检索结果-南通市图书馆

New Role for an Old Rule: N-end Rule-Mediated Degradation of Ethylene Responsive Factor Proteins Governs Low Oxygen Response in Plants

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2013年第1期55卷 31-39页

作者： francesco Licausi Chiara Pucciariello Pierdomenico Perata Plant Lab Institute of Life Sciences Scuola Superiore Sant' Anna

The N-end rule pathway regulates protein degradation, which depends on exposed N-terminal sequences in prokaryotes and eukaryotes. In plants, conserved and specific enzymes stimulate selective proteolysis. Although a number of developmental and growth phenotypes have been reported for mutants in the N-end rule, its function has remained unrelated to specific physiological pathways. The first report of the direct involvement of the N-end rule in stress responses focused on hypoxic signaling and how the oxygen-dependent oxidation of cystein promotes the N-end rule-mediated degradation of ethylene responsive factor （ERF）-VII proteins, the master regulators of anaerobic responses. It has been suggested that plants have evolved specific mechanisms to tune ERF-VII availability in the nucleus. In this review, we speculate that ERF-VII proteins are reversibly protected from degradation via membrane sequestration. The oxidative response in plants subjected to anoxic conditions suggests that reactive oxygen and nitrogen species （reactive oxygen species and reactive nitrogen species） may interact or interfere with the N-end rule pathway-mediated response to hypoxia.

关键词： Ethylene response factor flooding hypoxia N-end rule pathway ubiquitin.

Analysis of suitable geometrical parameters for designing a tendon-driven under-actuated mechanical finger

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2016年第2期11卷 184-194页

作者： francesco PENTA Cesare ROSSI Sergio SAVINO Department of Industrial Engineering University of Naples 'FedericoII' Naples 80125 Italy

This study aims to optimize the geometrical parameters of an under-actuated mechanical finger by conducting a theoretical analysis of these parameters. The finger is actuated by a flexion tendon and an extension tendon. The considered parameters are the tendon guide positions with respect to the hinges. By applying such an optimization, the correct kinematical and dynamical behavior of the closing cycle of the finger can be obtained. The results of this study are useful for avoiding the snap- through and the single joint hyperflexion, which are the two breakdowns most frequently observed during experi- mentation on prototypes. Diagrams are established to identify the optimum values for the tendon guides position of a finger with specified dimensions. The findings of this study can serve as guide for future finger design.

关键词： tendon-driven fingers mechanical fingerdesign under-actuated mechanical systems

Static Analysis of Anisotropic Doubly-Curved Shell Subjected to Concentrated Loads Employing Higher Order Layer-Wise Theories

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2023年第2期134卷 1393-1468页

作者： francesco Tornabene Matteo Viscoti Rossana Dimitri Department of Innovation Engineering School of EngineeringUniversity of SalentoLecce73100Italy

In the presentmanuscript,a Layer-Wise(LW)generalizedmodel is proposed for the linear static analysis of doublycurved shells constrained with general boundary conditions under the influence of concentrated and surface *** unknown field variable is modelled employing polynomials of various orders,each of them defined within each layer of the *** a particular case of the LW model,an Equivalent Single Layer(ESL)formulation is derived *** approaches are outlined for the assessment of external forces,as well as for non-conventional *** doubly-curved shell is composed by superimposed generally anisotropic laminae,each of them characterized by an arbitrary *** fundamental governing equations are derived starting from an orthogonal set of principal ***,generalized blending functions account for the distortion of the physical *** implementation of the fundamental governing equations is performed bymeans of the Generalized Differential Quadrature(GDQ)method,whereas the numerical integrations are computed employing theGeneralized IntegralQuadrature(GIQ)*** the post-processing phase,an effective procedure is adopted for the reconstruction of stress and strain through-the-thickness distributions based on the exact fulfillment of three-dimensional equilibrium equations.A series of systematic investigations are performed in which the static response of structures with various curvatures and lamination schemes,calculated by the present methodology,have been successfully compared to those ones obtained fromrefined finite element three-dimensional *** though the present LW approach accounts for a two-dimensional assessment of the structural problem,it is capable of well predicting the three-dimensional response of structures with different characteristics,taking into account a reduced computational cost and pretending to be a valid alternative to widespread numerical implementations.

