最新刊期
期 2 ， 2005
- 摘要：The Absorption spectral, acid-base equilibrium potential properties and formation and decay kinetics of four kinds of radicals from natural existing indole hormones were studied by pulse radiolysis.关键词：Pulse radiolysis;Melatonin;5-methoxygramine;5-methoxy-N;N-dimethylthytrytamine and 5-methoxy-N;N-diethylthytrytamine radical
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发布时间：2023-03-30 - 摘要：It is known that water exists in supercritical state above 374℃ and 22.1MPa, where gas phase and liquid phase are merged into a single phase. In the supercritical state, the density is controllable by changing the pressure. The properties such as the ionic product, solubilities of salts, gas and organic compounds, and dielectric constant of supercritical water are very different from those of water at room temperature.关键词：Pulse radiolysis;γ radiolysis;Supercritical water
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发布时间：2023-03-30 - 摘要：A compact pulse radiolysis apparatus using a BNL-type s-band photocathode RF gun is now under development at Waseda University. The laser pulse is used for excitation of the photocathode and for generation of white light, which is used for analyzing light in the pulse radiolysis.关键词：Pico-second pulse radiolysis system;Data deconvolution
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发布时间：2023-03-30 - 摘要：Reactions of 4-chlorophenol, and other phenols, with eaq-, •H, •N3 and •OH in aqueous solutions were studied by nano-second pulse radiolysis. The transient absorption spectra were attributed to determine the micro-reaction rate constants. It was found that the phenols were more easily oxidized by •OH than reduced by eaq-; and pH value and molecular structure of the phenols affected the rate constants of the reactions.关键词：Chlorophenols;Degradation mechanisms;Pulse-radiolysis;γ-ray radiolysis
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发布时间：2023-03-30 - 摘要：By use of steady photo-irradiation in the system of riboflavin aqueous solution containing methyl-sulf-amino acid and superoxide dismutase (SOD) as competitive scavenger of O2, the rate constant of superoxide anion radical (O2−·) scavenged by (Amberacid-chitosan-complex with copper (II), ACCC) was determined as 1.26×109, 1.11×109 and 4.98×108 mol-1 s-1 dm3 under irradiation of 254nm, 365nm UV lights and sun light, respectively. The results also show that the scavenge rate of O2−· by ACCC reached 91%, which is about the same as with natural SOD (93%), and is far more higher than the O2−· scavenge rate with just amberacid or chitosan, which is only 2.6% and 5.8%, respectively.关键词：Amberacid-chitosan- complex with copper (II);Superoxide anion radical;Scavenging effect;Rate constant
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发布时间：2023-03-30 - 摘要：Modified magnetic nanoparticles have gained considerable attention because of their great potential applications in biomedical fields, such as protein and enzyme immobilization, bioseparation, immunoassays and biosensor etc. In recent years, great efforts have been made in developing targeted drug carriers by use of magnetic nanogels.关键词：Magnetic nanogels;Photochemical method;Core-shell structure;Magnetic targeted drug carriers
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发布时间：2023-03-30 - 摘要：Quinoline and some of its derivatives were reported to be carcinogenic, toxic and mutagenic[1-3]. The widespread use of quinoline and its derivatives entails that these compounds are distributed in the environment, polluting soil and water together with many other environmental chemicals.关键词：Quinoline;Isoquinoline;Laser flash photolysis;Pulse radiolysis;Degradation;Radicals;Constant rate
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发布时间：2023-03-30 - 摘要：Ion irradiation of polymers can induce irreversible changes in their macroscopic properties such as electrical and optical properties and the surface-related mechanical properties. Electronic excitation, ionization, chains scission, cross-links and mass losses are accepted as the fundamental events that give rise to the observed macroscopic changes. Detailed and systematic study of radiation induced effects in polymers enriches not only the knowledge of ion-material interactions but also supplies new bases for polymeric materials synthesis through ion-beam technologies. Previous work has concentrated mainly on effects induced by low-ionization particles such as γ-rays and electrons. Since 1980’s the application of high energy heavy ion accelerators enables the use of high energy heavy ion as an irradiation source, and many new and exciting effects and phenomena have been revealed.关键词：Polymer;Heavy ion;Radiation effects
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发布时间：2023-03-30 - 摘要：N-4-desmethylwyosine (dYt), a derivative of rare tricyclic nucleosides is probably a new member of Y-nucleosides found in tRNA[1]. The structure of dYt has tricyclic ring with rigid conformation and high electron delocalization. Both the absorption and emission bands of dYt are well separated from normal bases, so it could probably be used as an effective natural fluorescent probe to study RNA structure and sequence[2].关键词：Rare tricyclic nucleoside;Laser photolysis;Pulse radiolysis;Ab initio
