Search

In the present work, a multi-pin-to-plate pulsed gas-liquid hybrid discharge reactor coupled with graphene/CdS catalysts was evaluated to eliminate Bisphenol A (BPA) in wastewater. The optimization of series of process parameters including pulse peak voltage, air flow rate, electrode gap, catalyst dosage, initial BPA concentration, initial solution pH, and solution conductivity was performed in terms of BPA degradation performance. The experimental results demonstrated that BPA removal rate increased with increasing the discharge voltage and decreasing the initial BPA concentration or solution conductivity. Nevertheless, too high or too low air flow rate, electrode gap, catalyst dosage, and initial solution pH would lead to the decrease in BPA degradation. Moreover, optical emission spectroscopy (OES) was gained to understand the information of short-life reactive species formed from the pulsed gas-liquid hybrid discharge plasma (PHDP) system. The results indicated the existence of several highly oxidative free radicals like ·O and ·OH. Finally, the activation pathway of O3 on the catalyst surface was analyzed by density functional theory (DFT).

In this paper, we investigate the Turing instability and pattern formation mechanism of a Plant-Wrack model with both self-diffusion and cross-diffusion terms. Firstly, we study the effect of self-diffusion on the stability of equilibrium. Secondly, we derive the conditions for the occurrence of the Turing patterns induced by cross-diffusion based on self-diffusion stability. Thirdly, we analyze the pattern selection by using the amplitude equation and obtain the exact parameter ranges of different types of patterns, including stripe patterns, hexagonal patterns, and mixed states. Finally, numerical simulations confirm the theoretical results.

As an ultra-wide bandgap semiconductor, hexagonal boron nitride (h-BN) has drawn great attention in solar-blind photodetection owing to its wide bandgap and high thermal conductivity. In this work, a metal-semiconductor-metal structural two-dimensional h-BN photodetector was fabricated by using mechanically exfoliated h-BN flakes. The device achieved an ultra-low dark current (16.4 fA), high rejection ratio (R 205nm/R 280nm = 235) and high detectivity up to 1.28 × 1011 Jones at room temperature. Moreover, due to the wide bandgap and high thermal conductivity, the h-BN photodetector showed good thermal stability up to 300 °C, which is hard to realize for common semiconductor materials. The high detectivity and thermal stability of h-BN photodetector in this work showed the potential applications of h-BN photodetectors working in solar-blind region at high temperature.

The core components of phased array radar have high power density. A pump-driven, two-phase cooling prototype was designed and built for their problems such as high heat consumption and high heat dissipation demand. The results showed that the flow rate through each branch was stable, and the heat dissipation performance was better in the case of PID control compared to the case of a flat-faced tube.

By expounding and proving the technical background of and demand for the platform for the take-off and landing of unmanned aerial vehicles (UAVs), and by analyzing the necessity in combination with current domestic and overseas situations, this paper reveals how a vehicle-mounted platform for take-off and landing of UAVs consisting of multiple connecting rods was developed. Meanwhile, the feasibility of the technology of the vehicle-mounted platform for take-off and landing consisting of multiple connecting rods was verified from multiple aspects by utilizing precision transmission technology, a general mechanical model, and a proof-of-principle prototype.

A study of the behaviors of air discharge plasma inside a catalyst’s pores is important to understand the plasma catalysis mechanism; however, few articles have reported the generation characteristics of air plasma in the pores of catalysts. The production of air microdischarge in a pore was studied by a two-dimensional fluid model, mainly focusing on the effect of pore size and applied voltage. The results show that an increase in the pore size in the range of 20–100 μm facilitates the occurrence of microdischarge in the pore. In addition, at an applied voltage of 9 kV, the ionization of air mainly occurs near the topside of the pore when the pore diameter is less than 20 μm, leading to a low plasma density in the pore, but the time-averaged plasma density in the pore reaches a maximum value at a 70 μm pore diameter. Moreover, the applied voltage also has an important effect on the production of air microdischarge in the pore. The existence of a pore of 80 μm diameter on the dielectric has no obvious influence on the plasma density in the pore at 2 kV applied voltage, but the plasma density in the pore begins to sharply rise when the voltage exceeds 3 kV due to the enhanced air ionization at higher applied voltage. The study indicates that microdischarge can be generated in a pore with a size of tens of micrometers, and the microdischarge in porous catalysts will affect the catalytic degradation efficacy of gaseous pollutants.

