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Applications of in-situ solid-state nuclear magnetic resonance in methanol to olefins reaction

Science China Chemistry 2025年第1期68卷 134-151页

作者： jing Niu shutao xu Yingxu Wei Zhongmin liu National Engineering Research Center of Lower-Carbon Catalysis Technology Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China

The methanol-to-olefins(MTO)reaction offers an alternative pathway for the production of low-carbon olefins from non-oil *** research has been impeded by a lack of comprehensive understanding of its underlying mechanism,despite the significant progress made in ***-situ solid-state nuclear magnetic resonance(ss NMR)spectroscopy has emerged as a pivotal tool,offering crucial insights into key species under real-time operando ***,the host–guest interaction between zeolites or surface species residing on zeolites and the reactant/active intermediates is revealed by the combination of in-situ^(13)C MAS NMR and 2D correlation ***,recent technological advancements in hyperpolarization(HP)methods,including HP^(129)Xe NMR and dynamic nuclear polarization(DNP),have significantly improved the sensitivity of ssNMR,enabling detailed structural and kinetic analysis as well as the detection of trace *** this feature article,we summarized recent advancements in(in-situ)ssNMR spectroscopy applied to MTO reaction processes,encompassing mechanistic investigations at various stages and the intricate host–guest *** theoretical insights into the dynamic evolution of MTO reactions lay a solid foundation for the optimization of catalytic processes and the development of efficient catalysts,thereby advancing the techniques towards more sustainable and economical production route for olefins.

关键词： MTO zeolites in-situ ssNMR reactive intermediates reaction mechanism

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Observation of topological charge transformations in acoustic vortex using passive periodic systems

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Science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 136-143页

作者： Di-Chao Chen Xie liu Changqing xu Da-jian Wu Ying Cheng Xiao-Jun liu School of Physics and Technology Nanjing Normal UniversityNanjing 210023China Key Laboratory of Modern Acoustics School of PhysicsNanjing UniversityNanjing 210093China

Vortex transmutation utilizes a periodic system,which not only enables the alteration of the topological charge(TC)of unstable input vortices but also facilitates their transformation into stable *** approach is crucial for investigating the characteristics of vortices in various wave ***,we achieve acoustic vortex TC transmutation by employing a welldesigned dual-structured plate external system(DPES).The interactions between the acoustic vortex and the finite-order discrete rotational symmetry lead to the transformation of its topological charge when complete rotational symmetry is broken to Nthorder discrete *** results experimentally demonstrate the acoustic vortex TC transmutation based on passive artificial structures,enabling numerous applications in particle manipulation and information multiplexing as well as advancing our understanding and control over free-space acoustic vortices.

关键词： acoustic vortex topological charge transformation artificial structure

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Mutual-structure weighted guided image filtering for depth map restoration

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Optoelectronics Letters 2025年第1期21卷 51-56页

作者： liu Zijian SONG jian CHEN Quanmin xu jiangtao Tianjin Key Laboratory of Imaging and Sensing Microelectronic Technology School of MicroelectronicsTianjin UniversityTianjin 300072China Spikesee Technology Co. Ltd.Beijing 100083China

Although guided image filtering(GIF) is known for preserving edges and fast computation,it may produce inaccurate outputs in depth map *** this paper,a novel confidence-weighted GIF called mutual-structure weighted GIF(MSWGIF) is proposed,which replaces the mean filtering strategy in GIF during handling overlapping *** confidence value is composed of a depth term and a mutual-structure term,where the depth term is utilized to protect the edges of the output,and the mutual-structure term helps to select accurate windows during the structure characteristics of the guidance image are transferred to the *** results show that MSWGIF reduces the root mean square error(RMSE) by an average of 12.37%,and the average growth rate of correlation(CORR) is 0.07% on ***,the average growth rate of structure similarity index measure(SSIM) is 0.34%.

