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Chinese Journal of Polymer Science 2024年第10期42卷 1566-1577,I0014页

作者： Shu-Juan Wang Lu Wang Hong-Zhe Su zhi-cheng Wu Qiao-Gen zhang Wei Fan Xin-Li Jing School of Chemistry Joint Innovation Center of Thermal Protection MaterialsXi’an Jiaotong UniversityXi’an710049China School of Electrical Engineering Xi’an Jiaotong UniversityXi’an710049China School of Textile Science and Engineering Xi’an Polytechnic UniversityXi’an710048China

Polydimethylsiloxane(PDMS)is an electron-withdrawing material that is widely used in triboelectric nanogenerators(TENGs).However,PDMS has poor mechanical properties after curing and is easily damaged when subjected to long-term ***,the long-term stable operation of TENGs under mechanical deformation cannot be *** this work,multiple hydrogen bonds and aromatic disulfide bonds were introduced into PDMS *** elastomers exhibited high toughness(a tensile strength of 1.91 MPa and an elongation at break of 340%),good recyclability,and room-temperature self-healing properties(healing efficiency of 96.4%in 24 h).Recyclable sandwich-like triboelectric nanogenerators with excellent electrical output performance(13.5 V)and room-temperature self-healing performance(24 h,98%recovery of self-generating performance)were prepared by utilizing the hydrogen bonding between the PDMS elastomer and *** work reported herein offers theoretical guidance and a compelling strategy for developing high-performance TENG negative friction layers.

关键词： Polydimethylsiloxane Aromatic disulfide bonds Hydrogen bonds Room temperature self-healing Triboelectric nanogenerator

Deciphering and integrating invariants for neural operator learning with various physical mechanisms

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National Science Review 2024年第4期11卷 111-122页

作者： Rui zhang Qi Meng zhi-Ming Ma Academy of Mathematics and Systems Science Chinese Academy of Sciences(CAS) Microsoft Research

Neural operators have been explored as surrogate models for simulating physical systems to overcome the limitations of traditional partial differential equation(PDE) solvers. However, most existing operator learning methods assume that the data originate from a single physical mechanism, limiting their applicability and performance in more realistic scenarios. To this end, we propose the physical invariant attention neural operator(PIANO) to decipher and integrate the physical invariants for operator learning from the PDE series with various physical mechanisms. PIANO employs self-supervised learning to extract physical knowledge and attention mechanisms to integrate them into dynamic convolutional *** to existing techniques, PIANO can reduce the relative error by 13.6%–82.2% on PDE forecasting tasks across varying coefficients, forces or boundary conditions. Additionally, varied downstream tasks reveal that the PI embeddings deciphered by PIANO align well with the underlying invariants in the PDE systems, verifying the physical significance of PIANO.

关键词： neural operator PDE solver contrastive learning physical invariants

Dual-curvilinear beam enabled tunable manipulation of high-and low-refractive-index particles

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Photonics Research 2024年第7期12卷 1427-1436页

作者： ZHENG YUAN CHENCHEN zhang YUAN GAO WENXIANG YAN XIAN LONG zhi-cheng REN XI-LIN WANG JIANPING DING HUI-TIAN WANG National Laboratory of Solid State Microstructures and School of Physics Nanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China Collaborative Innovation Center of Solid-State Lighting and Energy-Saving Electronics Nanjing 210093China

We present an innovative approach for the simultaneous agile manipulation of high-refractive-index(HRI) and low-refractive-index(LRI) particles. Our method involves introducing a dual-curvilinear optical vortex beam(DC-OVB) generated by superimposing a pair of curved beams: HRI and LRI particles are controlled by the bright curve and the dark channel between the two curves, respectively. The proposed DC-OVB provides customizable motion paths and velocities for both LRI and HRI particles. Each curve of the DC-OVB can support a distinct orbital flow density(OFD), enabling the application of torques to HRI and LRI particles, guiding them to orbit along specified trajectories and prompting them to execute various curvilinear motions simultaneously,including curvilinear movement, revolution, and rotation.

