Vol.24,

Tritium self-sustain and circulation is the core problem to use fusion energy peacefully. As the core component of the breeder in-pile irradiation test, the irradiation tritium production device provides irradiation space for breeders' tritium production and release. We take the Li₄SiO₄ as the research object and design the structure of the irradiation device. We complete the physical parameters computation, the irradiation device safety analysis and the flow field analysis of the breeder refueling, realizing the adjusting of the breeder irradiation temperature and the tritium release temperature window and making the control of gas operational parameters come true. The data could provide reference for breeders’ in-pile irradiation research.

699

431

309

Bench-scale gamma irradiation was conducted to investigate the influencing factors, such as initial cyanide concentration, absorbed dose, saturated gases, and pH value as well as water compositions on the γ radiolysis of cyanide in simulated aqueous solution. The decomposition rate of cyanide was observed as pseudo-first-order kinetic over the applied concentrations varied from 77 mg/L to 247 mg/L. Cyanide was decomposed more rapidly at a lower initial concentration than that at a higher initial concentration. However, the radical scavengers in natural waters, such as carbonate and bicarbonate, have negative effects on the remove of cyanide. This indicated that hydroxyl radical may play predominant role in the γ radiolysis of aqueous cyanide. Finally, ammonia and cyanate were identified as the main nitrogen-containing byproduct of γ radiolysis of cyanide. To remove toxic hydrogen cyanide (HCN) from carbon fiber industry waste gases, a pilot-scale experiment with a self-sheltered electron beam accelerator was demonstrated after two sprays of chemical absorption. The operating conditions for absorption and irradiation had been optimized. It was shown that after the first spray tower, HCN concentration decreased from (240±50) mg/m³ to 35 ± 15 mg/m³. While after the second spray tower, effluent HCN was reduced almost below the method detection limit. Then, the residual cyanide in aqueous solution was exposured to high energy electron beam (EB). Influent CN⁻ concentration was controled at (15±2) mg/L with a water regulating tank. This treatment allows CN⁻ to reach the regional limit (of 0.5 mg/L) for safe industrial wastewater discharge with a irradiation dose of 12 kGy. The obtained results showed that the combined process were effective for removing HCN from the waste gas.

279

A variety of techniques including chemical and enzymatic hydrolysis, and radiation degradation processes can be used to prepare low molecular weight chitosan. Degradation of chitosan by radiation can be carried out in solid state and liquid state. Radiation degraded polysaccharides has been reported to exhibit growth-stimulating activity like phytohormones thatinduce the promotion in germination, shoot and root elongation in variety of plants. In this study, the chitosan was irradiated in solid state (powder form) by gamma rays within the dose range of 25‒75 kGy. And the irradiated chitosan was then irradiated in solution form in the presence of hydrogen peroxide. The effects of irradiation on the molecular weight and viscosity of the chitosan were investigated using Ubbelohde Capillary Viscometer. The molecular weight and viscosity of the chitosan decreased with increment of absorbed doses. In the presence of hydrogen peroxide, the molecular weight of chitosan could be further decreased. The effect of radiation degraded chitosan on the growth promotion of rice was investigated and it was shown during seedling period of 15 days for transplanting whereby the growth is 15%‒20% faster than using chemicals growth promoters.

477

Carboxymethyl starch (CMS) can be cross-linked by electron beam radiation to form a biocompatible and environment-friendly hydrogel at a high absorbed dose and a condensed CMS concentration. Acrylic acid (AAc) can be used as a sensitizer in order to reduce the absorbed doses to an acceptable certain level. At an absorbed dose of 3‒4 kGy, the gel content of crosslinked CMS can be obtained about 50% with 5% (w/w) AAc concentration used. The compressive strength of CMS samples increased with increasing their cross-linked densities due to raising absorbed doses. The swelling ratio of cross-linked CMS was also attainable at a maximum of 50 times in the distilled water. The enzymatic degradation of cross-linked CMS was carried out in acetate buffer pH 4.6 with 0.1% α-amylase enzymatic solution incubated at 40ºC for 6 h. The crosslinked CMS samples were degraded slower than uncrosslinked CMS ones. The results indicated that the highly cross-linked CMS was almost fully degradable when the enzymatic hydrolysis was performed during 6 h. The FT IR spectra of cross-linked CMS in the presence of AAc were examined to observe the carboxyl group of AAc in the structure of cross-linked CMS. The hydrophilic of cross-linked CMS surface was determined by a contact-angle analysis.

