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Wafer-Scale Ag₂S-Based Memristive Crossbar Arrays with Ultra-Low Switching-Energies Reaching Biological Synapses

NANO-MICRO LETTERS 2025年第1期17卷 1-12页

作者： Zhu, Yuan Nyberg, Tomas nyholm, leif Primetzhofer, Daniel Shi, Xun Zhang, Zhen Uppsala Univ Dept Elect Engn Div Solid State Elect S-75121 Uppsala Sweden Uppsala Univ Dept Chem Uppsala Sweden Uppsala Univ Dept Phys & Astron Uppsala Sweden Chinese Acad Sci Shanghai Inst Ceram State Key Lab High Performance Ceram & Superfine M Shanghai 200050 Peoples R China

Memristive crossbar arrays (MCAs) offer parallel data storage and processing for energy-efficient neuromorphic computing. However, most wafer-scale MCAs that are compatible with complementary metal-oxide-semiconductor (CMOS) technology still suffer from substantially larger energy consumption than biological synapses, due to the slow kinetics of forming conductive paths inside the memristive units. Here we report wafer-scale Ag2S-based MCAs realized using CMOS-compatible processes at temperatures below 160 degrees C. Ag2S electrolytes supply highly mobile Ag+ ions, and provide the Ag/Ag2S interface with low silver nucleation barrier to form silver filaments at low energy costs. By further enhancing Ag+ migration in Ag2S electrolytes via microstructure modulation, the integrated memristors exhibit a record low threshold of approximately - 0.1 V, and demonstrate ultra-low switching-energies reaching femtojoule values as observed in biological synapses. The low-temperature process also enables MCA integration on polyimide substrates for applications in flexible electronics. Moreover, the intrinsic nonidealities of the memristive units for deep learning can be compensated by employing an advanced training algorithm. An impressive accuracy of 92.6% in image recognition simulations is demonstrated with the MCAs after the compensation. The demonstrated MCAs provide a promising device option for neuromorphic computing with ultra-high energy-efficiency.

关键词： Wafer-scale Ag2S films Reactive sputter Silver nucleation Ag+ migration Energy-efficient neuromorphic computing

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Polydopamine-based redox-active separators for lithium-ion batteries

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Journal of Materiomics 2019年第2期5卷 204-213页

作者： Ruijun Pan Zhaohui Wang Rui Sun Jonas Lindh Kristina Edstrom Maria Strømme leif nyholm Department of Chemistry-Ångstr€om Laboratory Uppsala UniversityBox 538SE-75121UppsalaSweden Nanotechnology and Functional Materials Department of Engineering SciencesTheÅngstr€om LaboratoryUppsala UniversityBox 534SE-75121UppsalaSweden

The performance of lithium-ion batteries(LIBs)can be effectively enhanced with functionalized ***,it is demonstrated that polydopamine-based redox-active(PRA)separators can provide additional capacity to that of typical anode materials,increase the volumetric capacity of the cell,as well as,decrease the cell resistance to yield an improved performance at higher cycling *** PRA separators,which are composed of a 2 mm thick electrically insulating nanocellulose fiber(NCF)layer and an 18 mm thick polydopamine(PDA)and carbon nanotube(CNT)containing redox-active layer,are readily produced using a facile paper-making *** PRA separators are also easily wettable by commonly employed electrolytes(***40)and exhibit a high dimensional *** addition,the pore structure endows the PRA separator with a high ionic conductivity(i.e.1.06 mS cm^(-1))that increases the rate performance of the *** to the presence of the redox-active layer,Li_(4)Ti_(5)O_(12)(LTO)half-cells containing PRA separator were found to exhibit significantly higher capacities than the corresponding cells containing commercial *** results clearly show that the implementation of this type of redox-active separators constitutes a straightforward and effective way to increase the energy and power densities of LIBs.

