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High visible light photocatalytic activities obtained by integrating g-C_(3)N_(4) with ferroelectric PbTiO_(3)

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Journal of Materials Science & Technology 2021年第15期74卷 128-135页

作者： Tingting Xu ping niu Shulan Wang Li Li Department of Chemistry School of ScienceNortheastern UniversityShenyang110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina School of Metallurgy Northeastern UniversityShenyang110819China

Graphitic carbon nitride(g-C_(3)N_(4))with the merits of high visible light absorption,proper electronic band structure with high conduction band edge and variable modulation,is viewed as a promising photocatalyst for practical *** alleviate its high recombination rate of photo-excited charge carriers and maximize the photocatalytic performances,it is paramount to design highly effective transfer channels for photo-excited charge *** materials can have the charge carriers transport in opposite directions owing to the internal spontaneous polarization,which may be suitable for constructing the heterostructure with g-C_(3)N_(4)for efficient charge *** by this concept,herein ferroelectric PbTiO_(3),which can be the visible-light absorber,is coupled with g-C_(3)N_(4)to construct PbTiO_(3)/g-C_(3)N_(4)heterostructure with close contact via Pb–N bond by the facile post thermal *** optimized Pb TiO_(3)/g-C_(3)N_(4)heterostructure exhibited excellent photocatalytic and photoelectrochemical activities under visible light ***,the simultaneous application of ultrasound-induced mechanical waves can further improve its photocatalytic activities through reinforcing the built-in piezoelectric *** work proposes a widely applicable strategy for the fabrication of high-performance ferroelectric based photocatalysts and also provides some new ideas for developing the understanding of ferroelectric photocatalysis.

关键词： Photocatalysis Ferroelectric Piezoelectric Carbon nitride Lead titanate

Hydrothermal Synthesis and Crystal Structure of a New 2D Layer Compound [{Ni(en)_2}_2Sb_8V_(14)O_(42)]·5.5H_2O

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Chemical Research in Chinese Universities 2009年第4期25卷 426-429页

作者： YU Li LIU Jiang-ping WANG Jing-ping niu Jing-yang Institute of Molecular and Crystal Engineering School of Chemistry and Chemical Engineering Ifenan University Kaifeng 475001 P. R. China

A new compound based on polyoxovanadate [{Ni（en）2}2Sb8V14O42]·5.5H2O（en=ethylenediamine）（1） was synthesised hydrothermally as black rhombus *** 1 crystallized in the monoclinic system with space group P21/n,Z=4,a=1.46953（9） nm,b=1.28623（8） nm,c=1.76008（11） nm,β=105.7230（10）°.In the asymmetric unit,cluster {Sb8V14O42} can be considered as an Sb derivative of the {V18O42} *** {Sb8V14O42} cluster as a building block interconnected to four other neighboring units by {Ni（en）2} bridging groups which are linked through the terminal oxygen atoms of the polyoxoanions,forming a two dimensional network.

关键词： Hydrothermal synthesis Antimony-substituted Polyoxovanadate

Constructing Crystalline g-C_(3)N_(4)/g-C_(3)N_(4-x)S_(x)Isotype Heterostructure for Efficient Photocatalytic and Piezocatalytic Performances

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Energy & Environmental Materials 2023年第2期6卷 8-16页

作者： Tingting Xu Zhonghui Xia Hongguan Li ping niu Shulan Wang Li Li Department of Chemistry School of ScienceNortheastern UniversityShenyang 110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China School of Metallurgy Northeastern UniversityShenyang 110819China

Graphitic carbon nitride(g-C_(3)N_(4))is viewed as a promising visible-light photocatalyst for industrialization due to its low processing temperature and high chemical ***,serious charge recombination caused by incomplete polymerization during direct calcination of nitrogen-rich precursors significantly limits its photocatalytic *** boost charge separation,herein,we propose a rational strategy by constructing a crystalline g-C_(3)N_(4)/g-C_(3)N_(4-x)S_(x) isotype heterostructure through the molten salt *** calculation reveals that apparent charge-transfer channels are formed between g-C_(3)N_(4) and S-doped g-C_(3)N_(4) layers in the *** to high crystallinity for decreasing charge recombination and isotype heterostructure for efficient charge transfer,the as-prepared g-C_(3)N_(4)/g-C_(3)N_(4-x)S_(x) showed remarkable photocatalytic performances with the hydrogen production rate elevated by up to 12.3 times of its singular *** novelty of this work is we investigated for the first time the piezocatalytic activity of crystalline g-C_(3)N_(4) by characterizing its performance for H2O2 generation and KMnO4 ***,its superior piezocatalytic performance over components can be further improved by NaBH4 treatment,which is uncovered to enhance the asymmetric structure of crystalline g-C_(3)N_(4) by introducing extra cyano groups and removing partial NHx species in its tri-s-triazine layer *** work opens up new strategies for the design of highly efficient polymeric photocatalysts and highlights the piezocatalytic studies of g-C_(3)N_(4).

