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Preparation and Unimolecular-Micellization Behavior of Homopolymer of Surface-Active Monomer AMC14AB

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Chinese Journal of Chemical Physics 2008年第5期21卷 469-475页

作者： kang-kai liu Lei Li Institute of Coal Chemistry Chinese Academy of Sciences Taiyuan 030001 China Economy and Commerce Committee of Shanxi Province Taiyuan 030001 China

（2-acrylamido） ethyl tetradecyl dimethylammonium bromide （AMC14AB） was polymerized in aqueous solu- tion to form the homopolymer P（AMC14AB）. The physicochemical properties of P（AMC14AB） in aqueous solution were mainly studied with fluorescent probe method, surface tension measurement and conductom- etry. The experimental results show that the aggregation morphology of P（AMC14AB） in aqueous solution is unimolecular micelle as expected. Being different from conventional multimolecular micelle systems, the unimolecular micelle system of P（AMC14AB） not only shows critical micellar concentration （CMC=0）, （i.e. once added to pure water, the surface tension decreases immediately in spite how small the density is）, but also the surface tension stays almost the same with the concentration increasing. That is to say, there is no mutational point on the relationship curve between surface tension and concentration. Furthermore, the unimolecular micelle system of P（AMC14AB） has no Krafft temperature, i.e. at any temperature, so long as it is dissolved in water, the unimolecular micelles will form. Besides this, for the solubilization of hydrophobic organic substances, the unimolecular micelle system of P（AMC14AB） is obviously different from the common multimolecular micelle system, having no turning point on the relationship curve between toluene solubi- lizaion amount and P（AMC14AB） concentration, and the solubilizing ability of the unimolecular-micelle system of P（AMC14AB） for hydrophobic organic substances is much higher than that of the conventional multimolecular micelle solutions of common surfactants, such as centyl trimethyl ammonium bromide.

关键词： Surface active monomer Unimolecular micelle Zero critical micellar concentration Krafft temperature

Influence of baffle position on liquid sloshing during braking and turning of a tank truck

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第5期11卷 317-324页

作者： Ning kang Kui liu School of Transportation Science and Engineering University of A eronautics and Asttvnautics Beijing 100191 China

The influence of baffle position on liquid sloshing during the braking and turning of a tank truck was studied using a volume of fluid (VOF) model. The forces,their positions and weight distribution during braking and the forces and rolling moment during turning were calculated. The reliability of the calculation method was validated by comparisons with experimental results. The results showed that during braking,liquid splashes in the tank and the maximum forces and G (the ratio of weight acting on the front axle to the rear axle) are large when A (the ratio of the arch area above the baffle to the area of cross section)≤0.1. When A≥0.2,as the position of the baffle is lowered,the maximum of Fx (the force in direction x) first decreases then increases,and the maximum of Fy (the force in direction y) and G increase. During turning,liquid splashes in the tank and the maximum forces and M (the rolling moment) are large when D (the ratio of the arch area above the baffle to the area of cross section)≤0.2. When D≥0.3,as the position of the baffle is lowered,the maximums of Fy,Fz (the force in direction z) and M increase.

关键词： Tank truck Volume of fluid (VOF) method Liquid sloshing Two phase flow Baffle

Influence of Soil Heterogeneity on the Behavior of Frozen Soil Slope under Freeze-Thaw Cycles

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Computer Modeling in Engineering & Sciences 2022年第4期131卷 119-135页

作者： kang liu Yanqiao Wang School of Civil Engineering Hefei University of TechnologyHefei230009China

Soil slope stability in seasonally frozen regions is a challenging problem for geotechnical *** freezethaw process of soil slope caused by the temperature fluctuation increases the difficulty in predicting the slope stability because the soil property is influenced by the freeze-thaw *** addition,the frozen soil,which has ice crystal,ice lens and experienced freeze-thaw process,could present stronger *** research has not investigated the combined effect of soil heterogeneity and freeze-thaw *** paper studies the influence of soil heterogeneity on the stability of frozen soil slope under freeze-thaw *** local average subdivision(LAS)is utilized to model the soil heterogeneity.A typical slope geometry has been chosen and analysed as an illustrative example and the strength reduction method is used to calculate the factor of safety(FOS)of *** has been found that when the temperature is steady,the FOS of the frozen soil slope is influenced by the spatial variability of the thermal conductivity,but the influence is not *** the standard deviation and the SOF of the thermal conductivity increase,the mean of the FOS is equal to the FOS of the homogeneous case and the standard deviation of the FOS also *** the frozen soil goes through freeze-thaw process,the FOS of the frozen soil slope decreases due to the reduction in the cohesion and the internal friction angle caused by the freeze-thaw ***,the decreasing ratio of the FOS becomes more scattered after the 5th freeze-thaw cycle compared to that of the FOS after the 1st freeze-thaw *** larger variability of the FOS could induce inaccuracy in the prediction of the frozen soil slope stability.

