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16篇 您的检索式:作者名="GU Jiaming"
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1Influences of preload on the friction and wear properties of high-speed instrument angular contact ball bearings显示文摘For starved-oil or solid lubrication of high-speed instrument angular contact ball bearings, friction heating and wear are the main reasons of bearing failures. This paper presents a dynamic wear simulation model to investigate the impacts of different preload methods and the changes of preload caused by wear on bearing wear life. The integral value QV of stress and sliding velocity in the contact ellipses between a ball and the inner and outer races determines friction heating and wear. The changes of QV with the friction coefficient and the wear volume under constantforce preload and fixed-position preload are analyzed. Results show that under the same initial preload, the QV decreases with an increase of the friction coefficient for both preload methods, and the latter is slightly larger. The wear of the ball and the race is equivalent to the ball diameter reduction.The QV of constant-force preload is almost not changed with a decrease of the ball diameter, but for fixed-position preload, the value decreases firstly and then increases substantially due to insufficient preload, and slipping occurs, the ball diameter is reduced by 0.025%, while the preload is reduced by 60.33%. An estimation of the bearing wear life under different preload methods requires a consideration of the changes in the wear rate of bearing parts.Tao ZHANG Xiaoyang CHEN Jiaming GU Zhengliang WANG 2018Chinese Journal of Aeronautics2018,31,3:9
2Friction moment analysis of space gyroscope bearing with ribbon cage under ultra-low oscillatory motion显示文摘This paper presents the model of calculating the total friction moment of space gyroscope ball bearings which usually work under ultra-low oscillatory motion and are very sensitive to the friction moment. The aim is to know the proportion of the friction moment caused by each frictional source in the bearing's total friction moment, which is helpful to optimize the bearing design to deduce the friction moment. In the model, the cage dynamic equations considering six degree-of-freedom and the balls dynamic equations considering two degree-of-freedom were solved.The good trends with different loads between the measured friction moments and computational results prove that the model under constant rate was validated. The computational results show that when the speed was set at 5 r/min, the bearing's maximum total friction moment when oscillation occurred was obviously larger than that occurred at a constant rate. At the onset of each oscillatory motion, the proportion of the friction moment caused by cage in the bearing's total friction moment was very high, and it increased with the increasing speed. The analyses of different cage thicknesses and different clearances between cage pocket and ball show that smaller thickness and clearance were preferred.Jiang Shaona Chen Xiaoyang Gu Jiaming Shen Xuejin 2014Chinese Journal of Aeronautics2014,27,5:5
3Autophagy enhanced by curcumin ameliorates inflammation in atherogenesis via the TFEB-P300-BRD4 axis显示文摘Disturbance of macrophage-associated lipid metabolism plays a key role in atherosclerosis.Crosstalk between autophagy deficiency and inflammation response in foam cells(FCs) through epigenetic regulation is still poorly understood. Here, we demonstrate that in macrophages, oxidized lowdensity lipoprotein(ox-LDL) leads to abnormal crosstalk between autophagy and inflammation,thereby causing aberrant lipid metabolism mediated through a dysfunctional transcription factor EB (TFEB)-P300-bromodomain-containing protein 4(BRD4) axis. ox-LDL led to macrophage autophagy deficiency along with TFEB cytoplasmic accumulation and increased reactive oxygen species generation. This activated P300 promoted BRD4 binding on the promoter regions of inflammatory genes, consequently contributing to inflammation with atherogenesis. Particularly, ox-LDL activated BRD4-dependent super-enhancer associated with liquid-liquid phase separation(LLPS) on the regulatory regions of inflammatory genes. Curcumin(Cur) prominently restored FCs autophagy by promoting TFEB nuclear translocation, optimizing lipid catabolism, and reducing inflammation. The consequences of P300 and BRD4 on super-enhancer formation and inflammatory response in FCs could be prevented by Cur. Furthermore, the anti-atherogenesis effect of Cur was inhibited by macrophage-specific Brd4 overexpression or Tfeb knock-out in Apoe knock-out mice via bone marrow transplantation. The findings identify a novel TFEB-P300-BRD4 axis and establish a new epigenetic paradigm by which Cur regulates autophagy, inhibits inflammation, and decreases lipid content.Xuesong Li Ruigong Zhu Hong Jiang Quanwen Yin Jiaming Gu Jiajing Chen Xian Ji Xuan Wu Haiping Fu Hui Wang Xin Tang Yuanqing Gao Bingjian Wang Yong Ji Hongshan Chen 2022Acta Pharmaceutica Sinica B2022,12,5:4
