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Copyright of Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. 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 zero-value piece of insulator string can be detected by measuring its electric field strength. The traditional way is always by measuring the electric field distribution curve of the whole string to judge out the zero-value piece position, which is inefficient and difficult to operate in field. In this paper, an improved method of identifying zero-value insulator by just measuring the partial electric field of insulator unit is proposed. Firstly, the simulation model of insulator string zero-value unit detection is established, and the partial electric field distortion characteristic caused by zero-value piece is analysed. Then the partial electric field variation criterion for zero-value identifying is obtained basing on the simulation result. Finally, the identification method is verified by designing the detection device and carrying out the point to point zero-value piece evaluating experiments. The results show that the point to point zero-value insulator detection can be realized using the three-array-probe electric field measuring method. The length of the array should be larger than the length of the electric field distortion interval, which can be taken as 130 mm for the research object in this paper. The identification criteria is that the deviation between probe 1 and 3 is less than 10%, and the deviation between probe 2 and the average is less than 50% at the same time. When detecting zero-value piece at the high-voltage and medium-voltage end, the best position for the sensor device identification is directly facing the steel foot, while for the low-voltage end, the best position is facing the shed edge. The results of the study can provide theoretical support for the intelligent operation and maintenance of external insulation in power transmission and distribution.

Partial discharge at the oil-paper interface is one of the main reasons for the failure of oil-paper insulation in oil-immersed transformers. In this article, based on the numerical model of multi-branching streamer discharge, a multi-branching streamer discharge model in oil-paper insulation system is constructed by further considering the charge transport characteristics of oil-paper interface. The surface discharge characteristics under the influence of the dielectric constant ratio between natural ester insulating oil and insulating paper, and the spacing between needle electrode and paperboard are studied by finite element method, respectively. The results show that the distance between the needle electrode and the paperboard, and the dielectric constant ratio of insulating oil and insulating paper both significantly affect the streamer branching. The smaller the clearance between the needle electrode and paper-board is, the more serious the inhibition of streamer branches at the oil-paper interface is, which resulting in the streamers near the oil-paper interface are more significant effect on the propagation of the z-axis streamer. When the dielectric constant of the insulating oil is larger than that of the paperboard, the development and branching of the streamer in the oil will be more significant. On the contrary, the streamer is more likely to develop along the surface of the paperboard and accumulate charge at the oil-paper interface.

Copyright of Electric Power Engineering Technology is the property of Editorial Department of Electric Power Engineering 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 Electric Power Engineering Technology is the property of Editorial Department of Electric Power Engineering 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 Electric Power Engineering Technology is the property of Editorial Department of Electric Power Engineering 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 Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. 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 Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica 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 Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao 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.)

Copyright of Chinese Journal of Liquid Crystal & Displays is the property of Chinese Journal of Liquid Crystal & Displays 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 Food Safety & Quality is the property of Journal of Food Safety & Quality 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.)

Electrokinetic remediation technology can effectively remove heavy metal ions from contaminated soil in coal mine area. In order to clarify the effect of electric field on the adsorption characteristics of heavy metal ions on the surface of kaolinite, three common heavy metal elements Pb(II), Cd(II) and Cu(II) in mine soil were studied, a three-dimensional visualization model was established, and a stable kaolinite-solution-kaolinite simulation system was optimized. Molecular dynamics simulation method was used. The adsorption mode, atomic density distribution, diffusion coefficient and radial distribution function of heavy metal ions on kaolinite (001) crystal plane under electric field were investigated. The results show that when the electric field direction is +Z, the electric field promotes the complexation between heavy metal ions and siloxane surface, and the coordination number of the first hydration shell of heavy metal ions decreases with the increase of electric field intensity. The adsorption percentage of outer complexes increases with the increase of electric field intensity. When the electric field direction is −Z, the adsorption percentage of the outer complex decreases with the increase of the electric field intensity, the interaction between the kaolinite surface and heavy metal ions weakens, and more heavy metal ions dissociate in the solution and pair with chloride ions; under the action of electric field polarization, there is no obvious boundary between the first and second hydration shells of heavy metal ions, and there is water molecular exchange between the hydration shells; under the action of electric field, the MSD curve of heavy metal ions on kaolinite shows anisotropy. The diffusion coefficient in X and Y direction is larger than that in Z direction, the total diffusion coefficient increases with the increase of electric field intensity, and the diffusion coefficient is not obviously affected by the positive and negative direction of electric field. Pb(II) ion and Cd(II) ion only have outer complexes on the surface of kaolinite, while Cu(II) ions have the adsorption mode of coexistence of inner and outer complexes. The adsorption priority of kaolinite to three heavy metal ions is Pb(II) > Cu(II) > Cd(II).

