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Enhanced CO sensing properties of Pd modified ZnO porous nanosheets

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Chinese Chemical Letters 2020年第8期31卷 2033-2036页

作者： na Luo Bo Zhang Dan Zhang Jiaqiang xu NEST Lab Department of ChemistryDepartment of PhysicsCollege of ScienceShanghai UniversityShanghai 200444China School of Materials Science and Engineering Cultivating Base for Key Laboratory of Environment-friendly Inorganic Materials in University of Henan ProvinceHenan Polytechnic UniversityJiaozuo 454000China

Noble metal is usually used to improve the gas sensing performance of metal oxide semiconductor(MOS)due to its better catalytic *** this work,we reported a synthesis of Pd/ZnO nanocomposite by an in situ reduction with ascorbic acid(AA).It was found that Pd/ZnO sensor has excellent selectivity to CO and the response of the Pd/ZnO sensor towards 100 ppm CO was as high as 15(Ra/Rg),obviously higher than that of the pristine ZnO sensor(1.4)when the working temperature is 220℃.Moreover,the pure ZnO sensor almost has no selectivity to CO,but the Pd/ZnO sensor has excellent selectivity to CO,which may be ascribed to the electronic sensitization of *** present results demonstrate that the Pd can significantly improve the gas-sensing performance of metal oxide semiconductor and the obtained sensor has great potential in monitoring coal mine gas.

关键词： CO sensor ZnO nanosheet Pd modifying Low concentration nanocomposite

Investigations on control algorithm of steady-state cornering and control strategy for dynamical correction in a steer-by-wire system

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第6期10卷 900-908页

作者： Ying xu Chang-fu ZONG Hsiao-hsiang na Lei LIU Department of Computer Science and Technology Jilin University Changchun 130025 China State Key Laboratory of Automobile Dynamic Simulation Jilin University Changchun 130025 China

To improve the handling performance of a steer-by-wire (SBW) vehicle, a series of control logics are proposed. Firstly, an algorithm for enhancing the maneuvering in steady-state cornering is presented. On this basis, two categories of control strategies are used to dynamically correct and compensate the transient state steering responses and vehicle behaviors. Simulator tests including subjective evaluations and virtual field tests are both conducted to make comprehensive investigations on the series of control logics. The subjective evaluations demonstrate that the SBW vehicle with a specifically selected value of steering sensitivity tends to be more desirable for driving than a conventional one in which a fixed steering ratio exists. The virtual field tests indicate that the control strategies for dynamical correction and compensation could effectively improve the handling per-formances of an SBW vehicle by reducing the work load of drivers, enhancing the track-holding performance, and improving steering response properties.

关键词： Steer-by-wire (SBW) Steady-state cornering Steering sensitivity Dynamical correction

Physical layer authentication in UAV-enabled relay networks based on manifold learning

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Science China(Information Sciences) 2022年第12期65卷 263-283页

作者： Shida XIA Xiaofeng TAO na LI Shiji WANG Jin xu national Engineering Lab for Mobile Network Technologies Beijing University of Posts and Telecommunications Beijing University of Posts and Telecommunications Research Institute

An unmanned aerial vehicle(UAV) relay network is a promising solution in the next-generation wireless networks due to its high capacity and unlimited geography. However, because of the openness of wireless channels and UAV mobility, it is remarkably challenging to guarantee the secure access of UAV relay. In this paper, we investigate the physical layer authentication(PLA) to verify the identity of the UAV relay for preventing unauthorized access to users’ information or network service. Unlike most existing PLA methods for UAV, the proposed PLA scheme fully considers the time-varying of physical layer attributes caused by UAV mobility, and transforms the authentication problem into recognizing nonlinearly separable physical layer data. Particularly, we propose a manifold learning-based PLA scheme that can authenticate the mobile UAV relay in real time by establishing the local correlation of physical layer attributes. The Markov chain of physical layer data in the time domain is established to evaluate UAV state transition probability through the proposed diffusion map algorithm. The legitimate UAV and spoofing attackers can always be authenticated by the different motion states. Performance analysis offered a comprehensive understanding of the proposed scheme. Extensive simulations confirm that the performance of the proposed scheme improves over 18% in resisting the intelligent spoofing UAV compared with the traditional methods.

