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Analysis of global and local stress changes in a longwall gateroad

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International Journal of Mining Science and Technology 2018年第1期28卷 127-135页

作者： I.B.Tulu G.S.Esterhuizen d.Gearhart T.M.Klemetti K.M.Mohamed d.w.h.su department of Mining Engineering West Virginia University NIOSh Pittsburgh Mining Research Division

A numerical-model-based approach was recently developed for estimating the changes in both the horizontal and vertical loading conditions induced by an approaching longwall *** this approach, a systematic procedure is used to estimate the model's *** along the bedding planes is modeled with ubiquitous joint elements and interface *** is modeled with a newly developed coal mass *** response of the gob is calibrated with back analysis of subsidence data and the results of previously published laboratory tests on rock *** model results were verified with the subsidence and stress data recently collected from a longwall mine in the eastern United States.

关键词： Longwall mining Gateroad design Flac3d horizontal angle Gob loading hollow inclusion cells

Shock Formation for 2d Isentropic Euler Equations with Self-similar Variables

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Chinese Annals of Mathematics,Series B 2024年第3期45卷 349-412页

作者： wenze su School of Mathematical Sciences Fudan UniversityShanghai 200433China

The author studies the 2d isentropic Euler equations with the ideal gas *** exhibits a set of smooth initial data that give rise to shock formation at a single point near the planar *** solutions to the 2d isentropic Euler equations are associated with non-zero vorticity at the shock and have uniform-in-time-1/3-holder ***,these point shocks are of self-similar type and share the same profile,which is a solution to the 2d self-similar Burgers *** proof of the solutions,following the 3d construction of Buckmaster,Shkoller and Vicol(in 2023),is based on the stable 2d self-similar Burgers profile and the modulation method.

关键词： 2d isentropic Euler equations Shock formation Self-similar solution

Multiresponsive,easy-reversible,and dual-visual Pt(Ⅱ)salt nanostructures for advanced anti-counterfeiting application

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Nano Research 2024年第1期17卷 372-381页

作者： Zhen su§ depeng Li§ Lixin Zhang Si Tian Yuhong su Xiaoyun hu duan Xiong Qingqing Guan Key Laboratory of Oil and Gas Fine Chemicals Ministry of Education College of Chemical EngineeringXinjiang UniversityUrumqi 830017China

Smart materials that integrate multi-stimuli response,full reversibility,and dual-visual read-out channel are highly desired for anticounterfeiting and information encryption ***,we developed a multiresponsive perchlorate terpyridyl Pt(Ⅱ)nano complex which could undergo fully reversible conversion between three forms stimulated by water or formaldehyde molecule due to the extent of Pt–Pt ***,a dual-visual channel,i.e.,the colorimetric channel changed from yellow to orange or red and the corresponding luminescent channel from orange to orange-red or red,has also been *** weak and equivalent strength of ion-dipole interaction and hydrogen bond that generated between formaldehyde/water and Pt(II)salt result in the easy-control reversibility between the three ***,by introducing different polymer matrices,1Cl·ClO_(4)@PMMA(1Cl·ClO_(4):[Pt(tpy)Cl]·ClO4,tpy:2,2':6',2''-terpyridine),PMMA:poly(methyl methacrylate))and 1Cl·ClO4@PVA(PVA:polyvinyl alcohol)are successfully constructed,which exhibit different reversible behaviors since the PMMA and PVA matrix exert different influences on the strength of *** smart Pt(II)salt nanostructures present great potential for high-security-level anticounterfeiting application.

关键词： Pt(II)complex multiresponse reversibility anticounterfeiting information encryption

surrogate modeling for unsaturated infiltration via the physics and equality-constrained artificial neural networks

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2282-2295页

作者： Peng Lan Jingjing su Sheng Zhang School of Civil Engineering Central South UniversityChangsha410075China discipline of Civil Surveying and Environmental EngineeringPriority Research Centre for Geotechnical Science and EngineeringThe University of NewcastleCallaghanNSW2308Australia Qinghai University Qinghai810016China

Machine learning(ML)provides a new surrogate method for investigating groundwater flow dynamics in unsaturated *** pure data-driven methods(*** neural network,dNN)can provide rapid predictions,but they do require sufficient on-site data for accurate training,and lack interpretability to the physical processes within the *** this paper,we provide a physics and equalityconstrained artificial neural network(PECANN),to derive unsaturated infiltration solutions with a small amount of initial and boundary *** takes the physics-informed neural network(PINN)as a foundation,encodes the unsaturated infiltration physical laws(*** equation,RE)into the loss function,and uses the augmented Lagrangian method to constrain the learning process of the solutions of RE by adding stronger penalty for the initial and boundary *** unsaturated infiltration cases are designed to test the training performance of PECANN,***-dimensional(1d)steady-state unsaturated infiltration,1d transient-state infiltration,two-dimensional(2d)transient-state infiltration,and 1d coupled unsaturated infiltration and *** predicted results of PECANN are compared with the finite difference solutions or analytical *** results indicate that PECANN can accurately capture the variations of pressure head during the unsaturated infiltration,and present higher precision and robustness than dNN and *** is also revealed that PECANN can achieve the same accuracy as the finite difference method with fewer initial and boundary training ***,we investigate the effect of the hyperparameters of PECANN on solving RE *** provides an effective tool for simulating unsaturated infiltration.