Both experimental and simulated studies of microdischarge (MD) are carried out in a dielectric barrier discharge with a pin-to-pin gap of 3.5 mm, ignited by a sinusoidal voltage with a peak voltage of 10 kV and a driving frequency of 5 kHz. Statistical results have shown that the probability of the single current pulse in the positive half-period (HP) reaches 73.6% under these conditions. Experimental results show that great luminous intensity is concentrated on the dielectric surface and the tip of the metal electrode. A 1D plasma fluid model is implemented by coupling the species continuity equations, electron energy density equations, Poisson equation, and Helmholtz equations to analyze the MD dynamics on the microscale. The simulated results are in good qualitative agreement with the experimental results. The simulated results show that the MD dynamics can be divided into three phases: the Townsend phase, the streamer propagation phase, and the discharge decay phase. During the streamer propagation phase, the electric field and electron density increase with the streamer propagation from the anode to the cathode, and their maximal values reach 625.48 Td and 2.31 × 1019 m−3, as well as 790.13 Td and 3.58 × 1019 m−3 in the positive and negative HP, respectively. Furthermore, a transient glow-like discharge is detected around the anode during the same period of streamer propagation. The formation of transient glow-like discharge is attributed to electrons drifting back to the anode, which is driven by the residual voltage in the air gap.

The weak magnetic anisotropy and low Curie temperature of two-dimensional Cr2Ge2Te6 greatly restrict its application in spintronics. In this work, a simple but effective strategy has been proposed to promote the perpendicular magnetic anisotropy and Curie temperature of monolayer Cr2Ge2Te6, via stacking into van der Waals heterostructure with monolayer PtTe2. Based on first-principles calculations, the Cr2Ge2Te6/PtTe2 heterostructures are demonstrated to significantly enhance the magnetic anisotropy, which is improved from −0.06 meV Cr−1 for the monolayer into 0.24 meV Cr−1 for the heterostructure. By analyzing the orbit-resolved magnetic anisotropy and the projected density of states, it is revealed that the enhancement of magnetic anisotropy energy is closely related to interface Te atoms of monolayer Cr2Ge2Te6. The Curie temperature of the heterostructure is estimated to be 90 K by Monte Carlo simulation, increased by 300% compared with the value of 30 K for monolayer Cr2Ge2Te6. These results suggest the magnetic performance of Cr2Ge2Te6 can be significantly improved by van der Waals engineering. Compared with other methods, such as doping atoms or applying strain, this stacking-strategy is more convenient and controllable. Although there are still important challenges toward the room-temperature ferromagnetism of two-dimensional Cr2Ge2Te6 and other semiconductors, our work has proved a new approach to solve this problem and is of reference value for the design of novel magnetic heterostructures.

The turbulent boundary layer (TBL) is actively controlled by the synthetic jet generated from a circular hole. According to the datasets of velocity fields acquired by a time-resolved particle image velocimetry (TR-PIV) system, the average drag reduction rate of 6.2% in the downstream direction of the hole is obtained with control. The results of phase averaging show that the synthetic jet generates one vortex pair each period and the consequent vortex evolves into hairpin vortex in the environment with free-stream, while the reverse vortex decays rapidly. From the statistical average, it can be found that a low-speed streak is generated downstream. Induced by the two vortex legs, the fluid under them converges to the middle. The drag reduction effect produced by the synthetic jet is local, and it reaches a maximum value at x + = 400, where the drag reduction rate reaches about 12.2%. After the extraction of coherent structure from the spatial two-point correlation analysis, it can be seen that the synthetic jet suppresses the streamwise scale and wall–normal scale of the large scale coherent structure, and slightly weakens the spanwise motion to achieve the effect of drag reduction.

