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Fabrication, Sintering and Electrical Properties of (Ca_(0.61),Nd_(0.26))TiO_3 Nanoparticles Doped with Li-Cu-B

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Journal of Materials Science & Technology 2011年第5期27卷 426-430页

作者： fei wu Qilong Zhang Hui Yang Department of Materials Science and Engineering Zhejiang University Hangzhou 310027 China

A sol-gel processing was used to low temperature. Orthorhombic synthesize （Cao.61,Ndo.26）TiO3 （CNT） perovskite structure phase with a smal nanoparticles doped with Li-Cu-B at amount of Li3BO3 secondary phase was formed by calcining the xerogels at 300℃, and monodisperse CNT nano-powders with the grain size of 10-15 nm could be obtained. By using these nanocrystalline CNT powders, dense CNT ceramics could be achieved at the low sintering temperature of 1100℃ due to the effect of the small size nanoparticles and liquid phase Li3BO3. And the dielectric properties with dielectric constant （εr= 89.52）, quality value factors with frequency （Q×f=17148 GHz） and the temperature coefficient of resonant frequency （τf） value of ＋239×10^-6/℃ were achieved.

关键词： Sol-gel preparation Nanomaterials Electrical properties Sintering

Heteropolyacids-Immobilized Graphitic Carbon Nitride:Highly Efficient Photo-Oxidation of Benzyl Alcohol in the Aqueous Phase

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Engineering 2021年第1期7卷 94-102页

作者： Lifu wu Sai An Yu-fei Song State Key Laboratory of Chemical Resource Engineering Beijing Advanced Innovation Center for Soft Matter Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China

Benzaldehyde is a highly desirable chemical due to its extensive application in medicine,chemical synthesis and food sector among ***,its production generally involves hazardous solvents such as trifluorotoluene or acetonitrile,and its conversion,especially selectivity in the aqueous phase,is still not up to ***,developing an environmentally benign,synthetic process for benzaldehyde production is of paramount ***,we report the preparation of a photocatalyst(PW_(12)-P-UCNS,where PW_(12)is H3PW_(12)O_(40)xH_(2)O and P-UCNS is phosphoric acid-modified unstack graphitic carbon nitride)by incorporating phosphotungstic acid on phosphoric acid-functionalised graphitic carbon nitride(g-C_(3)N_(4))*** performance of PW_(12)-P-UCNS was tested using the benzyl alcohol photo-oxidation reaction to produce benzaldehyde in H_(2)O,at room temperature(20℃).The asprepared PW12-P-UCNS photocatalyst showed excellent photocatalytic performance with 58.3%conversion and 99.5%selectivity within 2 ***,the catalyst could be reused for at least five times without significant activity *** importantly,a proposed Z-scheme mechanism of the PW_(12)-P-UCNScatalysed model reaction was *** carefully investigated its transient photocurrent and electrochemical impedance,and identified superoxide radicals and photogenerated holes as the main active species through electron spin-resonance spectroscopy and scavenger *** show that the designed PW_(12)-P-UCNS photocatalyst is a highly promising candidate for benzaldehyde production through the photo-oxidation reaction in aqueous phase,under mild conditions.

关键词： Photocatalysis Heteropolyacids Graphitic carbon nitride Benzaldehyde

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利用异配及同配关系的社交机器人检测方法

北京理工大学学报 2025年第1期45卷 77-86页

作者：罗森林费泽涛潘丽敏吴舟婷北京理工大学信息与电子学院

现有基于图的方法未区分用户间的异配、同配关系，造成用户表示中存在异配边带来的噪声，弱化了社交机器人与人类用户之间的差异性，检测准确率降低；社交机器人持续演化模拟人类用户的关注数、推文发布数等元数据，容易导致较难识别的... 详细信息

现有基于图的方法未区分用户间的异配、同配关系，造成用户表示中存在异配边带来的噪声，弱化了社交机器人与人类用户之间的差异性，检测准确率降低；社交机器人持续演化模拟人类用户的关注数、推文发布数等元数据，容易导致较难识别的仿真社交机器人比例增加，检测召回率降低.提出一种利用异配及同配关系的社交机器人检测方法，通过记忆网络构建异配、同配关系原型来识别用户关系类型，减少异配边对用户表示的干扰，增加不同类型用户的特征区分性；在损失函数中引入调节因子，提高较难分类用户在模型参数更新过程中的损失贡献，增强了模型对仿真社交机器人的识别效果.实验结果表明，提出的方法优于当前先进方法，此方法通过区分用户间的异配和同配关系，降低异配边的权重，增强了用户表示的类别区分度，即使在低同配性分数的情况下也有效提升了检测准确率.

