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A new 3D plastoelastohydrodynamic lubrication model for rough surfaces

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Friction 2024年第6期12卷 1176-1193页

作者： Shengyu YOU Jinyuan tang qiang WANG State Key Laboratory of Precision Manufacturing for Extreme Service Performance Central South UniversityChangsha 410083China

Plastoelastohydrodynamic lubrication of rough surfaces(R-PEHL)is a cutting-edge area of research in interface fluid-structure coupling *** existing R-PEHL model calculates the elastic-plastic deformation of rough surface by the Love equation in a semi-infinite space smooth surface,which deviates from the actual ***,it is an innovative work to study the exact solution of elastic-plastic deformation of rough surface and its influence on the solution results of R-PEHL *** this paper,a new contact calculation model of plastoelastohydrodynamic lubrication(PEHL)with three-dimensional(3D)rough surface is proposed by integrating numerical method of EHL and finite element *** new model eliminates an original error introduced by the assumption of semi-infinite space in contact calculation,providing wide applicability and high *** the given rough surfaces and working conditions,the study reveals that:(1)the oil film pressure calculated by the new model is lower than that of the smooth surface in semi-infinite space by 200–800 MPa;(2)the Mises stress of the new model is 2.5%–26.6%higher than that of the smooth surface in semi-infinite space;(3)compared with the semi-infinite space assumption,the rough surface plastic deformation of the new model is increased by 71%–173%,and the local plastic deformation singularity may appear under the semi-infinite space assumption;(4)the plastic deformation caused by the first contact cycle on the rough surface of the new model accounts for 66.7%–92.9%of the total plastic deformation,and the plastic deformation of the semi-infinite space accounts for 50%–83.3%.This study resolves the contradiction between the smooth surface assumption and the rough surface in the existing R-PEHL model,establishing a solid logic foundation for the accurate solution of R-PEHL model.

关键词： rough surface plastoelastohydrodynamic lubrication(PEHL) asperity plastic deformation semi-infinite space

An anti-icing scaling method for wind tunnel tests of aircraft thermal ice protection system

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Chinese Journal of Aeronautics 2024年第6期37卷 1-6页

作者： Yu LIU qiang WANG xian YI Ningli CHEN Jinghao REN Weihao LI Key Laboratory of Icing and Anti/de-icing China Aerodynamics Research and Development CenterMianyang 621000China State Key Laboratory of Aerodynamics Mianyang 621000China

The efficiency of the aircraft Ice Protection Systems(IPSs)needs to be verified through icing wind tunnel ***,the scaling method for testing the IPSs has not been systematically established yet,and further research is *** the present study,a scaling method specifically designed for thermal IPSs was derived from the governing equation of thin water *** scaling parameters were adopted to address the heat and mass transfer involved in the thermal anti-icing *** method validation,icing wind tunnel tests were conducted using a jet engine nacelle model equipped with a bleed air *** non-dimensional surface temperature and runback ice closely matched for both the reference and scaled *** validation confirms that the scaling method is capable of achieving the similarity of surface temperature and the runback ice *** anti-icing scaling method can serve as an important supplement to the existing icing similarity theory.

关键词： Scaling method Ice protection system Water film Anti-icing test Icing wind tunnel

Review of the research on the development and utilization of clay-type lithium resources

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Particuology 2024年第4期87卷 46-53页

作者： Ruiqi Xie Zhihui Zhao Xiong Tong xian Xie qiang Song Peiqiang Fan Faculty of Land Resource Engineering Kunming University of Science and TechnologyKunming650093China Yunnan Engineering Research Center for Metal Tailings Resource Utilization Kunming650093China

Since the demands for lithium have been in explosive growth recently and several great clay lithium resources were founded in China,the development and utilization of clay-type lithium resources become a hot *** order to provide a guidance for the concentration and extracting lithium of clay-type lithium resources,this review systematically summarized the main types and characteristics of clay-type lithium resources and the research status of lithium extraction from clay lithium ***,the flotation research status of the main mineral of clay lithium ore was also ***,we discussed the difficulties in the development and utilization of clay-type lithium ore and put forward the subsequent research *** paper can provide a guidance for the con-centration and extracting lithium of clay-type lithium resources in the future.