551

Radiation curable hyperbranched urethane acrylate (HBPUA) from oleic acid of palm oil was synthesized aided by p-toluene sulfonic acid as a catalyst. This mixture was then used as the core (HBP-1) and reacted with palm oil oleic acid to form the hyperbranched polyol (HBP-2). HBPUA was prepared by reacting HBP-2 resin with diisocyanate and hydroxyl-containing acrylate monomer with the presence of 0.1‒2wt% dibutyltin dilaurate as a catalyst. The reaction was confirmed by several analytical data i.e. hydroxyl value (OHV), Fourier Transform infrared (FT IR) spectroscopy gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy analyses. The HBPUA was easily curable when subjected to electron beam (EB) or ultraviolet (UV) radiation.

431

FEP-g-acrylaldehyde graft copolymers were prepared by pre-radiation induced graft copolymerization of acryladehyde onto FEP (poly(tetrafluoroethylene-co-hexa fluoropropylene)). The effects of grafting conditions such as monomer concentration, irradiation dose, and different solvents were investigated. The formation of graft copolymers was confirmed by FT IR analysis. The structural investigation with X-ray diffraction (XRD) has been shown that the degree of crystallinity content of such graft copolymers decreases with the increment of grafting. Moreover, the content of acraldehyde onto polymer and the immobilization of protein were investigated in correlation with the degree of grafting.

327

The surface of anatase TiO₂ was modified by maleic andydride (MAH) γ radiation. The properties of surface modified TiO₂ were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT IR), X-ray photoelectron spectrum (XPS), thermal gravimetric analysis (TGA), as well as transmission electron microscopy (TEM). The results suggest that the MAH anchored on the surface of TiO₂ through chemical bonding and the grafting ratio was approximately 2.7%. TEM image revealed that the modified particles had good dispersibility and compatibility with N,N-Dimethylformamide(DMF), which facilitated to hinder the aggregation of TiO₂ particles.

450

The multi-layer parylene (PP) films were irradiated by hot electrons with a dose of 2×10¹⁶ cm^‒2. The irradiated and non-irradiated films have been examined by FT IR, UV-Vis and strain-stress measurement instruments. The results show that the damage has been created for irradiated films, including benzene rings and broken C-C bonds. The absorbance on the vision light increases and the Yang’s modulus decreases greatly in irradiated films with the worse toughness. The experimental conditions determine whether these effects hinder hydrodynamic instability or not.

424

Silica-based adsorbent was prepared by radiation induced grafting of vinyl imidazole (VIM) onto the silanized silica, which was silanized by 3-(trimethoxysilyl) propyl methacrylate. The effects of monomer composition and absorbed dose on the grafting yield were investigated to optimize the reaction conditions. The results showed that a VIM concentration of 2.5 mol·dm^‒3 and an absorbed dose of 50 kGy were the optimal reaction conditions. FT IR and XPS spectra manifested that VIM was successfully grafted onto the silica surface. The SS-g-VIM adsorbent had excellent selectivity for Hg(II) adsorption in mixture divalent cationic metal solution and a maximum adsorption capacity of ca. 78 mg/g to Hg(II) at pH 5. The adsorption isotherm was investigated and the adsorption of Hg(II) fitted well with Langmuir mode. These results suggested that SS-g-VIM adsorbent has potential application for the removal of Hg(II) from wastewater.