To study the correlation of low-frequency line spectrum characteristics of underwater typical physical fields, an underwater joint measuring device was developed, which integrated the measurement functions of acoustic field, electric field, magnetic field, and pressure field. Secondly, the underwater physical field signals of more than 30 ships with different targets were obtained through tests in a sea area. Finally, based on the measured data, the correlation between the low-frequency (below 100 Hz) line spectrum characteristics of the acoustic field, electric field, magnetic field, and pressure field of typical ships was analyzed. The results show that the line spectrum characteristics of low-frequency pressure signal and low-frequency electric field are strongly correlated and have common sources. The line spectra of the low-frequency acoustic field, pressure field, and low-frequency electric field signal are correlated and have common sources at some frequency points, which provides a new idea for the joint detection and identification of targets based on underwater physical fields.

Protein is an important nutrient required by the human body. The change of protein structure during processing will lead to changes in its functional properties, in turn affecting the quality of foods. There are many physical methods available to alter the structure of proteins to expand their application in the food industry. The new electrophysical processing technology has become a hot spot in the field of food processing due to its advantages of high efficiency, low energy consumption, and slight loss of nutrients. Therefore, this paper reviews the effects of electric field technology (ohmic heating and electrostatic field) and electromagnetic field technology (microwave, radio frequency and magnetic field) on the change of protein structure at multiscales (macroscopic, molecular and microscopic levels), in order provide a theoretical basis for the development and utilization of electromagnetic field processed protein products.

The sterilization operation in food production is a key process to ensure the safety of food products, and most existing technologies for food sterilization utilizes thermal and/or non-thermal effects. Conventional heat sterilization requires a heat transfer medium, which is completed in a certain period of time at a certain temperature. Electric field processing, a non-conventional food processing technology which utilizes both thermal and non-thermal effects, can reduce the effective temperature threshold and time of conventional heat sterilization, thereby better retaining the nutritional value of foods with less impact on the sensory quality, flavor and color. This paper reviews the principles of ohmic heating sterilization, high-voltage pulsed electric field sterilization and induced electric field sterilization as well as the frontiers and progress in these sterilization technologies in the food industry, discusses the characteristics and differences between the current electric field technologies, and presents an outlook on their future development.

Copyright of Large Electric Machine & Hydraulic Turbine is the property of Large Electric Machine & Hydraulic Turbine 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.)