4Mechanical Properties and Biodegradability of Crosslinked Soy Protein Isolate/Water- borne Polyurethane Composites显示文摘Wang Niangui Zhang Lina Gu Jiaming 2005J Appl Polym Sci2005,95,2:1
5Physical properties of micro porous membranes prepared by hydrolyzing cellulose/soy protein blends显示文摘CHEN Yun ZHANG Lina GU Jiaming 2004Journal of Membrane Science2004,241,2:1
6Non-canonical STING-PERK pathway dependent epigenetic regulation of vascular endothelial dysfunction via integrating IRF3 and NF-κB in inflammatory response显示文摘Inflammation-driven endothelial dysfunction is the major initiating factor in atherosclerosis,while the underlying mechanism remains elusive.Here,we report that the non-canonical stimulator of interferon genes(STING)-PKR-like ER kinase(PERK)pathway was significantly activated in both human and mice atherosclerotic arteries.Typically,STING activation leads to the activation of interferon regulatory factor 3(IRF3)and nuclear factor-kappa B(NF-κB)/p65,thereby facilitating IFN signals and infammation.In contrast,our study reveals the activated non-canonical STING-PERK pathway increases scaffold protein bromodomain protein 4(BRD4)expression,which encourages the formation of super-enhancers on the proximal promoter regions of the proinflammatory cytokines,thereby enabling the transactivation of these cytokines by integrating activated IRF3 and NF-κB via a condensation process.Endothelium-specific STING and BRD4 deficiency significantly decreased the plaque area and inflammation.Mechanistically,this pathway is triggered by leaked mitochondrial DNA(mtDNA)via mitochondrial permeability transition pore(mPTP),formed by voltage-dependent anion channel 1(VDAC1)oligomer interaction with oxidized mtDNA upon cholesterol oxidation stimulation.Especially,compared to macrophages,endothelial STING activation plays a more pronounced role in atherosclerosis.We propose a non-canonical STING-PERK pathway-dependent epigenetic paradigm in atherosclerosis that integrates IRF3,NF-κB and BRD4 in inflammatory responses,which provides emerging therapeutic modalities for vascular endothelial dysfunction.Xuesong Li Xiang Chen Longbin Zheng Minghong Chen Yunjia Zhang Ruigong Zhu Jiajing Chen Jiaming Gu Quanwen Yin Hong Jiang Xuan Wu Xian Ji Xin Tang Mengdie Dong Qingguo Li Yuanqing Gao Hongshan Chen 2023Acta Pharmaceutica Sinica B2023,13,12:1
7Pathways of liquefied petroleum gas pyrolysis in hydrogen plasma:A density functional theory study显示文摘A density functional theory(DFT) study has been conducted in this work to investigate the pyrolysis pathways of propane and n-butane,which are the main components of liquefied petroleum gas(LPG),for better understanding the pyrolysis behavior of LPG in hydrogen thermal plasma. Over 60 possible reactions are considered.The reaction enthalpies and activation energies of these reactions are calculated and analyzed with a Gaussian method of B3LYP and basic set of 6-31G(d,p).A most possible reaction pathway is brought up.According to this reaction pathway, the main products of LPG pyrolysis are acetylene,ethylene,methane,ethane and extra hydrogen.Acetylene mainly comes from the pyrolysis of propylene and ethylene,and hydrogen ion reactions are the main source of extra hydrogen gas.Active H·radicals are found to play a very important role in many reactions,and they can remarkably lower the energies needed for reactions.Xiaoyuan Huang Jiaming Gu Dang-Guo Cheng Fengqiu Chen Xiaoli Zhan 2013Journal of Energy Chemistry2013,22,3:1
8Luminescence interference-free lifetime nanothermometry pinpoints in vivo temperature显示文摘Luminescence nanothermometry makes non-invasive and real-time temperature readings possible in living animals.However,the spectral fluctuation in tissues and fluids,as well as the interaction between fluorophores and environment hinders accuracy of the thermometry.Here,we report a luminescence lifetime-based nanothermometry which specifically addresses this problem.A temporal based calibration(lifetime sensing)in the NIR range,an endogenous thermal response as well as a polymer encapsulation evading environmental factors,altogether help to pinpoint temperature in vivo.Thanks to the highly condensed NdYb ions in a well-protected tiny core-shell nanocrystal(overall 11 nm),a temperature sensitivity about 2.07%K^(-1)(with 5%Yb^(3+)doped nanoparticles)and an accuracy of 0.27 K(with 25%Yb^(3+)doped nanoparticles)in biological fluids are achieved.Hopefully,combining thermally activated energy transfer nanothermometer with anti-interference lifetime thermometry would provide a more accurate temperature measurement for biological and preclinical studies.Mengya Kong Yuyang Gu Yingjie Chai Jiaming Ke Yulai Liu Xincheng Xu Zhanxian Li Wei Feng Fuyou Li 2021Science China Chemistry2021,64,6:1