关键词： Factor of safety(FOS) freeze-thaw cycle frozen soil slope soil heterogeneity thermal conductivity

Effect of temperature and mating pair on tribological properties of DLC and GLC coatings under high pressure lubricated by MoDTC and ZDDP

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Friction 2021年第6期9卷 1390-1405页

作者： kang liu Jia-jie kang Guang-an ZHANG Zhi-bin LU Wen YUE School of Engineering and Technology China University of Geosciences(Beijing)Beijing 100083China Key Laboratory of Deep GeoDrilling Technology of Ministry of Natural Resources Beijing 100083China Zhengzhou Institute China University of Geosciences(Beijing)Zhengzhou 451283China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Diamond-like carbon(DLC)and graphite-like carbon(GLC)coatings have good prospects for improving the surface properties of engine ***,further understanding is needed on the effect of working conditions on tribological *** this study,GLC and two types of DLC coatings were deposited on GCr15 substrate for *** friction and wear properties of self-mated and steel-mated pairs were *** temperatures(25 and 90℃),three lubrication conditions(base oil,molybdenum dithiocarbamate(MoDTC)-containing oil,MoDTC+zinc dialkyldithiophosphate(ZDDP)-containing oil),and high Hertz contact stress(2.41 GPa)were applied in the *** results showed that high temperature promoted the effect of ZDDP on steel-mated pairs,but increased wear under base oil *** increased wear for steel-mated pairs lubricated by MoDTC-containing oil was due to abrasive wear probably caused by MoO_(3) andβ-FeMoO_(4).It was also found that in most cases,the tribological properties of self-mated pairs were better than those of steel-mated pairs.

关键词： diamond-like carbon(DLC) graphite-like carbon(GLC) mating pair temperature oil additives

Solar-driven high-efficiency remediation of wastewater containing small dye molecules

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Science China(Technological Sciences) 2021年第10期64卷 2237-2245页

作者： WANG ZuBin liu kang HENG LiPing JIANG Lei Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education Beijing Key Laboratory of Bio-Inspired Energy Materials and DevicesSchool of ChemistryBeihang UniversityBeijing 100191China

Remediation of wastewater containing dye molecules is necessary to alleviate the significant threat that poses to human health and the *** treatment technologies are seriously limited by their low efficiency for removing small dye molecules or/and inferior ***,we report a bio-inspired,solar-driven,regenerable separation device capable of separating small dye molecules from the wastewater with high *** device is composed of porous super-hydrophilic ceramic and carbon nanotubes(CNTs).In comparison with previously reported systems,the resultant device not only achieved a highly promising separation efficiency of>99%for dye-containing wastewater,even for small dye molecules(<1.25 nm),but also demonstrated excellent separation stability and strong resistance to acid/***,the device demonstrated impressive regenerability on simple calcination and re-coating of the CNT layer after it was *** novel separation device shows potential for application in many fields,such as dye separation,wastewater purification and desalination.

关键词： dye separation wastewater purification solar-driven remediation high efficiency regenerability

A Unified Shared-Private Network with Denoising for Dialogue State Tracking

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Journal of Computer Science & Technology 2021年第6期36卷 1407-1419页

作者： Qing-Bin liu Shi-Zhu He kang liu Sheng-Ping liu Jun Zhao National Laboratory of Pattern Recognition Institute of AutomationChinese Academy of SciencesBeijing 100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China Beijing Unisound Information Technology Co. LtdBeijing 100096China

Dialogue state tracking(DST)leverages dialogue information to predict dialogues states which are generally represented as slot-value ***,previous work usually has limitations to efficiently predict values due to the lack of a powerful strategy for generating values from both the dialogue history and the predefined *** predicting values from the predefined value set,previous discriminative DST methods are difficult to handle unknown *** generative DST methods determine values based on mentions in the dialogue history,which makes it difficult for them to handle uncovered and non-pointable ***,existing generative DST methods usually ignore the unlabeled instances and suffer from the label noise problem,which limits the generation of mentions and eventually hurts *** this paper,we propose a unified shared-private network(USPN)to generate values from both the dialogue history and the predefined values through a unified ***,USPN uses an encoder to construct a complete generative space for each slot and to discern shared information between slots through a shared-private ***,our model predicts values from the generative space through a shared-private *** further utilize reinforcement learning to alleviate the label noise problem by learning indirect supervision from semantic relations between conversational words and predefined slot-value *** results on three public datasets show the effectiveness of USPN by outperforming state-of-the-art baselines in both supervised and unsupervised DST tasks.

