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Novel concept of nano-additive design:PTFE@silica Janus nanoparticles for water lubrication

Friction 2024年第2期12卷 258-270页

作者： Yanfei liu hailing HE Meng YANG Ruize ZHANG Shengtao YU Tiantian YANG Wenzhong WANG Fuxin LIANG School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Institute of Polymer Science&Engineering Department of Chemical EngineeringTsinghua UniversityBeijing 100084China MOE Key Laboratory of Bioinformatics Center for Plant BiologySchool of Life SciencesTsinghua UniversityBeijing 100084China Tsinghua-Peking Center for Life Sciences Beijing 100084China College of Biological Sciences China Agricultural UniversityBeijing 100193China

Polytetrafluoroethylene(PTFE)has been widely used as a lubrication additive for reducing friction and wear;however,the hydrophobic nature of PTFE restricts its application in eco-friendly water-based lubrication systems.In this study,for the first time,we designed novel PTFE@silica Janus nanoparticles(JNs)to meet the requirement for additives in water-based lubricants,which have excellent dispersion stability in water attributed to the unique amphiphilic structure.By introducing the lubrication of the aqueous dispersion of the JNs with a concentration of 0.5 wt%,the coefficient of friction(COF)and wear volume were reduced by 63.8%and 94.2%,respectively,comparing to those with the lubrication of pure water.Meanwhile,the JNs suspension also exhibits better lubrication and wear-resistance performances comparing to commercial silica and PTFE suspensions.The excellent tribological behaviors of PTFE@silica JNs as nano-additives could be attributed to the synergetic effect of the two components,where the PTFE provided lubrication through the formed tribofilms on the friction pairs,and the rigid silica further enhanced the wear-resistance performance.Most importantly,the unique structure of JNs makes it possible to use PTFE as an additive in water-lubrication systems.Our study shed light on the design and application of novel JNs nanomaterials as additives to meet the requirements of future industrial applications.

关键词： Janus nanoparticles(JNs) polytetrafluoroethylene(PTFE) nano-additives friction lubrication

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High-density triple-phase contact points for enhanced photocatalytic CO_(2) reduction to methanol

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Chinese Chemical Letters 2024年第2期35卷 252-256页

作者： Hanwen Jian Kaiming Deng Tongyu Wang Chengxi Huang Fang Wu hailing Huo Bo Ouyang Xuan liu Jingjing Ma Erjun Kan Ang Li MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing School of ScienceNanjing University of Science and TechnologyNanjing 210094China College of Information Science and Technology Nanjing Forestry UniversityNanjing 210037China State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering Ningxia UniversityYinchuan 750021China

The efficiency of photocatalytic CO_(2) reduction reaction(PCRR)is restricted by the low solubility and mobility of CO_(2) in water,poor CO_(2) adsorption capacity of catalyst,and competition with hydrogen evolution reaction(HER).Recently,hydrophobic modification of the catalyst surface has been proposed as a potential solution to induce the formation of triple-phase contact points(TPCPs)of CO_(2)(gas phase),H_(2) O(liquid phase),and catalysts(solid phase)near the surface of the catalyst,enabling direct delivery of highly concentrated CO_(2) molecules to the active reaction sites,resulting in higher CO_(2) and lower H+surface concentrations.The TPCPs thus act as the ideal reaction points with enhanced PCRR and suppressed HER.However,the initial synthesis of triple-phase photocatalysts tends to possess a lower bulk density of TPCPs due to the simple structure leading to limited active points and CO_(2) adsorption sites.Here,based on constructing a hydrophobic hierarchical porous TiO_(2)(o-HPT)with interconnected macropores and mesopores structure,we have significantly increased the density of TPCPs in a unit volume of the photocatalyst.Compared with hydrophobic macroporous TiO_(2)(o-MacPT)or mesoporous TiO_(2)(o-MesPT),the o-HPT with increased TPCP density leads to enhanced photoactivity,enabling a high methanol production rate with 1111.5μmol g^(−1) h^(−1) from PCRR.These results emphasize the significance of high-density TPCPs design and propose a potential path for developing efficient PCRR systems.

