检索结果-南通市图书馆

Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： H.T.Jeong S.w.Lee w.J.Kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

Pervasive Attentive Neural Network for Intelligent Image Classification Based on N-CDE’s

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第4期79卷 1137-1156页

作者： Anas w.Abulfaraj Department of Information Systems Faculty of Computing and Information TechnologyKing Abdulaziz UniversityRabigh21911Saudi Arabia

The utilization of visual attention enhances the performance of image classification *** attentionbased models have demonstrated notable performance,but many of these models exhibit reduced accuracy when confronted with inter-class and intra-class similarities and ***-Controlled Differential Equations(N-CDE’s)and Neural Ordinary Differential Equations(NODE’s)are extensively utilized within this ***’s possesses the capacity to effectively illustrate both inter-class and intra-class similarities and differences with enhanced *** this end,an attentive neural network has been proposed to generate attention maps,which uses two different types of N-CDE’s,one for adopting hidden layers and the other to generate attention *** distinct attention techniques are implemented including time-wise attention,also referred to as bottom N-CDE’s;and element-wise attention,called topN-CDE’***,a trainingmethodology is proposed to guarantee that the training problem is sufficiently *** classification tasks including fine-grained visual classification andmulti-label classification,are utilized to evaluate the *** proposedmethodology is employed on five publicly available datasets,including CUB-200-2011,ImageNet-1K,PASCAL VOC 2007,PASCAL VOC 2012,and MS *** obtained visualizations have demonstrated that N-CDE’s are better appropriate for attention-based activities in comparison to conventional NODE’s.

关键词： Differential equations neural-controlled DE image classification attention maps N-CDE’s

The quasi-Gramian solution of a non-commutative extension of the higher-order nonlinear Schr?dinger equation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第3期76卷 51-61页

作者： H w A Riaz J Lin Department of Physics Zhejiang Normal UniversityJinhua 321004China

The nonlinear Schr?dinger(NLS)equation,which incorporates higher-order dispersive terms,is widely employed in the theoretical analysis of various physical *** this study,we explore the non-commutative extension of the higher-order NLS *** treat real or complex-valued functions,such as g_(1)=g_(1)(x,t)and g_(2)=g_(2)(x,t)as non-commutative,and employ the Lax pair associated with the evolution equation,as in the commutation *** derive the quasi-Gramian solution of the system by employing a binary Darboux *** soliton solutions are presented explicitly within the framework of *** visually understand the dynamics and solutions in the given example,we also provide simulations illustrating the associated ***,the solution can be used to study the stability of plane waves and to understand the generation of periodic patterns within the context of modulational instability.

关键词： integrable systems Darboux transformation solitons

Recent Advances in the Synthesis and Polymerization of New CO_(2)-Based Cyclic

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第4期42卷 430-443页

作者： Matteo Lanzi Arjan w.Kleij Institute of Chemical Research of Catalonia(ICIQ) The Barcelona Institute of Science and Technology(BIST)Av.Països Catalans 1643007 TarragonaSpain Catalan Institute of Research and Advanced Studies(ICREA) Pg.Lluís Companys 2308010 BarcelonaSpain

Carbon dioxide can be converted into functional heterocycles known as cyclic carbonates,whose recent reactivity has been expanded towards the formation of tailor-made engineering *** minireview gives an overview of the most topical developments in this area with a special focus on the synthetic methods employed to prepare these CO_(2)based *** addition,their application potential in the area of polymer science using a variety of polymerization techniques is discussed that have in common the ring-opening of the carbonate *** perspectives are provided that provide impetus for the scientific communities aligning research to the use of sustainable processes for polymers from recyclable carbon sources such as CO_(2).

关键词： Carbon dioxide Cyclic carbonates Functional macromolecules Heterocycles Polycarbonates Recycling Ring opening polymerization

Effect of Eu3+,Bi3+,and Li+ doping on luminescent property of GdNbO4

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 Rare Earths 2024年第1期42卷 66-75页

作者： S.w.wi Y.S.Lee Department of Physics and Integrative Institute of Basic Sciences Soongsil University

we investigated the emission properties of Eu3+-doped GdNbO4-based oxide phosphors,aiming at improving the Eu3+emission by codoping of Bi3+and Li+.Eu3+singly doped,Eu3+and Bi3+doubly doped,and Eu3+,Bi3+,and Li+triply doped GdNbO4were prepared using a high-temperature solid-state reaction *** red-orange emissions from Eu3+in the singly doped samples are significantly improved by the codoping of Bi3+,mainly due to the energy transfer from Bi3+to Eu3+.The additional codoping of Li+is found to increase the Eu3+emission *** improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity.A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the photoluminescence spectra show that the local lattice environment around Eu3+in GdNbO4does not change significantly with the codoping of Bi3+and Li+.Our results indicate that Li+doping is a promising way to improve the emission properties of rare-earth ion-doped GdNbO4phosphors.

