To solve the kinetic and diffusion problem of surface-type infrared decoy, multi-chaff kinetic models are established and chaff cloud holistic kinetic performance are analyzed under the impact of high speed airflow in...To solve the kinetic and diffusion problem of surface-type infrared decoy, multi-chaff kinetic models are established and chaff cloud holistic kinetic performance are analyzed under the impact of high speed airflow in this work. Chaffs rotate rapidly during the motion under the impact of high speed airflow. The rotation speed is correlated with lift, position of pressure center and aerodynamic damping. Computational Fluid Dynamics(CFD) is used to compute the aerodynamic coefficients of chaff. It is found that there exists serious aerodynamic interference which mainly relates to the overlapping area and distance among chaffs during the diffusion of chaff cloud. The chaff wind tunnel test and rocket sled experiment are carried out to verify the credibility of the models in this work. Then, the variation of chaff cloud expectation and extremum are analyzed to achieve the holistic kinetic and diffusing performance of chaff cloud. Simulation results demonstrate that the chaffs diffuse rapidly under the impact of high speed airflow and chaff cloud can be formed rapidly within 0.5 s. The shape of the chaff cloud is similar to cone that forms a certain angle with the horizontal plane and most chaffs focus on the second half.展开更多
Aimed at the difficulty in finding an efficient method to depress and recognize chaff in both time and frequency domain,this paper tries to recognize chaff and target such as warship in polarization domain under the t...Aimed at the difficulty in finding an efficient method to depress and recognize chaff in both time and frequency domain,this paper tries to recognize chaff and target such as warship in polarization domain under the theoretical analysis of the polarization scattering cross section of chaff.In order to find target more exactly,non-linear polarization transformation and polarization smoothness are applied to process the polarization information of chaff and ship target.The resulting recognition is proved to be effective by simulation.展开更多
To calculate the diffusion law of chaff cloud launched by aircraft,taking rectangular chaff as an example,the diffusion model of chaff cloud is established in this paper.Firstly,the coordinate systems of chaff are def...To calculate the diffusion law of chaff cloud launched by aircraft,taking rectangular chaff as an example,the diffusion model of chaff cloud is established in this paper.Firstly,the coordinate systems of chaff are defined and the motion model of chaff is established.The motion model mainly includes chaff motion equation and rotation equation,which are obtained by combining the aerodynamic moment and aerodynamic damping.Then,the influence of multi-chaff aerodynamic interference on the movement of chaff is analyzed.Finally,considering the influence of overlap area between chaffs and chaff spacing on the aerodynamic coefficients,the multi-chaff motion model is obtained,and the simulation results are compared with the test results to verify the credibility of the model.展开更多
Tetracycline(TC)and tetracycline resistance genes(TRGs)in plant edible tissues pose a potential risk to the environment and then to human health.This study used a pot experiment to investigate the effects of different...Tetracycline(TC)and tetracycline resistance genes(TRGs)in plant edible tissues pose a potential risk to the environment and then to human health.This study used a pot experiment to investigate the effects of different remediation substances(worm castings,fungal chaff,microbial inoculum,and biochar)on the physiological characteristics of maize and the residues of TC and TRGs in the soil-maize system under TC stress.The results showed that TC significantly inhibited growth,disrupted the antioxidant defense system balance,and increased proline and malondialdehyde contents of maize plants.Tetracycline residue contents were significantly higher in root than in shoot,and followed the order root>stem-leaf>grain,which was consistent with the distribution of bioconcentration factors in the different organs of maize plants.The TC residue content in the soil under different treatments was 0.013–1.341 mg kg-1.The relative abundances of different antibiotic resistance genes in the soil-maize system varied greatly,and in maize plants followed the order intI1>tetW>tetG>tet B>tetM>tetX>tetO.In the soil,tetX had the highest relative abundance,followed by tetG and tetW.A redundancy analysis(RDA)showed that TC was positively correlated with TRGs.The addition of different remediation substances alleviated the toxicity of TC on maize physiological characteristics and reduced the TC and TRG residues in the soil-maize system,with biochar being the best remediation substance.These results provide new insights into the effect of biochar on the migration of TC and TRGs from soil to plants.展开更多
