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Effective data sampling strategies and boundary condition constraints of physics-informed neural networks for identifying material properties in solid mechanics

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Applied Mathematics and Mechanics(English Edition) 2023年第7期44卷 1039-1068页

作者： W.Wu M.DANEKER M.A.JOLLEY K.T.TuRNER L.Lu department of Anesthesiology and Critical Care Medicine Children's Hospital of PhiladelphiaPhiladelphiaPA 19104U.S.A. Division of Pediatric Cardiology Children's Hospital of PhiladelphiaPhiladelphiaPA 19104U.S.A. department of Chemical and Biomolecular Engineering University of PennsylvaniaPhiladelphiaPA 19104U.S.A. department of Mechanical Engineering and Applied Mechanics University of PennsylvaniaPhiladelphiaPA 19104U.S.A.

Material identification is critical for understanding the relationship between mechanical properties and the associated mechanical ***,material identification is a challenging task,especially when the characteristic of the material is highly nonlinear in nature,as is common in biological *** this work,we identify unknown material properties in continuum solid mechanics via physics-informed neural networks(PINNs).To improve the accuracy and efficiency of PINNs,we develop efficient strategies to nonuniformly sample observational *** also investigate different approaches to enforce Dirichlet-type boundary conditions(BCs)as soft or hard ***,we apply the proposed methods to a diverse set of time-dependent and time-independent solid mechanic examples that span linear elastic and hyperelastic material *** estimated material parameters achieve relative errors of less than 1%.As such,this work is relevant to diverse applications,including optimizing structural integrity and developing novel materials.

关键词： solid mechanics material identification physics-informed neural network(PINN) data sampling boundary condition(BC)constraint

Born of a Natural Disaster, 50 Years Later Bangladesh Faces More Environmental Challenges

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Journal of Environmental science and Engineering(A) 2021年第2期10卷 52-55页

作者： Douglas Batson Retired Geographer U.S.Department of DefenseWashington DC 20511USA

Rural-to-urban migration and globalized trade are swelling cities worldwide,but these forces are perhaps more powerfully concentrated in Dhaka,Bangladesh,than anywhere on *** of a natural disaster 50 years ago,the world’s most densely-populated country faces multiple environmental ***,with seasonal monsoons,is both a blessing and a curse.A one meter rise in sea level,for example,would displace as many as 25 million Bangladeshis,and cause the largest mass migration in *** drought,flood,or cyclone drives scores of environmental refugees from rural areas to the capital city of Dhaka,where air and water pollution run *** rapprochement with India over decades-long boundary disputes offers hope that environmental cooperation in the vulnerable Bay of Bengal can follow.

关键词： Bangladesh environment refugees water contamination floods megacity land boundary agreement.

Chromium adsorption on surface activated biochar made from tannery liming sludge:A waste-to-wealth approach

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Water science and Engineering 2022年第4期15卷 328-336页

作者： Abul Hashem sofia Payel sadia Mim Anik Hasan shahruk Nur-A-Tomal Aminur Rahman Majher I.sarker department of Leather Engineering Khulna University of Engineering&Technology(KUET)Khulna 9203Bangladesh department of Public Health Engineering(DPHE) Zonal LaboratoryJashore 7400Bangladesh Global Centre for Environmental Remediation(GCER) College of EngineeringScience and EnvironmentThe University of NewcastleCallaghanNSW 2308Australia sustainable Biofuels and Co-Products Research unit Eastern Regional Research CenterAgricultural Research ServiceU.S.Department of AgricultureWyndmoorPA 19038USA

In a beamhouse,liming plays a key role in the removal of hair/wool and epidermis,but problems are created when waste liming sludge is discharged to the *** treatment of tannery wastewater is another major challenge to the *** this study,thermally-activated biochars derived from liming sludge were studied for their effective adsorption of chromium(Cr)from the tannery *** thermally activated biochars(B500,B550,B600,and B650)were prepared at different temperatures from the liming *** characteristics before and after the treatment were investigated using Fourier transform infrared spectroscopy,energy dispersive X-ray spectroscopy,Bru-nauer-Emmett-Teller,and scanning electron microscopy *** related functional groups(C-H,O-H,C-N,and=C-O)and chromium adsorption capacity were determined according to the surface morphology,element contents(C,O,Ca,Na,Al,Mg,and si),surface area(5.8-9.2 m^(2)/g),pore size(5.22-5.53 nm),and particle size(652-1034 nm)of the experimental *** biochar originated at 600°C from the tannery liming sludge(B600)had a greater surface area with a chromium adsorption capacity of 99.8%in comparison to B500,B550,and B650 *** study developed an innovative way of utilizing liming sludge waste to minimize the pollution load and wastewater treatment cost in the tannery industry.