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发布时间：2023-03-30 - 摘要：Organisms produces reactive oxygen species (ROS) throughout their lives. ROS including superoxide anions, hydroxyl radicals, hydrogen peroxide and singlet oxygen whit known to oxidize biological macromolecules, The accumulation of oxidized, or modified, extra- and intra-cellular proteins in vivo cause age-related diseases such as Parkinson’s disease and cataract. Therefore, it is important to study the damage of proteins by photo-sensitizer. Singlet oxygen is a high reactive oxidant in biology systems, and that proteins are a major target for the damage initiated by this reactive species. Reaction with proteins occurs primarily at Trp, Met, Cys, His, and Tyr side-chains with this resulting in the formation of short-lived endo- or hydroperoxides on Trp, His, and Tyr residues. This paper is a brief introduction about the reactions of singlet oxygen with tyrosine and histidine.关键词：Reactive oxygen species;Singlet oxygen;Photo-sensitizer
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发布时间：2023-03-30 - 摘要：Based on establishing the nanosecond pulse radiolysis system in 1990 and chemical reaction dynamics studies with the system, a picosecond pulse radiolysis system has been proposed and is under installment at Shanghai Institute of Applied Physics. The paper gives a brief introduction to the ps pulse radiolysis system and its applications, especially in antioxidant studies.关键词：Pulse radiolysis;Antioxidant;Kinetics;Free radical
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发布时间：2023-03-30 - 摘要：Reactive oxygen species (ROS) induce a lot of disease when the balance breaks between ROS and the enzymic and non-znzymic systems in human body to effectively scavenge ROS and prevent them from damaging the body. Proteins, which account for about 20% dry weight of a human cell, may be major target of attacks by ROS.关键词：Free radical;Antioxidant;Protein
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发布时间：2023-03-30 - 摘要：In this paper, we report a novel method to synthesize polyethylenimine (PEI) nanogels in the range of 80—200nm with narrow size distribution by photo-chemistry at room temperature in aqueous solution. The nanogels’ size, size distributions and zeta potential were determined by photo correlation spectroscopy (PCS). Spherical morphology of the nanogels was characterized by scanning electron microscopy (SEM) and confirmed by atomic force microscopy (AFM). The nanogels are of high stability, low toxicity and low immunogenicity, as having been confirmed in in vivo tests with mice as animal model, and in vitro tests with human lung and liver cancer cells as well. Efforts are being made for further studies on synthesis and applications of the nanogels.关键词：Polyethylenimine;Photochemistry;Gene delivery
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发布时间：2023-03-30 - 摘要：Photoinduced electron transfer reactions of N,N,N’, N’- tetramethylbenzidine (TMB) with several electron poor olefins in acetonitrile solution have been studied by using laser flash photolysis and steady-state fluorescence quenching method. The triplet state of TMB at 480nm was found to undergo reductive quenching with the electron acceptors of fumaronitrile, dimethyl fumarate, cinnamonitrile, crotononitrile and diethyl fumarate. The detection of ion radical intermediates in the photolysis reactions confirms the proposed electron transfer mechanism, as expected from thermodynamics. The quenching rate constants of triplet TMB were determined at 510nm, where all the kqT values approach or reach to diffusion controlled limit. In addition, fluorescence quenching rate constant kqS was also obtained by calculating with Stern-Volmer equation.关键词：Transient absorption spectrum;Triplet;Electron-poor olefin;Electron transfer
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发布时间：2023-03-30 - 摘要：Terahertz time-domain spectroscopy (THz-TDS) is a new technique based on femto-second laser technology. It has shown important applicability in researches of different fields, such as condensed matter, gas-phase, and biochemistry, etc. The characteristic spectra of substances in THz range may provide important information of configuration, constitutes and the molecular interactions. This paper briefly introduces its applications in detecting and identifying gaseous free radicals.关键词：Terahertz (THz);Terahertz time-domain spectroscopy (THz-TDS);Free radical
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发布时间：2023-03-30
Radiation Chemistry
- 摘要：The work is to construct a hypoxia-activated adenovirus vector expressing suicide gene BCD and to evaluate anti-tumor effects of the hypoxia-targeted suicide gene therapy system with or without combination radiotherapy. The recombinant adenovirus Ad-5HRE/hCMVmp-BCD was generated by the COS-TPC methods. Hela cells were treated with Ad-5HRE/hCMVmp-BCD infection, followed by incubated with 5FC-containing medium under the aerobic conditions or hypoxic conditions for 24h. Cell growth inhibition was determined by MTS assay. Tumor xenografts were established by injecting Hela cells s.c into the right leg of nu/nu BALB/c mice. The tumor-bearing mice were given Ad-5HRE/hCMVmp-BCD- mediated gene therapy or combination therapy with radiotherapy. Western blot analysis clearly indicated that significant hypoxia-induced expression of BCD protein after Hela cells were infected with Ad-5HRE/hCMVmp-BCD. The actual amounts and the ratio of the BCD expression under aerobic and hypoxic conditions were increased with increasing MOI. MTS assay results indicated that hypoxia-induced sensitization to 5FC. Under the hypoxic incubation the IC50 is 20 folds lower than that of the aerobic condition. The increased cytotoxicity at each MOI of Ad-5HRE/hCMVmp-BCD infection with increasing 5FC concentration was also observed. Tumor growth delay assay results showed that with single radiation or fractionated radiation, the Ad-5HRE/hCMVmp-BCD+5FC +radiation group produced the longest times to tumor regrowth and average tumor doubling compared with the various control treatment groups. In vitro and in vivo studies demonstrated the combination of Ad-5HRE/hCMVmp-BCD and prodrug 5-FC can obviously inhibit the growth of Hela cells. Using the mouse xenografts model, we demonstrated the Ad-5HRE/hCMVmp-BCD and 5-FC can enhance the antitumor effects of conventional radiation therapy.关键词：Hypoxia;Adenovirus;Gene therapy;Tumor;Cytosine deaminase
