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Aggregation and stability of selenium nanoparticles: Complex roles of surface coating, electrolytes and natural organic matter

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Journal of Environmental Sciences 2023年第8期130卷 14-23页

作者： Sujuan Yu hao liu Rui Yang Wenjing Zhou Jingfu liu State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control Department of Environmental Science&EngineeringNorth China Electric Power UniversityBaoding 071000China

The application of selenium nanoparticles(SeNPs)as nanofertilizers may lead to the release of SeNPs into aquatic ***,the environmental behavior of SeNPs is rarely *** this study,using alginate-coated SeNPs(Alg-SeNPs)and polyvinyl alcohol-coated SeNPs(PVA-SeNPs)as models,we systematically investigated the aggregation and stability of SeNPs under various water ***-SeNPs were highly stable in mono-and polyvalent electrolytes,probably due to the strong steric hindrance of the capping ***-SeNPs only suffered from a limited increase in size,even at 2500 mmol/L NaCl and 200 mmol/L MgCl_(2),while they underwent apparent aggregation in CaCl_(2) and LaCl_(3) *** binding of Ca^(2+) and La^(3+) with the guluronic acid part in alginate induced the formation of cross-linking *** organic matter enhanced the stability of Alg-SeNPs in monovalent electrolytes,while accelerated the attachment of Alg-SeNPs in polyvalent electrolytes,due to the cation bridge *** long-term stability of SeNPs in natural water showed that the aggregation sizes of Alg-SeNPs and PVA-SeNPs increased to several hundreds of nanometers or above 10μm after 30 days,implying that SeNPs may be suspended in the water column or further settle down,depending on the surrounding water *** study may contribute to the deep insight into the fate and mobility of SeNPs in the aquatic *** varying fate of SeNPs in different natural waters also suggests that the risks of SeNPs to organisms living in diverse depths in the aquatic compartment should be concerned.

关键词： Selenium nanoparticles Aggregation Stability Surface coating Electrolytes Natural organic matter

Performance Analysis of a Combined Absorption Refrigeration-Liquid Desiccant Dehumidification THIC System Driven by Low-Grade Heat Source

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Journal of Thermal Science 2020年第5期29卷 1193-1205页

作者： XU Cong SUI Jun DAI Yuze liu Feng liu hao Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Traditional condensing air-conditioning systems consume large amounts of energy in hot and humid areas,and it is difficult to achieve simultaneous control of temperature and humidity.A combined absorption refrigeration(AR)and liquid desiccant dehumidification(LDD)air-conditioning system based on cascade utilization of low-grade heat source is *** system can realize independent control of temperature and humidity and carry out profound recovery of low-grade heat *** the design conditions,the heat utilization rate C reaches 21.05%,which is 2.73 times that of the conventional absorption refrigeration reference system.A parametric sensitivity analysis is performed to optimize the *** C increases from 9.79%to 18.55%and the coefficient of performance C O P t increases from 0.33 to 0.35 with an increase in chilled water temperature from 7°C to 15°*** an increase in regenerant solution temperature from 60°C to 70°C,the C achieves the optimal value of 21.05%at 68°C.C decreases from 21.05%to 15.05%as the concentration of the regenerant solution increases from 36%to 40%.Under variable environmental temperature and humidity,the C the proposed system changes within a small range and stays much higher than that of the reference system with the same quality heat source,which indicates that the proposed system has a better adaptability to changing environmental parameters.

关键词： temperature and humidity independent control(THIC) low-grade heat source cascade utilization heat utilization rate

PGSLM:Edge-Enabled Probabilistic Graph Structure Learning Model for Traffic Forecasting in Internet of Vehicles

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China Communications 2023年第4期20卷 270-286页

作者： Xiaozhu liu Jiaru Zeng Rongbo Zhu hao liu School of Automation Wuhan University of TechnologyWuhan 430070China College of Informatics Huazhong Agricultural UniversityWuhan 430070China

With the rapid development of the 5G communications,the edge intelligence enables Internet of Vehicles(IoV)to provide traffic forecasting to alleviate traffic congestion and improve quality of experience of users *** enhance the forecasting performance,a novel edge-enabled probabilistic graph structure learning model(PGSLM)is proposed,which learns the graph structure and parameters by the edge sensing information and discrete probability distribution on the edges of the traffic road *** obtain the spatio-temporal dependencies of traffic data,the learned dynamic graphs are combined with a predefined static graph to generate the graph convolution part of the recurrent graph convolution *** the training process,a new graph training loss is introduced,which is composed of the K nearest neighbor(KNN)graph constructed by the traffic feature tensors and the graph *** experimental results show that,compared with existing models,the proposed PGSLM improves the traffic prediction performance in terms of average absolute error and root mean square error in IoV.