关键词： filtering image mutual

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Analysis of vibration response characteristics of subway station and superstructure with hard combination

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Earthquake Engineering and Engineering Vibration 2025年第1期24卷 271-281页

作者： Jia jinglong xu Weiping liu xu Wei Yong Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSchool of Civil EngineeringSouthwest Jiaotong UniversityChengdu 610031China State Key Laboratory of Intelligent Geotechnics and Tunnelling Chengdu 610031China China Railway Eryuan Chongqing Survey and Design Institute Co.Ltd. Chongqing 400023China

The vibration response and noise caused by subway trains can affect the safety and comfort of *** study the dynamic response characteristics of subway stations and superstructures under train loads with a hard combination,a numerical model is developed in this *** indoor model test verified the accuracy of the numerical *** influence laws of different hard combinations,train operating speeds and modes were studied and evaluated *** results show that the frequency corresponding to the peak vibration acceleration level of each floor of the superstructure property is concentrated at 10–20 *** vibration response decreases in the high-frequency parts and increases in the lowfrequency parts with increasing distance from the ***,the factors,such as train operating speed,operating mode,and hard combination type,will affect the vibration of the *** vibration response under the reversible operation of the train is greater than that of the unidirectional *** operating speed of the train is proportional to its vibration *** vibration amplification area appears between the middle and the top of the superstructure at a higher train *** vibration acceleration level will exceed the limit value of relevant regulations,and vibration-damping measures are *** the scope of application,this study provides some suggestions for constructing subway stations and superstructures.

关键词： subway station superstructure vibration response hard combination

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An asymmetrically variable wingtip anhedral angles morphing aircraft based on incremental sliding mode control:Improving lateral maneuver capability

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Chinese Journal of Aeronautics 2025年第1期38卷 455-470页

作者： Xiaodong liu Yong xu jianqiao LUO School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Chongqing Innovation Center Beijing Institute of TechnologyChongqing 401120China

This paper presents the design of an asymmetrically variable wingtip anhedral angles morphing aircraft,inspired by biomimetic mechanisms,to enhance lateral maneuver ***,we establish a lateral dynamic model considering additional forces and moments resulting during the morphing process,and convert it into a Multiple Input Multiple Output(MIMO)virtual control system by importing virtual ***,a classical dynamics inversion controller is designed for the outer-loop system.A new Global Fast Terminal Incremental Sliding Mode Controller(NDO-GFTISMC)is proposed for the inner-loop system,in which an adaptive law is implemented to weaken control surface chattering,and a Nonlinear Disturbance Observer(NDO)is integrated to compensate for unknown *** whole control system is proven semiglobally uniformly ultimately bounded based on the multi-Lyapunov function ***,we consider tracking errors and self-characteristics of actuators,a quadratic programmingbased dynamic control allocation law is designed,which allocates virtual control inputs to the asymmetrically deformed wingtip and *** dynamic models are incorporated to ensure physical realizability of designed allocation ***,comparative experimental results validate the effectiveness of the designed control system and control allocation *** NDO-GFTISMC features faster convergence,stronger robustness,and 81.25%and 75.0%reduction in maximum state tracking error under uncertainty compared to the Incremental Nonlinear Dynamic Inversion Controller based on NDO(NDO-INDI)and Incremental Sliding Mode Controller based on NDO(NDO-ISMC),*** design of the morphing aircraft significantly enhances lateral maneuver capability,maintaining a substantial control margin during lateral maneuvering,reducing the burden of the rudder surface,and effectively solving the actuator saturation problem of traditional aircraft during lateral maneuvering.

关键词： Morphing aircraft Lateral maneuver capability Incremental sliding mode control Multi-Lyapunov function method Control theory Control allocation law

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Insights into spinal muscular atrophy from molecular biomarkers

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Neural Regeneration Research 2025年第7期20卷 1849-1863页

作者： Xiaodong Xing Xinzhu liu Xiandeng Li Mi Li Xian Wu Xiaohui Huang Ajing xu Yan liu jian Zhang Department of Clinical Pharmacy Xinhua HospitalShanghai Jiao Tong University School of MedicineShanghaiChina College of Pharmacy Chongqing Medical UniversityChongqingChina

