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[Objective] Gas--solid composite dielectrics are important electrical insulation materials widely used in civil and military high-tech fields, such as electrical/electronic engineering, aerospace, and strong electromagnetic pulse. However, composite insulation is prone to flashover under high electric fields, thus improving the surface flashover strength, which is a key issue in enhancing the overall performance of power equipment. The surface morphology of solid dielectrics has a significant impact on the flashover strength. However, existing surface microstructure tailoring methods are based on the etching approach, which can only construct surface holes or groove-like structures, and the morphology resolution is limited to the micrometer scale. In contrast to etching methods, which only change the surface morphology, this study constructs a three-dimensional foam-like porous structure to effectively enhance the surface flashover voltage. [Methods] Polydimethylsiloxane (PDMS) was selected as the matrix material to prepare bulk porous materials via the oil/water emulsion method. Deionized water was dispersed into PDMS by electrical stirring, and the PDMS and water droplets formed the oil/water emulsion. Afterward, PDMS was cross-linked and solidified by heating to form a porous structure with high mechanical strength. Three different mass ratios of deionized water to PDMS, namely 10%, 30%, and 50%, were considered in the experiments. A comprehensive experimental system was established to characterize the surface flashover characteristics of porous insulation materials under high voltage. The flashover strength in different gas atmospheres was tested in a closed gas discharge experimental chamber, and the initiation and development processes of surface discharge were analyzed through optoelectronic joint diagnosis. The isothermal surface potential decay method was employed to measure the trap energy distribution and explore the influence of porous structure on charge dissipation rate and trap distribution. A fluid simulation model for surface streamer propagation on porous solid dielectrics was built to analyze the influence of pores on the development process of surface discharge. [Results] Results showed that, with the increase in deionized water content, the pore size and porosity of porous PDMS gradually increased. Increasing the porosity and pore size can also effectively improve the hydrophobic performance. The porous structure effectively enhanced the surface flashover voltage, and the flashover strength increased with the porosity. The maximum increment in direct current flashover voltage was 53%. The surface potential scanning and streamer simulation results showed that the porous structure can effectively hinder the collision ionization process, thereby suppressing microdischarges. The measurement results of surface potential decay indicated that the mobility of charges in pores is higher than that on the surface of solid dielectrics. Therefore, the porous structure plays a role in promoting the dissipation of surface charges, which is enhanced with the increase in porosity. [Conclusions] The effects of hindering collision ionization and promoting surface charge dissipation by porous structures are beneficial for enhancing the surface flashover strength, and both effects are enhanced with the increase in porosity, resulting in an improvement in flashover strength with the increase in porosity. This experiment involves electrical engineering, materials, physics, and multiphysics field simulations, which can effectively improve students' comprehensive abilities in experimentation, simulation, and theoretical analysis. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of reactant concentration (O2 and NO), process parameters (discharge power and gas flow rate), key discharge indicators (average electron energy, average electron density, and energy density), and flue gas components (H2O and SO2) on the reaction performance were systematically studied by using a double-dielectric coaxial dielectric barrier discharge (DBD) reactor. By introducing a weighted composite index, the combined performance of oxidation efficiency and energy efficiency was evaluated and the optimal combination of reactant concentrations (0.02% of NO and 6% of O2) was determined. The results showed that lower discharge power 40 W and lower gas flow rate (1.5 L/min) can lead to higher oxidation efficiency and energy efficiency, and the optimal oxidation efficiency can reach 68%. The changes in discharge power and gas flow rate have a great influence on energy density (SED) . Higher SED will lead to the occurrence of the reverse reaction, while lower SED will lead to the difficulty of NO oxidation reaction, and the optimal SED range is between 480 J/L and 610 J/L. The above two process parameters have almost no effect on the average electron energy (Ee) and the average electron density (ne). The addition of H2O can promote the oxidation of NO, and the increase in efficiency can reach 6%, while the addition of S02 can inhibit the oxidation of NO. This work can provide the most basic reference for the design and optimization of the process of NO oxidation through a DBD reactor. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The process flow for production of tinplate is usually comprising electroplating, reflowing, passivation, and oiling to form a multilayer structure with excellent comprehensive performance. There are some differences between the edge and center of tinplate due to the edge effect during electroplating and passivation. The microstructure and composition of the multilayer at the edge and center of tinplate were compared using scanning electron microscope (SEM), ultraviolet-visible spectrophotometer, electrochemical workstation, X-ray photoelectron spectroscope (XPS), and glow discharge spectroscope (GDS). The results showed that the various layers at the edge of tinplate was nonuniform in morphology and composition. As compared with the center of tinplate, the content of each component in the metallic tin layer, tin alloy layer, and passivate layer were higher at the edge, indicating that the tin coating at the edge of tinplate was oxidized more seriously. [ABSTRACT FROM AUTHOR]

