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Two-dimensional(2D) materials with a high density and low power consumption have become the most popular candidates for next-generation semiconductor electronic devices. As a prototype 2D material, graphene has attracted much attention owing to its stability and ultrahigh mobility. However, zero band gap of graphene leads to very low on-off ratios and thus limits its applications in electronic devices, such as transistors. Although some new 2D materials and doped graphene have nonzero band gaps, the electronic mobility is sacrificed. In this study, to open the band gap of graphene with high electronic mobility, the structure and property of BN-doped graphene were evaluated using first-principles calculations. The formation energies indicate that the six-membered BN rings doped graphene has the most favorable configuration. The band structures show that the band gaps can be opened by such type of doping. Also, the Dirac-cone-like band dispersion of graphene is mostly inhibited, ensuring high electronic mobility. Therefore, codoping BN into graphene might provide 2D materials with nonzero band gaps and high electronic mobility.

Two-dimensional (2D) B–C–N alloys have recently attracted much attention but unfortunately, Chemical Vapor Deposition (CVD) B–C–N alloys typically phase separate. In spite of that, our analysis of the B–C–N alloy fabricated by electron-beam irradiation suggests that non-phase-separated B–C–N may in fact exist with a carbon concentration up to 14 at%. While this analysis points to a new way to overcome the phase-separation in 2D B–C–N, by first-principles calculations, we show that these B–C–N alloys are made of motifs with even numbers of carbon atoms, in particular, dimers or six-fold rings (in a molecule-like form), embedded in a 2D BN network. Moreover, by tuning the carbon concentration, the band gap of the B–C–N alloys can be reduced by 35% from that of BN. Due to a strong overlap of the wavefunctions at the conduction band and valance band edges, the non-phase-separated B–C–N alloys maintain the strong optical absorption of BN.

The inclusion complexation behavior, characterization and binding ability of hesperetin with β-cyclodextrin and its derivatives were investigated in both the solution and solid state by means of XRD, DSC, SEM, (1)H and 2D NMR and UV-vis spectroscopy. The results showed that the water solubility and stability of hesperetin were obviously increased in the inclusion complex with cyclodextrins. This satisfactory water solubility and high stability of the hesperetin/CD complexes will be potentially useful for their application as herbal medicines or healthcare products.

Sepsis-associated acute liver injury contributes to the pathogenesis of multiple organ dysfunction syndrome and is associated with increased mortality. Currently, no specific therapeutics for sepsis-associated liver injury are available. With excess levels of reactive oxygen species (ROS) being implicated as key players in sepsis-induced liver injury, we hypothesize that ROS-responsive nanoparticles (NPs) formed via the self-assembly of diblock copolymers of poly(ethylene glycol) (PEG) and poly(propylene sulfide) (PPS) may function as an effective drug delivery system for alleviating sepsis-induced liver injury by preferentially releasing drug molecules at the disease site. However, there are no reports available on the biocompatibility and effect of PEG-b-PPS-NPs in vivo. Herein, this platform was tested for delivering the promising antioxidant therapeutic molecule melatonin (Mel), which currently has limited therapeutic efficacy because of its poor pharmacokinetic properties. The mPEG-b-PPS-NPs efficiently encapsulated Mel using the oil-in-water emulsion technique and provided sustained, on-demand release that was modulated in vitro by the hydrogen peroxide concentration. Animal studies using a mouse model of sepsis-induced acute liver injury revealed that Mel-loaded mPEG-b-PPS-NPs are biocompatible and much more efficacious than an equivalent amount of free drug in attenuating oxidative stress, the inflammatory response, and subsequent liver injury. Accordingly, this work indicates that mPEG-b-PPS-NPs show potential as an ROS-mediated on-demand drug delivery system for improving Mel bioavailability and treating oxidative stress-associated diseases such as sepsis-induced acute liver injury.

Cadmium ion doping was carried out during electrochemically cathodic plating nickel hydroxide on platinum films coated n-silicon (Pt/n-n+-Si electrode) in 0.1 M nickel nitrate solution containing 0.035 M cadmium nitrate. The morphology and composition of the products were characterized by scanning electron microscope (SEM) and x-ray photoelectron spectroscopy (XPS), respectively. A two-electrode cell based on Cd-doped NiO/Pt/n-n+-Si electrode and a platinum counter has been used for determination of hydrogen peroxide in absence of reference electrode by photocurrent measurement at a zero bias. The emphasis is laid on that the cadmium doping remarkably improves the sensibility of the photoelectrochemical hydrogen peroxide sensor. Under optimizing conditions a sensitivity of 254.6 μA mM-1 cm-2 and a linear response range from 0.02 mM up to 0.12 mM with a determination limit of 2.0 μM were achieved in a potassium hydroxide (KOH) solution at pH =13.3.

In this work, about 100 nm palladium layer was coated on the front surface of n-type epitaxial silicon wafer by vacuum evaporating and etched electrochemically in 0.1 M HF-HCl solution to form palladium nanoparticle modifying n-silicon electrode. Scanning electron microscope (SEM) and x-ray photoelectron spectroscopy (XPS) were used to characterize the morphology and composition of the modified electrode surface. The modified electrode has been used to constitute a novel photo-electrochemical sensor for the detection of ascorbic acid (AA) with a two-electrode cell in absence of reference electrode by photocurrent measurement at a zero bias. The photocurrent determination of AA shows two linear dynamic responses over the concentration range of 2 μM–42 μM and 82 μM–642 μM with a detection limit of 2.0×10−6 M. Furthermore, this sensor demonstrated good stability, repeatability and selectivity remarkably.

