Switching control and its application to induction motors

Practical plants always contain some uncertainties, which require robust controllers to deal with. One such controller is the so called sliding mode controller, which has received a great deal of interest in theory and application. However, fast response of the sliding mode control systems is hard to reach without high cost control devices, due to their fixed switching surfaces which normally make the system state to reach the steady state with an exponential rate.We propose a new switching control design method which uses the self -tuning switching surface to achieve the fast convergence property. Both the single -input single-output and the multi-input multi-output systems are dealt with. The switching surfaces are obtained using the well known Linear Quadratic Regulator design. The stability and the existence conditions of sliding modes are obtained and the fast convergence properties of the control strategies are analysed in detail. Simulations are conducted to show the effectiveness of the control design.</p

Athermal Broadband Graphene Optical Modulator with 35 GHz Speed

Optical modulators with ultrahigh speed, small footprint, large bandwidth, robust athermal operation, and complementary metal-oxide semiconductor (CMOS) compatibility are important devices for optical communication and computing applications. Compared to the conventional optical modulators, graphene modulators have attracted great interest due to their large optical bandwidth with an ultracompact footprint. However, their practical applications are limited by the trade-off between speed and optical bandwidth, with a critical issue of temperature tolerance. In this work, we experimentally demonstrate an athermal graphene optical modulator with a 140 nm bandwidth in the entire optical communication regime (1500–1640 nm), with robust high-temperature operation. The device is based on a planar structure with double-layer graphene, leading to the high modulation speed, up to 35 GHz through reduction of the total resistance, and capacitance (9 fF). We observe speed stability in a wide range of temperatures (25–145 °C). The ultracompact footprint (18 μm²) of the device promises the next generation of on-chip optical interconnections for efficient communication

Classification and Simulation of Structural Phase Transformation-Induced Interfacial Defects in Group VI Transition-Metal Dichalcogenide Monolayers

Polymorphic 2D materials have recently emerged as promising candidates for use in nanoelectronic devices by way of their ability to undergo structural phase transformations induced by external fields. Under cyclic transformations, however, induced interfacial defects may proliferate and compromise the system properties. Herein, we first employ geometric analysis to classify such defects generated during the 2H ↔ 1T and 2H ↔ 1T′ transformations in group VI transition-metal dichalcogenide monolayers. Then, simulations of a mesoscale model with atomistic spatial resolution are conducted to assess the proliferation of such defects during cyclic 2H ↔ 1T transformations. It is shown that defect densities reach a steady state, with the 2H phase remaining more pristine than the 1T and 1T′ states. We expect that the effects of these defects on the device performance are application-dependent and will require further inquiry

Properties of axonal GABA_A receptors.

<p>A, DAB staining of an isolated axon bleb. The axon bleb was mechanically isolated from the main axon trunk before recording (see the Methods section). Arrow indicates the direction of the pia. Dashed line indicates the cut. Scale bar: 20 µm. B, Left, an example trace showing an increase in outward holding current after bath application of 5 µM muscimol (V_hold = 10 mV) and the blockade of this increase by 100 µM PTX. The dashed line indicates the baseline holding current. The mean values of I_hold for “Ctrl”, “Musci” and “Musci + PTX” group were 19.8, 41.4 and 16.9 pA, respectively. Right, histograms of the membrane currents shown on the left. The best-fit curves (dashed lines) were single Gaussian distributions. Axon blebs were recorded with patch pipettes filled with a low-Cl⁻ ICS (7 mM [Cl⁻]_i). C, Left, an example trace showing a decrease in inward holding current after bath application of 100 µM PTX (V_hold = –70 mV). The mean values of I_hold for “Ctrl” and “PTX” group were –22.8 and –12.5 pA, respectively. Right, histograms of the membrane currents shown on the left. Patch pipettes were filled with CsCl-based ICS (149 mM [Cl⁻]_i). D, Current traces recorded in an isolated bleb. V_hold  = –60 mV, CsCl-based ICS was used. Top, the actual current response; bottom, current trace with DC Remove. E, Power spectral density plots of membrane current fluctuations in control and muscimol-treated conditions (same data as in D). F, Subtraction of the power spectral density in the control from that with muscimol treatment (same data from D and E). The red line was the fitting curve of double Lorentzian functions. Cut-off frequencies () of the two components (arrowheads) were 3.5 and 18.1 Hz.</p

Data_Sheet_1_Longitudinal Associations Between Household Solid Fuel Use and Handgrip Strength in Middle-Aged and Older Chinese Individuals: The China Health and Retirement Longitudinal Study.pdf

BackgroundHousehold solid fuel have been associated with changes of handgrip strength (HGS). However, no study has explored the longitudinal associations between household solid fuel use and HGS. Thus, the aim of our cohort study was to investigate the longitudinal associations between household fuel use and HGS.MethodsThe study was based on the China Health and Retirement Longitudinal Study. A handheld dynamometer was used to measure HGS. Household fuel use statuses were collected using questionnaires. Analyses of covariance were performed to examine the associations between household fuel use and HGS.ResultsThe study included 9,382 participants during a 4-year follow-up. The participants who used solid fuel for cooking had more decreases of HGS than those who used clean fuel (P ConclusionUsing household solid fuel for cooking but not heating was associated with more decreases in HGS. Proper ventilation and clean fuel should be promoted for public health.</p

Activation of axonal GABA_A receptors decreases AP-induced Ca²⁺ transients.