关键词： UAV relay physical layer authentication mobility manifold learning diffusion map state transition probability

Secret key generation over a nakagami-m fading channel with correlated eavesdropping channel

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Science China(Information Sciences) 2022年第9期65卷 273-285页

作者： Shixun GONG Xiaofeng TAO na LI Haowei WANG Jin xu national Engineering Laboratory for Mobile Network Technologies Beijing University of Posts and Telecommunications Beijing University of Posts and Telecommunications Research Institute

The analysis of secret key capacity is an important investigation on the design of secret key agreement protocol. In this paper, we characterize the secret key capacity based on received signal envelopes obeying nakagami-m distribution between two legitimate users, in the presence of a passive eavesdropper,when the eavesdropping channel is correlated with the legitimate channel. The expression of secret key capacity is derived based on mutual information and applies to both integer and non-integer m. Simulation results indicate that the secret key capacity is proportional to m-fading parameter and average signal-tonoise ratio(SNR) and inversely proportional to the number of paths. In addition, some behaviors of secret key capacity over a high mobility fading channel, and microcell and macrocell environments are *** results cover the performance of secret key capacity when the received signal envelope follows Rayleigh,Rician, and Gaussian distributions.

关键词： physical layer security physical layer secret key generation nakagami-m fading correlated eavesdropping channel secret key capacity

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Enhanced photocatalytic performance of iron oxides@HTCC fabricated from zinc extraction tailings for methylene blue degradation:Investigation of the photocatalytic mechanism

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International Journal of Minerals,Metallurgy and Materials 2023年第12期30卷 2364-2374页

作者： Yang xue Xiaoming Liu na Zhang Yang Shao Chunbao(Charles)xu State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes National Laboratory of Mineral MaterialsSchool of Materials Science and TechnologyChina University of GeosciencesBeijing 100083China Department of Chemical&Biochemical Engineering Western UniversityLondonON N6A 5B9Canada

Photocatalytic processes are efficient methods to solve water contamination problems,especially considering dyeing wastewater ***,high-efficiency photocatalysts are usually very expensive and have the risk of heavy metal ***,an iron oxides@hydrothermal carbonation carbon(HTCC)heterogeneous catalyst was prepared by our group through co-hydrothermal treatment of carbohydrates and zinc extraction tailings of converter ***,the catalytic performance of the iron oxides@HTCC was verified by a nonbiodegradable dye,methylene blue(MB),and the catalytic mechanism was deduced from theoretical simulations and spectroscopic *** iron oxides@HTCC showed an excellent synergy between photocatalysis and Fenton-like *** visible-light illumination,the iron oxides@HTCC could be excited to generate electrons and holes,reacting with H_(2)O_(2)to produce·OH radicals to oxidize and decompose organic *** removal efficiency of methylene blue over iron oxides@HTCC at 140 min was 2.86 times that of *** enhanced catalytic performance was attributed to the advantages of iron oxides modification:(1)promoting the excitation induced by photons;(2)improving the charge ***,the iron oxides@HTCC showed high catalytic activity in a wide pH value range of 2.3-10.4,and the MB removal efficiency remained higher than 95% after the iron oxides@HTCC was recycled 4 *** magnetically recyclable iron oxides@HTCC may provide a solution for the treatment of wastewater from the textile industry.

