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Highly Regioselective Direct C-H Arylation: Facile Construction of Symmetrical Dithienophthalimide-Based π-Conjugated Molecules for Optoelectronics

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Research 2020年第1期2020卷 1709-1720页

作者： xiang-chun li Yibo Xue Wan Song Yu Yan Jie Min Fang liu Xu liu Wen-Yong Lai Wei Huang Key Laboratory for Organic Electronics and Information Displays Institute of Advanced Materials(IAM)Nanjing University of Posts&Telecommunications9 Wenyuan RoadNanjing 210023China Frontiers Science Center for Flexible Electronics Xi’an Institute of Flexible Electronics(IFE)and Xi’an Institute of Biomedical Materials&EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi’an 710072China

Controllable direct C-H arylation with high regioselectivity is highly desirable yet remains a formidable ***,a facile regioselective direct C-H arylation is developed for efficient construction of a variety of symmetrical dithienophthalimide-basedπ-conjugated *** resulting methodology is applicable to a wide range of substrates,from electron-rich units to electrondeficient units with large steric end *** halides have been confirmed to be able to couple with dithienophthalimide(DTI)via direct C-H arylation,showing high *** the functional end groups onto the DTI core has been demonstrated to fine tune the emission colors to cover most of the visible *** results suggest a facile strategy towards highly selective direct C-H arylation,opening the prospects towards efficient construction ofπ-conjugated molecules for various potential optoelectronic applications.

关键词： spectra conjugated facile

Application of Real-time Ultrasound Elastography in Diagnosing Benign and Malignant Thyroid Solid Nodules

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Clinical oncology and cancer researeh 2012年第2期9卷 124-127页

作者： Hai-ling Wang Sheng Zhang Xiao-jie Xin li-hui Zhao chun-xiang li Jia-li Mu Xue-qing Wei Department of Ultrasonographic Diagnosis and Therapy Tianjin Medical University Cancer Institute and Hospital

Objective Real-time ultrasound elastography(US-E) is a helpful tool in diagnosing thyroid *** study aims to evaluate thyroid solid nodules,to establish the accuracy of US-E in providing information on the nature of these nodules,and to assess the clinical value of elasticity scores(ES) and strain ratio(SR) in differentiating thyroid solid nodules and to explore its distribution characteristics using pathological analysis as reference. Methods Traditional ultrasonography and US-E were performed on 131 thyroid solid nodules(99 benign ones and 32 malignant ones) in 120 patients(78 females and 41 males).Three radiologists evaluated the nodules based on a four-degree elasticity scoring *** nodules were classified according to the ES as soft(ES 1-2) or hard(ES 3-4).The SR was calculated online. Results The sensitivity and specificity of the ES for thyroid cancer diagnosis were 78%and 80%,*** values > 2.9 used as a standard to distinguish benign from malignant nodules had a sensitivity of 87%and a specificity of 92%.The SR of the benign lesions was 1.64±1.37,which was significantly different from that of malignant lesions,which was 4.96±2.13(Plignant nodules than those in benign ***-time US-E was a useful index in the differential diagnosis of thyroid solid *** can provide quantitative information on thyroid nodule characterization and improve diagnostic confidence.

关键词： ultrasound elastography elasticity scores strain ratio thyroid solid nodule

APF-GAN:Exploring asymmetric pre-training and fine-tuning strategy for conditional generative adversarial network

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Computational Visual Media 2024年第1期10卷 187-192页

作者： Yuxuan li lingfeng Yang xiang li College of Computer Science Nankai UniversityTianjinChina School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjingChina

The use of generative adversarial network(GAN)-based models for the conditional generation of image semantic segmentation has shown promising results in recent ***,there are still some limitations,including limited diversity of image style,distortion of detailed texture,unbalanced color tone,and lengthy training *** address these issues,we propose an asymmetric pre-training and fine-tuning(APF)-GAN model.