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发布时间：2023-03-30 - 摘要：Because of its low sensitivity to radiations, therapeutic ratio of neuroglioma is relatively small. And chemotherapy is not ideal to the disease, either. Therefore, studies are needed towards finding radio-resistance gene. Human cerebral glioma SHG-44, mouse cerebral glioma C6, and small cell lung cancer NCI-H446 (for comparison), were irradiated by 60Co γ-rays to 1, 3 and 8Gy, and changes of DNA/RNA ratios in the cells were studied with LSCM (laser scanning confocal microscopy). It was found that the fluorescence dye of DNA in three kinds of cells in the control group is significantly higher than the RNA fluorescence dye (p<0.01). Degree of the damages to the irradiated NCI-H446 cells increased gradually with the dose, and damages to the cerebral glioma cells was less severe at the same radiation dose as the NCI-H446 cells.关键词：Confocal microscope;Cell strains (CNI- H446;C6;SHG-44);Deoxyribonucleic acid (DNA)
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发布时间：2023-03-30 - 摘要：BALB/c mice and human intestinal epithelial cells were irradiated to different doses by 60Co γ-rays. They were sampled for chromosome pattern analysis, intestinal morphology, and a number of other biomedical tests to investigate mechanisms of acute intestine injury by γ-ray irradiation and its effective treatment methods. The results indicated that:关键词：γ-ray;Mice;Intestine;Intestinal epithelium stem cells;Exogenous ribonucleic acid
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发布时间：2023-03-30 - 摘要：The work is to inquire clinical characteristic, diagnosis and treatment of radiation esophageal disease induced by radiation therapy for cancers in the thorax. Radiation esophageal disease is divided into acute radiation esophagitis and chronic radiation esophagitis. Acute radiation esophagitis is seen most often in the clinic and its main clinical symptoms are disphagia, odynophagia and substernal chest pain. Acute esophageal effect was observed in 5 of 28 patients (18%) of lung cancer during or after radiotherapy, there was no acute grade 4 or 5 esophageal effect. Less than or equal to grade 3 chronic effects were observed in 2 of 28 patients (5%), there was no chronic grade 4 or 5 esophageal effect. Acute radiation esophagitis usually happens in two weeks after the beginning of treatment, total dose is about 16—20Gy. Chronic radiation esophagitis usually appears in 90 days after the beginning of treatment. Diagnosis should include history of exposure to radiation, which dose exceed the dose threshold and typical clinical characteristics, but the dose threshold is only the reference because of variance of radiotherapy and the difference of individual sensitivity. Endoscopic finding of esophagus is the main way to diagnosis. The conservative measure is used for acute esophagiteal effect, and dilatation is required for chronic esophagiteal effect. The analysis of clinical characteristic, type and diagnostic basis can provide the reference for drawing up diagnostic standard.关键词：Radiation esophageal disease;Incidence;Dose;Diagnosis;Therapy
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发布时间：2023-03-30 - 摘要：In this paper, we intended to further investigate the effects of small intestine (Ribonucleic acid, RNA), on gene expression of intestines of irradiated mice. This will provide theoretical bases for repair of γ-ray caused damage in small intestine. Twelve BALB/c mice were randomly divided into two groups, one for irradiated control and the other for small intestine RNA therapy (100μg/mL, 0.4mL). Eighteen hours after γ-ray irradiation with a dose rate of 138.82 cGy/min and a total dose of 1150cGy, the mice were killed and their jejunum were taken out. Fluorescent cDNA probes labeled with Cy3 and Cy5 were prepared from RNA extracted from the intestines of the two groups. The probes of the two groups were hybridized against cDNA gene chip, the fluorescent signals were scanned with a scanner and the results were analyzed by a computer codes.关键词：Small intestine RNA;Ionizing radiation;cDNA microarray technology;Gene;Mice
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发布时间：2023-03-30 - 摘要：Human tumor cell lines of SMMC-7721 (liver cancer), hepG2 (liver cancer), HO-8910 (ovary cancer), and Hela (cervix cancer) were irradiated to 3Gy by 60Co γ rays and different cell cycle responses were found. The results showed that the SMMC-7721, hepG2 and HO-8910 cells displayed G2/M phase arrest and S phase temporally delayed after the irradiation. The Hela cells had an increased number of cells in both G2/M and S phase, which indicated that the G2/M and S checkpoints were both activated.关键词：Tumor cells;Cell cycle arrest;60Co γ-ray irradiation
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发布时间：2023-03-30 - 摘要：The work studies ROS (Reactive oxygen species) release in Deinococcus radiodurans (DR), the relationship between DR proliferation and ROS concentration, and ROS concentration change and its effect in irradiated DR.关键词：Deinococcus radiodurans;Radiation;Proliferation;Reactive oxygen species