Hydroxyapatite nanoparticles (HAP) have been widely used in various fields because of their natural biological origin and functional properties. The emerging evidence on their toxicities has attracted research interest. HAP-induced vascular smooth muscle cell (VSMC) damage is a key step in vascular calcification (VC), particularly in patients with chronic kidney disease. However, the injury effects and mechanism of action of HAP on VSMCs have not been extensively investigated. This study comprehensively characterized commercially available HAP and investigated its adverse biological effects in cultured A7R5 cells. In vitro experiments revealed that internalized HAP was localized in lysosomes, followed by the release of Ca2+ owing to the low pH microenvironment. Upon Ca2+ homeostasis, Ca2+ enters the mitochondria, leading to the simultaneous generation of reactive oxygen species (ROS). ROS subsequently attack mitochondrial transmembrane potentials, promote mitochondrial ROS production, and oxidize mitochondrial DNA (Ox-mtDNA). Mitochondrial permeability-transition pores open, followed by the release of more Ox-mtDNA from the mitochondria into the cytosol due to the redox imbalance. This activates NLRP3/caspase-1/gasdermin D-dependent pyroptosis and finally excretes inflammatory factors to induce VC; an antioxidant could rescue this process. It has been suggested that HAP could induce an imbalance in intracellular Ca2+ homeostasis in A7R5 cells, followed by the promotion of mitochondrial dysfunction and cell pyroptosis, finally enhancing VC. To detect the in vivo toxicity of HAP, mice were treated with Cy7-labelled HAP NPs for 24 h. In vivo results also demonstrated that HAP accumulated in the kidneys, accompined with increased Ca concentration, upregulated oxidative stress-related factor and kidney damage. Overall, our research elucidates the mechanism of calcium homeostasis and redox imbalance, providing insights into the prevention of HAP-induced cell death.

Streamer-to-spark transition and hydrodynamic expansion in a three-electrode pulsed surface dielectric barrier discharge are studied under atmospheric-pressure air. Three sequential discharge processes of the primary streamer, transitional streamer and spark phase during a single pulse are observed from the time-resolved plasma morphologies. The primary streamer and transitional streamer phases, with a rising voltage and low current, followed by a spark phase with a rapidly falling pulse and ascending current are characterized. Images of the discharge development show that the transitional streamer is maintained in the ionization channel after the primary streamer bridges the high-voltage electrode and the second grounded electrode. When the transitional streamer develops to a certain level, the streamer discharge transfers into the spark discharge. As a result, two shock waves are induced in the two exposed electrode domains, and then merge into a single ellipse during the process of hydrodynamic expansion. Boltzmann plots indicate that the electron temperature is 4.815 eV in the initial phase of spark discharge and gradually decreases in the spark phase. Stark broadening of the O atomic line shows that the electron density is 7.06 × 1017 cm−3 during the spark phase.

The mechanisms of streamer generation and propagation in double-sided pulsed surface dielectric barrier discharge (SDBD) on both sides have been analyzed and investigated by experiment and numerical simulation. The fully exposed asymmetric SDBD has two discharge processes located on the high voltage electrode (HVE) side and the ground electrode (GE) side. Discharge images of the HVE side and GE side are taken by a digital camera under continuous pulse and ICCD (Intensified Charge Coupled Device) is utilized to diagnose the generation and propagation of streamers in single pulse discharge. In order to understand the physical mechanisms of streamer evolution more deeply, we establish a 2D simulation model and analyze it from the aspects of electron density, ion density, reduced electric field and electron impact ionization source term. The results show that the primary and secondary discharges on the HVE side and the GE side of the double-sided SDBD are composed of positive streamer and negative streamer, respectively. On the HVE side, the accumulation of positive charges on the dielectric surface causes the direction of the electric field to reverse, which is the principal factor for the polarity reversal of the streamer. On the GE side, both the negative charges accumulated on the dielectric surface and the falling voltage are the key factors for the streamer polarity switch.

Surface-bound reactions have become a viable method to develop nanoarchitectures through bottom-up assembly with near atomic precision. However, the bottom-up fabrication of nanostructures on surfaces requires careful consideration of the intrinsic properties of the precursors and substrate as well as the complex interplay of any interactions that arise in the heterogeneous two-dimensional (2D) system. Therefore, it becomes necessary to consider these systems with characterization methods sensitive to such properties with suitable spatial resolution. Here, low temperature ultrahigh vacuum scanning tunneling microscopy (STM) and tip-enhanced Raman spectroscopy (TERS) were used to investigate the formation of 2D covalent networks via coupling reactions of tetra(4-bromophenyl)porphyrin (Br4TPP) molecules on a Ag(100) substrate. Through the combination of STM topographic imaging and TERS vibrational fingerprints, the conformation of molecular precursors on the substrate was understood. Following the thermally activated coupling reaction, STM and TERS imaging confirm the covalent nature of the 2D networks and suggest that the apparent disorder arises from molecular flexibility.