285

The present work investigated the radiolysis of HA (Humic acids) in aqueous solutions and under gamma radiation. Absorbances at the range of 200‒800 nm and chemical oxygen demand (COD) were used to characterize the degree of degradation of HA. The results indicated that absorbances and the concentrations of COD were decreased with increasing of irradiation dose while with increasing of irradiation dose the pH of the solutions was decreased at first and then increase. In addition, the effects of initial pH and primary solution concentrations on HA degradation were also investigated. It is shown that the higher primary solution concentrations, the lower degradation efficiency under the same irradiation dose. And the degradation efficiency of HA under neutral conditions is better than in acidic or alkaline conditions.

281

The ESR signal of black sesame, soybean, peanut irradiated with 0‒9 kGy absorbed dose was determined and the characteristics and intensity were different. The relationship between signal intensity and absorbed doses was also investigated .The results showed that the ESR spectra of irradiated samples inhibited obvious variation compared to those un-irradiated. The dose-response curves of the samples exposed to gamma rays could be described well by binomial function. Besides, the ESR signal intensity was related to the species of samples. This study may be a method for detection of irradiated oilseed by ESR.

416

In this paper, the changes of rice-starch’s viscosity at different dose irradiation treatment were studied, the rice can be easily distinguished whether it has been irradiated or not with the control of pH. The results showed that the starch’s viscosity was significantly declined with increasing irradiation absorb dose. With the control of pH 2.5, the irradiated starch’s viscosity was apparently higher than the un-irradiated ones, there are significant differences in terms of viscosity between the two parts. The rice absorbed dose can be estimated using the relationship among peak viscosity, hot pasting viscosity and absorbed dose.

300

A pulse radiolysis study was carried out to investigate the radical anion and radical cation of sparfloxacin (SPAX). The reactions of SPAX with hydrate electron (e_aq^‒), hydroxyl radical (·OH) and azide radical (·N₃^‒) were investigated in this study. The transient absorption spectra of SPAX radical anion and SPAX radical cation were obtained. Two transient rate constants 2.2×10¹⁰ dm³·mol^‒1·s^‒1 and 1.7×10¹⁰ dm³·mol^‒1·s^‒1 for the reactions of SPAX with e_aq^‒ and ·OH were determined, respectively. Finally, based on the results obtained in this study, rational mechanisms of transient reactions were proposed.

415

Pulse radiolysis studies of the reactions between balofloxacin (BFX) and e_aq^‒ , hydroxyl radical (˙OH), and N₃^· were carried out to investigate the photosensitive toxicity of BFX. The BFX radical anion formed in the reaction of BFX with e_aq^‒ was located at 380 nm. The transient species formed in the reaction of BFX with ˙OH radical were located in the region of 370 nm to 580 nm, with a maximum λ_max at 390 nm. The BFX radical cation was obtained by reacting BFX with N₃˙, and showed an absorption band at around 365 nm. The UV-Vis absorption of the BFX was found to be clearly dependent on pH. The pK_a value of BFX was estimated to be 6.0±0.2. Under neutral conditions, the rate constants of BFX reacting with N₃˙ and e_aq^‒ were determined to be 1.3×10¹⁰ dm³·mol^‒1·s^‒1 and 1.4×10¹⁰ dm³·mol^‒1·s^‒1, respectively.

327

Poly(lactic acid)/ basalt fiber (PLA/BF) composites were prepared by melt blending with a cross-linking agent, triallyl isocyanurate (TAIC). The thermal and mechanical properties of the composites were investigated through gel fraction, heat defection temperature (HDT), tensile tests and scanning electron microscopy (SEM). Under certain conditions, the HDT of composites was dramatically increased to 140ºC after irradiation. Tensile properties were enhanced as well. Both these improvements were consistent with changes of the fracture morphology. Compatibilization and concomitant enhancement of the interfacial adhesive between the polymer matrix and the inorganic fiber were achieved as seen from SEM photos, as a result of the formation of co-crosslinking and grafting structures at the interface according to the determination of gelation extraction.

452