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发布时间：2023-03-30 - 摘要：Nitric oxide (NO) has been implicated both in regression and progression of tumors due to its production by both tumor cells and infiltrating leukocytes. Ionizing radiation causes the regression of tumors, and can augment the production of NO by macrophages in vitro. The authors investigated the effect of X-ray irradiation on cell cycle of A172 human glioma cells pretreated with nitroprusside sodium (NPS), the NO donor.关键词：Nitric oxide;Glioma;radiation;Cell cycle
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发布时间：2023-03-30 - 摘要：Extremely low frequency magnetic field (ELFMF) produced by power lines and household electric appliances has been associated with increased incidence of cancers, as was suggested by several epidemiological studies[1]. To test the genotoxic effects of ELFMF, the induction of micronuclei by exposure to ELFMF and/or X-rays was investigated by cytokinesis-block method in cultured Chinese Hamster Ovary (CHO) cells. Approximately 4×105 cells were plated in 10cm dishes, following exposure to an ELF magnetic field (60Hz, 5mT) for 24h. The cells were irradiated to 1Gy by X-rays. After the irradiation, cytochalasin B was added to the medium at a final concentration of 3 μg / mL. The cells were then exposed to an ELF magnetic field or placed in a normal incubator for 18h, which is 1.5times the length of their cell cycle. The micronuclei derived from acentric fragments or from whole chromosomes were evaluated with the help of immunofluorescent staining using antikinetochore antibodies from the serum of scleroderma (CREST syndrome) patients[2,3].关键词：X-rays;Eextremely low frequency magnetic fields (ELFMF);CHO cells;Micronuclei
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发布时间：2023-03-30 - 摘要：The work is to investigate the effects of electromagnetic pulses (EMP) irradiation on the procreative system and to provide references for protecting EMP irradiation. BALB/C female or male mice were exposed to EMP radiation (95.41kVm-1 field intensity, 3×106 and 4×106 pulses). Using the method of embryos teratology, BALB/C female mice were examined to pregnancy rate, the numbers of embryos and gender ratio after the exposed female or male mice mated with the shamed male or female respectively at the 1day and 2 month. For part of the EMP 3×106 pulses exposed group, the birth filial generation and learning ability of filial generation was tested with Y type electricity labyrinth, and when the filial grew up, their reaction latency for thermal nociception was tested on a 50℃ surface. In comparison to the sham control, pregnancy rate decreased with the female group exposed to 3×106 pulses EMP radiation and mated 1d after the exposure, and fetal deaths rate increased with the 4×106 pulses EMP irradiation and 1d mated group, resorption embryos rate increased (p<0.05) with the exposed and 2 month mated male or female whereas, the other indexes didn’t change. Learning times of the filial generation whose either parent had been exposed increased distinctly with the control. The first latency on filial generation of the exposed female prolonged comparing to the control, but no significant differences were found in the other indexes. These results suggest that the EMP irradiation can induce some degree of injury on procreative system of mice, causing decreased pregnancy rate, increased fetal death rate and resorption embryos rate, and decreased learning ability of the filial generation. However, there were no evidence for effects of the EMP exposure on nociception of the filial generation. Further investigations are necessary to elucidate mechanisms of the EMP irradiation.关键词：Electromagnetic pulses (EMP);Mouse;Filial generation;Embryos
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发布时间：2023-03-30 - 摘要：The work is to observe ultrastructure of pituitary gland of rats exposed to electromagnetic pulse (EMP, 200 kV m-1, 200 times) with transmission electron microscope and to explore the effects of EMP on the endocrine system. At 6h and 12h after EMP exposure, the intercellular spaces were dilated, swellen mitochondria with cristae loss, dilatation of Golgi complex and diffused lysosomes were found in endocrine cells of pituitary gland, especially in prolactin cells and growth hormone cells. There were macrophages infiltrating in intercellular spaces at 24h after EMP exposure, and more mitochondrial vacuolization in prolactin cells, many myelin figures in growth hormone cells and distinct dilatation of endoplasmic reticulum in gonadotropic cells were found. These changes were gradually aggravated. Numerous secondary lysosomes, the gathering of heterochromatins under the nuclear membranes, and cell degeneration and necrosis could be observed at 48h. These results suggest that EMP may damage endocrine cells in pituitary gland of rats, mitochondria and endoplasmic reticulum are the sensitive organelles, and prolactin cells and growth hormone cells are perhaps the sensitive cells to EMP.关键词：Electromagnetic pulse (EMP);Rat;Pituitary gland;Ultrastructure