关键词： tunable refractive beam

Perforated gastric ulcer causing mediastinal emphysema: A case report

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World Journal of Clinical Cases 2024年第4期12卷 859-864页

作者： zhi-cheng Dai Xun-Wu Gui Feng-He Yang Hao-Yuan zhang Wen-Feng zhang Department of General Surgery Mengcheng County First People's HospitalMengcheng 233500Anhui ProvinceChina Department of Medical Imaging Mengcheng County First People's HospitalMengcheng 233500Anhui ProvinceChina

BACKGROUND Mediastinal emphysema is a condition in which air enters the mediastinum between the connective tissue spaces within the pleura for a variety of *** can be spontaneous or secondary to chest trauma,esophageal perforation,medi-cally induced factors,*** common symptoms are chest pain,tightness in the chest,and respiratory *** mediastinal emphysema patients have mild symptoms,but severe mediastinal emphysema can cause respiratory and circulatory failure,resulting in serious *** SUMMARY A 75-year-old man,living alone,presented with sudden onset of severe epigastric pain with chest tightness after drinking *** to the remoteness of his residence and lack of neighbors,the patient was found by his nephew and brought to the hospital the next morning after the disease *** tomography(CT)showed free gas in the abdominal cavity,mediastinal emph-ysema,and subcutaneous *** gastrointestinal angiography showed that the esophageal mucosa was intact and the gastric antrum was ***,we chose to perform open gastric perforation repair on the patient under thoracic epidural anesthesia combined with intravenous *** operative incision of the muscle layer of the patient's abdominal wall was made,and a large amount of subperitoneal gas was *** a continued incision of the peritoneum revealed the presence of a perforation of approx-imately 0.5 cm in the gastric antrum,which we repaired after pathological ***,the patient received high-flow oxygen and cough *** CT was performed on the first and sixth postoperative days,and the mediastinal and subcutaneous gas was gradually *** After gastric perforation,a large amount of free gas in the abdominal cavity can reach the mediastinum through the loose connective tissue at the esophageal hiatus of the diaphragm,and upper gastrointestinal angiography can clarify the site of *** pat

关键词： Gastric ulcer Perforated Mediastinal emphysema Case report

SNR-adaptive deep joint source-channel coding scheme for image semantic transmission with convolutional block attention module

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The Journal of China Universities of Posts and Telecommunications 2024年第1期31卷 1-11页

作者： Yang Yujia Liu Yiming zhang Wenjia zhang zhi State Key Laboratory of Networking and Switch Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

With the development of deep learning(DL),joint source-channel coding(JSCC)solutions for end-to-end transmission have gained a lot of *** deep JSCC schemes support dynamically adjusting the rate according to different channel conditions during transmission,enhancing robustness in dynamic wireless ***,most of the existing adaptive JSCC schemes only consider different channel conditions,ignoring the different feature importance in the image processing and *** uniform compression of different features in the image may result in the compromise of critical image details,particularly in low signal-to-noise ratio(SNR)*** address the above issues,in this paper,a dual attention mechanism is introduced and an SNR-adaptive deep JSCC mechanism with a convolutional block attention module(CBAM)is proposed,in which matrix operations are applied to features in spatial and channel dimensions *** proposed solution concatenates the pooling feature with the SNR level and passes it sequentially through the channel attention network and spatial attention network to obtain the importance evaluation *** show that the proposed solution outperforms other baseline schemes in terms of peak SNR(PSNR)and structural similarity(SSIM),particularly in low SNR scenarios or when dealing with complex image content.