Spinal muscular atrophy is a devastating motor neuron disease characterized by severe cases of fatal muscle *** is one of the most common genetic causes of mortality among infants aged less than 2 *** research is currently receiving more attention,and new candidate biomarkers are constantly being *** review initially discusses the evaluation methods commonly used in clinical practice while briefly outlining their respective pros and *** also describe recent advancements in research and the clinical significance of molecular biomarkers for spinal muscular atrophy,which are classified as either specific or non-specific *** review provides new insights into the pathogenesis of spinal muscular atrophy,the mechanism of biomarkers in response to drug-modified therapies,the selection of biomarker candidates,and would promote the development of future ***,the successful utilization of biomarkers may facilitate the implementation of gene-targeting treatments for patients with spinal muscular atrophy.

关键词： biomarkers disease progression gene-targeting therapy neurofilaments Nusinersen spinal muscular atrophy(SMA) survival motor neuron therapeutic evaluation treatment outcomes

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Construction of attapulgite-based one-dimensional nanonetwork composites with corrosion resistance for high-efficiency microwave absorption

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International Journal of Minerals,Metallurgy and Materials 2025年第3期32卷 689-698页

作者： Kai xu Qingqing Gao Shaoqi Shi Pei liu Yinxu Ni Zhilei Hao Gaojie xu Yan Fu Fenghua liu School of Materials Science and Chemical Engineering Ningbo UniversityNingbo 315211China Zhejiang Key Laboratory of Additive Manufacturing Materials Ningbo Institute of Materials Technology&EngineeringChinese Academy of SciencesNingbo 315201China Northwest Yongxin Coatings Limited Company Lanzhou 730046China

Exploring high-efficiency and broadband microwave absorption(MA)materials with corrosion resistance and low cost is ur-gently needed for wide practical ***,the natural porous attapulgite(ATP)nanorods embedded with TiO_(2)and polyaniline(PANI)nanoparticles are synthesized via heterogeneous precipitation and in-situ *** obtained PANI-TiO_(2)-ATP one-di-mensional(1D)nanostructures can intertwine into three-dimensional(3D)conductive network,which favors energy *** min-imum reflection loss(RL_(min))of the PANI-TiO_(2)-ATP coating(20wt%)reaches-49.36 dB at 9.53 GHz,and the effective absorption band-width(EAB)can reach 6.53 GHz with a thickness of 2.1 *** excellent MA properties are attributed to interfacial polarization,mul-tiple loss mechanisms,and good impedance matching induced by the synergistic effect of PANI-TiO_(2)nanoparticle shells and ATP *** addition,salt spray and Tafel polarization curve tests reveal that the PANI-TiO_(2)-ATP coating shows outstanding corrosion resist-ance *** study provides a low-cost and high-efficiency strategy for constructing 1D nanonetwork composites for MA and corrosion resistance applications using natural porous ATP nanorods as carriers.

关键词： microwave absorption corrosion resistance attapulgite TiO_(2) polyaniline

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Approach from the laboratory to the field: New strategies in the control of mosquito-borne infectious diseases

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Science China(Life Sciences) 2025年第1期68卷 303-305页

作者： Ziqian xu Lianpan Dai Jun liu National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases(NITFID) National Institute for Viral Disease Control and PreventionChineseCenter for Disease Control and PreventionBeijing 102206China CAS Key Laboratory of Pathogen Microbiology and Immunology Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China

Vector-borne viruses,transmitted among humans and animal hosts through bites of vectors such as mosquitoes and ticks,pose a great and ongoing threat to public health and biosafety(Yang et al.,2022).Among them,dengue virus-induced epidemics,have dramatically increased worldwide in recent *** report released by the World Health Organization(WHO)at the end of 2023 showed that dengue epidemic globally surged in 2023,with the number of reported cases nearing a historical *** the first four months of 2024,more than 6 million people worldwide were infected by dengue virus,with more than 2,000 *** countries around the world especially the American countries issued warnings,reporting three times the number of dengue cases compared with the same period last *** global climate change,population growth,and urbanization,flaviviral diseases transmitted by Aedes mosquitoes remain a major global biosecurity challenge.

