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Effect of Carbon Particles with Different Topological Shape on the Rheological Behavior of PVA Aqueous Dispersion

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Chinese Journal of Polymer Science 2022年第11期40卷 1402-1410页

作者： qing-Sheng ni Miao Du Guo-Rong shan Yi-Hu Song Qiang Zheng State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou310027China Institute of Zhejiang University-Quzhou Quzhou324000China Ministry of Education Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou310027China

Poly(vinyl alcohol)(PVA)is usually processed and used in a form of aqueous dispersion.A large number of inter-and intramolecular hydrogen bonds make it very difficult to obtain suitable rheological behavior for *** this study,carbon particles with different topological shapes were added into PVA aqueous dispersion to tune the steady and dynamic rheological *** results show that the zero-dimensional particles(carbon black,CB)increase monotonically the zero-shear viscosity of PVA dispersion,while the one-dimensional particles(carbon nanotubes,CNTs)make it first increase,and then decrease and rise again,like an N-shape,and the two-dimensional particles(graphene oxide,GO)can make it first decrease and then increase,exhibiting a *** is believed that the topological shape of the carbon particles brought about these *** zero-dimensional particles mainly act as physical crosslinking points due to their small *** at a certain content,both CNTs and GO can destroy the intermolecular hydrogen bonds between PVA chains because the PVA chains can twine around the slim CNTs and the large planar size of GO prevents the adsorbed PVA from forming hydrogen bond with other *** high hydroxyl value of carbon particle surface could strengthen this *** is expected that the viscosity of polymer dispersion can be regulated by particles with different topological shape and the surface characteristic,so as to widen the operable concentration range during preparing composite functional materials.

关键词： Topological shape Hydrogen bond Rheological behavior PVA aqueous dispersion

Injection molding and debinding of micro gears fabricated by micro powder injection molding

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International Journal of Minerals,Metallurgy and Materials 2013年第1期20卷 82-87页

作者： Xin-lei ni Hai-qing Yin Lin Liu shan-jie Yi Xuan-hui Qu School of Materials Science and Engineering University of Science and Technology Beijing School of Mechanical and Electrical Engineering China University of Mining and Technology (Beijing)

Micro powder injection molding （μPIM） was investigated for possible mass production of micro-components at rela- tively low cost. However, scaling down to such a level produces challenges in injection molding and debinding. Micro gears were fabricated by μPIM from in-house feedstock. The effect of injection speed and injection pressure on the replication of the micro gear cavity was investigated. Solvent debinding and thermal debinding processes were discussed. The results show that micro gears can be successfully fabricated under the injection pressure of 70 MPa and the 60% injection speed. Either too low or too high injection speed can cause incomplete filling of micro gears. The same is the case with too low injection pressure. Too high injection pressure can bring cracks. Solvent debinding of micro gears was performed in a mixture of petroleum ether and ethanol. Subsequently, micro gears were successfully debound by a multistep heating schedule.

关键词： gear manufacture micro gears injection molding debinding zirconia

Preparation of FeConi medium entropy alloy from Fe^(3+)-Co^(2+)-ni^(2+)solution system

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 92-101页

作者： Zongyou Cheng qing Zhao Mengjie Tao Jijun Du Xingxi Huang Chengjun Liu Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education) Northeastern UniversityShenyang 110819China School of Metallurgy Northeastern UniversityShenyang 110819China Engineering Research Center of Frontier Technologies for Low-carbon Steelmaking(Ministry of Education) Shenyang 110819China

In recent years,medium entropy alloys have become a research hotspot due to their excellent physical and chemical *** controlling reasonable elemental composition and processing parameters,the medium entropy alloys can exhibit similar properties to high entropy alloys and have lower *** this paper,a FeConi medium entropy alloy precursor was prepared via sol-gel and coprecipitation methods,respectively,and FeConi medium entropy alloys were prepared by carbothermal and hydrogen *** phases and magnetic properties of FeConi medium entropy alloy were *** showed that FeConi medium entropy alloy was produced by carbothermal and hydrogen reduction at 1500℃.Some carbon was detected in the FeConi medium entropy alloy prepared by carbothermal *** alloy prepared by hydrogen reduction was uniform and showed a relatively high ***,the hydrogen reduction product exhibited better saturation magnetization and lower coercivity.