关键词： semantic communication joint source-channel coding image transmission

Epimedin B exhibits pigmentation by increasing tyrosinase family proteins expression,activity,and stability

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Journal of Pharmaceutical Analysis 2024年第1期14卷 69-85页

作者： Chen Hong Yifan zhang Lili Yang Haoyang Xu Kang cheng zhi Lv Kaixian Chen Yiming Li Huali Wu Department of TCM Chemistry School of PharmacyShanghai University of Traditional Chinese MedicineShanghai200000China Department of Dermatology Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese MedicineShanghai200000China International Education College Shanghai University of Traditional Chinese MedicineShanghai200000China Shanghai Inoherb Cosmetics Co. Ltd.Shanghai200000China

Epimedin B(EB)is one of the main flavonoid ingredients present in Epimedium brevicornum Maxim.,a traditional herb widely used in *** previous study showed that EB was a stronger inducer of melanogenesis and an activator of tyrosinase(TYR).However,the role of EB in melanogenesis and the mechanism underlying the regulation remain ***,as an extension to our previous investigation,we provide comprehensive evidence of EB-induced pigmentation in vivo and in vitro and elucidate the melanogenesis mechanism by assessing its effects on the TYR family of proteins(TYRs)in terms of expression,activity,and *** results showed that EB increased TYRs expression through microphthalmia-associated transcription factor-mediated p-Akt(referred to as protein kinase B(PKB))/glycogen synthase kinase 3β(GSK3β)/β-catenin,p-p70 S6 kinase cascades,and protein 38(p38)/mitogen-activated protein(MAP)kinase(MAPK)and extracellular regulated protein kinases(ERK)/MAPK pathways,after which EB increased the number of melanosomes and promoted their maturation for melanogenesis in melanoma cells and human primary melanocytes/skin ***,EB exerted repigmentation by stimulating TYR activity in hydroquinone-and N-phenylthiourea-induced TYR inhibitive models,including melanoma cells,zebrafish,and ***,EB ameliorated monobenzone-induced depigmentation in vitro and in vivo through the enhancement of TYRs stability by inhibiting TYR misfolding,TYR-related protein 1 formation,and retention in the endoplasmic reticulum and then by downregulating the ubiquitination and proteolysis *** data conclude that EB can target TYRs and alter their expression,activity,and stability,thus stimulating their pigmentation function,which might provide a novel rational strategy for hypopigmentation treatment in the pharmaceutical and cosmetic industries.

关键词： Epimedin B Melanosome Tyrosinase Melanogenesis

A Local Tb Theorem for Square Functions and Parabolic Layer Potentials

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1941-1966页

作者： zhi Dan WANG Guo Ming zhang School of Physical and Mathematical Sciences Nanjing Tech UniversityNanjing 211816P.R.China Frontiers Science Center for Nonlinear Expectations Ministry of EductionResearch Center for Mathematics and Interdisciplinary SciencesShandong UniversityQingdao266237P.R.China

In this paper,we give a locally parabolic version of Tb theorem for a class of vector-valued operators with off-diagonal decay in L^(2) and certain quasi-orthogonality on a subspace of L^(2),in which the testing functions themselves are also *** an application,we establish the boundedness of layer potentials related to parabolic operators in divergence form,defined in the upper half-space Rn+2+:={(x,t,λ)∈R^(n+1)×(0,∞)},with uniformly complex elliptic,L^(∞),t,λ-independent coefficients,and satisfying the De Giorgi/Nash estimates.

关键词： Local Tb theorems Calderon-Littlewood-Paley family Parabolic layer potentials Carleson measure estimates

Bioinspired 3D flexible devices and functional systems

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National Science Review 2024年第3期11卷 271-295页

作者： Xu cheng zhangming Shen Yihui zhang Applied Mechanics Laboratory Department of Engineering Mechanics Tsinghua University Laboratory of Flexible Electronics Technology Tsinghua University

Flexible devices and functional systems with elaborated three-dimensional(3D) architectures can endow better mechanical/electrical performances, more design freedom, and unique functionalities, when compared to their two-dimensional(2D) counterparts. Such 3D flexible devices/systems are rapidly evolving in three primary directions, including the miniaturization, the increasingly merged physical/artificial intelligence and the enhanced adaptability and capabilities of heterogeneous *** challenges exist in this emerging research area, such as relatively poor controllability in the locomotion of soft robotic systems, mismatch of bioelectronic interfaces, and signal coupling in multi-parameter sensing. By virtue of long-time–optimized materials, structures and processes, natural organisms provide rich sources of inspiration to address these challenges, enabling the design and manufacture of many bioinspired 3D flexible devices/systems. In this Review, we focus on bioinspired 3D flexible devices and functional systems, and summarize their representative design concepts, manufacturing methods, principles of structure-function relationship and broad-ranging applications. Discussions on existing challenges, potential solutions and future opportunities are also provided to usher in further research efforts toward realizing bioinspired 3D flexible devices/systems with precisely programmed shapes,enhanced mechanical/electrical performances, and high-level physical/artificial intelligence.

