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Acta Mechanica Solida Sinica 2024年第3期37卷 396-405页

作者： Zuorong Chen Xiaofang Jiang Zhejun Pan robert g.Jeffrey National Key Laboratory of Continental Shale Oil Northeast Petroleum UniversityDaqing163318China SCT Operation Pty.Ltd. PO Box 824WollongongNSW2520Australia

Pressure and tilt data are jointly inverted to simultaneously map the orientation and dimensions of a hydraulic *** deformation induced by a fracture under internal pressure is modeled using the distributed dislocation *** planar fracture is represented by four quarter ellipses,joined at the center and sharing *** configuration provides a straightforward model for characterizing asymmetric fracture *** inverse problem of mapping the fracture geometry is formulated using the Bayesian probabilistic method,combining the a priori information on the fracture model with updated information from pressure and tilt *** the nonlinear inverse problem is achieved by pseudo-randomly sampling the posterior probability distribution through the Markov chain Monte Carlo *** resulting posterior probability distribution is then explored to assess uncertainty,resolution,and correlation between model *** experiments are conducted to verify the accuracy and validity of the proposed analysis method in mapping the fracture geometry using synthetic pressure and tilt data.

关键词： Hydraulic fracture mapping Coupled inversion Tilt Treating pressure

Hydrodynamic function and spring constant calibration of FluidFM micropipette cantilevers

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Microsystems & Nanoengineering 2024年第1期10卷 277-286页

作者： Attila Bonyár Ágoston g.Nagy Hans gunstheimer gotthold Fläschner robert Horvath Department of Electronics Technology Faculty of Electrical Engineering and InformaticsBudapest University of Technology and EconomicsBudapestHungary Nanobiosensorics Laboratory Institute of Technical Physics and Materials ScienceCentre for Energy ResearchHUN-RENBudapestHungary Nanosurf Ag Gräubernstrasse 12CH-4410 LiestalSwitzerland

Fluidic force microscopy(FluidFM)fuses the force sensitivity of atomic force microscopy with the manipulation capabilities of microfluidics by using microfabricated cantilevers with embedded fluidic *** innovation initiated new research and development directions in biology,biophysics,and material *** acquire reliable and reproducible data,the calibration of the force sensor is ***,the hollow FluidFM cantilevers contain a row of parallel pillars inside a rectangular *** precise spring constant calibration of the internally structured cantilever is far from trivial,and existing methods generally assume simplifications that are not applicable to these special types of *** addition,the Sader method,which is currently implemented by the FluidFM community,relies on the precise measurement of the quality factor,which renders the calibration of the spring constant sensitive to *** this study,the hydrodynamic function of these special types of hollow cantilevers was experimentally determined with different *** on the hydrodynamic function,a novel spring constant calibration method was adapted,which relied only on the two resonance frequencies of the cantilever,measured in air and in a *** on these results,our proposed method can be successfully used for the reliable,noise-free calibration of hollow FluidFM cantilevers.

关键词： spring cantilever function

Predicting the coefficient of friction in a sliding contact by applying machine learning to acoustic emission data

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Friction 2024年第6期12卷 1299-1321页

作者： robert gUTIERREZ Tianshi FANg robert MAINwARINg Tom REDDYHOFF Tribology group Department of Mechanical EngineeringImperial College LondonExhibition RoadLondon SW72AZUK Shell global Solutions(US)Inc.Shell Technology Center Houston 3333 Highway 6 SouthHoustonTX 77082USA Shell International Petroleum Company Limited Shell CentreYork RoadLondon SE17NAUK

It is increasingly important to monitor sliding interfaces within machines,since this is where both energy is lost,and failures *** emission(AE)techniques offer a way to monitor contacts remotely without requiring transparent or electrically conductive ***,acoustic data from sliding contacts is notoriously complex and difficult to ***,we simultaneously measure coefficient of friction(with a conventional force transducer)and acoustic emission(with a piezoelectric sensor and high acquisition rate digitizer)produced by a steel‒steel rubbing *** data is then used to train machine learning(ML)algorithms(e.g.,gaussian process regression(gPR)and support vector machine(SVM))to correlated acoustic emission with *** training requires the dense AE data to first be reduced in size and a range of processing techniques are assessed for this(e.g.,down-sampling,averaging,fast Fourier transforms(FFTs),histograms).Next,fresh,unseen AE data is given to the trained model and the resulting friction predictions are compared with the directly measured *** is excellent agreement between the measured and predicted friction when the gPR model is used on AE histogram data,with root mean square(RMS)errors as low as 0.03 and Pearson correlation coefficients reaching ***,predictions remain accurate despite changes in test conditions such as normal load,reciprocating frequency,and stroke *** paves the way for remote,acoustic measurements of friction in inaccessible locations within machinery to increase mechanical efficiency and avoid costly failure/needless maintenance.