To assist the development of scientific research prototype and engineering prototype of melten salt electrorefining equipment, electric field analysis was carried out. By using Comsol Multiphysics software, a mathematical model of electric field and electrochemical field in 10 kg/batch uranium metal spent fuel pyroprocessing molten salt electrorefining cell was built based on Maxwell principle and electrochemical theory, under the condition of constant input current density. The effects of the electrorefining cell structure, electrode distance and cathode shape on the cell electric field and electrochemical performance were studied. The simulation results show that for the PEER square cell, the energy consumption is low, current efficiency is high and economic performance is excellent. For the highthroughput frustum cone cell, the current density is high, the electrochemical current density distribution of cathode is concentrated on the anode side, the uranium deposition morphology is uniform, and the electrochemical performance is excellent. For the flat-plate cathode square cell, the current density and current efficiency are high, electrochemical dissolution and deposition rate of uranium is fast, the economic performance and electrochemical performance are excellent. For the rod cathode square cell, the energy consumption is low, the electrochemical current density distribution of cathode is concentrated on the anode side, and the uranium deposition morphology is uniform. Within the range of this study, with the increase of electrode distance, the electric field intensity of the electrolytic cell increases, the mass transfer rate of uranium ions in molten salt increases, the electrochemical anode current density increases, the electrochemical current density of high-throughput frustum cone cell increases, and the electrochemical performance of the cell is almost unchanged. But with the increase of electrode distance, the cell voltage increases, the absolute value of electrode overpotential increases, the total cathode current density decreases, the total anode current density increases, the uniformity of thermal field temperature distribution decreases, the electrochemical cathode current density of PEER square cell decreases, the current efficiency decreases, and the economic performance and thermal stability of the electrolytic cell weaken. The simulation calculated values are in good agreement with the experimental data abroad, which indicates that the model can wholly embody the uranium metal molten salt electrorefining test practice. Taking the above factors into consideration, the high-throughput frustum cone cell with parallel-plate cathode and short spaced electrodes may be the cell with the best technical and economic indicators of electric field and electrochemical field. And it should be selected according to the requirements and process conditions in actual test and application.

Copyright of Journal of Harbin University of Science & Technology is the property of Journal of Harbin University of 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 Molecular Science is the property of Journal of Molecular Science 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 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 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 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.)

Most serious breakdown faults of cross linked polyethylene(XLPE) cables in distribution network occur at cable joints, which are mainly caused by process defects in the manufacturing and installation of cable joints. In this paper, the charge simulation method is used to study the characteristics of electric field distribution near four typical defects of cable joints, namely, air gap, water film, metal debris and metal breakout. The electric field calculation and random walk theory are combined to analyze the distribution of electrical tree caused by several defects. At the same time, the actual electric field distribution around the sample of XLPE cable joints in the distribution network with defects is measured, and the measured results are compared with the calculated results. The results show that the electric field measurement method can directly and effectively identify the types of internal defects of cable joints, and the electric field distortion caused by conductive defects is more significant than that caused by air gap and water film defects. When the electric field distortion caused by defects is greater than the critical electric field value, the electric tree will develop. The track length of the electric tree development is positively related to the field strength. The electrical tree caused by conductive defects is more likely to develop towards the cable core, which is more likely to cause the breakdown of XLPE insulation.

To explore the demulsification mechanism of emulsion under electric fields, the movement process of dispersed phase droplets in water-in-oil emulsion was simulated with the finite element method. Herein, the oil-water distribution was represented with the phase field method, and the accuracy and efficiency of calculation on fluid flow process was improved with the structured quadrilateral grid. Besides, the influence laws of electric field parameters, as well as the physical parameters of emulsion, on the droplet deformation and coalescence were systematically studied to provide theoretical basis for the efficient application of electric demulsification technology. According to the results, the higher the electric field intensity, root mean square(RMS) of electric field waveform and droplet size, the greater the deformability and coalescence ability of droplets are. The droplet deformation is independent of frequency under the high-frequency conditions, and the frequency has little effect on the coalescence rate of droplets. Meanwhile, the droplet deformation and coalescence rate can been improved by decreasing the continuous phase viscosity and oil-water interfacial tension. In addition, the microcosmic mechanism of droplet deformation and coalescence was also discussed. It is found that the maximum droplet deformation is in strong linear relationship with the electric Weber number in the case of small deformation, and the electric field intensity,droplet size and interfacial tension affect the coalescence efficiency of droplets by influencing the evolution of liquid bridge between droplets.

