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Dynamic Sulfur-Rich Polymers from Elemental Sulfur and Epoxides

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Chinese Journal of Polymer Science 2024年第10期42卷 1479-1487,I0010页

作者： Ke-Xiang Chen Chen-Hui Cui Zhen Li Ting Xu Hao-qing Teng zhi-Yuan he Yin-Zhou Guo Xiao-qing Ming zhi-Shen Ge Yan-Feng Zhang Tie-Jun Wang School of Chemistry Engineering Research Center of Energy Storage Materials and DevicesMinistry of EducationXi’an Jiaotong UniversityXi’an710049China State Key Lab for Strength and Vibration of Mechanical Structures Department of Engineering MechanicsXi’an Jiaotong UniversityXi’an710049China

Sulfur-containing dynamic polymers had attracted significant attention due to their unique chemical structures with high *** sulfur, an inexpensive industrial waste product, to synthesize dynamic polysulfide polymers through reverse vulcanization has been a notable approach. However, this method required high temperatures and resulted in the release of unpleasant oders. In this study, we presented a robust method for the preparation of sulfur-rich polymers with dynamic polysulfide bonds from elemental sulfur and inexpensive epoxide monomers via a one-pot strategy at the mild room temperature. Different types of polysulfide molecules and polymers were synthesized by reacting various epoxide compounds with sulfur, along with the investigation of their structures and dynamic behaviors. It was noteworthy that the obatined polymers prepared from m-(2,3-epoxypropoxy)-N,N-bis(2,3-epoxypropyl)aniline and elemental sulfur exhibit multiple dynamic behaviors, including polysulfide metathesis and polysulfide-thiol exchange, enabling their rapid stress relaxation, self-healing, reprocessing and degradable properties of the cross-linked polymer. More importantly, the hydroxyl groups at the side chains from epoxide ring opening exhibited potential transesterification. This work provided a facile strategy for designing dynamic sulfur-rich polymers via a mild synthesis route.

关键词： Elemental sulfur Sulfur-containing polymer Dynamic covalent bond Dynamic polymer

Detachment-Independent Cationic-Dipeptide Beacons:Reduced False-Negative Signal and Accelerated Fluorescent Lighting in Cell Imaging

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Journal of Analysis and Testing 2022年第1期6卷 19-26页

作者： Guang-Wei Fu Guo-Yan Luo Xiao-Xuan Li Zhen Zou Yan-Li Lei zhi-he qing Jue-Wen Liu Rong-Hua Yang Hunan Provincial Key Laboratory of Cytochemistry School of Chemistry and Chemical EngineeringChangsha University of Science and TechnologyChangsha 410114China College of Chemistry and Chemical Engineering Hunan Normal UniversityChangsha 410081China Department of Chemistry Waterloo Institute for NanotechnologyUniversity of WaterlooWaterlooON N2L 3G1Canada

Nanocarriers have been developed to deliver DNA probes into cells for imaging analysis and improving their nuclease ***,we found obvious lowered sensitivity and even false-negative results in the traditional DNA detachment-dependent fluorescent lighting ***,we developed a detachment-independent fluorescent lighting mechanism integrated with cationic dipeptide nanoparticles(CDNs).CDNs displayed little quenching effect on fluorophores labeled on probes and improved the nuclease resistance of *** contrast to the traditional beacon,the fluorescence lighting was significantly accelerated without the need of desorption of the recognition products from the nanosurface,avoiding false-negative results from non-specific conformational *** work will open up new thoughts to improve the sensing performance of DNA probes in cell imaging,such as speed and sensitivity.

关键词： Cationic dipeptide nanoparticles DNA probe False-negative signal Fluorescence Cell imaging

Prediction of contact resistance of electrical contact wear using different machine learning algorithms

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Friction 2024年第6期12卷 1250-1271页

作者： Zhen-bing CAI Chun-lin LI Lei YOU Xu-dong CheN Li-ping he Zhong-qing CAO zhi-nan ZHANG Tribology Research Institute Southwest Jiaotong UniversityChengdu 610031China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

