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1.
《Advanced Powder Technology》2022,33(6):103595
Ceria (CeO2) particles are prevalent polishing abrasive materials. Trivalent lanthanide ions are the popular category of dopants for enriched surface defects and thus improved physicochemical properties, since they are highly compatible with CeO2 lattices. Herein, a series of dendritic-like mesoporous silica (D-mSiO2)-supported samarium (Sm)-doped CeO2 nanocrystals were synthesized via a facile chemical precipitation method. The relation of the structural characteristics and chemical mechanical polishing (CMP) performances were investigated to explore the effect of Sm-doping amounts on the D-mSiO2/SmxCe1?xO2?δ (x = 0–1) composite abrasives. The involved low-modulus D-mSiO2 cores aimed to eliminate surface scratch and damage, resulting from the optimized contact behavior between abrasives and surfaces. The trivalent cerium (Ce3+) and oxygen vacancy (VO) at CeO2 surfaces were expected to be reactive sites for the material removal process over SiO2 films. The optimal oxide-CMP performances in terms of removal efficiency and surface quality were achieved by the 40% Sm-doped composite abrasives. It might be attributed to the high Ce3+ and VO concentrations and the enhancement of tribochemical reactivity between CeO2SiO2 interfaces. Furthermore, the relationship between the surface chemistry, polishing performance as well as the actual role in oxide-CMP of the D-mSiO2/SmxCe1?xO2?δ abrasives were also discussed. 相似文献
2.
Liu Yang Pengfei Yu Wenyuan Li Fengliang Cao Xin Jin Sheng Xue Xianglong Zhang Tingwei Zhang Mingbo Wu Wenting Wu 《American Institute of Chemical Engineers》2022,68(9):e17760
Hydrogen peroxide (H2O2) has been listed as one of the 100 most important chemicals in the world. However, huge amount of residual H2O2 is hard to timely decomposed into O2 and H2O under acidic condition, easily resulting in explosion hazard. Here, we reported a core–shell structure catalyst, that is graphene with Co N structure encapsulated Co nanoparticles. Co N graphene shell serves as the active site for the H2O2 decomposition, and Co core further enhance this decomposition. Benefiting from it, the H2O2 decomposition were close to 100% after 6 cycles without pH adjustment, which increased 6 orders of magnitude compared with no catalyst. At the same time, the O2 generation reached 99.67% in 2 h with little metal leaching, and ·OH has been greatly inhibited to only 0.08%. This work can cleanly remove H2O2 with little deep oxidation and protect the process of H2O2 utilization to achieve a safer world. 相似文献
3.
Callistus Nonso Ude Dominic Okechukwu Onukwuli Jonah Chukwudi Umeuzuegbu Chinemelum Chukwujekwu Chukwuka 《化学工程与技术》2021,44(1):65-76
The heterogeneous catalysis of transesterification of gmelina seed oil to biodiesel is evaluated. The oil was extracted from the seeds with n‐hexane by solvent extraction and characterized to determine its physiochemical properties. Response surface methodology was applied to optimize the effect of process variables on the biodiesel yield. The base‐activated clay catalyst performed as montmorillonite clay with the characteristic property of a Brønsted acid. It has an improved surface area after activation that enhanced its catalytic activity on transesterification reaction. Under optimal conditions, the biodiesel yield was 70.1 %, thus demonstrating that the model predicted well the biodiesel production. 相似文献
4.
Jin-Bo Pan Sheng Shen Lang Chen Chak-Tong Au Shuang-Feng Yin 《Advanced functional materials》2021,31(36):2104269
Photoelectrochemical (PEC) water splitting into hydrogen and oxygen is a promising solution for the conversion and storage of solar energy. Because sluggish water oxidation is the bottleneck of water splitting, the design and preparation of an efficient photoanode is intensively investigated. Currently, all known photoanode materials suffer from at least one of the following drawbacks: ① low carriers separation efficiency; ② sluggish surface water oxidation reaction; ③ poor long-term stability; ④ insufficient water adsorption and gas desorption. Core–shell configurations can endow a photoanode with improved activity and stability by coating an overlayer that plays energetic, catalytic, and/or protective roles. The construction strategy has an important effect on the activity of a core–shell photoanode. Nonetheless, the mechanism for the improvement of performance is still ambiguous and is worthy of a closer examination. In this review, the successes and challenges of core–shell photoanodes for water oxidation, focusing on synthesis strategies as well as functionalities (facilitating carrier separation, surface reaction promotion, corrosion prevention, and bubble detachment) are explored. Finally, the perspectives of this class of materials in terms of new opportunities and efforts are discussed. 相似文献
5.
6.
罗凡王龙祥郭少海钟海雁 《中国油脂》2020,45(3):110-114
通过不同微波功率和时间辐射油茶籽,测定油茶粕中茶皂素、蛋白质、粗多糖、总酚、糠氨酸含量以及DPPH自由基清除能力的变化规律,研究榨前微波处理对油茶粕活性成分及抗氧化性的影响。结果表明:随微波加热时间延长,低功率(245、420 W)微波处理油茶籽后,油茶粕中茶皂素含量稍有上升,随后下降;较高功率(560、700 W)微波处理后,茶皂素含量呈上升趋势;微波处理对油茶粕中蛋白质含量影响不大;微波处理后油茶粕中粗多糖含量整体呈下降趋势,但420、560、700 W处理20、5、10 min后含量分别比初始升高66.9%、79.6%和116.0%;微波处理后油茶粕中总酚含量呈先降低后升高再降低的趋势,且微波功率越高,总酚含量越高;微波功率较低(245 W)时,糠氨酸含量先降低后略有升高,微波功率较高(420、560、700 W)时,糠氨酸含量先升高后降低。245 W和700 W微波功率处理时油茶粕对DPPH自由基清除率先升高后降低,560 W时呈整体上升趋势,420 W呈波动状态。 相似文献
7.