关键词： tuning network asymmetric

Thermal fatigue and wear of compacted graphite iron brake discs with various thermomechanical properties

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China Foundry 2024年第3期21卷 248-256页

作者： Gui-quan Wang Zhuo Xu Zhong-li liu xiang Chen Yan-xiang li School of Nuclear Equipment and Nuclear Engineering Yantai UniversityYantai 264005ShandongChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China

The increase in payload capacity of trucks has heightened the demand for cost-effective yet high performance brake *** this work,the thermal fatigue and wear of compacted graphite iron brake discs were investigated,aiming to provide an experimental foundation for achieving a balance between their thermal and mechanical *** graphite iron brake discs with different tensile strengths,macrohardnesses,specific heat capacities and thermal diffusion coefficients were produced by changing the proportion and strength of *** peak temperature,pressure load and friction coefficient of compacted graphite iron brake discs were analyzed through inertia friction *** morphology of thermal cracks and 3D profiles of the worn surfaces were also *** is found that the thermal fatigue of compacted graphite iron discs is determined by their thermal properties.A compacted graphite iron with the highest specific heat capacity and thermal diffusion coefficient exhibits optimal thermal fatigue *** of the matrix at low temperatures significantly weakens the function of alloy strengthening in hindering the propagation of thermal *** the reduced hardness,increasing the ferrite proportion can mitigate wear loss resulting from low disc temperatures and the absence of abrasive wear.

关键词： compacted graphite iron brake disc thermomechanical properties thermal fatigue wear

Auxiliary ball milling to prepare WS_(2)/graphene nanosheets composite for lithium-ion battery anode materials

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Tungsten 2024年第1期6卷 124-133页

作者： Yong-lin Wu Jia-Bin Hong Wei-Xu Zhong chun-xiang Wang Zhi-Feng li Sydorov Dmytro Jiangxi Provincial Key Laboratory of Power Batteries and Materials Jiangxi University of Science and TechnologyGanzhou 341000China Faculty of Materials Metallurgy and Chemistry Jiangxi University of Science and TechnologyGanzhou 341000China Institute of Bioorganic Chemistry and Petrochemistry National Academy of Sciences of UkraineKiev 02160Ukraine

A novel nano-WS_(2)/graphene nanosheets(GNSs)composite is obtained by ball milling with xylitol as auxiliary agent and hightemperature *** improves the shear force during ball milling and well overcomes the van der Waals interactions between the interlayer of graphite and WS_(2).Through high-temperature calcination,GNSs and WS_(2) nanosheets can form tight interface *** produced WS_(2)/GNSs composites can be used as anode materials for lithium-ion batteries,while maintaining a high reversible specific capacity of 705 mAh·g^(-1)with the capacity retention of 95%at a current density of 250 mA·g^(-1)after 200 cycles,mainly because WS_(2)/GNSs composites have a higher li^(+)diffusion coefficient of 2.2×10^(-9)cm^(2)·s^(-1)and a higher specific surface area of 70.10 m^(2)·g^(-1).As a result,the xylitol-assisted ball milling method designed in this work is suitable for extended preparation of peeling of two-dimensional layer materials into nanosheets.

关键词： lithium-ion battery Anode material WS_(2) Graphene nanosheets Auxiliary ball milling

Predict the evolution of mechanical property of Al-li alloys in a marine environment

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Defence Technology（防务技术） 2024年第1期31卷 557-566页

作者： Wei li lin xiang Guang Wu Hongli Si Jinyan Chen Yiming Jin Yan Su Jianquan Tao chunyang Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100036China Chongqing Innovation Center Beijing Institute of TechnologyChongqing400044China First Research Institute of the Ministry of Public Security for PR China Beijing100036China Southwest Technology and Engineering Research Institute Chongqing400039China

The ocean is one of the essential fields of national defense in the future,and more and more attention is paid to the lightweight research of Marine equipment and *** study it is to develop a Machine learning(ML)-based prediction method to study the evolution of the mechanical properties of Al-li alloys in the marine *** obtained the mechanical properties of Al-li alloy samples under uniaxial tensile deformation at different exposure times through Marine exposure *** obtained the strain evolution by digital image correlation(DIC).The strain field images are voxelized using 2D-Convolutional Neural Networks(CNN)autoencoders as input data for Long Short-Term Memory(LSTM)neural ***,the output data of LSTM neural networks combined with corrosion features were input into the Back Propagation(BP)neural network to predict the mechanical properties of Al-li *** main conclusions are as follows:*** variation law of mechanical properties of2297-T8 in the Marine atmosphere is *** the increase in outdoor exposure test time,the tensile elastic model of 2297-T8 changes slowly,within 10%,and the tensile yield stress changes significantly,with a maximum attenuation of 23.6%.*** prediction model can predict the strain evolution and mechanical response simultaneously with an error of less than 5%.*** study shows that a CNN/LSTM system based on machine learning can be built to capture the corrosion characteristics of Marine exposure *** results show that the relationship between corrosion characteristics and mechanical response can be predicted without considering the microstructure evolution of metal materials.