A conversion coating was formed on the surface of TC4 titanium alloy by sol--gel method in a solution comprising organic silane and zirconium alkoxide as main components with ethanol as solvent. The surface morphology and composition, and element distribution and valence state of oxygen along the depth direction of coating were analyzed by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), glow discharge mass spectrometry (GDMS), and X-ray photoelectron spectroscopy (XPS). The electrochemical properties and structure of the conversion coating were examined by electrochemical impedance spectroscopy (EIS). The effect of zirconium alkoxide content on the adhesion of organic primer coat was studied by long-term damp-heat test. The results showed that the sol--gel conversion coating consisted of an inorganic layer, which was mainly composed of covalently bonded Ti-O-Zr/Si structure, and an organic layer, which was formed by the crosslinking reaction of carbon chains attached to the silane. The sol--gel conversion coating obtained with 2 000 mg/kg of zirconium alkoxide featured the best structure integrity, and the primer sprayed on it had excellent adhesion and durability. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Naturalium Universitatis Pekinensis is the property of Editorial Office of Acta Scientiarum Naturalium Universitatis Pekinensis and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An atmospheric pressure plasma plume generated by pulsed discharge was produced with a dual-electrode coupled dielectric barrier electrode configuration. The characteristics and dynamics of plasma plume were investigated by applying pulse voltage at different phase of AC sinusoidal voltage. The temporal evolution of discharge image intensity and the spatial distribution of plasma bullet velocity were studied. It was demonstrated the plasma plume was a travelling plasma bullet in the discharge regime by the discharge spatial profile within time interval of pulse voltage. The results show that when the polarity of pulse voltage is the same or opposite to that of AC sinusoidal voltage, the generation and propagation of plasma bullet is suppressed or enhanced, respectively. [ABSTRACT FROM AUTHOR]

This study aims to explore the heat transfer characteristics of flow boiling in the minichannels under the action of phase separation structure. A test section of parallel counterflow minichannel was also fabricated with the different structures of phase separation. Furthermore, the pressure difference between the downstream and counterflow channel confined the bubbles to discharge the gas phase from the high- to the low-pressure channel through the phase separation film. The gas phase separation was realized under the high- and low-pressure switching between adjacent channels. Two kinds of structure channels were fabricated: Type 1 phase separation structure channel (SPS1 channel) (Structure of Phase Separation, SPS) with few vents, and type 2 phase separation structure channel (SPS2 channel) with multiple vents, compared with the SPS3 channel without phase separation structure. The aqueous glycerol solution with a mass fraction of 30% was used as the test working medium. The flow boiling test was performed on the rectangular mini channel with a cross-section of 2 mm×2 mm under the effective heat flux density is 151.43 kW/m², the mass flow rate of 121.25 kg/(m² ·s), and inlet temperature of 70°C. A systematic investigation was made to clarify the effects of high- and low-pressure switching cycles on the comprehensive performance and phase separation structures on the flow boiling heat transfer and temperature uniformity in mini channels. A high-speed camera was used to determine the length-to-diameter ratio of confined bubbles and the gas phase separation. An analysis was made to explore the heat transfer enhancement of the mini channel flow boiling under the action of the phase separation structure. The results show that the local saturated boiling heat transfer coefficient was the highest, and the total pressure drop was the lowest when the high- and low-pressure switching cycle was 120 s under the experimental conditions. An optimal value was achieved in the high- and low-pressure switching cycle. There was little difference in the boiling curve before the ONB point, while after the ONB point, the wall superheat of SPS2 and SPS3 channels was lower at the same heat flux. The maximum coefficients of local saturation boiling heat transfer in the SPS2 and SPS3 channels increased by 18.87% and 26.65%, respectively, compared with the SPS3. More importantly, the temperature uniformity of the SPS2 channel was the best in the two-phase region, SPS1 was the second, and SPS3 was the worst. The wall temperature standard deviations were reduced by 10.81% and 18.91%, respectively, along the SPS1 and SPS2 channels. The visual analysis results show that the phase separation structure reduced the length-to-diameter ratio of the confined bubbles, leading to the flow pattern transformation in the channel. Enhanced heat transfer was achieved in the first half cycle of the high- and low-pressure switching cycle. The length-to-diameter ratios of confined bubbles in the SPS1, SPS2, and SPS3 downstream channels were −118.71%, −158.16%, and 122.45% in the unit time, respectively. The phase separation structure can be expected to effectively enhance the heat transfer performance of flow boiling, and then improve the temperature uniformity of minichannels. The finding can provide new ideas for the application of the phase separation structure in minichannel heat exchangers.annel heat exchangers. [ABSTRACT FROM AUTHOR]