关键词： Concentrated load doubly-curved shells generalized differential quadrature laminated anisotropic materials layer-wise theory mapping technique

Static Analysis of Doubly-Curved Shell Structures of Smart Materials and Arbitrary Shape Subjected to General Loads Employing Higher Order Theories and Generalized Differential Quadrature Method

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2022年第12期133卷 719-798页

作者： francesco Tornabene Matteo Viscoti Rossana Dimitri Department of Innovation Engineering School of EngineeringUniversity of SalentoLecce73100Italy

The article proposes an Equivalent Single Layer(ESL)formulation for the linear static analysis of arbitrarily-shaped shell structures subjected to general surface loads and boundary conditions.A parametrization of the physical domain is provided by employing a set of curvilinear principal *** generalized blendingmethodology accounts for a distortion of the structure so that disparate geometries can be *** layer of the stacking sequence has an arbitrary orientation and is modelled as a generally anisotropic *** addition,re-entrant auxetic three-dimensional honeycomb cells with soft-core behaviour are considered in the *** unknown variables are described employing a generalized displacement field and pre-determined through-the-thickness functions assessed in a unified ***,a weak assessment of the structural problem accounts for shape functions defined with an isogeometric approach starting fromthe computational *** has been proposed to define two-dimensional distributions of static surface *** the same way,boundary conditions with three-dimensional features are implemented along the shell edges employing linear *** fundamental relations are obtained from the stationary configuration of the total potential energy,and they are numerically tackled by employing the Generalized Differential Quadrature(GDQ)method,accounting for nonuniform computational *** the post-processing stage,an equilibrium-based recovery procedure allows the determination of the three-dimensional dispersion of the kinematic and static *** case studies have been presented,and a successful benchmark of different structural responses has been performed with respect to various refined theories.

关键词： 3D honeycomb anisotropic materials differential quadrature method general loads and constraints higher order theories linear static analysis weak formulation

Globally generated vector bundles on a smooth quadric surface

维普期刊数据库评论

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 2015年第3期58卷 633-652页

作者： BALLICO Edoardo HUH Sukmoon MALASPINA francesco Department of Mathematics Università di Trento Department of Mathematics Sungkyunkwan University Department of Mathematical Science Politecnico di Torino

We give the classification of globally generated vector bundles of rank 2 on a smooth quadric surface with c1(2,2)in terms of the indices of the bundles,and extend the result to arbitrary higher rank *** also investigate their indecomposability and give the sufficient and necessary condition on numeric data of vector bundles for indecomposability.

关键词： higher rank vector bundles globally generated smooth quadric surface

THE ONE-DIMENSIONAL HUGHES MODEL FOR PEDESTRIAN FLOW:RIEMANN-TYPE SOLUTIONS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2012年第1期32卷 259-280页

作者： Debora Amadori M.Di francesco Dipartimento di Matematica Pura e Applicata Universita degli Studi dell'Aquila Departament de Matematiques Universitat Autonoma de Barcelona

This paper deals with a coupled system consisting of a scalar conservation law and an eikonal equation, called the Hughes model. Introduced in [24], this model attempts to describe the motion of pedestrians in a densely crowded region, in which they are seen as a ＇thinking＇（continuum） fluid. The main mathematical difficulty is the discontinuous gradient of the solution to the eikonal equation appearing in the flux of the conservation law. On a one dimensional interval with zero Dirichlet conditions （the two edges of the interval are interpreted as ＇targets＇）, the model can be decoupled in a way to consider two classical conservation laws on two sub-domains separated by a turning point at which the pedestrians change their direction. We shall consider solutions with a possible jump discontinuity around the turning point. For simplicity, we shall assume they are locally constant on both sides of the discontinuity. We provide a detailed description of the local- in-time behavior of the solution in terms of a ＇global＇ qualitative property of the pedestrian density （that we call ＇relative evacuation rate＇）, which can be interpreted as the attitude of the pedestrians to direct towards the left or the right target. We complement our result with explicitly computable examples.