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发布时间：2023-03-30 - 摘要：With wide applications of electromagnetic instruments and equipments in medical treatment, scientific research and national defense, and daily life items of computers, mobile telephones, and microwave ovens etc, electromagnetic radiations have brought us great benefit. However, there are potential damages with electromagnetic radiations,e.g. the electromagnetic pulse (EMP), which is not ionizing radiation but can cause vibration of atoms or molecules and alter electron energy levels. It has been reported that EMP could decrease the learning and recollection ability of mice and rats through inducing metabolic disorder of neurotransmitter in mice brain and affect the brain wave of anesthetized rats. EMP also has some effect on immune, procreation and endocrine system of mice.关键词：Electromagnetic pulse;J005A electromagnetic wave shielding textile;Blood-brain barrier
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发布时间：2023-03-30 - 摘要：The effect of natural hot and humid environment (HHE) and mock HHE on γ-irradiated mice and their preliminary mechanisms were studied by comparing the survival rate and the median time, etc. The results indicated that: (1) Comparing to the RT-treated mice, there were obvious death rate increase and median time promotion with the mice treated with mock HHE for over 60 min and 7Gy γ-ray irradiation, whereas no difference was observed within the 9Gy groups. (2) The mock HHE treatment had no obvious effect on peripheral blood lymphocyte of the γ-ray irradiated mice, however, lymphocyte of the RT-treated mice achieved minimum on the 3rd day after irradiation, whereas the lymphocyte minimum of (3.3±0.3) ×107 was achieved on the 5th day after irradiation with the HHE-treated mice, with marked difference between the two minimum data. (3) Comparing to the RT-treated mice, the differences in survival time was obvious with the 7Gy groups exposed to entire natural HHE and natural HHE for 9h,. In the 9Gy group, the survival time of the 6 h, 9h and entire natural HHE groups were all significantly shorter than that of the RT group. Descending rate of peripheral blood lymphocyte of the RT group was lower than that of all natural HHE groups, and the lymphocyte fluctuating resuscitation was found in the RT group, whereas no such changes in all natural HHE groups. It is concluded that the mock and natural HHE treatments decreased significantly survival indexes of the irradiated mice, giving rise to increased incipient descending rate of peripheral blood lymphocyte of the mice.关键词：Hot and humid environment;Radiation injury;Survival index;Lymphocyte
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发布时间：2023-03-30
Radiation Bio-medicine
- 摘要：Although radiation-chemical reactions have been applied to many industrial fields, especially to polymer industries, they are mainly aimed at improving mechanical, thermal and surface properties of the materials. Application of radiation chemical reactions to the construction of functional organic materials, such as electronic and optical materials, is relatively few. However, radiation-chemical reactions have the following characteristics that are advantageous for studying and constructing functional organic materials.关键词：γ-irradiation;N+ ion beam irradiation;Functional organic materials
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发布时间：2023-03-30 - 摘要：Fuel cell is in focus as a very low exhaust new dynamo system. Especially polymer electrolyte fuel cells (PEFC) using proton exchange membranes (PEM) have attracted much attention for the electrical vehicle and other mobile applications such as cellar phone and personal computer. Conventional perfluoro-sulfonic acid membranes such as Nafion® (DuPont de Nemours LTD.) have been the popular PEM used in PFEC. However, there are still several problems such as insufficient gas barrier properties, low thermal resistance, and their high costs.关键词：Radiation grafting;Proton exchange membranes;Perfluoro-sulfonic acid membranes
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发布时间：2023-03-30 - 摘要：In the world scenario understanding radiation chemistry in the time domain of hundreds of nano seconds to milliseconds started with the inception of pulse radiolysis technique. In India also research on time-resolved radiation chemistry started after the linear accelerator based pulse radiolysis system was set up in 1986 in Chemistry Division of Bhabha Atomic Research Centre. In the initial years the basic understanding of the mechanisms underlying redox reactions of organic compounds was the main area of research. The basic thrust was in characterizing the transients, determination of redox potentials, rate constants, ionic equilibria, etc.关键词：Pulse radiolysis;Antioxidant;γ-irradiation;Metal nanoparticles
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发布时间：2023-03-30 -
Micro-fabrication and surface modification of fluorinated polymers by means of synchrotron radiation
摘要：It is well-known that fluorinated polymers are very unique polymer materials because of their distinguished properties, such as high electrical resistivities, chemical and thermal stabilities, bio−compatibilities, etc. However, polytetrafluoroethylene (PTFE) is degraded by ionizing radiation with a low dose through main chain scission, and the mechanical properties are seriously deteriorated. In early 1990’s, it was found that irradiation for PTFE at elevating temperature enhances recombination of radicals induced by ionizing radiation. Thus, crosslinked PTFE had been obtained[1,2]. The crosslinked PTFE shows remarkable improvements for the radiation durability and mechanical properties, etc.关键词：Synchrotron radiation;Etching;PTFE- 2
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发布时间：2023-03-30 - 摘要：Superabsorbent polyacrylic acid/ montmorillonite composite (SAPC) with high water absorption capacity prepared using 9MeV electron beam irradiation is presented in this paper, which is different from others in material composition and preparation method[1-3].关键词：Montmorillonite;Acrylic acid;Electron beam irradiation;Superabsorbent composite