<p>A, Left, projection of 2-photon fluorescence images of a recorded pyramidal neuron filled with Alexa Fluor 594 (50 µM) and OGB-1 (200 µM). The dashed arrow indicates the direction of bath flow. Right, iontophoresis of GABA at the axon trunk (labeled by “GABA” in the left image) decreased Ca²⁺ transients evoked by single APs at nearby locations (ROI 1 and 2) but showed no effect on somatic transients. B, Group data showing the effect of GABA on single-AP-triggered Ca²⁺ transients. The results are presented as the ratio of the Ca²⁺ signal amplitude for “GABA” to “Ctrl.” Top, data collected from the axon trunk (n = 13 axons). Bottom, data collected from the soma. The site for GABA iontophoresis was defined as 0. If the ROI was located downstream from the iontophoresis site, the sign of the distance was positive; otherwise it was assigned a negative sign. *, P<0.05; **, P<0.01; ***, P<0.001, paired t-test. C, Group data showing the effect of GABA on Ca²⁺ transients induced by 3 APs (100 Hz). Data were collected from the axon trunk (n = 9 axons). D, PTX blocked GABA-induced decrease in Ca²⁺ transients. Gray, individual cells; black, average data.</p

The presence of GABA_A (but likely not GABA_B) receptors in the axon.

<p>A, Reversal potential of GABA responses (I_GABA) in the axon bleb. Left, representative currents induced by GABA application at different holding potentials (from –100 to –40 mV). At –60 mV (near reversal potential), GABA application induced no obvious change in baseline current (gray). Right, I-V curve of the GABA-induced responses shown on the left. B, I_GABA could be blocked by GABA_A receptor blocker PTX. Left, example traces before (black), during (gray) and after (Wash, dashed line) the bath application of PTX (25 µM). V_hold = –50 mV, GABA was applied via iontophoresis. Middle, time course of the effect of PTX. Right, group data showing the change of I_GABA during (n = 6) and after (n = 3) PTX application. The dashed line indicates 100% of control. C, Left, currents evoked by puffing baclofen (200 µM), a GABA_B receptor agonist, to the soma (16 psi, 15 ms). Right, no response was observed when baclofen was applied to the axon trunk (16 psi, 20 ms). D, Group data showing that GABA-induced currents at the axon blebs could not be blocked by the GABA_B receptor antagonist CGP 35348 (100 µM); however, PTX could diminish these responses. Different symbols indicate different cells.</p

Hierarchical CuO/NiO-Carbon Nanocomposite Derived from Metal Organic Framework on Cello Tape for the Flexible and High Performance Nonenzymatic Electrochemical Glucose Sensors

The orchestrated network of octahedron shaped Cu organic framework is developed via a simple aging protocol, and the partial cation swap reactions between Cu and Ni nodes in the Cu2-paddlewheel units of Cu-MOF generates Cu-Ni-MOF with similar octahedron morphology. Exploiting Cu-Ni-MOF as a template, the uniformly disseminated and tightly pinned CuO/​NiO spherical nanoparticles with hierarchical carbon are developed under controlled thermal and atmospheric conditions. The MOFs and metal oxide-carbon nanocomposites coated over the cello tapes (CTs) are exploited as electrochemical sensor probes for nonenzymatic glucose sensing. It adequately swamps the impediments of prevailing glucose sensor probes including time depletion, high cost, monotonous electrode cleaning and modification processes, and use of swellable inactive binders. Owing to the subsistence of an interconnected network and synergistic effect of bimetallic oxides, CuO/NiO-C expedites the considerable electrocatalytic behavior toward glucose sensing. Furthermore, the fabricated CuO/​NiO-C/​CT exercises the diagnosis of glucose in human serum samples. These flexible electrochemical sensor probes acquiesce the device to sustain deformation with high efficacy, opening an appealing access for the evolution of cost-efficient, binder-free, reliable, flexible, and eco-friendly sensing platforms for the development of futuristic electrochemical sensor devices

A daily container-to-train assignment model based on the passenger transportation-like organisation strategy for railway container transportation

The passenger transportation-like organisation strategy is conducive to enhancing the market competitiveness of railway container transportation. However, many problems incurred by this strategy should be solved. This study focuses on the daily container-to-train assignment problem. Considering the fluctuations of daily container demand, an integer linear programming model is formulated to deal with the normal, congested, and insufficient demand scenarios. The objectives correspond to the three scenarios are to minimise the total transportation time of all containers, the number of remaining containers, and the number of operating trains, respectively. Finally, numerical experiments were conducted on a hypothetical railway line and the Lianyungang-Alataw pass railway corridor to demonstrate the application of the proposed approach.</p