This paper analyses the principle of microwave humidity testing. According to the problems in the production procedure of ceramic products, a microwave humidity testing system is designed and analyzed for its advantag...This paper analyses the principle of microwave humidity testing. According to the problems in the production procedure of ceramic products, a microwave humidity testing system is designed and analyzed for its advantages. Furthermore, the system has been applied to the production line that produces ceramic products and the testing results are also satisfying.展开更多
Microwave-vacuum drying is an accepted drying method for agro-products, which is nonetheless still relatively unknown to some. This paper attempted to give an overview of the most important aspects of microwaves-vacuu...Microwave-vacuum drying is an accepted drying method for agro-products, which is nonetheless still relatively unknown to some. This paper attempted to give an overview of the most important aspects of microwaves-vacuum drying (MVD) and their relevance to agro-products processing. Some advantages on microwave-vacuum drying properties were discussed to provide a better insight into the reasons for the use of microwaves. Also the effects of the MVD on the quality of several agro-products and reasonable processing parameters were given, which develop the guidance to the application of MVD on the agro-products dehydration. As a potential drying technology, MVD will be broadly utilized for the other agro-products processing展开更多
This paper presents a preliminary study on the dielectric properties and curing of three different types of epoxy resins mixed at various stoichiometric mixture of hardener, flydust and aluminium powder under microwav...This paper presents a preliminary study on the dielectric properties and curing of three different types of epoxy resins mixed at various stoichiometric mixture of hardener, flydust and aluminium powder under microwave energy. In this work, the curing process of thin layers of epoxy resins using microwave radiation was investigated as an alternative technique that can' be implemented to develop a new rapid product development technique. In this study it was observed that the curing time and temperature were a function of the percentage of hardener and fillers presence in the epoxy resins. Initially dielectric properties of epoxy resins with hardener were measured which was directly correlated to the curing process in order to understand the properties of cured specimen. Tensile tests were conducted on the three different types of epoxy resins with hardener and fillers. Modifying dielectric properties of the mixtures a significant decrease in curing time was observed. In order to study the microstructural changes of cured specimen the morphology of the fracture surface was carried out by using scanning electron microscopy.展开更多
A switchable down-,up-and dual-chirped microwave waveform generation technique with improved time–bandwidth product(TBWP)is proposed and demonstrated based on a dual-polarization dual-parallel Mach–Zehnder modulator...A switchable down-,up-and dual-chirped microwave waveform generation technique with improved time–bandwidth product(TBWP)is proposed and demonstrated based on a dual-polarization dual-parallel Mach–Zehnder modulator(DPDPMZM)cascaded with a polarization modulator(Pol M).By properly controlling the phase shifts of the radio frequency signals applied to the DP-DPMZM,switchable down-,up-and dual-chirped waveforms with simultaneous frequency and bandwidth doubling can be generated.To enlarge the TBWP further,splitting parabolic signal and phase-encoding splitting parabolic signal are used to drive the Pol M for the enhancement of bandwidth and time duration.Numerical results demonstrate the generation of down-,up-and dual-chirped microwave waveform with TBWP of 8,160 and 10240.The proposed method may find applications in future multifunction radar systems due to the high performance and flexibility.展开更多
This study was undertaken to evaluate the efficiency of a liquid-solids separation process and microwave pretreatment, as well as anaerobic biodegradability of microwave pretreated dairy manure. Liquid-solids separati...This study was undertaken to evaluate the efficiency of a liquid-solids separation process and microwave pretreatment, as well as anaerobic biodegradability of microwave pretreated dairy manure. Liquid-solids separation of raw dairy manure resulted in solid and liquid fractions having different properties, with the solid fractions richer in total and volatile solids content and liquid fractions richer in nutrients and metal ions. Substantial amounts of soluble chemical oxygen demand and nutrients were released into the solution after the microwave treatment. The microwave pretreated dairy manure was also subjected to anaerobic digestion. The kinetic parameters of methane production potential, maximum methane production rate and lag time were determined using the modified Gompertz equation. Anaerobic digestion of liquid manure, without microwave treatment, outperformed the sets with microwave treatment. The microwave-treated liquid dairy manure, without acid addition had better results in terms of methane potential and methane production, than with acid addition. Thermophilic digestion exhibited a higher maximum methane production rate than that of mesophilic digestion, but lower methane yields. The microwave pretreatment of dairy manure resulted in high soluble chemical oxygen demand;however, methane yield was not increased.展开更多