关键词： Adsorption Waste recycling Biochar application Thermal modification Tannery solid waste

In-situ sHRIMP u-Pb Dating of Xenotime Outgrowth on Detrital Zircon Grains from the Changzhougou Formation of the Ming Tomb District, Beijing

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Acta Geologica sinica(English Edition) 2015年第1期89卷 304-305页

作者： sHI Yuruo Kennedy ALLEN Aleinikoff JOHN sONG Tianrui LI Linlin suN Huiyi Beijing sHRIMP Center Institute of Geology Chinese Academy of Geological Sciences department of Applied Physics Curtin University u.s. Geological survey

sHRIMP u-Pb dating of diagenetic xenotime from sedimentary rocks has provided age constraints for sedimentary diagenesis （McNaughton et al., 1999; Fletcher et al., 2000; England et al., 2001; Rasmussen et al., 2004; Vallini et al., 2007）. Xenotime （YPO4） may grow during early diagenesis, typically being present as a trace constituent in siliciclastic sedimentary rocks （Rasmussen, 2005）, in the form of syntaxial outgrowths on detrital zircon grains. Diagenetic xenotime occurs in a wide variety of rock types, including conglomerate,

关键词： sHRIMP Pb Beijing

On Ohtsuki's Invariants of Integral Homology 3-spheres

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Acta Mathematica sinica,English series 1999年第3期15卷 293-316页

作者： Xiaosong Lin Zhenghan Wang department of Mathematics, university of California, Riverside, CA 92521, u. s. A.department of Mathematics, Indiana university, Bloomington, IN 47405, u. s. A. department of Mathematics, university of California, La Jolla, CA 92093, u. s. A. department of Mathematics University of California Riverside U. S. A. department of Mathematics Indiana University Bloomington U. S. A. department of Mathematics University of California La Jolla U. S. A.

We provide some more explicit formulae to facilitate the computation of Ohtsuki’s rational invariants λn of integral homology 3-spheres extracted from Reshetikhin-Turaev su（2） quantum invari- ants. several interes... 详细信息

We provide some more explicit formulae to facilitate the computation of Ohtsuki’s rational invariants λsub>nsub> of integral homology 3-spheres extracted from Reshetikhin-Turaev su（2） quantum invari- ants. several interesting consequences will follow from our computation of λsub>2sub>. One of them says that λsub>2sub> is always an integer divisible by 3. It seems interesting to compare this result with the fact shown by Murakami that λsub>1sub> is 6 times the Casson invariant. Other consequences include some general criteria for distinguishing homology 3-spheres obtained from surgery on knots by using the Jones polynomial.

关键词： Finite type invariant Fermat limit Homology sphere surgery formula

Propagation of plane waves in thermoelastic cubic crystal material with two relaxation times

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Applied Mathematics and Mechanics(English Edition) 2007年第5期28卷 627-641页

作者： Rajneesh Kumar Manjeet singh department of Mathematics Kurukshetra University department of Mathematics S.U.S. Govt. College

A problem concerned with the reflection and refraction of thermoelastic plane waves at an imperfect interface between two generalized thermally conducting cubic crystal solid half-spaces of different elastic and thermal properties with two relaxation times has been investigated. The generalized thermoelastic theory with two relaxation times developed by Green and Lindsay has been used to study the problem. The expressions for the reflection and refraction coefficients which are the ratios of the amplitudes of reflected and refracted waves to the amplitude of incident waves are obtained for an imperfect boundary and deduced for normal stiffness, transverse stiffness, thermal contact conductance, slip and welded boundaries. Amplitude ratios of different reflected and refracted waves for different boundaries with angle of emergence have been compared graphically for different incident waves. It is observed that the amplitude ratios of reflected and refracted waves are affected by the stiffness and thermal properties of the media.

关键词： generalized thermoelasticity normal stiffness transverse stiffness thermal contact conductance cubic crystal amplitude ratios

Genetic assessment of inbred chicken lines indicates genomic signatures of resistance to Marek's disease

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Journal of Animal science and Biotechnology 2018年第4期9卷 803-812页

作者： Lingyang Xu Yanghua He Yi Ding George E.Liu Huanmin Zhang Hans H.Cheng Robert L.Taylor Jr. Jiuzhou song department of Animal & Avian sciences University of Maryland Animal Genomics and Improvement Laboratory U.S. Department of Agriculture-Agricultural Research Services Laboratory of Molecular Biology and Bovine Breeding Institute of Animal Science Chinese Academy of Agricultural Sciences united states department of agriculture-agriculture Research service (ARs) Avian Disease and Oncology Laboratory Animal and Nutritional sciences Davis College of Agriculture West Virginia University

