检索结果-南通市图书馆

Hydrodynamic function and spring constant calibration of FluidFM micropipette cantilevers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

A general mirror equivalence theorem for coset vertex operator algebras

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2024年第10期67卷 2237-2282页

作者： robert McRae Yau Mathematical Sciences Center Tsinghua UniversityBeijing 100084China

we prove a general mirror duality theorem for a subalgebra U of a simple conformal vertex algebra A and its commutant V=ComA(U).Specifically,we assume that A≌■_(i∈I)U_(i)■V_(i) as a U■V-module,where the U-modules Uiare simple and distinct and are objects of a semisimple braided ribbon category of Umodules,and the V-modules Viare semisimple and contained in a(not necessarily rigid) braided tensor category of *** also assume U=ComA(V).Under these conditions,we construct a braid-reversed tensor equivalence τ:u_(A)→v_(A),where u_(A)is the semisimple category of U-modules with simple objects Ui,i∈I,and v_(A)is the category of V-modules whose objects are finite direct sums of *** particular,the V-modules Viare simple and distinct,and v_(A)is a rigid tensor *** an application,we find a rigid semisimple tensor subcategory of modules for the Virasoro algebra at central charge 13+6p+6p^(-1),p∈Z_(≥2), which is braided tensor equivalent to an abelian 3-cocycle twist of the category of finite-dimensional ***,the Virasoro vertex operator algebra at central charge 13+6p+6p^(-1)is the PSL_(2)(C)-fixed-point subalgebra of a simple conformal vertex algebra w(-p),analogous to the realization of the Virasoro vertex operator algebra at central charge 13-6p-6p^(-1)as the PSL_(2)(C)-fixed-point subalgebra of the triplet algebra w(p).

关键词： vertex operator algebras coset conformal eld theory braid-reversed tensor equivalence Virasoro algebra

维普期刊数据库

Necrotic enteritis and antibiotic-free production of broiler chickens:Challenges in testing and using alternative products

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2024年第01期16卷 288-298页

作者： robert J.Moore School of Science RMIT University

The global trend towards raising broiler chickens without the use of in-feed antibiotics(IFAs) means that there is an ongoing need to develop alternative treatments capable of delivering the benefits that IFAs previously provided. IFAs supported the productivity performance of chickens and played a key role in maintaining their health. Necrotic enteritis(NE) is an important disease of broilers that affects health,productivity, and welfare, and was previously well controlled by IFAs. However, with the reduction in IFA use, NE is resurgent in some countries. Vaccines and various feed additives, including pre-, pro-, and postbiotics, phytobiotics, fatty acids, and phage therapies have been introduced as alternative methods of NE control. while some of these feed additives have specific activity against the NE pathogen, Clostridium perfringens, most have the more general goal of reinforcing gut health. Extensive reviews of the effects of many of these feed additives on gut health have been published recently. Hence, rather than cover previously well reviewed areas of research this review focuses on the challenges and pitfalls in undertaking experimental assessment of alternative NE treatments and translating laboratory research to real world commercial production settings. The review is based on the author's particular experience,reading, thoughts, and analysis of the available information and inevitably presents a particular understanding that is likely to be at odds with others thinking on these issues. It is put forward to stimulate thinking and discussion on the issues covered.

关键词： Necrotic enteritis Clostridium perfringens Vaccines Feed additive Farm management

Volumetric lattice Boltzmann method for pore-scale mass diffusionadvection process in geopolymer porous structures

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and geotechnical Engineering 2024年第6期16卷 2126-2136页

作者： Xiaoyu Zhang Zirui Mao Floyd w.Hilty Yulan Li Agnes grandjean robert Montgomery Hans-Conrad zur Loye Huidan Yu Shenyang Hu Purdue University IndianapolisIN46202USA Pacific Northwest National Laboratory RichlandWA99352USA CEA DESISECDMRCUniv.MontpellierMarcouleFrance Department of Chemistry and Biochemistry University of South CarolinaColumbiaSC29208USA

Porous materials present significant advantages for absorbing radioactive isotopes in nuclear waste *** improve absorption efficiency in nuclear waste treatment,a thorough understanding of the diffusion-advection process within porous structures is essential for material *** this study,we present advancements in the volumetric lattice Boltzmann method(VLBM)for modeling and simulating pore-scale diffusion-advection of radioactive isotopes within geopolymer porous *** structures are created using the phase field method(PFM)to precisely control pore *** our VLBM approach,we introduce a concentration field of an isotope seamlessly coupled with the velocity field and solve it by the time evolution of its particle population *** address the computational intensity inherent in the coupled lattice Boltzmann equations for velocity and concentration fields,we implement graphics processing unit(gPU)*** of the developed model involves examining the flow and diffusion fields in porous ***,good agreement is observed for both the velocity field from VLBM and multiphysics object-oriented simulation environment(MOOSE),and the concentration field from VLBM and the finite difference method(FDM).Furthermore,we investigate the effects of background flow,species diffusivity,and porosity on the diffusion-advection behavior by varying the background flow velocity,diffusion coefficient,and pore volume fraction,***,all three parameters exert an influence on the diffusion-advection *** background flow and diffusivity markedly accelerate the process due to increased advection intensity and enhanced diffusion capability,***,increasing the porosity has a less significant effect,causing a slight slowdown of the diffusion-advection process due to the expanded pore *** comprehensive parametric study provides valuable insights into the kinetics of isotope

关键词： Volumetric lattice Boltzmann method(VLBM) Phase field method(PFM) Pore-scale diffusion-advection Nuclear waste treatment Porous media flow graphics processing unit(gPU) parallelization

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

A detailed rock density model of the Hong Kong territories

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

geodesy and geodynamics 2024年第1期15卷 75-81页

作者： Albertini Nsiah Ababio robert Tenzer Department of Land Surveying and geo-Informatics Hong Kong Polytechnic UniversityHong KongChina

we used the geological map and published rock density measurements to compile the digital rock density model for the Hong Kong *** then estimated the average density for the whole *** to our result,the rock density values in Hong Kong vary from 2101 to 2681 kg·m^(-3).These density values are typically smaller than the average density of 2670 kg·m^(-3),often adopted to represent the average density of the upper continental crust in physical geodesy and gravimetric geophysics *** finding reflects that the geological configuration in Hong Kong is mainly formed by light volcanic formations and lava flows with overlying sedimentary deposits at many locations,while the percentage of heavier metamorphic rocks is very low(less than 1%).This product will improve the accuracy of a detailed geoid model and orthometric heights.