3D flame can directly represent the combustion status of combustible and fire scale, but flame pulsation makes it difficult for existing 3D reconstruction technology to achieve flame reconstruction. In response to this situation, we use computer image processing technology to propose a flame model based on the cylindrical hypothesis to realize the 3D reconstruction of the flame in this paper. On this basis, we measured the volume and height of flames with different fuel flow rates for 6 types of burners. The results show that the average flame height and volume increase with the increase of fuel flow rate, but the average flame height decreases with the increase of the burner size, and there is no obvious correlation between the average volume and burner size.

This work investigates the active control of a fully developed turbulent boundary layer by a submerged synthetic jet actuator. The impacts of the control are explored by measuring the streamwise velocities using particle image velocimetry, and reduction of the skin-friction drag is observed in a certain range downstream of the orifice. The coherent structure is defined and extracted using a spatial two-point correlation function, and it is found that the synthetic jet can efficiently reduce the streamwise scale of the coherent structure. Proper orthogonal decomposition analysis reveals that large-scale turbulent kinetic energy is significantly attenuated with the introduction of a synthetic jet. The conditional averaging results show that the induction effect of the prograde vortex on the low-speed fluid in a large-scale fluctuation velocity field is deadened, thereby suppressing the bursting process near the wall.

Various requirements for the repair of complex bone defects have motivated to development of scaffolds with adjustable degradation rates and biological functions. Tricalcium phosphate (TCP) and calcium sulfate are the most commonly used bone repair materials in the clinic, how to better combine TCP and calcium sulfate and play their greatest advantages in the repair of osteoporotic bone defect is the focus of our research. In this study, a series of scaffolds with multistage-controlled degradation properties composed of strontium-doped calcium sulfate (SrCSH) and strontium-doped tricalcium phosphate (Sr-TCP) microspheres scaffolds were prepared, and their osteogenic activity, in vivo degradation and bone regeneration ability in tibia of osteoporotic rats were evaluated. In vitro studies revealed that different components of SrCSH/Sr-TCP scaffolds significantly promoted the proliferation and differentiation of MC3T3-E1 cells, which showed a good osteogenic induction activity. In vivo degradation results showed that the degradation time of composite scaffolds could be controlled in a large range (6–12 months) by controlling the porosity and phase composition of Sr-TCP microspheres. The results of osteoporotic femoral defect repair showed that when the degradation rate of scaffold matched with the growth rate of new bone, the parameters such as bone mineral density, bone volume/total volume ratio, trabecular thickness, angiogenesis marker platelet endothelial cell adhesion molecule-1 and new bone formation marker osteocalcin expression were higher, which promoted the rapid repair of osteoporotic bone defects. On the contrary, the slow degradation rate of scaffolds hindered the growth of new bone to a certain extent. This study elucidates the importance of the degradation rate of scaffolds for the repair of osteoporotic bone defects, and the design considerations can be extended to other bone repair materials, which is expected to provide new ideas for the development of tissue engineering materials in the future.

Recently, packed-bed discharge plasma technologies have been widely studied for treatment of volatile organic compounds (VOCs), due to the good performance in improving the degradation and mineralization of VOCs. In this paper, a coaxial cylindrical dielectric barrier discharge reactor packed with porous material of micron-sized pores was used for degradation of benzene, and the discharge characteristics and ozone generation characteristics were studied. When the discharge length was 12 cm and the filling length was 5 cm, the packed particles in the discharge area significantly increased the number of micro-discharges, and the current amplitude and density increased with the pore size of packed particles, but the discharge power and ozone concentration showed a trend of first increasing and then decreasing. The discharge power and ozone production reached the maximum when the size of pore former was 75 μm, correspondingly, the degradation efficiency of benzene was the highest.

In this work, a knife-shaped gliding arc discharge (GAD) reactor driven by a modulated pulse power supply was used to convert CO2. The discharge image, voltage and current waveforms of GAD were recorded experimentally. The effects of gas flow rate, input voltage, and the duty cycle of power supply on CO2 conversion were studied. A CO2 conversion of 3.8% and energy efficiency of 39.6% could be achieved. Compared with other non-thermal plasmas, GAD has a slightly lower CO2 conversion but higher energy efficiency. In addition, the capacity of CO2 treated by GAD (6 L/min) was significantly higher than other non-thermal plasmas (e.g. 25 mL/min-125 mL/min in corona discharge and dielectric barrier discharge).

