检索结果-南通市图书馆

A review on the critical challenges and progress of SiO_(x)-based anodes for lithium-ion batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2022年第4期29卷 876-895页

作者： Nana Yao Yu Zhang Xianhui Rao Zhao Yang Kun Zheng konradświerczek Hailei Zhao School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Faculty of Energy and Fuels AGH University of Science and Technologyal.A.Mickiewicza 30Krakow30-059Poland Beijing Key Lab of New Energy Materials and Technology Beijing 100083China

With the advantages of abundant resources,high specific capacity,and relatively stable cycling performance,silicon suboxides(SiO_(x) ,x<2)have been recently suggested as promising anodes for next-generation lithium-ion batteries(LIBs).SiO_(x) exhibits superior storage capability because of the presence of silicon and smaller volume change upon charge/discharge than Si owing to the buffering effect of the initial lithiation products of inert lithium oxide and lithium silicates,enabling a stable cycle life of ***,significant improvements such as overcoming issues related to volume changes in cycling and initial irreversible capacity loss and enhancing the ionic and electronic charge transport in poorly conducting SiO_(x) electrodes,are still needed to achieve the satisfactory performance required for commercial *** review summarizes recent progress on the cycling performance and initial coulombic efficiency of SiO_(x) .Advances in the design of particle morphology and composite composition,prelithiation and prereduction methods,and usage of electrolyte additives and optimized electrode binders are *** on the promising research directions that might lead to further improvement of the electrochemical properties of SiO_(x) -based anodes are *** paper can serve as a basis for the research and development of high-energy-density LIBs.

关键词： silicon suboxides preparation structural optimization anode lithium-ion batteries

Light correcting light with nonlinear optics

在线全文

学校读者我要写书评

暂无评论

Advanced Photonics 2024年第2期6卷 41-49页

作者： Sachleen Singh Bereneice Sephton Wagner Tavares Buono Vincenzo D'Ambrosio Thomas konrad Andrew Forbes University of the Witwatersrand School of Physics Università degli studi di Napoli “Federico Ⅱ” Dipartimento di Fisica “E.Pancini” University of Kwa Zulu-Natal School of Chemistry and Physics

Structured light, where complex optical fields are tailored in all their degrees of freedom, has become highly topical of late, advanced by a sophisticated toolkit comprising both linear and nonlinear *** undesired structure from light is far less developed, leveraging mostly on inverting the distortion,e.g., with adaptive optics or the inverse transmission matrix of a complex channel, both requiring that the distortion be fully characterized through appropriate measurement. We show that distortions in spatially structured light can be corrected through difference-frequency generation in a nonlinear crystal without any need for the distortion to be known. We demonstrate the versatility of our approach using a wide range of aberrations and structured light modes, including higher-order orbital angular momentum(OAM) beams,showing excellent recovery of the original undistorted field. To highlight the efficacy of this process, we deploy the system in a prepare-and-measure communications link with OAM, showing minimal cross talk even when the transmission channel is highly aberrated, and outline how the approach could be extended to alternative experimental modalities and nonlinear processes. Our demonstration of light-correcting light without the need for measurement opens an approach to measurement-free error correction for classical and quantum structured light, with direct applications in imaging, sensing, and communication.

关键词： phase conjugation aberration correction orbital angular momentum nonlinear optics

The Silk roads: phylogeography of Central Asian dice snakes (Serpentes: Natricidae) shaped by rivers in deserts and mountain valleys