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发布时间：2023-03-30 - 摘要：There are many traditional ways to improve sensitivity and selectivity of semiconductor gas sensors, such as metal ions adulteration[1,2] and surface modification[3,4]. In this paper 1.75MeV electron beam was used to modify surface structure of tin dioxide gas sensors, and the gas sensing characteristics were studied. Results showed that the sensitivity and selectivity of SnO2 sensors were improved after the electron beam irradiation.关键词：Gas sensors;electron beam;Irradiation
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发布时间：2023-03-30 - 摘要：Track technology depends decisively on the track structure of the material after irradiation. In order to reveal microstructures of the ion-tracks, many techniques have been applied to characterize the track. Conductometric method is wildly used in the area as it can monitor in-situ the pore formation and growth processes that are closely related to structures of the ion track[1].关键词：Ion track;UV illumination;Chemical etching
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发布时间：2023-03-30 - 摘要：UV-radiation curing has become a well-accepted technology because of its distinct advantages mainly as environmental benign, efficiency, less energy consumption and mild curing condition. The free radical photopolymerizations have been based mainly on acrylate systems, which polymerize rapidly and can be adjusted with ease to modify materials with different properties for different applications. The primary limiting factor of the approaches, however, is that the reactions would be inhibited by oxygen. A main method to tackle the problem is to add tertiary amine. Nevertheless, this causes new problems in the curing products, which turn yellow easily and their deposited period becomes short.关键词：UV curing;Oxygen inhibition;Tertiary amine
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发布时间：2023-03-30 - 摘要：With the development of nuclear power industry, more attentions have been paid on reprocessing power reactor spent fuel. Up to now, PUREX process is the only process available commercially. The process achieves uranium and plutonium separation by means of quick and quantitative reduction of Pu (Ⅳ) to Pu (Ⅲ). Therefore the reductant is very important in PUREX process. Preliminary experiment results[1] show that N, N-dimethyl hydroxylamine not only reduces rapidly Np (Ⅵ) and Pu (Ⅳ) to Np (Ⅴ) and Pu (Ⅲ), but also stabilizes the Np (Ⅴ) and Pu (Ⅲ) in acid solution. It may become a salt-free reductant with promising future for applications in the area[2]. However, organics decompose under intense radiation environment, and this affects its reduction efficiency, and products from the degradation may affect separation of the radioactive elements.关键词：N;N-dimethyl hydroxylamine;Radiation degradation;Hydrogen;Carbon monoxide;Gas chromatogram
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发布时间：2023-03-30 - 摘要：Radiation crosslinked polyethylene foamed roll material is a new type of hi-tech product which has perfect close cell structure, smooth surface, good bounce, high mechanical strength, good heat resistance, waterproof, age defying and chemical corrosion resistance. The products can be re-processed by combination, connection and cutting for a wide range of application such as construction, thermodynamics industry, vehicle and ship manufacture, special packaging, agriculture and fishing, recreation and sports. The article introduces technological process of the irradiation crosslinked polyethylene foam, Emphases are made mainly on characteristics of key technology including the formula, radiation crosslinking, and the foam furnace, a special manufacturing device for the foamed PE rolls. Comparisons are made between similar technologies in the field worldwide. Structure and principle of the foam furnace are given. Discussions are given on current situations and the prospect in China in research and development and applications of radiation crosslinked polyethylene foam.关键词：Radiation crosslinking;Foamed plastics;Processing technology
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发布时间：2023-03-30 - 摘要：Multi-wall carbon nanotubes(MWNTs) were irradiated to different doses by 60Co γ-rays, and were subjected to chemical modification with decylamin. Elemental and TGA analyses of the modified MWNTs indicated that concentration of the functional groups bound to MWNTs increased monotonously with increasing doses, due to the defects created on the MWNTs by the γ-rays. In contrast with the results reported in Ref.1, no saturation of defect concentration was found at 170 kGy in this work.关键词：MWNTs;γ-ray irradiation;Chemical modification;Defect saturation
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发布时间：2023-03-30 - 摘要：A study was made on preparation of cation-exchange membranes including sulfonate and carboxylic acid groups by pre-irradiation grafting of acrylic acid (AA) and sodium styrene sulfonate (SSS) onto high-density polyethylene (HDPE). The grafting yield was strongly dependent on the synthesis conditions such as concentration and pH of the monomer solution, grafting temperature and type of solvent. An easy control over the grafting yield could be achieved by proper selection of reaction conditions. Water absorbance of grafted membranes increases with increasing grafting yield.关键词：High-density polyethylene;Acryli cacid;Sodium styrene sulfonate;Pre-irradiation grafting;X-ray diffraction
