Background:In order to clarify the inmpat ofγirradiation on the chemical composition of traditional Chinese medicine,this paper carefully choosed Chuanxiong Rhizoma to carry on a demonstration study.Methods:Through a...Background:In order to clarify the inmpat ofγirradiation on the chemical composition of traditional Chinese medicine,this paper carefully choosed Chuanxiong Rhizoma to carry on a demonstration study.Methods:Through a meticulous assessment,a comprehensive comparison was made between the irradiated and unirradiated Chuanxiong Rhizoma samples.The property characteristics were investigated by colorimeter and electronic nose.The changes in chemical structures and contents was analyzed by fourier infrared spectroscopy,high performance liquid chromatography and fingerprinting.In a quest to uncover the presence of any new radiolysis products,cutting-edge techniques like ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry and gas chromatography-mass spectrometry were employed.Moreover,the difference of antioxidant activity were investigated.Results:The irradiation doses within 12 kGy had no significant effects on the content of the main chemical components,characteristics and in vitro antioxidant activity of Chuanxiong Rhizoma,while changes in some functional groups and degradation of some volatile oil components containing olefins need further study.Conclusion:This study indicates that^(60)Co-γirradiation is a stable method for sterilization of Chuanxiong Rhizoma.It’s also provide a reference for the establishment of irradiation standards for Chuanxiong Rhizoma and other aromatic medicinal plants.展开更多
[Objective] The aim was to provide reference for research on radiation and breeding of cotton pollen through irradiating common ripe pollen grain of upland cotton by 60Co-γ Ray of varied doses. [Method] Ripe pollen g...[Objective] The aim was to provide reference for research on radiation and breeding of cotton pollen through irradiating common ripe pollen grain of upland cotton by 60Co-γ Ray of varied doses. [Method] Ripe pollen grains of upland cotton were irradiated by 60Co-γ Ray with doses of 5, 10, 15, and 20 Gy, respectively, to learn radiation effect and select appropriate dose. [Result] Most properties of M1 obviously showed variation when dose was over 10 Gy; vitality, growth, and fertility were greatly inhibited when dose was 15 Gy which was almost semi-lethal concentration, and variation species were richest at the same time, which provided materi- als for practical breeding. [Conclusion] 60Co-γ Ray of 15 Gy is more suitable for mutagenesis research on ripe pollen grains of upland cotton.展开更多
Lithium metal batteries are considered as high energy density battery systems with very promising prospects and have bee n widely studied.However,The uncon trollable plating/strippi ng behavior,infinite volume change ...Lithium metal batteries are considered as high energy density battery systems with very promising prospects and have bee n widely studied.However,The uncon trollable plating/strippi ng behavior,infinite volume change and den drites formation of lithium metal anode restrict the applicati on.The unc on trolled n ucleati on of lithium caused by the non uniform multi-physical field distributions,can lead to the undesirable lithium deposition.Herein,a graphene composite uniformly loaded with Ag nano-particles(Ag NPs)is prepared through a facile Gamma ray irradiation method and assembled into self-supported film with layered structure(Ag-rGO film).Whe n such film is used as a lithium metal an ode host,the uncontrolled deposition is converted into a highly nucleation-induced process.On one hand,the Ag NPs distributed between the in terlayers of graphe ne can preferentially induce lithium nu cleati on and en able uniform deposition morphology of lithium between interlayers.On the other hand,the stable layered graphene structure can accommodate volume change,stabilize the interface between anode and electrolyte and inhibit dendrites formation.Therefore,the layered Ag-rGO film as anode host can reach a high Coulombic efficiency over 93.3% for 200 cycle(786 h)at a current density of 1 mA cm^(-2) for 2 mAh cm^(-2) in carbonate-based electrolyte.This work proposes a facile Gamma ray irradiation method to prepare metal/3D-skeleton structure as lithium anode host and demonstrates the potential to regulate the lithium metal deposition behaviors via manipulating the distribution of lithiophilic metal(e.g.Ag)in 3D frameworks.This may offer a practicable thinking for the subsequent design of the lithium metal anode.展开更多
High-pressure chambers filled with gaseous hydrogen (HHPC), deuterium (DHPC) and helium (HeHPC) under different initial pressures from about I kbar up to 3 kbar were irradiated with braking γ-rays of threshold ...High-pressure chambers filled with gaseous hydrogen (HHPC), deuterium (DHPC) and helium (HeHPC) under different initial pressures from about I kbar up to 3 kbar were irradiated with braking γ-rays of threshold energy 10 MeV during varying periods of exposure at the electron beam currents 22-24μA. Upon opening of these chambers, a lot of new synthesized structures with unusual element compositions very different from the initial ones were found. The described phenomena agree well with a series of studies by authors carried out under the action of γ-rays on dense gases of hydrogen, deuterium and helium in the presence of chosen metals in the reaction chamber.展开更多
