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Research 2024年第1期2023卷 271-280页

作者： Qing Xia Rui liu Xueqin chen Zixuan chen jun-Jie Zhu State Key Laboratory of Analytical Chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023P.R.China Shenzhen Research Institute of Nanjing University Shenzhen 518000P.R.China

Metal nanomaterials can facilitate microbial extracellular electron transfer(EET)in the electrochemically active biofilm.However,the role of nanomaterials/bacteria interaction in this process is still unclear.Here,we reported the single-cell voltammetric imaging of Shewanella oneidensis MR-1 at the single-cell level to elucidate the metal-enhanced EET mechanism in vivo by the Fermi level-responsive graphene electrode.Quantified oxidation currents of~20 fA were observed from single native cells and gold nanoparticle(AuNP)-coated cells in linear sweep voltammetry analysis.On the contrary,the oxidation potential was reduced by up to 100 mV after AuNP modification.It revealed the mechanism of AuNP-catalyzed direct EET decreasing the oxidation barrier between the outer membrane cytochromes and the electrode.Our method offered a promising strategy to understand the nanomaterials/bacteria interaction and guide the rational construction of EET-related microbial fuel cells.

关键词： Fermi voltammetry Electron

Harness High-Temperature Thermal Energy via Elastic Thermoelectric Aerogels

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Nano-Micro Letters 2024年第8期16卷 196-210页

作者： Hongxiong Li Zhaofu Ding Quan Zhou jun chen Zhuoxin liu Chunyu Du Lirong Liang Guangming chen College of Materials Science and Engineering Shenzhen UniversityShenzhen 518055People’s Republic of China Department of Bioengineering University of CaliforniaLos AngelesCA 90095USA

Despite notable progress in thermoelectric(TE)materials and devices,developing TE aerogels with high-temperature resistance,superior TE performance and excellent elasticity to enable self-powered high-temperature monitoring/warning in industrial and wearable applications remains a great challenge.Herein,a highly elastic,flame-retardant and high-temperature-resistant TE aerogel,made of poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate)/single-walled carbon nanotube(PEDOT:PSS/SWCNT)composites,has been fabricated,displaying attractive compression-induced power factor enhancement.The as-fabricated sensors with the aerogel can achieve accurately pressure stimuli detection and wide temperature range monitoring.Subsequently,a flexible TE generator is assembled,consisting of 25 aerogels connected in series,capable of delivering a maximum output power of 400μW when subjected to a temperature difference of 300 K.This demonstrates its outstanding high-temperature heat harvesting capability and promising application prospects for real-time temperature monitoring on industrial high-temperature pipelines.Moreover,the designed self-powered wearable sensing glove can realize precise wide-range temperature detection,high-temperature warning and accurate recognition of human hand gestures.The aerogel-based intelligent wearable sensing system developed for firefighters demonstrates the desired self-powered and highly sensitive high-temperature fire warning capability.Benefitting from these desirable properties,the elastic and high-temperature-resistant aerogels present various promising applications including self-powered high-temperature monitoring,industrial overheat warning,waste heat energy recycling and even wearable healthcare.

关键词： Thermoelectrics Aerogel Self-powered High-temperature monitoring High-temperature warning

Outlier-resistant distributed fusion filtering for nonlinear discrete-time singular systems under a dynamic event-triggered scheme

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Frontiers of Information Technology & Electronic Engineering 2024年第2期25卷 237-249页

作者： Zhibin HU jun HU Cai chen Hongjian liu Xiaojian YI Department of Applied Mathematics Harbin University of Science and TechnologyHarbin150080China Heilongjiang Provincial Key Laboratory of Optimization Control and Intelligent Analysis for Complex Systems Harbin University of Science and TechnologyHarbin150080China School of Automation Harbin University of Science and TechnologyHarbin150080China School of Mathematics and Physics Anhui Polytechnic UniversityWuhu241000China School of Mechatronical Engineering Beijing Institute of TechnologyBeijing100081China Yangtze Delta Region Academy of Beijing Institute of Technology Jiaxing314003China Tangshan Research Institute Beijing Institute of TechnologyTangshan063099China