关键词： Density model Rock types gravimetric modeling Hong Kong

维普期刊数据库

The concept of gene therapy for glaucoma:the dream that has not come true yet

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第1期19卷 92-99页

作者： robert Sulak Xiaonan Liu Adrian Smedowski Department of Physiology Faculty of Medical Sciences in KatowiceMedical University of Silesia in KatowiceKatowicePoland Institute of Biotechnology HiLIFEUniversity of HelsinkiHelsinkiFinland glaucoTech Co. KatowicePoland

gene therapies,despite of being a relatively new therapeutic approach,have a potential to become an important alternative to current treatment strategies in *** glaucoma is not considered a single gene disease,the identified goals of gene therapy would be rather to provide neuroprotection of retinal ganglion cells,especially,in intraocular-pressure-independent *** most commonly reported type of vector for gene delivery in glaucoma studies is adeno-associated virus serotype 2 that has a high tro pism to retinal ganglion cells,res ulting in long-term expression and low immunogenic *** gene thera py studies recruit inducible and genetic animal models of optic neuropathy,like DBA/2J mice model of high-tension glaucoma and the optic nerve *** gene therapy-based neuroprotection of retinal ganglion cells is targeting specific genes translating to growth factors(i.e.,brain derived neurotrophic factor,and its receptor TrkB),regulation of apoptosis and neurodegeneration(i.e.,Bcl-xl,Xiap,FAS system,nicotinamide mononucleotide adenylyl transferase 2,Digit3 and Sarm1),immunomodulation(i.e.,Crry,C3 complement),modulation of neuroinflammation(i.e.,e rythropoietin),reduction of excitotoxicity(i.e.,Com KIlα)and transcription regulation(i.e.,Max,Nrf2).On the other hand,some of gene therapy studies focus on lowering intra ocular pressure,by impacting genes involved in both,decreasing aqueous humor production(i.e.,aquaporin 1),and increasing outflow facility(i.e.,COX2,prostaglandin F2a receptor,RhoA/RhoA kinase signaling pathway,MMP1,Myocilin).The goal of this review is to summarize the current stateof-art and the direction of development of gene therapy strategies for glaucomatous neuropathy.

关键词： adeno-associated virus gene editing gene therapy glaucoma IOP lowering IOP-independent mechanisms neuroprotection optic nerve optic neuropathy retinal ganglion cells

维普期刊数据库

Surgeon preferences in the treatment of thumb carpometacarpal osteoarthritis

在线全文

学校读者我要写书评

暂无评论

world Journal of Orthopedics 2024年第5期15卷 435-443页

作者： Edward J wu Bradley w Fossum wyatt Vander Voort Christopher O Bayne robert M Szabo Department of Orthopedic Surgery University of Minnesota Medical SchoolMinneapolisMN 55455United States Department of Orthopaedic Surgery UC Davis School of MedicineSacramentoCA 95817United States

BACKgROUND Primary thumb carpometacarpal(CMC)osteoarthritis is one of the most common conditions encountered by hand *** the vast number of operations that have been proposed,none have demonstrated results significantly superior to trapeziectomy *** The purpose of our study was to determine why surgeons opt for their technique in treating CMC *** A cross-sectional survey of active members of the American Society for Surgery of the Hand was conducted to evaluate the reasons behind their preferred technique in the treatment of isolated thumb CMC *** were contacted by email once and provided with a link to a de-identified survey consisting of 5 treatment questions and 5 demographic *** Of 950 responses were received.40.5%of surgeons preferred trapeziectomy+ligament reconstruction tendon interposition(LRTI),followed by trapeziectomy+suspensionplasty(28.2%),suture button suspension(5.9%),trapeziectomy alone(4.6%),prosthetic arthroplasty(3.2%),arthrodesis(1.1%),and other(6.6%).Proponents of trapeziectomy+LRTI cited familiarity(73.2%),exposure during fellowship(48.8%)and less proximal migration(60%)to be the main reasons affecting their *** who preferred trapeziectomy+suspensionplasty most reported simplicity(74.9%),fewer complications(45.3%),less proximal migration(43.8%),and avoidance of autogenous tissue harvest(42.7%).Advocates of suture button suspension cited avoidance of autogenous tissue harvest(80.4%),shorter immobilization(76.8%),and quicker recovery(73.2%)with their *** of trapeziectomy alone cited simplicity(97.7%),fewer complications(86.4%),and avoidance of autogenous tissue harvest(59.1%).In their comments,45%of surgeons choosing trapeziectomy alone cited evidence as an additional *** of prosthetic arthroplasty cited improved pinch strength(83.3%)and improved range of motion(63.3%),while those preferring arthrodesis cited better pinch strength(90%)and freque

关键词： Thumb carpometacarpal Osteoarthritis Trapeziectomy Ligament reconstruction tendon interposition Suspensionplasty Preferences Trends