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Nano Research 2024年第9期17卷 8036-8044页

作者： Song Kou Shu Lian Xiaodong Xie Wei Ren Yu Jin Jiahui Bao Honghui Ou Guidong Yang XJTU-Oxford International Joint Laboratory for Catalysis School of Chemical Engineering and TechnologyXi’an Jiaotong UniversityXi’an 710049China Fujian-Taiwan-Hongkong-Macao Science and Technology Cooperation Base of intelligent Pharmaceutics Institute of OceanographyCollege of Materials and Chemical EngineeringMinjiang UniversityFuzhou 350108China School of Food and Bioengineering Fujian Polytechnic Normal UniversityFuqing 350300China

Organic conjugated polymers have received extensive attention due to their unique electronic ***,there have been relatively few reports on the dark photocatalytic reactions utilizing organic conjugated ***,we report the successful synthesis of an organic conjugated polymer based on poly(heptazine imide)nanocrystals(CNNCs)for H_(2)O_(2)evolution and biomedical applications using a simple salt molten method and sonication-centrifugation *** results show that these colloid CNNCs have the characteristics of photogenerated electrons accumulation and realize dark photocatalysis with high reducibility under visible light ***,these accumulating photogenerated electrons can reduce O_(2)in darkness to produce H_(2)O_(2).In addition,cytotoxicity tests were conducted and it was found that H_(2)O_(2)produced under dark conditions could oxidize L-arginine(L-Arg)to NO,which effectively killed tumors in the *** work provides an important strategy to construct organic conjugated semiconductor nanocrystals and applying them to future energy and biomedical fields.

关键词： poly(heptazine imide) photocatalysis photogenerated electrons hydrogen peroxide evolution cancer treatment

Linear-fitting-based recursive filtering for nonlinear systems under encoding-decoding mechanism

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Science China(Information Sciences) 2024年第5期67卷 183-196页

作者： Bo JIANG Hongli DONG Zhiwei GAO Yuxuan SHEN Fan YANG Artificial Intelligence Energy Research institute Northeast Petroleum University Heilongjiang Provincial Key Laboratory of Networking and intelligent Control Sanya Offshore Oil & Gas Research institute Northeast Petroleum University School of Electrical & Information Engineering Northeast Petroleum University

This paper deals with a recursive filtering problem for a class of discrete time-varying nonlinear networked systems with the encoding-decoding mechanism. The linear fitting method is introduced to handle the nonlinearity. An encoding-decoding mechanism is constructed to describe the data transmission process in wireless communication networks(WCNs). To be specific, the measurement outputs are mapped by a quantizer to unique codewords for transmission in WCNs. Then, the codewords are decoded by the decoder to recover the measurement outputs which are sent to the filter. The processing/encoding delay and network delay have been considered. Firstly, on the premise that the upper bound of the filtering error covariance is minimum, the appropriate filtering gain is calculated. Then, the mean square exponential boundedness of the filtering error is analyzed. Finally, two simulation examples are presented to verify the effectiveness of the proposed algorithm.

关键词： encoding-decoding mechanism uniform quantizer linear fitting networked systems recursive filtering

Solvent-free carbon sphere nanofluids towards intelligent lubrication regulation

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Friction 2024年第1期12卷 95-109页

作者： Sheng ZHANG Wen LI Xiaoliang MA Xiaoqiang FAN Minhao ZHU Tribology Research institute School of Mechanical EngineeringSouthwest Jiaotong UniversityChengdu 610031China Key Laboratory of Advanced Technologies of materials Ministry of EducationSchool of Materials Science and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

By simply switching the electrical circuit installed on steel/steel contact,the tribological behaviors of nanofluids(NFs)can be regulated in real time,thereby achieving the desired performance of friction reduction and wear ***,solvent-free carbon spherical nanofluids(C-NFs)were successfully prepared for intelligent lubrication regulation.C-NFs with excellent lubrication performance can immediately reduce the coefficient of friction(COF)despite applying a weak electric potential(1.5 V).Moreover,polyethylene glycol 400(PEG400)containing 5.0 wt%C-NFs remained responsive to electrical stimulation under the intermittent voltage application with an average coefficient of friction(ACOF)reduction of 20.8%over *** intelligent lubrication regulation of C-NFs under an external electric field(EEF)mainly depends on the orderly arranged double-electric adsorption film of ion canopy-adsorbed carbon spheres(CSs).The intermittent electrical application can continuously reinforce the adsorption film and its durability for real-time controlling the sliding ***-stimulation-responsive intelligent lubricants provide a new technical support for realizing intelligent stepless control of devices.