A comparison between conventional pyrolysis and a novel developed low-temperature microwave-assisted pyrolysis methodology has been performed for the valorisation of a range of biomass feedstocks including waste resid...A comparison between conventional pyrolysis and a novel developed low-temperature microwave-assisted pyrolysis methodology has been performed for the valorisation of a range of biomass feedstocks including waste residues. Microwave pyrolysis was found to efficiently deliver comparable evolution of bio-gases in the system as compared with conventional pyrolysis at significantly reduced temperatures (120-180 ℃vs 250-400 ℃). The gas obtained from microwave-assisted pyrolysis was found to contain CO2, CH4 and CO as major components as well展开更多
Investigations were conducted to purify crude Li_(2)CO_(3)via direct carbonation with CO_(2)at atmospheric pressure and pyrolysis with both water bath heating method and microwave heating method.The reaction kinetics ...Investigations were conducted to purify crude Li_(2)CO_(3)via direct carbonation with CO_(2)at atmospheric pressure and pyrolysis with both water bath heating method and microwave heating method.The reaction kinetics of LiHCO_(3)pyrolysis was studied and the effect of different operating conditions including initial concentration of LiHCO_(3)solution,pyrolysis temperature and stirring speed on the purity of Li_(2)CO_(3)was investigated to obtain the optimal operating conditions.Results showed that the effect law is similar in the two pyrolysis processes.The purity of the Li_(2)CO_(3)increases firstly and then decreases with the increase of the initial concentration of LiHCO_(3)solution and the stirring speed,while the purity of Li_(2)CO_(3)first decreases and then increases with the increase of pyrolysis temperature.The product yield increases with the increase of initial concentration of LiHCO_(3)solution and pyrolysis temperature and is essentially unaffected by the stirring speed.Under the optimal operating conditions,the purity of Li_(2)CO_(3)can reach up to 99.86%and 99.81%in water bath heating and microwave heating process,respectively.In addition,the pyrolysis rate of microwave assisted pyrolysis is 6 times that of water bath heating process,indicating that the microwave heating technology can significantly improve pyrolysis efficiency and reduce energy consumption.展开更多
文摘This paper analyses the principle of microwave humidity testing. According to the problems in the production procedure of ceramic products, a microwave humidity testing system is designed and analyzed for its advantages. Furthermore, the system has been applied to the production line that produces ceramic products and the testing results are also satisfying.
文摘Microwave-vacuum drying is an accepted drying method for agro-products, which is nonetheless still relatively unknown to some. This paper attempted to give an overview of the most important aspects of microwaves-vacuum drying (MVD) and their relevance to agro-products processing. Some advantages on microwave-vacuum drying properties were discussed to provide a better insight into the reasons for the use of microwaves. Also the effects of the MVD on the quality of several agro-products and reasonable processing parameters were given, which develop the guidance to the application of MVD on the agro-products dehydration. As a potential drying technology, MVD will be broadly utilized for the other agro-products processing
文摘This paper presents a preliminary study on the dielectric properties and curing of three different types of epoxy resins mixed at various stoichiometric mixture of hardener, flydust and aluminium powder under microwave energy. In this work, the curing process of thin layers of epoxy resins using microwave radiation was investigated as an alternative technique that can' be implemented to develop a new rapid product development technique. In this study it was observed that the curing time and temperature were a function of the percentage of hardener and fillers presence in the epoxy resins. Initially dielectric properties of epoxy resins with hardener were measured which was directly correlated to the curing process in order to understand the properties of cured specimen. Tensile tests were conducted on the three different types of epoxy resins with hardener and fillers. Modifying dielectric properties of the mixtures a significant decrease in curing time was observed. In order to study the microstructural changes of cured specimen the morphology of the fracture surface was carried out by using scanning electron microscopy.