Abstract: In biomedical applications of cold atmospheric plasma (CAP), treatments of biomaterials with different CAP intensities will lead to significantly different treatment results. Therefore, it is urgent to introduce the concept of "plasma dosage" for quantitatively describing the action amounts of CAPS on the treated materials, and thus, for obtaining desired plasma treatment results. In pharmacy, the concept of median lethal dose (LD50) was frequently used to describe the drug toxicity; and our previous study has proved that this method was also suitable for the estimation of the plasma dosage with the features of versatility and easy manipulation. In this study, based on the foregoing LD50-plasma-dosage estimation method, the LD50 value of the radio-frequency atmospheric-pressure glow discharge (RF-APGD) plasma jet for the treatment of the Human Embryonic Kidney 293 cells was obtained and compared with that of another typical CAP source, i.e., the atmospheric-pressure dielectric-barrier-discharge (AP-DBD) plasma jet. This work not only further validated the reliability and versatility of the LD50-plasma-dosage estimation method, but also provided a theoretical guidance and dosage reference in CAP applications such as plasma biomedicine, etc. [ABSTRACT FROM AUTHOR]

In order to ensure safety of battery packs in electric vehicles, a battery management system ( BMS ) is required to estimate the state of battery packs. The state estimation accuracy depends on a suitable battery model and accurate model parameters. The offline parameter identification is based on the measured data in a laboratory. It can be used to quickly analyze the correlation between the change law of the battery parameters and the battery performance. It can also provide a reference for online parameter identification. Offline parameter identification is mostly carried out through Hybrid Pulse Power Characteristic ( HPPC ) experiment. Based on the previous discussion of offline parameter identification, most of the researchers conduct parameter identification through the zero-input response on "rebound characteristic" stage or zero-state response stage of the HPPC experiment, focusing on the establishment of different equivalent circuit models. Some researchers also find that the pulse time and standing time of the HPPC experiment affect the accuracy of the battery model, and the battery model parameters need to be modified at a low temperature. In order to study the effects in diferent stages of HPPC test on the accuracy of battery model, the HPPC tests are performed on Sony US18650VTC6 lithium-ion batteries at 5 °C, 25 °C and 55 °C respectively. Through the two stages ( 10 s zero-state response stage and 40 s zero input response stage ) of the HPPC test to get the model parameters of the Thevenin equivalent circuit model, the parameters are imported into the equivalent circuit model based on Simscape in Matlab/Simulink, and then verified under 0.5 C and 1 C discharge conditions. In the process of verification, the dynamic stress test (DST) condition is also verified. Through comparison, it is found that the discharge condition is more conducive to describing the deviation phenomenon than the DST condition. At 5 °C and 25 °C, there is a relatively stable voltage deviation between the simulation value and the experimental value under discharge conditions. At 55 °C, the simulation value is basically close to the experimental value. During the experiment, temperature rise of the battery is not very high, and slight temperature rise mainly occurs in the later stage of discharge. Through an analysis of the overall deviation of the voltage platform period under discharge conditions, there is no correlation between the deviation and the discharge rate. The influence of battery temperature and connection impedance during discharge can be excluded. Results show that the accuracy of the model at different temperatures is different. There is a correlation between accuracy of the model and temperature. According to the characteristics of the lithium-ion battery, the interior of the battery is an organic electrolyte system. With an increase of battery temperature, electrochemical reaction inside the battery and lithium-ion diffusion both accelerate, and polarization internal resistance reduces. At a low temperature, polarization time of the battery is longer than that at a high temperature. In order to further solve the problem of the deviation at 5 °C and 25 °C, the parameter identification is carried out by changing the time domain during the 6-min stage of HPPC test. The parameters are identified in three time domains of 20 s, 40 s and 60 s respectively. At 5 C, the average relative error at 0.5 C discharge current reduces from 1.49% to 0.55% in the 40 s and 60 s time domains, and the average relative error under 1 C discharge condition is only 0.42%. Similarly, the accuracy of the model apparently improves at 25 C. The results show that different time domains should be selected for parameter identification at different temperatures. The model accuracy at different temperatures can be effectively improved by changing the HPPC parameter identification time domain method. [ABSTRACT FROM AUTHOR]