关键词： solvent-free carbon spherical nanofluids(C-NFs) intelligent lubrication regulation lubrication performance adsorption film

Recent Developments in Metallic Degradable Micromotors for Biomedical and Environmental Remediation Applications

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Nano-Micro Letters 2024年第3期16卷 1-35页

作者： Sourav Dutta Seungmin Noh Roger Sanchis Gual Xiangzhong Chen Salvador Pané Bradley J.Nelson Hongsoo Choi Department of Robotics and Mechatronics Engineering Daegu Gyeongbuk Institute of Science and Technology(DGIST)Daegu 42988Republic of Korea DGIST‑ETH Microrobotics Research Center DGISTDaegu 42988Republic of Korea Multi‑Scale Robotics Lab Institute of Robotics and Intelligent SystemsETH Zurich8092 ZurichSwitzerland institute of Optoelectronics State Key Laboratory of Photovoltaic Science and TechnologyShanghai Frontiers Science Research Base of Intelligent Optoelectronics and PerceptionFudan UniversityShanghai 200433People’s Republic of China

Synthetic micromotor has gained substantial attention in biomedicine and environmental ***-based degradable micromotor composed of magnesium(Mg),zinc(Zn),and iron(Fe)have promise due to their nontoxic fuel-free propulsion,favorable biocompatibility,and safe excretion of degradation products Recent advances in degradable metallic micromotor have shown their fast movement in complex biological media,efficient cargo delivery and favorable biocompatibility.A noteworthy number of degradable metal-based micromotors employ bubble propulsion,utilizing water as fuel to generate hydrogen *** novel feature has projected degradable metallic micromotors for active in vivo drug delivery *** addition,understanding the degradation mechanism of these micromotors is also a key parameter for their design and *** propulsion efficiency and life span govern the overall performance of a degradable metallic *** we review the design and recent advancements of metallic degradable ***,we describe the controlled degradation,efficient in vivo drug delivery,and built-in acid neutralization capabilities of degradable micromotors with versatile biomedical ***,we discuss micromotors’efficacy in detecting and destroying environmental ***,we address the limitations and future research directions of degradable metallic micromotors.

关键词： Magnesium Zinc Iron Biodegradable microrobot Biomedical Environmental

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An axisymmetric characteristic model for enhancing prediction of centrifugal compressor characteristics

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Chinese Journal of Aeronautics 2024年第4期37卷 203-215页

作者： Peng REN Xiangjun FANG Zeyu JIAO Ying HAN School of Energy and Power Engineering Beihang UniversityBeijing 100191China Guangdong Key Laboratory of Modern Control Technology Institute of Intelligent ManufacturingGuangdong Academy of SciencesGuangzhou 510070China

Rapid and accurate determination of compressor characteristic maps is essential for the initial design of centrifugal compressors in aircraft power systems. The accuracy of existing methodologies, which rely on combinations of loss models, varies significantly depending on the compressor's geometry and operational range. This variance necessitates substantial experimental or Computational Fluid Dynamics(CFD) data for coefficient calibration. To address this challenge, this study presents an axisymmetric characteristic model for compressor performance assessment. This model incorporates the factors of blade angle, meridional passage area, and the radial deflection angle of meridional streamlines of the compressor. These factors are derived from fundamental aerodynamic equations encompassing mass, momentum, and energy conservation of the compressor. In contrast to conventional one-dimensional approaches, the proposed method reduces the number of loss coefficients and more effectively accounts for the impact of geometric alterations on centrifugal compressor properties. Furthermore, the model reduces dependence on experimental and CFD data. Efficacy of the model is validated using experimental data from four distinct types of centrifugal compressors. Correlation analysis reveals that the model's coefficients can be expressed as functions of the ratio of the Reynolds number to the impeller tip speed. This ratio serves as a characteristic parameter for the design and optimization of centrifugal compressors. Consequently, the proposed method offers an efficient and accurate means for the quick computation of centrifugal compressor characteristics. This is of great significance for improving the efficiency of centrifugal compressors and reducing energy consumption.