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 Electric Power Engineering Technology is the property of Editorial Department of Electric Power Engineering 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 Nanchang University (Engineering & Technology) is the property of Nanchang University 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: This study aimed to classify the mechanism of pullulanase-catalyzed hydrolysis of waxy rice starch under electric field treatment, by monitoring the changes in hydrolysis efficiency, pullulanase activity, and the structure and properties of waxy rice starch. Methods: The hydrolysis efficiency was determined, and the structure and thermal properties of hydrolysates were characterized, by using scanning electron microscope, X-ray diffractometer, differential scanning calorimeterand rapid viscosity analyzer. Results: Under the control of the following conditions, electric field with intensities ≤2.5 V/cm could increase pullulanase activity, accelerate the hydrolysis, induce the pores and cracks on the granule surface, increase the relative crystallinity, increase the gelatinization temperature and reduce the pasting viscosity of waxy rice starch. However, electric field with intensities ≥5 V/cm could cause the partial inactivation of pullulanase and reduce the hydrolysis efficiency, and consequently caused less change of the relative crystallinity and pasting viscosity. Conclusion: The strengthening effect of the electric field treatment on pullulanase hydrolysis of waxy rice starch mainly affected pullulanase activity, but has no significant effect on the structure of starch.

In order to promote the effective application of finite element analysis software in spinning field and better solve the problems in production practice, the specific application cases of finite element analysis technology in spinning equipment deformation, flow field, electrostatic field, magnetic field and force between fiber and equipment were reviewed. The problems in the application of finite element analysis technology in production practice are analyzed. On this basis, the bottlenecks and limitations in the application of finite element analysis software are summarized, and the future development trend is forecasted, which provides a favorable reference for the promotion and application of finite element analysis technology in the field of spinning and guiding production practice better. [ABSTRACT FROM AUTHOR]

This study aims to explore the boiling heat transfer characteristics of nanofluids in the microchannels under the action of electric fields. The linear electrodes were arranged in the geometric center of microchannels to generate a 0-800V non-uniform electric field, and the SiO2-R141b nanofluids with the different mass fractions were prepared by a two-step method. A flow boiling experiment was performed on the microchannel with a cross-section of 2 mm×2 mm under the system pressure of 140 kPa, the mass flow rate of 317.71 kg/(m²·s), the heat flux density ranges from 11.53 to 29.14 kW/m², and the inlet temperature of 32℃. A systematic investigation was made on the average saturated boiling heat transfer coefficient and the range of effective heat transfer heat flux density in the microchannel with the different mass fractions of nanofluids under the action of different electric voltages. The enhanced heat transfer mechanism of the nanofluid flow boiling was determined to simulate the detachment rate of the bubbles, the velocity of the confined bubbles, and the aspect ratio of the microchannels under the action of different voltages and electric fields. The comprehensive performance evaluation of the heat transfer (PEC) method was used to enhance the heat transfer of microchannels by different strengthening techniques. Both the electric field and the nanofluid were used to enhance the flow boiling heat transfer in the microchannel. Electric fields presented a better effect on the nucleate boiling heat transfer than single-phase heat transfer. The nanofluids were stable and enhanced heat transfer performance in the single- and multi-phase flow. An optimal mass fraction of nanoparticles was achieved in the nanofluids. The combination performance was better than that of the electric field or the nanofluid alone. The average saturated boiling heat transfer coefficient of nanofluids under the action of an electric field was higher than that without an electric field, which increased with the increase of voltage. The maximum coefficients of saturation boiling heat transfer increased by 44.9%, 20.9%, and 58.0%, respectively, for the electric field enhancement alone, nanoparticle enhancement alone, as well as the electric field and nanoparticle addition enhancement, compared with pure refrigerant. There was a significantly larger effective range of heat transfer enhancement that combined electric field and nanoparticles, compared with the electric field alone and the addition of nanoparticles to the pure refrigerant. The electric field can be expected to accelerate the bubble detachment frequency and the speed of the confined bubble, thereby reducing the aspect ratio of the confined bubble. At the same time, the nanoparticles can be used to improve the thermal conductivity of the working medium for the high heat exchange between the heat exchange wall and the working medium, indicating the enhanced heat transfer under the combined action. The nanofluid presented the highest enhancement performance of heat transfer under the electric field, where the average heat transfer comprehensive performance evaluation factor was 1.34. Consequently, the electric field combined with the addition of nanoparticles can effectively enhance the heat transfer of flow boiling in the microchannels. The finding can provide new ideas to improve the heat transfer performance of microchannels under the combined electric field and nanoparticle composites. [ABSTRACT FROM AUTHOR]

Copyright of Food & Machinery is the property of Food & Machinery 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 Materials Science & Engineering (1673-2812) is the property of Journal of Materials Science & 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.)

