Um estudo comparativo entre os indicadores de inovação utilizados pelos métodos de scorecard para o cálculo de ativos intangíveis com os utilizados pelos fundos de capital de risco para investimentos em empresas spin-offs acadêmicas incubadas.

Este trabalho pretende verificar o alinhamento entre os indicadores de inovação utilizados pelos métodos Scorecard de mensuração dos ativos intangíveis e pelas agências governamentais nacionais e internacionais com aqueles utilizados pelos fundos de capital de risco na cidade do Rio de Janeiro, para investimento em empresas spin-offs acadêmicas incubadas. A metodologia constou de uma revisão bibliográfica sobre os métodos de mensuração e valoração dos ativos intangíveis, indicadores de inovação propostos por agências governamentais nacionais e internacionais e fundos de capital de risco que atuam na cidade do Rio de Janeiro. Além de serem aplicados questionários nas empresas de fundos de capital de risco desta cidade. Foram levantados diversos métodos Scorecards na literatura com seus indicadores, além dos indicadores de inovação de agências governamentais nacionais e internacionais. Adicionando-se a isso, identificou-se o foco de investimento, o processo de seleção, o método utilizado de avaliação de oportunidades de investimento e indicadores relevantes para as empresas de capital de risco da cidade do Rio de Janeiro. Observou-se que os ativos intangíveis, entre eles os de inovação, não são avaliados individualmente. A informação obtida com as empresas que receberão investimentos dessas empresas de capital de risco é utilizada para se entender a origem dos fluxos de caixa projetados e os principais fatores de risco. E esses dados aplicados ao método do fluxo de caixa descontado permitem que se estime o valor da empresa. Pela vasta experiência dos gestores dos fundos de capital de risco com micro e pequenas empresas inovadoras, espera-se que o estudo das práticas deste segmento traga importantes reflexões para as discussões relativas aos ativos intangíveis e a inovação.

Tunable Rashba effect in two-dimensional LaOBiS2 films: Ultrathin candidates for spin field effect transistors

Rashba spin splitting is a two-dimensional (2D) relativistic effect closely related to spintronics. However, so far there is no pristine 2D material to exhibit enough Rashba splitting for the fabrication of ultrathin spintronic devices, such as spin field effect transistors (SFET). On the basis of first-principles calculations, we predict that the stable 2D LaOBiS2 with only 1 nm of thickness can produce remarkable Rashba spin splitting with a magnitude of 100 meV. Because the medium La2O2 layer produces a strong polar field and acts as a blocking barrier, two counter-helical Rashba spin polarizations are localized at different BiS 2 layers. The Rashba parameter can be effectively tuned by the intrinsic strain, while the bandgap and the helical direction of spin states sensitively depends on the external electric field. We propose an advanced Datta-Das SFET model that consists of dual gates and 2D LaOBiS2 channels by selecting different Rashba states to achieve the on-off switch via electric fields. © 2013 American Chemical Society.

Magnetic coupling properties of mn-doped ZnO nanowires: First-principles calculations

Based on the density functional theory, we study the magnetic coupling properties of Mn-doped ZnO nanowires. For the nanowires with passivated surfaces, the antiferromagnetic state is found and the Mn atoms have a clustering tendency. When the distance between two Mn atoms is large, the system energetically favors the paramagnetic or spin-glass state. For the nanowires with unpassivated surfaces, the ferromagnetic (FM) coupling states appear between the two nearest Mn atoms, and the zinc vacancies can further stabilize the FM states between them. The electrons with enough concentration possibly mediate the FM coupling due to the negative exchange splitting of conduction band minimum induced by the s-d coupling, which could be useful in nanomaterial design for spintronics. (C) 2008 American Institute of Physics.