As an important measure for China􀆳s pollution control, the environmental protection tax gives each provincial government the right to independently determine and adjust the specific applicable tax amount of pollutants within the specified scope. Studying the emission reduction effects of environmental protection tax from the perspective of increasing the applicable tax amount of pollutants has important theoretical value for the next step of adjusting pollution control measures. Using the panel data from 248 prefecture-level cit⁃ ies from 2015 to 2020, this study took the increase in the applicable tax amount of environmental protection tax in some provinces in 2018 as an external policy impact, and used the difference-in-differences method to empirically analyze the emission reduction effects of the Environmental Protection Tax Law on increasing the applicable tax amount of pollutant discharge. The study also analyzed the heterogeneity of foreign investment scale, regional location, and applicable tax increase between cities. The results showed that: ① In⁃ creasing the applicable tax amount of pollutants could significantly reduce pollutant emissions, the regression results of the DID model showed that the applicable tax on SO2 significantly reduced industrial SO2 emissions by 16.8% for each increase in SO2. The above re⁃ sults passed the robustness test. ② Heterogeneity analysis showed that the emission reduction effects were obvious in the central re⁃ gion, but those in the eastern and western regions were not significant. The scale of foreign investment was positively correlated with the emission reduction effects, and cities with a higher level of foreign investment were more affected by the policy, which could reduce pol⁃ lutant emissions by about 0.2% relative to the average. The pollution effects of the lower level of foreign investment were lower and the emission reduction effect of the policy was not significant. ③ Further research showed that the emission reduction effects of the applica⁃ ble tax amount increase of SO2 between 25% and 100% higher than the standard were better than the emission reduction effects of a more than 100% increase. However, it was not the higher the better for the applicable tax amount increase; better emissions reduction effects could be achieved by being maintained within a reasonable range. Based on the above research conclusions, it is proposed to im⁃ plement a regional coordinated environmental regulation policy, that is, the central and local governments negotiate to adjust the local environmental protection tax pollutant collection standards and increase the applicable tax amount of pollutants within an appropriate range. Furthermore, the range of the applicable tax amount of pollutants should not exceed 100%, and the quality level of foreign invest⁃ ment should be improved. [ABSTRACT FROM AUTHOR]

Hexagonal boron nitride (h-BN) lattice structure is a kind of hexagonal symmetric complex superlattice structure. In recent years, photonic crystals with h-BN superlattice structure have attracted growing attentions due to their unique properties of wide photonic band gaps. A new h-BN superlattice plasma photonic crystal (SPPC) constructed by periodically arranging gas discharge tubes and Al 2O3 dielectric rods is proposed in this paper. The positions, widths and numbers of band gaps for h-BN superlattice and triangular lattice plasma photonic crystal (PPC) have been compared. The effects of the discharge current, numbers of dielectric rod rows and incident angles of electromagnetic waves in different frequencies have been demonstrated. The results show that the introduction of plasma enables tunable structural configurations and plasma parameters for h-BN SPPC. It not only produces new photonic band gaps, but also selectively shifts the band gap positions. Compared with the simple triangular PPC, h-BN SPPC possesses more photonic band gaps. Moreover, the numbers of dielectric rod rows have significant influences on the positions, widths and numbers of band gaps. The correlation of transmission spectra decrease with the increase of incident angle of electromagnetic waves. The novel h-BN SPPC suggested in this work provides some inspiration for creating new types of tunable metamaterials, which has potential applications in the manipulation of microwave and terahertz waves. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective The aim is to find the bottleneck problem restricting the long-term operation of high-sulfur natural gas purification plant by the risk assessment technology, and an effective solution is proposed to realize the long-term safe and reliable operation of high-sulfur m1tuntl gas purification plant. Methods Starting from t he safety management of the process system of the plant, the joint analysis method of HAZOP/LOPA/SIL was adopted to evaluate and quantify the risks of the plant in the process of 'the double standard reconstruction project' which was designed to ensure the product temperament and tail gas discharge satisfying the latest standards. The SIL verification and calculation of the liquid level interlocking loop of t he regeneration tower were carried out by using reliability block diagram and fault tree method. Results Combined with the practical case of the natural gas purification plant, two feasible measures of improving the SIL grade and adopting double-face mechanical seal for the pump were put forward from the aspects of SIS and essential safety. Conclusion The risk assessment technology can provide technical support for the long-term operation of the natural gas purification plant. [ABSTRACT FROM AUTHOR]