关键词： pedestrian flow nonlocal conservation law eikonal equation

An action plan for the agri-food sector at the time of the climate and biodiversity crises

在线全文

学校读者我要写书评

暂无评论

National Science Review 2023年第7期10卷 16-18页

作者： francesco Cherubini Ting Hua Wenwu Zhao Industrial Ecology Programme Department of Energy and Process Engineering Norwegian University of Science and Technology (NTNU) State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical Science Beijing Normal University Institute of Land Surface System and Sustainable Development Faculty of Geographical Science Beijing Normal University

Land areas on our planet are facing unprecedented levels of *** than70%of the global ice-free land has been affected by human activities,30%of the land is threatened by degradation,biodiversity and other ecosystem services(ESs) are declining,and climate change is altering ecosystem functioning [1].Currently,agriculture is the dominant form of land use,with grazing land comprising27%and cropland 12%(and more than half of the cropland is used to produce animal feed).Agriculture is responsible for about one-third of global greenhouse gas(GHG) emissions [2] and it is the primary driver of deforestation,habitat destruction,global freshwater withdrawals,and global ocean and freshwater pollution [3].As land is a limited resource,

关键词：

DZ Lyn:a contact binary with components in poor thermal contact

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2009年第11期9卷 1270-1276页

作者： Massimiliano Martignoni francesco Acerbi Carlo Barani Via Don G. Minzoni 26/D 20020 Magnago(MI)Italy Via Zoncada 51 26845 Codogno(LO)Italy Via Molinetto 35 26845 Triulza di Codogno(LO)Italy

CCD photometric observations of the short-period eclipsing binary DZ Lyn were obtained during seven nights in March-April 2008 in the B, V, Rc and Ic bands; these observations confirm the short-period （P = 0.378 d） of the system. The presented light curves are analyzed by means of the 2003 version of the Wilson-Devinney （WD） program. A grid of solutions for several fixed values of mass ratio was calculated. The best fitting possible is for a mass ratio of q -- 0.885, a degree of contact f = 0.18 and a low orbital inclination of i = 57.6°. The results show that DZ Lyn is an A-subtype W Ursae Majoris contact binary in poor thermal contact; in fact the difference between the mean temperatures of the components is about 1800 K. The star DZ Lyn seems to be another member of the class of poorly understood close binaries in or near geometrical contact but far from thermal contact. The absolute dimensions are estimated and its dynamical evolution is inferred.

关键词： binaries eclipsing -- stars fundamental parameters -- stars individual DZ Lyn

Experimental characterization of the 3D linear viscoelastic behavior of cold recycled bitumen emulsion mixtures

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2019年第4期6卷 324-336页

作者： Andrea Graziani Carlotta Godenzoni francesco Canestrari Dipartimento di Ingegneria Civile Edile e Architettura Università Politecnica delle Marche

Cold mixtures with bitumen emulsion are produced at ambient temperature, leading to substantial reductions of energy consumption and atmospheric emissions. In cold recycling applications, cement is normally used to improve the mixture performance. Thus, the rheological behavior of cold recycled mixtures is different from that of conventional hot mixtures because it is due to the interaction of fresh bitumen, aged bitumen and cementitious bonds. In this study, we investigated the three-dimensional(3 D) linear viscoelastic(LVE) behavior of a cement-bitumen treated material(CBTM) mixture fabricated using bitumen emulsion and cement. For comparison, we also investigated the 3 D LVE behavior of hot-mix asphalt containing 25% of reclaimed asphalt and fabricated using polymermodified binder. Sinusoidal axial tests on cylindrical specimens, were carried out at various temperatures(from 0℃ to 50℃) and frequencies(from 0.1 to 12 Hz). The complex Young’s modulus E~*and the complex Poisson’s ratio v~*were determined through the measurement of axial and transverse strain. We show that when considering E*, CBTM mixtures may be considered thermo-rheologically simple and the Huet-Sayegh model can be used to simulate the frequencyetemperature dependence. On the other hand, when considering v*the behavior of CBTM mixtures is very different from that of hot mix asphalt. In particular, its absolute value is almost constant and very close to 0.15.

关键词： Bitumen emulsion Cold recycling Complex modulus Complex Poisson’s ratio Huet-Sayegh model