关键词： Lithium-ion battery Separator Cellulose Polydopamine Redox-active

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Nuclear Processes in Dark Interstellar Matter of H(0) Decrease the Hope of Migrating to Exoplanets

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Space(Science & Technology) 2021年第1期2021卷 127-132页

作者： leif Holmlid Department of Chemistry and Molecular Biology University of GothenburgSE-41296 GöteborgSweden

It is still generally assumed that interstellar travel will be possible after purely technical development and thus that mankind can move to some suitable exoplanet when ***,recent research indicates this not to be the case,since interstellar space is filled with enough ultradense hydrogen H(0)as stable condensed dark matter(Holmlid,Astrophysical Journal 2018)to make interstellar space travel at the required and technically feasible relativistic velocities(Holmlid et al,Acta Astronautica 2020)almost impossible.H(0)can be observed to exist in space from the so-called extended red emission(ERE)features observed in space.A recent review(Holmlid et al.,Physica Scripta 2019)describes the properties of H(0).H(0)gives nuclear processes emitting kaons and other particles,with kinetic energies even above 100 MeV after induction for example by fast particle(spaceship)*** high particle energies give radiative temperatures of 12000 K in collisions against a solid surface and will rapidly destroy any spaceship structure moving into the H(0)clouds at relativistic *** importance of preserving our ecosystem is pointed out,since travel to suitable exoplanets may be *** possibilities of instead clearing interstellar space from H(0)are discussed,eventually providing tunnels suitable for relativistic interstellar *** regions with low intensity of ERE could even be a way to identify space-cleaning activities and thus to locate earlier spacetravelling civilizations.

关键词： relativistic instead eventually

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An approach of the internal friction-dependent temperature changes for conventional and pure biogenic lubricating greases

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Friction 2024年第4期12卷 780-795页

作者： leif AHME Erik KUHN MiguelÁngel DELGADO Department of Mechanical Engineering and Production Management Hamburg University of Applied SciencesHamburg 20099Germany Department of Chemical Engineering Research in Product Technology and Chemical Processes(Pro2TecS)University of HuelvaHuelva 21071Spain

This work investigated the temperature changes inside the bulk of lubricating greases under controlled high-shear stress conditions(250-500 s-1).For this purpose,a newly developed temperature-measuring cell called Calidus was successfully *** temperature changes(ΔT)have been related to the greases'components(thickener,base oil-type,and composition)and the structural degradation of the lubricating ***,a theoretical approach was proposed for calculating the internal temperature change of lubricating greases during shear *** greases showed an internal temperature profile characterised by a sudden rise inΔT within the first 4 h from starting the test and subsequentΔT decay until it reaches the steady state ***,it was found that greases C1 and C5,formulated with lithium and calcium soap,respectively,with different soap content(16.1 wt%and 9.7 wt%,respectively),but the same base castor oil,showed the highest value of the maximumΔT,c.a.3.2 K,and the most drastic drop ofΔ*** greases showed both the highest specific densities and heat *** addition,they showed the lowest ratio of expended energies(Rtee),which means more structural degradation in the stressed *** the contrary,the grease C3,with 13 wt%of Li-soap but the lowest base oil's viscosity,showed the lowest maximumΔT and the temperature profile was characterised by a moderate variation ofΔT along the *** biogenic grease B3 developed a low-temperature change in the group of pure bio-genic greases close to grease C3.

关键词： shear-induced structural degradation rheology temperature measurements lubricating greases density lubricating greases specific heat capacities

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Sperm chromatin structure assay （SCSA）： a tool in diagnosis and treatment of infertility

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Asian Journal of Andrology 2011年第1期13卷 69-75页

作者： Mona Bungum leif Bungum Aleksander Giwercman Reproductive Medicine Centre （RMC） Skane University Hospital SE - 205 02 Maimo Sweden

Diagnosis of male infertility has mainly been based on the World Health Organization （WHO） manual-based semen parameter＇s concentration, motility and morphology. It has, however, become apparent that none of these parameters are reliable markers for evaluation of the fertility potential of a couple. A search for better markers has led to an increased focus on sperm chromatin integrity testing in fertility work-up and assisted reproductive techniques. During the last couple of decades, numerous sperm DNA integrity tests have been developed. These are claimed to be characterized by a lower intraindividual variation, less intralaboratory and interlaboratory variation and thus less subjective than the conventional sperm analysis. However, not all the sperm chromatin integrity tests have yet been shown to be of clinical value. So far, the test that has been found to have the most stable clinical threshold values in relation to fertility is the sperm chromatin structure assay （SCSA）, a flow cytometric test that measures the susceptibility of sperm DNA to acid-induced DNA denaturation in situ. Sperm DNA fragmentation as measured by SCSA has shown to be an independent predictor of successful pregnancy in first pregnancy planners as well as in couples undergoing intrauterine insemination, and can be used as a tool in investigation, counseling and treatment of involuntary childlessness. More conflicting data exist regarding the role of sperm DNA fragmentation in relation to fertilization, pre-embryo development and pregnancy outcome in in vitro fertilization and intracytoplasmic sperm injection （ICSI）.