关键词： carbon nitride high crystallinity isotype heterostructure photocatalysis piezoelectric catalysis

An Overview on Backscatter Communications

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Journal of Communications and Information Networks 2019年第2期4卷 1-14页

作者： Jin-ping niu Geoffrey Ye Li Shaanxi International Joint Research Centre for the Battery-Free Internet of Things School of Information and TechnologyNorthwest UniversityXi’anShaanxi 710127China School of Electrical and Computer Engineering Georgia Institute of TechnologyAtlantaGA30332USA

As a key low-power communication tech-nique,backscatter communications exploits the reflected or backscattered signals to transmit data,where the backscattered signals can be the reflection of ambient radio frequency(RF)signals,the RF signals from the dedicated carrier emitter or the signal photons in the non-classical quantum entangled pairs,*** the past 70 years,various kinds of backscatter communication systems have been developed,which will enable the low-power communications as required in the Internet of things(IoTs)and green *** article provides a historical view on the development and the research achievements on backscatter communications,including the fundamental principles,the applications,the challenges,and the potential research *** article will benefit the researchers and engineers concerning the area of backscatter communications,especially for applications in IoTs.

关键词： backscatter backscatter communications energy harvesting IoTs

High Precision Prediction of Rolling Force Based on Fuzzy and Nerve Method for Cold Tandem Mill

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Journal of Iron and Steel Research International 2008年第2期15卷 23-27页

作者： JIA Chun-yu SHAN Xiu-ying niu Zhao-ping College of Mechanical Engineering Yanshan University Qinhuangdao 066004 Hebei China

The rolling force model for cold tandem mill was put forward by using the Elman dynamic recursive network method,based on the actual measured ***,a good assumption is put forward,which brings a full universe of discourse self-adjusting factor fuzzy control,closed-loop adjusting,based on error feedback and expertise into a rolling force prediction model,to modify prediction outputs and improve prediction precision and *** simulated results indicate that the method is highly effective and the prediction precision is better than that of the traditional *** relative error is less than ±4%,so the prediction is high precise for the cold tandem mill.

关键词： Elman dynamic recursive network fuzzy control cold tandem mill rolling force prediction

Rational design of a hollow porous structure for enhancing diffusion kinetics of K ions in edge-nitrogen doped carbon nanorods

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Nano Research 2022年第9期15卷 8109-8117页

作者： ping niu Yang Yang Zhiqiang Li Gaohui Ding Lingzhi Wei Ge Yao Helin niu Yulin Min Fangcai Zheng Qianwang Chen Institutes of Physical Science and Information Technology Key Laboratory of Structure and Functional Regulation of Hybrid MaterialsAnhui UniversityMinistry of EducationHefei 230601China Hefei National Laboratory for Physical Science at Microscale and Department of Materials Science&Engineering University of Science and Technology of ChinaHefei 230026China Key Laboratory of Functional Inorganic Material Chemistry of Anhui Province Anhui UniversityHefei 230601China Shanghai Key Laboratory of Materials Protection and Advanced Materials Electric Power Shanghai Engineering Research Center of Energy-Saving in Heat Exchange SystemsShanghai University of Electric PowerShanghai 200090China

The high electrical conductivity makes it possible for one-dimensional(1D)carbon materials to be used as the promising anodes for potassium ion batteries(PIBs),however,the sluggish diffusion kinetics caused by large-sized potassium ions(K^(+))limits their practical applications in energy storage *** this work,hollow carbon nanorods were rationally designed as a case to verify the superiority of 1D hollow structure to improve the diffusion kinetics of K^(+).Simultaneously,edge-N(pyridinic-N and pyrrolic-N)atoms were also introduced into 1D hollow carbon structure,which can provide ample active sites and defects in graphitic lattices to adsorb K^(+),providing extra capacitive storage *** expected,the optimized edge-N doped hollow carbon nanorods(ENHCRs)exhibits a high reversible capacity of 544 mAh·g^(−1)at 0.1 A·g^(−1)after 200 *** at 5 A·g^(−1),it displays a long-term cycling stability with 255 mAh·g^(−1)over 10,000 *** electrochemical measurements confirm that the hollow structure is favorable to improve the transfer kinetics of K^(+)during *** the theoretical calculations demonstrate that edge-N doping can enhance the local electronegativity of graphitic lattices to adsorb much more K^(+),where edge-N doping synergizes with 1D hollow structure to achieve enhanced K^(+)-storage performances.