Diamond like carbon films, prepared by RF glow discharge on glass substrates, were irradiated by γ rays. The as deposited and irradiated films were characterized by Raman spectroscopy, electrical resistivity, a...Diamond like carbon films, prepared by RF glow discharge on glass substrates, were irradiated by γ rays. The as deposited and irradiated films were characterized by Raman spectroscopy, electrical resistivity, and infrared transmittance. It is shown that the irradiation of the γ rays can lead to the breaking of SP 3 C H and SP 2 C H bonds, slight increasing of SP 3 C C bonds, and induced hydrogen recombination with H 2 molecules, subsequently diffusing to the surface of the films. When the γ rays irradiation dose reached 10×10 4 Gy, the numbers of SP 3 C H bonds was decreased by about 50%, the resistivity of irradiated DLC films was increased, and the diamond like character of the films became more obvious. The structure of DLC films was modified when irradiated by γ rays. The irradiation mechanisms are briefly discussed.展开更多
This paper mainly reports the permanent impact of displacement damage induced by heavy-ion strikes on the deepsubmicron MOSFETs. Upon the heavy ion track through the device, it can lead to displacement damage, includi...This paper mainly reports the permanent impact of displacement damage induced by heavy-ion strikes on the deepsubmicron MOSFETs. Upon the heavy ion track through the device, it can lead to displacement damage, including the vacancies and the interstitials. As the featured size of device scales down, the damage can change the dopant distribution in the channel and source/drain regions through the generation of radiation-induced defects and thus have significant impacts on their electrical characteristics. The measured results show that the radiation-induced damage can cause DC characteristics degradations including the threshold voltage, subthreshold swing, saturation drain current, transconductanee, etc. The radiation-induced displacement damage may become the dominant issue while it was the secondary concern for the traditional devices after the heavy ion irradiation. The samples are also irradiated by Co- 60 gamma ray for comparison with the heavy ion irradiation results. Corresponding explanations and analysis are discussed.展开更多
Irradiation protection of the nonlinear optical devices used in the spacecraft and next generation active laser system must be solved. The first problem was to find the irradiation damage mechanism of the nonlinear ma...Irradiation protection of the nonlinear optical devices used in the spacecraft and next generation active laser system must be solved. The first problem was to find the irradiation damage mechanism of the nonlinear materials. In this paper the irradiation electronic field originating from high speed charged particle beams was discussed. The calculating model of the electronic field, based on the relativistic mechanics and electro-magnetic theory, was founded. The common characters of the irradiation electronic field were predicted and the fields of α ray and β ray were calculated by means of our model. The simulating results showed that the intensity of the electric field increased with the energy or the intensity of the beam. The results also showed that the field change trend of α ray and β ray was similar, but the field value was quite different. When the beam intensity I = 100 μA and the beam energy εm = 500 Mev, the electronic field values were about 3.5 × 107 v/m for α ray and 2.4 × 1011 v/m for β ray.展开更多
A carrier type gamma irradiator is an advanced device currently installed in Qingdao Irra- diation Center (QIC) and has been put into operation for nine years in Qingdao, China. It utilizes Co-60 as the radiation sour...A carrier type gamma irradiator is an advanced device currently installed in Qingdao Irra- diation Center (QIC) and has been put into operation for nine years in Qingdao, China. It utilizes Co-60 as the radiation source; the initial Co-60 loading is 1.48×1016 Bq (0.4 million Curies). Rubber, natural and synthetic polymers, heat-shrinkable films and tubes, disposable medical supplies, some foods and drugs have been irradiated for test in the past. Especially a great success achieved on the radiation of compound food for young shrimp. The practice demonstrates that the bacteria in the compound food can be de- stroyed by the irradiation at optimum dosage between 5 000–6 000 Gy.展开更多
A temperature measurement device can produce data deviations and can even be damaged in a high-dose radiation environment.To reduce the radiation damage to such a device and improve the temperature measurement accurac...A temperature measurement device can produce data deviations and can even be damaged in a high-dose radiation environment.To reduce the radiation damage to such a device and improve the temperature measurement accuracy in a radiation environment,a temperature sensor based on optical-fiber sensing technology is proposed.This sensor has a cascade structure composed of a single-mode fiber(SMF),a dispersion-compensation fiber(DCF),a nocore fiber(NCF),and another SMF(SDNS).The DCF and NCF are coated with a polydimethylsiloxane(PDMS)film,which is a heat-sensitive material with high thermal optical and thermal expansion coefficients.In experiments,PDMS was found to produce an irradiation crosslinking effect after irradiation,which improved the temperature sensitivity of the SDNS sensor.The experimental results showed that within a range of 30–100℃,the maximum temperature sensitivity after irradiation was 62.86 pm/℃,and the maximum transmission sensitivity after irradiation was 3.353×10^(-2)dB/℃,which were 1.22 times and 2.267 times the values before irradiation,respectively.In addition,repeated temperature experiments verified that the SDNS sensor coated with the PDMS film had excellent temperature repeatability.Furthermore,it was found that with an increase in the irradiation intensity,the irradiation crosslinking degree of PDMS increased,and the temperature sensitivity of the sensor was improved.The proposed sensor could potentially be applied to temperature measurement in a nuclear-radiation environment.展开更多