The adsorption ofEscherichia coli and Staphylococcus aureus on chaff and WMDP （waste of molasses dates production） has been studied. FTIR spectra were employed to investigate the adsorption ofEscherichia coli and St...The adsorption ofEscherichia coli and Staphylococcus aureus on chaff and WMDP （waste of molasses dates production） has been studied. FTIR spectra were employed to investigate the adsorption ofEscherichia coli and Staphylococcus aureus on surfaces. Adsorption of bacteria resulted in obvious shifts of some infrared bands of adsorbents. The adsorption isotherms ofEscherichia coli on two surfaces and Staphylococcus aureus on WMDP, are of L-curve type according to Giles classification. However, type H isotherm was observed in the adsorption of S. aureus on chaff. The adsorption isotherms of bacteria on the examined adsorbents conformed to the Langmuir and Temkin equations. The adsorption of bacteria was studied at different temperatures （10, 25 and 40 ℃）, the thermodynamic parameters （AH, AS and AG） have also been calculated and it has been found that the adsorption process of bacteria was exothermic in nature. The number of bacteria adsorbed on surfaces was decreased with the increase of sodium chloride concentration. The amount of bacteria cells adsorbed was increased in the presence of different cations and followed the sequence： FeCl3 〉 CaCl2 〉 KCl 〉 NaCl. The pseudo-first order and pseudo-second order models for describing the kinetic data were applied and it was found that the process was well described by pseudo-second order model. The desorption studies indicated that the bacteria were strongly retained by two adsorbents.展开更多
The generic temperature controller can keep the temperature in one zone, but in our practical industry control we need keep the temperature at several different zones, and at each temperature zone we need keep differe...The generic temperature controller can keep the temperature in one zone, but in our practical industry control we need keep the temperature at several different zones, and at each temperature zone we need keep different length of time. So we designed this system. The multi-step temperature controller is based on AT89C51, and programmed with assemble language (MCS-51 repertoire).展开更多
A mesophilic-dry anaerobic digestion process is valid in treating high-concentration substrates containing low moisture content. It has merits of lower wastewater discharge and lower heat capacity required in maintain...A mesophilic-dry anaerobic digestion process is valid in treating high-concentration substrates containing low moisture content. It has merits of lower wastewater discharge and lower heat capacity required in maintaining reactor temperature as compared with a thermophilic-wet anaerobic digestion process. In fact, chaff can be easily obtained in farming areas and used as a mixture substrate as one of bulking agents for controlling moisture and supplying carbon. For this reason, this study applies the chaff to improve livestock manure, which contains high moisture content and is discharged from domestic pig farms. This study aims at verifying its feasibility for improving methane production efficiency on a basis of BMP (Biochemical Methane Potential) assay obtained through a series of experiments. Finding results were methane gas production and gas production per volatile solid (VS) added, and methane gas production among biogas production were increased as the chaff added in the piggery manure was increased. According to experimental results for improving the methane production efficiency, mixture of the chaff and the piggery manure played an important role in controlling the moisture content and improving the methane gas production rate, and also verified its feasibility in the mesophilic-dry anaerobic digestion process indicating relatively less difficulty for operation and management.展开更多