Objective /\ good performance tail gas hydrogenation catalyst was developed to solve the problem of excessive SO, mass concentration in flue gas discharged from sulfur recovery unit. Methods The catalytic performance of active components of hydrogenation catalyst in tail gas treatment unit of natural gas purification plant for the main chemical reactions such as hydrogenation, hydrolysis and transformation was studied. The catalyst kinetics was studied by micro-reaction and dynamic characterization techniques to obtain the activation energy and reaction order of hydrogenation and hydrolysis reactions, so as to 1m prove the catalyst performance. Results Hydrogen adsorption on Co-Mo hydrogenation catalyst could inhibit the hydrogenation of SO,, and water adsorption on the catalyst could strongly inhibit and hinder the hydrolysis of COS. A hydrogenation catalyst was developed based on the research results of catalyst active components and kinetics. Conclusions Compared with Ni-W and Fe-Mo catalysts, the new developed catalyst has better SO, and sulfur hydrogenation performance, organic sulfur hydrolysis performance and CO conversion performance. It is suitable for the operating conditions of natural gas purification plant and refinery, and can achieve the goal of SO, mass concentration less than 400 mg/m" in the flue gas discharged from tail gas treatment unit. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Mining & Metallurgy (10057854) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Beijing University of Technology is the property of Journal of Beijing University of Technology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The livestock manure was effectively harmless and resourced by aerobic composting. However, during the aerobic composting process, a large amount of volatile gases are produced due to the isomerization of microorganisms, which is harmful to the environment and leads to serious loss of nutrients such as carbon and nitrogen, affecting the improvement of organic fertilizer quality. Therefore, it is necessary to adjust aerobic composting process parameters to reduce pollution gas emissions to fix carbon and nitrogen elements and improve maturity. Based on the previous research results, does the adjustment of ventilation rate to meet the normal oxygen demand of microorganisms help to degrade organic matter and reduce the emission of pollutants during composting? Based on this assumption, this study monitored compost maturity, gas emission and emission law by adjusting the low ventilation rate of 0.1 L/(kg·min) at the early stage of composting and setting intermittent ventilation mode and stopping ventilation at the late stage of composting. At the same time, biochar and microbial agents were added to strengthen the composting process. In order to investigate comprehensively the effects of exogenous materials (biochar addition and VT microbial inoculum) addition on maturity and greenhouse gas (NH3, CH4 and N2O) emissions during composting under low ventilation conditions. Three treatments were conducted in 60 L composting equipment for 42 days, pure sheep manure (CK) was set as control, which added with biochar (BC) and VT microbial inoculum (MC), respectively, as two treatments. In order to simulate the microaerobic environment, lower and intermittent ventilation rate was supplied during initial 14 days of composting, and stopped the ventilation in the rest of 28 days, Ventilation rate is 0.1 L/(kg·min). Results indicated that all treatments could meet the mature standard, such as germination index (GI)≥70%, pH≥8 and so on. Comparing with CK, BC and MC could improve GI by 27.8% and 38.8%, respectively, and prolonged the thermophilic phase to over 10 days, which satisfied the sanitation standard. Greenhouse gases discharged mainly in the first 14 days of composting, which was influenced by temperature, maturity and other physicochemical parameters. The addition of biochar and bacterial inoculum could reduce the total greenhouse gas emission. Comparing with the CK, the emission of NH3, CH4 and N2O from BC were reduced by 38.68%, 14.26% and 31.54%, and the total greenhouse effect was decreased by 31.11%. However, bacterial inoculum decreased NH3 emission by 18.41%, but increased N2O emission by 21.10%, and increased the total greenhouse effect by 20.70%. Therefore, In the microaerobic process of sheep manure, different exogenous additives have different effects on the emissions and laws of composting pollutants. Compared with microbial agents, biochar is a comprehensive additive that can be used in sheep manure microaerobic composting to improve compost maturity, accelerate degradation and humification of organic matters, reduce greenhouse gas emissions, increase the content of nutrition, as well as to provide theory references of sheep manure disposal in traditional heap composting, which is conducive to the promotion of microaerobic composting process. [ABSTRACT FROM AUTHOR]

Drip irrigation technology is one of the effective methods to solve the shortage of irrigation water source in arid and semi-arid areas. The emitter is the core of drip irrigation system, but the blockage of emitter hinders the development of drip irrigation technology. The sinusoidal dynamic pressure mode is expected to improve the anti-clogging performance of the emitters. This objective of this study was to clarify the influence of the combination of parameters of sinusoidal dynamic pressure on the outflow flow of trapezoidal labyrinth channel under muddy water condition. The sine wave dynamic pressure cycle parameters included amplitude, period and basic water pressure. The three factors with three levels each were designed by orthogonal design method. Based on previous studies and experience, the amplitude levels were designed including 2, 4 and 6 m considering the requirements of low pressure irrigation and avoiding negative pressure. The period levels were 1, 2, and 4 s. The three basic water pressures were 4, 6 and 8 m. A total of nine muddy water tests were carried out by using the method of periodic intermittent irrigation test. The muddy water concentration was 5 g/L. Meanwhile, tests with constant dynamic water pressures (4, 6 and 8 m) were also done in order to make a comparison with tests with the sine wave dynamic pressure mode. The measured and calculated indexes included the normal operating time, median size, low and upper particle sizes discharged from emitters and in the sediments of emitters. Range and variance analysis were used for data analysis. The results showed that the period was the only factor that could significantly affect the normal operating times, median size from discharged sediment and sediment deposition. The normal operating times of sinusoidal dynamic pressure under the water pressures (4, 6 and 8 m head) was 63.64%, 12.50% and 36.36%, more than that under the same constant pressure. The former had an average increase of 37.50%. Compared with the constant water pressure, the sinusoidal dynamic pressure was beneficial to the passage of sediments with different particle sizes. The upper limit, median, and low limit of particle sizes of discharged sediment were increased. Under the constant pressure, the large sediment particle size could easily deposit in the flow channel. When the sinusoidal wave period was 4 s, the amplitude was 2 m, and the basic water pressure was 8 m, the flow turbulence effect was the strongest, and the life of the emitter was the longest. Three different optimal results were obtained by range analysis for the three indexes. By a comprehensive score method with an entropy weight method, comprehensive score for each test was obtained. The range analysis of comprehensive scores showed that the optimal parameters were the combination with period 4 s, basic water pressure 8 m, and wave amplitude 2 m. Under the optimal conditions, the emitter could normally work for 16 times, which was 43.75% higher than the others. At this condition, the sinusoidal dynamic pressure can improve the anti-clogging performance of the emitter. [ABSTRACT FROM AUTHOR]