This paper investigates the problem of outlier-resistant distributed fusion filtering(DFF)for a class of multi-sensor nonlinear singular systems(MSNSSs)under a dynamic event-triggered scheme(DETS).To relieve the effect of measurement outliers in data transmission,a self-adaptive saturation function is used.Moreover,to further reduce the energy consumption of each sensor node and improve the efficiency of resource utilization,a DETS is adopted to regulate the frequency of data transmission.For the addressed MSNSSs,our purpose is to construct the local outlier-resistant filter under the effects of the measurement outliers and the DETS;the local upper bound(UB)on the filtering error covariance(FEC)is derived by solving the difference equations and minimized by designing proper filter gains.Furthermore,according to the local filters and their UBs,a DFF algorithm is presented in terms of the inverse covariance intersection fusion rule.As such,the proposed DFF algorithm has the advantages of reducing the frequency of data transmission and the impact of measurement outliers,thereby improving the estimation performance.Moreover,the uniform boundedness of the filtering error is discussed and a corresponding sufficient condition is presented.Finally,the validity of the developed algorithm is checked using a simulation example.

关键词： Distributed fusion filtering Multi-sensor nonlinear singular systems Dynamic event-triggered scheme Outlier-resistant filter Uniform boundedness

Remarkable Wear Resistance in a Complex Concentrated Alloy with Nanohierarchical Architecture and Composition Undulation

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Research 2024年第1期2023卷 403-416页

作者： Yushan Geng Wenyuan chen Hui Tan jun cheng Shengyu Zhu jun Yang Weimin liu State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000PR China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049PR China Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing Yantai 264000PR China

Sustained wear damages on the sliding surfaces of alloys are generally the culprit responsible for the failure of various mechanical systems.Inspired by high-entropy effects,here we deliberately deploy nanohierarchical architecture with composition undulation in a Ni50(AlNbTiV)_(50) complex concentrated alloy,which yields ultralow wear rate within the order of 10^(−7) to 10^(−6) mm^(3)/Nm between room temperature and 800℃.Such remarkable wear resistance heretofore represents one of the highest wear resistance reported for the bulk alloys or composites,and originates from the multi-type adaptive friction interface protection governed by intrinsically nano-coupled grains and nanoprecipitates.This cooperative heterostructure releases gradient frictional stress in stages upon wear at room temperature through the coexistence of multiple deformation pathways while activating a dense nanocrystalline glaze layer upon wear at 800℃ to minimize adhesive and oxidative wear.Our work uncovers a practical avenue for tailoring wear properties with multicomponent heterostructures over a wide temperature range.

关键词： wear alloys friction

Role of polarization evolution in the hysteresis effect of Pb-based antiferroelecrtics

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Chinese Chemical Letters 2024年第4期35卷 516-519页

作者： Botao Gao He Qi Hui liu jun chen Beijing Advanced Innovation Center for Materials Genome Engineering Department of Physical ChemistryUniversity of Science and Technology BeijingBeijing 100083China Shanghai Institute of Ceramics Chinese Academy of SciencesShanghai 201899China Hainan University Haikou 570228China

The electric field-induced irreversible domain wall motion results in a ferroelectric(FE) hysteresis. In antiferroelectrics(AFEs), the irreversible phase transition is the main reason for the hysteresis effects, which plays an important role in energy storage performance. Compared to the well-demonstrated FE hysteresis,the structural mechanism of the hysteresis in AFE is not well understood. In this work, the underlying correlation between structure and the hysteresis effect is unveiled in Pb(Zr,Sn,Ti)O_(3) AFE system by using in-situ electrical biasing synchrotron X-ray diffraction. It is found that the AFE with a canting dipole configuration, which shows a continuous polarization rotation under the electric field, tends to have a small hysteresis effect. It presents a negligible phase transition, a small axis ratio, and electric field-induced lattice changing, small domain switching. All these features together lead to a slim hysteresis loop and a high energy storage efficiency. These results offer a deep insight into the structure-hysteresis relationship of AFEs and are helpful for the design of energy storage material.

关键词： Antiferroelectric Hysteresis effect Structure refinement Perovskite In situ synchrotron radiation

A buffer overflow detection and defense method based on RiSC-V instruction set extension

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Cybersecurity 2024年第2期7卷 28-43页

作者： Chang liu Yan-jun Wu Jing-Zheng Wu chen Zhao Intelligent Software Research Center Institute of SoftwareChinese Academy of SciencesBejingChina University of Chinese Academy of Sciences BeijingChina State Key Laboratory of Computer Science Institute of SoftwareChinese Academy of SciencesBeijingChina