A modified chaff jamming recognition method of radar is investigated using grey relational analysis（ GRA） based on the difference in echo correlation characteristics between a complex rigid target and chaff cloud in...A modified chaff jamming recognition method of radar is investigated using grey relational analysis（ GRA） based on the difference in echo correlation characteristics between a complex rigid target and chaff cloud in time domain. Slice method（ SM）,a novel modeling approach,is proposed to construct an electromagnetic scattering model of chaff cloud in a scenario with slowly moving platform that is targeted. The diffusion characteristics and echo characteristics of the chaff cloud are analyzed. The GRA of a real target and chaff cloud shows that the adjacent return waves have a good correlation for the target but a weak correlation for chaff cloud. Since the correlation degree of chaff cloud＇s echo is far lower than that of a complex rigid target＇s,the chaff jamming can be identified by setting a reasonable threshold. Simulation results are presented to verify the effectiveness of this method.展开更多
在美国2000年总统大选(Election2000)中,佛罗里达州的选票点了又点(count.recount and more recount),出了不少新鲜事,也出了不少时髦词,其中之一就是原先不起眼的 chad(孔屑)。chad 这个词在电脑的词库里是没有的,用电脑写这篇小文章...在美国2000年总统大选(Election2000)中,佛罗里达州的选票点了又点(count.recount and more recount),出了不少新鲜事,也出了不少时髦词,其中之一就是原先不起眼的 chad(孔屑)。chad 这个词在电脑的词库里是没有的,用电脑写这篇小文章的时候,chad 的下面是一道红线。什么是 chad(孔屑)呢?根据 TheAmerican Heritage Dictionary of the EnglishLanguage 的定义,chad 是 small pieces or pa-展开更多
Devotion Group Made Breakthroughs in Bio-oil Technology Devotion Group,Guangzhou’s first oversealisted company,announced its success in theresearch of bio-oil preparation technology,providing a new green energy that ...Devotion Group Made Breakthroughs in Bio-oil Technology Devotion Group,Guangzhou’s first oversealisted company,announced its success in theresearch of bio-oil preparation technology,providing a new green energy that can serveas a kind of substitute for the traditional fuelused in industry sectors.Bio-oil is a new kind of energy,convertedfrom agricultural wastes,like wheat chaff,corncob or leaves and branches,within 2 secondsthrough moderate cracking temperature.Bio-oil is distinguished from bio-diesel with zeroemission in its manufacturing process andutilization."It’s a typical recycling economic technol-展开更多
In the battlefield against electromagnetic counter-measures,it has become a research hotspot to counter chaff jamming and improve the detection performance of radar with the help of new dimensions of electromagnetic w...In the battlefield against electromagnetic counter-measures,it has become a research hotspot to counter chaff jamming and improve the detection performance of radar with the help of new dimensions of electromagnetic waves.Intrinsic Orbital Angular Momentum(OAM),as a new dimension in the electromagnetic waves,has been employed in the target imaging and anti-stealth detection.However,the metal chaff has similar echo characteristics under the irradiation of vortex microwave photons and plane waves,and it is difficult to filter out chaff jamming signals only by the electric field strength.For this reason,this paper proposes a vortex microwave photon anti-chaff-jamming detection method based on mode-difference,which effectively detects the target by filtering out the chaff jamming signals through the different characteristics of the target and the metal chaff echo signals in different OAM modes.To verify the effectiveness and correctness of the method,this paper compares the performance of different detection schemes and optimizes the power allocation on different intrinsic OAM modes.The simulation results show that compared with the traditional plane wave and single-mode vortex microwave photon radar,the detection rate of the proposed anti-chaff-jamming scheme has been greatly improved.展开更多
基金supported by the National Natural Science Foundation of China (No. 61471390)
文摘To solve the kinetic and diffusion problem of surface-type infrared decoy, multi-chaff kinetic models are established and chaff cloud holistic kinetic performance are analyzed under the impact of high speed airflow in this work. Chaffs rotate rapidly during the motion under the impact of high speed airflow. The rotation speed is correlated with lift, position of pressure center and aerodynamic damping. Computational Fluid Dynamics(CFD) is used to compute the aerodynamic coefficients of chaff. It is found that there exists serious aerodynamic interference which mainly relates to the overlapping area and distance among chaffs during the diffusion of chaff cloud. The chaff wind tunnel test and rocket sled experiment are carried out to verify the credibility of the models in this work. Then, the variation of chaff cloud expectation and extremum are analyzed to achieve the holistic kinetic and diffusing performance of chaff cloud. Simulation results demonstrate that the chaffs diffuse rapidly under the impact of high speed airflow and chaff cloud can be formed rapidly within 0.5 s. The shape of the chaff cloud is similar to cone that forms a certain angle with the horizontal plane and most chaffs focus on the second half.