关键词： medium entropy alloy sol-gel co-precipitation carbothermal hydrogen reduction

Turán Problems for Berge-(k,p)-Fan Hypergraph

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Chinese Annals of Mathematics,Series B 2021年第4期42卷 487-494页

作者： Zhenyu ni Liying KANG Erfang shan Department of Mathematics Shanghai UniversityShanghai 200444China School of Management Shanghai UniversityShanghai 200444China

Let F be a graph.A hypergraph H is Berge-F if there is a bijection f:E(F)→E(H)such that e■f(e)for every e∈E(F).A hypergraph is Berge-F-free if it does not contain a subhypergraph isomorphic to a Berge-F *** authors denote the maximum number of hyperedges in an n-vertex r-uniform Berge-F-free hypergraph by ex_(r)(n,Berge-F).A(k,p)-fan,denoted by F_(k,p),is a graph on k(p-1)+1 vertices consisting of k cliques with p vertices that intersect in exactly one common *** this paper they determine the bounds of ex_(r)(n,Berge-F)when F is a(k,p)-fan for k≥2,p≥3 and r≥3.

关键词： Berge-hypergraph Turán number

Phosphorus sorption capacities in a headstream landscape—The pond chain structure

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Journal of Environmental Sciences 2006年第5期18卷 1004-1011页

作者： FU Qiang YIN Cheng-qing shan Bao-qing State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

Understanding phosphorus sorption phenomena in different wetland sediments is important in controlling the P output in headstream watersheds. The pond chain structure （PCS） is widespread in the headstream agricultural watersheds in the southeast of China. Phosphorus sorption characteristics were determined for pond surface sediments （0-12 cm） along a pond chain structure in Liuchahe watershed of Chaohu Lake. Results showed that P sorption capacities （expressed by P sorption index （PSI）） varied both with the landscape position of the ponds and sediment depth. From foothill ponds to riverside ponds the P sorption capacities indicated a significant gradient variability. The higher elevation ponds showed greater sorption capacities, and with the pond elevation decline, P sorption capacities gradually decreased. Some physico-chemical properties, such as pH, oxalate-extractable Fe （Feox）, organic matter （TOC） and Mehlich l-extractable Ca, Mg of pond sediments also indicated significant gradient variability from high elevation ponds to low elevation ponds. Feox was the sediment parameters most highly positively correlated with PSI and was the key factor in controlling P sorption capacity in the pond chain structure （r=0.92, p〈0.001）. Long-term hydrologic and sediment inputs can affect the distribution of sediment constituents and further affect the P sorption capacity. Making the best of the spatial difference of sorption capacities of ponds in watersheds to control nonpoint source P pollutant is necessary.

关键词： pond sediment adsorption spatial variability nonpoint source

Smooth second-order nonsingular terminal sliding mode control for reusable launch vehicles

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International Journal of Intelligent Computing and Cybernetics 2014年第1期7卷 95-110页

作者： Shaobo ni Jiayuan shan Flight Dynamics and Control Laboratory Beijing Institute of TechnologyBeijing Aerospace Automatic Control InstituteBeijingPeople’s Republic of China Flight Dynamics and Control Laboratory Beijing Institute of TechnologyBeijingPeople’s Republic of China

Purpose–The purpose of this paper is to present a sliding mode attitude controller for reusable launch vehicle(RLV)which is nonlinear,coupling,and includes uncertain parameters and external ***/methodology/approach–A smooth second-order nonsingular terminal sliding mode(NTSM)controller is proposed for RLV in reentry ***,a NTSM manifold is proposed for finite-time *** a smooth second sliding mode controller is designed to establish the sliding *** observer is utilized to estimate the lumped disturbance and the estimation result is used for feedforward compensation in the ***–It is mathematically proved that the proposed sliding mode technique makes the attitude tracking errors converge to zero in finite time and the convergence time is *** are made for RLV through the assumption that aerodynamic parameters and atmospheric density are *** results demonstrate that the proposed control strategy is effective,leading to promising performance and ***/value–By the proposed controller,the second-order sliding mode is *** attitude tracking error converges to zero in a finite ***,the chattering is alleviated and a smooth control input is obtained.