Buffer overflow poses a serious threat to the memory security of modern operating systems.It overwrites the con-tents of other memory areas by breaking through the buffer capacity limit,destroys the system execution environ-ment,and provides implementation space for various system attacks such as program control flow hijacking.That makes it a wide range of harms.A variety of security technologies have been proposed to deal with system security problems including buffer overflow.For example,No eXecute(NX for short)is a memory management technology commonly used in Harvard architecture.It can refuse the execution of code which residing in a specific memory,and can effectively suppress the abnormal impact of buffer overflow on control flow.Therefore,in recent years,it has also been used in the field of system security,deriving a series of solutions based on NX technology,such as ExecShield,DEP,StackGuard,etc.However,these security solutions often rely too much on the processor archi-tecture so that the protection coverage is insufficient and the accuracy is limited.Especially in the emerging system architecture field represented by RiSC-V,there is still a lack of effective solutions for buffer overflow vulnerabilities.With the continuous rapid development of the system architecture,it is urgent to develop defense methods that are applicable to different system application environments and oriented to all executable memory spaces to meet the needs of system security development.Therefore,we propose BOP,A new system memory security design method based on RISC-V extended instructions,to build a RISC-V buffer overflow detection and defense system and deal with the buffer overflow threat in RIsC-V.According to this method,NX technology can be combined with program control flow analysis,and Nx bit mechanism can be used to manage the executability of memory space,so as to achieve a more granular detection and defense of buffer overflow attacks that may occur in RISC-V system environment.In addition,The memory management an

关键词： RISc-V Operating system security Buffer overflow Control flow hijacking Nx bit Xibop

Geographical patterns and determinants of insect biodiversity in China

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Science China(Life Sciences) 2024年第6期67卷 1255-1265页

作者： Huizhong Fan Tongyi liu Youhua chen Ziyan Liao jun chen Yibo Hu Gexia Qiao Fuwen Wei CAS Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization&China-Croatia“Belt and Road”Joint Laboratory on Biodiversity and Ecosystem Services Chengdu Institute of BiologyChinese Academy of SciencesChengdu 610041China Jiangxi Provincial Key Laboratory of Conservation Biology College of ForestryJiangxi Agricultural UniversityNanchang 330045China University of Chinese Academy of Sciences Beijing 100049China

Insects play important roles in the maintenance of ecosystem functioning and the provision of livelihoods for millions of people.However,compared with terrestrial vertebrates and angiosperms,such as the giant panda,crested ibis,and the metasequoia,insect conservation has not attracted enough attention,and a basic understanding of the geographical biodiversity patterns for major components of insects in China is lacking.Herein,we investigated the geographical distribution of insect biodiversity across multiple dimensions(taxonomic,genetic,and phylogenetic diversity)based on the spatial distribution and molecular DNA sequencing data of insects.Our analysis included 18 orders,360 families,5,275 genera,and 14,115 species of insects.The results revealed that Southwestern and Southeastern China harbored higher insect biodiversity and numerous older lineages,representing a museum,whereas regions located in Northwestern China harbored lower insect biodiversity and younger lineages,serving as an evolutionary cradle.We also observed that mean annual temperature and precipitation had significantly positive effects,whereas altitude had significantly negative effects on insect biodiversity in most cases.Moreover,cultivated vegetation harbored the highest insect taxonomic and phylogenetic diversity,and needleleaf and broadleaf mixed forests harbored the highest insect genetic diversity.These results indicated that human activities may positively contribute to insect spatial diversity on a regional scale.Our study fills a knowledge gap in insect spatial diversity in China.These findings could help guide national-level conservation plans and the post-2020 biodiversity conservation framework.

关键词： insect spatial patterns multiple dimensions driving factors vegetation types

Neural stem cells promote neuroplasticity: a promising therapeutic strategy for the treatment of Alzheimer’s disease

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Neural Regeneration Research 2024年第3期19卷 619-628页

作者： jun Chang Yujiao Li Xiaoqian Shan Xi chen Xuhe Yan Jianwei liu Lan Zhao First Teaching Hospital of Tianjin University of Traditional Chinese Medicine TianjinChina National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion TianjinChina Tianjin University of Traditional Chinese Medicine TianjinChina

Recent studies have demonstrated that neuroplasticity,such as synaptic plasticity and neurogenesis,exists throughout the normal lifespan but declines with age and is significantly impaired in individuals with Alzheimer’s disease.Hence,promoting neuroplasticity may represent an effective strategy with which Alzheimer’s disease can be alleviated.Due to their significant ability to self-renew,differentiate,and migrate,neural stem cells play an essential role in reversing synaptic and neuronal damage,reducing the pathology of Alzheimer’s disease,including amyloid-β,tau protein,and neuroinflammation,and secreting neurotrophic factors and growth factors that are related to plasticity.These events can promote synaptic plasticity and neurogenesis to repair the microenvironment of the mammalian brain.Consequently,neural stem cells are considered to represent a potential regenerative therapy with which to improve Alzheimer’s disease and other neurodegenerative diseases.In this review,we discuss how neural stem cells regulate neuroplasticity and optimize their effects to enhance their potential for treating Alzheimer’s disease in the clinic.