文摘Aimed at the difficulty in finding an efficient method to depress and recognize chaff in both time and frequency domain,this paper tries to recognize chaff and target such as warship in polarization domain under the theoretical analysis of the polarization scattering cross section of chaff.In order to find target more exactly,non-linear polarization transformation and polarization smoothness are applied to process the polarization information of chaff and ship target.The resulting recognition is proved to be effective by simulation.
基金This work is supported by the National Natural Science Foundation of China(grant number 61471390).
文摘To calculate the diffusion law of chaff cloud launched by aircraft,taking rectangular chaff as an example,the diffusion model of chaff cloud is established in this paper.Firstly,the coordinate systems of chaff are defined and the motion model of chaff is established.The motion model mainly includes chaff motion equation and rotation equation,which are obtained by combining the aerodynamic moment and aerodynamic damping.Then,the influence of multi-chaff aerodynamic interference on the movement of chaff is analyzed.Finally,considering the influence of overlap area between chaffs and chaff spacing on the aerodynamic coefficients,the multi-chaff motion model is obtained,and the simulation results are compared with the test results to verify the credibility of the model.
基金the financial support of the Key R&D Program in Shanxi Province,China(Nos.201903D 221015 and 201803D221002-2)the Project 1331 in Shanxi Province,China(No.20211331-15)the Open Fund Project of Shanxi Key Laboratory of Soil,Environment and Nutrient Resources,China(No.2019004)。
文摘Tetracycline(TC)and tetracycline resistance genes(TRGs)in plant edible tissues pose a potential risk to the environment and then to human health.This study used a pot experiment to investigate the effects of different remediation substances(worm castings,fungal chaff,microbial inoculum,and biochar)on the physiological characteristics of maize and the residues of TC and TRGs in the soil-maize system under TC stress.The results showed that TC significantly inhibited growth,disrupted the antioxidant defense system balance,and increased proline and malondialdehyde contents of maize plants.Tetracycline residue contents were significantly higher in root than in shoot,and followed the order root>stem-leaf>grain,which was consistent with the distribution of bioconcentration factors in the different organs of maize plants.The TC residue content in the soil under different treatments was 0.013–1.341 mg kg-1.The relative abundances of different antibiotic resistance genes in the soil-maize system varied greatly,and in maize plants followed the order intI1>tetW>tetG>tet B>tetM>tetX>tetO.In the soil,tetX had the highest relative abundance,followed by tetG and tetW.A redundancy analysis(RDA)showed that TC was positively correlated with TRGs.The addition of different remediation substances alleviated the toxicity of TC on maize physiological characteristics and reduced the TC and TRG residues in the soil-maize system,with biochar being the best remediation substance.These results provide new insights into the effect of biochar on the migration of TC and TRGs from soil to plants.
文摘The adsorption ofEscherichia coli and Staphylococcus aureus on chaff and WMDP （waste of molasses dates production） has been studied. FTIR spectra were employed to investigate the adsorption ofEscherichia coli and Staphylococcus aureus on surfaces. Adsorption of bacteria resulted in obvious shifts of some infrared bands of adsorbents. The adsorption isotherms ofEscherichia coli on two surfaces and Staphylococcus aureus on WMDP, are of L-curve type according to Giles classification. However, type H isotherm was observed in the adsorption of S. aureus on chaff. The adsorption isotherms of bacteria on the examined adsorbents conformed to the Langmuir and Temkin equations. The adsorption of bacteria was studied at different temperatures （10, 25 and 40 ℃）, the thermodynamic parameters （AH, AS and AG） have also been calculated and it has been found that the adsorption process of bacteria was exothermic in nature. The number of bacteria adsorbed on surfaces was decreased with the increase of sodium chloride concentration. The amount of bacteria cells adsorbed was increased in the presence of different cations and followed the sequence： FeCl3 〉 CaCl2 〉 KCl 〉 NaCl. The pseudo-first order and pseudo-second order models for describing the kinetic data were applied and it was found that the process was well described by pseudo-second order model. The desorption studies indicated that the bacteria were strongly retained by two adsorbents.
文摘The generic temperature controller can keep the temperature in one zone, but in our practical industry control we need keep the temperature at several different zones, and at each temperature zone we need keep different length of time. So we designed this system. The multi-step temperature controller is based on AT89C51, and programmed with assemble language (MCS-51 repertoire).