Machine vision based on image processing has played a huge function in promoting the level of online monitoring of industrial products. It has a broad utilization prospect in the field of industrial online detection, so it has important research value. Based on this, this paper first analyses the principle of machine vision measurement system, then studies the industrial on-line detection utilization of machine vision measurement system, and finally gives the utilization and development prospect of machine vision measurement system in the field of industrial online detection.

In the present work, a magnetic-assisted DC superimposed nanosecond-pulsed streamer discharge (DC-NPSD) with a 0.4 T parallel magnetic field is developed that achieves good performance for ozone production and toluene degradation. The influence of the assisted parallel magnetic field on the electrical characteristics, streamer propagation behavior, reactive species generation and plasma chemical properties of the DC-NPSD are systematically investigated. The experimental results indicate that better impedance matching of a nanosecond pulsed power supply and a discharge reactor can be realized by superimposing DC voltage (U DC), which facilitates reactive species production and toluene degradation. The discharge current, input energy and reactive species production can be further enhanced by the application of a parallel magnetic field under different pulse and DC voltage conditions. There are two distinct streamer phases in the DC-NPSD: a primary streamer (PS) with longer propagation distance and higher propagation velocity and a secondary streamer (SS) with shorter propagation distance and lower propagation velocity. The propagation velocities of both the PS and the SS increase with increasing U DC. Only PS propagation velocity is accelerated by a parallel magnetic field; however, that of the SS remains almost constant with or without a magnetic field. Both ozone generation and toluene degradation performance are improved by a magnetic field, which is attributed to the lengthened electron motion path under the action of Lorentz force and the constraint effect on energetic electrons in the presence of a parallel magnetic field.

For decades, diabetes mellitus has been of wide concern with its high global prevalence, resulting in increasing social and financial burdens for individuals, clinical systems and governments. Continuous glucose monitoring (CGM) has become a popular alternative to the portable finger-prick glucometers available in the market for the convenience of diabetic patients. Hence, it has attracted much interest in various glucose sensing technologies to develop novel glucose sensors with better performance and longer lifetime, especially non-invasive or minimally invasive glucose sensing. Effort has also been put into finding biocompatible materials for implantable applications to achieve effective in vivo CGM. Here, we review the state-of-the-art researches in the field of CGM. The currently commercially available CGM technologies have been analyzed and a summary is provided of the potential types of recently researched non-invasive glucose monitors. Furthermore, the challenges and advances towards implantable applications have also been introduced and discussed, especially the novel biocompatible hydrogel aimed at minimizing the adverse impact from foreign-body response. In addition, a large variety of promising glucose-sensing technologies under research have been reviewed, from traditional electrochemical-based glucose sensors to novel optical and other electrical glucose sensors. The recent development and achievement of the reviewed glucose sensing technologies are discussed, together with the market analysis in terms of the statistical data for the newly published patents in the related field. Thus, the promising direction for future work in this field could be concluded.

Based on a set of experimental databases of turbulent boundary layers obtained from particle image velocimetry in the streamwise-wall-normal plane at friction-velocity-based Reynolds number Reτ = 612, the influence of uniform momentum zones (UMZs) on the skin-friction drag is investigated. The skin-friction drag is measured by the single-pixel ensemble correlation method. The results show that the velocity fields with the number of UMZs larger than the mean value have a relatively low skin-friction drag, while the velocity fields with the number of UMZs less than the mean value have a relatively high skin-friction drag. By analyzing the statistical characteristics of UMZs, the dynamic correlation between the UMZs and skin-friction drag is explored. The velocity fields with a low number of UMZs present a sweep event. These sweep motions intensify the small-scale Reynolds shear stress in the near-wall region by modulation effects. The enhancement of small-scale Reynolds shear stress is the direct reason for the high skin-friction drag. Increasing the proportion of velocity fields with high UMZs amount may be a direction to reduce the skin-friction drag within the TBL.