关键词： Alzheimer’s disease amyloid-β cell therapy extracellular vesicle neural stem cell synaptic plasticity tau

Precore mutation enhances viral replication to facilitate persistent infection especially in HBeAg-negative patients

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Virologica Sinica 2024年第2期39卷 319-330页

作者： Guixin Li Danli Yang Xin liu Ting Zhang Hui liu jun Zou Zimeng Xu Xiangmei chen Lizhong Dai Hongsong chen Fengmin Lu Peking University People's Hospital Peking University Hepatology InstituteBeijing Key Laboratory of Hepatitis C and Immunotherapy for Liver DiseasesBeijing International Cooperation Base for Science and Technology on NAFLD DiagnosisBeijing100044China Department of Microbiology and Infectious Disease Center School of Basic Medical SciencesPeking UniversityBeijing100191China Baruch S.Blumberg Institute DoylestownPA18901USA Shenzhen Sanyuansheng Biotechnology Co. LtdShenzhen518000China Precision Medicine Center of Zhengzhou University Academy of Medical SciencesZhengzhou UniversityZhengzhou450001China Peking University-Sansure Biotech Joint Laboratory of Molecular Medicine Sansure Biotech Co.LtdChangsha410205China

Naturally occurred precore(PC,G1896A)and/or basal core promoter(BCP,A1762T/G1764A)mutations are prevalent in chronic HBV-infected patients,especially those under HBeAg-negative status.However,the replicative capacity of HBV with PC/BCP mutations remains ambiguous.Herein,meta-analysis showed that,only under HBeAg-negative status,the serum HBV DNA load in patients with PC mutation was 7.41-fold higher than those without the mutation.Both PC mutation alone and BCPþPC mutations promoted HBV replication in cell and hydrodynamic injection mouse models.In human hepatocyte chimeric mouse model,BCPþPC mutations led to elevated replicative capacity and intrahepatic core protein accumulation.Mechanistically,preC RNA harboring PC mutation could serve as mRNA to express core and P proteins,and such pgRNA-like function favored the maintenance of cccDNA pool under HBeAg-negative status.Additionally,BCPþPC mutations induced more extensive and severe human hepatocyte damage as well as activated endoplasmic reticulum stress and TNF signaling pathway in livers of chimeric mice.This study indicates that HBeAg-negative patients should be monitored on HBV mutations regularly and are expected to receive early antiviral treatment to prevent disease progression.

关键词： Hepatitis B virus Precore mutation Basal core promoter mutations Endoplasmic reticulum stress

A Novel Design of a Pre-separation Panel Structure to Protect Against the Impact of an Explosion in an Aircraft Plenum Chamber

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Acta Mechanica Solida Sinica 2024年第1期37卷 166-180页

作者： Zongxing liu Xiang Yang jun liu School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China COMAC Shanghai Aircraft Design and Research Institute Shanghai 201210China

To reduce the damage of the pressurizing panel structure of a fuselage caused by an explosion at the“least risk bomb location”in an aircraft structure,a new pre-separation panel structure was designed to resist blast loading.First,the dynamic strain response and morphology of impact damage of the new pre-separation panel were measured in an impact damage test.Second,the commercial software LS-DYNA was used to calculate the propagation of the blast shock wave,and the results were compared with empirical equations to verify the rationality of the numerical calculation method.Finally,the fluid–structure coupling method was used to calculate the damage process of the pre-separation panel structure under the impact of an explosion wave and an impact block.The calculated results were in good agreement with the test results,which showed the rationality of the calculation method and the model.The residual strength of the damaged pre-separation panel was significantly higher than that of the original damaged panel.The results show that the new pre-separation panel structure is reasonable and has certain significance for guiding the design of plenum chambers with strong resistance to implosion for aircraft fuselages.

关键词： Pre-separation panel structure Explosive response Residual strength Aircraft plenum chamber Least risk bomb location