关键词： Eu 3+ GdNbO 4 Codoping of Li + Photoluminescence Sensitizer Rare earths

Transcranial Direct Current Stimulation: Effects on Motor and Non-Motor Symptoms of Parkinson’s Disease

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 Behavioral and Brain Science 2024年第5期14卷 135-160页

作者： Fayda Protásio Carlos Alberto bezerra Tomaz Joaquim Brasil-Neto Pedro Brandão Nasser Allam Maria Clotilde Henriques Tavares Laboratory of Neuroscience and Behavior Department of Physiological Sciences Institute of Biology University of Braslia Braslia Brazil Master Program in Environment University CEUMA So Lus MA and Faculty of Medicine Euro-American University Center-UNIEURO Braslia Brazil Faculty of Medicine Euro-American University Center-UNIEURO Braslia Brazil NA Neurologistas Associados Braslia Brazil

Introduction: In the last thirty years, brain neuromodulation techniques have been used as an alternative to pharmacological treatment of neurological disorders. Parkinson’s disease (PD) is a neurodegenerative disorder leading to bradykinesia, rest tremor, postural changes, and non-motor symptoms such as depression, anxiety, sleep disorders, pain, and cognitive decline that compromises executive functions (EFs), responsible for the orderly execution of behaviors and tasks of daily life and intentional and directed actions. To this date, a few studies with transcranial direct current stimulation (tDCS) have shown beneficial effects in PD patients concerning specific motor and non-motor symptoms, targeting the motor cortex and/or prefrontal regions. Objective: The main objective of this study was to evaluate the effects of left prefrontal tDCS across a broad spectrum of motor and non-motor symptoms of PD using established validated scales. Method: Single-blind randomized clinical trial with 18 volunteers with PD, aged between 45 and 80 years (66.1 ± 9.65), who met inclusion and exclusion criteria. Participants were submitted to assessments of motor and non-motor functions employing psychometric scales and tests to evaluate EFs and were randomly divided into two groups: control (sham stimulation) and experimental (active stimulation). All participants were involved in three separate tDCS sessions. The anode was positioned over the left dorsolateral prefrontal cortex and the cathode over the right supraorbital region, with a direct current intensity of 2 mA, lasting 20 minutes. At the end of the three sessions, all participants were reassessed. Results: Significant effects of tDCS on non-motor functions were observed for cognition (verbal fluency of actions, clock copy test, appointment by visual confrontation, and verbal memory with immediate free recall) and subjective assessment of sleep quality (overall restlessness and discomfort in the arms and legs at night, leg

关键词： Parkinson’s Disease Neuromodulation Transcranial Direct Current Stimulation—tDCS Movement Disorders Mood Sleep Cognition

Integrins and their potential roles in mammalian pregnancy

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 Animal Science and Biotechnology 2024年第1期15卷 1-19页

作者： Gregory A.Johnson Robert C.Burghardt Fuller w.Bazer Heewon Seo Joe w.Cain Department of Veterinary Integrative Biosciences School of Veterinary Medicine and Biomedical SciencesTexas A&M UniversityCollege StationTX 77843‑4459USA Department of Animal Science College of Agriculture and Life SciencesTexas A&M UniversityCollege StationTX 77843‑2471USA

Integrins are a highly complex family of receptors that, when expressed on the surface of cells, can mediate reciprocal cell-to-cell and cell-to-extracellular matrix(ECM) interactions leading to assembly of integrin adhesion complexes(IACs) that initiate many signaling functions both at the membrane and deeper within the cytoplasm to coordinate processes including cell adhesion, migration, proliferation, survival, differentiation, and metabolism. All metazoan organisms possess integrins, and it is generally agreed that integrins were associated with the evolution of multicellularity, being essential for the association of cells with their neighbors and surroundings, during embryonic development and many aspects of cellular and molecular biology. Integrins have important roles in many aspects of embryonic development, normal physiology, and disease processes with a multitude of functions discovered and elucidated for integrins that directly influence many areas of biology and medicine, including mammalian pregnancy, in particular implantation of the blastocyst to the uterine wall, subsequent placentation and conceptus(embryo/fetus and associated placental membranes) development. This review provides a succinct overview of integrin structure, ligand binding, and signaling followed with a concise overview of embryonic development, implantation, and early placentation in pigs, sheep, humans, and mice as an example for rodents. A brief timeline of the initial localization of integrin subunits to the uterine luminal epithelium(LE) and conceptus trophoblast is then presented, followed by sequential summaries of integrin expression and function during gestation in pigs, sheep, humans, and rodents. As appropriate for this journal, summaries of integrin expression and function during gestation in pigs and sheep are in depth, whereas summaries for humans and rodents are brief. Because similar models to those illustrated in Fig. 1, 2, 3, 4, 5 and 6 are present throughout the sc

