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负载型铜钴氧化物协同催化H_2O_2/HCO_3~–降解苯酚(英文) 被引量:7
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作者 李一冰 Ali Jawad +4 位作者 aimal khan 卢小艳 陈朱琦 刘卫东 尹国川 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第6期963-970,共8页
近年来,环境污染特别是水的严重污染使其治理成为一个极具挑战性的课题.各种污染物复杂的化学成分和催化剂在处理过程中的浸出、寿命及成本等问题是导致众多氧化催化剂难以实际应用的主要原因.相对而言,H_2O_2是一种活性氧含量高、清洁... 近年来,环境污染特别是水的严重污染使其治理成为一个极具挑战性的课题.各种污染物复杂的化学成分和催化剂在处理过程中的浸出、寿命及成本等问题是导致众多氧化催化剂难以实际应用的主要原因.相对而言,H_2O_2是一种活性氧含量高、清洁并可在温和条件下使用的氧化剂,在各种高级氧化技术中受到广泛关注.而碳酸氢盐是一种弱碱性物质,在自然界及水体系中广泛存在,且无明显毒害.它可活化H_2O_2,加快其氧化各种有机物,并在废水处理领域开始受到关注.该体系的明显优势在于处理体系始终处于微碱性环境,可以有效避免金属氧化物催化剂在处理过程中由于体系酸化而带来的催化剂流失,从而延长催化剂寿命,降低催化剂成本.本文采用浸渍法制备了一种双金属铜、钴氧化物催化剂及相关的对照催化剂体系,利用碳酸氢盐活化H2O2用于降解苯酚模拟废水.通过各种空白实验发现,负载于γ-Al_2O_3表面的钴、铜氧化物催化剂CuO-Co_3O_4@γ-Al_2O_3具有最好的催化降解活性,而CuO@γ-Al_2O_3,Co_3O_4@γ-Al_2O_3,Cu O-Co_3O_4及CuO和Co_3O_4的物理混合物均表现出较差的催化性能.由此可见,在CuO-Co_3O_4@γ-Al_2O_3催化剂中,铜、钴离子在苯酚降解过程中存在协同效应,这可能与催化剂中钴、铜金属离子的相互作用相关.X射线衍射和X射线光电子能谱结果表明,反应前后CuO-Co_3O_4@γ-Al_2O_3催化剂中金属的氧化状态并未发生改变,在使用过程中钴离子的浸出率可以忽略,铜离子的浸岀率也仅有0.6 ppm.荧光分析实验和自由基捕获实验表明,只有添加·O_2^-和·OH的捕获剂能明显抑制降解反应,因而推测该反应体系对有机物的降解是一个自由基氧化过程,起关键作用的可能是·O_2^-和·OH. 展开更多
关键词 协同效应 苯酚降解 铜/钴氧化物催化剂 机理研究 碳酸氢盐活化的过氧化氢
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A Cascaded Design of Best Features Selection for Fruit Diseases Recognition
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作者 Faiz Ali Shah Muhammad Attique khan +4 位作者 Muhammad Sharif Usman Tariq aimal khan Seifedine Kadry Orawit Thinnukool 《Computers, Materials & Continua》 SCIE EI 2022年第1期1491-1507,共17页
Fruit diseases seriously affect the production of the agricultural sector,which builds financial pressure on the country’s economy.The manual inspection of fruit diseases is a chaotic process that is both time and co... Fruit diseases seriously affect the production of the agricultural sector,which builds financial pressure on the country’s economy.The manual inspection of fruit diseases is a chaotic process that is both time and cost-consuming since it involves an accurate manual inspection by an expert.Hence,it is essential that an automated computerised approach is developed to recognise fruit diseases based on leaf images.According to the literature,many automated methods have been developed for the recognition of fruit diseases at the early stage.However,these techniques still face some challenges,such as the similar symptoms of different fruit diseases and the selection of irrelevant features.Image processing and deep learning techniques have been extremely successful in the last decade,but there is still room for improvement due to these challenges.Therefore,we propose a novel computerised approach in this work using deep learning and featuring an ant colony optimisation(ACO)based selection.The proposed method consists of four fundamental steps:data augmentation to solve the imbalanced dataset,fine-tuned pretrained deep learning models(NasNetMobile andMobileNet-V2),the fusion of extracted deep features using matrix length,and finally,a selection of the best features using a hybrid ACO and a Neighbourhood Component Analysis(NCA).The best-selected features were eventually passed to many classifiers for final recognition.The experimental process involved an augmented dataset and achieved an average accuracy of 99.7%.Comparison with existing techniques showed that the proposed method was effective. 展开更多
关键词 Fruits diseases data augmentation deep learning features fusion feature selection
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Morphology-dependent activation of hydrogen peroxide with Cu_(2)O for tetracycline hydrochloride degradation in bicarbonate aqueous solution
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作者 Xiuying Liu Qianna Xia +6 位作者 Jiao Zhou Bowen Li Shuaiqi Zhao Long Chen aimal khan Xiaoxia Li Aihua Xu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第3期567-579,共13页