Thermodynamic properties of Cu-3(CO3)(2)(OH)(2) and the spin-1/2 distorted diamond Heisenberg chain

The thermodynamic properties of the spin-1/2 diamond quantum Heisenberg chain model have been investigated by means of the transfer matrix renormalization group (TMRG) method. Considering different crystal structures, by changing the interactions among different spins and the external magnetic fields, we first investigate the magnetic susceptibility, magnetization, and specific heat of the distorted diamond chain as a model of ferrimagnetic spin systems. The susceptibility and the specific heat show different features for different ferromagnetic (F) and antiferromagnetic (AF) interactions and different magnetic fields. A 1/3 magnetization plateau is observed at low temperature in a magnetization curve. Then, we discuss the theoretical mechanism of the double-peak structure of the magnetic susceptibility and the three-peak structure of the specific heat of the compound Cu-3(CO3)(2)(OH)(2), on which an elegant measurement was performed by Kikuchi [Phys. Rev. Lett. 94, 227201 (2005)]. Our computed results are consistent with the main characteristics of the experimental data. Meanwhile, we find that the double-peak structure of susceptibility can be found in several different kinds of spin interactions in the diamond chain. Moreover, a three-peak behavior is observed in the TMRG results of magnetic susceptibility. In addition, we perform calculations relevant for some experiments and explain the characteristics of these materials. (c) 2007 American Institute of Physics.

Giant Zeeman splitting in manganese-doped ZnSe quantum spheres: Eight-band effective-mass calculations

We deduce the eight-band effective-mass Hamiltonian model for a manganese-doped ZnSe quantum sphere in the presence of the magnetic field, including the interaction between the conduction and valence bands, the spin-orbit coupling within the valence bands, the intrinsic spin Zeeman splitting, and the sp-d exchange interaction between the carriers and magnetic ion in the mean-field approximation. The size dependence of the electron and hole energy levels as well as the giant Zeeman splitting energies are studied theoretically. We find that the hole giant Zeeman splitting energies decrease with the increasing radius, smaller than that in the bulk material, and are different for different J(z) states, which are caused by the quantum confinement effect. Because the quantum sphere restrains the excited Landau states and exciton states, in the experiments we can observe directly the Zeeman splitting of basic states. At low magnetic field, the total Zeeman splitting energy increases linearly with the increasing magnetic field and saturates at modest field which is in agreement with recent experimental results. Comparing to the undoped case, the Zeeman splitting energy is 445 times larger which provides us with wide freedom to tailor the electronic structure of DMS nanocrystals for technological applications.

CALCULATION OF SPIN-REORIENTATION TEMPERATURE IN ND2FE14B

The spin-reorientation phenomenon in Nd2Fe14B has been investigated using an angular dependent free energy approach. A magnetic Hamiltonian which includes the crystal electric field term and the exchange term has been established using realistic band structure results. The temperature dependence of the molecular field is accounted for by introducing the Brillouin function and the magnetic Hamiltonian is diagonalized within the ground state multiplet of the Nd ion. The eigenstates are then used to form the partition function for the free energy. At each temperature, the direction of the molecular field is obtained by searching for the minimum in the angular parameter space of the free energy. Our calculations show that for Nd2Fe14B, the net magnetic anisotropy direction is canted away from the c axis at a temperature close to the experimentally reported spin-reorientation temperature of 150 K. The temperature dependence of the magnetic structure is found to be very sensitive to the size of the second order crystal field parameter B20.

Competition in rotation-alignment between high-j neutrons and protons in transfermium nuclei

The study of rotation-alignment of quasiparticles probes sensitively the properties of high-j intruder orbits. The distribution of very-high-j orbits, which are consequences of the fundamental spin-orbit interaction, links with the important question of single-particle levels in superheavy nuclei. With the deformed single-particle states generated by the standard Nilsson potential, we perform Projected Shell Model calculations for transfermium nuclei where detailed spectroscopy experiments are currently possible. Specifically, we study the systematical behavior of rotation-alignment and associated band-crossing phenomenon in Cf, Fm, and No isotopes. Neutrons and protons from the high-j orbits are found to compete strongly in rotation-alignment, which gives rise to testable effects. Observation of these effects will provide direct information on the single-particle states in the heaviest nuclear mass region.