Gamma radiation is an effective tool for inducing genetic variation in plant characters. In the present experiment, M<sub>5</sub> mulberry variety juvenile twigs were subjected to source Co<sup>60<...Gamma radiation is an effective tool for inducing genetic variation in plant characters. In the present experiment, M<sub>5</sub> mulberry variety juvenile twigs were subjected to source Co<sup>60</sup> gamma irradiation (1 kR - 10 kR)</span><span> </span><span style="font-family:"">and mutants grown in triplicates in randomized block design to raise M<sub>1</sub> and M<sub>2</sub><sup> </sup>generation. In M<sub>2</sub> generation plants were subjected to phytochemical and bioassay tests. Silkworm rearing parameters and commercial characters of cocoons were recorded by feeding cross breed silkworms. Results show that M<sub>5</sub> mutant leaves revealed significant variations in phytochemical constituents and moisture content. Bioassay tests recorded significant differences compared to control in M<sub>2</sub> generation. Commercial characters like cocoon weight (1.41 g), shell weight (0.24 g), shell percentage (16.29 %), filament length (821.00 mts), renditta (8.2), denier (2.24) and effective rate of rearing (92.14 %) were increased. It is concluded </span><span style="font-family:"">that, gamma rays treatment enhances the mulberry plants leaf </span><span style="font-family:"">bioactive components, silkworm rearing and cocoon parameters<b> </b>and shows beneficial variants in M<sub>2</sub> generation.展开更多
Colloidal silver nanoparticles (Ag-NPs) were obtained through γ-irradiation of aqueous solutions containing AgNO3 and gelatin as a silver source and stabilizer, respectively. The absorbed dose of γ-irradiation inf...Colloidal silver nanoparticles (Ag-NPs) were obtained through γ-irradiation of aqueous solutions containing AgNO3 and gelatin as a silver source and stabilizer, respectively. The absorbed dose of γ-irradiation influences the particle diameter of the Ag-NPs, as evidenced from surface plasmon resonance (SPR) and transmission electron microscopy (TEM) images. When the γ-irradiation dose was increased (from 2 to 50 kGy), the mean particle size was decreased continuously as a result of γ-induced Ag-NPs fragmentation. The antibacterial properties of the Ag-NPs were tested against Methicillinresistant Staphylococcus aureus (MRSA) (Gram-positive) and Pseudomonas aeruginosa (P.a) (Gram-negative) bacteria. This approach reveals that the γ-irradiation-mediated method is a promising simple route for synthesizing highly stable Ag-NPs in aqueous solutions with good antibacterial properties for different applications.展开更多
The frequencies of chromosome aberrationsand micronuclei showed an increase withdoses after irradiation of rabbitsexposed to fractionated or single whole-body <sup>60</sup>Co gamma rays.At most dose points,
The energy of solar radiation absorbed by the Earth,as well as the thermal radiation of the Earth’s surface,which is released to the space through the atmospheric transparency window,depends on variations of the area...The energy of solar radiation absorbed by the Earth,as well as the thermal radiation of the Earth’s surface,which is released to the space through the atmospheric transparency window,depends on variations of the area of the cloud cover.Svensmark et al.suggest that the increase in the area of the cloud cover in the lower atmosphere,presumably caused by an increase in the flux of galactic cosmic rays during the quasi-bicentennial minimum of solar activity,results only in an increase in the fraction of the solar radiation reflected back to the space and weakens the flux of the solar radiation that reached the Earth surface.It is suggested,without any corresponding calculations of the variations of the average annual energy balance of the EarthЕ,that the consequences will include only a deficit of the solar energy absorbed by the Earth and a cooling of the climate up to the onset of the Little Ice Age.These suggestions ignore simultaneous impact of the opposite aspects of the increase in the area of the cloud cover on the climate warming.The latter will result from a decrease in the power of thermal radiation of the Earth’s surface released to the space,and also in the power of the solar radiation reflected from the Earth’s surface,due to the increase in their absorption and reflection back to the surface.A substantial strengthening in the greenhouse effect and the narrowing of the atmospheric transparency window will also occur.Here,we estimate the impact of all aspects of possible long-term 2%growth of the cloud cover area in the lower atmosphere byЕ.We found that an increase in the cloud cover area in the lower atmosphere will result simultaneously both in the decrease and in the increase in the temperature,which will virtually compensate each other,while the energy balance of the Earth E before and after the increase in the cloud cover area by 2%will stay essentially the same:E1-E0≈0.展开更多