Active control of a fully developed turbulence boundary layer (TBL) over a flat plate has been investigated with a statistical view. The piezoelectric (PZT) oscillator is employed to produce periodic input into the inner region of the TBL. A wall probe is fixed upstream of the oscillator to identify the high- or low-speed fluctuations as the detecting signals. Then, the impact of the detecting signals on the small-scale bursting process is investigated based on the data acquired by the traversing probe downstream of the oscillator. The results indicate that the small-scale bursting intensity is restrained more apparently at high-speed detecting fluctuations but less impacted at low-speed detecting fluctuations. Furthermore, the perturbed-scale fluctuations arrange the small-scale bursting process in the near-wall region. The detecting signals have an obvious impact on this arrangement, especially the high-intensity regions of the small-scale bursting events: the vibration enhances the intensity at high-speed detecting signals but weakens it at low-speed detecting signals in these regions, which gives a direct evidence on how detecting signals interfering the small-scale bursting process.

Through coupling optical processes with the scanning tunneling microscope (STM), single-molecule chemistry and physics have been investigated at the ultimate spatial and temporal limit. Electrons and photons can be used to drive interactions and reactions in chemical systems and simultaneously probe their characteristics and consequences. In this review we introduce and review methods to couple optical imaging and spectroscopy with scanning tunneling microscopy. The integration of the STM and optical spectroscopy provides new insights into individual molecular adsorbates, surface-supported molecular assemblies, and two-dimensional materials with subnanoscale resolution, enabling the fundamental study of chemistry at the spatial and temporal limit. The inelastic scattering of photons by molecules and materials, that results in unique and sensitive vibrational fingerprints, will be considered with tip-enhanced Raman spectroscopy. STM-induced luminescence examines the intrinsic luminescence of organic adsorbates and their energy transfer and charge transfer processes with their surroundings. We also provide a survey of recent efforts to probe the dynamics of optical excitation at the molecular level with scanning tunneling microscopy in the context of light-induced photophysical and photochemical transformations.

Daqing oilfield has entered into the stage of extra-high water cut development, and the Class I and Class II Oil Reservoirs have been successively developed and completed chemical flooding, which has a significant recovery efficiency, while the Class III Oil Reservoirs, which are primarily thin and poor reservoirs and out of surface reservoirs, are mainly developed by water flooding, with low water drive recovery. Chemical flooding and stimulation and injection are not effective to further enhance the recovery of the Class III Oil Reservoirs. In view of the special reservoir and development characteristics of the Class III Oil Reservoirs, a new concept of “Class III Oil Reservoirs fracture-flooding to enhance oil recovery” is put forward. By using numerical simulation technology, the seepage field and flooding effect of the Class III Oil Reservoirs before and after fracturing-flooding are studied to provide technical support for the development and exploration of the Class III Oil Reservoirs in Daqing oilfield.

In thermal management systems, it is quite meaningful to achieve high thermal conductivity enhancement efficiency for polymer-based thermally conductive materials with low content filler. In this work, a novel 2D all-carbon allotrope, graphdiyne (GDY) was attempted as a filler to improve the thermal conductivity of the polymer matrix. The poly(vinylidene fluoride) (PVDF) composite films, with ultralow mass fraction (≤ 1 wt%) GDY, were fabricated by solution blend and hot pressing. As a consequence, the obtained composite film, at only 1 wt% GDY content, exhibited a high in-plane thermal conductivity of 3.86 W/mK, which revealed a 2249% thermal conductivity enhancement compared with neat PVDF. This excellent heat transport performance makes GDY an attractive filler for high-performance composite for electronic cooling applications.

In the computer field, graphics and image processing technology has occupied a relatively key core position in computer technology. Image processing not only provides convenience for people’s daily life, but also makes people’s visual experience have a strong impact. In today’s information age, science and technology play a leading role. Whether it is a cause, a field, a country, or the world, the rapid development and progress cannot be achieved without the integration and application of science and technology, as well as the digital digital image. At present, the background for the development of national digital imaging is the continuous and in-depth development of science and professionalism, and the growing international development trend. At present, the continuous improvement and development of computer image processing technology will have a profound impact on the field of national digital imaging. The purpose of this article is to study the application of ethnic digital images based on computer image processing technology. This paper uses the Dropout method to fit the training data and uses the Softmax function to calculate the probability distribution. In the experiment, 60% of the reference image is selected, 20% of the training set is used as the verification set, and 20% is used as the test set to repeat the median hundreds of times to reduce the error. And the data preprocessing method with local contrast normalization is adopted to improve the effect. The experimental results show that when the number of filters is 64, the image quality is the best. In the current IQA-Basic image processing results, the VSI is relatively poor. In IQA.Weighted2, the training image block is calibrated by the reference image quality assessment method, which has better results.

