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Gear walk instability caused by brake-disc friction characteristics

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Chinese Journal of Aeronautics 2024年第2期37卷 343-359页

作者： Xiaoqiong DU bin LI wen cai Linyin LUO School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Department of Mechanical Engineering University of MichiganAnn Arbor 48109USA AVIC General Huanan Aircraft Industry Co.Ltd. Zhuhai 519040China

A multi-body dynamic rigid-flexible coupling model of landing gear is established to study the gear walk instability caused by the friction characteristics of the brake disc.After validating the model with the experimental results,the influence of the landing gear structure and braking system parameters on gear walk is further investigated.Among the above factors,the slope of the graph for the friction coefficient of the brake disc and the relative velocity of brake stators and rotors is the most influential factor on gear walk instability.Phase trajectory analysis verifies that gear walk occurs when the coupling of multiple factors causes the system to exhibit an equivalent negative damping trend.To consider a more realistic braking case,a back propagation neural network method is employed to describe the nonlinear behavior of the friction coefficient of the brake disc.With the realistic nonlinear model of the friction coefficient,the maximum error in predicting the braking torque is less than 10%and the effect of the brake disc temperature on gear walk is performed.The results reveal that a more negative friction slope may contribute to a more severe unstable gear walk,and reducing the braking pressure is an effective approach to avoid gear walk,which provides help for future braking system design.

关键词： Gear walk Friction characteristics of brake disc Brake-induced vibration Negative damping Rigid-flexible coupling Negative slope of braking torque

Disentangling distinct Cu surface sites for electrocatalytic CO_(2)-to-CO and CO-to-C_(2+)conversion

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Science China Chemistry 2024年第4期67卷 1047-1048页

作者： Kun Jiang Wen-Bin Cai Interdisciplinary Science Research Centre School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Collaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryFudan UniversityShanghai 200438China

Electrochemical CO_(2)reduction reaction(CO_(2)RR)is a promising strategy to curb anthropogenic carbon emissions,for which intermittent renewable electricity could be stored as chemical energy within carbon-based fuel... 详细信息

关键词： carbon Electrochemical surface

Unraveling the interfacial effect of PdBi bimetallic catalysts on promoting CO_(2)electroreduction to formate

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Nano Research 2023年第8期16卷 10822-10831页

作者： wenhui Liu Lingtong Ding Minmin Liu Xiao Wang Zhengrong Zhang Tian-wen Jiang Shengjuan Huo Wen-Bin Cai International Joint Laboratory of Catalytic Chemistry Department of ChemistryInstitute for Sustainable EnergyCollege of SciencesShanghai UniversityShanghai 200444China Shenzhen Key Laboratory of Nanobiomechanics Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Paul C.Lauterbur Research Center for Biomedical Imaging Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Collaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryFudan UniversityShanghai 200438China

Through interface engineering and content control strategy,a PdBi bimetallic interface structure was constructed for the first time to selectively convert CO_(2)to formate with a remarkably high Faraday efficiency(FEformate)of 94%and a partial current density(jformate)of 34 mA·cm^(−2)at−0.8 V vs.reversible hydrogen electrode(RHE)in an H-cell.Moreover,the PdBi interface electrocatalyst even exhibited a high current density of 180 mA·cm^(−2)with formate selectivity up to 92%in a flow cell and could steadily operate for at least 20 h.Electrochemical in-situ attenuated total reflection surface enhanced infrared absorption spectroscopy(ATR-SEIRAS)confirmed that the PdBi interface could greatly weaken the adsorption of*CO intermediates due to electronic and geometric effects.Density functional theory(DFT)calculations also established that the PdBi interface regulated the CO_(2)-to-formate pathway by reducing the energy barrier toward HCOOH and largely weakening the adsorption of*CO intermediates on the catalyst surface.This study reveals that the unique PdBi bimetallic interface can provide a novel platform to study the reaction mechanism through combining in-situ ATR-SEIRAS and DFT calculations.