To understand the degree of injury and repair of mammalian tissues and cells based on dose-survival curve is of great importance for radiobiological research. There are quite a lot of papers on dose-survival curves of...To understand the degree of injury and repair of mammalian tissues and cells based on dose-survival curve is of great importance for radiobiological research. There are quite a lot of papers on dose-survival curves of small intestine, but, only a few papers on large in-展开更多
Fourier transform infrared spectroscopy (FTIR) was employed to study the human epidermis larynx carcinoma cell lines (Hep-2) which were irradiated by different doses of X-ray. The results show that (1) the irrad...Fourier transform infrared spectroscopy (FTIR) was employed to study the human epidermis larynx carcinoma cell lines (Hep-2) which were irradiated by different doses of X-ray. The results show that (1) the irradiation of X-ray damages the structure of the CH3 groups of the thymine in DNA, which restrains the reproduction of Hep-2 cells effectively, (2) the 8 Gy dose of X-ray irradiation changes the framework and the relative contents of some proteins, lipids and the nucleic acid molecules intercellular in the greatest degree, and (3) the 8 Gy dose of X-ray irradiation is the best irradiation dose for lowering the degree of the cancerization of Hep-2 cells according to the criteria for the degree of the cancerization reported recently. Meanwhile, the apoptosis of these cells were detected by using flow cytometry (FCM) primarily. It shows that the apoptotic ratio of the Hep-2 cells depends on the irradiation dose to some extent, but is not linearly. And the apoptotic ratio of the 12 Gy dose group is the maximum (20.36%), but the apoptotic ratios of the 2 to 8 Gy dose groups change little.展开更多
YCOB,a member of the new crystal family of ReCOB (ReCOB=ReCa 4O(BO 3) 3,Re=La 3+ ,Nd 3+ ,Sm 3+ ,Gd 3+ ,Er 3+ ,Y 3+ ),has received mo re and more attentions in recent few years,because of its excellent nonlinear op tic...YCOB,a member of the new crystal family of ReCOB (ReCOB=ReCa 4O(BO 3) 3,Re=La 3+ ,Nd 3+ ,Sm 3+ ,Gd 3+ ,Er 3+ ,Y 3+ ),has received mo re and more attentions in recent few years,because of its excellent nonlinear op tical (N LO) properties and a great promise as a laser host material.Unfortunately,liking most of nonlinear optical crystals,the laser induced damages were also created in the new crystal family when irradiated by ultraviolet laser.In this report we present our preliminary results of the investigation on the radiation induced damage in YCOB crystals.展开更多
Microstructural change of YBaCuO film/YSZ substrate with and without proton irradiation has been studied by scanning electron microscope and X- ray diffraction techniques. Structural analysis has shown that conversion...Microstructural change of YBaCuO film/YSZ substrate with and without proton irradiation has been studied by scanning electron microscope and X- ray diffraction techniques. Structural analysis has shown that conversion from tetragonal to orthorhombic phases, reduction of nonsuperconducting phase and preferential rearrangement of crystal grains are all favorable to the improvement of superconductivity in the YBaCuO film supported by YSZ substrate by proton beam bombardment.展开更多
Colloidal silver nanoparticles (AgNPs) with particle size less than 10 nm and concentration of 2 mM/L (~200 mg/L) were synthesized by gamma Co-60 ray irradiation of Ag+/chitosan solutions with different chitosan conce...Colloidal silver nanoparticles (AgNPs) with particle size less than 10 nm and concentration of 2 mM/L (~200 mg/L) were synthesized by gamma Co-60 ray irradiation of Ag+/chitosan solutions with different chitosan concentration of 0.5%, 1% and 2% (w/v). Incorporation of AgNPs onto cotton fabric was carried out by padding method with 100% wet pick-up. The content of AgNPs deposited on cotton fabric and released from cotton fabric after repeated washing was determined by inductively couple plasma-atomic emission spectroscopy (ICP-AES). The results indicated that cotton/AgNPs fabric made from padding into AgNPs solution with 0.5% - 1% chitosan was the best one of AgNPs adhesion ability on cotton fabric. Results on antibacterial activity against S. aureus showed that cotton/AgNPs fabric with AgNPs content more than 100 mg/kg exhibited highly antibacterial activity (η > 98%). The mechanical property (tensile strength and elongation) of cotton/AgNPs fabrics was almost unchanged in comparison with untreated cotton fabric. Thus, the resultant cotton/AgNPs fabric with highly antibacterial activity can be potentially used as bed drapes and/or patient uniforms in hospitals, etc.展开更多
We investigate how F exposure impacts the hot-carrier degradation in deep submicron NMOSFET with different technologies and device geometries for the first time. The results show that hot-carrier degradations on irrad...We investigate how F exposure impacts the hot-carrier degradation in deep submicron NMOSFET with different technologies and device geometries for the first time. The results show that hot-carrier degradations on irradiated devices are greater than those without irradiation, especially for narrow channel device. The reason is attributed to charge traps in STI, which then induce different electric field and impact ionization rates during hotcarrier stress.展开更多
