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Electrochemical capacitors based on the composite of graphene and nickel foam

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Science China Chemistry 2016年第4期59卷 405-411页

作者： Songwei Li Min Wang yongfu lian Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education School of Chemistry and Materials Science Heilongjiang University

An improved Hummers method was developed for the simple and efficient production of high-quality graphene oxide （GO）, and the composite of GO and nickel foam （NF）（GO/NF） was fabricated by ultrasonication-vacuum-assisted deposition of an aqueous solution of GO on NF. After chemical or thermal reduction, the composite of reduced GO and nickel foam （rGO/NF） was obtained. The electrochemical capacitance performance of rGO/NF was investigated using cyclic voltammetry and gal- vanostatic charge/discharge measurements. The chemically reduced rGO/NF composite （C-rGO/NF） exhibited high specific capacitance of 379 F/g at 1.0 A/g and 266.5 F/g at 10 A/g. We also prepared thermally reduced graphene oxide at 473 K in or- der to illuminate the difference in effect between the chemical and low-temperature thermal reduction methods on electro- chemical properties. The cycling performance of thermally reduced rGO/NF composite （T-rGO/NF） and C-rGO/NF had ~91% and ~95% capacitance retention after 2000 cycles in a 6 mol/L KOH electrolyte, respectively. Electrochemical experiments in- dicated that the obtained rGO/NF has very good capacitive performance and could be used as a potential application of elec- trochemical capacitors. Our work revealed high electrochemical capacitor performance of rGO/NF composite and provided a facile method of rGO/NF preparation.

关键词： electrochemical capacitor graphene oxide nickel foam reduction

Supercapacitors based on high-surface-area graphene

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Science China(Technological Sciences) 2014年第2期57卷 278-283页

作者： ZHOU XiaoLin WANG Min lian Jie lian yongfu Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education School of Chemistry and Material Science Heilongjiang University

Exfoliated graphite oxide was prepared by an improved Hummers method and was then reduced to graphene with hydrazine in the presence of ammonium hydroxide.N2adsorption–desorption measurement showed that graphene so obtained had a specific surface area as high as 818 m2/*** charge/discharge curves demonstrated that the as-prepared graphene exhibited a specific capacitance of 186.9 F/g at a current density of 0.1 A/g and that about 96%of the specific capacitance was retained after 2000 cycles at a current density of 5 A/g.

关键词： supercapacitor graphene high specific surface area high specific capacitance

Tb@C_(82)异构体的分离及其电化学性质研究

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化学学报 2017年第5期75卷 453-456页

作者：董薇聂梦思廉永福黑龙江大学化学化工与材料学院功能无机材料化学教育部重点实验室哈尔滨150080

通过制备型高效液相色谱分离获得了Tb@C_(82)的两种同分异构体,依据它们的UV-Vis-NIR吸收光谱推断它们分别具有C_(2v)和C_s对称性的碳笼结构,而且Tb是以+3价的形态内嵌于碳笼中的.电化学研究表明,C_(82)碳笼的对称性对Tb@C_(82)的还原... 详细信息

通过制备型高效液相色谱分离获得了Tb@C_(82)的两种同分异构体,依据它们的UV-Vis-NIR吸收光谱推断它们分别具有C_(2v)和C_s对称性的碳笼结构,而且Tb是以+3价的形态内嵌于碳笼中的.电化学研究表明,C_(82)碳笼的对称性对Tb@C_(82)的还原过程的影响较小,而对其氧化过程影响较大.Tb@C_(82)的两种异构体的第一还原电位都比较高,是较好的电子受体材料;而且与Tb@C_(2v)(9)-C_(82)相比,Tb@Cs(6)-C_(82)氧化还原电位更高一些,说明后者比前者具有更好的接受电子能力.此外,我们观察到了Tb@C_(2v)(9)-C_(82)的七对可逆的氧化-还原电位,丰富并修正了前人报道的结果.

