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Structure regulating of metal clusters in carbonized metallic organic frameworks for high-efficient microwave absorption via tuning interaction strength between metals and ligands

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Nano Research 2024年第3期17卷 1699-1709页

作者： Chang Sun Kun-Yan Zhao Ming-Lu Huang cheng-Long Luo xu-dong chen Ming Wang School of Chemistry and Chemical Engineering Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function ManufacturingSouthwest UniversityChongqing 400715China Jieyang Branch of Chemistry and Chemical Engineering Guangdong Laboratory(Rongjiang Laboratory) Jieyang 515200China

Carbonized metallic organic frameworks(CMOF)have been attracting attention in microwave absorption(MA)research area because of their diverse structures,tunable compositions,and rich ***,structure regulation on metal clusters in CMOF is achieved by tuning the interaction strength between metals and ligands to enhance microwave absorption *** to relatively weak interaction among copper cations and ligands,copper nanoclusters(CuNC)can be uniformly formed and embedded within the cobalt/zinc(Co/Zn)***,copper cations are added to the Co/Zn bimetallic zeolitic imidazolate frameworks(ZIFs).Secondly,the CMOF composite particles with CuNCs(CuNCs/CoZn-CMOF)were developed by a pyrolysis *** CuNCs/CoZn-CMOF with an appropriate amount of CuNCs can harmonize both dielectric and magnetic *** a result,the minimum reflection loss(RLmin)reaches–45.1 dB at a matching thickness of 2.30 mm and the effective absorption bandwidth(EAB)is 8.80 GHz at a thickness of 3.10 *** broadband response to electromagnetic waves is attributed to interfacial polarization at CuNCs surface and heterogeneous interfaces,impedance matching and multiple scattering of electromagnetic *** study provides a feasible method to develop CMOF microwave absorption materials with high EAB values.

关键词： heterogeneous interface carbonized metallic organic frameworks microwave absorption interfacial polarization

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

The Fang’s hypoglycemic formula improves insulin resistance in type 2 diabetes mellitus by regulating mitochondrial autophagy

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Integrative Medicine Discovery 2024年第16期8卷 1-7页

作者： Jia Zhu xu-dong chen Jie Zhao Department of Respiratory Jiaxing Hospital of Traditional Chinese MedicineJiaxing 314001China Department of Endocrinology Jiaxing Hospital of Traditional Chinese MedicineJiaxing 314001China Department of Endocrinology The First Affiliated Hospital of Yunnan University of Chinese MedicineKunming 650500China

Background:To investigate the pharmacological effects of Fangshi Jiangtang decoction(FSJT)on type 2 diabetes mellitus(T2DM)model rats and explore its mechanism of action from the perspective of mitochondrial ***:Sixty Sprague Dawley rats were randomly divided into six groups after one week of adaptive feeding:Control group,T2DM model group,metformin group(0.2 g/kg by gavage),and FSJT low,medium,and high dose groups(9.5,19,38 g/kg by gavage).Except for the Control group,the other five groups were given a high-fat *** treatment lasted for 8 weeks,and blood glucose levels were measured *** weeks later,blood samples were collected from the rats,and serum was separated for the determination of HbA1c,oral glucose tolerance test,and homeostatic model assessment for insulin resistance *** pancreas of the rats was collected,weighed,and *** same part of the pancreas was used for *** were used to detect triglycerides,total cholesterol,interleukin-1β,interleukin-6,tumor necrosis factor-α,malondialdehyde,glutathione peroxidase,and superoxide dismutase in pancreatic tissue to assess the effects of FSJT on inflammation and oxidative stress in T2DM *** blot analysis was performed to detect the expression of VDAC1,TOM20,COXⅣ,PINK1,Parkin,beclin1,light chain 3,and selective autophagy adaptor protein P62 to evaluate the effects of FSJT on mitochondrial autophagy in T2DM model ***:Compared with the T2DM model group,FSJT intervention significantly reduced blood glucose,HbA1c,oral glucose tolerance test,and homeostatic model assessment for insulin resistance index in T2DM model rats,alleviated pancreatic tissue lesions,reduced levels of total cholesterol,triglycerides,interleukin-1β,interleukin-6,tumor necrosis factor-α,and malondialdehyde,increased glutathione peroxidase and superoxide dismutase activities,downregulated the expression of VDAC1,TOM20,COXⅣ,and P62 proteins,and upregulated the expression of PINK1,