The dynamic viscoelastic properties of bamboo were tested by dynamic mechanics analyzer (DMA),and the measurements were done in the temperature range of 40℃ to 300℃at frequencies of 3 Hz.The results showed that with...The dynamic viscoelastic properties of bamboo were tested by dynamic mechanics analyzer (DMA),and the measurements were done in the temperature range of 40℃ to 300℃at frequencies of 3 Hz.The results showed that with the increase of irradiation dose,the decrease of storage modulus with increasing temperature became more dramatically.The decrease extent of storage modulus was the lowest for non-irradiated bamboo.Two mechanical relaxation processes were observed for all kinds of irradiated bamboo.The a relaxation process in lower temperature range was due to glass transition of hemicellulose and login,while the β relaxation process occurred in higher temperature range was based on glass transition of cellulose.The loss peak strength ofαrelaxation process went up as the irradiation dose increase,while the loss peak strength of β relaxation process became up first and then down,which was caused by the chemical reaction of the chief composition of bamboo.展开更多
基金This work was financially supported by Nationalities Introduces Talented Research Startup Project of Southwest Minzu University(RQD2021055)Sichuan Science and Technology Program(R22ZYZF0005)Innovative Scientific Research Project for Postgraduates of Southwest Minzu University(ZD2022798).
文摘Background:In order to clarify the inmpat ofγirradiation on the chemical composition of traditional Chinese medicine,this paper carefully choosed Chuanxiong Rhizoma to carry on a demonstration study.Methods:Through a meticulous assessment,a comprehensive comparison was made between the irradiated and unirradiated Chuanxiong Rhizoma samples.The property characteristics were investigated by colorimeter and electronic nose.The changes in chemical structures and contents was analyzed by fourier infrared spectroscopy,high performance liquid chromatography and fingerprinting.In a quest to uncover the presence of any new radiolysis products,cutting-edge techniques like ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry and gas chromatography-mass spectrometry were employed.Moreover,the difference of antioxidant activity were investigated.Results:The irradiation doses within 12 kGy had no significant effects on the content of the main chemical components,characteristics and in vitro antioxidant activity of Chuanxiong Rhizoma,while changes in some functional groups and degradation of some volatile oil components containing olefins need further study.Conclusion:This study indicates that^(60)Co-γirradiation is a stable method for sterilization of Chuanxiong Rhizoma.It’s also provide a reference for the establishment of irradiation standards for Chuanxiong Rhizoma and other aromatic medicinal plants.
基金Supported by National Natural Science Foundation of China (10475041)~~
文摘[Objective] The aim was to provide reference for research on radiation and breeding of cotton pollen through irradiating common ripe pollen grain of upland cotton by 60Co-γ Ray of varied doses. [Method] Ripe pollen grains of upland cotton were irradiated by 60Co-γ Ray with doses of 5, 10, 15, and 20 Gy, respectively, to learn radiation effect and select appropriate dose. [Result] Most properties of M1 obviously showed variation when dose was over 10 Gy; vitality, growth, and fertility were greatly inhibited when dose was 15 Gy which was almost semi-lethal concentration, and variation species were richest at the same time, which provided materi- als for practical breeding. [Conclusion] 60Co-γ Ray of 15 Gy is more suitable for mutagenesis research on ripe pollen grains of upland cotton.
基金support from the National Natural Science Foundation of China(Grant No.21875195,21875198 and 22005257)the Fundamental Research Funds for the Central Universities(20720190040).
文摘Lithium metal batteries are considered as high energy density battery systems with very promising prospects and have bee n widely studied.However,The uncon trollable plating/strippi ng behavior,infinite volume change and den drites formation of lithium metal anode restrict the applicati on.The unc on trolled n ucleati on of lithium caused by the non uniform multi-physical field distributions,can lead to the undesirable lithium deposition.Herein,a graphene composite uniformly loaded with Ag nano-particles(Ag NPs)is prepared through a facile Gamma ray irradiation method and assembled into self-supported film with layered structure(Ag-rGO film).Whe n such film is used as a lithium metal an ode host,the uncontrolled deposition is converted into a highly nucleation-induced process.On one hand,the Ag NPs distributed between the in terlayers of graphe ne can preferentially induce lithium nu cleati on and en able uniform deposition morphology of lithium between interlayers.On the other hand,the stable layered graphene structure can accommodate volume change,stabilize the interface between anode and electrolyte and inhibit dendrites formation.Therefore,the layered Ag-rGO film as anode host can reach a high Coulombic efficiency over 93.3% for 200 cycle(786 h)at a current density of 1 mA cm^(-2) for 2 mAh cm^(-2) in carbonate-based electrolyte.This work proposes a facile Gamma ray irradiation method to prepare metal/3D-skeleton structure as lithium anode host and demonstrates the potential to regulate the lithium metal deposition behaviors via manipulating the distribution of lithiophilic metal(e.g.Ag)in 3D frameworks.This may offer a practicable thinking for the subsequent design of the lithium metal anode.