关键词： edge computing traffic forecasting graph convolutional network graph structure learning Internet of Vehicles

面向自然资源资产清查的云南森林资源均质区划分研究

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Intent-Aware Graph-Level Embedding Learning Based Recommendation

西南林业大学学报 2025年第1期45卷 137-145页

作者：刘浩郑璞冰叶江霞魏晓燕西南林业大学林学院云南昆明650233 云南省测绘资料档案馆/云南省基础地理信息中心云南昆明650032

根据云南省各县与森林资源质量相关的森林起源、单位面积蓄积量、海拔、坡度、地形起伏、气候条件及社会经济等17个因子的空间差异，以县级单位之间的空间距离表示森林资源的相似程度，借助K−均值聚类和层次聚类的方法将云南省划分为空... 详细信息

根据云南省各县与森林资源质量相关的森林起源、单位面积蓄积量、海拔、坡度、地形起伏、气候条件及社会经济等17个因子的空间差异，以县级单位之间的空间距离表示森林资源的相似程度，借助K−均值聚类和层次聚类的方法将云南省划分为空间上较一致的均质单元，揭示云南森林资源空间分异性。结果表明：K−均值聚类方法能更有效将云南省划分为6个森林资源均质区;且在实际应用中K−均值聚类的可操作性更强，结果更趋聚集连通性。研究除考虑森林资源禀赋外，将经济与人为活动因素纳入聚类分析中，可以更为客观地反映森林资源资产区域差异。研究可为构建国家森林资源资产清查价格体系及资产核算提供参考，对于支撑国家森林资源清查工作具有重要理论与实践价值。

关键词：空间分异性 K−均值聚类层次聚类社会经济属性均质区划分

来源：博看期刊评论

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Journal of Computer Science & Technology 2024年第5期39卷 1138-1152页

作者： Peng-Yi hao Si-hao liu Cong Bai College of Computer Science and Technology Zhejiang University of TechnologyHangzhou 310012China

Recommendation has been widely used in business scenarios to provide users with personalized and accurate item lists by efficiently analyzing complex user-item ***,existing recommendation methods have significant shortcomings in capturing the dynamic preference changes of users and discovering their true potential *** address these problems,a novel framework named Intent-Aware Graph-Level Embedding Learning(IaGEL)is proposed for *** this framework,the potential user interest is explored by capturing the co-occurrence of items in different periods,and then user interest is further improved based on an adaptive aggregation algorithm,forming generic intents and specific *** addition,for better representing the intents,graph-level embedding learning is designed based on the mutual information comparison among positive intents and negative ***,an intent-based recommendation strategy is designed to further mine the dynamic changes in user *** on three public and industrial datasets demonstrate the effectiveness of the proposed IaGEL in the task of recommendation.

关键词： recommendation system graph embedding learning graph neural network intent-aware

Hydrothermal synthesis and optical properties of Zn_(1-x)Mn_xS nanorods

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Particuology 2011年第5期9卷 533-536页

作者： Yangfeng Huang Yebin Cai hao liu School of Mechanical ＆ Electrical Engineering Guangdong University of Petrochemical Technology Maoming 525000 China

Zn1-xMnxS （x = 0-0.05） nanorods were successfully synthesized through a hydrothermal route. The morphology, composition and microstructure of Zn1-xMnxS nanorods were characterized respectively by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and Raman spectrometer. The optical properties of Zn1-xMnxS nanorods were determineded by UV-Vis absorption spectroscopy and photo- luminescence （PL） emission spectroscopy. The results show that the introduction of Mn^2＋ on interstitial sites in ZnS lattice has significant influence on the Raman spectra, UV-Vis absorption spectra and PL emis- sion spectra. With the increase of Mn^2＋, the lengths of the sampled nanorods become shorter and the morphologies of the products show disorder accompanied by some nanoparticles. The absorption band edge shifts to longer wavelength. The intensity of the ZnS-related emission gradually becomes weaker, whereas, the Mn^2＋-related broad emission spectra located at 580 nm gradually red-shifts and increases. Occupation of Zn^2＋ sites in the lattice by Mn^2＋ ions results in lattice distortion and influences the energy level structure of ZnS. The Mn doping is found responsible for the changes in the defect-related emission of the ZnS nanorods.

