A Smith-Purcell （SP） free electron laser （FEL） ,composed of a metallic diffraction flat grating,an open cylindrical mirror cavity and a relativistic sheet electron beam with moderate energy, is presented. The char...A Smith-Purcell （SP） free electron laser （FEL） ,composed of a metallic diffraction flat grating,an open cylindrical mirror cavity and a relativistic sheet electron beam with moderate energy, is presented. The characteristics of this device are studied by theoretical analysis,experimental measurements and particle-in-cell （PIO） simulation method. Results indicate that the coherent radiation with an output peak power up to 50 MW at millimeter wavelengths can be generated by using relativistic electron beam of moderate energy.展开更多
Aiming at localizing the telemetric capsule for detecting gastrointestinal physiological parameters in vivo accurately,a portable alternating current(AC)electromagnetic localization system is designed.To verify the fe...Aiming at localizing the telemetric capsule for detecting gastrointestinal physiological parameters in vivo accurately,a portable alternating current(AC)electromagnetic localization system is designed.To verify the feasibility of the method,the model and construction of the localization system are detailed.And static and dynamic accuracy of the localization system are tested by experiments.Next,we compare the simulating results of the electromagnetic radiation aroused by the localization system with the electromagnetic safety standards of human(ICNIRP guidelines and IEEE standard C95.1-1991).Finally,in terms of the results of the static and dynamic experiments,conclusions are drawn that the accuracy of portable positioning system is high(less than 10 mm)enough to satisfy the localization need of the micro invasive medical devices in vivo,and there is no harm of electromagnetic radiation to human.展开更多
The paper deals with some questions of important aspects of food safety and application of principles of food physics in the food sector. Food production and processing of quality food and safe food are today of prima...The paper deals with some questions of important aspects of food safety and application of principles of food physics in the food sector. Food production and processing of quality food and safe food are today of primary importance. Food production is based on the principles of Good Agricultural Practice （GAP）, Good Manufactoring Practice （GMP） and Good Hygiene Practice （GHP）. Recently, the industrial food processing is focused dominantly on the quality, and one of the basic requirements of the quality is the safety. There are different methods and techniques to produce safe food. The up-to-date food technologies and quality measurements （quality control and quality assurance） involve the application of different physical methods, e.g., high pressure, pulsing electrical field, nondestructive techniques, e.g., nuclear magnetic resonance （NMR）, near infrared reflectance, near infrared transmittance （NIR-NIT）, photo acoustic spectroscopy （PAS） and instrumental neutron activation analysis （INAA） for chemical composition determination, radiation techniques, nanofiltration and reverse osmosis （RO） as well. Using ionizing radiation （nuclear methods） and non-ionizing radiation technologies, it is possible to fulfill a lot of expectations： decrease of microbial contamination, improve of sensory properties, increase of storability, etc..展开更多
The characteristics of low frequency electrical noise, voltage current ( V I ) and electrical derivation for 980 nm InGaAsP/InGaAs/GaAs high power double quantum well lasers(DQWLs) are measured under different conditi...The characteristics of low frequency electrical noise, voltage current ( V I ) and electrical derivation for 980 nm InGaAsP/InGaAs/GaAs high power double quantum well lasers(DQWLs) are measured under different conditions. The correlation of the low frequency electrical noise with surface non radiative current of devices is discussed. The results indicate the low frequency electrical noise of 980 nm DQWLs with high power is mainly 1/ f noise and has good relation with the device surface current at low injection.展开更多
In the last years, the production of optical fibers cables has made possible the development of a range of spectroscopic probes for in situ analysis performing beyond nondestructive tests, environmental monitoring, se...In the last years, the production of optical fibers cables has made possible the development of a range of spectroscopic probes for in situ analysis performing beyond nondestructive tests, environmental monitoring, security investigation, application in radiotherapy for dose monitoring, verification and validation. In this work, a system using an optical fiber cable to electromagnetic signal transmission from a NaI（TI） radiation detector is presented. The innovative device takes advantage mainly of the optical fibers large passband, small signal attenuation and immunity to electromagnetic interference to application for radiation detection systems. The main aim was to simplify the detection system making it to reach areas where the conventional device cannot access due to its lack of mobility and external dimensions. Some tests with this innovative system are presented and the results stimulate the continuity of the researches.展开更多