关键词： Clay lithium Clay mineral flotation Lithium extraction Leaching

A Scalable Pillar Layered Metal-Organic Framework for Natural Gas Purification

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Chemical Research in Chinese Universities 2024年第4期40卷 675-681页

作者： LU Nan LAN Lan GAO qiang LI Na BU xian-He School of Materials Science and Engineering Nankai UniversityTianjin300350P.R.China State Key Laboratory of Elemento-Organic Chemistry College of ChemistryNankai UniversityTianjin300071P.R.China School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang212003P.R.China

One-step harvest of high-purity methane(CH_(4))from ternary propane/ethane/methane(C_(3)H_(8)/C_(2)H_(6)/CH_(4))mixtures remains a desirable yet challenging goal for natural gas ***,adsorbents either suffer from high capacity and selectivity,or are caught in a dilemma of scalable ***,we demonstrate a scalable pillar layered metal-organic framework Ni-MOF for highly efficient one-step CH_(4)***-MOF exhibits high C_(2)H_(6)and C_(3)H_(8)uptakes of 83.3 and 86.1 cm^(3)/g at 298 K and 100 kPa and remarkable C_(2)H_(6)/CH_(4)(50/50,volume ratio,21.5)and C_(3)H_(8)/CH_(4)(50/50,volume ratio,212.0)***,high C_(2)H_(6)(42.2 cm^(3)/g at 10 kPa)and C_(3)H_(8)(64.7 cm^(3)/g at 5 kPa)capacities in the low-pressure region at 298 K were realized on Ni-MOF,suggesting the strong affinities of Ni-MOF towards C_(2)H_(6)and C_(3)H_(8).Furthermore,the dynamic breakthrough experiments revealed that purifying CH_(4)from natural gas in one-step can be achieved in Ni-MOF with high-purity(>99.8%)and productivity(346.0 cm^(3)/g).Most significantly,the production of Ni-MOF can be scalably synthesized at room temperature,rendering it promising potential for industrial *** combined advantages of exceptional separation performance,scalability,and cycle stability of Ni-MOF pave the way for one-step CH_(4)purification from natural gas.

关键词： Metal-organic framework Adsorption and separation Natural gas purification Scale-up synthesis

Projected changes in Köppen-Trewartha climate zones under 1.5-4℃global warming targets over mid-high latitudes of Northern Asia using an ensemble of RegCM4 simulations

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Advances in Climate Change Research 2024年第2期15卷 185-196页

作者： Jie WU Xue-Jie GAO xian-Bing tang Filippo GIORGI School of Geography and Environmental Engineering Gannan Normal UniversityGanzhou 341000China Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044China University of Chinese Academy of Sciences Beijing 100049China The Abdus Salam International Centre for Theoretical Physics Trieste 34100Italy

Mid-high latitude Northern Asia is one of the most vulnerable and sensitive areas to global warming,but relatively less studied *** used an ensemble of a regional climate model(RegCM4)projections to assess future changes in surface air temperature,precipitation and Köppen-Trewartha(K-T)climate types in Northern Asia under the 1.5-4℃global warming ***4 is driven by five CMIP5 global models over an East Asia domain at a grid spacing of 25 *** of the present day(1986-2005)simulations shows that the ensembles of RegCM4(ensR)and driving GCMs(ensG)reproduce the major characters of the observed temperature,precipitation and K-T climate zones reasonably *** and more realistic spatial detail is found in RegCM4 compared to the driving GCMs.A general warming and overall increases in precipitation are projected over the region,with these changes being more pronounced at higher warming *** projected warming by ensR shows different spatial patterns,and is in general lower,compared to ensG in most months of the year,while the percentage increases of precipitation are maximum during the cold *** future changes in K-T climate zones are characterized by a substantial expansion of Dc(temperature oceanic)and retreat of Ec(sub-arctic continental)over the region,reaching∼20%under the 4℃warming *** most notable change in climate types in ensR is found over Japan(∼60%),followed by Southern Siberia,Mongolia,and the Korean Peninsula(∼40%).The largest change in the K-T climate types is found when increasing from 2 to 3℃.The results will help to better assess the impacts of climate change and in implementation of appropriate adaptation measures over the region.