High-spin level structure in Mo-94,Mo-95

High-spin level structures of 94,95Mo have been reinvestigated via the 16O(82Se, xnγ)94,95Mo(x = 4, 3) reactions at E(82Se) = 460 MeV. The previously reported level schemes of these two nuclei have been largely modified up to ∼11 MeV in excitation energy due to identifications of some important linking transitions. Shellmodel calculations have been made in the model space of π(p1/2, g9/2, d5/2)4 and ν(d5/2, s1/2, d3/2, g7/2, h11/2)2(3) and compared with the modified level schemes. The structures of the newly assigned high-spin states in 94,95Mo have been discussed.

High-spin structure in Pt-187

High-spin states in Pt-187 were studied via the Yb-173(O-18, 4n) reaction. Rotational bands based on the vi(13/2), v7/2(-)[503], vi(13/2)(2)vj, v3/2(-)[512] and v1/2(-)[521] configurations were observed, and interpreted within the framework of the cranked shell model. The TRS calculations show that the vi(13/2) band has an appreciable negative gamma deformation, and the negative-parity bands tend to have a near prolate shape with small positive gamma values. Experimental values of B(M1)/B(E2) ratios have been extracted and compared with theoretical values from the semi-classical Donau and Frauendof approach, strongly suggesting a low frequency pi h(9/2) alignment in the v7/2(-)[503] band.

Quantum-mechanical calculations of vibrationally resolved cross sections for non-dissociative charge transfer of O3+ with H-2

Charge transfer due to collisions of ground state O3+ (2s(2)2p P-2) ions with molecular hydrogen is investigated using the quantum-mechanical molecular-orbital close-coupling (MOCC) method, and electronic and vibrational state-selective cross sections along with the corresponding differential cross sections are calculated for projectile energies of 100, 500, 1000 and 5000 eV/u at the orientation angles of 25 degrees,45 degrees and 89 degrees. The adiabatic potentials and radial coupling matrix elements utilized in the QMOCC calculations were obtained with the spin-coupled valence-bond approach. The infinite order sudden approximation (IOSA) and the vibrational sudden approximation (VSA) are utilized to deal with the rotation of H-2 and the coupling between the electron and the vibration of H-2. It is found that the distribution of vibrationally resolved cross sections with the vibrational quantum number upsilon' of H-2(+) (upsilon') varies with the increment of the projectile energy; and the electronic and vibrational stateselective differential cross sections show similar behaviors: there is a highest platform within a very small scattering angle, beyond which the differential cross sections decrease as the scattering angle increases and lots of oscillating structures appear, where the scattering angle of the first structure decreases as E-P(-1/2) with the increment of the projectile energy E-P; and the structure and amplitude of the differential cross sections are sensitive to the orientation of molecule H-2, which provides a possibility to identify the orientations of molecule H-2 by the vibrational state-selective differential scattering processes.

High-spin isomeric structures in exotic odd-odd nuclei: Exploration of the proton drip line and beyond

We investigate the role of two-quasiparticle isomeric states along the proton drip line, using configuration-constrained potential-energy-surface calculations. In contrast to even-even nuclei, odd-odd nuclei can have coexisting low-lying two-quasiparticle states. The low excitation energy and high angular momentum can lead to long-lived isomers. Also, because of the hindrance by spin selection, the probabilities of beta and proton decays from high-spin isomers can be reduced significantly. The present calculations reproduce reasonably well the available data for observed isomers in such nuclei. Unobserved high-spin isomers are predicted, which could be useful for future experimental studies of exotic nuclei at and beyond the proton drip line.

