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Interface strengthening for thermal sprayed WC-10Co4Cr coating subjected to pulsed magnetic treatment

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Rare Metals 2024年第2期43卷 780-795页

作者： Cheng-Kai Qian qu Liu Heng Wang Ke-Jian Li zhi-Peng Cai department of Mechanical Engineering Tsinghua UniversityBeijing100084China Tianjin Research Institute for Advanced Equipment Tsinghua UniversityTianjin300304China State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing100084China

The reliability of the coated industry components demands ideal fatigue properties of the coating,and it is mainly determined by the performance of the *** this study,pulsed magnetic treatment(PMT)was applied to the thermal sprayed WC-10Co4Cr coating,and the fatigue lifetime of the coated bolt increased by 219.82%under an imitation of the operating mode *** tests further proved that both the adhesion and cohesion strength were improved after PMT,and they benefit from the interface strengthening *** formation of coherent WC/Co interfaces was characterized by in-situ transmission electron microscopy(TEM),and the molecular dynamic simulations indicate that the work of separation of these interfaces is much higher than the original disordered *** stress was relaxed and distributed more homogeneously after PMT,and it mainly contributes to the coating/substrate *** work provides a new post-treatment method focusing on the interfaces in the WC-based coating and gives insight into its mechanism so that it is hopeful to be applied to other kinds of coatings.

关键词： Cemented carbide coating Pulsed magnetic treatment Interface strengthening Fatigue properties Adhesion strength

Berry-Esseen bounds and Cramér-type moderate deviations for the sample mean and the MLE of the growth rate for a jump-type CIR process

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Acta Mathematica Sinica,English Series 2024年

作者： Fuqing GAO zhi qu School of Mathematics and Statistics Wuhan University

We study Berry-Esseen bounds and Cramér-type moderate deviations of a jump-type CoxIngersoll-Ross(CIR) process driven by a standard Wiener process and a subordinator. In the subcritical case, we obtain the best Berry-Esseen bound of the sample mean and the MLE of the growth rate if the Lévy measure of the subordinator has finite third order moment. Under the Cramér condition,we establish the Cramér-type moderate deviations of the MLE of the growth rate. We first derive a Berry-Esseen bound, a deviation inequality and the Cramér-type moderate deviations for the sample mean of the CIR process by analyzing the asymptotic behaviors of the characteristic function and the moment generating function of the sample mean. Then we analyze a type of additive functional of the jump-type CIR process and use a transformation to study the Berry-Esseen bound and the Cramér-type moderate deviations for the MLE of the growth rate.

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Reinforcement of High Impact Polystyrene by Aramid Nanoparticle Fillers Prepared via an In situ Bottom-up Approach

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Chinese Journal of Polymer Science 2024年第8期42卷 1167-1176页

作者： Xiang-Jun Gong zhi-Ping Zhao Chang-Mei Sun Ying Zhang Rong-Jun qu Ying Wang School of Chemistry and Materials Science Ludong UniversityYantai 264025China

In this work,aramid nanoparticles(ANPs)were prepared in dimethyl formamide(DMF)solution containing high impact polystyrene(HIPS)via a bottom-up *** electron microscopy(TEM)images showed that the obtained ANPs were evenly distributed in the HIPS matrix without any *** composition of the ANPs,i.e.,poly(p-phenyl-p-phenylenediamine)(PPTA),was confirmed by Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and X-ray diffractometer(XRD).The ANP/HIPS composites,obtained after ethanol precipitation,were added to neat HIPS as fillers to fabricate ANP/HIPS composite *** surface roughness and the glass transition temperature(T_g)of the sheets were characterized by atomic force microscope(AFM)and differential scanning calorimetry(DSC),*** with neat HIPS,the mechanical properties of the composite sheet were significantly improved,and the Young's modulus increased from 246.55 MPa to 2025.12 MPa,the tensile strength increased from 3.07 MPa to 29.76 MPa,and the toughness increased from 0.32 N/mm^2 to 3.92 N/mm^2,with an increase rate of 721%,869%and 1125%,***,the thermal stability of the composites improved with the increase in ANP content.