Nanosecond pulsed plasma has broad application prospects in the field of environmental engineering and biomedicine. This paper introduced a high integration and low cost kHz pulse power generator and a simple, practical plasma generator. The cost of the pulse power supply mentioned in this paper was less than 2000 yuan, and the voltage peak and discharge frequency can be adjusted by modifying the circuit element parameters. The plasma generator can produce a uniform low-temperature plasma area with a volume of 25cm X 25cm X 2cm under atmospheric pressure. The working gas of the discharge device was air or nitrogen, and the discharge process can be completed in tens of nanoseconds (ns).The gaseous NOx, O, OH- and other particles in the plasma were dissolved in the droplet, and after the droplet passes through the plasma discharge area. After a series of reactions, NO2-, NO3- and NH4+ will be formed. ln this way, low temperature plasma nitrogen fixation under atmospheric pressure can be realized. [ABSTRACT FROM AUTHOR]

In this paper, by constructing an AC-DC coupled electrode structure, a large area of glow discharge was formed and air purification research was carried out. Firstly, the electric field distribution characteristics of the carbon fiber helical electrode were studied, and the possibility of non-uniform electric field to generate atmospheric pressure air glow discharge was analyzed. Secondly, the AC-DC coupling discharge mode between the carbon fiber spiral electrode and the mesh electrode was proposed, and the effect of applying DC voltages of different polarities to the mesh electrode on the electric field distribution was analyzed. The results showed that when a positive DC voltage was applied to the mesh electrode, seed electrons were generated by the carbon fiber spiral electrode discharge, and a diffuse glow discharge can be formed within a 5 mm gap. Finally, the air purification device made was used to reduce the concentration of pollutants such as formaldehyde, TVOC and fine particulate matter, to a level below the national standard with-in 60 minutes. [ABSTRACT FROM AUTHOR]

This study aims to explore the gas-liquid two-phase flows during the self-priming process in an external-mixing self-priming centrifugal pump using Euler-Euler modeling, with an emphasis on the transient flow characteristics and the underlying mechanisms for the oscillating of the gas-liquid interface in the suction pipe. A homogeneous multiphase model (without considering the interphase velocity slip), and the standard k-ε turbulence model were adopted in the simulation. The opening boundary conditions were applied for the fluid at the inlet and outlet of the calculation domain, in order to capture the rising process of liquid level in the suction pipe. The speed was measured to determine the rotating speed of the rotor. The speed acceleration was then performed on the self-priming during the start-up process of the pump. The transient flow fields of the main components were investigated to reveal the gross features of the gas-liquid interface rising in the suction pipe, the mass flow rate of the liquid at the impeller inlet, the average gas volume fractions of pump components, and gas-liquid distribution in the flow passage of the pump. The simulated rising process of the gas-liquid interface in the suction pipe was agreed well with the experimental measurements. It infers that the opening boundary conditions were suitable for the reverse flow in the suction pipe caused by pressure oscillation in the impeller. The transient liquid phase flow rate at the impeller inlet indicated that the self-priming process was divided into three stages, namely the rapid absorbing, the oscillating exhaust, and the accelerating exhaust stage. The duration of the three stages accounted for 11.7%, 61.3% and 27% of the total self-priming time, respectively. The impeller rotating speed increased sharply at the rapid absorbing stage, where the initially stored liquid in the suction chamber was quickly sucked into the impeller to discharge the gas in the impeller. The oscillating exhaust was the main stage of the self-priming process, where the liquid in the gas-liquid separation chamber repeatedly entered the volute and the vicinity of the impeller outlet through the reflux hole in the process of gas-liquid mixing and gas exhausting. There was a periodic change with 0.25 s in the volume fraction of gas in the main pump components and the oscillation of liquid level in the suction pipe. But the inertia of the liquid column caused a phase gap between the liquid level oscillation and the pressure fluctuation at the impeller entrance. The oscillation amplitude of the gas-liquid interface increased with the increase of liquid column height. The accelerating exhaust stage was the final stage of the self-priming process, where the liquid in the suction pipe rapidly entered the impeller and the gas in the pump was quickly discharged. The finding can also provide an important reference for the design and performance optimization of self-priming centrifugal pumps. [ABSTRACT FROM AUTHOR]

