Strain effect analysis on the thermoelectric figure of merit in n-type Si/Ge nanocomposites J. Appl. Phys. 111, 054318 (2012); 10.1063/1.3693307Theoretical study of the electrical transport of nickel nanowires and a single atomic chainThe thermal conductivity and electrical resistivity of a suspended nickel nanowire have been measured for T = 15-300 K. The temperature dependence of the thermal conductivity and the Lorenz number strongly differ from the bulk. The comparison of the transports in the Ni nanowire shows, that at temperatures 75Ͻ T Ͻ 300 K Wiedemann-Franz ͑WF͒ law holds, whereas at temperatures T Ͻ 75 K the WF law is violated, indicating that thermal current in this material is suppressed more than electrical current. The results are explained by combined effect of confined dimension, enhanced disorder, and grown contribution of N-processes. 063101-2 Ou et al. Appl. Phys. Lett. 92, 063101 ͑2008͒ 063101-3 Ou et al. Appl. Phys. Lett. 92, 063101 ͑2008͒

Based on the mechanism of spoof surface plasmon polaritions (spoof SPPs), a kind of microwave bandpass filter is presented in both theory and experiment, which is realised by a periodic subwavelength metallic Domino array. The transmission bandwidth of spoof SPPs is controllable by designing the geometric parameters of the periodic structure. Simulation and experimental results of the spoof SPPs agree well with each other and verify the feasibility in bandpass filter applications.Introduction: The periodic structure has been utilised in microwave and optical component applications in the past [1], such as the reflection mirror, the DFB laser, the light beam coupler in the optical regime, and the bandstop filter, leaky wave antenna at microwave frequencies [2]. In 2004, Pendry put forward a concept of spoof surface plasmon polaritons (SPPs) in the low frequency band using a subwavelength periodic hole on the surface of the metal to increase penetration depth [3], and the working frequency is controllable by the geometric parameters of the structure. The spoof SPPs in the microwave regime have been verified theoretically and experimentally in [4] and [5], and the mechanism of electromagnetic field confinement of the spoof SPPs is studied in [6].In this Letter, we put forward a new kind of bandpass filter in X-band based on the principle of spoof SPPs constructed by the periodic subwavelength Domino structure. The modal field of the guided mode in the Domino structure is almost constant inside the structure. By adjusting the lattice constant and the height of the Domino, we can control the transmission bandwidth and transmission efficiency. Such a structure can be applied in high power filter components.

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Terahertz spectroscopic properties in a one-dimensional superconductor-dielectric photonic crystal are theoretically investigated. Based on the calculated results, a terahertz multichanneled transmission filter can be achieved within the photonic passband. This structure possesses the comb-like resonant peaks in transmission spectrum at low temperature. The number of resonant peaks is directly related to the number of periods. The resonant peak height is lowered and broadened as the temperature increases. The dependence of the filling factor in the superconductor layer is also discussed. This filter containing no defect layer in structure is fundamentally different from the usual multichanneled filter based on a photonic crystal containing a photonic quantum well as a defect layer.

We apply the concept of spoof surface plasmon polaritons (SPPs) to the design of differential microstrip lines by introducing periodic subwavelength corrugations on their edges. The dispersion relation and field distribution of those lines are analyzed numerically. And then through designing practical coupling circuits, we found that compared with conventional differential microstrip lines, the electromagnetic field can be strongly confined inside the grooves of the corrugated microstrip lines, so the crosstalk between the differential pair and the adjacent microstrip lines is greatly reduced, and the conversion from the differential signal to the common mode signal can also be effectively suppressed. The propagation length of those lines is also very long in a wide band. Moreover, the experimental results in time domain demonstrate those lines perform very well in high-speed circuit. Therefore, those novel kinds of spoof SPPs based differential microstrip lines can be widely utilized in high-density microwave circuits and guarantee signal integrity in high-speed systems.

Acetoin (AC) is a volatile platform compound with various potential industrial applications. AC contains two stereoisomeric forms: (3)-AC and (3)-AC. Optically pure AC is an important potential intermediate and widely used as a precursor to synthesize novel optically active materials. In this study, chiral (3)-AC production from -2,3-butanediol (-2,3-BD) was obtained using recombinant cells co-expressing-2,3-butanediol dehydrogenase (-2,3-BDH), NADH oxidase (NOX), and hemoglobin protein (VHB) from sp. T241,, and , respectively. The new biocatalyst of/pET--- was developed and the bioconversion conditions were optimized. Under the optimal conditions, 86.74 g/l of (3)-AC with the productivity of 3.61 g/l/h and the stereoisomeric purity of 97.89% was achieved from 93.73 g/l -2,3-BD using the whole-cell biocatalyst. The yield and productivity were new records for (3)-AC production. The results exhibit the industrial potential for (3)-AC production via whole-cell biocatalysis.

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