关键词： carbon materials edge-nitrogen hollow structure theoretical calculation batteries

Scalable high performance de-duplication backup via hash join

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第5期11卷 315-327页

作者： Tian-ming YANG Dan FENG Zhong-ying niu Ya-ping WAN Wuhan National Laboratory for Optoelectronics School of Computer Science and Technology Huazhong University of Science and Technology Wuhan 430074 China

Apart from high space efficiency,other demanding requirements for enterprise de-duplication backup are high performance,high scalability,and availability for large-scale distributed *** main challenge is reducing the significant disk input/output(I/O) overhead as a result of constantly accessing the disk to identify duplicate *** inline de-duplication approaches mainly rely on duplicate locality to avoid disk bottleneck,thus suffering from degradation under poor duplicate locality *** paper presents Chunkfarm,a post-processing de-duplication backup system designed to improve capacity,throughput,and scalability for *** performs de-duplication backup using the hash join algorithm,which turns the notoriously random and small disk I/Os of fingerprint lookups and updates into large sequential disk I/Os,hence achieving high write throughput not influenced by workload *** importantly,by decentralizing fingerprint lookup and update,Chunkfarm supports a cluster of servers to perform de-duplication backup in parallel;it hence is conducive to distributed implementation and thus applicable to large-scale and distributed storage systems.

关键词： Backup system De-duplication Post-processing Fingerprint lookup Scalability

Synthesis of crystalline g-C_(3)N_(4) with rock/molten salts for efficient photocatalysis and piezocatalysis

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Green Energy & Environment 2024年第5期9卷 890-898页

作者： Tingting Xu Jung Hur ping niu Shulan Wang Sangwook Lee Sang-Eun Chun Li Li Department of Chemistry College of ScienceNortheastern UniversityShenyang110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819China School of Metallurgy Northeastern UniversityShenyang110819China School of Materials Science and Engineering Kyungpook National UniversityDaegu41566Republic of Korea School of Industrial Technology Advances Kyungpook National UniversityDaegu41566Republic of Korea

Graphitic carbon nitride(g-C_(3)N_(4))is emerging as a promising visible-light photocatalyst while the low crystallinity with sluggish charge separation/migration dynamics signiﬁcantly restricts its practical ***,synthesizing highly crystalline g-C_(3)N_(4) with sufﬁcient surface activities still remains ***,different from using alkali molten salts which is commonly reported,we propose an approach for synthesis of highly crystalline g-C_(3)N_(4) with FeCl3/KCl rock/molten mixed *** rock salt can serve as the structure-directing template while molten salt provides the required liquid medium for ***,the synthesized photocatalyst showed further enhanced crystallinity and improved surface area along with high p/p*excitation compared with crystalline C_(3)N_(4) prepared from conventional molten-salt *** catalytically advantageous features lead to its superior photocatalytic and piezocatalytic activities with a high reactivity for overall water splitting that is not commonly reported for C_(3)N_(4).This work provides an effective strategy for structural optimization of organic semiconductor based materials and may inspire new ideas for the design of advanced photocatalysts.

关键词： High crystallinity Carbon nitride Photocatalysis Piezocatalysis Overall water splitting

Fuzzy Neural Model for Flatness Pattern Recognition

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Journal of Iron and Steel Research International 2008年第6期15卷 33-38页

作者： JIA Chun-yu SHAN Xiu-ying LIU Hong-min niu Zhao-ping School of Mechanical Engineering Yanshan University Qinhuangdao 066004 Hebei China

For the problems occurring in a least square method model, a fuzzy model, and a neural network model for flatness pattern recognition, a fuzzy neural network model for flatness pattern recognition with only three-input and three output signals was proposed with Legendre orthodoxy polynomial as basic pattern, based on fuzzy logic expert experiential knowledge and genetic-BP hybrid optimization algorithm. The model not only had definite physical meanings in its inner nodes, but also had strong self-adaptability, anti interference ability, high recognition precision, and high velocity, thereby meeting the demand of high-precision flatness control for cold strip mill and providing a convenient, practical, and novel method for flatness pattern recognition.

关键词： flatness pattern recognition Legendre orthodoxy polynomial genetic-BP algorithm fuzzy neural network