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排序方式: 共有1298条查询结果,搜索用时 31 毫秒
1.
利用水力空化过程产生局部的高温、高压、高射流以及强大的剪切力等极端化学物理条件改质处理沙特重质原油,试验结果表明:沙特重质原油经过水力空化改质后粘度由13.61降低至7.22mm2/s,残碳由7.16%降低至6.48%,实沸点蒸馏后减压渣油降低1个百分点。进一步采用APPI FT-IR MS、XRD、FT-IR、SEM和粒度分布等技术研究了水力空化改质对沙重原油分子组成,沥青质团聚体微晶结构、沥青质胶束粒径分布、沥青质官能团、沥青质形貌等方面的影响,从分子角度阐述空化改质重油的机理。研究结果表明:水力空化改质后沙重原油分子量分布、芳烃类化合物缔合作用变小;沥青质对低DBE化合物吸附性能降低;沥青质团聚体微晶结构更加松散;沥青质胶束粒度分布降低;沥青质分子相互团聚作用力减弱。进一步考察了水力空化改质前后减压渣油延迟焦化性能,改质处理后焦炭产率降低1.85个百分点,液体收率和气体产率分别增加1.52和0.33个百分点,水力空化改质对沥青质性质、结构特点的改善能够有效的提高其加工性能。 相似文献
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招平断裂带中段金矿床控矿条件与成矿规律研究 总被引:1,自引:0,他引:1
招平断裂带中段为胶东地区重要的金成矿带,目前已查明的金矿床主要包括夏甸大型金矿床和大尹格庄特大型金矿床,姜家窑和曹家洼中型金矿床,以及焦格庄小型金矿床。研究人员对招平断裂带中段各类金矿床的构造控矿条件、分布规律和矿体赋存规律仍缺乏较系统的认识,亟待开展进一步研究。通过对金矿区地质特征、金矿床地质特征、构造控矿特征和金矿成矿规律进行分析和总结,得出大尹格庄特大型金矿主要受招平主干断裂控制;夏甸大型金矿床主要受控于主干控矿断裂下盘伴生、派生的低级和低序次断裂,夏甸北耩矿体主要受控于主断裂下盘岩体局部张性显微裂隙带;招平断裂带中段大尹格庄特大型金矿床、夏甸特大型金矿床和焦格庄中、小型金矿床大致呈等间距分布,近EW向断裂与招平断裂的交会部位是有利成矿部位;断裂的拐弯或交会部位为主要赋矿部位。 相似文献
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Prophages are temperate phages integrated into the host bacterial genome. They play an important role in the
adaptation and the pathogenicity of bacteria, especially pathogenic bacteria. In this review, we described the distribution
of prophages in different hosts and different environments, and focused on the significance of prophages. At the singlecell level, prophages can help the host adapt to harsh external environments by directly carrying virulence genes, encoding
regulatory factors and activating lysogeny. At the population level, prophages can influence the overall evolutionary
direction and ecological function of the host bacterial community. This review will help us understand the important
role of prophages as unique organisms in individual bacteria and microbial populations. 相似文献
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《International Journal of Hydrogen Energy》2022,47(11):7432-7442
The durability of metal plate proton exchange membrane fuel cell (PEMFC) stack is still an important factor that hinders its large-scale commercial application. In this paper, we have conducted a 1000 h durability test on a 1 kW metal plate PEMFC stack, and explored the degradation of the core components. After 1000 h of dynamic load cycles, the voltage decay percentage of the stack under the current densities of 1000 mA cm?2 is 5.67%. By analyzing the scanning electron microscopy (SEM) images, the surfaces of the metal plates are contaminated locally by organic matter precipitated from the membrane electrode assembly (MEA). The SEM images of the catalyst coated membrane (CCM) cross section indicate that the MEA has undergone severe degradation, including the agglomeration of the catalyst layer, and the thinning and perforation of the PEM. These are the main factors that cause the rapid increase in hydrogen crossover flow rate and performance decay of the PEMFC stack. 相似文献
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Partially self-polarized BiFeO3 (BFO) film was fabricated on Pt(111)/Ti/SiO2/Si substrate by a metal organic decomposition process at 480?°C. The influence of soaking times on leakage properties was discussed. The soaking times considered were those that could keep the leakage currents being measured in a steady state condition during the leakage tests. The length of soaking time during leakage measurement should be greater than or equal to 500?ms to rule out the contribution of backswitching to leakage properties. Different leakage characteristics induced by the built-in negative field occurred under positive and negative fields. The "flat-band" feature of the leakage current curves may result from competition between domain switching and the switching of defect complexes. It is suggested that the "unswitched" mode should be adopted during leakage measurement in BFO films. Additionally, negative bias should be adopted in negatively polarized BFO films and positive bias should be adopted in positively polarized BFO films. 相似文献
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Xia Li Ling Jianyang Xu Zhen Bi Rongshan Zhao Wenying Xiang Shuguang 《Clean Technologies and Environmental Policy》2022,24(1):413-422
Clean Technologies and Environmental Policy - On the platform of general chemical process simulation software (it was named Optimization Engineer, OPEN), a general optimization algorithm for... 相似文献
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