关键词： Photocatalysis CO_(2)reduction reaction Photocatalyst Triple-phase contact points Methanol

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Reconcile the contradictory wettability requirements for the reduction and oxidation half-reactions in overall CO_(2) photoreduction via alternately hydrophobic surfaces

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Journal of Energy Chemistry 2024年第6期93卷 202-212,I0006页

作者： hailing Huo Ting Hu Chengxi Huang Fang Wu Tongyu Wang Xuan liu Liang Zhang Qiang Ju Zhiqing Zhong Hongbin Xing Erjun Kan Ang Li MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing Nanjing University of Science and TechnologyNanjing 210094JiangsuChina College of Information Science and Technology Nanjing Forestry UniversityNanjing 210037JiangsuChina

The overall photocatalytic CO_(2) reduction reaction(OPCRR)that can directly convert CO_(2) and H_(2)O into fuels represents a promising renewable energy conversion technology.As a typical redox reaction,the OPCRR involves two half-reactions:the CO_(2) reduction half-reaction(CRHR)and the water oxidation half-reaction(WOHR).Generally,both half-reactions can be promoted by adjusting the wettability of catalysts.However,there is a contradiction in wettability requirements for the two half-reactions.Specifically,CRHR prefers a hydrophobic surface that can accumulate more CO_(2) molecules on the active sites,ensuring the appropriate ratio of gas-phase(CO_(2))to liquid-phase(H_(2)O)reactants.Conversely,the WOHR prefers a hydrophilic surface that can promote the departure of the gaseous product(O_(2))from the catalyst surface,preventing isolation between active sites and the reactant(H_(2)O).Here,we successfully reconciled the contradictory wettability requirements for the CRHR and WOHR by creating an alternately hydrophobic catalyst.This was achieved through a selectively hydrophobic modification method and a charge-transfer-control strategy.Consequently,the collaboratively promoted CRHR and WOHR led to a significantly enhanced OPCRR with a solar-to-fuel conversion efficiency of 0.186%.Notably,in ethanol production,the catalyst exhibited a 10.64-fold increase in generation rate(271.44μmol g^(-1)h~(-1))and a 4-fold increase in selectivity(55.77%)compared to the benchmark catalyst.This innovative approach holds great potential for application in universal overall reactions involving gas participation.

关键词： Hydrophobic Hydrophilic Gas transport Overall CO_(2)photoreduction Z-scheme

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Novel quantum circuit implementation of Advanced Encryption Standard with low costs

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Science China(Physics,Mechanics & Astronomy) 2022年第9期65卷 11-26页

作者： ZhenQiang Li BinBin Cai HongWei Sun hailing liu LinChun Wan SuJuan Qin QiaoYan Wen Fei Gao State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China State Key Laboratory of Cryptology Beijing 100878China

In this study, we examine how the quantum circuit of the Advanced Encryption Standard(AES) can be optimized from two aspects, i.e., number of qubits and T-depth. To reduce the number of qubits, we present three kinds of improved quantum circuits of S-box for different phases in the AES. We found that the number of qubits in the round function can be decreased by introducing the circuit sending |a> to |S(a)>. As a result, compared with the previous quantum circuits where 400/640/768 qubits are required,our circuits of AES-128/-192/-256 only require 270/334/398 qubits. To reduce the T-depth, we propose a new circuit of AES's S-box with a T-depth of 4. Accordingly, the T-depth of our AES-128/-192/-256 quantum circuits become 80/80/84 instead of120/120/126 in a previous study.

关键词： AES S-box quantum circuit composite field arithmetic

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Smoking Is a Risk Factor of Colorectal Advanced Adenomas Compared to Nonadvanced Adenomas

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Open Journal of Gastroenterology 2022年第10期12卷 278-285页

作者： Siyong Chen hailing liu Tongfeng Zhao Department of Endocrinology The Sixth Affiliated Hospital Sun Yat-sen University Guangzhou China Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases The Sixth Affiliated Hospital Sun Yat-sen University Guangzhou China Department of Pathology The Sixth Affiliated Hospital Sun Yat-sen University Guangzhou China

Background: It is uncertain that whether smoking is a risk factor of colorectal advanced adenomas compared to nonadvanced adenomas, so we peformed the case-control study to explore this issue. Material and Methods: The cases were defined as patients with advanced adenomas and the controls were patients with nonadvanced adenomas. Clinical data were extracted from the hospital information system. Missing data were imputed with the multiple imputation of chained equations method, and the effect of smoking on the risk of advanced adenomas was calculated by binary logistic regression models to obtain odds ratios (ORs) and 95% confidence interval. Results: Current smoking rate in patients with advanced adenomas was significantly higher than that in patients with nonadvanced adenomas (31.6% VS 23.1%), the OR of advanced adenoma for current smoking compared with nonsmoking was 1.54 (1.09, 2.18), P = 0.013, and the weighted ORs ranged from 1.50 (1.01, 2.23) to 1.58 (1.09, 2.30), and the results of sensitivity analyses were still consistent. Conclusion: In adults with Han ethnicity in South China, current smoking is a risk factor of colorectal advanced adenomas compared to nonadvanced adenomas.