关键词：社交机器人异配关系记忆网络

The topological entropy for autonomous Lagrangian systems on compact manifolds whose fundamental groups have exponential growth

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Science China Mathematics 2020年第7期63卷 1323-1338页

作者： fei Liu Fang Wang Weisheng wu College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China School of Mathematical Sciences Capital Normal UniversityBeijing 100048China Department of Applied Mathematics China Agricultural UniversityBeijing 100083China

In this article,we consider the topological entropy for autonomous positive definite Lagrangian systems on connected closed Riemannian manifolds whose fundamental groups have exponential *** prove that on each energy level E(x,v)=k with k>c(L),where c(L)is Mane’s critical value,the EulerLagrange flow has positive topological *** extends the classical Dinaburg theorem from geodesic flows to general autonomous positive definite Lagrangian systems.

关键词： Euler-Lagrange flow positive topological entropy fundamental group exponential growth

A new polar motion prediction method combined with the difference between polar motion series

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Geodesy and Geodynamics 2022年第6期13卷 564-572页

作者： Leyang Wang Wei Miao fei wu Faculty of Geomatics East China University of TechnologyNanchang 330013China Key Laboratory of Mine Environmental Monitoring and Improving Around Poyang Lake Ministry of Natural ResourcesNanchang 330013China

After the first Earth Orientation Parameters Prediction Comparison Campaign(1 st EOP PCC),the traditional method using least-squares extrapolation and autoregressive(LS+AR)models was considered as one of the polar motion prediction methods with higher *** traditional method predicts individual polar motion series separately,which has a single input data and limited improvement in prediction *** address this problem,this paper proposes a new method for predicting polar motion by combining the difference between polar motion *** X,Y,and Y-X series were predicted separately using LS+AR ***,the new forecast value of X series is obtained by combining the forecast value of Y series with that of Y-X series;the new forecast value of Y series is obtained by combining the forecast value of X series with that of Y-X *** hindcast experimental comparison results from January 1,2011 to April 4,2021 show that the new method achieves a maximum improvement of 12.95%and 14.96%over the traditional method in the X and Y directions,*** new method has obvious advantages compared with the differential *** study tests the stability and superiority of the new method and provides a new idea for the research of polar motion prediction.

关键词： Earth rotation parameters Polar motion prediction LS+AR Differences between series Mean absolute error

Asymmetric chlorophyll responses enhanced by internal waves near the Dongsha Atoll in the South China Sea

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Journal of Oceanology and Limnology 2023年第2期41卷 418-426页

作者： Meilin wu Huijie XUE fei CHAI State Key Laboratory of Marine Environmental Science College of Ocean and Earth SciencesXiamen UniversityXiamen 361102China State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Innovation Academy of South China Sea Ecology and Environmental Engineering Chinese Academy of SciencesGuangzhou 510301China

Internal waves(IWs)are small-scale physical processes that occur frequently in stratified marginal *** are ubiquitous and well documented in the northern South China Sea(n SCS),but few studies have explored the ecosystem responses to the *** chlorophyll-a(Chl-a)data from 2002 to 2014 were used to examine the distribution of Chl a near the Dongsha Atoll(DSA).Composite Chl a from about 40 IWs during spring and summer showed stronger response on the northern side than on the southern side of the *** day after the passage of IWs,composite surface Chl a on the northern side increased from 0.11 mg/m3 to a maximum mean value of 0.18 mg/*** decreased to 0.13 mg/m3 after two days and maintained that level for several days after the passage of *** enhanced surface Chl a likely caused subsurface Chl-a maximum and nutrients in the surface *** 64%of the increase in surface Chl a was due to the uplift of the subsurface Chl-a maximum one day after the passage of IWs,while nutrient-induced new phytoplankton growth contributed about 18%of the increase a few days *** the IWs occurred frequently in spring and summer,Chl-a level on the northern side was about 30%higher than that on the southern *** dissipation and its impact on nutrients and chlorophyll were stronger on the northern side of the DSA than on the south,which caused a north-south asymmetric distribution of Chl a in the region.