The design of efficient heterogeneous catalysts in bicarbonate-activated hydrogen peroxide systems(BAP)is a hot topic in wastewater treatment.In this work,Cu_(2)O nanoparticles with different morphologies including cu... The design of efficient heterogeneous catalysts in bicarbonate-activated hydrogen peroxide systems(BAP)is a hot topic in wastewater treatment.In this work,Cu_(2)O nanoparticles with different morphologies including cubic shape(c-Cu_(2)O),octahedron shape(o-Cu_(2)O)and spherical shape(s-Cu_(2)O),were applied in BAP for the first time to degrade tetracycline hydrochloride(TC).Compared with Cu^(2+)ions and CuO,TC degradation was boosted in the presence of Cu_(2)O in the BAP system,with the degradation rate following the order c-Cu_(2)O>o-Cu_(2)O>s-Cu_(2)O.The morphology-dependent effects could be linearly correlated with the ratio of surface oxygen species(O_S),but not with the surface area or Cu(Ⅰ)ratio.The c-Cu_(2)O catalyst with exposure of(100)facets contained 76.6%O_Sas the active site for H_(2)O_(2)adsorption and activation,while the value was much lower for o-Cu_(2)O and s-Cu_(2)O with dominant(111)facets.The presence of HCO_(3)-enhanced the interactions among Cu_(2)O,H_(2)O_(2)and TC,leading to facile oxidation of Cu(Ⅰ)to Cu(Ⅱ)by H_(2)O_(2),and the formation of various reactive species such as hydroxyl radicals and Cu(Ⅲ)contributed to TC degradation.This work provides a new method for enhancing H_(2)O_(2)activation with heterogeneous catalysts by crystal facet engineering. 展开更多
关键词 Hydrogen peroxide BICARBONATE Cu_(2)O Morphology-dependent effects
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Control of Bird Feeding Behavior by Tannin1 through Modulating the Biosynthesis of Polyphenols and Fatty Acid-Derived Volatiles in Sorghum 被引量:11
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作者 Peng Xie Jiayang Shi +10 位作者 Sanyuan Tang Chengxuan Chen aimal khan Fengxia Zhang Ying Xiong Chao Li Wei He Guodong Wang Fumin Lei Yaorong Wu Qi Xie 《Molecular Plant》 SCIE CAS CSCD 2019年第10期1315-1324,共10页
Bird predation during seed maturation causes great loss to agricultural production.In this study,through GWAS analysis of a large-scale sorghum germplasm diversity panel,we identified that Tannin1,which encodes a WD40... Bird predation during seed maturation causes great loss to agricultural production.In this study,through GWAS analysis of a large-scale sorghum germplasm diversity panel,we identified that Tannin1,which encodes a WD40 protein functioning in the WD40/MYB/bHLH complex,controls bird feeding behavior in sorghum.Metabolic profiling analysis showed that a group of sorghum accessions preferred by birds contain mutated tan1-a/b alleles and accumulate significantly lower levels of anthocyanins and condensed tannin compounds.In contrast,a variety of aromatic and fatty acid-derived volatiles accumulate at significantly higher levels in these bird-preference accessions.We subsequently conducted both sparrow feeding and sparrow volatile attractant assays,which confirmed,respectively,the antifeedant and attractant functions of these differentially accumulated metabolites.In addition,the connection between the biosynthesis pathway of anthocyanin and proanthocyanidin and the pathway of fatty acid–derived volatile biosynthesis was demonstrated by discovering that Tannin1 complex modulates fatty acid biosynthesis by regulating the expression of SbGL2 in sorghum,thus affecting the accumulation of fatty acid-derived volatiles.Taken together,our study identified Tannin1 as the gene underlying the major locus controlling bird feeding behavior in sorghum,illustrating an example of the identification of an ecologically impactful molecular mechanism from field observation and providing significant insights into the chemistry of bird–plant ecological interactions. 展开更多
关键词 BIRD damage GWAS metabolism TANNIN VOLATILES
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