The ground state properties of the spin-1/2 transverse Ising chain with periodically varying bonds and fields

Using continued fractions we study the ground state properties of the spin-1/2 Ising chain in a transverse field with periodically varying interaction strengths and external fields. We consider in detail the chain having the period of modulation of interactions equals 2 and compare the results obtained with those corresponding to the spin-1/2 isotropic XY chain in a transverse field. In contrast to the behaviour of the transverse XY chain, the transverse Ising chain does not exhibit a step-like magnetization vs. field dependence caused by the alternation of bonds, its susceptibility exhibits a logarithmic singularity at the field determined by interaction strengths, and it is stable with respect to spin-Peierls dimerization.Comment: 11 pages, latex, 4 figure

Teca (Tectona grandis L. f.): principais perguntas do futuro empreendedor florestal.

Introdução; Características da espécie; demandas ambientais; Produção de mudas; Plantio definitivo; Tratos culturais; Manejo florestal; Produção e economia; Conceitos florestaisbitstream/CPAF-AC/13198/1/doc97.pdfA bt. possui um exemp. na Produção Científica da Ud

Privacy-Preserving Outsourcing of Large-Scale Nonlinear Programming to the Cloud

The increasing massive data generated by various sources has given birth to big data analytics. Solving large-scale nonlinear programming problems (NLPs) is one important big data analytics task that has applications in many domains such as transport and logistics. However, NLPs are usually too computationally expensive for resource-constrained users. Fortunately, cloud computing provides an alternative and economical service for resource-constrained users to outsource their computation tasks to the cloud. However, one major concern with outsourcing NLPs is the leakage of user's private information contained in NLP formulations and results. Although much work has been done on privacy-preserving outsourcing of computation tasks, little attention has been paid to NLPs. In this paper, we for the first time investigate secure outsourcing of general large-scale NLPs with nonlinear constraints. A secure and efficient transformation scheme at the user side is proposed to protect user's private information; at the cloud side, generalized reduced gradient method is applied to effectively solve the transformed large-scale NLPs. The proposed protocol is implemented on a cloud computing testbed. Experimental evaluations demonstrate that significant time can be saved for users and the proposed mechanism has the potential for practical use.Comment: Ang Li and Wei Du equally contributed to this work. This work was done when Wei Du was at the University of Arkansas. 2018 EAI International Conference on Security and Privacy in Communication Networks (SecureComm

Analytical results for a Bessel function times Legendre polynomials class integrals

When treating problems of vector diffraction in electromagnetic theory, the evaluation of the integral involving Bessel and associated Legendre functions is necessary. Here we present the analytical result for this integral that will make unnecessary numerical quadrature techniques or localized approximations. The solution is presented using the properties of the Bessel and associated Legendre functions.Comment: 4 page

Uso de inseticidas alternativos no controle de pragas agrícolas.

Vantagens e desvantagens dos inseticidas naturais; Precauções durante a manipulação; Extratos vegetais: métodos artesanais de extração dos princípios ativos; Receitas para obtenção de inseticidas naturais de origem vegetal; Outros inseticidas ou métodos alternativos de controle.bitstream/CPATSA/33455/1/SDC191.pd

Manejo e controle da Cochonilha Ortézia (Orthezia praelonga), em plantios irrigados de acerola, no Submédio São Francisco.

O cultivo da acerola é uma importante alternativa econômica para a Região Nordeste do Brasil. No Submédio São Francisco, há cerca de mil hectares cultivados e a expansão do cultivo deve-se, basicamente, ao apreciado sabor da fruta e ao alto teor de ácido ascórbico (vitamina C), que, em algumas variedades, alcança até 5.000 miligramas por 100 gramas de polpa.bitstream/CPATSA/37176/1/CTE83.pd

Neuromorphometric characterization with shape functionals

This work presents a procedure to extract morphological information from neuronal cells based on the variation of shape functionals as the cell geometry undergoes a dilation through a wide interval of spatial scales. The targeted shapes are alpha and beta cat retinal ganglion cells, which are characterized by different ranges of dendritic field diameter. Image functionals are expected to act as descriptors of the shape, gathering relevant geometric and topological features of the complex cell form. We present a comparative study of classification performance of additive shape descriptors, namely, Minkowski functionals, and the nonadditive multiscale fractal. We found that the proposed measures perform efficiently the task of identifying the two main classes alpha and beta based solely on scale invariant information, while also providing intraclass morphological assessment

Levantamento de Diaphorina citri (Hemiptera: psylidae), vetor do Huanglongbing (HLB), em três regiões produtoras de citros no estado da Bahia.

O psilídeo Diaphorina citri, Kuwayama, inseto-vetor da bactéria Candidatus Liberibacter causadora da devastadora doença dos citros: a Huanglongbing ? HLB - (ex-greening), ocorre praticamente em todas regiões produtoras de citros do país. A Bahia é considerada área livre desta doença. A transmissão do HLB ocorre por meio de enxertia com material contaminado ou por inoculação da bactéria no floema da planta pelo inseto vetor.PDF. 153_11