检索结果-南通市图书馆

Concentration of dimension in extremal points of left-half lines in the Lagrange spectrum

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年

作者： Carlos Gustavo MOREIRA christian Camilo SILVA VILLAMIL SUSTech International Center for Mathematics Shenzhen Guangdong People's Republic of China and IMPA SUSTech International Center for Mathematics Shenzhen Guangdong People's Republic of China and IMPA

We prove that for any η that belongs to the closure of the interior of the Markov and Lagrange spectra,the sets k-1(（-∞,η]） and k-1（η）,which are the sets of irrational numbers with best constant of Diophantine approximation bounded by η and exactly η respectively,have the same Hausdorff *** also show that,as η varies in the interior of the spectra,this Hausdorff dimension is a strictly increasing function.

关键词：

Enhanced activity and durability of FeCoCrMoCBY nanoglass in acidic hydrogen evolution reaction

同方期刊数据库评论

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 Materials Science & Technology 2024年第3期170卷 212-220页

作者： Mengyang Yan Shuangqin Chen Shangshu Wu Xuechun Zhou Shu Fu Di Wang christian Kübel Horst Hahn Si Lan Tao Feng Herbert Gleiter Institute of Nanoscience School of Material Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Institute of Nanotechnology Karlsruhe Institute of TechnologyKarlsruhe 76021Germany

In the present work,a multi-element nanoglass(m-NG)of FeCoCrMoCBY is obtained first time by the laser ablation combined with inert gas condensation(laser-IGC)*** with the conventional rapid-quenched metallic glass(MG)with identical composition,the Fe-based m-NG demonstrates a superior performance as a self-supported electrocatalyst for hydrogen evolution reaction(HER)in acidic *** enhanced HER activity of m-NG is proposed to be closely related to its high en-ergy states,which is originated from the unique inhomogeneous nanostructures with a high density of low-coordinated ***,the Fe-based m-NG exhibits an outstanding comprehensive catalytic performance even beyond the commercial Pt/C catalyst in long-term test due to its self-optimization *** work not only opens the way to the preparation of m-NGs by the novel laser-IGC technique,but also makes a great contribution to developing low-cost,high-efficient,and super-durable HER electrocat-alysts in acidic environment.

关键词： Nanoglass Inert gas condensations High energy states Hydrogen evolution reactions

Wear-resistant CoCrNi multi-principal element alloy at cryogenic temperature

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 Bulletin 2024年第2期69卷 227-236页

作者： Yue Ren Qing Zhou Dongpeng Hua Zhuobin Huang Yulong Li Qian Jia Peter Gumbsch christian Greiner Haifeng Wang Weimin Liu State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an 710072China Institute for Applied Materials Karlsruhe Institute of TechnologyKarlsruhe 76131Germany IAM-ZM MicroTribology CenterμTC Karlsruhe Institute of TechnologyKarlsruhe 76131Germany Fraunhofer IWM Freiburg 79108Germany State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Traditional high strength engineering alloys suffer from serious surface brittleness and inferior wear performance when servicing under sliding contact at cryogenic ***,we report that the recently emerging CoCrNi multi-principal element alloy defies this trend and presents dramatically enhanced wear resistance when temperature decreases from 273 to 153 K,surpassing those of cryogenic austenitic *** temperature-dependent structure characteristics and deformation mechanisms influencing the cryogenic wear resistance of CoCrNi are clarified through microscopic observation and atomistic *** is found that sliding-induced subsurface structures show distinct scenarios at different deformation *** cryogenic condition,significant grain refinement and a deep plastic zone give rise to an extended microstructural gradient below the surface,which can accommodate massive sliding deformation,in direct contrast to the strain localization and delamination at 273 ***,the temperature-dependent cryogenic deformation mechanisms(stacking fault networks and phase transformation)also provide additional strengthening and toughening of the subsurface *** features make the CoCrNi alloy particularly wear resistant at cryogenic conditions and an excellent candidate for safety–critical applications.

关键词： Multi-principal element alloy Cryogenic temperature Wear CoCrNi

Event segmentation in ADHD:neglect of social information and deviant theta activity point to a mechanism underlying ADHD

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

General Psychiatry 2024年第3期37卷 431-439页

作者： Astrid Prochnow Xianzhen Zhou Foroogh Ghorbani Veit Roessner Bernhard Hommel christian Beste Cognitive Neurophysiology Department of Child and Adolescent PsychiatryFaculty of MedicineTU DresdenDresdenGermany Faculty of Psychology Shandong Normal UniversityJinanShandongChina