基金the National Natural Science Foundation of China(Grant Nos.U2006217,61775015,and 62101027)the Fundamental Research Funds for the Central Universities(Grant Nos.2021JBZ103 and 2021YJS002)。
文摘A switchable down-,up-and dual-chirped microwave waveform generation technique with improved time–bandwidth product(TBWP)is proposed and demonstrated based on a dual-polarization dual-parallel Mach–Zehnder modulator(DPDPMZM)cascaded with a polarization modulator(Pol M).By properly controlling the phase shifts of the radio frequency signals applied to the DP-DPMZM,switchable down-,up-and dual-chirped waveforms with simultaneous frequency and bandwidth doubling can be generated.To enlarge the TBWP further,splitting parabolic signal and phase-encoding splitting parabolic signal are used to drive the Pol M for the enhancement of bandwidth and time duration.Numerical results demonstrate the generation of down-,up-and dual-chirped microwave waveform with TBWP of 8,160 and 10240.The proposed method may find applications in future multifunction radar systems due to the high performance and flexibility.
文摘This study was undertaken to evaluate the efficiency of a liquid-solids separation process and microwave pretreatment, as well as anaerobic biodegradability of microwave pretreated dairy manure. Liquid-solids separation of raw dairy manure resulted in solid and liquid fractions having different properties, with the solid fractions richer in total and volatile solids content and liquid fractions richer in nutrients and metal ions. Substantial amounts of soluble chemical oxygen demand and nutrients were released into the solution after the microwave treatment. The microwave pretreated dairy manure was also subjected to anaerobic digestion. The kinetic parameters of methane production potential, maximum methane production rate and lag time were determined using the modified Gompertz equation. Anaerobic digestion of liquid manure, without microwave treatment, outperformed the sets with microwave treatment. The microwave-treated liquid dairy manure, without acid addition had better results in terms of methane potential and methane production, than with acid addition. Thermophilic digestion exhibited a higher maximum methane production rate than that of mesophilic digestion, but lower methane yields. The microwave pretreatment of dairy manure resulted in high soluble chemical oxygen demand;however, methane yield was not increased.
基金supported by the Gobierno de Espaa for the Provision of a Ramon y Cajal Contract (RYC-2009-04199),Projects P10 FQM-6711(Consejeria de Ciencia e Innovacion,Junta de Andalucia) and CTQ2011 28954-C02-02 (MICINN)
文摘A comparison between conventional pyrolysis and a novel developed low-temperature microwave-assisted pyrolysis methodology has been performed for the valorisation of a range of biomass feedstocks including waste residues. Microwave pyrolysis was found to efficiently deliver comparable evolution of bio-gases in the system as compared with conventional pyrolysis at significantly reduced temperatures (120-180 ℃vs 250-400 ℃). The gas obtained from microwave-assisted pyrolysis was found to contain CO2, CH4 and CO as major components as well
基金supported by the National Natural Science Foundation of China(Nos.U1607114,21878009,21725601)。
文摘Investigations were conducted to purify crude Li_(2)CO_(3)via direct carbonation with CO_(2)at atmospheric pressure and pyrolysis with both water bath heating method and microwave heating method.The reaction kinetics of LiHCO_(3)pyrolysis was studied and the effect of different operating conditions including initial concentration of LiHCO_(3)solution,pyrolysis temperature and stirring speed on the purity of Li_(2)CO_(3)was investigated to obtain the optimal operating conditions.Results showed that the effect law is similar in the two pyrolysis processes.The purity of the Li_(2)CO_(3)increases firstly and then decreases with the increase of the initial concentration of LiHCO_(3)solution and the stirring speed,while the purity of Li_(2)CO_(3)first decreases and then increases with the increase of pyrolysis temperature.The product yield increases with the increase of initial concentration of LiHCO_(3)solution and pyrolysis temperature and is essentially unaffected by the stirring speed.Under the optimal operating conditions,the purity of Li_(2)CO_(3)can reach up to 99.86%and 99.81%in water bath heating and microwave heating process,respectively.In addition,the pyrolysis rate of microwave assisted pyrolysis is 6 times that of water bath heating process,indicating that the microwave heating technology can significantly improve pyrolysis efficiency and reduce energy consumption.