关键词： acoustic emission condition monitoring friction machine learning gaussian process regression support vector machine

Increases in the incremental exercise mean response time across the steady state domain:Implications for exercise testing&prescription

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Sports Medicine and Health Science 2024年第4期6卷 315-323页

作者： Bridgette g.J.O'Malley robert A.Robergs Todd A.Astorino Queensland University of Technology Faculty of Health:School of Exercise and Nutrition SciencesBrisbaneAustralia Department of Kinesiology CSU-San MarcosSan MarcosCAUSA

we hypothesized that slowed oxygen uptake(VO_(2))kinetics for exercise transitions to higher power outputs(PO)within the steady state(SS)domain would increase the mean response time(MRT)with increasing exercise intensity during incremental *** highly trained cyclists(mean±standard deviation[SD]);age(39±6)years[yr];and VO_(2) peak=(61±9)mL/kg/min performed a maximal,ramp incremental cycling test and on separate days,four 6-min bouts of cycling at 30%,45%,65%&75% of their incremental peak PO(wpeak).SS trial data were used to calculate the MRT and verified by mono-exponential and linear curve *** the ramp protocol attained the value from SS,the PO,in watts(w),was converted to time(min)based on the ramp function w to quantify the incremental MRT(iMRT).Slope analyses for the VO_(2) responses of the SS versus incremental exercise data below the gas exchange threshold(gET)revealed a significant difference(p=0.003;[0.437±0.08]vs.[0.382±0.05]L·min^(-1)).There was a significant difference between the 45%wpeak steady state VO_(2)(ss VO_(2))([3.08±0.30]L·min^(-1),respectively),and 30% wpeak ss VO_(2)(2.26±0.24)(pween the iMRT for 45% and 30% wpeak ss VO_(2) values([50.58±36.85]s vs.[32.20±43.28]s).These data indicate there is no single iMRT,which is consistent with slowed VO_(2) kinetics and an increasing VO_(2) deficit for higher exercise intensities within the SS domain.

关键词： Mean responsetime(MRT) Incremental exercise Steady state(SS) Exercise testing Exercise prescription

High-Intensity Focused Ultrasound-Induced Disulfide Mechanophore Activation in Polymeric Nanostructures for Molecule Release

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CCS Chemistry 2024年第8期6卷 1895-1907页

作者： Jilin Fan Kuan Zhang Mingjun Xuan Xiang gao Rostislav Vinokur robert göstl Lifei Zheng Andreas Herrmann DwI—Leibniz Institute for Interactive Materials 52056 Aachen Institute of Technical and Macromolecular Chemistry RWTH Aachen University52074 Aachen wenzhou Institute University of Chinese Academy of Sciences325001 Wenzhou

Ultrasound(US)activation of mechanophores in polymers that initiates cascade chemical reactions is a promising strategy for on-demand molecule ***,the typical US frequency used for mechanochemistry is around 20 kHz,producing inertial cavitation that exceeds the tolerance threshold of biological ***,high-intensity focused US(HIFU)as a mechanical stimulus is introduced to drive the activation of disulfide mechanophores in hyperbranched star polymers(HBSPs)and microgels(MgLs).The mechanism of molecular release is attributed to the thiol-disulfide exchange reaction and subsequent intramolecular *** reveal that HBSPs and MgLs effectively transduce HIFU as mechanical input to chemical output,demonstrated by the quantification of the release of fluorescent umbelliferone(UMB).Moreover,an in vitro study of drug release is carried out using camptothecin as the model drug,which is covalently loaded in MgLs,demonstrating the potential of our system for controlled drug delivery to cancer cells.