关键词： Richards equation(RE) Unsaturated infiltration data-driven solutions Numerical modeling Machine learning(ML)

Experimental Investigation of the Operating Characteristics of a Pulsating heat Pipe with Ultra-Pure water and Micro Encapsulated Phase Change Material suspension

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Journal of Thermal Science 2024年第2期33卷 457-468页

作者： ShI weixiu su Xiaoyang ChEN hongdi PAN Lisheng Beijing Engineering Research Center of sustainable Energy and Buildings Beijing University of Civil Engineering and ArchitectureBeijing100044China School of Environment and Energy Engineering Beijing University of Civil Engineering and ArchitectureBeijing100044China State Key Laboratory of high Temperature Gas dynamics Institute of MechanicsChinese Academy of SciencesBeijing100190China

The specific heat capacity of working fluid is an important influence factor on heat transfer characteristic of the pulsating heat pipe(PhP).due to the relatively large specific heat capacity of micro encapsulated phase change material(MEPCM) suspension,a heat transfer performance experimental facility of the PhP was *** heat transfer characteristic with MEPCM suspension of different mass concentrations(0.5% and 1.0%) and ultra-pure water were compared *** was found that when the PhP uses MEPCM suspension as its working fluid,operating stability is impoverished under lower heating power and the operating stability is better under higher heating *** the inclination angle of 90°,the temperature at heating side decreases compared to ultra-pure water and the temperature at heating side decreases with the raising of MEPCM suspension mass *** heat transfer characteristic of the PhP is positively correlated with the inclination angle and the 90° is *** unfavorable effect of the inclination angle decreases with heating power *** the inclination angle is 90°,the PhP with MEPCM suspension at 1.0% of mass concentration has the lowest thermal transfer resistance and followed by ultra-pure water and MEPCM suspension at 0.5% of mass concentration has the highest thermal transfer *** the inclination angles are 60° and30°,the effect of gravity on the flow direction is reduced to 86.6% and 50% of that on the inclination angle of 90°,respectively,and the promoting effect of gravity on the working fluid is further weakened as the inclination angle further *** to the high viscosity of MEPCM suspension,the PhP with ultra-pure water has the lowest heat transfer *** the inclination angles is 60°,the thermal resistance with MEPCM suspension at0.5% of the mass concentration is lower than that at 1.0% at the heating power below 230 *** thermal resistance of MEPCM suspension tends to be simila

关键词： pulsating heat pipe(PhP) micro encapsulated phase change material(MEPCM) heat transfer characteristic inclination angle

Investigation on combustion and emission characteristics of diesel polyoxymethylene dimethyl ethers blend fuels with exhaust gas recirculation and double injection strategy

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第4期11卷 614-630页

作者： Xin su Rui su Nan Gao hao Chen Zhenhua Ji hongming Xu Biao wang Shaanxi Key Laboratory of New Transportation Energy and Automotive Energy Saving Chang'an UniversityXi'an 710064China School of Vechicle Engineering Xi'an Aeronautical UniversityXi'an 710077China department of Mechanical Engineering University of BirminghamBirmingham B152TTUK

As a kind of renewable and high oxygen content fuel,polyoxymethylene dimethyl ether(POdE)can be added in diesel to realize energy saving and emissions *** evaluate the combustion and emission characteristics of a diesel engine fueled with diesel and diesel/POdE mixtures,exhaust gas recirculation(EGR)and main-pilot injection strategies with various injection timings were *** was blended with diesel by volume to form mixtures which were marked as d100(pure diesel),d90P10(90%diesel+10%POdE),and d80P20(80%diesel+20%POdE).The results showed that the ignition delay(Id)and combustion duration(Cd)of d80P20 were the shortest because of the highest cetane number(CN)and high oxygen content of POdE,indicating more concentrated heat *** low and medium loads,d80P20 achieved the highest peak heat release ratio(PhRR)and peak combustion temperature(PCT)among the three fuels,and it was 14.3%and 3.6%higher than those of *** blending with diesel can significantly reduce particulate matter(PM)and d80P20 has the lowest PM emissions at all *** with d100,both PM and nitrogen oxide(NO_(x))emissions of POdE blends decreased simultaneously with 20%EGR at all *** the increase of pilot-main interval,the Id and Cd of all test fuels increased,while the NO_(x)and PM emissions *** conclusions of the present research provide a state of the application in light-duty engines fueled with diesel/POdE blends in future work.