杨晨孔凡田华雷芬芬何东平郑竟成 《中国油脂》2020,45(5):123-127
葵花籽粕是葵花籽提油后的副产品。葵花籽粕蛋白品质优,各氨基酸组成平衡,此外葵花籽粕中还含有绿原酸、黄酮等多种活性物质,营养价值高,具有广阔的应用前景。从葵花籽粕作为原料提取有效成分及作为饲料用原料两方面对葵花籽粕资源的综合利用情况进行了阐述,以期为葵花籽粕的进一步开发利用提供参考。 相似文献
8.
Kai Han Xin‐Yang Li Ye‐Qi Zhang Yong‐Lin He Rui Hu Xiu‐Li Lu Qi‐Jiu Li Jing Hui 《European Journal of Lipid Science and Technology》2020,122(4)
Hyperlipidemia is a common cardiovascular disease. At present, the influence of high fat diet (HFD) on this is being explored. Recently, vegetable oils rich in omega‐3 have been reported that can treat hyperlipidemia caused by HFD. However, the effects of chia seed oil (CSO) on HFD‐induced hyperlipidemia and oxidative stress are poorly studied. Hence, in this study, the effects of CSO on hyperlipidemia and oxidative stress induced by HFD in mice are analyzed by various commercial kits, section staining, and protein expression. The results show that CSO decreases body weight and organ index. Meanwhile, CSO reduces serum lipid levels of total cholesterol, triglyceride, and low‐density lipoprotein cholesterol. It can also elevate superoxide dismutase and glutathione peroxidase activities and reduce malondialdehyde content in serum and liver. The results of histopathological analysis prove that CSO improves hepatic steatosis and reduces lipid deposition. Further, the results of western blot demonstrate that CSO upregulates the expression of peroxisome proliferator‐activated receptor alpha and carnitine palmitoyltransferase 1a in the liver. As a result, CSO may be a potential lipid‐lowering oil to prevent and treat HFD‐induced hyperlipidemia and oxidative stress. Practical Applications CSO, as a byproduct of chia seed processing, is a rich source of α‐linolenic acid. This study investigates the effects of CSO on HFD‐induced hyperlipidemia and oxidative stress in mice. It is concluded that dietary CSO can improve the hyperlipidemia in HFD‐induced mice via analysis of lipid parameters, histopathology study of the liver, and lipid metabolism related genes. In addition, supplementation of CSO also can improve the oxidative stress in mice. Therefore, CSO can be used for the prevention of hyperlipidemia and oxidative stress. This research provides a theoretical basis for the comprehensive development and utilization of functional chia seed oil. 相似文献
9.
Inga Miina Elise Sipeniece Magdalena Rudziska Anna Grygier Monika Radzimirska‐Graczyk Edte Kaufmane Dalija Seglia Gunrs Lcis Pawe Grna 《European Journal of Lipid Science and Technology》2020,122(4)
Tocopherols, phytosterols, carotenoids, and squalene are present in mature seeds of Japanese quince. Yet, little is known about the relationship between these compounds and oil yield during fruit and seed development. The profile change of lipophilic compounds during fruit and seed development in Japanese quince cultivars “Darius,” “Rondo,” and “Rasa” is investigated. It is shown here that during fruit and seed development, there is a significant reduction, three‐ to over tenfold, in the concentration of minor bioactive compounds in seed oil. It is recorded that delay between synthesis of tocopherols and oil in Japanese quince seeds during the fruit development results in a logarithmic relationship between the oil content and tocopherols concentration in the seed oil (R2 = 0.980). Similar trends are observed between oil yield and phytosterols, and carotenoids (R2 = 0.927 and R2 = 0.959, respectively). The profile of fatty acids during the development of the seeds significantly is changed. The reduction of linoleic, palmitic, and gondoic acids levels and increment of oleic acid is noted. The oil content, profile of fatty acids, and concentration of bioactive compounds in all three genotypes of Japanese quince do not change significantly statistically during the last month of fruit development. Practical Applications: Some fruits are harvested at different degrees of maturity mainly due to a logistic issue and uneven ripening of fruits, which affects the chemical composition of whole fruit including seeds. Therefore, it would be good to know how the chemical composition is changing in plant material during development especially in the last month before harvest. Production of Japanese quince continues to rise year to year and with it the volume of generated by‐products such as seeds. This study demonstrates how it changes the oil content, profile of fatty acid, and concentration of tocopherols, squalene, phytosterols, and carotenoids in the seeds and seed oil of three Japanese quince cultivars “Rondo,” “Darius,” and “Rasa” during plant development. The provided information can be very useful for the manufactories oriented on the processing of by‐products, mainly seeds, generated by other branches of industry, for instance, fruit‐processing. 相似文献
10.