关键词： carbon dioxide reduction reaction bimetallic PdBi interface engineering formate in-situ attenuated total reflection surface enhanced infrared absorption spectroscopy(ATR-SEIRAS)

Quantitative image analysis for evaluation of tumor response in clinical oncology

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Chronic Diseases and Translational Medicine 2018年第1期4卷 18-28页

作者： wen-Li cai Guo-bin Hong Department of Radiology Massachusetts General HospitalHarvard Medical SchoolBostonMA 02114USA Department of Radiology The Fifth Affiliated Hospital of Sun Yat-Sen UniversityZhuhaiGuangdong 519000China

The objective, accurate, and standardized evaluation of tumor response to treatment is an indispensable procedure in clinical oncology. Compared to manual measurement, computer-assisted linear measurement can significantly improve the accuracy and reproducibility of tumor burden quantification. For irregular-shaped and infiltrating or diffuse tumors, which are difficult to quantify by linear measurement, computer-assisted volumetric measurement may provide a more objective and sensitive quantification to evaluate tumor response to treatment than linear measurement does. In the evaluation of tumor response to novel oncologic treatments such as targeted therapy, changes in overall tumor size do not necessarily reflect tumor response to therapy due to the presence of internal necrosis or hemorrhages. This leads to a new generation of imaging biomarkers to evaluate tumor response by using texture analysis methods, also called radiomics. Computer-assisted texture analysis technology offers a more comprehensive and in-depth imaging biomarker to evaluate tumor response. The application of computer-assisted quantitative imaging analysis techniques not only reduces the inaccuracy and improves the reliability in tumor burden quantification, but facilitates the devel-opment of more comprehensive and intelligent approaches to evaluate treatment response, and hence promotes precision imaging in the evaluation of tumor response in clinical oncology. This article summarizes the state-of-the-art technical developments and clinical applications of quantitative imaging analysis in evaluation of tumor response in clinical oncology.

关键词： Quantitative image analysis Tumor imaging biomarker Response evaluation

Hubble parameter estimation via dark sirens with the LISA-Taiji network

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National Science Review 2022年第2期9卷 52-62页

作者： Renjie Wang wen-Hong Ruan Qing Yang Zong-Kuan Guo Rong-Gen cai bin Hu Department of Astronomy Beijing Normal University CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences School of Physical Sciences University of Chinese Academy of Sciences College of Engineering Physics Shenzhen Technology University School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences

The Hubble parameter is one of the central parameters in modern cosmology,and describes the present expansion rate of the universe.The values of the parameter inferred from late-time observations are systematically higher than those inferred from early-time measurements by about 10%.To reach a robust conclusion,independent probes with accuracy at percent levels are crucial.Gravitational waves from compact binary coalescence events can be formulated into the standard siren approach to provide an independent Hubble parameter measurement.The future space-borne gravitational wave observatory network,such as the LISA-Taiji network,will be able to measure the gravitational wave signals in the millihertz bands with unprecedented accuracy.By including several statistical and instrumental noises,we show that,within a five-year operation time,the LISA-Taiji network is able to constrain the Hubble parameter within 1% accuracy,and possibly beats the scatters down to 0.5% or even better.

关键词： gravitational waves Hubble parameter super massive black hole

Role of mitophagy in the hallmarks of aging

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The Journal of Biomedical Research 2023年第1期37卷 1-14页

作者： Jie wen Tingyu Pan Hongyan Li Haixia Fan Jinhua Liu Zhiyou cai bin Zhao Department and Institute of Neurology Guangdong Medical UniversityZhanjiangGuangdong 524001China Guangdong Key Laboratory of Aging-related Cardiac and Cerebral Diseases ZhanjiangGuangdong 524001China Chongqing Key Laboratory of Neurodegenerative Diseases Chongqing 400013China Department of Neurology Chongqing General HospitalChongqing 400013China Department of Neurology the Affiliated Hospital of Southwest Medical UniversityLuzhouSichuan 646000China Chongqing Medical University Chongqing 400042China

Aging, subjected to scientific scrutiny, is extensively defined as a time-dependent decline in functions that involves the majority of organisms. The time-dependent accretion of cellular lesions is generally a universal trigger of aging, while mitochondrial dysfunction is a sign of aging. Dysfunctional mitochondria are identified and removed by mitophagy, a selective form of macroautophagy. Increased mitochondrial damage resulting from reduced biogenesis and clearance may promote the aging process. The primary purpose of this paper is to illustrate in detail the effects of mitophagy on aging and emphasize the associations between mitophagy and other signs of aging, including dietary restriction, telomere shortening, epigenetic alterations, and protein imbalance.The evidence regarding the effects of these elements on aging is still limited. And although the understanding of relationship between mitophagy and aging has been long-awaited, to analyze details of such a relationship remains the main challenge in aging studies.