关键词： Humans Implantation Integrins Pigs Pregnancy Rodents Sheep

Sensors Applied to Plant Breeding: Leaf Reflectance Indices (LRIs) and Resistance to Anthracnose in Capsicum annuum L. var. annuum

在线全文

学校读者我要写书评

暂无评论

Advances in Remote Sensing 2024年第1期13卷 1-17页

作者： Rosimara Barboza Bispo Maria Do Socorro bezerra Araújo Antônio André da Silva Alencar Cláudia Pombo Sudré Rosana Rodrigues Plant Breeding Laboratory Darcy Ribeiro North Fluminense State University Campos dos Goytacazes Brazil Plant Breeding Laboratory University of the State of Mato Grosso Cáceres Brazil

The present work investigated the efficiency of leaf reflectance indices in the identification of Capsicum annuum L. var. annuum resistant to anthracnose in the fruit. Twenty-five F5:6 families originating from contrasting parents were assessed;the parents were accession UENF 2285 (susceptible to anthracnose) and accession UENF 1381, a hot pepper resistant to anthracnose in the fruit. The experiment was carried out in an experimental field in Campos dos Goytacazes, Rio de Janeiro, Brazil, between May and October of 2021. The treatments were arranged in a randomized block design, with three replications and five plants per plot. Fifteen LRIs were estimated using a CI-710 portable mini leaf spectrometer. The assessments covered all plant growth after flowering, and a total of six assessments were performed at 15-days intervals, beginning at 35 and ending 120 days after flowering (DAFs). Analysis of variance in a split-plot scheme was performed, as were tests of mean groupings and principal components analysis (PCA). The best period for evaluating leaf reflectance indices in C. annuum var. annuum is 120 days after flowering. The leaf reflectance indices PRI, CNDVI and Ctr2 stood out as effective in distinguishing between resistant and susceptible genotypes.

关键词： Phenotyping Bell Pepper CI-710 Colletotrichum scovillei

Immune response to inactivated bacterial vector carrying the recombinant K39 antigen of Leishmania infantum in mice

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2024年第5期14卷 199-206页

作者： Lucelina S.Araújo Bruno B.Silva Eduarda N.F.N.Santos Arnaldo S.bezerra Samuel S.Frota Assis R.Montenegro Eridan O.P.T.Florean Maurício Fvan Tilburg Maria Izabel F.Guedes Laboratory of Biotechnology and Molecular Biology Northeast Biotechnology NetworkState University of CearáFortalezaBrazil Faculty of Veterinary Medicine State University of CearáFortalezaBrazil

Objective:To evaluate the immunological response elicited by an inactivated bacterial vector carrying the K39 antigen of Leishmania infantum,and a purified ***:Mice were subjected to the following treatments:(1)Purified recombinant K39(rK39)protein at a 20μg dose with complete Freund’s adjuvant;(2)Inactivated Escherichia coli(BL21 DE3)carrying the K39 protein at an equivalent total protein content of 200μg;(3)Inactivated bacteria lacking the K39 protein;(4)Non-immunized control *** monitoring was *** groups were challenged by intraperitoneal injection of 10^(7) Leishmania infantum *** euthanasia,the liver and spleen were collected to analyze the levels of TNF,IFN-γ,IL-12,IL-4,and ***:Mice immunized with purified rK39 or the inactivated bacterial vector carrying the K39 antigen of Leishmania infantum showed a long-lasting immune response with high levels of polyclonal antibodies specifically recognizing the recombinant *** IgG1 subclass was the predominant immunoglobulin;however,the induction of IgG2a and the profile of cytokines produced were indicative of the induction of a mixed-type ***:The inactivated bacterial vector carrying the K39 antigen,as well as the purified antigen can induce a long-lasting immune response in immunized mice,predominantly favouring a Th2 profile response.

关键词： Visceral leishmaniasis K39 Inactivated bacterial vector Vaccine Immune response Th1 Th2 Leishmania infantum