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2024年第2期70卷 150-162页

作者： Daniel Jablonski konrad Mebert Rafaqat Masroor Evgeniy Simonov Oleg Kukushkin Timur Abduraupov Sylvia Hofmann Department of Zoology Comenius University in BratislavaBratislavaSlovakia Global Biology BirrSwitzerland Pakistan Museum of Natural History ShakarparianIslamabadPakistan Severtsov Institute of Ecology and Evolution Russian Academy of SciencesMoscowRussia T.I.Vyazemski Karadag Scientific Station-Nature Reserve—Branch of A.0.Kovalevsky Institute of Biology of the Southern Seas TheodosiaCrimea Zoological Institute of the RAS Saint PetersbourgRussia Institute of Zoology Academy of Sciences of the Republic of UzbekistanYunusabadTashkentUzbekistan Museum Koenig Bonn LIBLeibniz Institute for the Analysis of Biodiversity ChangeBonnGermany UFZ-Helmholtz Centre for Environmental Research Department of Conservation BiologyPermoserstrasse 1504318 LeipzigGermany

Influenced by rapid changes in climate and landscape features since the Miocene,widely distributed species provide suitable models to study the environmental impact on their evolution and current genetic *** dice snake Natrix tessellata,widely distributed in the Western Palearctic is one such *** aimed to resolve a detailed phylogeography of *** with a focus on the Central Asian clade with 4 and the Anatolia clade with 3 mitochondrial lineages,trace their origin,and correlate the environmental changes that affected their distribution through *** expected time of divergence of both clades began at 3.7 Mya in the Pliocene,reaching lineage differentiation approximately 1 million years *** genetic diversity in both clades is rich,suggesting different ancestral areas,glacial refugia,demographic changes,and colonization *** Caspian lineage is the most widespread lineage in Central Asia,distributed around the Caspian Sea and reaching the foothills of the Hindu Kush Mountains in Afghanistan,and Eastern European lowlands in the *** distribution is limited by deserts,moun-tains,and cold steppe ***,Kazakhstan and Uzbekistan lineages followed the Amu Darya and the Syr Darya water systems in Central Asia,with ranges delimited by the large Kyzylkum and Karakum *** the western side,there are several lineages within the Anatolia clade that converged in the central part of the peninsula with 2 being endemic to Western *** distribution of both main clades was affected by expansion from their Pleistocene glacial refugia around the Caspian Sea and in the valleys of Central Asia as well as by environmental changes,mostly through aridification.

关键词： biogeography colonization Eurasia genetic diversity mitochondrial DNA Paratethys refugia water snakes.

Fusobacterium nucleatum:Unraveling its potential role in gastric carcinogenesis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第35期30卷 3972-3984页

作者： Vytenis Petkevicius konrad Lehr Juozas Kupcinskas Alexander Link Department of Gastroenterology Lithuanian University of Health SciencesKaunas 44307Lithuania Department of Gastroenterology Hepatology and Infectious DiseasesOtto-von-Guericke University HospitalMagdeburg 39120Germany Institute for Digestive Research Lithuanian University of Health SciencesKaunas 50161Lithuania

Fusobacterium nucleatum(***)is a Gram-negative anaerobic bacterium that plays a key role in the development of oral inflammation,such as periodontitis and *** the last 10 years,*** has been identified as a prevalent bacterium associated with colorectal adenocarcinoma and has also been linked to cancer progression,metastasis and poor disease *** the role of *** in colon carcinogenesis has been intensively studied,its role in gastric carcinogenesis is still poorly *** Helicobacter pylori infection has histo-rically been recognized as the strongest risk factor for the development of gastric cancer(GC),with recent advances in DNA sequencing technology,other members of the gastric microbial community,and *** in particular,have received increasing *** this review,we summarize the existing knowledge on the involvement of *** in gastric carcinogenesis and address the potential translational and clinical significance of *** in GC.