关键词：内嵌金属富勒烯铽异构体电化学氧化-还原电位

优化电弧放电条件提高内嵌钬氧团簇富勒烯的合成产率

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黑龙江大学自然科学学报 2021年第6期38卷 679-684页

作者：李驰廉永福黑龙江大学化学化工与材料学院功能无机材料化学教育部重点实验室哈尔滨150080

利用改进的电弧放电法,以CO_(2)为氧源,成功合成了一系列内嵌钬氧团簇富勒烯Ho_(2)O@C_(2n)(n=43-55)。通过对放电电流、反应室气体压力、反应室气体组成和催化剂种类等实验参数的调控,将内嵌钬氧团簇富勒烯的合成产率提高了数倍。发现... 详细信息

利用改进的电弧放电法,以CO_(2)为氧源,成功合成了一系列内嵌钬氧团簇富勒烯Ho_(2)O@C_(2n)(n=43-55)。通过对放电电流、反应室气体压力、反应室气体组成和催化剂种类等实验参数的调控,将内嵌钬氧团簇富勒烯的合成产率提高了数倍。发现在内嵌钬氧团簇富勒烯的电弧放电合成过程中,铁是较钴、镍和铜更佳的金属催化剂。

关键词：内嵌富勒烯钬氧团簇电弧放电法合成产率

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单壁碳纳米管的纯化

哈尔滨师范大学自然科学学报 2013年第2期29卷 41-43页

作者：孙芳廉永福牡丹江师范学院黑龙江大学

单壁碳纳米管因其独特的一维结构,具有优良的力学和电学性质等优点而倍受人们青睐,但由于在制备过程中会产生大量如无定形碳、碳纳米颗粒和金属催化剂等杂质,限制了对其化学性质和应用的研究.采用焙烧、温和氧化、离心的方法对SWNTs进... 详细信息

单壁碳纳米管因其独特的一维结构,具有优良的力学和电学性质等优点而倍受人们青睐,但由于在制备过程中会产生大量如无定形碳、碳纳米颗粒和金属催化剂等杂质,限制了对其化学性质和应用的研究.采用焙烧、温和氧化、离心的方法对SWNTs进行提纯,利用XRD、UV-VIS-NIR和SEM仪器对提纯前后的样品进行了表征.研究表明,通过对碳管进行氧化、离心等方法可以显著地提高其纯度.

关键词：单壁碳纳米管提纯离心

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二次电弧放电法调控单壁碳纳米管的直径分布

黑龙江大学自然科学学报 2015年第5期32卷 641-644,701页

作者：黄瑶李里修姝袁明明郎敏吴秀力廉永福黑龙江大学化学化工与材料学院功能无机材料化学教育部重点实验室哈尔滨150080

首先以Y-Ni合金为催化剂,利用电弧法制备了单壁碳纳米管粗品。然后以该粗品为碳源,在不另外添加催化剂的情况下,利用二次电弧放电法制备了单壁碳纳米管。对二次电弧放电制备的单壁碳纳米管进行了紫外-近红外吸收光谱、拉曼光谱和热重分... 详细信息

首先以Y-Ni合金为催化剂,利用电弧法制备了单壁碳纳米管粗品。然后以该粗品为碳源,在不另外添加催化剂的情况下,利用二次电弧放电法制备了单壁碳纳米管。对二次电弧放电制备的单壁碳纳米管进行了紫外-近红外吸收光谱、拉曼光谱和热重分析的表征,结果表明,二次电弧放电所制备的单壁碳纳米管的管径比首次电弧放电制备的直径略小,约为1.36 nm,且较为均一。

关键词：电弧放电法单壁碳纳米管管径分布二次电弧放电

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水中可分散单壁碳纳米管的制备

黑龙江八一农垦大学学报 2020年第3期32卷 116-122页

作者：高金玲廉永福冯世德刘佳雪黑龙江八一农垦大学理学院大庆163319 黑龙江大学化学化工与材料学院

水中可分散的单壁碳纳米管在众多领域中被广泛应用。试验利用直流电弧放电法制备了单壁碳纳米管粗品。经灼烧、酸化和在有机溶剂中选择性溶解处理后,获得了纯度较高的单壁碳纳米管。采用紫外-可见-近红外光谱、共振拉曼光谱和高分辨率... 详细信息