关键词： assisted reproductive techniques infertility sperm chromatin structure assay sperm DNA

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The Siberian moth(Dendrolimus sibiricus),a pest risk assessment for Norway

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Forest Ecosystems 2020年第4期7卷 635-645页

作者： Daniel Flø Trond Rafoss Michael Wendell leif Sundheim Norwegian Institute of Bioeconomy Research Høgskoleveien 71433ÅsNorway The Norwegian Scientific Committee for Food and Environment Sandakerveien 24 C0473 OsloNorway

Background:The Siberian moth(Dendrolimus sibiricus)is a serious pest of conifers in Russia,Northern Kazakhstan,Mongolia and *** western border of the pest’s distribution in Russia is disputed,but it is present west of the 60th meridian *** pest has the potential to defoliate a wide range of ***:The pest is not present in Norway or other European countries,except *** spread and human mediated transport are potential pathways for the *** mediated pathways considered are:Living trees for planting,coniferous wood in the rough and foliage and *** has been no import of living trees from Russia to Norway during the past 30 years,and there is currently no import of coniferous wood commodities containing bark from areas,where *** ***:The probability of *** entry by natural spread is unlikely,mainly because of the geographical distance and the partial sea barriers between Norway and the infested *** probability of entry by human mediated pathways is unlikely due to the very limited volume of the *** the pest enter Norway,the probability of establishment and spread is unlikely,due to the suboptimal climatic conditions,and the fact that the two dominant conifers in the country,Norway spruce(Picea abies)and Scots pine(Pinus sylvestris),are intermediate and poor hosts,*** potential damage,should *** enter Norway,is considered low.

关键词： Lepidoptera Invasive species Geographical distribution Forest pest

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Influence of location of large-scale asperity on shear strength of concrete-rock interface under eccentric load

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第3期12卷 449-460页

作者： Dipen Bista Gabriel Sas Fredrik Johansson leif Lia SINTEF Narvik As Narvik8517Norway Norwegian University of Science and Technology(NTNU) Trondheim7491Norway Royal Institute of Technology(KTH) Stockholm10044Sweden

The location and geometry of large-scale asperity present at the foundation of concrete gravity dams and buttress dams affect the shear resistance of the concrete-rock ***,the parameters describing the frictional resistance of the interface usually do not account for these *** could result in an underestimate of the peak shear stre ngth,which leads to significantly conservative design for new dams or unnecessary stability enhancing measures for existing *** aim of this work was to investigate the effect of the location of first-order asperity on the peak shear strength of a concrete-rock interface under eccentric load and the model discrepancy associated with the commonly used rigid body methods for calculating the factor of safety(FS)against *** this,a series of direct and eccentric shear tests under constant normal load(CNL)was carried out on concrete-rock *** peak shear strengths measured in the tests were compared in terms of asperity location and with the predicted values from analytical rigid body *** results showed that the large-scale asperity under eccentric load significantly affected the peak shear ***,unlike the conventional assumption of sliding or shear failure of an asperity in direct shear,under the effect of eccentric shear load,a tensile failure in the rock or in the concrete could occur,resulting in a lower shear strength compared with that of direct shear *** results could have important implications for assessment of the FS against sliding failure in the concrete-rock interface.