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective treatement unit in sulfur The process principle. operation status and problems of complex iron tail gas recovery plant were described to solve the bottleneck that restricted the long- term operation of the complex iron tail treatement unit. The complex iron desulfurization process was applied in tail gas up-to-standard discharge transformation of large scale sulfur recovery pant. A series of measures were adopted which included optimizing steps of stoppage blowing sulfur. changing the stainless steel packing. optimizing the height of packing layer. determining the additives amount and adding time, and changing the filter cloth. etc. Results After the transformation, the SO2 mass concentration in discharged tail gas of sulfur recovery unit was less than or equal to 70 mg/m3, which meets the requirements of GB 31570一2015 Emission Stan rd of Pollutants Petroleum Refu,ting Industry,and was better than that before reformation. Conclusions The stable operation time of the complex iron tail gas treatment unit has exceeded 365 days and the annual comprehensive economic benefit has reached 1. 28 million yuan. and good economic benefit has been achieved. At the same time, the long-term operation achieved great social and environmental protection benefits, which could provide a reference for the technical transformation of similar devices. [ABSTRACT FROM AUTHOR]

Dielectric barrier discharge (DBD) is a common form of discharge that generates low temperature plasma.In this paper,a one-dimensional PIC/MCC model for the DBD of atmospheric pressure is developed. We used adapted particle management ( APM) and parallel computing strategy based on OpenMPI, and considered the accumulation of charged particles on the dielectric board and recombination reactions. In this paper, the spatial and temporal evolution of the discharge driven by sinusoidal voltage with a frequency of 500 kHz and amplitude of 3 kV is studied.The discharge characteristics in its Townsend discharge and glow discharge process are obtained,and the effects of parameters including voltage amplitude, gap distance, relative permittivity of dielectric on the discharge characteristics are studied. [ABSTRACT FROM AUTHOR]

Glow discharge ionization source can be used to analyze solid sample, liquid sample and gas sample. At present, glow discharge optical emission spectrometer (GD-OES) and glow discharge mass spectrometer (GD-MS) are mainly used to the elemental analysis of inorganic solid samples and quantitative depth profile analysis, including direct current (DC) power supply and radio frequency (RF) power supply. In this paper, the ionization of liquid sample and gas sample by low frequency radio frequency glow discharge (Lf-RFGD) was researched, and the glow discharge structure constructed was connected to time-of-flight mass spectrometer (TOF MS). The influences of the vacuum degree of ionization chamber, the size of sample inlet capillary, the auxiliary gas pressure, the discharge radio frequency and the voltage difference between electrode plates on the ionization efficiency were studied. The optimal analysis conditions are the vacuum degree of ionization chamber is about 30 Pa, the length of sample inlet capillary is 150 mm and the inner diameter is 0.25 mm, the auxiliary gas pressure is about 1.0 MPa, the low discharge frequency is 2 MHz, the voltage difference between electrode plates is about 100 V. Under these conditions, the discharge power is about 20 W, the detection limit of liquid sample is 0.1 pg and volatile sample is 20 mg/m3, and the detection resolution (full width at half maximum, FWHM) is about 3 000. Combined with samples testing, the Lf-RFGD TOF MS was preliminarily applied to the drug solution and volatile organic compounds (VOCs). However, the sensitivity of this instrument for detecting non-volatile liquid sample was not good compared with the conventional detection instrument. The reason is that high proton affinity and low ionization potential are needed to obtain good detection sensitivity in the positive ion mode of mass spectrometer, and non-volatile liquid sample without pretreatment is not easy to meet the condition of high proton affinity under low power glow discharge condition. Successfully, a low-cost, portable approach based on the application of atmospheric sampling Lf-RFGD TOF MS has been developed for near real-time measurement of trace VOCs. In this context, the glow discharge excitation source offers attractive alternative for development of low-cost VOCs and elemental analysis instrument. Lf-RFGD as an excitation source has unique advantages with respect to development of hand-held instrument such as low cost, low power consumption, and analytical versatility. [ABSTRACT FROM AUTHOR]