With the development of society, digital image, the product of the development of digital technology, is more and more used in multimedia image art. With the rapid development of science and technology, in the 21st century, the use of digital image in art works has been very popular, showing a blowout trend. Digital technology is integrated into image art in a way of mutual integration. How to make digital image play a very good auxiliary role in art works? It makes the finishing point, but it doesn’t make the works dazzle and lose one thing or another. The purpose of this paper is to explore the role of digital image processing in the image art under the background of big data, so as to combine the Internet of things application technology and update the existing mode of art performance. In this paper, we will use the research method of specific analysis to compare the data and come to a conclusion. The research results show that image communication plays an important role in promoting the spread of economy, culture and daily life. In the process of image communication, creativity is essential. In the current industrial development, creative industry, as a new industrial form, can organically combine with other industries, and effectively promote the rise and development of other industries.

The ground level ion current density produced by corona discharge in high voltage direct current (HVDC) transmission lines can reflect the operation status of the lines, but the distorted electric field at the edge of Wilson plate seriously affects the measuring results of ion current density. In order to measure the ground level ion current density accurately and directly, a new reduced scale wire-plate experimental device in which the Wilson plate is flush with the grounding plate is designed. The influence of protective annulus width and the height of Wilson plate from the grounding plate on ground level ion current density are studied. In addition, the differences between the micro-current galvanometer method and the sampling resistance method in the measurement of ion current density are compared. Finally, the ground level ion current density distributions of unipolar and bipolar HVDC transmission lines are measured, respectively. The results show that the edge effect of Wilson plate can be neglected when the width of protective annulus is less than 2 mm, and the ion current density is nonlinear with the height of Wilson plate from the grounding plate. Moreover, the internal resistance of the digital voltmeter seriously affects the measuring results and it is necessary to correct the results. Finally, at the same applied voltage, the ground level ion current density in the negative conductor region is higher than that in the positive conductor region.

The degradation of toluene by DC discharge has been evaluated in a multi-wire-plate reactor with MgO/NiO/Ni (MNN) cathode and compared with a normal discharge with Ni cathode. The effects of various operating parameters, including the position distribution of wire electrodes, discharge gap, gas flow rate and toluene initial concentration have been systematically investigated. Morphological characterizations demonstrate that in addition to the normal discharge around the wire electrodes, extra discharge also occurs on the MNN cathode surface which is mainly concentrated in the vertical corresponding region of the wire electrodes and diffuses to both sides. The position distribution of two wires influences the total discharge current. It is because that it affects not only the discharge around the wire electrode, but also the discharge on MNN cathode surface. Beside, a wire-wire spacing of 25 mm in discharge reactor with MNN cathode is optimized due to a relative large discharge current. A small discharge gap between wire electrode and cathode contributes to the improvement of toluene degradation and mineralization and it is optimized of 15.3 mm. The effects of discharge power, gas flow rate and toluene initial concentration and the interactions between these parameters on toluene removal performance by discharge with MNN cathode are investigated using Box-Behnken design (BBD). The Analysis of Variance (ANOVA) is employed to evaluate the significance of the independent variables and their interactions. The results show that the initial concentration plays the most important role in determining the toluene removal efficiency, while discharge power is the most significant factor affecting the energy efficiency in this discharge process.

During the exploitation of bottom water gas reservoirs, the gas wells have a serious impact on the development of gas reservoirs. Based on the systematic analysis of the production dynamics and water intrusion characteristics of the bottom water gas reservoir in the XS gas field, combined with seismic, geological, well logging, production testing and other data, a numerical simulation model was established to demonstrate the rational gas production rate after gas reservoir seeing water. Research on the mechanism of water control. The gas reservoir numerical simulation technology is used to determine the reasonable gas production speed of the gas well, which can alleviate the bottom water coning rate and prolong the waterless gas production period. Combined with measures such as drainage, water shutoff, and shut-in, the rational gas production rate and adjustment measures for the bottom water gas reservoir are formulated.

