suitable to understand surface features of thin films which are substantially advantageous for the energy devices, detectors, optoelectronic devices operating at high temperatures. 相似文献
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《Advanced Powder Technology》2022,33(11):103627
Naringin (NAR), a major flavanone (FVA) glycoside, is a component of food mainly obtained from grapefruit. We used NAR as a food additive to improve the solubility and permeability of hydrophobic polyphenols used as supplements in the food industry. The spray-dried particles (SDPs) of NAR alone show an amorphous state with a glass transition temperature (Tg) at 93.2 °C. SDPs of hydrophobic polyphenols, such as flavone (FVO), quercetin (QCT), naringenin (NRG), and resveratrol (RVT) were prepared by adding varying amounts of NAR. All SDPs of hydrophobic polyphenols with added NAR were in an amorphous state with a single Tg, but SDPs of hydrophobic polyphenols without added NAR showed diffraction peaks derived from each crystal. The SDPs with NAR could keep an amorphous state after storage at a high humidity condition for one month, except for SDPs of RVT/NAR. SDPs with NAR enhanced the solubility of hydrophobic polyphenols, especially NRG solubility, which was enhanced more than 9 times compared to NRG crystal. The enhanced solubility resulted in the increased membrane permeability of NRG. The antioxidant effect of the hydrophobic NRG was also enhanced by the synergetic effect of NAR. The findings demonstrated that NAR could be used as a food additive to enhance the solubility and membrane permeability of hydrophobic polyphenols. 相似文献
6.
CoCrNiCux (x=0.16,0.33,0.75,and 1) without macro-segregation medium-entropy alloys (MEAs) was prepared using laser directed energy deposition (LDED).The microstructure and mechanical properties of CoCrNiCux alloys with increas-ing Cu content were investigated.The results indicate that a single matrix phase changes into a dual-phase structure and the tensile fracture behaviors convert from brittle to plastic pattern with increasing Cu content in CoCrNiCux alloys.In addi-tion,the tensile strength of CoCrNiCux alloys increased from 148 to 820 MPa,and the ductility increased from 1 to 11%with increasing Cu content.The nano-precipitated particles had a mean size of approximately 20 nm in the Cu-rich phase area,and a large number of neatly arranged misfit dislocations were observed at the interface between the two phases due to Cu-rich phase precipitation in the CoCrNiCu alloy.These misfit dislocations hinder the movement of dislocations during tensile deformation,as observed through transmission electron microscopy.This allows the CoCrNiCu alloy to reach the largest tensile strength and plasticity,and a new strengthening mechanism was achieved for the CoCrNiCu alloy.Moreover,twins were observed in the matrix phase after tensile fracture.Simultaneously,the dual-phase structure with different elastic moduli coordinated with each other during the deformation process,significantly improving the plasticity and strength of the CoCrNiCu alloy. 相似文献
7.
以鲟鱼为原料,采用固相微萃取-气相色谱-质谱联用法,研究其发酵过程中挥发性风味物质种类和相对含量的变化情况,结合感觉阈值,采用相对气味活度值评价挥发性风味物质对总体风味的影响,探讨发酵过程中的关键性风味物质。分别检测新鲜鲟鱼,腌制鲟鱼,发酵5、10、20、25、35 d 7个阶段的挥发性风味物质,结果表明:新鲜、腌制、发酵5、10、20、25、35 d 7个阶段的挥发性风味物质种类分别为38、48、66、72、75、76种和84种。新鲜鲟鱼肉的主体风味物质为2,4-癸二烯醛、1-辛烯-3-醇、壬醛、癸醛、己醛等;腌制后的鲟鱼肉主体风味物质为壬醛、1-辛烯-3-醇、己醛、癸醛、柠檬烯等;发酵5 d鲟鱼肉的主体风味物质为1-辛烯-3-醇、柠檬烯、壬醛、乙酸乙酯、庚醇等;发酵10 d鲟鱼肉的主体风味物质为壬醛、1-辛烯-3-醇、乙酸乙酯、柠檬烯、癸醛等;发酵20 d鲟鱼肉的主体风味物质为壬醛、柠檬烯、1-辛烯-3-醇、癸醛、乙酸乙酯等;发酵25 d鲟鱼肉的主体风味物质为壬醛、柠檬烯、1-辛烯-3-醇、乙酸乙酯、癸醛等;发酵35 d鲟鱼肉的主体风味物质为乙酸乙酯、柠檬烯、壬醛、1-辛烯-3-醇、庚醇等。 相似文献
8.
