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二价镍离子修饰TS-1分子筛纳米片用于有效光催化醇氧化及污染物降解 被引量:4
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作者 Imran Khan 初小宇 +3 位作者 刘彦铎 Salman Khan 白林鹭 井立强 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2020年第10期1589-1602,共14页
以O2为绿色氧化剂实现高效光催化有机物氧化转化过程如醇等有机物的选择性氧化及污染物降解是当前光催化发展的重要方向之一.成功实现高活性及高选择性的上述转化过程主要在于设计并制备有效的光催化材料.二氧化钛作为最广泛应用的光催... 以O2为绿色氧化剂实现高效光催化有机物氧化转化过程如醇等有机物的选择性氧化及污染物降解是当前光催化发展的重要方向之一.成功实现高活性及高选择性的上述转化过程主要在于设计并制备有效的光催化材料.二氧化钛作为最广泛应用的光催化材料被报道用于光催化空气醇氧化选择性转化,但通常活性有限且因其表面催化活性位均为含有Ti-O6活性中心而具有较低的产物选择性.相比之下,同样作为Ti基材料的钛硅分子筛如TS-1分子筛具有高选择性的Ti-O4催化中心、丰富的孔结构及良好的稳定性,被广泛用于多种传统催化氧化反应.近年来,TS-1分子筛因具有光催化活性而成为一类具有工业应用潜力的光催化材料,特别是其独特的Ti-O4催化中心有望实现高选择性的光催化氧化转化.然而,其活性仍受限于较差的光生电荷分离,提升TS-1分子筛的电荷分离是促进其光催化活性的关键.本工作以特定结构的季铵盐表面活性剂为结构导向剂,通过低温水热法成功制备了TS-1分子筛纳米片,并通过离子交换法于TS-1分子筛纳米片的离子交换位引入二价镍离子,显著地提升了其光催化醇氧化及污染物降解的反应活性.在全光下,最佳镍修饰样品表现出优异活性,苯甲醇转化率达到78.9%,对应产物苯甲醛选择性达到98.8%,收率为普通块状TS-1分子筛6倍,循环活性维持5次无明显降低.镍修饰TS-1分子筛纳米片的优异活性源于介孔的二维TS-1纳米片具有显著增大的比表面积以及提升的电荷分离.与块状TS-1分子筛相比,镍修饰TS-1纳米片具有更短的电荷传输距离.引入镍物种能够捕获光生电子,从而提升了电荷分离,同时可作为催化氧化剂O2活化的催化活性位.捕获剂实验证明,氧二负自由基为镍修饰TS-1纳米片光催化醇氧化过程的主要氧活性物种.本工作开启了一类具有工业应用潜质的用于光催化醇选择性氧化及污染物降解的高效、高选择性且廉价的钛硅分子筛基光催化剂,为同类型光催化反应催化剂制备提供策略. 展开更多
关键词 TS-1纳米片 光催化醇氧化 电荷分离 Ni物种电子捕获 O2活化
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A Discussion on the Practical Teaching Reform of Intelligent Mobile Terminal Technology Course
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作者 xiaoyu chu Jian Wu 《Journal of Contemporary Educational Research》 2022年第8期16-22,共7页
In this intelligent era,there is a high market demand for professional engineering talents in the computer industry.Based on engineering education accreditation,this paper briefly discusses the practical teaching refo... In this intelligent era,there is a high market demand for professional engineering talents in the computer industry.Based on engineering education accreditation,this paper briefly discusses the practical teaching reform of the intelligent mobile terminal technology course,which involves integrating theory with practical,taking students as the center,focusing on practical teaching,strengthening students’practical skills and computer application development skills,as well as promoting the construction and development of engineering accreditation. 展开更多
关键词 New engineering Engineering education professional certification Intelligent mobile terminal technology Practical teaching Curriculum reform
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KLF4 facilitates chromatin accessibility remodeling in porcine early embryos
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作者 Wei Zhu Guowei Bu +17 位作者 Ruifeng Hu Jixiang Zhang Lianyong Qiao Kai Zhou Tingting Wang Qiao Li Jingjing Zhang Linhui Wu Yali Xie Taotao Hu Shichun Yang Jiaqi Guan xiaoyu chu Juanjuan Shi Xia Zhang Falong Lu Xin Liu Yi-Liang Miao 《Science China(Life Sciences)》 SCIE CAS CSCD 2024年第1期96-112,共17页
Chromatin accessibility remodeling driven by pioneer factors is critical for the development of early embryos.Current studies have illustrated several pioneer factors as being important for agricultural animals,but wh... Chromatin accessibility remodeling driven by pioneer factors is critical for the development of early embryos.Current studies have illustrated several pioneer factors as being important for agricultural animals,but what are the pioneer factors and how the pioneer factors remodel the chromatin accessibility in porcine