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MOF-derived Cu embedded into N-doped mesoporous carbon as a robust support of PdAu nanocatalysts for ethanol electrooxidation

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Rare Metals 2024年第3期43卷 1083-1094页

作者： Yu-Fu Huang Peng Wu Jun-Ping Tang Jian Yang Jing Li Shuai Chen Xue-Ling Zhao ChengChen Bin-wei Zhang Yan-Yun Ma wei-heng shi Dong-Hai Lin shi-Gang Sun School of Energy and Materials Shanghai Engineering Research Center of Advanced Thermal Functional MaterialsShanghai Key Laboratory of Engineering Materials Application and EvaluationShanghai Polytechnic UniversityShanghai201209China State Key Laboratory of Physical Chemistry of Solid Surfaces Department of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China School of Chemistry and Chemical Engineering Chongqing UniversityChongqing401331China Center of Advanced Energy Technology and Electrochemistry Institute of Advanced Interdisciplinary StudiesChongqing UniversityChongqing400044China Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesSoochow UniversitySuzhou215123China Department of Materials Science and Engineering Drexel UniversityPhiladelphiaPA19104USA

Metal-organic frameworks(MOFs)h ave attracted widespread attention due to their large surface area and porous *** designing the nanostructures of MOFs to promote their application in ethanol electrooxidation is still a ***,a novel Cu-NCNs(Cu-nitrogen-doped carbon nanotubes)support was synthesized by pyrolysis of melamine(MEL)and Cu-ZIF-8 together,and then,Pd-Au nanoalloys were loaded by sodium borohydride reduction method to prepare PdAu@Cu-NCNs *** generating mesoporous carbon with high specific surface area and favorable electron and mass transport can be used as a potential excellent carrier for PdAu *** addition,the balance of catalyst composition and surface structure was tuned by controlling the content of Pd and ***,the best-performed Pd_(2)Au_(2)@Cu-NCN-1000-2(where 1000 means the carrier calcination temperature,and 2 means the calcination constant temperature time)catalyst exhibits better long-term stability and electrochemical activity for ethanol oxidation in alkaline media(4.80 A·mg^(-1)),which is 5.05 times higher than that of commercial Pd/C(0.95 A·mg^(-1)).Therefore,this work is beneficial to further promoting the application of MOFs in direct ethanol fuel cells(DEFCs)and can be used as inspiration for the design of more efficient catalyst support structures.

关键词： Metal-organic frameworks(MOFs) N-doped Mesoporous carbon PdAu Ethanol electrooxidation

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Concise extraction and characterization of the pore-throat network in unconventional hydrocarbon reservoirs: A new perspective

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Petroleum Science 2024年第3期21卷 1474-1487页

作者： Shu-heng Du Yong-Min shi State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing100190China School of Engineering Science University of Chinese Academy of SciencesBeijing100049China School of Earth and Space Sciences Peking UniversityBeijing100871China

In this study,a new image-based method for the extraction and characterization of pore-throat network for unconventional hydrocarbon storage and exploitation is proposed.“Pore-throat solidity”,which is analogous to particle solidity,and a new method for automatic identification of pores and throats in tight sandstone oil reservoirs are ***,the“pore-throat combination”and“pure pore”are defined and distinguished by drawing the cumulative probability curve of the pore-throat solidity and by selecting an appropriate cutoff *** the discrete grid set is recognized as a pore-throat combination,Legendre ellipse fitting and minimum Feret diameter are *** the pore and throat grid sets are identified as pure pores,the pore diameter can be directly *** the new method,the analytical results for the physical parameters and pore radius agree well with most prior *** results comparing the maximum ball and the new model could also prove the accuracy of the latter's in micro and nano *** new model provides a more practical theoretical basis and a new calculation method for the rapid and accurate evaluation of the complex processes of oil migration.