Yuling Ma Litao Tong Juan Li Jawad Ashraf Shanshan Wang Bo Zhao Liya Liu Christophe Blecker Sumei Zhou 《International Journal of Food Science & Technology》2021,56(4):1562-1573
In this study, the accumulation of GABA and its inherent factors across different varieties of mung bean (Vigna radiata L.) in response to heat and relative humidity (HRH) were investigated. Results showed the average GABA content in mung bean varieties was increased 7.52 times following HRH treatment, and the black mung bean variety (A8) exhibited the highest GABA accumulation capability (1.76–84.57 mg per 100 g DW). From the perspective of GABA shunt metabolites, the free glutamic acid content of mung beans significantly decreased (P < 0.05) after HRH treatment and presented a significant correlation (P < 0.05) with GABA content. In polyamine degradation pathway, although the average levels of spermine and spermidine of mung bean varieties significantly decreased (P < 0.05) after HRH treatment, no significant correlation with GABA content was identified. Hence, the GABA accumulation was predominantly attributed to GABA shunt. Besides, free amino acids including glutamic acid, serine, ornithine, arginine and glycine in mung beans showed a significant positive correlation (P < 0.05) with GABA content and increment following HRH treatment, which suggested that mung beans enriched in these free amino acids might accumulate higher amounts of GABA after HRH treatment and be useful for industrial applications. 相似文献
9.
为了解决当前模糊测试技术中变异存在一定的盲目性以及变异生成的样本大多经过相同的高频路径的问题,提出并实现了一种基于轻量级程序分析技术的二进制程序模糊测试方法。首先对目标二进制程序进行静态分析来筛选在模糊测试过程中阻碍样本文件深入程序内部的比较指令;随后对目标文件进行插桩来获取比较指令中操作数的具体值,并根据该具体值为比较指令建立实时的比较进度信息,通过比较进度衡量样本的重要程度;然后基于模糊测试过程中实时的路径覆盖信息为经过稀有路径的样本增加其被挑选进行变异的概率;最后根据比较进度信息并结合启发式策略有针对性地对样本文件进行变异,通过变异引导提高模糊测试中生成能够绕过程序规约检查的有效样本的效率。实验结果表明,所提方法发现crash及发现新路径的能力均优于模糊测试工具AFL-Dyninst。 相似文献
10.
本文针对碳纤维增强聚合物(CFRP)复合材料修补结构,基于连续损伤力学和粘结单元模型,在ABAQUS软件中对低速冲击载荷下不同冲击位置和补片层数的CFRP复合材料层合板内部和层间损伤进行了数值分析,并与试验结果进行了对比。选择相对冲击位置为0 mm、10 mm、20 mm、30 mm和40 mm时对应的五种修补结构,通过数值计算和试验,获得了修补结构在低速冲击过程中的冲击力、冲击能量等数据。在保持补片单层厚度不变的前提下,使补片层数从1层增加到5层,计算获得了修补结构的低速冲击响应。研究结果表明:冲头接触修补结构时会对补片造成较大的损伤,补片可以提高含孔损伤母板的抗冲击性能;冲击点离修补结构损伤孔越近,结构受冲击所产生的分层损伤越严重;增加补片的层数可以提高修补结构的抗冲击性能;通过对补片层数进行优化,得到优化层数为2,其对应的修补结构与无修补结构相比分层损伤面积减少了19.9%,较好地提升了母板的抗冲击性能。 相似文献