Background Attention-deficit/hyperactivity disorder(ADHD)is one of the most frequently diagnosed psychiatric conditions in children and *** the symptoms appear to be well described,no coherent conceptual mechanistic framework integrates their occurrence and variance and the associated problems that people with ADHD *** The current study proposes that altered event segmentation processes provide a novel mechanistic framework for understanding deficits in *** Adolescents with ADHD and neurotypically developing(NT)peers watched a short movie and were then asked to indicate the boundaries between meaningful segments of the *** recorded electroencephalography(EEG)data were analysed for differences in frequency band activity and effective connectivity between brain *** Compared with their NT peers,the ADHD group showed less dependence of their segmentation behaviour on social information,indicating that they did not consider social information to the same extent as their unaffected *** divergence was accompanied by differences in EEG theta band activity and a different effective connectivity network architecture at the source ***,NT adolescents primarily showed error signalling in and between the left and right fusiform gyri related to social information processing,which was not the case in the ADHD *** the ADHD group,the inferior frontal cortex associated with attentional sampling served as a hub instead,indicating problems in the deployment of attentional *** This study shows that adolescents with ADHD perceive events differently from their NT peers,in association with a different brain network architecture that reflects less adaptation to the situation and problems in attentional sampling of environmental *** results call for a novel conceptual view of ADHD,based on event segmentation theory.

关键词： instead meaningful primarily

Small mammal community composition impacts bank vole (Clethrionomys glareolus) population dynamics and associated seroprevalence of Puumala orthohantavirus

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2024年第1期19卷 52-65页

作者： Felicitas Maria BUJNOCH Daniela REIL Stephan DREWES Ulrike MROSENFELD Rainer G.ULRICH Jens JACOB christian IMHOLT Julius Kühn-Institute Federal Research Centre for Cultivated PlantsInstitute for Epidemiology and Pathogen DiagnosticsRodent ResearchMünsterGermany University of Münster Institute for Evolution and BiodiversityMünsterGermany Friedrich-Loeffler-Institut Federal Research Institute for Animal HealthInstitute of Novel and Emerging Infectious DiseasesGreifswald-Insel RiemsGermany

Rodents are important reservoirs for zoonotic pathogens that cause diseases in *** is hypoth-esized to be closely related to pathogen prevalence through multiple direct and indirect *** example,the presence of non-host species can reduce contact rates of the main reservoir host and thus reduce the risk of transmission(“dilution effect”).In addition,an overlap in ecological niches between two species could lead to increased interspecific competition,potentially limiting host densities and reducing density-dependent pathogen transmission *** this study,we investigated the relative impact of population-level regulation of direct and indirect drivers of the prevalence of Puumala orthohantavirus(PUUV)in bank voles(Clethrionomys glareolus)during years with high *** compiled data on small mammal community composition from four regions in Germany between 2010 and *** equation modeling revealed a strong seasonality in PUUV control mechanisms in bank *** abundance of shrews tended to have a negative relationship with host abundance,and host abundance positively influenced PUUV seroprevalence,while at the same time increasing the abundance of competing non-hosts like the wood mouse(Apodemus sylvaticus)and the yellow-neckedfield mouse(Apodemusflavicollis)were associated with reduced PUUV seroprevalence in the *** results indicate that for PUUV in bank voles,dilution is associated with increased interspecific *** pressures leading to the decline of Apodemus *** a specific habitat could lead to the amplification of mechanisms promoting PUUV transmission within the host populations.

关键词： bank vole biodiversity Puumala orthohantavirus small mammals

Perceived value of microfinance and SME performance: The role of exploratory innovation

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 Innovation Studies 2024年第2期8卷 172-185页

作者： christian Sarfo Jing A.Zhang Conor O'Kane Paula O'Kane Department of Management University of LincolnBrayford PoolLincoln LN67TSUnited Kingdom Department of Management Otago Business SchoolUniversity of OtagoPO Box 56Dunedin9054New Zealand

This study examines how perceived value of microfinance and exploratory innovation affect small and medium-sized enterprises(SME)performance in the context of a developing *** on the strategic innovation and microfinance literature,we hypothesize that(1)perceived value of microfinance affects exploratory innovation and SME performance,and(2)exploratory innovation serves as an effective mechanism through which microfinance enhances SME *** employ partial least squares structural equation modeling(PLS-SEM)to test our *** a sample of 581 Ghanaian SMEs with microfinance,the results of the PLS SEM support our *** further conducted a qualitative analysis of comments provided by the SMEs(n=144)to gain a deeper understanding of exploratory innovation in developing *** findings show that SMEs purposefully attempt to strengthen their exploratory inno-vation in *** discuss the theoretical and practical implications of these findings as well as future research avenues.

关键词： Perceived value of microfinance Exploratory innovation SME performance

Degeneration of foundation cushion species induced by ecological constraints can cause massive changes in alpine plant communities

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(Life Sciences) 2024年第4期67卷 789-802页

作者： Jianguo Chen Xufang Chen Lishen Qian Yazhou Zhang Bo Li Honghua Shi Lu Sun christian Schöb Hang Sun Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China University of Chinese Academy of Sciences Beijing 100049China College of Resources and Environment Yunnan Agricultural UniversityKunming 650500China Área de Biodiversidad y Conservación Universidad Rey Juan CarlosMóstoles 28933Spain