Sulfonate groups were introduced to the surfaces of multiwalled carbon nanotubes by the radiation-induced graft polymerization of sodium 4-styrene sulfonate for the use as biosensor supports. Alcohol dehydrogenase was...Sulfonate groups were introduced to the surfaces of multiwalled carbon nanotubes by the radiation-induced graft polymerization of sodium 4-styrene sulfonate for the use as biosensor supports. Alcohol dehydrogenase was immobilized onto a sulfonated nanotube-supporting electrode with tris（2,2＇-bipyridyl） ruthenium（II） complex to form an electrogenerated chemilluminesce sensor of alcohol. When it was used to detect alcohol in cyclic voltammetric measurements, the sensor showed the linearity over the range of 1.0 × 10^-4 M-5.0 ×10^-2 M, with a correlation coefficient of 0.992 and a detection limit of 1.9 ×10^-6 M. In electrogenerated chemilluminesce detection, it showed linearity over 5.0 × 10^-4 M-1.0 × 10^-2 M, with a correlation coefficient of 0.986 and a detection limit of 1.0 × 10^-6 M. The sensor was demonstrated to be able to detect ethanol in commercial drinks.展开更多
The bonding process of space solar cells is a very complicated task undertaken by manual labor before.An automatic approach based on robot technology is presented to deal with the difficult problem.The architecture of...The bonding process of space solar cells is a very complicated task undertaken by manual labor before.An automatic approach based on robot technology is presented to deal with the difficult problem.The architecture of the bonding robot for space solar cells is described.The two processes carried out by the robot,adhesive dispensing and cover-glass bonding,are studied.Based on the mechanical model,the flow velocity field of the adhesive in needles is obtained and the cover-glass bonding theory is interpreted.According to the studies,the thickness of the adhesive can be controlled accurately by robot and bubbles can be avoided coming about inside the adhesive.展开更多
Measures of ionizing radiation were observed in a tower which is 20 meters above the ground relative height. They show a distinct period of 24 hours oscillation during this Februaryl 1 to April 11, 2015. It is suggest...Measures of ionizing radiation were observed in a tower which is 20 meters above the ground relative height. They show a distinct period of 24 hours oscillation during this Februaryl 1 to April 11, 2015. It is suggested that these oscillations originate from radon gas （222Rn） vented from the ground floor. One Russian specific Geiger tube with associated electronics developed at ITA was used, Monitoring of ionizing radiation from 30 keV to l0 MeV shows that the X and gamma rays up to 3.0 MeV is prevalent in the region comes from the Radon gas 222Rn that decay in 214Bi and 214pb in the energies of the gamma rays 0.269, 0.609 and 1.05 MeV respectively. Then, with this simple, portable instrument was possible to monitoring the dynamics of radon gas in the region every interval minutes.展开更多
Dynamitron DC1500/25/04 type EBA （Electron beam accelerator）, model JOB 188, was manufactured by IBA Industrial （Radiation Dynamics, Inc.） and installed at IPEN-CNEN/SP, in 1978. The technical specifications of th...Dynamitron DC1500/25/04 type EBA （Electron beam accelerator）, model JOB 188, was manufactured by IBA Industrial （Radiation Dynamics, Inc.） and installed at IPEN-CNEN/SP, in 1978. The technical specifications of the EBA are： energy 0.5 to 1.5 MeV; beam current： 0.3 to 25.0 mA; beam scanning： 60 to 120 cm; beam width： 25.4 mm and frequency： 100 Hz. Nowadays, this accelerator has been used for innumerable applications, such as： For sterilization of medical, pharmaceutical and biological products, treatment of industrial and domestic effluents and sludge, preservation and disinfestations of foods and agricultural products. Other important application are lignocellulosic material irradiation as a pre-treatment to produce ethanol bio-fuel, decontamination of pesticide packing, solid residues remediation, organic compounds removal from wastewater, treatment of effluent from petroleum production units, crosslinking of foams, wires and electric cables. Electron accelerator JOB 188 is, also, very important composite and nanocomposite materials and carbon fibers irradiation, irradiated grafting ion-exchange membranes for fuel cells application, natural polymers and multilayer packages irradiation and biodegradable blends production. The energy of the electron beam is calculated as a function of the current in the accelerator high-voltage divisor, taking into account the thickness and density of the material to be irradiated. This energy is calculated considering the electron through the entire material and the distance from the titanium foil window, so that the absorbed doses at the points of entrance and exit are equivalent on the material. The dose is directly proportional to the beam current and the exposure time of the material under the electron beam and inversely proportional to the scan width. The aim of this paper is to analyze the power system parameters of the EBA Dynamitron DC 1500/25/04, such as, voltage and RMS （Root-mean-square） current in the oscillator system, high voltage generator and waveform. For this purpose software developed in the Radiation Technology Center at IPEN/CNEN-SP to simulate the energy efficiency of this industrial accelerator. Finally, it is also targeted to compare theoretical dosimetry using parameters of energy and beam current with data from the accelerator power system. This knowledge and technology will be very useful and essential for the control system upgrade of EBA, mainly Dynamitron DC 1500/25/04 taking into consideration that radiation processing technology for industrial and environmental applications has been developed and used worldwide.展开更多
文摘A Smith-Purcell （SP） free electron laser （FEL） ,composed of a metallic diffraction flat grating,an open cylindrical mirror cavity and a relativistic sheet electron beam with moderate energy, is presented. The characteristics of this device are studied by theoretical analysis,experimental measurements and particle-in-cell （PIO） simulation method. Results indicate that the coherent radiation with an output peak power up to 50 MW at millimeter wavelengths can be generated by using relativistic electron beam of moderate energy.
