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Soft X-ray ptychography method at SSRF

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Nuclear Science and Techniques 2017年第6期28卷 86-94页

作者： Chun-Peng Wang zi-jian xu Hai-Gang Liu xulei Tao Ren-Zhong Tai Shanghai Institute of Applied Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

Ptychography is a diffraction-based X-ray microscopy technique in which an extended sample is scanned by a coherent beam with overlapped illuminated areas and complex transmission function of the sample is obtained by applying iterative phase retrieval algorithms to the diffraction patterns recorded at each scanned *** permits quantitatively imaging of non-crystalline specimens at a resolution limited only by the X-ray wavelength and the maximal scattering angle *** this paper,the development of soft X-ray ptychography method at the BL08U1 A beamline of Shanghai Synchrotron Radiation Facility is *** experimental setup,experimental parameters selection criteria,and post-experimental data analyzing procedures are presented in detail with a prospect of high-resolution image reconstruction in real *** performance of this newly implemented method is demonstrated through the measurements of a resolution test pattern and two real samples:Pt-Co alloy nanoparticles and a breast cancer *** results indicate that strong scattering specimens can be reconstructed to sub-20 nm resolution,while a sub-25 nm resolution for biological specimens can be achieved.

关键词： Ptychography Coherent diffraction imaging X-ray microscopy Phase retrieval

Numerical and experimental study on the response characteristics of warhead in the fast cook-off process

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Defence Technology（防务技术） 2021年第4期17卷 1444-1452页

作者： Min Zhu Sheng-ao Wang Huang Huang Gui Huang Fei Wu Shao-hua Sun Biao Li zi-jian xu College of Nuclear Science and Technology Naval University of EngineeringWuhan430033China

The response characteristics of the warhead under thermal stimuli conditions are important to the safety *** goal of this study is to obtain data on the warhead in the fast cook-off *** this paper,a numerical calculation method is proposed,whose reliability is supported by comparison with experimental *** the numerical calculation,the temperature distribution,temperature change,and ignition time are *** numerical results show that the ignition time is 76 s after the warhead started to burn and that the maximum temperature of the explosive’s outer surface is 238.3℃ at the ignition *** fast cook-off experiment of the warhead is implemented so as to get the flame temperature and reaction grades that are not available through numerical *** experimental results show that the overpressure fails to reach the preset minimumvalue which is equivalent to 6 kg of TNT and that the reaction grade is *** research results have reference value for the design of the warhead and the reduction of detonation risks.

关键词： Warhead Explosives Fast cook-off Numerical calculations

Diffractive neural networks with improved expressive power for gray-scale image classification

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Photonics Research 2024年第6期12卷 1159-1166页

作者： MINJIA ZHENG WENZHE LIU LEI SHI jian zi State Key Laboratory of Surface Physics Key Laboratory of Micro-and Nano-Photonic Structures(Ministry of Education)and Department of PhysicsFudan UniversityShanghai 200433China Institute for Nanoelectronic Devices and Quantum Computing Fudan UniversityShanghai 200433China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China Shanghai Research Center for Quantum Sciences Shanghai 210315China

In order to harness diffractive neural networks(DNNs)for tasks that better align with real-world computer vision requirements,the incorporation of gray scale is ***,DNNs are not powerful enough to accomplish gray-scale image processing tasks due to limitations in their expressive *** our work,we elucidate the relationship between the improvement in the expressive power of DNNs and the increase in the number of phase modulation layers,as well as the optimization of the Fresnel number,which can describe the diffraction *** demonstrate this point,we numerically trained a double-layer DNN,addressing the prerequisites for intensitybased gray-scale image ***,we experimentally constructed this double-layer DNN based on digital micromirror devices and spatial light modulators,achieving eight-level intensity-based gray-scale image classification for the MNIST and Fashion-MNIST data *** optical system achieved the maximum accuracies of 95.10%and 80.61%,respectively.

关键词： process mirror limitations

Modulation of d-orbital to realize enriched electronic cobalt sites in cobalt sulfide for enhanced hydrogen evolution in electrocatalytic water/seawater splitting

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Rare Metals 2024年第2期43卷 511-521页

作者： jian-Peng Sun Yu Zheng zi-Sheng Zhang Xiang-Chao Meng zi-Zhen Li Key Laboratory of Marine Chemistry Theory and Technology(Ministry of Education) College of Chemistry and Chemical EngineeringOcean University of ChinaQingdao266100China Shanxi Institute of Energy Taiyuan030600China Department of Chemical and Biological Engineering Faculty of EngineeringUniversity of OttawaOttawaONK1N6 N5Canada