关键词： mitophagy aging dietary restriction telomere shortening epigenetic alterations protein imbalance

One-step construction of strongly coupled Co_(3)V_(2)O_(8)/Co_(3)O_(4)/MXene heterostructure via in-situ Co-F bonds for high performance all-solid-state asymmetric supercapacitors

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Rare Metals 2024年第2期43卷 682-691页

作者： Ji Zhou bin-bin Liu Hu Zheng wen-Qing Ma Qian Li cai-Xia Xu Institute for Advanced Interdisciplinary Research(iAIR) Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of ShandongSchool of Chemistry and Chemical EngineeringUniversity of JinanJinan250022China

Co_(3)V_(2)O_(8)/Co_(3)O_(4)/Ti_(3)C_(2)T_(x) composite was easily synthesized via one-step succinct-operated hydrothermal process.The interconnected Co_(3)V_(2)O_(8)/Co_(3)O_(4) nanowires network can in-situ grow and anchor on the surface of Ti_(3)C_(2)T_(x) via the strong Co-F bonds and contribute tremendously to depress Ti_(3)C_(2)T_(x) self-restacking.Profiting from the synergistically interplayed effect among the multiple interfaces and high conductivity of Ti_(3)C_(2)T_(x) as well as outstanding stability of the as-designed nanostructure,the optimum Co_(3)V_(2)O_(8)/Co_(3)O_(4)/Ti_(3)C_(2)T_(x)electrode reaches a commendable specific capacitance(up to 3800 mF·cm^(−2)),great rate capability(80%capacitance retention after 20-times current increasing),and preeminent cycling stability(95.4%/85.5%retention at 7000th/20,000th cycle).Moreover,the all-solid-state asymmetric supercapacitor based on Co_(3)V_(2)O_(8)/Co_(3)O_(4)/Ti_(3)C_(2)T_(x) and active carbon can deliver a high energy density of 84.0μWh·cm^(−2) at the power energy of 3.2 mW·cm^(−2),and excellent cycling durability with 87.0%of initial capacitance retention upon 20,000 loops.This work provides a practicable pathway to tailor MXene-based composites for high-performance supercapacitor.

关键词： Ti_(3)C_(2)T_(x) Co_(3)V_(2)O_(8)/Co_(3)O_(4) Heterostructure Cathode Supercapacitor

An efficient,recoverable fluorous organocatalyst for accelerating the DABCO-promoted Morita-Baylis-Hillman reaction

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Chinese Chemical Letters 2011年第9期22卷 1055-1058页

作者： Yi Bo Huang wen bin Yi Chun cai School of Chemical Engineering Nanjing University of Science & Technology Nanjing 210094 China Department of Pharmacy Changzhou Institute of Engineering Technology Changzhou 213164 China

A convenient method for Morita-Baylis-Hillman reaction of arylaldehydes with methyl acrylate has been developed by using fluorous-tag organocatalyst 1-[4-（perfluorooctyl）phenyl]-3-phenylthiourea and DABCO at room temperature. The fluorous organocatalyst could be recovered from the reaction mixture by fluorous solid-phase extraction （F-SPE） with excellent purity for direct reuse.

关键词： Organocatalyst Morita-Baylis-Hillman reaction Fluorous solid phase extraction （F-SPE）

Risk Factors of Anastomotic Leakage After Anterior Resection for Rectal Cancer Patients

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Current Medical Science 2022年第6期42卷 1256-1266页

作者： Xiang-nan YU Lu-ming XU Ya-wen bin Ye YUAN Shao-bo TIAN Bo cai Kai-xiong TAO Lin WANG Guo-bin WANG Zheng WANG Department of Gastrointestinal Surgery Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China Research Center for Tissue Engineering and Regenerative Medicine Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China Department of Clinical Laboratory Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China

Objective Anastomotic leakage(AL)is one of the serious complications after anterior resection for rectal cancer.Defunctioning stoma(DS)is one of the most widely used approaches to prevent it;however,the effect of DS on the occurrence of AL remains controversial.This study aimed to investigate risk factors of AL and assess the effect of DS after anterior resection for rectal cancer patients.Methods A retrospective analysis was conducted for the data of 1840 patients who underwent anterior resection for rectal cancer from January 2014 to December 2019.Results The results showed the overall AL incidence was 7.5%.Multivariate analyses revealed that males[odds ratio(OR)1.562]and T3–T4 stage(OR 1.729)were independent risk factors for all patients.After propensity score matching analysis,the AL incidence was 14.1%in the group with no DS and 6.4%in the DS group(P<0.001).The clinical AL(grade B+grade C)incidence was 12.4%in no DS group and 4.6%in the DS group(P<0.001).Conclusion The study suggested that males and T3–T4 stage were independent risk factors of AL.In addition,DS could reduce the rate of symptomatic AL.

关键词： anastomotic leakage risk factor defunctioning stoma propensity score matching