基金National Natural Science Foundation of China(NSFC)(No.30570485)National High Technology Research and Development Program of China(863)(No.2006AA04Z368)Natural Science Foundation of Shanghai,China(No.06ER1406)
文摘Aiming at localizing the telemetric capsule for detecting gastrointestinal physiological parameters in vivo accurately,a portable alternating current(AC)electromagnetic localization system is designed.To verify the feasibility of the method,the model and construction of the localization system are detailed.And static and dynamic accuracy of the localization system are tested by experiments.Next,we compare the simulating results of the electromagnetic radiation aroused by the localization system with the electromagnetic safety standards of human(ICNIRP guidelines and IEEE standard C95.1-1991).Finally,in terms of the results of the static and dynamic experiments,conclusions are drawn that the accuracy of portable positioning system is high(less than 10 mm)enough to satisfy the localization need of the micro invasive medical devices in vivo,and there is no harm of electromagnetic radiation to human.
文摘The paper deals with some questions of important aspects of food safety and application of principles of food physics in the food sector. Food production and processing of quality food and safe food are today of primary importance. Food production is based on the principles of Good Agricultural Practice （GAP）, Good Manufactoring Practice （GMP） and Good Hygiene Practice （GHP）. Recently, the industrial food processing is focused dominantly on the quality, and one of the basic requirements of the quality is the safety. There are different methods and techniques to produce safe food. The up-to-date food technologies and quality measurements （quality control and quality assurance） involve the application of different physical methods, e.g., high pressure, pulsing electrical field, nondestructive techniques, e.g., nuclear magnetic resonance （NMR）, near infrared reflectance, near infrared transmittance （NIR-NIT）, photo acoustic spectroscopy （PAS） and instrumental neutron activation analysis （INAA） for chemical composition determination, radiation techniques, nanofiltration and reverse osmosis （RO） as well. Using ionizing radiation （nuclear methods） and non-ionizing radiation technologies, it is possible to fulfill a lot of expectations： decrease of microbial contamination, improve of sensory properties, increase of storability, etc..
文摘The characteristics of low frequency electrical noise, voltage current ( V I ) and electrical derivation for 980 nm InGaAsP/InGaAs/GaAs high power double quantum well lasers(DQWLs) are measured under different conditions. The correlation of the low frequency electrical noise with surface non radiative current of devices is discussed. The results indicate the low frequency electrical noise of 980 nm DQWLs with high power is mainly 1/ f noise and has good relation with the device surface current at low injection.
文摘In the last years, the production of optical fibers cables has made possible the development of a range of spectroscopic probes for in situ analysis performing beyond nondestructive tests, environmental monitoring, security investigation, application in radiotherapy for dose monitoring, verification and validation. In this work, a system using an optical fiber cable to electromagnetic signal transmission from a NaI（TI） radiation detector is presented. The innovative device takes advantage mainly of the optical fibers large passband, small signal attenuation and immunity to electromagnetic interference to application for radiation detection systems. The main aim was to simplify the detection system making it to reach areas where the conventional device cannot access due to its lack of mobility and external dimensions. Some tests with this innovative system are presented and the results stimulate the continuity of the researches.