Herein,a novel single-atomic Pt doping and interface-rich CoS/Co(OH)_(2)(Pt-CoS/Co(OH)_(2)/C)electrocatalyst has been successfully *** from precise regulation of d-orbital electronic structure modulation on Co site,Pt-CoS/Co(OH)_(2)/C exhibited remarkable HER activity and high stability for hydrogen evolution in splitting both water(73 mV@10 mA·cm^(−2)) and seawater(87 mV@10 mA·cm^(−2)).Notably,atomic Pt doping was introduced into CoS/Co(OH)_(2),which could produce local unbalanced Coulombic force and significantly increased the number of S vacancies,and then expose abundant Co ***,Co(OH)_(2) in Pt-CoS/Co(OH)_(2)/C could act as the adsorption sites for H_(2)O in hydrogen evolution reaction *** functional theory results also proved that atomic Pt doping,S vacancies and Co(OH)_(2) coupling could result in the formation of enriched electronic Co sites and optimize d_(z2) orbital electronic structure,and then realize the depth upward shift of d-band center and enhance the adsorption of H*on Co sites.

关键词： Electrocatalysts Hydrogen evolution reaction Pt-CoS/Co(OH)_(2) d-band center Electronic structure Water/seawater electrolysis

Evidence-based practices in sustainable travel behavior intervention: A knowledge graph-based systematic review

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第2期11卷 293-311页

作者： jian Li Chenjie xu Key Laboratory of Road and Traffic Engineering of the Ministry of Education College of Transportation EngineeringTongji UniversityShanghai 201804China

Sustainable travel behavior intervention is an essential strategy to promote the development of urban *** interventions offer personalized strategies based on certain scenario and participants to promote its effectiveness over hard travel ***,personalized strategies may also bring about difficulties to identify the actual effect of the ***,based on current practice,to make full use of travel behavior interventions,it is necessary to construct a unified methodological evidencebased framework to assess the reliability and effectiveness of travel behavior intervention *** response to these issues,we applied evidence-based knowledge graph to the field of sustainable travel behavior interventions to help decision supporters design sustainable travel behavior interventions wisely and in turn avoid excessive use of hard travel *** introduced concept of evidence-based practice to conduct a systematic analysis concerning reliability and validity of current full volume empirical studies by dimensions of scenarios,types of interventions and *** addition,we took advantage of high extensivity and integrability of knowledge graph to organize evidence-based related *** of the systematic analysis shows that in terms of reliability of evidence,school intervention is the best scenario,knowledge incentive is the best intervention type and promoting public transit and walking proportion are the best ***,the reliability of interventions in workplace,belonging to reward and threat along with aiming at changing travel patterns generally and lowering travel carbon emission need to be *** the study,various research prospects are raised to promote evidence quality in the field of travel behavior intervention *** a pioneer study,our research contributes to the field of urban transportation in introducing concepts of evidence-based practice and enabling optimization and

关键词： Evidence-based decision-making Evidence assessment Knowledge graph Travel behavior intervention Sustainable travel

The Essential 2-rank for Classical Groups

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2169-2186页

作者： jian Bei AN Yong xu Department of Mathematics University of AucklandAucklandNew Zealand School of Mathematics and Statistics He’nan University of Science and TechnologyLuoyang 471023P.R.China

Let G be a symplectic or orthogonal group defined over a finite field with odd characteristic and let D≤G be a Sylow *** this paper,we classify the essential 2-subgroups and determine the essential 2-rank of the Frobenius category FD(G).Together with the results of An–Dietrich and Cao–An–Zeng,this completes the work of essential subgroups and essential ranks of classical groups.

关键词： Frobenius category conjugation families essential 2-rank symplectic groups orthogonal groups

Portable fluorogenic probe for monitoring of volatile amine vapour and food spoilage

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Chinese Chemical Letters 2024年第3期35卷 257-261页

作者： jian-Hao Zhao Wen-Xing xu Bin Li Wei xu Wu-Kun Zhang Ming-Shuai Yuan Hui-zi Li Qing-Guo He Xiang Ma jian-Gong Cheng Yan-Yan Fu State Key Lab of Transducer Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of the Chinese Academy of SciencesBeijing 100039China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center Frontiers Science Center for Materiobiology and Dynamic Chemistry School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

There are urgent needs of volatile amine gas sensors with high-performance in food quality control,disease monitoring and environmental ***-film fluorescent probe is suitable for amine vapour sensing due to its high sensitivity,high selectivity,and no polluting ***,a novel fluorescent probe based on indacenodithiophene structure withπconjugated system was designed and *** experimental results show that the films prepared by this material exhibit rapid and distinct fluorescence quenching after being exposed to saturated vapours of primary amine,secondary amine and tertiary amine represented by n-propylamine,diethylamine and trimethylamine,*** quenching of fluorescence is 84%,87%and 96%,respectively,within 10 *** detection mechanism of probe for primary amine is based on specific chemical reaction,while the detection mechanism for secondary amine and tertiary amine is intramolecular charge *** experiments show that the detection limit of the fluorescent probe for trimethylamine,an important marker of food spoilage,could reach 4.610 ***-site detection based on spoilage of small yellow croaker suggests the material possesses the potential for food freshness *** simple fluorogenic probe is an original approach to simplify real-time visual monitoring of volatile amine vapour.