关键词： dialogue state tracking unified strategy shared-private network reinforcement learning

Event co-reference resolution via a multi-loss neural network without using argument information

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Science China(Information Sciences) 2019年第11期62卷 31-39页

作者： Xinyu ZUO Yubo CHEN kang liu Jun ZHAO Institute of Automation Chinese Academy of Sciences University of Chinese Academy of Sciences

Event co-reference resolution is an important task in natural language processing, and nearly all the existing approaches for this task rely on event argument information. However, these methods tend to suffer from error propagation from event argument extraction. Additionally, not every event mention contains all arguments of an event, and the argument information may confuse the model where events contain arguments to detect an event co-reference in real text. Furthermore, the context information of an event is useful to infer the co-reference between events. Thus, to reduce the errors propagated from event argument extraction and use context information effectively, we propose a multi-loss neural network model that does not require any argument information relating to the within-document event co-reference resolution task; furthermore, it achieves a significantly better performance than the state-of-the-art methods.

关键词： event co-reference resolution neural network information extraction multi-loss function event extraction

Solution evaporation processed high quality perovskite films

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Science Bulletin 2018年第23期63卷 1591-1596页

作者： Aqiang liu kang liu Huimin Zhou Hongmei Li Xiaoqing Qiu Yang Yi Min liu School of Physics and Electronics and Key Laboratory of Low-dimensional Quantum Structures and Quantum Control of the Ministry of Education Synergetic Innovation Center for Quantum Effects and Applications Hunan Normal University Institute of Super-microstructure and Ultrafast Process in Advanced Materials School of Physics and Electronics Central South University School of Chemistry and Chemical Engineering Central South University State Key Laboratory of Powder Metallurgy Central South University

Organic-inorganic hybrid perovskite solar cells(PSCs), due to their high power conversion efficiency(PCE) and low cost, have been considered as one of the most promising photovoltaic devices. Welldistributed large-grain perovskite crystals play an important role for light adsorption and charge ***, high quality perovskite crystals closely relate to the preparation method. Generally, the preparation of perovskite films requires a nitrogen atmosphere and toxic anti-solvents, which hinder their practical applications. Here, we reported a novel and simple solution evaporation process followed with a methylammonium iodide(MAI) solution immersion to prepare high quality perovskite films. Porous lead iodide(PbI_2) films were firstly formed by evaporation of PbI_2 precursor solution. The obtained porous PbI_2 films were completely transformed into well-distributed large-grain perovskite films after a quick MAI solution immersion. As a result, the corresponding PCE was enhanced by 30% compared to that prepared with a regular sequential deposition. This solution evaporation method provides a convenient and practical way for preparing high-quality perovskite films.

关键词： Perovskite Solution evaporation High-quality films Power conversion efficiency

Terahertz wave generation from ring-Airy beam induced plasmas and remote detection by terahertz-radiation- enhanced-emission-of-fluorescence: a review

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Frontiers of Optoelectronics 2019年第2期12卷 117-147页

作者： kang liu Pingjie HUANG Xi-Cheng ZHANG The Institute of Optics University of Rochester Rochester NY14627USA State Key Laboratory of Industrial Control Technology College of Control Science and Engineering Zhejiang University Hangzhou 310027China The Beijing Advanced Innovation Centerfor Imaging Technology Capital Normal University Beijing 100037China

With the increasing demands for remote spectroscopy in many fields ranging from homeland security to environmental monitoring, terahertz (THz) spectroscopy has drawn a significant amount of attention because of its capability to acquire chemical spectral signatures non-invasively. However, advanced THz remote sensing techniques are obstructed by quite a few factors, such as THz waves being strongly absorbed by water vapor in the ambient air, difficulty to generate intense broadband coherent THz source remotely, and hard to transmit THz waveform information remotely without losing the signal to noise ratio, etc. In this review, after introducing different THz air-photonics techniques to overcome the difficulties of THz remote sensing, we focus mainly on theoretical and experimental methods to improve THz generation and detection performance for the purpose of remote sensing through tailoring the generation and detection media, air-plasma. For the THz generation part, auto-focusing ring-Airy beam was introduced to enhance the THz wave generation yield from two-color laser induced air plasma. By artificially modulated exotic wave packets, it is exhibited that abruptly auto-focusing beam induced air-plasma can give an up to 5.3-time-enhanced THz wave pulse energy compared to normal Gaussian beam induced plasma under the same conditions. At the same time, a red shift on the THz emission spectrum is also observed. A simulation using an interference model to qualitatively describe these behaviors has be developed. For the THz detection part, the results of THz remote sensing at 30 m using THz-radiation-enhanced-emission- of-fluorescence (THz-REEF) technique are demonstrated, which greatly improved from the 10 m demonstration last reported. The THz-REEF technique in the counter-propagation geometry was explored, which is proved to be more practical for stand-off detections than co-propagation geometry. We found that in the counter- propagating geometry the maximum amplitude

关键词： ultrafast terahertz (THz) techniques THz air- photonics ring-Airy beams THz-radiation-enhanced-emis- sion-of-fluorescence (THz-REEF) of air-plasma in co- propagation geometry THz-REEF of air-plasma in coun-ter-propagation geometry