关键词： High impact polystyrene PPTA nanoparticle Reinforce Mechanical property

Electrically Driven Nonresonant Single Molecular Switches

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CCS Chemistry 2024年第2期6卷 465-472页

作者： Rui Wang Ajun Tang zhi Li Yunpeng Li Dahui qu Hongxiang Li Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterFrontiers Science Center for Materiobiology and Dynamic ChemistryInstitute of Fine ChemicalsSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237

Electrical switching of a single-molecule junction provides a practical module to perform sophisticated operations in electronic ***,designing an all-electrically-driven molecular switch is a great ***,we experimentally and theoretically investigated the charge transport characteristics of isoindigo(ISO)-molecules at the single-molecule level using the scanning tunneling microscope break junction *** find that the single-molecule junctions of ISO-molecules display bias voltage-driven switching *** switches are realtime,reversible,and nondestructive under low-bias *** results show that the mechanism of the switch is not the transition from nonresonant charge transport to resonant charge transport,but it is the shift of the frontier orbital energy levels of ISO-molecules and the change of the interfacial electronic coupling with bias *** results will advance the design of high-performance bias voltage-driven molecular switches.

关键词： single-molecule junction isoindigo molecular switch bias voltage nonresonant charge transport molecular electronics

Synthesis and Characterization of Fluorinated Polyurethane Containing Carborane in the Main Chain: Thermal, Mechanical and Chemical Resistance Properties

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Chinese Journal of Polymer Science 2018年第1期36卷 85-97页

作者： Ning Li Fang-Lei Zeng Yu Wang de-zhi qu Chun Zhang Juan Li Jin-Zhao Huo Yong-Ping Bai School of Chemistry and Chemical Engineering Harbin Institute of Technology School of Materials Science & Engineering Beijing Institute of Technology School of Materials Engineering Yancheng Institute of Technology Foshan Nan Hai Gotop Packaging Material Co. Ltd

In this study, two fluorinated polyurethanes（FPU） containing carborane groups in the main chains were firstly designed and synthesized via the reaction of hexamethylene diisocyanate trimer（HDI trimer） with fluorinated polyesters（CFPETs） having hydroxyl-terminated carborane groups at room temperature. The structures of carborane fluorinated polyesters（CFPETs） and polyurethanes（CFPUs） were characterized by gel permeation chromatography（GPC）, Fourier transform infrared（FTIR） spectroscopy and nuclear magnetic resonance（NMR） measurements. The thermal stability, mechanical properties, Shore A hardness, solvent resistance and acid-alkali resistance of the carborane fluorinated polyurethane films were also studied. Thermogravimetric analysis（TGA） tests manifested that the introduction of carborane groups into the main chain of fluorinated polyurethane endowed the obtained fluorinated polyurethane with excellent thermal stability. The thermal decomposition temperature of carborane fluorinated polyurethane（CFPU） increased by 190 °C compared with that of the carborane-free fluorinated polyurethane（FPU）. Even at 800 °C, CFPU showed the char yield of 66.5%, which was higher than that of FPU（34.3%）. The carborane-containing fluorinated polyurethanes also showed excellent chemical resistance and prominent mechanical property even after the cured films being immersed into Jet aircraft oil or 37% HCl for 168 h or at high temperature（700 °C）. It is found that the structural characteristics of carborane group and the compacted structure of CFPU effectively improve the thermal stability, mechanical property, solvent resistance and acid-alkali resistance of the carborane-free fluorinated polyurethane. These excellent properties make CFPU as the useful raw materials to prepare the high temperature resistant coatings or adhesives for automotive engines, engine or fuel tank of aircraft and other equipment working in high-temperature or high concentrations of acid-alkali environments.