Two-dimensional layered materials represented by MoS2 and GeS exhibit excellent physical properties in optical and electrical aspects. How to combine the excellent properties of the two materials and obtain composite materials with new synergistic functions are of great significance to the development and application of electronic devices. This work uses the first principles calculation method of density functional theory to systematically study the electronic structures and optical properties of GeS / MoS2 heterojunctions, at the same time, the influence of interface distance, strain and electric field on the electronic structures and the optical properties of the heterojunctions was also explored. The research results show that the GeS / MoS2 heterojunctions is a type Ⅱ band arrangement, which is conducive to the separation of photogenerated electron-hole pairs. Further research found that the band arrangement and light absorption coefficient of GeS / MoS2 heterojunctions can be effectively controlled by means of strain and electric field. The research results show that GeS / MoS2 heterojunctions has potential applications in photocatalysis, optoelectronic devices and other fields, and the research in this paper provides theoretical guidance for the design and preparation of GeS / MoS2 related optoelectronic devices. [ABSTRACT FROM AUTHOR]

Copyright of Refractories / Naihuo Cailiao is the property of Naihuo Cailia (Refractories) 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 Central China Normal University is the property of Huazhong Normal University 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 Electronic Components & Materials is the property of Electronic Components & Materials 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 Energy Chemical Industry is the property of Energy Chemical Industry 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.)

Applied electric field dependence of spatially indirect luminescence spectra of N-doped ZnSe/BeTe/ZnSe type- II quantum wells was studied. Experimental results indicate that each of the luminescence spectra exhibits a main luminescence peak with a lower linear polarization degree. This phenomenon can be attributed to the equalizing potential of both wells, which is due to the screening of the built-in electric field caused by the doped electrons in the structure. Meanwhile, each of the luminescence spectra exhibits an asymmetry peak with an inverse-Boltzmann line-shape, and the line-shape and linear polarization degree remain unchanged within the entire voltage range. However, the integrated luminescence intensity depends strikingly on various external voltages: with changing the positive gate voltage ( in the range of + 7 V to 0 V), the integrated luminescence intensity almost maintains a constant, but with increasing negative gate voltage ( - 1 V to - 7 V), the integrated luminescence intensity reduces significantly. These behaviors indicate that the spatially indirect luminescence spectra show a characteristic feature for a negatively charged exciton transition. The constant integrated luminescence intensity is explained as screening of the applied electric field with the doped layer, while the significantly reduced integrated luminescence intensity is ascribed to excitation of doping electrons by applied electric field ( leading to a decrease in the electron concentration in the region excited by laser ), thus resulting in a reduction in the number of negatively charged exciton. In addition, the possible particle configuration of the spatially indirect negatively charged exciton was also explored. [ABSTRACT FROM AUTHOR]

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.)

In order to solve the agglomeration problem of carbon nanotubes (CNTs) in solution, n-butanol was used as dispersion and carboxylated carbon nanotubes as inorganic particles. After ultrasonic dispersion, n-butanol carbon nanotubes dispersion was prepared. The influence of the electric field on the dispersion of carbon nanotubes was investigated systematically. The directional arrangement of carbon nanotubes in solvent dispersion was observed by a microscope. The results show that under 2 000 V/cm, 400 Hz AC electric field, 0.3 g/L CNTs can have a better arrangement in n-butanol with low surface tension and dielectric constant under external electric field for 10 s at 25°C, prolonging the time, the carbon nanotubes gradually form bundles; when the concentration of carbon nanotubes is 0.5 g/L, the dispersion is difficult, and the degree of directional arrangement is reduced; increasing the electric field intensity and frequency can improve the dispersion and orientation of CNTs. [ABSTRACT FROM AUTHOR]