early embryos is not clear.By employing low-input DNase-seq(liDNase-seq),we profiled the landscapes of chromatin accessibility in porcine early embryos and uncovered a unique chromatin accessibility reprogramming pattern during porcine preimplantation development.Our data revealed that KLF4 played critical roles in remodeling chromatin accessibility in porcine early embryos.Knocking down of KLF4 led to the reduction of chromatin accessibility in early embryos,whereas KLF4 overexpression promoted the chromatin openness in porcine blastocysts.Furthermore,KLF4 deficiency resulted in mitochondrial dysfunction and developmental failure of porcine embryos.In addition,we found that overexpression of KLF4 in blastocysts promoted lipid droplet accumulation,whereas knockdown of KLF4 disrupted this process.Taken together,our study revealed the chromatin accessibility dynamics and identified KLF4 as a key regulator in chromatin accessibility and cellular metabolism during porcine preimplantation embryo development. 展开更多
关键词 porcine embryos liDNase-seq chromatin accessibility KLF4 MITOCHONDRION lipid droplets
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Efficient singlet oxygen generation by excitonic energy transfer on ultrathin g-C_(3)N_(4) for selective photocatalytic oxidation of methyl-phenyl-sulfide with O_(2) 被引量:4
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作者 Fan Yang xiaoyu chu +6 位作者 Jianhui Sun Yuhang Zhang Zhijun Li Haiyue Liu Linlu Bai Yang Qu Liqiang Jing 《Chinese Chemical Letters》 SCIE CAS CSCD 2020年第10期2784-2788,共5页
Efficient generation of singlet oxygen(1 O_(2)) by an excitonic ene rgy transfer process is highly desired on a semiconductor photocatalyst for selective oxidation of methyl phenyl sulfide(MPS).Herein,it is demonstrat... Efficient generation of singlet oxygen(1 O_(2)) by an excitonic ene rgy transfer process is highly desired on a semiconductor photocatalyst for selective oxidation of methyl phenyl sulfide(MPS).Herein,it is demonstrated that a large amount of 1 O_(2) is produced on pristine graphitic carbon nitride(CN) nanosheet compared with bismuth oxybromide(BiOBr) and comme rcial P25 titanium dioxide(TiO_(2)).This leads to a certain photoactivity of CN for MPS oxidation.The observed ~77% selectivity for CN depends on the competitive results of excitonic energy transfer for 1 O_(2) formation and charge carrier separation for superoxide radical(O_(2)·) production,which are based on the phosphorescence spectra and electron paramagnetic resonance signals,respectively.Moreover,ultrathin CN nanosheets are synthesized by thermal treatment with the cyanuric acid-melamine hydrogen bonded aggregates as precursors.It is confirmed that the amount of produced 1 O_(2) could be increased by decreasing the thickness of resultant CN nanosheets.The optimized ultrathin CN nanosheet(~4 nm) exhibits excellent photoactivity with high selectivity(~99%).It is suggested that the excitonic energy transfer for 1 O_(2) formation is close related to the intrinsic exciton binding energy and the two-dimensional quantum confinement effect.This work establishes a basic mechanistic understanding on the excitonic processes in CN,and develops a feasible route to design CN-based photocatalysts for efficient 1 O_(2) generation. 展开更多
关键词 g-C_(3)N_(4)nanosheet Singlet oxygen generation Excitonic energy transfer Photocatalysis Organic selective oxidat
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