辐射加工是民用非动力核技术的重要组成部分,在国民经济发展中占有重要地位.目前辐照加工的主要技术手段有钴源和电子加速器.由于成本、安全性等问题,钴源辐照装置正逐步被电子加速器所取代.讨论了利用原有退役钴源辐照屏蔽装置改造电子加速器辐照场所方案的可行性,结果显示此方案是可行的.

许多钴源辐照装置存在于人口密集区域,其存在的卡源、强烈地震导致辐射泄露等安全隐患对周边群众造成潜在威胁.随着对放射源的安全管控日趋严格,钴源辐照装置的数量会逐渐减少.在完成装置退役后,对屏蔽结构完好的辐照装置进行改造,成为电子加速器辐照中心.电子加速器在安全性上优于钴源,改造方法可行,具备一定的操作性和经济性,可在短时间内完成改造,转变成为电子加速器辐照装置,继续从事辐照加工行业.

Poly(butylenes succinate)(PBS)was crosslinked with a chemical method,and benzoyl peroxide(BPO)was used as a crosslinking agent.The Effect of the amount of the crosslinking agent on the properties of cross-linked system was studied.The gel fraction,crystallization and melting behavior,as well as dynamic rheological properties were also researched on with swelling method,DSC,XRD,parallel plates rheometer,etc.The results indicated that the gel fraction,complex viscosity,storage modulus,and storage loss all increased with the increase of BPO content.Whereas,the degree of crystallinity and melting point decreased while the crystallization temperature increased with the increase of BPO content.

The multiple melting behavior of poly(butylene succinate)(PBS)was investigated using differential scanning calorimetry(DSC)and wide-angle x-ray diffraction(WAXD)under isothermal crystallization conditions and the origin of multiple endotherms was discussed in detail.The representative DSC curves showed that PBS had up to four endothermic peaks.WAXD revealed that PBS has the same crystal structure as α-form over a wide range of crystallization temperatures.A melting and recrystallization model was,therefore,proposed to interpret the multiple melting peaks.Peaks 1,2 and 4,were respectively ascribed to the melting of the secondary,primary and the most stable lamellar crystals.Peak 3,which had a competitive relationship with peak 4,in terms of kinetics,was assigned to the melting of crystallites recrystallized from peak 2.

The influence of low-energy low-dose electron-beam irradiation on the light emitting diode(LED)has been studied in this paper.Using the space electron-beam irradiation simulated by ion-beam emitted from experimental accelerator,the LED emitting different color light were irradiated under the different electron irradiation dose.We compare the optical and electronical character results of the intial and irradiated LED.The results demonstrate that the light intensity of irradiated LED increases,and the disctrete property of the statistical light intensity of plenty of LED is better.During the current accelerated aging experiment,the light intensity of the irradiated LED trends to significant decreasing compared with the intial LEDs.Using the electron beam irradiation mechanism the experiment results are discussed and analysed.

辐射加工已逐渐成为一门前景乐观的新兴加工技术,其主要包括:辐射食品保鲜、辐射消毒灭菌、辐射化工等方面。

颗粒材料破裂过程实质上是外力作用下力学缺陷和损伤形成和演化的过程.电子束辐射在颗粒体内部形成的大能量释放和电击穿,可在颗粒体内造成微观缺陷及显微裂隙,从而强化颗粒的磨碎过程.研究了电子束辐照对石英等几种颗粒材料磨碎细度的影响,试验结果显示:电子束辐照可以大幅度提高细粒级的产率.辐照剂量700kGy时,石英磨碎产品中＜45 μm粒级产率提高了13.7个百分点;铁矿石则表现为辐照后粗粒级产率明显降低.讨论了电子束辐照对可磨性影响的机理.