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发布时间：2023-03-30 - 摘要：The paper gives a review on industrial developments of radiation crosslinked polymeric materials in China. As one of the fast-growing Chinese industries, the annul productions of various kinds of radiation crosslinked products totaled over 3.2 billion Yuan in 2002. Recent progresses are reviewed in radiation crosslinked cable and wires, low smock halogen-free fire-retardant heat-shrinkable materials, polymeric positive temperature coefficient materials, rubber latex vulcanization, and foamed plastics.关键词：Cable and wires;Heat-shrinkable materials;Vulcanization;Polymer positive temperature coefficient;Foamed plastics
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发布时间：2023-03-30 - 摘要：The effect of UV irradiation on the structure and properties of linear low-density polyethylene (LLDPE) and the mechanical properties of nylon 66 (PA66)/LLDPE blends were studied with FTIR and XPS, measurements of gel, melt index, and water contact angle, and mechanical property tests. The results show that oxygen-containing groups such as C-O, C=O and C (=O) O were introduced onto molecular chains of LLDPE by the UV irradiation in air without adding any additives. The content of these groups increased with irradiation time. Gel formation was found in LLDPE after 12 h UV irradiation, and the gel fraction increased with the irradiation time. Melt index and water contact angle of the irradiated LLDPE decreased. Due to the introduction of the oxygen-containing groups, interfacial interactions between PA66 and the irradiated LLDPE increased. Therefore mechanical properties of PA66/irradiated LLDPE blends were improved compared with PA66/LLDPE blend. Tensile strength and notch impact strength of the PA66/irradiated LLDPE blends increased with irradiation time.关键词：LLDPE;UV irradiation;PA66/LLDPE blends;Mechanical properties
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发布时间：2023-03-30 - 摘要：A new method has been established to graft vinyl monomers onto silk fabrics by ultraviolet rays without any initiator or photosensitizer, in an attempt to improve undesirable properties of the materials with increased wrinkle recovery, better dyeing ability and color-fastness, and higher resistance to photo-yellowing, etc. In this work, effectiveness of different types of UV devices and experimental conditions of the photo-induced graft-copolymerization were investigated to control the influential factors on the grafting yield and properties of the graft-copolymer. Surface characteristics and structure changes, thermal properties and wrinkle resistance of grafted silk fabrics were studied. The grafted silk fabrics showed improved properties in crease resistance, dyeing ability and color-fastness, and heat stability as well. In detail, graft-copolymerization of 2-(Dimethylamino)ethyl methacrylate onto silk fabrics can make silk fabrics undergo from slight to drastic changes in their dyeing behavior, i.e., rate of dyeing and uptake of acid dyes. Different reaction systems of the same monomer can lead to reverse dyeing properties, indicating not only the function but also the structure affects the properties of grafted silk fabrics, especially the color-fastness. The UV light graft copolymerization method is of significance in silk industrial applications in terms of the facility cost, operation convenience and grafting efficiency, in comparison to 60Co γ-ray and electron beam irradiation facilities.关键词：Silk fabrics;Photo-induced graft-copolymerization;Dyeing properties;2-(Dimethylamino) ethyl methacrylate
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发布时间：2023-03-30
Radiation Modification of Polymeric Materials
- 摘要：1, 2, 4-trichlorobenzene is a kind of organic contamination which is difficult to be decomposed by normal methods[1-5].1, 2, 4-trichlorobenze at initial mass concentration of 200mg/L in aqueous was irradiated with electron beam in a laboratory-scale.The irradiation was performed at room temperatures with a GJ-2-Ⅱaccelerator (Shanghai Xianfeng Motors), with 1.5MeV1mA E-beams. Practical range of the electrons is about 0.7g/cm2. The samples, each of 20mL with a 4mm depth, were placed at 30cm under the titanium window and scanned by the E-beams at a dose rate of 3.5kGy/s, as was determined by membrane. concentration method with GC. Doses delivered to the samples were 35, 70, 105, 140, 210 and 280kGy, respectively.关键词：Tichlorobenzene;electron beam;Decomposition
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发布时间：2023-03-30 - 摘要：The degradation of aniline, p-nitroaniline and m-chloroaniline by electron beam irradiation was studied. Removal of aniline, p-nitroaniline and m-chloroaniline reached 95% at an initial concentration of 0.5mmol/L at 23kGy. The results showed that electron beam irradiation is an effective process for the degradation of aniline and its derivatives.关键词：Electron beam irradiation;Aniline;p-nitroaniline;m-chloroaniline;Chemical oxygen demand
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发布时间：2023-03-30 - 摘要：Aqueous dye solutions were irradiated by 60Co γ-rays or electron beams and the irradiation induced decoloration and degradation of the dyes were studied with UV/visuable absorption spectra and pH value measurement. In addition, (Chemical oxygen demand, COD) removal rate of the irradiated solutions, and synergetic effect of hydrogen peroxide and the irradiations, were investigated, The results show that the combination of radiation technology and other wastewater treatment can be a promising process for treating dyeing and finishing waste effluents.关键词：KRYWORDS Radiation degradation;Aqueous dye solution;Decoloration