Intense pulse light (IPL) technology is a new non-toxic and environmentally friendly cold treatment technology, which can be applied to mutation breeding of microorganisms and to obtain high-producing strains. Aspergillus Niger is the main strain producing pectinase in food industry at present, but its pectinase yield is low. In order to verify the feasibility of applying intense pulse light technology to mutagenize Aspergillus Niger strains for high yield of pectinase, this experiment used intense pulse light technology to mutagenize Aspergillus Niger. With pulse voltage, pulse number and pulse distance as independent variables and ratio of transparent circle to colony diameter as dependent variables, steepest slope moving tests, response surface tests and result analysis are carried out to determine the optimum conditions for high-yield pectinase induced by the intense pulse light. At the same time, secondary screening of mutant strains was carried out and the genetic stability of the mutant strain was determined and the enzymatic properties of the mutant strain with high pectinase production were explored. The results showed that the multiple quadratic regression equation of transparent circle and colony diameter ratio (Y) against impulse voltage (A), pulse number (B) and pulse distance (C) is as follows: Y=1.59+0.068A+0.048B−0.033C− 0.011AB−0.019AC−0.022BC−0.071A²−0.087B 2−0.13C². All the factors in the response surface design test were significant, and the interaction between two factors was not significant. The optimum mutagenesis conditions were when the pulse voltage was 2 075 V, the pulse number 36 times and the pulse distance 5.4 cm. Under the optimum conditions, the ratio of transparent circle to colony diameter could reach 1.58, which was in good agreement with the predicted value of response surface fitting equation, indicating that the model was credible. Induce mutation to the Aspergillus Niger under such optimized condition, screen mutant strains using transparent circle for 60 mutant strains with bigger ratio of transparent circle to colony diameter. The mutant strain L9 with high pectinase production was finally selected by re-screening the above-mentioned 60 strains by determining pectinase activity, which was as high as (188.21+1.22) U/mL, which was 82.2% higher than that of the original strains. The results of genetic stability analysis showed that the mutant strain L9 had stable pectinase performance within 6 generations and no significant changes were seen in terms of pectinase activity, which indicated that the mutant strain L9 had good genetic stability. The optimum pH value and temperature for producing pectinase were 5.0 and 45℃. Compared with the original strain, the mutant strain L9 produced pectinase with better activity at the optimum pH and temperature. The range of the pH stability and thermal stability of the mutant strain were also significantly wider than that of the original strain, indicating that the mutant strain had good pH stability and thermal stability. Through the above experimental results, we can know that the application of intense pulse light technology to Aspergillus Niger mutation is feasible. After the intense pulse light induced mutation and secondary screening, a mutant strain of Aspergillus Niger with higher pectinase production with high enzymatic activity and good genetic stability can be obtained. [ABSTRACT FROM AUTHOR]

Microchannel heat exchanger is highly efficient in heat exchange due to its microscopic structure and large heat exchange surface area ratio. Compared with conventional heat exchanger, it not only improves heat exchange efficiency but also saves space and reduces the weight of heat dissipation equipment. In agriculture, microchannel heat dissipation technology has been widely used in cultivation, machinery, and product drying. Microchannel increases resistance to fluid flow and could thus result in an increase in energy consumption. It could also give rise to a pressure-drop oscillation affecting operation of the system. Previous work showed that electric field has a beneficial impact on heat transfer efficiency in the microchannel heat exchanger. The purpose of this paper is to investigate how different electrodes (needle type and linear types) affect pressure drop of the boiling R141b coolant when it flows in the microchannel. The pressure in the system was kept at 140 kPa, the working inlet temperature was 32.5, the mass flow rate ranged from 277.35 ℃ to 531.75 kg/(m²·s), the heat flux density ranged from 7.50 to 21.49 kW/m², the voltage ranged from 0 to 850 V, and the microchannel was rectangular with a cross section of 2 mm×2 mm. The results showed that the electric field under both electrodes increased the frictional pressure drop in the microchannel, compared with that without electric field. The frictional pressure drop of the two-phase along per unit length increased with both voltage and heat flux. The average two-phase frictional pressure drop along per unit length under the needle and the linear electrode was increased 0.7% to 15.4% and 1.3% to 18.7%, respectively, that without electric field. When the voltage changed from 0 to 250 V, the effect of the needle electrode on the pressure drop was greater than that of the linear electrode, while when the voltage was higher than 400 V, the effect of the linear electrode on the pressure drop was more significant. We simulated the electric field distribution in a microchannel 6 mm long using COMSOL for both electrodes. The results showed that under the same voltage, the maximum of the electric field intensity in the needle electrode was higher than that in the linear electrode, but the effective range of the electric field in the linear electrode was higher than that in the needle electrode. The results presented in this paper provide an alternative to improve performance of microchannel heat exchanger and reduce its energy consumption. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Guangxi Normal University - Natural Science Edition is the property of Gai Kan Bian Wei Hui 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.)