关键词： Flight control Nonlinear control Finite-time convergence Reusable launch vehicles Sliding mode control

Collision-induced Rotational Energy Transfer in an Atom-Diatom System

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Chinese Journal of Chemical Physics 2008年第5期21卷 457-462页

作者： Yan-qing ni Jian Li Feng-cai Ma Department of Physics Liaoning University Shenyang 110036 China Department of Science Shenyang Institute of Aeronautical Engineering Shengyang 110036 China

As a further theoretical study of the collision-induced quantum interference on rotational energy transfer in an atom-diatom system, based on the first-Born approximation of time-dependent perturbation theory, taking into account the anisotropic Lennard-Jones interaction potential and the long-range interaction potential, the differential interference angles in singlet-triplet mixed states of CO A^1Π（v=9）-e3∑-（v=1） system in collision with He, Ne, Ar, and other partners were calculated theoretically. The relationships of differential interference angle versus impact parameters, including collision parameter b and velocity, are obtained.

关键词： Rotational energy transfer Collision-induced quantum interference Interference angle

A review on charging behavior of electric vehicles:data,model,and control

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Control Theory and Technology 2020年第3期18卷 217-230页

作者： qing-shan JIA Teng LONG Center for Intelligent and Networked Systems(CFINS) Department o f AutomationBeijing National Research Center for Information Science and Technology(BNRist)Tsinghua UniversityBeijing 100084China

The adoption and usage of electric vehicles(EVs)have emerged recently due to the increasing concerns on the greenhouse gas issues and energy *** a part of the smart grid,EVs can provide valuable ancillary services beyond consumers of ***,EVs are gradually considered as nonnegligible loads due to their increasing penetration,which may result in negative effects such as voltage deviations,lines saturation,and power *** and interaction among EVs,charging stations,and micro grid have to be considered in the next generation of smart ***,the topic of smart charging has been the focus of many works where a wide range of control methods have been *** one of the bases of simulation,the EV charging behavior and characteristics have also become the focus of many *** this work,we review the charging behavior of EVs from the aspects of data,model,and *** provide the links for most of the data sets reviewed in this work,based on which interested researchers can easily access these data for further investigation.

关键词： Electric vehicle charging behavior data and model

On large action space in EV charging scheduling optimization

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Science China(Information Sciences) 2022年第2期65卷 45-60页

作者： Zhaoyu JIANG qing-shan JIA Xiaohong GUAN Center for Intelligent and Networked Systems Beijing National Research Center for Information Science and Technology Department of Automation Tsinghua University MOE KLINNS Lab Xi'an Jiaotong University

In order to reduce the air pollution by traditional fossil fuel and save the charging cost, much attention has been paid to the charging scheduling of electric vehicles(EVs) in the uncertain supplement of wind power and solar power. Owing to the randomness in the renewable power generation and the EV charging demand, simulation-based policy improvement(SBPI) has been well adopted for making charging decision. However, it is challenging to explore the large action space which grows exponentially with respect to the system scale. We consider this important problem in this paper and make the following ***, we explore the structural property of the problem and develop an urgency index to rank the ***, we apply three methods to search in the action space. Third, we numerically demonstrate the performance of the urgency index and the search methods, and compare the SBPI methods with the CPLEXbased method. It shows that SBPI improves the base policies in all these cases.

关键词： EV simulation-based policy improvement large action space sampling

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