关键词： Hydrocarbon exploitation Pore Throat Porous media Identification

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Preparation and Rheological Characterization of Long Chain Branching Polyglycolide

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Chinese Journal of Polymer Science 2024年第8期42卷 1177-1184页

作者： wei-Lin Liu Ming-Fu Lyu heng-Yuan Zhang Jian-Ye Liu shi-Jun Zhang Beijing University of Chemical Technology Beijing 100029China SINOPEC(Beijing)Research Institute of Chemical Industry Co. Ltd.Beijing 100013China

The long chain branching(LCB)polyglycolide(PGA)was successfully prepared by the successive reactions of the terminal hydroxyl groups of PGA with triglycidyl isocyanurate(TGIC)and pyromellitic dianhydride(PMDA).The influence of LCB produced by functional group reaction on rheological and crystallization behavior was studied and discussed through linear rheology,uniaxial elongation and DSC(differential scanning calorimetry).The much higher viscosity and the more notable strain hardening behavior of modified PGA indicates the LCB with high degree of entanglements are *** melt strength of PGA is finally improved greatly and can make su re that the supercritical CO_(2)foaming can be carried out successfully.

关键词： Polyglycolide(PGA) Long chain branching(LCB) Rheology

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Protective Graphite Coating for Two-Dimensional Carbon/Carbon Composites

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Fluid Dynamics & Materials Processing 2024年第1期20卷 97-108页

作者： wei shi Zhengyi Li Xiaobing Xu Yingshui Yu Xiaofei Ding heng Ju School of Mechanical and Power Engineering Dalian Ocean UniversityDalian116023China School of Mechanical and Electrical Engineering Gongqing Institute of Science and TechnologyJiujiang332020China

Two-dimensional carbon/carbon(2D C/C)composites are a special class of carbon/carbon composites,generally obtained by combining resin-impregnated carbon fiber clothes,which are then cured and *** study deals with the preparation of a protective coating for these *** coating,based on graphite,was prepared by the slurry *** effect of graphite and phenolic resin powders with different weight ratios was *** results have shown that the coating slurry can fill the pores and cracks of the composite surface,thereby densifying the surface layer of the *** the increase of the graphite powder/phenolic resin weight ratio,the coating density is enhanced while the coating surface flatness decreases;moreover,the protective ability of coating against erosion first increases(from 1:3 to 2:2)and then decreases(from 2:2 to 3:1).When the weight ratio is about 1:1,the coating for 2D C/C composites exhibits the best erosion resistance,which greatly aids these materials during gas *** this case,the erosion rate is decreased by approximately 41.5%at the impact angle of 30°and 52.3%at normal impact,*** can be attributed to the ability of the coating slurry to infiltrate into the substrate,thereby bonding the fibers together and increasing the compactness of the 2D C/C composites.

关键词： Carbon/carbon composites graphite coating microstructure erosion resistance

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反射型立体视觉系统的视差估计和图像复原

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光学精密工程 2011年第7期19卷 1701-1707页

作者：姜伟魏世衡浙江大学工业控制技术国家重点实验室浙江杭州310027

根据反射型立体视觉系统的成像特点,提出了一种基于倒谱分析的反射型立体视觉系统视差估计方法,并利用逆滤波原理对反射型立体视觉系统的重影图像进行复原,获得目标场景的清晰图像。反射型立体视觉系统是一种新型单目测距方式,可以实时... 详细信息

根据反射型立体视觉系统的成像特点,提出了一种基于倒谱分析的反射型立体视觉系统视差估计方法,并利用逆滤波原理对反射型立体视觉系统的重影图像进行复原,获得目标场景的清晰图像。反射型立体视觉系统是一种新型单目测距方式,可以实时获取目标场景的重影图像。首先,将图像分割为矩形观测区域小块;然后,对各观测区域块进行倒谱分析,并通过检测倒谱域峰值位置估计图像的重影位移量（即视差）,计算目标点的三维空间距离;最后,利用估计的视差构造逆滤波器,对重影图像进行逆滤波复原,获取场景清晰图像。通过真实场景实验验证了本文方法的正确性和有效性,结果表明,本文方法的视差估计结果比自相关法提高了15%~20%,实现了稳定视差估计,复原了场景的清晰图像。