文摘High-pressure chambers filled with gaseous hydrogen (HHPC), deuterium (DHPC) and helium (HeHPC) under different initial pressures from about I kbar up to 3 kbar were irradiated with braking γ-rays of threshold energy 10 MeV during varying periods of exposure at the electron beam currents 22-24μA. Upon opening of these chambers, a lot of new synthesized structures with unusual element compositions very different from the initial ones were found. The described phenomena agree well with a series of studies by authors carried out under the action of γ-rays on dense gases of hydrogen, deuterium and helium in the presence of chosen metals in the reaction chamber.
文摘Diamond like carbon films, prepared by RF glow discharge on glass substrates, were irradiated by γ rays. The as deposited and irradiated films were characterized by Raman spectroscopy, electrical resistivity, and infrared transmittance. It is shown that the irradiation of the γ rays can lead to the breaking of SP 3 C H and SP 2 C H bonds, slight increasing of SP 3 C C bonds, and induced hydrogen recombination with H 2 molecules, subsequently diffusing to the surface of the films. When the γ rays irradiation dose reached 10×10 4 Gy, the numbers of SP 3 C H bonds was decreased by about 50%, the resistivity of irradiated DLC films was increased, and the diamond like character of the films became more obvious. The structure of DLC films was modified when irradiated by γ rays. The irradiation mechanisms are briefly discussed.
基金Project supported by the National Natural Science Foundation of China (Grants No. 60625403,60836004,60925015 and 90207004)the Major State Basic Research Development Program of China (973 Program) (Grant No. 2006CB302701)
文摘This paper mainly reports the permanent impact of displacement damage induced by heavy-ion strikes on the deepsubmicron MOSFETs. Upon the heavy ion track through the device, it can lead to displacement damage, including the vacancies and the interstitials. As the featured size of device scales down, the damage can change the dopant distribution in the channel and source/drain regions through the generation of radiation-induced defects and thus have significant impacts on their electrical characteristics. The measured results show that the radiation-induced damage can cause DC characteristics degradations including the threshold voltage, subthreshold swing, saturation drain current, transconductanee, etc. The radiation-induced displacement damage may become the dominant issue while it was the secondary concern for the traditional devices after the heavy ion irradiation. The samples are also irradiated by Co- 60 gamma ray for comparison with the heavy ion irradiation results. Corresponding explanations and analysis are discussed.
文摘Irradiation protection of the nonlinear optical devices used in the spacecraft and next generation active laser system must be solved. The first problem was to find the irradiation damage mechanism of the nonlinear materials. In this paper the irradiation electronic field originating from high speed charged particle beams was discussed. The calculating model of the electronic field, based on the relativistic mechanics and electro-magnetic theory, was founded. The common characters of the irradiation electronic field were predicted and the fields of α ray and β ray were calculated by means of our model. The simulating results showed that the intensity of the electric field increased with the energy or the intensity of the beam. The results also showed that the field change trend of α ray and β ray was similar, but the field value was quite different. When the beam intensity I = 100 μA and the beam energy εm = 500 Mev, the electronic field values were about 3.5 × 107 v/m for α ray and 2.4 × 1011 v/m for β ray.
基金Supported by National Natural Science Foundation of China (No. 40276026), and also by Open Foundation of State Key Laboratory of Estuarine and Coastal Research, East China Normal University (No. 200406).
文摘A carrier type gamma irradiator is an advanced device currently installed in Qingdao Irra- diation Center (QIC) and has been put into operation for nine years in Qingdao, China. It utilizes Co-60 as the radiation source; the initial Co-60 loading is 1.48×1016 Bq (0.4 million Curies). Rubber, natural and synthetic polymers, heat-shrinkable films and tubes, disposable medical supplies, some foods and drugs have been irradiated for test in the past. Especially a great success achieved on the radiation of compound food for young shrimp. The practice demonstrates that the bacteria in the compound food can be de- stroyed by the irradiation at optimum dosage between 5 000–6 000 Gy.
基金the National Natural Science Foundation of China(Nos.62075057 and 11975091)the Program for Innovative Research Team(in Science and Technology)in University of Henan Province(No.21IRTSTHN011).