文摘Sulfonate groups were introduced to the surfaces of multiwalled carbon nanotubes by the radiation-induced graft polymerization of sodium 4-styrene sulfonate for the use as biosensor supports. Alcohol dehydrogenase was immobilized onto a sulfonated nanotube-supporting electrode with tris（2,2＇-bipyridyl） ruthenium（II） complex to form an electrogenerated chemilluminesce sensor of alcohol. When it was used to detect alcohol in cyclic voltammetric measurements, the sensor showed the linearity over the range of 1.0 × 10^-4 M-5.0 ×10^-2 M, with a correlation coefficient of 0.992 and a detection limit of 1.9 ×10^-6 M. In electrogenerated chemilluminesce detection, it showed linearity over 5.0 × 10^-4 M-1.0 × 10^-2 M, with a correlation coefficient of 0.986 and a detection limit of 1.0 × 10^-6 M. The sensor was demonstrated to be able to detect ethanol in commercial drinks.
文摘The bonding process of space solar cells is a very complicated task undertaken by manual labor before.An automatic approach based on robot technology is presented to deal with the difficult problem.The architecture of the bonding robot for space solar cells is described.The two processes carried out by the robot,adhesive dispensing and cover-glass bonding,are studied.Based on the mechanical model,the flow velocity field of the adhesive in needles is obtained and the cover-glass bonding theory is interpreted.According to the studies,the thickness of the adhesive can be controlled accurately by robot and bubbles can be avoided coming about inside the adhesive.
文摘Measures of ionizing radiation were observed in a tower which is 20 meters above the ground relative height. They show a distinct period of 24 hours oscillation during this Februaryl 1 to April 11, 2015. It is suggested that these oscillations originate from radon gas （222Rn） vented from the ground floor. One Russian specific Geiger tube with associated electronics developed at ITA was used, Monitoring of ionizing radiation from 30 keV to l0 MeV shows that the X and gamma rays up to 3.0 MeV is prevalent in the region comes from the Radon gas 222Rn that decay in 214Bi and 214pb in the energies of the gamma rays 0.269, 0.609 and 1.05 MeV respectively. Then, with this simple, portable instrument was possible to monitoring the dynamics of radon gas in the region every interval minutes.
文摘Dynamitron DC1500/25/04 type EBA （Electron beam accelerator）, model JOB 188, was manufactured by IBA Industrial （Radiation Dynamics, Inc.） and installed at IPEN-CNEN/SP, in 1978. The technical specifications of the EBA are： energy 0.5 to 1.5 MeV; beam current： 0.3 to 25.0 mA; beam scanning： 60 to 120 cm; beam width： 25.4 mm and frequency： 100 Hz. Nowadays, this accelerator has been used for innumerable applications, such as： For sterilization of medical, pharmaceutical and biological products, treatment of industrial and domestic effluents and sludge, preservation and disinfestations of foods and agricultural products. Other important application are lignocellulosic material irradiation as a pre-treatment to produce ethanol bio-fuel, decontamination of pesticide packing, solid residues remediation, organic compounds removal from wastewater, treatment of effluent from petroleum production units, crosslinking of foams, wires and electric cables. Electron accelerator JOB 188 is, also, very important composite and nanocomposite materials and carbon fibers irradiation, irradiated grafting ion-exchange membranes for fuel cells application, natural polymers and multilayer packages irradiation and biodegradable blends production. The energy of the electron beam is calculated as a function of the current in the accelerator high-voltage divisor, taking into account the thickness and density of the material to be irradiated. This energy is calculated considering the electron through the entire material and the distance from the titanium foil window, so that the absorbed doses at the points of entrance and exit are equivalent on the material. The dose is directly proportional to the beam current and the exposure time of the material under the electron beam and inversely proportional to the scan width. The aim of this paper is to analyze the power system parameters of the EBA Dynamitron DC 1500/25/04, such as, voltage and RMS （Root-mean-square） current in the oscillator system, high voltage generator and waveform. For this purpose software developed in the Radiation Technology Center at IPEN/CNEN-SP to simulate the energy efficiency of this industrial accelerator. Finally, it is also targeted to compare theoretical dosimetry using parameters of energy and beam current with data from the accelerator power system. This knowledge and technology will be very useful and essential for the control system upgrade of EBA, mainly Dynamitron DC 1500/25/04 taking into consideration that radiation processing technology for industrial and environmental applications has been developed and used worldwide.