Background: Marek’s disease(MD) is a highly contagious pathogenic and oncogenic disease primarily affecting chickens. However, the mechanisms of genetic resistance for MD are complex and not fully understood. MD-resistant line 63and MD-susceptible line 72are two highly inbred progenitor lines of White Leghorn. Recombinant Congenic strains(RCs) were developed from these two lines, which show varied susceptibility to ***: We investigated genetic structure and genomic signatures across the genome, including the line 63and line72, six RCss, and two reciprocally crossed flocks between the lines 63and 72(F1 63× 72and F1 72× 63) using Affymetrix~? Axiom~? HD 600 K genotyping array. We observed 18 chickens from RCs lines were specifically clustered into resistance sub-groups distributed around line 63. Additionally, homozygosity analysis was employed to explore potential genetic components related to MD resistance, while runs of homozygosity(ROH) are regions of the genome where the identical haplotypes are inherited from each parent. We found several genes including sIK, sOX1, LIG4, sIK1 and TNFsF13B were contained in ROH region identified in resistant group(line 63and RCs), and these genes have been reported that are contribute to immunology and survival. Based on FsTbased population differential analysis, we also identified important genes related to cell death and anti-apoptosis, including AKT1, API5, CDH13, CFDP and usP15,which could be involved in divergent selection during inbreeding ***: Our findings offer valuable insights for understanding the genetic mechanism of resistance to MD and the identified genes could be considered as candidate biomarkers in further evaluation.

关键词： Genetic structure Genomic signature Homozygosity Marek's disease Recombinant Congenic strains(RCs)

Anion structural effects on interaction of rare earth element ions with Dowex 50W X8 cation exchange resin

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Journal of Rare Earths 2018年第8期36卷 879-890页

作者： Duane D.Miller Ranjani siriwardane Dustin Mcintyre u.s. department of Energy National Energy Technology Laboratory AECOM

The effect of the anion in the original rare earth element（REE） solution on the reversible ion exchange of Ce nitrate and Ce sulfate with the Dowex 50 W X8 was investigated using attenuated total reflection infrared（ATR-IR） spectroscopy, continuous flow reactor studies coupled with inductively coupled plasma mass spectroscopy（ICP-Ms）, and density functional theory（DFT）. The simulated IR spectrum at the DFT B3 LYP/6-31 G（d） level was compared to the experimental results to characterize the IR spectrum, molecular interactions, and bonding of the ion exchanged species. The continuous liquid flow reactor studies show a capacity of 0.72 mmol/g sorbent for the Ce nitrateand 0.96 mmol/g sorbent for the Ce sulfate with the Dowex 50 W X8. The flow reactor studies reveal the type of solute anion（sO_4^（（2-）） or NO_3^（（-））） associated with the REE during cation exchange significantly affects the sorption capacity of the Dowex 50 W X8 ion exchange resin. The calculated REE binding energy（BE） and the DFT optimized structures suggest that the differences in sorption capacity is the result of the formation of different types of partially ionexchanged Ce_2^（（3＋））2 sO_4^（（2-）） and Ce^（（3＋）） 3 NO_3^（（-））. These results suggest that the solute anion affects the equilibrium constants of the Dowex resin by the formation of a charged layer capable of retaining the counterion. Modifying the sulfonic acid site（H＋） in the Dowex 50 W X8 with the NH_4~＋ counterion does not affect the sorption capacity and retention times of the Ce nitrate and Ce sulfate species. These results suggest that the counterions and co-ions having a finite size, may limit access to the Dowex sulfonate active site where the type of REE cation as a nitrate or sulfate in solution may significantly modify the sorption capacity of the ion exchange resin. similar results are obtained during sorption with nitrates and sulfates of sm and Yb.

关键词： Ion exchange Dowex Anion effects Rare earth metal sorption

Probabilistic Adaptive Anonymous Authentication in Vehicular Networks

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Journal of Computer science & Technology 2008年第6期23卷 916-928页

作者：习勇沙科伟施巍松 Loren schwiebert 张涛 department of Computer science Wayne State UniversityDetroitMichiganU.S.A. Telcordia Technologies Inc.New JerseyU.S.A.

Vehicular networks have attracted extensive attention in recent years for their promises in improving safety and enabling other value-added services. Most previous work focuses on designing the media access and physical layer protocols. Privacy issues in vehicular systems have not been well addressed. We argue that privacy is a user-specific concept, and a good privacy protection mechanism should allow users to select the levels of privacy they wish to have. To address this requirement, we propose an adaptive anonymous authentication mechanism that can trade off the anonymity level with computational and communication overheads （resource usage）. This mechanism, to our knowledge, is the first effort on adaptive anonymous authentication. The resources used by our protocol are few. A high traffic volume of 2000 vehicles per hour consumes about 60kbps bandwidth, which is less than one percent of the bandwidth of DsRC （Dedicated short Range Communications）. By using adaptive anonymity, the protocol response time can further be improved 2-4 times with less than 20% bandwidth overheads.

关键词： anonymous authentication vehicular network privacy adaptive anonymity