关键词： diseases globally

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Spatial and Temporal Distribution Patterns of Bemisia tabaci biotypes/haplotypes in Zhejiang,China

Spatial and Temporal Distribution Patterns of Bemisia tabaci...

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第二届全国生物入侵学术研讨会

作者： xu jing,liu jian,liu shu-sheng~* (Institute of Insect Sciences,Zhejiang University,Hangzhou 310029,China)

Introduction:The whitefly Bemisia tabaci consists of 12 major genetic groups distributed throughout tropical and subtropical regions of the world(Boykin et al.2007,***.,44: 1306-1319).In the past 20 years,the B biotype(***(Mediterranean/Asia Minor/Africa)) of this species complex has been spreading into many regions of the world,and in many regions of invasion the B biotype has rapidly displaced indigenous whiteflies and caused serious damage to *** China,the B biotype was first recorded in mid to late 1990s and since then has been recorded in nearly all regions of the *** Zhejiang,China,the B biotype was first detected in *** order to determine the composition of the whitefly biotypes/haplotypes in Zhejiang and the process of invasion by alien biotypes,regular field surveys were conducted from 2004-2007.

关键词： B biotype Q biotype Bemisia tabaci displacement distribution Zhejiang

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Light Use Efficiency Model Based on Chlorophyll Content Better Captures Seasonal Gross Primary Production Dynamics of Deciduous Broadleaf Forests

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Chinese Geographical Science 2025年第1期35卷 55-72页

作者： YANG Rongjuan liu Ronggao liu Yang CHEN jingming xu Mingzhu HE Jiaying State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory for Humid Subtropical Ecogeographical Processes of the Ministry of Education School of Geographical SciencesFujian Normal UniversityFuzhou 350007China Department of Geography and Planning University of TorontoTorontoON M5S 3G3Canada

Gross primary production(GPP)is a crucial indicator representing the absorption of atmospheric CO_(2) by *** present,the estimation of GPP by remote sensing is mainly based on leaf-related vegetation indexes and leaf-related biophysical para-meter leaf area index(LAI),which are not completely synchronized in seasonality with *** this study,we proposed chlorophyll content-based light use efficiency model(CC-LUE)to improve GPP estimates,as chlorophyll is the direct site of photosynthesis,and only the light absorbed by chlorophyll is used in the photosynthetic *** CC-LUE model is constructed by establishing a linear correlation between satellite-derived canopy chlorophyll content(Chlcanopy)and *** method was calibrated and validated utiliz-ing 7-d averaged in-situ GPP data from 14 eddy covariance flux towers covering deciduous broadleaf forest ecosystems across five dif-ferent climate *** showed a relatively robust seasonal consistency between Chlcanopy with GPP in deciduous broadleaf forests under different climatic *** CC-LUE model explained 88% of the in-situ GPP seasonality for all validation site-year and 56.0% of in-situ GPP variations through the growing season,outperforming the three widely used LUE models(MODIS-GPP algorithm,Vegetation Photosynthesis Model(VPM),and the eddy covariance-light use efficiency model(EC-LUE)).Additionally,the CC-LUE model(RMSE=0.50 g C/(m^(2)·d))significantly improved the underestimation of GPP during the growing season in semi-arid region,re-markably decreasing the root mean square error of averaged growing season GPP simulation and in-situ GPP by 75.4%,73.4%,and 37.5%,compared with MOD17(RMSE=2.03 g C/(m^(2)·d)),VPM(RMSE=1.88 g C/(m^(2)·d)),and EC-LUE(RMSE=0.80 g C/(m^(2)·d))*** chlorophyll-based method proved superior in capturing the seasonal variations of GPP in forest ecosystems,thereby provid-ing the possibility of a more precise depiction of forest seasonal carbon uptake.

关键词： canopy chlorophyll content(Chlcanopy) photosynthesis gross primary production(GPP) light use efficiency(LUE)model seasonal dynamics deciduous broadleaf forest(DBF)

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