关键词： Inorganic compound Chemical synthesis Nanostructures Optical properties

k_(eff)uncertainty quantification and analysis due to nuclear data during the full lifetime burnup calculation for a small-sized prismatic high temperature gas-cooled reactor

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Nuclear Science and Techniques 2021年第11期32卷 105-118页

作者： Rong-Rui Yang Yuan Yuan Chen hao Ji Ma Guang-hao liu Fundamental Science on Nuclear Safety and Simulation Technology Laboratory College of Nuclear Science and TechnologyHarbin Engineering UniversityHarbin 150001China Department of Reactor Technology Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.LtdBeijing 100089China

To benefit from recent advances in modeling and computational algorithms,as well as the availability of new covariance data,sensitivity and uncertainty analyses are needed to quantify the impact of uncertain sources on the design parameters of small prismatic high-temperature gascooled reactors(HTGRs).In particular,the contribution of nuclear data to the k_(eff)uncertainty is an important part of the uncertainty analysis of small-sized HTGR physical *** this study,a small-sized HTGR designed by China Nuclear Power Engineering Co.,*** selected for k_(eff)uncertainty analysis during full lifetime burnup *** of the cold zero power(CZP)condition and full lifetime burnup process were constructed using the Reactor Monte Carlo Code RMC for neutron transport calculation,depletion calculation,and sensitivity and uncertainty *** the sensitivity analysis,the Contribution-Linked eigenvalue sensitivity/Uncertainty estimation via Track length importance Characterization(CLUTCH)method was applied to obtain sensitive information,and the "sandwich" method was used to quantify the k_(eff)*** also compared the k_(eff)uncertainties to other typical *** results show that ^(235)U is the largest contributor to k_(eff)uncertainty for both the CZP and depletion conditions,while the contribution of ^(239)Pu is not very significant because of the design of low discharge *** is worth noting that the radioactive capture reaction of ^(28)Si significantly contributes to the k_(eff)uncertainty owing to its specific fuel ***,the k_(eff)uncertainty during the full lifetime depletion process was relatively stable,only increasing by 1.12%owing to the low discharge burnup design of small-sized *** numerical results are beneficial for neutronics design and core parameters optimization in further uncertainty propagation and quantification study for small-sized HTGR.

关键词： Small-sized HTGR SU analysis Nuclear data Burnup

Anti-corrosive mechanism of poly(N-ethylaniline)/sodium silicate electrochemical composites for copper:Correlated experimental and in-silico studies

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Journal of Materials Science & Technology 2021年第13期72卷 202-216页

作者： hao liu Baomin Fan Guifeng Fan Yucong Ma Hua hao Wen Zhang College of Chemistry and Materials Engineering Beijing Technology and Business UniversityBeijing 100048China Institute of Chemistry Chinese Academy of SciencesBeijing 100190China College of Biology and Environmental Engineering Zhejiang Shuren UniversityHangzhou 310015China

Poly(N-ethylaniline)(PNEA)composites with varying silicate content were fabricated on copper through a novel electropolymerized strategy in acidic ***,compactness,conductivity and adhesive strength of the composite(PNEA-10 Si)were optimized as silicate content reached 10 m ***,morphological and solution analyses were employed to evaluate the protective performance of PNEA and PNEA-10 Si coatings for copper in 3.5%Na Cl *** of electrochemical analyses indicated that as-prepared coatings retarded the oxygen reduction process efficiently for copper in 3.5%Na Cl solution,drained corrosion current density and elevated interfacial charge transfer *** to favorable barrier effect,compact structure and low porosity index,PNEA-10 Si composite exhibited superior anti-corrosive performance,which was more tolerant than PNEA during long-time ***-10 Si coated sample exhibited a stable topography after 144 h immersion with the minimum concentration of released ions revealing the improved protection ***/atomic-multiscale calculations were conducted to clarify the deposition and protection mechanism of as-prepared *** of density functional theory corroborated that silicate is stabilized in the PNEA layer via electrostatic force;and immobile silicate positively contributed to the charge transfer barrier of the *** dynamics simulations evidenced that the favorable compatibility between PNEA and silicate facilitated polymer deposition and confined in-situ ions diffusion.

关键词： Electrochemical deposition Composite coating Anti-corrosion Density-functional theory Molecular dynamic simulation

Bias-controlled spin memory and spin injector scheme in the tunneling junction with a single-molecule magnet

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Chinese Physics B 2021年第6期30卷 552-558页

作者： Zheng-Zhong Zhang hao liu Faculty of Mathematics and Physics Huaiyin Institute of TechnologyHuaian 223003China Nano Science and Technology Institute University of Science and Technology of ChinaSuzhou 215123China

A bias-controlled spin-filter and spin memory is theoretically proposed, which consists of the junction with a singlemolecule magnet sandwiched between the nonmagnetic and ferromagnetic(FM) leads. By applying different voltage pulses Vwriteacross the junction, the spin direction of the single-molecule magnet can be controlled to be parallel or anti-parallel to the magnetization of the FM lead, and the spin direction of SMM can be "read out" either by the magneto-resistance or by the spin current with another series of small voltage pulses V_(probe). It is shown that the polarization of the spin current is extremely high(up to 100%) and can be manipulated by the full-electric manner. This device scheme can be compatible with current technologies and has potential applications in high-density memory devices.

关键词： single-molecule magnet spin-transfer torque spin-dependent electron tunneling