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发布时间：2023-03-30 - 摘要：Nuclear technique is a powerful scientific tool in agricultural research, an area with fruitful achievements in China. Nuclear technique application in agriculture, based on developments of related sciences and technology, is of a high technical area, and also a meaningful aspect of non-electrical power applications of nuclear techniques. Nuclear agricultural science is an important component of agricultural science and technology, and has been making a great number of significant achievements, which have made remarkable contributions to economical, social and ecological developments in China. The paper gives a brief review on the achievements and present situation of nuclear agricultural sciences in China. For promoting its development, the author strongly suggests that even more attentions and supports be made by Chinese government bodies to promote studies on nuclear agriculture sciences, enabling it to make further more contributions to the nation’s endeavor to ensure every family a relatively comfortable life by solving problems in China’s agriculture, farm villages and farmers.关键词：Nuclear technique in agriculture;Isotopic tracer;Crop mutation genetics and breeding;Food irradiation
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发布时间：2023-03-30 - 摘要：In this paper, radiation decontamination effects of mycelium powder of sinensis with 60Co γ-rays and influence on its components were studied. The results showed that the irradiation was very effective in killing bacteria and moulds in mycelium powder. The D10 value for bacteria and moulds were 5.51kGy and 5.72kGy respectively. The optimum dose for decontamination of mycelium powder was 8—9kGy. Irradiating the mycelium powder to 8—9kGy did not cause obvious changes in the content of fatty acid, protein, total polysaccharide, total free amino acid and major nutrient components of adenosine, mannitol, and nitrogen. The irradiated mycelium powder, lost respectively 8.4%—9.5% and 29.6%—33.3% vitamin C and E, but they are minor nutrient components. After radiation decontamination, the quality-guaranteed mycelium powder has extended shelf life.关键词：Irradiation;Mycelium powder of sinensis;Sterilization
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发布时间：2023-03-30 - 摘要：To verify quality of irradiated products by a 3.9PBq single plate (1m×1m) source, Ag2Cr2O7 dosimeters were used for measuring extreme doses in three kinds of Chinese medicine in a actual irradiation area of 1.4m×1.4m facing the source. The product cartons were piled on the irradiation area, and their positions were exchanged to improve dosimetry uniformity of the products. The dosimeters for monitoring the minimum dose were placed in center of the cartons. The minimum doses of the three kinds of Chinese medicine products were 2.98, 1.03 and 1.37kGy respectively, and the maximum doses were 4.61, 2.00 and 2.24kGy, respectively. The dosimetry uniformities were 1.55, 1.94 and 1.64, respectively, which are within the quality control requirement of U≤2.关键词：Dosimetry uniformity;γ-ray irradiation
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发布时间：2023-03-30 - 摘要：Sugars are major constituents in many food systems. In this study, we tried to establish a rapid identification method to detect irradiated food which contained sugars by analyzing ultraweak luminescence of the food. The results indicated that the ultraweak luminescence behavior of glucose and sucrose changed greatly after gamma ray irradiation. Under dry condition, there were little changes in ultra luminescence intensities with the irradiated samples of glucose and sucrose, however, they did show marked changes in their ultra luminescence intensities when water was added during the measurement. It seemed that photon numbers of luminescence peak could be correlated to the dose delivered to the samples. The difference in the luminescence behavior of glucose and sucrose may provide an effective way to differentiate irradiated food.关键词：Ultraweak luminescence;Sugar;Detection;Irradiated food
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发布时间：2023-03-30 - 摘要：Fuhui 838, an indica restorer in rice, was developed after 15 years breeding by ways of irradiation and crossing. It has been used by a number of Chinese institutes of rice research and 15 hybrid rice combinations have been bred from Fuhui 838. The first hybrid rice combination of restorer Fuhui 838 is II You 838, which has high yield, better adaptability and outstanding ability to resist rice diseases in extremely hot weather. II You 838 is now the most popular hybrid rice in china. Up to 2003, all combinations of Fuhui 838 have been planted in an accumulative area of 13 million hectares all over China, among them 10 M is II You 838.关键词：Radiation mutating and hybridization;Hybrid rice restorer;Fuhui 838
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发布时间：2023-03-30
Environment Protection, Agriculture and Food Industry
- 摘要：Sponsored by Chinese Society of Radiation Research and Radiation Processing (CSRRRP), and with the No.4 Military Medical University as the holster, the 6th Conference on Radiation Research and Radiation Processing (CRRRP-6) in China was held successfully on October 22-26, 2004 in Xi’an.
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发布时间：2023-03-30
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