关键词： Mid-high latitudes of Northern Asia Köppen climate zones Global warming targets Regional climate model

Experimental Study of Local Scour Around Four Piles Under Different Attack Angles and Gap Ratios

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China Ocean Engineering 2024年第4期38卷 612-624页

作者： LIU Ming-ming tang Guo-qiang JIN Xin GENG Shao-yang School of Architecture and Engineering Liaocheng UniversityLiaocheng 252000China Water-Sediment Regulation and Sand Effective Utilization Special Laboratory of Shandong Provincial Education Department Liaocheng UniversityLiaocheng 252000China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China College of Electronic Engineering Chengdu University of Information TechnologyChengdu 610225China College of Energy Chengdu University of TechnologyChengdu 610059China

In an effort to investigate and quantify the patterns of local scour,researchers embarked on an in-depth study using a systematic experimental *** research focused on the effects of local scour around a set of four piles,each subjected to different hydromechanical *** particular,this study aimed to determine how different attack angles—the angles at which the water flow impinges on the piles,and gap ratios—the ratios of the spacing between the piles to their diameters,influence the extent and nature of scour.A comprehensive series of 35 carefully designed experiments were orchestrated,each designed to dissect the nuances in how the gap ratio and attack angle might contribute to changes in the local scour observed at the base of pile *** these experimental trials,a wealth of local scour data were collected to support the *** data included precise topographic profiles of the sediment bed around the pile groups,as well as detailed scour time histories showing the evolution of scour at strategic feature points throughout the test *** analysis of the experimental data provided interesting *** study revealed that the interplay between the gap ratio and the attack angle had a pronounced influence on the scouring dynamics of the pile *** of the key observations was that the initial phases of scour,particularly within the first hour of water flow exposure,were characterized by a sharp increase in the scour depth occurring immediately in front of the *** this initial rapid development,the scour depth transitioned to a more gradual change *** contrast,the scour topography around the piles continuously *** suggests that sediment displacement and the associated sculpting of the seabed around pile foundations are sustained and progressive processes,altering the underwater landscape over *** results of this empirical investigation have significant implications for the design and constructio

关键词： local scour piles gap ratio attack angle

Coordination environments build up and tune a superior synergistic “genome” toward novel trifunctional (TM-N_(x)O_(4−x))@g- C_(16)N_(3)-H_(3): High-throughput inspection of ultra-high activity for water splitting and oxygen reduction reactions

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Nano Research 2024年第4期17卷 2337-2351页

作者： Chunyao Fang xian Wang qiang Zhang Xihang Zhang Chenglong Shi Jingcheng Xu Mengyu Yang Department of Physics University of Shanghai for Science and TechnologyShanghai 200093China School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China

Emerging as a prominent area of focus in energy conversion and storage technologies,the development of highly active metal-based single-atom catalysts(SACs)holds great signiﬁcance in searching alternatives to replace precious metals toward the efficient,stable,and low-cost hydrogen evolution reaction(HER),as well as the oxygen evolution reaction(OER)and the oxygen reduction reaction(ORR).Combining the tremendous tunability of ligand and coordination environment with rich metal-based electrocatalysts can create breakthrough opportunities for achieving both high stability and ***,we propose a novel and stable holey graphene-like carbon nitride monolayer g-C_(16)N5(N_(4)@g-C_(16)N_(3))stoichiometries interestingly behaving as a natural substrate for constructing SACs((TM-N_(4))@g-C_(16)N_(3)),whose evenly distributed holes map rich and uniform nitrogen coordination positions with electron-rich lone pairs for anchoring transition metal(TM)***,we employed density functional theory(DFT)calculations to systematically investigate the electrocatalytic activity of(TM-N_(4))@g-C_(16)N_(3) toward HER/OER/ORR,meanwhile considering the synergistic modulation of H-loading and O-coordination((TM-N_(x)O_(4-x))@g-C_(16)N_(3)^(-)H_(3),x=0–4).Together a“four-step procedure”screening mechanism with the first-principles high-throughput calculations,we find that(Rh-N_(4))and(Ir-N_(2)O_(2)-II)distributed on g-C_(16)N_(3)^(-)H_(3) can modulate the adsorption strength of the adsorbates,thus achieving the best HER/OER/ORR performance among 216 candidates,and the lowest overpotential of 0.098/0.3/0.46 V and 0.06/0.48/0.45 V,***,the d-band center,crystal orbital Hamilton population(COHP),and molecular orbitals are used to reveal the OER/ORR activity ***,the Rh/Ir-d orbital is dramatically hybridized with the O-p orbital of the oxygenated adsorbates,so that the lone-electrons incipiently locate at the antibonding orbital pair up and popula