文摘A mesophilic-dry anaerobic digestion process is valid in treating high-concentration substrates containing low moisture content. It has merits of lower wastewater discharge and lower heat capacity required in maintaining reactor temperature as compared with a thermophilic-wet anaerobic digestion process. In fact, chaff can be easily obtained in farming areas and used as a mixture substrate as one of bulking agents for controlling moisture and supplying carbon. For this reason, this study applies the chaff to improve livestock manure, which contains high moisture content and is discharged from domestic pig farms. This study aims at verifying its feasibility for improving methane production efficiency on a basis of BMP (Biochemical Methane Potential) assay obtained through a series of experiments. Finding results were methane gas production and gas production per volatile solid (VS) added, and methane gas production among biogas production were increased as the chaff added in the piggery manure was increased. According to experimental results for improving the methane production efficiency, mixture of the chaff and the piggery manure played an important role in controlling the moisture content and improving the methane gas production rate, and also verified its feasibility in the mesophilic-dry anaerobic digestion process indicating relatively less difficulty for operation and management.
基金Supported by the National Natural Science Foundation of China(61571043)111 Project of China(B14010)
文摘A modified chaff jamming recognition method of radar is investigated using grey relational analysis（ GRA） based on the difference in echo correlation characteristics between a complex rigid target and chaff cloud in time domain. Slice method（ SM）,a novel modeling approach,is proposed to construct an electromagnetic scattering model of chaff cloud in a scenario with slowly moving platform that is targeted. The diffusion characteristics and echo characteristics of the chaff cloud are analyzed. The GRA of a real target and chaff cloud shows that the adjacent return waves have a good correlation for the target but a weak correlation for chaff cloud. Since the correlation degree of chaff cloud＇s echo is far lower than that of a complex rigid target＇s,the chaff jamming can be identified by setting a reasonable threshold. Simulation results are presented to verify the effectiveness of this method.
文摘在美国2000年总统大选(Election2000)中,佛罗里达州的选票点了又点(count.recount and more recount),出了不少新鲜事,也出了不少时髦词,其中之一就是原先不起眼的 chad(孔屑)。chad 这个词在电脑的词库里是没有的,用电脑写这篇小文章的时候,chad 的下面是一道红线。什么是 chad(孔屑)呢?根据 TheAmerican Heritage Dictionary of the EnglishLanguage 的定义,chad 是 small pieces or pa-
文摘Devotion Group Made Breakthroughs in Bio-oil Technology Devotion Group,Guangzhou’s first oversealisted company,announced its success in theresearch of bio-oil preparation technology,providing a new green energy that can serveas a kind of substitute for the traditional fuelused in industry sectors.Bio-oil is a new kind of energy,convertedfrom agricultural wastes,like wheat chaff,corncob or leaves and branches,within 2 secondsthrough moderate cracking temperature.Bio-oil is distinguished from bio-diesel with zeroemission in its manufacturing process andutilization."It’s a typical recycling economic technol-
文摘In the battlefield against electromagnetic counter-measures,it has become a research hotspot to counter chaff jamming and improve the detection performance of radar with the help of new dimensions of electromagnetic waves.Intrinsic Orbital Angular Momentum(OAM),as a new dimension in the electromagnetic waves,has been employed in the target imaging and anti-stealth detection.However,the metal chaff has similar echo characteristics under the irradiation of vortex microwave photons and plane waves,and it is difficult to filter out chaff jamming signals only by the electric field strength.For this reason,this paper proposes a vortex microwave photon anti-chaff-jamming detection method based on mode-difference,which effectively detects the target by filtering out the chaff jamming signals through the different characteristics of the target and the metal chaff echo signals in different OAM modes.To verify the effectiveness and correctness of the method,this paper compares the performance of different detection schemes and optimizes the power allocation on different intrinsic OAM modes.The simulation results show that compared with the traditional plane wave and single-mode vortex microwave photon radar,the detection rate of the proposed anti-chaff-jamming scheme has been greatly improved.
