脉冲啁啾对于阿秒脉冲的影响

采用单电子近似和软核势模型，通过数值求解一维含时薛定谔方程，理论研究了当脉冲分别带有正、负啁啾的情况下所产生的阿秒脉冲，分析了不同脉冲啁啾特性对阿秒脉冲的强度和宽度的影响，研究结果表明，无论是正啁啾还是负啁啾，随着啁啾量的增加，都将使激光脉冲由产生单个阿秒脉冲趋向于产生阿秒脉冲链，正啁啾和负啁啾对于阿秒脉冲宽度的影响是不同的，负啁啾对于阿秒脉冲宽度影响很小，适当的负啁啾有利于缩小阿秒脉冲的宽度；而正啁啾脉冲产生的阿秒脉冲较无啁啾时展宽，且随着啁啾量的增加，其阿秒脉冲宽度迅速增大。

Soft-core Stream Processor for Sliding Window Applications

Software-programmable `soft' processors have shown tremendous potential for efficient realisation of high performance signal processing operations on Field Programmable Gate Array (FPGA), whilst lowering the design burden by avoiding the need to design fine-grained custom circuit archi-tectures. However, the complex data access patterns, high memory bandwidth and computational requirements of sliding window applications, such as Motion Estimation (ME) and Matrix Multiplication (MM), lead to low performance, inefficient soft processor realisations. This paper resolves this issue, showing how by adding support for block data addressing and accelerators for high performance loop execution, performance and resource efficiency over four times better than current best-in-class metrics can be achieved. In addition, it demonstrates the first recorded real-time soft ME estimation realisation for H.263 systems.

Solutions of the bound-state Faddeev-Yakubovsky equations in three dimensions by using NN and 3N potential models

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Exploring the parameter space of a rabbit ventricular action potential model to investigate the effect of variation on action potential and calcium transients

Computational models for cardiomyocyte action potentials (AP) often make use of a large parameter set. This parameter set can contain some elements that are fitted to experimental data independently of any other element, some elements that are derived concurrently with other elements to match experimental data, and some elements that are derived purely from phenomenological fitting to produce the desired AP output. Furthermore, models can make use of several different data sets, not always derived for the same conditions or even the same species. It is consequently uncertain whether the parameter set for a given model is physiologically accurate. Furthermore, it is only recently that the possibility of degeneracy in parameter values in producing a given simulation output has started to be addressed. In this study, we examine the effects of varying two parameters (the L-type calcium current (I(CaL)) and the delayed rectifier potassium current (I(Ks))) in a computational model of a rabbit ventricular cardiomyocyte AP on both the membrane potential (V(m)) and calcium (Ca(2+)) transient. It will subsequently be determined if there is degeneracy in this model to these parameter values, which will have important implications on the stability of these models to cell-to-cell parameter variation, and also whether the current methodology for generating parameter values is flawed. The accuracy of AP duration (APD) as an indicator of AP shape will also be assessed.

Towards a potential model to enhance language learner autonomy in the Vietnamese higher education context

This constructivist theory-led case study explored how the term language learner autonomy (LLA) is interpreted and the appropriate pedagogy to foster LLA in the Vietnamese higher education context. Evidence through the exploration of the government policies and the cases of three EFL classes confirms the interpretation that learner autonomy and language acquisition are mutually supported. The study has proposed project work as a potential model while demonstrating the role of the teacher and the use of target language as mediators to enhance LLA in the local context. Findings of the study contribute a theoretical and pedagogical justification for encouraging LLA in Vietnam and other similar contexts.

Influence lines for bending under a ring load of a free shell, a shell embedded in a soft medium and a shell containing a soft core

Theoretical expressions for stresses and displacements have been derived for bending under a ring load of a free shell, a shell embedded in a soft medium, and a shell containing a soft core. Numerical work has been done for typical cases with an Elliot 803 Digital Computer and influence lines are drawn therefrom.