关键词： Marine environment Al-li alloy Machine learning Corrosion

Fabrication of micro-nano patterned materials mimicking the topological structure of extracellular matrix for biomedical applications

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Nano Research 2024年第5期17卷 4244-4258页

作者： Yifeng Nie Dong Han xiang li CAS Center for Excellence in Nanoscience National Center for Nanoscience and TechnologyBeijing 100190China School of Future Technology University of Chinese Academy of SciencesBeijing 100049China

With the advent of tissue engineering and biomedicine,the creation of extracellular matrix(ECM)biomaterials for in vitro applications has become a prominent and promising *** ECM materials provide physical,biochemical,and mechanical properties that guide cellular behaviors,such as proliferation,differentiation,migration,and *** micro-and nano-patterned materials have a unique surface topology and low energy replication process that directly affect cellular biological behaviors at the interface,the fabrication of micro-nano pattern biomaterials and the regulation of surface physical and chemical properties are of great significance in the fields of cell regulation,tissue engineering,and regenerative ***,we provide a comprehensive review of the progress in the fabrication and application of patterned materials based on the coupling of mechanical action at the micro-and nano-meter scale,including photolithography,micro-contact printing,electron beam lithography,electrospinning,and 3D printing ***,a summary of the fabrication process,underlying principles,as well as the advantages and disadvantages of various technologies are *** also discuss the influence of material properties on the fabrication of micro-and nano-patterns.

关键词： micro/nano hybrid materials patterning fabrication techniques extracellular matrix substrate-cell interaction biomedical engineering

A Parameter Adaptive Method for Image Smoothing

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Tsinghua Science and Technology 2024年第4期29卷 1138-1151页

作者： Suwei Wang xiang Ma Xuemei li School of Computer Science and Technology Shandong UniversityJinan 250101China School of Software Shandong UniversityJinan 250101China

Edge is the key information in the process of image smoothing. Some edges, especially the weak edges, are difficult to maintain, which result in the local area being over-smoothed. For the protection of weak edges, we propose an image smoothing algorithm based on global sparse structure and parameter adaptation. The algorithm decomposes the image into high frequency and low frequency part based on global sparse structure. The low frequency part contains less texture information which is relatively easy to smoothen. The high frequency part is more sensitive to edge information so it is more suitable for the selection of smoothing parameters. To reduce the computational complexity and improve the effect, we propose a bicubic polynomial fitting method to fit all the sample values into a surface. Finally, we use Alternating Direction Method of Multipliers (ADMM) to unify the whole algorithm and obtain the smoothed results by iterative optimization. Compared with traditional methods and deep learning methods, as well as the application tasks of edge extraction, image abstraction, pseudo-boundary removal, and image enhancement, it shows that our algorithm can preserve the local weak edge of the image more effectively, and the visual effect of smoothed results is better.

关键词： image smoothing parameter adaptation bicubic interpolation polynomial fitting

The dynamics beamline at SSRF

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Nuclear Science and Techniques 2024年第9期35卷 56-67页

作者： Zhen liu li-Hua Wang Yong Jiang Ya-Jun Tong Hua-chun Zhu Te Ji Min Chen Zheng Jiang xiang-Jun Wei Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China ShanghaiTech University Shanghai 201210China

The dynamics beamline(D-line),which combines synchrotron radiation infrared spectroscopy(SR-IR)and energy-disper-sive X-ray absorption spectroscopy(ED-XAS),is the first beamline in the world to realize concurrent ED-XAS and SR-IR measurements at the same sample position on a millisecond time-resolved *** combined technique is effective for investigating rapid structural changes in atoms,electrons,and molecules in complicated disorder systems,such as those used in physics,chemistry,materials science,and extreme ***,ED-XAS and SR-IR can be used independently in the two branches of the *** ED-XAS branch is the first ED-XAS beamline in China,which uses a tapered undulator light source and can achieve approximately 2.5×10^(12)photons/s·300 eV BW@7.2 keV at the sample *** exchange-able polychromator operating in the Bragg-reflection or Laue-transmission configuration is used in different energy ranges to satisfy the requirements for beam size and energy *** focused beam size is approximately 3.5μm(H)×21.5μm(V),and the X-ray energy range is 5–25 *** one-and two-dimensional position-sensitive detectors with frame rates of up to 400 kHz enables time resolutions of tens of microseconds to be *** distinctive techniques,such as the concurrent measurement of in situ ED-XAS and infrared spectroscopy,time-resolved ED-XAS,high-pressure ED-XAS,XMCD,and pump-probe ED-XAS,can be applied to achieve different scientific goals.

关键词： ED-XAS SR-IR Time-resolved D-line SSRF