关键词： Smoking Colorectal Adenomas Advanced Adenomas

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基于增强型龙格库塔优化算法的跳频序列设计

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计算机工程 2024年第4期50卷 267-276页

作者：张毅恒刘以安宋海凌江南大学人工智能与计算机学院江苏无锡214122 海军研究院北京100161

跳频技术具有优秀的抗干扰性能和多址组网性能,跳频序列(FHS)作为其关键,在设计时面临性能指标差、难以兼顾多指标的问题。提出一种基于增强型龙格库塔优化算法(ERUN)的跳频序列设计方法。利用跳频序列的汉明相关性、复杂度、均匀性和... 详细信息

跳频技术具有优秀的抗干扰性能和多址组网性能,跳频序列(FHS)作为其关键,在设计时面临性能指标差、难以兼顾多指标的问题。提出一种基于增强型龙格库塔优化算法(ERUN)的跳频序列设计方法。利用跳频序列的汉明相关性、复杂度、均匀性和平均跳频间隔构建目标函数,建立适用于启发式优化算法的跳频序列设计模型。针对龙格库塔优化算法(RUN)在复杂优化问题上收敛速度慢、寻优精度差的问题,提出增强型龙格库塔优化算法。利用混沌反向学习机制提高初始种群质量,基于二次插值法得到更好的个体更新方向,并根据自适应t分布扰动帮助种群跳出局部最优。在6个基准测试函数和目标函数上的测试结果表明,与RUN的3个最新变体相比,ERUN具有更快的收敛速度和更高的解精度。将得到的跳频序列应用于跳频系统中,实验结果表明,该方法在固定干扰环境下误码率为4%左右,在变化干扰环境下误码率没有明显上升,展现出了较强的抗干扰能力和复杂环境适应能力。

关键词：抗干扰跳频序列龙格库塔优化算法二次插值自适应t分布

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不同颜色风力机叶片缺陷检测系统研究与验证

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传感技术学报 2024年第3期37卷 513-518页

作者：严海领刘雄飞李密兰银川科技学院信息工程学院宁夏银川750001

针对目前风力机叶片缺陷检测方法检测精度低、危险系数大、设备价格高等问题,提出一种基于LabVIEW+无人机的风力机叶片缺陷检测系统,实现了硬件平台搭建和系统软件设计,对图像处理算法进行研究,针对传统二值化算法中不同颜色风力机叶片... 详细信息

针对目前风力机叶片缺陷检测方法检测精度低、危险系数大、设备价格高等问题,提出一种基于LabVIEW+无人机的风力机叶片缺陷检测系统,实现了硬件平台搭建和系统软件设计,对图像处理算法进行研究,针对传统二值化算法中不同颜色风力机叶片阈值不同的问题,提出了应用边缘提取的检测方法。通过理论分析和实验对比了LabVIEW中边缘提取缺陷检测算子及组合算子的检测效果,并最终确定Sobel算子应用于本风力机叶片缺陷检测系统。实验表明,该系统能够实现不同颜色风力机叶片缺陷的自动、低成本检测,检测精度高达93%。

关键词：缺陷检测风力机叶片 Sobel算子无人机 LabVIEW算法验证

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Nanoparticles Study on the Indosinian Xiaomei Shear Zone in the Hainan Island,China:Implication to Developmental Stage and Formation Mechanism of Nanoparticles in a Fault Zone

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Journal of Earth Science 2020年第5期31卷 957-967页

作者： Yang Zhou Baoyun Shen Yi Yan hailing liu Yan Yan Key Laboratory of Ocean and Marginal Sea Geology Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China University of Chinese Academy of Sciences Beijing 100049China Guangdong University of Technology Guangzhou 510006China South China Sea Institute of Oceanology Chinese Academy of SciencesGuangzhou 510301China

Nanoparticles are widely observed in the natural shear zone and experimental slip faults, which can lubricate the fault and significantly reduce the friction coefficient during seismic slip. But it is still not clear how the nanoparticles develop during the process of sliding. Clarifying the development stage of nanoparticles in a fault zone is critical to understanding the formation mechanisms of nanoparticles and the mechanism of fault weakening from a nanoperspective. In this study, four types of nanoparticles were found in the Indosinian Xiaomei shear zone, including spherical nanoparticles, rod-like nanograins and their aggregations. Ultramicroscopic analyses indicate that polished patches are highly smooth and composed of tightly packed spherical nanoparticles and well orientated rod-like nanograins during slip at high velocities. Meanwhile, the dome nanoparticles were formed by the calcite thermal decomposition due to frictional heat during highspeed sliding. The polygonal grooves are possibly related to high temperature(>900℃) grain boundary sliding deformation mechanisms. However, the porous and rough surfaces are accompanied by a series of holes and parallel "scratches" during a subsequent low-velocity stage. To ascertain the chemical composition of these nanoparticles, the energy dispersive spectrometer(EDS) test were conducted. The results suggest that materials rich in Fe, MgO and wollastonite are likely to form the rod-like nanograins, while materials rich in SiO2 are likely to form the spherical nanoparticles.