关键词： single atom catalysts loading and coordination hydrogen evolution reaction oxygen evolution reaction oxygen reduction reaction

Attention-based network embedding with higher-order weights and node attributes

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CAAI Transactions on Intelligence Technology 2024年第2期9卷 440-451页

作者： xian Mo Binyuan Wan Rui tang Junkai Ding Guangdi Liu School of Information Engineering Ningxia UniversityYinchuanChina School of Cyber Science and Engineering Sichuan UniversityChengduChina Computer Science and Information Technology University of MalayaKuala LumpurMalaysia Academy of Medical Sciences Zhengzhou UniversityZhengzhouChina

Network embedding aspires to learn a low-dimensional vector of each node in networks,which can apply to diverse data mining *** real-life,many networks include rich attributes and temporal ***,most existing embedding approaches ignore either temporal information or network attributes.A self-attention based architecture using higher-order weights and node attributes for both static and temporal attributed network embedding is presented in this article.A random walk sampling algorithm based on higher-order weights and node attributes to capture network topological features is *** static attributed networks,the algorithm incorporates first-order to k-order weights,and node attribute similarities into one weighted graph to preserve topological features of *** temporal attribute networks,the algorithm incorporates previous snapshots of networks containing first-order to k-order weights,and nodes attribute similarities into one weighted *** addition,the algorithm utilises a damping factor to ensure that the more recent snapshots allocate a greater *** features are then incorporated into topological ***,the authors adopt the most advanced architecture,Self-Attention Networks,to learn node *** results on node classification of static attributed networks and link prediction of temporal attributed networks reveal that our proposed approach is competitive against diverse state-of-the-art baseline approaches.

关键词： data mining deep neural networks social network

Rational Engineering of Secondary Metabolic Pathways in a Heterologous Host to Enable the Biosynthesis of Hibarimicin Derivatives with Enhanced Anti-Melanomic Activity

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Engineering 2024年第7期38卷 113-123页

作者： xiangyang Liu Fei-Peng Zhao Tian Tian Wei-Chen Wang Zaizhou Liu qiang Zhou xian-Feng Hou Jing Wang Wenli Guo Shuangjun Lin Yasuhiro Igarashi Gong-Li tang State Key Laboratory of Chemical Biology Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China State Key Laboratory of Microbial Metabolism&Joint International Research Laboratory on Metabolic and Developmental Sciences School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghai 200240China Biotechnology Research Center Toyama Prefectural UniversityImizu 939-0398Japan

A 61-kb biosynthetic gene cluster(BGC),which is accountable for the biosynthesis of hibarimicin(HBM)B from Microbispora rosea *** TP-A0121,was heterologously expressed in Streptomyces coelicolor M1154,which generated a trace of the target products but accumulated a large amount of shunt *** on rational analysis of the relevant secondary metabolism,directed engineering of the biosynthetic pathways resulted in the high production of HBM B,as well as new HBM derivates with improved antitumor *** results not only establish a biosynthetic system to effectively synthesize HBMs-a class of the largest and most complex Type-Ⅱpolyketides,with a unique pseudo-dimeric structure-but also set the stage for further engineering and deep investigation of this complex biosynthetic pathway toward potent anticancer drugs.

关键词： Hibarimicin Biosynthesis Heterologous expression Biosynthetic gene cluster Rational engineering Type-II polyketide