关键词： bioinspired designs biomimetic 3D structures 3D flexible electronics 3D functional systems direct 3D manufacture 2D-to-3D assembly

Deflagration and detonation induced by shock wave focusing at different Mach numbers

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Chinese Journal of Aeronautics 2024年第2期37卷 249-258页

作者： Zezhong YANG Jun cheng Bo zhang School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China

Shock wave focusing is an effective way to create a hot spot or a high-pressure and hightemperature region at a certain place,showing its unique usage in detonation initiation,which is beneficial for the development of detonation-based *** flame propagation behavior after the autoignition induced by shock wave focusing is crucial to the formation and self-sustaining of the detonation *** this study,wedge reflectors with two different angles(60°and 90°)and a planar reflector are employed,and the Mach number of incident shock waves ranging from 2.0 to 2.8 is utilized to trigger different flame propagation *** pressure transducers and the high-speed schlieren imaging system are both employed to investigate the shock-shock collision and ignition *** results reveal a total of four flame propagation modes:deflagration,DDT(Deflagration-to-Detonation Transition),unsteady detonation,and direct *** detonation wave formed in the DDT and unsteady detonation mode is only approximately 75%-85%of the Chapman-Jouguet(C-J)speed;meanwhile,the directly induced detonation wave speed is close to the C-J *** waves,which are strong evidence for the existence of detonation waves,are discovered in *** usage of wedge reflectors significantly reduces the initial pressure difference ratio needed for direct detonation *** also provide a practical method for differentiating between detonation and deflagration modes,which involves contrasting the speed of the reflected shock wave with the speed of the theoretically nonreactive reflected shock *** findings should serve as a reference for the detonation initiation technique in advanced detonation propulsion engines.

关键词： Deflagration Detonation Hydrogen Ignition Shock wave focusing

Nutrient transport following water transfer through the world's largest water diversion channel

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Journal of Environmental Sciences 2024年第1期135卷 703-714页

作者： Yuanhui cheng Hong zhang Wei Yin State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085 China Changjiang Water Resources Protection Institute Wuhan 430051China University of Chinese Academy of Sciences Beijing 100049China

Nutrient levels in the artificial channel constructed for the Middle Route Project are significant indicators of water quality safety and aquatic ecological integrity for this large,interbasin ***,the distribution and transport of nutrients along the channel were poorly *** on a time-series dataset as well as mass balance and material flow analysis methods,the water and nutrient transport fluxes in the Middle Route of the South-to-North Water Diversion Project were identified in this *** results indicate that the nutrient concentrations varied considerably with time,but there was no significant difference among the 30 stations of the main *** temperature difference was the major factor in the large fluctuations of water quality indicators over *** nutrient loadings varied with the water volume outputs from the main channel to the waterreceiving *** deposition was an important source of nutrients in the main channel,accounting for 9.13%,20.6%,and 0.635%of the nitrogen,phosphorus,and sulfur input from the Danjiangkou Reservoir,*** 2021,a net accumulation of 988 tons of N,29 tons of P,and 2,540 tons of S,respectively,were present in the main *** increase of these external and internal nutrient loadings would cause water quality fluctuation and deterioration in some local sections of the main *** study quantified the spatial and temporal patterns of nutrient transport in the Middle Route and revealed the ecological effects on the aquatic environment,assisting authorities on the project to develop effective water conservation strategies.

关键词： Nutrient transport Spatiotemporal patterns The Middle Route The South-to-North Diversion Project Hydro-ecological effects Water-receiving cities