关键词： Shear strength Concrete-rock interface Asperity location Eccentric load Model discrepancy Dam foundation

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The impact of male overweight on semen quality and outcome of assisted reproduction

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Asian Journal of Andrology 2014年第5期16卷 749-754,I0010页

作者： Lise Thomsen Peter Humaidan leif Bungum Mona Bungum The Fertility Clinic Viborg Hospital Skive Aarhus University Faculty of Health Aarhus N The Fertility Clinic Herlev Hospital Herlev Denmark Reproductive Medicine Centre Skanes University Hospital Malmo Sweden

It is well-documented that male overweight and obesity causes endocrine disorders that might diminish the male reproductive capacity; however, reports have been conflicting regarding the influence of male body mass index （BMI） on semen quality and the outcome of assisted reproductive technology （ART）. The aim of this study was to investigate whether increased male BMI affects sperm quality and the outcome of assisted reproduction in couples with an overweight or obese man and a non-obese partner. Data was prospectively collected from 612 infertile couples undergoing ART at a Danish fertility center. Self-reported information on paternal height and weight were recorded and BMI was calculated. The men were divided into four BMI categories： underweight BMI 〈 20 kgm^-2, normal BMI 20-24.9 kg m^-2, overweight BMI 25-29.9 kgm^-2 and obese BMI 〉 30 kgm^-2. Conventional semen analysis was performed according to the World Health Organization guideline and sperm DNA integrity was analyzed by the Sperm Chromatin Structure Assay （SCSA）. No statistically significant effect of male BMI was seen on conventional semen parameters （sperm concentration, total sperm count, seminal volume and motility） or on SCSA-results. Furthermore, the outcome of ART regarding fertilization rate, number of good quality embryos （GQE）, implantation and pregnancy outcome was not influenced by the increasing male BMIo

关键词： assisted reproductive technology body mass index male obesity sperm chromatin structure assay sperm quality

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Estimation of a basal area growth model for individual trees in uneven-aged Caspian mixed species forests

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Journal of Forestry Research 2018年第5期29卷 1205-1214页

作者： Zohreh Mohammadi Soleiman Mohammadi Limaei Peter Lohmander leif Olsson Department of Forestry Faculty of Natural ResourcesUniversity of Guilan P.O. Box 1144 Sowmeh Sara Iran Optimal Solutions in Cooperation with Linnaeus University Umea Sweden Department of Information Systems and Technology Facultyof Sciences Technology and Media Mid Sweden UniversitySundsvall Sweden

The aim of this study was to estimate a basal area growth model for individual trees in uneven-aged Caspian forests.A survey was conducted in order to find a natural forest without any harvesting activities,a so called ＇untouched forest＇ and an area was selected from the Iranian Caspian *** sample plots in the same aspect and of the same forest type were *** each plot,total tree height,diameter at breast height,distance of neighbor trees and azimuth were *** trees were selected and drilled with increment borer to determine the increment *** analysis was used to estimate the growth *** show that,for individual trees,there is a significant nonlinear relationship between the annual basal area increment,as the dependent variable,and the basal *** results also show that the basal area of competing trees has a positive influence on *** the increment is higher with more competing neighboring trees is possibly because plots with higher volume per hectare and more competition,most likely also have higher site index or better soil or better site productivity than the plot with lower volume per hectare.

关键词： Basal area increment Diameter growth Regression analysis Caspian forests

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Advanced Computational Methods of Rapid and Rigorous 3-D Inversion of Airborne Electromagnetic Data

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Communications in Computational Physics 2008年第1期3卷 160-179页

作者： leif H.Cox Michael S.Zhdanov Department of Geophysical Engineering Montana Tech of the University of Montana1300W Park StreetButteMT 59701-8997USA Department of Geology and Geophysics University of Utah135 S.1460 E.Rm 719Salt Lake CityUT 84112USA.

We develop a new computational method for modeling and inverting frequency domain airborne electromagnetic(EM)*** method is based on the contraction integral equation method for forward EM modeling and on inversion using the localized quasi-linear(LQL)approximation followed by the rigorous inversion,if *** LQL inversion serves to provide a fast image of the *** results are checked by a rigorous update of the domain electric field,allowing a more accurate calculation of the predicted *** the accuracy is poorer than desired,rigorous inversion follows,using the resulting conductivity distribution and electric field from LQL as a starting *** rigorous inversion iteratively solves the field and domain equations,converting the non-linear inversion into a series of linear *** test this method on synthetic and field *** results of the inversion are very encouraging with respect to both the speed and the accuracy of the algorithm,showing this is a useful tool for airborne EM interpretation.

关键词： Computational geophysics airborne electromagnetics inversion 3-D LQL rigorous

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