关键词： nanoparticles slip faults development stage Xiaomei shear zone composition

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The Cenozoic activities of Yangjiang-Yitongdong Fault: insights from analysis of the tectonic characteristics and evolution processes in western Zhujiang(Pearl) River Mouth Basin

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Acta Oceanologica Sinica 2019年第9期38卷 87-101页

作者： Yuhan Li Rongwei Zhu hailing liu Xuelin Qiu Haibo Huang Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China Guangzhou Marine Geological Survey Guangzhou 510760 China University of Chinese Academy of Sciences Beijing 100049 China

The Yangjiang-Yitongdong Fault (YJF) is an important NW-trending regional fault, which divides the Zhujiang (Pearl) River Mouth Basin (ZRMB) into western and eastern segments. In Cenozoic, the northern continental margin of the South China Sea (SCS) underwent continental rifting, breakup, seafloor spreading and thermal subsidence processes, and the Cenozoic activities of YJF is one part of this series of complex processes. Two long NW-trending multichannel seismic profiles located on both sides of the YJF extending from the continental shelf to Continent-Ocean Boundary (COB) were used to study the tectonic and sedimentary characteristics of western ZRMB. Using the 2D-Move software and back-stripping method, we constructed the balance cross-section model and calculated the fault activity rate. Through the comprehensive consideration of tectonic position, tectonic evolution history, featured structure, and stress analysis, we deduced the activity history of the YJF in Cenozoic. The results showed that the YJF can be divided into two segments by the central uplift belt. From 65 Ma to 32 Ma, the YJF was in sinistral motion as a whole, inherited the preexisting sinistral motion of Mesozoic YJF, in which, the southern part of YJF was mainly in extension activity, controlling the formation and evolution of Yunkai Low Uplift, coupled with slight sinistral motion. From 32 Ma to 23.8 Ma, the sinistral motion in northern part of YJF continued, while the sinistral motion in southern part began to stop or shifted to a slightly dextral motion. After 23.8 Ma, the dextral motion in southern part of YJF continued, while the sinistral motion in northern part of YJF gradually stopped, or shifted to the slightly dextral motion. The shift of the YJF strike-slip direction may be related to the magmatic underplating in continent-ocean transition, southeastern ZRMB. According to the analysis of tectonic activity intensity and rift sedimentary structure, the activities of YJF in Cenozoic played a regulating role in the rift extension pro

关键词： Yangjiang-Yitongdong Fault Zhujiang (Pearl) River Mouth Basin tectonic evolution strike slip movement Cenozoic

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基于大规模多目标优化的跳频序列设计方法

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计算机应用研究 2024年第3期41卷 887-893页

作者：张毅恒刘以安宋海凌江南大学人工智能与计算机学院江苏无锡214122 海军研究院北京100161

针对跳频序列设计中存在的规模小和难以兼顾多指标的问题,提出一种基于大规模多目标优化的跳频序列设计方法。首先,综合考虑跳频序列的多项性能指标,建立跳频序列多目标优化模型;然后,引入大规模多目标优化方法,并提出决策变量洗牌策略... 详细信息

针对跳频序列设计中存在的规模小和难以兼顾多指标的问题,提出一种基于大规模多目标优化的跳频序列设计方法。首先,综合考虑跳频序列的多项性能指标,建立跳频序列多目标优化模型;然后,引入大规模多目标优化方法,并提出决策变量洗牌策略和反向差分进化,通过重新分配决策变量位置以形成具有多样性的非支配集,并通过使反向个体参与差分进化来为后续进化持续提供有效的方向;最后,通过提出算法对模型进行优化得到跳频序列集。实验结果表明,所提方法相较于其他多目标优化方法具有更强的寻优能力,得到跳频序列集的性能指标具有明显优势;所提方法在不同干扰环境中相较于其他方法具有更低的误码率,验证了提出方法的有效性和优越性。

关键词：抗干扰跳频序列大规模多目标优化洗牌策略反向学习

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