关键词： mechanophores polymer mechanochemistry polymeric nanostructures ultrasound drug release sonopharmacology

Three-dimensional analysis of age and sex differences in femoral head asphericity in asymptomatic hips in the United States

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world Journal of Orthopedics 2024年第8期15卷 754-763页

作者： Mahad M Hassan Aliya g Feroe Brenton w Douglass Andrew E Jimenez Benjamin Kuhns Charles F Mitchell robert L Parisien Daniel A Maranho Eduardo N Novais Young-Jo Kim Ata M Kiapour Department of Orthopedic Surgery University of MinnesotaMinneapolisMN 55454United States Department of Orthopedic Surgery TRIA Orthopaedic CenterBloomingtonMN 55122United States Department of Orthopedic Surgery Boston Children’s HospitalBostonMA 02115United States Department of Orthopedic Surgery Mayo ClinicRochesterMN 55901United States Department of Orthopaedics and Rehabilitation Yale School of MedicineNew HavenCT 06510United States Department of Orthopedic Surgery American Hip Institute Research FoundationDes PlainesIL 60018United States Department of Orthopedic Surgery Mount SinaiNew YorkNY 10029United States Department of Biomechanics Medicineand Rehabilitation of the Locomotor SystemRibeirao Preto Medical SchoolUniversity of São PauloRibeirao Preto 14048-900São PauloBrazil

BACKgROUND The sphericity of the femoral head is a metric used to evaluate hip pathologies and is associated with the development of osteoarthritis and femoral-acetabular *** To analyze the three-dimensional asphericity of the femoral head of asymptomatic pediatric *** hypothesized that femoral head asphericity will vary significantly between male and female pediatric hips and increase with age in both *** Computed tomography scans were obtained on 158 children and adolescents from a single institution in the United States(8-18 years;50%male)without hip *** femoral measurements including the femoral head diameter,femoral head volume,residual volume,asphericity index,and local diameter difference were used to evaluate femoral head *** In both sexes,the residual volume increased by age(Pgnificantly smaller femoral head size in older ages(>13 years)in females,there were no sex-differences in residual volume and aspherity *** were no age-related changes in mean diameter difference in both sexes(P=0.07)with no significant sex-differences across different age groups(P=0.06).In contrast,there were significant increases in local aspherity(maximum diameter difference)across whole surface of the femoral head and all quadrants except the inferior regions in males(P=0.03).There were no sex-differences in maximum diameter difference at any regions and age group(P>0.05).Increased alpha angle was only correlated to increased mean diameter difference across overall surface of the femoral head(P=0.024).CONCLUSION There is a substantial localized asphericity in asymptomatic hips which increases with age *** 2D measured alpha angle can capture overall asphericity of the femoral head,it may not be sensitive enough to represent regional asphericity patterns.

关键词： Hip Femoral head Sphericity Skeletal growth Sex differences

Conducting Polymer-Based e-Refinery for Sustainable Hydrogen Peroxide Production

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Energy & Environmental Materials 2024年第2期7卷 334-342页

作者： Zhixing wu Penghui Ding Viktor gueskine robert Boyd Eric Daniel g■owacki Magnus Odén Xaνier Crispin Magnus Berggren Emma M.Björk Mikhail Vagin Nanostructured Materials Department of PhysicsChemistry and Biology(IFM)Linköping UniversitySE 58183LinköpingSweden Laboratory of Organic Electronics Department of Science and Technology(ITN)Linköping UniversitySE 60174NorrköpingSweden

Electrocatalysis enables the industrial transition to sustainable production of chemicals using abundant precursors and electricity from renewable ***-centralized production of hydrogen peroxide(H_(2)O_(2))from water and oxygen of air is highly desirable for daily life and *** report an effective electrochemical refinery(e-refinery)for H_(2)O_(2)by means of electrocatalysis-controlled comproportionation reaction(2_(H)O+o→2HO),feeding pure water and oxygen *** nickel(Ⅱ)oxide(NiO)was used as electrocatalyst for oxygen evolution reaction(OER),producing oxygen at the *** polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)drove the oxygen reduction reaction(ORR),forming H_(2)O_(2)on the *** reactions were evaluated in both half-cell and device *** performance of the H_(2)O_(2)e-refinery,assembled on anion-exchange solid electrolyte and fed with pure water,was limited by the unbalanced ionic *** of the operation conditions allowed a conversion efficiency of 80%.

关键词： conducting polymer hydrogen peroxide nickel(Ⅱ)oxide oxygen evolution reaction oxygen reduction reaction

Optical measurements of dissolved organic matter as proxies for COD_(Mn)and BOD_(5)in plateau lakes

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Environmental Science and Ecotechnology 2024年第3期19卷 132-138页