关键词： Fluorinated polyurethane Carborane Thermal stability Mechanical property Chemical resistance

A positive feedback inhibition of isocitrate dehydrogenase 3β on paired-box gene 6 promotes Alzheimer-like pathology

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Signal Transduction and Targeted Therapy 2024年第5期9卷 2324-2340页

作者： Xin Wang Qian Liu Hai-tao Yu Jia-zhao Xie Jun-ning Zhao zhi-ting Fang Min qu Yao Zhang Ying Yang Jian-zhi Wang department of Pathophysiology School of Basic MedicineKey Laboratory of Education Ministry of China/Hubei Province for Neurological DisordersTongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina department of Fundamental Medicine Wuxi School of MedicineJiangnan UniversityWuxiJiangsu 214122China Hubei Provincial Key Laboratory for Applied Toxicology Hubei Provincial Center for Disease Control and PreventionHubei Provincial Academy of Preventive MedicineWuhan 430000China Endocrine department of Liyuan Hospital Key Laboratory of Ministry of Education of China for Neurological DisordersTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430077China Co-innovation Center of Neuroregeneration Nantong UniversityNantong 226000China

Impaired brain glucose metabolism is an early indicator of Alzheimer’s disease(AD);however,the fundamental mechanism is *** this study,we found a substantial decline in isocitrate dehydrogenase 3β(IDH3β)levels,a critical tricarboxylic acid cycle enzyme,in AD patients and AD-transgenic mice’s *** investigations demonstrated that the knockdown of IDH3βinduced oxidation-phosphorylation uncoupling,leading to reduced energy metabolism and lactate *** resulting increased lactate,a source of lactyl,was found to promote histone lactylation,thereby enhancing the expression of paired-box gene 6(PAX6).As an inhibitory transcription factor of IDH3β,the elevated PAX6 in turn inhibited the expression of IDH3β,leading to tau hyperphosphorylation,synapse impairment,and learning and memory deficits resembling those seen in *** AD-transgenic mice,upregulating IDH3βand downregulating PAX6 were found to improve cognitive functioning and reverse AD-like ***,our data suggest that impaired oxidative phosphorylation accelerates AD progression via a positive feedback inhibition loop of IDH3β-lactate-PAX6-IDH3β.Breaking this loop by upregulating IDH3βor downregulating PAX6 attenuates AD neurodegeneration and cognitive impairments.

关键词： metabolism Alzheimer impaired

Picroside Ⅱ promotes HSC apoptosis and inhibits the cholestatic liver fibrosis in Mdr2^(−/−)mice by polarizing M1 macrophages and balancing immune responses

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Chinese Journal of Natural Medicines 2024年第7期22卷 582-598页

作者： JIA Kexin MA zhi ZHANG Yinhao XIE Kaihong LI Jianan WU Jianzhi qu Jiaorong LI Fanghong LI Xiaojiaoyang School of Life Sciences Beijing University of Chinese MedicineBeijing 100029China School of Chinese Materia Medica Beijing University of Chinese MedicineBeijing 100029China

Liver fibrosis is characterized by chronic inflammatory responses and progressive fibrous scar *** play a central role in the pathogenesis of hepatic fibrosis by reconstructing the immune *** Ⅱ(PIC Ⅱ),extracted from Picrorhizae Rhizoma,has demonstrated therapeutic potential for various liver ***,the mechanisms by which macrophage polarization initiates immune cascades and contributes to the development of liver fibrosis,and whether this process can be influenced by PIC Ⅱ,remain *** the current study,RNA sequencing and multiple molecular approaches were utilized to explore the underlying mechanisms of PIC Ⅱ against liver fibrosis in multidrug-resistance protein 2 knockout(Mdr2^(−/−))*** findings indicate that PIC Ⅱ activates M1-polarized macrophages to recruit natural killer cells(NK cells),potentially via the CXCL16-CXCR6 ***,PIC Ⅱ promotes the apoptosis of activated hepatic stellate cells(aHSCs)and enhances the cytotoxic effects of NK cells,while also reducing the formation of neutrophil extracellular traps(NETs).Notably,the anti-hepatic fibrosis effects associated with PIC Ⅱ were largely reversed by macrophage depletion in Mdr2^(−/−)***,our research suggests that PIC Ⅱ is a potential candidate for halting the progression of liver fibrosis.