In this work, A molecularly imprinted polymers (MIPs) electrochemical sensor based on chitosan (CS) and nickel electrode was constructed, finally used in glucose measurement. The MIPs sensor was prepared through electrodepositing glucose–CS composited film on the electrochemical treated nickel then removing glucose from the film via water elution. The morphology and electrochemical properties of the sensor were characterized via scanning electron microscope (SEM) , cyclic voltammetry (CV), respectively. Amperometric responses of the CS (MIP)-NiO electrode toward glucose was well-proportional to the concentration of the range from 10 μM to 200 μM. The developed sensor obtained the specific recognition to glucose against coexisting interferences such as oxalic acid, uric acid and ascorbic acid.

Recently, a silicon-based ultrashallow-junction photodiode (B-layer diode) has been reported, with very high and very stable sensitivity in the vacuum-ultraviolet and extreme-ultraviolet spectral ranges. However, the ultrashallow nature of the junction leads to a high series resistance of the photodiode if no conductive capping layers are used. In a recent paper by Shi , a study on the relation between the sensitivity and the series resistance of the B-layer diodes, which can be large due to the shallow-junction depth, was presented. In this paper, an extensive analysis of the photodiode electrical and optical performance parameters and their interrelation is given. The influence of the series resistance on the response time of the photodiode for different illumination patterns is studied theoretically and also experimentally verified. It has been proven by modeling, simulations, and experiments that the time constant of the photodiode does not change significantly with the illumination spot area. This effect is due to temporary variations, going in opposite directions, of the equivalent series resistance, and the junction capacitance values found at the first instant a photogenerated charge are locally stored in the photodiode p-n junction. Also, the dependence of the degradation of the sensitivity on the incident wavelength and the diode vertical stack is examined through analysis and experimentation.

In this paper, the detection of common defects such as inclusion, delamination for curved composite materials is studied. The principle of measuring porosity is focused on introducing. The technology of trajectory planning and motion control for twin-robot system of testing various curved composite parts using ultrasonic transmission method is also discussed. An ultrasonic NDT system is developed for testing large-scaled curved composite components used in aerospace and other fields. With many advantages, it will be very significant for our nondestructive testing work.

We report an integrated front-end circuit for capacitive displacement sensors, suitable for measuring small displacements, superimposed on a much larger stand-off distance between the sensing and the target electrodes. In order to cancel the effect of the resulting offset capacitance, a circuit technique called electrical zoom-in is applied in the interfacing circuit. The zoom-in front-end can achieve an input referred capacitance resolution of 28 aF (RMS) from a sensor with nominal capacitance of 10 pF with a measurement latency of only 5 us.

We report an integrated front-end circuit for capacitive displacement sensors, suitable for measuring small displacements superimposed on a much larger stand-off distance between the sensing and the target electrodes. In order to cancel the effect of the resulting offset capacitance, a circuit technique called electrical zoom-in is applied in the interfacing circuit. After removing the offset capacitance of a sensor with 10 pF nominal capacitance, the output-swing of the front-end corresponds to 100 fF of capacitance variation only, relaxing the specification of the following analog-to-digital converter (ADC) stage by a factor of 40.The zoom-in front-end can achieve an input referred capacitance resolution of 30 aF (RMS) from a nominal sensor capacitance of 10 pF, with a measurement latency of only 5 us. This result is achieved with 2.4 mW power consumption in the front-end.

The design of a CMOS temperature-to-digital converter (TDC) is presented. It operates by measuring the phase shift of an electrothermal filter (ETF), which is a function of the temperature-dependent thermal diffusivity of bulk silicon. Compared to previous work, this TDC employs an improved ETF, whose layout has been optimized to minimize the phase spread caused by lithographic inaccuracy. Furthermore, the TDCpsilas front-end consists of a gain-boosted transconductor, whose wide bandwidth minimizes electrical phase spread. The resulting current is then digitized by a phase-domain SigmaDelta modulator. The phase-subtracting node of the modulator is realized by a chopper demodulator, whose switching action, however, will give rise to a residual offset current. This is minimized by locating the demodulator at the virtual grounds of the transconductorpsilas gain boosting amplifiers. Any residual offset is then eliminated by chopping the entire front-end. Measurements on 16 samples show that the TDC has an untrimmed inaccuracy of less than plusmn0.4degC (3sigma) over the military range (-55degC to 125degC).

There is a strong relation between the size, the shape and the location of the illuminated part of a shallow-junction photodiode, and its series resistance [2, 3, 4]. This relation creates an expectation for a big variation of the response time (the time for which the photo-generated charge will be removed from the photodiode) with the illuminated spot size. This is because the time constant of the photodiode, which is one of the main factors defining the response time, is a product of the series resistance multiplied by the junction capacitance. In this work the dependence of the charge removal time of a shallow photodiode on the size of the illuminated area, is studied. Simulation results, as well as measurement data, show that the response time is changing only slightly with the position and the size of the illuminated spot size, when very short light pulses are used. After the incidence light is over, the discharging of the photodiode continues with a time constant, which is highly independent of the size and the location of the illuminated part of the photodiode.