关键词： Polyoxymethylene dimethyl ethers diesel engine NOx Particulate number Pilot plus main injections

Structure and Representations for Electrical Lie Algebra of Type d_(5)

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Algebra Colloquium 2024年第2期31卷 271-284页

作者： Yulu Chen Ran Shen Yucai su College of Science Donghua UniversityShanghai 201620China 不详

In this paper,we prove that the electrical Lie algebra e d_(5)is isomorphic to the semidirect product of sp_(4)and a 2-step nilpotent Lie ***,we classify the irreducible highest weight modules for e d_(5).

关键词： electrical Lie algebra 2-step nilpotent Lie algebra highest weight module

Molecular evolution of Toll-like receptors in rodents

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Integrative Zoology 2024年第3期19卷 371-386页

作者： Qianqian su Yi ChEN hongxuan hE College of Forestry Central South University of Forestry and TechnologyChangshaChina National Research Center for wildlife-Borne diseases Institute of ZoologyChinese Academy of SciencesBeijingChina

Toll-like receptors(TLRs),the key sensor molecules in vertebrates,trigger the innate immunity and prime the adaptive immune *** TLR family of rodents,the largest order of mammals,typically contains 13 TLR ***,a clear picture of the evolution of the rodent TLR family has not yet emerged and the TLR evolutionary patterns are unclear in rodent ***,we analyzed the natural variation and the evolutionary processes acting on the TLR family in rodents at both the interspecific and population *** results showed that rodent TLRs were dominated by purifying selection,but a series of positively selected sites(PSSs)primarily located in the ligand-binding domain was also *** numbers of PSSs differed among TLRs,and nonviralsensing TLRs had more PSSs than those in viral-sensing ***-conversion events were found between TLR1 and TLR6 in most rodent *** genetic analyses showed that TLR2,TLR8,and TLR12 were under positive selection in Rattus norvegicus and ***,whereas positive selection also acted on TLR5 and TLR9 in the former species,as well as TLR1 and TLR7 in the latter ***,we found that the proportion of polymorphisms with potentially functional change was much lower in viral-sensing TLRs than in nonviral-sensing TLRs in both of these rat *** findings revealed the first thorough insight into the evolution of the rodent TLR genetic variability and provided important novel insights into the evolutionary history of TLRs over long and short timescales.

关键词： adaptive evolution gene conversion positive selection rodents Toll-like receptors

Risk factors for long COVId in children and adolescents:a systematic review and meta-analysis

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world Journal of Pediatrics 2024年第2期20卷 133-142页

作者： daniel G.Rayner Elaine wang Cloris su Om d.Patel Stephanie Aleluya Alessandra Giglia Evelyn Zhu Maha Siddique department of health Research Methods Evidenceand ImpactFaculty of Health SciencesMcMaster University1280 Main St WHamiltonONL8S 4K1Canada Faculty of health Sciences McMaster University1280 Main St WHamiltonON L8S 4K1Canada Faculty of Science McMaster University1280 Main St WHamiltonONL8S 4K1Canada

Background The long-term sequelae of COVId-19 in children and adolescents remain poorly understood and *** systematic review and meta-analysis sought to summarize the risk factors for long COVId in the pediatric *** we searched six databases from January 2020 to May 2023 for observational studies reporting on risk factors for long COVId or persistent symptoms those were present 12 or more weeks post-infection using multivariable regression *** registries,reference lists of included studies,and preprint servers were hand-searched for relevant ***-effects meta-analyses were conducted to pool odds ratios for each risk *** study risk of bias was rated using QUIPS,and the GRAdE framework was used to assess the certainty of evidence for each unique *** Sixteen observational studies(N=46,262)were included,and 19 risk factors were amenable to *** moderate certainty in the evidence,age(per 2-year increase),allergic rhinitis,obesity,previous respiratory diseases,hospitalization,severe acute COVId-19,and symptomatic acute COVId-19 are probably associated with an increased risk of long *** sex,asthma,comorbidity,and heart diseases may be associated with an increased risk of long COVId,and Asian and Black races may be associated with a decreased risk of long *** did not observe any credible subgroup effects for any risk *** The current body of literature presents several compelling risk factors for the development of long COVId in the pediatric *** research is necessary to elucidate the pathophysiology of long COVId.

关键词： COVId-19 Long COVId Post-acute COVId-19 syndrome Pediatrics Risk factors