作者： Xuan Yang Yongqiang Zhou Xiaoying Yang Yunlin Zhang robert g.M.Spencer Justin D.Brookes Erik Jeppesen Hucai Zhang Qichao Zhou Institute for Ecological Research and Pollution Control of Plateau Lakes School of Ecology and Environmental SciencesYunnan UniversityKunming650500China Institute of International River and Eco-security Yunnan UniversityKunming650500China Zhejiang College of Security Technology Wenzhou325016China Taihu Laboratory for Lake Ecosystem Research State Key Laboratory of Lake Science and EnvironmentNanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing210008China Department of Earth Ocean and Atmospheric ScienceFlorida State UniversityTallahassee32306United States water Research Centre School of Biological ScienceThe University of AdelaideAdelaide5005Australia Department of Ecoscience Aarhus UniversityAarhus8000Denmark Sino-Danish Centre for Education and Research Chinese Academy of SciencesBeijing100101China Limnology Laboratory Department of Biological Sciences and Centre for Ecosystem Research and ImplementationMiddle East Technical UniversityAnkara06800Turkey Institute of Marine Sciences Middle East Technical UniversityErdemliMersin33731Turkey Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake-watershed Yunnan Research Academy of Eco-environmental SciencesKunming650034China

The presence of organic matter in lakes profoundly impacts drinking water supplies,yet treatment processes involving coagulants and disinfectants can yield carcinogenic disinfection *** assessments of organic matter,such as chemical oxygen demand(COD_(Mn))and biochemical oxygen demand(BOD_(5)),are often ***,optical measurements of dissolved organic matter(DOM)offer a rapid and reliable means of obtaining organic matter composition *** we employed DOM optical measurements in conjunction with parallel factor analysis to scrutinize COD_(Mn)and BOD_(5)*** was performed using an independent dataset encompassing six lakes on the Yungui Plateau from 2014 to 2016(n=256).Leveraging multiple linear regressions(MLRs)applied to DOM absorbance at 254 nm(a254)and fluorescence components C1-C5,we successfully traced COD_(Mn)and BOD_(5)variations across the entire plateau(68 lakes,n=271,R^(2)>0.8,Pgher R^(2))of COD_(Mn)and BOD_(5)during the rainy season compared to the dry season and demonstrated increased accuracy(R^(2)>0.9)in mesotrophic lakes compared to oligotrophic and eutrophic *** study underscores the utility of MLR-based DOM indices for inferring COD_(Mn)and BOD_(5)variability in plateau lakes and highlights the potential of integrating in situ and remote sensing platforms for water pollution early warning.

关键词： Dissolved organic matter Chemical oxygen demand Biochemical oxygen demand water quality Yungui plateau lakes

Importance of periphytic biofilms for carbon cycling in paddy fields:A review

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Pedosphere 2024年第1期34卷 36-43页

作者： Lei ZHOU Yonghong wU Junzhuo LIU Pengfei SUN Ying XU Jan DOLFINg robert gMSPENCER Erik JEPPESEN State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China Zigui Three gorges Reservoir Ecosystem Observation and Research Station of Ministry of Water Resources of the People's Republic of ChinaYichang 443605China College of Nanjing University of Chinese Academy of SciencesNanjing 211135China Faculty of Energy and Environment Northumbria UniversityNewcastle upon Tyne NE18QHUK Department of Earth Ocean and Atmospheric ScienceFlorida State UniversityTallahassee FL 32306USA Department of Ecoscience&Centre for water Technology(wATEC) Aarhus UniversityAarhus DK-8000Denmark Sino-Danish Centre for Education and Research Beijing 100049China Limnology Laboratory Department of Biological Sciences and Centre for Ecosystem Research and Implementation(EKOSAM)Middle East Technical UniversityAnkara 06800Turkiye Institute of Marine Sciences Middle East Technical UniversityMersin 33731Turkiye

Paddy fields play an important role in global carbon(C) cycling and are an important source of methane(CH_(4)) emissions. Insights into the processes influencing the dynamics of soil organic C(SOC) in paddy fields are essential for maintaining global soil C stocks and mitigating climate change. Periphytic biofilms composed of microalgae, bacteria, and other microorganisms are ubiquitous in paddy fields, where they directly mediate the transfer of elements at the soil-water interface. However, their contributions to C turnover and exchange have been largely neglected. Periphytic biofilms affect and participate in soil C dynamics by altering both abiotic(e.g., pH and redox potential) and biotic conditions(e.g., microbial community composition and metabolism). This review summarizes the contributions of periphytic biofilms to soil C cycling processes, including carbon dioxide fixation, SOC mineralization, and CH_(4) emissions. Future research should be focused on: i) the mechanisms underlying periphytic biofilm-induced C fixation and turnover and ii) quantifying the contributions of periphytic biofilms to soil C uptake, stabilization, and sequestration in paddy fields.

关键词： carbon fixation carbon mineralization carbon sequestration methane emission microbial aggregates soil organic carbon