Aspergillus niger is an important microorganism in biotechnology and its metabolites play an important role in fermenting feed, food ingredients, enzymatic production and medicine; it is known as a cell-production plant for heterologous proteins and enzymes. Glucoamylase produced by Aspergillus niger is widely used to hydrolyze starch into glucose in brewery industry, calcium lactate industry and a variety of fermentation industry; it is regarded as a generally safe product by food and drug administrations. Although glucoamylase produced by Aspergillus niger has been studied for many years, there is still room for improvement such as enhancing glucoamylase activity, reducing energy and production costs. As such, Aspergillus niger still attracts research interest. Compared with chemical mutation and recombination technology, the pulsed electric field is able to improve microbial activity and its fermentation ability with limited chemical residues and short cultivation period. In this work, we cultured and processed aspergillus niger spore suspension under different pulsed electric field in attempts to understand the responsive changes in its biological activities and glucoamylase production. The pulsed electric fields we examined had pulse intensity: 5-15 kV/cm, pulse duration: 10-100 s and pulse numbers: 50-99, and they were compared to the surface method. The results showed that both pulse intensity and pulse number affected the dry weight of Aspergillus niger mycelium and the production of glucoamylase. When the pulse intensity and pulse width were 12.975 kV/cm and 54 μs, respectively, and the pulse number was 66, the dry weight of Aspergillus niger mycelium was 28.05 mg and the productivity of the glucoamylase was 18.01 U/mL, increasing by 68.27% and 14.71% respectively up the control. Compared with clear colony circles of untreated colonies, the colonies processed by the PEF was round while the colony circles were hardly distinguishable from the star-shaped folds and higher colony circles. The PEF treatment significantly increased the spore number, with a distinct dark yellow appearing around the spores while the color of the spores remained unchanged. The observed colony morphology showed that the PEF treatment boosted the growth of Aspergillus niger due to the change in its metabolism. Statistical analysis showed that PEF treatment improved the spore germination rate by 77.8%-231%, thereby promoting mycelial growth. Esterase isozyme analysis showed that PEF treatment altered the brightness and width of the bands but not the band number. It was also found that the PEF treatment affected the enzymatic activity in all experiments although it did not have significant effects on genetic mutagen. This work provides a theoretical basis to improving enzyme synthesis of Aspergillus niger and its industrial production. [ABSTRACT FROM AUTHOR]

The phenomenon of excessive concentration of particulate dust exists in many cities in China. Inhalable dust has great harm to the environment and human body,so it is imperative to control the dust pollution. However, it is difficult to be directly caught by precipitator because of the small particle size. Agglomeration is a simple and easy way to accumulate the dust particles by the action of electric field and to coagulate and increase the effective diameter to facilitate trapping. The agglomeration of homopolar and heteropole charged particles in alternating electric field,the coulomb agglomeration of heteropole charged particles and the agglomeration of heteropole charged particles in direct-current electric field are introduced. Several new electric agglomeration structures are introduced, and the main development tendency is proposed, which provides theoretical and technical support for the industrial application of electric agglomeration technology. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Liquid Crystal & Displays is the property of Chinese Journal of Liquid Crystal & Displays 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 China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS 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.)