9显示文摘Wang Niangui Zhang Lina Gu Jiaming 2005Applied Pol- ymer Science2005,95,2:1
10Feasible strategies for studying the involvement of DNA methylation and histone acetylation in the stress-induced formation of quality-related metabolites in tea(Camellia sinensis)显示文摘Tea plants are subjected to multiple stresses during growth,development,and postharvest processing,which affects levels of secondary metabolites in leaves and influences tea functional properties and quality.Most studies on secondary metabolism in tea have focused on gene,protein,and metabolite levels,whereas upstream regulatory mechanisms remain unclear.In this review,we exemplify DNA methylation and histone acetylation,summarize the important regulatory effects that epigenetic modifications have on plant secondary metabolism,and discuss feasible research strategies to elucidate the underlying specific epigenetic mechanisms of secondary metabolism regulation in tea.This information will help researchers investigate the epigenetic regulation of secondary metabolism in tea,providing key epigenetic data that can be used for future tea genetic breeding.Jie Yang Dachuan Gu Shuhua Wu Xiaochen Zhou Jiaming Chen Yinyin Liao Lanting Zeng Ziyin Yang 2021Horticulture Research2021,8,1:1
11Real-Time Analysis and Prediction System for Rail Transit Passenger Flow Based on Deep Learning显示文摘With the rapid development of urban rail transit,rail transit plays an important role in alleviating city congestion.In recent years,with increasing pas-sengerflow,there has been huge pressure on passengerflow management.To address this problem,we propose a novel system to provide real-time statistics and predictions of passengerflow based on big data technology and deep learning technology.Moreover,the passengerflow is visualized efficiently in this system.It can provide refined passengerflow information so that people can make more rational decisions in terms of operation and planning,deploy contingency plans to avoid emergency situations,and integrate passengerflow analysis with train production,scheduling and operation to achieve cost reduction and efficiency enhancement.Xujun Che Gang Cen Shuhui Wu Jiaming Gu Keying Zhu 2023国际计算机前沿大会会议论文集2023,,2:0
12A topological polymer network with Cu(Ⅱ)-coordinated reversible imidazole-urea locked unit constructs an ultra-strong self-healing elastomer显示文摘It is exceedingly desired, but difficult to construct self-healing materials with both excellent mechanical properties and healing efficiency, which are usually realized by using mutually exclusive methods. Here, we reconcile this contradiction by utilizing copper-bis-(imidazole-2-yl)-methane-urea(Cu-BIMU) locked units based on novel designed dynamic imidazole-urea bonds with coupled multiple noncovalent bonds(coordination bonds, π-π stacking bonds, and hydrogen bonds). The coordination of Cu(II) greatly reduces the electron-cloud density of imidazole, which lowers the free energy barrier of imidazole-urea bonds and promotes their reversible dissociation, as demonstrated by the density functional theory and small-molecule model reaction. The topological design of Cu-BIMU polyurethane(Cu-BIMU-PU), which concentrates multiple crosslinking-in-one locked unit to avoid the formation of excessive crosslinking sites to ensure high chain mobility, facilitates self-healing. Accumulative extensive intermolecular interactions endowed excellent mechanical properties to the resulting Cu-BIMU-PU elastomer with a tensile strength of 65.3 MPa, among the highest ever-reported value. This work provides a novel molecular design principle for fabricating high-performance dynamic polymers.Lei Yang Zenghe Liu Rasoul Esmaeely Neisiany Jiaming Lou Yifan Guo Luzhi Zhang Huijie Liu Shuo Chen Shijia Gu Zhengwei You 2023Science China Chemistry2023,66,3:0
13Transparency Induced by Two-Photon Coherence in the V-Shaped Three-Level System显示文摘We have investigated th steady-state behavior of a V-shape three-level system submitted to the radiative field and to the relaxation process.The coherence induced by simultaneous two-photon transition leads to a strong decrease of medium absorption.In this case,the peak of transparent spectrum is 7 times higher than that of saturant spectrum.XU Gu WANG Yuzhu YE Chao ZHOU Shanyu ZHAO Jiaming LIU Yashu 1994Chinese Physics Letters1994,11,7:0