beta-delayed proton decays and spin assignments for Sm-133 and Yb-149

The proton-rich isotope Sm-133 was produced via the fusion evaporation reaction Ca-40 + Ru-96. Its beta-delayed proton decay was studied by p-gamma coincidence in combination with a He-jet tape transport system, and half-lives, proton energy spectra, gamma-transitions following the proton emission, as well as beta-delayed proton branching ratios to the low-lying states in the grand-daughter nucleus were determined. Comparing the observed beta-delayed proton branching ratios with statistical model calculations, the best agreement is found assuming that only one level with the spin of 3/2 in Sm-133 decays or two levels with the spins of 1/2 and 5/2 decay with similar half-lives. The configuration-constrained nuclear potential energy surfaces of Sm-133 were calculated using the Woods-Saxon-Strutinsky method, which suggests a 1/2-ground state and a 5/2(+) isomer with an excitation energy of 120 keV. Therefore, the simple(EC+beta(+)) decay scheme of Sm-133 in Eur. Phys. J.A 11,277(2001) has been revised. In addition, our previous experimental data on the beta-delayed proton decay of Yb-149 reported in Eur. Phys. J. A 12,1 ( 2 0 0 1) was also analyzed using the same method. The spin-parity of Yb-149 is suggested to be 1/2(-).

beta-delayed proton decays and spin assignments for Tb-140, Dy-141 and Dy-143

The proton-rich isotopes Tb-140 and Dy-141 were produced via the fusion evaporation reaction Ca-40+ Cd-106. Their beta-delayed proton decays were studied by p-gamma coincidence in combination with a He-jet tape transport system, and half-lives, proton energy spectra, gamma-transitions following the proton emission, as well as beta-delayed proton branching ratios to the low-lying states in the grand-daughter nuclei were determined. Comparing the experimental data with statistical model calculations, the ground-state spins of Tb-140 and Dy-141 were found to be consistent with 7 and 9/2, respectively. The configuration-constrained nuclear potential energy surfaces (NPES) of Tb-140 and Dy-141 were calculated using the Woods-Saxon-Strutinsky method, which suggest the ground-state spins and parities of Tb-140 and Dy-141 to be 7(+) and 9/2(-), respectively. In addition, the configuration-constrained NPES of Dy-143 were calculated, which predict a 1/2(+) ground state and a 11/2(-) isomer with excitation energy of 198 keV. These findings are consistent with our previous experimental data on Dy-143 reported in Eur. Phys. J. A 16, 347 (2003).

High-spin states in Au-188: Further evidence for nonaxial shape

The high-spin level structure of Au-188 has been investigated via the Yb-173(F-19,4n gamma) reaction at beam energies of 86 and 90 MeV. The previously reported level scheme has been modified and extended significantly. A new I-pi = 20(+) state associated with pi h(11/2)(-1) circle times nu i(13/2)(-2)h(9/2)(-1) configuration and two new rotational bands, one of which is built on the pi h(9/2) circle times nu i(13/2) configuration, have been identified. The prolate-to-oblate shape transition through triaxial shape has been proposed to occur around Au-188 for the pi h(9/2) circle times nu i(13/2) bands in odd-odd Au isotopes. Evidence for pi h(11/2)(-1) circle times nu i(13/2)(-1) structure of nonaxial shape with gamma < -70 degrees has been obtained by comparison with total Routhian surface and cranked-shell-model calculations.

Importance of self-consistency in relativistic continuum random-phase approximation calculations

A fully consistent relativistic continuum random phase approximation (RCRPA) is constructed, where the contribution of the continuum spectrum to nuclear excitations is treated exactly by the single-particle Green's function technique. The full consistency of the calculations is achieved that the same effective Lagrangian is adopted for the ground state and the excited states. The negative energy states in the Dirac sea are also included in the single-particle Green's function in the no-sea approximation. The currents from the vector meson and photon exchanges and the Coulomb interaction in RCRPA are treated exactly. The spin-orbit interaction is included naturally in the relativistic frame. Numerical results of the RCRPA are checked with the constrained relativistic mean-field theory. We study the effects of the inconsistency, particularly the currents and Coulomb interaction in various collective multipole excitations.