关键词： Fangshi Jiangtang decoction type 2 diabetes mellitus mitochondrial autophagy oxidative stress

Side-Chain-Type Polyimide-Cu Complexes with Suppressed Activation Energy of Relaxation for Advanced High-Temperature Capacitor

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Chinese Journal of Polymer Science 2024年第8期42卷 1038-1048页

作者： Bai-Yang Zhou Ze-Tong Ma Shi-Long Zhong Zhen-Jie Huang Qi Guo Deng-Chong Feng Zhong-Ke Yuan Shao-Lin Lu Yu-Zhao Yang cheng Wang Ding-Shan Yu xu-dong chen Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education Guangdong Engineering Technology Research Centre for High Performance Organic and Polymer Photoelectric Functional FilmsSchool of ChemistrySun Yat-sen UniversityGuangzhou 510275China School of Chemical Engineering and Light Industry Guangdong University of TechnologyGuangzhou 510006China Guangdong Provincial Laboratory of Chemistry and Fine Chemical Industry Jieyang Centre Jieyang 515200China Chemistry and Chemical Engineering Guangdong Laboratory Shantou 515031China

The burgeoning growth of the new energy vehicles and aviation industry has escalated the need for energy storage capacitors capable of stable operation in harsh *** advent of metal-polyimide complexes has illuminated a novel approach for preparing tem perature-resistant ***,the general application of these metal-polyimide com plexes is impeded by the high dielectric loss and low breakdown strength,consequences of main-chain coordination and excessive metal ions ***,our study proposes a novel polyimideCu complex material(POP-Cu)predicated on side-chain-type pyridine-Cu coordination,utilizing the structural backbone PMDA-ODA of mature commercial PI(Kapton)with reliable *** to the high degree of freedom afforded by the side chain with suppressed relaxation activation energy and the long-range electron delocalization formed by d-πcoordination,the dielectric constant of this material containing merely 2.7 mol%Cu increases from 3.25(POPI)to 5.58,while maintaining a remarkably low dielectric loss of ***,this material exhibits a substantial DC breakdown strength of 436.2 MV·m^(-1)and a high energy density of 5.42 J·cm^(-3),coupled with superior mechanical and thermal *** at 150℃,it retains over 90%of its room-temperature energy density,demon strating notable dielectric stability under high *** attributes underscore its promising application for capacitors operating in harsh environments.

关键词： Dielectric performance Polyimide complexes Side-Chain-Type High-temperature capacitor

Signaling pathways in Parkinson’s disease:molecular mechanisms and therapeutic interventions

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Signal Transduction and Targeted Therapy 2023年第3期8卷 1094-1111页

作者： xu dong-chen chen Yong xu Yang ShenTu chen-Yu Peng Li-Hua College of Pharmaceutical Sciences Zhejiang University310058 HangzhouP.R.China State Key Laboratory of Quality Research in Chinese Medicine Macao University of Science and TechnologyMacaoP.R.China

Parkinson’s disease(PD)is the second most common neurodegenerative disease worldwide,and its treatment remains a big *** pathogenesis of PD may be related to environmental and genetic factors,and exposure to toxins and gene mutations may be the beginning of brain *** identified mechanisms of PD includeα-synuclein aggregation,oxidative stress,ferroptosis,mitochondrial dysfunction,neuroinflammation,and gut *** interactions among these molecular mechanisms complicate the pathogenesis of PD and pose great challenges to drug *** the same time,the diagnosis and detection of PD are also one of obstacles to the treatment of PD due to its long latency and complex *** conventional therapeutic interventions for PD possess limited effects and have serious side effects,heightening the need to develop novel treatments for this *** this review,we systematically summarized the pathogenesis,especially the molecular mechanisms of PD,the classical research models,clinical diagnostic criteria,and the reported drug therapy strategies,as well as the newly reported drug candidates in clinical *** also shed light on the components derived from medicinal plants that are newly identified for their effects in PD treatment,with the expectation to provide the summary and outlook for developing the next generation of drugs and preparations for PD therapy.