关键词： Liver fibrosis PicrosideⅡ M1 macrophage Hepatic stellate cell Natural killer cell Neutrophil

Cyclic Pulsating Pressure Enhanced Segregating Structuration of Ultra-High Molecular Weight Polyethylene/Graphene Composites as High-performance Light-Weight EMI Shields

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Chinese Journal of Polymer Science 2024年第7期42卷 958-967,I0008页

作者： Yun-zhi Huang Xiao-Xiao Liu Lan-Wei Li Guang-Ming Huang Zhao-Xia Huang Jin-Ping qu National Engineering Research Center of Novel Equipment for Polymer Processing Key Laboratory of Polymer Processing EngineeringMinistry of EducationGuangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced ManufacturingSchool of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou 510641China School of Advanced Manufacturing Technology Guangdong Mechanical&Electrical PolytechnicGuangzhou 510550China

Currently,the enhancement in electromagnetic interference(EMI)performance of polymeric composite generally relies on either improving electrical conductivity(σ)for stronger electromagnetic(EM)reflections or tailoring structure for higher EM ***,we proposed a novel technique called cyclic pulsating pressure enhanced segregating structuration(CPP-SS),which can reinforce these two factors *** structural information was supplied by optical microscopy(OM)and scanning electron microscopy(SEM),both of which confirmed the formation and evolution of segregate structured ultra-high molecular weight polyethylene(UHMWPE)/graphene ***,the result showed that CPP-SS can significantly improve theσof ***,advanced specific EMI shielding efficiency of 31.1 d B/mm was achieved for UHMWPE/graphene composite at 1-mm thickness and a low graphene loading of 5 wt%.Meanwhile,it also confirmed that the intrinsic disadvantage of poor mechanical properties of conventional segregated structure composites can be *** work is believed to provide a fundamental understanding of the structural and performance evolutions of segregated structured composites prepared under CPPSS,and to bring us a simple and efficient approach for fabricating high-performance,strong and light-weight polymeric EMI shields.

关键词： Cyclic pulsating pressure Segregated structure Ultra-high molecular weight polyethylene Graphene Electromagnetic interface

Photodynamic eradication of intratumoral microbiota with bacteria-targeted micelles overcomes gemcitabine resistance of pancreatic cancer

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Aggregate 2024年第1期5卷 377-384页

作者： Renfa Liu Huanyu Yang Shuai qu Peipei Yang Xin zhi Yunxue Xu zhifei Dai Linxue Qian department of Biomedical Engineering College of Future TechnologyNational Biomedical Imaging CenterPeking UniversityBeijingChina department of Ultrasound Beijing Friendship HospitalCapital Medical UniversityBeijingChina

Increasing evidence suggests that intratumoral microbiota plays a pivotal role in tumor progression,immunosurveillance,metastasis,and ***,in pancreatic ductal adenocarcinoma,tumor-resident Gammaproteobacteria could transform the chemotherapeutic drug gemcitabine(Gem)into its inactive form,thus rendering chemotherapy ***,a strategy for selectively eradicating intratumoral bacteria was described for overcoming Gem resistance in a pancreatic cancer animal *** antimicrobial peptide was linked with photosensitizer through a poly(ethylene glycol)chain,which can self-assemble into micelles with a diameter of∼20 *** micelles could efficiently kill bacteria under light irradiation by inducing membrane depolarization,thereby inhibiting Gem *** a bacteria-resident pancreatic cancer animal model,the selective photodynamic eradication of intratumoral bacteria was demonstrated to efficiently reverse Gem *** research highlights antibacterial photodynamic therapy as a promising adjuvant strategy for cancer therapy by modulating intratumoral microbiota.

关键词： antimicrobial peptide gemcitabine resistance intratumoral microbiota pancreatic ductal adenocarcinoma photodynamic antibacterial therapy