High transmission efficiency for surface plasmon resonance by use of a dielectric grating

The efficiency of the transmission of surface plasmon waves by use of a dielectric diffraction grating is discussed. The Kretschmann device allows us to obtain a surface plasmon resonance that consists of an absorption peak in the reflection spectrum. When surface plasmon resonance occurs, the TM-polarization mode of the incident electromagnetic wave is neither transmitted nor reflected. The procedure to transform an 4bsorption peak into a transmission peak is described. Transmittivity of 68% is obtained for a simple structure that consists of a thin-film layer of Ag coated on a volume diffraction grating and embedded between two dielectric media. The results presented herein were obtained by numerical simulations that were carried out by use of an algorithm based on the rigorous coupled-wave theory.     

Predicting phase noise in crystal oscillators

In order to predict the phase noise in crystal oscillators an enhanced phase-noise model has been built. With this model, the power spectral densities of phase fluctuations can be computed in different points of the oscillator loop. They are calculated from their correlation functions. The resonator-caused noise as well as the amplifier-caused noise are taken into account and distinguished. To validate this enhanced model, the behavior of a batch of 10 MHz quartz crystal oscillators is observed and analyzed. The tested batch has been chosen in a facility production. Their associated resonators have been selected according to the value of their resonant frequency and their motional resistance. Open-loop and closed-loop measurements are given. The phase noise of the overall oscillator working in closed loop is provided by the usual active method. Theoretical and experimental results are compared and discussed.     

Burstiness and resource management in ATM networks

Networks based upon the asynchronous transfer mode (ATM) provide for high flexibility to cope with a wide range of applications, some of them producing highly sporadic traffic. Therefore, the problem of burstiness has become in the last few years a key issue for such networks. A basic question is how to dimension network buffers in the presence of bursty traffic? In this paper we investigate the concept of burstiness and its impact on resource management. In burstiness characterization encountered in the literature, special attention has been given to the squared coefficient of variation of inter-arrival time Cv² in a cell arrival process. In order to observe the impact of bursty traffic on a queue, we develop in the present paper a ‘bursty’ traffic model, namely the two-stage hyper-Bernoulli cell arrival process, HBP₂, for short. We numerically solve the HBP₂/D/1/K queue. We especially derive the rejection probability P_loss. Numerical results are then thoroughly studied and we discuss the relevance for burstiness characterization of Cv² and peak to mean rate ratio B. We draw attention to the concept of local overload, i.e. when the arrival rate is greater than the server rate. This seems to be the most relevant phenomenon in the impact of a bursty traffic on a queue. These results are finally applied to the problem of resource management in ATM networks.     

应对生物样品中生长促进剂领域的新挑战

Xevo TQ质谱系统能在规定的最大残留量（maximum residue limit,MRL）水平上高灵敏地检测皮质类固醇,为复杂体系如肝脏分析方法的缺少提供了一条解决途径。此外,中性丢失模式的高灵敏度使得皮质类固醇和β-兴奋剂新的种属筛选变得更为容易。     

Robot training of upper limb in multiple sclerosis: comparing protocols with or without manipulative task components

In this pilot study, we compared two protocols for robot-based rehabilitation of upper limb in multiple sclerosis (MS): a protocol involving reaching tasks (RT) requiring arm transport only and a protocol requiring both objects' reaching and manipulation (RMT). Twenty-two MS subjects were assigned to RT or RMT group. Both protocols consisted of eight sessions. During RT training, subjects moved the handle of a planar robotic manipulandum toward circular targets displayed on a screen. RMT protocol required patients to reach and manipulate real objects, by moving the robotic arm equipped with a handle which left the hand free for distal tasks. In both trainings, the robot generated resistive and perturbing forces. Subjects were evaluated with clinical and instrumental tests. The results confirmed that MS patients maintained the ability to adapt to the robot-generated forces and that the rate of motor learning increased across sessions. Robot-therapy significantly reduced arm tremor and improved arm kinematics and functional ability. Compared to RT, RMT protocol induced a significantly larger improvement in movements involving grasp (improvement in Grasp ARAT sub-score: RMT 77.4%, RT 29.5%, p=0.035) but not precision grip. Future studies are needed to evaluate if longer trainings and the use of robotic handles would significantly improve also fine manipulation.     

Comparison among emission and susceptibility reduction techniques for electromagnetic interference in digital integrated circuits

This paper presents a comparative study of susceptibility reduction techniques for electromagnetic interference (EMI) in digital integrated circuits (ICs). Both direct power injection (DPI) and very-fast transmission-line pulsing (VF-TLP) methods are used to inject interference into the substrate of a single test chip. This IC is built around six functionally identical cores, differing only by their EMI protection strategies (RC protection, isolated substrate, meshed power supply network) which were initially designed for low emission design rules. The ranking of three of these cores in terms of electromagnetic immunity is then compared with the one of their radiated emission, thanks to near-field scanning (NFS) measurements. This leads to the establishing of design guidelines for low EMI in digital ICs.     

Characterising polysaccharides in cherimoya (Annona cherimola Mill.) purée and their enzymatic liquefaction

Polysaccharides isolated in the alcohol-insoluble residues (AIR) from cherimoya (Annona cherimola Mill.) were characterised for contents of soluble pectin, cellulose, hemicellulose and lignin, and the distribution of neutral sugars and uronides in water-soluble pectin (WSP) and water-insoluble AIR (WAIR) fractions. For WSP, the predominant neutral sugar was arabinose and, for WAIR, cellulosic glucose and xylose. Two enzyme preparations were tested for their capacity to release neutral sugars and uronides from WAIR. The optimal incubation temperature (45 °C) and the most effective preparation—rich in pectinase, cellulase and xylanase activities—were selected according to a central composite rotatable design (CCRD). Enzyme was also applied to native cherimoya purée according to another CCRD, varying the enzyme concentration and incubation time. Native purée exhibited strong shear-thinning behaviour with high, extrapolated, yield stress. During enzymatic treatment, behaviour was less shear thinning, and yield stress, consistency index and Bostwick consistency tended to decrease, giving rise to purées of different rheological properties.     

Effects of scattering resonances on carrier-carrier entanglement in charged quantum dots

We address the problem of the entanglement generation in an electron-scattering by a 1D double-barrier resonant tunnelling device. In particular we analyze the role played by transport resonances in the appearance of quantum correlations between the energy states of the electrons. The entanglement is not sensitive to the presence of Breit-Wigner resonances, while it may be controlled by manipulating Fano resonances. Such a behavior is ascribed to the different mechanisms characterizing the two types of processes.     

Proxies and measurement techniques for mineral dust in Antarctic ice cores

To improve quantitative interpretation of ice core aeolian dust records, a systematic methodological comparison was made. This involved methods for water-insoluble particle counting (Coulter counter and laser-sensing particle detector), soluble ion analysis (ion chromatography and continuous flow analysis), elemental analysis (inductively coupled plasma mass spectroscopy at pH 1 and after full acid digestion), and water-insoluble elemental analysis (proton induced X-ray emission). Antarctic ice core samples covering the last deglaciation from the EPICA Dome C (EDC) and the EPICA Dronning Maud Land (EDML) cores were used. All methods correlate very well among each other, but the ratios of glacial age to Holocene concentrations, which are typically a factor approximately 100, differ between the methods by up to a factor of 2 with insoluble particles showing the largest variability. The recovery of ICP-MS measurements depends on the digestion method and is differentfor different elements and during different climatic periods. EDC and EDML samples have similar dust composition, which suggests a common dust source or a common mixture of sources for the two sites. The analyzed samples further reveal a change of dust composition during the last deglaciation.