关键词：反射型立体视觉视差估计倒谱分析图像复原

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Motion-pressure coupled control and simulation of long-endurance capability for multicapsule stratospheric airships

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Chinese Journal of Aeronautics 2024年第6期37卷 137-150页

作者： Zhiguang shi wei HUO Zongyu ZUO School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Beijing Near Space Airship Technology Development Co. LtdBeijing 100070China

The current study focuses on the motion-pressure coupled control for a multicapsule stratospheric airship and transforms the path-tracking and heading-hold control of airships into guidance tracking with a time-varying weighted sum of longitudinal and lateral velocities by the definition of compound ***,an improved nonlinear predictive control method is provided to reduce the control energy consumption by the rolling optimization of controller parameters based on finite time intervals,ensuring infinite-time path-tracking ***,combined with the proposed cyclic regulation process of safe pressure between internal and external capsules,this study can fully reflect the force-thermal coupled rule of airships under the actions of atmospheric environment and maneuvering force,while evaluating the long-endurance capability of airships under the conditions of safe superheating and *** effectiveness of the motionpressure coupled controller was verified through numerical simulations,which can overcome the influence of environmental wind and achieve a tracking effect for the desired cruise path and compound *** airspeed provided during the cyclic circadian time caused the maximum superheating of the helium controlled within 30*** helium in the internal and external capsules achieved circadian *** equivalent micropore diameter of the capsule of 5 mm can achieve 55 days of long-endurance *** controller satisfies the requirements of cruise-flight application modes for multicapsule stratospheric airships with important engineering value.

关键词： Compound speed Nonlinear predictive control Cyclic pressure regulation Long-endurance capability Stratospheric airship

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Mastering air combat game with deep reinforcement learning

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Defence Technology（防务技术） 2024年第4期34卷 295-312页

作者： Jingyu Zhu Minchi Kuang Wenqing Zhou heng shi Jihong Zhu Xu Han Department of Precision Instruments Tsinghua UniversityBeijing 100084China Department of Computer Science and Technology Tsinghua UniversityBeijing 100084China Chengdu Aircraft Design&Research Institute Aviation Industry Corporation of ChinaChengdu 610000China

Reinforcement learning has been applied to air combat problems in recent years,and the idea of curriculum learning is often used for reinforcement learning,but traditional curriculum learning suffers from the problem of plasticity loss in neural *** loss is the difficulty of learning new knowledge after the network has *** this end,we propose a motivational curriculum learning distributed proximal policy optimization(MCLDPPO)algorithm,through which trained agents can significantly outperform the predictive game tree and mainstream reinforcement learning *** motivational curriculum learning is designed to help the agent gradually improve its combat ability by observing the agent's unsatisfactory performance and providing appropriate rewards as a ***,a complete tactical maneuver is encapsulated based on the existing air combat knowledge,and through the flexible use of these maneuvers,some tactics beyond human knowledge can be *** addition,we designed an interruption mechanism for the agent to increase the frequency of decisionmaking when the agent faces an *** the number of threats received by the agent changes,the current action is interrupted in order to reacquire observations and make decisions *** the interruption mechanism can significantly improve the performance of the *** simulate actual air combat better,we use digital twin technology to simulate real air battles and propose a parallel battlefield mechanism that can run multiple simulation environments simultaneously,effectively improving data *** experimental results demonstrate that the agent can fully utilize the situational information to make reasonable decisions and provide tactical adaptation in the air combat,verifying the effectiveness of the algorithmic framework proposed in this paper.