关键词： therapeutic mechanisms summarized

Hydrocarbon generation and organic matter enrichment of limestone in a lacustrine mixed sedimentary environment: A case study of the Jurassic Da'anzhai member in the central Sichuan Basin, SW China

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Petroleum Science 2023年第2期20卷 670-688页

作者： Qi-Lu xu Bo Liu Xin-Min Song Qing-Ping Wang xu-dong chen Yang Li Yu Zhang Shandong Provincial Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)QingdaoShandong266580China Institute of Oil and Gas Peking UniversityBeijing100871China PetroChina Research Institute of Petroleum Exploration and Development Beijing100083China Petroleum Exploration and Production Research Institute SINOPECBeijing100083China

The hydrocarbon generation effectiveness of lacustrine limestone has been gradually proven. The Da'anzhai Member limestone is the most important Jurassic oil-producing layer in the central Sichuan Basin, and the characteristics of limestone organic matter are often overlooked. 175 typical samples of different lithologies from 19 wells were systematically analyzed to determine hydrocarbon generation, controlling factors and formation models by analyses of organic matter, minerals, elements, isotopes and petrography. (1) Lacustrine paleoenvironments can be beneficial for the enrichment of organic matter in limestone. A favorable environment would be a quiet, low-energy zone in a warm and humid climate with an appropriate supply of terrestrial inputs. (2) Lacustrine limestone has a higher organic matter conversion rate, and a lower hydrocarbon generation threshold than argillaceous source rocks, and can be effective source rock. (3) The mud-bearing shell limestone from the forebeach to the lake slope is thick, with a relatively high abundance of organic matter, and its hydrocarbon generation is effective. This study can clarify the effectiveness and enrichment of the limestone organic matters in the study area, and contribute to an understanding of hydrocarbon generation for full-rock system in a lacustrine mixed sedimentary environment.

关键词： Lacustrine limestone Full-rock system Organic matter evaluation Paleoenvironments Lake evolution Terrestrial inputs

Improving dispersion and delamination of graphite in biodegradable starch materials via constructing cation-π interaction: Towards microwave shielding enhancement

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Journal of Materials Science & Technology 2022年第34期129卷 196-205页

作者： Yi Yang Jun-Ru Tao Dian Yang Qian-Ming He xu-dong chen Ming Wang Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing School of Chemistry and Chemical EngineeringSouthwest UniversityChongqing 400715China Key Laboratory of Polymer Composite and Function Materials of Ministry of Education Key Laboratory for Designed Synthesis and Applied Polymer MaterialsSchool of Chemistry and Chemical EngineeringSun Yat-sen UniversityGuangzhou 510275China

Herein, a low-cost, biodegradable, and high-performance microwave shielding graphite/starch material was fabricated via constructing a cation-π interaction between ammonium ions and graphite. The graphite flakes and starch were firstly mixed with distilled water containing ammonium hydroxide to form graphite/starch slurry under an ultrasonic assistant. The cation-π interaction could improve delamination degree and dispersion of graphite in starch matrix. The slurry was first used as a coating material on the surface of wood and paper to develop shielding packages. The effect of coating thickness and coating layers on EM shielding property of the materials was investigated. Second, the composites with a high orientation of graphite were fabricated by compression at high pressures. The electrical conductivity and EM shielding effectiveness(SET) of the materials were greatly enhanced by construction of cation-πinteraction and orientation of graphite. Specifically, the EM SETvalues increased from 56.9 to 66.8 d B for the composites with 50 wt.% graphite and 2.0 mm in thickness by constructing cation-π interaction. The EM SETvalues raised from 17.4 to 66.8 d B via the graphite orientation in the materials with the same components and thickness. The shielding mechanism of the compressed composites with orientation dispersion of graphite was also discussed in comparison to the coating layer with random dispersion of graphite.