关键词： Centrifugal compressor Positive problem Characteristic prediction Aerodynamic characteristic Axisymmetric model

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Combined UAMP and MF Message Passing Algorithm for Multi-Target Wideband DOA Estimation with Dirichlet Process Prior

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Tsinghua Science and Technology 2024年第4期29卷 1069-1081页

作者： Shanwen Guan Xinhua Lu Ji Li Rushi Lan Xiaonan Luo Guangxi Key Laboratory of Image and Graphic intelligent Processing Guilin University of Electronic TechnologyGuilin 541004China Guilin Huigu institute of AI Industrial Technology Guilin 541004China School of Information Engineering Nanyang Institute of TechnologyNanyang 473000China

When estimating the direction of arrival (DOA) of wideband signals from multiple sources, the performance of sparse Bayesian methods is influenced by the frequency bands occupied by signals in different directions. This is particularly true when multiple signal frequency bands overlap. Message passing algorithms (MPA) with Dirichlet process (DP) prior can be employed in a sparse Bayesian learning (SBL) framework with high precision. However, existing methods suffer from either high complexity or low precision. To address this, we propose a low-complexity DOA estimation algorithm based on a factor graph. This approach introduces two strong constraints via a stretching transformation of the factor graph. The first constraint separates the observation from the DP prior, enabling the application of the unitary approximate message passing (UAMP) algorithm for simplified inference and mitigation of divergence issues. The second constraint compensates for the deviation in estimation angle caused by the grid mismatch problem. Compared to state-of-the-art algorithms, our proposed method offers higher estimation accuracy and lower complexity.

关键词： wideband direction of arrival(DOA)estimation sparse Bayesian learning(SBL) unitary approximate message passing(UAMP)algorithm Dirichlet process(DP)

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非扭转双层石墨烯中异质应变诱导的平带

Acta Mechanica Sinica 2024年第1期40卷 296-304页

作者：杭阳张助华 State Key Laboratory of Mechanics and Control for Aerospace Structures Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Educationand Institute for Frontier ScienceNanjing University of Aeronautics and AstronauticsNanjing 210016China

双层石墨烯中扭转诱导的晶格失配会导致摩尔纹图案并产生具有强关联效应的平带,但这需要复杂的过程来精确控制扭转角度,这里,通过分别沿两个不同的扶手椅方向单轴拉伸上下层石墨烯,我们提出了一种不同的方法来生成双层石墨烯中的六边形... 详细信息

双层石墨烯中扭转诱导的晶格失配会导致摩尔纹图案并产生具有强关联效应的平带,但这需要复杂的过程来精确控制扭转角度,这里,通过分别沿两个不同的扶手椅方向单轴拉伸上下层石墨烯,我们提出了一种不同的方法来生成双层石墨烯中的六边形摩尔纹.两个石墨烯层之间的变形导致了等效于扭角石墨烯中的错位角,异质应变诱导的摩尔纹在费米能级附近产生平带,表现出和扭角双层石墨烯等效的电子性质.我们证明2.1%异质应变下的电子平带等价于1.05°第一魔角下的能带.然而,由于单轴应变,狄拉克点相对于K点轻微偏移,将平带分成两个相隔18meV的分别位于费米能级上方和下方的范霍夫奇点峰.我们的研究结果提出了一种控制自然双层石墨烯电子强关联性的可能方法.

关键词：电子强关联双层石墨烯费米能级摩尔纹扭转角度狄拉克点单轴拉伸单轴应变

Smartphone-assisted Electrochemical Sensors for Environmental Monitoring

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Instrumentation 2024年 1-12页

作者： Baizun Cheng Bingzhi Ren Shun Lu School of Metallurgy and materials Engineering Chongqing University of Science and Technology Chongqing institute of Green and intelligent Technology Chinese Academy of Sciences