Development of a New Finite Element for the Analysis of Sandwich Beams with Soft Core

A new super convergent sandwich beam finite element formulation is presented in this article. This element is a two-nodded, six degrees of freedom (dof) per node (3 dof u(0), w, phi for top and bottom face sheets each), which assumes that all the axial and flexural loads are taken by face sheets, while the core takes only the shear loads. The beam element is formulated based on first-order shear deformation theory for the face sheets and the core displacements are assumed to vary linearly across the thickness. A number of numerical experiments involving static, free vibration, and wave propagation analysis examples are solved with an aim to show the super convergent property of the formulated element. The examples presented in this article consider both metallic and composite face sheets. The formulated element is verified in most cases with the results available in the published literature.

Diruthenium(III) compounds, Ru2O(O2CAr)2(MeCN)4(PPh3)2(ClO4)2.cntdot.H2O and Ru2O(O2CAr)4(PPh3)2, with an (Ru2(.mu.-O)(.mu.-O2CAr)22+) core as model systems for the diiron centers in hemerythrin

Diruthenium(II1) compounds, Ru20(02CAr)2(MeCN)4(PPh3)2(C104)(z1~) Hazn0d R U ~ O ( O ~ C A ~ ) ~(2() P(PA~r ~= )P~h,C6H4-p-OMe), were prepared by reacting R U ~ C I ( O ~ CaAnd~ P)P~h 3 in MeCN and characterized by analytical and spectral data. The molecular structures of 1 with Ar = Ph and of 2 with Ar = C&p-OMe were determined by X-ray crystallography. Crystal data for Ru~~(~~CP~)~(M~CN),(PP~(~la)):~ m(oCnIoc~lin,ic), n~/~cH, ~a O= 27.722 (3) A, b = 10.793 (2) A, c = 23.445 ( 2 )A , fi = 124.18 (l)', V = 5803 A3, and 2 = 4. Cr stal data for Ru~O(O~CC~H~-~-O(M2b~): )o~rth(orPhoPm~bi~c, )Pn~n a, a = 22.767 (5) A, b = 22.084 (7) A, c = 12.904 (3) 1, V = 6488 AS; and 2 = 4. Both 1 and 2 have an (Ruz0(02CAr)z2t1 core that is analogous to the diiron core present in the oxidized form of the nonheme respiratory protein hemerythrin. The Ru-Ru distances of 3.237 (1) and 3.199 ( I ) A observed in 1 and 2, respectively, are similar to the M-M distances known in other model systems. The essentially diamagnetic nature of 1 and 2 is due to the presence of two strongly interacting t22 Ru"' centers. The intense colors of 1 (blue) and 2 (purple) are due to the charge-transfer transition involving an ( R ~ ~ ( f i - 0m)o~ie~ty.) The presence of labile MeCN and carboxylato ancillary ligands in I and 2, respectively, makes these systems reactive toward amine and heterocyclic bases.

Application of the zero-range potential model to positron annihilation on molecules

In this paper we use a zero-range potential (ZRP) method to model positron interaction with molecules. This allows us to investigate the e?ect of molecular vibrations on positron–molecule annihilation using the van der Waals dimer Kr2 as an example. We also use the ZRP to explore positron binding to polyatomics and examine the dependence of the binding energy on the size of the molecule for alkanes. We ?nd that a second bound state appears for a molecule with ten carbons, similar to recent experimental evidence for such a state emerging in alkanes with twelve carbons.

FPGA based Soft-core SIMD Processing: A MIMO-OFDM Fixed-Complexity Sphere Decoder Case Study

To enable reliable data transfer in next generation Multiple-Input Multiple-Output (MIMO) communication systems, terminals must be able to react to fluctuating channel conditions by having flexible modulation schemes and antenna configurations. This creates a challenging real-time implementation problem: to provide the high performance required of cutting edge MIMO standards, such as 802.11n, with the flexibility for this behavioural variability. FPGA softcore processors offer a solution to this problem, and in this paper we show how heterogeneous SISD/SIMD/MIMD architectures can enable programmable multicore architectures on FPGA with similar performance and cost as traditional dedicated circuit-based architectures. When applied to a 4×4 16-QAM Fixed-Complexity Sphere Decoder (FSD) detector we present the first soft-processor based solution for real-time 802.11n MIMO.