水中可分散的单壁碳纳米管在众多领域中被广泛应用。试验利用直流电弧放电法制备了单壁碳纳米管粗品。经灼烧、酸化和在有机溶剂中选择性溶解处理后,获得了纯度较高的单壁碳纳米管。采用紫外-可见-近红外光谱、共振拉曼光谱和高分辨率透射电子显微镜等表征手段考察了纯化前后单壁碳纳米管样品的纯度。在超声破碎仪辅助下把纯化后单壁碳纳米管样品分散在聚乙烯醇水溶液中,经过离心分离,得到了在水中可分散的单壁碳纳米管分散液。采用紫外-可见-近红外光谱和共振拉曼光谱等表征手段进一步考察了纯化后单壁碳纳米管在聚乙烯醇水溶液中的分散行为。利用电化学工作站测试了分散前后单壁碳纳米管的循环伏安曲线,探究了分散前后单壁碳纳米管的电子传递行为。

关键词：单壁碳纳米管聚乙烯醇离心分离紫外-可见-近红外光谱共振拉曼光谱

A robust QRS detection and accurate R-peak identification algorithm for wearable ECG sensors

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Science China(Information Sciences) 2021年第8期64卷 213-229页

作者： Kai ZHAO yongfu LI Guoxing WANG Yu PU Yong lian Department of Micro and Nano Electronics Shanghai Jiao Tong University Alibaba Group

This paper presents a robust QRS detection algorithm that is capable of detecting QRS complexes as well as accurately identifying R-peaks. The proposed bilateral threshold scheme combined with QRS watchdog greatly improves the detection accuracy and robustness, resulting in consistent detection performance on 9 available ECG databases. Simulations show that the proposed algorithm achieves good results on the datasets from both QTDB healthy database and MITDB arrhythmia database, i.e. the sensitivity of99.99% and 99.88%, the precision of 99.98% and 99.88%, and the detection error rate of 0.04% and 0.31%,respectively. Furthermore, it also outperforms many existing algorithms on six other ECG databases, such as NSTDB, TWADB, STDB, SVDB, AFTDB, and FANTASIADB.

关键词： signal processing QRS detection R-peak detection wearable ECG sensors bilateral threshold

Detection of the interictal epileptic discharges based on wavelet bispectrum interaction and recurrent neural network

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Science China(Information Sciences) 2021年第6期64卷 203-221页

作者： Nabil SABOR yongfu LI Zhe ZHANG Yu PU Guoxing WANG Yong lian Department of Micro-Nano Electronics Shanghai Jiao Tong University Electrical Engineering Department Assiut University MoE Key Lab of Artificial Intelligence Shanghai Jiao Tong University Alibaba DAMO Academy

Detection of interictal epileptic discharges(IED) events in the EEG recordings is a critical indicator for detecting and diagnosing epileptic seizures. We propose a key technology to extract the most important features related to epileptic seizures and identifies the IED events based on the interaction between frequencies of EEG with the help of a two-level recurrent neural network. The proposed classification network is trained and validated using the largest publicly available EEG dataset from Temple University *** results clarified that the interaction between β and β bands, β and γ bands, γ and γ bands,δ and δ bands, θ and α bands, and θ and β bands have a significant effect on detecting the IED ***, the obtained results showed that the proposed technique detects 95.36% of the IED epileptic events with a false-alarm rate of 4.52% and a precision of 87.33% by using only 25 significant features. Furthermore,the proposed system requires only 164 ms for detecting a 1-s IED event which makes it suitable for real-time applications.

关键词： interictal epileptic discharges epilepsy discrete wavelet transform wavelet bispectrum long short-term memory recurrent neural network