关键词： internal waves(IWs) phytoplankton nutrients Dongsha Atoll northern South China Sea

Bioinspired Passive Tactile Sensors Enabled by Reversible Polarization of Conjugated Polymers

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Nano-Micro Letters 2025年第1期17卷 361-377页

作者： Feng He Sitong Chen Ruili Zhou Hanyu Diao Yangyang Han Xiaodong wu School of Mechanical Engineering Sichuan UniversityChengdu 610065People’s Republic of China School of Software Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065People’s Republic of China State Key Laboratory of Polymer Materials Engineering Sichuan UniversityChengdu 610065People’s Republic of China

Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced *** to active sensing devices,passive piezoelectric and triboelectric tactile sensors consume less power,but lack the capability to resolve static ***,we address this issue by utilizing the unique polarization chemistry of conjugated polymers for the first time and propose a new type of bioinspired,passive,and bio-friendly tactile sensors for resolving both static and dynamic ***,to emulate the polarization process of natural sensory cells,conjugated polymers(including poly(3,4-ethylenedioxythiophen e):poly(styrenesulfonate),polyaniline,or polypyrrole)are controllably polarized into two opposite states to create artificial potential *** controllable and reversible polarization process of the conjugated polymers is fully in situ ***,a micro-structured ionic electrolyte is employed to imitate the natural ion channels and to encode external touch stimulations into the variation in potential difference *** with the currently existing tactile sensing devices,the developed tactile sensors feature distinct characteristics including fully organic composition,high sensitivity(up to 773 mV N^(−1)),ultralow power consumption(nW),as well as superior *** demonstrations,both single point tactile perception(surface texture perception and material property perception)and two-dimensional tactile recognitions(shape or profile perception)with high accuracy are successfully realized using self-defined machine learning *** tactile sensing concept innovation based on the polarization chemistry of conjugated polymers opens up a new path to create robotic tactile sensors and prosthetic electronic skins.

关键词： Passive tactile sensors Reversible polarization of conjugated polymers Tactile perception Machine learning algorithm Object recognition

Inception point of air entrainment over stepped spillways

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Journal of Hydrodynamics 2013年第1期25卷 91-96页

作者： wu Jian-hua ZHANG Bin MA fei College of Water Conservancy and Hydropower Engineering Hohai University

The location of the inception point of the air entrainment directly affects the energy dissipation ratio, the cavitation damage control, and the training wall height designs for a stepped spillway and a stilling basin. In this paper, the boundary layer theory of plates is used to predict the location of the inception point of the air entrainment over the stepped spillways by assuming the steps on the spillways as a kind of roughness. An empirical formula is presented based on the physical model experiments, with the maximum error less than 1% except at one point where the error is 1.6%, as compared to the experimental data. Meanwhile, it is shown that the location of the inception point of the air entrainment for the stepped spillway is much nearer to the top of the spillway than that for a smooth spillways, which explains why the high ratio of the energy dissipation is provided for the stepped spillway.

关键词： air entrainment cavitation energy dissipation inception point stepped spillway unit discharge

Water quality improvement of a lagoon containing mixed chemical industrial wastewater by micro-electrolysis-contact oxidization

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第5期12卷 390-398页

作者： Ya-fei ZHOU Mao LIU Qiong wu College of Environmental Science and Engineering Nankai University Tianjin 300071 China The Eleventh Design & Research Institute of IT Co. Ltd Dalian Qffice Dalian 116600 China

A lagoon in the New Binhai District, a high-speed developing area, Tianjin, China, has long been receiving the mixed chemical industrial wastewater from a chemical industrial park. This lagoon contained complex hazardous substances such as heavy metals and accumulative pollutants which stayed over time with a poor biodegradability. According to the characteristics of wastewater in the lagoon, the micro-electrolysis process was applied to improve the biodegradability before the bioprocess treatment. By the orthogonal experimental study of main factors influencing the efficiency of the treatment method, the best control parameters were obtained, including pH=2.0, a volume ratio of Fe and reaction wastewater of 0.03750, a volume ratio of Fe and the granular activated carbon (GAC) of 2.0, a mixing speed of 200 r/min, and a hydraulic retention time (HRT) of 1.5 h. In the meantime, the removal rate of chemical oxygen demand (COD) was up to 64.6%, and NH4+-N and Pb in the influent were partly removed. After the micro-electrolysis process, the ratio of biochemical oxygen demand (BOD) to COD (B/C ratio) was greater than 0.6, thus providing a favorable basis for bioprocess treatment.

关键词： Memetic algorithm (MA) Neural network (NN) learning Back propagation (BP) Extremal optimization (EO) Levenberg-Marquardt (LM) gradient search Basic oxygen furnace (BOF)