文摘A temperature measurement device can produce data deviations and can even be damaged in a high-dose radiation environment.To reduce the radiation damage to such a device and improve the temperature measurement accuracy in a radiation environment,a temperature sensor based on optical-fiber sensing technology is proposed.This sensor has a cascade structure composed of a single-mode fiber(SMF),a dispersion-compensation fiber(DCF),a nocore fiber(NCF),and another SMF(SDNS).The DCF and NCF are coated with a polydimethylsiloxane(PDMS)film,which is a heat-sensitive material with high thermal optical and thermal expansion coefficients.In experiments,PDMS was found to produce an irradiation crosslinking effect after irradiation,which improved the temperature sensitivity of the SDNS sensor.The experimental results showed that within a range of 30–100℃,the maximum temperature sensitivity after irradiation was 62.86 pm/℃,and the maximum transmission sensitivity after irradiation was 3.353×10^(-2)dB/℃,which were 1.22 times and 2.267 times the values before irradiation,respectively.In addition,repeated temperature experiments verified that the SDNS sensor coated with the PDMS film had excellent temperature repeatability.Furthermore,it was found that with an increase in the irradiation intensity,the irradiation crosslinking degree of PDMS increased,and the temperature sensitivity of the sensor was improved.The proposed sensor could potentially be applied to temperature measurement in a nuclear-radiation environment.
文摘Gamma radiation is an effective tool for inducing genetic variation in plant characters. In the present experiment, M<sub>5</sub> mulberry variety juvenile twigs were subjected to source Co<sup>60</sup> gamma irradiation (1 kR - 10 kR)</span><span> </span><span style="font-family:"">and mutants grown in triplicates in randomized block design to raise M<sub>1</sub> and M<sub>2</sub><sup> </sup>generation. In M<sub>2</sub> generation plants were subjected to phytochemical and bioassay tests. Silkworm rearing parameters and commercial characters of cocoons were recorded by feeding cross breed silkworms. Results show that M<sub>5</sub> mutant leaves revealed significant variations in phytochemical constituents and moisture content. Bioassay tests recorded significant differences compared to control in M<sub>2</sub> generation. Commercial characters like cocoon weight (1.41 g), shell weight (0.24 g), shell percentage (16.29 %), filament length (821.00 mts), renditta (8.2), denier (2.24) and effective rate of rearing (92.14 %) were increased. It is concluded </span><span style="font-family:"">that, gamma rays treatment enhances the mulberry plants leaf </span><span style="font-family:"">bioactive components, silkworm rearing and cocoon parameters<b> </b>and shows beneficial variants in M<sub>2</sub> generation.
文摘Colloidal silver nanoparticles (Ag-NPs) were obtained through γ-irradiation of aqueous solutions containing AgNO3 and gelatin as a silver source and stabilizer, respectively. The absorbed dose of γ-irradiation influences the particle diameter of the Ag-NPs, as evidenced from surface plasmon resonance (SPR) and transmission electron microscopy (TEM) images. When the γ-irradiation dose was increased (from 2 to 50 kGy), the mean particle size was decreased continuously as a result of γ-induced Ag-NPs fragmentation. The antibacterial properties of the Ag-NPs were tested against Methicillinresistant Staphylococcus aureus (MRSA) (Gram-positive) and Pseudomonas aeruginosa (P.a) (Gram-negative) bacteria. This approach reveals that the γ-irradiation-mediated method is a promising simple route for synthesizing highly stable Ag-NPs in aqueous solutions with good antibacterial properties for different applications.
文摘The frequencies of chromosome aberrationsand micronuclei showed an increase withdoses after irradiation of rabbitsexposed to fractionated or single whole-body <sup>60</sup>Co gamma rays.At most dose points,
文摘The energy of solar radiation absorbed by the Earth,as well as the thermal radiation of the Earth’s surface,which is released to the space through the atmospheric transparency window,depends on variations of the area of the cloud cover.Svensmark et al.suggest that the increase in the area of the cloud cover in the lower atmosphere,presumably caused by an increase in the flux of galactic cosmic rays during the quasi-bicentennial minimum of solar activity,results only in an increase in the fraction of the solar radiation reflected back to the space and weakens the flux of the solar radiation that reached the Earth surface.It is suggested,without any corresponding calculations of the variations of the average annual energy balance of the EarthЕ,that the consequences will include only a deficit of the solar energy absorbed by the Earth and a cooling of the climate up to the onset of the Little Ice Age.These suggestions ignore simultaneous impact of the opposite aspects of the increase in the area of the cloud cover on the climate warming.The latter will result from a decrease in the power of thermal radiation of the Earth’s surface released to the space,and also in the power of the solar radiation reflected from the Earth’s surface,due to the increase in their absorption and reflection back to the surface.A substantial strengthening in the greenhouse effect and the narrowing of the atmospheric transparency window will also occur.Here,we estimate the impact of all aspects of possible long-term 2%growth of the cloud cover area in the lower atmosphere byЕ.We found that an increase in the cloud cover area in the lower atmosphere will result simultaneously both in the decrease and in the increase in the temperature,which will virtually compensate each other,while the energy balance of the Earth E before and after the increase in the cloud cover area by 2%will stay essentially the same:E1-E0≈0.