关键词： Electromagnetic shielding Graphite Starch Bio-degradable Cation-πinteraction

Palladium-assisted Metal Patterning on Polyimide Surfaces

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Chinese Journal of Polymer Science 2022年第10期40卷 1287-1296,I0011页

作者： Shi-Long Zhong Bai-Yang Zhou Xi-Rui Gu Ding-Shan Yu xu-dong chen Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education Key Laboratory of High Performance Polymer-based Composites of Guangdong Province School of Chemistry Sun Yat-sen UniversityGuangzhou 510275China

A novel method of patterning high precision copper conductive micropatterns on flexible polymer substrate(polyimide)is *** utilized the coordination effect between palladium salts and pyridine structures to fix the palladium chloride(PdCl_(2))on the surface of polymer film while the 2,6-dimethylpyridine structures formed in the specific areas under ultraviolet light guaranteed the resolution of final *** thermal reduction of PdCl_(2) on the surface can be achieved in the process of thermal cyclization of the polymer *** a consequence,the obtained polyimide(PI)film can be patterned with conductive copper micropatterns directly by electroless *** particular,we accomplished the deposition of high precision copper pattern with a minimum line width of 50μm and minimum line spacing of 20μm on PI thin films(thickness~10μm)by electroless *** prepared conductive copper micropatterns exhibit a low resistivity of 1.78μΩ·cm the same as the pure block *** the relationship between the structures of the polymer chains and the physical properties of polymer substrates,such as the dimensional stability,mechanical and dielectric properties were also discussed in *** simple and novel method of patterning metal on the polymer surface does not need to achieve the catalytic metal adhesion required for electroless plating at the cost of destroying the substrate surface and avoiding the introduction of unstable *** patterning method is compatible with the current roll-to-roll production process and can be used to develop high-performance micro-integrated circuits.

关键词： Polyimide Metal patterning Electroless plating Palladium chloride Coordination effect

Divalent nitrogen-rich cationic salts with great gas production capacities

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Defence Technology（防务技术） 2023年第4期22卷 54-68页

作者： Hao Gu cheng-chuang Li Chang-hao Dai dong-xu chen Hong-wei Yang Guang-bin cheng School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyXiaolingwei 200Nanjing210094PR China

Monocyclic nitrogen-rich 3-(aminomethyl)-4,5-diamine-1,2,4-triazole(1)and fused cyclic 3,7-diamine-6-(aminomethyl)-[1,2,4]triazolo[4,3-b][1,2,4]triazole(9)were synthesized through the convenient cyclization reaction from the readily available *** energetic salts with high nitrogen content were proved to be rare examples of divalent monocyclic/fused cyclic cationic salts according to the single crystal *** structure of intermediate B was also identified and verified by its trivalent cation crystal 17.5H_2O *** compounds 2-8 and 10-17 were fully characterized by NMR spectroscopy,infrared spectroscopy,differential scanning calorimetry,elemental *** energetic salts exhibit good thermal stability with decomposition temperatures ranged from 182℃to 245℃.The sensitivity of compounds 2,6,10 and 14 is similar or superior to that of RDX while the others were much more insensitive to mechanical ***,detonation velocity of 10(8843 m/s)surpass that of RDX(D=8795 m/s).Considering the high gas production volume(≥808 L/kg)of 2,4,10and 12,constant-volume combustion experiments were conduct to evaluate their gas production capacities *** compounds possess much higher maximum gas-production pressures(P_(max):7.88-10.08 MPa)than the commonly used reagent guanidine nitrate(GN:P_(max)=4.20 MPa),which indicate their strong gas production capacity.

关键词： Fused cyclic compound Triazole Divalent cation Gas production Energetic materials