关键词： Air combat MCLDPPO Interruption mechanism Digital twin Distributed system

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A Comprehensive Study of the Association between LEPR Gene rs1137101 Variant and Risk of Digestive System Cancers

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Biomedical and Environmental Sciences 2024年第5期37卷 445-456页

作者： HU wei Qiong ZHOU wei Guang ZHOU Guang wei LIAO Jia Xi shi Jia Xing XIE FengYang LI Shou heng WANG Yong FENG Xian Hong GU Xiu Li CHEN Bi Feng Department of Biological Science and Technology School of ChemistryChemical Engineering and Life SciencesWuhan University of TechnologyWuhan 430070HubeiChina Institute of WUT-AMU Wuhan University of TechnologyWuhan 430070HubeiChina Department of Clinical Laboratory Wuhan Xinzhou District People’s HospitalWuhan 430499HubeiChina Department of Reproductive Genetics Wuhan Huake Reproductive HospitalWuhan 430013HubeiChina

Objective The leptin receptor,encoded by the LEPR gene,is involved in tumorigenesis.A potential functional variant of LEPR,rs1137101(Gln223Arg),has been extensively investigated for its contribution to the risk of digestive system(DS)cancers,but results remain conflicting rather than ***,we performed a case–control study and subsequent meta-analysis to examine the association between rs1137101 and DS cancer *** A total of 1,727 patients with cancer(gastric/liver/colorectal:460/480/787)and 800 healthy controls were *** of rs1137101 was conducted using a polymerase chain reactionrestriction fragment length polymorphism(PCR-RFLP)assay and confirmed using Sanger ***-four eligible studies were included in the *** After Bonferroni correction,the case–control study revealed that rs1137101 was significantly associated with the risk of liver cancer in the Hubei Chinese *** meta-analysis suggested that rs1137101 is significantly associated with the risk of overall DS,gastric,and liver cancer in the Chinese *** The LEPR rs1137101 variant may be a genetic biomarker for susceptibility to DS cancers(especially liver and gastric cancer)in the Chinese population.

关键词： LEPR gene rs1137101 Digestive system cancers Genetic susceptibility Meta-analysis

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Interface Engineering on Constructing Physical and Chemical Stable Solid-State Electrolyte Toward Practical Lithium Batteries

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Energy & Environmental Materials 2024年第4期7卷 28-47页

作者： Honggang He Litong Wang Malek Al-Abbasi Chunyan Cao heng Li Zhu Xu shi Chen wei Zhang Ruiqing Li Yuekun Lai Yuxin Tang Mingzheng Ge School of Textile and Clothing Nantong University School of Science Qingdao University of Technology Department of Biomedical Sciences City University of Hong Kong Institute of Applied Physics and Materials Engineering University of Macau College of Chemical Engineering Fuzhou University

Solid-state lithium batteries (SSLBs) with high safety have emerged to meet the increasing energy density demands of electric vehicles,hybrid electric vehicles,and portable electronic ***,the dendrite formation,high interfacial resistance,and deleterious interfacial reactions caused by solid-solid contact between electrode and electrolyte have hindered the commercialization of SSLBs.

关键词： dendrite formation high energy density interface instability interfacial resistance solid-state electrolyte

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A discussion of fatigue properties of notched specimens subjected to prestressing treatment machined from FGH4097

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Chinese Journal of Aeronautics 2024年第4期37卷 508-523页

作者： Rongxi shi Dasheng wei Le HAN Shun YANG School of Energy and Power Engineering Beihang UniversityBeijing 100191China Jiangxi Research Institute Beihang UniversityNanchang 330096China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China

Experimental and numerical investigations were performed to reveal the effect of prestress on the fatigue properties of FGH4097 so as to quantitatively evaluate the overspeed benefit of the disc of aeroengine. A corresponding experiment was performed to examine the effect of prestress on the fatigue life of FGH97. A complete model describing the fatigue properties of the prestressed notch specimen was proposed. After the modification of mean stress, stress gradient and prestressing treatment, the model is finally verified by fatigue test of presstressed notch specimens machined from FGH4097 with satisfactory accuracy and good engineering applicability. The new model highlights that for the variable fatigue loads, the introduction of appropriate prestress is expected to benefit to the notch specimens and certainly to the disc of aeroengine regards of their fatigue properties. Both the calculation method of fatigue life parameters and the prestress correction model are proved to have good prediction accuracy.

关键词： Turbine blisk Overspeed test Prestress Fatigue life prediction FGH4097

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