Foundational cushion plants can re-organize community structures and sustain a prominent proportion of alpine biodiversity,but they are sensitive to climate *** loss of cushion species can have broad consequences for associated *** potential plant community changes with the population dynamics of cushion plants remain,however,*** eight plant communities along a climatic and community successional gradient,we assessed cushion population dynamics,the underlying ecological constraints and hence associated plant community changes in alpine communities dominated by the foundational cushion plant Arenaria *** population dynamics of Arenaria are attributed to ecological constraints at a series of life history *** functions are constrained by increasing associated beneficiary plants;subsequent seedling establishment is constrained by temperature,water and light availability,extreme climate events,and interspecific competition;strong competitive exclusion may accelerate mortality and degeneration of cushion *** with cushion dynamics,species composition,abundance and community structure gradually *** cushion plants completely degenerate,previously cushion-dominated communities shift to relatively stable communities that are overwhelmingly dominated by *** warming may accelerate the degeneration process of *** of this foundational cushion plant will possibly induce massive changes in alpine plant communities and hence ecosystem functions in alpine *** assessment of the population dynamics of foundation species is critical for an effective conservation of alpine biodiversity.

关键词： alpine ecosystem biodiversity change climate change plant community dynamics foundation species global warming population dynamics

Prospective cohort study on facial profile changes in infants with Robin sequence and healthy controls

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2024年第6期20卷 581-589页

作者： Cornelia Wiechers Julian Sowula Karen Kreutzer Christoph E.Schwarz Christina Weismann Michael Krimmel christian F.Poets Bernd Koos Department of Neonatology Tuebingen University HospitalCalwerstrasse 772076 TuebingenGermany Center for Cleft Lip Palate and Craniofacial MalformationsTuebingen University HospitalTuebingenGermany Department of Orthodontics Tuebingen University HospitalTuebingenGermany Department of Oral and Maxillofacial Surgery Tuebingen University HospitalTuebingenGermany

Background Various conservative and surgical approaches exist to treat Robin sequence(RS),but their effects on facial profile and mandibular catch-up growth are unclear.A functional treatment concept,used in our centre for 25 years,includes an individualized palatal plate with a velo-pharyngeal extension and intensive feeding *** We performed a prospective study to objectively describe facial profiles in infants with RS treated with the above *** with isolated RS were admitted to our tertiary perinatal and national referral centre for craniofacial malformations between May 2018 and Nov *** with RS received 3D-photographs during clinically indicated *** controls were recruited from Dec 2018 to Sep 2019 and received 3D-photographs every 3 *** digitally measured jaw index(JI),defined as alveolar overjet(O)x maxillary arch(U)/mandibular arch(L),and the soft tissue reference points A’-point,Nasion’,B’-point angle(ANB’),describing the relative position of maxilla to mandible,were *** mixed models were used to examine time trajectories in JI and ANB’.Results A total of 2073D images,obtained in 19 infants with RS and 32 controls,were *** and ANB’decreased over time in both groups[for JI−0.18(95%CI−0.25 to−0.10);for ANB’:−0.40°per month[(95%CI−0.48 to−0.32)]]but remained lower in controls[for JI−2.5(95%CI−3.2 to−1.8);for ANB’-1.7°(95%CI−2.4 to−1.0)].Also,the ANB’model showed a significant effect of the interaction term diagnosis x *** Based on longitudinal 3D images,we describe changes in objective parameters of facial profile in infants with and without RS during the first year of *** findings indicate catch-up growth in infants treated for RS.

关键词： Infant Mandibular catch-up growth Pre-epiglottic Baton Plate Robin sequence Three-dimensional photography

Least Square Finite Element Model for Analysis of Multilayered Composite Plates under Arbitrary Boundary Conditions

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 Engineering and Technology 2024年第1期12卷 40-64页

作者： christian Mathew Yao Fu Department of Engineering Mechanics Virginia Polytechnic Institute and State University Blacksburg Virginia USA Department of Aerospace and Ocean Engineering Virginia Polytechnic Institute and State University Blacksburg Virginia USA

Laminated composites are widely used in many engineering industries such as aircraft, spacecraft, boat hulls, racing car bodies, and storage tanks. We analyze the 3D deformations of a multilayered, linear elastic, anisotropic rectangular plate subjected to arbitrary boundary conditions on one edge and simply supported on other edge. The rectangular laminate consists of anisotropic and homogeneous laminae of arbitrary thicknesses. This study presents the elastic analysis of laminated composite plates subjected to sinusoidal mechanical loading under arbitrary boundary conditions. Least square finite element solutions for displacements and stresses are investigated using a mathematical model, called a state-space model, which allows us to simultaneously solve for these field variables in the composite structure’s domain and ensure that continuity conditions are satisfied at layer interfaces. The governing equations are derived from this model using a numerical technique called the least-squares finite element method (LSFEM). These LSFEMs seek to minimize the squares of the governing equations and the associated side conditions residuals over the computational domain. The model is comprised of layerwise variables such as displacements, out-of-plane stresses, and in- plane strains, treated as independent variables. Numerical results are presented to demonstrate the response of the laminated composite plates under various arbitrary boundary conditions using LSFEM and compared with the 3D elasticity solution available in the literature.

关键词： Multilayered Composite and Sandwich Plate Transverse Stress Continuity Condition Arbitrary Boundary Condition Layerwise Theory Least-Squares Formulation