关键词： Fluorescent probe Volatile amine Gas sensing Trimethylamine Food spoilage

Carbon nanofibers embedded with Fe-Co alloy nanoparticles via electrospinning as lightweight high-performance electromagnetic wave absorbers

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Rare Metals 2024年第6期43卷 2769-2783页

作者： Wen-Jun Cai jian-Guo jiang zi-Dong Zhang zi-xuan Liu Lu-JieZhang Zhen-Kun Long Ke Bi Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials(Ministry of Education) Shandong UniversityJinan 250061China School of Materials Science and Engineering Shandong UniversityJinan 250061China Energy Institute Qilu University of Technology(Shandong Academy of Sciences)Jinan 250014China State Key Laboratory of Information Photonics and Optical Communications School of ScienceBeijing University of Posts and TelecommunicationsBeijing 100876China

As a lot of electromagnetic pollution and interference issues have emerged,to overcome electromagnetic interference,prevent electromagnetic hazards,and develop new high-performance electromagnetic wave(EMW)absorbers have become a significant task in the field of materials *** this paper,a three-dimensional(3D)carbon nanofibers network with core-shell structure,embedded with varied molar ratios of iron and cobalt(4:0,3:1,2:2,1:3,0:4),was effectively synthesized(Fe/Co@C-CNFs)via *** phase,microstructure,magnetic and EMW absorption properties were *** is discovered that Fe/Co@C-CNFs doped with iron:cobalt=1:1 have excellent EMW absorption *** the matching thickness is 1.08 mm,the minimum reflection loss(RL)value is-18.66 dB,while the maximum effective absorption bandwidth(EAB)reaches 4.2 GHz(13.9-18 GHz)at a thickness of 1.22 *** is owing to the absorbers'superior impedance matching and multiple reflections as well as the conductivity,dielectric,and magnetic losses of carbon nanofibers embedded with Fe-Co alloy *** addition,the radar cross section(RCS)of the absorbers has been calculated by CST Studio Suite,showing that the absorbing coating can effectively reduce the RCS at various angles,especially for Fe/Co@C-CNFs doped with iron:cobalt=1:*** findings not only provide new insights for the preparation of light-weight and high-performance electromagnetic wave absorbers,but also contribute to energy storage and conversion.

关键词： Electromagnetic wave(EMW)absorbers Fe/Co@C-CNFs Core-shell structure EMW absorbing mechanism Radar cross section(RCS)

Sequence structure controllable polymerization-induced self-assembly

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Science China Chemistry 2024年第1期67卷 390-397页

作者： zi-xuan Chang Ren-Man Zhu Chun-Yan Hong Wen-jian Zhang Department of Polymer Science and Engineering University of Science and Technology of ChinaHefei 230026China Institute of Physical Science and Information Technology Anhui UniversityHefei 230601China Key Laboratory of Environment-Friendly Polymeric Materials of Anhui Province Anhui UniversityHefei 230601China

Polymerization-induced self-assembly(PISA)combines synthesis and self-assembly of artificial polymers in one-pot,which brings us one step closer to emulating ***,the reported PISA formulations primarily focus on developing nano-objects with new chemical compositions and rarely on structural regulation of polymers with specific ***,sequence structure controllable polymerization-induced self-assembly(SCPISA)is reported by using 7-(2-methacryloyloxyethoxy)-4-methylcoumarin(CMA)as a *** the copolymerization of 2-hydroxyethyl methacrylate(HEMA)and CMA,controlled incorporation of CMA units into the polymer chains can be realized by programmable light/heat ***-based P(HEMA-co-CMA)copolymers with the same composition but different sequence structures generate a range of ***,the morphologies of the resultant nano-objects can also be controlled by regulating the feed molar ratio of CMA and HEMA,which is similar to the conventional PISA,but the synthesis procedure is obviously simplified in *** versatility of the methodology is further demonstrated by the fabrication of different functional nano-objects with sequence structure-dependent morphologies in SCPISA systems with different functional monomers.

关键词： polymerization-induced self-assembly sequence-controlled polymers PET-RAFT polymerization