The rise of industrialization and urbanization has exacerbated environmental pollution,raising public concern about environmental ***-time pollutant detection and rapid responses to environmental changes are crucial for safeguarding both the environment and human *** chemical analysis methods,though accurate and sensitive,are expensive,complex,and require specialized equipment and *** contrast,smartphone-assisted electrochemical sensors could offer a novel,rapid,sensitive,and cost-effective solution for environmental *** this review,the working principle of electrochemical sensors was first introduced,including how their sensing elements and conversion systems work together to generate an electrical signal proportional to the concentration of the target ***,the role of smartphones in this system was *** challenges faced in designing smartphone assisted electrochemical sensor systems were also discussed in *** terms of applications,this article reviews the latest progress of smartphone assisted electrochemical sensors in detecting heavy metal ions,mycotoxins,bacteria,the veterinary drug and pesticide residues,and other compounds,and discusses their potential in environmental monitoring and public *** hurdles in technology integration and data processing,smartphone-assisted electrochemical sensors are poised to become increasingly vital in environmental monitoring as technology progresses and is gradually becoming a powerful tool for cross industry monitoring and analysis.

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The beauty of multi-active sites

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cMat 2024年第1期1卷 20-21页

作者： Yu-Qing Wang Sha-Sha Guo Zheng Liu School of materials Science and Engineering Nanyang Technological UniversitySingaporeSingapore Department of Chemistry and Chemical Biology Cornell UniversityIthacaNew YorkUSA CINTRA CNRS/NTU/THALES UMI 3288Research Techno PlazaSingaporeSingapore institute for functional intelligent materials National University of SingaporeSingaporeSingapore

The Sabatier principle—which states that the best catalyst should be at the peak of the volcano plot,with neither too strong nor too weak intermediate binding strength—plays the golden rule in designing highly active *** instance,Pt with a“just right”hydrogen adsorption free energy(ΔG_(H^(*))=~0 eV)is the most efficient catalyst for hydrogen evolution reaction(HER).^(1)Nevertheless,the pressing demand for renewable energy has sparked a quest beyond the top of the volcano plot,driving the innovation towards more effective,economical.

关键词： catalyst instance adsorption

A CNN-SVR model for NO_(2)profile prediction based on MAX-DOAS observations:The influence of Chinese New Year overlapping the 2020 COVID-19 lockdown on vertical distributions of tropospheric NO_(2)in Nanjing,China

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Journal of Environmental Sciences 2024年第7期141卷 151-165页

作者： Xin Tian Zijie Wang Pinhua Xie Jin Xu Ang Li Yifeng Pan Feng Hu Zhaokun Hu Mingsheng Chen Jiangyi Zheng Information materials and intelligent Sensing Laboratory of Anhui Province Institutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China Key laboratory of Environmental Optical and Technology Anhui Institute of optics and Fine MechanicsHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China School of Environmental Science and Optoelectronic Technology University of Science and Technology of ChinaHefei 230026China

In this study,a hybrid model,the convolutional neural network-support vector regression model,was adopted to achieve prediction of the NO_(2)profile in Nanjing from January 2019to March *** the sudden decline in NO_(2)in February 2020,the contribution of the Coronavirus Disease-19(COVID-19)lockdown,Chinese New Year(CNY),and meteorologi cal conditions to the reduction of NO_(2)was ***_(2)vertical column densities(VCDs) from January to March 2020 decreased by 59.05%and 32.81%,relative to the same period in 2019 and 2021,*** the period of 2020 COVID-19,the average NO_(2)VCDs were 50.50%and 29.96%lower than those during the pre-lockdown and post-lockdown pe riods,*** NO_(2)volume mixing ratios(VMRs)during the 2020 COVID-19 lock down significantly decreased below 400 *** NO_(2)VMRs under the different wind fields were significantly lower during the lockdown period than during the pre-lockdown period This phenomenon could be attributed to the 2020 COVID-19 *** NO_(2)VMRs be fore and after the CNY were significantly lower in 2020 than in 2019 and 2021 in the same period,which further proves that the decrease in NO_(2)in February 2020 was attributed to the COVID-19 *** source analysis of an NO_(2)pollution episode during the lockdown period showed that the polluted air mass in the Beijing-Tianjin-Hebei was trans ported southwards under the action of the north wind,and the subsequent unfavorable meteorological conditions(local wind speed of<2.0 m/sec)resulted in the accumulation o pollutants.

关键词： MAX-DOAS CNN-SVR Nitrogen dioxide COVID-19 Chinese New Year Regional transport

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