H62 brass material is one of the important materials in the process of electrical energy transmission and signal transmission,and has excellent performance in all *** the wear behavior of electrical contact pairs is particularly complex when they are in service,we evaluated the effects of load,sliding velocity,displacement amplitude,current intensity,and surface roughness on the changes in contact *** learning(ML)algorithms were used to predict the electrical contact performance of different factors after wear to determine the correlation between different factors and contact *** forest(RF),support vector regression(SVR)and BP neural network(BPNN)algorithms were used to establish RF,SVR and BPNN models,respectively,and the experimental data were trained and *** was proved that BP neural network model could better predict the stable mean resistance of H62 brass alloy after *** analysis shows that the load and current have great influence on the predicted electrical contact *** wear behavior of electrical contacts is influenced by factors such as load,sliding speed,displacement amplitude,current intensity,and surface roughness during *** learning algorithms can predict the electrical contact performance after wear caused by these *** results indicate that an increase in load,current,and surface roughness leads to a decrease in stable mean resistance,while an increase in displacement amplitude and frequency results in an increase in stable mean resistance,leading to a decline in electrical contact *** reduce testing time and costs and quickly obtain the electrical contact performance of H62 brass alloy after wear caused by different factors,three algorithms(random forest(RF),support vector regression(SVR),and BP neural network(BPNN))were used to train and test experimental results,resulting in a machine learning model suitable for predicting the stable mean

关键词： electrical contact wear contact resistance machine learning(ML) neural network

Working condition recognition of sucker rod pumping system based on 4-segment time-frequency signature matrix and deep learning

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Petroleum Science 2024年第1期21卷 641-653页

作者： Yun-Peng he Hai-Bo Cheng Peng Zeng Chuan-zhi Zang qing-Wei Dong Guang-Xi Wan Xiao-Ting Dong State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016LiaoningChina Key Laboratory of Networked Control Systems Chinese Academy of SciencesShenyang 110016LiaoningChina Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169LiaoningChina University of Chinese Academy of Sciences Beijing100049China School of Artifcial Intelligence Shenyang University of TechnologyShenyang 110870LiaoningChina

High-precision and real-time diagnosis of sucker rod pumping system(SRPS)is important for quickly mastering oil well *** learning-based method for classifying the dynamometer card(DC)of oil wells is an efficient diagnosis ***,the input of the DC as a two-dimensional image into the deep learning framework suffers from low feature utilization and high computational ***,different SRPSs in an oil field have various system parameters,and the same SRPS generates different DCs at different ***,there is heterogeneity in field data,which can dramatically impair the diagnostic *** solve the above problems,a working condition recognition method based on 4-segment time-frequency signature matrix(4S-TFSM)and deep learning is presented in this ***,the 4-segment time-frequency signature(4S-TFS)method that can reduce the computing power requirements is proposed for feature extraction of DC ***,the 4S-TFSM is constructed by relative normalization and matrix calculation to synthesize the features of multiple data and solve the problem of data ***,a convolutional neural network(CNN),one of the deep learning frameworks,is used to determine the functioning conditions based on the *** on field data verify that the proposed diagnostic method based on 4S-TFSM and CNN(4S-TFSM-CNN)can significantly improve the accuracy of working condition recognition with lower computational *** the best of our knowledge,this is the first work to discuss the effect of data heterogeneity on the working condition recognition performance of SRPS.

关键词： Sucker-rod pumping system Dynamometer card Working condition recognition Deep learning Time-frequency signature Time-frequency signature matrix

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一类区间矩阵特征值界的性质

华东理工大学学报（自然科学版） 2008年第6期34卷 917-920,936页

作者：袁泉何志庆华东理工大学数学系上海200237

对称三对角区间矩阵特征值界的计算在工程领域和力学问题中具有很重要的应用价值。证明了对满足一定条件的对称三对角区间矩阵,区间特征值的上下界必定在矩阵元素区间的端点上取到。本文的结果为计算此类对称三对角区间矩阵特征值界的... 详细信息

对称三对角区间矩阵特征值界的计算在工程领域和力学问题中具有很重要的应用价值。证明了对满足一定条件的对称三对角区间矩阵,区间特征值的上下界必定在矩阵元素区间的端点上取到。本文的结果为计算此类对称三对角区间矩阵特征值界的方法提供了良好的判据。

关键词：特征值界对称三对角矩阵区间矩阵区间分析

Classification of complete 3-dimensional self-shrinkers in the Euclidean space R^(4)

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Science China Mathematics 2024年第4期67卷 873-882页

作者： qing-Ming Cheng zhi Li Guoxin Wei Department of Applied Mathematics Faculty of ScienceFukuoka UniversityFukuoka 814-0180Japan College of Mathematics and Information Science Henan Normal UniversityXinxiang 453007China School of Mathematical Sciences South China Normal UniversityGuangzhou 510631China

In this paper,we completely classify 3-dimensional complete self-shrinkers with the constant norm S of the second fundamental form and the constant f3in the Euclidean space R^(4),where hij’s are components of the sec... 详细信息

