7,325 research outputs found
Fast DGT Based Receivers for GFDM in Broadband Channels
Generalized frequency division multiplexing (GFDM) is a recent multicarrier
5G waveform candidate with flexibility of pulse shaping filters. However, the
flexibility of choosing a pulse shaping filter may result in inter carrier
interference (ICI) and inter symbol interference (ISI), which becomes more
severe in a broadband channel. In order to eliminate the ISI and ICI, based on
discrete Gabor transform (DGT), in this paper, a transmit GFDM signal is first
treated as an inverse DGT (IDGT), and then a frequency-domain DGT is formulated
to recover (as a receiver) the GFDM signal. Furthermore, to reduce the
complexity, a suboptimal frequency-domain DGT called local DGT (LDGT) is
developed. Some analyses are also given for the proposed DGT based receivers.Comment: 28 pages, 8 figure
Angular Stripe Phase in Spin-Orbital-Angular-Momentum Coupled Bose Condensates
We propose that novel superfluid with supersolid-like properties - angular
stripe phase - can be realized in a pancake-like spin-1/2 Bose gas with
spin-orbital-angular-momentum coupling. We predict a rich ground-state phase
diagram, including the vortex-antivortex pair phase, half-skyrmion phase, and
two different angular stripe phases. The stripe phases feature modulated
angular density-density correlation with sizable contrast and can occupy a
relatively large parameter space. The low-lying collective excitations, such as
the dipole and breathing modes, show distinct behaviors in different phases.
The existence of the novel stripe phase is also clearly indicated in the
energetic and dynamic instabilities of collective modes near phase transitions.
Our predictions of the angular stripe phase could be readily examined in
current cold-atom experiments with Rb and K.Comment: 5+3 pages, 4+2 figure
Cross-Layer Adaptive Feedback Scheduling of Wireless Control Systems
There is a trend towards using wireless technologies in networked control
systems. However, the adverse properties of the radio channels make it
difficult to design and implement control systems in wireless environments. To
attack the uncertainty in available communication resources in wireless control
systems closed over WLAN, a cross-layer adaptive feedback scheduling (CLAFS)
scheme is developed, which takes advantage of the co-design of control and
wireless communications. By exploiting cross-layer design, CLAFS adjusts the
sampling periods of control systems at the application layer based on
information about deadline miss ratio and transmission rate from the physical
layer. Within the framework of feedback scheduling, the control performance is
maximized through controlling the deadline miss ratio. Key design parameters of
the feedback scheduler are adapted to dynamic changes in the channel condition.
An event-driven invocation mechanism for the feedback scheduler is also
developed. Simulation results show that the proposed approach is efficient in
dealing with channel capacity variations and noise interference, thus providing
an enabling technology for control over WLAN.Comment: 17 pages, 12 figures; Open Access at
http://www.mdpi.org/sensors/papers/s8074265.pd
Electrochemical codeposition of nickel oxide and polyaniline
Nickel oxide (NiOx) and polyaniline (PAni) were
electrocodeposited from NiSO4 and aniline through cyclic
voltammetric scans to afford PAniâNiOx composite film at
controlled pH environment. The electrochemical activities of
the film were investigated by cyclic voltammetry in 0.1 M
NaOH and 0.1 M H2SO4, respectively. Typical redox couples
of PAni in 0.1 M H2SO4 appeared at approximately 0.2 and
0.4 V vs. saturated calomel electrode (SCE); Ni(II)/Ni(III)
redox couple was observed at approximately 0.4 V vs. SCE in
0.1 M NaOH. The morphologies and elemental components
of the films were inspected by scanning electron microscopy
and energy dispersive X-ray diffraction. The stability of nickel
oxide in the films was found to be enhanced against acidic
environments. Electrochemical catalytic behavior of NiOx
within the composite film was conserved and demonstrated
by catalytic oxidation of methanol and ethanol
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Dexmedetomidine post-treatment attenuates cardiac ischaemia/reperfusion injury by inhibiting apoptosis through HIF-1α signalling.
Hypoxia-inducible factor 1α (HIF-1α) plays a critical role in the apoptotic process during cardiac ischaemia/reperfusion (I/R) injury. This study aimed to investigate whether post-treatment with dexmedetomidine (DEX) could protect against I/R-induced cardiac apoptosis in vivo and in vitro via regulating HIF-1α signalling pathway. Rat myocardial I/R was induced by occluding the left anterior descending artery for 30 minutes followed by 6-hours reperfusion, and cardiomyocyte hypoxia/reoxygenation (H/R) was induced by oxygen-glucose deprivation for 6 hours followed by 3-hours reoxygenation. Dexmedetomidine administration at the beginning of reperfusion or reoxygenation attenuated I/R-induced myocardial injury or H/R-induced cell death, alleviated mitochondrial dysfunction, reduced the number of apoptotic cardiomyocytes, inhibited the activation of HIF-1α and modulated the expressions of apoptosis-related proteins including BCL-2, BAX, BNIP3, cleaved caspase-3 and cleaved PARP. Conversely, the HIF-1α prolyl hydroxylase-2 inhibitor IOX2 partly blocked DEX-mediated cardioprotection both in vivo and in vitro. Mechanistically, DEX down-regulated HIF-1α expression at the post-transcriptional level and inhibited the transcriptional activation of the target gene BNIP3. Post-treatment with DEX protects against cardiac I/R injury in vivo and H/R injury in vitro. These effects are, at least in part, mediated via the inhibition of cell apoptosis by targeting HIF-1α signalling
Synthesis of electrochemically-reduced graphene oxide film with controllable size and thickness and its use in supercapacitor
An electrochemical synthesis method of reducing graphene oxide (GO) under constant potential is reported. Electrochemical technique offers control over reaction parameters such as the applied voltage, electrical current and reduction time; whereas the desired size and thickness of the film can be pre-determined by controlling the amount of precur- sor GO deposited on the electrode with defined shape and surface area. This synthesis technique produces high quality electrochemically reduced GO (ERGO) film with control- lable size and thickness. Electrochemical symmetrical supercapacitors based on ERGO films achieved a specific capacitance of 128 F/g with an energy density of 17.8 Wh/kg operating within a potential window of 1.0 V in 1.0 M NaNO3. The supercapacitor was shown to be stable, retaining ca. 86% of the original specific capacitance after 3500 chargeâdischarge cycles. The results indicate that this simple synthesis technique for providing graphene-like materials has great potential in various applications such as energy storage
AquaÂ(2,2âČ-bipyridine-Îș2 N,NâČ)[2-(3-thienÂyl)malonato-Îș2 O,OâČ]zinc(II) dihydrate
In the crystal structure of the title compound, [Zn(C7H4O4S)(C10H8N2)(H2O)]·2H2O, the ZnII ion assumes a trigonalâbipyramidal coordination geometry completed by two N atoms from a 2,2âČ-bipyridine ligand, two O atoms from a 2-(3-thienÂyl)malonate anion and a water molÂecule. The S atom of the 2-(3-thienÂyl)malonate ligand is disordered over two sites with an occupancy ratio of 0.701â
(5):0.299â
(5). InterÂmolecular OâHâŻO hydrogen bonding is present in the crystal structure
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