关键词： Fusobacterium nucleatum Gastric microbiota Gastric cancer Preneoplastic changes Prognosis

Chronic effects of stretching on range of motion with consideration of potential moderating variables:A systematic review with meta-analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2024年第2期13卷 186-194页

作者： Andreas konrad Shahab Alizadeh Abdolhamid Daneshjoo Saman Hadjizadeh Anvar Andrew Graham Ali Zahiri Reza Goudini Chris Edwards Carina Scharf David George Behm Institute of Human Movement Science Sport and HealthGraz UniversityGraz A-8010Austria School of Human Kinetics and Recreation Memorial University of NewfoundlandSt.John’sNL A1C 5S7Canada Department of Sport Injuries and Corrective Exercises Faculty of Sport SciencesShahid Bahonar University of KermanKerman 76169-13439Iran

Background:It is well known that stretch training can induce prolonged increases in joint range of motion(ROM).However,to date more information is needed regarding which training variables might have greater influence on improvements in ***,the purpose of this metaanalysis was to investigate the effects of stretch training on ROM in healthy participants by considering potential moderating variables,such as stretching technique,intensity,duration,frequency,and muscles stretched,as well as sex-specific,age-specific,and/or trained state-specific adaptations to stretch ***:We searched through PubMed,Scopus,Web of Science,and SportDiscus to find eligible studies and,finally,assessed the results from 77 studies and 186 effect sizes by applying a random-effect ***,by applying a mixed-effect model,we performed the respective subgroup *** find potential relationships between stretch duration or age and effect sizes,we performed a ***:We found a significant overall effect,indicating that stretch training can increase ROM with a moderate effect compared to the controls(effect size=-1.002;Z=-12.074;95%confidence interval:-1.165 to-0.840;p<0.001;I^(2)=74.97).Subgroup analysis showed a significant difference between the stretching techniques(p=0.01)indicating that proprioceptive neuromuscular facilitation and static stretching produced greater ROM than did ballistic/dynamic ***,there was a significant effect between the sexes(p=0.04),indicating that females showed higher gains in ROM compared to ***,further moderating analysis showed no significant relation or ***:When the goal is to maximize ROM in the long term,proprioceptive neuromuscular facilitation or static stretching,rather than ballistic/dynamic stretching,should be *** to consider in future research as well as sports practice is that neither volume,intensity,nor frequency of stretching were

关键词： Flexibility Long-term stretching Stretch training

Slow and fast light in quantum-well and quantum-dot semiconductor optical amplifiers Invited Paper

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2008年第10期6卷 736-742页

作者： Piotr konrad Kondratko Akira Matsudaira Department of Electrical and Computer Engineering University of Illinois at Urbana-ChampaignUrbana IL61801USA

Slow and fast light in quantum-well （QW） and quantum-dot （QD） semiconductor optical amplifiers （SOAs） using nonlinear quantum optical effects are presented. We demonstrate electrical and optical controls of fast light using the coherent population oscillation （CPO） and four wave mixing （FWM） in the gain regime of QW SOAs. We then consider the dependence on the wavelength and modal gain of the pump in QW SOAs. To enhance the tunable photonic delay of a single QW SOA, we explore a serial cascade of multiple amplifiers. A model for the number of QW SOAs in series with variable optical attenuation is developed and matched to the experimental data. We demonstrate the scaling law and the bandwidth control by using the serial cascade of multiple QW SOAs. Experimentally, we achieve a phase change of 160^o and a scaling factor of four at 1 GHz using the cascade of four QW SOAs. Finally, we investigate CPO and FWM slow and fast light of QD SOAs. The experiment shows that the bandwidth of the time delay as a function of the modulation frequency changes in the absorption and gain regimes due to the carrier-lifetime variation. The tunable phase shift in QD SOA is compared between the ground- and first excited-state transitions with different modal gains.

关键词： SOA CPO Slow and fast light in quantum-well and quantum-dot semiconductor optical amplifiers Invited Paper FWM well

在线全文

学校读者我要写书评

暂无评论

德国南部钻石城太空送来的七万吨礼物

环球人文地理 2024年第3期 96-103页

作者：袁莘捷 lebaer Wolfgang Ralf ArTo konrad filbert Andrey＿Lobachev Sina Ettmer flickr

钻石受到无数人追捧，其高昂的价格也让人望而却步。让人意外的是，在德国巴伐利亚州的西部山区，人们竟用七万吨钻石，建造了一座闪闪发光的钻石城。诺德林根是一座中世纪小镇，距今已有上千年历史。这里四面都有围墙，是德国目前仅有...