Atmospheric pressure plasma jets are widely used in many fields. In order to improve the processing efficiency of large-area materials, it is usually necessary to The jets are arranged in a jet array, but it is practically difficult to generate a large-area uniform plasma plume due to the interaction between the plasma plumes in the array. Here, a single-electrode argon jet array is excited by a DC voltage to generate a large-area uniform plasma plume. It is found that the discharge at low voltage is Discrete plasma plume, while at high voltage a homogeneous flaky plasma plume. Flaky plasma plume increases with voltage, argon flow, and air flow The electrical and optical measurement results show that the discharge current and luminescence signal of the discrete plasma plume are small pulses with very high frequency. The current and luminescence signals of the body plume are large pulses with very low frequency, and there are also small pulses between the two large pulses. The generation mechanism of the sheet plume was studied. The results showed that the anode plume in the discrete plume corresponds to the positive streamer discharge mechanism, while the cathode plume corresponds to the Townsend discharge mechanism. The breakdown mechanism of the plume is also a streamer mechanism. After the streamer breaks down, a glow discharge filament will be generated, and then the glow microdischarge filament will move downstream along the airflow. The gas temperature of the sheet-like plasma plume was studied with a fiber-optic thermometer, and it was found that the gas temperature of the sheet-like plasma plume did not exceed 65°C. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chongqing University of Posts & Telecommunications (Natural Science Edition) is the property of Chongqing University of Posts & Telecommunications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nowadays, trend of novel mass spectrometer development concentrates on fast, on-line analysis of samples with minor or without pretreatment. An important branch of modern mass spectrometer development is to build a fast and on-line instrument for volatile organic compounds ( VOCs) analysis. In this study, a high-performance small size proton transfer reaction-time of flight mass spectrometer ( PTR-TOF MS) was developed. The structure of the instrument was described in detail as well as the performance test and applications in exhaled gas analysis. The ion source of the described PTR-TOF MS utilized a simple structure hollow cathode discharge to produce hydronium ion. A linear drift tube was designed as the ion molecule reactor. The mass spectrum of reagent ion showed that the base peak of reagent ion was H3O+ (m/ z 19). Intensity of (H20)nH3O+ (n=l, m/z 37) was 5% of H3O+ (m/z 19). The main pollution ion NO+ (m/z 30) was o. 5% of H3O+ (m/z 19) which indicated that the purity of the ion source was good for proton transfer reaction. A direct current was arranged evenly across the whole reaction tube to maintain a consistent reaction E/N. The interface between ion source and TOF MS was a RF-only quadruple. The frequency and voltage of the RF-only quadruple were adjusted for the best transferring of V OCs ions. A set of focus lenses and collimation lenses was followed for ion beam refining before entering m ass analyzer. The mass analyzer used in this instrument was a small sized time of flight mass spectrometer. The total length of the mass analyzer was 360 mm which ensured the small size of the instrument. The time of flight mass spectrometer used orthogonal acceleration, twin pulse, reflect second-order focusing was used to maximum the resolution. Experiment result showed that the full width half maximum m/ z 115 is better than 2500. The detect limit for acetone, benzene a nd toluene is from 6 X 10-12 mol/mol to 9. 6 X 10-11 mol/mol. The instrument also shows good linearity between concentration 1 X 10-8 mol/mol and 1 X 10-6 mol/mol. The instrument was successfully applied to component analysis of human exhaled gas. Further works will be concentrated on the quantitative analysis of components of real samples. The developed highperformance small size PTR-TOF MS has potential in applications in environment, biology, petrochemical industry etc. [ABSTRACT FROM AUTHOR]

This study aims to improve the low NOx conversion efficiency of the selective catalytic reduction (SCR) system caused by the soluble organic fraction (SOF) deposition of SCR carrier in a diesel engine. A sediment quantity model of SOF deposition was proposed to optimize key parameters using a multi-objective genetic algorithm (GA). Firstly, a road spectrum test at low temperatures was conducted to collect the data of SOF deposition amount in four groups. A SOF high-temperature pyrolysis was carried out to obtain 10 groups of experimental data at a steady-state temperature. Secondly, a model of SOF deposition was established using Matlab/Simulink tools, including SOF raw emission, the SCR carrier of SOF capture, and SOF pyrolysis module. Two ways were selected to calculate the SOF raw emission. One was the theoretical estimation using an approximate linear relationship of SOF with the gaseous unburned hydrocarbons (HC). Another was the direct measurement of SOF raw emission, where the excess air coefficient was used to correct the transient SOF raw emission. The capture efficiency of SOF by SCR carrier was evaluated via mapping the upstream discharge and exhaust gas flow of SCR. A correction was also introduced using the deposition amount of SOF. The SOF pyrolysis was prepared under the component analysis and chemical reaction kinetics model of SOF. Three stages were divided in a pyrolysis process of SOF, including the short, medium, and long chain. The key parameters of SOF pyrolysis were determined, such as the transient correction MAP, activation energy of three stages, pre-exponential factor, and mass proportion coefficient. Thirdly, various multi-objective GAs were evaluated prior to optimization. An interactive adaptive-weight GA (i-awGA) was selected to optimize the key parameters considering both efficiency and accuracy, whereas, a non-dominated sorting GA II (nsGA II) was used to identify the optimal solution, and a strength Pareto evolutionary algorithm (spEA) was utilized to generate the penalty function. Finally, a multi-objective GA optimization was performed on the transient correction MAP and three groups of pyrolysis parameters. In MAP optimization, the number, range, and distribution of MAP points acted by each gene were calculated using the type of MAP, combined with the basic value of MAP and the number of genes. In optimization of pyrolysis parameters, pre-exponential factors were calculated using the activation energy and compensation effect for the physical significance of the model. The average error of low temperature deposition of 4 groups of SOF reached 2.42%, the average error of high temperature pyrolysis of 12 groups reached 4.03%. Specifically, the largest average error of 3.04% was obtained for the low-temperature path deposition in one group of SOF, whereas, the largest average error of 5.41% was for the steady-temperature pyrolysis in two groups. It demonstrates that the proposed model of SOF deposition and the GA optimization was well suitable for the engineering application. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)