文摘To understand the degree of injury and repair of mammalian tissues and cells based on dose-survival curve is of great importance for radiobiological research. There are quite a lot of papers on dose-survival curves of small intestine, but, only a few papers on large in-
基金the Science and Technol-ogy Department of Henan province (No.0624410052)the key Ion Beam Bioengineering Laboratory of Henan Province+1 种基金the Pathology Laboratory of Zhengzhou Uni-versitythe People's Hospital of Henan Province.
文摘Fourier transform infrared spectroscopy (FTIR) was employed to study the human epidermis larynx carcinoma cell lines (Hep-2) which were irradiated by different doses of X-ray. The results show that (1) the irradiation of X-ray damages the structure of the CH3 groups of the thymine in DNA, which restrains the reproduction of Hep-2 cells effectively, (2) the 8 Gy dose of X-ray irradiation changes the framework and the relative contents of some proteins, lipids and the nucleic acid molecules intercellular in the greatest degree, and (3) the 8 Gy dose of X-ray irradiation is the best irradiation dose for lowering the degree of the cancerization of Hep-2 cells according to the criteria for the degree of the cancerization reported recently. Meanwhile, the apoptosis of these cells were detected by using flow cytometry (FCM) primarily. It shows that the apoptotic ratio of the Hep-2 cells depends on the irradiation dose to some extent, but is not linearly. And the apoptotic ratio of the 12 Gy dose group is the maximum (20.36%), but the apoptotic ratios of the 2 to 8 Gy dose groups change little.
文摘YCOB,a member of the new crystal family of ReCOB (ReCOB=ReCa 4O(BO 3) 3,Re=La 3+ ,Nd 3+ ,Sm 3+ ,Gd 3+ ,Er 3+ ,Y 3+ ),has received mo re and more attentions in recent few years,because of its excellent nonlinear op tical (N LO) properties and a great promise as a laser host material.Unfortunately,liking most of nonlinear optical crystals,the laser induced damages were also created in the new crystal family when irradiated by ultraviolet laser.In this report we present our preliminary results of the investigation on the radiation induced damage in YCOB crystals.
文摘Microstructural change of YBaCuO film/YSZ substrate with and without proton irradiation has been studied by scanning electron microscope and X- ray diffraction techniques. Structural analysis has shown that conversion from tetragonal to orthorhombic phases, reduction of nonsuperconducting phase and preferential rearrangement of crystal grains are all favorable to the improvement of superconductivity in the YBaCuO film supported by YSZ substrate by proton beam bombardment.
文摘Colloidal silver nanoparticles (AgNPs) with particle size less than 10 nm and concentration of 2 mM/L (~200 mg/L) were synthesized by gamma Co-60 ray irradiation of Ag+/chitosan solutions with different chitosan concentration of 0.5%, 1% and 2% (w/v). Incorporation of AgNPs onto cotton fabric was carried out by padding method with 100% wet pick-up. The content of AgNPs deposited on cotton fabric and released from cotton fabric after repeated washing was determined by inductively couple plasma-atomic emission spectroscopy (ICP-AES). The results indicated that cotton/AgNPs fabric made from padding into AgNPs solution with 0.5% - 1% chitosan was the best one of AgNPs adhesion ability on cotton fabric. Results on antibacterial activity against S. aureus showed that cotton/AgNPs fabric with AgNPs content more than 100 mg/kg exhibited highly antibacterial activity (η > 98%). The mechanical property (tensile strength and elongation) of cotton/AgNPs fabrics was almost unchanged in comparison with untreated cotton fabric. Thus, the resultant cotton/AgNPs fabric with highly antibacterial activity can be potentially used as bed drapes and/or patient uniforms in hospitals, etc.
文摘We investigate how F exposure impacts the hot-carrier degradation in deep submicron NMOSFET with different technologies and device geometries for the first time. The results show that hot-carrier degradations on irradiated devices are greater than those without irradiation, especially for narrow channel device. The reason is attributed to charge traps in STI, which then induce different electric field and impact ionization rates during hotcarrier stress.
文摘The dynamic viscoelastic properties of bamboo were tested by dynamic mechanics analyzer (DMA),and the measurements were done in the temperature range of 40℃ to 300℃at frequencies of 3 Hz.The results showed that with the increase of irradiation dose,the decrease of storage modulus with increasing temperature became more dramatically.The decrease extent of storage modulus was the lowest for non-irradiated bamboo.Two mechanical relaxation processes were observed for all kinds of irradiated bamboo.The a relaxation process in lower temperature range was due to glass transition of hemicellulose and login,while the β relaxation process occurred in higher temperature range was based on glass transition of cellulose.The loss peak strength ofαrelaxation process went up as the irradiation dose increase,while the loss peak strength of β relaxation process became up first and then down,which was caused by the chemical reaction of the chief composition of bamboo.