关键词： photocatalysis photo-Fenton reaction methylene blue degradation tailings utilization

Of genes and microbes： solving the intricacies in host genomes

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Protein & Cell 2018年第5期9卷 446-461页

作者： Jun Wang Liang Chen na Zhao Xizhan xu Yakun xu Baoli Zhu CAS Key Laboratory of Pathogenic Microbiology and Immunology Institute of Microbiology Chinese Academy of Science Beijing 100101 China University of Chinese Academy of Sciences Beijing 100049 China Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases First Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310058 China

Microbiome research is a quickly developing field in biomedical research, and we have witnessed its poten- tial in understanding the physiology, metabolism and immunology, its critical role in understanding the health and disease of the host, and its vast capacity in disease prediction, intervention and treatment. However, many of the fundamental questions still need to be addressed, including the shaping forces of microbial diversity between individuals and across time. Microbiome research falls into the classical nature vs. nurture sce- nario, such that host genetics shape part of the micro- biome, while environmental influences change the original course of microbiome development. In this review, we focus on the nature, i.e., the genetic part of the equation, and summarize the recent efforts in understanding which parts of the genome, especially the human and mouse genome, play important roles in determining the composition and functions of microbial communities, primarily in the gut but also on the skin. We aim to present an overview of different approaches in studying the intricate relationships between host genetic variations and microbes, its underlying philos- ophy and methodology, and we aim to highlight a few key discoveries along this exploration, as well as current pitfalls. More evidence and results will surely appear in upcoming studies, and the accumulating knowledge will lead to a deeper understanding of what we could finally term a ＂hologenome＂, that is, the orga- nized, closely interacting genome of the host and the microbiome.

关键词： gut microbiota host genetics quantitativegenetics gene-microbiome association

Sedimentary geochemistry and provenance of the Lower and Middle Devonian Laojunshan Formation,the North Qilian Orogenic Belt

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Science China Earth Sciences 2010年第3期53卷 356-367页

作者： xu YaJun du YuanSheng YANG JiangHai HUANG Hu Key Laboratory of Biogeology and Environmental Geology of China Education Ministry China University of GeosciencesWuhan 430074China State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China

The Laojunshan Formation is a suite of molasse formed during the rapid uplift of the North Qilian Orogenic Belt (NQOB). Forty-one samples of sandstone have been collected from the Sunan and Minle sections in the western sector and the Gulang and Jingyuan sections in the eastern sector of the NQOB belt. Geochemical analyses of those samples indicated: 1) The MgO+Fe2O3T and Al2O3/SiO2 values are higher, and K2O/na2O ratios are lower in the western sector than those in the eastern sector. 2) All of them are depleted in Nb and Ta elements. The samples from the western sector are depleted in Rb element and enriched with Sc, Co, Ni, V, and Cr elements in the Upper Crust-normalized patterns. However, those from the eastern sector are depleted in Sr without enrichments of Sc, Co, Ni, V, and Cr. 3) All of the samples display a right-inclined REE pattern af- ter Chondrite-normalized REE pattern. But LaN/YbN and Eu/Eu* ratios of the samples from the western sector are lower than those of the samples from the eastern sector. These geochemical characteristics suggest the prominent input of mafic clast with minor granitic rocks into the Sunan area, felsic clast into the Gulang and Jingyuan area, and both mafic and felsic clast into the Minle area. The angular shapes of gravels imply that these ill-sorted sediments were deposited near their sources without recy- cling. Geochemical features above also demonstrated that no major chemical weathering occurred for the western provenance, but deposits in the eastern sector resulted from low or middle degree chemical weathering. Evidences combining tectonic discriminations and comparisons with potential provenances revealed that sediments in the Sunan area were derived mainly from the North Qilian Continental arc, whereas sediments in the Minle, Gulang, and Jingyuan areas were derived not only from the North Qilian Continental arc but also from the basement of the Middle Qilian block. Integrated with the characteristics of development of

关键词： North Qilian Orogenic Belt (NQOB) Laojunshan Formation sedimentary geochemistry provenance orogeny

Aberrant expression of BDNF might serve as a candidate target for cocaine- induced psychosis: insights from bioinformatics analysis and microarray validation

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General Psychiatry 2021年第5期34卷 45-52页