A double-chamber gas-liquid phase DBD reactor (GLDR), consisting of a gas-phase discharge chamber and a gas-liquid discharge chamber in series, was designed to enhance the degradation of benzene and the emission of NO x . The performance of the GLDR on discharge characteristics, reactive species production and benzene degradation was compared to that of the single-chamber gas phase DBD reactor (GPDR). The effects of discharge gap, applied voltage, initial benzene concentration, gas flow rate and solution conductivity on the degradation and energy yield of benzene in the GLDR were investigated. The GLDR presents a higher discharge power, higher benzene degradation and higher energy yield than that of the GPDR. NO2 emission was remarkably inhibited in the GLDR, possibly due to the dissolution of NO2 in water. The benzene degradation efficiency increased with the applied voltage, but decreased with the initial concentration, gas flow rate, and gas discharge gap, while the solution conductivity presented less influence on benzene degradation. The benzene degradation efficiency and the energy yield reached 61.11% and 1.45 g kWh–1 at 4 mm total gas discharge gap, 15 kV applied voltage, 200 ppm benzene concentration, 0.2 L min−1 gas flow rate and 721 μS cm−1 water conductivity. The intermediates and byproducts during benzene degradation were detected by FT-IR, GC-MS and LC-MS primarily, and phenols, CO x , and other aromatic substitutes, O3, NO x , etc, were determined as the main intermediates. According to these detected byproducts, a possible benzene degradation mechanism was proposed.

A crack-free aluminum nitride (AlN) layer of 9 ± 1 μm thickness was grown on a nanopatterned sapphire substrate (NPSS) with a sputter-deposited AlN buffer layer. The buffer layer was thermally annealed and AlN was regrown by hydride vapor-phase epitaxy (HVPE). The dependence of the crystallinity of HVPE-grown AlN layers on the growth temperature was investigated. It was found that undesired misaligned AlN growth can be prevented by choosing an appropriate growth temperature. The full widths at half maximum of the (0002)- and (10–12)-plane X-ray rocking curves were improved to as low as 102 and 219 arcsec, respectively, by applying an NPSS with a sputter-deposited annealed AlN film. Compared with substrates without nanopatterning, the NPSS was also effective for suppressing cracks owing to the formation of voids at the interface of the HVPE-grown AlN layer and NPSS template.

In this paper, an improved corona discharge in air at atmospheric pressure is ignited by a MgO/NiO/Ni sandwich cathode with high secondary electron emission and is then employed for volatile organic compound degradation. Current–voltage characteristics, discharge images, and spectroscopic investigations are compared for two corona discharges with a MgO/NiO/Ni cathode and a Ni cathode, respectively. The discharge current with the MgO/NiO/Ni cathode is about 2.5–3.3 times larger than the one with the Ni cathode at various applied voltages from 12 to 19 kV. Besides, discharge images show that, as well as the expected glow discharge around the needle tips, luminous points also occur on the surface of the MgO/NiO/Ni cathode simultaneously, indicating that ionization and excitation processes take place around the cathode surface. This is attributed to the fact that an internal field within the oxide layer calculated by the measured surface potential, which is induced by positive charges accumulated on the oxide layers, is sufficient to induce field emission and further cause the improved corona discharge generation. Such improved corona discharge with the MgO/NiO/Ni cathode is then applied to toluene degradation, and the toluene degradation efficiency and energy yield are much higher than those with the Ni cathode, respectively.

Morphology control, surface functionalization and doping are effective ways to improve photocatalytic performance. In this paper, bi-functional Zn doped TiO2 aerogels were obtained by sol–gel method combined with ambient pressure drying. The Zn dopant promoted the crystallization of anatase and rutile TiO2, a significant red shift of absorption edge and an increase of BET specific surface area. The adsorption and photocatalytic degradation experiments showed that the efficiency for Zn doped TiO2 aerogels were higher than that of pure TiO2 aerogel and P25 under visible light irradiation. This was mainly because the sub-bands in TiO2 caused by Zn dopant extended the light absorption range of TiO2. Rhodamine B (RhB) degradation was achieved through a synergistic mechanism of adsorption and photocatalysis. Zn doped TiO2 aerogels could be used as an effective and alternative materials for the treatment of water contaminated with organic pollutants.