钻石受到无数人追捧，其高昂的价格也让人望而却步。让人意外的是，在德国巴伐利亚州的西部山区，人们竟用七万吨钻石，建造了一座闪闪发光的钻石城。诺德林根是一座中世纪小镇，距今已有上千年历史。这里四面都有围墙，是德国目前仅有的三座完全被城墙环绕的城市之一。小镇曾经安宁祥和，也曾经饱经硝烟，而许多建筑，甚至差点毁于一场大火。

关键词：

Gap formation around Ω_e/2 and generation of low-band whistler waves by Landau-resonant electrons in the magnetosphere: Predictions from dispersion theory

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2020年第2期4卷 138-150页

作者： konrad Sauer Klaus Baumgartel Richard Sydora Max-Planck-Institute for Solar System Research GöttingenGermany(up to 2005 Leibnitz-Institut für Astrophysik(AIP) PotsdamGermany(up to 2008 Institute for Geophysical Research University of AlbertaEdmontonCanada

In this paper we show that two significant phenomena of magnetospheric chorus emission can be explained by the participation of beam-like electron structures,created by Landau-resonant interaction with growing oblique whistler *** first concerns the widely observed spectral gap near half the electron cyclotron frequency Ωe;the second is related to the observation of very obliquely propagating lower-band waves that cannot be directly generated by temperature *** the gap,kinetic dispersion theory reveals that interference of the beam-related cyclotron mode ω~Ωe-kVb with the conventional whistler mode leads to mode splitting and the appearance of a ’forbidden’ area in the ω-k *** the beam velocity appears as an essential *** is directly related to the phase velocity of the most unstable whistler wave mode,which is close to VAe/2 for sufficiently hot electrons(VAe is the electron Alfven velocity).To clarify the second point,we show that Landau-resonant beams with Vb Vb

关键词： important role play Landau-resonant electrons modification of the electron distribution function gap formation at half the electron cyclotron frequency

Acupuncture treatment in gastrointestinal diseases: A systematic review

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第25期13卷 3417-3424页

作者： Antonius Schneider konrad Streitberger Stefanie Joos University Hospital Heidelberg Department of General Practice and Health Services Research Germany University Hospital Heidelberg Department of Anaesthesiology Germany

The purpose of this work was to assess the evidence for effectiveness of acupuncture （AC） treatment in gastrointestinal diseases. A systematic review of the Medline-cited literature for clinical trials was performed up to May 2006. Controlled trials assessing acupuncture point stimulation for patients with gastrointestinal diseases were considered for inclusion. The search identified 18 relevant trials meeting the inclusion criteria. Two irritable bowel syndrome （IBS） trials, 1 Crohn＇s disease and 1 colitis ulcerosa trial had a robust random controlled trial （RCT） design. In regard to other gastrointestinal disorders, study quality was poor. In all trials, quality of life （QoL） improved significantly independently from the kind of acupuncture, real or sham. Real AC was significantly superior to sham acupuncture with regard to disease activity scores in the Crohn and Colitis trials. Efficacy of acupuncture related to QoL in IBS may be explained by unspecific effects. This is the same for QoL in inflammatory bowel diseases （IBD）, whereas specific acupuncture effects may be found in clinical scores. Further trials for IBDs and in particular for all other gastrointestinal disorders would be necessary to evaluate the efficacy of acupuncture treatment. However, it must be discussed on what terms patients benefit when this harmless and obviously powerful therapy with regard to QoL is demystified by further placebo controlled trials.

关键词： Irritable bowel syndrome Inflammatorybowel disease Gastrointestinal disease Placebo Acupuncture