关键词： mean curvature ow self-shrinker the generalized maximum principle

Switching,explosion,and chaos of multi-wavelength soliton states in ultrafast fiber lasers

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 82-90页

作者： zhi-Zeng Si Yue-Yue Wang Chao-qing Dai College of Optical Mechanical and Electrical EngineeringZhejiang A&F UniversityLin’an 311300China

Because of the complexity and difficulty of realizing a multi-wavelength soliton state,reports on its internal dynamic characteristics are *** this study,the switching and periodic soliton explosion processes of the multi-wavelength soliton state in a negative dispersion passively mode-locked fiber laser are *** generation of the multi-wavelength soliton state undergoes the process of noise,oscillation,and stable mode-locking,and the splitting and annihilation of solitons with different group velocities directly impact the generation and disappearance of three *** and negative dispersion lead to different group velocities of *** presence and displacement of solitons with different group velocities cause soliton collisions,which lead to soliton explosions.A soliton experiences relative phase oscillation,chaos,and oscillation,as well as convergence and separation before and after an *** an increase in parameters related to pump power,single-soliton oscillation,multi-wavelength solitons,and chaos are found in experiments and simulations,proving the relevance and reliability between simulation and experimental *** work promotes the dynamical study of multi-soliton collisions in nonlinear science and the development of chaos theory in multi-comb lasers.

关键词： multi-wavelength fiber laser soliton explosion chaos state switching real-time dynamics

A generalized deep neural network approach for improving resolution of fluorescence microscopy images

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Journal of Innovative Optical health Sciences 2024年第6期17卷 53-65页

作者： Zichen Jin qing he Yang Liu Kaige Wang State Key Laboratory of Cultivation Base for Photoelectric Technology and Functional Materials National Center for International Research of Photoelectric Technology&Nano-Functional Materials and ApplicationKey Laboratory of Photoelectronic Technology of Shaanxi ProvinceInstitute of Photonics and Photon-TechnologyNorthwest UniversityXi'an 710127P.R.China

Deep learning is capable of greatly promoting the progress of super-resolution imaging technology in terms of imaging and reconstruction speed,imaging resolution,and *** paper proposes a deep neural network based on a generative adversarial network(GAN).The generator employs a U-Net-based network,which integrates Dense Net for the downsampling *** proposed method has excellent properties,for example,the network model is trained with several different datasets of biological structures;the trained model can improve the imaging resolution of different microscopy imaging modalities such as confocal imaging and wide-field imaging;and the model demonstrates a generalized ability to improve the resolution of different biological structures even out of the *** addition,experimental results showed that the method improved the resolution of caveolin-coated pits(CCPs)structures from 264 nm to 138 nm,a 1.91-fold increase,and nearly doubled the resolution of DNA molecules imaged while being transported through microfluidic channels.

关键词： Deep learning super-resolution imaging generalized model framework generation adversarial networks image reconstruction.

Intermediate phase-assisted growth of CsPbBr_(3) for high performance of carbon-based perovskite solar cells

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Rare Metals 2024年第5期43卷 2222-2229页

作者： Bo-Yan Liu he-Ming Yang Yu-Dong Zuo zhi-Hao Tao Jun-Chun Li Ya-Jing Chang Guo-qing Tong Yang Jiang School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China State Key Laboratory of Pulsed Power Laser Technology National University of Defense TechnologyHefei 230037China

CsPbBr_(3)inorganic perovskites have been regarded as the promising materials in the field of photo-voltaics because of the high tolerance against *** high energy barrier of phase transition from lead bromide(PbBr_(2))to CsPbBr_(3)perovskite and low solubility of perovskite in organic solvent impede the further improvement of device performance in terms of CsPbBr_(3)solar ***,an intermediate phase-assisted growth of CsPbBr_(3)perovskite was proposed by introducing tetraphenylphosphonium bromide(TPPB)as *** TPPB is expected to react with PbBr_(2)in organic solvent to form an intermediate phase of[***]-PbBr_(2),which not only effectively improves the crystallinity of PbBr2 crystals,but also greatly reduces the phase transition energy barrier,leading to uniform and compact CsPbBr_(3)perovskite films with large grain size and high *** combination with carbon electrode,the CsPbBr_(3)solar cells yield a champion device performance of 9.57%in comparison of pristine CsPbBr_(3)solar cells showing a low efficiency of 8.17%.Furthermore,the intermediate phaseassisted growth of CsPbBr_(3)-based solar cells displays an outstanding storage over720 h.

关键词： CsPbBr_(3) Perovskite solar cells Carbon electrode Hole transport layer free Intermediate phase