作者： Youwei Zhu Yan Zhao Xiaomin xu Hang Su Xiaotong Li na Zhong Haifeng Jiang Jiang du Min Zhao Shanghai Drug Abuse Treatment Center Shanghai Mental Health CenterShanghai Jiao Tong University School of MedicineShanghaiChina Shanghai Key Laboratory of Psychotic Disorders ShanghaiChina Institute of Psychological and Behavioral Science Shanghai Jiao Tong UniversityShanghaiChina

Background Cocaine use disorder(CUD)and associated psychosis are major public health issues worldwide,along with high relapse outcome and limited treatment *** the molecular mechanisms underlying cocaine-induced psychosis(CIP)could supply integrated insights for understanding the pathogenic mechanism and potential novel therapeutic *** The aim of the study was to explore common alterations of CUD-schizophrenia target genes and identify core risk genes contributing to CIP through data mining and network pharmacology *** Target genes of CUD were obtained from GeneCards,Comparative Toxicogenomics Database,Swiss Target Prediction platform and ***-related target genes were derived from DisGeNET,GeneCards,MalaCards and Online Mendelian Inheritance in Man ***,the overlap genes of these two sets were regarded as risk genes contributing to *** on these CUD-schizophrenia target genes,functional annotation and pathway analysis were performed using the clusterProfiler package in ***-protein interaction network construction and module detection were performed based on the Search Tool for the Retrieval of Interacting Genes(STRING)database and Cytoscape *** expression datasets GSE54839 and GSE93577 were applied for data validation and diagnostic capacity evaluation of interested hub *** A total of 165 CUD-schizophrenia target genes were *** genes were mainly contributing to chemical synaptic transmission,neuropeptide hormone activity,postsynaptic membrane and neuroactive ligand-receptor interaction *** analysis and validation analysis indicated that BDNF might serve as an important risk gene in mediating *** This study generates a holistic view of CIP and provides a basis for the identification of potential CUD-schizophrenia target genes involved in the development of *** abnormal expression of BDNF would be a candidate therapeutic target underlyi

关键词： alterations analysis insight

Temporal heterogeneity in climatic responses of four tree species in the Altai Mountains, northwest China

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Journal of Forestry Research 2024年第6期35卷 230-241页

作者： Hanxue Liang Leibo Che Wenyang Si na Liu Zhitao Wu Ziqiang du Jianwei Shi Tianjie Lei Bin Sun Shaowei Jiang Institute of Loess Plateau Shanxi UniversityTaiyuan 030006People’s Republic of China Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems South China Botanical GardenChinese Academy of SciencesGuangzhou 510650People’s Republic of China Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesBeijing 100081People’s Republic of China Institute of Forest Resource Information Techniques(IFRIT) Chinese Academy of ForestryBeijing 100091People’s Republic of China

In the context of ongoing climate change,rela-tionships between tree growth and climate present uncertain-ties,which limits the predictions of future forest *** China is a region undergoing notable warming and increased precipitation;how forests in this region will respond to climate change has not been fully *** used dendrochronological methods to examine the rela-tionship between climate and the radial growth of four tree species in a riparian forest habitat in Altai region:European aspen(Populus tremula),bitter poplar(Populus laurifolia),Swedish birch(Betula pendula),and Siberian spruce(Picea obovata).The results reveal that European aspen was insen-sitive to climate *** contrast,bitter poplar showed a positive response to elevated temperatures and negative to increased moisture during the growing *** birch and Siberian spruce were adversely affected by higher temperatures but benefited from increased precipitation.A moving correlation analysis suggested that,against a back-drop of continuous warming,growth patterns of these spe-cies will diverge:European aspen will require close moni-toring,bitter poplar may likely to show accelerated growth,and the growth of Swedish birch and Siberian spruce may be inhibited,leading to a *** findings offer insight into the future dynamics of riparian forests under changing climate.

关键词： Broadleaf species Coniferous species Warming and increased precipitation SPEI Riparian forests