14Absence of metallicity and bias-dependent resistivity in low-carrier-density EuCd_(2)As_(2)显示文摘EuCd_(2)As_(2)was theoretically predicted to be a minimal model of Weyl semimetals with a single pair of Weyl points in the ferromagnet state.However,the heavily p-doped Eu Cd_(2)As_(2)crystals in previous experiments prevent direct identification of the semimetal hypothesis.Here,we present a comprehensive magneto-transport study of high-quality Eu Cd_(2)As_(2)crystals with ultralow bulk carrier density(10^(13)cm^(-3)).In contrast to the general expectation of a Weyl semimetal phase,Eu Cd_(2)As_(2)shows insulating behavior in both antiferromagnetic and ferromagnetic states as well as surface-dominated conduction from band bending.Moreover,the application of a dc bias current can dramatically modulate the resistance by over one order of magnitude,and induce a periodic resistance oscillation due to the geometric resonance.Such nonlinear transport results from the high nonequilibrium state induced by an electrical field near the band edge.Our results suggest an insulating phase in Eu Cd_(2)As_(2)and put a strong constraint on the underlying mechanism of anomalous transport properties in this system.Yuxiang Wang Jianwen Ma Jian Yuan Wenbin Wu Yong Zhang Yicheng Mou Jiaming Gu Peihong Cheng Wu Shi Xiang Yuan Jinglei Zhang Yanfeng Guo Cheng Zhang 2024Science China(Physics,Mechanics & Astronomy)2024,67,4:0
15Effect of microbial agent ARC-BBBE demonstration application on peanut production in the Huang-huai-hai area of China显示文摘The microbial agent ARC-BBBE demonstration trials were conducted in four provinces in the main peanutproducing areas of the Huang-huai-hai plain of China.The results revealed that the application of ARC-BBBE led to a 1.09–1.70 fold increase in the number of nodules in the treatment group at the demonstration site compared to the control group.Moreover,the nodule weight in the treatment group was 0.80–3.32 times higher than that of the control group,and nitrogenase activity per plant showed a significant enhancement by 1.00–2.83 fold compared to controls.Additionally,notable improvements were observed in terms of increased fresh weight of whole plants,well-filled pod numbers,and enhanced growth performance;ultimately resulting in a harvest yield increase ranging from 9.46%to 49.04%.The abundance of Aspergillus flavus in rhizosphere soil was determined by the dilution spread plate method,and the inhibition rate was up to 86.7%.The application of ARC-BBBE in the significant peanut-producing areas of Huang-huai-hai has effects of promoting growth,nodulation,and increasing production.At the same time,it has the effect of inhibiting and controlling soil Aspergillus flavus,which provides a new green and low-carbon way to promote the high-quality development of the peanut industry.Pingping Ji Haohua Gu Mingbo Wen Hang Cai Jiaming Zhu Xiaofeng Yue Qi Zhang Peiwu Li 2023Oil Crop Science2023,8,3:0
16Starved lubrication analysis of angular contact ball bearing based on a multi-degree-of-freedom tribo-dynamic model显示文摘When the oil supply is not adequate to maintain the ideal lubrication,angular contact ball bearing will enter into the starved lubrication regime resulting in the potential performance degradation and consequently the severe failures.To study the effects of starved lubrication on the performance of angular contact ball bearing,this paper first proposes a multi-degree-of-freedom(DOF)tribo-dynamic model by introducing five-DOF inner ring,six-DOF balls,and six-DOF cage.The model considers the starved lubrication in the ball-raceway contact and the full multi-body interactions between the bearing components.With different ball-raceway starvation degrees being analyzed,the effects of starved lubrication on the bearing tribo-dynamic performance are first revealed.By comparison,it is found that the oil film thickness,the skidding performance,and the traction forces in the ball-raceway contact are significantly influenced by the starvation degrees.It is also found that the starvation-induced change of the ball-pocket contact force is dramatical under combined loads,and the maximum contact force under this load condition increases with the increasing starvation degrees.Chengwei WEN Xianghui MENG Jiaming GU Lin XIAO Shuang JIANG Hanbing BI 2023Friction2023,11,8:0
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